obiao Gu

Direct Drive Permanent Magnet Wind Generator Design and Electromagnetic Field Finite Element Analysis

The wind generators simulation model is set up to study the electromagnetic field by finite element method. Based on Maxwell electromagnetic theory, the distribution of magnetic field is obtained and generator characteristics are calculated in the case of no load and load transient operation. The post processing helps to optimize the design of the generator. Meanwhile, some practical project problems are solved.

Research on two-phase flow instability in two parallel hollow conductors in the evaporating cooling generator

As a new generator cooling technology, the evaporative cooling technology has been researched on various aspects to a certain extent, such as the two-phase flow pressure drop, temperature distribution and etc. But there has no research reported on the two-phase flow instability in the parallel hollow conductors in the evaporative cooling system. The occurrence of two-phase flow instability phenomena can probably make some system parameters change abnormally, such as flux and temperature, and make the cooling system operate abnormally. So its necessary to pay more attention to the instability of two-phase flow to assure the generators cooling effects. In this paper, the two-phase flow instability in two parallel hollow conductors was researched through theoretical simulation and experiments and the boundaries of the instability starting were obtained. The conclusion provides the reference basis for the actual operation of the evaporative cooling system in a certain sense.

The application of evaporative cooling technology for an electromagnetic separator

An immersed type evaporative cooling electromagnetic separator is presented, including the prototypes configuration, procedures and outcomes of the temperature distribution simulation, as well as the results by experimental research. The comparison between the stimulation and experimental study show that the simulation methods are accurate; meanwhile, the evaporative cooling technique is an effective way for larger capacity electromagnetic separator

Review of liquid cooling technology for rotor of turbo generator and application research of open channel evaporative cooling technology

Liquid cooling is an effective method to cool the rotor of turbo generator. Evaporative cooling technology is the frontier field of liquid cooling technology at present. This paper reviews fluid cooling technology for rotor of turbo generator and introduces research progress on open channel evaporative cooling technology.

Analysis and Design of Cooling System in High Temperature Superconducting Synchronous Machines

Various cooling systems for High Temperature Superconducting (HTS) synchronous machines were analysed and discussed in this paper. Thermosyphon cooling has been applied in several demonstration HTS synchronous machines. The heat transfer characteristics of this method and the temperature field of rotor were investigated in details. Furthermore, open evaporative cooling and piping evaporative cooling were originally pointed out for HTS machines with different rotate speed ranges. The simulated results showed that open evaporative cooling can acquire more uniform temperature distribution of HTS windings. Piping evaporative cooling is preferred for cooling rotor of low rotate speed HTS machines. Based on above analysis, an integrated rotor cooling platform has been designed to investigate the characteristics of different cooling systems.

Developing of turbo generator based on evaporative cooling technique and analysis to key factors

Cooling technique is one of the most important parts to improve the development of turbo generator. From the earliest air cooling technique to the modern water and hydrogen cooling technique, turbo generator is optimized constantly. Evaporative cooling technique is the latest one utilized to cool turbo generator, and we believe that it ought to bring a great progress in improving the efficiency, reliability, security and economics of turbo generator. In this paper, we describe the applications of evaporative cooling technique to cool the electrically active components of generator and analysis to the key factors. The advanced cooling systems are outlined according to the capability of turbo generator, which will provide references for generator designers.

Study of large wind power generator with evaporative cooling system

Evaporative cooling system has the advantage of high cooling performance, good insulation properties, less electrical fault, easy to maintain and high reliability, can meet the requirements of the cooling system in wind power generators. Based on a large number of theoretical researches and engineering practices, we had a comprehensive study of evaporative cooling wind power generator. Studies show that evaporative cooling system has advantage as the cooling system of wind power generator.

Double closed-loop brushless DC motor control based on variable structure sliding mode

The brushless DC motor, which emerged as the development of technology of electronics, is a new kind of DC motor, and it is also the important part of modern industry [1]. Because of its reliability of operation, brushless DC motor has been widely used in many special areas, such as aerospace and mining.

Design of experimental device used for heat transfer research of single-phase and two-phase spray cooling

Spray cooling is a very efficient mean for dissipating high heat flux with low volumetric flux and Low surface temperature, which is used in many fields. However, there are many differences about the heat transfer mechanism of spray cooling academically. This paper introduces in detail an experimental device, which can be used for heat transfer research of single-phase and two-phase spray cooling. The analysis of experimental data from this device is presented finally, which will be a good reference for the design of the real spray cooling equipment.

Research on small-signal stability of power system connected with different wind turbines based on PSAT

In order to analyze the small signal stability of the grid interconnection of different types of wind turbines, in the PSAT simulation environment, this paper establishes simulation model with IEEE3 machine 9-bus system as a prototype, and the small signal stability of power system connected with 3 kinds of wind farms is respectively simulated and compared. The results show that, due to the isolation effect of converter, different connections of generator and grid have a greater impact on the small signal stability of the system; the converter will reduce the small signal stability of the system.