Surge arrester failure and ferroresonance in a medium voltage distribution system | |
| Author | Tassanai Siripala |
| Call Number | AIT Thesis no.ET-99-22 |
| Subject(s) | Electric power distribution Transients (Electricity) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. School of Environment Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Ferroresonance is the phenomena that can produces overvoltage, the violence may be enough to damage some equipment such as arrester which used to protect distribution transformer and also effect on the frequently breakdown of fuses and the flashover of the insulator. Nowadays this phenomenon is increasingly found because the high efficiency transformer, low loss, and underground cable, high capacitance, are generally used. Walailuk University also faces the ferroresonant overvoltage and lost 15 gapless arresters during energizing and de-energizing transformer. Ring main scheme is used for electricity supply configuration, of course underground cable is used to supply power to high efficiency transformer that scatter around the campus. Delta/Grounded-Wye connection is used, so ferroresonant circuit can be formed when single phase drop out fuse, which used for protection main circuit and sub-circuit, operates to energize or de-energize transformer. The overvoltage rise up to 3.4 p.u. which higher than TOV limit of 30 kV, 24.4 MCOV, 10 kA rating of arrester and temperature exceeds limit, the current that flows through the arrester is converted to heat. The incremental heat exceed the incremental power dissipation, the accumulated heat gradually increase and exceed the equilibrium and then arrester thermal run away is the result. Due to this system has already performed. Thus some method that can solve this problem may be too much cost such as rearrange position of transformer (change length of underground cable), change switching device from single phase type to three phase type. Switching when transformer has properly load is the cheap way but may be cause of load switching transient voltage. Operating switching device at the front of transformer before at the main or remote circuit can reduce the potential of ferro resonance occurring. |
| Year | 1999 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Surapong Chirarattananon ; |
| Examination Committee(s) | Yu, Cun Yi;Dhadbanjan, Thukaram |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |