KR101539397B1 - Simulator with Direct Current and Alternating Current Output for Multi-Function Test - Google Patents

Abstract

The present invention can be operated by a simulator or simple DC power source of a solar battery or a fuel cell which is a direct current output by using one device, and also by a power system simulator which is an AC output, A multifunctional simulator for testing or certification.

Description

Simulator with Direct Current and Alternating Current Output for Multi-Function Test "

The present invention relates to a simulator for both direct current and alternating current, and more particularly, to a simulator capable of performing a multifunctional function such as a test or authentication of a power source or a load of a device by a single device.

The prior art related to the present technology includes a DC or AC simulator that operates by a power source such as a dedicated solar cell simulator, a fuel cell simulator, a power system simulator, etc. The electronic load device includes a device that operates by DC or AC load, There is no integrated simulator or power supply. Since conventional simulators operate only with power or load, they can perform unidirectional power control instead of bidirectional power control. Korean Patent Registration No. 10-2009-0046438 (published on September 20, 2011), Korean Patent Registration No. 10-0726024 (published on May 31, 2007), etc. may be referred to as related prior arts.

In order to test inverters for new and renewable energy and other power conversion devices, various types of power supplies or simulators are required. As a result, problems such as increase in installation cost, difficulty in operation, increase in maintenance cost, A simulator for solving the problem is required. For example, a solar simulator is required for testing solar inverters and a fuel cell simulator is required for testing inverters for fuel cells. To test the grid-connected protection functions of these inverters, the voltage and frequency of the power supply can be arbitrarily varied A power system simulator is needed. In order to apply a load to these inverters, an electronic load device or manual load is required.

1 is an example of a configuration diagram of a conventional solar cell or a fuel cell simulator.

Since the parameters 11 for the voltage-current characteristic curve are determined according to the insolation amount and the temperature or the fuel injection amount, respectively, of the solar cell or the fuel cell, and the operating point is determined according to the load condition, It is a device that simulates electrical characteristics through these parameters. Since both the solar cell and the fuel cell are DC output, the simulator 6 receives the input from the AC power source 1, passes through the transformer 2 for electrical insulation and voltage matching, and then, using the rectifier 3, Make a DC power supply (4). The simulator 6 includes a structure in which a step-down converter 5 and a reactor-capacitor filter 7 are provided in the direct-current power supply 4. An inverter, which is a device under test (8), is connected to this output and operated. The controller 9 functions to control the converter 5 in accordance with the parameters 11 corresponding to the voltage-current characteristic curve varying according to the operating condition of the device under test 8. The controller 9 is connected to a user interface (MMI) 10 in communication with the controller 9 to receive the parameters 11 required for the test. In the case of the solar cell, the characteristics of the solar cell, temperature, Parallel circuit configuration, and the like are input. In the case of the fuel cell, the voltage-current characteristic and the fuel input amount are important parameters.

In the simulator 6 having such a structure, since the input section is the rectifier 3 and the converter 5 is unidirectional step-down type, it can perform only the power source function and can not serve as the regeneration and the load in the reverse direction.

2 is an example of a configuration diagram of a conventional power system simulator.

2, the conventional power system simulator 24 receives an input from the alternating current power supply 1, and the insulating transformer 20, the rectifier 21, and the direct current power supply end 22 have a configuration shown in FIG. same. However, there are two differences from the solar cell or the fuel cell simulator 6 of Fig. One is that the number of the switching elements 23 at the output stage is increased so that one-phase and three-phase outputs can be obtained because the output is AC, and the other is that an AC waveform generator 27 is required instead of the battery characteristic. When conditions such as AC voltage and frequency required for the test are inputted in the user interface 29, the waveform generator 27 in the controller 28 generates a reference signal, and the switching element 23 controls the switch in accordance with the reference signal The desired AC output is obtained through the reactor-capacitor filter 25. And the output of the filter 25 is output to the device under test 26.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a method and apparatus for operating a solar battery or a fuel cell simulator or a simple DC power source, System simulator and the like, and to provide a multifunction simulator for testing or authenticating the power or load of various test equipments.

In order to accomplish the above object, according to one aspect of the present invention, there is provided a simulator including: a three-phase AC power output transformer; An input filter connected to each phase of the transformer output side, the filter being composed of a reactor and a capacitor; A converter having switches of a three-phase bridge structure; Smoothing capacitors; And an AC output filter having a reactor, an AC switch, and a capacitor sequentially connected to respective phases of the inverter output side, wherein inverters having switches of a three-phase bridge structure are sequentially connected; A direct current output filter having a direct current electromagnetic switch and a capacitor which are commonly connected to the reactor using the reactors of the first output filter in common; And a control unit for controlling the AC power supply, the DC power supply, or the load on the alternating current or the DC power source through the PWM control of the switches of the converter and the inverter, and the on / off control of the AC electromagnetic switch and the DC electromagnetic switch. And a control unit for controlling the operation.

The simulator may further include a user interface for inputting the parameters for operation of the AC power source, the DC power source, or the load to the AC or DC power source.

The control unit may control the AC power supply through the AC output filter, the DC power supply through the DC output filter, the load of the smoothing capacitors with respect to the AC power input to the plurality of terminals connected to the AC output filter, And to control the operation of the smoothing capacitors to the load with respect to the DC power input to the terminal connected to the output filter.

The simulator can be used for a simulation test as a load device for a solar cell DC power source, a fuel cell DC power source, a power system AC power source, or a DC or AC power source.

Wherein the plurality of terminals connected to the AC output filter are short-circuited to be used as a one-phase AC power source, and the control unit controls the plurality of switches in accordance with the control of the interleaving scheme for delaying the respective switching times of the three switch pairs of the three- It is possible to reduce the voltage and current pulsation outputted to the terminal with the terminal short-circuited.

In order to perform PWM control of the switches of the converter, the controller may include an input voltage Vin (abc) corresponding to the transformer output, an input current Iin (abc) flowing through the rectifier of the input filter, Receives the direct current voltage Vdc, receives the direct current reference voltage Vdc * and the effective current reference value Ide * from the user interface, outputs the phase angle information using the first dq-converter and the PLL with respect to Vin (abc) Based on the difference between Ide * and Ide and the difference between Vdc * and Vdc using the d-axis current Ide and the q-axis current Iqe, which are the outputs of the second dq-converter for Iin (abc) using phase angle information Axis and q-axis current compensation based on the difference between the ineffective current reference values Iqe * and Iqe, and generates the current reference values for the d-axis and q-axis current compensation based on the phase angle information and the respective current reference values, Phase for action It includes PWM section for PWM control the switches of the converter.

The control unit includes a voltage control block for receiving the q-axis reference voltage Vqe * and the d-axis reference voltage Vde * in the user interface for controlling the switches of the inverter for operation with the AC power supply , An internal phase angle obtained by integrating the angular speed with respect to the reference output frequency f * received from the user interface by an integrator is generated, and the output voltage Vout (abc) of the inverter is converted to d Axis voltage Vde and a q-axis voltage Vqe to the voltage control block, and the voltage control block generates a d-axis and a q-axis based on a difference between Vde * and Vde and a difference between Vqe * and Vqe Generate respective voltage reference values for voltage compensation, and output an inverse converted voltage dq of each of the voltage reference values based on the PWM control of the switches of the inverter.

And can operate as a simulator for a power system AC power source whose voltage and frequency are variable according to Vqe * and f * input through the user interface.

The control unit includes a current control block for receiving the q-axis reference current Iqe * and the d-axis reference current Ide * in the user interface for controlling the switches of the inverter for operation with the AC load And outputs phase angle information using the first dq-converter and the PLL with respect to the output voltage Vout (abc) of the inverter, and outputs a second dq- Axis current Ide and a q-axis current Iqe, which are outputs of the converter, to the current control block, and the current control block calculates d-axis current Ide and q-axis current Iqe based on the difference between Ide * and Ide and the difference between Iqe * and Iqe - generate respective current reference values for axial current compensation and output the dq inverse converted current of each of the current reference values based on the PWM control of the switches of the inverter.

Wherein the control unit includes a DC control block for receiving voltage-current characteristic curve data of a test object from the user interface and controlling the switch to follow the switch, in order to control the switches of the inverter for operation with the DC power supply, The DC control block includes a reference value calculator for calculating a reference current Idc * with respect to the output voltage Vout of the inverter by referring to the voltage-current characteristic curve data of the test object; A current controller for calculating a compensation current based on a difference between an Idc * and an output current Iout of the inverter; And an interleaving unit for generating a switching control signal for the switches of the inverter according to the compensation current.

The control unit includes a DC control block for receiving a power command Pdc * from the user interface and controlling the DC power consumption to follow the DC power consumption for controlling the switches of the inverter for operation to the DC load, The DC control block sets the reference current Idc * for power compensation based on the difference between Pdc * and the output power Pout of the inverter to the power controller; A current controller for calculating a compensation current based on a difference between an Idc * and an output current Iout of the inverter; And an interleaving unit for generating a switching control signal for the switches of the inverter according to the compensation current.

According to the simulator for both direct current and alternating current according to the present invention, it is possible to use a single power source device as a fuel cell, a solar cell, a simple direct current power source, a variable ac power source device, a direct current or alternating current load device, and so on. That is, it is possible to perform various tests such as power supply or load only by changing the internal setting with one multifunctional simulator device of the present invention without using individual equipment according to the purpose of the test, thereby solving the space for installing the test equipment, It can reduce the maintenance cost of equipment and can reduce the power cost for the test because it can regenerate the power consumed by heat when used as a resistor in the test when used as a load device.

In AC, it can operate in one phase or three phases. Since three DC power sources operate by interleaving in DC, it can be used as a high quality power source device which minimizes the ripple of the output voltage and current. There is an advantage that one simulator of the invention can be utilized for various purposes.

1 is an example of a configuration diagram of a conventional solar cell or a fuel cell simulator.
2 is an example of a configuration diagram of a conventional power system simulator.
3 is a view for explaining a simulator according to an embodiment of the present invention.
FIG. 4 is a diagram for explaining an interleaving control method for reducing pulsation of an output in the simulator of FIG. 3; FIG.
5 is a block diagram of a controller for controlling the converter section of FIG.
6 is a block diagram of a controller for AC control of the inverter of FIG.
7 is a block diagram of a DC control block of the controller for DC control of the inverter section.
8 is a practical example of the simulator of FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

3 is a diagram for explaining a simulator 55 according to an embodiment of the present invention.

3, a simulator 55 according to an embodiment of the present invention operates under the control of a controller 51, and the controller 51 communicates with a user interface (MMI) And input parameters necessary for the simulation test. Parameters such as the setting of the operation mode, the input or the output command and the like can be input through the user interface 54 and the operation state of each part of the simulator 55 can be monitored in real time.

Input means or display means of parameters for the user interface 54 may be included in the simulator 55 and the simulator 55 may include a transformer 31, an input filter, a converter 51, And the AC output filter 43-1 and the DC output filter 43-2 are connected in series so as to be connected in series between the power supply unit 36, the smoothing capacitors 38, and the inverter unit 39, And an electromagnetic switch (55) for direct current.

In other words, the simulator 55 is connected to an input terminal 30, a transformer 31 for voltage matching and insulation, an input filter (consisting of a reactor 33 and a capacitor 34) whose output on each transformer 31 is connected to a reactor 33 And the capacitor 34 is connected between the output of each phase of the transformer 31 and the ground), the input voltage Vin detection sensor 32 (the transformer A converter section 36 in the form of a bidirectional converter using a PWM (Pulse Width Modulation) method, an input current (Iin) detecting sensor 35, a DC voltage Vdc A three-phase bridge structure inverter unit 39 having three switches 39-1, 39-2 and 39-3, a detection sensor 37, smoothing capacitors 38, an output current Iout detection A sensor 40, an output voltage Vout detection sensor 42, an output filter composed of a reactor 41 and a capacitor 43-1 / 43-2, an electromagnetic switch 44 for selecting an AC output And a magnetic switch), the electromagnetic switch 55 (DC magnetic switch for) for selecting a DC output. That is, the output of each phase of the inverter unit 39 is connected to the capacitor 43-1 between the other terminal of the electromagnetic switch 44 and the ground via the reactor 41 and the electromagnetic switch 44, and the reactor 41 And the capacitor 43-2 is connected between the other terminals of the electromagnetic switch 55 of each phase through the electromagnetic switch 55 and the ground.

The three-phase AC output can be output in a three-phase four-wire system using the AC output terminal 46 and the neutral point terminal 48 and the DC output can be output through the DC output terminal 47 and the neutral point terminal 48 have.

3, an AC voltage of three phases is inputted through an input terminal 30, a transformer 31 converts an AC voltage into a three-phase AC voltage according to a winding ratio, and the converted voltage of each phase is supplied to a reactor 33 and a capacitor 34 Phase input filter, and is output to a converter section 36 including switches of a three-phase bridge structure. The input voltage Vin and the input current Iin of each phase to the converter section 36 are detected through the input voltage Vin detection sensor 32 and the input current Iin detection sensor 35, ) Display means.

The converter section 36 outputs the AC-DC converted voltage under the control of the controller 51 and two smoothing capacitors 38 are connected in series to the DC stage, which is the output terminal of the converter section 36 , The contacts of the smoothing capacitors 38 are used as the neutral point 48. The DC voltage Vdc which is the output of the converter section 36 can be detected through the DC voltage Vdc detection sensor 37 and displayed through the display means of the user interface 54. [

An inverter unit 39 of a three-phase bridge structure connected in parallel at both ends of the outputs of the converter unit 36 and the smoothing capacitors 38 is controlled by the three switches 39-1, 39-2, 39-3) to output the appropriate converted voltage of each phase.

The output of the inverter unit 39 is supplied to the reactor 41 and the capacitor 43-1 of each phase by controlling the electromagnetic switch 44 under the control of the controller 51. In this case, And the three-phase AC output is output using the AC output terminal 46 and the neutral point terminal 48.

The output of each phase of the inverter unit 39 is supplied to the capacitor 43 via the reactor 41. The output of each phase of the inverter unit 39 is controlled by the control of the controller 51, -2 and a direct current output can be output through the direct current output terminal 47 and the neutral point terminal 48.

The output current Iout detection sensor 40 can detect the output current Iout of each phase of the inverter unit 39 and the output voltage Vout detection sensor 42 can detect the output current Iout of each phase of the inverter unit 39 The voltage Vout can be detected and the detection result can be displayed through the display means of the user interface 54. [ Because these sensors are electronic, both DC and AC can be detected.

The converter unit 36 and the inverter unit 39 are controlled by the digital controller 51. The controller 51 controls the on and off states of the six switches of the converter unit 36 and the inverter unit 39, ) And the off state are controlled by PWM. In addition, the controller 51 turns on or off the switches for each phase of the necessary electromagnetic switches 44, 55 through the digital control signal 52 for selection of the output. The controller 51 is connected to the user interface 54 through the communication 53 to receive the type of the simulator and necessary parameters and displays the operation status of each part.

Using this structure, DC output and AC output can be obtained through internal control, and the principle of using it as a load device as well as a power supply device will be described.

Since the inverter unit 39 is composed of three-phase bridge structures 39-1, 39-2 and 39-3, three-phase alternating current output is basically possible and bidirectional power control is possible, so that it can be used as a power supply device or a load device . Further, in order to make it a direct current output, the present invention is provided with an electromagnetic switch 55 capable of short-circuiting three phases at the output terminal.

By doing so, the three switches 39-1, 39-2, and 39-3 are connected in parallel, and a circuit can be configured for DC or AC power of the so-called interleaving method (see FIG. 4) . 39-2, and 39-3 connected in parallel at both ends of the output of the converter unit 36 and the smoothing capacitors 38 in the case of a simulator for a solar cell or a fuel cell, DC converter can be operated by turning off the three switches 58 and turning on / off only the three switches 59 according to the control of the switch 51. [ On the contrary, it can operate as a step-up DC-DC converter by turning off the three switches 59 and by using the three switches 58 below. Therefore, the structure of the inverter unit 39 and the electromagnetic switch 44/55 enable direct current and alternating current power output, and also, for example, a direct current or alternating current power input through the 46 or 47 terminal, DC and AC load devices for testing the DC voltage (Vdc) state of the smoothing capacitors 38 under the control of the electromagnetic switches 44/55 and inverter 39 .

When three terminals of the AC output terminal 46 are short-circuited from the outside, they can also be used as a one-phase AC power supply. At this time, the three switches 39-1, 39-2, In addition, it can operate with interleaving method to reduce the voltage and current pulsation of the output and increase the output current three times, so that it can supply power equivalent to three phase rated output in one phase.

4 is a diagram for explaining an interleaving control method for reducing the pulsation of the output of the simulator 55 in Fig.

FIG. 4 shows a case where three interleaving is applied, and two or more interleaving is possible. Three switches 39-1, 39-2, and 39-3 of the inverter unit 39 are connected to the phase difference 73 by 1/3 of the PWM control period 74 in the case of the DC power supply of three interleaving systems. Lt; RTI ID = 0.0 > of switching time < / RTI > When the three switches 39-1, 39-2 and 39-3 are operated with delayed phases as shown in 70, 71 and 72 of FIG. 4, respectively, the switches 39-1, 39-2 and 39- 3) are 75, 76, and 77, and since they are connected in parallel, the pulsating frequency of the DC output terminal 47 is increased to 3 times as shown in FIG. 78, but the amount of pulsation is reduced to 1/3 Stable output characteristics can be obtained.

5 is a block diagram of the controller 51 for controlling the converter unit 36 of FIG.

5, the controller 51 has three inputs of three-phase input voltage Vin (abc) and three-phase input current Iin (abc), which are three-phase outputs of the transformer 31 corresponding to a system input, Receives the voltage Vdc * and the detected direct current voltage Vdc, and controls each switch of the converter section 36 by the PWM output 49. [

First, in order to detect the phase of the input power source, the first dq-converter 90 performs dq-conversion on the input voltage Vin (abc), and outputs the resultant d-axis voltage Vde 91 to the output The phase locked loop 92 for finding the phase identical to the phase of the input voltage outputs the phase angle information 93 so that the first dq-converter 90 and the second dq-converter 94 Respectively, to have a fixed phase with respect to the three-phase input voltage Vin (abc) and the three-phase input current Iin (abc). The phase angle information 93 is also used in the PWM unit 108. [

The second dq-converter 94 multiplies the d-axis current ide 95, which is the effective DC current component of each of the three-phase input current Iin (abc), and the q-axis current Ide, Axis current controller 104 and the q-axis current controller 105, respectively.

The control of the converter unit 36 keeps the voltage of the DC single use capacitor 38 constant. When the inverter unit 39 operates as a simulator operation, that is, as a power source, the input power Vin (abc), Iin when the inverter unit 39 operates as a load, the regenerative operation is performed to return the power regenerated to the DC single-phase utilization capacitor 38 to the input terminal 30 side .

Therefore, the control of the converter unit 36 controls the flow of the current so as to keep the voltage of the DC single-use capacitor 38 constant. When the calculation unit 99 determines that the predetermined direct current When the error between the reference voltage Vdc * 98 and the detected DC voltage Vdc is calculated and input to the voltage controller 100, the voltage controller 100 calculates the reactive current reference lqe * ( 101) as a command value.

Since the normal active power need not be controlled, the effective current reference value Ide * (96) is set to 0 (Ide * (96) can also be input from the MMI 54). The calculation units 97 and 103 calculate the current reference value Ide (96) and the ineffective current reference value Iqe * (101) of the d-axis and q-axis received from the MMI 54, (difference) between the d-axis current Ide 95 of the dq-converter 94 and the q-axis current Iqe 102 and calculates the difference (error) between each of the current controllers 104 and 105 ) Outputs respective current reference values 106 and 107 for current compensation of the d-axis and the q-axis, respectively. This output is combined with the phase angle information 93 in the PWM section 108 to control the three-phase switch of the converter section 36 by generating the pulse width modulation signal. Through this control operation, the converter unit 36 controls the magnitude and direction of the current so that the voltage of the DC short-circuiting capacitor 38 can be constantly maintained regardless of the operation mode of the inverter unit 39.

6 is a block diagram of the controller 51 for AC control of the inverter 39 of FIG.

6, the controller 51 receives the output voltage Vout and the output current Iout of the inverter unit 39 as an input and receives the output current Iout from the voltage control block 130, the current control block 148, The control signal generated by the control block 166 is selected by the signal selection switch 153 in accordance with the respective operation modes such as the alternating current, the direct current output, the alternating current and the direct current load device, and is output to the PWM output 50 of the PWM section 155 And controls the switches of the inverter unit 39. A detailed block diagram of the DC control block 166 is shown in FIG.

First, a voltage control block 130 is used to operate as a power system (AC power source) simulator. To this end, the voltage control block 130 receives the reference output frequency f * 139 input from the user interface 54, And an integral phase angle 140 is generated by integrating the angular velocity value with the integrator 136. This value is initially selected by the selection switch 135 and input to the dq-converters 132 and 141 .

The dq-converter 132 generates the d-axis voltage Vde 122 and the q-axis voltage Vqe (127) through the dq-conversion based on the internal phase angle 140 for the output voltage Vout (abc) do.

The q-axis reference voltage Vqe * (125) is set as the peak value of the voltage reference provided at the user interface 54, and the d-axis reference voltage Vde * 120 is usually set to zero.

In the voltage control block 130, the calculators 121 and 126 calculate the d-axis voltage Vde 122 of the dq-converter 132 with respect to the reference voltages 120 and 125 of the d-axis and q- Axis voltage controller 123 and the q-axis voltage controller 128 calculate the difference (error) between the q-axis voltage Vqe and the q-axis voltage Vqe (127) and outputs respective voltage reference values 124 and 129 for q-axis voltage compensation.

The outputs 124 and 129 of the respective voltage controllers 123 and 128 are converted into a voltage 131 that is dq reverse transformed (dq-abc transformed) with respect to each phase in the inverse conversion block 168. In the PWM unit 155, And a control signal 50 for turning on and off the switches of the switch 39. Through this process, the inverter unit 39 can generate the AC voltage matching the voltage and the frequency reference set by the user interface 54. [

The following describes the current control block 148 that operates as an AC load. In a case where an AC test device (see 200 in FIG. 8) generates AC power and needs to apply a load thereto (for example, a load test of a synchronous generator or a test of a wind power generator) A phase locked loop (PLL) 134 is used for supplying the load in accordance with the phase of the alternating current power outputted by the phase locked loop

The input of the phase locked loop 134 is the voltage detected at the input of the output voltage Vout (abc) of the inverter section 39, i. E. The test point (see 200 in FIG. 8) Only the d-axis voltage Vde 122 is input. The phase locked loop 134 tracks the phase angle 140 using the principle that the d-axis voltage Vde 122 becomes zero if the internal phase angle coincides with each phase of the three-phase alternating current measured. Phase locked loop 134 calculates phase angle 140 and feeds phase angle 140 through selector switch 135 to dq-converter 132 so that the phase angle can be fixed at internal phase angle 140 And the phase angle 140 is also passed to the dq-converter 141.

The dq-converter 141 dq-converts the angular phase output current Iout (abc) flowing in the device under test (see 200 in Fig. 8) using this phase angle 140 to obtain dq- and generates the d-axis current Ide 143 and the q-axis current Iqe 150.

The d-axis reference current Ide * 142 and the q-axis reference current Iqe * 149 may be provided at the user interface 54 or the invalid and active power reference values given at the user interface 54 to the output voltage Vout As shown in FIG.

In the current control block 148, the calculators 144 and 151 calculate the d-axis current Ide 143 of the dq-converter 141 with respect to the reference currents 142 and 149 of the respective d-axis and q- Axis current controller 150 and the q-axis current controller 150 according to the difference (error) between the q-axis current Iqe 150 and the q-axis current controller 150, The current reference values 146,

The outputs 146 and 153 of the respective current controllers 145 and 152 are converted into a current dq inverse transformed (dq-abc transformed) with respect to each phase in the inverse conversion block 147. In the PWM unit 155, Lt; RTI ID = 0.0 > 50 < / RTI > Through this process, the inverter unit 39 regenerates the current as much as the set current from the AC DUT (see 200 in FIG. 8) to the DC stage 38 and applies the load.

7 is a block diagram of the direct current control block 166 of the controller 51 for direct current control of the inverter section 39. [ The inverter unit 39 and the like are controlled through the DC control block 166 so that the simulator 55 is used as a DC power source or a DC load.

The DC control block 166 includes two blocks: a solar cell or a fuel cell simulator function and a DC load function. In the case of a simulator (DC power) function, a reference value calculation section 179 calculates an output voltage Vout (180 degrees) with reference to the voltage-current characteristic curve (data) of the solar cell or the fuel cell corresponding to the reference current Idc * (any one of the three phases abc).

The reference current Idc * 180 is selected in the switch 181 (the simulator mode and the load mode can be switched by the changeover switch 181 under the control of the controller 51) An error (difference) between the reference current Idc * 180 and the output current Iout of the inverter section 39 (at least one of the three phases abc) is calculated and if the current controller 183 calculates the compensation current, Unit 184 controls the switching of the switches of the inverter unit 39 on the basis thereof by generating a switching control signal 185 for the corresponding interleaving compensation (see Fig. 4). Through this process, the inverter unit 39 follows the voltage-current characteristic curve data of the solar cell or the fuel cell that has been already inputted through the user interface unit 54.

The calculation unit 187 calculates the actual power Pout 188 which is the product of the DC output voltage Vout and the DC output current Iout from the power command Pdc * 186 input from the user interface 54, And the power controller 189 generates a reference current Idc * (190) for power compensation in accordance with the power error. Here, the reference current Idc * 190 is selected in the switch 181 (the simulator mode and the load mode can be switched by the changeover switch 181 under the control of the controller 51) Calculates the difference between the reference current Idc * 190 and the output current Iout of the inverter unit 39 and calculates the compensated current value of the current controller 183 accordingly, the interleaving unit 184 calculates And controls the switching of the switches of the inverter unit 39 on the basis thereof by generating a switching control signal 185 for interleaving compensation (see Fig. 4). Through this procedure, the DC testing apparatus (see 201 in FIG. 8) consumes the DC power so as to follow the desired power command Pdc *.

8 is a practical example of the simulator 55 of Fig. When the AC testing apparatus 200 is tested, the electromagnetic switch 44 is short-circuited and the electromagnetic switch 55 is opened. In the case of the power system simulator, that is, the power supply apparatus, The power flows from the connected commercial power source to the device under test 200 in the direction 202 and flows in the opposite direction 203 when the device is used as an AC load device. In the case of a single-phase unit or a power supply unit, the three terminals of the AC output terminal 46 may be short-circuited and the neutral terminal 48 may be used together.

When the DC device 201 is used, the electromagnetic switch 44 may be opened and the electromagnetic switch 55 may be short-circuited. In the DC test, if only the mode and setting values are changed in the user interface 54, it can be used as a power supply or a load as described above.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

30: AC input terminal
31: Transformer
33, 34: input filter
32: Input voltage sensor
35: Input current sensor
36: Converter section
38: DC capacitor
39:
41, 43: Output filter
40: Output current sensor
42: Output voltage sensor
44, 55: electromagnetic switch for output switching
51: Digital controller
54: Man Machine Interface (MMI)

Claims (11)

3-phase AC power output transformer; An input filter connected to each phase of the transformer output side, the filter being composed of a reactor and a capacitor; A converter having switches of a three-phase bridge structure; Smoothing capacitors; And inverters having switches of three-phase bridge structure are sequentially connected,
An AC output filter having a reactor sequentially connected to each phase of the inverter output side, an AC electromagnetic switch, and a capacitor; A DC output filter having a DC electromagnetic switch and a capacitor sequentially connected to the reactor using the reactors of the AC output filter in common; And
A DC power source, or an AC or DC power source through the PWM control of the switches of the converter and the switches of the inverter, and the ON / OFF control of the AC electromagnetic switch and the DC electromagnetic switch. And a control section
The control unit may control the AC power supply through the AC output filter, the DC power supply through the DC output filter, the load of the smoothing capacitors with respect to the AC power input to the plurality of terminals connected to the AC output filter, And controls the operation of the smoothing capacitors to a load with respect to a DC power input to a terminal connected to the output filter. The method according to claim 1,
A user interface for inputting parameters for operating the AC power source, the DC power source, or the load to the AC or DC power source,
Further comprising a simulator. delete The method according to claim 1,
Wherein the simulator is used for a simulation test as a load device for a solar cell DC power supply, a fuel cell DC power supply, a power system AC power supply, or a DC or AC power supply. The method according to claim 1,
A plurality of terminals connected to the AC output filter are short-circuited and used as a one-phase AC power source,
Wherein the controller reduces the voltage and current pulsations output to the terminals having the short-circuited terminals according to the control of the interleaving scheme for delaying the respective switching times of the three switch pairs of the three-phase bridge structure of the inverter. . The method according to claim 1,
In order to perform PWM control of the switches of the converter,
The input voltage Vin (abc) corresponding to the transformer output, the input current Iin (abc) flowing in the rectifier of the input filter, and the DC voltage Vdc detected from the smoothing capacitors are input. *, And the effective current reference value Ide *
The phase angle information is output to the Vin (abc) using the first dq-converter and the PLL,
Based on the difference between Ide * and Ide and the difference between Vdc * and Vdc using the d-axis current Ide and the q-axis current Iqe, which are outputs of the second dq-converter for Iin (abc) using the phase angle information, Based on the difference between the generated reactive current reference value Iqe * and Iqe, each current reference value for d-axis and q-axis current compensation is generated,
And a PWM unit for PWM-controlling the switches of the converter for operation with the power source or the load according to the phase angle information and the respective current reference values. The method according to claim 1,
The control unit includes a voltage control block for receiving the q-axis reference voltage Vqe * and the d-axis reference voltage Vde * in the user interface for controlling the switches of the inverter for operation with the AC power supply ,
An internal phase angle obtained by integrating an angular speed with respect to a reference output frequency f * received from the user interface by an integrator and generating an internal phase angle with respect to an output voltage Vout (abc) of the inverter through a dq- Generates an axial voltage Vde and a q-axis voltage Vqe to output to the voltage control block,
The voltage control block includes:
Generates respective voltage reference values for d-axis and q-axis voltage compensation based on the difference between Vde * and Vde and the difference between Vqe * and Vqe, And outputs the inverse-converted voltage of the voltage reference value of dq. 8. The method of claim 7,
Wherein the simulator operates as a simulator for a power system AC power source whose voltage and frequency vary according to Vqe * and f * input through the user interface. The method according to claim 1,
The control unit includes a current control block for receiving the q-axis reference current Iqe * and the d-axis reference current Ide * in the user interface for controlling the switches of the inverter for operation with the AC load ,
And outputs the phase angle information to the output voltage Vout (abc) of the inverter using the first dq-converter and the PLL, and outputs the phase angle information to the second dq-converter Axis current Ide and the q-axis current Iqe to the current control block,
The current control block includes:
Based on the difference between Ide * and Ide and the difference between Iqe * and Iqe, a current reference value for each of the d-axis and q-axis current compensation is generated, and each of the current reference values based on the PWM control for the switches of the inverter And outputs the inverse-converted current of dq of the current reference value of the current reference value. The method according to claim 1,
Wherein the control unit includes a DC control block for receiving voltage-current characteristic curve data of a test object from the user interface and controlling the switch to follow the switch, in order to control the switches of the inverter for operation with the DC power supply,
The DC control block includes:
A reference value calculation unit for calculating a reference current Idc * with respect to the output voltage Vout of the inverter with reference to the voltage-current characteristic curve data of the test object;
A current controller for calculating a compensation current based on a difference between an Idc * and an output current Iout of the inverter; And
An inverter for generating a switching control signal for the switches of the inverter according to the compensation current,
And a simulator. The method according to claim 1,
The control unit includes a DC control block for receiving a power command Pdc * from the user interface and controlling the DC power consumption to follow the DC power consumption for controlling the switches of the inverter for operation to the DC load,
The DC control block includes:
A reference current Idc * for power compensation based on the difference between Pdc * and the output power Pout of the inverter;
A current controller for calculating a compensation current based on a difference between an Idc * and an output current Iout of the inverter; And
An inverter for generating a switching control signal for the switches of the inverter according to the compensation current,
And a simulator.

Images