Highly Optimized Inverter Control Unit for Monitoring and Control of Permanent Magnet Synchronous and Induction Motors

The work presents a flexible high optimized control unit for PWM voltage source inverter-fed AC motors. The sample period of the main control cycle can be set with arbitrary value between 1 KHz and 100 KHz. The control software is managed by a real time multitasking operating system with task switching time less than 300 ns. The analog/digital interface has up to 12 channels with sample and conversion times equaling 250 ns. The system is made configurable via a user graphical interface running on a touch screen terminal. Furthermore graphical and numerical monitoring of motor parameters and modifying of control variables can be done on-line via the terminal. The work gives an example for concerted hardware design combined with programming techniques for reduced overhead and better system resources exploitation.

I. Introduction

The research work in the field of electrical motors reveals from year to year new rapidly increasing requirements on electrical drives commissioning systems. A state-of-art control software for electrical drives no longer includes only a general field-oriented vector control, but also additional modules such as on-line diagnostic for fault detection in the controlled drive, loss minimization modules based on loss models or search controllers, communication protocols for user interaction capability or even more advanced, protocols for interfacing HIL (Hardware In the Loop) systems. To pack all these software components in a single control, a software and hardware platform with sufficient computing power and fast IO interface is required. This is so far important, that advanced research work can be carried out comfortably, without facing often restricting system limitations. Hardware platforms must also be applicable in different areas of motor research which suppose increased flexibility and reusability.