JP2000166124A - Auxiliary power supply - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To compensate for a voltage drop of a commercial power supply by using a secondary battery, and to supplement the voltage drop of the secondary battery while the capacity of the commercial power supply is sufficiently ensured. In case of shortage of commercial power. SOLUTION: A secondary battery 7 converts DC power of the secondary battery into AC power, outputs the AC power to an AC output terminal, and converts AC power of a commercial power supply S applied to the AC output terminal into DC. An inverter 5 for charging the rechargeable battery and an AC output terminal of the inverter and a system interconnection protection device 21 for connecting the AC load 17 and the commercial power supply S constitute an auxiliary power supply device. The DC power of the secondary battery 7 is converted into AC power by the inverter 5 and supplied to the AC load 17 via the AC output terminal. If there is no load, the AC power of the commercial power supply S applied to the AC output terminal is The secondary battery is charged by converting the direct current into a direct current by an inverter, and is prepared for the next use of the secondary battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an auxiliary power supply device using a secondary battery.

[0002]

2. Description of the Related Art In isolated villages and remote islands, the capacity of the main commercial power supply is small, and when large-capacity electrical equipment is used in each house, the voltage of the commercial power supply drops, and in some cases, the electrical equipment cannot operate normally. Sometimes. For this reason, it is widely practiced to install in-house power generation facilities at particularly important facilities to compensate for the shortage when the commercial power supply is reduced.

[0003]

However, such a conventional private power generation system has a problem that the installation cost and the operation cost are too high to be installed in each house.

When the capacity of the commercial power supply is small, if the power is used all at once in each house, the power will not reach the power outage and the voltage will often drop, and the voltage required for normal operation of the electric equipment will be reduced. It is sufficient to make up for the power necessary to raise the power to the maximum, but there is also a problem that private power generation equipment is not suitable for generating such a small amount of AC power.

[0005] The present invention has been made in view of such conventional problems, and uses a secondary battery to compensate for a voltage drop in a commercial power supply, and to ensure that the capacity of the commercial power supply is sufficiently ensured. It is an object of the present invention to provide an auxiliary power supply device capable of replenishing a voltage drop of a secondary battery while the power supply is in use and preparing for a shortage of commercial power.

[0006] Another object of the present invention is to provide an auxiliary power supply device that uses a solar cell power generation system to charge a secondary battery when solar energy is excessive, thereby making up for a lack of capacity of a commercial power supply. I do.

[0007]

According to the first aspect of the present invention, there is provided an auxiliary power supply device, comprising: a secondary battery; converting DC power of the secondary battery into AC power and outputting the AC power to an AC output terminal; An inverter that converts the AC power of the commercial power applied to the DC power to DC and charges the secondary battery, and a system interconnection protection device for connecting the AC output terminal of the inverter to an AC load and the commercial power. It is provided.

According to the first aspect of the present invention, the DC power of the secondary battery is converted into AC power by an inverter and supplied to an AC load via an AC output terminal. The AC power of the commercial power supply is converted to DC by an inverter to charge the secondary battery, and prepare for the next use of the secondary battery. Further, by connecting the AC output terminal of the inverter to the AC load and the commercial power supply by the system interconnection protection device, the commercial power supply is prevented from being adversely affected.

According to a second aspect of the present invention, there is provided the auxiliary power supply device according to the first aspect, further comprising a battery voltage detecting means for detecting a voltage of the secondary battery, and a commercial power supply voltage detecting means for detecting a voltage of the commercial power supply. An inverter control that, when the commercial power supply voltage is higher than a target voltage of the commercial power supply and the secondary battery is chargeable, causes the inverter to perform a regenerative operation to charge the secondary battery with the commercial power supply; The secondary battery voltage is reduced due to discharge and is in a rechargeable state.If the commercial power voltage becomes higher than the target voltage, the secondary battery is automatically charged. Thus, it is possible to prepare for an operation as an auxiliary power supply for reducing the voltage of the commercial power supply.

According to a third aspect of the present invention, in the auxiliary power supply device according to the first or second aspect, the inverter control circuit determines that the voltage of the commercial power supply is lower than a target voltage of the commercial power supply, When the discharge is possible, the DC power of the secondary battery is converted to AC power and the load is discharged to the load to perform the sequential operation. When the voltage of the commercial power supply is reduced, the secondary battery is automatically operated. Insufficient power can be supplemented from the secondary battery.

According to a fourth aspect of the present invention, in the auxiliary power supply device of the first to third aspects, the inverter control circuit causes the inverter to perform an AC output corresponding to an AC waveform of the commercial power supply. In addition, it is possible to prevent the AC waveform of the inverter output from being superimposed on the AC waveform of the commercial power supply and adversely affecting the AC waveform.

According to a fifth aspect of the present invention, in the auxiliary power supply device according to the first to fourth aspects, the secondary battery is used for charging the secondary battery or utilizing its own power. The solar cell power generation system is capable of replenishing the voltage drop of the secondary battery during the power generation operation. Power consumption can be reduced.

According to a sixth aspect of the present invention, in the auxiliary power supply device of the first to fifth aspects, the secondary battery is connected to a solar cell power generation system together with the inverter for charging the secondary battery and driving the load. It is connected in parallel, and the power generated by the solar cell power generation system is supplied to the load via an inverter, and if the power generated by the solar cell power generation system is insufficient, power can be supplemented from the secondary battery. In addition, more effective use of energy can be achieved, and power consumption of a commercial power supply can be suppressed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a circuit configuration of one embodiment of the present invention. The solar cell power generation system 1 generally includes a large number of solar cell modules 3 installed on a roof.
Are connected in parallel or for every predetermined section, and the DC output is supplied to an inverter 5 as a DC / AC converter. The solar cell module 3 has a configuration in which a large number of solar cells are connected in series or in parallel, and the output thereof is boosted by a DC / DC converter. In addition, this solar cell power generation system 1 is not limited to this, and may have a configuration capable of supplying DC power to the inverter 5.

The inverter 5 applies the DC power generated by the solar cell power generation system 1 to a predetermined voltage and frequency (for example,
50Hz or 60Hz, 100V or 200V (single phase alternating current) is converted to AC and output to the AC side. Conversely, the AC power supplied from the AC side is converted back to AC / DC and output to the DC side. A possible PWM control system is employed.

A large-capacity battery (secondary battery) 7 is connected to the solar cell power generation system 1 in parallel with the inverter 5, and a charge control unit 9 is provided for controlling the charge of the battery 7. Have been.

The battery 7 has a current capacity capable of supplying ordinary home electric equipment for about 1 to 5 hours. The charge control unit 9 outputs the output voltage Vpv of the solar cell power generation system 1.
And the open voltage Vbt of the battery 7 is measured, and the battery 7 is charged when the voltage Vpv of the solar cell power generation system 1 is higher than the battery voltage Vbt, and the charging is stopped in the opposite case.

The control circuit 11 for performing PWM control on the inverter 5 includes a voltage Vcm of the commercial power supply S detected by the voltage detection unit 13 and an AC load 17 detected by the current waveform detection unit 15.
The inverter 5 generates a gate signal capable of outputting AC power of a predetermined voltage and a predetermined voltage based on the current waveform Ifm of the commercial power supply current flowing through 5 performs switching control of the switching element. Further, the battery voltage Vbt detected by the charge control circuit 9 and the voltage detection unit 13
Is compared with the commercial power supply voltage Vcm (effective voltage) detected by
It has a function of switching between the forward conversion operation and the reverse conversion operation of the inverter 5.

On the AC side of the inverter 5, a reactor 19 for shaping the AC output waveform of the inverter 5 into a smooth sine waveform, and a system interconnection protection device 21 for preventing an adverse effect on the commercial power supply S side. Is provided. An AC load 17 is connected to the outside of the system interconnection protection device 21. Thus, the commercial power supply S and the AC output of the inverter 5 are connected in parallel to the AC load 17.

Next, the operation of the auxiliary power supply device having the above configuration will be described.

<When the solar cell power generation system is operating> When the solar cell power generation system 1 is fully operated,
The control circuit 11 causes the inverter 5 to perform a forward conversion operation and supplies the generated power of the solar cell power generation system 1 to the AC load 17.
At the same time, the battery 7 is charged using the power generated by the solar cell power generation system 1.

<When the solar cell power generation system is stopped> (1) When the commercial power supply voltage is high When the voltage Vpv of the generated power of the solar cell power generation system 1 decreases, the charge control unit 9 charges the battery 7. Stop, and once prohibit the discharge. However, when there is a certain amount of output of the solar cell power generation system 1, the control circuit 1
As long as the inverter 1 can operate, the inverter 5 is continuously operated to supply the generated power of the solar cell power generation system 1 to the AC load 17. In this case, the output voltage of the inverter 5 decreases, and it becomes impossible to supply sufficient power to the AC load 17 from the inverter 5 side, but the shortage is compensated for by the power of the commercial power supply S.

The battery 7 detected by the charging control unit 9
If the voltage Vbt is low, the control circuit 11 causes the inverter 5 to perform an inverse conversion operation, and the commercial load S
7 and the battery 7 is charged until it is fully charged.

(2) When the commercial power supply voltage is low The voltage Vpv of the generated power of the solar cell power generation system 1 decreases,
Alternatively, when the voltage becomes zero and the voltage Vcm of the commercial power supply S decreases, the control circuit 11 performs the forward conversion operation of the inverter 5 to convert the DC power of the battery 7 to AC to compensate for the power shortage to the AC load 17. Let it.

When the control circuit 11 performs the forward conversion operation, the current waveform detecting section 15 outputs the current waveform Ifm of the commercial power source S.
And the phase of the output waveform of the inverter 5 is
Gate control is performed so as to match the phase.

As described above, in the auxiliary power supply device of this embodiment, when the solar cell power generation system 1 is generating enough power, the battery 7 is charged by using a part of the generated power, and Even when the battery power generation system 1 is stopped, if the voltage of the commercial power supply S is high, the battery 7 is charged by the power of the commercial power supply S, and the power generation of the solar battery power generation system 1 becomes insufficient. If the voltage of S also decreases and the power to the AC load 17 becomes insufficient, the power of the battery 7 is used to make up for the shortage. In areas where the power supply voltage drops when the power supply voltage falls, for example, during periods when the voltage of the commercial power supply rises at midnight or during periods when the solar cell power generation system can be fully operated, such as during a sunny day The battery 7 leave fully charged,
It is possible to prepare for such a time zone in which the voltage of the commercial power supply decreases, which is useful.

In the above embodiment, the solar power generation system 1 and the charge control circuit 9 for charging the battery 7 with the power generated from the solar power generation system 1 are provided for the auxiliary power supply. When the battery power generation system 1 is not used, these elements can be omitted.
In this case, the battery 7 is charged while the voltage of the commercial power source S is high, and the battery 7 is controlled to compensate for the power shortage when the voltage of the commercial power source S decreases. .

[0028]

As described above, according to the first aspect of the present invention,
The DC power of the secondary battery is converted to AC power by an inverter and supplied to an AC load via an AC output terminal.In some cases, the AC power of a commercial power supply applied to the AC output terminal is converted to DC by the inverter. To charge the secondary battery,
Be prepared for the next use of the secondary battery, and connect the AC output terminal of the inverter to the AC load and the commercial power by using the grid connection protection device so that the commercial power is not adversely affected. Can be.

According to a second aspect of the present invention, in the auxiliary power supply device according to the first aspect, there are further provided a battery voltage detecting means for detecting a voltage of the secondary battery, and a commercial power supply voltage detecting means for detecting a voltage of the commercial power supply. Since the commercial power supply voltage is higher than the target voltage and the secondary battery is rechargeable, the inverter control circuit performs regenerative operation on the inverter and charges the secondary battery with the commercial power supply. The voltage of the secondary battery is reduced due to discharge and is in a rechargeable state,
When the voltage of the commercial power supply becomes higher than the target voltage, the secondary battery can be automatically charged, and the secondary battery can be prepared for operation as an auxiliary power supply when the voltage of the commercial power supply drops.

According to the invention of claim 3, claim 1 or 2
In the auxiliary power supply device, when the commercial power supply voltage is lower than the target voltage and the secondary battery can be discharged, the inverter control circuit converts the DC power of the secondary battery into AC power to load the secondary battery. In this case, when the voltage of the commercial power supply decreases, the shortage of power from the secondary battery can be automatically compensated.

According to the fourth aspect of the present invention, in the auxiliary power supply device of the first to third aspects, the inverter control circuit causes the inverter to perform an AC output corresponding to the AC waveform of the commercial power supply. Can be prevented from being adversely affected by the AC waveform of the inverter output being superimposed on the AC waveform.

According to the fifth aspect of the present invention, in the auxiliary power supply device according to the first to fourth aspects, in order to charge the secondary battery or use its own electric power, the secondary battery is powered by a solar cell. Connected to the system, there is plenty of sunlight, the voltage drop of the secondary battery can be replenished while the solar cell power generation system is generating power, effective use of energy can be achieved, and the power of commercial power Consumption can be reduced.

According to the invention of claim 6, in the auxiliary power supply device of claims 1 to 5, the secondary battery is connected in parallel with the inverter to the solar cell power generation system for charging the secondary battery and driving the load. Power, the power generated by the photovoltaic power generation system is supplied to the load via the inverter. If the power generated by the photovoltaic power generation system is insufficient, power can be supplemented from the secondary battery, and the energy Further effective use can be achieved, and power consumption of the commercial power supply can be suppressed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 solar cell power generation system 3 solar cell module 5 inverter 7 battery 9 charge control circuit 11 control circuit 13 voltage detection unit 15 current waveform detection unit 17 load 19 reactor 21 system interconnection protection device S commercial power supply

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masao Isshiki 1-1-1, Shibaura, Minato-ku, Tokyo Inside Toshiba Corporation Head Office (72) Inventor Tsuneka Tsuchiya 1-1-1, Shibaura, Minato-ku, Tokyo Inside Toshiba Corporation Head Office (72) Inventor Takuo Ono 1-1-1 Shibaura, Minato-ku, Tokyo Inside Toshiba Corporation Head Office (72) Inventor Eiichiro Fujii 336 Tatehara, Fuji City, Shizuoka Prefecture Inside Toshiba Fuji Factory ( 72) Inventor Yutaka Sada 1 Toshiba-cho, Komukai-Toshiba-cho, Yuki-ku, Kawasaki-shi, Kanagawa Prefecture (72) Inventor Tatsuaki Security Inc. 1 Toshiba-cho, Fuchu-shi, Fuchu-shi, Tokyo 5F051 JA17 KA03 KA05 5G015 FA16 GA02 GA05 HA04 JA24 JA34 JA35 JA52 JA64

Claims (6)

[Claims] A secondary battery; converting DC power of the secondary battery into AC power and outputting the AC power to an AC output terminal; and converting AC power of a commercial power supply applied to the AC output terminal into DC. An auxiliary power supply device comprising: an inverter for charging the secondary battery; and a system interconnection protection device for connecting an AC output terminal of the inverter to an AC load and the commercial power supply. 2. A battery voltage detecting means for detecting a voltage of the secondary battery; a commercial power supply voltage detecting means for detecting a voltage of the commercial power supply; and wherein the commercial power supply voltage is higher than a target voltage of the commercial power supply. 2. The auxiliary power supply device according to claim 1, further comprising: an inverter control circuit that causes the inverter to perform a regenerative operation and charge the secondary battery with the commercial power when the secondary battery is rechargeable. 3. 3. The inverter control circuit, wherein a voltage of the commercial power supply is lower than a target voltage of the commercial power supply,
3. The auxiliary power supply device according to claim 1, wherein when the secondary battery is capable of discharging, the secondary battery is operated in the order of converting DC power of the secondary battery into AC power and discharging the AC power to the load. 4. . 4. The auxiliary power supply device according to claim 1, wherein the inverter control circuit causes the inverter to output an AC output that matches an AC frequency of the commercial power supply. 5. The system according to claim 1, wherein the secondary battery is connected to a solar cell power generation system in order to charge the secondary battery or use its own power.
5. The auxiliary power supply device according to any one of 4. 6. The battery according to claim 1, wherein the secondary battery is connected to a solar cell power generation system in parallel with the inverter for charging the secondary battery and driving the load. An auxiliary power supply according to any one of the above.