Design, Planning and Layout of high voltage laboratory

Presentationon

Design, Planning and Layout of high voltage laboratory

• Introduction

• Test equipment provided in high voltage lab

• Activity and study in high voltage lab

• Classification of high voltage lab

• Clearance of high voltage Lab

• Layout of high voltage lab

• Safety

• Shielding of the high voltage lab

CONTENT

Introduction

• In this industrial developing world the need of power is increasing exponentially thus to transfer high power at long distance is necessary.

• So the transmission at h.v is possible which is up to 720 kv and 1000kv.

• So extensively study is made on high voltage d.c. testing at 400 kv .

• Thus to perform tests and research the lab providing high voltage is needed.

• Transformers

• Lighting arrester

• Isolator and C.B

• Different type of insulators

• Cables

• Capacitors

• Line hardware and accessories

• Other equipment like reactors

Test equipment provided in high voltage lab

Activities and studies in high voltage laboratory

• Main is testing on equipment

• Other than it is research

• So research include

i. Breakdown strength of different material like solid ,liquid and gas.

ii.Electrical interference of transmission line.

iii.High voltage power system’s insulation.

iv.High current phenomena such as electrics arc and plasma physics.

Small size lab

Medium size lab: an industrial lab

Large size lab

Withstand Voltages, Test Voltages and the Ratingof Equipment in High Voltage Lab

• Generally up to 230 KV design it does not pose any problem but above 400 KV it is to be handle with care.

• For research and development work, the voltage levels needed are usually about 1.3 times the maximum test voltage needed. Hence, the laboratories intended for different system voltages should have the test voltages

Size and Dimensions of the Equipment In High Voltage lab• Mainly two type of lab:

1. indoor type & 2.outdoor type

• indoor type has the advantage of 1. protection of testing equipment against variable weather conditions, 2. simplicity in design and control of the test equipment, 3. provision of observation facilities during testing.

• outdoor laboratories have the advantage of1. less cost due to the absence of building cost and 2. the planned facility 3. layout cost

• But it has disadvantages 1. absence of lifting and supporting facilities, 2.reproducibility of results not being guaranteed due to uncontrolled atmospheric conditions, and 3.artificial and wet test studies which are difficult due to wind variation, etc.

• When high voltage laboratories are planned as indoor laboratories, the following figures fix the dimensions of the laboratories:

1. Size of the test equipment for a.c., d.c., or impulse generators.

2. Distances or clearances between the test object and ground during test conditions and also between all the high voltage terminals and earthed or grounded surroundings such as walls, roofs of buildings, and other test equipment not energized.

Clearance of HV Lab

a) For power frequency test

b) Lightning impulse clearance

c) D.C. Generator clearance

a) For power frequency test

• The 50% flashover voltage is expressed as,

• V50%=652 × d0.576 where, d –air-gap distance,

• For example,

1)For 1000 kV(rms) – d=3.835 m

2)For 1500 kV - d=7.754 m

3)For 2000 kV d=12.8 m

b) Lightning impulse clearance• Generally a clearance of 2 meters for each 1000 kV is necessary for lightning

impulse generator. Impulse flashover voltage is given by,

• V50= 500 × d for a rod plane gap.

• The withstand voltage can be assumed to be 80% of V50.

• It means, 2 meters gap will withstand 800kV(peak).

• For d.c. generators, a clearance of 4 meters for every 1000kV is recommended.

c) D.C. Generator clearance

Layout of high voltage lab

• Laboratory arrangements differ very much from a single equipment to multiple d.c., a.c., & impulse arrangements in different testing program.

• It is based on type of equipment to be tested, available space,other accessories needed for the tests……

• EARTHING, SAFETY and CONTROL GEAR is foremost consideration ……

Lab

build

ing

Shielding of the high voltage lab

• Safety is one of the most important requirements in a high voltage lab ,

• Proper operation of the high voltage lab include the presence of qualified personnel,

• The use of systematic procedures, safety ropes, signs, visual and audible warning & alarms, the use of grounding rods, the periodic review of safety rules, the availability of fire extinguishers, emergency phone numbers, first aid kit, and smoke alarm system.

• The walls, two supporting pillars and ceiling of the HV Lab require shielding with a system of interconnected modular steel sheet elements mounted on wood framework.

Safety