JP3276815B2 - Solar power generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic power generator that generates power using sunlight as an energy source and supplies the generated power as a commercial power source.

[0002]

2. Description of the Related Art An air conditioner (hereinafter, referred to as an "air conditioner") that performs indoor air conditioning performs heat exchange with a refrigerant, for example, a "heating mode", a "cooling mode", a "dry mode", and the like. The operation is performed in various operation modes such as an "automatic operation mode" in which the operation mode is automatically selected according to various operation modes and set temperatures. As such an air conditioner, a so-called solar air conditioner using solar energy as a power source has been developed (for example, see Japanese Patent Application Laid-Open No.
-74522).

In this solar air conditioner, electric power generated in response to sunlight absorbed by a solar panel is used as a power supply for the air conditioner, and the generated electric power depends on the weather and time. In addition, there is a method in which the usage distribution of the power generated by the sunlight and the power using the commercial power source is controlled in accordance with the amount of power generated by the sunlight, so that a stable air-conditioning operation can be secured.

In the above-described solar air conditioner, the power generated by the sunlight can be used only by the solar air conditioner alone. ,
The power from this sunlight was not able to be used effectively. For this reason, proposals have been made to supply electric power generated by a solar air conditioner to a general commercial power supply.

[0005] Such a solar air conditioner is configured with a power supply system in which electric power generated by sunlight is temporarily supplied as a commercial power supply, and a commercial power supply combined with the electric power generated by the sunlight is used. Yes,
Thereby, the power generated by the sunlight can be effectively used.

Generally, solar panels are used to convert sunlight into electrical energy. In order to generate DC power, the solar panel is provided with an inverter circuit in the photovoltaic power generator so that DC is converted to AC and output by switching ON / OFF of a switching element based on PMW theory. In this case, in order to stably output the same single-phase 200 V voltage as a commercial lamp power supply, four switching elements are output from one power supply circuit and are separately driven using drive power to form a sine wave. A high side (for example, a voltage waveform on the + side) and a low side (for example, a voltage waveform on the − side) are separately generated, and two waveforms having a phase shift of 180 degrees are output.

In addition, since a photovoltaic power generator needs to output AC power having the same phase, voltage, and frequency as a commercial power supply, the frequency, phase, and voltage of the commercial power supply are detected, and based on the detection result, Control is performed so as to output appropriate AC power, and control is performed to stop power supply when commercial power is interrupted (prevention of isolated operation).

By the way, in a solar power generation device, appropriate control can be performed even at night when power generation by the solar panel is stopped.
Since monitoring needs to be performed, commercial power is supplied to the power supply unit. Thus, the inside of the device always operates properly, and it is possible to monitor the presence or absence of an abnormality inside the device and to keep the switching element operable at all times.

[0009]

However, if the photovoltaic power generator is controlled using a commercial power supply, the operation stops when a power failure or the like occurs, and proper self-monitoring of the photovoltaic power generator is impossible. turn into.

The present invention has been made in view of the above facts, and has a simple configuration that enables appropriate operation and monitoring even in the event of a commercial power failure, and that can output stable AC power. An object is to provide a power generator.

[0011]

The invention according to claim 1 is
A solar power generation device that converts DC power generated by concentrating sunlight by a solar panel of a power generation unit into a voltage and frequency corresponding to a commercial power supply, outputs the converted power to an air conditioner, and supplies an operation power supply for the air conditioner. Is provided between the power generation unit and the connection point of the commercial power supply, and operates in response to the supplied switching signal to alternately energize / cut off the input terminal on the power generation unit side and the output terminal on the commercial power supply side. An inverter unit that converts DC power into AC power by at least two switching elements, an inverter control unit that supplies a predetermined switching signal to the switching elements when the power generation unit is in a power generation state, and a switching element of the inverter unit. A rectifying element that is provided between the input terminal and the output terminal in parallel with the rectifying device and supplies a current from the output terminal to the input terminal when the switching element is in an inactive state; A power supply unit connected to the input end of the inverter unit for converting DC power into predetermined constant-voltage power and supplying power to the inside of the device. Is supplied to

According to the present invention, the DC power generated by the power generation unit is converted into AC by energization / interruption (ON / OFF) according to the switching signal of the switching element of the inverter unit and output. At this time, by using two swing elements, it is possible to output a waveform corresponding to a single-phase 100 V of a commercial power supply. Further, since the power supply unit is connected to the input terminal of the inverter unit, the power generated by the power generation unit is supplied.

On the other hand, when the power generation in the power generation unit stops, in the inverter unit, since the switching element does not operate, the power of the commercial power supply is input from the output terminal, and after being rectified by the rectification element, the power is supplied from the input terminal to the power supply unit. Supplied.

Thus, the power supply section is supplied with a commercial power supply at night or the like when the power generation section is stopped, and the power generation section is in a power generation state. The power generated by the power generation section is supplied to the power supply section. For this reason, even if the commercial power supply is interrupted, power is supplied to the power supply unit, so that the inside of the apparatus can be appropriately controlled and monitored. In addition, since there is no need to switch between a storage battery and a power supply, the configuration is extremely simple.

According to a second aspect of the present invention, a DC power generated by concentrating sunlight by a solar panel of a power generation unit is converted into a voltage and a frequency corresponding to a commercial power supply, and output to an air conditioner to operate the air conditioner. A photovoltaic power generator for supplying power, provided between a power generation unit and a connection point of commercial power, and connected in a bridge between an input terminal on the power generation unit side and an output terminal on the commercial power supply side. An inverter unit that operates in response to switching signals supplied to each of the four switching elements and alternately turns on / off an input terminal and an output terminal to convert DC power into AC power; Between the input terminal and the output terminal in parallel with each of the inverter control unit that supplies a predetermined switching signal to the switching element when is in the power generation state. A rectifying element that is provided to conduct electricity from the output terminal to the input terminal when the switching element is in an inactive state; and that is connected to the input terminal of the inverter unit to convert DC power to predetermined constant-voltage power and supply power inside the device. A power supply unit, and supplies commercial power to the air conditioner and the power supply unit even when power generation by the power generation unit is stopped.

According to the present invention, the switching elements are connected in a bridge-like manner, whereby a single-phase two-phase
A waveform corresponding to 00V can be output. At this time, even if the power generation of the power generation unit is stopped, the power of the commercial power supply is rectified by the rectifying elements provided in parallel with the respective switching elements and supplied to the power supply unit, so that appropriate control inside the device can be performed. Becomes

Note that using six switching elements,
When outputting three-phase AC power, a rectifying element can be provided in parallel with each switching element.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an air conditioner 10 which is an air conditioner with a solar power generation device according to the present embodiment. The air conditioner 10 includes an indoor unit 12 and an outdoor unit 14, and a remote control switch 44
Operation signals sent from the device (for example, signals using infrared rays)
Is received by the indoor unit 12, and the temperature, air volume, and wind direction are set according to the received signal, and various operation modes such as “heating”, “cooling”, “defrosting”, and “dry” based on the settings are performed. Air-conditioning operation and stoppage.

The outdoor unit 1 of the air conditioner 10
4 is connected to a solar panel 102 that absorbs sunlight and converts it into electric energy. The electric energy (hereinafter referred to as “generated power”) generated by the solar panel 102 is supplied to a commercial power supply unit (hereinafter referred to as “SOL100”) attached to the outdoor unit 14.
The SOL 100 and the solar panel 102 constitute a photovoltaic power generator 11.

The SOL 100 is operable separately from the indoor unit 12 and the outdoor unit 14 of the air conditioner 10. That is, the indoor unit 1 of the air conditioner 10
2. The SOL 100 operates even when the outdoor unit 14 is stopped, and the indoor unit 12 and the outdoor unit 14 can perform air-conditioning operation even when the SOL 100 is stopped at night or the like.

First, the indoor unit 12 and the outdoor unit 14 of the air conditioner 10 will be described.

As shown in FIG. 2, between the indoor unit 12 and the outdoor unit 14 of the air conditioner 10, a thick refrigerant pipe 15A for circulating the refrigerant and a thin refrigerant pipe 15
B are provided, and one end of each of the
2 is connected to the heat exchanger 16.

The outdoor unit 14 has one refrigerant pipe 1
The other end of 5A is connected to valve 18. This valve 18 is connected to a four-way valve 22 via a muffler 20A. The four-way valve 22 has an accumulator 24,
Both sides of the pipe line to which the compressor 26 and the muffler 20B are connected are connected, and further connected to one of the heat exchangers 28. The other end of the refrigerant pipe 15 </ b> B is connected to the other end of the heat exchanger 28 via a capillary tube 30, a strainer 32, and a valve 34. Also, muffler 3
OB and the four-way valve 22 and the heat exchanger 28 and the capillary tube 30 are connected via an electromagnetic valve 36.

Thus, a closed refrigerant circulation path, that is, a refrigeration cycle, is formed between the indoor unit 12 and the outdoor unit 14, and the operation mode is set to the cooling mode by switching the four-way valve 22 and opening and closing the solenoid valve 36. Mode, heating mode or defrost (dry) mode. FIG. 2 shows the flow of the refrigerant in each operation mode.

FIG. 3 shows a schematic configuration of an electric circuit in the indoor unit 12, and FIG. 4 shows a schematic configuration of an electric circuit in the outdoor unit 14.

As shown in FIG. 3, the indoor unit 12
Is provided with a power supply board 38 and a control board 40. The AC power for operating the air conditioner 10 is supplied to the power supply board 38, and the indoor unit 1
2, a motor power supply 46 for outputting electric power for driving various motors, a control circuit power supply 48 for outputting electric power for a control circuit,
Serial circuit power supply 50 for outputting power for serial circuit
Is provided.

The control board 40 includes a serial circuit 5
2. A driving circuit 54 for driving various motors, a serial circuit 52, and a microcomputer 56 connected to the driving circuit 54 and controlling the operation of the air conditioner 10 are provided. A fan motor 42 (DC brushless motor) that drives a cross flow fan (not shown) that blows warm air, a power relay 60 that opens and closes a contact 58 of a power circuit to the outdoor unit 14, and a vertical flap motor 62 that adjusts the wind direction Is connected.

The drive circuit 54 changes the DC voltage supplied from the motor power supply in accordance with a signal from the microcomputer 56, and adjusts the rotation speed of the fan motor 42, that is, the amount of air blown from the indoor unit 12 by the cross flow fan. ing. For example, if the supply voltage to the fan motor 42 is 12V
By changing the range of up to 36 V in 256 steps, the amount of air to be blown can be finely adjusted. At this time, the microcomputer 56 controls the upper and lower flap motors 62 as necessary to control the air flow from the indoor unit 12 as well as the air direction.

The microcomputer 56 displays an operation state and an operation mode of the air conditioner 10 with LEDs and the like, and has a display board 68 provided with a transmission / reception circuit with the remote control switch 44, and a sensor provided with a floor sensor and an optical sensor. A board 70, a self-diagnosis switch, a switch board 72 provided with an operation changeover switch together with a self-diagnosis LED, a room temperature sensor 74 for detecting room temperature, and a heat exchanger temperature sensor 76 for detecting the temperature of the refrigerant coil in the heat exchanger 16 are provided. It is connected.

As shown in FIG. 4, the outdoor unit 14
Is provided with a rectifier circuit 78 and a control board 80, and terminals 82A to 82C are connected to terminals 84A to 84C (see FIG. 3) of the indoor unit 12 by a communication line 83A and a power supply line 83B (see FIG. 1). Then, while receiving power supply, transmission and reception of a serial signal according to a control signal from the microcomputer 56 are performed between the indoor unit 12 and the frequency (for example, between 18 Hz and 150 Hz) of AC power supplied to the compressor 26. , And operation control of each device.

The control board 80 is provided with a serial circuit 86 for transmitting and receiving a serial signal to and from the serial circuit 52 of the indoor unit 12. The control board 80 includes a plurality of noise filters 88A, 88B, 88 for removing noise.
C, a switching power supply 92 for supplying power to an inverter circuit 90 for driving the compressor 26, and a microcomputer 94
Is provided.

In the air conditioner 10, the frequency of driving the compressor 26, which is output from the inverter circuit 90, is varied to change the number of revolutions of the compressor 26 and adjust the cooling / heating capacity.

The control board 80 is connected to the four-way valve 22 and the solenoid valve 36 in the outdoor unit 14. The four-way valve 22 is switched and the solenoid valve 36 is opened and closed to switch the operation mode. It has become. Also,
The control board 80 is connected to a fan motor 96 and a fan motor condenser 96A of the heat exchanger 28. The microcomputer 94 of the control board 80 includes an outside air temperature thermistor 98A for detecting outside air temperature, a heat exchanger 2
A coil temperature thermistor 98B for detecting the temperature of the refrigerant coil inside the compressor 8 and a compressor thermistor 98C for detecting the temperature of the compressor 26 are connected, and operate the fan motor 96, detect the operating state of the compressor 26, and detect the outside air temperature. , The compressor 26 is driven.

As shown in FIG. 5, the SOL 100 of the photovoltaic power generator 11 includes an inverter circuit 1
04, microcomputer (hereinafter, “microcomputer 106”)
And the solar panel 102
The power generated by the power supply is supplied to the inverter circuit 104. The SOL 100 includes a power generation current detection unit 110 and a power generation voltage detection unit 112 for detecting the power generation state of the solar panel 102 and a system power failure detection unit 114 for determining a system connection with a commercial power supply. A detection unit 116 is provided, and power for operation is supplied to these units from the switching power supply 108.

The solar panel 102 that absorbs sunlight is
A plurality of modules are set in a frame and installed on a place illuminated by sunlight, such as a building roof. The generated power obtained by converting sunlight with the solar panel 102 is supplied to the inverter circuit 104. That is, in the solar panel 102, a plurality of modules generate DC power of a predetermined voltage, and the DC power is supplied to the inverter circuit 104.

In the inverter circuit 104, the microcomputer 10
The DC power is converted to the same frequency as the commercial power supply (for example, 50 Hz or 60 Hz) in accordance with the switching signal supplied from
Hz) (the output of the inverter circuit 104 has a role of converting into, for example, a sawtooth wave). The power converted into AC by the inverter circuit 104 is supplied to a commercial power supply via a transformer 118. At this time,
The AC power output from the inverter circuit 104 passes through the transformer 116 to remove a DC component.

A disconnecting conductor 120 is provided at a connection point between the transformer 118 and the commercial power supply. When an abnormality occurs in either the photovoltaic power generator 11 or the commercial power supply, the disconnecting conductor 120 is used. By SOL100
And commercial power supply.

Here, first, the outline of the operation of the inverter circuit 104 will be described with reference to FIGS.

The microcomputer 106 generates a switching signal for obtaining a pseudo sine wave signal based on the PWM theory. The switching signal generated by the microcomputer 106 is output to the inverter circuit 104.

As shown in FIG. 6, the inverter circuit 1
04 has four switching elements Xa, Xb, Ya,
Yb and switching amplifiers 122, 124, 126, 1 for driving the respective switching elements Xa to Yb.
28 are provided. Four switching elements Xa ~
As Yb, a power transistor, a power FET, I
GBT or the like can be used, and these switching elements Xa and Yb are connected in a bridge between the solar panel 102 and the AC power supply. A flywheel diode (hereinafter referred to as “diode 130”) is connected in parallel to each of the switching elements Xa, Xb, Ya, and Yb.
Are in a state where the diodes 130 are connected in a bridge shape in a specific operation state.

The switching signal generated by the microcomputer 106 is supplied to each switching amplifier 122
To 128. The switching amplifiers 122 to 128 are supplied with power from the switching power supply 108. The switching amplifiers 122 to 128 supply the power to the switching elements Xa to Yb in accordance with the switching signal, and supply the switching elements Xa to Yb. Drive the so-called 3
The power supply system is used.

Therefore, in the inverter circuit 104,
Each of the switching elements Xa to Yb is driven according to a predetermined switching signal, so that the power input from the solar panel 102 (for example, DC 200 V)
Is output as a single-phase pseudo sine wave corresponding to. The pseudo sine wave is supplied to the commercial power supply after the DC component is removed by passing through the transformer 118.

Further, a smoothing capacitor 132 is provided in the inverter circuit 104.
32 are connected to a switching power supply 108 at both ends, and power generated by the solar panel 102 is supplied to the switching power supply 108.
When the power generation of the solar panel 102 stops,
A so-called dual AC / DC power supply system in which AC power of a commercial power supply is rectified by a diode 130 connected in parallel with the switching elements Xa to Yb, smoothed by a smoothing capacitor 132, and supplied to the switching power supply 108. Has become.

FIG. 7 shows a principle diagram when the microcomputer 106 generates a switching signal.
b switching signal (ON / OFF signal) Sx1, Sx
x2 is shown as an example. The switching signal Sx2 of the switching element Xb is obtained by inverting the switching signal Sx1 of the switching element Xa. That is, the switching signal Sx1 of the switching element Xa
Is ON when the modulation wave M0 (for example, a sine wave, a stepwise sine wave, etc.) for the carrier wave C0 (for example, a triangle wave, a stepwise triangle wave, a sine wave, etc.) is such that the modulation wave M0> the carrier wave C0.
The switching signal Sx2 of the switching element Xb is turned on when the modulation wave M0 <the carrier wave C0. This is an example, and the present invention is not limited to this.

The switching signal (ON / OFF signal) Sy1 of the switching element Ya is turned on when the phase angle of the modulated wave M0 is advanced by 180 degrees and when the modulated wave M0 is M0> C0 with respect to the carrier wave C0. Signal. That is, the switching signal Sy1 of the switching element Ya
Is a switching signal Sx2, and a switching signal Sy2 of the switching element Yb is a signal that is turned on / off at the same timing as the switching signal Sx1.

Such switching signals Sx1 to Sy
2, the phases of the outputs of the switching elements Xa and Xb and the outputs of the switching elements Ya and Yb are set to 1
A pseudo sine wave shifted by 80 degrees can be generated.

The cycle of the modulated wave M0 is determined by the inverter circuit 10
4, that is, the frequency (50 Hz or 60 z) of the commercial power supply,
, The frequency f of the pseudo sine wave output from the inverter circuit 104 can be changed. Further, it is preferable to shorten the cycle of the carrier wave C0, because the number of ON / OFF times in one cycle of the pseudo sine wave increases, and the resolution of the pseudo sine wave increases. In FIG. 7, for the sake of explanation, the frequency of the modulated wave M0 is higher than that of the carrier wave C0 (the period is shortened).

FIGS. 8A to 8D show modulated waves M
0 and a modulated wave M whose amplitude is changed with respect to this modulated wave M0
1, M2 (see FIG. 8A), the switching signals Sx1 (see FIG. 8B), Sx0 (see FIG. 8C), and Sx2 (see FIG. 8D). In addition,
Each of the switching signals Sx0 to Sx2 is a signal that is turned on when the modulation wave M> the carrier wave C0.

As described above, in the modulated wave M1 whose amplitude is larger than that of the modulated wave M0, the ON time and the OFF time of the switching signal S1 are each partially longer than the switching signal S0 for the modulated wave M0. As a result, the pseudo voltage of the pseudo sine wave S1 (the voltage generated across the coil when applied to the transformer 118) increases. On the other hand, in the modulated wave M2 having an amplitude smaller than that of the modulated wave M0,
The ON time and the OFF time, which are partially long, are shortened. As a result, the pseudo voltage of the pseudo sine wave S2 can be reduced. That is, the pseudo voltage can be changed by changing the amplitude of the modulated wave to change the difference between the maximum ON time and the minimum ON time.

FIG. 9 is a functional block diagram showing the switching signal generator 134 included in the microcomputer 106. The switching signal generation unit 134 includes a storage unit 136 that stores sin data for generating a sine wave, a sine wave control unit 138, and a 16-bit UP / DOW.
N counter 140, distributor 142, comparators 144, 14
6 and an inverter 148.

The UP / DOWN counter 140 adds a count value in synchronization with an input clock signal, and decrements the count value when the count value reaches FFFFH.
When the count value reaches 0H in this way, addition is started again, and thereafter, addition and subtraction of the count value are repeated. As a result, the output of the UP / DOWN counter 140 changes in a triangular waveform, and is used as the carrier C0 by the comparators 144 and 14.
6 are input.

The sine wave control section 138 outputs a sine wave according to the frequency f and the voltage v (amplitude) data.
The sine wave data is stored in the storage unit 136, for example, from 0H to FF.
One cycle is divided and stored in the FFH, and the sine wave control unit 138 reads out the sine wave data in order according to the frequency f, corrects the amplitude according to the voltage v, and outputs the corrected sine wave data. The distributor 142 is a sine wave control unit 1
The phase angle of the sine wave output from 38 is shifted by 180 degrees and output to each of the comparators 144 and 146 as a modulated wave M0.

The comparators 144 and 148 compare the input carrier wave (triangular wave) C0 and the modulated wave M0 (sine wave of frequency f), and switch ON / OFF signals according to the comparison result to the switching signals SX1 and Sy1. Output as Also, each inverter 148 is provided with a comparator 144, 146.
Of the switching signals Sx2, Sy2
Output.

The switching signals Xa to Yb are turned on / off by the switching signals output in this manner.
When the delay time is large (especially from ON to OFF), the switching signal S is sent to the switching elements Xa to Yb.
x1 to Sy2 (for example, switching amplifiers 122 to 128) are provided with delay circuits (signals are turned OFF → O
N, a circuit for delaying this change by a predetermined time may be inserted. Alternatively, the modulated wave M0 and the carrier wave C0 supplied to the comparators 144 and 146 may be D / A-converted, and analog voltage levels may be compared and output. Further, the above description shows an example of generation of the switching signals Sx1 to Sy2, and the present invention is not limited to this, and switching signals generated by various configurations can be used.

FIG. 10 shows an example of the switching power supply 108. The switching transformer 134 of the switching power supply 108 has a diode D at each output terminal.
1 to D10, capacitors C1 to C10, smoothing capacitors C15 to C35, and three-terminal regulators SR1 to SR1
A rectifier circuit constituted by 0 is provided. Outputs of the rectifier circuits 152A to 152E are supplied to the microcomputer 106, the generated current detection unit 110, the generated current detection unit 112, the series power failure detection unit 114, and the series power supply detection unit 116.

The switching power supply 108 is supplied with DC power from the inverter circuit 104 between the terminals 154A and 154B (see FIG. 6). The DC power supplied from the inverter circuit 104 is converted into AC by the inverter circuit 156, and
Supplied to At this time, as described above, the inverter circuit 104 can supply DC power to the switching power supply 108 even when the solar panel 102 fails. This allows each component in the SOL 100 to operate properly even when the power generation of the solar panel 102 is stopped at night or the like.

On the other hand, the rectifier circuits 158A, 158B, 15
8C is connected to the switching amplifiers 122 to 128 of the inverter circuit 104,
Driving power is supplied from 58A to 158C to switching elements Xa to Yb. That is, FIG.
As shown in FIG. 3, the switching elements Xa and Ya for high-side output of single-phase power include a switching power supply 10.
The drive power output from the rectifier circuits 158A and 158B is supplied via the switching amplifiers 122 and 126, and the switching elements Xb and Yb for low-side output of the single-phase power are rectified by the rectification of the switching power supply 108. Switching amplifiers 124 and 128 from section 158C
The driving power is supplied via the.

As described above, the switching element X that outputs single-phase AC power (in this case, single-phase 200 V AC power)
rectifier circuits 158A to 158 different for each of a to Yb
Since the driving power is supplied from C, even if the outputs of the switching elements Xa to Yb are large, the individual rectifier circuits 158
The load on A to 158C can be reduced, and the respective switching elements Xa to Yb can be operated in a stable state. The switching power supply 1 shown in FIG.
08, the three-terminal regulators SR1 to SR10,
Resistors R1 to R7, capacitors C1 to C14, smoothing capacitors C15 to C37, diodes D1 to D13, IC1
Etc. may be determined by design.

On the other hand, the series power supply detecting section 116 matches the voltage, frequency and phase of the output of the SOL 100 with the commercial power supply. The timing at which the value becomes “0” is detected (hereinafter referred to as “zero-cross detection”). Here, an example of zero-cross detection in the series power supply detection unit 116 will be described with reference to FIGS. 11A to 11C.

FIG. 11A shows a zero-cross detection circuit 1 for detecting a point at which the instantaneous value of the AC voltage of the commercial power supply becomes zero.
60 is shown. This zero cross detection circuit 160
Is a simple configuration including a comparator 162, a photocoupler 164, and resistors R10 to R13 determined by design. When commercial power is input to the comparator 162,
The change in the instantaneous value is output to the microcomputer 106 via the photocoupler 164.

The microcomputer 106 A / D converts the output of the zero cross detection circuit 160. As a result, FIG.
As shown in FIG. 1 (B), it is possible to detect the zero cross point P0 at which the instantaneous value of the commercial power becomes zero.

When the microcomputer 106 detects the zero-cross point P0 of the commercial power supply, the delay t0 caused by the time constant of the circuit in the microcomputer 106 and the inverter circuit 104 is detected.
(See FIG. 11C), the inverter circuit 10
4, the switching signals Sx1 to Sy2 are output. As a result, as shown in FIG. 11C, the sine wave S0 having the same phase as the waveform A0 of the commercial power supply.
Can be output.

On the other hand, it is known that when the commercial power supply is interrupted, the level of the harmonics of the circuit of the commercial power supply increases, and the level of the third harmonic with respect to the frequency of the commercial power supply becomes maximum. Here, the series power failure detection unit 114 of the SOL 100 detects the third harmonic of the circuit of the commercial power supply and outputs the third harmonic to the microcomputer 106. When the level of the third harmonic exceeds a preset value (threshold value), the microcomputer 106 determines that a power failure has occurred in the commercial power supply, activates the parallel-off conductor 120,
The OL 100 is disconnected from the commercial power supply to protect components inside the SOL 100, particularly from overload of the switching elements Xa to Yb of the inverter circuit 104.

FIG. 12 and FIG.
14 shows an example of a harmonic detection circuit 166 provided in FIG.

The third harmonic detection circuit 166 has a filter circuit 168 composed of a plurality of low-pass filters and high-pass filters.
140-180H including the second harmonic (for example, 150Hz)
Only the frequency of z is passed. FIG.
The output of the filter circuit 168 is supplied to the interface circuit 170 as shown in FIG. The interface circuit 170 detects the output level (the level of the third harmonic) of the filter circuit 168, and supplies an ON / OFF signal having a cycle corresponding to the level of the third harmonic to the photocoupler 172. The ON / OFF output of the photocoupler 172 is smoothed by a resistor and a capacitor, and then output to the microcomputer
Is supplied to the microcomputer 106.
Based on the output voltage level of the series power failure detection unit 114, it is determined whether a power failure has occurred in the commercial power supply.

A generated current detecting unit 110 provided between the solar panel 102 and the inverter circuit 104
(A current lance using a Hall element) and a generated voltage detection unit 112 detect a current and a voltage generated by the solar panel 102 and supplied to the inverter circuit 104 and output the detected current and voltage to the microcomputer 106.

The microcomputer 106 controls the generated current detection unit 1
10 and the detection result of the generated voltage detection unit 112, whether or not the solar panel 102 is in the power generation state and the generated power are calculated, and the switching signal is converted into an inverter so that a voltage that maximizes the generated power is obtained. Circuit 10
4 so that the output voltage from the inverter circuit 104 is slightly higher than the voltage of the commercial power supply and substantially equal to the output voltage.

That is, as shown in FIG. 14, the switching signal generator 134
At the same time, the frequency of the commercial power
Frequency detector 18 for setting the frequency f output from the frequency detector 04
0, a voltage detection unit 182 for detecting the voltage of the commercial power supply, a current input from the solar panel 102, an input current detection unit 184 for detecting the voltage, an input voltage detection unit 168, and zero-cross detection for detecting the zero-cross point P0 of the commercial power supply. Part 18
8, the voltage setting unit 190 that sets the voltage v output from the inverter circuit 104 based on the detection results of the voltage detection unit 182, the input current detection unit 184, and the input voltage detection unit 186, and the inverter circuit 104 based on the detection result of the zero-cross detection unit 188. A zero-cross setting unit 192 for setting a zero-cross point of the output waveform, and a power failure determination unit 194 for determining whether or not a commercial power failure occurs, are configured by a CPU, a ROM, a RAM,
It is controlled by a main control unit constituted by a timer and the like.

As a result, the microcomputer 106 sets the SOL
The frequency, the voltage, and the phase of the power supplied from the power supply 100 to the commercial power supply are matched with each other, and when a failure occurs in the commercial power supply, the SOL 100 is protected.

The microcomputer 106 measures the input to the inverter circuit 104 and the output from the inverter circuit 104, and stops the inverter circuit 104 when the frequency, current, and voltage exceed the predetermined ranges (switching element Xa). To stop Yb: gate block).

The microcomputer 106 of the SOL 100
Inside, a serial circuit (not shown) is provided,
A communication line 120 connected to the serial circuit is connected to a terminal 82C of the outdoor unit 14 (one is grounded). Thereby, the microcomputer 106 communicates with the microcomputer 5 of the indoor unit 12 through the communication lines 120 and 83C.
6 and the microcomputer 56 of the indoor unit 12.
The operation information of the SOL 100 and the solar panel 102 such as the power generation state of the solar panel 102 and the operation state of the SOL 100 is output.

Next, the operation of the present embodiment will be described first with respect to indoor air conditioning operation performed by the indoor unit 12 and the outdoor unit 14 of the air conditioner 10.

In the air conditioner 10, when the remote control switch 44 is operated in the operation stop state and the operation mode, temperature, air volume, wind direction, and the like are set, the air conditioner 10 is converted into a code corresponding to the set operation condition and is transmitted from the remote control switch 44. It is transmitted to the indoor unit 12. The indoor unit 12 analyzes the code transmitted from the remote control switch 44, sets operating conditions based on the analysis result, and operates the outdoor unit 14 based on the set operating conditions to perform indoor air conditioning operation. Start.

Thereafter, when an operation signal from the remote control switch 44 is received, the code of the received operation signal is analyzed, and the operating conditions are changed based on the analyzed contents.
In this way, the air conditioner 10 is operated by the indoor unit 12 and the outdoor unit 14 based on the operation of the remote control switch 44 to maintain a desired air-conditioning state.

Next, the operation of the photovoltaic power generator 11 will be described.

In the solar power generator 10, the solar panel 1
When the sunlight is irradiated on 02, the sunlight is converted into electric energy and transmitted to the commercial power supply unit SOL100. In SOL100, this solar panel 100
Is input to the inverter circuit 104.

On the other hand, the microcomputer 106 of the SOL 100
In addition to detecting the generated power (current and voltage) of the solar panel 102, the voltage and frequency of the commercial power supply and the zero-cross point P0
Is detected, and based on the detection result, the switching signal S
x1 to Sy2 are output to the inverter circuit 104. The switching power supply 10 is connected to the inverter circuit 104.
8 supplies power for driving the switching elements Xa to Yb.

In the inverter circuit 104, the switching element Xa is driven by the driving power supplied from the switching power supply 108 based on the switching signals Sx1 to Sy2.
To YB to convert DC supplied from the solar panel 102 into AC and output. At this time, power is separately supplied from the switching power supply 108 to the switching elements Xa and Ya that output high-side waveforms, and separately from the switching elements Xa and Yb that output these high-side waveforms. Power is supplied to the switching elements Xb and Yb that output a waveform.

For this reason, each of the switching elements Xa to Yb
And stable AC power corresponding to the power generated by the solar panel 102 is output from the inverter circuit 104. The output of the inverter circuit 104 is supplied to a commercial power supply as a sine wave via the transformer 118.

Since the switching signals Sx1 to Sy2 are input from the microcomputer 106 to the inverter circuit 104 in accordance with the output of the solar panel 102, the frequency, voltage, and phase of the commercial power supply, the power output from the inverter circuit 104 is , The voltage and the frequency are the same as those of the commercial power supply, and no phase shift occurs, and the power is supplied to the commercial power supply as appropriate power.

In particular, if a phase shift occurs between the output of the inverter circuit 104 and the commercial power supply, a large current may flow through the switching elements Xa to Yb of the switching circuit 104 and cause damage. Is accurately detected, and the phases of the output of the inverter circuit 104 and the commercial power supply can be accurately matched in order to drive the switching elements Xa to Yb according to the detection result.

On the other hand, in the microcomputer 106, the generated current detecting section 110, the generated voltage detecting section 112, the series power failure detecting section 11
4. The power generation state of the solar panel 102, abnormalities inside the apparatus, and changes in the commercial power supply are constantly monitored and controlled based on the detection results of the series power supply detection unit 116 and the like. When an abnormality occurs in the voltage and frequency of the power supply, the output power of the inverter circuit 104, the output frequency, and the like, the inverter circuit 104 is stopped (a gate block of a switching element), or the disconnecting conductor 120 is operated to disconnect from the commercial power supply. SOL100
The protection of the parts inside is aimed at. In addition, microcomputer 1
In step 06, when it is determined from the detection result of the series power failure detection unit 114 that the commercial power supply has failed, the disconnection conductor 12
0 is activated to prevent the solar power generation device 11 from operating alone.

Further, in the microcomputer 106, the generated current detecting section 110, the generated voltage detecting section 112, the series power detecting section 1
16 and the like, the output of the inverter circuit 104 is controlled based on a large number of parameters detected by S.
The internal configuration of the OL 100 can be simplified and made compact, the installation space for the SOL 100 can be reduced, and the OL 100 can be provided integrally with the outdoor unit 14 of the air conditioner 10.

By the way, when the solar panel 102 is generating power, the commercial power supply is in a power outage state to the switching power supply 108 that supplies power to the microcomputer 106 and various detection units inside the solar power generation device 11. Also, power is supplied from the solar panel 102, and the microcomputer 106 and each detection unit in the SOL 100 operate normally.

Here, when the power generated by the solar panel 102 is reduced or the power generation is stopped, the microcomputer 10
6 stops outputting the switching signal to the inverter circuit 104, and the switching elements Xa to Yb enter a non-operating state. In this state, AC power is input to the inverter circuit 104 from a commercial power supply. The AC power from the commercial power source is supplied to a diode 1 connected in a bridge.
The current is rectified by 30, smoothed by the smoothing capacitor 132, and flows into the switching power supply 108.

Therefore, the switching power supply 108 keeps the microcomputer 106
And a predetermined power can be supplied to each of the detection units, and the inside of the solar power generation device 11 is appropriately controlled.

As described above, each of the switching elements Xa to X
If the rectifying diode 130 is provided in parallel with the b, and the AC power of the commercial power supply is supplied to the inverter circuit 104 when the operation of the switching elements Xa to Xb is stopped, the power generation of the solar panel 102 is stopped. Even so, power can be supplied to the switching power supply 108, and the inside of the photovoltaic power generation device 11 can always be in a state where it is appropriately controlled and monitored.

In the present embodiment, the switching elements Xa to Yb are arranged in a bridge shape, and the description has been made using the inverter circuit 104 that outputs single-phase AC power.
The present invention may be applied to an inverter circuit that outputs three-phase AC power using six switching elements.

[0089]

[0090]

As described above, the photovoltaic power generator according to the present invention has a simple configuration in which a rectifying element is arranged in parallel with a switching element. It can be supplied to the power supply unit. Thereby, the inside of the solar power generation device is appropriately controlled and monitored. Further, in the present invention, since driving power is supplied from a plurality of power supply circuits to the switching elements, the capacity of each power supply circuit can be small, and stable AC power corresponding to the generated power can be obtained. It has an excellent effect that can output.

[0091]

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of an air conditioner applied to the present embodiment.

FIG. 2 is a schematic diagram of a refrigerant pipe of an air conditioner applied to the present embodiment.

FIG. 3 is a schematic configuration diagram of an electric circuit of the indoor unit.

FIG. 4 is a schematic configuration diagram of an electric circuit of the outdoor unit.

FIG. 5 is a block diagram illustrating a schematic configuration of a commercial power supply unit (SOL) to which a solar panel is connected.

FIG. 6 is a circuit diagram schematically showing an inverter circuit applied to the present embodiment.

FIG. 7 is a diagram illustrating an example of outputting a switching signal from a modulated wave with respect to a carrier wave.

8A is a diagram illustrating an example in which the amplitude of a modulated wave is changed, and FIGS. 8B to 8D are diagrams illustrating an example of a change in a switching signal when the amplitude of the modulated wave is changed. FIG.

FIG. 9 is a functional block diagram schematically showing a switching signal generator.

FIG. 10 is a circuit diagram schematically showing a switching power supply applied to the present embodiment.

FIG. 11A is a circuit diagram schematically showing zero-cross detection,
(B) is a diagram showing a zero crossing point detected by the microcomputer,
(C) is a diagram showing a waveform of a commercial power supply and a waveform output from SOL.

FIG. 12 is a circuit diagram schematically illustrating a filter circuit provided in the series power failure detection circuit of the present embodiment.

FIG. 13 is a circuit diagram schematically showing an interface circuit provided in the series power failure detection circuit of the present embodiment.

FIG. 14 is a functional block diagram showing internal functions of a microcomputer applied to the present embodiment.

[Explanation of symbols]

Reference Signs List 10 air conditioner 11 solar power generation device 12 indoor unit (air conditioning operation unit) 14 outdoor unit (air conditioning operation unit) 100 commercial power supply unit SOL 102 solar panel (power generation unit) 104 inverter circuit 106 microcomputer (inverter control unit) 108 switching Power supply (power supply unit) 130 Diode (rectifier element) 158A, 158B, 158C Rectifier circuit (power supply circuit) Xa, Xb, Ya, Yb Switching element

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-1830 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02J 3/38 H02M 7/48

Claims (2)

(57) [Claims] 1. A DC power generated by concentrating sunlight by a solar panel of a power generation unit is converted into a voltage and a frequency corresponding to a commercial power supply, and output to an air conditioner to operate the air conditioner.
Power A photovoltaic power generator to supply, provided between the connection point of the power generation unit and the commercial power supply, the input and the commercial power supply side and operates in response to a switching signal supplied power generation section side An inverter unit for converting DC power into AC power by at least two switching elements that alternately energize / cut off an output terminal; and supplying a predetermined switching signal to the switching element when the power generation unit is in a power generation state. An inverter control unit that is provided between the input terminal and the output terminal in parallel with each of the switching elements of the inverter unit, and a rectifying element that conducts electricity from the output terminal to the input terminal when the switching element is in an inactive state. , and a power supply unit for supplying power to the internal device connected to the DC power is converted into a predetermined constant voltage power to the input terminal of the inverter, the power generating unit Even if power generation stops, the commercial power
A photovoltaic power generator, which is supplied to an air conditioner and the power supply unit . 2. DC power generated by concentrating sunlight by a solar panel of a power generation unit is converted into a voltage and a frequency corresponding to a commercial power supply, and output to an air conditioner to operate the air conditioner.
A rolling photovoltaic power generator for supplying power, provided between the connection point of the power generation unit and the commercial power supply, connected like a bridge between the input end and the commercial power supply side of the output end of the power generation portion An inverter unit that operates in response to the switching signals supplied to each of the four switching elements and alternately turns on / off an input terminal and an output terminal to convert DC power into AC power; An inverter control unit that supplies a predetermined switching signal to the switching element when the power generation unit is in a power generation state; and a switching unit provided between the input terminal and the output terminal in parallel with each of the switching elements of the inverter unit. A rectifying element that conducts electricity from the output terminal to the input terminal when the element is in an inoperative state; And a power supply unit for supplying power to置内portion, the said commercial power generation by the power generating unit is be stopped
A photovoltaic power generator, which is supplied to an air conditioner and the power supply unit .