Design and Simulation of Control strategies for Voltage Source PWM Rectifier

Power Electronics is defined as branch of science, engineering and technology which deals with Power Electronics Modulators (PEM) in which efficient conversion, conditioning, processing, controlling and modulating the flow of large electric power using Solid State Power Semiconductor Device (SSPSD) in order to supply high quality power to the load which causes minimum pollution of physical characteristics of electric power with regulating stability and response characteristics of the closed loop system and its application. Diode rectified circuit and thyristor rectifiers circuit are widely used in the conventional rectifier circuit, but the problems arising during operating should not be ignored, such as, harmonic problems and low power factor. These problems may do harm to the grid, which in turn cause a series consequences, therefore, the application of such rectifier will be limited. With the continuous development of PWM technology people pay attention to the PWM rectifier gradually. The paper first analyzes the mathematical model of three-phase voltage-source PWM rectifier and then introduces double closed-loop control of voltage and current system, in which the active and reactive power can be controlled independently. PWM rectifier control system is built based on the DSP2812 after modeling and simulating in MATLAB / SIMULINK environment. The result shows that the system has the characteristic of good anti-interference performance and fast dynamic response

Analysis and Assessment of Motor Drive Speed Control through Variable Frequency Drive

Electric Motor Drive System is employed in the various industrial applications such as pumping, air blowing, cooling and compression refrigeration. The motor drive speed control can be achieved by variety of techniques, but an emerging one is Variable Frequency Drive System. The motor driven equipment on a typical industrial site accounts for approximately two thirds of the electricity consumption. Therefore, any type of measure taken to improve the efficiency of a motor system consequently can offer major energy savings. There are multiple benefits of variable frequency drive system utilizing along with speed control. For the technical and economic reliability of such integrated approach of motor with variable frequency drive, analysis and assessment is the key tool. This paper first outlines the benefits of Variable Frequency Drives (VFD) compared to classical drivers or control methods (i.e. steam/gas turbines, hydraulic coupling and Direct-On-Line operation with, for example, valve/damper control). The paper then focuses on analysis and assessment of typical variable frequency drive applications in the sugar industry and also describes a real case study, namely a VFD soft-starter application at Narmada Sugar Factory, Bharuch

Design of Resistance Spot Welding System using Integral Switching Cycle Control Technique

The process of combining metal of similar composition by heating at suitable temperature with or without pressure and application of filler material is known as Welding. Resistance Spot Welding (RSW) is defined as a process which requires simultaneous application of high electrical current and appropriate pressure over short periods in order to keep the molten material inside the weld zone. Values of these parameters are varied in function of the characteristics of the materials to be welded. The application of the electrical current carrying two copper electrodes brought in contact with the welded parts while the required pressure is applied by means of pneumatic or hydraulic systems. This paper presents a novel design of resistance welding system using Integral Switching Cycle Control Technique used for performing a welding process. The paper is discussed about two aspects. First, a brief introduction about welding, methods of welding control and electronic control used in resistance welding. Secondly, the critical factors in design of a welding process are dealt along with the principle of the welding process. Following this, the introduction to the design of control scheme employed with the basic block diagram of welding system and its functioning is presented

A Comparative Evaluation of Wave Shaping Methods for AC-DC Power Electronics Converter

Power Electronics is defined as branch of science, engineering and technology which deals with Power Electronics Modulators (PEM) in which efficient conversion, conditioning, processing, controlling and modulating the flow of large electric power using Solid State Power Semiconductor Device (SSPSD) in order to supply high quality power to the load which causes minimum pollution of physical characteristics of electric power with regulating stability and response characteristics of the closed loop system and its application. The comparative study of Passive and Active Wave Shaping (AWS) filter based on Current-Source Fed Switch Mode Rectifier (CSFSMR) converter supplied from single-phase AC supply is carried out in this paper in which two circuit are designed and implemented in MATLAB Simulink. Usually a boost converter is working as Active Harmonic Filter to reduce the harmonics at the main supply by controlling the duty cycle of the filter while Passive wave shaping filter reduce the harmonics at the supply in a simple way. Depending on rating, schematic and control complexities, control performance and cost, there are many possible power factor correction approaches. The suited and cost effective one can be chosen according to the desired performance for specific application

A Comparative Analysis of Field Oriented Control and Direct Torque Control of Induction Motor Drive

Electric Motor Drive System is employed in the various industrial applications such as pumping, air blowing, cooling and compression refrigeration. The motor drive speed control can be achieved by variety of techniques, but an emerging one is Variable Frequency Drive System (VFDS). The motor driven equipment on a typical industrial site accounts for approximately two thirds of the electricity consumption. Now-a-days induction motor is the main work-horse of the industries. So controlling of performance of induction motor is most precisely required in many high performance applications. Scalar control method gives good steady state response but poor dynamic response. While vector control method gives good steady state as well as dynamic response. But it is complicated in structure so to overcome this difficulty, direct torque control introduced. This paper discusses the comparative analysis of Field Oriented Control (FOC) and Direct Torque Control (DTC) methods of Polyphase Induction Motor (PIM) according to their working principle, structure complexity, performance, merits and demerits