How To Calculate The Energy Loss Of The Voltage Transformer Of Power Fittings?

How to calculate the power loss of Isolator switch voltage transformer?
The loss of voltage transformer is mainly no-load loss, which is related to the model and capacity of the transformer. For general electromagnetic voltage transformer, its no-load loss is about 10% of its capacity.
How many ways are there for secondary wiring of electric power hardware current transformer?
There are five ways for secondary wiring of current transformer: V-shaped wiring and differential wiring when two transformers are used; star wiring, triangle wiring, and zero-sequence wiring when three transformers are used. Different wiring methods are used according to different usage conditions.
What is the negative polarity of current transformer? Why should the polarity of transformer be measured?
The polarity of electric power hardware current transformer refers to the relationship between the direction of its primary current and secondary current. When the primary current flows in from the head end L1 and flows out from the tail end L2, the induced secondary current flows out from the head end K1 and flows in from the tail end K2. The magnetic flux direction generated by them in the iron core is the same. At this time, the current transformer is negative polarity.
Measuring the size and polarity of the current transformer is to prevent wiring errors, relay protection malfunctions, and inaccurate measurement.

What items should be checked before the power hardware voltage transformer is put into operation?
Before the voltage transformer is put into operation, it should be tested and qualified according to the handover test items of the relevant regulations. The specific inspection items are as follows.
(1) The appearance of the oil-filled transformer should be clean, the oil level should be correct, and there should be no leakage.
(2) The porcelain bushing or other insulating medium should not be cracked or damaged.
(3) The screws of the primary side lead and the secondary side circuit connection parts are tightened and the contact is good.
(4) The housing and the secondary circuit should be well grounded.