A high frequency injection (HF) technique for rotor position estimation using Sliding Mode Control (SMC) in Permanent Magnet Synchronous Machines (PMSMs) is presented. Since SMC is used, instead of the Field Oriented Control (FOC), the injected HF test signals for tracking the machine's saliency are naturally eliminated. Such angle information suppression is tackled using"the equivalent control" principle. Simulation results confirm not only the proper angle estimation but also the sensorless control at low speed reversal and load impact at zero speed.
The work presented in this paper addresses the unwanted windup phenomenon reviewing and comparing different PI anti-windup
strategies employed in speed control of electric drives. The tuning process of PI controllers is usually carried out considering the system as linear and therefore disregarding its physical limits such as maximum current and voltage. To safeguard the system’s integrity, the PI output is normally limited eventually causing the windup phenomenon characterized by long periods of overshoots which may even result in instability. Firstly, this paper models and tunes the current and speed PI controllers with the root locus method for Field Oriented Control of a Permanent Magnet
Synchronous Machines. Secondly, it is shown the mentioned unwanted Windup phenomenon in the speed loop. Finally, the Anti-Windup strategies are simulated and their behavior are compared when driving a Permanent Magnet Synchronous Machine with Field Oriented Control. Finally, some experimental results obtained from a PMSM Matrix Converter-fed set up have been carried out. These results corroborate the mathematical study and simulations presented all over this paper.
The main drawback of Shunt Hybrid Filters is the need of leading current injection. This paper describes a strategy to reduce the leading current in a three phase four wires LC coupled parallel hybrid filter for harmonics cancellation. Simulation and experimental results are given to show the behaviour of the system.