A customer needs to purchase withstand voltage testing equipment for testing high-voltage GIS switchgear and high-voltage power cables . The core rated parameters are: output voltage 300kV and capacity 200kVA (power frequency withstand voltage test device, AC power frequency).
The customer requires a 300kV/200kVA power frequency series resonant/power frequency withstand voltage test system .
Breakdown of customer underlying needs
The test subjects were of two types:
- HV GIS (High Voltage Gas Insulated Switchgear) : GIS factory test, field acceptance withstand voltage test (main circuit power frequency withstand voltage, disconnector/grounding switch withstand voltage, gas chamber withstand voltage); voltage level corresponding to 220kV voltage level GIS (rated operating voltage 220kV, acceptance withstand voltage test voltage standard ≤300kV);
- HV cable (high voltage power cable) : High voltage cross-linked XLPE cable with cross-connection power frequency withstand voltage/conversion frequency resonant withstand voltage, suitable for 110kV~220kV high voltage cable after on-site laying and final testing.
Hard requirements for key electrical parameters
- Maximum output test voltage: AC 300kV (RMS, 50Hz) .
- Rated output capacity: 200kVA
- Application scenarios: On-site installation and handover testing (outdoor/substation site) , very few are manufactured for laboratory use, and the equipment needs to be portable/split-type.
Two mainstream equipment solutions are available to meet the testing requirements of
300kV/200kVA GIS + high-voltage cables (choose one for export pricing)
The industry offers solutions for traditional power frequency withstand voltage test transformers and variable frequency series resonant withstand voltage devices (the mainstream choice for overseas cables/GIS, and the preferred option) . 90% of overseas projects use series resonant (AC Resonant Test System) for high-voltage cables and GIS .
Option 1: Variable Frequency Series Resonant Test System [Preferred Choice, Standard Configuration for Overseas GIS + Cable Systems]
1. Complete set of equipment list & specifications matching 300kV/200kVA
| Equipment components | Specifications | effect |
| Variable frequency power supply (excitation source) | Rated input 380V/50Hz, output 0~400V inverter, power ≥60kW | Frequency and voltage regulation, the driver source for the entire system |
| Excitation transformer | Input 0~400V, output 10kV, capacity ≥200kVA | Boost Matching Resonant Reactor |
| High-voltage resonant reactor | Single reactor section: Rated voltage 50kV / Capacity ≈ 35kVA, 6 sections in series (50kV×6=300kV), total capacity ≥ 210kVA , meeting a 200kVA margin. | Series boost to 300kV, GIS/cable capacitive load resonant boost (cable is a capacitive load, resonant is the most power-efficient). |
| High voltage divider | 300kV pure capacitor voltage divider, accuracy ≤1%, with matching digital display instrument. | High-voltage precision measurement and overvoltage protection |
| Compensation capacitor (optional) | Suitable for 220kV cable high-capacity loads; generally not used in GIS testing. | Capacitive compensation for long-distance, large-section cables |
Advantages of application (key points to reply to customers)
- GIS and high-voltage cables are compatible : GIS is suitable for small capacitive loads and long-distance high-voltage cables with ultra-large capacitive loads. Resonance is naturally compatible with capacitive test samples and is a test equipment specified by international IEC and IEEE standards.
- Low input power: Only 60kW of mains power is required to achieve 200kVA high voltage output, making it highly adaptable to poor temporary power supply conditions at overseas construction sites;
- The equipment is modular and can be exported in containers or wooden crates, making sea freight convenient.
- Meets the international testing standards of IEC60840, IEC62067 (high voltage cables) and IEC62271 (GIS switches).
Option 2: Traditional dry-type power frequency test transformer (optional, only for small-scale projects, not recommended)
Configuration specifications:
- High-voltage test transformer: 300kV/200kVA dry-type integrated/split-type power frequency withstand voltage tester + high-power voltage regulator (220kVA induction voltage regulator) + 300kV capacitive voltage divider
Disadvantages (to be disclosed to the client)
The total input power is approximately 200kVA. A high-power external power supply is required on site. The power consumption of long-distance high-voltage cable testing is high and the equipment is bulky. It is rarely used in overseas cable projects and is only suitable for small GIS short test specimens.
5 key pieces of information that need additional verification (to avoid customization errors)
- Customer’s country’s power grid frequency: 50Hz (most of Asia and Europe) / 60Hz (parts of Southeast Asia and the Americas) , the frequency converter resonant power supply needs to be modified accordingly;
- The maximum single-segment length of the cable under test (determines the reactor margin).
- Rated voltage of the GIS under test (110kV/220kV);
- Local power supply voltage: 380V/415V three-phase input;
- Test execution standard (IEC national standard or local power standard).
Commercial Offer
Itemized pricing: Separate pricing for frequency converter, excitation transformer, reactor group, voltage divider, and accessories (connecting wires, equalizing galvanometer, grounding cable) + total price of the whole machine;
Trade terms: FOB Shanghai / FOB Ningbo / CIF port of destination (as per customer requirements);
Payment terms, delivery time, and warranty (international standard 18-month warranty);
Packaging: Export-grade fumigated solid wood crate/IP65 protective wooden crate packaging, suitable for sea freight.
DEMIKS Power Company is a professional HV Testing Equipment Supplier. If you have any HV Hi-pot testing demands welcome to contact our company via contact@demikspower.com
Thank you!
