Control unit for a laboratory motor test bench for monitoring and controlling PMSM and induction motors

The work presents a state-of-art control unit for pulse width modulated inverter-fed AC motors. The unit is suitable for a wide range of voltage source inverters with frequencies ranging from 1 KHz to up to 100 KHz. The hardware is characterized by a powerful floating point DSP, FPGA unit, asynchronous serial and IEEE 1394 communication interface, and 12 channels Analog/Digital interface with sample and conversion times together equaling 250 ns. The control software is managed by a specially designed real-time multitasking operating system. The operating system guarantees less than 300 ns time duration when jumping from one task to another upon internal or external event. The operating system can be adapted easily for arbitrary number of tasks with various prioritization levels and triggering events, and therefore suitable for interfacing hardware in the loop (HIL) simulation environments. The on-line interaction between the user and the running control software is implemented by a specially designed IEEE1394 driver for Windows XP and a graphical user interface (GUI). This allows graphical and numerical monitoring of software variables and their modification at will.