Liangzhen Lin

Recent Progress of Power Application of Superconductor in China

The significant progresses in high Tc superconducting wires or tapes have excited a great deal of research interests in power application. This paper will review the recent progresses of power application of superconductor in China. An improved bridge-type fault current limiter was tested and a 10.5 kV/1.5 kA demonstrator has been operated at a substation in Hunan Province in 2005. A 75 meter, 10.5 kV/1.5 kA three phase HTS cable has been installed and operated at the Changtong Cable Headquarter in the end of 2004, and a 30 meter, 35 kV/2 kA HTS power cable was installed at substation and has been operated since July 2004. A 10.5 kV/400 V/630 kVA HTS transformer has been installed and operated at TBEA electric factory in 2005. A 500 kj/150 kVA SMES unit was developed and tested. 1.0 MJ/0.5 MW SMES will be installed in a power grid in 2006. Besides, a new kind equipment of fault-current-limiting SMES is being developed and a 100 kJ/25 kW prototype has been made and tested.

Development of a 630 kVA Three-Phase HTS Transformer With Amorphous Alloy Cores

This paper describes design and operation of a three-phase HTS power transformer with capacity of 630 kVA operated in liquid nitrogen of 77 K for primary/secondary voltages of 10.5 kV/0.4 kV. The windings were wound by hermetic stainless steel-enforced multifilamentary Bi2223/Ag tapes. The structures of primary and secondary windings are solenoid and double-pancake respectively. Cryostat is made from electrical insulating materials with room temperature bore for commercial amorphous alloy core. Fundamental characteristics of the transformer are obtained by standard short-circuit and no-load tests. The ac losses were calculated and measured by method of conventional transformer. The HTS power transformer successfully operated in a live power grid.

Design of a High Temperature Superconducting Generator for Wind Power Applications

High temperature superconducting (HTS) generator was promising in the wind power applications for its advantages in the weight, size and thermal stability against load fluctuations, especially in the “direct-driven” design. A 100 kW generator was proposed for the demonstration of the feasibility of using HTS in 10 MW wind turbine generators. The electromagnetic design and optimization of the rotor were done using finite element method (FEM). The excitation coil of the rotor was designed considering variable working conditions. According to the numerical results, a number of suggestions in the design and winding techniques of the superconducting rotor were proposed.

Development and Test of 10.5 kV/1.5 kA HTS Fault Current Limiter

Superconducting Fault Current Limiter (SFCL) is an attractive appliance for modern electrical power system. A 10.5kV/1.5 kA three-phase HTS fault current limiter was developed by IEE, CAS. This improved rectifier-type SFCL with HTS coil of 6.25 mH is going on a demonstrated long-term reliable operation in a real 10.5 kV substation located in Hunan, China. In a three-phase-to-ground short circuit test of grid, the prospective fault current of 3.5 kA was limited to 635 A at the pre-setup short-circuit point successfully

HTS Power Technology for Future DC Power Grid

The growing environmental pressure resulting from the use of fossil fuels is leading mankind to make a transition from the use of traditional energy sources to that of renewable energy based clean energy. Because renewable energy has the feature of instability, it thus brings significant challenges on real-time power balance and power dispatching. Therefore, to secure the power supply, the grid needs to be upgraded by the selection of a reasonable grid structure and operation mode. In this paper, a multiple-level direct current (dc) loop grid, which would be the suitable mode for the future power grid, is suggested. Then, the high-temperature superconducting (HTS) dc power technology such as the HTS dc power cable and dc fault current limiter for the future power grid are discussed. We also report on the test and operation of a 360-m/10-kA HTS dc cable that is being built and would be used for an electrolytic aluminum plant of Zhongfu Group in Henan Province, China.

Fabrication and Tests of a 1 MJ HTS Magnet for SMES

In this paper, the design, fabrication and tests of a I MJ HTS magnet for SMES was presented. The magnet was fabricated by BSSCO tapes, it consisted of 44 pancakes, the inner diameter of the winding is 400 mm, the outer diameter is 568 mm and the height is 648 mm, the inductance is 6.38 H and the rated operation current is 560 A at 4.2 K. The tests show the magnet could be operated at the design parameters. The magnet will be used for the 1 MJ/500 kVA SMES unit which will be demonstrated at a 10 kV substation in Beijing.

Design of a 380 m DC HTS Power Cable

High temperature superconducting (HTS) power cable is an effective power transmission utility with large capacity, high efficiency, and low loss, especially in DC power transmission. This paper describes the design of a 380 m HTS power cable with rated current of 10 kA for an aluminum electrolysis enterprise. The power cable connects the rectifier at a substation at one end with the bus bar of an aluminum electrolysis plant at the other end at Henan Zhongfu Industrial Co. LTD. The power cable will be energized in late of 2010. The design of the cable conductor, cryogenic envelope, termination, refrigeration, and online monitoring system of the 380 m HTS power cable are discussed in this paper.

Development of the World's First HTS Power Substation

With the increasing depletion of fossil fuels and growing environmental pressure, the mankind has got known the need to vigorously develop the renewable energy and the energy-saving technology. The high Tc superconducting (HTS) power technology will be very helpful to enhance the stability, reliability, and efficiency and transmission capacity of the power grid which would be dominated by the renewable energy. In this paper, we will report the installation and operation of a 10 kV HTS power substation which includes a 75 m/1.5 kA HTS power cable, a 10 kV/1.5 kA HTS fault current limiter, a 1 MJ/0.5 MVA high Tc SMES and a 630 kVA/10 kV/0.4 kV HTS power transformer.

Development of a 10 kA HTS DC Power Cable

The new energy revolution which will be dominated by renewable energy will need to develop a corresponding new power grid. Based on the characteristics of renewable energy resources, and the stability problem of AC network, it was proposed that the DC-based transmission grid should be developed in the future. The high Tc Superconducting (HTS) power cable will be a competitive candidate for large-capacity power transmission of renewable energy. In this paper, the progress of the development of a 360 m/10 kA HTS DC power cable is presented, and the prospects of HTS cable is discussed.

Development of HTS transmission power cable

A 1500 A/6 m HTS DC transmission power cable has been developed and tested at the Institute of Electrical Engineering, Chinese Academy of Sciences. The conductor of the HTS cable consists of 4 layers of Bi-2223/Ag tapes helically wound on a flexible stainless steel former. The Bi-2223/Ag tapes have been developed by the Northwest Institute for Nonferrous Metal Research and the Beijing General Research Institute for Nonferrous Metals. The cable core has a 45.3 mm outer diameter and 6 m length and is housed in a cryogenic envelope. The E-I characteristic and the total joint resistance of the cable have been measured at 77 K. The critical current of the cable is 1473 A and the total joint resistance is 0.1 /spl mu//spl Omega/ at 77 K. The main properties of the Bi-2223/Ag tape and the development and test results of the HTS cable are presented in this paper.