ANALYSIS OF THE AUXILIARY RESONANT COMMUTATED POLE INVERTER

A study of the Auxiliary Resonant Commutated Pole (ARCP) converter and a comparison with standard hard-switched inverters is presented. A thorough description of the AELCP circuit topology is made with three switching scenarios discussed: commutation from a diode, commutation from a switch with low current, and commutation from a switch with high current. The efficiency of the ARCP inverter is attributed to the fact that switching losses are eliminated by switching under zero voltage or zero current conditions. To accomplish this task, addition circuitry is introduced which colntributes to additional conduction losses. An example H-bridge is presented using both ARCP phase legs and hard-switched phase legs. Losses for each case are calculated and a comparison is made. From simulations, it is shown that the additional conduction losses introduced by the ARCP circuit are small in comparison with the switching losses found in a standard hard-switched circuit. A simulation of a three-phase example ARCP inverter is briefly discussed

A Maximum Torque per Ampere Control Strategy for Induction Motor Drives

Abstract- In this paper, a new control strategy is proposed which is simple in structure and has the straightforward goal of minimizing the stator current amplitude for a given load torque. It is shown that the resulting induction motor efficiency is reasonably close to optimal and that the approach is insensitive to variations in rotor resistance. Although the torque response is not as fast as in field-oriented control strategies, the response is reasonably fast. In fact, if the mechanical time constant is large relative to the rotor time constant, which is frequently the case, the sacrifice in dynamic performance is insignificant relative to FO strategies. I

Doubly fed induction generator-based variable-speed wind turbine: proposal of a simplified model under a faulty grid with short-duration faults

The aim of this study is to provide a simplified model of a variable-speed wind turbine (VSWT) with the technology of a doubly-fed induction generator (DFIG) which operates under faulty grid conditions. A simplified model is proposed, which consists of a set of electrical and mechanical equations that can be easily modeled as simplistic electrical circuits. It makes it an excellent tool to achieve fault ride-through capability of grid-connected VSWT with DFIGs. Both symmetrical and unsymmetrical grid faults, which cause symmetrical and unsymmetrical voltage sags, have been applied to the system in order to validate the model. The proposed simplified model has been compared with the traditional full-order model under multiple sags (different durations and depths), and the results reveal that both models present similar accuracy. As the idea is to reduce the computational time required to simulate the machine behavior under faulty grid conditions, the proposed model becomes suitable for that purpose. The analytical study has been validated by simulations carried out with MATLAB.Peer Reviewe