Programmable Device Circuits and Systems

S. Rajagopal ¹, S. S. Dash ¹

Affiliations
1 Sathya Bama University, IN

Abstract

The aim of this paper is to present that four level converters are most suitable for excitation of high speed switched reluctance motor drives. Switched reluctance motor drives are preferred for high speed industrial applications because they offer a wide speed range and that their are torque/inertia ratio is very high . Conventional asymmetric convertors are not suitable for excitation of high speed switched reluctance motor drives because the excitation time is very short. While exciting switched reluctance motors the excitation current in a phase should be switched on at the time inductance begins to rise and it must build up sufficiently during the raising period of the inductance to produce required positive torque output. Further the excitation current must be reduced to zero before the inductance begins to fall. During its fall time of excitation current it should not extend to the decreasing period of inductance to avoid production of negative torque. Four level convertor is recommended to achieve the above mentioned facts in excitation of high speed switched reluctance motor drives. The Four level convertor has an additional capacitor and an active power switch. The high voltage in the charged capacitor is applied to the phase winding in the fast excitation mode and the phase current gets rapidly decreased without extending to the negative region during demagnetisation mode. The simulation results of such a four level convertor used for operation of high speed switched reluctance motor drives show that current stress is less than the voltage stress during excitation conditions.

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V. Sivachidambaranathan ¹, S. S. Dash ²

Affiliations
1 Sathyabama University, Chennai, IN
2 EEE Department, SRM University, Chennai, IN

Abstract

This paper presents the modeling and simulation of closed loop controlled Half Bridge Series Resonant Power Factor Correction (PFC) DC – DC converter with high frequency transformer isolation using Matlab Simulink. Half bridge converters are well suitable for low input voltage and high current applications. High power density and high efficiency are the major driving force for this application. The operation at higher frequencies considerably reduces the size of passive components, such as transformers and filters, however switching losses have been an obstacle for high frequency operation. To reduce switching losses and allow high frequency operation, resonant techniques have been developed. This technique reduces distortion and results in almost sinusoidal output. The switching processes are softly commutated. Therefore the switching losses and noises are reduced. The open loop and closed loop models for DC – DC Half Bridge Series Resonant PFC converter have been developed and the MATLAB simulation results are presented.

Keywords

Resonant Half-Bridge to Dc-Dc High Frequency, Low Switching Loss Converters.

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