JP2000152652A - System interconnection inverter controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system interconnection inverter controller which can stably obtain a system current of low distortion with a resonance type inverter, using one transistor. SOLUTION: In a system interconnection inverter using a resonance type inverter 2 which uses one transistor and a bridge inverter 7, a control means 10 generates with a reference wave generating means 20, a reference wave synchronized with the system voltage detected with a system voltage-detecting means 12. This reference wave is a full-wave rectified waveform of a low distortion sine wave which is generated on the basis of the low distortion sine wave data 21. A first PWM signal generating means 18 compares a reference wave with a carrier wave generated with a first carrier generating means 16 to generate the PWM signal of the resonance type inverter 2, using a transistor, and the second PWM signal generating means 19 compares the reference wave with the carrier generated with a second carrier generating means 17 to generate the PWM signal of the bridge inverter 7. Stable and low distortion data are realized with the feed-forward control on the basis of the low distortion reference wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system interconnection inverter control device for interconnecting DC power from a solar cell, a fuel cell, or the like to an electric power system and supplying the same as AC power.

[0002]

2. Description of the Related Art A conventional system interconnection inverter control device will be described below with reference to the drawings.

FIG. 10 is a block diagram showing a configuration of an example of a conventional system interconnection inverter control device. In FIG. 10, the grid-connected inverter control device inputs DC power from a DC power supply 1, receives a single-stone resonant inverter 2, a high-frequency transformer 3, a current-limiting coil 4, a rectifier 5, a high-frequency filter 6, a bridge inverter 7, The system includes a noise filter 8, a current monitor 9 for detecting an output current, and a control unit 10, and supplies AC power to a system 11. DC power supply 1
Is provided on the primary side of the high-frequency transformer 3 and includes a switching element 2a, and a resonance capacitor 2b connected in parallel to the primary winding of the high-frequency transformer 3; This constitutes a voltage resonance type inverter in which the voltage waveform of the element 2a becomes a resonance voltage waveform.

The rectifier 5 connected to the secondary side of the high-frequency transformer 3 performs half-wave voltage rectification using diodes 5a to 5b and a capacitor 5c. This output is coil 8
The control means 10 detects the output current by the current monitor 9 and switches the switching element 2a of the one-stone resonant inverter 2 and the four switching elements 7a of the bridge inverter 7 while detecting the output current by the current monitor 9. By controlling the on-time of ~ 7d, AC power of the commercial frequency is supplied to the system 11, which is a load.

The operation of the above configuration will be described.
The switching element 2 is connected to the primary winding of the high-frequency transformer 3.
High frequency power is generated by the opening / closing operation of “a”, and power is supplied to the secondary side via the high frequency transformer 3. The rectifier 5 connected to the secondary winding of the high-frequency transformer 3 charges the capacitor 5c in either the conduction or non-conduction state of the switching element 2a, and when the polarity of the secondary winding of the high-frequency transformer 3 changes, In addition to the output voltage of the high-frequency transformer 3, the voltage of the already charged capacitor 5c is applied to the bridge inverter 7. Since the current limiting coil 4 is connected between the high frequency transformer 3 and the rectifier 5,
The output is constant current.

In order to output a sinusoidal current having a power factor of 1 to the system 11, the single-stone resonance type inverter 2 is frequency-modulated, but the output of the single-stone resonance type inverter 2 is sufficient for the ON time of the switching element 2a. In this case, a large short-circuit current flows due to residual charges in the resonance capacitor 2b, and a large loss occurs. Therefore, there is a limit to the minimum on-time of the switching element 2a. Therefore, in the conventional system interconnection inverter control device, when the voltage of the system 11 is near zero voltage, the bridge inverter 7 for switching the polarity is switched at a high frequency to perform the PWM operation.
By performing the control, a low distortion output current is obtained.

A low distortion sine wave synchronized with the system voltage is generated by the system synchronous low distortion sine wave generating means 13 in synchronization with the system voltage obtained by the system voltage detecting means 12. Also,
The output current is detected by the output current detection means 14, and the error amplification means 15 outputs a reference wave for PWM generation so that an error from the low distortion sine wave becomes zero, thereby performing feedback control. The first PW is compared with the outputs of the carrier generation means 16 and the second carrier generation means 17.
The switching element 2a and the switching elements 7a to 7d are driven through the M signal generating means 18 and the second PWM signal generating means 19, respectively.

The above operation is repeatedly executed at a sufficiently high speed with respect to the commercial frequency, and the ON time of the switching element 2a is appropriately controlled.

[0009]

In such a conventional grid-connected inverter control device, modulation is applied to the switching element 2a by PWM control in order to obtain a sine-wave output current from a DC voltage whose input is smoothed. However, if the conventional single-stone resonance type inverter 2 is modulated to obtain a sine wave, the following problem occurs.

The single-stone resonance type inverter 2 has a feature that enables zero volt switching in order to minimize the stress on the switching element 2a. For this reason, the resonance time, which is the off time of the switching element 2a, is almost equal. When the PWM control is performed, the operating frequency changes, for example, from about 10 kHz to about 40 kHz. Further, the obtained output current is a low-frequency current of a commercial frequency whose high-frequency component has been cut by the capacitor 8b,
Since the phase is delayed with respect to the high-frequency voltage generated by the switching in the single-stone resonance type inverter 2, sufficient speed and stability for control are necessary to detect the output current and realize appropriate feedback control. Desired.

From the above, it is difficult to realize an inexpensive control means in the configuration including the conventional single-stone resonance type inverter 2 or the current waveform is changed due to the fluctuation of the input power supply or the fluctuation of the system 11. It has the problem of distortion.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. In a grid-connected inverter control apparatus using a single-stone resonance type inverter, a simple control means is used to control input power fluctuations and system swings. An object of the present invention is to provide a grid-connected inverter control device capable of stably supplying high-quality AC power without distorting a current waveform.

[0013]

According to a first aspect of the present invention, there is provided a high-frequency transformer and a switching device for connecting and disconnecting a primary winding of the high-frequency transformer to a DC power supply at a high frequency by a single switching element together with a resonance capacitor. A resonant inverter; rectifying means for rectifying a high-frequency voltage output from a secondary winding of the high-frequency transformer to output a DC voltage; and four rectifying means for switching the DC voltage output by the rectifying means to convert the DC voltage to an AC voltage. A bridge inverter including a switching element, a noise filter that removes noise at an output of the bridge inverter, a system voltage detecting unit that detects a system voltage connected to an output of the noise filter as a system voltage, and the system Output current detecting means for detecting a current to be output to the controller, and control means for controlling the entire operation. Means generates a PWM signal by comparison with a predetermined reference wave and a predetermined carrier wave, and PWM controls the respective switching elements in the stone resonant inverter and the bridge inverter with feedforward
The grid-connected inverter control device may be a full-wave rectified wave of a low distortion sine wave generated in synchronization with the grid voltage.

According to the present invention, it is possible to realize a system interconnection inverter capable of obtaining a stable output waveform with respect to input voltage fluctuations and system voltage disturbances and forming a substantially sine wave as an output current waveform.

According to a second aspect of the present invention, the control means includes:
2. The system interconnection inverter control device according to claim 1, wherein the reference wave is corrected in a next cycle in response to a distortion of an output current in an arbitrary cycle.

According to the present invention, an output current with low distortion can be obtained by stable operation without oscillation by low-speed feedback with respect to the reference wave.

According to a third aspect of the present invention, the control means includes:
When a reference wave is given by data at a predetermined unit time,
3. The grid-connected inverter control according to claim 2, wherein the reference wave of the next cycle is corrected by a phase preceding by one or more units of the unit time in response to the distortion of the output current for each unit time in an arbitrary cycle. Device.

According to the present invention, correction is made so as to compensate for a delay in control of the system from the single-stone resonance type inverter to the system, so that a lower distortion output current can be obtained.

According to a fourth aspect of the present invention, in the region where the absolute value of the system voltage is equal to or less than the predetermined value, the correction amount of the reference wave is made larger than in other regions. It is a system interconnection inverter control device related to any of them.

According to the present invention, since the amount of correction is increased for a low level at which PWM control is not effective, it is possible to obtain an output current with low distortion even near the zero voltage of the system voltage.

According to a fifth aspect of the present invention, the control means includes:
5. The method according to claim 1, wherein a phase difference is provided between a reference wave for generating a PWM signal for controlling the one-stone resonance type inverter and a reference wave for generating a PWM signal for the bridge inverter. It is a system interconnection inverter control device related to any of them.

According to the present invention, a low distortion output current can be obtained by positively shifting the phase of the reference wave in accordance with the phase shift of the system at a low level at which PWM control is not effective.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention according to the first aspect, the control means means for controlling opening and closing operations of a switching element in a single-stone resonance type inverter and a switching element in a bridge inverter.
A PWM signal is generated by comparing the level of a carrier wave such as a triangular wave, a sawtooth wave, or the like with a carrier wave of about kHz to 40 kHz and a PWM signal by feed forward.
The reference wave is controlled, and a low distortion sine wave full-wave rectified wave synchronized with a system voltage is used as the reference wave.

In the embodiment, the first carrier generation means generates a triangular waveform carrier, and the first PWM signal generation means compares the triangular wave of the first carrier generation means with the reference wave to generate a PWM signal. Then, the switching element of the one-stone resonance type inverter is driven. Further, a carrier wave having a triangular waveform is generated by the second carrier wave generation means, and the second carrier wave is generated.
The level of the triangular wave of the second carrier wave generator and the reference wave is compared by the WM signal generator to generate a PWM signal and drive the switching element of the bridge inverter. At this time, a polarity switching signal and a PWM signal are collectively generated for the bridge inverter. Further, the low distortion sine wave can be generated in synchronization with the system voltage from the low distortion sine wave data stored in a ROM or the like in advance.

In the present invention according to the second aspect, when the on-time of all the switching elements of the one-stone resonance type inverter and the bridge inverter is PWM-controlled by feedforward, the control means can control a low distortion sine at an arbitrary cycle of the commercial frequency. The reference wave is corrected in the next cycle in accordance with the distortion of the output current with respect to the wave, and in the embodiment, the reference wave correction means is provided, and the difference between the reference wave and the waveform of the output current is added to the reference wave in the next cycle. Correction is performed by addition and subtraction. This correction is a low-speed feedback control with respect to the ON time of each switching element, and a low-distortion output current is obtained by a stable operation that cannot be realized by a high-speed feedback control.

In the present invention according to claim 3, the control means forms the reference wave output in synchronization with the system voltage as a set of time-divided data in units of several tens of μsec, and suppresses the distortion of the output current. When the reference wave is correspondingly corrected in the next cycle, in the embodiment, the reference wave correction means corrects the distortion in the arbitrary phase of the output current by one unit of the unit time as compared with the same phase in the next cycle. The reference current is corrected by the preceding phase, that is, the phase advanced by one unit time in the next cycle, and the output current having lower distortion is controlled as a control that allows for a phase delay between the input and output from the single-stone resonant inverter to the system. To get

[0027] In the present invention according to claim 4, the control means includes: a control unit for controlling the control unit in a region where the absolute value of the system voltage is equal to or less than a predetermined value.
The correction amount of the reference wave is corrected to be larger than the other regions, and the correction is made more effective, so that an output current with lower distortion is obtained.

[0028] In the present invention according to claim 5, when the absolute value of the system voltage is equal to or more than a predetermined value, the control means sets a phase difference between the reference wave corresponding to the one-stone resonance type inverter and the reference wave corresponding to the bridge inverter. In this embodiment, a phase delay unit is provided to delay the phase of the reference wave on the bridge inverter side, and to obtain a lower distortion output current in accordance with the phase delay in the system.

Hereinafter, embodiments of the present invention will be described.

[0030]

(Embodiment 1) Hereinafter, Embodiment 1 of a system interconnection inverter control device of the present invention will be described with reference to the drawings. The present invention relates to claim 1.

FIG. 1 is a block diagram showing the configuration of this embodiment. The same components as those in FIG. 10 are denoted by the same reference numerals, and detailed description will be omitted. The present embodiment differs from the conventional example in the configuration and operation of the control means 10.

In FIG. 1, a grid-connected inverter receives a DC power supply 1 as an input and supplies a 50 Hz or 60 H
AC power is supplied at the commercial frequency of z. As in the conventional example shown in FIG. 10, the grid-connected inverter includes a one-stone resonant inverter 2, a high-frequency transformer 3, a current-limiting coil 4, a rectifier 5, a high-frequency filter 6, a bridge inverter 7, a noise filter 8, an output current detection. And a control unit 10 for controlling the conduction time of the switching element 2a and the switching elements 7a to 7d.

The control means 10 of this embodiment includes a system voltage detecting means 12 for detecting an absolute value of a system voltage of the system 11 and a zero voltage phase, a first carrier wave generating means 16, a second carrier wave generating means 17, a first PWM. It comprises a signal generation means 18, a second PWM signal generation means 19, a reference wave generation means 20, and low distortion sine wave data 21.

The operation of the above configuration will be described with reference to the drawings. FIG. 2 is a waveform chart showing the operation of the present embodiment. In synchronization with the system voltage obtained by the system voltage detecting means 12, a waveform obtained by performing full-wave rectification of a sine wave based on the low-distortion sine wave data 21 from the reference wave generating means 20, that is, shown in FIG. A reference wave is output. The output reference wave is compared with the output of the first carrier wave generating means 16 in the first PWM signal generating means 18, and the PWM drive pulse of the single-stone resonance type inverter 2, that is, shown in FIG. The first PWM signal is generated, and drives the switching element 2a of the one-stone resonance type inverter 2.
Similarly, the output of the second carrier signal generator 17 is compared with the output of the second carrier signal generator 17 in the second PWM signal generator 19 to generate the second PWM signal shown in FIG. 2F, and drives the switching elements 7a to 7d of the bridge inverter 7. .

At this time, the output of the second carrier generation means 17 is, as shown in FIG.
Since the amplitude is set smaller than the output of the bridge inverter 7, the bridge inverter 7 performs a polarity switching operation corresponding to the commercial frequency in a region where the absolute value of the voltage of the system 11 is equal to or larger than a predetermined value. 2 has reached the minimum value, the bridge inverter 7 performs a PWM operation at a high frequency, and the on-time of the bridge inverter 7 is reduced as the absolute value of the system voltage decreases, so that the output current generally becomes a sine wave. .

As described above, according to this embodiment, a so-called feedforward control in which a reference wave is determined in advance is used, and a full-wave rectified wave of a low distortion sine wave synchronized with the system voltage is used as a reference wave of the PWM control. By using the same, it is possible to obtain a stable output waveform with respect to the fluctuation of the input voltage and the disturbance of the system voltage, and it is possible to realize a system interconnection inverter control device capable of forming a substantially sine wave as the waveform of the output current. .

(Embodiment 2) Hereinafter, Embodiment 2 of a system interconnection inverter control device of the present invention will be described with reference to the drawings. This embodiment relates to claim 2.

FIG. 3 is a block diagram showing the configuration of this embodiment. The same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted. This embodiment is different from the first embodiment in that the control means 10 is provided with the output current detecting means 14 and the reference wave correcting means 22 and the low distortion sine wave data 21
Is provided outside the reference wave generation means 20 and the reference wave generation means 2
The configuration is provided with a reference wave correcting means 22 capable of correcting both the amplitude and the phase of the reference wave at 0.

The operation in the above configuration will be described with reference to the drawings. FIG. 4 is a waveform chart showing the operation of this embodiment. The output current is detected by the output current detecting means 14 via the current monitor 9, and data of the output current for one cycle of the commercial frequency in the system 11 is taken into the control means 10. Data of a period of about 20 ms for 50 Hz and about 16.6 ms for 60 Hz are captured as data at predetermined time intervals, for example. Next, this data is converted into low-distortion sine wave data 21 by the reference wave correcting means 22.
The difference is added to or subtracted from the reference wave output one cycle later in the reference wave generation means 20. By repeating the above operation, the output current gradually approaches a low distortion sine wave.

As described above, according to this embodiment, after operating the inverter, the data of one cycle of the output current of the commercial frequency in the system 11 is compared with the target ideal low distortion sine wave. By adding a low-speed feedback that corrects the reference wave in the next one cycle due to the difference, a single-stone resonance type inverter 2 that becomes unstable due to phase delay of the system if high-speed feedback control is used is used. Also in the configuration described above, it is possible to realize a grid-connected inverter control device capable of stably obtaining a low-distortion output current without causing a control loop to oscillate.

(Embodiment 3) Hereinafter, Embodiment 3 of a system interconnection inverter control device of the present invention will be described with reference to the drawings. This embodiment relates to claim 3.

FIG. 5 is a block diagram showing the configuration of this embodiment. The same components as those in FIG. 3 are denoted by the same reference numerals, and detailed description is omitted. This embodiment is different from the second embodiment in that a phase advance unit 23 for advancing the output phase of the reference wave correction unit 22 is additionally provided.

The operation in the above configuration will be described with reference to the drawings. FIG. 6 is a waveform chart showing the operation of this embodiment. The output current is detected by the output current detecting means 14 via the current monitor 9, and time-divided data of one cycle of the commercial frequency in the system 11 having a unit time of about 50 μsec is taken into the control means 10. Next,
This data is compared with the low-distortion sine wave data 21, and a correction value at each unit time is determined by the reference wave correction means 22. Next, the phase advance means 23 adds or subtracts the correction value for the n-th data counted from the zero voltage phase of the system voltage to the (n-1) -th reference wave data. The corrected reference wave data for one cycle thus obtained is subjected to PWM control for the grid-connected inverter in one cycle of the next commercial frequency together with the carrier wave.

As described above, according to the present embodiment, the correction value at each time divided by time is obtained by correcting the reference wave in the advanced phase of about 50 μs or more from the data obtained by the output current detecting means. Since the phase delay between the input and output of the grid-connected inverter that performs high-frequency switching is sufficiently compensated and the result is reflected after one cycle, accurate and stable operation can be obtained. A possible system interconnection inverter control device can be realized.

(Embodiment 4) A system interconnection inverter control apparatus according to Embodiment 4 of the present invention will be described below with reference to the drawings. This embodiment relates to claim 4.

FIG. 7 is a block diagram showing the configuration of this embodiment. The same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted. This embodiment is different from the first embodiment in that the system voltage detecting unit 12 detects that the system voltage of the system 11 is equal to or less than a predetermined value, and the reference wave correcting unit 2
2 in that a correction amplitude switching means 24 is added to the output of the reference wave generating means 20 for output.

The operation in the above configuration will be described.
In FIG. 7, since it is difficult for the system interconnection inverter to make the output of the single-stone resonance type inverter 2 zero when the system 11 is at a predetermined voltage or less, the bridge inverter 7 controls the output current waveform by a high-frequency switching operation. are doing. The switching elements 7a and 7b connected in series in the bridge inverter 7 have a dead time set so that the input voltage is not short-circuited and the bridge inverter 7 does not break down due to the characteristics. When the system voltage detecting means 12 detects the absolute value of the amplitude with respect to the ON time obtained by the reference wave correcting means 22, the correction value is expanded by the correction amplitude switching means 24 when the absolute value is less than a predetermined value. Get closer to a sine wave.

As described above, according to the present embodiment, by appropriately varying the correction value according to the amplitude of the absolute value of the system voltage, the output current can be reduced to a low distortion sine wave even near the zero voltage of the system 11. It is possible to realize a system interconnection inverter control device that can perform the operation.

(Embodiment 5) Hereinafter, Embodiment 5 of the system interconnection inverter control device of the present invention will be described with reference to the drawings. This embodiment relates to claim 5.

FIG. 8 is a block diagram showing the configuration of this embodiment. Note that the same components as those in FIG. 7 are denoted by the same reference numerals, and detailed description will be omitted. This embodiment is different from the seventh embodiment in that a phase delay unit 25 is provided, and during a period when the system voltage is equal to or less than a predetermined value, a phase delay is applied to a reference wave after amplitude correction for PWM control of the bridge inverter 7. I had to give it.

The operation in the above configuration will be described with reference to the drawings. FIG. 9 is a waveform chart showing the operation of this embodiment. In FIG. 8, the reference wave for controlling the bridge inverter 7 among the reference waves after the amplitude correction output from the reference wave generation means 20 delays the phase when the absolute value of the system voltage of the system 11 is equal to or less than a predetermined value. By
PW one-stone resonant inverter 2 and bridge inverter 7
A phase difference is generated for the reference wave to be M-controlled. Therefore, when the absolute value of the system voltage is small, that is, when the output of the single-stone resonance type inverter 2 is minimum and the waveform of the output current cannot be reduced to zero, the single-stone resonance type inverter 2 is formed. The delay time difference of the system until the current is further shaped to near zero as an input of the bridge inverter 7 can be compensated, and an output current with lower distortion can be obtained.

As described above, according to the present embodiment, the phase delay means 25 is provided, and the phase of the system voltage is less than or equal to the predetermined value with respect to the reference wave for controlling the bridge inverter 7 among the reference waves after the amplitude correction. By providing a delay, it is possible to realize a grid-connected inverter control device capable of obtaining a lower distortion output current.

[0053]

According to a first aspect of the present invention, there is provided a high-frequency transformer, and a single-stone resonance-type inverter for connecting and disconnecting a primary winding of the high-frequency transformer to a DC power supply at a high frequency by a single switching element together with a resonance capacitor. A rectifier for rectifying a high-frequency voltage output from a secondary winding of the high-frequency transformer and outputting a DC voltage; and four switching elements for switching a DC voltage output by the rectifier and converting the DC voltage to an AC voltage. A bridge inverter, a noise filter for removing noise in an output of the bridge inverter, a system voltage detecting means for detecting a system voltage connected to an output of the noise filter as a system voltage, and a current output to the system Output current detecting means for detecting the current, and control means for controlling the overall operation, wherein the control means Generates a PWM signal by comparing the reference wave and the predetermined carrier, and PWM controls the respective switching elements in the stone resonant inverter and the bridge inverter with feedforward, wherein the reference wave,
By using a system interconnection inverter control device that generates a full-wave rectified wave of a low distortion sine wave generated in synchronization with the system voltage, a stable output waveform is obtained with respect to input voltage fluctuation and system voltage disturbance. In addition, it is possible to realize a system interconnection inverter capable of forming a substantially sine wave as a waveform of an output current.

According to a second aspect of the present invention, the control means includes:
The system interconnection inverter control device according to claim 1, wherein the reference wave is corrected in the next cycle in response to the distortion of the output current in an arbitrary cycle, thereby stably reducing the control loop without causing oscillation. A grid-connected inverter that can obtain a distorted output current can be realized.

According to a third aspect of the present invention, the control means includes:
When a reference wave is given by data at a predetermined unit time,
3. The grid-connected inverter control according to claim 2, wherein the reference wave of the next cycle is corrected by a phase preceding by one or more units of the unit time in response to the distortion of the output current for each unit time in an arbitrary cycle. By using the device, the phase delay between the input and output of the grid-connected inverter that performs high-frequency switching is sufficiently compensated for, and the result is reflected one cycle later or slightly before, so that it is stable. It is possible to realize a highly accurate system interconnection inverter with a simple operation.

According to a fourth aspect of the present invention, the control means includes:
4. The system interconnection inverter control device according to claim 2, wherein a correction amount of the reference wave is made larger in a region where the absolute value of the system voltage is equal to or less than a predetermined value as compared with other regions. This makes it possible to realize a grid-connected inverter that can output a low-sine sine wave even near zero voltage of the system.

According to a fifth aspect of the present invention, the control means comprises:
5. The method according to claim 1, wherein a phase difference is provided between a reference wave for generating a PWM signal for controlling the one-stone resonance type inverter and a reference wave for generating a PWM signal for the bridge inverter. By using any one of the grid-connected inverter control devices, a grid-connected inverter capable of obtaining a lower distortion output current can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a system interconnection inverter control device according to a first embodiment of the present invention;

FIG. 2 is a waveform chart showing the operation of the embodiment.

FIG. 3 is a block diagram illustrating a configuration of a system interconnection inverter control device according to a second embodiment of the present invention;

FIG. 4 is a waveform chart showing the operation of the embodiment.

FIG. 5 is a block diagram illustrating a configuration of a system interconnection inverter control device according to a third embodiment of the present invention;

FIG. 6 is a waveform chart showing the operation of the embodiment.

FIG. 7 is a block diagram illustrating a configuration of a system interconnection inverter control device according to a fourth embodiment of the present invention;

FIG. 8 is a block diagram showing a configuration of a system interconnection inverter control device according to a fifth embodiment of the present invention;

FIG. 9 is a waveform chart showing the operation of the embodiment.

FIG. 10 is a block diagram showing a configuration of a conventional system interconnection inverter control device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 DC power supply 2 1 stone resonant inverter 2 a switching element 2 b resonant capacitor 3 high frequency transformer 4 current limiting coil 5 rectifier 5 a, 5 b diode 5 c capacitor 6 high frequency filter 7 bridge inverter 7 a, 7 b, 7 c, 7 d switching element 8 noise filter 8 a Coil 8b Capacitor 9 Current monitor 10 Control means 11 System 12 System voltage detecting means 13 System synchronous low distortion sine wave generating means 14 Output current detecting means 15 Error amplifying means 16 First carrier wave generating means 17 Second carrier wave generating means 18 First PWM signal Generation means 19 Second PWM signal generation means 20 Reference wave generation means 21 Low distortion sine wave data 22 Reference wave correction means 23 Phase advance means 24 Correction amplitude switching means 25 Phase delay means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02M 7/5387 H02M 7/5387 Z (72) Inventor Yoshimi Iwamoto 1006 Odakadoma, Kadoma, Osaka Matsushita Electric Industrial Inside (72) Inventor Katsunori Tanie 1006 Kadoma, Kazuma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Hideki Omori 1006, Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Koji Niiyama 1006 Kadoma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Takahiro Miyauchi 1006 Kadoma Kadoma, Kadoma-shi Osaka Pref. CB04 CB05 CB07 CB25 CC03 CC32 DA03 DA05 DA06 DB05 DC02 DC04 DC05 EA02

Claims (5)

[Claims] 1. A high-frequency transformer, a single-stone resonant inverter for connecting and disconnecting a primary winding of the high-frequency transformer together with a resonance capacitor to a DC power supply at a high frequency by one switching element, and a secondary winding of the high-frequency transformer A rectifier for rectifying a high-frequency voltage output from the rectifier to output a DC voltage; a bridge inverter including four switching elements for switching the DC voltage output by the rectifier to convert the DC voltage to an AC voltage; A noise filter that removes noise at the output of the system, a system voltage detection unit that detects a system voltage connected to an output of the noise filter as a system voltage, and an output current detection unit that detects an output current to the system. Control means for controlling the entire operation, wherein the control means compares a predetermined reference wave with a predetermined carrier wave. To generate a PWM signal,
Each of the switching elements in the stone resonance type inverter and the bridge inverter is PWM-feed-forwarded.
A system interconnection inverter control device for controlling, wherein the reference wave is a full-wave rectified wave of a low distortion sine wave generated in synchronization with the system voltage. 2. The system interconnection inverter control device according to claim 1, wherein the control means corrects the reference wave in a next cycle in response to a distortion of the output current in an arbitrary cycle. 3. The control means, when giving a reference wave by data at a predetermined unit time, in response to the distortion of the output current at the unit time in an arbitrary period, outputs the reference wave of the next period at the unit time. 3. The system interconnection inverter control device according to claim 2, wherein the correction is performed with a phase preceding by one unit or more. 4. The control unit according to claim 2, wherein the control unit increases the correction amount of the reference wave in a region where the absolute value of the system voltage is equal to or less than a predetermined value as compared with the other regions. The grid-connected inverter control device described in the above. 5. A control means for providing a phase difference between a reference wave for generating a PWM signal for controlling a one-stone resonance type inverter and a reference wave for generating a PWM signal for a bridge inverter. Claims 1 to 4
A system interconnection inverter control device according to any one of the above.