Virtual AC system controllers

Curtis Instruments has launched a series of programmable AC motor controllers for vehicle traction designs from 24 to 96 V and up to 425 A continuous current (writes Nick Flaherty).

The 1238SE series uses the Curtis Vehicle Control Language (VCL), which allows vehicle developers to write powerful logic functions and create a ‘virtual system controller’.

Field-oriented control algorithms generate the maximum possible torque and efficiency across the entire speed range, and the SE controllers support any AC induction or permanent magnet (PMAC) motor.

Automatic characterisation of the motor simplifies the set-up, and the controller includes a comprehensive library of induction and PMAC motor types, as well as a dual drive function that allows correct control of applications with twin traction motors. That ensures smooth and safe operation, minimal tyre wear and correct load-sharing between the motors.

The CAN bus connection can be configured using VCL, and allows comms with up to 24 other CAN bus devices, 10 more than the previous controller family. This allows the 1238SE to be used as an integrated system controller with allocation of multi-function I/O pins for use as analogue inputs, digital inputs, contactor coil drivers and proportional valve drivers, again using the VCL.

The family ranges from the 1238SE- 4971 for 24-36 V three-phase motor designs taking a peak current of 1000 A with­ a constant current of 425 A, to the 1238SE-771 for those with a peak voltage of 96 V, a peak current of 900 A and a constant current of 305 A.