Inverter Driven Induction Motor Research Articles

Coupling the circuit equations to the non-linear time dependent field solution in inverter driven induction motors

The conventional way of analysing electric machinery has been to impose currents or current densities, to calculate from them the electromagnetic field and from that the self and mutual inductances of the windings. Circuit equations using these inductances would give correct values for the currents in the windings. In this paper, the field and circuit equations are coupled, giving a time dependent set of nonlinear equations, the solution of which gives the magnetic vector potential at every point in the cross section of the machine and the electric field intensity at the cross section of the conductors. The method is of particular interest when the harmonic content of the excitation is large, prohibiting the calculation of permeability of iron from only the fundamental.

Selection and Design of an Inverter-Driven Induction Motor for a Traction Drive System

The considerations and trade-offs involved in the selection and design of an inverter-driven induction motor for a traction drive system are described. The inverter is transistorized and operates in a pulsewidth modulation (PWM) mode in the constant torque region and in a six-step square wave mode in the constant power region. Drive system requirements establish the 50-hp peak motor rating and the motor voltage. The aspects of an induction motor designed to be driven from an inverter are presented. These include the number of poles and rotor bar shape of the motor. Expressions relating the motor performance to motor design parameters are derived. The aspects of the inverter power source are presented. These include the constant volt-ampere characteristics of the inverter and the relationship of motor inductance to the inverter design. A final motor design is reached, Contrary to previous expectations, the best design is a two-pole motor.

Analysis of Field Orientation Control of Current Source Inverter Drive Induction Motor Systems

The field orientation control of current source inverter (CSI) drive induction motor (IM) systems has been known to give an induction motor dc motorlike characteristics. As a result of an analysis, the characteristic of these systems does not necessarily coincide with that of dc motor systems, especially with light loads. The result of the analysis is verified by experiments.

Stability Synthesis of Control System in Current FED Inverter Driven Induction Motor

This paper presents a new method of synthesizing a stabilizing control system in current fed inverter driven induction motor (CFIDIM). The method is focused on rotor dynamics and a concept of ``damping torque coefficient (DTC)'' is introduced concerning the electrical torque. At first the control system is synthesized on the assumption that an induction motor is driven by an ideally controllable current source. Then perturbed linearized technique indicates that the system can be stabilized if the stator current or frequency is controlled so as to make the DTC positive by feeding back a signal composed of rotor speed. Next, based on this fact, an approach of synthesizing the converter output voltage is presented under a fixed stator frequency. This result clarifies that the stable operation can be achieved by controlling the voltage in proportion to the acceleration of rotor speed or the deviation of electrical torque. These analytical results are verified by laboratory field tests.

Stability Synthesis of Control System in Current Fed Inverter Driven Induction Motor

This paper presents a new method of synthesizing a stabilizing control system in current fed inverter driven induction motor (CFIDIM). The method is focused on rotor dynamics and a concept of ``damping torque coefficient (DTC)'' is introduced concerning the electrical torque. At first the control system is synthesized on the assumption that an induction motor is driven by an ideally controllable current source. Then perturbed linearized technique indicates that the system can be stabilized if the stator current or frequency is controlled so as to make the DTC positive by feeding back a signal composed of rotor speed. Next, based on this fact, an approach of synthesizing the converter output voltage is presented under a fixed stator frequency. This result clarifies that the stable operation can be achieved by controlling the voltage in proportion to the acceleration of rotor speed or the deviation of electrical torque. These analytical results are verified by laboratory field tests.

Operational modes of a current source inverter driven induction motor under constant voltage/frequency control

Operational modes of a current source inverter driven induction motor under constant voltage/frequency control