J. Bangarraju

Implementation of three -leg VSC based DVR using IRPT Control Algorithm

The proposed Dynamic Voltage Restorer(DVR) is used to mitigate voltage sag, swell, harmonics and unbalance in the supply voltage. This paper presents Instantaneous Reactive Power Theory(IRPT) Control Algorithm for three-leg Voltage Source Converter (VSC) based DVR in the three-phase distribution system. The proposed DVR injects voltages in series with source voltage to regulate rated voltage. The gating signals for three-leg VSC based DVR are extracted from reference load voltages. The proposed IRPT Control Algorithm based DVR results are validated through computer simulation studies using MATLAB/SIMULINK.

Reduced DC-link voltage for six-leg DSTATCOM using IcosФ control algorithm

The six-leg DSTATCOM is used for suppression of harmonics and regulation of terminal voltage. The proposed algorithm is based on IcosΦ control algorithm for DSTATCOM which uses unit templates instead of phased locked loop (PLL) to generate cosθ and sinθ to reduce the execution time. The six-leg IGBT based VSC when compared with three-leg IGBT uses unipolar switching, which will double the PWM switching frequency. The advantage of increasing the PWM switching frequency reduces the filter requirement and improves performance. The star/three single phase transformer reduces the dc-link voltage and compensates the neutral current. This paper deals with six-leg DSTATCOM using IcosΦ control algorithm using star/three single-phase transformer. The simulation results demonstrate effectiveness of DSTATCOM with linear and non-linear loads on MATLAB/SIMULINK environment.

Reduced Switch Technique for Solar PV System Based Multilevel Inverter for PQ Improvement

Abstract 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.

Enhancement of PQ Using Adaptive Theorybased Improved Linear Tracer SinusoidalControl Strategy for DVR

This paper presents the Adaptive Theory based Improved Linear Tracer Sinusoidal (ATILS) Control Strategy for PQ Enhancement using DVR in the Distribution System. The proposed DVR effectively mitigates voltage sag/swell, unbalanced voltage sag/swell for linear loads along with harmonic compensation using ATILS Control Strategy. The DVR consists of voltage source converter (VSC), transformer with capacitor. The main advantages are more efficiency, reliability and its effective control of reactive power. The ATILS Control Strategy is used for extraction of fundamental reference load voltages quickly and accurately to mitigate PQ problems. The proposed ATILS Control Strategy for DVR is modeled using RT-LAB and MATLAB/SIMULINK and its performance is verified for various Power Quality (PQ) problems.

Unit vectors of SRF control algorithm based DVR for power quality improvement

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.

A new VcosΦ control scheme of capacitor supported DVR for Power Quality improvement

This paper presents a new VcosΦ control scheme based DVR for mitigation of Power Quality problems like voltage sag, swell, unbalance in the voltage sag and harmonics in three phase distribution system. The proposed self-supported capacitor based DVR reduces cost and more efficient compared to battery based DVR because battery based DVR requires regular maintenance. The proposed VcosΦ control algorithm is used in control of self-supported capacitor based DVR to control reactive power. In the literature IcosΦ control algorithm is used DSTATCOM to mitigate current related power quality problems efficiently and hardware implementation is easy. This paper also presents modified IcosΦ control algorithm used as VcosΦ control scheme to mitigate voltage related power quality problems. The performance of DVR depends upon extraction of fundamental component of active and reactive voltages for generation of reference load voltages. The reference load voltages are compared with sensed load voltages to generate switching pulses for three leg VSC and the DVR injects voltages in series with source voltage to regulate voltage to rated value. The proposed VcosΦ control scheme is validated through simulation studies using the MATLAB R2012b software with its Simulink and Simpower System (SPS) toolboxes.

Load balancing and voltage regulation for two leg VSC based islanded DG set supply system

This paper discusses the unit template control strategy for load balancing and voltage regulation of induction generator based DG (Diesel generator) set for islanded system. The proposed system consists of DG set along with DSTATCOM (Distributed Static Compensator) and BESS (Battery Energy Storage System) is used for load balancing along with harmonics elimination and reactive power compensation. An isolated T-T Connected transformer is used to reduce size of two-leg VSC and also neutral current compensation. The battery on two-leg VSC (Voltage Source Converter) of DSTATCOM with BESS is able to supply active power when the load requirement is more than rating of DG set and battery can store energy when load requirement is less than DG set rating. The reference sources for two-leg VSC are estimated using unit template control strategy and this algorithm has quick dynamic response. The proposed DG set system with DSTATCOM is modeled in MATLAB R2009a along with Simulink and results are verified under three phase linear/non-linear loads.

Control of DVR using SPLL strategy in distribution system

This paper discuss control of DVR using SPLL (Software Phased Locked Loop) strategy for compensation of PQ disturbances in power DS (Distribution System) network. Using this control strategy, fundamental reference load voltages are estimated using magnitude of fundamental active and reactive components of source voltages. The SPLL strategy based DVR is modeled in MATLAB R2013b environment using SIMULINK to mitigate voltage related PQ Issues are sag/swell, unbalance and harmonics. The MATLAB based DVR model is used for simulation under dynamic and static conditions. Simulation performance of SPLL based DVR is found that satisfactory performance under time varying linear/non-linear loads.

Neural network control for three-leg VSC based DVR in distribution system

This paper deals with neural network control for three-leg Voltage Source Converter (VSC) based DVR in distribution system to mitigate voltage sag, swell and harmonics etc. The proposed neural network control is based on the least mean-square algorithm which is known as adaptive linear element to extract the fundamental component of load voltages. The reference signals for three-leg VSC based DVR are extracted from reference load voltages. The neural network control for DVR is able to self-support its dc bus through the control under varying loads. The main advantage of neural network control is to eliminate filter and which improves performance of DVR. The proposed DVR injects voltages in series with source voltage to regulate voltage at rated voltage. The proposed neural network control based DVR is validated through computer simulation studies using MATLAB/SIMULINK.

Power quality improvement using solar PV H-bridge based hybrid multilevel inverter

This paper proposes a novel H-bridge based hybrid multilevel inverter consists of small number of switching devices and output of H-bridge multilevel by switching the solar PV voltage sources in series and parallel. The proposed H-bridge multilevel inverter reduces number of switching devices which reduces the power consumption and size of the gate driver circuits. The proposed inverter gives more number of output voltages which reduces total harmonic distortion of the output voltage waveform. The hybrid modulation method is used to control H-bridge multilevel inverter. The proposed inverter is validated through simulation results are validated by using MATLAB/SIMULINK.