基于FPGA的高频逆变装置的变频移相控制实现

Phase-Shift and Frequency-Varied Control Method for High frequency inverter based on FPGA

摘要:

为实现电动汽车无线充电系统中逆变部分的有效控制，比较分析了高频逆变器移相控制和调频控制的特性，确定了移相和调频相结合的方案。提出了实现该方案的DSP+FPGA的控制硬件构架，主要描述了控制构架中FPGA根据DSP指令进行实时移相调频的实现原理，以及FPGA中的硬件语言设计，提出了该原理容易出现的窄脉冲的避免办法。最终在11kW无线充电高效高密度地端功率装置中进行验证，实现了频率和相位更新时PWM波的无缝切换以及逆变器在系统中的有效控制，装置通过调节移相角可以稳定工作在不同功率范围，工作效率均超过国标要求的92.5%，证明了该控制方法的正确性，且满足了实际工程的需求。

Abstract:

In order to realize the control of the inverter in the wireless charging system of electricvehicle,compared and analyzed the characteristics of phase-shift control and frequency-varied control for high frequency inverter, a novel kind of control strategy which combined phase-shift and frequency-variedand based on DSP and FPGA control hardware platform was proposed. This paper mainly describes the design of hardware language and the realization principle of real-time phase-shift and frequency modulation based on FPGA, and puts forward a method to avoid the narrow pulse which is easy to appear in this principle. Finally, it is verified in the wireless charging device of electric vehicle.It realizes the seamless switching of PWM wave after frequency and phase updating and the control function of high-frequency inverter in the system, by adjusting the phase-shifting Angle, the device can work stably in different power ranges with efficiency greater than national standard requirements of 92.5%, which proves the correctness of the control technique and realizes the demand of actual engineering.