Constant Output Voltage Control Method For Contactless Traction Power Supply System Under Mutual-Inductance Disturbance

Recently, with the development of high-frequency power conversion technology, semi-conductor materials and other engineering disciplines, contactless power transmission tech-nology has become one of the research hotpots in electrical engineering. In the application of rail transport, compared to the physical contact power supply devices such as catenary and the third rail, contactless traction power supply (CTPS) system presents more advantages:flexibil-ity in the implementation of urban traffic system, electrical safety, convenience of equipment maintenance and adaptability to various weather conditions.However, due to unavoidable locomotive vibration, misalignment and other mechanical disturbances, the electromagnetic coupling condition in CTPS system is in an unstable state, which will result in a mutual-inductance parameter perturbation, causing an instability of the energy transfer. To fulfill an output voltage tracking control of CTPS system with regard to the mutual-inductance disturbance of the coupler, the main works of this thesis are as follows:1. Develop a high-efficient mutual-inductance calculation method based on vol-ume integral method. An accurate and efficient magnetic flux computation post-processing method based on the volume integral method and vector potential is discussed and applied in the analysis of coupler in CTPS system for mutual-inductance calculation. All the mutual-inductance variations characteristics of three typical couplers calculated by this method have been verified by experimental measurements and FEM simulation results.2. Establish the CTPS system model under multi-parameter disturbance. Several typical resonant compensation topologies (SS-type, SP-type, PS-type, PP-type and LCL-S-type) have been built up based on generalized state space averaging method. And the esti-mation of mutual-inductance disturbance range of the coupler is extracted by the variations characteristics, to further generalize CTPS system disturbed models. Moreover, the robust stability of different compensated topologies under multi-parameter disturbance have been analyzed before the controller design.3. Design and verify the constant output voltage robust controller for CTPS system. Based on the established CTPS disturbed model, several improved robust controllers have been designed by the robust control theory to realize an output DC voltage tracking control. All the performances and stabilities of closed-loop systems have been firstly analyzed by simulation. Furthermore, a 1 kW experimental platform has been built up to verify the designed control method.All the simulation and experimental results have verified that the robust control method with the consideration of the parameters disturbance can realize a better tracking control per-formance than the traditional PID controller. Such control method can then be an essential solution to ensure the stability and security of the CTPS system operation.