Reactive Power Compensation for Unbalanced Fluctuating Loads by Using Two-Dimensional Space Vector and a Static Var Compensator

2014 ◽  
Vol 533 ◽  
pp. 397-400 ◽  
Author(s):  
Chi Jui Wu ◽  
Yu Wei Liu ◽  
Shou Chien Huang
Keyword(s):  
Power Factor ◽  
Reactive Power ◽  
Dimensional Space ◽  
Measurement Data ◽  
Power Source ◽  
Active Power ◽  
Two Dimensional ◽  
Static Var Compensator ◽  
Space Vector ◽  
Three Phase

To modify the power factor and balance the three-phase currents simultaneously, this paper proposes the instantaneous compensator to calculate the compensation current. The instantaneous compensator utilizes two-dimensional instantaneous space vector and setting the active power as a constant for each cycle which can improve power quality effectively. Moreover, the instantaneous compensator requires an independent power source, whose capacity can be reduce by using a static var compensator (SVC). An SVC does not interfere with the capability of the instantaneous compensator. Field measurement data were analyzed. Simulation results confirmed the feasibility of correcting the power factor and balancing load currents simultaneously using the proposed method.

Designing Static VAr Compensator capacity to enhance power quality in electric arc furnaces

SIMULATION ◽  
2017 ◽  
Vol 93 (6) ◽  
pp. 515-525 ◽  
Author(s):  
Mohammad Reza Asban ◽  
Jamshid Aghaei ◽  
Taher Niknam ◽  
Mohammad Amin Akbari
Keyword(s):  
Power Factor ◽  
Reactive Power ◽  
Electric Arc ◽  
Active Power ◽  
Static Var Compensator ◽  
Power Functions ◽  
Voltage Fluctuations ◽  
Electric Arc Furnaces ◽  
Arc Furnaces ◽  
Electro Magnetic

This paper introduces a method for reducing damages arising from voltage fluctuations, voltage flicker, imbalance in the three-phase and power factor reduction caused by electric arc furnaces. A novel equation is defined to calculate the susceptance values of the static var compensator control system, the active power functions of phase load as well as the reactive power ones that have been used to suppress the voltage fluctuation. By compensating the impulsive part of active power component in the impulsive loads, not only can we reduce voltage fluctuations, flicker effects, balance the system and increase the power factor, but also voltage stabilization can be directly controlled. By studying this method and simulating on Electro-Magnetic Transients Program (EMTP) software, we can see that, according to the allowable flicker limit, a compensation method can balance the system, increase power factor and resolve the problem of voltage fluctuations and flicker.

Reactive Power Compensation for Unbalanced Fluctuating Loads by Using Two-Dimensional Instantaneous Space Vector Approach

2013 ◽  
Vol 732-733 ◽  
pp. 1444-1449 ◽  
Author(s):  
Chi Jui Wu ◽  
Yu Wei Liu
Keyword(s):  
Power Factor ◽  
Reactive Power ◽  
Measurement Data ◽  
Current Compensation ◽  
Three Phase ◽  
Instantaneous Current ◽  
Unbalanced Load ◽  
Space Vectors ◽  
Unbalanced Loads ◽  
Vector Approach

To improve the power quality and efficiency on feeding unbalanced loads, this paper proposes a scheme of instantaneous current compensation that can modify the power factor and balance the three-phase currents simultaneously. The method of instantaneous space vectors can compensate the reactive power effectively, but the problems of unbalanced load currents remains. This paper suggests a method that can mitigate the unbalanced load currents by setting the active power as a constant for each cycle. Field measurement data were analyzed. Simulation results confirmed the feasibility of correcting the power factor and balancing load currents simultaneously using the proposed method.

scholarly journals Optimal P-Q Control of Grid-Connected Inverters in a Microgrid Based on Adaptive Population Extremal Optimization

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2107 ◽  
Author(s):  
Min-Rong Chen ◽  
Huan Wang ◽  
Guo-Qiang Zeng ◽  
Yu-Xing Dai ◽  
Da-Qiang Bi
Keyword(s):  
Constrained Optimization ◽  
Optimization Problem ◽  
Reactive Power ◽  
Active Power ◽  
Adaptive Genetic Algorithm ◽  
Constrained Optimization Problem ◽  
Extremal Optimization ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Grid Connected Inverter

The optimal P-Q control issue of the active and reactive power for a microgrid in the grid-connected mode has attracted increasing interests recently. In this paper, an optimal active and reactive power control is developed for a three-phase grid-connected inverter in a microgrid by using an adaptive population-based extremal optimization algorithm (APEO). Firstly, the optimal P-Q control issue of grid-connected inverters in a microgrid is formulated as a constrained optimization problem, where six parameters of three decoupled PI controllers are real-coded as the decision variables, and the integral time absolute error (ITAE) between the output and referenced active power and the ITAE between the output and referenced reactive power are weighted as the objective function. Then, an effective and efficient APEO algorithm with an adaptive mutation operation is proposed for solving this constrained optimization problem. The simulation and experiments for a 3kW three-phase grid-connected inverter under both nominal and variable reference active power values have shown that the proposed APEO-based P-Q control method outperforms the traditional Z-N empirical method, the adaptive genetic algorithm-based, and particle swarm optimization-based P-Q control methods.

scholarly journals Decoupled Control of Three Phase Grid Connected Solar PV System

2019 ◽  
Vol 9 (2) ◽  
pp. 4218-4222
Keyword(s):  
Solar Energy ◽  
Power Factor ◽  
Control Strategy ◽  
Reactive Power ◽  
Standard Test ◽  
Effective Control ◽  
Solar Pv ◽  
Pv System ◽  
Three Phase ◽  
Decoupled Control

A reliable grid connected Photovoltaic (PV) system require effective control schemes for efficient use of solar energy. This paper presents a three-phase grid tied PV system with decoupled real and reactive power control to achieve desired power factor with Maximum Power Point Tracking (MPPT) controller to get maximum solar energy. The synchronous reference frame (dq) control along with decoupling concept is used to control the DC-AC inverter output, while the Phase Locked Loop (PLL) synchronization technique is used to monitor and synchronize the voltage and current at the grid side. The DC-DC converter with Incremental Conductance (InC) based MPPT model is also designed in this paper due to better accuracy compared to Perturb & Observe (P&O) algorithm. The simulation is performed in MATLAB/SIMULINK and a 31.5 kW PV system is modelled to get 30 kW power with the help of MPPT at Standard Test Conditions (STC). Any power factor value between 0.85 lagging to 0.9 leading can be obtained by changingreference q current in this inverter control strategy. The simulation results show that the change of reactive powerdoes not affecttheactive power values of the system, which verifies the effectiveness of the decoupled control strategy of the inverter.

scholarly journals Asymmetrical four-wire cascaded h-bridge multi-level inverter based shunt active power filter supplied by a photovoltaic source

2021 ◽  
Vol 12 (3) ◽  
pp. 1673
Author(s):  
Kamel Saleh ◽  
Omar Mahmoud
Keyword(s):  
Reactive Power ◽  
Dimensional Space ◽  
Active Power Filter ◽  
Power Converter ◽  
Open Circuit ◽  
Active Power ◽  
Nonlinear Load ◽  
Shunt Active Power Filter ◽  
Power Filter ◽  
Multi Level

<span>This paper presents a novel shunt active power filter (SAPF). The power converter that is used in this SAPF is constructed from a four-leg asymmetric multi-level cascaded H-bridge (CHB) inverter that is fed from a photovoltaic source. A three-dimensional space vector modulation (3D-SVPWM) technique is adopted in this work. The multi-level inverter can generate 27-level output with harmonic content is almost zero. In addition to the capability to inject reactive power and mitigating the harmonics, the proposed SAPF has also, the ability to inject real power as it is fed from a PV source. Moreover, it has a fault-tolerant capability that makes the SAPF maintaining its operation under a loss of one leg of the multi-level inverter due to an open-circuit fault without any degradation in the performance. The proposed SAPF is designed and simulated in MATLAB SIMULINK using a single nonlinear load and the results have shown a significant reduction in total harmonics distortion (THD) of the source current under the normal operating condition and post a failure in one phase of the SAPF. Also, similar results are obtained when IEEE 15 bus network is used.</span>

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