Study On Some Key Technologies Of Superconducting Magnetic Energy Storage System

Superconducting Magnetic Energy Storage (SMES) uses a superconducting coil to store energy and contains such main components as rectifier, superconducting coil, quench protection equipment, and cooling equipment.In this thesis the structure of superconducting coil and the method of design superconducting coil are studied. Finite difference method, finite element method and the software of finite element method were used for this study.A math model and power model of two-level PWM rectifier is deduced. Based on the principle of VODPC (Voltage Orientation Direct Power Control) and VFDPC (Virtual Flux Orientation Direct Power Control), the application of DPC in superconducting magnetic energy storage (SMES) system was analyzed and a new type of switching table was proposed by analyzing how the switching vector affected the active and reactive power in different sectors of the vector-space. The performance of traditional DPC and DPC based on new switching table was compared by simulation. The method based on three level rectifier was also studied. As a result, a new table of three level rectifier was given, and a design method of rectifier is accordingly proposed.In addition, the quench effect and the method of quench detection and protection of superconducting coils are discussed. Static Synchronous Compensator (STATCOM), Active Power Filter (APF), Unified Power Flow Controller (UPFC) based on SMES are also studied.