This paper presents a new synchronous-reference-frame (SRF)-based control method to compensate power-quality (PQ) problems through a three-phase four-wire unified PQ conditioner (UPQC) under unbalanced and distorted load conditions. The proposed UPQC system can improve the power quality at the point of common coupling on power distribution systems under unbalanced and distorted load conditions. The simulation results based on Matlab/Simulink are discussed in detail to support the SRF-based control method presented in this paper. The proposed approach is also validated through experimental study with the UPQC hardware prototype.

Synchronous-Reference-Frame-Based Control Method for UPQC Under Unbalanced and Distorted Load Conditions

In this paper, different Distribution Static Compensators (DSTATCOMs) topologies, state of the art, their performance, design considerations, future developments, and potential applications are investigated for power quality improvement. These DSTATCOMs for three-phase three-wire systems and three-phase four-wire systems are developed and installed in the distribution system for many functions, such as reactive power compensation, harmonics elimination, load balancing, and neutral current compensation. This paper is aimed to explore a broad perspective on DSTATCOMs to researchers, engineers, and the community dealing with the power quality improvement. A classified list of some latest research publications is also provided for quick reference.

Comprehensive Study of DSTATCOM Configurations

New control approach for capacitor supported DSTATCOM in three-phase four wire distribution system under non-ideal supply voltage conditions based on synchronous reference frame theory

Neutral current compensation in three-phase, four-wire systems: A review

In this study, the equation for the reactive and harmonic power compensation of a shunt active power filter (APF) system has been derived by studying the power exchange mechanism and power tetrahedron phasor diagram. The switching dynamics of a voltage source inverter (VSI)-based three-phase, three-wire (three-leg /half-bridge) shunt APF system with hysteresis band current control has been studied and verified by simulation. The relation between the design parameters and their effects on the active losses has also been identified. Detailed calculation and extensive simulation have been performed for a three-phase, three-wire shunt APF implemented in a 400VL-L distribution system, as an example, to study the effects of design parameter selection and their role in active power loss calculation. Simulated and calculated results are presented for the important design parameters for different switching frequencies together with their associated losses and kVA ratings. The procedure can be followed to design the parameters for other topologies, such as three-phase, four-wire or single-phase systems.

/pdf/harmonic-power-compensation-capacity-of-shunt-active-power-48fwvt1hk8.pdf

Harmonic power compensation capacity of shunt active power filter and its relationship with design parameters

Control of a 3-phase 4-leg active power filter under non-ideal mains voltage condition

3-Phase 4-leg unified series–parallel active filter system with ultracapacitor energy storage for unbalanced voltage sag mitigation

In this study, design and implementation of a shunt active power filter (APF) based on a simplified control method is given without load and filter current measurement The proposed simplified control method is based on instantaneous reactive power theory (IRP) and requires only measuring the source currents to reduce the number of current sensors (CSs) required in the conventional control approach The source currents are exactly in phase with the line voltages and approximately in sinusoidal waveform after reactive power and harmonic compensation The proposed control technique has been tested under different load conditions using Matlab/Simulink simulations and validated with a 10 kVA/380 V experimental prototype based on digital signal processor (DSP) TMS320F2812 Both simulation and experimental test results demonstrate that the proposed method is feasible in meeting the IEEE 519-1992 recommended harmonic standard limits

The Design and Implementation of a Shunt Active Power Filter based on Source Current Measurement

http://laboratuar.kocaeli.edu.tr/gucelektronik/sci/gucelektronik03.03.2011_15.29.08sci.pdf

A four-leg unified series–parallel active filter system for periodic and non-periodic disturbance compensation

This paper presents a three-phase three-level neutral point clamped (NPC) inverter based single-stage gridconnected photovoltaic (PV) system with shunt active power filter (APF) functionality. The proposed system can perform both the maximum real power injection with the perturb and observe (PO active power filter; grid connected; multilevel inverter; maximum power point tracking.

http://laboratuar.kocaeli.edu.tr/gucelektronik/sci/gucelektronik08.01.2015_19.50.00sci.pdf

Mehmet Ucar

Papers

Control of a 3-phase 4-leg active power filter under non-ideal mains voltage condition

3-Phase 4-leg unified series–parallel active filter system with ultracapacitor energy storage for unbalanced voltage sag mitigation

The Design and Implementation of a Shunt Active Power Filter based on Source Current Measurement

A four-leg unified series–parallel active filter system for periodic and non-periodic disturbance compensation

A three-phase three-level NPC inverter based grid-connected photovoltaic system with active power filtering