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What are you looking for?
Lower input power requirement
Pure AC Sine Wave at output
Easy to combine reactor to output different voltage.
Through the reactor of the combined device, it can output stable AC high voltage, which is mostly used for AC voltage withstand test of on-site electrical equipment, such as cross-linked cables, transformers, GIS, motors and generators.
According to different users, different tested equipment, different test requirements, the device can be customized according to needs.
product names: Ac voltage resonant device、Variable frequency resonant、Frequency conversion series resonance、Series resonance、Series resonant transformer、Frequency conversion series resonance voltage withstand device for electrical equipment、Series resonance test equipment、Complete equipment for frequency conversion series resonance test.
Cables
GIS
Motors and generators
Other Possible Applications (Transformers, CTs, PTs; Bushings; PD Testing)
vs.Traditional Power-Frequency Test Transformers
Compact & Lightweight: Conventional transformers require bulky power supplies for high-voltage output. Series resonance uses frequency conversion to reduce power supply capacity needs, cutting weight by over 60% for easy onsite deployment.
High Adaptability: Auto-adaptation to test object capacitance (cables, GIS, generators) by adjusting frequency (30-300Hz). Eliminates capacity limitations of traditional transformers with high capacitive loads.
Energy Efficiency & Safety: In-phase current/voltage during resonance minimizes energy consumption (70% less). Advanced overcurrent/overvoltage protection reduces insulation damage risks.
vs.VLF (Very Low Frequency) Systems
Faster Testing: VLF requires prolonged testing (e.g., 15 mins at 0.1Hz ≈ 1 min at 50Hz). Series resonance uses near-power-frequency output, cutting test time by 80% while complying with IEC/IEEE accelerated aging standards.
Accurate Diagnostics: Pure sinusoidal waveforms under resonance reveal true insulation defects, avoiding misjudgment caused by VLF waveform distortion.
Multi-Application Support: Covers cable AC withstand, transformer induced voltage, and GIS tests. VLF is limited to partial cable types.
Control Unit: Converts 50/60Hz grid power to adjustable frequency (30-300Hz).
Excitation transformer: Boosts converter output to energize reactors.
High voltage resonant reactor: Tunable inductance (series/parallel) to form resonant circuit with test object capacitance (C).
Capacitive voltage divider: Monitors high-voltage output with ±1% accuracy for closed-loop control.
Output voltage | 0-500kV and below |
Output frequency | 20-300Hz |
Output waveform | Sine Wave |
High voltage measurement accuracy | 1.0％ |
Frequency resolution | 0.01Hz |
Duty Cycle | 60 min ON / 30 min OFF |
Insulation level | 1.2U0/1min |
Power Supply | Single-phase 220V or three-phase 380V±10%,50/60Hz±2% |
Typical product data
Model | Rated capacity | Rated voltage | The main purpose |
ESR-800(160/60） | 160kVA | 0-60kV | 1. Meet the 10kV/400mm² cable 3.0km, capacitance ≤1.25µF, test frequency 30-300Hz, test voltage ≤17.4kV, test time ≤15min. |
ESR-800(240/130） | 240kVA | 0-130kV | 1. Meet the 35kV/400mm² cable 2.0km, capacitance ≤0.418µF, test frequency 30-300Hz, test voltage ≤52kV, test time ≤60min. |
ESR-800(1800/600） | 1800kVA | 0-600kV | 1. Meet the 400kV transformers, circuit breakers, GIS and other AC withstand voltage test, test voltage ≤600kV, test frequency 30-300Hz, test time ≤60min. |
ESR-800(4000/800） | 4000kVA | 0-800kV | Meet the 765kV transformer AC withstand voltage test, test voltage ≤800kV, test frequency 30-300Hz, test time ≤60min. |
