CN114400754A - Centralized charging system and method for photovoltaic energy storage micro-grid - Google Patents

Abstract

The invention relates to a centralized charging system and a centralized charging method for a photovoltaic energy storage microgrid, which comprise a photovoltaic charger, a shunt distribution device, a power detection device and a system controller, wherein the photovoltaic charger is connected with the shunt distribution device; the photovoltaic charger is used for receiving power supply of the photovoltaic input and is connected to the shunt distribution equipment; the branch distribution equipment is connected with a plurality of loads, and each load branch is provided with one power detection equipment; the system controller acquires the actual power capacity of the photovoltaic charger and different actual power of each load in real time, and controls the shunt distribution equipment according to the actual power capacity and the different actual power of each load so as to adjust the working time of each load. The centralized charging system and the centralized charging method for the photovoltaic energy storage microgrid overcome the defects that the power supply system of the conventional photovoltaic charger cannot adjust the load due to the fact that the actual load power changes, and the photovoltaic input electric energy cannot be adjusted, so that the electric energy is wasted, and the service efficiency of the photovoltaic energy storage system is improved.

Description

Centralized charging system and method for photovoltaic energy storage microgrid

technical field

The invention relates to a photovoltaic charger power supply system, in particular to a centralized charging system and method for a photovoltaic energy storage microgrid.

Background technique

At present, the charging mode of many photovoltaic energy storage power stations is to convert the photovoltaic inverter into direct current to charge the battery, and the concentrated power converts the photovoltaic direct current into alternating current through the inverter. Charge different battery clusters. Allocated power and battery charging time are fixed, which makes it ineffective when the actual power of different loads (inverters and battery clusters) changes or due to changes in the rated output power capacity of the photovoltaic charger. The backup usage time of the load (inverter and battery cluster) can be controlled locally, and the power adjustment cannot be performed, resulting in waste of power and greatly reducing the use efficiency of the photovoltaic charger.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a centralized charging system and method for a photovoltaic energy storage microgrid that can solve the problem that the electric energy generated by photovoltaics cannot be reasonably distributed and utilized in the existing power supply mode.

A centralized charging system for a photovoltaic energy storage microgrid, comprising a photovoltaic charger, a shunt power distribution device, a power detection device and a system controller; the photovoltaic charger is used to receive power input from photovoltaics, and is connected to the branch circuit power distribution equipment; the shunt power distribution equipment is connected to multiple loads, and a power detection device is installed on each load branch; the system controller obtains the actual power capacity of the photovoltaic charger and the power of each load in real time. Different actual power, and use this to control the shunt power distribution equipment to adjust the working time of each load.

Further, the system controller sets the priority of each load, and is used to adjust the cut-off time and sequence of each load according to the priority when the actual power capacity of the photovoltaic charger is insufficient.

Further, when there are multiple system controllers, they are connected in parallel with each other and backup each other.

Further, the system controller includes a communication interface, a hardware circuit, a CPU processor, an output control interface and a control function module; the communication interface is connected with a photovoltaic charger and a power detection device to obtain the actual power capacity and each load respectively. The different actual power of the device; the CPU processor and the control function module receive the data signal from the communication interface, and after processing, output to the output control interface through the hardware circuit; the output control interface is connected with the branch power distribution equipment to control the branch power distribution The action of each load on the equipment disconnecting the relay.

A centralized charging method for photovoltaic energy storage microgrid, comprising the following steps:

The system controller obtains the actual power capacity of the photovoltaic charger and the different actual power of each load in real time;

The system controller calculates the backup time of each load according to the actual power capacity and different actual power;

The system controller controls the backup time of each load through the shunt power distribution device according to multiple load priority relationships.

其中P1为每个负载的实际功率，P0为每个负载的额定功率，T0为每个负载额定的后备工作时间。Further, the load backup time

Among them, P1 is the actual power of each load, P0 is the rated power of each load, and T0 is the rated backup working time of each load.

The above-mentioned centralized charging system and method of photovoltaic energy storage microgrid overcomes the shortage of power waste caused by the fact that the load of the photovoltaic charger power supply system cannot be adjusted after the load is changed due to the change of the actual power of the load, and the photovoltaic input electric energy cannot be adjusted. problems and improve the efficiency of photovoltaic energy storage systems.

Description of drawings

Figure 1 is a schematic diagram of a centralized charging system;

Fig. 2 is the structural representation of the system controller;

Fig. 3 is the working logic flow schematic diagram of the system controller;

4 is a schematic diagram of a photovoltaic charger;

FIG. 5 is a schematic diagram of a shunt power distribution device.

In the figure: 100, photovoltaic charger; 200, shunt power distribution equipment; 300, power detection equipment; 400, system controller.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in FIG. 1, in one embodiment, a centralized charging system for a photovoltaic energy storage microgrid includes a photovoltaic charger 100, a shunt power distribution device 200, a power detection device 300 and a system controller 400; photovoltaic charging The charger 100 is the energy provider of the charging system, which is used to receive the power input from the photovoltaic and is connected to the shunt power distribution equipment 200. The structure of the photovoltaic charger 100 is shown in FIG. The example does not describe the details in the figure; the shunt power distribution device 200 is connected to multiple loads (battery clusters and inverters), and a power detection device 300 is installed on each load shunt. The structure of the shunt power distribution device 200 As shown in FIG. 5 , also because it is the prior art, this embodiment does not specifically describe the details in the figure; the system controller 400 is the core part of the charging system, and is used to obtain the actual power capacity of the photovoltaic charger 100 in real time. and the different actual power of each load, and use this to control the shunt power distribution device 200 to adjust the working time of each load.

In this embodiment, the system controller 400 sets the priority of each load, and is used to adjust the cut-off time and sequence of each load according to the priority when the actual power capacity of the photovoltaic charger 100 is insufficient.

In the present embodiment, when there are multiple system controllers 400, they are connected in parallel with each other and serve as backups for each other. to increase safety performance.

As shown in FIG. 2, in this embodiment, the system controller 400 includes a communication interface, a hardware circuit, a CPU processor, an output control interface and a control function module; the communication interface is connected to the photovoltaic charger 100 and the power detection device 300, Obtain the actual power capacity and the different actual power of each load respectively; the CPU processor and the control function module receive the data signal from the communication interface, and after processing, output to the output control interface through the hardware circuit; the output control interface and the shunt power distribution equipment 200 The connection is used to control the action of each load cut-off relay on the shunt power distribution device 200 .

As shown in FIG. 3 , the system controller 400 accepts the actual backup power capacity reported by the photovoltaic charger 100 in real time, and calculates the backup working time of each load according to the actual power of different shunt loads, and flexibly adjusts the backup working time according to the load priority. For the backup time, the load AC element in the shunt power distribution equipment 200 is controlled to realize the free adjustment of the backup working time, so as to achieve the purpose of maximizing the utilization of photovoltaic power.

On the basis of the centralized charging system of the photovoltaic energy storage microgrid, the present embodiment also proposes a centralized charging method for the photovoltaic energy storage microgrid, which includes the following steps:

In step S110, the system controller 400 acquires the actual power capacity of the photovoltaic charger 100 and the different actual powers of each load in real time. For subsequent power distribution.

其中T1为负载的实际后备工作时间，P1为负载当前的实际功率，P0为负载的额定功率，T0位负载额定的后备工作时间。例如，假设光伏充电器100某路负载的额定设计功率规格为5KW，后备时间为1小时，而现在该负载实际的功率是2.5KVA，该系统控制器400可以将该负载的后备时间调整到2小时，以充分利用充电器分配电能的目的。In step S120, the system controller 400 calculates the backup time of each load according to the actual power capacity and different actual powers. When the output power of the photovoltaic charger 100 is normal, the formula for calculating the load backup time control by the system controller 400 is:

Among them, T1 is the actual backup working time of the load, P1 is the current actual power of the load, P0 is the rated power of the load, and T0 is the rated backup working time of the load. For example, assuming that the rated design power specification of a certain load of the photovoltaic charger 100 is 5KW, the backup time is 1 hour, and now the actual power of the load is 2.5KVA, the system controller 400 can adjust the backup time of the load to 2 hours, in order to make full use of the charger for the purpose of distributing electric energy.

In step S130, the system controller 400 controls the backup time of each load through the shunt power distribution device 200 according to a plurality of load priority relationships. When there is a conflict between the remaining photovoltaic input power and the maximum distributed power of the load, the system controller 400 controls different loads according to preset priorities to perform protection and disconnection in a certain safe order, so as to protect the charger and maximize its energy. Excellent use.

The above-mentioned centralized charging system and method for photovoltaic energy storage microgrid overcomes the problem that the power supply system of photovoltaic charger 100 cannot adjust the working time after the load caused by the change of the actual power of the load, and the photovoltaic input electric energy cannot be adjusted, resulting in waste of electric energy. Insufficient problem, improve the efficiency of photovoltaic energy storage system.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (6)

1. a centralized charging system of photovoltaic energy storage microgrid, it is characterized in that, comprise photovoltaic charger, shunt power distribution equipment, power detection equipment and system controller; Described photovoltaic charger is used for receiving the power supply of photovoltaic input, and connected to the shunt power distribution equipment; the shunt power distribution equipment is connected to multiple loads, and a power detection device is installed on each load shunt; the system controller obtains the actual power of the photovoltaic charger in real time The capacity and the different actual power of each load are used to control the shunt power distribution equipment to adjust the working time of each load. 2. The centralized charging system of the photovoltaic energy storage microgrid according to claim 1, wherein the system controller is set with a priority of each load, for when the actual power capacity of the photovoltaic charger is insufficient, Adjust the cut-off time and sequence of each load according to the priority. 3 . The centralized charging system for photovoltaic energy storage microgrids according to claim 1 , wherein when there are multiple system controllers, they are connected in parallel with each other and serve as backups for each other. 4 . 4 . The centralized charging system for photovoltaic energy storage microgrid according to claim 1 , wherein the system controller comprises a communication interface, a hardware circuit, a CPU processor, an output control interface and a control function module; the communication The interface is connected with the photovoltaic charger and power detection equipment to obtain the actual power capacity and the different actual power of each load respectively; the CPU processor and the control function module receive the data signal from the communication interface, and after processing, output to the output control through the hardware circuit Interface; the output control interface is connected with the shunt power distribution equipment, and is used to control the action of each load cut-off relay on the shunt power distribution equipment. 5. A centralized charging method for photovoltaic energy storage microgrid, characterized in that, comprising the following steps: The system controller obtains the actual power capacity of the photovoltaic charger and the different actual power of each load in real time; The system controller calculates the backup time of each load according to the actual power capacity and different actual power; The system controller controls the backup time of each load through the shunt power distribution device according to multiple load priority relationships. 6 . The centralized charging method for photovoltaic energy storage microgrid according to claim 5 , wherein the load backup time

Among them, P1 is the actual power of each load, P0 is the rated power of each load, and T0 is the rated backup working time of each load.

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