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Madhu Palati ¹

Affiliations
1 Assistant Professor, Department of EEE, School of Engineering and Technology, Jain University, Jakkasandra Post, Kanakapura Taluk, Ramanagara District, Karnataka -562112, IN

Abstract

Rectangular pulses of short duration find more importance in applications like charged particle accelerators, microwave sources, Lasers and microbial deactivation in food. Rectangular pulses of short duration in the order of few microseconds are generated commonly by using pulse forming networks. In the present work, a low voltage, type-B Pulse Forming Network (PFN) for generating rectangular pulses of duration 1.8 μs is designed, and developed. Simulation is carried out in PSPICETM and the effect of first and last stage inductances on the overshoot of the output waveform is studied. The characteristic impedance of the type-B PFN is 10 Ω. Load impedance is chosen as 10 Ω to discharge maximum energy of the generated pulses effectively into the load circuit. A low voltage rectangular pulse of output voltage of 560 V and duration 1.6 μs is achieved experimentally

Keywords

Type-B pulse forming network, low voltage rectangular pulses, overshoot, characteristic impedance, pulse width and PSPICETM.

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Madhu Palati ¹

Affiliations
1 Assistant Professor, Department of EEE, School of Engineering and Technology, Jain University, Jakkasandra Post, Kanakapura Taluk, Ramanagara District, Karnataka - 562112, IN

Abstract

Power is transmitted at high voltages to reduce the transmission losses. Power transformer is used at generating and intermediate substations to step up and step down the voltage to the required levels. Transformers above 10 MVA are fitted with air cell in conservator. Non-linear loads connected to the system induce harmonics into the system resulting in rise in hot spot temperature and oil temperature which dictates the ageing of insulation. This paper discusses in detail the need of air cell in conservator, advantages and causes for the failure of Air cell.

Keywords

Conservator, Air Cell, Hot Spot Temperature, Ambient Temperature, Top Oil Temperature, Insulation, Breather And Oil Gauge.

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Madhu Palati ¹

Affiliations
1 *Research Scholar, Department of Electrical & Electronics Engineering, School of Engineering and Technology, Jain University, Bangalore-560041, IN

Abstract

This paper discusses the characterization of 200 kV, 20 J mini Marx generator. Marx generators are extensively used in very high voltage fast pulse generation. Capacitors are the major components of Marx generator, apart from the capacitance of the capacitor the other parameters such as internal inductance (Equivalent series Inductance) and Equivalent series resistance (ESR) has significant effect on the output current waveform. The internal inductance of the capacitor, ESR and the discharge path to the load circuit has to be kept as minimum as possible so as to achieve lower characteristic impedance, higher peak current, faster rise time and reduced Full Width Half Maximum(FWHM). Therefore there is a need to determine the internal inductance and ESR of Marx generator. Short circuit discharge test is conducted on the Marx generator to determine the value of total inductance of Marx generator during erection. From the determined value of total inductance of Marx generator L_T and erected capacitance of the Marx C_T, ESR is estimated from the PSPICE circuit. Also maximum output of Marx is estimated using the PSPICE circuit.

Keywords

Marx Generator, Capacitor, Equivalent Series Inductance, Equivalent Series Resistance, Full Width Half Maximum, Characteristic Impedance, Short Circuit Discharge, PSPICE Software.

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Aditya Bafna ¹, Nirmal Shankar ¹, Ashish Jain ¹, Pravin Kothari ¹, Madhu Palati ²

Affiliations
1 B.E., Students, IN
2 Assistant Professor, Dept of Electrical & Electronics Engg, School of Engineering and Technology, Jain University, Bangalore, IN

Abstract

Insulating materials subjected to electrical and thermal-electrical stresses exhibit life line characteristics which show a tendency to reach an electrical threshold. Their fit is investigated with reference to several sets of data derived from accelerated life tests performed on different insulating materials.

Life line models provide the estimates of failure time percentiles at selected probabilities and stresses so that life curves at fixed failure probabilities can be drawn. These characteristics should help in the choice of compatible thermal and electrical stresses for the design of insulation systems, apparatus and components.

The tests to be conducted to plot the characteristic curves involve Class B insulation (up to 8 specimens) under three active stress levels. Subsequently, using the data acquired, the Weibull probability distribution curves are plotted using STATISTICA software.

Keywords

Scale parameter, Shape parameter, Endurance coefficient, Failure time probability, Weibull distribution.

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