Design of a Current Regulator with Extended Bandwidth for Servo Motor Drive

To increase the productivity of the manufacturing process, the high bandwidth of the current regulation should be achieved. The bandwidth of the current regulator is dependent on the switching frequency and digital delay. The limited switching frequency is inevitable to reduce the switching loss due to excessive switching frequency. Also, the digital delay is inherent problem where the Digital Signal Processor (microcontroller) and PWM are used. This paper proposes the novel current regulation strategy to enhance the performance of the current regulation by reducing the digital delay which is the sum of the execution time and PWM delay and modifying the voltage reference. The proposed strategy is robust to the parameter and reference variation. Experimental results are shown to verify the effectiveness of the proposed method.