JP2002017043A - Home power supply system combined with solar power generation and midnight power storage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize a level of power load and prevent reverse power transmission of the power stored in a storage battery to a power company by promotion of use of midnight electrical power and shift of peak power generated in the day time to midnight. SOLUTION: A home power supply system combined with solar power generation and midnight power storage is provided. The storage battery is charged, as a rule, in the midnight period using the midnight power via an inverter which also operates as an automatic charger, and the commercial power supply is used for household consumption. In the solar power generation period in the day time, when the electrical power generated with the solar system is higher than the preset value, an extra power is sold to the power company via the inverter/ automatic charger. In the intermediate time period between the midnight period and solar power generation period in the day time, the power stored in the storage battery is supplied for household consumption, and storage, if it is generated, is compensated by the commercial electrical power of the power company. In the case where the power stored in the storage battery is supplied for household consumption, a reverse transmission preventing circuit consisting of parallel connection of a forward thyristor and a backward thyristor is provided between the storage battery and the commercial power supply and a control circuit for preventing reverse transmission of power to the power company is also provided. As a result, the reverse transmission of the power stored in the storage battery to the power company is forcibly prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for promoting the use of midnight power and the use of solar power.

[0002]

2. Description of the Related Art As a measure to promote solar power generation as clean energy, there is a power purchase system of a power company, and solar power generation is widely used. Also, there is a low-price system for late-night power as a measure for surplus power of late-night power. FIG. 3 is a known photovoltaic power generation system diagram. The inverter 30 and the tripping electromagnetic contactor M0 are inserted between the solar cell array 4 and the integrated power receiving wattmeter 7 and the integrated reverse power transmitting wattmeter 8, and the synchronous operation and reverse power transmission control unit 9 outputs the voltages Em and Ed. , Ir, I
Based on d, the inverter 30 and the failure trip electromagnetic contactor M0 are controlled.

[0003]

SUMMARY OF THE INVENTION The present invention utilizes a surplus electric power generated at midnight by a power company and stores it in a storage battery for use during the daytime, thereby shifting peak electric power generated during the daytime to midnight. Leveling the power load,
By doing so, it is an issue for electric power companies to reduce the expansion of thermal power generation and nuclear power generation, to reduce carbon dioxide emissions and reduce radioactive pollution. Another object is to forcibly prevent the stored power of the storage battery from being reversely transmitted to the power company.

[0004]

According to the present invention, there is provided a home power supply system using a combination of photovoltaic power generation and midnight power storage, comprising the following means. In the midnight hours, in principle, the storage battery is charged via the inverter / automatic charger using the midnight power, and the house power is supplied with commercial power. In the daytime photovoltaic power generation time period, when the photovoltaic power is equal to or higher than the set value, the power is sold to a power company via an inverter / automatic charger as surplus power. During an intermediate time period between the midnight time period and the daytime solar power generation time period, the stored power of the storage battery is supplied as house power consumption, and if a shortage occurs, the power is supplied with commercial power from a power company. When the storage power of the storage battery is supplied as house power, a reverse power transmission prevention circuit consisting of a parallel connection of a forward thyristor and a negative thyristor is interposed between the storage battery and the commercial power, and the reverse of the stored power to the commercial power is performed. Power transmission is forcibly stopped. The second invention of the present application is a home power supply system of a combined solar power generation / midnight storage system, characterized in that, in addition to the first invention, instantaneous automatic switching means for switching to storage power of a storage battery at the time of commercial power failure is provided. is there.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIG. FIG. 1 is a system diagram showing a combination of solar power generation and midnight power storage showing an embodiment of the present invention. The solar power generation / midnight storage system diagram of FIG. 1 is different from the solar power system diagram of FIG. 3 in that the storage battery 1 and the electromagnetic contactor M1 (M1
The main differences are that a and M1b are simultaneously controlled to open and close contacts, an electromagnetic contactor M2 is added, and the inverter 30 is used as the "inverter / automatic charger 3" and the reverse power transmission prevention thyristor circuit 5 is provided.

In FIG. 1, synchronous operation and reverse power transmission control unit 1
0 controls the electromagnetic contactor M1, the inverter / automatic charger 3, and the reverse power transmission prevention thyristor 5 to operate synchronously with the commercial power and regulate the reverse power transmission. In other words, the synchronous operation and reverse power transmission control unit 10 removes the storage battery 1 from the circuit in the control state of the b-contact and operates in the same manner as the solar power generation system of FIG. In the reverse power transmission blocking thyristor circuit 5 inserted between the positive power thyristor 5A and the negative power thyristor 5B, the gate current is controlled by the synchronous operation and reverse power transmission control unit 10 in accordance with the positive region and the negative region of the AC waveform of the commercial power. By being supplied, they act alternately to prevent reverse transmission to commercial power.

The main difference between the solar power generation system and the late-night power storage system diagram of FIG. 2 is that an auxiliary inverter 2 and an electromagnetic contactor M2 are added as compared with FIG. The synchronous operation and reverse power transmission control unit 10 controls the electromagnetic contactor M2 and the auxiliary inverter 2 in addition to FIG. 1 to supply AC power synchronized with commercial power to the residential load via the distribution board 6. Control.

Hereinafter, a control mode of the household power supply system of the present invention will be described. The synchronous operation and reverse power transmission control unit 10
When the commercial power reception voltage Em is constantly detected and the signal is supplied to the inverter / charger 3, the inverter / charger 3 obtains AC power synchronized with the commercial power reception voltage Em and shifts to the operation as the “inverter”. Is the commercial receiving voltage Em
An AC voltage slightly higher (for example, 1 V) than that is output.
In addition, the detection at the time of the interruption of the commercial received power is also enabled by the commercial received voltage Em.

At 7 o'clock in the morning, the control unit 10 sends a signal to the inverter / charger 3, and the inverter / charger 3 shifts from the “charger” operation to the “inverter” operation and operates in synchronization with the commercial power. Start. In this state, when the amount of power generated by the solar cell array 4 reaches an arbitrary current set in advance from Id (for example, 1 A to 5 A, a value at which solar power is normally transmitted back to commercial power). And control unit 10
Commands the electromagnetic contactor M1b to open the electromagnetic contactor and b
By setting the contact point, reverse power transmission to commercial power is started. At that time, the electromagnetic contactor M1a disconnects the connection with the storage battery 1.

When the amount of photovoltaic power generation is small and Id is less than the set value, the photovoltaic power is charged to the storage battery via the electromagnetic contactor M1. In addition, the inverter / charger 3 operates as an “inverter” and supplies electric power to the residential load via the a contact of the electromagnetic contactor M1. If the starting current of the residential load exceeds the inverter output of the inverter / charger 3 due to the activation of the cooler or the like,
The control unit 10 alternately sends a signal synchronized with the commercial power reception to each gate of the thyristor 5A and the thyristor 5B of the reverse power transmission prevention thyristor circuit 5, and receives the power with insufficient inverter output to the residential load while preventing the reverse power transmission. Only the required amount is supplied from the electric power via the distribution board 6.

Referring to FIG. 2, when the amount of photovoltaic power generation exceeds the set current value by Id, inverter / charger 3 operates as an "inverter" to convert AC output to commercial power. Reverse power transmission. Therefore, the electric power always supplied to the load for the house is controlled by the control signal of the control unit 10, the electromagnetic contactor M2 operates, and the storage battery 1 constantly supplies DC power to the auxiliary inverter 2 in a state synchronized with commercial power reception, and outputs the AC power. Supplies to a residential load via a distribution board 6. As already described in the previous section, if the AC load of the auxiliary inverter 3 becomes insufficient instantaneously due to the start of the cooler or the like when the residential load is used, Ia detects this and the control unit 10 causes the reverse power blocking thyristor 5 to determine whether the load is positive or negative. The gate signal is sent to satisfy the shortage of residential load from the commercial power received.

When the system is operated without the auxiliary inverter 2 (at the time of reverse transmission of the photovoltaic power described in the preceding paragraph), the detected value of the photovoltaic current setting value Id is increased (for example, 5 A). It also supplies solar power to residential loads. If the residential load exceeds the inverter output of the inverter / charger 3 due to the current detection of Im,
The control unit 10 immediately opens the gates of the reverse power transmission blocking thyristor 5 alternately, and satisfies the shortage of the residential load from the power of commercial power reception.

In the evening, when the photovoltaic power generation current falls below a set value (for example, 1 A to 5 A), Id detects it and the control unit 10 gives the signal to the electromagnetic contactor M 1,
The AC power of the inverter / charger 3 is supplied to the residential load via the b contact of the electromagnetic contactor M1b. At that time, if excessive power is supplied to the residential load and the storage amount of the storage battery 1 becomes insufficient, Ed detects the voltage of the storage battery,
The control unit 10 activates the electromagnetic contactors M1, M2 and M3 to cut off the storage battery 1 from the inverter / charger 3 and the auxiliary inverter 2, and at the same time alternately sends a signal to the gate signal of the reverse transmission prevention thyristor 5 to receive commercial power. Supplies power to the residential load via the distribution board 6.

The power rate at 23:00 reaches the night rate of the hourly rate, and the inverter / charger 3
Shifts from the “inverter” to the “charger” and supplies DC power to the storage battery 1 to perform charging. At the same time, the control unit 10
Supplies an alternating signal to each gate of the thyristor 5A and the thyristor 5B of the reverse power transmission blocking thyristor circuit 5, and supplies commercial power to all of the residential loads via the distribution board 6.
When the storage of the storage battery 1 is monitored by Id and Eb detects that the charging is nearing completion, the control unit 10 commands the inverter / charger 3 being charged to slightly increase the voltage and completes the charging by the next morning. .

[0015]

As described above, the present invention promotes clean energy by utilizing solar power generation by using solar power generation in combination with late-night power storage, and also stores surplus power of late-night power by storing late-night power. It contributes to countermeasures. In addition, power consumers can effectively reduce the cost of electricity at home by effectively utilizing the low-price system of late-night power. The second invention has an effect that it can be used as an emergency power supply measure at the time of a power failure.

[Brief description of the drawings]

FIG. 1 is a system diagram of a combined photovoltaic power generation / midnight power storage system according to the first invention of the present application.

FIG. 2 is a system diagram of a combined photovoltaic power generation / midnight power storage system according to a second invention of the present application.

FIG. 3 is a system diagram of a known photovoltaic power generation system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage battery 2 Auxiliary inverter 3 Inverter and automatic charger 4 Solar cell array 5 Reverse power transmission prevention thyristor circuit 6 Distribution board 10 Synchronous operation and reverse power transmission control unit M1 Magnetic contactor M2 Magnetic contactor

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[Procedure amendment]

[Submission date] September 29, 2000 (2009.2)
9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

Hereinafter, a control mode of the household power supply system of the present invention will be described. Synchronous operation and reverse power transmission control unit 10
Detects the commercial power reception voltage Em at all times and supplies the signal to the inverter / charger 3, which obtains AC power synchronized with the commercial power reception voltage Em and shifts to the operation as the “inverter” In some cases, the commercial receiving voltage E
An AC voltage slightly higher (for example, 1 V) than m is output. In addition, the detection at the time of the interruption of the commercial received power is also enabled by the commercial received voltage Em.

Claims (2)

[Claims] 1. In the late night time zone, in principle, the storage battery is charged using the late night electric power via an inverter / automatic charger, and the residential electric power is supplied by commercial electric power. In the daytime photovoltaic power generation time period, when the photovoltaic power is equal to or higher than the set value, the power is sold to a power company via an inverter / automatic charger as surplus power. During the mid-hours between the midnight hours and the daytime solar power generation hours, the storage power of the storage batteries will be supplied as house power, and in the event of a shortage, it will be more than the commercial power from the power company. When the storage power of the storage battery is supplied as house power, a reverse power transmission prevention circuit composed of a parallel connection of a positive thyristor and a negative thyristor is interposed between the storage battery and the commercial power, and the stored power is converted to the commercial power. Reverse transmission is forcibly prevented. A home power supply system using a combination of photovoltaic power generation and midnight power storage, comprising the above means. 2. In the late night time zone, the storage battery is charged through the inverter / automatic charger using the late night power in principle, and the house power is supplied by commercial power. In the daytime photovoltaic power generation time period, when the photovoltaic power is equal to or higher than the set value, the power is sold to a power company via an inverter / automatic charger as surplus power. During the intermediate time between the late night time and the daytime solar power generation time, the storage power supplied from the storage battery through the auxiliary inverter is supplied as house power,
In the event of a shortage, it will be more than commercial power from the power company. When the storage power of the storage battery is supplied as house power, a reverse power transmission prevention circuit composed of a parallel connection of a positive thyristor and a negative thyristor is interposed between the storage battery and the commercial power, and the stored power is converted to the commercial power. Reverse transmission is forcibly prevented. Further, there is provided an instantaneous automatic switching means for switching to the stored power of the storage battery in the event of a commercial power failure. A home power supply system using a combination of photovoltaic power generation and midnight power storage, comprising the above means.