JP6398057B2 - AC power supply apparatus and instantaneous voltage fluctuation detection method thereof - Google Patents

Description

  The present invention relates to an AC power supply apparatus and an instantaneous voltage fluctuation detection method thereof, and more particularly to an AC power supply apparatus capable of interconnection operation with a commercial power supply and an instantaneous voltage fluctuation detection method thereof.

  In recent years, an AC power supply device that outputs electric power generated using a solar battery panel or the like as an AC power supply has been popularized. Such an AC power supply device covers a part of electric power used in a home or the like in connection with a commercial power supply supplied from a power plant or the like. However, in commercial power supplies, the voltage may drop instantaneously. When such an instantaneous voltage fluctuation occurs, the output power must be reduced also in the AC power supply apparatus. In such a case, if the output power of the AC power supply apparatus is not reduced, a reverse power flow is generated from the AC power supply apparatus to the commercial system power supply side, and the controllability of the system is reduced on the commercial system power supply side. Thus, techniques for detecting voltage fluctuations in the system power supply signal are disclosed in Patent Documents 1 and 2.

Patent document 1 relates to a large public power generator that stops an inverter by detecting an instantaneous voltage fluctuation of a power system at high speed. In patent document 1, it has a system voltage level drop detection means for detecting that the system voltage has become a predetermined voltage level or less, and a detection duration measurement means for measuring the detection duration of the detection means. When the level drop detecting means detects the level drop and the measurement time by the detection duration measuring means is a predetermined time or more, the instantaneous voltage fluctuation of the system is detected. Moreover, in patent document 1, it has the gate block means which interrupts | blocks the gate signal of an inverter, and when an instantaneous voltage fluctuation occurs, the output is stopped by interrupting the gate signal of the inverter and the device is protected from overcurrent, When power is restored, a gate signal is sent to the inverter to resume operation.

  Patent Document 2 relates to an isolated operation detection device and an isolated operation detection method having an FRT (Fault Ride Through) function without malfunction even when the frequency changes suddenly or changes for a long time. In Patent Document 2, the frequency f of the output voltage of the inverter promotes a change by positive feedback, and a value that changes stepwise according to the frequency change rate df / dt of the frequency f in a direction that promotes a change by positive feedback. The reactive power Q or the current phase θ is controlled, and when the value based on the value that changes stepwise according to the value of the frequency change rate df / dt is equal to or higher than the isolated operation detection level K, it is determined to be abnormal. While synchronizing with the voltage phase of the power supply system and the inverter output, it is controlled to a predetermined reactive power Q or current phase θ, and when the inverter is disconnected from the AC power system, based on the frequency f and a value that changes stepwise. The inverter is driven so that the reactive power Q changes, and when an abnormality is detected, the inverter 2 is stopped.

JP 2003-153433 A JP 2012-120285 A

  However, in the method disclosed in Patent Document 1, it is necessary to measure the length of the period in which the level drop occurs after the grid voltage level drop detection means detects the level drop, and the voltage level of the grid power supply signal is There is a problem that it takes a long time from when the voltage level is lowered until it is detected that the voltage level is lowered. In the method disclosed in Patent Document 2, reactive power Q or current phase θ is controlled, and then a value based on a value that changes stepwise according to the value of frequency change rate df / dt is detected as an independent operation. When the level is K or higher, it is determined that there is an abnormality. Therefore, even in Patent Document 2, there is a problem that it takes a long time to detect that a fluctuation has occurred in the system power supply signal. In other words, Patent Documents 1 and 2 have a problem that it is not possible to shorten the time until the decrease in the voltage level of the system power supply signal is detected.

  An aspect of the AC power supply apparatus according to the present invention includes an inverter that generates an AC power supply signal from a DC power supply signal, outputs the AC power supply signal to a system wiring to which power from a commercial system power supply is supplied, and a voltage fluctuation detection pulse. Output a signal and change the duty ratio of the voltage fluctuation detection pulse signal to a first value in response to a change in the magnitude relationship between the effective value of the system power signal transmitted to the system wiring and a predetermined voltage fluctuation detection threshold. An instantaneous voltage fluctuation detection unit that switches between a duty ratio and a second duty ratio, and the inverter are controlled, and the AC power supply signal is output to the inverter in accordance with the switching of the duty ratio of the voltage fluctuation detection pulse signal And a control unit that gives an instruction to change power.

  One aspect of the instantaneous voltage fluctuation detection method according to the present invention is an inverter that generates an AC power supply signal from a DC power supply signal and outputs the AC power supply signal to a system wiring supplied with power from a commercial power supply, and the system An AC power supply having an instantaneous voltage fluctuation detection unit that detects that a magnitude relationship between an effective value of a system power supply signal transmitted to the wiring and a predetermined voltage fluctuation detection threshold is switched, and a control unit that controls the inverter An instantaneous voltage fluctuation detection method for an apparatus, wherein the instantaneous voltage fluctuation detection unit generates a voltage fluctuation detection pulse signal, and the voltage is changed in accordance with a change in magnitude relationship between the effective value and the voltage fluctuation detection threshold. The duty ratio of the fluctuation detection pulse signal is switched between a first duty ratio and a second duty ratio, and the voltage fluctuation detection pulse signal is changed by the control unit. An instruction for changing the output power of the AC power supply signal to the inverter in response to that it is detected that the duty ratio is switched.

  In the AC power supply apparatus and the instantaneous voltage fluctuation detection method according to the present invention, in particular, the voltage according to the change in the magnitude relationship between the effective value of the system power supply signal transmitted to the system wiring and the predetermined voltage fluctuation detection threshold value. The duty ratio of the fluctuation detection pulse signal is switched between the first duty ratio and the second duty ratio. As a result, in the AC power supply apparatus and the instantaneous voltage fluctuation detection method according to the present invention, it is possible to immediately detect a drop in the voltage level of the system power supply signal and reduce the output power of the inverter.

  ADVANTAGE OF THE INVENTION According to this invention, the alternating current power supply device which can detect the fluctuation | variation of the signal level of a system | strain power supply signal at high speed can be provided.

1 is a block diagram of an AC power supply device according to a first exemplary embodiment; 3 is a detailed block diagram of an instantaneous voltage fluctuation detection unit and an energy management unit of a power conditioner in the AC power supply according to the first embodiment. FIG. 3 is a timing chart for explaining the operation of the AC power supply device according to the first exemplary embodiment; It is a block diagram of the alternating current power supply device concerning Embodiment 2. FIG. It is a detailed block diagram of the instantaneous voltage fluctuation | variation detection part in the alternating current power supply device concerning Embodiment 2, and the energy management part of a power conditioner. 6 is a timing chart for explaining the operation of the AC power supply device according to the second exemplary embodiment; FIG. 6 is a block diagram of an AC power supply device according to a third exemplary embodiment. It is a detailed block diagram of the instantaneous voltage fluctuation | variation detection part in the alternating current power supply device concerning Embodiment 3, and the energy management part of a power conditioner.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings. The AC power supply device 1 according to the first embodiment operates in conjunction with a commercial power supply SPS that supplies power generated by a power plant or the like to consumers. Then, the AC power supply 1 according to the first embodiment immediately uses the PV PCS 10 or the BAT PCS 20 when the voltage level of the system power signal supplied from the commercial system power SPS shows an instantaneous fluctuation. Control is performed so that the power (for example, voltage level) of the AC power supply signal output from the power supply follows the voltage level of the system power supply signal. In the following, an instantaneous voltage fluctuation detection method and control of the PV PCS 10 and the BAT PCS 20 with respect to the instantaneous voltage fluctuation in the AC power supply apparatus 1 according to the first embodiment will be described. Note that the AC power supply apparatus 1 according to the first embodiment performs other operations for performing a linked operation with the commercial power supply SPS in addition to the operation according to the instantaneous voltage fluctuation detection method described below.

  FIG. 1 shows a block diagram of an AC power supply device 1 according to the first exemplary embodiment. In the example shown in FIG. 1, the commercial power supply SPS and the load to be supplied with power are shown so that the usage form of the AC power supply 1 can be understood. The load is, for example, an electric appliance used at home.

  As shown in FIG. 1, the AC power supply apparatus 1 according to the first embodiment includes a PV PCS (Power Conditioner System) 10, a BAT PCS 20, an instantaneous voltage fluctuation detection unit 30, and a system power supply signal monitor unit 31. Note that the AC power supply device 1 does not necessarily have the BAT PCS 20, and may have another PCS other than the BAT PCS 20.

  The PV PCS 10 includes a control unit (for example, an energy management unit 11), a DC / DC converter 12, a DC / AC inverter 13, and an instantaneous voltage fluctuation detection unit 14. The energy management unit 11 includes a computing device such as a CPU (Central Processing Unit).

  The DC / DC converter 12 converts the voltage level of the DC voltage of the electric power generated by the solar battery panel PV and outputs it to the DC / AC inverter 13. The DC / AC inverter 13 converts the DC power provided by the DC / DC converter 12 into AC power and outputs the AC power to the system wiring to which power from the commercial system power supply SPS is supplied. That is, the DC / AC inverter 13 generates an AC power signal from the DC power signal, and outputs the generated AC power signal to the system wiring to which the power from the commercial system power supply SPS is supplied. Details of the instantaneous voltage fluctuation detector 14 will be described later.

  The BAT PCS 20 includes a control unit (for example, an energy management unit 21), a DC / DC converter 22, a DC / AC inverter 23, and an instantaneous voltage fluctuation detection unit 24. The energy management unit 21 includes an arithmetic device such as a CPU, for example.

  The DC / DC converter 22 converts the voltage level of the direct current voltage of the power stored in the battery BAT and outputs it to the DC / AC inverter 23. The DC / AC inverter 23 converts the DC power supplied from the DC / DC converter 22 into AC power and outputs the AC power to the system wiring supplied with the power from the commercial system power supply SPS. That is, the DC / AC inverter 23 generates an AC power signal from the DC power signal, and outputs the generated AC power signal to the system wiring to which the power from the commercial system power supply SPS is supplied.

  The battery BAT provided corresponding to the BAT PCS 20 is charged based on electric power supplied from the PV PCS 10 or the commercial power supply SPS. Description of this charging operation is omitted.

  The instantaneous voltage fluctuation detection units 14 and 24 output voltage fluctuation detection pulse signals S11 and S21, respectively, and the magnitude relationship between the effective value of the system power supply signal transmitted to the system wiring and a predetermined voltage fluctuation detection threshold changes. In response to this, the duty ratio of the voltage fluctuation detection pulse signals S11 and S21 is switched between the first duty ratio and the second duty ratio. The waveform of the system power supply signal is acquired by the system power supply signal monitoring unit 31 described later. The voltage fluctuation detection pulse signals S11 and S21 output from the instantaneous voltage fluctuation detection units 14 and 24 are signals synchronized with the zero cross timing at which the system power supply signal crosses the common voltage of the system power supply signal. In accordance with the voltage fluctuation detection pulse signals S11 and S21, the energy management units 11 and 21 control the frequency of the AC power supply signal output by the PCS.

  Next, an instantaneous voltage fluctuation detection method in the AC power supply device 1 according to the first embodiment will be described. First, a description will be given of a portion that performs voltage fluctuation detection processing and output power control when instantaneous voltage fluctuation occurs. Thus, FIG. 2 shows a detailed block diagram of the instantaneous voltage fluctuation detection units 14 and 24 and the energy management units 11 and 21 of the power conditioner in the AC power supply according to the first embodiment. The instantaneous voltage fluctuation detection unit 14 and the instantaneous voltage fluctuation detection unit 24 have the same configuration as that shown in FIG. 1, and the energy management unit 11 and the energy management unit 21 have the same configuration as that shown in FIG. In FIG. 2, only the instantaneous voltage fluctuation detection unit 14 and the energy management unit 11 are shown.

  As shown in FIG. 2, the instantaneous voltage fluctuation detector 14 includes an analog-digital converter 41, an effective value calculator 42, a comparator (for example, a hysteresis comparator 43), a zero-cross detector 44, a first signal generator 45, A second signal generator 46 and a selector 47 are included.

  The analog-to-digital converter 41 performs an analog-digital conversion process on the system power signal monitored by the system power signal monitor unit 31 and outputs a system power signal represented by a digital value. The effective value calculation unit 42 calculates the effective value of the system power supply signal based on the value of the system power supply signal output from the analog-digital converter 41. This effective value may be, for example, a voltage value indicated by an analog value or a value indicated by a digital value. In the first embodiment, a voltage value indicated by an analog value is used as an effective value. The hysteresis comparator 43 compares the effective value of the system power signal output from the effective value calculator 42 with the voltage fluctuation detection threshold. The hysteresis comparator 43 compares two values with hysteresis. The hysteresis comparator 43 switches the logical level of the output in accordance with the change in the magnitude relationship between the effective value and the voltage fluctuation detection threshold.

  The zero cross detector 44 detects the zero cross timing of the system power signal output from the analog-digital converter 41, synchronizes with the zero cross timing, and maintains a constant pulse width regardless of the effective value of the system power signal. Is output.

  The first signal generator 45 outputs a first pulse signal having a first duty ratio in synchronization with the edge of the synchronization pulse signal S2. In the AC power supply device 1 according to the first exemplary embodiment, 50% is set as the first duty ratio. The second signal generator 46 outputs a second pulse signal having a second duty ratio in synchronization with the edge of the synchronization pulse signal. In the AC power supply device 1 according to the first exemplary embodiment, 10% is set as the second duty ratio. The selector 47 selects either the first pulse signal or the second pulse signal according to the output of the hysteresis comparator 43 and outputs it as the voltage fluctuation detection pulse signal S11.

  The energy management unit 11 includes a duty change detector 51, a voltage fluctuation determination unit 52, and an in-unit power command unit 53. The duty change detector 51 monitors the duty ratio of the voltage fluctuation detection pulse signal S11 and outputs a duty ratio detection signal whose logic level is switched according to the duty ratio of the voltage fluctuation detection pulse signal S11. This duty ratio detection signal is high level if the duty ratio of the voltage fluctuation detection pulse signal S11 is the first duty ratio (for example, 50%), and the duty ratio of the voltage fluctuation detection pulse signal S11 is the second duty ratio ( For example, the signal is a low level if 10%).

  The voltage fluctuation determination unit 52 determines whether or not there is a voltage fluctuation in the system power supply signal according to the logic level of the duty ratio detection signal. More specifically, when the logic level of the duty ratio detection signal is a low level, the voltage fluctuation determination unit 52 determines that the system power supply signal is in an effective value higher than the voltage change detection threshold value. The logic level is set to low level. On the other hand, when the logic level of the duty ratio detection signal is high, the voltage fluctuation determination unit 52 determines that the system power supply signal is in an effective value lower than the voltage change detection threshold and sets the logic level of the fluctuation determination signal. High level.

  The in-unit power command unit 53 is a PWM signal or output power set value (for example, a digital control signal and a set value) applied to the DC / DC converter 12 and the DC / AC inverter 13 based on the variation determination signal output from the voltage variation determiner 52. Including at least one of the electric power). More specifically, the in-unit power command unit 53 supplies output power from the commercial power supply SPS to the DC / DC converter 12 and the DC / AC inverter 13 when the fluctuation determination signal is at a high level. Instruct to match the grid power signal. On the other hand, when the fluctuation determination signal is at a low level, the in-unit power command unit 53 sends the DC / DC converter 12 and the DC / AC inverter 13 to the DC / DC inverter 12 regardless of the system power signal whose output power is known at that time. Instruct the power to be below a certain level.

  Next, the operation of the AC power supply device 1 according to the first embodiment will be described. Here, the operation of instantaneous voltage fluctuation detection in the AC power supply apparatus 1 will be described in particular. FIG. 3 shows a timing chart for explaining the operation of the AC power supply apparatus according to the first embodiment. In addition, although the operation | movement of the energy management part 11 is demonstrated below, in the energy management part 21, the same operation | movement as the energy management part 11 is performed. In FIG. 3, the common voltage of the system power supply signal is shown as Vcm.

  As shown in FIG. 3, in the AC power supply device 1, the zero cross detector 44 outputs a synchronization pulse signal S <b> 2 whose rising edge is synchronized with the zero cross timing of the system power signal. Further, the first signal generator 45 outputs a first pulse signal having a duty ratio of 50% in synchronization with the rising edge of the synchronization pulse signal S2. The second signal generator 46 outputs a second pulse signal having a duty ratio of 10% in synchronization with the rising edge of the synchronization pulse signal S2.

  In the AC power supply device 1, the hysteresis comparator 43 determines that the effective value of the AC power supply signal is equal to or greater than the voltage fluctuation detection threshold (period before the timing T 0), and the output of the hysteresis comparator 43 has the first logic level ( For example, the selector 47 selects the first pulse signal. Therefore, in the period before the timing T0, the instantaneous voltage fluctuation detecting unit 30 outputs the first pulse signal having a duty ratio of 50% as the voltage fluctuation detecting pulse signal S11. At this time, the duty change detector 51 of the energy management unit 11 outputs a duty change detection signal that becomes a low level. In a period before the timing T0, the energy management unit 11 instructs the DC / DC converter 12 and the DC / AC inverter 13 to output output power that follows the amplitude or cycle of the system power signal. Note that since the effective value of the AC power signal calculated by the effective value calculation unit 42 is the effective value of the AC power signal one cycle before, the change in the effective value output by the effective value calculation unit 42 is the actual AC power supply. Delays one cycle with respect to changes in signal amplitude.

  At the timing T0, when the voltage level of the system power supply signal decreases and the effective value becomes smaller than the voltage fluctuation detection threshold, the output of the hysteresis comparator 43 becomes the second logic level (for example, low level), so the selector 47 Selects the second pulse signal. Therefore, during the period from the timing T0 to the timing T1, the instantaneous voltage fluctuation detection unit 30 outputs a second pulse signal having a duty ratio of 10% as the voltage fluctuation detection pulse signal S11. At this time, the duty change detector 51 of the energy management unit 11 outputs a duty change detection signal that becomes a high level. Then, at this timing T0, the energy management unit 11 recognizes the DC / DC converter 12 and the DC / AC inverter 13 at that time according to the change of the duty ratio of the voltage fluctuation detection pulse signal S11. An instruction is given so that the amplitude of the AC power supply signal is smaller than the amplitude of the system power supply signal. In the period from timing T0 to timing T1, after the power of the AC power signal output from the PV PCS 10 is sufficiently reduced, the AC power signal is generated in accordance with the amplitude of the system power signal.

  After that, when the amplitude of the system power supply signal is recovered at timing T1 and the effective value becomes equal to or higher than the fluctuation detection voltage threshold value, the output of the hysteresis comparator 43 becomes the first logic level (for example, low level). A first pulse signal is selected. Therefore, in the period after the timing T1, the instantaneous voltage fluctuation detection unit 30 outputs the first pulse signal having a duty ratio of 50% as the voltage fluctuation detection pulse signal S11. At this time, the duty change detector 51 of the energy management unit 11 outputs a duty change detection signal that becomes a low level. Then, at this timing T1, the energy management unit 11 recognizes the DC / DC converter 12 and the DC / AC inverter 13 at that time according to the switching of the duty ratio of the voltage fluctuation detection pulse signal S11. An instruction is given to follow the amplitude of the grid power supply signal. In the period after the timing T1, after the voltage of the AC power signal output from the PV PCS 10 is increased, the AC power signal is generated in accordance with the amplitude of the system power signal.

  From the above description, in the AC power supply device 1 according to the first exemplary embodiment, the instantaneous voltage fluctuation detection unit 14 detects that the effective value of the system power supply signal has changed, and sets the duty ratio of the voltage fluctuation detection pulse signal S11 to the first. The duty ratio is switched to the second duty ratio. And in the alternating current power supply device 1 concerning Embodiment 1, the voltage fluctuation of a system | strain power supply signal is detected based on switching of the duty ratio of this voltage fluctuation detection pulse signal S11. By performing such processing, in the AC power supply device 1 according to the first exemplary embodiment, the voltage of the system power supply signal is immediately transmitted to the energy management unit 11 and the energy management unit 21, and the PV PCS 10 and the BAT PCS 20 The output power can be reduced. Further, in the AC power supply device 1 according to the first exemplary embodiment, when the effective value of the system power supply signal is restored, the duty ratio of the voltage fluctuation detection pulse signal S11 is changed from the second duty ratio to the first duty ratio again. Therefore, when the effective value of the system power supply signal is recovered, the outputs of the PV PCS 10 and the BAT PCS 20 can be quickly recovered.

  Further, the AC power supply device 1 according to the first embodiment employs a format in which the voltage fluctuation detection pulse signal S11 is directly transmitted from the instantaneous voltage fluctuation detection unit 14 to the PV PCS 10 or the BAT PCS 20. The presence or absence of voltage fluctuation of the system power supply signal can also be transmitted to the energy management unit in the PCS using communication using a general-purpose communication standard such as CAN (Contoroller Area Network). However, in the general-purpose communication standard, there are various arrangements for information transmission, and there is a problem that information transmission cannot be started immediately. On the other hand, as in the AC power supply device 1 according to the first embodiment, the voltage fluctuation detection pulse signal S11 is directly transmitted to the energy management unit in the PCS, thereby reducing the time until the start of communication. It is possible to transmit the voltage fluctuation of the system power signal more quickly.

  In particular, in recent years, in order to protect the system, since it is required to shorten the time until the AC power supply side reacts to the voltage fluctuation of the system power supply signal, like the AC power supply apparatus 1 according to the first embodiment. The effect of detecting the voltage fluctuation of the system power supply signal in a short time is great.

Embodiment 2
In the second embodiment, an AC power supply apparatus 2 that is another form of the AC power supply apparatus 1 will be described. FIG. 4 shows a block diagram of the AC power supply device 2 according to the second embodiment. In the description of the second embodiment, the components described in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted.

  As illustrated in FIG. 4, the AC power supply device 2 according to the second embodiment includes a PV PCS 10 a and a BAT PCS 20 a instead of the PV PCS 10 and the BAT PCS 20.

  The PV PCS 10 a has an energy management unit 11 a instead of the energy management unit 11. The BAT PCS 20 a has an energy management unit 21 a instead of the energy management unit 21. In the second embodiment, a pulse signal corresponding to the synchronization pulse signal S2 is generated by the voltage fluctuation detection pulse signals S11 and S21. FIG. 5 is a detailed block diagram of the instantaneous voltage fluctuation detection unit and the energy management unit in the AC power supply according to the second embodiment. In FIG. 5, only the instantaneous voltage fluctuation detection unit 14 and the energy management unit 11a are shown, but the instantaneous voltage fluctuation detection unit 24 and the energy management unit 21a have the same configuration.

  As shown in FIG. 5, the energy management unit 11 a is obtained by adding a trigger signal generator 54 to the energy management unit 11. The trigger signal generator 54 outputs a trigger signal used for controlling the cycle of the AC power supply signal output from the inverter based on the voltage fluctuation detection pulse signal S11. The in-unit power command unit 53 controls the cycle of the AC power supply signal using the trigger signal output from the trigger signal generators 54 and 64.

  Next, the operation of the AC power supply device 2 according to the second embodiment will be described. FIG. 6 is a timing chart for explaining the operation of the AC power supply according to the second embodiment. The timing chart shown in FIG. 6 shows the operation of the AC power supply apparatus 2 when the same system power supply signal fluctuation as that in the timing chart shown in FIG. 3 occurs.

  As shown in FIG. 6, also in the AC power supply device 2 according to the second embodiment, the duty ratio of the voltage fluctuation detection pulse signal S11 is switched according to the fluctuation of the system power signal. Also in the AC power supply device 2 according to the second embodiment, the output power of the PV PCS 10 and the BAT PCS 20 is based on the duty ratio of the voltage fluctuation detection pulse signal S11 as in the AC power supply device 1 according to the first embodiment. Control is performed.

  At this time, in the AC power supply device 2 according to the second embodiment, the trigger signal generator 54 generates a trigger signal corresponding to the synchronization pulse signal S2 from the voltage fluctuation detection pulse signal S11. The trigger signal is a pulse signal having a constant pulse width and an edge synchronized with the voltage fluctuation detection pulse signal S11. As shown in the timing chart of FIG. 6, since the voltage fluctuation detection pulse signal S11 has an edge synchronized with the synchronization pulse signal S2 output from the zero cross detector 44, a trigger signal is generated based on the voltage fluctuation detection pulse signal S11. , The trigger signal becomes a pulse signal having an edge equivalent to that of the synchronization pulse signal S2. Then, by controlling the cycle of the AC power supply signal output from the PV PCS 10 and the BAT PCS 20 based on the trigger signal, the AC power supply device 2 according to the second embodiment uses the AC power supply device 1 according to the first embodiment. It is possible to control the AC power signal equivalent to the above.

  From the above description, the AC power supply device 2 according to the second embodiment can perform control equivalent to the control of the AC power supply signal using the synchronization pulse signal S2 by the voltage fluctuation detection pulse signal S11.

Embodiment 3
In the third embodiment, an AC power supply apparatus 3 that is another form of the AC power supply apparatus 1 will be described. FIG. 7 shows a block diagram of the AC power supply device 3 according to the third embodiment. In the description of the third embodiment, the components described in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted.

  As illustrated in FIG. 4, the AC power supply device 2 according to the second embodiment includes a PV PCS 10 b and a BAT PCS 20 b instead of the PV PCS 10 and the BAT PCS 20.

  The PV PCS 10b includes an energy management unit 11b and an instantaneous voltage fluctuation detection unit 14b instead of the energy management unit 11 and the instantaneous voltage fluctuation detection unit 14. The BAT PCS 20b includes an energy management unit 21b and an instantaneous voltage fluctuation detection unit 24b instead of the energy management unit 21 and the instantaneous voltage fluctuation detection unit 24.

  The energy management units 11b and 21b perform frequency control of output power based on the synchronization pulse signal S2 output from the instantaneous voltage fluctuation detection units 14b and 24b, respectively. Further, the instantaneous voltage fluctuation detectors 14b and 24b each output the synchronization pulse signal S2 output from the internal zero-cross detector to the energy management unit.

  FIG. 8 is a detailed block diagram of the instantaneous voltage fluctuation detection unit and the energy management unit in the AC power supply device 3 according to the third embodiment. In FIG. 8, only the instantaneous voltage fluctuation detection unit 14b and the energy management unit 11b are shown, but the instantaneous voltage fluctuation detection unit 24b and the energy management unit 21b also have the same configuration.

  As shown in FIG. 8, the instantaneous voltage fluctuation detection unit 14b outputs the synchronization pulse signal S2 output from the zero cross detector 44 to the in-unit power command unit 53 of the energy management unit 11b.

  With such a configuration, in the AC power supply device 3 according to the third embodiment, the output is not affected by the delay generated by the first signal generator 45, the second signal generator 46, and the selector 47. The frequency of power can be controlled.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

1, 2, 3 AC power supply 10, 10a, 10b PV PCS
11, 11a, 11b Energy management unit 12 DC / DC converter 13 DC / AC inverter 20, 20a, 20b PCS for BAT
21, 21a, 21b Energy management unit 22 DC / DC converter 23 DC / AC inverter 14, 24, 14b, 24b Instantaneous voltage fluctuation detection unit 31 System power supply signal monitoring unit 41 Analog-digital converter 42 Effective value calculation unit 43 Hysteresis comparator 44 Zero cross detector 45 First signal generator 46 Second signal generator 47 Selector 51 Duty change detector 52 Voltage fluctuation detector 53 In-unit power command device 54 Trigger signal generator S1 Monitor signal S2 Synchronous pulse signal S11, S21 Voltage fluctuation detection pulse signal PV Solar panel BAT Battery SPS Commercial power supply

Claims (6)

An inverter that generates an AC power signal from a DC power signal and outputs the AC power signal to a system wiring to which power from a commercial power supply is supplied;
The duty ratio of the voltage fluctuation detection pulse signal is output in accordance with the change in the magnitude relationship between the effective value of the system power supply signal transmitted to the system wiring and the predetermined voltage fluctuation detection threshold while outputting the voltage fluctuation detection pulse signal. An instantaneous voltage fluctuation detecting unit that switches between the first duty ratio and the second duty ratio;
A control unit for controlling the inverter and instructing the inverter to change the output power of the AC power supply signal in accordance with switching of a duty ratio of the voltage fluctuation detection pulse signal ;
The instantaneous voltage fluctuation detecting unit is
An effective value calculation unit for calculating an effective value of the system power supply signal;
A comparator for comparing the effective value and the voltage fluctuation detection threshold with hysteresis;
The system power supply signal detects a zero-cross timing that crosses the common voltage of the system power-supply signal, and synchronizes with the zero-cross timing, and outputs a synchronized pulse signal that maintains a constant pulse width regardless of the effective value of the system power-supply signal. A zero-cross detector,
A first signal generator for outputting a first pulse signal having the first duty ratio in synchronization with an edge of the synchronization pulse signal;
A second signal generator that outputs a second pulse signal having the second duty ratio in synchronization with an edge of the synchronous pulse signal;
An AC power supply apparatus comprising: a selector that selects one of the first pulse signal and the second pulse signal according to an output of the comparator and outputs the selected signal as the voltage fluctuation detection pulse signal . The AC power supply apparatus according to claim 1, wherein the control unit controls a cycle of the AC power supply signal output from the inverter based on the synchronization pulse signal.   The AC power supply apparatus according to claim 1, wherein the control unit controls a cycle of the AC power supply signal output by the inverter based on the voltage fluctuation detection pulse signal. An inverter that generates an AC power signal from a DC power signal and outputs the AC power signal to a system wiring to which power from a commercial power supply is supplied;
An instantaneous voltage fluctuation detection unit that detects that the magnitude relationship between the effective value of the system power supply signal transmitted to the system wiring and a predetermined voltage fluctuation detection threshold is switched;
A control unit for controlling the inverter; and an instantaneous voltage fluctuation detection method for an AC power supply device,
In the instantaneous voltage fluctuation detection unit,
Calculate the effective value of the system power signal,
Perform a comparison process that compares the effective value and the voltage fluctuation detection threshold with hysteresis,
The system power signal detects a zero-cross timing that crosses the common voltage of the system power signal, and synchronizes with the zero-cross timing, and outputs a synchronized pulse signal that maintains a constant pulse width regardless of the effective value of the system power signal. ,
In synchronization with the edge of the synchronous pulse signal, a first pulse signal having a first duty ratio is output,
In synchronization with the edge of the synchronization pulse signal, a second pulse signal having a second duty ratio is output,
Depending on the result of the comparison process, either the first pulse signal or the second pulse signal is selected and output as a voltage fluctuation detection pulse signal,
In the control unit,
An instantaneous voltage fluctuation detection method for instructing the inverter to change the output power of the AC power supply signal in response to detecting that the duty ratio of the voltage fluctuation detection pulse signal is switched. The instantaneous voltage fluctuation detection method according to claim 4 , wherein the control unit controls a cycle of the AC power supply signal output from the inverter based on the synchronization pulse signal. The instantaneous voltage fluctuation detection method according to claim 4 , wherein the control unit controls a cycle of the AC power supply signal output from the inverter based on the voltage fluctuation detection pulse signal.

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