Low-voltage area photovoltaic cluster batch control system and method

Abstract

The present application relates to a kind of low-voltage area photovoltaic cluster batch control systems, including dispatching main station, edge side proxy substation, field controllable equipment: the edge side proxy substation is communicated with field controllable equipment by downlink communication mode, the operating state of field controllable equipment is collected, power, and sends it to send switch-off, switch-on instruction, switch-off instruction removes field controllable equipment, switch-on instruction will field controllable equipment be connected to grid;The edge side proxy substation is communicated with dispatching main station by uplink communication mode, and sends the total power of area, the number of photovoltaic switches that area has been put into, area photovoltaic total power, photovoltaic power actual cut-off value, and accepts photovoltaic power cut-off target value issued by dispatching main station.The present application reduces the decision-making amount of dispatching main station, and can balance the cut-off times of each photovoltaic user, guarantee the fairness of each photovoltaic user to accept dispatching control.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of low-voltage area photovoltaic cluster control, and particularly relates to a low-voltage area photovoltaic cluster batch control system and method. BACKGROUND

[0002] Distributed photovoltaic grows rapidly, leading to increasing pressure of local power distribution network consumption and grid-connected service, and bringing power quality problems such as voltage and harmonic, and power balance problem, which has an impact on safe and stable operation of power distribution network, operation and maintenance management and safety of maintenance work. It is a great challenge to realize effective monitoring and control of a large number of distributed photovoltaic. At present, the management of 10 / 35kV distributed photovoltaic grid connection has been strengthened in various places. However, for 380 / 220V photovoltaic in low-voltage area, the current monitoring is only through the marketing meter data to the marketing master station, and then to the dispatching master station, without control means. Considering the growing trend of low-voltage area photovoltaic, it is necessary to strengthen the monitoring to ensure the safe and stable operation of the power grid and promote the coordinated development of the power grid and distributed power. SUMMARY

[0003] Therefore, the present application aims to provide a low-voltage area photovoltaic cluster batch control system and method to solve the above problems.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] A low-voltage area photovoltaic cluster batch control system, comprising a dispatching master station, an edge-side proxy substation and a field controllable device; the edge-side proxy substation communicates with the field controllable device through a downlink communication mode, collects the running state and power of the field controllable device, and sends a disconnecting command and a closing command to the field controllable device; the disconnecting command disconnects the field controllable device, and the closing command connects the field controllable device to the grid; the edge-side proxy substation communicates with the dispatching master station through an uplink communication mode, and uploads the total power of the area, the number of photovoltaic switches put into the area, the total power of photovoltaic in the area, and the actual cut-off value of photovoltaic power, and accepts the target value of photovoltaic power cut-off issued by the dispatching master station.

[0006] Further, the dispatching master station is arranged in a power grid dispatching department; the dispatching master station visually displays a low-voltage area topology structure diagram; a list is arranged beside the topology structure diagram to describe the overview of the area, including the total power of the area, the number of photovoltaic switches put into the area, the total power of photovoltaic in the area, the target value of photovoltaic power cut-off, and the actual cut-off value of photovoltaic power; right-clicking on the specific numerical value of the total power of the area and the total power of photovoltaic in the area calls out a function menu, and the function menu contains a power curve option; selecting the power curve option obtains a power curve to display the current and historical power values.

[0007] Further, the field controllable device is a photovoltaic grid-connected switch installed at a photovoltaic grid-connected point.

[0008] Furthermore, the edge-side proxy substation is set at the distribution transformer in the substation area, and can collect data such as the low-voltage side voltage and current of the distribution transformer to calculate the total power of the substation area.

[0009] A control method for a low-voltage photovoltaic cluster batch control system includes the following steps:

[0010] The edge-side proxy substation sorts each field-controllable device;

[0011] Initialize the historical number of times each field controllable device has been cut off;

[0012] When the edge-side proxy substation receives the photovoltaic power removal target value issued by the dispatching master station, the strategy performs analysis and calculation to determine the on-site controllable devices that need to be removed;

[0013] After calculating the N field-controllable devices that need to be disconnected, the edge-side proxy substation sends a trip command to them. After the execution is completed, the total power of the N field-controllable devices is used as the actual PV power disconnection value and sent to the dispatch master station. At the same time, the new total power of the substation, the number of PV switches already in use in the substation, and the total PV power of the substation are also sent.

[0014] The historical number of times the N field controllable devices have been removed is increased by 1, and the new historical number of times the devices have been removed is used as the sorting basis for the batch control strategy to calculate the field controllable devices that need to be removed next time;

[0015] The command of the dispatching master station to release the photovoltaic power removal in the substation is also issued through the photovoltaic power removal target value, which is 0;

[0016] When the edge-side proxy substation receives a PV power removal target value of 0 from the dispatching master station, it issues a closing command to the controlled field devices to be removed. After the command is executed, the actual PV power removal value of 0 is transmitted to the dispatching master station, along with the new total power of the substation, the number of PV switches in operation in the substation, and the total PV power of the substation.

[0017] Furthermore, the order is based on the number of times the history is cut off. The more times the history is cut off, the lower the order.

[0018] Furthermore, the number of historical removals is set to 0; since the number is 0, the strategy can arbitrarily sort the field controllable devices; when a new field controllable device is connected to the power grid, the number of historical removals of the field controllable device is set to 0 and added to the sorting with other field controllable devices.

[0019] Further, the N preceding field controllable devices are cut off, so that the power sum of the N preceding field controllable devices is greater than or equal to the photovoltaic power cut-off target value, and the power sum of N-1 preceding field controllable devices is less than the photovoltaic power cut-off target value.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] 1、The present application dispatches and controls the transformer area as a whole, and coordinates and controls the photovoltaic through the edge side proxy substation in the transformer area, thereby reducing the decision calculation amount of the dispatch master station.

[0022] 2、The present application can balance the cut-off times of each photovoltaic user, and guarantee the fairness of the photovoltaic users receiving dispatch control. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic diagram of the system architecture of the present application. DETAILED DESCRIPTION

[0024] The present application will be further described below in combination with the drawings and embodiments.

[0025] Please refer to Figure 1 The present application provides a low-voltage transformer area photovoltaic cluster batch control system, which comprises a dispatch master station, an edge side proxy substation and field controllable devices.

[0026] The dispatch master station is arranged in the power grid dispatch department; the dispatch master station can visually display a low-voltage transformer area topology structure diagram; the topology structure diagram describes the overview of the transformer area in the form of a list, including the total power of the transformer area, the number of photovoltaic switches put into the transformer area, the total photovoltaic power of the transformer area, the photovoltaic power cut-off target value, the actual photovoltaic power cut-off value, right-clicking on the specific numerical values of the total power of the transformer area and the total photovoltaic power of the transformer area, calling out a function menu, the function menu containing a power curve option, selecting the power curve option, and obtaining a power curve to display the current and historical power values.

[0027] The field controllable device is a photovoltaic grid-connected switch installed at the photovoltaic grid-connected point.

[0028] The edge side proxy substation is arranged at the transformer substation of the transformer area, and can collect data such as the low-voltage side voltage and current of the transformer substation to calculate the total power of the transformer area. The edge side proxy substation communicates with the field controllable device through a downward communication mode, collects the running state and power of the field controllable device, and sends a disconnecting and closing instruction to the field controllable device, the disconnecting instruction cuts off the field controllable device, and the closing instruction connects the field controllable device to the grid; the edge side proxy substation communicates with the dispatch master station through an upward communication mode, and uploads the total power of the transformer area, the number of photovoltaic switches put into the transformer area, the total photovoltaic power of the transformer area, and the actual photovoltaic power cut-off value, and receives the photovoltaic power cut-off target value issued by the dispatch master station.

[0029] In this embodiment, a control method for a low-voltage photovoltaic cluster batch control system is also provided, comprising the following steps:

[0030] The strategy is loaded into the control program of the edge-side proxy substation in the form of functional software.

[0031] The edge-side proxy substation ranks each field-controllable device based on the number of times it has been removed in the past. The more times it has been removed in the past, the lower the ranking.

[0032] When the strategy is initially implemented, the historical number of times each field-controllable device has been removed is initialized to 0. Since these numbers are all 0, the strategy can arbitrarily sort the field-controllable devices. When a new field-controllable device is connected to the grid, its historical number of times it has been removed is reset to 0, and it is added to the ranking with other field-controllable devices.

[0033] When the edge-side proxy substation receives the photovoltaic power removal target value issued by the dispatching master station, the strategy performs analysis and calculation to determine the field controllable devices that need to be removed. The calculation is based on:

[0034] Remove the N field controllable devices that are ranked first, so that

[0035] The total power of the top N field controllable devices is ≥ the photovoltaic power removal target value, and

[0036] The total power of the top N-1 on-site controllable devices is less than the photovoltaic power removal target value.

[0037] After calculating the N field-controllable devices that need to be disconnected, the edge-side proxy substation sends a trip command. Once the command is executed, the total power of these N field-controllable devices is used as the actual PV power disconnect value and sent to the dispatch master station. This value is also transmitted to the new total power of the substation, the number of PV switches already in operation, and the total PV power of the substation.

[0038] The historical number of times the N field controllable devices are removed is increased by 1, and the new historical number of times they are removed is used as a ranking basis for the next calculation of the field controllable devices that need to be removed by the batch control strategy.

[0039] The command of the dispatching master station to release the photovoltaic power removal in the substation is also issued through the photovoltaic power removal target value, which is 0.

[0040] When the edge-side proxy substation receives a PV power removal target value of 0 from the dispatching master station, it issues a closing command to the controlled field devices to be removed. After the command is executed, the actual PV power removal value of 0 is transmitted to the dispatching master station, along with the new total power of the substation, the number of PV switches in operation in the substation, and the total PV power of the substation.

[0041] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A low-voltage photovoltaic cluster batch control system, characterized in that: It includes a dispatching master station, an edge-side proxy substation, and field-controllable equipment: the edge-side proxy substation communicates with the field-controllable equipment through downlink communication, collects the operating status and power of the field-controllable equipment, and sends opening and closing instructions to it. The opening instruction cuts off the field-controllable equipment, and the closing instruction connects the field-controllable equipment to the grid; the edge-side proxy substation communicates with the dispatching master station through uplink communication to send the total power of the substation area, the number of photovoltaic switches put into use in the substation area, the total photovoltaic power of the substation area, and the actual photovoltaic power removal value, and accepts the photovoltaic power removal target value issued by the dispatching master station; The dispatching master station is set up in the power grid dispatching department; the dispatching master station visually displays the low-voltage substation topology diagram; the topology diagram describes the overview of the substation in the form of a list, including the total power of the substation, the number of photovoltaic switches put into use in the substation, the total photovoltaic power of the substation, the target photovoltaic power removal value and the actual photovoltaic power removal value. Right-click on the specific values ​​of the total power of the substation and the total photovoltaic power of the substation to call out the function menu, which includes a power curve option. Select the power curve option to obtain the power curve to display the current and historical power values; The control method of the low-voltage photovoltaic cluster batch control system comprises the following steps: The edge-side proxy substation sorts each field-controllable device; Initialize the historical number of times each field controllable device has been cut off; When the edge-side proxy substation receives the photovoltaic power removal target value issued by the dispatching master station, the strategy performs analysis and calculation to determine the on-site controllable devices that need to be removed; After calculating the N field-controllable devices that need to be disconnected, the edge-side proxy substation sends a trip command to them. After the execution is completed, the total power of the N field-controllable devices is used as the actual PV power disconnection value and sent to the dispatch master station. At the same time, the new total power of the substation, the number of PV switches already in use in the substation, and the total PV power of the substation are also sent. The historical number of times the N field controllable devices have been removed is increased by 1, and the new historical number of times the devices have been removed is used as the sorting basis for the batch control strategy to calculate the field controllable devices that need to be removed next time; The command of the dispatching master station to release the photovoltaic power removal in the substation is also issued through the photovoltaic power removal target value, which is 0; When the edge-side proxy substation receives the photovoltaic power removal target value of 0 issued by the dispatching master station, it sends a closing command to the on-site controllable equipment to be removed; after the execution is completed, the actual photovoltaic power removal value of 0 is sent to the dispatching master station, and the new total power of the substation, the number of photovoltaic switches put into use in the substation, and the total photovoltaic power of the substation are also sent.

2. A low-voltage photovoltaic cluster batch control system according to claim 1, characterized in that: The on-site controllable device is a photovoltaic grid-connected switch installed at a photovoltaic grid-connected point.

3. A low-voltage photovoltaic cluster batch control system according to claim 1, characterized in that: The edge-side agent substation is set up at the distribution transformer in the substation area to collect the low-voltage side voltage and current data of the distribution transformer to calculate the total power of the substation area.

4. The low-voltage photovoltaic cluster batch control system according to claim 1 is characterized in that: The basis for the sorting is the number of times the history is cut off. The more times the history is cut off, the lower the sorting is.

5. The low-voltage photovoltaic cluster batch control system according to claim 1 is characterized in that: The historical number of times a device has been removed is set to 0. Since the number is 0, the strategy can arbitrarily sort the field controllable devices. When a new field controllable device is connected to the power grid, the historical number of times the field controllable device has been removed is set to 0 and the device is added to the sorting with other field controllable devices.

6. The low-voltage photovoltaic cluster batch control system according to claim 1 is characterized in that: The top N field-controllable devices are cut off so that the total power of the top N field-controllable devices is greater than or equal to the target photovoltaic power cut-off value, and the total power of the top N-1 field-controllable devices is less than the target photovoltaic power cut-off value.

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