JP-7855301-B2 - Solar power generation system

JP7855301B2JP 7855301 B2JP7855301 B2JP 7855301B2JP-7855301-B2

Inventors

氏橋和之

Assignees

日東工業株式会社

Dates

Publication Date: 20260508
Application Date: 20220517

Claims (3)

A solar power generation system comprising a load that consumes electricity, a commercial power source capable of supplying commercial power to the load, a solar cell capable of supplying generated solar power to the load and a storage battery, and a storage battery capable of supplying the charged power to the load, It is equipped with a calculation unit capable of calculating a switching index value , which is the value obtained by dividing the generated solar power by the total power consumption. A solar power generation system that controls the system to start the battery charging mode when the switching indicator value is equal to or greater than threshold A, and to start the battery discharging mode when the switching indicator value is less than threshold B , which is lower than threshold A. (However, total power consumption is calculated as "load power consumption - battery discharge power" or "load power consumption + battery charging power.")
A solar power generation system comprising a load that consumes electricity, a commercial power source capable of supplying commercial power to the load, a solar cell capable of supplying generated solar power to the load and a storage battery, and a storage battery capable of supplying the charged power to the load, It is equipped with a calculation unit capable of calculating a switching index value, which is the value obtained by dividing the total power consumption by the amount of solar power generated. A solar power generation system that controls the system to start the battery charging mode when the switching indicator value is less than threshold A, and to start the battery discharging mode when the switching indicator value is greater than or equal to threshold B, which is higher than threshold A. (However, total power consumption is calculated as "load power consumption - battery discharge power" or "load power consumption + battery charging power.")
The control unit for solar power generation can set a correction value used to suppress the output of solar power to the load. The calculation unit can determine the amount of power to be sent from the solar panel to the load at regular intervals, based on the status of solar power generation and load power consumption at regular intervals, and a set correction value, so that the amount of power sent from the solar panel to the load does not exceed the load's power consumption . The solar power generation system according to claim 1 or 2 , wherein the amount of charge and discharge is determined based on the result of a calculation performed by the calculation unit on "load power consumption - (solar power generation power / correction value)" .

Description

This invention relates to a solar power generation system. As described in Patent Document 1, a solar power generation system that supplies solar power (PV power) to a storage battery and load is known. In such a solar power generation system, the charging and discharging of the storage battery was controlled based on the battery voltage or at a preset time. Japanese Patent Publication No. 2014-143784 With this control system, even in good weather conditions where PV power was being generated in large quantities, the battery sometimes did not charge. Conversely, even in bad weather conditions where PV power was being generated very little, the battery power sometimes did not discharge to the load. In other words, depending on the weather and power consumption at the load, the PV power and the power stored in the battery were sometimes not used effectively, resulting in inefficiency. This is a block diagram of a photovoltaic power generation system in one embodiment.This figure shows an example of the change in the switching index value and the corresponding change in the amount of charge. Note that the switching index value here is the value obtained by dividing the generated solar power by the total power consumption.This figure shows an example of the change in the switching index value and the corresponding change in discharge amount. Note that the switching index value here is the value obtained by dividing the generated solar power by the total power consumption.This is a flowchart illustrating an example of a solar power generation system in operation.This diagram shows the metal box of the battery PCS connected to the cubicle-type high-voltage power receiving equipment. The following describes embodiments for carrying out the invention. As can be understood from Figure 1, this embodiment is a solar power generation system 1 connected to a load 11 that consumes power, a commercial power supply 12 that can supply commercial power to the load 11, a solar cell 14 that can supply generated solar power to the load 11 and a storage battery 13, and a storage battery 13 that can supply the charged power to the load 11. The system also includes a calculation unit 15 that can calculate a switching index value representing the difference between generated solar power and total power consumption. The system controls the charging mode of the storage battery 13 to start when the switching index value is greater than or equal to threshold A, and controls the discharging mode of the storage battery 13 to start when the switching index value is less than threshold B, which is lower than threshold A. Alternatively, the system controls the charging mode of the storage battery 13 to start when the switching index value is less than threshold A, and controls the discharging mode of the storage battery 13 to start when the switching index value is greater than or equal to threshold B, which is higher than threshold A, thereby enabling the use of commercial power to be suppressed. (However, the total power consumption is either "power consumption of load 11 - discharge power of battery 13" or "power consumption of load 11 + charging power of battery 13.") Therefore, power control can be performed according to the situation of PV power generation and power consumption at load 11. Furthermore, by using two thresholds, a certain time interval can be secured between the start of charging and the start of discharging, preventing repeated charging and discharging in short periods, thereby suppressing degradation and failure of the battery 13. Thus, in a solar power generation system 1 equipped with a battery 13, it becomes possible to efficiently charge and discharge the battery 13. Note that when the battery 13 is neither charging nor discharging, the power consumption of load 11 becomes the total power consumption. In the solar power generation system 1 shown in Figure 1, a solar power conditioner 18 (PV PCS) is connected to the solar cell 14. The solar power conditioner 18 is capable of converting DC solar power to AC. Furthermore, the solar power conditioner 18 is connected to a solar power control unit 16 (PV control unit), and the solar power controlled by the solar power control unit 16 can be output to the load 11 and the battery 13. The solar power control unit 16 may also be located inside the solar power conditioner 18. In this example, the switching index value is calculated by dividing the generated solar power by the total power consumption. The solar power generation control unit 16 is configured to initiate the charging mode of the battery 13 when the switching index value is equal to or greater than threshold A (see Figure 2). Furthermore, in the solar power generation system 1 shown in Figure 1, a battery power conditioner 19 (battery PCS) is connected to the battery 13. The battery power conditioner 19 is capable of converting DC discharge power from the battery 13 to AC, and also converting AC charging power t