Wang Erzhi

Dynamic arc modeling based on computation of couple electric field and flow field for high voltage SF/sub 6/ interrupter

In this paper, a dynamic arc model based on computation of coupled electric field and flow field for a high voltage (HV) SF/sub 6/ interrupter has been investigated and analyzed. Moreover, for simulating the insulating performance and interrupting characteristics of the SF/sub 6/ interrupter, dynamic variation of the arc in different interrupting cases, such as before current zero, approaching zero and after current zero have been established, and the compressibility and viscosity of SF/sub 6/ gas in the whole interrupting course has been taken into consideration. Interrupting performance and dielectric recovery characteristic of the HV SF/sub 6/ interrupter have been obtained and discussed. Fairly good representations of interrupting evolutionary processes within the arc-quenching chamber and arc dynamic characteristics have been achieved using the proposed model. And interrupting performance with higher precision has been obtained.

Hybrid finite element-charge simulation method for SF/sub 6/ tank type circuit breaker with double breaks analysis

The electric field simulation for the axisymmetric configuration of the SF/sub 6/ tank type circuit breaker is proposed based on the domain decomposition method in this paper. The mathematical model is based on coupling finite element method (FEM) and charge simulation method (CSM). It is shown that the hybrid FEM-CSM is capable in calculating the complex open boundary problem, demonstrating the great potential of the hybrid method in different fields.

Optimization design of the contact and shield in vacuum interrupter based on the genetic algorithm

In this paper, based on the electric field analysis, the optimizations for the end of floating shield and the back of contacts are realized using the combined method, charge simulation method (CSM) and genetic algorithm (GA). The floating shield potential has been successfully determined by the CSM. With the aid of solving the inverse problem and the computer simulation, the improved external dimensions of the floating shield and the contacts are presented. The theoretical basis for the insulation design is provided. Compared with the experiment on 35 kV vacuum interrupter, the computer results are reasonable.

Design on permanent magnet actuator and simulation of dynamic characteristic for vacuum circuit breaker

A novel Permanent Magnet Actuator (PMA) is put forward in this paper. The 3D magnetic distributions of PMA in different conditions have been computed, adopting ANSOFT9.0 software. In order to determine the size of each part of PMA, the variations of each parameter haw been simulated in dynamic course of breaking and closing. Based on the simulation results, the prototype is manufactured and assembled. The feasibility of the proposed PMA and the simulation veracity of the dynamic characteristic of breaking and closing hare been proved by the tested data of the prototype.

Survey on the external insulation of 10 kV outdoor vacuum circuit breaker

Taking the combined effects of porcelain insulation casing, the silicon rubber external insulation and floating shield on the electric field into account, the electric field has been calculated for three kinds of vacuum circuit breakers with different external insulation structures using the finite element method (FEM). The potential of floating shield has been well considered and calculated. Based on the computing results, the influences of floating shield and the silicon rubber insulation are analyzed. The theoretical basis for further optimization design of external silicon rubber and the development of outdoor vacuum circuit breaker is provided.

Electric field optimization design of the vacuum interrupter based on the Tabu search algorithm

During interrupting in the vacuum interrupter, the reignition between the contact and the shield are influenced by the shape of the contact and the size of the shield. The design for the contact and the shield is an intricate global optimization problem. In this paper, the Tabu search (TS) approach is used to optimize the contacts for the 35 kV vacuum interrupter. Optimization design is based on the electric field computation using the finite element method (FEM). By solving the inverse problem, the optimizations of the contacts are achieved, the reasonable distribution of the electric field is obtained. Based on the combinatorial optimization TS algorithm, an improved universal approach for the continuous variables global optimization is proposed. The feasibility and practicability are verified by the experimental results.

A new boundary element method for calculating the magnetic field of permanent magnetic machine

Compared with the finite element method (FEM), one dimension can be reduced in magnetic field calculation using the boundary element method (BEM). It has been proved by this paper that the convergence of integrand of integrated equation is equal to zero in magnetic field calculation and so that again one more dimension can be reduced in the investigated problems. For the 3D magnetic problem, the quadratic form function has been chosen as the correspondent magnetic potential and the singular integral has been avoided. Using these results, a new boundary element method has been developed. As an example, a 3D static magnetic field of 160 kVA rare earth permanent magnet machine with 16 poles is calculated by this new method. The calculation result shows that this new method possesses high precision.

Periodic statistical prediction adaptive memory incremental control

In terms with the characteristic of real-time control of system on analog signal, propose a statistical control method based on control micro-unit, define a statistical steady coefficient to expend control micro-unit; obtain quantization control state statistical figures by quantization statistical identification; define the average statistical state deviation, statistical trend, statistical overshooting, end deviation and so on. Meanwhile, identify the proportional relationship between the parameters and the control increments, confirm statistical control policy and optimization qualification; present the design scheme of the adaptive memory incremental controller. It has a high resolution of control parameters so as to enable the object rapid, smooth and reliable. The statistical increment control method facilities programming on microprocessor for its high computing speed and high efficiency control of the simulation. Combining distributing control systempsilas characteristics, present application examples of simulation statistical control.

Application of the multiple grid method in electric field calculation of high-voltage interrupter

In view of the disadvantages of conventional finite difference method (FDM) in handling the complicated boundary of electric fields and in eliminating the smooth error of iteration, in this paper, the differential equation is employed to generate regular calculation grids from the original region to be calculated. So, the approximation of the boundary condition in calculation is avoided. The multiple grid method (MGM) is adopted in the electric field calculation on the transformed region for eliminating the smooth error, expediting the convergence, and increasing the calculation precision. The convergence property of the MGM has been verified by both the theoretical analysis and the numerical solution. The merits of the method provided in this paper have been verified by comparing with FDM, finite-element method (FEM), and boundary-element method (BEM).

Monitor of electrical endurance of vacuum circuit breaker's contacts

This paper discusses an approach to the monitoring of the electrical endurance of a vacuum circuit breakers contacts, and gives the measurement circuit and signal processing method used.