JP2012016196A - Parallel driving method of inverter generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parallel driving method which can obtain accurate and stable output even when driving multiple inverter generators connected in parallel.SOLUTION: A parallel driving method which connects multiple inverter generators in parallel has a parallel driving determination circuit 28 inserted to determine whether or not the inverter generators are connected in parallel between a reference sine wave signal circuit 26 to generate data signals for reference sine wave generation and a sine wave conversion circuit 24 to generate the reference sine wave based on the data signals. Herewith, one of the inverter generators becomes a main generator as a master while another generator becomes a subordinate generator as a slave so that the main generator and the subordinate generator share the data signals for the reference sine wave generation which are generated on the master side.

Description

  The present invention relates to an inverter generator parallel operation system.

  A number of forms are known for private power generation that obtains power independently from the power company. Regardless of the type of in-house power generation, if the load connected to the supplied power is a heating element such as an electric light or an electric heater, it is sufficient if the specified voltage and current are secured for the power, and the power frequency Variations in are generally not considered a problem.

  However, when the load connected to the supplied power is a rotating device such as a motor, a fluorescent lamp, or a personal computer, it is required that the power frequency does not vary and is stable. For example, since many of the recent motor rotation controls depend on the power supply frequency, the frequency needs to be accurate and unaltered. In response to this request, as a stationary private generator or portable generator, the converter converts the three-phase alternating current generated by the three-phase generator into direct current with a converter, and then converts this direct current into three-phase alternating current or single Inverter generators that convert to phase alternating current have been put into practical use. The inverter has a commutation control circuit that turns off direct current to turn it into alternating current, and the circuit performs alternating current turn-off and turn-on (switching) at a desired cycle, thereby obtaining alternating current at a desired frequency. In order to obtain an accurate and stable frequency, pulse width modulation (PWM) control using a reference sine wave is performed.

  Since the present invention relates to a system in which a plurality of inverter generators using a reference sine wave are connected in parallel, the basic configuration of the inverter generator will be described first with reference to FIG. Reference numeral 10 indicates a three-phase generator having three armature windings U, V, W arranged at a phase angle of 120 degrees. The three-phase generator 10 is connected to a rotation source (not shown) such as an engine and rotated to generate a three-phase alternating current.

  Three-phase alternating current from the three-phase generator 10 is input to a converter 14 provided with a rectifier such as a thyristor or triac, and is converted into direct current by the converter 14. The converted direct current is smoothed by the capacitor 15 and then converted into a single-phase alternating current by the inverter 20. The inverter 20 is formed of a self-extinguishing type switching element such as an IGBT (insulated gate bipolar transistor) or a power MOSFET, for example, and drives the gate to turn off and turn on (switch) the direct current. Convert to phase alternating current. The obtained single-phase alternating current is output to the U1 phase end and the V1 phase end via the smoothing filters 30 connected in series to the inverter 20.

  The gate of the self-extinguishing switching element built in the inverter 20 is driven by an inverter drive circuit 22. For example, the inverter drive circuit 22 includes a pulse width modulation (PWM) circuit, and a combined signal in which a sine wave having a reference frequency generated from a sine wave data signal and a carrier wave (triangular wave) are superimposed is input to the circuit. Here, the pulse width-modulated pulse drives the gate of the self-extinguishing switching element to perform commutation control.

  That is, in FIG. 8, the reference sine wave signal circuit 26 generates a data signal necessary for generating a sine wave having a desired frequency as a reference. Actually, there are eight output lines for sending out a data signal from the reference sine wave signal circuit 26. However, since they are exactly the same, only one is shown in FIGS. A data signal for creating a sine wave from the reference sine wave signal circuit 26 is input to a sine wave conversion circuit 24 connected to the circuit 26. In the sine wave conversion circuit 24, a desired reference sine wave is generated using the data signal. The reference sine wave is output-compared with a carrier wave (triangular wave set at a higher frequency than the reference sine wave) generated by the carrier wave generation circuit 31 to form a superimposed composite signal. This composite signal is input to the inverter drive circuit 22 and subjected to pulse width modulation (PWM), and the pulse after the pulse width modulation drives the self-extinguishing switching element of the inverter 20 described above to direct current. The commutation control is performed.

  The three-phase generator 10 shown in FIG. 8 includes single armature windings U, V, and W, and finally outputs a single-phase alternating current. However, the three-phase generator 10 in the inverter generator of FIG. 9 has a master armature winding 10a and a slave armature winding 10b, and finally outputs a three-phase alternating current. The basic configuration is the same as that of the inverter generator of FIG. However, the converter includes a first converter 16 that converts the three-phase alternating current generated by the master winding 10a into direct current, and a second converter 18 that converts the three-phase alternating current generated by the slave winding 10b into direct current. Is done. Each direct current from the first and second converters 16 and 18 is converted into a three-phase alternating current in the inverter 20. The obtained three-phase alternating current is output to the U1 phase end, the V1 phase end, and the W1 phase end via each smoothing filter 30. Further, since the three-phase alternating current consists of three sine waves having a time difference, a timing signal for determining this time difference is required. Therefore, the timing signal is generated by the reference sine wave signal circuit 26 of FIG. Therefore, three output lines for timing signals are added.

  The three-phase AC generator 10 having the master armature winding 10a and the slave armature winding 10b shown in FIG. 9 has a neutral point 0 independent of the U1 phase end, the V1 phase end, and the W1 phase end described above. have. The neutral point 0 is connected to a line 13 that connects the anode side of the first converter 16 and the cathode side of the second converter 18. The first converter 16 and the second converter 18 are individually connected to a gate control circuit 12 for driving a semiconductor switching device (for example, a thyristor) incorporated therein, and output from the first and second converters 16 and 18. The direct current voltage is controlled by the gate control circuit 12.

  As shown in FIG. 9, two DC voltage sources, a first converter 16 connected to the master armature winding 10a and a second converter 18 connected to the slave armature winding 10b, are provided. A system in which the intermediate point of the sources 16 and 18 is set to the neutral point 0 is referred to as a three-phase four-wire system. In the three-phase four-wire inverter generator, the gate control circuits 12 and 12 can control the voltages of the corresponding DC voltage sources 16 and 18 to be constant. Therefore, for example, when only the U1 phase end and the neutral point 0 are connected to obtain a single-phase output, there is a disadvantage that an unbalanced load is applied to the other V1 phase end and the W1 phase end. However, according to the configuration of FIG. 9, even if an unbalanced load is applied, the DC voltages from the two DC voltage sources 16 and 18 balance each other, so that the three-phase AC voltage is well balanced. By providing two DC voltage sources in this way, the output voltages of the master armature winding 10a and the slave armature winding 10b can be suppressed to ½. In addition, the device design has the advantage that the pressure resistance can be lowered and the advantage that the manufacturing cost can be suppressed.

JP 2008-2370099 A

  Incidentally, the power generation capacity per inverter generator is limited. Therefore, when the load connected to the AC output of the generator has a large capacity, a system in which two inverter generators are connected in parallel to increase the power generation capacity has been put into practical use. When performing this parallel operation, it is important that the reference sine waves generated by the two inverter generators are synchronized.

  However, the conventional inverter generator has means for generating a reference sine wave in each control circuit, but it is designed to synchronize with a reference sine wave generated by another inverter generator. Absent. For this reason, when a plurality of inverter generators are connected in parallel and operated, the frequencies that are unique to each inverter generator interfere with each other and are superimposed on the alternating current output from each inverter generator. There is a drawback that the output becomes unstable due to disturbance in the frequency of the period.

In order to solve the above problems, an inverter generator that generates single-phase alternating current according to the present invention includes a three-phase generator that is driven by a rotation source to generate three-phase alternating current, and the three-phase power generated by the three-phase generator. A converter that converts alternating current into direct current, an inverter that converts direct current from the converter into single-phase alternating current, an inverter drive circuit that drives a self-extinguishing switching element in the inverter, and a data signal for generating a reference sine wave A reference sine wave signal circuit for generating, a sine wave conversion circuit for generating a reference sine wave based on the data signal, and a carrier wave generation circuit for generating a carrier wave having a higher frequency than the reference sine wave. The self-extinguishing switching element is generated by a pulse obtained by pulse-modulating a mixed waveform obtained by superimposing the carrier wave and the carrier wave by the inverter driving circuit. To drive the, an inverter generator to output single-phase alternating current of a desired frequency from said inverter, in parallel operation system to increase the load capacity by more group connecting the inverter generator in parallel,
One of the inverter generators is a master generator as a master, and the other is a slave generator as a slave. When these are connected in parallel, the main generator is a reference from its reference sine wave signal circuit. While the sine wave generation data signal is used, the sub-generator uses the reference sine wave generation data signal supplied from the main generator.

A three-phase generator having a master winding and a slave winding, which is driven by a rotation source to generate a three-phase alternating current from each winding, and a first that converts the three-phase alternating current generated by the master winding into a direct current A converter, a second converter that converts the three-phase alternating current generated by the slave winding into a direct current, an inverter that converts each direct current from the first and second converters into a three-phase alternating current, and a self-extinguishing type in the inverter An inverter drive circuit for driving a switching element; a reference sine wave signal circuit for generating a data signal for generating a reference sine wave; a sine wave conversion circuit for generating a reference sine wave based on the data signal; and the reference sine wave A carrier wave generation circuit that generates a carrier wave of a higher frequency, and the inverter drive circuit generates a mixed waveform obtained by superimposing the reference sine wave and the carrier wave. An inverter generator that drives the self-extinguishing type switching element with a pulse modulated with a pulse width and outputs a three-phase alternating current of a desired frequency from the inverter, wherein a plurality of the inverter generators are connected in parallel. In the parallel operation method that increases the load capacity,
One of the inverter generators is a master generator as a master, and the other is a slave generator as a slave. When these are connected in parallel, the main generator is a reference from its own reference sine wave signal circuit. While the sine wave generation data signal is used, the sub-generator uses the reference sine wave generation data signal supplied from the main generator.

  When connecting multiple inverter generators in parallel, the data signal for generating the reference sine wave in the inverter generator on the master side is supplied to the inverter generator on the slave side. The single-phase or three-phase alternating current that is produced has the effect of always having an accurate and stable frequency.

It is a state figure by the side of the master of the parallel operation determination circuit in the inverter generator which outputs single phase alternating current. It is a state figure by the side of the slave of the parallel operation determination circuit in the inverter generator which outputs single phase alternating current. It is a state diagram of the master side parallel operation determination circuit in the inverter generator which outputs a three-phase alternating current. It is a schematic block diagram of the parallel operation system which outputs the single phase alternating current which concerns on this invention, Comprising: The master side inverter generator and the slave side inverter generator are connected in parallel. It is a schematic block diagram of the parallel operation system which outputs the three-phase alternating current based on this invention, Comprising: The master side inverter generator which employ | adopts a three-phase four-wire system, and the slave side inverter power generation which employs a three-phase four-wire system Machine connected in parallel. It is an inverter generator which outputs a three-phase alternating current, Comprising: It is a state diagram of the master side parallel operation determination circuit in the type which employ | adopts a three-phase three-wire system. FIG. 2 is a schematic configuration diagram of a parallel operation method for outputting a three-phase alternating current according to the present invention, a master-side inverter generator that employs a three-phase three-wire method, and a slave-side inverter generator that employs a three-phase three-wire method; Are connected in parallel. It is a whole circuit diagram of the inverter generator which outputs the conventional single phase alternating current. It is a whole circuit diagram of the inverter generator which outputs the conventional three-phase alternating current.

  FIG. 1 shows a circuit of an inverter generator that outputs a single-phase alternating current in which a parallel operation system according to the present invention is implemented. A parallel operation determination circuit denoted by reference numeral 28 includes a reference sine wave signal circuit 26 and a sine wave conversion circuit. 24. The parallel operation determination circuit 28 determines whether or not a plurality of inverter generators are connected in parallel. When the parallel connection is determined, the sine from the reference sine wave signal circuit 26 of the main generator on the master side is determined. The data signal for generating the wave is used as the data signal for generating the reference sine wave of the slave generator on the slave side.

  The parallel operation determination circuit 28 in FIG. 1 is basically composed of a logic circuit combining an AND circuit, an OR circuit, and a NOT circuit, and is always a data signal for generating a sine wave generated by the reference sine wave signal circuit 26. Is sent to the sine wave conversion circuit 24. However, when the slave inverter generator on the slave side is connected in parallel to the master inverter generator on the master side, this is determined, and the inverter generator on the slave side generates its own reference sine wave signal circuit 26. The transmission of the sine wave generation data signal to the sine wave conversion circuit 24 is interrupted, and the sine wave generation data signal supplied exclusively from the master side is used.

Here, the reference sine wave signal circuit 26 generates a data signal for generating a single-phase alternating current sine wave converted by the inverter 20. This data signal is input to one input terminal X ₂ of the first AND circuit 32 in the parallel operation determination circuit 28, and an external power supply terminal DC + VCC (DC voltage) is connected to the other input terminal X ₁ of the _first AND circuit 32. Applied. The output terminal of the first AND circuit 32 is connected to one input terminal X ₂ of the OR circuit 34. The output terminal of the OR circuit 34 is connected to the sine wave conversion circuit 24. The + VCC direct current is input to the NOT circuit 36 in the parallel operation determination circuit 28, and the output terminal of the NOT circuit 36 is connected to _one input terminal X ₁ of the second AND circuit 38.

The output terminal of the second AND circuit 38 is connected to the other input terminal X ₁ of the OR circuit 34. Together with the data signal output terminal X of the sine wave generator is connected to the other input terminal X ₂ of the second 2AND circuit 38, and through a forward diode 42 is connected to an output terminal of said first 1AND circuit 32 Yes.

  The parallel operation determination circuit 28 has a switch circuit 40, and a terminal C of the switch circuit 40 is connected to the external power supply terminal DC that supplies a direct pressure of + VCC. The terminal E of the switch circuit 40 is grounded (grounded), and the terminal G is connected to the external signal terminal S. When an external signal is input to the terminal S, the gate of the switch circuit 40 is driven, the terminal C and the terminal E are brought into conduction, and the + VCC direct current is grounded. 1 shows a state in which the signal input to the terminal S is turned off (OFF), and FIG. 2 shows a state in which the signal input to the terminal S is turned on.

As shown in FIG. 4, one inverter generator is a master side that is a main generator, and another inverter generator that is connected in parallel to this is a slave side that is a slave generator. Therefore, the operation of the parallel operation determination circuit 28 will be described separately for the master side (FIG. 1) and the slave side (FIG. 2). As described above, on the master side in FIG. 1, no external signal is input to the terminal G of the switch circuit 40, so that the terminal C and the terminal E are non-conductive. A DC voltage of + VCC is supplied to the power supply terminal DC, and _one input terminal X1 of the _first AND circuit 32 and the input terminal of the NOT circuit 36 are both at a high level (hereinafter referred to as H).

When a data signal of the reference sine wave for generating a reference sine wave signal circuit 26 is supplied to the input terminal X ₂ of the second 1AND circuit 32 also becomes H level of the input X _2. Thus from the 1AND circuit 32 are output data signals for the reference sine wave generator, a level of the input terminal X ₂ of the OR circuit 34 connected to the output of said 1AND circuit 32 to H.

The NOT circuit 36, since the input level is H, the output level is Low (hereinafter L), and the thus the level of the input terminal _{X 1} of the first 2AND circuit 38 is L. As described above, the other input terminal X ₂ of the _second AND circuit 38 is connected to the output terminal of the first AND circuit 32 and has a level of H, but the level of _one input terminal X ₁ of the second AND circuit 38 is high. Since L is L, the output level of the second AND circuit is L. Thus it serves as one also input terminal X ₁ of level L of the OR circuit 34 connected to the output of the second 2AND circuit 38, because the other level of the input terminal X ₂ of the OR circuit 34 is H, the reference A data signal for generating a reference sine wave from the sine wave signal circuit 26 is supplied to the sine wave conversion circuit 24 through the OR circuit 34. The sine wave conversion circuit 24 generates a reference sine wave having a desired frequency based on the data signal. The reference sine wave obtained by the sine wave conversion circuit 24 is output-compared with the carrier wave generated by the carrier wave generation circuit 31, and a superimposed mixed waveform is input to the inverter drive circuit 22. The pulse modulated by the inverter drive circuit 22 drives the gate of the inverter 20 as described above.

Next, an inverter generator on the slave side is shown in FIG. When the slave generator is connected in parallel to the master generator, a signal of level H is input from the external signal terminal S to the terminal G of the switch circuit 40 in FIG. C and terminal E are conducted. That is, the + VCC direct current applied to the terminal C is grounded (grounded), the input level of the NOT circuit 36 is inverted and the output level becomes H, and the input terminal X ₁ of the second AND circuit 38 is inverted. Let H be the level of. In the first AND circuit 32 to which the voltage of + VCC is supplied, the level of _one input terminal X1 becomes L due to the interruption of the DC voltage, and the data signal for generating the sine wave from the reference sine wave signal circuit 26 is supplied. Is blocked by the first AND circuit 32. For this reason, the inverter-side generator on the slave side cannot use the data signal for generating the sine wave generated by the reference sine wave signal circuit 26 provided therein.

2 and 4, since the data signal input / output terminal X provided on the slave side is supplied with a sine wave data signal from the master-side inverter generator shown in FIG. 1, one input of the second AND circuit 38 is provided. level of the end _{X 2} becomes H. The other level of the input terminal X ₁ of the first 2AND circuit 38, since at the H according to the output level H of the NOT circuit 38, the data signal for the sine wave generating supplied from the master side, said Passing through the 2AND circuit 38, the level of _one input terminal X1 of the OR circuit 34 is set to H. The other level of the input terminal _{X 2} of the OR circuit 34 is L in accordance with the output level L of the first 1AND circuit 32. For this reason, the OR circuit 34 allows the data signal for sine wave generation supplied from the master side to pass therethrough and inputs it to the sine wave conversion circuit 24. That is, the data signal for sine wave generation generated by the reference sine wave signal circuit 26 in the slave-side inverter generator is blocked by the first AND circuit 32 and is instead supplied from the master-side inverter generator. A data signal for generating a wave passes through the second AND circuit 38 and the OR circuit 34 and is input to the sine wave conversion circuit 24.

  Next, FIG. 3 shows an outline of an inverter generator using a three-phase generator 10 having a master armature winding 10a and a slave armature winding 10b. FIG. 3 shows the master side of the inverter generator. Therefore, the signal from the terminal S is not input to the terminal G of the switch circuit 40. The reference sine wave signal circuit 26 outputs a data signal for generating a sine wave and a timing signal for generating three sine waves (three phases). That is, the timing signal is a timing signal for generating a three-phase AC waveform (sine wave) having a desired time difference on the time axis, and is not necessary for the single-phase AC shown in FIGS. Accordingly, in FIG. 3, three first AND circuits 32, three OR circuits 34, and two second AND circuits 38 are added correspondingly. However, other than that, the circuit configuration and logical development are basically the same as those in the entire circuit of FIGS.

  FIG. 5 is a diagram in which the inverter generators that output the three-phase alternating current shown in FIG. 3 are connected in parallel, with one inverter generator being the master side and the other inverter generator being the slave side. The operation of this parallel operation method is the same as that described with reference to FIGS.

  Next, the inverter generator that outputs the three-phase alternating current described in FIG. 3 and FIG. 5 employs the three-phase four-wire system described in FIG. However, the parallel operation system of the inverter generator according to the present invention can also be adopted for a three-phase three-wire system type having no neutral point 0. For example, FIG. 6 shows an inverter generator that outputs three-phase alternating current, but is a three-phase three-wire system type that does not have a neutral point 0. However, this configuration is basically the same as the configuration of the three-phase AC generator shown in FIG. 3 except that it is a three-phase three-wire system and the armature winding is not divided into a master and a slave. FIG. 7 shows a state in which the three-phase three-wire inverter generators of FIG. 6 are connected in parallel, and the logic developed by the parallel operation determination circuit 28 is similar to the logic development explained in FIG.

  This parallel operation system of inverter generators that output three-phase alternating current or single-phase alternating current is suitably used for both commercial installation type private power generation devices for business use and portable portable power generation devices for consumer use.

  If the capacity of the load connected to the output of the inverter generator that outputs three-phase AC or single-phase AC is large, the capacity can be increased by operating two inverter generators connected in parallel. . However, if the reference sine waves that generate the pulses for driving the inverter are generated by a plurality of inverter generators, there is a problem that the AC frequency as the combined output varies and becomes unstable. However, according to the present invention, when a plurality of inverter generators are connected in parallel, the master side and the slave side share the data signal for generating the reference sine wave generated on the master side. Thus, the stabilizing effect can be obtained.

DESCRIPTION OF SYMBOLS 10 Three-phase generator 10a Master armature winding 10b Slave armature winding 12 Gate control circuit 13 Line 14 Converter 15 Capacitor 16 First converter 18 Second converter 20 Inverter 22 Inverter drive circuit 24 Sine wave conversion circuit 26 Reference sine wave Signal circuit 28 Parallel operation determination circuit 31 Carrier wave generation circuit
32a, 32b, 32c, 32d First AND circuit 34a, 34b, 34c, 34d OR circuit 36 NOT circuit 38a, 38b, 38c, 38d Second AND circuit 40 Switch circuit

Claims (6)

A three-phase generator (10) that is driven by a rotation source to generate a three-phase alternating current, a converter (14) that converts the three-phase alternating current generated by the three-phase generator (10) into a direct current, and the converter (14 ) From the inverter (20) for converting the direct current to single-phase alternating current, the inverter drive circuit (22) for driving the self-extinguishing switching element in the inverter (20), and generating the data signal for generating the reference sine wave A reference sine wave signal circuit (26), a sine wave conversion circuit (24) for generating a reference sine wave based on the data signal, and a carrier wave generation circuit (31) for generating a carrier wave having a higher frequency than the reference sine wave The self-extinguishing type switching element is driven by a pulse obtained by pulse-width-modulating a mixed waveform obtained by superimposing the reference sine wave and the carrier wave by the inverter driving circuit (22), and the inverter (20) to desired frequency An inverter generator to output single-phase AC, in parallel operation system to increase the load capacity by more group connecting the inverter generator in parallel,
One of the inverter generators is a master generator as a master and the other is a slave generator as a slave. When these are connected in parallel, the main generator has its own reference sine wave signal circuit (26). Inverter generator parallel operation system characterized in that a data signal for generating a reference sine wave is used from the main generator and a data signal for generating a reference sine wave supplied from the main generator is used for the slave generator . A three-phase generator (10) having a master winding (10a) and a slave winding (10b), driven by a rotation source to generate a three-phase alternating current from each winding (10a, 10b), and the master winding; A first converter (16) for converting the three-phase alternating current generated by the wire (10a) into direct current; a second converter (18) for converting the three-phase alternating current generated by the slave winding (10b) into direct current; An inverter (20) for converting each direct current from the first and second converters (16, 18) into a three-phase alternating current; an inverter drive circuit (22) for driving a self-extinguishing switching element in the inverter (20); A reference sine wave signal circuit (26) for generating a data signal for generating a reference sine wave, a sine wave conversion circuit (24) for generating a reference sine wave based on the data signal, and a frequency higher than that of the reference sine wave A carrier wave generating circuit (31) for generating a carrier wave, and superimposing the reference sine wave and the carrier wave An inverter that drives the self-extinguishing type switching element with a pulse whose pulse width is modulated by the inverter drive circuit (22), and outputs a three-phase alternating current of a desired frequency from the inverter (20). In a parallel operation system in which a plurality of inverter generators are connected in parallel to increase the load capacity,
One of the inverter generators is a master generator as a master, and the other is a slave generator as a slave. When these are connected in parallel, the main generator has its own reference sine wave signal circuit (26). Inverter generator parallel operation system characterized in that a data signal for generating a reference sine wave is used from the main generator and a data signal for generating a reference sine wave supplied from the main generator is used for the slave generator .   3. The inverter generator according to claim 2, wherein the reference sine wave signal circuit (26) in the inverter generator for outputting the three-phase alternating current of the desired frequency also generates a timing signal for generating three alternating current waveforms with a time difference. Parallel operation method.   The three-phase alternating current from the inverter (20) is output corresponding to the U1-phase end, the V1-phase end, and the W1-phase end, and the anode side of the first converter (16) and the cathode side of the second converter (18). The inverter generator in parallel operation system according to claim 2, wherein the DC voltages are connected in common and output to the neutral point 0.   The reference sine wave signal circuit (26) and the sine wave conversion circuit (24) are connected via a parallel operation determination circuit (28), and the parallel operation determination circuit (28) includes a plurality of inverter generators connected in parallel. When the parallel generator determines that the connection is parallel, the slave generator inputs the data signal for generating the reference sine wave from its reference sine wave signal circuit (26) to the sine wave conversion circuit (24). The parallel operation of the inverter generator according to claim 1 or 2, wherein a data signal for generating a reference sine wave supplied from a main generator is input to the sine wave conversion circuit (24). method. The parallel operation determination circuit (28)
The terminal C connected to the external power supply terminal DC, the ground terminal E, and the gate terminal G have a voltage applied to the terminal C when the trigger signal is input from the external signal terminal S to the gate terminal G. A switch circuit (40) to be short-circuited through the ground terminal E, and
A NOT circuit (36) having an input terminal connected to the terminal C and an inverting output terminal;
Has a second input terminal X ₂ to be connected to an output terminal of the one input terminal to be connected to the terminal C X ₁ and the reference sine wave signal circuit (26), its output terminal is forward diode (42) A first AND circuit (32) connected to the data signal input / output terminal X for sine wave generation via
The 2AND circuit having a NOT circuit (36) the other input terminal X ₂ to be connected to the data signal output terminal X of the inverting output terminal to one input terminal X ₁ and the sine wave for generating the connection (38) ,
Has a second input terminal X ₂ connected to the output terminal of the one input terminal X ₁ and a 1AND circuit connected (32) to the output terminal of the first 2AND circuit (38), its output is a sine wave converter The OR circuit (34) connected to the input terminal of the circuit (24),
A voltage of a predetermined value is always applied to the external power supply terminal DC, and a signal is supplied to the external signal terminal S of the slave generator when the main generator and the slave generator are connected in parallel. ,
The sine wave generating data signal input / output terminal X always outputs a sine wave generating data signal in the main generator, and the sine wave only in the slave generator when connected in parallel to the main generator. 6. The inverter generator parallel operation system according to claim 5, wherein a data signal for generation can be inputted.

Images