Modified Direct Torque Control Application-Specific Integrated Circuit with Five-Stage Fuzzy Hysteresis and a Proportional–Integral–Derivative Controller for a Three-Phase Induction Motor

This paper presents a modified direct torque control (MDTC) application-specific integrated circuit (ASIC), which includes a proportional-integral-derivative (PID) speed controller and five-stage fuzzy hysteresis, for reducing torque and flux ripples, which are induced by the low vector voltage and slow response speed of the traditional DTC circuit. The high-speed fuzzy PID controller and five-stage fuzzy hysteresis improve control stability. The proposed PID controller reduces the flux and torque ripples through the modified discrete multiple vector voltage (MDMVV). The proposed MDTC ASIC not only reduces torque and flux ripples but also enhances the stability of the control system. The proposed MDMVV generates four voltage vectors in a sampling cycle, whereas the conventional DTC generates a single voltage vector. Hardware description language was used to design and implement the motor control, and a programmable logic gate array board was used to verify the designed functions. The MDTC ASIC was fabricated using the 0.18-um CMOS process with a chip area of 1.193 * 1.190 mm2. At an operating frequency of 10 MHz and a voltage of 1.8 V, the power consumption was determined to be 2.457 mW.