Id Iq Research Articles

Adaptive Fuzzy Logic Control of Hybrid, Active Power Filters, for Harmonic Mitigation

In industrial applications which include power systems, it notices that, harmonics which generated due to nonlinear load (power electronic switches) cause issues for the power quality. Generally, the rectifiers accounted as one of the main elements which produce currents harmonics, where these harmonics will transmit through power system and the generated harmonic distortion will be led to enormous issue and damage for the equipment’s. This study deals with hybrid active filter that consist of shunt active power filter(APF) and passive power filter(PPF) in series with grid based on the instantaneous active and reactive current component (id–iq) control strategy to calculate the reference signal of compensation current which is needed to cancelled the non-linear load current. Furthermore, this new technique method handles with adaptive fuzzy logic control with proportional integral control(PI) to obtain perfect controllable dc input of the inverter across capacitor. Therefore, ac output voltage of active power filter with assist of passive power filter is the desirable value in magnitude and frequency, this led to achieve a perfect attenuation of harmonics, where both harmonics and reactive power are compensating. The simulation results show that, the new control method is very effective to reduce harmonic and improve power quality.

A Certain Investigation on Harmonic Reduction and Design of Fuzzy Gain Scheduler for Shunt Compensation for Power Quality Enhancement

Abstract This article describes a Synchronous reference frame based current control scheme for three phase shunt active power filters (SAPFs) to reduce or to remove harmonics, correct power factor, and balance asymmetrical load is analyzed. This active power filter (APFs) is used to compensate harmonic currents and reactive power generated from the nonlinear loads. In this article, to determine reference compensation currents under balanced source voltages, the voltage source inverter for harmonic filtering of a three phase shunt active filter is used. In this proposed method, a fuzzy gain scheduling controller is used and the response of the DC link voltage is compared with PI controller during transient and steady state. The main objective of this article is to analyze shunt active filters with fuzzy gain scheduling controllers and PI controllers. To carry out this analysis, active and reactive current methods (Id–Iq) are considered. Extensive simulations were carried out. The simulations were performed under balance sinusoidal conditions. The results validate the dynamic behavior of a fuzzy gain scheduling controller over PI controllers. The simulation of the proposed system is evaluated using MATLAB Simulink and the results show that the proposed method is more effective than the existing methods.

Analysis of cascaded multilevel inverters for active harmonic filtering in distribution networks

Abstract This paper aims at the investigation of an active power filter (APF) comprised of a transformerless multilevel inverter (MLI) for power conditioning in three-phase three-wire distribution network. The inverter topologies used here are three, five, seven and nine-level. The system configuration mainly involves cascaded MLI structure of APF, generation of compensation filter currents based on instantaneous active and reactive current component (id–iq) method and dc-link voltage regulation using a PI controller. Not many papers focus on the regulation of dc-link capacitor voltage. Here we have proposed the implementation of bacterial foraging optimization (BFO) to extract the gains of PI controller. The proposed work provides improved dc-link voltage regulation, quick prevail over current harmonics and reduction of overall source current THD. Adequate MATLAB/Simulink simulation results are presented for the different cascaded MLIs discussed above. Additionally, the performance has been validated in real-time using Opal-RT Lab simulator considering three different conditions of supply i.e., balanced sinusoidal, balanced non-sinusoidal and unbalanced sinusoidal.

Real-Time Implementation of Type-2 FLC–Based Shunt Active Filter Control Strategies (p–q and Id–Iq) with Different Fuzzy MFs for Power Quality Improvement

Abstract This research article proposes the shunt active filter (SHAF) control strategies (p–q and Id–Iq), which are used to improve the power quality of the electrical network by mitigating the harmonics with the help of Type-2 fuzzy logic controller (Type-2 FLC) different membership functions (MFs). Three-phase reference current waveforms generated by proposed scheme are tracked by the three-phase voltage source converter in a hysteresis band control scheme. The performance of the proposed control strategies has been evaluated in terms of harmonic mitigation and DC link voltage regulation under various source conditions. In order to maintain DC link voltage constant and to generate the compensating reference currents, we have developed Type-2 FLC with different fuzzy MFs (trapezoidal, triangular and Gaussian). The SHAF with proposed Type-2 FLC using Gaussian MF is able to eliminate the uncertainty in the system and SHAF gains outstanding compensation abilities. The detailed real-time results using real-time digital simulator are presented to support the feasibility of proposed control strategies.

PI and Fuzzy-Controlled 3-Phase 4-Wire Interleaved Buck Active Power Filter with Shoot-Through Elimination for Power Quality Improvement using RTDS Hardware

Abstract In this paper, shoot-through current elimination DC–AC converter circuit has been presented with the application of active power filter (APF). The intuitive analysis of the shoot-through in the conventional DC–AC converter has been reported first. Interleaved buck (IB) converter is adopted to eliminate the shoot-through current, thereby increasing the reliability of the interleaved buck–based active power filter (IB-APF). The 3-phase 4-wire IB-APF eliminates the current harmonics produced by the load just as a conventional one does and are innately immune to “shoot-through” phenomenon, with the elimination of special protection features required in conventional inverter circuits. A comparison has been made about the compensation capabilities of the IB-APF with the PI and fuzzy logic controller (FLC) used by id–iq control strategy under different supply voltage conditions. The id–iq control strategy used for extracting the three-phase reference current for IB-APF, evaluating their performance here in MATLAB/Simulink environment and also implemented using real-time digital simulator hardware (OPAL-RT hardware). The RTDS result verifies that the total harmonic distortion percentage of the source current can be reduced below 5% according to IEEE-519 standard recommendations on harmonic limits.

Real time implementation of PI and fuzzy logic controller based 3-phase 4-wire interleaved buck active power filter for mitigation of harmonics with id–iq control strategy

The “shoot-through” failure, one of the most hazardous failure modes encountered in conventional inverter circuit which is used as the main circuit of the 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. A novel 3-phase 4-wire active power filter (APF) based on interleaved buck (IB) DC-to-AC converter with the instantaneous active and reactive current component (id–iq) control strategy is proposed here to mitigate the harmonics having PI and fuzzy logic (FLC) controllers. This interleaved buck (IB) DC-to-AC converter is an augmented version of the conventional phase leg configuration and is innately immune to “shoot-through” phenomenon, with the elimination of special protection features required in conventional inverter circuits. Here in this paper, a comparison has been made between the compensation capabilities of the 3-phase IB-APF with the PI and fuzzy logic controller (FLC) used by id–iq control strategy under different supply voltage conditions. The performance of the control strategies have been evaluated in terms of harmonic mitigation and DC link voltage regulation. Extensive simulations have been carried out in the MATLAB / SIMULINK environment and also implemented using Real-Time Digital Simulator Hardware (RTDS-Hardware).

Real-time performance analysis and comparison of various control schemes for particle swarm optimization-based shunt active power filters

Selection of proper reference compensation current extraction scheme plays the most crucial role in the performance of an active power filter (APF). This paper mainly describes three different control schemes used in APFs namely, Conventional instantaneous active and reactive power (p–q), Modified p–q, and Instantaneous active and reactive current component (id–iq) schemes. Our objective here is to bring down the total harmonic distortion (THD) of source current sufficiently below 5% at the point of common-coupling (PCC), in order to satisfy the IEEE 519-1992 Standard recommendations on harmonic limits. Comparative evaluation of the three control schemes shows that, id–iq method is the best control scheme to be implemented on shunt APFs, irrespective of the supply voltage conditions, even under sudden load fluctuations. Results have been validated using MATLAB/Simulink simulations followed by real-time performance verification in Opal-RT Lab simulator. Here, the APF is comprised of a voltage source inverter (VSI) based on pulse-width modulation (PWM) technique. Hence, undesirable power loss takes place inside VSI due to the presence of inductors and frequent switching of IGBTs. This is effectively minimized with inverter DC-link voltage regulation using a PI controller, whose gains are optimized using particle swarm optimization (PSO).

FLC based shunt active filter (p–q and Id–Iq) control strategies for mitigation of harmonics with different fuzzy MFs using MATLAB and real-time digital simulator

Problems caused by power quality have great adverse economical impact on the utilities and customers. Current harmonics are one of the most common power quality problems and are usually resolved by the use of shunt active filters (SHAFs). Control strategies (p–q and Id–Iq) for extracting the three-phase reference currents for shunt active power filters are compared, evaluating their performance under different source conditions. Three-phase reference current waveforms generated by proposed scheme are tracked by the three-phase voltage source converter in a hysteresis band control scheme.The performance of the control strategies has been evaluated in terms of harmonic mitigation and DC link voltage regulation. The proposed SHAF with different fuzzy MFs (Trapezoidal, Triangular and Gaussian) is able to eliminate the uncertainty in the system and SHAF gains outstanding compensation abilities. The detailed simulation results using MATLAB/SIMULINK software are presented to support the feasibility of proposed control strategies. To validate the proposed approach, the system is also implemented on a real-time digital simulator (OPAL-RT) Hardware and adequate results are reported for its verifications.

Real-time implementation of PI and fuzzy logic controllers based shunt active filter control strategies for power quality improvement

Instantaneous active and reactive power (p–q) and current (Id–Iq) control strategies for extracting the three-phase reference currents for shunt active power filters are compared, evaluating their performance under different source voltage conditions with PI and fuzzy logic controllers in MATLAB/Simulink environment and also implemented using Real-Time Digital Simulator Hardware (RTDS Hardware). When the supply voltages are balanced and sinusoidal, then all control strategies with both controllers converge to the same compensation characteristics. However, when the supply voltages are distorted and/or un-balanced sinusoidal, these control strategies result in different degrees of compensation in harmonics. The p–q control strategy unable to yield an adequate solution when source voltages are not ideal. Extensive simulations are carried out with PI as well as fuzzy logic controller for both p–q and Id–Iq control strategies by considering different voltage conditions and adequate results were presented. On owing Id–Iq method with fuzzy logic controller gives away an out-standing performance under balanced, un-balanced and non-sinusoidal supply conditions. The detailed simulation and RTDS Hardware results are included.

Incorporating control trajectories with the direct torque control scheme of interior permanent magnet synchronous motor drive

Interior permanent magnet (IPM) synchronous machines have gained increased attention for applications in electric vehicle, variable speed wind turbine, industrial drives, etc., because of their high torque density, wider speed range and compact construction. The authors present a detailed analysis and modelling of control trajectories and incorporate those trajectories in the direct torque control (DTC) scheme of an IPM synchronous motor drive, for constant-torque and constant-power operating regions. The control trajectories are implemented on a real-time digital signal processor. Because the inputs to the inner torque control loop of DTC are the references for the torque and the amplitude of the stator flux linkage (λs), they are transformed in the T–λs plane, than in the id–iq plane in the indirect control. The modelling and experimental results are presented. Results show very good dynamic and steady-state performances of direct torque controller, incorporating these control trajectories.