Network construction type energy storage converter multi-machine parallel semi-physical simulation platform and simulation method

Abstract

The invention provides a network construction type energy storage converter multi-machine parallel semi-physical simulation platform, which comprises an energy storage converter control case, an energy storage converter simulation server, a regional power grid simulation server and an upper computer controller, the regional power grid simulation server is connected with the energy storage converter simulation server, the energy storage converter controller and the upper computer in sequence; the simulation platform performs joint simulation on the constructed regional power grid model and the semi-physical model of the energy storage converter, modifies the short-circuit ratio of the regional power grid model, switches a load to produce power grid voltage frequency fluctuation or broadband oscillation, and tests the anti-interference capability of the network construction type energy storage converter under the large disturbance of the power grid. Under the small disturbance of the power grid, the self-supporting effect on the frequency of the power grid is achieved; through interconnection of the energy storage converter simulation service chassis and the energy storage converter simulation server, the operation condition of the energy storage converter in an actual regional power grid is simulated, the grid-connected point power flow is calculated and analyzed, and the rationality of a grid frequency support algorithm of the network construction type energy storage converter is verified.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochemical energy storage, and in particular relates to a multi-machine parallel semi-physical simulation platform and a simulation method for a grid-type energy storage converter. Background Art

[0003] Due to the uncertainty of primary wind and solar resources, as the penetration rate of wind and solar continues to increase, the current random fluctuations in wind power and photovoltaic output make it difficult to build a stable voltage / frequency, and the small disturbance stability of wind and solar power stations is challenged. The grid-type energy storage converter can make the energy storage system have voltage source characteristics and provide voltage, frequency and other support capabilities under grid disturbances. Using grid-type energy storage to support new energy stations can effectively improve the stability of weak power grids. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a semi-physical simulation platform and simulation method for multi-machine parallel connection of a grid-type energy storage inverter, which can simulate the grid-connected operation conditions of the grid-type energy storage inverter in a convenient and accurate manner, and verify the system's transient support capability for weak power grids through modeling and simulation, which greatly saves verification and design development costs, and is more convenient, safe and reliable.

[0005] The present invention is specifically a semi-physical simulation platform for multi-machine parallel connection of a grid-type energy storage converter, the semi-physical simulation platform includes an energy storage converter control chassis, an energy storage converter simulation server, a regional power grid simulation server and a host computer controller, the regional power grid simulation server is sequentially connected to the energy storage converter simulation server, the energy storage converter control machine and the host computer; the simulation platform jointly simulates the constructed regional power grid model with the semi-physical model of the grid-type energy storage converter, modifies the short-circuit ratio and load switching of the regional power grid model to create grid voltage frequency fluctuations or broadband oscillations, tests the anti-interference ability of the grid-type energy storage converter under large grid disturbances, and its frequency support function for the grid under small grid disturbances; by interconnecting the energy storage converter simulation service chassis with the energy storage converter simulation server, the operation of the energy storage converter in an actual regional power grid is simulated, the grid connection point flow is calculated and analyzed, and the rationality of the grid-type energy storage converter frequency support algorithm is verified.

[0006] The present invention also proposes a semi-physical simulation method for multiple parallel machines of a grid-type energy storage converter, and the simulation method for multiple parallel machines of a grid-type energy storage converter comprises the following steps:

[0007] Step (1): Connect the signal output by the analog board of the energy storage converter simulation server to the analog sampling terminal of the energy storage converter control chassis, and connect the PWM wave signal emitted by the electric pulse terminal of the energy storage converter control chassis to the digital input board of the energy storage converter simulation server;

[0008] Step (2): constructing a semi-physical model of a network-type energy storage converter according to the topology of the energy storage converter, associating and matching the semi-physical model of the network-type energy storage converter with the measurement and control signals input and output by the actual physical interface, realizing the signal interaction between the energy storage converter simulation chassis and the energy storage converter control chassis, and forming hardware in the loop;

[0009] Step (3): The semi-physical model of the grid-connected energy storage converter built on the energy storage converter simulation server generates voltage and current values ​​of each node in the energy storage converter topology that needs to participate in the control calculation during operation, such as grid connection point voltage, grid connection point current, capacitor voltage, capacitor current, DC bus voltage and current signals;

[0010] Step (4): During the simulation process, the signal in the semi-physical model of the grid-type energy storage inverter interacts with the energy storage inverter control chassis in the manner described in step (1). The energy storage inverter control chassis will perform calculations based on the current operating conditions and sampling values ​​to generate a PWM wave. The PWM wave signal is input into the energy storage inverter simulation server, and then the voltage and current values ​​of each node of the energy storage inverter topology are adjusted in real time to form a control closed loop;

[0011] Step (5): Customize the communication protocol to open up the communication channel between the regional power grid simulation server and the energy storage inverter simulation server. Build a regional power grid model and connect the AC port of the energy storage inverter to the grid connection point of the regional power grid. Input the voltage, frequency, current and other information of the inverter grid connection point in the regional power grid model into the energy storage inverter simulation server through communication;

[0012] Step (6): The host computer communicates and interacts with the energy storage inverter control box to display the energy storage inverter operating status, fault alarm information, and sampling data in real time. The host computer issues remote control commands to adjust the operating status of the energy storage inverter, such as power on, power off, constant power charging, constant power discharging, constant voltage floating charge, off-grid VF, etc. The host computer issues remote adjustment commands to adjust the active power and reactive power output by the energy storage inverter;

[0013] Step (7): During the operation of the grid-type energy storage converter, the short-circuit ratio of the regional grid model is modified, and the load is switched on and off to create grid voltage frequency fluctuation or broadband oscillation, and the voltage amplitude fluctuation is created by switching on and off the fault grounding resistance;

[0014] Step (8): The above steps are used to complete the construction of a semi-physical simulation platform based on the energy storage inverter control chassis, the energy storage inverter simulation server, and the regional power grid simulation server. The semi-physical simulation platform provides a test environment similar to the actual regional power grid, simulating the grid-connected operation scenario of the energy storage inverter under grid voltage and frequency fluctuations. Then, the grid-connected energy storage inverter's own anti-interference ability under grid disturbance and its supporting role for grid voltage and frequency are tested.

[0015] Compared with the prior art, the beneficial effects are:

[0016] (1) The present invention provides a method for simulating multiple parallel machines of a grid-type energy storage converter. The method is applicable to a semi-physical simulation scenario of multiple parallel machines of a grid-type energy storage converter. The energy storage converter grid-connected joint simulation is performed by setting up an environment. The short-circuit ratio and load switching of the model are modified to create grid voltage frequency fluctuations or wide-band oscillations, and the anti-interference ability of the grid-type energy storage converter under large disturbances in the grid is tested, and its frequency support function for the grid under small disturbances in the grid is tested;

[0017] (2) By interconnecting the grid-connected energy storage converter simulation chassis with the simulation server, the operation of the energy storage converter in the actual regional power grid is simulated, the grid connection point power flow is calculated and analyzed, and the rationality of the grid-connected energy storage converter's frequency support algorithm is verified;

[0018] (3) The complex operation process is simplified. The human-machine interface can issue control instructions in real time and facilitate the observation of data and waveform curves during system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a schematic structural diagram of a semi-physical simulation platform for multi-machine parallel connection of a grid-type energy storage converter. DETAILED DESCRIPTION

[0020] The specific implementation methods of a multi-machine parallel semi-physical simulation platform and simulation method for a grid-type energy storage converter of the present invention are described in detail below in conjunction with the accompanying drawings.

[0021] Example 1

[0022] like Figure 1As shown, the semi-physical simulation platform of the present invention includes an energy storage inverter control chassis, an energy storage inverter simulation server, a regional power grid simulation server and a host computer controller, wherein the regional power grid simulation server is sequentially connected to the energy storage inverter simulation server, the energy storage inverter control machine and the host computer; the simulation platform jointly simulates the constructed regional power grid model with the semi-physical model of the grid-forming energy storage inverter, modifies the short-circuit ratio and load switching of the regional power grid model to create grid voltage frequency fluctuations or wide-band oscillations, tests the anti-interference ability of the grid-forming energy storage inverter under large grid disturbances, and its frequency support function for the grid under small grid disturbances; by interconnecting the energy storage inverter simulation service chassis with the energy storage inverter simulation server, the operation of the energy storage inverter in the actual regional power grid is simulated, the grid connection point flow is calculated and analyzed, and the rationality of the grid-forming energy storage inverter frequency support algorithm is verified.

[0023] Example 2

[0024] The present invention also proposes a semi-physical simulation method for multiple parallel machines of a grid-type energy storage converter, and the simulation method for multiple parallel machines of a grid-type energy storage converter comprises the following steps:

[0025] Step (1): Connect the signal output by the analog board of the energy storage converter simulation server to the analog sampling terminal of the energy storage converter control chassis, and connect the PWM wave signal emitted by the electric pulse terminal of the energy storage converter control chassis to the digital input board of the energy storage converter simulation server;

[0026] Step (2): constructing a semi-physical model of a network-type energy storage converter according to the topology of the energy storage converter, associating and matching the semi-physical model of the network-type energy storage converter with the measurement and control signals input and output by the actual physical interface, realizing the signal interaction between the energy storage converter simulation chassis and the energy storage converter control chassis, and forming hardware in the loop;

[0027] Step (3): The semi-physical model of the grid-connected energy storage converter built on the energy storage converter simulation server generates voltage and current values ​​of each node in the energy storage converter topology that needs to participate in the control calculation during operation, such as grid connection point voltage, grid connection point current, capacitor voltage, capacitor current, DC bus voltage and current signals;

[0028] Step (4): During the simulation process, the signal in the semi-physical model of the grid-type energy storage inverter interacts with the energy storage inverter control chassis in the manner described in step (1). The energy storage inverter control chassis will perform calculations based on the current operating conditions and sampling values ​​to generate a PWM wave. The PWM wave signal is input into the energy storage inverter simulation server, and then the voltage and current values ​​of each node of the energy storage inverter topology are adjusted in real time to form a control closed loop;

[0029] Step (5): Customize the communication protocol to open up the communication channel between the regional power grid simulation server and the energy storage inverter simulation server. Build a regional power grid model and connect the AC port of the energy storage inverter to the grid connection point of the regional power grid. Input the voltage, frequency, current and other information of the inverter grid connection point in the regional power grid model into the energy storage inverter simulation server through communication;

[0030] Step (6): The host computer communicates and interacts with the energy storage inverter control box to display the energy storage inverter operating status, fault alarm information, and sampling data in real time. The host computer issues remote control commands to adjust the operating status of the energy storage inverter, such as power on, power off, constant power charging, constant power discharging, constant voltage floating charge, off-grid VF, etc. The host computer issues remote adjustment commands to adjust the active power and reactive power output by the energy storage inverter;

[0031] Step (7): During the operation of the grid-type energy storage converter, the short-circuit ratio of the regional grid model is modified, and the load is switched on and off to create grid voltage frequency fluctuation or broadband oscillation, and the voltage amplitude fluctuation is created by switching on and off the fault grounding resistance;

[0032] Step (8): The above steps are used to complete the construction of a semi-physical simulation platform based on the energy storage inverter control chassis, the energy storage inverter simulation server, and the regional power grid simulation server. The semi-physical simulation platform provides a test environment similar to the actual regional power grid, simulating the grid-connected operation scenario of the energy storage inverter under grid voltage and frequency fluctuations. Then, the grid-connected energy storage inverter's own anti-interference ability under grid disturbance and its supporting role for grid voltage and frequency are tested.

[0033] The semi-physical simulation platform is suitable for simulation and analysis scenarios of grid-type energy storage inverters. In response to the frequency and voltage regulation requirements of the power system, a simulation platform is built to simulate the working conditions of the grid-type energy storage inverter and conduct joint simulation. The short-circuit ratio and load switching of the model are modified to create grid voltage frequency fluctuations or wide-band oscillations, and the anti-interference ability of the grid-type energy storage inverter under large grid disturbances and its frequency support for the grid under small grid disturbances are tested. The system's transient support capability for weak grids is verified by modeling and simulation, which greatly saves verification and design development costs, and is more convenient, safe, and reliable.

[0034] The energy storage converter of the present invention has a simple topology, complete measurement, control and protection functions, and is easy to debug, which helps to improve the safety and reliability of weak power grid operation.

[0035] The human-machine interface of the present invention is friendly, and the switch quantity, analog quantity and fault alarm information in the system can be intuitively monitored in real time. The monitoring system records important variables when the system is started and operated, which is convenient for fault analysis.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit the present invention. A person skilled in the art should understand that the specific implementation of the present invention can be modified or replaced by equivalents, but these modifications or changes are within the scope of protection of the pending claims.

Claims

1. A semi-physical simulation platform for multi-machine parallel connection of grid-type energy storage converters, characterized in that: The semi-physical simulation platform includes an energy storage inverter control chassis, an energy storage inverter simulation server, a regional power grid simulation server and a host computer controller, wherein the regional power grid simulation server is sequentially connected to the energy storage inverter simulation server, the energy storage inverter control machine and the host computer; the simulation platform jointly simulates the constructed regional power grid model with the semi-physical model of the grid-forming energy storage inverter, modifies the short-circuit ratio and load switching of the regional power grid model to create grid voltage frequency fluctuations or wide-band oscillations, tests the anti-interference ability of the grid-forming energy storage inverter under large grid disturbances, and its frequency support function for the grid under small grid disturbances; by interconnecting the energy storage inverter simulation service chassis with the energy storage inverter simulation server, the operation of the energy storage inverter in the actual regional power grid is simulated, the grid connection point flow is calculated and analyzed, and the rationality of the grid-forming energy storage inverter frequency support algorithm is verified.

2. The simulation method of a multi-machine parallel semi-physical simulation platform for a grid-type energy storage converter according to claim 1 is characterized in that: The simulation method comprises the following steps: Step (1): connecting the signal output by the analog board of the energy storage converter simulation server to the analog sampling terminal of the energy storage converter control chassis, and connecting the PWM wave signal emitted by the electric pulse terminal of the energy storage converter control chassis to the digital input board of the energy storage converter simulation server; Step (2): constructing a semi-physical model of a network-type energy storage converter according to the topology of the energy storage converter, associating and matching the semi-physical model of the network-type energy storage converter with the measurement and control signals input and output by the actual physical interface, realizing signal interaction between the energy storage converter simulation chassis and the energy storage converter control chassis, and forming hardware-in-the-loop; Step (3): generating voltage and current values ​​of each node in the energy storage converter topology that needs to participate in the control calculation, such as the grid connection point voltage, grid connection point current, capacitor voltage, capacitor current, and DC bus voltage and current signals, based on the grid-connected energy storage converter semi-physical model built by the energy storage converter simulation server during operation; Step (4): During the simulation process, the signal in the semi-physical model of the grid-type energy storage converter interacts with the control chassis of the energy storage converter in the manner described in step (1); Step (5): Customizing a communication protocol to open up a communication channel between the regional power grid simulation server and the energy storage converter simulation server; Step (6): the host computer communicates and interacts with the energy storage converter control chassis to display the energy storage converter operation status, fault alarm information, and sampling data in real time; Step (7): During the operation of the grid-type energy storage converter, the short-circuit ratio of the regional grid model is modified, and the load is switched on and off to create grid voltage frequency fluctuation or broadband oscillation, and the voltage amplitude fluctuation is created by switching on and off the fault grounding resistance; Step (8): Through the above steps, the construction of a semi-physical simulation platform based on the energy storage inverter control chassis, the energy storage inverter simulation server, and the regional power grid simulation server is completed.

3. A method for semi-physical simulation of multiple parallel machines of a grid-type energy storage converter according to claim 2, characterized in that: The signal in the semi-physical model of the grid-type energy storage inverter in step (4) interacts with the energy storage inverter control chassis in the manner described in step (1), specifically: the energy storage inverter control chassis calculates according to the current operating conditions and sampling values ​​to generate the PWM wave signal; the PWM wave signal is input into the energy inverter simulation server, and then the voltage and current values ​​of each node of the energy storage inverter topology are adjusted in real time to form a control closed loop.

4. A method for semi-physical simulation of multiple parallel machines of a grid-type energy storage converter according to claim 3, characterized in that: In step (5), a communication protocol is customized to open up a communication channel between the regional power grid simulation server and the energy storage converter simulation server, specifically: Construct a regional power grid model, connect the AC port of the energy storage inverter to the grid connection point of the regional power grid, and input the voltage, frequency, and current information of the inverter grid connection point in the regional power grid model into the energy storage inverter simulation server through communication.

5. A method for semi-physical simulation of multiple parallel machines of a grid-type energy storage converter according to claim 4, characterized in that: The host computer issues remote control commands to adjust the operating status of the energy storage inverter, such as power on, power off, constant power charging, constant power discharging, constant voltage floating charging, and off-grid VF; the host computer issues remote adjustment commands to adjust the active power and reactive power output by the energy storage inverter.

6. A method for semi-physical simulation of multiple parallel machines of a grid-type energy storage converter according to claim 5, characterized in that: The semi-physical simulation platform provides a test environment similar to the actual regional power grid, simulating the grid-connected operation scenario of the energy storage inverter under grid voltage and frequency fluctuations; and then tests the anti-interference ability of the grid-connected energy storage inverter under grid disturbances and its supporting role for the grid voltage and frequency.

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