The Research On The Construction Theory And Key Technologies Of Multiple Energy-Storage System

China is a country with many natural disasters.The disasters cause the huge losses every year.Storage systems can provide reliable power supply for critical applications such as nuclear power plants,data centers,militaries and etc.Thus,it is essential to develop high reliable and long backup time storage systems with the technology of integration of multiple energy storages such as Fuel Cells,li-ion batteries,Super Capacitors.Base on the review of state-of-art of multiple storage systems,this thesis focuses on the researches of architecture,protection and fault tolerant of multiple energy storage systems.The application and trends of multiple energy storage system are reviewed in Chapter 1.The state-of-art and the future trends of key technologies for multiple energy storage system are introduced.The architecture of multiple energy storage system has large effects on the efficiency,cost and reliability of system.Firstly,the simplified model of architecture is built in Chapter 2.Based on the simplified model,the deduction of architecture is provided for multiple energy storage systems.The mathematic model of architecture is built based power conversion efficiency,reliability and cost.The evaluation method is proposed for multiple energy storage system.Take the high reliable power supply for critical application-Super UPS as example,architecture design is introduced based on proposed simplified model and evaluation method.The short-circuit protection is vital to guarantee the high-reliable operation for multiple energy storage system.In Chapter 3,the short-circuit fault model is built first.Based on the model,the mechanism of fault is analyzed.Then a fault protection method based on the fault current direction is proposed.It does not depend on the communications.It achieves fast and selective fault detection.In addition,a fault isolation method based on solid state circuit breaker is introduced,and the effects of stray inductance of breakers on current measurement is analyzed.The effects are suppressed by proposed method to achieve high accurate measurement.Finally,the proposed protection scheme is verified by experiment results.The fault tolerant technique is a key factor of the reliability improvement for multiple energy storage system.In Chapter 4,the system-level fault tolerant method is analyzed.First,the fault tolerant operation strategy under different fault conditions is analyzed.Based on the characteristics of multiple energy storage system,a two-level fault tolerant control strategy is proposed based on local bus voltage detection.It minimizes the dependence on communication and improve the robustness of strategy.The parameter design is also given.Take Super UPS as example,the realization of fault tolerant strategy and converters suitable for fault tolerant operation are also provided.Finally,the fault tolerant strategy is verified by experiment results.The coordination control and experimental platform are introduced in Chapter 5.First,the priority of multiple energy is introduced.The coordination control is proposed,and the operation modes are designed.In order to verify the key technology of multiple energy storage system,the 100 kW experimental platform is built.The power conversion system is designed modularly.The center controller and communication system is also introduced.The coordination control and system design is verified on the platform.Finally,the demonstration of the multiple energy storage system is introduced.Finally,the main contribution of the thesis is summarized.The further works are presented.