Virtual Damping Control Of Loop Compensation For Wireless Power Transmission System With Constant Power Load

Wireless power transmission technology is one of the research hotspots in the field of power electronics.Its greater freedom and one-to-many charging methods bring great convenience to people's lives,and the electrical isolation in the process of power transmission provides a high safety and reliability.Wireless power transmission technology has developed rapidly,and control algorithms for wireless power transmission systems with various loads such as EVs,LEDs,and resistors are emerging.However,due to the low robustness of wireless power transmission systems and the negative impedance characteristics of constant power loads,the system is often unstable.Aiming at the problem that the constant power load characteristics affect the system stability performance,a loop compensation strategy is proposed to expand the system stability domain and reduce the output oscillation amplitude.The main research contents are as follows:1.Aiming at the stability of series-parallel(SP)wireless power transmission systems with constant power loads,a generalized state-space average model is established.Based on closed-loop PID control,the effect of zero poles on system stability is discussed,and add feedback loop to adjust system damping.In view of the high-order complexity of the wireless power transmission system,the method of order reduction is adopted,the system is equivalent to a Buck converter and then the design of the controller is carried out,and the effectiveness of the control algorithm is verified by simulation.2.The loop compensation strategy is applied to the series-series(SS)wireless power transmission system,and the system stability is determined by the Lyapunov stability theorem.A phase shift controller is designed to adjust the output current value.According to the change of load power and loop compensation coefficient,the eigenvalue trajectory is drawn,the stability condition of the system is analyzed,and the analysis and design results are simulated and verified.3.Set up a hardware platform of SS type wireless power transmission control system.The correctness and practicability of the loop compensation control strategy are verified.The research results show that the loop compensation control strategy proposed in this paper is suitable for SP-type and SS-type wireless power transmission systems,can achieve system stability in a larger range,without adding additional equipment,without adding excessive losses,and is a constant power.Optimizing the performance of load wireless power transmission systems provides an effective method.