High-voltage hipot tester UHV-300kVA/100kV

portableAC

Overview
The UHV(L) AC series resonant test system is engineered for AC withstand testing of large‑capacity electrical equipment (for example 11 kV / 30 MW hydro‑generators), cables, GIS, transformers and other high‑voltage apparatus. The modular system integrates an AC power source, excitation transformer, high‑voltage reactors (inductive tuning), high‑voltage divider and a DSP‑based control and measurement unit. It supports generator supply and on‑site use in a −10 °C to 40 °C range.

Main functions and advantages

• High‑voltage AC output range: 0–500 kV.
• Configurable withstand duration: 1–9999 s (user definable).
• Waveform distortion ≤ 2% to ensure high‑quality sine output.
• Automatic tuning: calculation of resonant frequency from sample capacitance and one‑click inductance/frequency matching.
• Multiple operating modes: fully automatic, semi‑automatic, manual.
• Protection functions: overvoltage, overcurrent, zero‑start and system detuning (flashover) protection.
• Real‑time data processing: voltage, current and frequency curves; automatic Q‑factor calculation; standardized test report generation.
• Low input power for large‑capacity tests via resonant amplification (example case: long‑distance 110 kV cable testing with significantly reduced power compared with traditional transformers).
• Modular adaptability to cover typical test classes (cables 6–500 kV, GIS 35–500 kV, transformers 10–500 kV).

Typical composition

• AC power source
• Excitation transformer
• High‑voltage reactors (inductive tuning)
• High‑voltage divider
• Control and DSP measurement unit

Applications and use cases
Factory acceptance testing for GIS and transformers, sample testing for cable manufacturers, field commissioning and maintenance of generators and underground cable projects, batch cable testing and preventive tests for renewable energy collector lines. Suitable for remote/outdoor work due to modular design and generator supply capability.

Technical notes — resonance modes
The product supports two principal series resonance approaches: inductive series resonance (adjust inductance while holding frequency and capacitance constant) and frequency‑modulation series resonance (vary output frequency/power to reach resonance). Each approach offers different advantages for reactor combination and operational flexibility.

AC withstand voltage test parameters — Rubber cable lines
Rated voltage U0/U (kV) | Test voltage | Time (min)
18/30 and below | 2U0 | 15 (or 60)
21/35–64/110 | 2U0 | 60
127/220 | 1.7U0 (or 1.4U0) | 60
190/330 | 1.7U0 (or 1.3U0) | 60
290/500 | 1.7U0 (or 1.1U0) | 60

AC withstand voltage test parameters — Cross linked polyethylene (XLPE) cable lines
Rated voltage U0/U (kV) | Test voltage (new operational lines ≤3 years / non‑new operational routes) | Time (min)
48/66 | 2U / 1.6U | 60
64/110 | 2U / 1.6U | 60
127/220 | 2U / 1.7U (non‑new) / 1.36U (other) | 60
190/330 | 2U / 1.7U | 60
290/550 | 2U / 1.7U | 60

Common Q&A (selected)

• Q: What is the difference between series resonance and DC withstand tests? A: Series resonance is used for AC withstand testing under simulated operating conditions; DC tests evaluate DC dielectric strength and DC‑related defects.
• Q: How can resonant voltages reach very high values? A: Resonant circuits transfer energy between inductance and capacitance, enabling voltage amplification at resonance with lower input power.
• Q: What causes inaccurate results? A: Power fluctuations, incorrect resonance frequency, environmental interference or improper operation.
• Q: Is calibration required? A: Yes, regular calibration per metrological requirements is recommended.

Technical specifications

• Designed test targets: up to 11 kV / 30 MW hydro‑generators and smaller; cables, GIS, transformers and other high‑voltage equipment.
• Maximum output voltage: 0–500 kV AC.
• Withstand duration range: 1–9999 s (configurable).
• Waveform distortion rate: ≤ 2%.
• Automatic tuning: yes (resonant frequency calculation and inductance/frequency auto‑match).
• Operating modes: fully automatic, semi‑automatic, manual.
• Protections: overvoltage, overcurrent, zero‑start, system detuning (flashover) protection.
• Working temperature range: −10 °C to 40 °C.
• Power supply adaptability: supports generator supply for field operation.
• Typical applied voltage classes: modular coverage for 6–500 kV equipment.