Flywheel energy storage offline dynamic test system and test method based on compressed air energy storage

Abstract

The invention discloses a flywheel energy storage offline dynamic test system and test method based on compressed air energy storage. A flywheel energy storage unit is used for executing charging and discharging operation under the simulated power grid working condition and receiving a dynamic performance test; the compressed air energy storage unit is used for providing the power supply / absorption capability of the simulated power grid for the flywheel energy storage unit in the test process; the energy management and cooperative control unit is used for cooperatively controlling energy flow between the compressed air energy storage unit and the flywheel energy storage unit according to a preset long-time-history complex dynamic power grid working condition curve; the data acquisition and analysis unit is used for acquiring operation parameters of the flywheel energy storage unit and the compressed air energy storage unit in real time and feeding back abnormal conditions recognized in real time in the testing process to the energy management and cooperative control unit; the compressed air energy storage unit serves as a controllable power supply / load, performance evaluation and optimization of the flywheel energy storage unit under the simulated complex power grid working condition are achieved, and the function of flexible switching of grid-connected / off-grid modes is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy storage technology, and in particular to a flywheel energy storage off-line dynamic test system and method based on compressed air energy storage. BACKGROUND

[0002] Flywheel energy storage system (FESS) has great potential in power system frequency regulation, power quality improvement, uninterruptible power supply (UPS) and electric vehicle energy recovery due to its millisecond-level response speed, high power density and ultra-long cycle life. However, the energy capacity of the flywheel energy storage unit is relatively limited, which limits its ability to operate independently for a long time. When testing its performance, it usually relies on the external power grid, which is not only subject to the operating conditions of the power grid, has poor test flexibility, and is difficult to accurately simulate the effects of various extreme or complex power grid conditions on the flywheel energy storage unit, such as long-term continuous power supply / energy absorption, extreme frequency fluctuation or voltage sag, etc.

[0003] The existing test methods mainly focus on the flywheel energy storage unit's own characteristics test in the laboratory level, or limited field verification through grid-connected operation. This lacks a test platform that can simulate real power grid long-term, high-power dynamic demand while flexibly switching between grid-connected / off-grid states to comprehensively evaluate the dynamic performance, energy conversion efficiency and reliability of the flywheel energy storage unit under different operating scenarios. In particular, when simulating the continuous power supply or energy absorption demand of the power grid, ordinary test power supply or load is difficult to meet the long-term, high-power dynamic response requirements, which limits the performance verification of the flywheel energy storage unit in a wider application scenario. SUMMARY

[0004] In view of the above existing problems, the present application is proposed. Therefore, the present application provides a flywheel energy storage off-line dynamic test system and method based on compressed air energy storage to solve the problems of strong dependence on the power grid, inability to simulate long-term complex operating conditions and inflexible grid-connected / off-grid switching in the existing flywheel energy storage system test.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] In a first aspect, the present application embodiment provides a flywheel energy storage off-line dynamic test system based on compressed air energy storage, comprising: a compressed air energy storage unit, a flywheel energy storage unit, an energy management and collaborative control unit, a data acquisition and analysis unit, and a grid-connected / off-grid mode total switch.

[0007] The flywheel energy storage unit is connected to the compressed air energy storage unit, and is used for performing charging and discharging operations and receiving dynamic performance tests under simulated power grid conditions.

[0008] The compressed air energy storage unit is programmable long-term power supply / load, and is connected to the flywheel energy storage unit, and is used for providing the flywheel energy storage unit with power supply / drainage capacity of the simulated power grid during the test process.

[0009] The energy management and cooperative control unit is connected to the compressed air energy storage unit and the flywheel energy storage unit in communication, and is used for cooperatively controlling the energy flow between the compressed air energy storage unit and the flywheel energy storage unit according to a preset long-term complex dynamic power grid condition curve.

[0010] The data acquisition and analysis unit is connected to the energy management and cooperative control unit in interconnection, and the data acquisition and analysis unit is used for collecting operation parameters of the flywheel energy storage unit and the compressed air energy storage unit in real time, and feeding back abnormal conditions recognized in real time during the test process to the energy management and cooperative control unit.

[0011] The grid-connected / off-grid mode total switch is arranged at a total output end of the test system, one end of the grid-connected / off-grid mode total switch is connected to an external power grid, and the other end of the grid-connected / off-grid mode total switch is connected to the compressed air energy storage unit and the flywheel energy storage unit, and the energy management and cooperative control unit controls on-off states of the grid-connected / off-grid mode total switch.

[0012] As a preferred scheme of the flywheel energy storage off-line dynamic test system based on compressed air energy storage, the compressed air energy storage unit comprises an expander-generator and a compressor-motor, wherein the expander-generator is used for operating as a power supply during charging test of the flywheel energy storage unit, and the compressor-motor is used for operating as a load during discharging test of the flywheel energy storage unit.

[0013] As a preferred scheme of the flywheel energy storage off-line dynamic test system based on compressed air energy storage, the flywheel energy storage unit comprises a wheel body, a high-speed motor / generator, and a matched power electronic converter and control system.

[0014] As a preferred scheme of the flywheel energy storage off-line dynamic test system based on compressed air energy storage, the energy management and cooperative control unit comprises a condition simulation database, and the condition simulation database stores a power grid condition curve of the flywheel energy storage unit.

[0015] The energy management and cooperative control unit dynamically adjusts the operation mode of the compressed air energy storage unit according to a current state and a test target of the flywheel energy storage unit.

[0016] As a preferred scheme of the flywheel energy storage off-line dynamic test system based on compressed air energy storage according to the application, wherein: the grid-connected / off-grid mode total switch comprises:

[0017] When the grid-connected / off-grid mode total switch is closed, the system accesses the external power grid to enter the grid-connected mode, and is used for testing the grid-connected operation performance of the flywheel energy storage unit in the real power grid environment;

[0018] When the grid-connected / off-grid mode total switch is opened, the system enters the off-grid mode, and the compressed air energy storage unit is used as a virtual large-capacity power grid to independently support the flywheel energy storage unit to complete the off-line dynamic test.

[0019] In the second aspect, the application provides a flywheel energy storage off-line dynamic test method based on compressed air energy storage, comprising: generating a corresponding long-term dynamic power grid fluctuation model according to the performance index of the flywheel energy storage unit to be tested, and setting a test safety threshold and an operation mode;

[0020] In the off-grid mode, the energy management and cooperative control unit schedules the compressed air energy storage unit to operate in different modes to construct a programmable virtual large-capacity power grid;

[0021] The energy management and cooperative control unit controls the compressed air energy storage unit to output programmable power, performs dynamic test on the flywheel energy storage unit, and real-time coordinates the energy interaction and power distribution between the compressed air energy storage unit and the flywheel energy storage unit to complete the dynamic performance test;

[0022] According to the test requirement, the grid-connected / off-grid mode total switch is switched by the energy management and cooperative control unit to switch the system operation state;

[0023] Synchronously collect the key operation parameters of the flywheel energy storage unit and the compressed air energy storage unit, evaluate the performance index of the flywheel energy storage unit based on the collected data, and generate a comprehensive performance evaluation report.

[0024] As a preferred scheme of the flywheel energy storage off-line dynamic test method based on compressed air energy storage according to the application, wherein: generating a corresponding long-term dynamic power grid fluctuation model comprises: continuous frequency disturbance, long-time power fluctuation, power regulation under long-time voltage deviation, and system recovery process with the flywheel energy storage unit as a starting power supply under the black start scenario.

[0025] As a preferred scheme of the flywheel energy storage off-line dynamic test method based on compressed air energy storage according to the application, wherein: in the off-grid mode, the energy management and cooperative control unit schedules the compressed air energy storage unit to operate in different modes, comprising: a simulated load mode, a simulated power supply mode, and a simulated long-term dynamic disturbance mode;

[0026] When the compressed air energy storage unit is scheduled by the energy management and collaborative control unit to operate in a simulated load mode according to the set test operating condition, start the compressor-motor system of the compressed air energy storage unit as a programmable load to absorb the electric energy released by the flywheel energy storage unit, simulate the continuous charging demand of the power grid on the flywheel energy storage unit or the energy storage of the flywheel energy storage unit in the power grid valley;

[0027] When the compressed air energy storage unit is scheduled by the energy management and collaborative control unit to operate in a simulated power supply mode according to the set test operating condition, start the expander-generator system of the compressed air energy storage unit as a programmable power supply to supply power to the flywheel energy storage unit, simulate the power supply capacity of the power grid in the peak period or the power support in the island operation;

[0028] When the compressed air energy storage unit is scheduled by the energy management and collaborative control unit to operate in a simulated long-term dynamic disturbance mode according to the set test operating condition, dynamically adjust the power generation or power consumption of the compressed air energy storage unit according to the long-term power grid fluctuation model to reproduce the long-term complex power grid dynamic characteristics.

[0029] As a preferred scheme of the flywheel energy storage off-line dynamic test method based on compressed air energy storage, wherein: the energy interaction and power distribution between the compressed air energy storage unit and the flywheel energy storage unit are coordinated in real time, and a dynamic test sequence including one or more of the following is performed:

[0030] When performing long-term power regulation tests, evaluate the dynamic response and continuous operation capability of the flywheel energy storage unit to long-term high-power fluctuations in the virtual large-capacity power grid environment constructed by the compressed air energy storage unit;

[0031] When performing energy sustainability tests, test the available energy capacity and endurance time of the flywheel energy storage unit under simulated specific load curves;

[0032] When performing collaborative optimization tests, evaluate the power supply delay and dynamic support optimization capability of the flywheel energy storage unit and the compressed air energy storage unit in energy complementation and collaboration;

[0033] When performing off-grid black start simulation tests, simulate the power grid outage scenario, and under the condition that the flywheel energy storage unit is provided with initial energy support by the compressed air energy storage unit, act as a start-up power source to independently drive the load to resume operation, and verify the voltage and frequency building and load carrying capability of the flywheel energy storage unit in the black start scenario.

[0034] As a preferred scheme of the flywheel energy storage off-line dynamic test method based on compressed air energy storage according to the application, wherein: the energy management and collaborative control unit controls the operation state of the grid-connected / off-grid mode total switch switching system, including: when the energy management and collaborative control unit controls the grid-connected / off-grid mode total switch to be on, the system is connected with the external power grid; when the system is connected with the external power grid, the compressed air energy storage unit works as an auxiliary power supply / load or energy storage device, and works together with the power grid and the flywheel energy storage unit to test the grid-connected performance of the flywheel energy storage unit in the real power grid environment.

[0035] Compared with the prior art, the application has the beneficial effects: the application uses the large capacity and long-time energy storage characteristics of the compressed air energy storage unit as a virtual large-capacity power grid of the flywheel energy storage unit, solves the problem that the traditional method cannot simulate long-time continuous power supply / energy absorption working conditions, and greatly expands the test range and depth of the flywheel energy storage unit. The compressed air energy storage unit as a programmable power supply / load, combined with the intelligent control of the energy management and collaborative control unit, can accurately simulate the complex dynamic characteristics of the long-time frequency / voltage deviation and continuous load change of the power grid, so that the test environment of the flywheel energy storage unit is closer to the actual operation scene.

[0036] By setting the controllable total switch, the system can freely switch between the grid-connected and off-grid modes according to the test requirements, and the performance verification of the flywheel energy storage unit under different operation scenes can be completed in the laboratory environment, improving the comprehensiveness and flexibility of the test. The off-line test environment eliminates the interference of the external power grid, and combined with the high-precision data acquisition system, more pure and accurate performance data of the flywheel energy storage unit can be obtained, which is beneficial to its fine evaluation. At the same time, the repeatable and controllable test process greatly shortens the research and verification period of the flywheel energy storage unit. Avoid the high cost of power grid access and the possible operation risk to the power grid, significantly reduce the total cost of the flywheel energy storage unit test, and improve the test safety.

[0037] By simulating diversified long-term working conditions, the application can more deeply explore the performance and optimization potential of the flywheel energy storage unit in different application scenes such as the power grid side, the user side and the micro-grid, providing data support for its development in a wider field. The application provides a novel research method for the internal energy flow and control strategy of the composite energy storage system from the perspective of the compressed air energy storage unit serving the flywheel energy storage unit, which is helpful to improve the overall efficiency and performance of the composite energy storage in the future. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor. Among them:

[0039] Figure 1 The overall architecture schematic diagram of a flywheel energy storage off-line dynamic test system based on compressed air energy storage according to an embodiment of the present application.

[0040] Figure 2 The method flow schematic diagram of a flywheel energy storage off-line dynamic test method based on compressed air energy storage according to an embodiment of the present application.

[0041] Figure 3 The control logic schematic diagram of grid-connected / off-grid mode master switch of a flywheel energy storage off-line dynamic test system based on compressed air energy storage according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0043] Embodiment 1, refer to Figure 1 According to an embodiment of the present application, the embodiment provides a flywheel energy storage off-line dynamic test system based on compressed air energy storage, as shown in Figure 1 , comprising: a compressed air energy storage unit, a flywheel energy storage unit, an energy management and collaborative control unit, a data acquisition and analysis unit, and a grid-connected / off-grid mode master switch.

[0044] The flywheel energy storage unit as the measured object is connected to the compressed air energy storage unit, used to perform charge and discharge operations and accept dynamic performance tests under simulated grid operating conditions;

[0045] The compressed air energy storage unit as a programmable long-term power supply / load is interactively connected with the flywheel energy storage unit, used to provide the flywheel energy storage unit with simulated grid power supply / drain capacity during the test process;

[0046] The energy management and collaborative control unit is communicatively connected to the compressed air energy storage unit and the flywheel energy storage unit, used to collaboratively control the energy flow between the compressed air energy storage unit and the flywheel energy storage unit according to a preset long-term complex dynamic grid operating condition curve.

[0047] The data acquisition and analysis unit is connected to the energy management and collaborative control unit, and is used to collect the operating parameters of the flywheel energy storage unit and the compressed air energy storage unit in real time, and feed back the abnormal conditions identified in real time during the test to the energy management and collaborative control unit.

[0048] The grid-connected / off-grid mode main switch is arranged at the total output end of the test system, and is connected to the external power grid at one end and to the compressed air energy storage unit and the flywheel energy storage unit at the other end. The energy management and collaborative control unit controls the on-off state of the grid-connected / off-grid mode main switch.

[0049] The compressed air energy storage unit comprises an expander-generator and a compressor-motor, wherein the expander-generator is used as a power source to operate during the charging test of the flywheel energy storage unit, and the compressor-motor is used as a load to operate during the discharging test of the flywheel energy storage unit.

[0050] In the discharging test mode, the expander-generator serves as a long-term programmable power source of the flywheel energy storage system, providing stable and adjustable power output to simulate the continuous power supply capability of the power grid.

[0051] In the charging test mode, the compressor-motor serves as a long-term programmable load of the flywheel energy storage system, absorbing and consuming the electric energy released by the flywheel energy storage system to simulate the continuous load demand of the power grid.

[0052] It should be noted that the compressed air energy storage unit, as the core programmable long-term power source / load, has multi-mode operation capability and energy regulation capability, and can provide different power levels of output or absorption according to the test requirements, and the long-term stable and efficient operation of the compressed air energy storage unit is ensured through the optimized design of the gas storage device and the heat exchange system.

[0053] The flywheel energy storage unit comprises a wheel body, a high-speed motor / generator, and a matching power electronic converter and control system.

[0054] The energy management and collaborative control unit comprises a working condition simulation database, and the working condition simulation database stores the power grid working condition curve of the flywheel energy storage unit.

[0055] Specifically, the test working condition can be loaded self-defined, and the power grid working condition curve includes continuous frequency modulation, high-power charge-discharge cycle, long-time black start power supply simulation, etc.

[0056] It should be noted that the energy management and collaborative control unit adopts a multi-level, distributed control architecture to realize accurate collaborative control and energy scheduling of the compressed air energy storage unit and the flywheel energy storage unit.

[0057] The energy management and collaborative control unit dynamically adjusts the operation mode of the compressed air energy storage unit according to the current state and test target of the flywheel energy storage unit. The operation mode includes expansion power generation or compression power consumption.

[0058] Further, the energy management and collaborative control unit has a predictive control and optimization scheduling algorithm, which dynamically adjusts the operation mode of the compressed air energy storage unit according to the current state and test target of the flywheel energy storage unit, ensures the stability and effectiveness of the test process, realizes the optimization circulation and management of energy in the composite energy storage system, maximizes the reduction of external energy loss, and provides necessary energy support for the compressed air energy storage unit.

[0059] Further, the data acquisition and analysis unit integrates a multi-channel, high-speed data acquisition module, which acquires real-time voltage, current, power, frequency, speed and other electrical and mechanical parameters of the flywheel energy storage unit, as well as key operating parameters of the compressed air energy storage unit. The built-in data anomaly detection and fault diagnosis algorithm can identify abnormal conditions in real time during the test process. A time synchronization mechanism is used to ensure the time consistency of all data, facilitating accurate correlation analysis. A visual analysis interface is provided to generate detailed flywheel energy storage unit performance reports, including charge and discharge efficiency, dynamic response time, power regulation capability, energy management strategy adaptability, and running stability under long-term working conditions.

[0060] The grid-connected / off-grid mode total switch includes: when the grid-connected / off-grid mode total switch is closed, the system accesses the external power grid to enter the grid-connected mode, which is used to test the grid-connected operation performance of the flywheel energy storage unit in the real power grid environment;

[0061] When the grid-connected / off-grid mode total switch is open, the system enters the off-grid mode, and the compressed air energy storage unit is used as a virtual large-capacity power grid to independently support the flywheel energy storage unit to complete the off-line dynamic test.

[0062] Embodiment 2, refer to Figures 2-3 For an embodiment of the present application, which is different from the first embodiment, a flywheel energy storage off-line dynamic test method based on compressed air energy storage is provided, comprising:

[0063] S100: According to the performance indicators of the flywheel energy storage unit to be tested, a corresponding long-term dynamic power grid fluctuation model is generated, and a test safety threshold and an operation mode are set;

[0064] S200: In the off-grid mode, the energy management and collaborative control unit schedules the compressed air energy storage unit to operate in different modes to build a programmable virtual large-capacity power grid;

[0065] S300: The energy management and collaborative control unit controls the programmable power output of the compressed air energy storage unit, performs dynamic testing on the flywheel energy storage unit, and coordinates the energy interaction and power distribution between the compressed air energy storage unit and the flywheel energy storage unit in real time, and completes the dynamic performance test;

[0066] S400: According to the test requirements, the energy management and collaborative control unit controls the grid-connected / off-grid mode total switch switching system operating state;

[0067] S500: Synchronously collect the key operating parameters of the flywheel energy storage unit and the compressed air energy storage unit, evaluate the performance indicators of the flywheel energy storage unit based on the collected data, and generate a comprehensive performance evaluation report.

[0068] In the embodiment of the application, the corresponding long-term dynamic power grid fluctuation model generated in step S100 includes: continuous frequency disturbance, long-time power fluctuation, power regulation under long-time voltage deviation, and system recovery process under black start scenario with flywheel energy storage unit as starting power supply.

[0069] It should be noted that according to the performance indicators of the flywheel energy storage unit to be evaluated, a series of long-term, high-power dynamic power grid operating condition curves are selected or self-defined from the operating condition simulation database to generate a corresponding long-term dynamic power grid fluctuation model. By setting test targets and safety thresholds, and selecting off-grid test mode or grid-connected test mode.

[0070] Further, ensure that the compressed air energy storage unit and the flywheel energy storage unit are in a state ready for testing. In the off-grid test mode, the compressed air energy storage unit is initially charged to have the ability to act as a "virtual large-capacity power grid". The energy management and collaborative control unit and the data acquisition and analysis unit are initialized.

[0071] In the embodiment of the application, in step S200, in the off-grid mode, the energy management and collaborative control unit schedules the compressed air energy storage unit to operate in different modes, including: simulated load mode, simulated power supply mode, and simulated long-term dynamic disturbance mode.

[0072] When the compressed air energy storage unit is scheduled by the energy management and collaborative control unit to operate in the simulated load mode according to the set test operating condition, the compressor-motor system of the compressed air energy storage unit is started to absorb the electric energy released by the flywheel energy storage unit as a programmable load, simulating the continuous charging demand of the power grid on the flywheel energy storage unit or the energy storage of the flywheel energy storage unit in the power grid valley.

[0073] When the compressed air energy storage unit is scheduled by the energy management and collaborative control unit and operates in the simulated power supply mode according to the set test working condition, the expander-generator system of the compressed air energy storage unit is started to supply power to the flywheel energy storage unit as a programmable power supply, simulating the power supply capacity of the power grid during the peak period or the power support in the island operation mode.

[0074] When the compressed air energy storage unit is scheduled by the energy management and collaborative control unit and operates in the simulated long-term dynamic disturbance mode according to the set test working condition, the power generation or power consumption of the compressed air energy storage unit is dynamically adjusted according to the long-term power grid fluctuation model to reproduce the long-term complex power grid dynamic characteristics.

[0075] It should be noted that the dynamic adjustment of the power generation or power consumption of the compressed air energy storage unit to reproduce the long-term complex power grid dynamic characteristics includes accurate simulation of the influence of long-term frequency / voltage deviation, continuous power shortage / surplus, etc. on the flywheel energy storage unit.

[0076] In the embodiment of the present application, the energy interaction and power distribution between the compressed air energy storage unit and the flywheel energy storage unit are coordinated in real time in step S300, and the dynamic test sequence including one or more of the following is performed:

[0077] When the long-term power regulation test is performed, the dynamic response and continuous operation capability of the flywheel energy storage unit to long-term large power fluctuation are evaluated in the virtual large-capacity power grid environment constructed by the compressed air energy storage unit;

[0078] When the energy persistence test is performed, the available energy capacity and endurance time of the flywheel energy storage unit are tested under the simulation of a specific load curve;

[0079] When the collaborative optimization test is performed, the power supply delay and dynamic support optimization capability of the flywheel energy storage unit and the compressed air energy storage unit in energy complementary cooperation are evaluated;

[0080] When the off-grid black start simulation test is performed, the power grid outage scenario is simulated, and the flywheel energy storage unit is used as a starting power source to independently drive the load to resume operation under the condition of initial energy support provided by the compressed air energy storage unit, verifying the voltage and frequency building and load carrying capacity of the flywheel energy storage unit in the black start scenario.

[0081] It should be noted that the energy management and collaborative control unit controls the energy flow and power distribution between the compressed air energy storage unit and the flywheel energy storage unit in real time according to the test working condition.

[0082] In the embodiment of the present application, the energy management and collaborative control unit controls the on-off switch of the grid-connected / off-grid mode to switch the system to the running state, which includes: when the energy management and collaborative control unit controls the on-off switch of the grid-connected / off-grid mode to be on, the system is connected to the external power grid; when the system is connected to the external power grid, the compressed air energy storage unit works as an auxiliary power supply / load or energy storage device together with the power grid and the flywheel energy storage unit to test the grid-connected performance of the flywheel energy storage unit in the real power grid environment.

[0083] For example, under certain test requirements, the energy management and collaborative control unit controls the on-off switch of the grid-connected / off-grid mode to be on, so that the system is connected to the external power grid. At this time, the compressed air energy storage unit can work as an auxiliary power supply / load or energy storage device together with the power grid and the flywheel energy storage unit to test the grid-connected performance of the flywheel energy storage unit in the real power grid environment, such as reactive power compensation, fault ride-through, power quality improvement, etc.

[0084] In the embodiment of the present application, the key operating parameters of the flywheel energy storage unit and the compressed air energy storage unit are synchronously collected in step S500, which include: the electrical and mechanical parameters of the flywheel energy storage unit such as voltage, current, power, frequency and rotating speed, and the operating parameters of the compressed air energy storage unit such as gas storage pressure, gas temperature and air mass flow.

[0085] Furthermore, all the key parameters are collected in real time, and deep mining and intelligent analysis are performed to evaluate the long-time transient response characteristics of the flywheel energy storage unit in the simulated working conditions, i.e. power response time, overshoot, steady-state error, energy conversion efficiency, i.e. charging and discharging efficiency, energy loss in specific working conditions, operating stability and reliability, i.e. performance in long-time and high-power working conditions, and the collaborative effect with the compressed air energy storage unit, to generate a customized test report, which provides data support for product research and development and application scenario expansion of the flywheel energy storage unit.

[0086] The present application changes the compressed air energy storage unit from a tested object to a test platform of the flywheel energy storage unit, and improves it to a virtual large-capacity power grid, which uses its long-time and large-capacity characteristics to simulate the continuous power supply / energy absorption scenarios that the traditional power grid cannot provide. A total switch is arranged at the outlet of the system to allow seamless switching between off-grid test and grid-connected test, which greatly enhances the flexibility and applicability of the test. Focusing on simulating long-time and high-power grid dynamic working conditions, the test target and working condition setting are more focused on the transient response, energy continuity and adaptability of the flywheel energy storage unit in different application scenarios. High-precision and off-line testing of the flywheel energy storage unit in various complex dynamic working conditions is realized. At the same time, the system is provided with a grid-connected / off-grid mode total switch, which allows free switching between the two modes according to the test requirements.

[0087] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced, without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. An offline dynamic testing system for flywheel energy storage based on compressed air energy storage, characterized in that, include: Compressed air energy storage unit, flywheel energy storage unit, energy management and collaborative control unit, data acquisition and analysis unit, and grid-connected / off-grid mode main switch; The flywheel energy storage unit, as the object under test, is connected to the compressed air energy storage unit to perform charging and discharging operations and undergo dynamic performance testing under simulated power grid conditions. The compressed air energy storage unit, as a programmable long-duration power source / load, is interactively connected with the flywheel energy storage unit to provide the flywheel energy storage unit with simulated power grid supply / absorption capabilities during testing. The energy management and coordination control unit is communicatively connected to the compressed air energy storage unit and the flywheel energy storage unit, and is used to coordinately control the energy flow between the compressed air energy storage unit and the flywheel energy storage unit according to a preset long-term complex dynamic power grid operating condition curve. The data acquisition and analysis unit is interactively connected to the energy management and collaborative control unit. The data acquisition and analysis unit is used to collect the operating parameters of the flywheel energy storage unit and the compressed air energy storage unit in real time, and to feed back the abnormal conditions identified in real time during the test to the energy management and collaborative control unit. The grid-connected / off-grid mode main switch is located at the main output terminal of the test system. One end of the grid-connected / off-grid mode main switch is connected to the external power grid, and the other end is connected to the compressed air energy storage unit and the flywheel energy storage unit. The energy management and coordination control unit controls the on / off state of the grid-connected / off-grid mode main switch.

2. The flywheel energy storage offline dynamic testing system based on compressed air energy storage as described in claim 1, characterized in that, The compressed air energy storage unit includes an expander-generator and a compressor-motor, wherein the expander-generator is used as a power source during the flywheel energy storage unit charging test, and the compressor-motor is used as a load during the flywheel energy storage unit discharging test.

3. The flywheel energy storage offline dynamic testing system based on compressed air energy storage as described in claim 2, characterized in that, The flywheel energy storage unit includes: the flywheel body, a high-speed motor / generator, and a matching power electronic converter and control system.

4. The flywheel energy storage offline dynamic testing system based on compressed air energy storage as described in claim 3, characterized in that, The energy management and collaborative control unit includes: an operating condition simulation database; the operating condition simulation database stores the grid operating condition curves of the flywheel energy storage unit; The energy management and collaborative control unit dynamically adjusts the operating mode of the compressed air energy storage unit based on the current state of the flywheel energy storage unit and the test objectives.

5. The flywheel energy storage offline dynamic testing system based on compressed air energy storage as described in claim 4, characterized in that, The main switch for grid-connected / off-grid mode includes: When the main switch for the grid-connected / off-grid mode is closed, the system connects to the external power grid and enters grid-connected mode, which is used to test the grid-connected operation performance of the flywheel energy storage unit in a real power grid environment; When the main switch for the grid-connected / off-grid mode is disconnected, the system enters the off-grid mode, and the compressed air energy storage unit acts as an independent virtual large-capacity grid to support the flywheel energy storage unit in completing offline dynamic testing.

6. An offline dynamic testing method for flywheel energy storage based on compressed air energy storage, applied to an offline dynamic testing system for flywheel energy storage based on compressed air energy storage, characterized in that, include: Based on the performance indicators of the flywheel energy storage unit under test, a corresponding long-term dynamic power grid fluctuation model is generated, and test safety thresholds and operating modes are set. In off-grid mode, the energy management and coordination control unit schedules the compressed air energy storage unit to operate in different modes, constructing a programmable virtual large-capacity power grid; The energy management and coordination control unit controls the compressed air energy storage unit to output programmable power, performs dynamic testing on the flywheel energy storage unit, and coordinates the energy interaction and power distribution between the compressed air energy storage unit and the flywheel energy storage unit in real time to complete the dynamic performance test. According to the testing requirements, the energy management and coordination control unit controls the grid-connected / off-grid mode main switch to switch the system operating status. Key operating parameters of the flywheel energy storage unit and the compressed air energy storage unit are collected simultaneously. Based on the collected data, the performance indicators of the flywheel energy storage unit are evaluated, and a comprehensive performance evaluation report is generated.

7. The offline dynamic testing method for flywheel energy storage based on compressed air energy storage as described in claim 6, characterized in that, The corresponding long-term dynamic power grid fluctuation model includes: continuous frequency disturbance, long-term power fluctuation, power regulation under long-term voltage deviation, and system recovery process with flywheel energy storage unit as the starting power source in black start scenario.

8. The offline dynamic testing method for flywheel energy storage based on compressed air energy storage as described in claim 7, characterized in that, In off-grid mode, the energy management and coordination control unit schedules the compressed air energy storage unit to operate in different modes, including: simulated load mode, simulated power supply mode and simulated long-term dynamic disturbance mode. When the compressed air energy storage unit operates in simulated load mode under the scheduling of the energy management and coordination control unit according to the set test conditions, the compressor-motor system of the compressed air energy storage unit is started to absorb the electrical energy released by the flywheel energy storage unit as a programmable load, simulating the continuous charging demand of the power grid for the flywheel energy storage unit or the energy storage of the flywheel energy storage unit during the power grid off-peak. When the compressed air energy storage unit operates in simulated power supply mode under the scheduling of the energy management and coordination control unit according to the set test conditions, the expander-generator system of the compressed air energy storage unit is started to supply power to the flywheel energy storage unit as a programmable power source, simulating the power supply capacity of the power grid during peak hours or the power support under islanded operation. When the compressed air energy storage unit operates in a simulated long-term dynamic disturbance mode under the scheduling of the energy management and coordination control unit according to the set test conditions, the power generation or power consumption of the compressed air energy storage unit is dynamically adjusted according to the long-term power grid fluctuation model to reproduce the dynamic characteristics of the complex power grid over a long period of time.

9. The offline dynamic testing method for flywheel energy storage based on compressed air energy storage as described in claim 8, characterized in that, Real-time coordination of energy interaction and power distribution between the compressed air energy storage unit and the flywheel energy storage unit, executing a dynamic test sequence including one or more of the following: When conducting long-term power regulation tests, the dynamic response and continuous operation capability of the flywheel energy storage unit to long-term high-power fluctuations are evaluated in a virtual large-capacity power grid environment constructed by the compressed air energy storage unit. When conducting energy sustainability tests, the available energy capacity and range of the flywheel energy storage unit are tested under a simulated specific load curve. When conducting collaborative optimization tests, evaluate the power supply delay and dynamic support optimization capabilities of the flywheel energy storage unit and the compressed air energy storage unit in energy complementarity and collaboration; When conducting off-grid black start simulation tests, the scenario of grid power failure is simulated. Under the condition that the flywheel energy storage unit provides initial energy support from the compressed air energy storage unit, it independently drives the load to resume operation as a starting power source, verifying the flywheel energy storage unit's voltage and frequency building and load-carrying capabilities in the black start scenario.

10. The offline dynamic testing method for flywheel energy storage based on compressed air energy storage as described in claim 9, characterized in that, The system operating status controlled by the energy management and coordination control unit to switch between grid-connected and off-grid modes includes: when the grid-connected / off-grid mode main switch is closed, the system is connected to the external power grid; when the system is connected to the external power grid, the compressed air energy storage unit acts as an auxiliary power source / load or energy storage device, working together with the power grid and the flywheel energy storage unit to test the grid-connected performance of the flywheel energy storage unit in a real power grid environment.

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