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Differential Voltage Discharge Coils

China Differential Voltage Discharge Coils, Find details about China Discharge Coil, Differential Voltage Protection from Differential Voltage Discharge Coils

Model NO.
Differential voltage protection
Usage
Single-phase Transformer
Frequency Characteristics
Power Frequency
Shape of Core
Ring
Brand
Jingcheng Electric
Trademark
Jingcheng electric
Transport Package
Wooden Package
Specification
FDGE35
Origin
China
HS Code
8504909000
Model NO.
Differential voltage protection
Usage
Single-phase Transformer
Frequency Characteristics
Power Frequency
Shape of Core
Ring
Brand
Jingcheng Electric
Trademark
Jingcheng electric
Transport Package
Wooden Package
Specification
FDGE35
Origin
China
HS Code
8504909000
Introduction of discharge coil
The discharge coil is used in power system to connect with high voltage shunt capacitor, so that the residual charge of capacitor bank after being cut off from power system can be released rapidly. Therefore, the installation of discharge coil is a necessary technical safety measure for shunt capacitors in substation, which can effectively prevent switching overvoltage and over-current endangering equipment safety due to the capacitor still carrying charge when the capacitor bank is switched on again, and ensure the safety of maintenance personnel. This product has secondary winding, which can be used for line monitoring, monitoring and secondary protection.
Discharge coil is a common discharge element in capacitor cabinet. Sometimes, discharge coil will be replaced by discharge Pt. Whether discharge coil or voltage transformer is used for capacitor discharge mainly depends on the capacity of capacitor. Generally, voltage transformer can be used for discharge of small capacity capacitance, and discharge coil must be used for large capacity capacitance.
The discharge coil is suitable for 35kV and below power system and connected with high voltage shunt capacitor bank in parallel
The residual voltage of the capacitor can reach the required value within the specified time. The secondary coil can be used for line monitoring
Principle of discharge coil
Discharge coil is a common discharge element in capacitor cabinet. Sometimes, discharge coil will be replaced by discharge Pt. Whether discharge coil or voltage transformer is used for capacitor discharge mainly depends on the capacity of capacitor. Generally, voltage transformer can be used for discharge of small capacity capacitance, and discharge coil must be used for large capacity capacitance.
When the capacitor is out of power, the discharge coil acts as a discharge load to quickly discharge the residual charge at both ends of the capacitor. In standard, the high voltage seems to require the capacitor to exit. The terminal voltage of the capacitor should be less than 50V within 5 minutes.
During operation, the discharge coil is used as a voltage transformer, and the secondary winding is often connected into an open triangle,
So as to provide protection for internal fault of capacitor bank (PT on bus cannot be used). We often say open triangle protection and unbalanced voltage protection of capacitor bank, and zero sequence unbalanced protection is actually this kind of protection.
This kind of protection is widely used in 10kV single Y connection capacitor bank.
Function of discharge coil in high voltage compensation device
Ordinary electricians will hear about this kind of experience. After one or two days of power failure, they went to repair the capacitor, but they were shocked. When your power grid is cut off, the capacitor can store electric charges. In order to prevent people from being hit by electricity,
So add a discharge coil to reduce the voltage of the capacitor bank to the specified voltage in the specified time, so as to ensure the safety of people. In fact, the principle is that a coil will discharge several poles of the capacitor together, consuming the internal storage charge of the capacitor.
The setting out coil has two functions. During normal operation, it monitors whether the three-phase voltage is balanced. When it is out of balance, an open delta voltage is generated and the voltage relay is input. Then the protection action can select trip or alarm. When the capacitor is cut off, the voltage at the capacitor terminal can be reduced to below 50V within 5 minutes for the safety of maintenance personnel.
It is said that the input time must be more than 5 minutes, so as to avoid the superposition of the power supply on the capacitor, burning the capacitor, or using electrical appliances. This is without scientific basis. The limit of switching times is realized through the secondary control logic software.
Discharge coil
The discharge coil is used in power system to connect with high voltage shunt capacitor, so that the residual charge of capacitor bank after being cut off from power system can be released rapidly. Therefore, the installation of discharge coil is a necessary technical safety measure for shunt capacitors in substation, which can effectively prevent switching overvoltage and over-current endangering equipment safety due to the capacitor still carrying charge when the capacitor bank is switched on again, and ensure the safety of maintenance personnel. This product has secondary winding, which can be used for line monitoring, monitoring and secondary protection.
Discharge coil is suitable for 66kV and below power system. It is connected with high voltage shunt capacitor bank in parallel, so that the residual charge of capacitor after being cut off from the power system can be released quickly. The residual voltage of capacitor can reach the required value within the specified time. With secondary coil, it can be used for line monitoring. Discharge coil is a common discharge element of capacitor cabinet, sometimes it will be used for discharge
Instead of Pt, the discharge coil or voltage transformer is mainly determined by the capacity of the capacitor. Generally, the discharge of small capacity (< 1.7mvar) capacitor bank can be discharged with voltage transformer, and the large capacity capacitor bank (≥ 1.7mvar) must use discharge coil, otherwise the voltage transformer will be burned or exploded.
When the capacitor is out of power, the discharge coil, as a discharge load, will rapidly discharge two capacitors
In order to meet the need of automatic switching for 5 times in 5min. The standard requires that the terminal voltage of the withdrawn capacitor should be less than 50V within 5 seconds.
The outlet ends of the discharge coil are connected in parallel with the two outlet terminals of the capacitor bank
By the voltage of capacitor bank, the secondary winding reflects the primary transformation ratio, and the accuracy is usually 0
50VA / 0.5 grade,
It can operate for a long time under 1.1 times of rated voltage. The secondary winding is usually connected with an open delta or phase voltage differential to protect the internal faults of the capacitor bank
Pt on bus bar). We often say that the open delta voltage protection and unbalanced voltage protection of capacitor banks are actually such protection.

 

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