Installation and precautions of zero sequence current transformer
The symbol of zero-sequence current transformer Zero-sequence current transformer is a kind of current transformer, used to detect neutral unbalanced current, generally used in cooperation with relay protection equipment. The meaning of electrical symbols is the same as that of general current transformers.
The zero sequence current transformer is a single-turn through-core current transformer, which is generally used with power protection equipment such as:
Small current grounding line selection equipment, microcomputer harmonic elimination equipment and other supporting use.
1. The zero-sequence transformer is a literal meaning to test the zero-sequence current.
2, the zero sequence current refers to the three-phase current vector
with. Under normal circumstances the sum is zero.
3. When the zero-sequence current is relatively large, it means that there is a fault in the system.
Use this to protect against tripping. Zero-sequence protection is often used in outlet cabinets of 10 kV and above.
A zero-sequence transformer must be installed. 1. According to the definition, it is known that it is the sum of three phases. Therefore, there is a through-core transformer at the bottom of the cabinet.
2. Then the secondary outlet of the zero-sequence transformer is connected to the protection device or current relay. Through protective equipment or relay, trip switch. Play a protective effect. Ready to go: The integral transformer should be installed before the cable is laid, and the cable should pass through the transformer when laying.