用于变频电机绝缘测试的高频高压脉冲发生器设计

Design of high frequency and high voltage pulse generator for insulation testing of inverter-fed motors

高频高压脉冲是变频电机绝缘评估的关键技术之一,其产生、控制、保护与传统高压直流、正弦条件下的相应技术具有较大差异,已成为高频高压脉冲技术的关键难题。为此,采用时钟可达纳秒级的现场可编程逻辑门阵列,研制了一套边沿时间40~500 ns可调的高频高压脉冲发生器。基于半桥结构的脉冲发生器,提出测试容量达1600 pF、电压峰峰值可达24 kV的全桥拓扑结构。通过设计多级电压突降保护算法、电流脉宽实时检测、纳秒级脉冲控制技术以及多种抗干扰措施,保障了脉冲发生器在高频电磁干扰环境下安全稳定运行。实验结果表明,该脉冲发生器产生电压的脉宽和死区时间最小1μs,最大重复频率100 kHz,为变频电机全参数绝缘测试提供了新平台。

The high frequency and high voltage pulse is one of the key technologies for the insulation evaluation of inverter-fed motors.Generating,managing,and safeguarding such pulses deviates significantly from traditional high voltage DC and sinusoidal conditions,presenting critical challenges in their creation.Consequently,a high frequency and high voltage pulse generator has been devised,boasting an adjustable edge time ranging from 40 to 500 ns.This generator leverages field programmable gate array technology,achieving clock precision at the nanosecond level.Adopting a half-bridge structure initially,the design advances to a full-bridge topology capable of handling a test capacity of 1600 pF and yielding a peak-to-peak voltage of 24 kV.Incorporating a meticulously crafted multi-level voltage drop protection algorithm,along with real-time pulse width detection,nanosecond-level pulse control,and various anti-interference measures,ensures the generator′s reliable operation amidst high-frequency electromagnetic interference.Experimental validation confirms that the generated voltage maintains a pulse width and dead time of no less than 1μs,with a maximum repetition frequency of 100 kHz.This innovation heralds a groundbreaking platform for comprehensively testing the insulation parameters of inverter-driven motors.