JPH06153404A - Battery power system - Google Patents

Abstract

PURPOSE:To provide a battery power system which can quickly dissolve the reverse charge phenomena by introducing a transfer break system into a sun-ray power generation system at a low price. CONSTITUTION:This is a battery power system equipped with a solar battery array 1, a DC-AC inverter 2, a breaker 3 for a commercial power system, and a wireless communication means 4 as a control means controlling the continuity and break of the breaker, based on the information being gotten by wireless communication.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery power supply system, and more particularly to an inexpensive battery power supply system capable of quickly canceling a reverse charging phenomenon.

[0002]

2. Description of the Related Art In recent years, interest in the global environment has greatly increased, and great expectations have been placed on a typical solar cell as a battery power source which is an inexhaustible and clean energy source. Nowadays, the cost of solar cells is also 1000 yen / W.
It has become the following, which is 1/10 of that of a few years ago. Electricity obtained from solar cells is more expensive than existing commercial power as of 1994, but it is said that the cost of solar cells will be less than ¥ 200 / W in the year 2000, and at that time it will be comparable to commercial power. You can get electricity at.

Since the solar cell works only in the daytime, some kind of backup means is required for use in a general household at night or in the rain. For this reason, a system has been proposed and put into practical use in which the power system and the output of the solar cell are linked via an inverter.

FIG. 13 shows an example of the system linkage system. DC power generated from the solar cell array 1 is converted into AC power through the DC-AC inverse converter 2, and the AC power is supplied to the load 5. When there is no sunshine, commercial power is supplied to the load 5 through the interruption device 3 for disconnecting from the commercial power system. The circuit breaker 3 disconnects the photovoltaic power generation system from the system line in response to a short circuit accident in the system or an accident in the commercial system. In most cases, DC-AC inverse converter 2
To stop.

[0005]

However, in the daytime, in many cases, the electric power generated by the solar cell is surplus. The flow of excess power to the power grid is called "reverse power flow". If the reverse flow is performed, the electricity generated by the solar cell will be used without waste. Such a reverse flow solar power generation system would be an ideal usage form of solar cells. However, the problem of "reverse charging phenomenon" peculiar to the above-mentioned reverse flow system has not been solved yet.

The "reverse charging phenomenon" may occur when the power generation amount of the solar power generation system and the power consumption of the load connected thereto are almost equal. In such a case, the PV system cannot detect the stop of the commercial power system even if the power of the commercial power system is stopped or it is stopped for some reason, and the PV system continues to operate independently. I will end up. In that case, an electric wire that is not in a live state will be charged, which poses a problem that the electric wire maintenance work is endangered. Further, when the commercial power system is closed again, there is a problem that the commercial power system and the solar power generation system cannot be synchronized with each other, an overcurrent is generated, and the reclosing fails. If many solar power generation systems become widespread in the future, the above-mentioned “reverse charging phenomenon” may occur over a wide area.

In order to prevent the above-mentioned "reverse charging phenomenon", various methods as shown in Table 1 have been proposed and these verification tests have been conducted. However, at present, no definitive solution has been found.

[0008]

[Table 1]

On the other hand, in the extra high voltage power transmission system, the reverse charging state is avoided by using the "transfer interruption method".
"Transfer cutoff" is to shut down the system by activating the cutoff device in response to a cutoff signal from the upper substation. However, in order to apply this to a low-voltage solar power generation system, it is necessary to draw a communication line for each solar power generation system, which requires enormous cost and is difficult to realize.

A method of using a telephone line as a communication line for blocking transfer can be considered. In this way, the cost of drawing individual communication lines would be significantly reduced. However, as described above, the reverse charging phenomenon may occur over a wide range when a large number of solar power generation systems have become popular. In this case, all or most of the solar power generation system in the area where the reverse charging phenomenon occurs must be shut off.

In order to shut off several tens to several thousands of solar power generation systems all at once, a telephone line system in which one-to-one numbers are assigned to consumers is unsuitable.
For example, to shut down 100 systems, you have to make at least 100 Baidu calls, and even if you can access a place in 5 seconds, it takes 500 seconds, that is, 8 minutes or more. .

In view of the above, an object of the present invention is to provide a battery power supply system which can quickly cancel the reverse charging phenomenon at low cost. Further, an object of the present invention is to provide a device for preventing reverse power flow and reverse charging by modifying the photovoltaic power generation system capable of reverse power flow without modifying the inverter.

[0013]

The present invention provides a battery power source, a DC-AC converter for converting a DC output of the battery power source into an AC output and supplying the AC output to a load, and between a power system and the load. A battery power supply system having an electrically connected breaking device, a wireless communication means, and a breaking device control means for controlling conduction / breaking of the breaking device based on information obtained by the wireless communication means. Further, in the battery power supply system, the frequency of the wireless communication means belongs to the vicinity of the medium-wave broadcasting band or both of the TV bands. Further, the circuit breaker control device is a battery power supply system having at least one of a time information control unit that controls based on time information and an identification information control unit that controls based on identification information.

A DC-AC inverse converter for converting the DC output of the battery power source into an AC output and supplying it to the load, a first power measuring means for measuring the output of the DC-AC inverse converter, and a supply to the load. Second power measuring means for measuring inflow power from the power system or power consumption of the load, a dummy load device capable of controlling a load amount electrically connected between the power system and the load, A battery power supply system having: a control unit that controls the load amount of the dummy load device based on the measurement values from the first and second power measurement units. Furthermore, the dummy load device is a battery power supply system having a secondary battery.

[0015]

According to the present invention, the interruption device is controlled by the reception result of the wireless communication means, or the reverse charging of the inverse conversion device is prevented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of a battery power supply system according to the present invention.

The solar cell array 1 including a plurality of solar cell modules converts sunlight into DC power. As the solar cell module, one using a single crystal silicon, a polycrystalline silicon, an amorphous silicon type, or a photovoltaic element combining them can be used. DC-AC inverse converter (hereinafter also referred to as inverter 2)
Is connected to the load 5 by converting DC power from the solar cell array into AC power. DC-AC inverse converter 2
There are various types such as a self-excited type and a separately excited type. Among them, a PWM self-excited inverter using an IGBT, a power MOSFET, and a power transistor as a switching element is preferable. This inverter has a built-in gate control means for the switching element, which starts and stops the inverter. Shut-down device 3 with built-in control means
Is a system that can mechanically separate the commercial power system and the solar power generation system. In order to introduce the output from the wireless communication means 4, it is connected to the wireless communication means, the interruption device 3 and the control means built in the DC-AC inverse conversion device 2. An example of the wireless communication means 4 is shown in FIG.

In FIG. 2, 41 is an antenna,
A bar antenna, a Yagi antenna, a parabolic antenna, a rod antenna, or the like can be used depending on the frequency and field strength of the electromagnetic wave used. 42 is a tuning circuit for receiving a target frequency. A demodulation circuit 43 has a function of extracting a signal from the received radio wave. The frequencies used for communication range from long waves to extremely high frequencies.
Although it can be arbitrarily selected, it has a drawback that a large antenna is required in principle at a frequency of short wave or shorter having a relatively long wavelength. In order to receive the frequency band below short wave with a small antenna, it is necessary to transmit strong radio waves of broadcasting station class. In particular, if the frequency around the frequency used in television broadcasting is used, the existing television antenna can be used in each home, so that it is not necessary to install a new antenna, which is very convenient. The simplest signal to use for communication is a coded signal using on / off of radio waves and a coded signal using frequency deviation. In addition, a method using a signal in the audio frequency domain can be applied. The cutoff signal preferably includes at least ID information for specifying a region and operation command information. The ID information (code number) may be assigned to an area including several hundred or more consumers. If one ID information is assigned to many consumers, it is possible to shut off more photovoltaic power generation systems with one signal transmission. For example, if the same ID number code is assigned to all over Japan and a cutoff signal is transmitted using a communication satellite, the photovoltaic power generation systems in Japan can be cut off at the same time. In reality, it is sufficient to determine the allocation area, etc., considering the power transmission system. Further, time information, sender identification information, and the like can be added to the transmission signal, so that detailed operation can be performed.

For example, when the time information is used as shown in FIG. 6, if the information "return time" is transmitted,
After the power failure, the timer circuit 56 can restart the photovoltaic power generation system at any time. By sending the "start-up time" and the "stop-time", it is possible to operate the system for a time that is convenient for the sender.

Further, as shown in FIG. 7, if the sender identification information and the time information are used, the storage device 58 stores who and when the time signal detector 55 and the sender detector 57 cut off.
Can be recorded on. With this, it is possible to control whether the controller (power company, etc.) that manages many areas is blocked due to reverse charging or whether a worker shuts it down for on-site work. However, in this case, if the amount of information is too large, the transmission speed and the reliability of communication may decrease, so the amount of information to be transmitted must be carefully determined. The wireless communication means does not need to include a transmitting means, and the receiving means alone can sufficiently achieve the object of the present invention.

Example 1 As a solar cell array 1, an amorphous silicon solar cell module (rated voltage 1
240 using 2V rated output 22W) in combination
A V440W solar cell array was constructed. As the inverter 2, a self-excited transistor inverter (rated output 5
00W, 100V) was used. As the circuit breaker 3, a sequencer and a transducer are combined to have the same configuration as that of FIG. 1 so as to disconnect from the commercial power system when an AC overcurrent or overvoltage occurs.

The wireless communication means 4 is constructed as shown in FIG. As the antenna 44, a medium-wave broadcasting par antenna is used, and the reception frequency is 1630 KHz. The received signal is detected by the diode 45, pulsed by the transistor 46, and guided to the pulse counter 47. The output of the pulse counter 47 is compared with the ID number stored in the ID-ROM 48 in the code comparator 49, and if both match, a control output is generated. The control output is input to the control device in the inverter 2 and the circuit breaker 3. In this case, since only the shutoff operation is performed, the ID information and the operation command information are shared. The ID number was 5. Thus, when five pulses are input, the count value “5” from the pulse counter 47 and I
Value from D-ROM 48 (ID number, ie "5")
Therefore, the control output is generated from the code comparator 49 and the interruption is performed.

As the load 5, four 100 W light bulbs were used. The implementation procedure is as follows.

(1) First, the solar power generation system is operated with the commercial power system turned on.

(2) Next, the commercial power system is turned off and the solar power generation system is operated independently.

(3) The transmitter generates a shutoff signal pulse to shut off the solar power generation system.

An operation chart is shown in FIG. When five pulses are input, the control output turns ON, the inverter and the circuit breaker operate, and the solar power generation system is stopped.

(Embodiment 2) The solar cell array 1, the inverter 2 and the breaker 3 have the same construction as that of the embodiment 1, and the wireless communication means 4 is constructed as shown in FIG. In this embodiment, a code is transmitted in the voice frequency domain using a telephone line modem. The radio wave modulation method is frequency modulation, and the frequency is 140 MHz. In this frequency band, the antenna 50
A cheap Yagi antenna for TV broadcasting can be used as.
The signal received by the antenna 50 is input to the FM demodulator 51 to demodulate ID information consisting of a code in the voice frequency domain, then converted to digital data by the voice frequency digital converter 52, and then parallelized by the serial / parallel converter 53. Converted to data, the code comparator 54
-It is compared with the ID information from the ROM 55, and when both match, a control output is generated. ID information is "TEST
2 ", and the operation command information was also used as ID information. The operation was confirmed by the same procedure as in Example 1. Next," WRONG "was transmitted as the ID information by the same procedure, but the system was It was confirmed that the system worked as designed without being shut off.

(Embodiment 3) With a communication frequency of 420 MHz, three photovoltaic power generation systems having the same construction as that used in Embodiment 2 were arranged in parallel to construct a photovoltaic power generation system group as shown in FIG. A UHF television antenna was used as the antenna. Two of the three PV systems (PV systems 1, 2)
The ID information "A" was given, and the remaining one (photovoltaic power generation system 3) was given ID information "B". When the solar power generation system was set to the independent operation state by adjusting the load amount and the ID code "A" was transmitted, immediately after the two systems 1 and 2 with the same ID code were stopped, the ID code "B" was changed. The granted system 3 also stopped. this is,
This is because the load balance is lost and an overvoltage is generated in the final system 3, and the shutoff operation is performed by the overvoltage. In this way, this system is very safe because even if some systems do not work, it will affect all reverse charging systems and consequently other PV systems can also shut off. I can say.

In each of the above embodiments, in the solar power generation system including the solar cell array 1, the DC-AC inverse conversion device 2, the commercial power system interruption device 3, and the wireless communication means 4, the interruption device 3 is used. By the wireless communication means 4, continuity /
This is a solar power generation system whose shutoff is controlled, and has the following effects.

(1) Since the photovoltaic power generation system in a specific area can be shut off at once by transmitting the shutoff signal once, it is possible to quickly cancel the reverse charging phenomenon that has occurred over a wide area.

(2) Since the transfer cutoff method is used, the solar power generation system can be cut off without fail.

(3) If the operation command information is complicated, such as time information and sender identification information, a detailed operation can be performed by the photovoltaic power generation system.

(4) Since the electric power company or the like can centrally control the solar power generation system, the solar power generation system can be safely incorporated in the operation sequence such as automatic reclosing.

(5) Even if there is a system that is insensitive to the cutoff signal, if most of the systems are cut off, the cutoff operation of other systems will be carried out in a safe manner.

(6) If the frequency of wireless communication is used in the frequency band used for television broadcasting, there is no need to install a new antenna, so the solar power generation system of the present invention can be easily and inexpensively used. Can be introduced.

The industrial utility value of the present invention having the above-mentioned excellent effects is extremely high.

(Embodiment 4) FIG. 9 shows an example of a solar power generation system using the reverse flow reverse charge prevention device according to the present invention. In FIG. 9, the portion surrounded by the dotted line is the reverse flow reverse charge prevention device according to the present invention.

The solar cell array 1 including a plurality of solar cell modules converts sunlight into DC power. The DC power from the solar cell array is converted into AC power by the DC-AC reverse conversion device (inverter 2). The inverter 2 has various types such as a self-excited type and a separately excited type.
A PWM self-excited inverter using T, a power MOSFET, and a power transistor as a switching element is preferable. This inverter has a built-in gate control means for a switching element, which starts and stops the inverter. In addition, it has a built-in maximum power tracking function for solar cells, and always outputs the maximum power that can be extracted from the solar cell array. The cutoff device 3 can mechanically separate the commercial power system and the solar power generation system. Reference numeral 4 is a load of a general consumer or the like, which is a home electric appliance in a tangible manner.

Reference numeral 101 is a power measuring means for measuring the output of the inverse conversion device 2, which is composed of a power meter or a combination of an ammeter and a voltmeter. When a combination of an ammeter and a voltmeter is used, electric power can be obtained by multiplying the measured values and calculating the integral value in the cycle of the commercial power system frequency.
A current transformer, a transformer, a digital power meter, etc. can be used as these measuring means. Reference numeral 102 is a power measuring means for measuring the inflow power from the commercial power system. Of course, a power meter or a combination of an ammeter and a voltmeter can be used as in the power measuring means. 103 is a control device,
The measurement output from the power measuring means 101 and 102 is input, this is calculated, and a control output is calculated. A programmable controller or the like can be used as the control means.
104 is a dummy load device capable of controlling the load amount,
An electronic load device, a combination of a resistance load and a slider transformer, a combination of a resistance load and a triac element, a plurality of resistance loads switched by a relay, a secondary battery, and the like are used.

The controller 103 measures the output of the inverse converter 2 and the power consumption of the load 4 into two power measuring means 101, 10.
2 is constantly monitored, and when the difference obtained by subtracting the output of the inverse conversion device 2 from the power consumption of the load 4 based on the measurement values of the respective means 101 and 102 becomes smaller than the minimum received power, the dummy load device The dummy load device 104 so that the 104 consumes the output of the inverse conversion device 2 and maintains the minimum received power.
To control.

The reverse flow reverse charge prevention apparatus of the present invention constantly monitors the power consumption of the inverter output and the load, and when the difference obtained by subtracting the inverter output from the power consumption of the load is larger than the minimum received power, the load apparatus is loaded. A control command is issued so that the power consumption is equal to or more than the minimum received power. As a result, all the output from the inverter is consumed in the customer premises, and reverse power flow to the system and reverse charging are prevented.

(Embodiment 5) A solar power generation system using the device of the present invention as shown in FIG. 9 was constructed as follows.

As the solar cell array 1, an amorphous silicon solar cell module (rated voltage 12V rated output 2
2W) was used in combination to obtain an array of 240V440W. As the reverse conversion device 2, a self-excited transistor inverter (rated output 500 W, 100 V, reverse power flow possible) was used. As the circuit breaker 3, a sequencer and a transducer are combined so that the system is disconnected when an AC overcurrent or overvoltage occurs. Load 4
For this, three 100 W light bulbs were used.

The minimum received power was 10 W.

Next, the power measuring means 101 measures the inverter output power and outputs the measured value as a digital value. The power measuring means 102 measures the load power consumption and outputs the measured value as a digital value. Was installed, and each measurement output was connected to the measurement control computer that functions as the control device 103 through the GPIB interface. Further, the control output of the control device 103 is output to the dummy load device 1 using the GPIB interface.
It was connected to an electronic load device serving as 04.

FIG. 10 shows an example of an operation chart of the reverse flow reverse charge prevention device in the present solar power generation system on a sunny day. The horizontal axis represents time and the vertical axis represents power.

In the morning, the inverter output shown by the solid line A starts to increase from around 8 am when the sun rises and the insolation becomes strong.

At about 10:33 am, the inverter output exceeded 290 W, and at the same time, the electronic load device started to work, and thereafter, the received power indicated by the solid line B was 10 W which is the minimum received power until 13:30. It can be seen that the reverse flow and the reverse charge are prevented.

In the figure, the electric power shown by the dotted line C is
This is the reverse flow power generated when the device is not used.

(Embodiment 6) The solar cell array 1, the reverse converter 2, the circuit breaker 3, and the load 4 have the same construction as in Embodiment 5, and the reverse flow reverse charge prevention device is constructed as shown in FIG.

Current transformers (CT) 201, 202
The potentiometers (PT) 203 and 204 were connected to the power transducers 205 and 206 to form two sets of power meters. This was installed so that the output of the reverse converter and the inflow power from the commercial power system can be measured, respectively. These outputs are output as 8-bit digital values and input to the general-purpose parallel ports of the control device 103, respectively. The dummy load device 104 of this embodiment is 30 W
It consists of eight light bulbs and eight relays connected in series. The drive input of the relay is connected to another general-purpose parallel port of the controller 103. As a result, the dummy load device 104 has a power consumption that is an integral multiple of 30W.

In the case of the present embodiment, the dummy load device 10
Since 4 has a value that is an integral multiple of 30 W, the received power is slightly higher than that in the fifth embodiment. However, it is not necessary to use an expensive electronic load device, and the control device becomes compact.

(Embodiment 7) The solar cell array, the reverse converter, the circuit breaker, and the load have the same configurations as in Embodiment 5, and the reverse flow reverse charge prevention device is constructed as shown in FIG.

As the power measuring means 101, 102, a power meter capable of outputting the measured value as an analog voltage value is prepared.
Each of them was installed so that the output of the reverse converter and the inflow power from the commercial power system could be measured.

These outputs were input to the control device 103 composed of operational amplifiers. The operational amplifier 11 is an adder, and calculates and outputs the difference between the output of the inverse conversion device 2 and the power consumption of the load 4 from the measurement values of the power meters 101 and 102. The output of the operational amplifier 11 is guided to the comparator 12, compared with the voltage 13 corresponding to the minimum received power, and when the difference obtained by subtracting the output of the inverse conversion device 2 from the power consumption of the load 4 is less than the minimum received power, Print the output. The output of the control device 103 is a digital value of 1 to 0 and drives the relay 104R in the dummy load device 104. 400 ahead of relay 104R
A W electric heater 104F was used as a load.

In the case of this embodiment, the received power is larger than that in the case of the sixth embodiment, but the structure of this device is very simple.

As described above, Examples 5 to 7 are
Solar cell array, DC-AC reverse converter capable of reverse power flow,
A reverse flow reverse charge prevention device added to a photovoltaic power generation system having a load, the power measuring means for measuring the output of the reverse conversion device, and the power measurement for measuring the inflow power from the power system or the power consumption of the load. And a dummy load device capable of controlling a load amount, and a control device which receives a measured value from the power measuring unit as an input and gives a load amount control signal to the dummy load device. Therefore, it is possible to construct a solar power generation system without reverse power flow and reverse charging by adding this device without modifying the reverse power flow inverter as the reverse conversion device.

[0060]

As described above, according to the present invention, reverse charging can be promptly released, and reverse power flow can be prevented.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a battery power supply system according to the present invention.

FIG. 2 is a diagram showing a configuration of wireless communication means used in the battery power supply system of the present invention.

FIG. 3 is a diagram showing an embodiment of a wireless communication means used in the battery power supply system of the present invention.

FIG. 4 is a timing chart showing the operation of the same embodiment of the present invention.

FIG. 5 is a diagram showing another embodiment of the wireless communication means used in the battery power supply system of the present invention.

FIG. 6 is a diagram showing a system that restores power after a fixed time by using time information used in the battery power supply system of the present invention.

FIG. 7 is time information used in the battery power supply system of the present invention,
It is a figure which shows the system which records a blocking operation | movement using sender identification information.

FIG. 8 is a diagram showing a system group in which the systems of the present invention are combined.

FIG. 9 is a diagram showing an example of a battery power supply system including the reverse flow reverse charge prevention device of the present invention.

FIG. 10 is a diagram showing an operation chart of the reverse flow reverse charge prevention device used in the battery power supply system of the present invention.

FIG. 11 is a diagram showing another example of the battery power supply system including the reverse flow reverse charge prevention device of the present invention.

FIG. 12 is a diagram showing still another example of the battery power supply system including the reverse flow reverse charge prevention device of the present invention.

FIG. 13 is a configuration diagram of a conventional battery power supply system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solar cell array 2 DC-AC reverse conversion device 3 Breaking device 4 Wireless communication means 5 Load

Claims (7)

[Claims] 1. A battery power source, a DC-AC converter for converting a DC output of the battery power source into an AC output and supplying the AC output to a load, and a breaker electrically connected between a power system and the load. And a circuit breaker control means for controlling conduction / interruption of the circuit breaker based on information obtained by the wireless communication means. 2. The battery power supply system according to claim 1, wherein the frequency of the wireless communication means belongs to the vicinity of a medium-wave broadcasting band. 3. The battery power supply system according to claim 1, wherein the frequency of the wireless communication means belongs to the vicinity of a TV broadcasting band. 4. The battery power supply system according to claim 1, wherein the circuit breaker control means includes time information control means for controlling based on time information. 5. The battery power supply system according to claim 1, wherein the shutoff device control means has identification information control means for controlling based on identification information. 6. A battery power supply, a DC-AC inverse conversion device for converting a DC output of the battery power supply into an AC output and supplying it to a load, and a first power measurement for measuring the output of the DC-AC inverse conversion device. Means, second power measuring means for measuring inflow power from a power system supplied to the load or power consumption of the load, and controlling a load amount electrically connected between the power system and the load A dummy load device that can be used, and the first
And a control unit that controls the load amount of the dummy load device based on the measurement value from the second power measurement unit. 7. The battery power supply system according to claim 6, wherein the dummy load device has a secondary battery.