Xueliang Huang

The impact and simulation on large wind farm connected to power system

Doubly-fed induction generator (DFIG) wind turbines are widely utilized in large wind farm. Research of the dynamic behaviors of DFIG wind turbine is of great importance. Impact of large scale wind farm integration on power systems transient stability is studied in this paper. Then the dynamic model of wind turbines based on DFIG is used to study the impact of wind power integration on the transient stability of the grid. In the paper, the 8th and 5th order dynamic models of DFIG wind turbine are discussed respectively. The simulations by MATLAB and PSS/E verify the theoretical analysis. It is concluded in the paper that the performance of DFIG for integration is better than that of synchronous generation units at a same point in the power systems as far as transient stability is concerned. Also with the voltage control, the transient stability of power system is enhanced as the fault happens.

A new CIM-based cross-platform graphic system for power system applications

In accordance with CIM standard (IEC 61970-301 ~ IEC 61970-303) [6-8], this paper presents a new graphic system for power system applications. This system, which is base on cross- platform design, is extensible and general-purposed. With the effective combination of CIM and cross-platform, this system can satisfy the needs of most power system applications. The characteristics of this system include the simplicity of the class hierarchies, the convenience of extension, and the ease to build up large application. It provides a useful reference for other CIM applications which needs to run on multiple platforms other than a single platform.

Design and analysis of a novel ironless trapezoid winding array with single-sided and well sinusoidal magnetic field

By analogy with Halbach permanent magnet (PM) array, a novel ironless trapezoid winding array (TWA) is designed to achieve a primarily single-sided and well sinusoidal magnetic field. After deriving the TWAs current density formula in Fourier series, via the magnetic vector potential we derive the analytical solution of its magnetic field, which is verified by ANSYS finite-element method.

Calculation and investigation of end-effect for a high-precision planar magnetic levitation

In this paper, a novel high-precision planar magnetic levitation is proposed, which combines the advantages of Halbach PM array with the controllable maglev structure. For accurate motion control of the levitation the end-magnetic-field-effect on the stator windings is taken into account, thus the equivalent magnetic charge method is proposed to calculate the 3D end-magnetic-field and compared with the finite element analyses (FEA). The well matched comparison results are given to verify the validity of the method.

High voltage devices in transmission and transformation engineering and public environment

The paper analyzes the electromagnetic pollution existing in the high voltage engineering and the principle of its production at the very beginning. Then it discourses the protection from the high voltage facilities electromagnetic field and show us the actual measurement result of environmental protection. Do a specific analysis on the misunderstanding questions concerned by the public. At last, the author makes an objective conclusion on the effect of transmission and transformation engineering on the environment.

Field-oriented vector control and simulation of linear motors with Halbach permanent magnets

This paper presents a new method for dynamical control of the linear motor which consists of Halbach permanent array. This motor is designed for micro-motion or micro-location precision instruments. Based on a novel mathematic model of the linear motor, which takes the lateral and normal force into account, an improved field-oriented control method is applied. This method enables the operation of the drive at minimum direct axis stator current. A modified matrix converter is applied to divide the three-phase input voltages into sections and three pairs of current control signals are deduced by comparing with the reference values. Thus a more accurate dynamic control performance is achieved. The validity of this method is proved by the simulation results of the practical test motor.