- The phase detector has strong anti-interference performance and can adapt to various electromagnetic field interference occasions
- Dary Electric recommends
- The phase detector, also known as a phase verifier, can be used for phase verification and phase sequence verification in power lines and substations. It has functions such as phase verification, phase sequence measurement, and voltage detection, and has strong anti-interference performance, complying with
- (EMC) standard requirements, adapting to various electromagnetic field interference occasions. The phase detector has changed the previous contact measurement method, eliminating the danger of contact measurement, effectively ensuring the personal safety of measurement personnel. The measurement method is simple and the measurement results are reliable.
- The internal insulation of the transformer in the phase detector operates under working voltage for a long time. Especially with the increase of voltage level, the electric field strength that the insulation bears is very high, and partial discharge is easily generated at weak insulation points. The reason for partial discharge is: the electric field is too concentrated at a certain point, or the electric field strength at a certain point is too high. In different dielectric combinations, there is severe electric field distortion at the interface. The traces of partial discharge often only leave a small spot on solid insulation, or branch-shaped burn marks. In oil, some decomposed small bubbles appear.
Although the partial discharge time of the phase detector is short and the energy is small, it is very harmful. Its long-term existence will cause significant damage to insulation materials. First, the insulation materials near the partial discharge are directly bombarded by discharge particles, causing local insulation damage. Second, the heat, ozone, nitrogen oxides and other active gases generated by the discharge have chemical effects, causing local insulation to be corroded and aged, increasing conductivity, leading to thermal breakdown. In operating transformers, the aging and damage of internal insulation often start from partial discharge.
To determine which phase of A, B, C three phases a wire is, it is necessary to know the standard phase value of phase A φa, the standard phase value of phase B φb, and the standard phase value of phase C φc.
If the phase of a wire is φa, it is phase A, and so on. The voltage expression is Ua=A*sin(w*t+φa). The vector expressions of the three-phase line ABC have the same amplitude A and angular velocity w, only |φa-φb|=|φb-φc|=|φc-φa|=120°. The phases A, B, C are based on the standard phase values φ. Simple understanding: assuming φa=0°, φb=120°, φc=240°, if you measure a line's phase value as 120°, it is phase B.
Before use, it is necessary to correctly connect the power of the transmitter of the device, and also turn on the power of the transmitter. If the installation distance of the transmitter from the ground is less than thirty centimeters, the receiving sensitivity will be affected to some extent. After turning on the power switch of the receiver, you should also turn on the test button, so that the receiver will enter.
