H-Bridge VSC with a T-Connected Transformer for a 3-Phase 4- Wire Voltage and Frequency Controller of an Isolated Asynchronous Generator

Kasal, Gaurav Kumar,Singh, Bhim The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.1

This paper deals with a novel solid state controller (NSSC) for an isolated asynchronous generator (IAG) feeding 3-phase 4-wire loads driven by constant power prime movers, such as uncontrolled pico hydro turbines. AC capacitor banks are used to meet the reactive power requirement of the asynchronous generator. The proposed NSSC is realized using a set of IGBTs (Insulated gate bipolar junction transistors) based current controlled 2-leg voltage source converters (CC- VSC) and a DC chopper at its DC bus, which keeps the generated voltage and frequency constant in spite of changes in consumer loads. The neutral point of the load is created using aT-configuration of the transformers. The IAG system is modeled in MATLAB along with Simulink and PSB (power system block set) toolboxes. The simulated results are presented to demonstrate the capability of the isolated generating system consisting of NSSC and IAG driven by uncontrolled pico hydro turbine and feeding 3-phase 4-wire loads.

A Voltage and Frequency Controller for Stand Alone Pico Hydro Generation

Kasal, Gaurav Kumar,Singh, Bhim The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.2

This paper deals with a voltage and frequency (VF) controller for an isolated power generation system based on an asynchronous generator (AG) driven by a pico hydro turbine. The proposed controller is a combination of a static compensator (STATCOM) and an electronic load controller (ELC) for decoupled control of the reactive and active powers of the AG system to control the voltage and frequency respectively. The proposed generating system along with its VF controller is modeled in MATLAB using SIMULINK and PSB (Power System Block Sets) toolboxes. The performance of the controller is verified for the proposed system and feeding various types of consumer load such as linear/non-linear, balanced/unbalanced and dynamic loads.

Three-Phase 4-Wire Isolated Wind Energy Conversion System Employing VSC with a T-Connected Transformer for Neutral Current Compensation

Kasal, Gaurav Kumar,Singh, Bhim The Korean Institute of Electrical Engineers 2009 Journal of Electrical Engineering & Technology Vol.4 No.2

This paper presents a voltage and frequency controller (VFC) for a 4-wire stand-alone wind energy conversion system (WECS) employing an asynchronous generator. The proposed VF con-troller consists of a three leg IGBT (Insulated Gate Bipolar Junction Transistor) based voltage source converter and a battery at its DC bus. The neutral terminal for the consumer loads is created using a T-connected transformer, which consists of only two single phase transformers. The control algorithm of the VF controller is developed for the bidirectional flow capability of the active power and reactive power control by which it controls the WECS voltage and frequency under different dynamic conditions, such as varying consumer loads and varying wind speeds. The WECS is modeled and simulated in MATLAB using Simulink and PSB toolboxes. Extensive results are presented to demonstrate the capability of the VF controller as a harmonic eliminator, a load balancer, a neutral current compensator as well as a voltage and frequency controller.

An Institutional Work Perspective to Performance Management: The Case of Botswana National Sport Organizations

Lobone Lloyd Kasale,Stephen Morrow,Mathieu Winand 글로벌지식마케팅경영학회 2023 Journal of Global Sport Management Vol.8 No.1

Performance management practices are used by organizations to monitor the efficiency and effectiveness of organizational proc- esses. However, how National Sport Organizations adopt and implement these practices is still unknown. To fill this gap, this research investigates how and why performance management practices are adopted and implemented by National Sport Organizations. Data was collected from documents, 31 semi-struc- tured interviews and five focus group meetings held with 14 Botswana National Sport Organizations and 10 of their stakehold- ers. The results indicate that stakeholders and individuals within National Sport Organizations play different roles in the creation and maintenance of performance management practices. This information can help sport managers to improve how they imple- ment performance management practices, ensuring the efficiency and effectiveness of their organizational processes and the satis- faction of their stakeholders.

Three-Phase 4-Wire Isolated Wind Energy Conversion System Employing VSC with a T-Connected Transformer for Neutral Current Compensation

Gaurav Kumar Kasal,Bhim Singh 대한전기학회 2009 Journal of Electrical Engineering & Technology Vol.4 No.2

This paper presents a voltage and frequency controller (VFC) for a 4-wire stand-alone wind energy conversion system (WECS) employing an asynchronous generator. The proposed VF controller consists of a three leg IGBT (Insulated Gate Bipolar Junction Transistor) based voltage source converter and a battery at its DC bus. The neutral terminal for the consumer loads is created using a Tconnected transformer, which consists of only two single phase transformers. The control algorithm of the VF controller is developed for the bidirectional flow capability of the active power and reactive power control by which it controls the WECS voltage and frequency under different dynamic conditions, such as varying consumer loads and varying wind speeds. The WECS is modeled and simulated in MATLAB using Simulink and PSB toolboxes. Extensive results are presented to demonstrate the capability of the VF controller as a harmonic eliminator, a load balancer, a neutral current compensator as well as a voltage and frequency controller.

H-Bridge VSC with a T-Connected Transformer for a 3-Phase 4-Wire Voltage and Frequency Controller of an Isolated Asynchronous Generator

Gaurav Kumar Kasal,Bhim Singh 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.1

This paper deals with a novel solid state controller (NSSC) for an isolated asynchronous generator (IAG) feeding 3-phase 4-wire loads driven by constant power prime movers, such as uncontrolled pico hydro turbines. AC capacitor banks are used to meet the reactive power requirement of the asynchronous generator. The proposed NSSC is realized using a set of IGBTs (Insulated gate bipolar junction transistors) based current controlled 2-leg voltage source converters (CC-VSC) and a DC chopper at its DC bus, which keeps the generated voltage and frequency constant in spite of changes in consumer loads. The neutral point of the load is created using a T-configuration of the transformers. The IAG system is modeled in MATLAB along with Simulink and PSB (power system block set) toolboxes. The simulated results are presented to demonstrate the capability of the isolated generating system consisting of NSSC and IAG driven by uncontrolled pico hydro turbine and feeding 3-phase 4-wire loads.

A Voltage and Frequency Controller for Stand Alone Pico Hydro Generation

Gaurav Kumar Kasal,Bhim Singh 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.2

This paper deals with a voltage and frequency (VF) controller for an isolated power generation system based on an asynchronous generator (AG) driven by a pico hydro turbine. The proposed controller is a combination of a static compensator (STATCOM) and an electronic load controller (ELC) for decoupled control of the reactive and active powers of the AG system to control the voltage and frequency respectively. The proposed generating system along with its VF controller is modeled in MATLAB using SIMULINK and PSB (Power System Block Sets) toolboxes. The performance of the controller is verified for the proposed system and feeding various types of consumer load such as linear/non-linear, balanced/unbalanced and dynamic loads.

Battery Energy Storage System Based Controller for a Wind Turbine Driven Isolated Asynchronous Generator

Singh, Bhim,Kasal, Gaurav Kumar The Korean Institute of Power Electronics 2008 JOURNAL OF POWER ELECTRONICS Vol.8 No.1

This paper presents an investigation of a voltage and frequency controller for an isolated asynchronous generator (IAG) driven. by a wind turbine and supplying 3-phase 4-wire loads to the isolated areas where a grid is not accessible. The control strategy is based on the indirect current control of the VSC (voltage source converter) using the frequency PI controller. The proposed controller consists of three single-phase IGBT (Insulated Gate Bipolar Junction Transistor) based VSC, which are connected to each phase of the IAG through three single phase transformers and a battery at their DC link. The controller has the capability of controlling reactive and active powers to regulate the magnitude and frequency of the generated voltage, harmonic elimination, load balancing and neutral current compensation. The proposed isolated system is modeled and simulated in MATLAB using Simulink and PSB (Power System Block-set) toolboxes to verify the performance of the controller.

A Novel Solid State Controller for Parallel Operated Isolated Asynchronous Generators in Pico Hydro Systems

Singh, Bhim,Kasal, Gaurav Kumar The Korean Institute of Electrical Engineers 2007 Journal of Electrical Engineering & Technology Vol.2 No.3

This paper deals with a novel solid state controller (NSSC) for parallel operated isolated asynchronous generators (IAG) feeding 3-phase 4-wire loads in constant power applications, such as uncontrolled pico hydro turbines. AC capacitor banks are used to meet the reactive power requirement of asynchronous generators. The proposed NSSC is realized using a set of IGBTs (Insulated gate bipolar junction transistors) based current controlled 4-leg voltage source converter (CC-VSC) and a DC chopper at its DC bus, which keeps the generated voltage and frequency constant in spite of changes in consumer loads. The complete system is modeled in MATLAB along with simulink and PSB (power system block set) toolboxes. The simulated results are presented to demonstrate the capability of isolated generating system consisting of NSSC and parallel operated asynchronous generators driven by uncontrolled pico hydro turbines and feeding 3-phase 4-wire loads.

Analysis of light-frame, low-rise buildings under simulated lateral wind loads

Fischer, C.,Kasal, B. Techno-Press 2009 Wind and Structures, An International Journal (WAS Vol.12 No.2

The Monte Carlo procedure was used to simulate wind load effects on a light-frame low-rise structure of irregular shape and a main wind force resisting system. Two analytical models were studied: rigid-beam and rigid-plate models. The models assumed that roof diaphragms were rigid beam or rigid plate and shear walls controlled system behavior and failure. The parameters defining wall stiffness, including imperfections, were random and included wall stiffness, wall capacity and yield displacements. The effect of openings was included in the simulation via a set of discrete multipliers with uniform distribution. One and two-story buildings were analyzed and the models can be expanded into multiple-floor structures provided that the assumptions made in this paper are not violated.