Programmable Device Circuits and Systems

A. Ramya ¹, R. L. Helen Catherine ¹

Affiliations
1 Anna University of Technology, Coimbatore, IN

Abstract

In this paper, a vibration suppression scheme is proposed for the riding comfort of elevator using dead time elimination scheme. Dead time is used for pulse width-modulation (PWM) controlled inverter/converter control to avoid shoot through of high-side and low-side power devices. To deal with dead time problems polarity of current detection is necessary The presented scheme does not require current sensors for polarity detection. Depending on the polarity of terminal voltage of each leg the current polarity is determined. Current polarity is detected regularly with a sampling frequency which is higher than the switching frequency to reduce the detection error. Hence separate power supplies are not required which reduces the bulkiness and cost of this scheme. Based on the polarity of sensed voltage the SPWM signals are generated to turn ON the switches of inverter. The presented scheme eliminates the dead time and therefore improves output voltage loss and current distortion and torque ripples. The corresponding elevator vibrations are conspicuously reduced. Simulation results for single phase and three phase inverter are done in MATLAB. The above scheme is verified by implementing it in a single phase inverter controlled motor. Hardware results are presented to demonstrate the effectiveness of the scheme.

Keywords

Dead-Time Elimination, Elevator, Pulse Width Modulation, Vertical Vibration.

Full Text

     

S. Nithya Priya ¹, A. Ramya ¹

Affiliations
1 Anna University of Technology, Coimbatore, IN

Abstract

In this paper, a single phase z source matrix converter is proposed for wind turbine generation system for induction heating application. The converter can buck and boost with step-changed frequency, and both the frequency and the voltage can be stepped up or stepped down. The matrix converter converts the high frequency of the micro turbine generator output to conventional frequency based upon applications. In addition, the converter employs a safe-commutation strategy to conduct along a continuous current path, which results in the elimination of voltage spikes on switches without the need for a snubber circuit. The operating principles of the proposed single-phase Z-source buck–boost matrix converter are described, and a circuit analysis is provided. Hence by using this method the output voltage from a wind turbine generation system can be buck and boost with step-changed frequency. Simulation results and experimental results are presented to demonstrate the effectiveness of the scheme and the results are verified for the output voltage of frequency 100Hz.

Keywords

Matrix Converter, Micro-Turbine Generator, Z-Source Converter, Step-Up and Step-Down Frequency.

Full Text