Anti-reverse power transmission control system of photovoltaic energy storage station

Abstract

The invention discloses a photovoltaic energy storage station reverse power transmission prevention control system which is characterized in that when a load (6) is started, electric energy output by a transformer (10) is consumed firstly, a forward and reverse electric energy meter (11) measures the electric quantity in the forward direction, and meanwhile a data acquisition controller (1) starts to detect the power consumed by the load (6) and sends a power generation output instruction to a photovoltaic inverter (3); and performing subtraction operation on the consumed power of the load (6) and the photovoltaic power generation power, when the consumed power of the load (6) is greater than the photovoltaic power generation power, judging whether the current period is a peak period or not, starting an energy storage inverter (8) to output electric energy when the current period is the peak period, and controlling the output power of the energy storage inverter (8) in real time. The output power data is kept to be equal to or slightly smaller than the difference between the power of the load (6) and the output power of the photovoltaic inverter (3), it is ensured that the transformer (10) outputs no electric energy or outputs a small amount of electric energy, and the purposes of photovoltaic power generation self-use and time-phased charging and discharging are achieved to reduce the power utilization cost are achieved. When the power of the load (6) is smaller than the output power of the photovoltaic inverter (3), the output of the energy storage inverter (8) is forbidden, the excess power output by the photovoltaic inverter (3) is reversely sent to the power grid (1), and the forward and reverse electric energy meter (11) meters the reverse electric energy to realize the photovoltaic excess power networking function.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic energy storage, and in particular to a photovoltaic energy storage station anti-reverse power transmission control system. Background Art

[0002] Photovoltaic power generation and battery energy storage have developed rapidly in my country in recent years. In order to reduce electricity costs, many companies have invested heavily in building large-scale photovoltaic power stations to meet their production needs. When there is surplus electricity generated, it is sent back to the power grid. The State Grid measures and purchases the reverse input electricity, realizing the self-generation and self-use of surplus electricity and connecting it to the grid. In order to reduce electricity costs, many companies have also invested heavily in building large-scale battery energy storage power stations, using the peak-valley price difference to store battery energy during flat and valley periods, and discharge during peak and peak periods to save electricity costs. They are also equipped with anti-reverse power transmission equipment to prevent electricity from being sent back to the power grid.

[0003] During the operation of a photovoltaic power station that generates electricity for its own use and connects the surplus power to the grid, the output power of the inverter depends on the intensity of sunlight. The output power changes with the increase or decrease of the light intensity. When the load power exceeds the power generation power, the power grid automatically makes up for the shortfall. When the load power is less than the power generation power, the excess power is sent back to the grid, achieving self-generation and self-consumption of surplus power connected to the grid to ensure maximum benefits.

[0004] During the operation of the battery energy storage power station, it is not allowed to buy electricity at a low price and sell it at a high price. An anti-backflow device must be equipped to prevent the occurrence of backflow. The working principle of the anti-backflow device is: real-time monitoring of load power data and using this power data as a basis to control the output power of the inverter. Its output power is always kept equal to or less than the load power to prevent the occurrence of backflow.

[0005] When some enterprises are equipped with both photovoltaic power stations and battery energy storage stations and connected to the grid for power transmission, the surplus electricity of the photovoltaic power stations is allowed to be fed back to the grid and generate income, but the battery power is not allowed to be fed back into the grid. This is because the positive and negative electricity meters cannot distinguish whether the reverse electricity comes from the surplus electricity of the photovoltaic power station or the electricity of the energy storage station. The reverse electricity generated by the enterprise cannot be settled. Currently, there is no corresponding system to solve this problem. Enterprises equipped with photovoltaic power stations and battery energy storage stations can only send the reverse photovoltaic electricity to the grid for nothing. Summary of the invention

[0006] In response to the above problems: the present invention provides a photovoltaic energy storage station anti-reverse power transmission control system that can effectively solve the above defects.

[0007] In order to achieve the above objectives, the present invention provides the following solutions: a photovoltaic energy storage station anti-reverse power transmission control system, which is mainly composed of a data acquisition control system and a power distribution system.

[0008] The data acquisition control system comprises: a data acquisition controller (1), a photovoltaic current transformer (4), a load current transformer (5), and an energy storage current transformer (7).

[0009] The power distribution system includes: a photovoltaic panel (2), a photovoltaic inverter (3), a load (6), an energy storage inverter (8), an energy storage battery (9), a transformer (10), a forward and reverse electric energy meter (11), and a power grid (12). BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the overall layout of the present invention. DETAILED DESCRIPTION

[0011] Combine the following Figure 1 The specific implementation of the present invention is described: 1. A photovoltaic current transformer (4) is installed on an output cable of a photovoltaic inverter (3), a load current transformer (5) is installed on an input cable of a load (6), an energy storage current transformer (7) is installed on an output cable of an energy storage inverter (8), and a forward and reverse electric energy meter (11) and a transformer (10) are installed on a high-voltage output busbar of a power grid (12) in sequence. A low-voltage output end of the transformer (10) is connected to an output end of the photovoltaic inverter (3), an output end of the energy storage inverter (8) and an input end of the load (6) respectively.

[0012] 2. The data acquisition controller (1) is provided with a signal input terminal, a control output terminal and a power input terminal, which are respectively connected to the photovoltaic current transformer (4), the load current transformer (5), the energy storage current transformer (7), the forward and reverse electric energy meter (11), the load (6), the photovoltaic inverter (3), the energy storage inverter (8) and the transformer (10).

[0013] The following is a detailed and complete explanation of the technical solutions and logical relationships in the embodiments of the present invention in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Other embodiments obtained by ordinary technicians in this field without making creative improvements all belong to the scope of protection of the present invention. The implementation of these functions is explained one by one in conjunction with the above drawings.

[0014] When the load (6) is started, the electric energy output by the transformer (10) is first consumed and the forward and reverse electric energy meters (11) measure the electric energy in the forward direction. At the same time, the data acquisition controller (1) starts to detect the power consumed by the load (6) and issues a power generation output instruction to the photovoltaic inverter (3). The power consumed by the load (6) and the photovoltaic power generation are subtracted. When the power consumed by the load (6) is greater than the photovoltaic power generation, it is first determined whether this time period is a peak period. If this is a peak period, the energy storage inverter (8) is started to output electric energy and the output power of the energy storage inverter (8) is controlled in real time. This output power data is kept equal to or slightly less than the load (6) power minus the output power of the photovoltaic inverter (3), ensuring that the transformer (10) has no power output or outputs a small amount of power, thereby achieving the purpose of self-use of photovoltaic power generation and time-divided charging and discharging to reduce electricity costs.

[0015] When the power of the load (6) is less than the output power of the photovoltaic inverter (3), the energy storage inverter (8) is prohibited from outputting, and the excess power output by the photovoltaic inverter (3) is reversely sent to the power grid (1), and the forward and reverse electric energy meters (11) measure the reverse electric energy to realize the function of connecting the photovoltaic surplus power to the grid.

Claims

1. A photovoltaic energy storage station anti-reverse power transmission control system, characterized in that The data acquisition control system comprises: a data acquisition controller (1), a photovoltaic current transformer (4), a load current transformer (5), and an energy storage current transformer (7).

2. A photovoltaic energy storage station anti-reverse power transmission control system according to claim 1, characterized in that: When the load (6) is started, the electric energy output by the transformer (10) is first consumed and the forward and reverse electric energy meters (11) measure the electric energy in the forward direction. At the same time, the data acquisition controller (1) starts to detect the power consumed by the load (6) and issues a power generation output instruction to the photovoltaic inverter (3). The power consumed by the load (6) and the photovoltaic power generation are subtracted. When the power consumed by the load (6) is greater than the photovoltaic power generation, it is first determined whether this time period is a peak period. If this is a peak period, the energy storage inverter (8) is started to output electric energy and the output power of the energy storage inverter (8) is controlled in real time. This output power data is kept equal to or slightly less than the load (6) power minus the output power of the photovoltaic inverter (3), ensuring that the transformer (10) has no power output or outputs a small amount of power, thereby achieving the purpose of self-use of photovoltaic power generation and time-divided charging and discharging to reduce electricity costs.

3. A photovoltaic energy storage station anti-reverse power transmission control system according to claim 1, characterized in that: When the power of the load (6) is less than the output power of the photovoltaic inverter (3), the energy storage inverter (8) is prohibited from outputting, and the excess power output by the photovoltaic inverter (3) is reversely sent to the power grid (1), and the forward and reverse electric energy meters (11) measure the reverse electric energy to realize the function of connecting the photovoltaic surplus power to the grid.

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