基于变结构补偿网络的WPT恒流/恒压充电系统

WPT charging system with constant current or constant voltage output based on configurable compensation network

针对电动汽车充电无线电能传输(WPT)系统的网络补偿技术,研究了一种LCC-LCC/S型变结构补偿网络。通过开关控制,能够将松耦合变压器的原/副边补偿网络由恒流源-恒流源特性,切换为恒流源-恒压源特性,从而实现变化负载工况下的恒流或恒压输出,用以满足动力电池的充电需求。针对变结构切换过程中硬开关能量冲击导致的高电压应力问题,本文提出了根据电流极性切换开关的控制策略,进一步优化了开关切换时序,实现模式切换的平滑过渡。最后搭建一个1 kW等级的实验样机,输入为400 V稳压源、输出为模拟电池假负载;利用定宽定频控制实现了10 A恒流输出及105 V恒压输出,在负载变化扰动下的稳态输出波动较小,且实现了逆变器的零电压开通。通过模式切换暂态冲击实验验证了本文所提方案的合理性。

An LCC-LCC/S configurable compensation network based wireless power transfer(WPT)charging system for the electric vehicle battery is studied in this paper.The primary and secondary compensation network topology of loosely coupled transformer can be shifted from constant current-constant current(CC-CC)structure to constant current-constant voltage(CC-CV)structure by topologies switching according to battery management system to achieve CC or CV output characteristic under variable load.Furthermore,a current direction based control strategy is proposed,which can reduce the hard-switch voltage stresses on the bidirectional semiconductor switches.Specifically,the switching order in mode transition is optimized to suppress the transient voltage spikes.Finally,an 1 kW experimental prototype is built with a 400 V input and a battery-charging simulating resistor load.A CC output of 10 A and a CV output of 105 V are realized against time-variable load.The current or voltage fluctuation is tested to be small and the voltage spiker during the mode transition process is ignorable.The zero voltage switch of the inverter is realized.Experimental results verify the effectiveness and feasibility of the proposed solution.