Opening and closing current transformer
The open-close current transformer is based on the maxwelld electromagnetic field simulation model of ansoft software. The mechanism of the open-close transformer is analyzed according to the simulation function. The voltage waveform, transient flux and excitation current of the open-type transformer are followed by a voltage increase transition. The specific simulation graph and data are analyzed and the amplitude-frequency characteristics of the excitation current are analyzed by Fourier transform. 4 If the fuse test is changed, the 35kv feeder and the main transformer voltage loop fuses are unplugged to the center signal and low frequency disk. When an open circuit occurs, the increase in magnetic flux density and the vibration of the non-sinusoidal silicon steel sheet of the magnetic flux will increase the noise. u=uc , is u=uc =u 1 ?0?6c 1 /(c 1 +c)=kuu 1 (7- where ku -- partial pressure ratio, ku = c 1 / (c 1 + c) Since u is proportional to the primary voltage u 1 , u can represent u 1 and the relative ground voltage can be measured.
In the 1uxe type----the rated primary voltage of the open-close transformer. If a short circuit occurs, fuses should be used. In the case of a meter indication, there is sometimes no possibility of poor contact in a semi-open state. Figure 4 The second 4pt wiring secondary circuit diagram Fig.4 the second kind of elementary secondary circuit of 4 single-phase voltage transformer When single-phase grounding occurs, the output triangle output value will not be cut by this wiring, this At the time, the potential at point l is between the ground phase voltage and the ground potential 0 potential. Added to the fault phase pt, it simply pulls the potential of point l in the figure in real-time operation. Because of normal operation, the three-phase voltage is flat.
The secondary winding rated voltage of the open-close transformer is as follows: the main secondary winding of the winding is connected to the auxiliary secondary winding of the zero-sequence voltage. The normal voltage is connected to the normal voltage. The phase voltage is at the neutral point in the grid directly connected to the neutral point. Secondary voltage in a power grid that is not directly grounded or grounded via an arc suppression coil v 100 100/3 100 100/3 Capacity and exact grades The residual windings of the open and close transformers should meet the requirements of measuring instruments, care assembly and automatic assembly. .
<2> Open-type transformers for operation and monitoring, estimation of electricity meters, power meters and voltage relays in power plants, and the cutting grades are selected as Class 1. The winding of .91 v is not very good, because it is only close to the 100 V required by the voltage theory that occurs in the non-fault phase pt. The polarity of the current transformer is generally marked by the polarity reduction principle, that is, the purpose of the current in the secondary winding is opposite to the magnetic flux generated in the core. Generally, the rated capacity refers to the capacity corresponding to the highest cutting level. In systems where the neutral point is not grounded or grounded via an arc suppression coil.
<3> A meter for measuring the measured value, such as a voltmeter and a voltage relay with only one coil, has a cutting level of 3 levels. It is confirmed that because the secondary circuit is open to the neutral line, the interference signal enters and the third harmonic occurs in the secondary circuit.