Zhigang Di

Special Display Instrument for Fiber Current Transformer

To meet the requirement of fiber current transformer, special display instrument was deigned. SCM and advanced signal process technology were adopted in the instrument, so that the output voltage signal of low voltage terminal can be utilized by instrument to display measured busbar current value real-time. Besides, section linearization and distinguish calibration methods were adopted to improve measurement precision of display instrument. The experiment results indicated that this instrument has virtues of reliability, high precision and low cost, importantly, it can come up to the 0.2 standard. So we can draw a conclusion that this instrument can meet the industrial requirement for display instrument.

Signal Process of Gas Monitoring System in Fiber Sensor

Gas monitoring has been the most important project in coal mining, and the main basis of gas is CH4. As a result, it is fatal to develop a safe and highly sensitive CH4 sensing system to detect CH4 concentration real-time. Moreover, signal process system is important for this sensing system. The novel signal process system was proposed in this paper, and phase lock amplifying and signal sampling processing technology was utilized to monitor CH4 concentration steadily and reliably. The experiment results indicated that the steady is 0.4%, and relative error is less than 0.02%. So this signal process system is feasible and effective, and can meet the requirement of technology

Design of a newfashioned high precision electronic current transducer

The electric current transducer plays a significant role in electric power system. In order to measure small current accurately, a newfashioned high precision electronic current transducer was designed. A novel high mutual inductance, high precision Rogowski coil was adopted as sensor head, and a novel analog signal process system, including magnifying, filtering, phase compensating was designed to improve precision and reduce power dissipation. Besides, the application of CPLD technique harmonized the system. High precision components improved the precision of transducer. By experimentation we drew a conclusion that this system worked steadily at the range of −40∼70°C, and its precision could meet 0.2 level of international criterion.

Design of High Voltage Signal Processing System of Fiber Current Transducer

Fiber current transducer has been applied in power system to measure current. In order to improve measurement precision, also reduce power dissipation, the customized high precise Rogowski coil was utilized as sensor head, most importantly, a novel analog signal processing system was designed, namely, one circuit was utilized to achieve measurement and over loading protection functions. Besides, high precise low consumption elements were adopted to design circuits. As a result, measurement precision was improved, also power dissipation was reduced. The experiment result indicated that this system is convenient and feasible. And the precision can meet 0.2 level of national standard.