Motor q axis inductance with no current in the q axis and the current defined by Id Test Current for Inductance Measurement (B41) in the d axis of the

motor. If this parameter is left at its default value of zero then no compensation is made to the value of Lq with changes in Id.

B43

Mode

Minimum

Default

Type

Display Format

Coding

In sensorless mode the drive estimates a value for Lq to use in the control algorithm. Estimated Lq (B43) shows the calculated value.

B44

Mode

Minimum

Default

Type

Display Format

Coding

See Motor Thermal Time Constant 1 (B20).

B45

Mode

Minimum

Default

Type

Display Format

Coding

If Quasi-square Enable (B45) = 0 then the output of the drive is limited to a modulation index of unity, which limits the output voltage to a level just

below D.c. Bus Voltage (J65) / √2. Therefore, if the drive is being supplied via its own rectifier input stage the output voltage is limited to a level just

below that of the supply voltage or Motor Rated Voltage (B03) whichever is lower.

If Quasi-square Enable (B45) = 1 then the limit imposed by Quasi-square Enable (B45) is ignored and the modulation index is allowed to increase

beyond unity. As the output voltage increases the output voltage changes through trapezoidal waveforms to a quasi-square wave output. This mode

is useful where the ratio between the switching frequency and the fundamental output frequency is less than 12, as it removes any sub-harmonic

effects that occur. However, it does produce significant multiple odd harmonics of the output frequency in the output currents which cause acoustic

noise, torque ripple and motor heating.

E300 Design Guide

Issue Number: 1

Electrical

Getting

User Menu A Commissioning

installation