An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers

Journal Article · Mon Jul 15 00:00:00 EDT 2013 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4815831· OSTI ID:22220566

Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi ^[1]

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1. CEEE of Huazhong University of Science and Technology, Wuhan 430074 (China)

Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class.

• OSTI ID: 22220566
• Journal Information: Review of Scientific Instruments, Vol. 84, Issue 7; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ACCURACY
CALIBRATION
CURRENTS
DESIGN
ELECTRIC POTENTIAL
FAILURES
POWER SYSTEMS
POWER TRANSMISSION LINES
SHAPE
TRANSFORMERS