Discharge Coil Dry-Type
First. The purpose and scope:
When installed in a substation's shunt capacitor group that is ceasing operation, it is essential to have a discharge device to safely dissipate any internal charges. This ensures that the automatic control switching of capacitor banks occurs smoothly and within specified safety thresholds. Current domestic production often relies on internal discharge resistors, which frequently face quality issues and fail to meet performance standards. Thus, implementing a dedicated discharge coil is a crucial technical safety measure for parallel capacitor substations.
For the operational safety and reliability of shunt capacitors and their accompanying equipment, the use of a single-star connection for capacitor banks is highly recommended and has become a widespread wiring practice. This setup involves each discharge coil being directly paralleled with its respective phase capacitor bank, while the secondary winding forms an open delta connected with protection relays for unbalanced voltage protection. If any phase within the capacitor group experiences a fault or damage, the unbalance voltage protection can swiftly detect and disengage the capacitor from the grid, ensuring the discharge coil provides sufficient accuracy to uphold protection performance.
Within large-capacity capacitor banks, where capacitors are paralleled with significant individual capacities, original internal fuses typically isolate faults, allowing continued operation. However, capacity imbalance can result in electrical faults and affect non-fault-phase capacitor elements. Discharge coils, connected via intermediate taps to each phase capacitor, are critical for measuring line and tap voltages. With two independent secondary windings connected in a differential mode, these coils are integral to a robust differential protection setup. This ensures that any unwanted voltage rise triggers a safety switch, promptly disconnecting the capacitor from the grid. When large capacitors are used in series across multiple segments, or when a single-volume capacitor is chosen, traditional single external fuse protection may lack sensitivity. Here, the FDGRC discharge coil's precision in differential pressure measurement ensures high sensitivity, effectively safeguarding against internal faults. The high-voltage coil with a center tap A2, used in conjunction with shunt capacitors, serves as a differential protection system, optimizing fault protection.
The 10~35kV dry discharge coil is meticulously designed to fulfill all the aforementioned safety and performance requirements, making it an ideal choice for non-oil installation sites.
Forth. The structural features
1. The product harnesses an epoxy resin vacuum casting structure, completely eliminating the hazards associated with flammable oil leaks, ensuring a clean, oil-free operation.
2. With a simple yet robust structure, the product is designed for exceptional ease of installation and use.
3. This product is built with high mechanical strength, ensuring reliability and durability. Its epoxy resin vacuum casting process enhances both internal and external insulation, significantly improving the product's safety and reliability.
5. With minimal maintenance requirements, the product only necessitates wiping the discharge coil surface to remove any contamination during maintenance outages.
6. Leveraging advanced technology, the product boasts superior performance, fully aligning with JBT8970-1999 and DL/T653-2009 standards.
7. The product conforms to domestic power transmission site management requirements, being oil-free and offering excellent environmental benefits.
Fifth. Environmental Conditions
1. The installation location is strictly intended for indoor environments. 2. The ambient temperature must be within the range of -40°C to +55°C. 3. Ensure the altitude does not exceed 2000 meters. 4. The seismic levels at the installation site should not experience severe mechanical shocks. 5. The installation site should remain free from harmful gases, vapors, and non-conductive or explosive dust. 6. The relative humidity should be carefully monitored, with the monthly average not exceeding 90% and the daily average below 95%.
| Sixth.The main technical parameters |
| System nominal voltage |
10kV |
20kV |
35kV |
| Rated primary voltage |
11,11.5,12,12.5,
13,11/ √3,12 √3,
11/2 √3+11/2 √3,
12/2 √3+12/2 √3 |
21,23,22/ √3,
24/ √3,
11/ √3+11/ √3,
12 √3+12/ √3 |
38.5/ √3,40/ √3,
42/√3,43.3/ √3,
45/√3,11+11, 11.5+11.5, 12+12, 12.5+12.5, 13+13 |
| Rated secondary voltage |
100V,100V+100V,100V+100/ √3V,100/3V+100/ √3V |
| Single-phase matching capacitor capacity |
0.5~24Mvar |
| Phase /rated frequency |
Singular/50Hz |
| Rated output/accuracy class |
50VA/0.5 Class,100VA/1 Class |
| Wiring |
Less polar |
| Partia discharae |
≤20pC |
| Discharge performance |
When the capacitor bank power 5s,its terminal
voltage drops between 50V and below the √2U1N. |
| Insulation Level |
Rated frequency withstand
voltage(rms) |
35/42 |
55/65 |
80/95 |
Rated lightning impulse withstand
voltage(rms) |
75 |
125 |
185 |
| Withstand voltage between turns |
3 times the rated frequency,
2.5 times the rated voltage, which lasted 60s |
Seventh.
Installation and Transport Considerations
1. When connecting with the high-voltage terminal of the capacitor bank, it is recommended to use flexible cables. If using aluminum row connections, ensure the section does not exceed 30 x 4mm, and take measures to secure the terminal head telescopic site. 2. The discharge coil core and any exposed feet should be properly grounded. 3. The discharge coil mounting foot must be grounded, especially in the northern cold season, to facilitate routine maintenance and prevent high-side short circuits due to snow. 4. During transport, ensure the machine is balanced and not upside down. 5. Handle with care to avoid contact with hard objects or scratches. 6. Avoid secondary reverse polarity, short-circuiting the secondary circuit, and multi-point grounding. 7. If the product is side-mounted, covering up the secondary wiring is strictly prohibited. 8. To prevent water ingress, the product should be mounted with secondary wiring leads positioned lower, protecting against potential shorting.
Advanced Dry Type Technology
Reliable Oil Type Solution
Frequently Asked Questions
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Answer: We offer outstanding products at competitive prices with unparalleled service.
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Answer: Our ISO90001 certified factory is located in the thriving city of Yueqing, withinZ hejiang Province,People's RepublicOF China.
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3. Question: Can you provide OEM services?
Answer: Certainly, we possess the capability to offer OEM/ODM solutions tailored to your specific needs and requirements.
4. Question: What are the terms of payment?
Answer: We generally accept T/T, L/C, Paypal, or other methods upon discussion.
5. Question:What is the expected delivery time?
Answer: If we have stock available, delivery occurs within 3 working days.
For production orders, lead times range from 10-20 working days, depending on the order quantity.
6. Question: What are the available shipping methods?
Answer: Samples and small orders are shipped via international couriers like DHL, FEDEX, TNT, UPS, EMS, etc.
Large orders are delivered by sea or air, following buyers' shipping instructions.
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