The Analysis Of Frequency Stability In ICPT System And Research On Coupling Transfer Power

Inductive coupled power transfer technology (ICPT) is a new and practical technology which is used in power transfer area. This technology comprehensively uses the power electronics technology, magnetic coupling technology and modern control theory. Through the coupling magnetic between the primary and secondary coils to achieve the power transfer from the stationary power system to one or some mobile electric device non-electrical directly contact power.The background of this paper is the Chongqing science committee key fundation program and the National Natural Science Foundation program. It mainly bases on four compensation mode of ICPT system, and does research on the system frequency stability and coupled transmission power. In the research of ICPT system, frequency stability and coupled transmission power is always important and difficult. The frequency stability is directly related to the system can achieve the goal that whether the power is high efficiency and the transmission is steady and high power; the coupled transmission power is directly related to whether the system can meet the power requirement of the electrical device. This paper contains the following parts:Regarding the four compensation mode of ICPT system, the relation model between the primary resonance frequency and pick-up load resistance and primary-secondary inductive coupling coefficient is established. During the modeling process, the specific equivalent change parameters are introduced, thus the primary launch coils inductance and the primary resonance network compensation capacitance,the secondary pick-up coil inductance,the secondary resonance network compensation capacitance,the primary-secondary inductive coupling coefficient,the pick-up rated load resistance and other parameters are not contained in the relation model, the primary-secondary equality coefficient,primary relative resonance frequency,pick-up relative load resistance,the formula of the primary-secondary relative inductive coupling coefficient are only contained in it, the structure of the relation model is simplified and the analysis difficulty is reduced.Regarding the four compensation mode of ICPT system, the root locus is introduced which specifically analyzes the law that the primary resonance frequency changes with the pick-up load resistance and the law that the primary resonance frequency changes with the primary-secondary inductive coupling coefficient. The four compensation mode is compared in terms of the characteristics in the frequency stability and the characteristics in the frequency stability in the same compensation mode while the device parameters are different. The basic principle of the graphic method is introduced, and an example verified the particle frequency stability conclusions that are got through the root locus method.Regarding the four compensation mode of ICPT system, the relation model of the coupling transfer power under the ideal state(the system working frequency is secondary resonant frequency) is established, the characteristics of the coupling power transfer performance under different parameter in the four compensation mode and the same compensation mode are compared. When the established system adopt floating frequency control, under the non-ideal state(the system working frequency isn't secondary rated resonance frequency), the relation model of coupling transmission power is established, and the method of how to investigate the characteristic of the system coupling transmission power is introduced exemplifying the PP topology.