Design and Analysis of PCB Rogowski Coil Current Transformer

Electronic current transformers are more suitable for the development of power system compared with traditional electromagnetic current transformers. Rogowski coil current transformer is one of three electric current transformers. According to the measurement principle of Rogowski coils, the equivalent circuit of PCB Rogowski coils is analyzed. By using four PCB Rogowski coils combined, a PCB Rogowski coil current transformer is designed and tested. The results show that the designed PCB Rogowski coil transformer has good linearity and high sensitivity and measurement accuracy and it can meet the requirement of power system.

An On-Site Calibration System for Electronic Instrument Transformers Based on Labview

Electronic voltage transformers (EVT) and electronic current transformers (ECT) are important instruments in a digital substation. For simple, rapid and convenient development, the paper proposed an on-site calibration system for electronic instrument transformers based on LabVIEW. In the system, analog signal sampling precision and dynamic range are guaranteed by the Agilent 3458A digital multimeter, and data synchronization is also achieved based on a self-developed PCI synchronization card. To improve the measurement accuracy, an error correction algorithm based on the Hanning window interpolation FFT has good suppression of frequency fluctuation and inter-harmonics interference. The human-computer interface and analysis algorithm are designed based on LabVIEW, and the adaptive communication technology is designed based on IEC61850 9-1/2. The calibration system can take into account pairs of digital output and analog output of the electronic voltage/current transformer calibration. The results of system tests show that the calibration system can meet the requirements of 0.2 class calibration accuracy, and the actual type test and on-site calibration also show that the system is easy to operate with convenience and satisfactory stability.

DESIGN AND TEST OF A NEW HIGH-CURRENT ELECTRONIC CURRENT TRANSFORMER WITH A ROGOWSKI COIL

This paper describes the design and test of a new high-current electronic current transformer based on a Rogowski coil. For better performances, electronic current transformers are used to replace conventional electro-magnetic inductive current transformers based on ferromagnetic cores and windings to measure high-current on the high voltage distribution grids. The design of a new high-current electronic current transformer is described in this paper. The principal schemes of the prototype and partial evaluation results are presented. Through relative tests it is known that the prototype has a wide dynamic range and frequency band, and it can allow high accuracy measurements.

Study on Testing System for Real-Time of Communication of the Digital Substation's Secondary Equipments

Digital substations primary equipments make use of many intelligent primary equipment, for example, Electronic Transformers (including Electronic Voltage Transformers EVT and Electronic Current Transformers ECT,which meet the standards IEC 60044-7/8),intelligent switch and so on,digital substations secondary equipments include many IED(Intelligent Electronic Device). This thesis studys on the function,design,hardware and testing method of the testing system for real-time of communication of the digital substations secondary equipments.