Dynamic power adjusting device of photovoltaic grid-connected system

Abstract

The utility model discloses a dynamic power adjusting device of a photovoltaic grid-connected system, the photovoltaic grid-connected system comprises at least one inverter, and the alternating current side of the inverter is connected with a power grid through a grid-connected point; the dynamic power adjusting device comprises at least one metering module, a collector and a power controller. The metering module is used for measuring power data at a grid-connected point; the collector is in communication connection with the inverter, the metering module and the power controller, and the collector is used for collecting the power, measured by the metering module, of the grid-connected point and sending the collected power of the grid-connected point to the power controller; and the power controller is configured to determine a power regulation value issued to the inverter according to the power at the grid-connected point and a power regulation target value. The dynamic power adjusting device of the photovoltaic grid-connected system provided by the utility model can meet the application requirements of single-feed network and double-parallel feed network power distribution systems, and realizes active and reactive dynamic adjustment.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic power generation technology, and in particular to a dynamic power regulation device for a photovoltaic grid-connected system. Background Art

[0002] With the development of the photovoltaic industry, high-voltage grid-connected projects, such as 10KV grid-connected projects, are becoming more and more common. In high-voltage grid-connected projects, there is a high demand for dynamic power regulation. Dynamic power regulation includes active power regulation and reactive power regulation. Active power regulation is applicable to scenarios with anti-backflow application requirements, such as projects where photovoltaic power generation can only be used for self-use and surplus power is not allowed to be connected to the grid. Reactive power regulation is applicable to projects where the power factor is lower than the grid requirement due to the reduction of active power of the grid after the photovoltaic station is installed.

[0003] In high-voltage grid-connected projects, the commonly used feeder distribution systems include single-feeder and dual-parallel-feeder distribution systems. Existing power conditioning devices cannot meet the application requirements of single-feeder and dual-parallel-feeder distribution systems, nor can they meet the requirements of active and reactive dynamic regulation. Utility Model Content

[0004] The purpose of this application is to provide a dynamic power regulation device for a photovoltaic grid-connected system to meet the application requirements of single-fed and dual-parallel-fed distribution systems and realize dynamic regulation of active and reactive power.

[0005] The present application provides a dynamic power regulation device for a photovoltaic grid-connected system, wherein the photovoltaic grid-connected system comprises at least one inverter, and the AC side of the inverter is connected to the power grid through a grid connection point; the dynamic power regulation device comprises at least one metering module, a collector, and a power controller;

[0006] The metering module is used to measure the power data at the grid connection point;

[0007] The collector is in communication connection with the inverter, the metering module and the power controller, and is used to collect the power at the grid connection point measured by the metering module, and transmit the collected power at the grid connection point to the power controller;

[0008] The power controller is configured to determine a power regulation value to be sent to the inverter according to the power at the grid connection point and the power regulation target value.

[0009] In one example, the collector communicates with the inverter and the power controller using the MODBUS RTU protocol, and the collector communicates with the metering module using the MODBUS RTU or DL / T645 protocol.

[0010] In one example, the power controller is configured to send the power regulation value to the inverter when the power at the grid connection point is greater than the power regulation target value.

[0011] In one example, a wireless communication module and a target power setting module are also included;

[0012] The collector is in communication connection with the target power setting module via the wireless communication module. The target power setting module is configured to receive the power adjustment target value set by a user and send the power adjustment target value to the power controller.

[0013] In one example, the collector is also used to collect power data of the inverter, and transmit the collected power at the grid connection point and the power data of the inverter to the target power setting module through the wireless communication module.

[0014] In one example, the collector is further used to collect the power at the grid connection point measured by the metering module again, and send the collected power at the grid connection point to the power controller;

[0015] The power controller is configured to generate power regulation completion information according to the power at the grid connection point and the power regulation target value collected again, and send the information to the target power setting module.

[0016] In one example, the target power setting module includes a PC client or a mobile terminal.

[0017] In one example, a cloud server is further included, the collector is communicatively connected to the cloud server via the wireless communication module, and the target power setting module is communicatively connected to the cloud server.

[0018] In one example, the metering module includes a voltage detection unit and a current detection unit, the voltage detection unit is used to detect the voltage at the grid connection point, and the current detection unit is used to detect the current at the grid connection point.

[0019] In one example, the photovoltaic grid-connected system further includes a transformer and a photovoltaic grid-connected cabinet;

[0020] The AC side of the inverter is connected to the power grid through the transformer and the photovoltaic grid-connected cabinet in sequence.

[0021] The dynamic power regulation device of the photovoltaic grid-connected system provided in the present application can meet the application requirements of single-fed grid and dual-parallel-fed grid distribution systems, and realize dynamic regulation of active and reactive power. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1A schematic diagram of photovoltaic grid-connected system application access provided in an embodiment of the present application;

[0023] Figure 2 Schematic diagram of a dynamic power regulation device for a photovoltaic grid-connected system provided in an embodiment of the present application.

[0024] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer and more understandable, 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.

[0026] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0027] like Figure 1-Figure 2 As shown, the photovoltaic grid-connected system includes at least one inverter, and the AC side of the inverter is connected to the grid through a grid connection point. Specifically, the AC side of the inverter is connected to the grid through the transformer and the photovoltaic grid-connected cabinet in turn; wherein the connection point between the photovoltaic grid-connected cabinet and the grid is the grid connection point. For example, inverter 1 to inverter N in the figure, the AC side of the inverter is connected to the 10KV grid through a 10KV transformer and a 10KV photovoltaic grid-connected cabinet. The load terminal can be powered by a 10KV grid or a 10KV photovoltaic grid-connected cabinet.

[0028] The dynamic power regulation device of the photovoltaic grid-connected system includes at least one metering module, a collector and a power controller;

[0029] The metering module is used to measure the power data at the grid connection point;

[0030] The collector is in communication connection with the inverter, the metering module and the power controller, and is used to collect the power at the grid connection point measured by the metering module, and transmit the collected power at the grid connection point to the power controller;

[0031] The power controller is configured to determine a power regulation value to be sent to the inverter according to the power at the grid connection point and the power regulation target value.

[0032] In one example, the metering module includes a voltage detection unit and a current detection unit, wherein the voltage detection unit is used to detect the voltage at the grid connection point, and the current detection unit is used to detect the current at the grid connection point, and the power at the grid connection point can be obtained through the voltage at the grid connection point and the current at the grid connection point. In a further implementation, the metering module also includes a multifunctional smart meter, and data such as electric energy can be obtained through the multifunctional smart meter.

[0033] In one example, the collector communicates with the inverter and the power controller using the MODBUS RTU protocol, and the collector communicates with the metering module using the MODBUS RTU or DL / T645 protocol.

[0034] Specifically, the collector automatically identifies the metering module through MODBUS RTU or DL / T645 protocol, can identify multiple devices according to the device ID, and perform real-time data collection and efficient data statistical processing. For example, the collector can collect multiple metering modules in real time, accumulate their vector values, and store the data at a certain period; the collector collects active or reactive data of multiple inverters in real time, accumulates their vector values, and stores the data at a certain period.

[0035] Inverters or metering modules from different manufacturers can be mapped to the protocol by customizing the MODBUS RTU protocol of the device, so that devices from different manufacturers can be effectively collected and processed. For example, the data of devices such as inverters and metering modules are aggregated to the Modbus master station through the MODBUS RTU protocol, and synchronously mapped to the Modbus slave station in the collector to realize data interaction between the master station and the slave station.

[0036] In one example, a wireless communication module, a cloud server and a target power setting module are also included; the collector is connected to the cloud server through the wireless communication module, a mobile base station or a router and other devices may be set between the wireless communication module and the cloud server, and the target power setting module is connected to the cloud server. The target power setting module includes a PC client or a mobile terminal.

[0037] The target power setting module is configured to receive the power adjustment target value set by a user, and send the power adjustment target value to the power controller.

[0038] Specifically, users can set the power adjustment target value through the mobile terminal app, and send it to the power controller through the cloud server-wireless communication module-collector-power controller communication link.

[0039] In one example, the collector is also used to collect power data of the inverter, and transmit the collected power at the grid connection point and the power data of the inverter to the target power setting module through the wireless communication module.

[0040] Specifically, the collector sends the Modbus slave data to the Modbus master in the wireless communication module. The wireless communication module interacts with the cloud server through a mobile base station or router. The cloud server also interacts with the PC client and mobile phone APP to achieve remote data monitoring and maintenance, target power value setting, etc.

[0041] In one example, the power controller is configured to send the power regulation value to the inverter when the power at the grid connection point is greater than the power regulation target value.

[0042] The task training cycle is the target control cycle. When the task training cycle is reached, the power controller collects the latest statistical data stored in the inverter and metering module from the collector, and executes the control algorithm according to the current target setting value, generates power adjustment instructions, and sends them to each inverter.

[0043] In one example, the collector is further used to collect the power at the grid connection point measured by the metering module again, and send the collected power at the grid connection point to the power controller;

[0044] The power controller is configured to generate power regulation completion information according to the power at the grid connection point and the power regulation target value collected again, and send the information to the target power setting module.

[0045] In the specific implementation, the percentage can be used to distribute the information to all inverters to solve the problem of different inverter models. After the collector sends the power adjustment command to each inverter, it will read back the current grid-connected power output, compare it with the target value (power adjustment target value), generate power adjustment completion information, and feedback it to the PC client, mobile phone APP, etc.

[0046] In the above implementation, the power regulation control cycle needs to be greater than the communication time of various lower-level devices, and the communication data of various devices is stored regularly. The latest data is used for each control to ensure the real-time effectiveness of power control.

[0047] The preferred embodiments of the present application are described above with reference to the accompanying drawings, but the scope of the present application is not limited thereby. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present application shall be within the scope of the present application.

Claims

1. A dynamic power regulation device for a photovoltaic grid-connected system, wherein the photovoltaic grid-connected system comprises at least one inverter, and the AC side of the inverter is connected to the power grid through a grid connection point; characterized in that: The dynamic power regulation device includes at least one metering module, a collector and a power controller; The metering module is used to measure the power data at the grid connection point; The collector is in communication connection with the inverter, the metering module and the power controller, and is used to collect the power at the grid connection point measured by the metering module, and transmit the collected power at the grid connection point to the power controller; The power controller is configured to determine a power regulation value to be sent to the inverter according to the power at the grid connection point and the power regulation target value.

2. The dynamic power regulation device according to claim 1, characterized in that: The collector communicates with the inverter and the power controller using the MODBUS RTU protocol, and the collector communicates with the metering module using the MODBUS RTU or DL / T645 protocol.

3. The dynamic power regulation device according to claim 1, characterized in that: The power controller is configured to send the power regulation value to the inverter when the power at the grid connection point is greater than the power regulation target value.

4. The dynamic power regulation device according to claim 3, characterized in that: Also includes a wireless communication module and a target power setting module; The collector is in communication connection with the target power setting module via the wireless communication module, and the target power setting module is configured to receive the power adjustment target value set by a user and send the power adjustment target value to the power controller.

5. The dynamic power regulation device according to claim 4, characterized in that: The collector is also used to collect power data of the inverter, and send the collected power at the grid connection point and the power data of the inverter to the target power setting module through the wireless communication module.

6. The dynamic power regulation device according to claim 4, characterized in that: The collector is also used to collect the power at the grid connection point measured by the metering module again, and send the collected power at the grid connection point to the power controller; The power controller is configured to generate power regulation completion information according to the power at the grid connection point and the power regulation target value collected again, and send the information to the target power setting module.

7. The dynamic power regulation device according to claim 4, characterized in that: The target power setting module includes a PC client or a mobile terminal.

8. The dynamic power regulation device according to claim 4, characterized in that: It also includes a cloud server, the collector is connected to the cloud server through the wireless communication module, and the target power setting module is connected to the cloud server.

9. The dynamic power regulation device according to claim 1, characterized in that: The metering module includes a voltage detection unit and a current detection unit. The voltage detection unit is used to detect the voltage at the grid connection point, and the current detection unit is used to detect the current at the grid connection point.

10. The dynamic power adjustment device according to claim 1, characterized in that: The photovoltaic grid-connected system also includes a transformer and a photovoltaic grid-connected cabinet; The AC side of the inverter is connected to the power grid through the transformer and the photovoltaic grid-connected cabinet in sequence.

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