High Voltage

Capacitances Potential Dividers Q. Explain With neat diagrams, why are capacitance voltage dividers preferred for high ac voltages measurement ? Q. With a neat sketch explain trigatron spark gap used in impulse generators. Are ideal for measurements fast rising voltage and pulses. Capacitances resistances is independent of frequency if their leakage resistances is high enough … Read more

Testing of Power Transformers Transformer is heart of power system. These are important and costly elements in power system. The transformers are provided with protection against faults due o lightening strokes, over voltages and short circuit In this topic only over voltages tests are discussed. These tests are tabulated in Table. Item Sr. No Test … Read more

Types of Medium Sizes of Laboratory Layout The layout of a h.v. laboratory is an important aspect for providing an efficient testing facility.  Laboratory arrangements differ very much from single equipment to multiple d.c., a.c., and impulse arrangements in different testing program. Each laboratory has to be designed individually considering the type of equipment to … Read more

Planning, Design and Layout of High Voltage Laboratory Q. What are the various factors to be considered while designing a High voltage laboratory? High voltage laboratories are an essential requirement for conducting various tests for the equipment. In addition, they are also used in the development work on equipment for conducting research, and for planning … Read more

Classification of HV Laboratories (As per Size and Rating) A Small Size Laboratory Medium Size Laboratory 1. A Small Size Laboratory A small size laboratory is one that contains d.c. or power frequency test equipment of less than 10 kW / 10 WA rating and impulse equipment of energy rating of about 10 kJ or … Read more

High voltage motor testing The tests to be conducted on high voltage motors are as below High Voltage DC Test Sustained low Frequency Tests High Frequency Test Surge or Impulse Test High Voltage DC Test A DC voltage about two times of the normal rated voltage is applied across the motor under test. The voltage … Read more

Radio Interference Measurement Due to various reasons the noise voltage is produced such as : Over head conductors subjected to high voltage stresses and abrupt changes in the climatic conditions. Bonding between the porcelain body of the solid insulator fitted on the metallic-pin. Binding of H.V. conductor to the body (grove) of the insulator body … Read more

Power Frequency Test Power Frequency Sparkover Test (Dry and Wet) The test setup is shown in Figure. A standard voltage source is used. This source is connected between live terminal and earth terminal of surge arrester. A voltage of 1.5 times rated voltage is applied to surge arrester consecutively for 5 times. Sparkover should not … Read more

Test of Cables 1. Thermal Duty Test Figure A Figure B For measuring temperature to find temperature rise either thermocouples, self resistance method or thermometer is used: In the above circuit thermocouple is used : In the test circuit a special transformer is used. This transformer has primary 230 V to 440 Volts rating when … Read more