Meta-heuristics algorithms for optimization of gains for dynamic voltage restorers to improve power quality and dynamics Rajagopal Veramalla, Sabha Raj Arya, Vishwas Gundeboina, Bangarraju Jampana, Rajasekharareddy Chilipi, Santhosh Madasthu Optimal Control Applications and Methods, 2023 Abstract This article discusses metaheuristic algorithms for optimizing controller gains for dynamic voltage restorers (DVRs) that use an impedance control strategy to compensate for unbalance in source voltages, voltage harmonics, and sag/swell in source voltages. The gains of the proportional‐integral (PI) controllers become critical for proper DVR load voltage extraction. Various techniques for optimization, such as whale optimization technique, gray wolf optimization technique, particle swarm optimization technique, and ant lion optimization technique, are used to obtain DC and AC PI controller gains for DVR. The impedance control strategy employs simple calculations to determine the resistance and reactance of a polluted source voltage, without the use of frame conversions as in synchronous reference theory, instantaneous reference power theory, and so on. The quick calculations of the impedance control scheme improve the power quality and dynamics. The Metaheuristic algorithms are used to calculate the number of iterations required to achieve the best possible controller gains, which further helps to improve power quality and dynamics. Among these optimization techniques, the antlion optimization technique provides fast convergence and the best possible controller gain values to improve the dynamics of the dc‐link voltage of voltage source converter and terminal voltage, thereby improving power quality. The proposed antlion optimization technique‐based DVR model is simulated in MATLAB R2019, and the results are validated with RT‐LAB.
Optimized Controller Gains Using Grey Wolf Algorithm for Grid Tied Solar Power Generation with Improved Dynamics and Power Quality Veramalla Rajagopal, Danthurthi Sharath, Gundeboina Vishwas, Jampana Bangarraju, Sabha Raj Arya, Challa Venkatesh Chinese Journal of Electrical Engineering, 2022 This study proposes a control algorithm based on synchronous reference frame theory with unit templates instead of a phase locked loop for grid-connected photovoltaic (PV) solar system, comprising solar PV panels, DC-DC converter, controller for maximum power point tracking, resistance capacitance ripple filter, insulated-gate bipolar transistor based controller, interfacing inductor, linear and nonlinear loads. The dynamic performance of the grid connected solar system depends on the effect operation of the control algorithm, comprising two proportional-integral controllers. These controllers estimate the reference solar-grid currents, which in turn generate pulses for the three-leg voltage source converter. The grey wolf optimization algorithm is used to optimize the controller gains of the proportional-integral controllers, resulting in excellent performance compared to that of existing optimization algorithms. The compensation for neutral current is provided by a star-delta transformer (non-isolated), and the proposed solar PV grid system provides zero voltage regulation and eliminates harmonics, in addition to load balancing. Maximum power extraction from the solar panel is achieved using the incremental conductance algorithm for the DC-DC converter supplying solar power to the DC bus capacitor, which in turn supplies this power to the grid with improved dynamics and quality. The solar system along with the control algorithm and controller is modeled using Simulink in Matlab 2019.
DC Component Extraction of Notch Filter Algorithm for Active Power Filters Bangarraju Jampana, Jayalaxmi Askani, Rajagopal Veramalla Journal Europeen Des Systemes Automatises, 2022 This work presents a way to handle the DC component of input signals for PLL and notch filter applications, which are utilized for filtering and synchronization. The input signal of a DC component may be due to some sort of malfunction, or it may be the result of the structure and restrictions of the measurement/conversion procedures. This part makes the system's loop oscillate at low frequencies and no filter can fully filter them out because that would significantly harm the system's dynamic response. The proposal involves augmenting the PLL structure with a new loop. It is basic architecturally and in contrast to a currently presented method and it does not detract from the algorithm's high-frequency filtering level. This Orthogonal Signal Generators (OSG) control algorithm is used for active power filter to maintain unity power factor, neutral current compensation using star/three single transformer & current harmonics mitigation. The MATLAB/Simulink results are demonstrated for the above stated Power Quality (PQ) problems.
Peak detection control strategy based STATCOM for suppression of power quality problems J. Bangarraju, V. Rajagopal, V. Sharada, K. Lakshmaiah E3s Web of Conferences, 2019 This paper explains about control of VSC using uni-polar switching based Static Compensator (STATCOM) using Peak Detection Control Strategy for elimination of PQ Problems. The proposed STATCOM are operated in PFC (Power Factor Correction) mode and ZVR (Zero Voltage Regulation) mode. Under these operation modes of STATCOM is able to suppression of harmonics, PFC at source, reactive power compensation, load balancing and compensation of neutral current. A non-isolated star/three individual single- phase transformers are connected at PCC (Point of Common Coupling) to mitigate neutral current. The Peak Detection Control Strategy is simple to implement for estimating switching pulses for VSC. This peak detection control strategy based STATCOM is modelled, simulated results are validated using MATLAB R2013b.
Unit vectors of SRF control algorithm based DVR for power quality improvement J. Bangarraju, V. Rajagopal, B. Pallavi, K. Amritha, K. Sainadh Singh Proceedings of the 2017 International Conference on Smart Technology for Smart Nation Smarttechcon 2017, 2018 Today India trends towards the Research Development as the Research leads to make the country developed. In all the several Disciplines in Research Power System shows the great embark in development. DVR is used for compensation of Voltage sensible problems like swell sag etc. The Unit Vectors of SRF control algorithm used for the compensator plays a major role in power quality improvement. Unit Vectors of SRF Synchronous Reference Theory is considered as control algorithm for the compensator. Generally, control algorithm generates the reference signal. In the conventional SRF control algorithm the reference is generated with the help of Phased Locked Loops but it consumes more time. Hence this paper proposed the unit vectors for the generation of references for the load voltage. Hence the generated reference signal is compared with load voltages. Thus, obtained error is converted into the pulses with the help of a PWM converter and is given to DVR. Form the pulses DVR inject this error into the system and compensate the power quality problems. The projected DVR is simulated in Matlab 2012a and the results are validated by simulation results.
Power quality improvement for grid interconnected solar PV system using neural network control algorithm Bellamkonda Pragathi, Rajagopal Veramalla, Fazal Noorbasha, Bangarraju Jampana International Journal of Power and Energy Conversion, 2018 This paper deals with neural network control algorithm-based grid connected to solar photo voltaic (PV) system consisting of DC-DC converter, solar PV with maximum power point tracking (MPPT) controller, three-leg voltage source converter (VSC), ripple filter at PCC, interfacing inductor and three phase grid connected to three phase linear/nonlinear loads. The reference solar-grid current for three-leg VSC are estimated using neural network control algorithm. The neural network based on least mean square (LMS) control algorithm is also known as adaptive linear element to estimate reference fundamental grid currents. A three phase non-isolated zigzag transformer is connected to solar grid PCC for neutral current compensation. The proposed solar PV grid connected system maintains UPF at the grid, reactive power compensation for ZVR operation along with load balancing, neutral current compensation and harmonic compensation. In the proposed solar PV system, MPPT is obtained using DC-DC boost converter and DC bus voltage is controlled by using DC bus proportional integral (PI). The neural network control algorithm based solar PV system is modelled in MATLAB R2013a along with SIMULINK.
Reduced Switch Technique for Solar PV System Based Multilevel Inverter for PQ Improvement V. Rajagopal, V. Nagamalleswari, Papia Ray, Sabha Raj Arya, J. Bangarraju International Journal of Emerging Electric Power Systems, 2018 This paper describes reduced number of switches technique for Solar Photo Voltaic (SPV) voltage source based 31-level Multi Level Inverter (MLI) for Power Quality (PQ) improvement. The proposed topology reduces number of IGBT switches to ten, which is very less compared to diode clamped, capacitor and cascaded multilevel inverter. The desired multistep AC output voltage with minimum number of switches is obtained using this topology which reduces cost of system. The proposed MLI reduces number of harmonics at the AC output voltage which improves the PQ. The square wave switching used in this topology reduces the switching losses compared to pulse width modulation technique. The performance of four solar PV voltage sources with Buck/Boost converter has been discussed in this paper. The proposed MLI is mainly used in this paper for off grid system. The results of the Solar PV System based 31-level MLI have been simulated in MATLAB R2013a environment and hardware results have been validated using Opal-RT real time simulator OP-5142.
