Control Methods for Good Dynamic Performance Induction Motor Drives Based on Current and Voltage as Measured Quantities

Abstract

A family of schemes for the control of torque and speed of the induction machine is described. It has been developed with the intention of closing the gap between high dynamic performance drives, requiring measurement of the rotor position or the field, and the simpler schemes with poor dynamic performance. Dynamic behavior and a static accuracy have been achieved which promise a broad range of applications. This is due also to the relative simplicity of the equipment and insensitivity to changes in resistance parameters. Implementation with a voltage source inverter and a current source inverter are shown. I. REVIEW OF THE PREVIOUS STATE OF THE ARTFOR MANY applications of controlled ac drives, mainly the steady-state behavior is of interest for the user (best possible utilization of the machine, sufficient static accuracy of the control). In these cases emphasis is put on simple signal processing and not on high dynamic performance. On the other hand, the dynamic behavior of the machine is wellknown. Control schemes have been developed for which the only limitation for dynamic performance is how well the chosen inverter type is able to follow the reference values set by the control scheme.Because of the ability of the inverter to change voltage and frequency very quickly, a direct or indirect current limitation is always necessary. Furthermore, the machine is run only in operation modes where the losses are nearly minimal. The classical mode is operation with approximately constant field and field weakening only in an upper speed range.

A microprocessor-based induction motor drive system using sliding mode control

“…From Fig. 1, it can be seen that for a constant flux operation and at low slip frequency, a linear relationship between T, and u2, can be derived [6]. Hence, (l), can de rewritten as:…”

Improved rotor speed estimation using two Kalman filter-based algorithms

“…Using the complete mathematical model of the motor allows one to estimate rotor speed at both steady state and transient conditions [3]. However, the computation of slip frequency and speed depends on motor parameters, and therefore on temperature, saturation, and frequency variations.…”

Sensorless variable structure speed control of an induction motor

“…Furthermore, in high performance applications, good knowledge of the electromagnetic and mechanic magnitudes is required at all times to derive proper control actions. Most electromagnetic magnitudes can be inferred from measurements of stator voltages and currents [4]- [14]. Besides, it is highly desirable to avoid the use of mechanical sensors coupled to the rotor, since they deteriorate the overall reliability, increase cost and require additional wiring and hardware.…”

“…Besides, it is highly desirable to avoid the use of mechanical sensors coupled to the rotor, since they deteriorate the overall reliability, increase cost and require additional wiring and hardware. In this paper the sensorless control of an IM is addressed, and as in [4]- [5], the induced rotor fem is used to compute the orientation of the controller. Variable structure concepts are applied to sinthetize the control law, directly in terms of the inverter switches, avoiding additional modulation tasks such as space vector modulation [3].…”