JP2019080379A - Power conversion device and elevator - Google Patents

Abstract

To effectively reduce the number of breaking circuits each connected to a power conversion device in the power conversion device configured by connecting a plurality of power conversion circuits in parallel.SOLUTION: According to one embodiment of the present invention, there are provided a first power conversion circuit group configured by connecting at least one power conversion circuit in parallel; a second power conversion circuit group configured by connecting a plurality of power conversion circuits in parallel, that have the same or substantially the same characteristic as that of the power conversion circuits in the first power conversion circuit group; a cut-off unit for cutting off a circuit during occurrence of abnormality, that is connected onto an input side and/or an output side of the power conversion circuits in the first power conversion circuit group; and a control circuit operated in such a manner that a time average output of the power conversion circuits in the second power conversion circuit group is smaller than another time average output of the power conversion circuits in the first power conversion circuit group.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power converter and an elevator suitable for an inverter device, a converter device and the like.

  As a power conversion device, there are an inverter device that converts direct current power to alternating current power, and a converter device that converts alternating current power to direct current power. In these power converters, power conversion is performed by the switching operation of the power semiconductor element. The power converter includes a power semiconductor device, a diode (rectifier), a capacitor for supplying instantaneous power, a drive circuit of the power semiconductor device, a sensor for monitoring the output current and output voltage of the power converter, and data output from the sensor It comprises a control circuit unit or the like that calculates a desired operation based on the above and sends a command signal for performing the required operation to the drive circuit. For example, as a power semiconductor element, an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) or the like is used.

  In the power converter, the above-described components are designed in accordance with various specifications such as output current and output voltage, and a usage period (lifetime) expected for the power converter. Further, in the power converter, in order to increase the conversion power capacity, a plurality of power semiconductor devices are connected in parallel, and the plurality of power semiconductor devices are simultaneously switched and driven. In this case, a standardized power conversion circuit (a power conversion circuit with a small capacity) with a small output current on which the power semiconductor element is mounted is connected in parallel. The power conversion circuit is configured by combining power semiconductor elements having similar characteristics.

  In such a power conversion device, in order to prevent an unplanned stop due to a failure or the like, interrupt circuits are provided on the input side and the output side of the power conversion circuit. When the power conversion circuit breaks down, there is a demand that the broken power conversion circuit is separated by the cutoff circuit and the operation is continued by the remaining sound power conversion circuit.

  For example, in Patent Document 1, “a plurality of semiconductor switch elements for limiting power supplied to each power conversion unit are individually interposed between each power conversion unit and the DC power supply unit, and each power conversion is performed. It is described that the control circuit individually monitoring the short circuit current generated in the unit turns off the semiconductor switch element connected to the power conversion unit in which the short circuit current flows to cut off the power supply to the power conversion unit.

JP 2014-236530 A

  By the way, when the shutoff circuit is connected to all the power conversion circuits, the number of signal lines and processing circuits attached to the shutoff circuit and the shutoff circuit is increased, and the volume of the power conversion device is increased. In addition, manufacturing operations for assembling components and circuits used for these circuits are required, which increases costs.

  The present invention has been made in consideration of the above situation, and in a power conversion device configured by connecting a plurality of power conversion circuits in parallel, the number of blocking circuits connected to the power conversion device is effectively set. The purpose is to reduce.

  The power converter in one aspect of the present invention is the same as or substantially the same as or substantially the same as the first power conversion circuit group configured by connecting at least one power conversion circuit in parallel and the power conversion circuit of the first power conversion circuit group And a second power conversion circuit group configured by connecting in parallel a plurality of power conversion circuits having the same characteristics, and an input side and / or an output side of the power conversion circuit of the first power conversion circuit group An interrupting unit connected and interrupting the circuit at the time of occurrence of abnormality, and a time average output of the power conversion circuit of the second power conversion circuit group are an output of a time average of the power conversion circuit of the first power conversion circuit group And d) operating the control circuit so as to be smaller than the control circuit.

According to at least one aspect of the present invention, it is possible to predict a failed power conversion circuit with high accuracy, so it is possible to reduce the number of blocking circuits compared to the prior art. Therefore, it is possible to reduce the circuits, parts, and work necessary for manufacturing the power converter and to reduce the cost.
Problems, configurations, and effects other than those described above will be apparent from the description of the embodiments below.

It is a circuit diagram showing an example of composition of a motor drive system to which a power converter concerning the present invention was applied. It is an explanatory view showing the characteristic of each power conversion circuit with which the power conversion device concerning the present invention is provided. The upper diagram of FIG. 2 is a graph showing an example of the average output of each power conversion circuit, and the lower diagram of FIG. 2 is a graph showing an example of the remaining life of each power conversion circuit. It is a circuit diagram showing an example of composition of a small capacity power conversion circuit used for a power conversion device concerning a 1st embodiment of the present invention. It is a circuit diagram showing an example of composition of the 1st power inverter circuit group concerning a 1st embodiment of the present invention. It is a circuit diagram showing an example of composition of the 2nd power inverter circuit group concerning a 1st embodiment of the present invention. FIG. 2 is a circuit diagram showing a configuration example of a power conversion device including a first power conversion circuit group and a second power conversion circuit group according to the first embodiment of the present invention. FIG. 6 is an explanatory view showing an operation of a second power conversion circuit group in the case where the first power conversion circuit group fails. The upper diagram of FIG. 7 is an explanatory diagram showing an example of time change of the output of the power converter, and the lower diagram of FIG. 7 is an explanatory diagram showing an average output of each power converter circuit constituting the power converter. It is a graph for demonstrating the average output of a power inverter circuit. It is a circuit diagram showing the 1st example of relaxation operation of the 2nd power inverter circuit group concerning a 1st embodiment of the present invention. It is an explanatory view showing the 2nd example of relaxation operation of the 2nd power inverter circuit group concerning a 1st embodiment of the present invention, and it is the current which a plurality of power inverter circuits which constitute a power converter output. It is a graph which shows typically the time change example of the sum total (sum current), and the time change example of the current which each power inverter circuit outputs. It is an explanatory view showing the 3rd example of relaxation operation of the 2nd power inverter circuit group concerning a 1st embodiment of the present invention. The upper diagram of FIG. 11 is a graph showing an example of the time change of the sum (total current) of the currents output by the plurality of power conversion circuits, and the lower diagram of FIG. It is a graph. It is an explanatory view showing the 4th example of relaxation operation of the 2nd power conversion circuit group concerning a 1st embodiment of the present invention, and is a graph showing an example of time change of the current which each power conversion circuit outputs. is there. FIG. 7 is a circuit diagram showing a configuration example of a power conversion device according to a second embodiment of the present invention in which a plurality of power conversion circuits forming the first power conversion circuit group are provided with a common blocking circuit. FIG. 13 is a circuit diagram showing a configuration example of a power conversion device in which a cutoff circuit is provided in each of a plurality of power conversion circuits constituting a first power conversion circuit group according to a third embodiment of the present invention. It is a circuit diagram showing an example of composition of an elevator system to which a power converter concerning a 4th embodiment of the present invention was applied.

  Hereinafter, examples of modes for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described with reference to the attached drawings. About the component which has an essentially the same function or structure in an accompanying drawing, the same numerals are attached and the overlapping explanation is omitted.

<1. Overview>
The power conversion device has an inverter function (inverter device) that converts direct current power to alternating current power, or a converter function (converter device) that converts alternating current power to direct current power or converts direct current power to direct current power. An uninterruptible power supply system (Uninterruptible Power System) aims to supply AC power without interruption to loads such as servers using energy stored in storage batteries etc., for example. (UPS) can be used.

  However, the application illustrated here is an example, and is not limited to the application to the uninterruptible power supply. That is, in addition to uninterruptible power supply devices, it is used for various applications such as power converters for industrial equipment, power converters for railways, power converters for elevators, power converters for automobiles, and power converters for home electric appliances. Can. The outline of the power converter according to the present invention will be described below using an example in which the power converter according to the present invention is applied to a motor drive system.

[Motor drive system]
FIG. 1 is a circuit diagram showing a configuration example of a motor drive system to which a power conversion device according to the present invention is applied. The motor drive system is generally three-phase, but FIG. 1 shows only one of them. A motor drive system 1 shown in FIG. 1 includes a DC power supply 2, an inverter system 3, a load device 4, and a control circuit unit 7. The load device 4 is, for example, a hoist that raises and lowers a car 95 (FIG. 15 described later) of the elevator system. The inverter system 3 has a circuit configuration in which small-capacity power conversion circuits 100-1, 100-2, ..., 100-N are connected in parallel. Each of the power conversion circuits 100-1, 100-2,..., 100 -N converts DC power of the DC power supply 2 into AC power, and drives a motor (winding machine) which is a load device 4.

  The power conversion circuit 100-1 to which the blocking circuits 5 and 6 (an example of the blocking unit) are connected constitutes a first power conversion circuit group described later, and the power conversion circuit 100 to which the blocking circuits 5 and 6 are not connected. -2 to 100-N constitute a second power conversion circuit group described later. In the following, when the power conversion circuits 100-1, 100-2,..., 100-N are not distinguished, the power conversion circuits 100-1, 100-2,. It is described as "conversion circuit 100".

  Motor drive system 1 includes interrupting circuits 5, 6 for interrupting the path of the main circuit to power conversion circuit 100-1 among power conversion circuits 100-1, 100-2, ..., 100-N connected in parallel. Is connected. The blocking circuit 5 is connected between the input side of the power conversion circuit 100-1 and the DC power supply 2, and the blocking circuit 6 is connected between the output side of the power conversion circuit 100-1 and the load device 4. The power conversion circuit 100-1 is disconnected from the inverter system 3 by interrupting the power of the main circuit by the blocking circuits 5 and 6.

  For example, a fuse or a circuit breaker is used for the circuit breakers 5 and 6, and when an abnormality occurs, the path is opened to cut off the circuit (power). The fuse is a wiring member that melts and shuts off the circuit when an excessive current flows in the main circuit. The circuit breaker automatically shuts off the circuit if it consumes more than a certain amount of power or an abnormal current flows in the main circuit.

  The control circuit unit 7 (an example of a control circuit) controls a drive circuit 30 (see FIG. 3 described later) included in each power conversion circuit 100. The drive circuit 30 outputs a drive signal to a power semiconductor element (power semiconductor elements 11 and 12 in FIG. 3 described later) included in the power conversion circuit 100 to drive the power semiconductor element.

[Characteristics of each power conversion circuit]
Here, the characteristics of each power conversion circuit 100 included in the inverter system 3 will be described. FIG. 2 is an explanatory view showing the characteristics of each power conversion circuit 100 provided in the inverter system 3. The upper diagram of FIG. 2 is a graph showing an example of the average output current of each power conversion circuit 100, and the lower diagram of FIG. 2 is a graph showing an example of the remaining life of each power conversion circuit 100. In both the upper and lower views of FIG. 2, the horizontal axis indicates time.

  The control circuit unit 7 normally outputs the time average output of each of the power conversion circuit 100-2 (INV 2) to the power conversion circuit 100 -N (INVN) from the power conversion circuit 100-2 (INV 2). It operates so as to become smaller than the time average output of −1 (INV 1) (upper figure in FIG. 2). For example, the power conversion circuit 100-1 performs rated operation. For this reason, when the operation is continued, the life of power conversion circuit 100-1 will surely be shorter than that of the other power conversion circuits 100-2 to 100-N, and it can be expected that the power conversion circuit 100-1 will be broken first (lower figure in FIG. 2) . When power conversion circuit 100-1 fails and control circuit 5 and / or 6 is opened, control circuit unit 7 uses inverter circuits 3 with power conversion circuits 100-2 to 100-N (INV1 to N). Continue driving. At this time, the control circuit unit 7 increases the average output of each of the power conversion circuits 100-2 to 100-N as compared with before opening the blocking circuits 5 and 6 (upper broken line in FIG. 2).

  With such a configuration, the power conversion circuit 100 that fails first can be predicted with high accuracy. As a result, the number of blocking circuits 5 and 6 connected to the power conversion circuit 100 can be reduced compared to the prior art, and the power conversion device can be manufactured more economically. Operation so that the time average output of power conversion circuits 100-1 to 100-N becomes smaller than the time average output of power conversion circuit 100-1 to which blocking circuits 5 and 6 are connected (hereinafter referred to as "relaxation operation" The method to carry out is also mentioned later.

<2. First embodiment>
[Power conversion circuit]
Next, the power conversion device according to the present invention will be described in more detail. FIG. 3 is a circuit diagram showing a configuration example of a small-capacity power conversion circuit 100 used in the power conversion device according to the first embodiment of the present invention. The power conversion circuit 100 is responsible for the main power conversion function of the power conversion device according to the present invention.

  In FIG. 3, the power conversion circuit 100 includes three power semiconductor modules 10-1, 10-2, and 10-3 connected in parallel, and a drive circuit 30. The power semiconductor modules 10-1, 10-2, and 10-3 are legs (switching circuit units) configured of the upper arm power semiconductor device 11, the lower arm power semiconductor device 12, and the diodes 13 and 14, respectively. The upper arm power semiconductor element 11, the lower arm power semiconductor element 12, and the diodes 13 and 14 are modularized to constitute each of the power semiconductor modules 10-1, 10-2, and 10-3. The diode 13 is connected to the power semiconductor element 11 in reverse polarity, and the diode 14 is connected to the power semiconductor element 12 in reverse polarity.

  Below, when not distinguishing power semiconductor modules 10-1, 10-2, and 10-3, power semiconductor modules 10-1, 10-2, and 10-3 are only described as "power semiconductor module 10". In the present embodiment, the power semiconductor module 10 has a 2 in 1 configuration in which the power semiconductor element 11 is mounted as the upper arm and the power semiconductor element 12 is mounted as the lower arm.

  The upper arm power semiconductor element 11 and the lower arm power semiconductor element 12 are semiconductor switching elements that switch a high voltage power supply voltage according to a gate voltage, and perform power conversion by this switching operation. Hereinafter, the upper arm power semiconductor device 11 and the lower arm power semiconductor device 12 may be simply referred to as “power semiconductor device 11” and “power semiconductor device 12”. As the power semiconductor elements 11 and 12, an insulated gate bipolar transistor (IGBT) or the like, which is an example of a voltage drive type element, can be used.

  The upper arm power semiconductor device 11 and the lower arm power semiconductor device 12 are provided in the main circuit of the power conversion circuit 100, and are connected in series between the high potential power supply and the low potential power supply. That is, the collector of the upper arm power semiconductor device 11 is connected to the high potential side power supply, and the emitter of the lower arm power semiconductor device 12 is connected to the low potential side power supply. Furthermore, the emitter of the upper arm power semiconductor device 11 and the collector of the lower arm power semiconductor device 12 are commonly connected to an output terminal (not shown). And the voltage (output voltage) derived | led-out to an output terminal is supplied to load apparatuses 4 (refer FIG. 1), such as a motor.

  A capacitor 15 for supplying instantaneous power of the DC power supply 2 is connected in parallel to each power semiconductor module 10. The positive electrode 22 connected to the collector of the upper arm power semiconductor element 11 and the positive electrode 16p of the capacitor 15 are connected to a DC wiring 20P such as a bus bar. Further, the negative electrode 23 connected to the emitter of the lower arm power semiconductor element 12 and the negative electrode 16n of the capacitor 15 are connected to the DC wiring 20N such as a bus bar. Power conversion circuit 100 has an external DC terminal composed of positive electrode 101 and negative electrode 102 connectable to an external circuit, positive electrode 101 is connected to positive electrode 16 p of capacitor 15, and positive electrode 101 is connected to negative electrode 16 n of capacitor 15.

  Further, the output terminal of the power semiconductor module 10-1 and the external AC terminal 21U of the power conversion circuit 100 are connected. Furthermore, the output terminal of the power semiconductor module 10-2 and the external AC terminal 21V are connected, and the output terminal of the power semiconductor module 10-3 and the external AC terminal 21W are connected. The gates and emitters of the power semiconductor elements 11 and 12 are connected to the drive circuit 30 via the signal transmission wiring 31 respectively. The control signal generated by the control circuit unit 7 (see FIG. 1) is input to the drive circuit 30 via the control signal terminal 103.

  The drive circuit 30 adjusts the gate voltage supplied to the power semiconductor elements 11 and 12 based on the gate voltage command received from the control circuit unit 7 (FIG. 1 and FIG. 6 described later). The output current (collector current) of the power semiconductor elements 11 and 12 in the on state (steady state) is proportional to the difference between the gate applied voltage (Vge) and the threshold voltage, and the on voltage is proportional to the output current. Therefore, the output current of the power semiconductor elements 11 and 12 can be controlled by adjusting the gate application voltage.

  The power conversion circuit 100 further includes a temperature detection element (temperature sensor) 40. The temperature detection element 40 is disposed in the vicinity of the upper arm power semiconductor element 11 or the lower arm power semiconductor element 12 and corresponds to the junction temperature (also called “junction temperature” or “element temperature”) of the power semiconductor element to be measured. A signal is output to the drive circuit 30. The drive circuit 30 sends this signal to the control circuit unit 7. The temperature detection element 40 is preferably provided in the power semiconductor module 10 in order to obtain the accurate junction temperature of the power semiconductor elements 11 and 12.

  The control circuit unit 7 can calculate the output current of the power conversion circuit 100 shown in FIG. 8, FIG. 10, and FIG. 11 described later from the junction temperature of the power semiconductor elements 11 and 12. In place of the temperature detection element 40, a current sensor such as a coreless current sensor (for example, logo coil) may be used. In this case, the current sensor is disposed between the emitter of the lower arm power semiconductor device 12 and the negative electrode 23.

  Although the power semiconductor circuit 10 having a 2 in 1 configuration in which both the high potential side upper arm power semiconductor device 11 and the low potential side lower arm power semiconductor device 12 are mounted on the power conversion circuit 100 is illustrated, I can not. That is, the power semiconductor module 10 according to the present embodiment may have a 1 in 1 configuration in which a power semiconductor element of one arm is mounted in addition to the 2 in 1 configuration.

[First power conversion circuit group]
FIG. 4 is a circuit diagram showing a configuration example of a first power conversion circuit group according to the first embodiment. In the present specification, a power conversion circuit group configured of the power conversion circuit 100 in which current can be cut off by the cut-off circuit is referred to as a first power conversion circuit group.

  The first power conversion circuit group 200 shown in FIG. 4 includes a plurality of power conversion circuits 100 connected in parallel. The positive electrode 101 and the negative electrode 102 of the plurality of power conversion circuits 100 are electrically connected to the DC connection point 201P and the DC connection point 201N through the DC external wiring 205, respectively. The DC connection points 201P and 201N are respectively connected to one ends of DC cutoff switches 203P and 203N (an example of a cutoff unit) such as fuses by electrical wiring such as a bus bar. The other end of each of the DC blocking switches 203P and 203N is connected to the external DC terminals 211 and 212 of the first power conversion circuit group 200 by electrical wiring such as a bus bar.

  Further, the external AC terminals 21U, 21V, 21W of the plurality of power conversion circuits 100 are electrically connected to the AC connecting points 202U, 202V, 202W, respectively, via AC external wires. Each of AC connection points 202U, 202V, 202W is connected to one end of AC blocking switches 204U, 204V, 204W (an example of a blocking portion) such as an electromagnetic contactor by electrical wiring such as a bus bar. The other end of each of the AC cutoff switches 204U, 204V, 204W is connected to the external AC terminals 213U, 213V, 213W of the first power conversion circuit group 200 by electrical wiring such as a bus bar. The control signal input from control circuit unit 7 (see FIGS. 1 and 6) to control signal terminal 214 of first power conversion circuit group 200 is input to control signal terminal 103 of corresponding power conversion circuit 100.

  Hereinafter, when the direct current cut-off switches 203P and 203N are not distinguished from one another, the direct current cut-off switches 203P and 203N will be simply described as "the direct current cut-off switch 203". Similarly, when the AC blocking switches 204U, 204V, and 204W are not distinguished from one another, the AC blocking switches 204U, 204V, and 204W are simply described as "AC blocking switch 204". Note that only one of the DC blocking switch 203 and the AC blocking switch 204 may be used.

  When any power conversion circuit 100 fails or an abnormality such as a ground fault occurs in the DC external wiring 205 or the AC external wiring, the DC blocking switch 203 or the AC blocking switch 204 is opened to shut off the power.

  Although FIG. 4 shows an example in which the first power conversion circuit group 200 includes a plurality of power conversion circuits 100, if the first power conversion circuit group 200 includes at least one power conversion circuit 100. Good.

[Second power conversion circuit group]
FIG. 5 is a circuit diagram showing a configuration example of a second power conversion circuit group according to the first embodiment. In the present specification, a power conversion circuit group configured by the power conversion circuit 100 to which the blocking circuit is not connected is referred to as a second power conversion circuit group.

  Like the first power conversion circuit group 200, the second power conversion circuit group 300 shown in FIG. 5 includes a plurality of power conversion circuits 100 connected in parallel. The positive electrode 101 and the negative electrode 102 of the plurality of power conversion circuits 100 are electrically connected to the DC connection point 301P and the DC connection point 301N through the DC external wiring 305, respectively. The DC connection points 301P and 301N are connected to the external DC terminals 311 and 312 of the second power conversion circuit group 300, respectively, by electrical wiring such as a bus bar.

  Also, the external AC terminals 21U, 21V, 21W of the plurality of power conversion circuits 100 are electrically connected to the AC connection points 302U, 302V, 302W, respectively, through AC external wires. The AC connection points 302U, 302V, 302W are connected to the external AC terminals 313U, 313V, 313W of the second power conversion circuit group 300 by electrical wiring such as a bus bar. A control signal input from control circuit unit 7 (see FIGS. 1 and 6) to control signal terminal 314 of second power conversion circuit group 300 is input to control signal terminal 103 of corresponding power conversion circuit 100.

  As shown in FIGS. 4 and 5, in the first power conversion circuit group 200 and the second power conversion circuit group 300, a plurality of power conversion circuits 100 are connected in parallel to each other and used. That is, the collector of upper arm power semiconductor element 11 of power semiconductor module 10 mounted in one power conversion circuit 100 and the collector of upper arm power semiconductor element 11 of power semiconductor module 10 mounted in another power conversion circuit 100 Are electrically connected to the same potential at the DC connection point.

  Further, the emitter of the lower arm power semiconductor device 12 of the power semiconductor module 10 mounted in one power conversion circuit 100 and the emitter of the lower arm power semiconductor device 12 of the power semiconductor module 10 mounted in another power conversion circuit 100. Are electrically connected to the same potential at the DC connection point. The emitter of upper arm power semiconductor element 11 of power semiconductor module 10 and the collector of lower arm power semiconductor element 12 are connected to the same potential for each of U, V and W phases, and each connection point is AC-connected. Electrically connected at the point.

  As described above, the power conversion circuit 100 mounted with the upper arm power semiconductor element 11 and the lower arm power semiconductor element 12 is connected in parallel, and the power semiconductor elements 11 and 12 in the plurality of power conversion circuits 100 are simultaneously switched and driven. The conversion power capacity can be increased. The larger the number of parallel connections of the power conversion circuit 100 (power semiconductor elements 11 and 12), the larger the effect of increasing the conversion power capacity.

  In the present invention, the power conversion circuit 100 configuring the first power conversion circuit group 200 and the power conversion circuit 100 configuring the second power conversion circuit group 300 are equivalent in hardware configuration except for the presence or absence of the cutoff switch. It may be configured to have a certain degree of output capacity. That is, as the power conversion circuit 100, one having the same or substantially the same characteristics is used. By making these power conversion circuits 100 have the same hardware configuration, there are manufacturing advantages such as the number of component types can be minimized. Furthermore, by doing this, the power conversion circuit 100 that fails can be predicted with higher accuracy.

  In FIG. 5, an example is shown in which the second power conversion circuit group 300 includes a plurality of power conversion circuits 100. In the present embodiment, when the power conversion circuit 100 of the first power conversion circuit group 200 breaks down, the output of the power conversion circuit 100 of the second power conversion circuit group 300 is increased, and the output for the shortage due to the failure. In order to compensate the duty, it is desirable that a plurality of power conversion circuits 100 of the second power conversion circuit group 300 be provided.

[Power converter]
Next, a configuration of a power conversion device including the first power conversion circuit group 200 and the second power conversion circuit group 300 will be described with reference to FIG. FIG. 6 is a circuit diagram showing a configuration example of a power conversion device including the first power conversion circuit group 200 and the second power conversion circuit group 300.

  The power conversion device 400 includes a first power conversion circuit group 200, a second power conversion circuit group 300, and a control circuit unit 7. Each of external DC terminals 211 and 212 of first power conversion circuit group 200 and each of external DC terminals 311 and 312 of second power conversion circuit group 300 are connected via DC connecting points 401P and 401N. . The DC connection points 401P and 401N are connected to the DC power supply 2. Further, each of external AC terminals 213U, 213V, 213W of first power conversion circuit group 200 and each of external AC terminals 313U, 313V, 313W of second power conversion circuit group 300 are AC connection points 402U, 402V. , 402 W are connected. Further, the AC connection points 402U, 402V, 402W are connected to a load device 4 such as a motor.

  Further, each control signal terminal 214 of the first power conversion circuit group 200 is connected to the signal transmission wiring 403-1, and each control signal terminal 314 of the second power conversion circuit group 300 is connected to the signal transmission wiring 403-2. Are connected to the control circuit unit 7.

  The control circuit unit 7 controls the drive circuit 30 of each power conversion circuit 100 included in the first power conversion circuit group 200 and the second power conversion circuit group 300 as a pulse train signal as a control signal for controlling them. Supply. The pulse train signal is, for example, a pulse width modulation (PWM) signal using a carrier wave in which the on time width of the pulse changes at a constant frequency. When the pulse train signal is a PWM signal, the control frequency can be increased to improve the control accuracy.

  The control circuit unit 7 has a non-volatile memory 7M. Data of the operation pattern of each power conversion circuit 100 is stored in the memory 7M. The memory 7M may be provided outside the control circuit unit 7. For example, the control circuit unit 7 reads out data of the operation pattern from the memory 7M, generates a control signal for each of the power semiconductor elements 11 and 12 based on the operation pattern, and converts the first power conversion circuit group 200 and the second power conversion. A control signal is supplied to each power conversion circuit 100 of the circuit group 300.

  The control circuit unit 7 may output a control signal to the drive circuit 30 (feedback control) based on the temperature information of the power semiconductor elements 11 and 12 obtained using the temperature detection element 40. .

[Basic operation of power converter]
Next, the basic operation of power converter 400 will be described. In the initial state, the power semiconductor elements 11 and 12 of all the power conversion circuits 100 are in the off state, and the power supply to the load device 4 is stopped. At the time of initial operation (at the time of initial charge), DC power supplied from the DC power supply 2 is connected to the first power conversion circuit group 200 and the second power conversion circuit group via the DC external wiring and the DC connection points 401P and 401N. It is input to 300. The DC power distributed to each is input to the power conversion circuit 100 via the DC connection points 201P and 201N inside the first power conversion circuit group 200, and the DC power of the second power conversion circuit group 300. The power conversion circuit 100 is internally input via the DC connection points 301P and 301N.

  In each power conversion circuit 100, DC power is supplied to the capacitors 15 for charging. At the time of operation of the load device 4, the control circuit unit 7 sends an on / off control signal to the drive circuit 30 of each power conversion circuit 100 via the signal transmission wirings 403-1 and 403-2. When receiving the control signal, the drive circuit 30 forms a drive signal, and sends the drive signal to the power semiconductor elements 11 and 12 of each power semiconductor module 10 via the signal transmission wiring 31. Each of the power semiconductor elements 11 and 12 converts direct current power into alternating current power based on a control signal from the control circuit unit 7 which is sent along a combination pattern of on and off formed according to a desired driving operation. Power is supplied to the load device 4.

[Operation at the time of failure of the first power conversion circuit group]
Next, the output characteristics of the power conversion device 400, the first power conversion circuit group 200, and the second power conversion circuit group 300 and the operation at the time of failure occurrence will be described with reference to FIG. FIG. 7 is an explanatory view showing the operation of the second power conversion circuit group 300 when the first power conversion circuit group 200 fails. The upper diagram of FIG. 7 is an explanatory diagram showing an example of time change of the output of the power conversion device 400, and the lower diagram of FIG. 7 is an explanatory diagram showing an average output of each power conversion circuit 100 configuring the power conversion device 400.

  In the present embodiment, the average output current (INGV2) per power conversion circuit 100 configuring the second power conversion circuit group 300 is converted by the control circuit unit 7 to the power conversion of the first power conversion circuit group 200. The control signal is formed so as to be smaller than the average output current per one of the circuits 100 (INGV1) (lower diagram in FIG. 7). The output of the power conversion device 400 is the total output of each power conversion circuit of the first power conversion circuit group 200 and the second power conversion circuit group 300 (upper diagram in FIG. 7). In the upper diagram of FIG. 7, one of the power conversion circuits 100 of the power conversion circuits 100 constituting the first power conversion circuit group 200 has a failure, and the output of the corresponding power conversion circuit 100 is zero. It is shown that.

  In each power conversion circuit 100, power loss occurs due to the flow and switching of the current of the power semiconductor elements 11, 12, and the power semiconductor elements 11, 12 generate heat. Although the temperature rise of the power semiconductor elements 11 and 12 is suppressed to a predetermined temperature or less by a heat sink or a fan (not shown), thermal fatigue (fatigue due to joule loss etc.) by long-term use Accumulate and lead to breakage after a certain period of time.

  Therefore, the control circuit unit 7 alternates the power conversion circuits 100 of the second power conversion circuit group 300 so that the average output current per power conversion circuit 100 of the second power conversion circuit group 300 decreases. To operate the second power conversion circuit group 300 in a relaxed manner. Alternatively, the control circuit unit 7 controls the output current of the power conversion circuit 100 of the second power conversion circuit group 300 to be smaller than that of the first power conversion circuit group 200 in the operation cycle T. It is also good.

[Average output of power conversion circuit]
Here, the average output of the power conversion circuit 100 will be described. FIG. 8 is a graph for explaining the average output of the power conversion circuit 100. The average output of the power conversion circuit 100 is an output current averaged over a predetermined time, for example, an average output current within an arbitrary operation cycle T. As shown in FIG. 8, although the current value of the average output current before failure of the power conversion circuit 100 is Ib, the current value of the average output current is equalized by equalizing the output time after the failure and increasing the output current. Can be raised to Ia. In addition, the current value of the average output current can also be increased by lengthening the output time within the operation cycle T. Furthermore, both the output time and the output current in the operation cycle T may be adjusted to increase the current value of the average output current.

  For example, in the power conversion device 400, the first power conversion circuit 100 in the second power conversion circuit group 300 is paused in the first operation cycle, and the second power conversion circuit 100 is paused in the second operation cycle. Do the driving etc. As described above, the power conversion circuit 100 to be paused is sequentially replaced at each operation cycle, and the accumulation of thermal fatigue in the power conversion circuit 100 of the second power conversion circuit group 300 is alleviated.

  By such an operation, the operation fatigue of the power conversion circuit 100 of the second power conversion circuit group 300 can be suppressed as compared with the first power conversion circuit group 200. As compared with the second power conversion circuit group 300, the first power conversion circuit group 200 having a relatively large operation load leads to failure earlier. At the time of failure, the DC blocking switches 203P and 203N and the AC blocking switches 204U, 204V and 204W are opened, and the operation of the first power conversion circuit group 200 is suspended.

  On the other hand, the operation of the power conversion device 400 is continued by the remaining second power conversion circuit group 300. When continuing the operation, the output responsibility of the paused first power conversion circuit group 200 is added to the output responsibility of the second power conversion circuit group 300. That is, the current value of the average output current of the power conversion circuit 100 of the second power conversion circuit group 300 is instantaneously raised from Ia to Ib (lower diagram in FIG. 7). Accordingly, the output responsibility equivalent to that before the separation of the first power conversion circuit group 200 is secured, and the output of the power conversion device 400 can be maintained (upper diagram in FIG. 7).

  How much the average output current needs to be increased from the current value Ia of the average output current before the failure depends on the target output value of the power conversion device 400, the first power conversion circuit group 200, and the second power conversion circuit group 300. This differs depending on the number of power conversion circuits 100 constituting each of the above.

  In the first embodiment of the configuration described above, the power conversion circuit 100 that fails due to the load being applied to the specific power conversion circuit 100 compared to the other power conversion circuits 100 (the first power conversion circuit group 200) Can be predicted with high accuracy. Therefore, the first embodiment can reduce the number of cutoff switches compared to the prior art, and can manufacture the power conversion device 400 more economically.

  Further, in the first embodiment, since the power conversion circuit 100 that fails can be predicted with high accuracy, the failure of the power conversion device 400 can be predicted with high accuracy. Thereby, an unplanned failure (stop) of the power conversion device 400 can be prevented. Then, when the first power conversion circuit group 200 including the corresponding power conversion circuit 100 breaks down, the first power conversion circuit group 200 and the second power conversion circuit group 300 are deliberately exchanged. Thus, the above-mentioned function for preventing unplanned outages can be used continuously.

  Furthermore, in the first embodiment, since the failure of the power conversion circuit 100 can be predicted with high accuracy, the failure of the power conversion device 400 can be predicted with high accuracy. Therefore, it is possible to prevent an unplanned stop of power conversion device 400 and to improve the reliability of power conversion device 400.

  Hereinafter, various embodiments of the relaxation operation of the second power conversion circuit group 300 will be described in detail with reference to FIGS. 9 to 12.

First Embodiment
First, as a first example of the relaxation operation of the second power conversion circuit group 300, an example will be described in which the power conversion circuits 100 to be paused are sequentially replaced for each operation cycle. In the first embodiment and the following second to fourth embodiments, the power conversion device 400 having the configuration shown in FIG. 9 is assumed.

  FIG. 9 is a circuit diagram showing a first example of the relaxation operation of the second power conversion circuit group 300. As shown in FIG. The power converter 400 performs rated operation using (N-1) power converter circuits 100. In the example shown in FIG. 9, among the power conversion circuits 100 configuring the power conversion device 400, the DC conversion switches 203P and 203N and the AC cutoff switches 204U to 204W are connected to the power conversion circuit 100-1, and the power conversion circuit 100- The cutoff switch is not connected to 2 to 100-N. The power conversion circuit 100-1 constitutes a first power conversion circuit group 200, and the power conversion circuits 100-2 to 100 -N constitute a second power conversion circuit group 300. However, in FIG. 9, the description of the frame lines and reference numerals of each power conversion circuit group is omitted. An operation pattern table 7T is stored in the memory 7M of the control circuit unit 7.

  In the operation pattern table 7T, the number (#) of the power conversion circuit 100 to be operated or stopped (paused) is defined for each number of operation cycles (numbers of operation cycles). In the figure, ○ indicates operation, and x indicates stop. According to the operation pattern table 7T, the power conversion circuit 100-1 to which the cut-off circuit is connected is defined to always operate. Further, according to the operation pattern table 7T, the first power conversion circuit 100-2 in the second power conversion circuit group 300 is suspended in the first operation cycle, and the second power conversion is performed in the second operation cycle. It is defined that the circuit 100-3 is suspended, and that the (N-1) th power conversion circuit 100-N is suspended in the Nth operation cycle. As described above, the power conversion circuit 100 to be paused is sequentially replaced every operation cycle. That is, the information on the rotation of the power conversion circuit 100 to be paused is stored in the driving pattern table 7T.

  The first embodiment is an example of a power converter that repeatedly implements a certain operation pattern as used in an elevator system. For example, in an elevator system (see FIG. 15) provided with a plurality of car cages 95 (winding machines), the plurality of car cages 95 are sequentially operated according to the car call registration of the passengers. One operation cycle (operation cycle) in FIG. 9 is a time from when the car 95 starts moving according to car call registration until it arrives at the destination floor or the like and the car 95 stops. The operation cycle in this case is on the order of several seconds to several tens of seconds.

  When an abnormality occurs in the power conversion circuit 100-1, the power conversion circuit 100-1 is disconnected from the main circuit by the DC blocking switches 203P and 203N and the AC blocking switches 304P and 304N. Then, the control circuit unit 7 controls the normal power conversion circuits 100-2 to 100-N to continue the operation.

  According to the method of relaxation operation in the first embodiment described above, the power conversion circuit 100 paused in the second power conversion circuit group 300 is sequentially replaced according to the operation cycle of the load device 4 such as an elevator. The load of the second power conversion circuit group 300 can be alleviated. The control is simple because the operation / stop of each power conversion circuit 100 of the second power conversion circuit group 300 may be controlled based on the rotation defined in the operation pattern table 7T.

Second Embodiment
Next, a second example of the mitigation operation of the second power conversion circuit group 300 will be described. In the first embodiment, although the power conversion circuit 100 to be paused is replaced every operation cycle of the load, it is also possible to replace the power conversion circuit to pause every fixed period such as a longer day or week.

  FIG. 10 is an explanatory diagram of a second embodiment of the second power conversion circuit group 300, and shows the total (total current) of the currents output by the plurality of power conversion circuits 100 configuring the power conversion device 400. It is a graph which shows typically the time change example and the time change example of the electric current which each power inverter circuit 100 outputs. Although the vertical axis of the graph in FIG. 10 indicates the current, the same waveform can be obtained by using the temperature measured by the temperature detection element 40.

  In an elevator installed in an office building, as shown in FIG. 10, the sum (total current) of the currents output by the plurality of power conversion circuits 100 included in the power conversion device 400 has a cycle of one day. Generally, there are time periods during which the number of users increases when working at work, at lunch time, when leaving work, etc., as the use status of elevators in office buildings. From the waveform of the total current, it can be seen that as the number of users increases from morning to noon, the number of users decreases rapidly from evening to night. Each of the six spike-like peak portions in the current waveform in units of one day represents the operation period T described above. The daily use of the elevator is frequently performed, so in practice there are many peak portions corresponding to the operation cycle T.

  In the second embodiment, the power conversion circuit 100-1 to which the shutoff circuit is connected is defined to always operate. In addition, all the power conversion circuits 100 of the second power conversion circuit group 300 are operated in the first operation cycle, and the first power conversion circuit 100-2 (INV2) is suspended in the second operation cycle. In the driving cycle of the third day, it is defined that the second power conversion circuit 100-3 (INV3) is paused. As described above, the power conversion circuit 100 to be paused is sequentially replaced every operation cycle of one day. That is, the operation pattern table 7T stores information on the rotation of the power conversion circuit 100 which is paused at an operation cycle of one day.

  According to the method of relaxation operation in the second embodiment described above, in the second power conversion circuit group 300 in accordance with a cycle (such as one day or one week) longer than the operation cycle of the load device 4 such as an elevator. The power conversion circuits 100 to be paused are sequentially replaced. In the second embodiment, since the replacement cycle of the power conversion circuit 100 to be paused is longer than that in the first embodiment, the control is not complicated and is simple.

Third Embodiment
Next, as a third example of the relaxation operation of the second power conversion circuit group 300, an example in which the power conversion circuit 100 is stopped within the operation cycle T will be described.

  FIG. 11 is an explanatory diagram showing a third example of the relaxation operation of the second power conversion circuit group 300, and the upper diagram of FIG. 11 is the sum of the currents output by the plurality of power conversion circuits 100 (total current 11 is a graph showing an example of time change of FIG. 11, and the lower part of FIG. 11 is a graph showing an example of time change of current output from each power conversion circuit 100. This FIG. 10 is an example of the output characteristic of the power converter device 400 applied to the elevator system.

  As shown in the upper diagram of FIG. 11, the sum (total current) of the currents output by the plurality of power conversion circuits 100 configuring the power conversion device 400, that is, the output of the power conversion device 400 is of the elevator (car 95). It changes for every acceleration operation (power running), constant speed operation (rating), and deceleration operation (regeneration) (upper figure of FIG. 11). First, when the operation of the elevator is started, the output of the power conversion device 400 is increased to accelerate the car 95. Next, when the operation of the car 95 is switched from acceleration to constant speed, the output of the power conversion device 400 continues to be constant after decreasing for a certain period. Thereafter, in order to decelerate the car 95 in order to stop the car 95 at the destination floor, the output of the power conversion device 400 decreases, and the output of the power conversion device 400 is zero when the car 95 arrives at the destination floor. become.

  At this time, the control circuit unit 7 increases the output of the power conversion circuit 100-1 (INV1) constituting the first power conversion circuit group 200 in accordance with the acceleration of the car 95 as indicated by a solid line. Therefore, the output waveform (operation pattern) of the power conversion device 400 and the output waveform of the power conversion circuit 100-1 are similar (lower part of FIG. 11). On the other hand, in the period when the output of the power conversion device 400 is large, the control circuit unit 7 shows all the power conversion circuits 100-2 to 100-N (second dashed lines) of the second power conversion circuit group 300. Control to stop INV2 to N) is performed. During this time, the output of INV1 of the first power conversion circuit group 200 is increased by the stop of INV2 to N.

  Then, when the operation of the car 95 is switched from acceleration to constant speed, the control circuit unit 7 controls all the power conversion circuits of the second power conversion circuit group 300 to maintain the constant speed of the car 95. Control to increase the output of 100. Thereafter, the control circuit unit 7 controls, for example, the output of the power conversion circuit 100 of the second power conversion circuit group 300 to the same level as the output of the power conversion circuit 100 of the first power conversion circuit group 200. The output control of each power conversion circuit 100 in FIG. 11 is an example, and the present invention is not limited to this example.

  According to the method of relaxation operation in the third embodiment described above, each power conversion of the second power conversion circuit group 300 is performed in a period in which the output within the operation cycle T of the load device 4 (power conversion device 400) becomes large. By stopping the circuit 100, the second power conversion circuit group 300 can be relieved. Further, in the third embodiment, in order to control the operation / stop of each power conversion circuit 100 of the second power conversion circuit group 300 in accordance with the output waveform in the operation cycle T of the load device 4, fine relief is achieved. It becomes possible to drive. Furthermore, in the third embodiment, in order to stop the operation of each power conversion circuit 100 of the second power conversion circuit group 300 within the operation cycle T, the second electric power is compared with the fourth embodiment described later. Each power conversion circuit 100 of the conversion circuit group 300 has a long life.

  In the third embodiment, not all the power conversion circuits 100 of the second power conversion circuit group 300 are stopped, but only some of the power conversion circuits 100 may be stopped sequentially for each operation cycle. Good. In this case, each power conversion circuit 100 of the second power conversion circuit group 300 can be extended in life.

Fourth Embodiment
In the fourth embodiment, the output of the power conversion circuit 100 of the second power conversion circuit group 300 is compared with that of the first power conversion circuit group 200 in a period during which the output of the power conversion device 400 within the operation cycle T increases. It is an example controlled smaller than the power conversion circuit 100.

  FIG. 12 is an explanatory diagram showing a fourth example of the second power conversion circuit group 300, and is a graph showing an example of time change of current output from each power conversion circuit 100. As shown in FIG. In the third embodiment, the control circuit unit 7 performs all the power conversion circuits 100-2 to 100-2 of the second power conversion circuit group 300 as indicated by the one-dot chain line in a period during which the output of the power conversion device 400 increases. Control is performed to make the output of 100-N (INV2 to N) smaller than the output of the power conversion circuit 100-1 (INV1) of the first power conversion circuit group 200. During this time, the output of INV1 of the first power conversion circuit group 200 may be increased as much as the output of INV2 to N decreases.

  Then, when the operation of the car 95 is switched from acceleration to constant speed, the control circuit unit 7 controls all the power conversion circuits of the second power conversion circuit group 300 to maintain the constant speed of the car 95. Control to reduce the output of 100 is performed. Thereafter, the control circuit unit 7 controls, for example, the output of the power conversion circuit 100 of the second power conversion circuit group 300 to the same level as the output of the power conversion circuit 100 of the first power conversion circuit group 200. The output control of each power conversion circuit 100 in FIG. 12 is an example, and the present invention is not limited to this example.

  According to the method of relaxation operation in the fourth embodiment described above, each power conversion of the second power conversion circuit group 300 is performed in a period in which the output within the operation cycle T of the load device 4 (power conversion device 400) becomes large. By reducing the output of the circuit 100, the second power conversion circuit group 300 can perform a relaxation operation. Further, in the fourth embodiment, since the output of each power conversion circuit 100 of the second power conversion circuit group 300 is controlled according to the output waveform in the operation cycle T of the load device 4, the fourth embodiment is more than the third embodiment. It is possible to carry out more detailed mitigation operation.

  Furthermore, in the fourth embodiment, since each power conversion circuit 100 of the second power conversion circuit group 300 is not stopped within the operation cycle T, the power conversion circuit 100 constituting the first power conversion circuit group 200 is applied. The burden is less than in the third embodiment. Therefore, the life of the power conversion circuit 100 of the first power conversion circuit group 200 is extended, and the life of the power conversion device 400 is also extended.

  The method of the relaxation operation of the second power conversion circuit group 300 is not limited to the method described above. For example, the control circuit unit 7 can perform the relaxation operation of the second power conversion circuit group 300 by combining the methods of the third embodiment and the fourth embodiment.

<3. Second embodiment>
FIG. 13 is a circuit diagram showing a configuration example of a power conversion device in which a plurality of power conversion circuits 100 configuring the first power conversion circuit group 200 are provided with a common blocking circuit in the second embodiment. In addition, although the load apparatus 4 is single phase alternating current in FIG. 3, it may be three phases.

  In FIG. 13, INVG 1-1 and INVG 1-2 connected in parallel are power conversion circuits that constitute the first power conversion circuit group 200. Further, the INVG 2-1 and the INVG 2-2 connected in parallel are power conversion circuits that constitute the second power conversion circuit group 300. However, in FIG. 13, the description of the frame lines and reference numerals of each power conversion circuit group is omitted. In FIG. 13, the configuration of each of first power conversion circuit group 200 and second power conversion circuit group 300 is the same as that shown in FIGS. 4 and 5.

  As shown in FIG. 13, the positive electrodes 101 (see FIG. 4) of each of INVG 1-1 and INVG 1-2 constituting the first power conversion circuit group 200 are connected at a DC connection point 401 P. Further, the negative electrodes 102 of the INVG 1-1 and the INVG 1-2 are connected at a DC connection point 401 N. The DC connection point 401P is connected to the positive electrode of the DC power supply 2 via the DC cutoff switch 203P. Further, the DC connection point 401N is connected to the negative electrode of the DC power supply 2 through the DC cutoff switch 203N.

  On the other hand, the output terminal (refer to FIG. 5) of each R phase of INVG1-1 and INVG1-2 is connected by an AC connecting point 402R. Further, the T-phase output terminals of INVG1-1 and INVG1-2 are connected at an AC connection point 402T. The AC connection point 402R is connected to the R phase of the load device 4 via the AC cutoff switch 204R. Further, the AC connection point 402T is connected to the T phase of the load device 4 via the AC cutoff switch 204T.

  In the second embodiment described above, the plurality of power conversion circuits INVG1-1 and INVG1-2 configuring the first power conversion circuit group 200 are powered by the DC blocking switches 203P and 203N and the AC blocking switches 204R and 204T. It can be separated from the conversion device 400 collectively.

<4. Third embodiment>
FIG. 14 is a circuit diagram showing a configuration example of a power conversion device in which a cutoff circuit is provided in each of the plurality of power conversion circuits 100 configuring the first power conversion circuit group 200 in the third embodiment.

  As shown in FIG. 14, a DC blocking switch 203P is individually connected between the positive electrode 101 of each of INVG1-1 and INVG1-2 constituting the first power conversion circuit group 200 and the DC connection point 401P. . Further, between the negative electrode 102 of each of INVG1-1 and INVG1-2 and the DC connection point 401N, the DC blocking switch 203N is individually connected. The DC connection points 401P and 401N are connected to the positive electrode and the negative electrode of the DC power supply 2, respectively.

  On the other hand, an alternating current cutoff switch 204R is individually connected between the output terminal of each R phase of INVG1-1 and INVG1-2 and the alternating current coupling point 402R. Also, an AC blocking switch 204T is connected between the T-phase output terminals of each of INVG1-1 and INVG1-2 and the AC connecting point 402T. The AC connection points 402R and 402T are connected to the R phase and the T phase of the load device 4, respectively.

  In the third embodiment described above, among the plurality of power conversion circuits INVG1-1 and power conversion circuits INVG1-2 that constitute the first power conversion circuit group 200, only the power conversion circuit that has failed from the power conversion device 400 is selected. It can be separated individually. Therefore, compared with the second embodiment, the load applied to each power conversion circuit 100 of the second power conversion circuit group 300 after failure can be reduced.

<5. Fourth embodiment>
Next, as a fourth embodiment, an example in which the power conversion device according to the present invention is applied to an elevator system will be described with reference to FIG. FIG. 15 is a schematic view showing a configuration example of an elevator system to which the power conversion device according to the fourth embodiment is applied. Although the example of FIG. 15 is a three-phase alternating current, it may be a single phase.

  The elevator system 90 shown in FIG. 15 converts AC power supplied from the grid 91 into DC power by the converter system 500 via the filter circuit 92 that removes noise such as high frequency. Converter system 500 includes a first power conversion circuit group 600 and a second power conversion circuit group 700, and converts AC power into DC power. Similar to the first power conversion circuit group 200, the first power conversion circuit group 600 includes one or more power conversion circuits storing a plurality (for example, three) of power semiconductor modules 10 and a drive circuit 30. . Further, like the second power conversion circuit group 300, the second power conversion circuit group 700 includes a plurality of (for example, three) power semiconductor modules 10 and a plurality of power conversion circuits storing the drive circuits 30. Ru. The drive circuit 30 for driving the power semiconductor module 10 of each power conversion circuit operates based on a command from the control circuit unit 7.

  Further, elevator system 90 converts DC power output from converter system 500 into AC power by inverter system 3. The inverter system 3 includes the first power conversion circuit group 200 and the second power conversion circuit group 300 described above. The drive circuit 30 for driving the power semiconductor module 10 of each power conversion circuit 10 operates based on a command from the control circuit unit 7. Then, the elevator system 90 supplies the AC power output from the inverter system 3 to the load device 4 (winding machine: motor) via the filter circuit 93 to drive the load device 4.

  The loading of the loading device 4 includes a car 95 of an elevator system 90 connected to a rope 94 and a weight 96 for balancing with the car 95. The power of the load device 4 is consumed to raise and lower the car 95 via the rope 94.

  Control circuit unit 7 may be provided separately for converter system 500 and inverter system 3.

  It is necessary to increase the output power of the load device 4 in order to move the heavy load placed on the cage 95 quickly, and to increase the output power, the power conversion circuit mounted on the converter system 500 and the inverter system 3 is The number of parallel needs to be increased. Even if the number of paralleled power conversion circuits increases, the power conversion circuit to be broken can be predicted with high accuracy by using the configurations according to the first to third embodiments described above. It can be expected that the reliability of the elevator system 90 can be improved.

  Furthermore, the present invention is not limited to the embodiments described above, and it goes without saying that various other applications and modifications can be taken without departing from the scope of the present invention described in the claims. is there. For example, the above-described embodiment is a detailed and specific description of the configuration of the apparatus and system for the purpose of easy understanding of the present invention, and is not necessarily limited to one having all the components described. In addition, it is possible to replace part of the configuration of one embodiment with the component of another embodiment. In addition, it is also possible to add components of other example embodiments to the configuration of one example embodiment. Moreover, it is also possible to add, delete, and replace other components for part of the configuration of each embodiment.

  Further, some or all of the above-described components, functions, processing units, processing means, etc. may be realized by hardware, for example, by design of an integrated circuit. In addition, each component, function, and the like described above may be realized by software by, for example, a processor included in the control circuit unit 7 interpreting and executing a program that realizes each function. Information such as programs, tables, and files that realize each function should be placed in memory (for example, memory 7M), hard disk, recording device such as SSD (Solid State Drive), or recording medium such as IC card, SD card, DVD, etc. Can.

  Further, control lines and information lines indicate what is considered to be necessary for the description, and not all control lines and information lines in the product are necessarily shown. In practice, almost all components may be considered to be connected to each other.

  DESCRIPTION OF SYMBOLS 2 DC power supply 4 Load device 5, 6 Interrupting circuit 7 Control circuit unit 7 M Memory 7 T Operation pattern table 10, 10-1 to 10-3 Power semiconductor module 11 Top Arm power semiconductor device, 12: lower arm power semiconductor device, 13, 14: diode, 15: capacitor, 30: drive circuit, 90: elevator system, 100, 100-1 to 100 to N: power conversion circuit, 200: first 1, power conversion circuit group 300, second power conversion circuit group, 203P, 203N, DC blocking switch, 204R, 204T, 204U, 204V, 204W, AC blocking switch

Claims (10)

A first power conversion circuit group configured by connecting at least one power conversion circuit in parallel;
A second power conversion circuit group configured by connecting in parallel a plurality of power conversion circuits having the same or substantially the same characteristics as the power conversion circuit of the first power conversion circuit group;
A blocking unit connected to an input side and / or an output side of the power conversion circuit of the first power conversion circuit group, which disconnects the circuit when an abnormality occurs;
A control circuit operating such that the time-averaged output of the power conversion circuit of the second power conversion circuit group is smaller than the time-averaged output of the power conversion circuit of the first power conversion circuit group Power converter. The power conversion device according to claim 1, wherein the control circuit continues the operation of the power conversion device using the second power conversion circuit group when the shutoff unit is opened. The control circuit makes an average output per power conversion circuit constituting the second power conversion circuit group larger than that before the opening of the shutoff unit when the shutoff unit is opened. The power converter device according to 2. The power conversion device according to any one of claims 1 to 3, wherein the control circuit switches a power conversion circuit to be paused at each operation cycle of a load in the second power conversion circuit group. The power conversion device according to any one of claims 1 to 3, wherein the control circuit switches the power conversion circuit to be paused in each of the second power conversion circuit group for each constant period longer than the operation cycle. In the second power conversion circuit group, the control circuit performs power conversion of all or part of the second power conversion circuit group in a period during which an output within one operation cycle of the power conversion device increases. The power conversion device according to any one of claims 1 to 3, wherein the circuit is suspended. The power conversion circuit is
A switching circuit unit in which a plurality of semiconductor switching elements and rectifying elements are connected in reverse parallel;
A capacitor connected in parallel with the switching circuit unit;
A switching circuit unit including reverse parallel connection of a plurality of semiconductor switching elements and rectifying elements;
The power conversion device according to any one of claims 1 to 3, comprising: a drive circuit that drives the semiconductor switching element. The power conversion device according to any one of claims 1 to 3, wherein output powers of the first power conversion circuit group and the second power conversion circuit group are consumed by a motor as a load. There is one power converter that constitutes the first power converter circuit group,
There are two or more power conversion devices constituting the second power conversion circuit group,
The power conversion circuit includes a switching circuit unit in which an upper arm in which a semiconductor switching element and a rectifying element are connected in antiparallel and a lower arm in which a semiconductor switching element and a rectifying element are connected in antiparallel are connected in series; The power conversion device according to claim 1, comprising: a capacitor connected in parallel to the switching circuit unit; and a drive circuit that drives each of the semiconductor switching elements. A first power conversion circuit group configured by connecting at least one power conversion circuit in parallel;
A second power conversion circuit group configured by connecting in parallel a plurality of power conversion circuits having the same or substantially the same characteristics as the power conversion circuit of the first power conversion circuit group;
A blocking unit connected to an input side and / or an output side of the power conversion circuit of the first power conversion circuit group, which disconnects the circuit when an abnormality occurs;
A control circuit that operates such that a time average output of a power conversion circuit of the second power conversion circuit group is smaller than a time average output of a power conversion circuit of the first power conversion circuit group;
Ascending / descending carriage,
An elevator comprising: a first power conversion circuit group; and a hoist that raises and lowers the car using power output from the second power conversion circuit group.

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