Secondly, Kwh watt-hour meter, TA 1~TA3 current transformer measure separately, and three-phase signal lamp power supply indicates.
Second, three-phase current measurement, TA 1~TA3 current transformer measurement respectively. Three-phase voltage indication and three-phase voltage measurement.
The circle+bar is the current transformer. 3 transformer+1 watt-hour meter, and the transformer provides current signals to the watt-hour meter respectively, which is called sub-meter measurement. The current transformer provides the measuring current signal to the ammeter independently, which is called independent measurement. PA is an ammeter, SA is a changeover switch, and PV is a voltmeter. In the third picture, SA 1 is a voltage transfer switch. The other is a current transfer switch.
structure
The application of automation technology in electrical system can form an automatic electrical control system. Automatic electrical control system can include three levels: the first is isolation level, the second is communication level, and the third is control level. As far as the first stage is concerned, cables need to be placed in the isolation room to realize signal control and line measurement.
As far as the second level is concerned, it is necessary to install various communication devices, promote the connection between substations and main stations, and realize data sharing among devices. As far as the third level is concerned, a network control system needs to be formed to manage each subsystem separately.