Automatic high voltage measurement

Project Title

Automatic high voltage measurement

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

Spark gap method is the most common method of measuring the peak values of high voltage. It is adopted as a standard by IEC and IEEE for calibration purposes. The breakdown strength of a gas (or air) depends on the ionization of the gas (or air) molecules, the density of the gas (or air), electrode field configuration and other factors. The breakdown voltage varies with the gap spacing and for a uniform field gap a high consistency could be obtained so that the spark gap is very useful as a measuring device. The breakdown voltage of the spark gap is dependent on humidity of the atmosphere, type of voltage being measured (AC, DC or impulse) and distance between gaps. In this project, stable spark gap is considered. Spark gap is placed in the vertical position, with lower electrode being earthed and upper electrode being connected to the high voltage. Peak values of voltages could be measured up to 500 kV by means of developed spark gap hardware. The values are corrected by applying appropriate correction factor for air density and comparison is made between experimental and calculated values for measuring 120 KV.

Project Objectives

Automatic measurement of HV by the method of Spark-gap

Design, simulation and fabrication of assembly

Maximum integration 

Modified design 

Enhanced efficiency 

Risk elevation

Loss reduction in measurement

Project Implementation Method

The deriving factor behind this project is the need for the development of high voltage measurement hardware by the method of spark gap for use in demonstration purposes and field work.

In electrical power system, high voltage power equipment is mainly subjected to spark over voltages. These over voltages are caused by the lighting strikes, switching actions and some other reasons and determine the safe clearance required for proper insulation level. Spark gap method is considered as standard method for the measurement of peak values of DC, AC and impulse voltages. Also spark gaps are widely used as protective device in electrical power equipment. Spark gap method is also used for measuring breakdown strength of an insulating material.

The main focus of the project is:

• • • To carry out the practical experiment of air breakdown in high voltage laboratory.
    • To study different high voltage measurement methods and their limitations.

• • • To find the air breakdown and electric field for different distances between electrodes.
    • To observe the performance characteristics of air breakdown with respect to gap spacing and electrode dimensions.
    • To analyze the critical effects on electric field relative to air density factor.

Benefits of the Project

Spark gaps are largely used to prevent voltage surges from damaging instruments. Spark gaps are employed in high-voltage switches, large power transformers, in power plants and electrical substations.

A spark-gap transmitter is a device that generates radio frequency electromagnetic waves employing a spark gap.

Special purpose, high-energy trigger-able spark gaps is significantly used to continuously switch high voltages and intensely high currents for specific periodic (pulsed) power applications, like pulsed lasers, rail-guns, fusion, ultra-strong pulsed magnetic field analysis, and within the triggering of nuclear bombs

In power system, high voltage power instrumentation is principally subjected with spark over voltage. These over voltage that are caused by the lighting strikes,

switching action additionally verify the safe clearance needed for correct insulation level. To avoid these issues in high voltage power instrumentation, spark gap technique is taken into account as a conventional way for the measurement of peak values of DC, AC and impulse voltage. This technique is employed for determining breakdown strength of insulating materials and considers the material which has greater breakdown strength. The sphere gap technique isn't complicated and therefore the accuracy is suitable. This technique is employed in high voltage power networks as a result of its benefits like less magnitude of current, low power loss, reduction in voltage drop at line electric impedance and provides higher voltage regulation.

Technical Details of Final Deliverable

Final Deliverable of the Project HW/SW integrated systemCore Industry OthersOther Industries Education Core Technology OthersOther Technologies Artificial Intelligence(AI)Sustainable Development Goals Industry, Innovation and InfrastructureRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	50000
Assembley	Equipment	1	15000	15000
external casing	Equipment	1	8000	8000
control instruments	Equipment	1	17000	17000
manufacturing cost	Miscellaneous	1	10000	10000