Application Research Of Metering Standard Device Of Heavy Direct Current

Heavy direct current has been widely applied in industrial production, transportation and many other aspects. With the rapid development of UHVDC and high-speed railway, heavy direct current will account for larger proportions in energy consumption in the society. However, it is more and more eager to develop a unified metering standard and transfer standard of heavy direct current, which are lagged behind hugely, in order to avoid inaccuracy of measurement and thus the prodigality of energy. What is more, a solid foundation will be built in the long-term planning of high energy consumption field in our country and an enhanced theory and technology basis will be laid on energy saving. This thesis is supported by Special Projects as Scientific Research for General Administration of Quality Supervision, Inspection and Quarantine of China(No.200710107). Some metering and transfer standard devices are designed, and problems following the test in the lab and industry are deeply studied.This thesis introduces the present situation in this field and indicates the significance of such research first. The basic principles are illustrated in Chapter 2, ranging from difference double-cores magnetic modulator to current comparator based on magnetic modulator, and then to multi-channel and openable-core type. It is indicated that the design of the transfer standard devices applied in industry will be designed based on multi-channel and openable-core comparator. After that, some characteristics of this compactor, such as antimagnetic and openable-loop features, are discussed.In Chapter 4, the emphasis is put on the application of multi-channel and openable-core comparator and analysis of the problems followed in industry. First, the problem of some channels are closed when doing simulated experiments in Heavy Direct Lab of HUST. Then simulations based on electromagnetic software are adopted in terms of sensor heads, obtaining that fluctuations of magnetic field intensity will influence the balance of multi-channels, which is proved by experiments. The environmental magnetic field intensity affects the operating point of the comparator according to the test in industrial enterprise, and related mathematical calculations indicate the condition of the environmental magnetic field intensity that will influence the operating point of the comparator.In the end of this thesis, summing-ups and prospects of this research are proposed.