Puneet K. Goel

Isolated Wind–Hydro Hybrid System Using Cage Generators and Battery Storage

This paper deals with a new isolated wind-hydro hybrid generation system employing one squirrel-cage induction generator (SCIG) driven by a variable-speed wind turbine and another SCIG driven by a constant-power hydro turbine feeding three-phase four-wire local loads. The proposed system utilizes two back-to-back-connected pulsewidth modulationcontrolled insulated-gate-bipolar-transistor-based voltage-source converters (VSCs) with a battery energy storage system at their dc link. The main objectives of the control algorithm for the VSCs are to achieve maximum power tracking (MPT) through rotor speed control of a wind-turbine-driven SCIG under varying wind speeds and control of the magnitude and the frequency of the load voltage. The proposed wind-hydro hybrid system has a capability of bidirectional active- and reactive-power flow, by which it controls the magnitude and the frequency of the load voltage. The proposed electromechanical system using SCIGs, an MPT controller, and a voltage and frequency controller are modeled and simulated in MATLAB using Simulink and Sim Power System set toolboxes, and different aspects of the proposed system are studied for various types of linear, nonlinear, and dynamic loads, and under varying wind-speed conditions. The performance of the proposed system is presented to demonstrate its capability of MPT, voltage and frequency control (VFC), harmonic elimination, and load balancing.

A Comparative Study of Fixed Speed and Variable Speed Wind Energy Conversion Systems Feeding the Grid

In the early development of the wind energy, the majority of the wind turbines have been operated at constant speed. Subsequently, the number of variable-speed wind turbines installed in wind farms has increased. In this paper, a comparative study of fixed and variable speed wind turbines incorporating squirrel cage induction generator take into consideration all realistic constraints has been presented. These two systems are modeled and simulated using Matlab. The variable speed induction generator system has been modeled using power electronic converters and vector control technology combined with peak power extraction technique (PPET) enabling the system to run at the most optimal speed. The results are presented for 55 kW induction generator, and variable speed operation is highlighted as preferred mode of operation.

Modeling and control of autonomous Wind Energy Conversion System with Doubly Fed Induction Generator

This paper deals with the modeling and control of a three phase four wire autonomous Wind Energy Conversion System (AWECS) using Doubly Fed Induction Generator (DFIG) feeding local loads. It presents a procedure for design and selection of the components and a vector control algorithm for AWECS. The proposed control algorithm for AWECS is realized using back to back connected Pulse Width Modulated (PWM) Insulated Gate Bipolar Transistors (IGBTs) based voltage source converters (VSCs) with a battery energy storage system (BESS) at their dc link. The main objectives of the control algorithm are maximum power tracking (MPT) through rotor speed control, and voltage and frequency control (VFC) at the stator terminals of the DFIG under dynamic electrical and mechanical conditions. A zigzag transformer is used between stator side converter and the stator for harmonic elimination, optimum selection of the voltage of dc link and providing the neutral terminal for the three phase four wire system. The proposed electro-mechanical system is modeled and simulated in MATLAB using Simulink and Sim Power System (SPS) set toolboxes. The performance of the proposed AWECS is presented to demonstrate its capability of MPT, VFC at stator terminals, harmonic elimination, load balancing and load leveling.

Parallel Operation of DFIGs in Three-Phase Four-Wire Autonomous Wind Energy Conversion System

This paper deals with a control algorithm for two parallel-operated doubly fed induction generators (DFIGs) driven by wind turbines in a three-phase four-wire autonomous system feeding local loads. The proposed autonomous wind energy conversion system (AWECS) is using back-to-back-connected pulsewidth-modulated insulated-gate-bipolar-transistor-based voltage source converters with a battery energy storage system at their dc link. The system utilizes separate rotor-side converters for each DFIG for maximum power tracking (MPT) through its rotor speed control. However, a common dc bus and a battery bank and stator-side converter are used for voltage and frequency control at the stator terminals of the DFIGs. A delta-star transformer is connected between the stator-side converter and the stator terminals of DFIGs for optimizing the voltage of dc bus, and the load-side neutral is connected to the neutral of the star side of the transformer. The proposed electromechanical system is modeled and simulated in MATLAB using Simulink and Sim Power Systems set toolboxes. The performance of the proposed AWECS is presented to demonstrate its capability of MPT, stator voltage and frequency control, harmonic elimination, load balancing, and load leveling.

Autonomous hybrid system using SCIG for hydro power generation and variable speed PMSG for wind power generation

This paper deals with an isolated wind-hydro hybrid generation system employing a Squirrel Cage Induction Generator (SCIG) driven by hydro turbine and a Permanent Magnet Synchronous Generator (PMSG) driven by a variable speed wind turbine feeding three-phase four-wire local loads. The proposed system utilizes two back to back connected Pulse Width Modulated (PWM) Insulated Gate Bipolar Transistors (IGBTs) based voltage source converters (VSCs) with a battery energy storage system (BESS) at their dc link. The main objectives of the control algorithm for VSCs are to achieve maximum power tracking (MPT) through rotor speed control of wind turbine driven PMSG under varying wind speeds, and control of the magnitude and the frequency of the load voltage. The proposed wind hydro hybrid system is having capability of bidirectional active and reactive powers flow, by which it controls the magnitude and the frequency of the load voltage. The proposed electro-mechanical system using PMSG and SCIG, a MPT controller and a voltage and frequency controller (VFC) are modeled and simulated in MATLAB using Simulink and Sim Power System (SPS) set toolboxes and different aspects of the proposed system are studied for various types of linear loads and nonlinear loads and under varying wind speed conditions. The performance of the proposed system is presented to demonstrate its capability of MPT, VFC, harmonic elimination and load balancing.

Parallel Operation of DFIGs in Three Phase Four Wire Autonomous Wind Energy Conversion System

This paper deals with a control algorithm for two parallel-operated doubly fed induction generators (DFIGs) driven by wind turbines in a three-phase four-wire autonomous system feeding local loads. The proposed autonomous wind energy conversion system (AWECS) is using back-to-back-connected pulsewidth-modulated insulated-gate-bipolar-transistor-based voltage source converters with a battery energy storage system at their dc link. The system utilizes separate rotor-side converters for each DFIG for maximum power tracking (MPT) through its rotor speed control. However, a common dc bus and a battery bank and stator-side converter are used for voltage and frequency control at the stator terminals of the DFIGs. A delta-star transformer is connected between the stator-side converter and the stator terminals of DFIGs for optimizing the voltage of dc bus, and the load-side neutral is connected to the neutral of the star side of the transformer. The proposed electromechanical system is modeled and simulated in MATLAB using Simulink and Sim Power Systems set toolboxes. The performance of the proposed AWECS is presented to demonstrate its capability of MPT, stator voltage and frequency control, harmonic elimination, load balancing, and load leveling.

Three-phase Four-wire Autonomous Wind Energy Conversion System Using Permanent Magnet Synchronous Generator

Abstract This article deals with an autonomous wind energy conversion system employing a permanent magnet synchronous generator feeding three-phase four-wire local loads in stand-alone mode without using a mechanical position sensor. The proposed autonomous wind energy conversion system utilizes two back-to-back connected pulse width modulated insulated gate bipolar transistors based voltage source converters with a battery energy storage system at their DC link. The main objectives of the control algorithm for voltage source converters are to achieve a maximum power tracking through the rotor speed control of a permanent magnet synchronous generator under varying wind speeds and control of the magnitude and frequency of the load voltage. The proposed system is capable of bidirectional active and reactive power flows, by which it controls the magnitude and the frequency of the load voltage. The proposed electro-mechanical system, consisting of a permanent magnet synchronous generator, a maximum power tracking controller, and a voltage and frequency controller, is designed, modeled, and simulated in MATLAB using Simulink and Sim-Power System toolboxes. Also, different aspects of the proposed autonomous wind energy conversion system are studied for various types of linear and non-linear loads under varying wind speed conditions. The performance of the proposed autonomous wind energy conversion system is presented to demonstrate its capability for maximum power tracking, voltage and frequency control, harmonic elimination, and load balancing for the isolated power generation.

Autonomous hybrid system using PMSGs for hydro and wind power generation

This paper deals with an isolated wind-hydro hybrid generation system employing one Permanent Magnet Synchronous Generator (PMSG) driven by hydro turbine and another PMSG driven by a variable speed wind turbine feeding three-phase four-wire local loads. The proposed system utilizes two back to back connected Pulse Width Modulated (PWM) Insulated Gate Bipolar Transistors (IGBTs) based voltage source converters (VSCs) with a battery energy storage system (BESS) at their dc link. The main objectives of the control algorithm for VSCs are to achieve maximum power tracking (MPT) through rotor speed control of a wind turbine driven PMSG under varying wind speeds, and control of the magnitude and the frequency of the load voltage. The proposed wind hydro hybrid system is having capability of bidirectional active and reactive powers flow, by which it controls the magnitude and the frequency of the load voltage. The proposed electro-mechanical system using PMSGs, a MPT controller and a voltage and frequency controller (VFC) are modeled and simulated in MATLAB using Simulink and Sim Power System (SPS) set toolboxes and different aspects of the proposed system are studied for various types of linear loads and nonlinear loads and under varying wind speed conditions. The performance of the proposed system is presented to demonstrate its capability of MPT, VFC, harmonic elimination and load balancing.

Parallel Operation of Permanent Magnet Generators in Autonomous Wind Energy Conversion System

This paper deals with a new Autonomous Wind Energy Conversion System (AWECS) employing parallel operated Permanent Magnet Synchronous Generators (PMSGs) driven by variable speed wind turbines and feeding three-phase four-wire local loads. The proposed system utilizes three Pulse Width Modulated (PWM) Insulated Gate Bipolar Transistors (IGBTs) based voltage source converters (VSCs) with a battery energy storage system (BESS) at their dc link. The system utilizes two separate machine side converters one for each PMSG for maxi-mum power tracking (MPT) through their rotor speed control. However a common dc bus, a battery bank, and a common load side converter are used for voltage and frequency control (VFC) at the load terminals. The proposed electro-mechanical system using PMSGs, MPT controllers and a voltage and frequency con-troller (VFC) are modeled and simulated in MATLAB using Si-mulink and Sim Power System (SPS) set toolboxes. The perfor-mance of the proposed AWEC system is presented to dem-onstrate its capability of MPT, control of load voltage magnitude and frequency, harmonic elimination, and load balancing.

Design and Control of Autonomous Wind-Solar Hybrid System with DFIG Feeding a 3-Phase 4-Wire System

This paper presents the design, control, and experimental investigation of an autonomous wind–solar hybrid energy system feeding 3-phase 4-wire loads. The wind energy block consisting of a double fed induction generator (DFIG) is equipped with maximum power point tracking (MPPT) algorithm. The control of DFIG consists of two converters, namely rotor side converter (RSC) and load side converter (LSC) connected back to back at dc link. The MPPT operation requires speed control, which is realized using field oriented control through RSC. The rotor position required for vector control is estimated with model reference and adaptive system algorithm. The voltage and frequency control is realized through LSC. The solar photovoltaic (PV) power is extracted using a dc–dc boost converter to the common dc link. The dc–dc converter is also equipped with MPPT algorithm to extract maximum power from the incident irradiance. The system is modeled in MATLAB and its performance is presented at conditions, e.g., unbalanced nonlinear load, varying wind speeds, and solar irradiation. Under all these conditions, currents flowing through stator windings of DFIG are balanced with low total harmonics distortion (THD). The THDs of load voltages under all operating conditions are also within requirement of IEEE 519 standard. Finally, simulated results are validated experimentally by developing a prototype of the system using a 5-kW solar array simulator and a 3.7-kW DFIG.