Analysis of induction motor drives under sensor faults with mine hoist load diagram

Field Oriented Control (FOC) of induction motor drive is more popular in process and manufacturing industries as it controls the motor as desired. To perform FOC, Variable Voltage Variable Frequency (VVVF) operation of an inverter, connected in the stator or rotor circuit (in case of wound rotor) of the machine, is mandatory. For VVVF control, the rotor speed and stator currents have to be measured by sensors and the measured signals have to be fed back to the controllers. The proper operation of the control system depends on the feedback signals from sensors. When sensors are undergone a fault, the stability of control system, may be designed for an industrial process, is disturbed and hence the reliability of the system is decreased. The fault in speed sensors may be open circuit fault, omission fault, gain, bias, and saturation. In this paper three different speed controllers like PI Controller, Fuzzy Logic Controller (FLC), Fuzzy Pre compensated Proportional Integral Controllers (FPPI) are used in the speed control loops of FOC and analyze their performances under sensor faults. A 30-hp induction motor drive is considered with mine-hoist load diagram as case study.