A PHASE FAULT DETECTOR FOR POWER TRANSFORMER

ABSTRACT

A power  transformer is a very  simple device. It  is a vital  link in the  electronic  distribution  system. A power transformer is associated with faults. 

The design and construction of the phase fault detector is to provide simple, reliable and comprehensive electrical phase fault detections and response system. The system  includes  means for  detecting  any of the  various electrical  faults, such  as  impermissible  low voltage  levels, impermissible  high  voltage  levels, phase dropouts, single  phasing , phase reversals and or total   power loss. The construction  of a   phase fault  detector provides fault detections customized  to the  power transformer, providing  power cut- off at  an appropriate  time  after a given  fault  is detected. The system  is able  to  provide  the fault detections  without  the  need  for electrical  power  of its own. Its operations are also independent of line   voltage, batteries or back-up generators. This feature of independent is achieved by the use of a pneumatic arrangement for interrupting power to the equipment.

The fault detection system is comprised of a power supply source, which contains a signal transformer, a rectifier, a filter and regulator units. The detection circuit or unit is comprised of a processor. The  processor  unit   consist of a sensor (buzzer) and a detector  (LED) and an oscillator circuit)  the  detection   circuit  also  involves  a soft touch  switch  and a relay  which  is meant to control  the  energization  of the  transformer. The fault in the system is initiated through the soft-touch switch, which operates the relay. The relay is normally open, and there is no power in the power transformer. The secondary of the power transformer is connected to a lamp (bulb) which is the load to the transformer and as well the indicator of the fault to the system.

According, an object of the construction  is to provide  an improved fault  diagnosis system  for power transformer, which  makes it possible  to  instantaneously  detect the timing  or condition  of  occurrence  of a fault and portion  of the system  in which  the fault has taken  place.

To this end, according to the present invention, there is provided or fault detection system for power transformer in which, in the event of a failure, the self detection function of one of the electronic devices transmits a code signal indicative of the faulty part. The code signal is directly received  by the  processor which  in turn  operates  the system  while  activating  an aural   alarm so as  to indicate  the  occurrence  of fault.

In this fault detection system, when a fault has taken place in the sensor, the actuator, the associated  electronic devices detects the fault by its self diagnosis function   and produces the fault detection  signal representing  the result of the self- diagnosis.

During this project, a device is going to be constructed which  senses  and detects faults in the power transformers and this device  will be  known  as a phase - fault detector. The detector will monitor sense and detect the various faults associated with power transformers.