Renewable Energy Grounding Transformer-13.2kV, 13.8kV, 24.94kV, 34.5kV

1.Renewable Energy Grounding Transformer Product Overview
The 6kV, 10kV, and 35kV power grids in the power system generally adopt a neutral point ungrounded operation mode. The low-voltage side of the main transformer in the power grid is generally connected in a delta configuration, and there is no neutral point that can be grounded. With the continuous expansion of urban power grids and the increasing number of cable outlets, the system's capacitance current to ground increases sharply, and the capacitance current flowing through the fault point after single-phase grounding is relatively large (exceeding 10A). In order to reduce the ground capacitance current during single-phase grounding faults, compensation devices such as arc suppression coils need to be installed at the neutral point of the transformer. Therefore, a neutral point needs to be artificially established to connect the arc suppression coil at the neutral point, reduce the ground short-circuit breaking current, and improve the reliability of the system power supply.
In addition, single-phase grounding is a common fault during the operation of the generator, and the occurrence of arc grounding at the fault point will further expand the insulation damage of the stator winding. The high resistance grounding of the neutral point of the generator can effectively suppress the grounding fault current of the generator, thereby preventing the stator winding of the generator from burning out and reducing the transient overvoltage of arc grounding. For this purpose, our company has developed a motor neutral point grounding resistor cabinet for single-phase grounding faults in motors. It mainly consists of a single-phase grounding transformer and a resistor, which can effectively avoid damage to the generator stator winding and insulation caused by grounding current.
2.Renewable Energy Grounding Transformer Product Features
Our company produces professional 6kV, 10kV, 20kV, and 35kV Renewable Energy Grounding Transformer, including epoxy cast dry-type and oil-immersed grounding transformer, as well as single-phase grounding transformers specifically designed for motors.

A. Iron core

High quality cold-rolled oriented silicon steel sheets are used, with 45 ° full diagonal joints. The iron yoke is clamped with a through screw, and the core column is tied with fiberglass tape. The surface of the iron core is sprayed with silicone resin adhesive to prevent moisture, tighten and minimize noise.

B. Winding

Both the inner and outer windings are made of high-quality copper wires, with a segmented cylindrical structure to enhance interlayer insulation. Vacuum drying technology is used, and the formed windings have good electrical performance, high mechanical strength, and low local discharge capacity.

C. Epoxy resin is not filled with vacuum casting for dry-type grounding transformers, which has stronger smoke and water resistance compared to non encapsulated products. The oil-immersed grounding transformer adopts a fully sealed structure and uses corrugated fins for heat dissipation to eliminate the oil storage tank. The oil tanks are sealed with oil resistant rubber strips to prevent the transformer oil from coming into contact with air. The transformer oil does not come into contact with air, ensuring the insulation performance and service life of the product. The product has the characteristics of small footprint, beautiful appearance, and maintenance free.
D. Protective device
Oil-immersed grounding transformer are equipped with pressure relief valves and gas relays, as well as oil level gauges for easy monitoring of transformer oil levels at any time. The dry-type grounding transformer is equipped with a temperature control device and has remote transmission function, making it convenient to inspect the operating temperature of the product at any time.

3. Renewable Energy Grounding Transformer Main Technical Parameter

Note:  

• Neutral Short time Current I0=IG, Neural Zero Sequence Impedance Z0=Zphase /3±5% off load tap change switch
• Declare Z0 before producing if not a self-limiter Z0 tolerance ≤10%
• If a resistor will be connected between the brought out Neutral and ground, choose Z0 as small as possible, and better make Z0+R= VLN/IG

SJD-Dry or Oil-immersed Grounding Transformer(Popular products)