Gitanjali Mehta

Grid interconnection of distributed generation system with power quality improvement features

This paper presents the modelling and control of grid interfaced Distributed Generation (DG) system with embedded active filter function. The output of the DG is given to the DC side of the Voltage Source Inverter for interfacing to the Grid. In the presented work, the features of Active Power Filter have been incorporated in the control circuit of the current controlled-voltage source inverter interfacing the DG to the grid. Thus the same inverter is utilised to inject power generated from DG source to the Grid and also to act as Shunt Active Power Filter to compensate for load current harmonics and reactive power demand. Thus, after compensation, the Grid current is sinusoidal and in-phase with Grid voltage. The entire system is modelled in MATLAB/Simulink environment and simulations carried out to verify the operation and the control principle. Various simulation results are presented for the proposed Grid interfaced DG system.

Non-linear load compensation in Fuel Cell grid interfaced system using active power filter

The increasing global warming concerns and diminishing fossil fuels have made us necessary to look for alternative sources of energy. Fuel Cell technology holds promise towards sustainable power generation, it being pollution free and using readily available fuels. This paper presents the modeling, control and design analysis of a three-phase Grid-interactive Fuel Cell system with active filter functions. The main focus of this paper is to control the active power supplied by the Fuel Cell Distributed Generation system while compensating harmonics and reactive currents caused by the nonlinear loads using shunt active power filter. The developed Fuel Cell model is connected to the DC-side of the voltage source inverter for interfacing with the grid. Thus the same inverter is utilized as power converter to inject the power generated from the Fuel Cell to the grid and to act as active power filter to compensate load current harmonics and load reactive power demand. The designed controller either regulates the power flow between the Fuel Cell and the Grid or works as an active power filter or performs both the functions simultaneously. The simulation model of the overall system is developed in MATLAB/Simulink environment using SimPower Systems blocksets and then PIL simulated using TMS320F2812 DSP. The results are obtained for different operating conditions with varying load demands to prove the effectiveness of the entire system.

Power Quality Improvement Through Grid Integration of Renewable Energy Sources

Abstract Renewable energy sources (RES) are rapidly gaining popularity for sustainable power generation, they being less polluting and using readily available resources. This paper presents the modelling, control, and design analysis of a single-stage, three-phase RES-based distributed generation system where the grid-interfacing inverter is controlled to perform multi-functions by simultaneously incorporating active power filter (APF) functionality. The RES is connected to the DC-side of the voltage source inverter for interfacing with the grid. The inverter is utilized as power converter to inject the power generated from the RES to the PCC and shunt APF to compensate load current harmonics, load reactive power demand, and load current imbalance under distorted supply voltage conditions. Both these functions may be accomplished either individually or simultaneously. Thus, the designed controller either regulates the power flow between the RES and the grid or works as an APF or performs both the functions simultaneously. Simulation in MATAB and experimentation using DSP is carried out to verify the operation and the control principle.

Active, Reactive and Harmonic compensation control of grid interfaced fuel cell system

Abstract This paper presents the modelling and control of grid interfaced fuel cell distributed generation system with embedded active filter function. The features of active power filter have been incorporated in the control circuit of the current controlled-voltage source inverter interfacing the fuel cell to the grid. Thus the same inverter is utilised to inject power generated from fuel cell source to the grid and to act as shunt active power filter to compensate for load current harmonics, load reactive power demand and load current imbalance. Thus, after compensation, the grid current is sinusoidal and in-phase with grid voltage. Simulation in MATAB and experimentation using DSP is carried out to verify the operation and the control principle. The results are obtained for different operating conditions with varying load demands to prove the effectiveness of the entire system.

Design, analysis and implementation of DSP based single-phase shunt active filter controller

A simplified current reference control for single-phase shunt active power filter (APF) to compensate the current harmonics and reactive power required by nonlinear loads is being presented in this paper. The key intention of this method is to represent the APF in parallel with nonlinear load as an equivalent conductance. In the proposed technique, first the distorted voltage signal of PCC is made sinusoidal within the controller, to make the compensated source current sinusoidal and in-phase with the source voltage. A self-charging technique is used to regulate the dc-link capacitor voltage to a desired level. The proposed controller is first realized under MATLAB simulink environment and then experimentally verified using a low cost fixed-point eZdsp to show the effectiveness of the controller.

Active and reactive power control of Proton Electrolyte Membrane Fuel Cell based Distributed Generation System

This paper deals with the design, analysis, modeling and control of Fuel Cell based Distributed Generation System. This includes the modeling of Proton Electrolyte Membrane Fuel Cell and the Power Conditioning Unit interfacing the Fuel Cell to the Utility Grid with proper power flow control. The output of the Fuel Cell Stack is connected to the DC side of the Voltage Source Inverter for interfacing to the Grid. The active power transfer is based on the phase angle between DC-AC converter output voltage and Grid voltage and reactive power management is based on magnitude of these voltages. The entire system is modeled in MATLAB/Simulink environment and simulations carried out to verify the operation and the control principle. Various simulation results are presented for the proposed Fuel Cell Grid interfaced system.

Design of single-stage three-phase grid-connected photovoltaic system with MPPT and reactive power compensation control

This paper proposes a single stage three-phase grid-connected photovoltaic (PV) system topology, it being simpler and more efficient. This includes the modelling of PV module and the power conditioning unit interfacing the PV to the utility grid with proper power flow control. The output of the PV panel is connected to the DC-side of the voltage source inverter for interfacing to the grid. The maximum power point tracking, grid synchronisation, reactive power compensation, output current harmonic reduction is included simultaneously in the control. The entire system is modelled in MATLAB/Simulink environment and simulations carried out to verify the operation and the control principle. Various simulation results are presented for the proposed PV grid-interfaced system. The results confirm high stability and efficiency of the single-stage grid-connected PV system.

Design and analysis of photovoltaic-fuel cell hybrid distributed generation system

This paper proposes a hybrid system consisting of photovoltaic and fuel cell to realize a reliable power supply for a grid connected critical load. The designed system ensures maximum utilization of the photovoltaic array, and necessary utilisation of fuel cell stack thus providing optimum operational costs. Both the sources are operated independently or in conjunction as per requirement. The sources are first connected to a common DC-link through separate DC-DC converters and then to the grid through a common inverter. The inverter power angle is controlled to maintain a constant DC-link voltage to ensure complete power transfer and the inverter modulation index is controlled to maintain the reactive power requirement of load. The inverter control also provides harmonic compensation for any non-linear load connected at the point of common coupling thus maintaining the grid current free of any distortions because of the load.

Improvement of Power Quality at PCC through Grid Interfacing Photovoltaic System

Photovoltaic technology holds promise towards sustainable power generation, it being pollution free and using freely available solar energy. This paper presents the modeling, control and design analysis of a singlephase grid-interactive photovoltaic system with active filter functions. The main focus of this paper is to control the active power supplied by the photovoltaic distributed generation system while compensating harmonics and reactive currents caused by the nonlinear loads using shunt active power filter. Thus the same inverter is utilized as power converter to inject the power generated from the photovoltaic to the grid and to act as active power filter to compensate load current harmonics and load reactive power demand. The designed controller either regulates the power flow between the photovoltaic and the grid or works as an active power filter when solar energy is not available or performs both the functions simultaneously. Simulation in MATAB is carried out and results are obtained for different operating conditions with varying solar insolation and varying load demands to prove the effectiveness of the entire system.

Fuel cell-based distributed generation system with power flow and power quality control

This paper presents the modelling and control of fuel cell-based distributed generation system with embedded active filter functioning. It includes the modelling of proton electrolyte membrane fuel cell and the power conditioning unit interfacing the fuel cell to the utility grid with proper power flow control. The output of the fuel cell stack is given to the DC-DC boost converter before connecting to the DC side of the voltage source inverter for interfacing to the grid. In the presented work, the features of active power filter have been incorporated in the control circuit of the current controlled-voltage source inverter interfacing the fuel cell to the grid. Thus the inverter is utilised to inject fuel cell power generated to the grid and also to act as shunt active power filter to compensate for load current harmonics and reactive power demand. Simulation and experimentation is carried out to verify the operation and the control principle.