科创中国

The condenser is the key component for the evaporative cooling system of hydro-generators. And the over-all heat transfer coefficient is primary standard to judge the condenser's performance. In order to more comprehensively understand the evaporative cooling system and evaluate the condenser's work efficiency, it is important to calculate the over-all heat transfer coefficient of the condenser. In our works the over-all heat transfer was calculated in each stage and a kind of calculational methods was brought forward, thus the over-all heat transfer which is a value related to a process was proved.

Feihui Liu;Lin Ruan;国彪 顾;Jiayi Yuan

2009

As a clean and renewable energy, the wind power has attracted the attention of all nations in the world. Evaporative cooling technology has successfully been used in the research and development of wind power generator, but some key technique has to be studied in advance to insure the reliability of the very technology. The application of evaporative cooling technology in the cooling of large wind power generator is a new attempt in the discovery of wind power energy. Thorough study is carried out on the key technique of the application of close-loop self-circulation (CLSC) evaporative cooling technology on the running of wind power generator. The flow resistance of the coolant in the air cooling condenser is discussed in this paper, and a new approach is founded for the improvement of the reliability.

Jingming Li;Fuchuan Song;国彪 顾;Xindong Tian

2012

This paper discusses 3-D temperature estimation for the electric generator in rim-driven marine current power (RMCP) system. The structures of RMCP system, especially the structure of permanent magnet generator are presented in this paper. Based on the hydromechanics and heat transfer theories, the 3-D thermodynamics simulation model is modeled and its related parameters are discussed. Computational fluid dynamics (CFD) method is adopted to analyze the temperature distribution of generator. At last, the calculation results and discussion are presented in the paper. The calculation results demonstrate that the temperature rise of generator in RMCP system is small.

Song Xu;海峰 王;国彪 顾

2013

Firstly, in order to solve the problems of traditional predict torque control with large flux and torque ripples, unfixed switching frequency, etc., a duty cycle modulation method based on the traditional predict torque control is proposed to improve the control performance. Secondly, in view of the complexity of the traditional predictive torque control with duty cycle modulation, the flux and torque are completely decoupled based on the stator flux coordinate system. Then, a simpler predictive torque control strategy with duty cycle modulation is proposed, which eliminates weight coefficient and converts torque error into the action time of voltage vector. Thirdly, an adaptive sliding mode observer is designed for solving the problems of poor robustness of model reference adaptive system and large-scale switch chattering of the sliding mode observer. The sliding mode observer and adaptive sliding mode observer are applied to the optimized predict torque control and the stability and parameter robustness of two observers are compared. Finally, the superiority of the proposed strategy and adaptive sliding mode observer are verified by simulation studies.

Fei Ban;Guangkun Lian;彪 陈;国彪 顾

Diangong Jishu Xuebao/Transactions of China Electrotechnical Society

2018-12-31

Flux-switching permanent magnet machines (FSPM) show high-reliability and are quite suitable for the fields such as new energy, electric vehicle and aerospace. In this paper, the i_d=0 vector control strategy based on SVPWM was proposed. Besides, the high frequency signal injection method was used to identify the initial rotor position of FSPM. The experimental results proved the feasibility of the strategy in FSPM.

Huitao Li;Guangkun Lian;彪 陈;国彪 顾

2017-10-2

A novel high-reliability DC generator system integrating flux-switching machine with segmental rotor, of which both armature and excited windings are located in the stator, rectifier and excitation controller was proposed in this paper. At first, the working principle of SFSM and the DC generator was introduced in detail. Further, a prototype was designed based on finite element analysis of flux-switching machine with segmental rotor, analysis of working modes of the excitation main circuit topology and the closed loop control strategy. At last, a platform was built and the experiment study including static and dynamic state characteristic was conducted. The experimental result proved the design and analysis above well.

Guangkuan Lian;Fuchuan Song;Fengfei Luan;彪 陈;Jiayi Yuan;国彪 顾

2016-7-13

In this paper, we introduce an applied engineering design of Three Gorges' 840MVA hydro-generator with close loop self circulating evaporative cooling (CLSCEC) System and its designing principles. We also make a comparison between the internal water cooling (IWC) hydro-generator used in Three Gorges power plant and the new CLSCEC hydro-generator in fields of their operating characteristics, working performances, technical features, working safety and reliability. In addition, based on the design permanents, engineering structures, modeling tests results and systematic emulating calculation of CLSCEC schemes are analyzed.

Jiayi Yuan;国彪 顾;Lin Ruan;Xindong Tian;Lin Duo;Tianpeng Zhang

2008

Turbo generator with evaporative cooling stator and air cooling rotor possesses many excellent qualities for mid unit. The stator bars and core are immerged in evaporative coolant, which could be cooled fully. The rotor bars are cooled by air inner cooling mode, and the cooling effect compared with hydrogen and water cooling mode is limited. So an effective ventilation system has to been employed to insure the reliability of rotor. This paper presents the comparisons of stator temperature distribution between evaporative cooling mode and air cooling mode, and the designing of rotor ventilation system combined with evaporative cooling stator.

Bin Xiong;国彪 顾

2008

The application of evaporative cooling technology in the cooling of large wind power generator is a new attempt in the discovery of wind power energy. In some particular circumstances, the air-cooling condenser must be adopted as the secondary cooler in the evaporative cooling system of large wind generator. For the cooling medium in the air-cooling condenser is the air and the distribution of temperature is uneven along the cooling tube, so it's necessary to do deep research on it. Experiments are carried out to study the heat transfer characteristics of the air-cooling condenser used in the Close-loop Self-circulating (CLSC) evaporative cooling system. The temperature distribution and the heat transfer can be acquired from the experiment. Thorough study is carried out on restart up of the close-loop evaporative cooling system of the wind power generator. Experiments are done in the laboratory and real wind power generator, and it's found that there is a critical point in the restart up of the generator. Only if the flow head overcome the critical point can the wind power generator restart automatically. The result shows that heat transfer can be enhanced by some special method and the air-cooling condenser can satisfy the demand of the cooling system.

Jingming Li;Fuchuan Song;国彪 顾;Xindong Tian

2012

A prototype of high gradient magnetic filter is designed and fabricated, and the electrical coils, which generate a 1 Tesla background magnetic field, are cooled by evaporative cooling system. The operating magnetic flux density distribution is computed carefully by magnetic circuit method and finite element method, and the operating temperature distribution of electrical coils is computed too by finite element method. The test values of the distribution of magnetic flux density and temperature are in accord with design computations.

Fuchuan Song;Jiayi Yuan;Xindong Tian;国彪 顾

2008