Sherif A. Zaid

Improved Active Power Filter Performance Based on an Indirect Current Control Technique

This paper presents a method for the performance improvement of a shunt active power filter (SAPF) using the indirect current control (ICC) scheme. Compared to the conventional direct current control (DCC) scheme, the ICC gives better performance with a lower number of sensors. A simplified and efficient control algorithm using a low cost Intel 80C196KC microcontroller is implemented using only two current sensors for the source current and one voltage sensor for the DC-link voltage of the SAPF circuit. The objective is to eliminate harmonics and to compensate the reactive power produced by non-linear loads such as an uncontrolled rectifier feeding an inductive load. The APF is realized using a three phase voltage source inverter (VSI) with a dc bus capacitor. Experimental results are presented to prove the better performance of the ICC method over the DCC one.

Simulation Study of a New Approach for Field Weakening Control of PMSM

In this paper, the different techniques for the field weakening, also known as constant power speed range (CPSR) operation, for permanent magnet synchronous motor (PMSM) will be introduced and analysed. Field weakening of PMSM, can be done using either vector control (VC) or conventional phase in advance (CPA). Implementation of these techniques depending on some features and constrains. Most of these features and constrains came from the motor parameters. One of these constrains is the motor inductance which determining whether the motor can be driven in the CPSR or not. A new approach for the field weakening will be discussed and to be verified to overcome this constrain. The new approach will be verified through both techniques VC and CPA.

Development of a new approach for wide speed range of PMSM

Permanent Magnet Synchronous Motor (PMSM) with lower inductance values suffering from the narrow Constant Power Speed Range (CPSR). The traditional approaches for extending CPSR operation included adding an additional inductance or a thyristor controlled inductance in series with the motor. However, these approaches increase the cost, complexity, and derate the inverter of the drive system. In this paper, a new solution to increase the CPSR of the PMSM is introduced to avoid the drawbacks of traditional approaches. The idea is to select the inverter reference currents values to maintain Maximum Torque Per Ampere (MTPA) and to increase the output inductance seen by the inverter without adding any physical inductance or thyristor. This is achieved by adding a virtual inductance to the stator current equation. The value of the virtual inductance indicates how broaden is the speed range. The proposed system has the advantages of wide speed range operation, low size, low cost, and simple control. MATLAB simulations and complete hardware setup based on the Texas DSP (TMS320F28335) has been constructed to verify the new approach.

Performance comparison of shunt active power filter for interval type-2 fuzzy and adaptive backstepping controllers

The control technique used with the three-phase shunt active power filter (SAPF), has an important role in its performance. In this paper, a comparison between the SAPF performance controlled with interval type-2 fuzzy controller (IT2FC), adaptive backstepping non-linear control (ABNC), and proportional integral (PI) controllers is accomplished. The simulation results show the key features of each technique. It is also found that the parameters’ variations and uncertainties of the system can be compensated by ABNC or IT2FC controllers without any prior knowledge of real parameters. However, ABNC has better performance than the IT2FC.

A Simple Algorithm for SRF Theory with Three Phase Shunt Active Power Filter

Shunt Active Power Filters (APFs) are the up-to-date solution to power quality problems. Harmonic reference detection is the key word for the proper operation of shunt APF. One of the most famous detection control schemes for shunt APFs is the Synchronous Reference Frame (SRF). In this paper, two new modifications of (SRF) detection control scheme are presented. The first modification is done by introducing a new scheme for the dc bus control loop. The second modification is accomplished by implementing the SRF without load current sensors and using only the supply current sensors. These improvements, compared to the conventional (SRF), simplify the control system, minimize the system delay time, improve the APF performance, and reduce the cost of the system. The simulation results, using MATLAB/SIMULINK, demonstrate the viability and simplicity of the modified control scheme, its success in meeting power quality standards limits, and increasing the accuracy of generated reference signal.