Advanced Materials Research Vols. 860-863

Abstract: Abstract. The aperiodic impulse voltage generator is huge and difficult to move in field, thereby limits its application in field significantly. For this problem, the oscillating impulse voltage (OIV) is recommended in standard IEC60060-3. In order to study the influence factor of oscillating impulse voltage generator, the simulation circuit is set up using ATP software. The influence of parameters such as shaping resistors, load capacitance and shaping inductance are study in this paper.

Abstract: In order to find a new kind of insulates gas to substitute for SF₆ gas, a discharge device has been development with shifter electrodes and adjusts distances automatic. Uniform electric field, non-uniform electric field had been achieved in this discharge device. The power-frequency voltage-withstand test of CO₂ gas has been taken in these three kinds of electric field. In this test, data of breakdown voltage were obtained under different pressure and distances of electrodes with 99.99% purity of CO₂. It can be seem from these data that the value of breakdown voltage is positive correlation to pressure and distances of electrodes. Whats more For uniform electric field, the dielectric strength meet the requirement of power-frequency voltage-withstand of 110kV gas insulation device when the distance of test electrodes no less than 30mm. For non-uniform electric field, the dielectric strength of gas insulation of CO₂ gas has little difference until the pressure increased to 0.5MPa. According to the data of power-frequency voltage-withstand test it can be conclude that the 0.5MPa is a key indicator to improve the insulating properties.

Abstract: The diameter of non-thermal arc plasma is one of the main parameters that determine the current density of arc, so as to the temperature and the density of electrons. The imagines of gliding arc discharge driven by magnetism at atmosphere are captured observed and its dimension is measured by commercial CCD. The diameter projecting in the direction of motion of the arc (diameter in positive direction) is attained. And the relationship between diameter and current, magnetic field is analyzed, too.

Abstract: In the paper, combining the advantages of interface design of VB and secondary design of ANSYS, the electric calculating software for epoxy resin casting dry-type transformer was designed. In the procedure of designing transformer, designers only need to input the structure parameters and electrical parameters of the transformer, which would be transferred to ANSYS Parametric Design Language (APDL) program automatically. Then, the different loading conditions and post-procedure programs can be selected. Furthermore, VB calls ANSYS from the background program and reads the APDL file to calculate electric field distribution. Finally, the case analysis verifies that the software can establish the finite element model automatically and calculate the electrical field distribution under any fundamental frequency voltage and lighting surge.

Abstract: This paper proposes a new application of dynamic particle swarm optimization (PSO) algorithm for parameter identification of vector controlled asynchronous propulsion motor (APM) in electric propulsion ship. The dynamic PSO modifies the inertia weight, learning coefficients and two independent random sequences which affect the convergence capability and solution quality, in order to improve the performance of the standard PSO algorithm. The standard PSO and dynamic PSO algorithms use measurements of the mt-axis currents, voltages of APM as the inputs to parameter identification system. The experimental results obtained compare the identified parameters with the actual parameters. There is also a comparison of the solution quality between standard PSO and dynamic PSO algorithms. The results demonstrate that the dynamic PSO algorithm is better than standard PSO algorithm for APM parameter identification. Dynamic PSO algorithm can improve the performance of ship propulsion motor under abrupt load variation.

Abstract: This paper studies the method of determining switch-on and switch-off time of on-line monitoring system for vacuum circuit breakers in traction substation based on engineering project. In switch-on and switch-off process, the on-line monitoring system gets displacement signal of moving contact through the guyed displacement sensor, and gets vibration signal through the piezoelectric acceleration sensor, then the signal monitored is sent to the industrial personal computer through the data acquisition unit taking DSP as the core and the communication network. After comprehensive analysis by the backstage management software in the computer, switch-on and switch-off time can be determined.

Abstract: In this paper, a new method for doubly-fed induction machine electrical faults diagnosis is presented. It is based on the so-called the Lissajous curve of an auxiliary winding voltage Park components. For this purpose, time domain mathematical model of a three phase doubly-fed induction machine and expressions of the inserted winding voltage and its Park components are presented. Simulation results curried out for non defected and defected machine show the effectiveness of the proposed method.

Abstract: With the development of high voltage long distance transmission and the expansion of the capacity of power grid, it is becoming more and more important to develop new device to realize reactive power compensation. A hybrid controllable rector is developed in this paper. The principle is introduced in detail and a 220V single phase prototype is made. Relevant experiments have been done to test its adjustment performance. Results show that there is no harmonic exist. Hybrid controllable reactor can realize many adjustment levels between 0 to 100%. Also, the shortage is given in the paper which is needed to research in the future work.

Abstract: In order to restrict over-voltage and compensate line charging power, there is a need to install high compensation shunt reactors in ultra-high voltage AC transmission lines. Due to the saturation characteristic of core limb during the working progress in the magnetically controlled shunt reactor (MCSR), the current higher harmonics exist in the high voltage winding. Based on finite element, the method which analyzes the controlling characteristic of high voltage winding with 500kV MCSR demonstration project in the Jiangling converter station is presented in this paper. The magnitude and frequency of harmonic current in the high voltage winding current is derived by this method. Through the comparison with the measured results of 500kV MCSR, the validity of method is proved.

Abstract: Sensorless control of PMSM is becoming increasingly important among the whole control system. This paper introduced Integral Separation Technology to the PI regulators to decrease overshoot or oscillation of the system. In addition, on the basis of the mathematical model of PMSM, Vector Control System for PMSM is got. Then a simplified model reference adaptive method using the zero excitation current control to modify the adaptive rate is given. At last, the corresponding waveforms are presented and the reasonability and validity has been proved by the simulation.