Instrumentation for high-speed digital recording of switching surges

Journal Article · Fri Mar 31 23:00:00 EST 1989 · IEEE Trans. Power Del.; (United States)

DOI:https://doi.org/10.1109/61.25572· OSTI ID:6154142

Lloyd, B A; Gupta, B K; Campbell, S R; Sharma, D K

Voltage surges are often blamed for the failure of large ac motors in generating stations. Fast risetime surges resulting from circuit breaker switching operations distribute non-linearly across the coils and turns of a motor winding and can cause turn insulation failure eventually leading to motor failure. The ability to accurately measure surges found in typical motor supply systems was a critical part of a study to characterize the surge environment of utility motors. As part of this study, three sophisticated monitoring systems were developed and used to make unattended measurements of over 600 switching surges on 33 motors at 11 different utilities. This paper describes in detail one of the recording systems which relies on ECL digital electronics and high speed commercial digitizers to measure the multiple, fast risetime, high voltage surges, typically created by vacuum circuit breaker switching operations. This three-channel monitoring system is capable of digitizing a voltage waveform at 5 ns intervals and has 64K bytes of memory per channel. The digitizers sampling rate is varied in real time to allow a high speed recording of up to 256 transients. Wideband capacitive voltage dividers with a flat response from below power frequencies to 20 MHz were designed to bolt directly onto the motor terminals and were used to couple the surges to the monitoring system. Results from typical field measurements made with this system on motors controlled by vacuum switchgear are also reported.

• Research Organization: Ontario Hydro Research Div., Toronto, Ontario (CA); Electric Power Research Institute, Palo Alto, CA (US)
• OSTI ID: 6154142
• Journal Information: IEEE Trans. Power Del.; (United States), Journal Name: IEEE Trans. Power Del.; (United States) Vol. 4:2; ISSN ITPDE
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
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29 ENERGY PLANNING, POLICY, AND ECONOMY
296002 -- Energy Planning & Policy-- Electric Power Transmission & Distribution-- (-1989)
CIRCUIT BREAKERS
CONTROL SYSTEMS
DIGITAL SYSTEMS
ELECTRIC MOTORS
ELECTRIC UTILITIES
ELECTRICAL EQUIPMENT
ELECTRONIC EQUIPMENT
EQUIPMENT
EQUIPMENT PROTECTION DEVICES
FIELD TESTS
MOTORS
ON-LINE CONTROL SYSTEMS
ON-LINE SYSTEMS
PUBLIC UTILITIES
SURGES
TESTING