Testing and loss measurement of HV shell-type shunt-reactors at ...

to the total loss of the capacitor bank.at 180 Hz operating mode the capacitor bank is connected to lower voltage (20 kV±5%) winding ofthe step-up transformer and at 60 Hz to the higher voltage winding (46kV±5%). Tuning to the requiredresonant frequency is performed by the step-up transformer off-load tap changer and by switching onor off capacitors in each level of the capacitor bank.6. Conclusions• An inherently rigid structure of shell-form winding enabled use of the continuously transposed wirethat enabled a further reduction of the shunt-reactor loss. Although the major design achievement,the very low loss has been difficult to measure at the manufacturer HV laboratory, especiallyunder the condition of power frequency fluctuations. A modified Schering bridge with doubleintegratorwas used to measure this loss with a sufficiently high accuracy.• Dielectric test of 50 MVA, 400kV shunt-reactor involved an excitation at 180 Hz by ~1 MVAgenerator. A large capacitor bank was designed and put in operation to compensate the reactivepower, and several protection schemes were developed to prevent an explosion and fire of the sixlevelbank containing ~600 capacitors, each rated at 200 kVAr.• Tuning of the capacitor bank to resonance at ~180 Hz with the shunt-reactor has been critical, sincethe rotating machine could have been damaged by a capacitive load, and the operating frequencymust have been close enough to the tuned-circuit resonant-frequency to attain the required testvoltage on the shunt-reactor.7. AcknowledgementsWe are very much obliged to Messers. Javier Alcántara, Carlos Servin, David Mota and Luís Ortízwho set-up the resonant test-circuit and performed the shunt-reactor test at IEM HV laboratory.Advice and assistance of Mr. Jean Douville, and of Mr. Sebastian Widmer of Tettex in solving theSchering bridge stability problems are gratefully acknowledged.8. References1. Christoffel, M., “The Design and Testing of EHV Shunt Reactors”, IEEE Trans. Vol. PAS-86,Nr. 6., 1967, p. 684-692.2. Grundmark, B., “High Voltage Shunt Reactors, Trends in Design and Testing”, CIGRE, 1968,paper #12-08.3. Malewski, R., Arsenau, J., So, E., Moore, W.J.M., "A Comparison of Instrumentation forMeasuring the Losses of Large Power Transformers", IEEE Transactions, Vol. PAS-101, No.6, 1983, pp. 1570-1573.4. More, W., Raftis, L., “Measurement of Shunt Reactor at High Voltage with an AlternatingCurrent-Comparator Bridge”, IEEE Trans. Vol. PAS-92, 1973, p.662-667.5. So, E., “An Improved Frequency-Compensated Capacitance Bridge for Accurate ShuntReactor Loss Measurements at Very Low Power Factors”, IEEE Trans. Vol. PAS-103, Nr. 5,1984, p. 1099-1103.6. So, E., “The Application of Current Comparator in Instrumentation for HV PowerMeasurements at Very Low Power Factors”, IEEE Trans. Vol. PWRD-2, 1986, p. 98-1017. Foley, A.H., “A Direct Reading Non-Frequency-Sensitive Bridge for Line Shunt ReactorMeasurements”, IEEE Trans. Vol. IM, December, 1973, p. 416-420.8. Malewski, R., Douville, J., “A Modified C-tgδ Bridge for Measurement of Losses in EHVShunt Reactors”, IEEE Canadian Conference, Montréal 1978, Cat. No. 78 CH 1373.0, Reg. 7.9. Malewski, R., Moore, W.J., Anderson, W.E., "Inter-laboratory Comparison ofInstrumentation Used for the Measurement of Losses in EHV Shunt Reactors", IEEETransactions, PAS-99, No. 4, 1980, pp. 1634-1641.10. Train, D., et al., “Decontamination of High Voltage Laboratory Following A PCB Fire”, IEEETrans. Vol. PWRD-2, Nr. 1, 1987, p. 77-86.8