Performance Of Distribution Static Compensator Research Articles

A new robust modified capuchin search algorithm for the optimum amalgamation of DSTATCOM in power distribution networks

Very sensitive loads require the safe operation of electrical distribution networks, including hospitals, nuclear and radiation installations, industries used by divers, etc. To address this issue, the provided paper suggests an innovative method for evaluating the appropriate allocation of Distribution STATic COMpensator (DSTATCOM) to alleviate total power losses, relieve voltage deviation, and lessen capital annual price in power distribution grids (PDGs). An innovative approach, known as the modified capuchin search algorithm (mCapSA), has been introduced for the first time, which is capable of addressing several issues regarding optimal DSTATCOM allocation. Furthermore, the analytic hierarchy process method approach is suggested to generate the most suitable weighting factors for the objective function. In order to verify the feasibility of the proposed mCapSA methodology and the performance of DSTATCOM, it has been tested on two standard buses, the 33-bus PDG and the 118-bus PDG, with a load modeling case study based on real measurements and analysis of the middle Egyptian power distribution grid. The proposed mCapSA technique's accuracy is evaluated by comparing it to other 7 recent optimization algorithms including the original CapSA. Furthermore, the Wilcoxon sign rank test is used to assess the significance of the results. Based on the simulation results, it has been demonstrated that optimal DSTATCOM allocation contributes greatly to the reduction of power loss, augmentation of the voltage profile, and reduction of total annual costs. As a result of optimized DSTATCOM allocation in PDGs, distribution-level uncertainties can also be reduced.

Power Quality Improvement by Using Discrete Wavelet Transform Based DSTATCOM

Abstract: The discrete wavelet transform-based control technique for the distribution static compensator (DSTATCOM) is utilized in this paper to improve power quality at common points of interconnection (CPI). The discrete wavelet transform, the time frequency analysis technique, is used here to split distorted load current of each phase in order to recover the line frequency of harmonic components for estimating the respective active power components. The difference between the estimated reference active component and the detected load currents is utilized to create reference currents for DSTATCOM's voltage source converter (VSC) management. The performance of DSTATCOM is presented using MATLAB software under varied linear and non-linear load circumstances. Under various load situations, total harmonic distortion (THD) of the source current is less than 5% with a power factor of unity.

Analysis of sliding mode controller based DSTATCOM for power quality improvement in distribution power system

In this paper, Sliding Mode Controller-based Distribution Static Compensator (DSTATCOM) is proposed for enhancement of power quality in the distribution network. The DSTATCOM plays a vital role to enhance the quality of power in the distribution network with linear and nonlinear loads under non-stiff sources. During the load disturbance in the systems, there is a sudden variation of voltage in DC link capacitor voltage connected with compensating device. The performance of DSTATCOM purely depends on the capacitor voltage level during load variation. It should be maintained within the prescribed limits. In general, the conventional controller is used in the converter to control dc-link capacitor voltage. Through, the conventional controller like PI transient response is still slow. Due to this reason, the harmonic elimination, load balancing, and reactive power compensation process are not satisfactory during different load variations in the distribution systems. To overcome these problems sliding mode controller is proposed in the control circuit for the proper operation of the compensator. The sliding mode controller regulates the DC link capacitor voltage to generate required reference currents. The reference currents play a vital role for switching pulse generation and control of DSTATCOM during various load disturbances. Sliding mode controller is designed to limit variation of DC-link voltage within limits. The proposed technique is modelled and its performance is simulated in MATLAB/SIMULINK platform and results are shown to validate the design and control of DSTATCOM under various load disturbance.

Control of DSTATCOM using nonparametric variable step-size NLMS: An experimental study

The development of distribution static compensator (DSTATCOM) using nonparametric variable step-size normalized least mean square (NPVSS-NLMS) based control technique is presented in this paper. Numerous features of DSTATCOM such as harmonic alleviation, reactive power compensation and load balancing are demonstrated using NPVSS-NLMS controller. The laboratory prototype of shunt compensator is developed using a dSPACE DS1104 R&D controller having TMS320F240 as a slave DSP. Both MATLAB/SIMULINK based simulations and experimental test results are presented for demonstrating the steady state as well as dynamic performance of DSTATCOM. The developed control technique is compared with variable step size LMS (VSS-LMS) and modern control techniques viz. sliding mode controller (SMC) and model predictive control (MPC) in terms of filter type, weight convergence, complexity, harmonic compensation and sampling time taken. The NPVSS-NLMS based control algorithm for shunt compensator is performing satisfactory in all the above mentioned terms over conventional VSS-LMS controller. The scheme is found to be effective in reducing the total harmonic distortion (THD) of supply current as per IEEE-519 standard.

A new voltage control strategy to improve performance of DSTATCOM in electric grid

A new voltage control strategy of distribution static compensator (DSTATCOM) has been proposed in this paper for electric grid applications. The proposed control scheme combines two methods of DSTATCOM operation to improve its performance. Considering power factor and voltage magnitude as degree of freedom, the DSTATCOM provides features such as mitigation of voltage and current harmonics, balancing of source currents, improvement of power factor, voltage regulation during voltage sag and swell, reduction in inverter losses, and control of load power to achieve energy conservation. The performance of proposed DSTATCOM control is better as compared to its conventional operation at any time of operation. PSCAD simulation and experimental results validate the performances.

Design and control of a DSTATCOM for power quality improvement using cross correlation function approach

This paper presents the design of a three phase DSTATCOM (Distribution Static Compensator) and its control algorithm based on correlation and cross correlation function approach for power quality improvement under linear/ nonlinear loads in a distribution system. In this approach, an extraction of fundamental active and reactive power components of load currents is based on correlation and cross correlation functions in time domain. For estimation of fundamental active and reactive power components of load currents, a numerical integration is applied in correlation and cross correlation function. The DSTATCOM is modeled under linear and nonlinear loads and its performance is simulated in the MATLAB environment using SIMULINK and Sim Power System (SPS) toolboxes. The performance of DSTATCOM is found satisfactory under time varying and unbalanced loads.Keywords: Correlation and cross-correlation coefficients, DSTATCOM, Power factor correction, Zero voltage regulation

Generalised neural network‐based control algorithm for DSTATCOM in distribution systems

This study presents a new concept to control a distribution static compensator (DSTATCOM) based on generalised neural network in a three-phase power distribution system. Artificial neural network (ANN)-based controllers play the vital role in the performance improvement of DSTATCOM. However, their application is limited by the increase in complexity as well as the computational time. The proposed generalised neural network algorithm is a combination of Gaussian, sigmoidal and linear transfer functions within a layer to improve the DSTATCOM control strategy. This algorithm estimates the amplitude of the wattful and wattless current components of the load currents for harmonics elimination and reactive power compensation by the DSTATCOM. The algorithm is developed in MATLAB. The case studies validate its superiority over ANN-based control algorithms. The proposed method needs a less number of training patterns and unknown weights compared to other algorithms which reduces the complexity and the computational time. It also improves the performance of DSTATCOM estimating the weights and its learning online which is of the main merits of this algorithm. Its other inherent advantages are ease in design, robustness and its adaptivity with dynamics of load at utility end.

Dual-Tree Complex Wavelet Transform-Based Control Algorithm for Power Quality Improvement in a Distribution System

This paper presents a dual tree-complex wavelet transform-based control algorithm for a distribution static compensator (DSTATCOM) to improve the power quality (PQ) in a distribution system. PQ disturbances like harmonics and starting as well as ending of unbalancing in all phase load currents are also assessed simultaneously. The distorted load current of each phase is decomposed into various frequency levels with this technique to extract respective line frequency component for the estimation of the reference active power component. The deviations of respective sensed load currents from these estimated reference components are used to generate the reference currents for the control of voltage source converter used as DSTATCOM. Simulated performance of DSTATCOM is presented at varying load conditions. The proposed control algorithm is also validated experimentally on a laboratory prototype of DSTATCOM. The total harmonic distortion (THD) of supply current is obtained below 5 percent with unity power factor under different load conditions which is satisfactory as per IEEE-519 standard.

Power Quality Enhancement Using DSTATCOM in Distributed Power Generation System

In this paper, a distribution static compensator (DSTATCOM) is implemented for controlling a distributed power generating system using a proposed composite observer based control technique. The proposed control technique is employed for the fundamental components extraction of distorted load currents. These extracted components are used in the estimation of reference source currents to generate gating signals of DSTATCOM. The proposed control technique is implemented for the mitigation of reactive power, distortion in term of harmonics, and load balancing under linear/nonlinear loads. The performance of DSTATCOM is observed satisfactory for these consumer loads with regulated generator voltage at point of common coupling and self-supported dc link of voltage-source converter of DSTATCOM.

Performance analysis of distribution static compensator for power quality perspective

In recent years the use of nonlinear loads in the distribution system has increased drastically. Due to these nonlinear loads, power quality problems occurs in the system. Distribution Static Compensator (DSTATCOM) is a voltage source converter based shunt connected custom power device, used in distribution system for performance improvement. DSTATCOM will maintain constant voltage at load terminals and limit the Total Harmonic Distortion (THD). This paper presents a case study on investigation of performance of DSTATCOM at different operating scenarios. IEEE 13 bus industrial system is used to study the performance of three leg DSTATCOM. Voltage control mode with PI controller is used to control RMS voltage at Point of Common Coupling (PCC). PSCAD/EMTDCTM tool is used to study the performance. From the study it is found that DSTATCOM is able to maintain voltage at 1 pu.

Design of External Inductor for Improving Performance of Voltage Controlled DSTATCOM

A distribution static compensator (DSTATCOM) is used for load voltage regulation, and its performance mainly depends upon the feeder impedance and its nature (resistive, inductive, stiff, nonstiff). However, a study for analyzing voltage regulation performance of DSTATCOM depending upon network parameters is not well defined. This paper aims to provide a comprehensive study of design, operation, and flexible control of a DSTATCOM operating in voltage control mode. A detailed analysis of the voltage regulation capability of DSTATCOM under various feeder impedances is presented. Then, a benchmark design procedure to compute the value of external inductor is presented. A dynamic reference load voltage generation scheme is also developed, which allows DSTATCOM to compensate load reactive power during normal operation, in addition to providing voltage support during disturbances. Simulation and experimental results validate the effectiveness of the proposed scheme.

Power Quality Improvement in Isolated Distributed Power Generating System Using DSTATCOM

This paper presents the control of a synchronous reluctance generator (SyRG) driven by a biogas/biomass diesel engine as a prime mover in a distributed power generating system. This generator is used as a source to feed linear and nonlinear loads. A three-leg voltage source converter (VSC)-based distribution static compensator (DSTATCOM) is implemented using an adaptive neural network-based control algorithm for harmonic suppression, load balancing, and voltage regulation in a three-phase SyRG system with a battery energy storage system. This control algorithm is used for extraction of active and reactive power components of distorted load currents. These components of load currents are used for estimation of reference source currents to generate the gating pulses of VSC used as DSTATCOM. The performance of DSTATCOM is observed satisfactory for this type of power generating system under balanced and unbalanced loads.

Variable Forgetting Factor Recursive Least Square Control Algorithm for DSTATCOM

This paper proposes an implementation of distribution static compensator (DSTATCOM) for the three-phase distribution system. The functions of DSTATCOM are harmonics elimination, compensation of reactive power, and load balancing in power factor correction and voltage regulation modes. A variable forgetting factor recursive least square (VFFRLS)-based control algorithm is proposed for effective operation of DSTATCOM to estimate weighted values of active and reactive power components of load current. The proposed control algorithm is fast in convergence and has quick response. A prototype of DSTATCOM is developed in the laboratory using a digital signal processor (dSPACE 1104) and voltage-source converter and tested for various operating conditions under nonlinear load. The performance of DSTATCOM is found satisfactory in mitigating various power-quality problems with the VFFRLS-based control algorithm.

Double deadbeat‐loop control method for distribution static compensator

This study presents a double deadbeat-loop control method for distribution static compensator (DSTATCOM), which aims to simplify design of the controller for DSTATCOM and improve the dynamic performance of DSTATCOM. The proposed control method comprises of dc-link voltage deadbeat controller and the ac-side instantaneous current deadbeat controller, in which the dc-link voltage deadbeat control method is proposed for simplifying the design of the outer voltage controller of DSTATCOM. The output of the dc-link voltage deadbeat controller and the reactive current reference obtained from the load are imported into the ac-side instantaneous current controller based on the deadbeat current method. The parameters of the proposed control method can be directly calculated according to the parameters of the given circuit components, and the proposed control method is very easy to be realised in digital processor and with fast dynamic response. Finally, the feasibility of the proposed control method is validated through both simulation and experiment results.

Hyperbolic tangent function‐based least mean‐square control algorithm for distribution static compensator

A variable learning rate least mean-square (LMS) based on hyperbolic tangent function is used to enhance the rate of convergence and to suppress the existing noise in the system for the control of distribution static compensator (DSTATCOM) consisting of a three-leg voltage source converter (VSC) with a zig-zag transformer to eliminate the significant neutral current caused by non-linear unbalanced loads in a three-phase four-wire supply system. Simulation is made for the proposed control algorithm in three-phase four-wire DSTATCOM system and its performance is compared with the conventional Adaline-based LMS control algorithm. It is also shown that the convergence rate of the proposed control algorithm is quite faster in comparison with the conventional control algorithm. A prototype of DSTATCOM is developed and the real-time implementation of the proposed control algorithm is performed on a digital signal processor. Test results have demonstrated the satisfactory performance of DSTATCOM with the proposed control algorithm under linear and non-linear loads.

Implementation of Adaptive Filter in Distribution Static Compensator

This paper presents an implementation of an adaptive filter in a three-phase distribution static compensator (DSTATCOM) used for compensation of linear/nonlinear loads in a three-phase distorted voltage ac mains. The proposed filter, which is based on adaptive synchronous extraction, is used for extraction of fundamental active- and reactive-power components of load currents in estimating the reference supply currents. This control algorithm is implemented on a developed DSTATCOM for reactive-power compensation, harmonics elimination, load balancing, and voltage regulation under linear and nonlinear loads. The performance of DSTATCOM is observed satisfactory under unbalanced time-varying loads.

Simple peak detection control algorithm of distribution static compensator for power quality improvement

This study deals with the control of a three-phase, four-wire distribution static compensator (DSTATCOM) based on the peak detection of load currents for power quality improvement under linear/non-linear loads. This control algorithm is simple and easy in real time implementation. In this control algorithm, an extraction of active and reactive power components of load currents is based on a low-pass filter and the voltage unit vector in time domain. It is based on the mathematical formulations for fast and accurate estimation of reference supply currents. A four-wire DSTATCOM is modelled and implemented for the compensation of linear and non-linear loads using a digital signal processor. Performance of DSTATCOM is found quite satisfactory under balanced and unbalanced loads in three-phase, four-wire distribution system.

Implementation of four‐leg distribution static compensator

An implementation of a four-leg distribution static compensator (DSTATCOM) using an adaptive neural network-based control algorithm for compensation of linear/non-linear loads using voltage source converter is presented here. The proposed control algorithm, which is based on adaptive neural network, is used for extraction of fundamental active and reactive power components of load currents which are major components in the estimation of reference supply currents. This control algorithm is implemented on a developed four-leg DSTATCOM for reactive power compensation, harmonics elimination, load balancing and neutral current mitigation under linear and non-linear loads. The performance of DSTATCOM is observed quite satisfactory under various linear and non-linear loads.

Back-Propagation Control Algorithm for Power Quality Improvement Using DSTATCOM

This paper presents an implementation of a three phase distribution static compensator (DSTATCOM) using a back propagation (BP) control algorithm for its functions such as harmonic elimination, load balancing and reactive power compensation for power factor correction, and zero voltage regulation under nonlinear loads. A BP-based control algorithm is used for the extraction of the fundamental weighted value of active and reactive power components of load currents which are required for the estimation of reference source currents. A prototype of DSTATCOM is developed using a digital signal processor, and its performance is studied under various operating conditions. The performance of DSTATCOM is found to be satisfactory with the proposed control algorithm for various types of loads.

Adaptive Theory-Based Improved Linear Sinusoidal Tracer Control Algorithm for DSTATCOM

This paper presents a hardware implementation of three-phase distribution static compensator (DSTATCOM) using an adaptive theory-based improved linear sinusoidal tracer (ILST) control algorithm for different functions of DSTATCOM such as reactive power compensation for power factor correction, harmonics elimination, load balancing, and zero-voltage regulation under linear/nonlinear loads. An ILST-based control algorithm is used for the extraction of fundamental load currents and their active and reactive power components. These components are used for the estimation of reference source currents. A prototype of DSTATCOM is developed and its real-time performance is studied using a digital signal processor. The performance of DSTATCOM is found satisfactory with the proposed control algorithm under various types of loads.