Parag Nijhawan

Z-Source Inverter based DC-DC converter using SPWM technique for fuel cell application

The renewable energy based power generation like wind energy and solar energy is increasing at alarming rate and has been implemented at mass level worldwide. The DC voltage obtained from any renewable energy source like fuel cell and solar cell having low output voltage can meet the demand of end user loads having high voltage requirement. Due to the new inverter topology incorporated into the system that are up to the notch as compared to traditional inverters. Isolated DC-DC interface is included in the system for safety purpose so that low voltage output renewable energy sources at the input side gets decoupled from the converter side having high voltage output. The Z-Source Inverter is utilized at the input side of the converter as one of the striking feature of the topology used in this paper. The proposed topology is simulated in MATLAB Simulink and the desired results were obtained.

Improved performance of ten-pulse converter based DSTATCOM for flicker mitigation

With the advent of time, the concern of customers over the quality of voltage waveform or to say the quality of electric power, which they receive, is increasing. Modern sophisticated electronic equipments used in industries are quite sensitive to poor voltage quality, which may lead to maloperation or failure of device. These electronic devices use electronic switching devices which can lead to power quality problems. Due to the increase in competition among the electric utilities in a modern deregulated market, customer satisfaction is becoming the top notch priority. Voltage flicker is the one of the many power quality problems which seeks the interest of both the utility and engineers. The source of this problem is voltage fluctuations occurring due to heavy nonlinear loads. This paper presents the detailed analysis of voltage flicker on a designed test system and its mitigation using a DSTATCOM firstly using a conventional six-pulse voltage source converter and then using a ten-pulse converter. Though the performance of ten-pulse converter will be marginally inferior to twelve-pulse converter (which is composed of two, six-pulse converters), but it reduces the amount of circuit switching and circuit complexity. The performance based comparison is also charted out for the system. The results are presented to validate the feasibility of proposed topology. Results obtained using ten-pulse converters DSTATCOM are found to be superior over the six-pulse based DSTATCOM. The simulation tool applied to carry out the said task is MATLAB/SIMULINK power system block set.

Power quality enhancement using SVPWM Z-source inverter based DVR

To protect the sensitive loads from voltage disturbances or fluctuations, series active power filters are useful. This type of custom power device, known as dynamic voltage restorer (DVR) can be realized using different inverter topologies. In this paper, Z-source inverter (ZSI) based DVR to compensate the voltage disturbances such as voltage sag, voltage swell, voltage harmonic distortion, voltage unbalance and voltage perturbation, is proposed. Due to ease of digitalization, high utilization of dc bus voltage and reduced harmonic content, space vector pulse width modulation (SVPWM) technique has been used to operate the Z-source inverter. The simulation results based on MATLAB/Simulink are presented to illustrate the effectiveness of SVPWM Z-source inverter based DVR for reducing the harmonic distortion and unbalance in the load voltage, and to compensate voltage sag, voltage swell and voltage perturbation conditions, in the distribution network.

DC-DC conversion based on ZSI and boost rectifier using fuzzy logic control

This paper presents the application of ZSI for DC-DC conversion where both the inverter and converter stages is being controlled. The application of such system is in fuel cell. The fuel cell voltage output is very less which needs to be boosted up as per the requirement. So, ZSI performs both the boosting and inversion of voltage in single stage. The ZSI is controlled by simple boost control technique with the modification in traditional sinusoidal pulse width modulation. For second stage, the controller is designed for PWM boost rectifier. Fuzzy logic controller is integrated in the feedback loop and linear programming method is applied to shape the input current waveform. With fuzzy logic controller, the constant voltage is being obtained across the resistive load. The proposed method is simulated in SimPower System in MATLAB.

Role of DSTATCOM in distribution network with non-linear and active loads

The effectiveness of DSTATCOM in a distribution network with Field Oriented Control (FOC) induction motor drive as nonlinear load and wind turbine coupled with the asynchronous generator is examined. The abovementioned FOC induction motor drive being nonlinear in nature introduces harmonics into the distribution network. Simulation of DSTATCOM based upon dqo transformation technique using PI controller has been performed in MATLAB/SIMULINK. The performance of DSTATCOM for both nonlinear load and active load is analyzed. DSTATCOM being connected in shunt with the distribution network injects compensating current into the network so as to provide compensation for the harmonics present in the source current

Simulation-Based performance analysis of three-level 48-pulse STATCOM with constant DC link voltage for reactive power compensation

Sudden change in reactive power demand from load side leads to the voltage instability problem of the power system. This disturbance can be tackled by the proposed STATCOM (static synchronous compensator) model. It consists of four three-level VSC (voltage source converter) along with four zigzag transformers to form 48-pulse VSC. To reduce the voltage stress on the switching devices the DC link voltage is maintained constant which is not found in the common STATCOM operation. The proposed model of STATCOM is built using MATLAB/SimPowerSystems Toolbox. The performance is analyzed by switching the leading and lagging loads.

Review on solar and wind power potential in India

Renewable energy is expected to play an increasingly prominent role in the Indian power sector in the coming decades. India has targeted to reach 175GW of renewable energy by 2022 which includes 60GW from Wind Power, 100GW from Solar Power, 10GW from Biomass Power and 5GW from small Hydro Power, which is a way head from todays level of 37GW. This paper presents a review of the renewable sources like wind and solar. With the advancement of technology, the integration of the renewable sources in the grid is a great step but the power quality problems cannot be avoided.

Performance analysis of 3-phase 17-level inverter based DSTATCOM feeding induction furnace load

Distribution static compensator (DSTATCOM) is receiving increasing attention from power utilities for enhancing reliability and power quality levels. In order to attain high voltage and high power with available switching devices and to improve output waveforms cascaded H-bridge multilevel inverters (CHBMLI) are being preferred. In this paper, the performance analysis of three-phase 17-level inverter based DSTATCOM is demonstrated to improve power quality of a distribution network with induction furnace load.

Effectiveness of UPQC in a distribution network with DTC drive as load

Power quality is a hot topic of concern for both suppliers and consumers. The increased use of non-linear loads like adjustable speed drives also deteriorates the power quality levels. Therefore, greater emphasis is now being given to the study, evaluation and improvement of power quality especially in power distribution network. In this paper, the application of Unified Power Quality Conditioner (UPQC) with PI controller to improve the power quality in a distribution network with Direct Torque Control (DTC) induction motor drive is investigated. The Simulink model and results of the test system are presented to draw the conclusions.

Improved performance of IPDPWM CHBMLI based DSTATCOM in a distribution network with induction furnace load

Cascaded H-bridge multilevel inverter (CHBMLI) is based on a series connection of several single-phase inverters which is helpful in raising the output voltage to the desired level. These are also modular in nature as each inverter can be seen as an individual module with similar circuit topology, control structure and modulation [1]. Every converter topology has different switching configurations to achieve the desired output signals. The converter switching needs to be controlled to follow a control reference and modulation strategies are in charge to define the switching control in the converter. The main goal of the modulation algorithm is to synthesize a control reference obtaining a pulse train with the same averaged value. In this work, in-phase disposition pulse width modulation (IPDPWM) and carrier phase-shifted pulse width modulation (CPSPWM) have been applied to CHB 5-level inverter based distribution static compensator (DSTATCOM) to improve the power quality level of a distribution network with induction furnace load [2].