What is field weakening range?

What is field weakening range?

Field weakening is a method of raising the speed in DC motors. If the field (magnetic field) is weakened by reducing field current, back emf is reduced and thereby more armature current is drawn.

What should we have to do for field weakening mode for PMSM?

This example implements the field-oriented control (FOC) technique to control the torque and speed of a three-phase permanent magnet synchronous motor (PMSM). The FOC algorithm requires rotor position feedback, which is obtained by a quadrature encoder sensor.

What is flux weakening in induction motor?

Abstract. The high-speed operation of the field oriented induction motor control requires a flux decreasing to counteract the back electromotor force (EMF) increasing that will approach the available inverter voltage. Decreasing the flux causes the available torque is reduced.

What does field weakening mean?

Field weakening enables higher motor speeds by reducing the back EMF generated by the motor. Recall that back EMF (electromotive force) is voltage created when a coil turns inside a magnetic field, and it opposes the supply (driving) voltage.

What does flux weakening mean?

Flux weakening allows a machine to operate above base speed in constant-power, high speed region when there is a fixed inverter voltage and current [7] .

What is field weakening method?

Field weakening enables higher motor speeds by reducing the back EMF generated by the motor. In order to “weaken” the field that creates back EMF, field weakening relies on a control method known as field oriented control (FOC).

How does a field weakening motor control system work?

A flux weakening module for a permanent magnet electric machine includes a feedforward stator flux term and a compensating feedback flux correction term. The feedforward stator flux term provides the dominant field weakening flux value.

How does a stator flux vector control work?

It is based on a control algorithm that decreases the d-component of the stator flux as soon as the voltage corresponding to the maximum torque exceeds the available voltage. The control scheme produces a smooth transition into and out of the field weakening region and preserves the torque dynamic.

How is field weakening used in torque control?

The control scheme produces a smooth transition into and out of the field weakening region and preserves the torque dynamic. The feasibility of the field weakening technique is confirmed by computer simulations and experimental tests. Block diagram of the torque control scheme, including the field weakening strategy.

How does flux weakening in a PM motor work?

Flux weakening in a PM motor can be accomplished by adjusting the stator excitation. During a constant torque region, closed loop current regulators control the applied PWM voltage excitation so that the instantaneous phase currents follow their commanded values.