一种改进的定频数字滞环电流控制策略

An improved constant-frequency digital hysteresis current control strategy

针对机载电动静液作动器(EHA)用20 k W级大功率无刷直流电机,提出了一种改进的定频数字滞环电流控制策略(HCCS)。在此控制策略中,通过对PWM_ON调制模式下相电流数学模型的构建以及相应电流环控制模式的分析,对一种综合三角载波控制和滞环电流控制的混合滞环电流控制进行改进,设计了一种实现简单、控制稳定、具有过流保护功能以及功率元件开关频率有条件固定的改进的准定频滞环电流控制策略,并通过数字化处理,引入数字化规则,实现完全的定频控制。仿真和实验结果表明,此控制策略能够实现大功率无刷直流电机控制时固定的功率元件开关频率以及高频率响应,将为高性能大功率无刷直流电机高效的电流控制提供一条新路径。

An improved constant-frequency digital hysteresis current control strategy（ HCCS） was introduced for high-power 20 k W brushless DC motor used in airborne integrated electrical hydrostatic actuator（ EHA）. In this control strategy,by the modeling of phase current using PWM_ON modulation mode and analysis of different types of current control strategy,a quasi-constant-frequency HCCS with simple implementation,inherited stability and over current protection capability was designed by improving the hybrid HCCS integrating the triangular carrier based control strategy and HCCS. Furthermore,completely constant-frequency was obtained by applying digitalized implementation and digital processing rules. Simulation and experiment show that this strategy can achieve constant switch frequency of power electric component and high frequency response of current loop in high power brushless DC motor simultaneously. This will provide a new approach for the high performance control of brushless DC motor.