Semi-physical simulation method for wind-solar hydrogen storage direct-current coupled off-grid power supply system

Abstract

The invention relates to the technical field of multi-energy coupled off-grid power supply systems, and discloses a wind-solar hydrogen storage direct current coupled off-grid power supply system semi-physical simulation method, which comprises the following steps of building an off-grid power supply system real-time simulation model; designing and communicating a communication link; software and hardware development of an equipment controller; and constructing and testing a semi-physical real-time simulation platform. According to the semi-physical simulation method for the wind-solar hydrogen storage direct current coupled off-grid power supply system, modeling is improved through model simplification, network subdivision and electrical decoupling real-time simulation, and high-precision real-time simulation of the off-grid power supply system is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-energy coupled off-grid power supply systems, and in particular to a semi-physical simulation method for a wind-solar-hydrogen storage DC coupled off-grid power supply system. Background Art

[0002] Wind, light, storage and other types of power sources supply power to the power-adjustable hydrogen production load through DC networking, which can achieve 100% new energy consumption. At the same time, the DC off-grid operation mode also avoids the shortcomings of traditional AC grid-connected operation, such as dependence on large power grid support, complex control, and energy scheduling requiring communication. In order to verify the effectiveness of the control strategy and energy management strategy of the wind-light-storage-hydrogen DC-coupled off-grid power supply system, and further reveal the operating characteristics of the off-grid power supply system under normal operating conditions and extreme conditions, a combination of digital simulation and physical testing is generally used. However, there are certain differences between digital simulation and actual equipment, and physical testing has high cost, low scalability, and poor compatibility. Both methods cannot meet the test and debugging needs of large-scale DC off-grid power supply systems.

[0003] To this end, a semi-physical simulation method with actual controller hardware access is used to fully verify the system operating characteristics and control strategies, which can effectively reduce the test cost. The hardware equipment is "plug and play" and can grasp the operating status data of the entire system and any position of the entire mission profile. It has a good supporting role in the design of system solutions, control strategies and energy management strategies. However, for the wind-solar-storage-hydrogen DC-coupled off-grid power supply system, its semi-physical real-time simulation implementation and verification still have the following difficulties:

[0004] 1) The large scale of the system and the large number of power electronic devices make it difficult to achieve high-precision real-time simulation of the entire system. Various energy forms such as wind, light, storage, and hydrogen are coupled through the DC bus. The interconnection of networks of different voltage levels leads to multiple system topology levels, many types of power electronic devices, and complex structures. It is extremely difficult to achieve high-precision real-time simulation of the entire system;

[0005] 2) The wind-solar-storage-hydrogen DC power supply system has tight coupling between devices, and high requirements for dynamic control response. The off-grid power supply system adopts a multi-level power electronic topology coupled through a high-voltage DC bus, and has high requirements for source-load power matching. It is necessary to set up a dedicated energy dispatching control command network to manage the energy of the system, ensure the rapid response of energy dispatching commands, and prevent the system source-load power mismatch caused by slow response of energy management commands, which may cause the power supply system to collapse;

[0006] 3) It is difficult to simulate the characteristics of power-adjustable equipment such as hydrogen production loads. Alkaline electrolyzers and PEM electrolyzers are both power-adjustable load equipment. It is often difficult to simulate their power-adjustable characteristics in experimental tests. It is necessary to adopt a DC / DC converter + fixed resistor method to switch the DC / DC converter control strategy to achieve real-time adjustment of the load power;

[0007] 4) The off-grid power supply system has high requirements for operational stability and great technical risks. The equipment control strategy and energy management strategy need to be fully tested and verified. Off-grid power supply is adopted without the voltage support of the large power grid. The system control strategy and energy management strategy have high matching requirements. It needs to be fully verified through hardware-in-the-loop tests, and comprehensive test design and verification should be carried out for normal operating conditions and fault conditions to eliminate technical risks.

[0008] In order to solve the above-mentioned practical problems faced by the semi-physical simulation and testing of the wind-solar-storage-hydrogen DC coupled off-grid power supply system, it is necessary to design an efficient system real-time simulation method, build a general hardware-in-the-loop semi-physical real-time simulation software and hardware platform, and carry out sufficient experimental verification, so as to form a semi-physical simulation method for the wind-solar-storage-hydrogen DC coupled off-grid power supply system, improve the efficiency of experimental verification, and fully release the technical risks of the DC off-grid power supply system solution and its control and energy management strategies. Summary of the invention

[0009] The purpose of the present invention is to address the deficiencies of the above-mentioned technologies and provide a semi-physical simulation method for a wind-solar-hydrogen storage DC coupled off-grid power supply system, which improves the modeling through model simplification, network segmentation and electrical decoupling real-time simulation to achieve high-precision real-time simulation of the off-grid power supply system.

[0010] To achieve the above-mentioned purpose, the semi-physical simulation method of the off-grid power supply system of wind-solar-hydrogen storage DC coupling involved in the present invention includes:

[0011] A semi-physical simulation method for a wind-solar-hydrogen storage DC-coupled off-grid power supply system comprises the following steps:

[0012] A) Build a real-time simulation model for off-grid power supply system: Establish an offline simulation model for off-grid power supply system with wind, solar, hydrogen storage and DC coupling, simplify the model of power electronic equipment, divide the network and electrically decouple it, obtain the real-time simulation model of off-grid power supply system, and realize small-step real-time simulation of the whole system model

[0013] B) Communication link design and interconnection: Design the communication mode to establish a fast network reliable communication link and a slow network reliable communication link between the off-grid power supply system real-time simulation model and the equipment controller and energy management controller;

[0014] C) Equipment controller software and hardware development: Design and develop the software architecture and hardware of equipment controller and energy management controller;

[0015] D) Construction and testing of semi-physical real-time simulation platform: A semi-physical real-time simulation platform is constructed based on the real-time simulation model of the off-grid power supply system, the software architecture and hardware of the equipment controller and the energy management controller, and the controller hardware is subjected to in-loop semi-physical simulation testing.

[0016] Preferably, the wind-solar-hydrogen storage DC-coupled off-grid power supply system includes a new energy microgrid, an energy storage device, power electronic conversion devices at various levels, and power adjustable load equipment.

[0017] Preferably, in the step A), when simplifying the model of the power electronic equipment, the multi-phase motor is replaced by a single three-phase motor model, and the multi-phase multi-branch power electronic equipment is replaced by a single-branch or less-branch power electronic equipment model, and the main topological connection relationship is kept unchanged, so as to obtain a simplified multi-phase power electronic equipment model with a reduced order;

[0018] When performing network segmentation, a network segmentation point is set on the DC transmission line in the offline simulation model of the off-grid power supply system, and a network segmentation point is not set inside a single device model or between models with strong coupling. The number of switch elements in a single segmentation group formed by segmentation shall not exceed 12. After network segmentation, the entire system is divided into multiple subsystems.

[0019] When performing electrical decoupling, electrical decoupling is performed at the network division point by using a controlled voltage source + controlled current source + reverse compensation current source in parallel with a virtual resistor. The topological structure is as follows: the power supply side of the decoupled interface adopts a circuit topology of a controlled current source + reverse compensation current source in parallel with a virtual resistor, and the load side of the decoupled interface adopts a circuit topology of a controlled voltage source, wherein the given input of the controlled current source is the output current measured by the controlled voltage source on the load side, the given input of the controlled voltage source is the voltage on both sides of the controlled current source on the power supply side, and the given input of the reverse compensation current source is the current flowing through the virtual resistor. Through electrical decoupling, the electrically coupled circuit topology is decoupled into a circuit topology transmitted by digital signals, thereby reducing the order of the system model.

[0020] Preferably, in step B), the commercial real-time simulator and the host computer communicate via Ethernet, the real-time simulation model of the wind-solar-hydrogen storage DC-coupled off-grid power supply system is calculated in real time in the commercial real-time simulator, and typical characteristic quantities including system voltage and current are uploaded to the host computer, and the host computer synchronously monitors the real-time operating status of the commercial real-time simulator;

[0021] The commercial real-time simulator and the DSP hardware circuit of the device controller are connected via an I / O board and an optical fiber transmission line. The analog input and analog output directly exchange data with the DSP hardware circuit of the device controller via the I / O interface of the commercial real-time simulator. The digital output and digital input realize data exchange between the commercial real-time simulator and the DSP hardware circuit of the device controller via an optical fiber adapter board and an optical fiber transmission line.

[0022] The commercial real-time simulator and the energy management controller communicate via Ethernet using UDP or TCP communication protocol, and the energy management controller and the hardware circuit of the device controller communicate via Ethernet using Modbus TCP communication protocol.

[0023] Preferably, in the step C), the software architecture includes an FPGA module, an ARM module and a DSP module, the FPGA module is responsible for the control pulse sending and phase shift control of the device controller; the ARM module is responsible for the switching action and energy management communication of the device controller; the DSP module is responsible for state control, algorithm control and fault diagnosis; the core DSP control code of each power electronic converter controller in the system is compiled based on the device control strategy to complete the online closed-loop control of the device controller, and the device controller programming host computer adjusts the PI control parameters to obtain the output voltage and current waveforms required by the device controller.

[0024] Preferably, in the step C), the hardware includes a device controller, a commercial real-time simulator, an energy management controller and various types of interface boards, and a platform hardware architecture is constructed with commercial real-time simulation as the center and the device controller and energy management controller as the periphery. The analog quantity of the commercial real-time simulator is connected to the voltage and current conversion board through the DB37 interface, and then connected to the device controller or voltage and current sensor; the digital quantity of the commercial real-time simulator is connected to the fiber optic conversion board through the DB37 interface, and then connected to the device controller; the simulator and the energy management controller are connected through Ethernet; the energy management controller and the device controller are connected through Ethernet.

[0025] Preferably, in the step D), when building a semi-physical real-time simulation platform, a real-time simulation model of the off-grid power supply system is built in the real-time simulation software of the host computer, and simulation verification is carried out in a commercial real-time simulator, and real-time operation without timeout is achieved under the specified simulation step size, and the system operation status is observed to be normal through an oscilloscope.

[0026] Preferably, in the step D), the device controller includes controllers of a DC / DC converter on the energy storage side, a DC / DC boost converter on the power supply side, a hydrogen production power converter, an electrolyzer simulated load DC / DC converter, a photovoltaic side DC / DC converter, and a fan side AC / DC converter;

[0027] The photovoltaic side DC / DC converter or the wind turbine side AC / DC converter receives the voltage and current signals output by the commercial real-time simulator. The photovoltaic side DC / DC converter or the wind turbine side AC / DC converter controller generates the power module IGBT drive signal based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

[0028] The DC / DC converter on the energy storage side receives the voltage and current signals output by the commercial real-time simulator. The DC / DC converter controller on the energy storage side calculates and generates the IGBT drive signal of the power module based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

[0029] The DC / DC boost converter on the power supply side receives the voltage and current signals output by the commercial real-time simulator, and outputs the SVPWM pulse signal through the DC / DC boost converter controller hardware circuit on the power supply side to control the IGBT switch device of the main circuit of the DC / DC boost converter on the power supply side;

[0030] The hydrogen production power converter receives the voltage and current signals output by the commercial real-time simulator. The hydrogen production power converter controller calculates and generates the power module IGBT drive signal based on the feedback reference value in the control loop transmitted back by the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

[0031] The electrolyzer simulated load DC / DC converter receives the voltage and current signals output by the commercial real-time simulator. The electrolyzer simulated load DC / DC converter generates the power module IGBT drive signal based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

[0032] Preferably, in the step D), the energy management controller includes designing a system black start control strategy, a normal operating condition energy scheduling strategy, and an abnormal operating condition energy scheduling strategy, and realizes energy scheduling of the system in combination with the energy management software code. Normal operating conditions include abundant wind and solar resources, scarce wind resources and abundant light resources, abundant wind resources and scarce light resources, and scarce wind and solar resources; abnormal operating conditions include wind turbine failure, photovoltaic failure, energy storage failure, hydrogen production power supply failure, and simulated electrolyzer load failure.

[0033] Preferably, in step D), the semi-physical simulation test includes:

[0034] Semi-physical simulation verification of equipment control strategy: First, a semi-physical simulation test of a single device is carried out. The actual controller is used to control a single device, and other devices are controlled by simulation models. The correctness of the control strategy of a single device and the software and hardware platform are verified through hardware-in-the-loop testing;

[0035] Secondly, a semi-physical simulation test of a single functional partition is carried out, including the photovoltaic power supply area, the wind turbine power supply area, the hydrogen production power supply area and the hydrogen production load area. The actual controller is used for each single functional partition, and the simulation model is used for other functional areas. The correctness of the control strategy of the single functional partition and the software and hardware platform is verified through hardware-in-the-loop testing;

[0036] Then, a semi-physical simulation test of a single power supply link is carried out. The actual controller is used for the entire single power supply link from the photovoltaic or wind turbine power supply area to the simulated hydrogen production load area, and the simulation model is used for other power supply links. The correctness of the control strategy of the single power supply link and the software and hardware platform is verified through hardware-in-the-loop testing.

[0037] Finally, a semi-physical simulation test is conducted on all controllers in the whole system. All device controllers in the whole system use actual controllers, and the system circuit topology uses a simulation model. The correctness of the system control strategy and the software and hardware platform is verified through hardware-in-the-loop testing.

[0038] Semi-physical simulation verification of system energy management strategy: Hardware-in-the-loop semi-physical simulation tests are performed on the energy management strategies under black start, normal operating conditions, and abnormal operating conditions of the off-grid power supply system to verify the correctness of the energy management strategy and the hardware and software platform.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] 1. Through equipment model simplification, network segmentation, and electrical decoupling, the system offline simulation model is transformed into a real-time simulation model that can be efficiently calculated in real time, thus achieving high-precision real-time calculation of the entire system;

[0041] 2. Designed two data communication links, the status information network and the control command network, and adopted the "dual network separation" method to achieve rapid response to energy management scheduling instructions;

[0042] 3. The DC / DC converter + constant load method can simulate the actual power adjustable characteristics of the electrolyzer;

[0043] 3. Combined with any device controller hardware and energy management system hardware, the semi-physical real-time simulation platform for the device controller hardware in the loop can be built and tested to solve the problems of high cost, high risk and complex operation caused by hardware-based test;

[0044] 4. Combine the real-time simulation system model with the energy management hardware and controller hardware to carry out semi-physical simulation verification of the wind, solar, hydrogen storage DC-coupled off-grid power supply system under normal operating conditions and emergency operating conditions, fully releasing technical risks. It can provide an efficient and convenient verification method for the engineering application of the wind, solar, hydrogen storage and other energy DC-coupled off-grid power supply system, and lay a technical foundation for the reliable development and application of new energy hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of a semi-physical simulation method of a wind-solar-hydrogen storage DC-coupled off-grid power supply system of the present invention;

[0046] Figure 2 It is a structural schematic diagram of an embodiment of a semi-physical simulation method for an off-grid power supply system with wind-solar-hydrogen storage DC coupling according to the present invention;

[0047] Figure 3 to Figure 7 It is a diagram of a real-time simulation improved modeling method of a semi-physical simulation method of an off-grid power supply system with wind-solar-hydrogen storage DC coupling according to the present invention;

[0048] Figure 8 It is a hardware circuit diagram of the semi-physical simulation method of the off-grid power supply system with wind-solar hydrogen storage DC coupling of the present invention;

[0049] Figures 9 to 16 The semi-physical simulation test results of the off-grid power supply system with wind-solar-hydrogen storage DC coupling when the energy management controller is normally dispatched were carried out based on the semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling of the present invention, among which: Fig. 9 This is a single fan output power diagram. Fig.10 This is a single photovoltaic output power diagram. Fig.11 It is the wind turbine energy storage output power diagram; Fig.12 is the photovoltaic energy storage output power diagram, Fig.13 This is the SOC change diagram of the wind turbine energy storage. Fig.14 This is the SOC change diagram of photovoltaic energy storage. Fig.15 This is the power diagram of a single alkaline electrolyzer. Fig.16 This is the power diagram of a single PEM electrolyzer. DETAILED DESCRIPTION

[0050] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0051] like Figure 1 As shown, a semi-physical simulation method for a wind-solar-hydrogen storage DC-coupled off-grid power supply system comprises the following steps:

[0052] A) Build a real-time simulation model for off-grid power supply system: Establish an offline simulation model for off-grid power supply system with wind, solar, hydrogen storage and DC coupling, simplify the model of power electronic equipment, divide the network and electrically decouple it, obtain the real-time simulation model of off-grid power supply system, and realize small-step real-time simulation of the whole system model

[0053] B) Communication link design and interconnection: Design the communication mode to establish a fast network reliable communication link and a slow network reliable communication link between the off-grid power supply system real-time simulation model and the equipment controller and energy management controller;

[0054] C) Equipment controller software and hardware development: Design and develop the software architecture and hardware of equipment controller and energy management controller;

[0055] D) Construction and testing of semi-physical real-time simulation platform: A semi-physical real-time simulation platform is constructed based on the real-time simulation model of the off-grid power supply system, the software architecture and hardware of the equipment controller and the energy management controller, and the controller hardware is subjected to in-loop semi-physical simulation testing.

[0056] The off-grid power supply system of wind, solar and hydrogen storage DC coupling includes new energy microgrid, energy storage device, power electronic conversion devices at all levels and power adjustable load equipment. The new energy microgrid includes new energy power generation equipment such as wind turbines and photovoltaics. The power adjustable load equipment includes alkaline electrolyzers and PEM electrolyzers, such as Figure 2 As shown, it is an off-grid power supply system with wind, solar, hydrogen storage and DC coupling. The new energy power generation area consists of n photovoltaic power generation subsystems and m wind power generation subsystems. The n photovoltaic power generation subsystems consist of n photovoltaic power generation simulation devices, n photovoltaic output DC / DC converters, n energy storage battery simulation power supplies, and n energy storage DC / DC converters. The m wind power generation subsystems consist of m wind power generation simulation devices, m wind turbine output AC / DC converters, m energy storage battery simulation power supplies, and m energy storage DC / DC converters. The DC boost area consists of k DC bidirectional DC / DC boost converters, k=n+m. The DC distribution area contains k reactors and resistors to replace the impedance of the transmission cable during the long-distance transmission of electric energy. The hydrogen production power supply area contains p alkaline electrolyzer hydrogen production power supplies and q PEM electrolyzer hydrogen production power supplies. The simulated load area contains p alkaline electrolyzer simulation load devices and q PEM electrolyzer simulation load devices. The hydrogen production simulation load device consists of a DC / DC converter and a resistive load.

[0057] That is, the power generation sub-area adopts the method of distributed energy storage access to each new energy side to provide voltage support for the medium-voltage DC off-grid new energy microgrid. The photovoltaic power generation sub-system consists of a controllable DC voltage source, a DC / DC converter and an energy storage sub-system, and the wind power generation sub-system consists of a controllable AC voltage source, an AC / DC rectifier and an energy storage sub-system. The energy storage battery sub-system consists of an energy storage battery simulation power supply and a DC / DC converter. The control of the DC / DC converter and AC / DC rectifier in the new energy power generation area is realized in an online closed loop using the actual controller and the software code embedded therein.

[0058] The DC boost area is composed of k DC bidirectional DC / DC boost converters, which can achieve voltage level changes on both sides of the device and realize long-distance transmission of electric energy by raising the voltage level of renewable energy. The control of the DC bidirectional DC / DC boost converter is realized online in a closed loop using an actual controller and the software code embedded in it. The DC distribution area uses k reactors and resistors to replace the impedance of the transmission cable during the long-distance transmission of electric energy, simulating the voltage drop phenomenon of the transmission line.

[0059] The hydrogen production load area uses power-adjustable simulated loads such as alkaline electrolyzers and PEM electrolyzers for power consumption, and configures the electrolyzer hydrogen production power supply to power the simulated load. The main external characteristic of the hydrogen production power supply is the output of low voltage and high current, which supplies power to the back-end hydrogen production simulated load. The hydrogen production simulated load consists of a DC / DC converter and a resistive load. The DC / DC converter adopts the input voltage + output current control method, substitutes the output current of the hydrogen production power supply into the electrolyzer load power characteristic formula, calculates the electrolyzer input voltage expression, sets the input voltage as the DC / DC converter double closed-loop voltage outer loop reference value, and controls the DC / DC converter output current at the same time, so that the load power can be adjusted according to the output current of the hydrogen production power supply, thereby meeting the demand for automatic adjustment of the load power. Both the hydrogen production power supply and the DC / DC converter control are implemented in an online closed loop using the actual controller and the software code embedded therein.

[0060] In step A) of this embodiment, when simplifying the model of the power electronic equipment, the multi-phase motor is replaced by a single three-phase motor model, and the multi-phase multi-branch power electronic equipment is replaced by a single branch or a few branches of power electronic equipment. The main topological connection relationship is kept unchanged to obtain a simplified multi-phase power electronic equipment model with a reduced order. Taking this embodiment as an example, in the original equipment model, the circuit topology of k DC bidirectional DC / DC boost converters is 26 Figure 3 The branches are connected in series on the input side and in parallel on the output side to achieve the boost of the energy storage output voltage to the DC main grid; the circuit topology of p alkaline electrolyzer hydrogen production power sources is 26 Figure 4The branches are connected in series on the input side and in parallel on the output side to supply power to the alkaline electrolyzer with medium-voltage main grid power. The circuit topology of the hydrogen production power supply of q PEM electrolyzers is 26 Figure 5 The input side is connected in series and the output side is connected in parallel to realize the supply of medium-voltage network power to the PEM electrolyzer, thereby reducing the number of switching elements in the main power electronic converter from 3744 to 432, greatly reducing the amount of calculation.

[0061] When performing network segmentation, a network segmentation point is set on the DC transmission line in the offline simulation model of the off-grid power supply system, and the network segmentation point is not set inside a single device model or between models with strong coupling. The number of switch elements in a single segmentation group formed by segmentation does not exceed 12. After network segmentation, the entire system is divided into multiple subsystems. When performing electrical decoupling, electrical decoupling is performed at the network segmentation point in the form of a controlled voltage source + a controlled current source + a reverse compensation current source in parallel with a virtual resistor. The topological structure is: the power supply side of the decoupled interface adopts a circuit topology of a controlled current source + a reverse compensation current source in parallel with a virtual resistor, and the load side of the decoupled interface adopts a circuit topology of a controlled voltage source, wherein the given input of the controlled current source is the output current measured by the controlled voltage source on the load side, the given input of the controlled voltage source is the voltage on both sides of the controlled current source on the power supply side, and the given input of the reverse compensation current source is the current flowing through the virtual resistor. The circuit topology of electrical coupling is decoupled into a circuit topology transmitted by digital signals through electrical decoupling, thereby reducing the order of the system model.

[0062] Specifically in this embodiment, network segmentation and decoupling are performed between the new energy power generation area and the DC boost area; network segmentation and decoupling are performed between each DC boost converter and each hydrogen production power source in the DC boost area; network segmentation and decoupling are performed between the hydrogen production power source and the hydrogen production simulation load, and the internal structure of the main equipment is kept intact. The network segmentation points are set as follows: Figure 6 As shown, at the above network segmentation point, the Figure 7 The decoupling interface shown is electrically decoupled. After the above-mentioned model simplification, network segmentation and electrical decoupling processing, the whole system model can be divided into several smaller subsystems. By utilizing the parallel computing function of commercial simulation software, real-time simulation with a simulation step of 40μs for the whole system can be achieved.

[0063] In step B) of this embodiment, Figure 8 As shown, the commercial real-time simulator and the host computer communicate via Ethernet, the real-time simulation model of the off-grid power supply system with wind-solar-hydrogen storage DC coupling is calculated in real time in the commercial real-time simulator, and the typical characteristic quantities including the system voltage and current are uploaded to the host computer, and the host computer synchronously monitors the real-time operation status of the commercial real-time simulator;

[0064] The commercial real-time simulator and the DSP hardware circuit of the device controller are connected via an I / O board and an optical fiber transmission line. The analog input and analog output directly exchange data with the DSP hardware circuit of the device controller via the I / O interface of the commercial real-time simulator. The digital output and digital input realize data exchange between the commercial real-time simulator and the DSP hardware circuit of the device controller via an optical fiber adapter board and an optical fiber transmission line.

[0065] The commercial real-time simulator and the energy management controller communicate via Ethernet using UDP or TCP communication protocol, and the energy management controller and the hardware circuit of the device controller communicate via Ethernet using Modbus TCP communication protocol.

[0066] By constructing dual Ethernet communication channels between the energy management controller and the device controller, one Ethernet communication channel ensures that the energy management controller obtains the real-time operating status of the off-grid power supply system from the commercial real-time simulator, and one Ethernet communication channel ensures that the energy management scheduling software generates scheduling instructions and sends them to the device controller. The device controller then feeds back the updated operating status after scheduling to the commercial real-time simulator, thereby realizing closed-loop control of energy management scheduling.

[0067] In step C) of this embodiment, the software architecture includes an FPGA module, an ARM module and a DSP module. The FPGA module is responsible for the control pulse sending and phase shift control of the device controller; the ARM module is responsible for the switching action and energy management communication of the device controller; the DSP module is responsible for state control, algorithm control and fault diagnosis; the core DSP control code of each power electronic converter controller in the system is compiled based on the device control strategy to complete the online closed-loop control of the device controller, and the device controller programming host computer adjusts the PI control parameters to obtain the output voltage and current waveforms required by the device controller.

[0068] In step C) of this embodiment, the hardware includes a device controller, a commercial real-time simulator, an energy management controller and various types of interface boards, constructing a platform hardware architecture with commercial real-time simulation as the center and the device controller and energy management controller as the periphery. The analog quantity of the commercial real-time simulator is connected to the voltage and current conversion board through the DB37 interface, and then connected to the device controller or voltage and current sensor; the digital quantity of the commercial real-time simulator is connected to the fiber optic conversion board through the DB37 interface, and then connected to the device controller; the simulator and the energy management controller are connected through Ethernet; the energy management controller and the device controller are connected through Ethernet.

[0069] In step D) of this embodiment, when building a semi-physical real-time simulation platform, a real-time simulation model of the off-grid power supply system is built in the real-time simulation software of the host computer, and simulation verification is carried out in a commercial real-time simulator. Real-time operation without timeout is achieved under the specified simulation step size, and the system operation status is normal when observed through an oscilloscope.

[0070] In step D), the device controller includes controllers of a DC / DC converter on the energy storage side, a DC / DC boost converter on the power supply side, a hydrogen production power converter, an electrolyzer simulated load DC / DC converter, a photovoltaic side DC / DC converter, and a fan side AC / DC converter;

[0071] The photovoltaic side DC / DC converter or the wind turbine side AC / DC converter receives the voltage and current signals output by the commercial real-time simulator. The photovoltaic side DC / DC converter or the wind turbine side AC / DC converter controller generates the power module IGBT drive signal based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

[0072] The DC / DC converter on the energy storage side receives the voltage and current signals output by the commercial real-time simulator. The DC / DC converter controller on the energy storage side calculates and generates the IGBT drive signal of the power module based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

[0073] The DC / DC boost converter on the power supply side receives the voltage and current signals output by the commercial real-time simulator, and outputs the SVPWM pulse signal through the DC / DC boost converter controller hardware circuit on the power supply side to control the IGBT switch device of the main circuit of the DC / DC boost converter on the power supply side;

[0074] The hydrogen production power converter receives the voltage and current signals output by the commercial real-time simulator. The hydrogen production power converter controller calculates and generates the power module IGBT drive signal based on the feedback reference value in the control loop transmitted back by the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

[0075] The electrolyzer simulated load DC / DC converter receives the voltage and current signals output by the commercial real-time simulator. The electrolyzer simulated load DC / DC converter generates the power module IGBT drive signal based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

[0076] In step D), the energy management controller includes designing a system black start control strategy, a normal operating condition energy scheduling strategy, and an abnormal operating condition energy scheduling strategy, and realizes energy scheduling of the system in combination with the energy management software code. Normal operating conditions include abundant wind and solar resources, scarce wind resources and abundant light resources, abundant wind resources and scarce light resources, and scarce wind and solar resources; abnormal operating conditions include wind turbine failure, photovoltaic failure, energy storage failure, hydrogen production power supply failure, and simulated electrolyzer load failure.

[0077] In step D), the semi-physical simulation test includes:

[0078] Semi-physical simulation verification of equipment control strategy: First, a semi-physical simulation test of a single device is carried out. The actual controller is used to control a single device, and other devices are controlled by simulation models. The correctness of the control strategy of a single device and the software and hardware platform are verified through hardware-in-the-loop testing;

[0079] Secondly, a semi-physical simulation test of a single functional partition is carried out, including the photovoltaic power supply area, the wind turbine power supply area, the hydrogen production power supply area and the hydrogen production load area. The actual controller is used for each single functional partition, and the simulation model is used for other functional areas. The correctness of the control strategy of the single functional partition and the software and hardware platform is verified through hardware-in-the-loop testing;

[0080] Then, a semi-physical simulation test of a single power supply link is carried out. The actual controller is used for the entire single power supply link from the photovoltaic or wind turbine power supply area to the simulated hydrogen production load area, and the simulation model is used for other power supply links. The correctness of the control strategy of the single power supply link and the software and hardware platform is verified through hardware-in-the-loop testing.

[0081] Finally, a semi-physical simulation test is conducted on all controllers in the whole system. All device controllers in the whole system use actual controllers, and the system circuit topology uses a simulation model. The correctness of the system control strategy and the software and hardware platform is verified through hardware-in-the-loop testing.

[0082] Semi-physical simulation verification of system energy management strategy: Hardware-in-the-loop semi-physical simulation tests are performed on the energy management strategies under black start, normal operating conditions, and abnormal operating conditions of the off-grid power supply system to verify the correctness of the energy management strategy and the hardware and software platform.

[0083] When the present embodiment performs simulation, Fig. 9 This is a single fan output power diagram. Fig.10 This is a single photovoltaic output power diagram. It can be seen that the output power of wind turbines and photovoltaics is highly intermittent. Fig.11 is the wind turbine energy storage output power diagram, Fig.12It is the output power diagram of photovoltaic energy storage. When the system is operating normally, the output power of the energy storage on the wind turbine side and the photovoltaic side is zero; when the wind turbine or photovoltaic output is not enough to maintain the load operating in its minimum power range, the energy storage is discharged according to its charge state; Fig.13 This is the SOC change diagram of the wind turbine energy storage. Fig.14 It is the SOC variation diagram of photovoltaic energy storage; when the charge state of the energy storage is greater than its upper limit, the energy storage is discharged; when the charge state of the energy storage is less than its lower limit, the energy storage is on standby; when the wind turbine or photovoltaic output is in excess and exceeds the maximum power range of the load, the energy storage is charged according to its charge state; when the charge state of the energy storage is greater than its upper limit, the energy storage is on standby, and there is wind and solar abandonment at this time; when the charge state of the energy storage is less than its lower limit, the energy storage is charged. Fig.15 This is the power diagram of a single alkaline electrolyzer. Fig.16 is the power diagram of a single PEM electrolyzer, Fig.15 and Fig.16 It can be seen that the load always operates within its adjustable power range. Therefore, the accuracy and reliability of the system semi-physical simulation platform are verified.

[0084] The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling of the present invention converts the system offline simulation model into a real-time simulation model capable of efficient real-time calculation through device model simplification, network segmentation and electrical decoupling, thereby realizing high-precision real-time calculation of the whole system; two data communication links, namely the state information network and the control instruction network, are designed, and the "dual network separation" method is adopted to realize the rapid response of the energy management scheduling instruction; the DC / DC converter + constant load method is adopted to simulate the actual power adjustable characteristics of the electrolyzer; in combination with any controller hardware of the device under test and the hardware of the energy management system, the semi-physical real-time simulation platform of the controller hardware of the device under test can be constructed and tested, so as to solve the problems of high cost, high risk and complex operation caused by the experimental test based on the hardware; the real-time simulation system model is combined with the energy management hardware and the controller hardware, and the semi-physical simulation verification of the off-grid power supply system with wind-solar-hydrogen storage DC coupling under normal operating conditions and emergency operating conditions is carried out, so as to fully release the technical risks, and can provide an efficient and convenient verification means for the engineering application of the off-grid power supply system with wind-solar-hydrogen storage DC coupling of multiple energy sources, and lay a technical foundation for the reliable development and application of hydrogen production from new energy.

[0085] In the above implementation cases, the descriptions of various embodiments have different emphases. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0086] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the embodiments described above, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A semi-physical simulation method for a wind-solar-hydrogen storage DC-coupled off-grid power supply system, characterized in that: The steps include: A) Build a real-time simulation model for off-grid power supply system: Establish an offline simulation model for off-grid power supply system with wind, solar, hydrogen storage and DC coupling, simplify the model of power electronic equipment, divide the network and electrically decouple it, obtain the real-time simulation model of off-grid power supply system, and realize small-step real-time simulation of the whole system model B) Communication link design and interconnection: Design the communication mode to establish a fast network reliable communication link and a slow network reliable communication link between the off-grid power supply system real-time simulation model and the equipment controller and energy management controller; C) Equipment controller software and hardware development: Design and develop the software architecture and hardware of equipment controller and energy management controller; D) Construction and testing of semi-physical real-time simulation platform: A semi-physical real-time simulation platform is constructed based on the real-time simulation model of the off-grid power supply system, the software architecture and hardware of the equipment controller and the energy management controller, and the controller hardware is subjected to in-loop semi-physical simulation testing.

2. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1 is characterized by: The wind-solar-hydrogen storage DC-coupled off-grid power supply system includes a new energy microgrid, energy storage devices, power electronic conversion devices at various levels, and power-adjustable load equipment.

3. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1 is characterized by: In the step A), when simplifying the model of the power electronic equipment, the multi-phase motor is replaced by a single three-phase motor model, and the multi-phase multi-branch power electronic equipment is replaced by a single-branch or less-branch power electronic equipment model, and the main topological connection relationship is kept unchanged, so as to obtain a simplified multi-phase power electronic equipment model with a reduced order; When performing network segmentation, a network segmentation point is set on the DC transmission line in the offline simulation model of the off-grid power supply system, and a network segmentation point is not set inside a single device model or between models with strong coupling. The number of switch elements in a single segmentation group formed by segmentation shall not exceed 12. After network segmentation, the entire system is divided into multiple subsystems. When performing electrical decoupling, electrical decoupling is performed at the network division point by using a controlled voltage source + controlled current source + reverse compensation current source in parallel with a virtual resistor. The topological structure is as follows: the power supply side of the decoupled interface adopts a circuit topology of a controlled current source + reverse compensation current source in parallel with a virtual resistor, and the load side of the decoupled interface adopts a circuit topology of a controlled voltage source, wherein the given input of the controlled current source is the output current measured by the controlled voltage source on the load side, the given input of the controlled voltage source is the voltage on both sides of the controlled current source on the power supply side, and the given input of the reverse compensation current source is the current flowing through the virtual resistor. Through electrical decoupling, the electrically coupled circuit topology is decoupled into a circuit topology transmitted by digital signals, thereby reducing the order of the system model.

4. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1 is characterized by: In the step B), the commercial real-time simulator and the host computer communicate via Ethernet, the real-time simulation model of the wind-solar-hydrogen storage DC-coupled off-grid power supply system is calculated in real time in the commercial real-time simulator, and typical characteristic quantities including system voltage and current are uploaded to the host computer, and the host computer synchronously monitors the real-time operating status of the commercial real-time simulator; The commercial real-time simulator and the DSP hardware circuit of the device controller are connected via an I / O board and an optical fiber transmission line. The analog input and analog output directly exchange data with the DSP hardware circuit of the device controller via the I / O interface of the commercial real-time simulator. The digital output and digital input realize data exchange between the commercial real-time simulator and the DSP hardware circuit of the device controller via an optical fiber adapter board and an optical fiber transmission line. The commercial real-time simulator and the energy management controller communicate via Ethernet using UDP or TCP communication protocol, and the energy management controller and the hardware circuit of the device controller communicate via Ethernet using Modbus TCP communication protocol.

5. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1 is characterized by: In the step C), the software architecture includes an FPGA module, an ARM module and a DSP module, wherein the FPGA module is responsible for the control pulse transmission and phase shift control of the device controller; the ARM module is responsible for the switch action and energy management communication of the device controller; The DSP module is responsible for state control, algorithm control and fault diagnosis. The core DSP control code of each power electronic converter controller in the system is compiled based on the device control strategy to complete the online closed-loop control of the device controller. The device controller programming host computer adjusts the PI control parameters to obtain the output voltage and current waveforms required by the device controller.

6. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1 is characterized by: In the step C), the hardware includes a device controller, a commercial real-time simulator, an energy management controller and various types of interface boards, and a platform hardware architecture is constructed with the commercial real-time simulator as the center and the device controller and the energy management controller as the periphery. The analog quantity of the commercial real-time simulator is connected to the voltage and current conversion board through the DB37 interface, and then connected to the device controller or the voltage and current sensor; the digital quantity of the commercial real-time simulator is connected to the fiber optic conversion board through the DB37 interface, and then connected to the device controller; the simulator and the energy management controller are connected through Ethernet; the energy management controller and the device controller are connected through Ethernet.

7. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1 is characterized by: In the step D), when building a semi-physical real-time simulation platform, a real-time simulation model of the off-grid power supply system is built in the real-time simulation software of the host computer, and simulation verification is carried out in a commercial real-time simulator, and real-time operation without timeout is achieved under the specified simulation step size, and the system operation status is observed by an oscilloscope to be normal.

8. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1 is characterized by: In the step D), the device controller includes controllers of a DC / DC converter on the energy storage side, a DC / DC boost converter on the power supply side, a hydrogen production power converter, an electrolyzer simulated load DC / DC converter, a photovoltaic side DC / DC converter, and a fan side AC / DC converter; The photovoltaic side DC / DC converter or the wind turbine side AC / DC converter receives the voltage and current signals output by the commercial real-time simulator. The photovoltaic side DC / DC converter or the wind turbine side AC / DC converter controller generates the power module IGBT drive signal based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code. The DC / DC converter on the energy storage side receives the voltage and current signals output by the commercial real-time simulator. The DC / DC converter controller on the energy storage side calculates and generates the IGBT drive signal of the power module based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code. The DC / DC boost converter on the power supply side receives the voltage and current signals output by the commercial real-time simulator, and outputs the SVPWM pulse signal through the DC / DC boost converter controller hardware circuit on the power supply side to control the IGBT switch device of the main circuit of the DC / DC boost converter on the power supply side; The hydrogen production power converter receives the voltage and current signals output by the commercial real-time simulator. The hydrogen production power converter controller calculates and generates the power module IGBT drive signal based on the feedback reference value in the control loop transmitted back by the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code. The electrolyzer simulated load DC / DC converter receives the voltage and current signals output by the commercial real-time simulator. The electrolyzer simulated load DC / DC converter generates the power module IGBT drive signal based on the feedback reference value in the feedback control loop of the commercial real-time simulator, and completes the online closed-loop control of the equipment in combination with the control strategy DSP software code.

9. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1 is characterized by: In the step D), the energy management controller includes designing a system black start control strategy, a normal operating condition energy scheduling strategy, and an abnormal operating condition energy scheduling strategy, and realizes energy scheduling of the system in combination with the energy management software code. Normal operating conditions include abundant wind and solar resources, scarce wind resources and abundant light resources, abundant wind resources and scarce light resources, and scarce wind and solar resources; abnormal operating conditions include wind turbine failure, photovoltaic failure, energy storage failure, hydrogen production power supply failure, and simulated electrolyzer load failure.

10. The semi-physical simulation method of the off-grid power supply system with wind-solar-hydrogen storage DC coupling as claimed in claim 1, characterized in that: In the step D), the semi-physical simulation test includes: Semi-physical simulation verification of equipment control strategy: First, a semi-physical simulation test of a single device is carried out. The actual controller is used to control a single device, and other devices are controlled by simulation models. The correctness of the control strategy of a single device and the software and hardware platform are verified through hardware-in-the-loop testing; Secondly, a semi-physical simulation test of a single functional partition is carried out, including the photovoltaic power supply area, the wind turbine power supply area, the hydrogen production power supply area and the hydrogen production load area. The actual controller is used for each single functional partition, and the simulation model is used for other functional areas. The correctness of the control strategy of the single functional partition and the software and hardware platform is verified through hardware-in-the-loop testing; Then, a semi-physical simulation test of a single power supply link is carried out. The actual controller is used for the entire single power supply link from the photovoltaic or wind turbine power supply area to the simulated hydrogen production load area, and the simulation model is used for other power supply links. The correctness of the control strategy of the single power supply link and the software and hardware platform is verified through hardware-in-the-loop testing. Finally, a semi-physical simulation test is conducted on all controllers in the whole system. All device controllers in the whole system use actual controllers, and the system circuit topology uses a simulation model. The correctness of the system control strategy and the software and hardware platform is verified through hardware-in-the-loop testing. Semi-physical simulation verification of system energy management strategy: Hardware-in-the-loop semi-physical simulation tests are performed on the energy management strategies under black start, normal operating conditions, and abnormal operating conditions of the off-grid power supply system to verify the correctness of the energy management strategy and the hardware and software platform.

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