JPS60256824A - Controller of solar power generating system - Google Patents

Abstract

PURPOSE:To ensure the stable supply of electric power to a system by using a command device consisting of a mode selection switch, a memory circuit, etc. and carrying out the charge/discharge control and the night charging control of a storage battery based on the output of said command device. CONSTITUTION:A command device 21 consists of a mode selection switch for selection of modes of sunshine variation, a memory circuit which stores both upper and lower limit power commands for supply to a system as well as a command for final holding power amount, etc. A voltage setter 8 sets the voltage of an optimum working point, and a voltage control circuit 9 controls the ignition phase of an inverter 5 so that the output voltage of a solar battery 1 is equal to said voltage at an optimum working point and then controls the electric power to be supplied to a system 6. In this case, the output of the inverter 5 is controlled by the lower and upper power commands delivered from the device 21. This secures the stable supply of power. Furthermore the night charging is also controlled by a command for final holding power amount given from the device 21. In such a way, the stable supply of power is secured to the system 6 by means of the device 21.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a photovoltaic power generation system that supplies power generated by a solar cell to a power grid (herein also simply referred to as a grid), and particularly relates to a solar power generation system that supplies power generated by a solar cell to a power grid (herein also simply referred to as a grid), and particularly relates to a system for stabilizing the supplied power. The present invention relates to a control device for achieving

[Prior art]

The maximum value of power that can be extracted from solar cells varies with changes in solar radiation. On the other hand, it is desirable that the power supply to the grid matches the load pattern and that it does not fluctuate as much as possible.

For this reason, storage batteries are provided to store excess power from the power generated by solar cells and to make up for the shortage when the power generated is insufficient. However, due to installation space and cost considerations, the number or capacity of storage batteries must be minimized.

In this case, unless the power supplied to the grid is properly adjusted in response to fluctuations in the amount of solar radiation, that is, fluctuations in the output of the solar cells, the storage battery will not be overcharged or overdischarged, and as a result, power to the grid will not be stably supplied.

On the other hand, there is a solar system that not only stores surplus power from solar cells, but also stores surplus power from the grid at night, and supplies it to the grid during the day along with the output of the solar cells. .

In such a power generation system, if the final amount of power stored in the storage battery is not properly determined when charging at night, overcharging and overdischarging cannot be reliably prevented in relation to the power supplied to the grid. Therefore, it was possible to have a stable power supply at all times.

[Summary of the invention]

The present invention was made in consideration of the above circumstances, for example,
An upper limit power command that classifies solar radiation fluctuations into several mode patterns and calculates in advance the optimal permissible fluctuation range of power supplied to the grid according to each mode and the final amount of power held by the storage battery during nighttime charging, and then supplies the power to the grid. , store the lower limit power command and the final power reserve command, read out these commands with a simple operation such as selecting the above mode, and charge and charge the storage battery based on the upper limit power command and the lower limit power command.
This invention proposes a control device for a solar power generation system that can stably supply power to the grid by controlling discharge and controlling nighttime charging of storage batteries based on the final power consumption command.O [Invention] [Embodiment] 7.1 Figure 1 is a diagram showing the configuration of an embodiment of the present invention, in which a solar cell (1) and a storage battery (2) are connected to each other for charging and charging the storage battery (2). A charge/discharge control device (8) for controlling the discharge current is provided, and a solar cell (1) is provided between the solar cell (1) and the power system bus (hereinafter simply referred to as the system) (6).
An inverter (5) is provided that converts the DC output of the storage battery (2) and the storage battery (2) into alternating current and supplies it to the grid (6). (2) A nighttime charging control device (1 type) is provided to store the battery.

Here, the charge/discharge control device (8) is a discharge chopper (4a
), a charging chopper (4b), a power detector (10) that detects the power supplied to the grid (6), and a deviation amplifier (1
2a).

(12b) and limiters (13a) and (13b), and based on the output signal of the power detector α0) and the upper limit power command AH1 and lower limit power command of the command device (21), which will be described later, a discharge chopper (4a), Charging chopper (4b)
In addition, the inverter (5) is connected to a voltage detector (γ) that detects the terminal voltage of the solar cell (1), and a power limit control circuit that controls the solar cell (1). A power converter is configured with a voltage setting device (8) that sets the optimum operating voltage of the battery (1), and a voltage control circuit (9) that adjusts the firing phase of the inverter (5) based on the output signals of both of them. are doing.

Furthermore, the nighttime charging control device (141 is a storage battery (2
); a power measuring circuit (company) that measures the amount of power held by the storage battery (2) based on the output signal of the power detector (15); Setting device (1), power control circuit (e) and operation command circuit (2)
Denari' power detector (to)), power measurement circuit (sha),
A command device (nighttime charging control circuit α6 that inputs the final power amount command 211 and controls the nighttime charging control device (1→)) constitutes a nighttime charging control section.

On the other hand, the command device (21), as shown in FIG. It consists of an output port and a digital-to-analog converter (hereinafter referred to as an A/P converter) that converts these signals into analog signals and outputs them.

The operation of this embodiment configured as described above is shown in Fig. 2, which shows daily solar radiation fluctuations, amount of supplied power, etc., and Fig. 4, which shows several modes of solar radiation fluctuations, and the correspondence to these modes. The following description also refers to FIG. 5, which is a diagram of precalculated commands.

First, solar power varies significantly depending on the amount of solar radiation and operating voltage, but the optimal operating point voltage at which maximum output is obtained hardly changes regardless of the amount of solar radiation. The voltage setting device (8) sets this optimum operating point voltage, and the voltage control circuit (9) sets the point of the inverter (6) so that the output voltage of the solar cell (1) becomes this optimum operating point voltage. Adjust the arc phase to create a system (6
). However, solar cells (1)
is operated near the optimum operating point.

Now, when the output of the inverter (5) becomes smaller than the lower limit power command AL output from the command device (21), the deviation amplifier (1) of the power control circuit 01) is set so that the deviation becomes zero.
2a) and the limiter (13a), the discharge chopper (4a) of the charge/discharge control device (8) operates to supply power for the deviation from the storage battery (2), and the power supplied to the grid reaches the lower limit. It is held at the value of power command AL.

On the other hand, when the output of the inverter (5) becomes larger than the upper limit power command AH output from the command device (21), the deviation amplifier (+ to 12) and limiter (1, 3b) work again. Then, the charging chopper (4b) of the charging/discharging control device (8) operates to charge the storage battery (2) with the power corresponding to the deviation, and the power supplied to the grid is maintained at the upper limit power command value. be done.

Figures 2 (a) to (c) show this relationship, assuming that the power generated by the solar cell (1) changes as shown in Figure 2 (a) as the solar radiation changes on -day. When the lower limit power command AL and the upper limit power command AH corresponding to the permissible variation range of power supply are output in the same figure (b
), the minimum power is always guaranteed during the day, and the maximum power is also held to a constant value, thereby ensuring a stable supply of power.

Next, here, surplus power of the grid during the night is stored in the storage battery (2) via the nighttime charging control device (14). =,'! ,,.

In this case, the charging power and discharging power of the storage battery (2) are detected by the power detector (■), and the detected value and the output of the setting device (17) that sets the charging power are sent to the power control circuit (E).
, and this power control circuit (g) controls the nighttime charging control device o→ so as to reduce the deviation to zero, so that constant power charging is performed.

On the other hand, the amount of power held by the storage battery (2) is determined by the power detector (b).
(2) As a result of the electric energy measurement circuit integrating the output of (2), this retained electric energy signal is taken into the operation command circuit α mark.

The operation command circuit 09) uses this signal and the command device it'
The final power amount command output from +211. When the two become equal, a signal is given to the power command circuit (4) to stop charging at night.

FIG. 2(d) shows the state of change in the amount of power held by the storage battery (2).During the daytime 1, at the time when power supply by the solar cell is started, the final amount of power held is commanded. is charged to the value corresponding to .

In this way, the surplus power at night can be utilized, and the degree of operational freedom is increased because the battery is charged to a desired level at night to supplement charging and discharging only during the daytime, which is subject to many uncertainties.

Next, the storage circuit example of the command device (21) stores the pre-calculated optimal level lower limit power command A1, upper limit power command, and final possessed power amount command D0.

In general, the amount of solar radiation that determines the output of a solar cell may cause the storage battery to over-discharge or over-charge if the solar cell is exposed to sunlight. Therefore,
As shown in the chart shown in Figure 5, solar radiation modes A, B, C-a
・The upper limit power command A1 (the lower limit power command AL and the final power consumption command) are calculated in advance and stored in the storage circuit next to each other, and the appropriate mode selection switch is selected depending on the weather forecast, etc. When you manipulate (goods),
The optimum data is read out from the storage circuit 128), D/A converted by the output capacitor 11241, and applied to the power limit control circuit 01) and the night charging control circuit (16).

In the above embodiment, the mode (i-memorized) based on the daily solar radiation model is used, but each mode may be modified or modified as necessary.
If command data for change modes (for example, AB mode) are also stored, more stable power supply becomes possible.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, for example, by specifying the solar radiation fluctuation mode, the allowable range of power supplied to the grid and the final amount of power stored in the storage battery are completed, and the lighting There is a command device that reads out the upper limit power command, lower limit mental force command, and final power sweep command, and charge/discharge control of the storage battery and nighttime charging control are performed based on the output of this command device, so the installed capacity of the storage battery can be kept relatively low. Even when the power is reduced, the effect is that power can be stably supplied to the grid.

Furthermore, according to the present invention, automatic operation and remote control are extremely easy because the operator only has to select a mode.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIGS. 2(a) to 2(d) are time charts showing the state of electric power and electric current power in order to explain the operation of the embodiment. Chart, FIG. 3 is a block diagram showing the detailed configuration of the main parts of the same embodiment,
FIG. 4 is a solar radiation mode diagram for explaining the operation of the embodiment, and FIG. 5 is a chart showing stored data of the main elements of the embodiment. (1)...Solar battery (2)...Storage battery (8)...Charging...
Discharge control device (6)...Inverter (6)...Power system bus (10)
) l■)・Fist power detector (1η・Medium power limit control circuit (14)・・Night charging control device (16)・・Night charging control circuit (company)・・Electric power measurement circuit (23)・・Command Equipment agent Masuo Oiwa 5.1 Figure 1 Figure 2 Figure 3 Figure 2.5 Figure 4 Clause 5' Procedural amendment (voluntary) Kuchisawa 5 prefectures October 26th 2, Name of invention Solar power generation System control device 3. Representative of the person making the amendment: Hitoshi Katayama (and one other person) 5. Scope of claims of the specification to be amended. 6. Scope of claims of the specification to be amended. Amend the description as shown in the attached sheet. 7. Document stating the scope of claims after the amendment to the list of attached documents 1 or more Documents stating the scope of claims after amendment In a solar power generation system, power is supplied to the power supply system, surplus power to the specified power supply is stored in a storage battery, and insufficient power is supplied from the storage battery, and power is obtained from the grid at night and stored in the storage battery. A command device that reads an upper limit power command, a lower limit power command, and a final power amount command of the storage battery from a storage device that is stored in advance, and electric power that is supplied to the grid based on the upper limit power command and lower limit power command of this command device. a charging/discharging control unit that stores a part of the output of the solar cell in the storage battery when the output exceeds a permissible fluctuation range, and applies the power of the storage battery to the power conversion unit when the output falls below the permissible fluctuation range; The system includes a retained power calculating means for calculating the amount of electric power, and uses the grid power to the storage battery at night until the retained electric power of the storage battery reaches the final retained electric power amount based on the retained electric power signal and the final retained electric power command of the command device. A control device for a photovoltaic power generation system, characterized in that it is equipped with a nighttime charging control unit that stores data in the solar cell. The upper limit power command can be set by selecting the solar radiation pattern mode.
2. The control device for a solar power generation system according to claim 1, wherein the control device is configured to read a lower limit power command and a final power amount command.

Claims (1)

[Claims] (1) The power generated by the solar cells is supplied to the grid, and the excess power for the specified supply power is stored in a storage battery, the insufficient power is supplied from this storage battery, and the power is obtained from the grid at night and stored in this storage battery. In solar power generation systems,
A storage device that stores in advance an upper limit power command, a lower limit power command, and a final power amount command of the storage battery to be supplied to the grid by setting an allowable fluctuation range of power to be supplied to the grid and a final power amount of the storage battery. When the power supplied to the grid exceeds the allowable fluctuation range, a part of the output of the solar cell is stored in the storage battery based on the upper limit power command and lower limit power command of this command device. a charging/discharging control unit that applies the power of the storage battery to the power conversion unit when the storage battery falls out of range, and a retained power calculation means that calculates the amount of retained power of the storage battery, and includes a retained power signal and the final retained power of the command device. A control device for a solar power generation system, comprising: a night charging control unit that stores grid power in the storage battery at night until the amount of power held in the storage battery reaches the final amount of power held in the storage battery based on a power amount command. C2) The command device classifies various solar radiation patterns into modes and has a storage device that stores calculated values for each mode, and outputs an upper limit power command by selecting a solar radiation pattern mode.
2. The control device for a solar power generation system according to claim 1, wherein the control device is configured to read a lower limit power command and a final power amount command.