Photovoltaic power station monitoring system and control method thereof

Abstract

The invention provides a photovoltaic power station monitoring system and a control method thereof. The photovoltaic power station monitoring system comprises a system station control layer module and a sub-matrix spacing layer module, the system station control layer module is used for issuing a scheduling instruction, the sub-matrix spacing layer module is provided with an on-site operation unit, an exchange port and a plurality of acquisition ports, the exchange port is used for communicating with the system station control layer module, and the acquisition ports are used for acquiring the on-site operation unit. And the in-situ operation unit is used for performing in-situ calculation on the data acquired by the acquisition port to form a control instruction of the sub-matrix. The data acquired by the acquisition port is subjected to in-situ calculation by using the in-situ operation unit to form a control instruction of the sub-matrix, so that the amount of data uploaded to a station control layer is reduced, the calculation amount of the station control layer is reduced, the data processing time delay is reduced, and the system responsivity is improved.

Description

Technical Field

[0001] The present application belongs to the field of renewable energy power generation technology, and specifically, relates to a photovoltaic power station monitoring system and a control method thereof. Background Art

[0002] The photovoltaic power station monitoring system consists of two parts: the interval layer and the station control layer. The station control layer is the central control layer for the operation and management of the entire photovoltaic power station, and is composed of various servers, operator stations, remote interface devices, etc.; the interval layer is composed of (intelligent) I / O units, control units, control networks and protection interface machines, and is an on-site measurement control layer for unit equipment.

[0003] The photovoltaic power station monitoring system realizes active control, reactive control, data monitoring and other functions through the organic combination of the interval layer equipment and the station control layer equipment, and must have the ability to communicate and exchange information with the power grid dispatching organization. At present, the photovoltaic power station configures a data acquisition cabinet in the sub-array to realize the interval layer function. The main components in the data acquisition cabinet are switches and data acquisition units. They mainly collect information about inverters, box transformers, energy storage PCS, junction boxes, bracket tracking systems, and intelligent equipment in the photovoltaic power station, and send the collected information to the monitoring system station control layer. The station control layer receives the interval layer information, and then calculates the active and reactive power according to the instructions of the power grid dispatching organization and sends control instructions to the interval layer. Such a reciprocating operation is monitored and adjusted in real time to ensure that the photovoltaic power station operates and generates electricity according to the requirements of the dispatching organization.

[0004] At present, the equipment in the interval layer of the photovoltaic power station monitoring system mainly realizes the collection and forwarding functions of sub-array equipment information, and the equipment in the station control layer of the photovoltaic power station monitoring system mainly realizes the functions of receiving and calculating the control instructions. With the development of photovoltaic technology, the number of photovoltaic power station sub-arrays is increasing, the single capacity of large-scale photovoltaic power generation projects has entered the gigawatt level, and the number of photovoltaic system monitoring objects has increased. The photovoltaic sub-array communication unit collects the sub-array equipment information and uploads it to the station control layer of the photovoltaic power station monitoring system in full capacity, resulting in a sharp increase in the amount of calculation at the station control layer of the photovoltaic power station monitoring system, and the communication control cannot be executed quickly and accurately. In addition, after the photovoltaic sub-array is configured with energy storage, it is also necessary to execute the photovoltaic system monitoring system's control instructions to the energy storage system through the photovoltaic sub-array communication control unit, which further aggravates the control objects of the photovoltaic power station monitoring system. Since a large number of monitoring objects need to be calculated and analyzed at the station control layer of the photovoltaic power station monitoring system, it consumes a lot of time, resulting in an increase in the time for energy storage to adjust the photovoltaic system and reduce the application effect of energy storage. Thirdly, the application of intelligent means in large-scale photovoltaic power stations has become an effective way to reduce operation and maintenance costs. Large-scale intelligent application functions require the collection of a large amount of photovoltaic sub-array information to the monitoring background, which increases the system communication volume. Summary of the invention

[0005] The technical problem solved by the present application is: how to provide a photovoltaic power station monitoring system and a control method thereof which can reduce the background calculation amount and system communication volume of the photovoltaic power station monitoring system and shorten the system response time.

[0006] The present application provides a photovoltaic power station monitoring system, the photovoltaic power station monitoring system comprising:

[0007] A system station control layer module, which is used to issue dispatching instructions;

[0008] The sub-array spacing layer module is provided with an on-site operation unit, a switching port and a plurality of collection ports. The switching port is used to communicate with the system station control layer module. The on-site operation unit is used to perform on-site calculations on the data collected by the collection port to form control instructions for the sub-array.

[0009] Optionally, the data collected by the collection port includes electricity meter information, box transformer information, combiner cabinet information, inverter information, tracking system information, energy storage battery information, energy storage PCS information and climate sensor information.

[0010] Optionally, the control instructions include charging and discharging instructions, primary frequency modulation control instructions, active / reactive power control instructions, and sub-array output control instructions formed according to predicted optical power.

[0011] Optionally, the switching port is also used to transmit data processed by the local computing unit to the system station control layer module.

[0012] The present application also discloses a control method for a photovoltaic power station monitoring system, the control method comprising:

[0013] Collect data using the collection port of the sub-array spacing layer module;

[0014] The local computing unit of the sub-array spacing layer module is used to perform local computing on the collected data to form a control instruction;

[0015] The operation of the sub-matrix is ​​controlled according to the control instruction.

[0016] Optionally, the control method further includes:

[0017] The switching port of the sub-array spacing layer module is used to receive the dispatching instructions issued by the system station control layer module, and the switching port is used to upload the data processed by the local operation unit.

[0018] The photovoltaic power station monitoring system provided by the present application has the following technical effects:

[0019] The photovoltaic power station monitoring system and control method thereof use an on-site computing unit to perform on-site calculations on the data collected at the collection port to form control instructions for the sub-array, thereby reducing the amount of data uploaded to the station control layer, alleviating the amount of calculation at the station control layer, reducing data processing delays, and improving system responsiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the architecture of a photovoltaic power station monitoring system according to one or more embodiments;

[0021] Figure 2 is a communication control principle diagram of a photovoltaic power station monitoring system according to one or more embodiments;

[0022] Figure 3 A communication control schematic diagram of a photovoltaic power station monitoring system according to the prior art;

[0023] Figure 4 The present invention is a flow chart of controlling the primary frequency modulation output of a sub-array by an on-site computing unit according to one or more embodiments. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] Before describing in detail the various embodiments of the present application, the technical concept of the present application is first briefly described: in the current photovoltaic power station monitoring system, after the interval layer collects data, it is uploaded to the station control layer for calculation to form the control instructions of the sub-array. As the amount of data increases, it will cause the station control layer to have too much calculation and the system communication volume to increase, which will have a great impact on the background of the monitoring system, and will also cause problems such as data delay. For this reason, the photovoltaic power station monitoring system provided by the present application sets an on-site operation unit in the sub-array interval layer module, and uses the on-site operation unit to perform on-site calculations on the data collected by the collection port to form the control instructions of the sub-array, thereby reducing the amount of data uploaded to the station control layer, reducing the amount of calculation of the station control layer, reducing the data processing delay, and improving the system responsiveness. The specific principles of the photovoltaic power station monitoring system and its control method of the present application are described below in combination with more embodiments.

[0026] Specifically, Figure 1 As shown, the photovoltaic power station monitoring system of the first embodiment includes a system station control layer module and a sub-array spacing layer module. The system station control layer module is used to issue scheduling instructions. The sub-array spacing layer module is provided with an on-site computing unit, a switching port and a plurality of collection ports. The switching port is used to communicate with the system station control layer module. The on-site computing unit is used to perform on-site calculations on the data collected by the collection port to form control instructions for the sub-array.

[0027] Exemplarily, the data collected by the collection port includes information of electricity meters, transformer boxes, junction boxes, inverters, tracking systems, energy storage batteries, energy storage PCS and climate sensors. Control instructions include charge and discharge instructions, primary frequency modulation control instructions, active / reactive control instructions, and sub-array output control instructions formed according to predicted optical power. Among them, the switching port is also used to transmit the data processed by the local operation unit to the system station control layer module. Since a system station control layer module can control multiple sub-array spacing layer modules, after the calculated data of each sub-array spacing layer module is uploaded to the system station control layer module, the system station control layer module can comprehensively analyze the data, coordinate and control each sub-array, and ensure the overall smooth operation of the photovoltaic power station.

[0028] In one or more embodiments, the control method of the photovoltaic power station monitoring system includes: collecting data using the collection port of the sub-array spacing layer module; performing on-site calculations on the collected data using the on-site calculation unit of the sub-array spacing layer module to form control instructions; and controlling the operation of the sub-array according to the control instructions.

[0029] In order to illustrate the effects of the photovoltaic power station monitoring system and control method thereof of this embodiment, specific examples are listed below for comparison.

[0030] like Figure 3 As shown in the figure, in the conventional photovoltaic power station monitoring system, each sub-array interval layer data acquisition cabinet collects information in the sub-array through the acquisition port. The standard sub-array information is about 3470 points, and these points need to be uploaded to the photovoltaic power station monitoring system station control layer by the communication system. A photovoltaic power station with an installed capacity of 1GW is composed of about 320 photovoltaic sub-arrays of 3.15MW. Through simple calculations, it can be concluded that the amount of information that needs to be processed simultaneously at the photovoltaic power station monitoring system station control layer is about 3470×320≈10 million points. Such a large amount of communication information is bound to require the photovoltaic power station monitoring system station control layer to configure expensive equipment for calculation, and the calculation amount is large, and it cannot guarantee that the photovoltaic instructions are transmitted to each sub-array in a timely and rapid manner. Especially when a certain communication node fails, this kind of communication needs to be reconnected before it can be carried out. Generally, when a single node fails, the sub-array reply communication time is at the minute level, about 4 to 10 minutes, which brings inconvenience to the operation and maintenance of the photovoltaic power station.

[0031] like Figure 2As shown, the improved photovoltaic power station monitoring system of this embodiment adds an on-site calculation function to the data acquisition unit of the sub-array spacing layer module, calculates the information collected by the acquisition ports 1 to 4, and after the calculation of the photovoltaic power station monitoring system, the number of available points in the station control layer is reduced from 3470 to 2000 points, and the number of data packet queues processed by the station control layer computers and network equipment of the entire photovoltaic power station monitoring system is also greatly reduced, the data processing delay can be reduced, and the communication control speed of the photovoltaic power station is improved.

[0032] As an example, Figure 4 A flow chart showing the control of the primary frequency modulation output of the sub-array by the local computing unit is shown. Figure 4 In the process, the first step is that the communication control unit of the sub-array determines the frequency at the grid connection point and the rated frequency of the grid, and determines whether to increase or decrease the power; the second step is that the predicted power of the sub-array is compared with the dispatching AGC command power, and determines whether to select the energy storage system power or the inverter power for power regulation; the third step is that according to the energy storage system power SOC, the energy storage power regulation input and exit control is performed.

[0033] The photovoltaic power station monitoring system and control method provided in this embodiment use the local computing unit to perform local calculations on the data collected by the collection port to form control instructions for the sub-array, thereby reducing the amount of data uploaded to the station control layer, reducing the amount of calculation at the station control layer, reducing the data processing delay, and improving the system responsiveness. Through the hierarchical distributed communication control method, the communication control of photovoltaic power stations in large-capacity photovoltaic power station sub-arrays is solved to be rapid and accurate, and the energy storage's ability to regulate and support photovoltaic systems is effectively improved.

[0034] The specific implementation methods of the present application are described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that these embodiments can be modified and improved without departing from the principles and spirit of the present application whose scope is defined by the claims and their equivalents. These modifications and improvements should also be within the scope of protection of the present application.

Claims

1. A photovoltaic power station monitoring system, characterized in that: The photovoltaic power station monitoring system comprises: A system station control layer module, which is used to issue dispatching instructions; The sub-array spacing layer module is provided with an on-site operation unit, a switching port and a plurality of collection ports. The switching port is used to communicate with the system station control layer module. The on-site operation unit is used to perform on-site calculations on the data collected by the collection port to form control instructions for the sub-array.

2. The photovoltaic power station monitoring system according to claim 1, characterized in that: The data collected by the collection port includes electricity meter information, box transformer information, combiner cabinet information, inverter information, tracking system information, energy storage battery information, energy storage PCS information and climate sensor information.

3. The photovoltaic power station monitoring system according to claim 1, characterized in that: The control instructions include charging and discharging instructions, primary frequency modulation control instructions, active / reactive power control instructions, and sub-array output control instructions formed according to predicted optical power.

4. The photovoltaic power station monitoring system according to claim 1, characterized in that: The switching port is also used to transmit data processed by the local computing unit to the system station control layer module.

5. A control method for a photovoltaic power station monitoring system according to any one of claims 1 to 4, characterized in that: The control method comprises: Collect data using the collection port of the sub-array spacing layer module; The local computing unit of the sub-array spacing layer module is used to perform local computing on the collected data to form a control instruction; The operation of the sub-matrix is ​​controlled according to the control instruction.

6. The control method according to claim 5, characterized in that: The control method further comprises: The switching port of the sub-array spacing layer module is used to receive the dispatching instructions issued by the system station control layer module, and the switching port is used to upload the data processed by the local operation unit.

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