Mitigation of Power Quality Problems Using Custom Power Devices: A Review

Electrical power quality (EPQ) in distribution systems is a critical issue for commercial, industrial and residential applications. The new concept of advanced power electronic based Custom Power Devices (CPDs) mainly distributed static synchronous compensator (D-STATCOM), dynamic voltage restorer (DVR) and unified power quality conditioner (UPQC) have been developed due to lacking the performance of traditional compensating devices to minimize power quality disturbances. This paper presents a comprehensive review on D-STATCOM, DVR and UPQC to solve the electrical power quality problems of the distribution networks. This is intended to present a broad overview of the various possible DSTATCOM, DVR and UPQC configurations for single-phase (two wire) and three-phase (three-wire and four-wire) networks and control strategies for the compensation of various power quality disturbances. Apart from this, comprehensive explanation, comparison, and discussion on D-STATCOM, DVR, and UPQC are presented. This paper is aimed to explore a broad prospective on the status of D-STATCOMs, DVRs, and UPQCs to researchers, engineers and the community dealing with the power quality enhancement. A classified list of some latest research publications on the topic is also appended for a quick reference

A photovoltaic integrated unified power quality conditioner with a 27-level inverter

Abstract This paper presents a Unified Power Quality Conditioner (UPQC) with a 27- level inverter based on an asymmetric H-bridge topology. Each phase of the inverter is composed of three H-bridges, supplied by three DC sources scaled in the power of three. The output of the multilevel inverter is connected directly to the point of common coupling (PCC) without the need to a transformer or a filter. The calculation of the Shunt Active Power filter (SAPF) compensation current is based on the generalized theory of synchronous frame (d-q theory) while the calculation of a series active filter voltage is based on Instantaneous Reactive Power (p-q theory). The control of the SAPF is achieved by using a closed loop vector control followed by a new multilevel modulation technique. In addition to the capability of harmonic elimination of both current and voltage drawn from the source, the UPQC can produce real and reactive power to feed the loads during prolonged voltage outages or source shortage.  The injection of real and reactive power depends on the state of charge (SOC) of batteries, the frequency of the system, real and reactive power of the load, and power factor at the point of PCC. The proposed UPQC strategy is simulated in MATLAB SIMULINK and the results has shown a significant improved in Total Harmonics Distortion (THD) of both the voltage and currents. 

ANFIS control of a shunt active filter based with a five-level NPC inverter to improve power quality

© 2021 The Author(s). This is an open access article under the CC BY-SA license (https://creativecommons.org/licenses/by-sa/4.0/).This paper addresses the problem of power quality, and the degradation of the current waveform in the distribution network which results directly from the proliferation of the nonlinear loads. We propose to use a five-level Neutral Point Clamped (NPC) inverter topology for the implementation of the shunt active filter (SAPF). The aim of the SAPF is to inject harmonic currents in phase opposition at the connection point. The identification of harmonics is based on the pq method. A neuro-fuzzy controller based on ANFIS (Adaptive Neuro Fuzzy Inference System) is designed for the SAPF. The simulation study is carried out using MATLAB/Simulink and the results show a significant improvement in the quality of energy and a reduction in Total Harmonic Distortion (THD) in accordance with IEC standard, IEEE-519, IEC 61000, EN 50160.Peer reviewe

A fault-tolerant photovoltaic integrated shunt active power filter with a 27-level inverter

This paper introduces a fault-tolerant shunt active power filter (SAPF). The novility in of this work is that it poposes a solutions to increase the reliability of shunt active power filter to maintain its operation under a single-phase open-circuit fault in the SAPF. This will increase the reliability of the whole power system. The SAPF is composed of a 4-leg 27-level inverter based on asymmetric cascaded H-bridge topology. If an open-circuit fault is introduced to the operation of the SAPF, a special control technique will be implemented and the redundant leg of the SAPF will be activated. The fault-tolerant SAPF can do many tasks under healthy operating conditions and post and open circuit fault depending on the state of charge (SOC) of the batteries. It can mitigate harmonics in the power system, improve power factor in the system by injecting reactive power, and inject real power to the system. The proposed SAPF is tested and simulated in MATLAB/Simulink and the results have shown a significant improvement in total harmonics distortion (THD) of the source current from 13.9% to 3.9% under the normal operating condition and from 42% to 8.4% post and open circuit fault

Enhanced decoupling current scheme with selective harmonic elimination pulse width modulation for cascaded multilevel inverter based static synchronous compensator

This dissertation is dedicated to a comprehensive study and performance analysis of the transformer-less Multilevel Cascaded H-bridge Inverter (MCHI) based STATic synchronous COMpensator (STATCOM). Among the shunt-connected Flexible AC Transmission System (FACTS) controllers, STATCOM has shown extensive feasibility and effectiveness in solving a wide range of power quality problems. By referring to the literature reviews, MCHI with separated DC capacitors is certainly the most versatile power inverter topology for STATCOM applications. However, due to the ill-defined transfer functions, complex control schemes and formulations were emerged to achieve a low-switching frequency high-bandwidth power control. As a result, adequate controller parameters were generally obtained by using trial and error method, which were practically ineffective and time-consuming. In this dissertation, the STATCOM is controlled to provide reactive power (VAR) compensation at the Point of Common Coupling (PCC) under different loading conditions. The goal of this work is to enhance the performance of the STATCOM with the associated proposed control scheme in achieving high dynamic response, improving transient performance, and producing high-quality output voltage waveform. To evaluate the superiority of the proposed control scheme, intensive simulation studies and numerous experiments are conducted accordingly, where a very good match between the simulation results and the experimental results is achieved in all cases and documented in this dissertation

Application of the cascaded multilevel inverter as a shunt active power filter

Abstract unavailable please refer to PD

Interleaved Buck Converter Based Shunt Active Power Filter with Shoot-through Elimination for Power Quality Improvement

The “shoot-through” phenomenon defined as the rush of current that occurs while both the devices are ON at the same time of a particular limb is one of the most perilous failure modes encountered in conventional inverter circuits of active power filter (APF). Shoot-through phenomenon has few distinct disadvantages like; it introduces typical ringing, increases temperature rise in power switches, causes higher Electromagnetic Interference (EMI) and reduces the efficiency of the circuit. To avert the “shoot-through”, dead time control could be added, but it deteriorates the harmonic compensation level. This dissertation presents active power filters (APFs) based on interleaved buck (IB) converter. Compared to traditional shunt active power filters, the presented IB APFs have enhanced reliability with no shoot-through phenomenon. The instantaneous active and reactive power (p-q) scheme and instantaneous active and reactive current component (id-iq) control scheme has been implemented to mitigate the source current harmonics. Type-1 and Type-2 fuzzy logic controller with different membership functions (MFs) viz. Triangular, Trapezoidal and Gaussian have been implemented for the optimal harmonic compensation by controlling the dc-link voltage and minimizing the undesirable losses occurred inside the APF. Additionally, the adaptive hysteresis band current controller (AHBCC) is being implemented to get the nearly constant switching frequency. The performance of the control strategies and controllers for the presented IB APF topologies has been evaluated in terms of harmonic mitigation and dc-link voltage regulation under sinusoidal, unbalanced sinusoidal and non-sinusoidal voltage source condition. This dissertation is concerned with the different topologies of 3-phase 4-wire IB APFs viz. split capacitor (2C) topology, 4-leg (4L) topology, transformer based full-bridge IB APF or single capacitor based FB IB APF (1C 3 FB IB APF) and full-bridge IB APF (FB IB APF) for low to medium power application. Moreover, APF topology is now being expanded to multilevel VSIs for high power application. Thanks to flexible modular design, transformerless connection, extended voltage and power output, less maintenance and higher fault tolerance, the cascade inverters are good candidates for active power filters with the utility of high power application. The cascaded FB IB APF is modelled with no shoot-through phenomenon by using multicarrier phase shifted PWM scheme. Extensive simulations have been carried out in the MATLAB / Simulink environment and also verified in the OPAL-RT LAB using OP5142-Spartan 3 FPGA to support the feasibility of presented IB APF topologies, control strategies and controllers during steady and dynamic condition. The performance shows that IB-APF topologies bring the THD of the source current well below 5% adhering to IEEE-519 standard. A comparison has also been made, based on SDP (switch device power) between the IB-APF topologies

A review on power electronics technologies for power quality improvement

Nowadays, new challenges arise relating to the compensation of power quality problems, where the introduction of innovative solutions based on power electronics is of paramount importance. The evolution from conventional electrical power grids to smart grids requires the use of a large number of power electronics converters, indispensable for the integration of key technologies, such as renewable energies, electric mobility and energy storage systems, which adds importance to power quality issues. Addressing these topics, this paper presents an extensive review on power electronics technologies applied to power quality improvement, highlighting, and explaining the main phenomena associated with the occurrence of power quality problems in smart grids, their cause and effects for different activity sectors, and the main power electronics topologies for each technological solution. More specifically, the paper presents a review and classification of the main power quality problems and the respective context with the standards, a review of power quality problems related to the power production from renewables, the contextualization with solid-state transformers, electric mobility and electrical railway systems, a review of power electronics solutions to compensate the main power quality problems, as well as power electronics solutions to guarantee high levels of power quality. Relevant experimental results and exemplificative developed power electronics prototypes are also presented throughout the paper.This work has been supported by FCT-Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017 and by the FCT Project newERA4GRIDs PTDC/EEIEEE/30283/2017