Power control method for micro inverter system networking

Abstract

The invention discloses a power control method for micro inverter system networking, which comprises an energy scheduling controller and a plurality of micro inverters in wireless communication connection with the energy scheduling controller, and the energy scheduling controller is in wired connection with an electric meter; the energy scheduling controller obtains the set grid-connected power of the system, reads the current real-time grid-connected power of the system through the electric meter in wired connection, calculates the execution power of the micro inverters through the set grid-connected power and the real-time grid-connected power, and sends the execution power to the micro inverters, and the micro inverters adjust the output power of the grid-connected side. According to the invention, the energy scheduling controller is used as a control center to form a local area network, the information of the micro inverter is obtained and counted in a TCP mode, wired connection is established with the ammeter, the grid-connected power of the micro inverter system is read in real time, the power value required by the micro inverter is calculated, and the micro inverter in the system is controlled in real time. Therefore, the parallel operation power control and adjustment of the micro-inverse system of wireless WIFI communication are realized.

Description

Technical Field

[0001] The invention relates to a power control method for micro inverter system networking, and belongs to the technical field of inverter networking control. Background Art

[0002] Micro inverters need to be networked and controlled. Currently, the micro inverter networking system using WIFI communication can only communicate and control through wireless transmission, and cannot connect to wired meters to obtain real-time grid-connected power. At the same time, when the micro inverter system is composed of multiple micro inverters in parallel, the system grid-connected power cannot be reliably and effectively regulated. Summary of the invention

[0003] The purpose of the present invention is to solve the deficiencies of the above-mentioned prior art, and to propose a power control method for micro-inverter system networking in view of the problem that micro-inverters of traditional WIFI communication networking cannot achieve grid-connected power regulation.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A power control method for a micro-inverter system network, wherein the micro-inverter system comprises an energy dispatching controller and a plurality of micro-inverters wirelessly connected to the energy dispatching controller, wherein the energy dispatching controller and the plurality of micro-inverters constitute a system local area network, and the energy dispatching controller is wiredly connected to an electric meter;

[0006] The energy dispatch controller obtains the set grid-connected power of the system, and reads the current real-time grid-connected power of the system through a wired electric meter. The execution power of the micro-inverter is calculated by the set grid-connected power and the real-time grid-connected power, and the execution power is sent to several micro-inverters. The micro-inverter adjusts the output power on the grid side.

[0007] Preferably, the energy regulation controller obtains the total rated power Pw of the rated powers Pn of several micro-inverters currently connected, reads the real-time grid-connected power Pmt, sets the grid-connected power Pset, the system power regulation ratio Pret, 0≤Pret≤1, the initial value of Pret is 1, the absolute value of the difference between the set grid-connected power and the real-time grid-connected power is Pdel, the difference percentage is Pr, and the execution power is Pact; Pr=Pdel / Pw;

[0008] When Pset>Pmt, then Pret'=Pret-Pr; when Pset≤Pmt, then Pret'=Pret+Pr;

[0009] Verify Pret'. When Pret'<0, then Pret'=0; when Pret'>1, then Pret'=1;

[0010] Pact=Pret'*Pn.

[0011] Preferably, the energy dispatching controller establishes a TCP server through WIFI to listen to the TCP client connection, connects the micro inverter to the wireless hotspot signal of the energy dispatching controller, the micro inverter creates a TCP client, and sends the data packet of the micro inverter through the TCP server, the data packet including the serial number, MAC address, and rated power information.

[0012] Preferably, the energy dispatching controller is connected to the electric meter via RS485, and reads the real-time grid-connected power of the electric meter in real time via the Modbus_Rtu protocol.

[0013] The beneficial effects of the present invention are mainly reflected in:

[0014] The energy dispatching controller is used as the control center. The energy dispatching controller and the micro-inverter are connected wirelessly through WIFI to form a local area network. The micro-inverter information is obtained and counted through TCP, and a wired connection is established with the electric meter to read the grid-connected power of the micro-inverter system in real time, calculate the power value required by the micro-inverter, and control the micro-inverters in the system in real time, thereby realizing the parallel power control and adjustment of the micro-inverter system with wireless WIFI communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0016] Figure 1 It is a structural schematic diagram of the micro inverter system of the present invention.

[0017] Figure 2 It is a schematic diagram of the process of the energy dispatching controller in the present invention collecting statistics on micro-inverter information.

[0018] Figure 3 It is a schematic diagram of the flow chart of the energy dispatching controller calculating the execution power in the present invention.

[0019] Figure 4 It is a schematic diagram of the grid connection of the energy dispatching controller and the micro inverter in the present invention.

[0020] Figure 5 It is a flow chart of the algorithm for executing power in the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant inventions, rather than to limit the inventions. It should also be noted that, for ease of description, only the parts related to the relevant inventions are shown in the accompanying drawings. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0023] The present invention provides a power control method for a micro inverter system network, such as Figure 1 As shown, the micro inverter system includes an energy dispatching controller EC, and a plurality of micro inverters wirelessly connected to the energy dispatching controller. The energy dispatching controller and the plurality of micro inverters constitute a system local area network, and the energy dispatching controller is wiredly connected to the electric meter.

[0024] like Figures 1 to 5 As shown, the energy dispatch controller obtains the set grid-connected power of the system, and reads the current real-time grid-connected power of the system through a wired electric meter. The execution power of the micro-inverter is calculated by the set grid-connected power and the real-time grid-connected power, and the execution power is sent to several micro-inverters. The micro-inverter adjusts the output power on the grid side.

[0025] Specifically, the micro-inverter system consists of micro-inverters, energy dispatch controllers, and electric meters. The energy dispatch controllers establish a wireless connection with the micro-inverters to form a micro-inverter system local area network, obtain basic information about the micro-inverters through TCP communication, and the energy dispatch controllers collect statistics on the micro-inverter information in the system. By reading the current real-time grid-connected power of the system through the wired electric meter, the power setting value is compared with the real-time power, and the power value required for the micro-inverters in the system to be connected to the grid is calculated, and sent to each micro-inverter in the system through TCP.

[0026] In a specific embodiment, the energy scheduling controller establishes a TCP server through WIFI to listen for TCP client connections, connects the micro inverter to the energy scheduling controller wireless hotspot signal, the micro inverter creates a TCP client, and sends the micro inverter's data packet through the TCP server, the data packet including the serial number, MAC address, and rated power information.

[0027] The energy dispatching controller turns on the AP mode of WIFI, listens to the TCP client connection through the TCP server, connects the micro inverter to the wireless hotspot signal of the energy dispatching controller, and the micro inverter creates a TCP client, connects to the corresponding server address and port number, and sends the basic information data packet of the micro inverter through TCP. After receiving the basic information of each micro inverter, the energy dispatching controller sends a confirmation message to the corresponding micro inverter.

[0028] After receiving the micro-inverter connection information, the energy dispatch controller extracts the micro-inverter serial number, MAC address, and rated power information, creates a micro-inverter client information table, and updates the current total rated power P of the micro-inverter system. w , send confirmation information to the corresponding micro-inverter to avoid the micro-inverter repeatedly sending device information data due to failure to receive confirmation information.

[0029] In a specific embodiment, the energy dispatch controller is connected to the electric meter via RS485, and reads the real-time grid-connected power of the electric meter in real time via the Modbus_Rtu protocol.

[0030] like Figures 2 to 5 As shown, the energy regulation controller obtains the total rated power Pw of the rated powers Pn of several micro-inverters currently connected, reads the real-time grid-connected power Pmt, sets the grid-connected power Pset, and the system power regulation ratio Pret, 0≤Pret≤1, the initial value of Pret is 1, the absolute value of the difference between the set grid-connected power and the real-time grid-connected power is Pdel, the difference percentage is Pr, and the execution power is Pact; Pr=Pdel / Pw;

[0031] When Pset>Pmt, then Pret'=Pret-Pr; when Pset≤Pmt, then Pret'=Pret+Pr;

[0032] Verify Pret'. When Pret'<0, then Pret'=0; when Pret'>1, then Pret'=1;

[0033] Pact=Pret'*Pn.

[0034] Specifically, all micro-inverters of the micro-inverter system are adjusted as a whole, and the energy scheduling controller statistically accumulates the rated power of the micro-inverters in the system as the system rated power, calculates the execution power percentage of the micro-inverter, and thus obtains the same-proportional power adjustment of each micro-inverter.

[0035] Assume that the power of the micro-inverter system current flowing from the grid to the micro-inverter system is positive, the rated power of each micro-inverter is Pn, the total rated power is Pw, the set grid-connected power is Pset, the real-time grid-connected power is Pmt, the system power adjustment ratio is Pret, 0≤Pret≤1, the default is 1, the difference between the target set value and the real-time power of the meter is Pdel, the difference percentage is Pr, and the execution power is Pact;

[0036] First, calculate the absolute value Pdel of the absolute value of the difference between the set grid-connected power and the real-time grid-connected power, Pdel = |Pset-Pmt|;

[0037] Then calculate the difference percentage Pr based on the difference, Pr = Pdel / Pw;

[0038] If the target power setting value Pset is greater than the real-time power Pmt of the electric meter, then Pret'=Pret-Pr; otherwise Pret'=Pret+Pr; after calculating Pret', check whether Pret' is between 0 and 1, if it is less than 0, then Pret'=0, if it is greater than 1, then Pret'=1; finally, calculate the execution power value Pact of the micro inverter according to the adjustment ratio, Pact=Pret'*Pn.

[0039] After receiving the execution power value sent by the energy scheduling controller, the micro inverter responds immediately to control the power output on the AC power output side. Since the power control is a broadcast instruction issued by the energy scheduling controller, the micro inverter does not need to feed back the result to the energy scheduling controller after receiving it.

[0040] More specific process implementation:

[0041] Turn on the AP hotspot mode of the energy dispatch controller and enable the TCP server to listen for client connections;

[0042] Connect the wireless network of the micro inverter to the hotspot signal of the energy dispatch controller, transmit the basic information of the device to the energy dispatch controller via TCP, and wait for the information response from the energy dispatch controller;

[0043] After receiving the basic information of the micro-inverter, the energy dispatch controller changes the micro-inverter system information linked list, accumulates the system rated grid-connected power, and responds to the newly connected micro-inverter;

[0044] Connect the electric meter between the micro system and the power grid, and connect it to the RS485 interface of the energy dispatch controller through the RS485 bus;

[0045] The energy dispatch controller obtains the set grid-connected power value, and periodically reads the grid-connected power of the micro-inverter system, and calculates the current micro-system power regulation percentage through the PI feedback regulation algorithm;

[0046] The energy dispatch controller sends the power percentage to all micro-inverters in the system through TCP communication according to the established micro-inverter system information linked list;

[0047] After receiving the power regulation ratio sent by the energy dispatching controller, the micro inverter adjusts the output power on the grid side.

[0048] From the above description, it can be found that the energy dispatching controller is used as the control center. The energy dispatching controller and the micro inverter are connected to form a local area network through WIFI wireless connection. The micro inverter information is obtained and counted through TCP, and a wired connection is established with the electric meter. The grid-connected power of the micro inverter system is read in real time, the power value required by the micro inverter is calculated, and the micro inverter in the system is controlled in real time, thereby realizing the parallel power control and adjustment of the micro inverter system with wireless WIFI communication.

[0049] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0050] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A power control method for a micro-inverter system network, characterized in that: The micro-inverter system includes an energy dispatching controller, and a plurality of micro-inverters wirelessly connected to the energy dispatching controller, the energy dispatching controller and the plurality of micro-inverters constitute a system local area network, and the energy dispatching controller is wiredly connected to the electric meter; The energy dispatch controller obtains the set grid-connected power of the system, and reads the current real-time grid-connected power of the system through a wired electric meter. The execution power of the micro-inverter is calculated by the set grid-connected power and the real-time grid-connected power, and the execution power is sent to several micro-inverters. The micro-inverter adjusts the output power on the grid side.

2. The power control method for micro-inverter system networking according to claim 1, characterized in that: The energy regulation controller obtains the total rated power Pw of the rated powers Pn of several micro-inverters currently connected, reads the real-time grid-connected power Pmt, sets the grid-connected power Pset, and the system power regulation ratio Pret, 0≤Pret≤1, the initial value of Pret is 1, the absolute value of the difference between the set grid-connected power and the real-time grid-connected power is Pdel, the difference percentage is Pr, and the execution power is Pact; Pr=Pdel / Pw; When Pset>Pmt, then Pret'=Pret-Pr; when Pset≤Pmt, then Pret'=Pret+Pr; Verify Pret'. When Pret'<0, then Pret'=0; when Pret'>1, then Pret'=1; Pact=Pret'*Pn.

3. The power control method for micro-inverter system networking according to claim 1, characterized in that: The energy dispatching controller uses the TCP server established through WIFI to listen to the TCP client connection, connects the micro inverter to the wireless hotspot signal of the energy dispatching controller, creates a TCP client, and sends the data packet of the micro inverter through the TCP server. The data packet includes the serial number, MAC address, and rated power information.

4. The power control method for micro-inverter system networking according to claim 1, characterized in that: The energy dispatch controller is connected to the electric meter via RS485 and reads the real-time grid-connected power of the electric meter in real time via the Modbus_Rtu protocol.

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