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Tuesday 1 December 2015

Simulation of Field Oriented Control in Induction Motor Drive System

Abstract--

In this paper, a 3-phase induction motor model for simulation the field oriented control (FOC) system based on space vector pulse width modulation (SVPWM) is established in Ansoft/Simplorer software. The theory of field oriented control (FOC) and the principle of space vector pulse width modulation (SVPWM) were introduced. The simulation results are presented and analyzed. A Simulink simulation model of field oriented control system is presented as a comparison under the same conditions. The results indicated that the Simplorer model had quick response speed, small torque fluctuations and good performance both in steady and dynamic states. Furthermore, the Simplorer model can be coupled with the finite element model of the motor to achieve field-circuit coupling simulation of induction motor’s field oriented control system.







High Power Factor Operation of a Three-Phase Rectifier for an Adjustable-Speed Drive

Abstract—

This paper presents a novel approach to improve the power factor (PF) and reduce the harmonics generated by an adjustable-speed drive (ASD). A high-frequency (HF) current injection technique is used to improve the PF and harmonic performance. The HF current at the same switching frequency (33 kHz) is injected into the input of a front-end rectifier from the output of an HF inverter. The main feature of the circuit is that it does not require any additional active devices for current injection. The inverter driving the induction motor is operated using a sinusoidal pulsewidth-modulation technique. The circuit simulation and experimental prototype results are presented for 67-hp (50 kW) and 3-hp three-phase induction motors, respectively.






Single Power-Conversion AC–DC Converter With High Power Factor and High Efficiency

Abstract—

This paper proposes a single power-conversion ac–dc converter with high power factor and high efficiency. The proposed converter is derived by integrating a full-bridge diode rectifier and a series-resonant active-clamp dc–dc converter. To obtain a high power factor without a power factor correction circuit, this paper proposes a novel control algorithm. The proposed converter provides single power-conversion by using the novel control algorithm for both power factor correction and output control. Also, the active-clamp circuit clamps the surge voltage of switches and recycles the energy stored in the leakage inductance of the transformer. Moreover, it provides zero-voltage turn-on switching of the switches. Also, a series-resonant circuit of the output-voltage doubler removes the reverse-recovery problem of the output diodes. The proposed converter provides maximum power factor 0.995 and maximum efficiency of 95.1% at the full load. The operation principle of the converter is analyzed and verified. Experimental results for a 400 W ac–dc converter at a constant switching frequency of 50 kHz are obtained to show the performance of the proposed converter.




DSTATCOM with Reduced Switches Using Two-Leg VSC and a Zig-Zag Transformer for Power Quality Improvement in Three-Phase Four-Wire Distribution System

Abstract-

In this paper, a new topology of DSTATCOM (Distribution Static Compensator) is proposed consisting of a two-leg VSC (voltage source converter) and a zig-zag transformer for power quality improvement in three-phase four-wire distribution systems. The DSTATCOM along with a zig-zag transformer is employed for the compensation of reactive power for the voltage regulation or power factor correction along with elimination of harmonic currents, load balancing and neutral current compensation at the point of common coupling (PCC). The performance of the proposed DSTATCOM system is validated through simulations using MATLAB software with its Simulink and Power System Blockset (PSB) toolboxes.






MATLAB/PSB BASED MODELING AND SIMULATION OF 25 KV AC RAILWAY TRACTION SYSTEM- A PARTICULAR REFERENCE TO LOADING AND FAULT CONDITIONS

Abstract --

This paper presents the modeling and simulation of a 25 kV 50 Hz AC traction system using Power System Block set (PSB) / SIMULINK software package. The three-phase system with substations, track section with rectifier-fed DC locomotives and a detailed traction load are included in the model. The model has been used to study the effect of loading and fault conditions in 25 kV AC traction. The relay characteristic proposed is a combination of two quadrilaterals in the X-R plane. A brief summary of the hardware set-up used to implement and test the relay characteristic using a Texas Instruments TMS320C50 digital signal processor (DSP) has also been presented.






Design and Performance of a Cost-Effective BLDC Drive for Water Pump Application

Abstract—

This paper presents a promising solution to the problem of the bad environmental impacts of the induction-motor-based water pumps. Due to the low wire-to-water efficiency of the current residential water heaters (around 30%), a high energy cost is paid by every household in North America and even worldwide. The contribution of this paper comes in twofolds. The first is the development of a mapping algorithm that relates the pressure head H and the water flow rate Q to a corresponding torque and speed under the chart of best efficiency point, which was programmed to the controller. The second is the development of a cost-effective brushless direct-current (BLDC) motor through an extensive numerical analysis technique. The proposed motor solution designs the BLDC with minimal pulsating torque by comparing two different designs. The new controller is based on a modified field-oriented control. The controller printed circuit board is of two layers to offer a cost-effective solution. The proposed pump eliminates the need of a battery for the controller as the control voltage is fed directly from the line together with the motor. The motor simulation model and the controller design procedure are presented with simulation results of two possible prototypes. An experimental prototype for a 150-W residential pump was built, and preliminary results are given to highlight the merits of the work.