Analysis of starting and synchronization process for line start IPM motors
This paper presents an improved analytical method for determining the synchronizing capability of a line start interior permanent magnet (IPM) synchronous motor. Approximate solution techniques based on average torque analysis for determining the critical slip and maximum inertia are also presented. A dynamic d-q axis model of the motor is developed to investigate the run-up response as well as synchronization capability of line start IPM synchronous motors. The start-up and synchronization performances of a 1hp 208V 4-pole line start IPM motor for various loads have been obtained using MATLAB. Experimental investigations have been also carried out for the same 1 hp IPM motor and test results are presented to support simulation results.
Evaluation of Spoke Type IPM Synchronous Motors for IE4 Efficiency Class
In this paper, the assessment of a line-start spoke type rotor IPMSM (interior permanent magnet synchronous motor) design for super premium efficiency class (IE4) is discussed. Due to the hybrid rotor structure, these motors have three torque components: reluctance, PM and cage (induction) torques. Cage torque characteristics determine the motor's starting and synchronization capabilities while the reluctance and the PM torques form steady-state behavior. The design study shows that spoke type rotor structure can carry these features properly. A 2.2 kW, 4-pole, general purpose, line-start, spoke type IPMSM is arranged satisfying the requirements of IE4 efficiency class. And also, the addressed design is compared to the other line-start IPMSM types, in terms of performance parameters, ease of manufacturing, cost and synchronization capabilities.
Fast seismic data compression based on high-efficiency SPIHT
Based on the set positioning in hierarchical tree (SPIHT) algorithm, fast seismic data compression based on the high-efficiency SPIHT (HESPIHT) algorithm is presented. To verify the validity of the algorithm, 10 seismic cross-sections are selected for the experiment. The result shows that the algorithm can reserve the quality of data better, meanwhile improving the efficiency of encoding and decoding.