Three-phase frequency inverter UHV(W)

single-phasedigitaldigital display

Overview
The instrument is designed for installation and testing with the equipment in operation. A high-speed AD conversion circuit digitizes signals and detection data reliability is ensured by digital signal processing, adaptive filtering and interference suppression algorithms.

Application
No partial discharge variable frequency power supply is used for AC withstand voltage testing and partial discharge measurement of electrical equipment. Using an excitation transformer to drive a series or parallel resonant circuit and adjusting the output frequency causes the reactor inductance L and sample capacitance C to resonate; the resonant voltage is applied to the sample. Alternatively, the output can be routed through an intermediate transformer to the primary for induction withstand testing.

Technical parameters

• Rated input voltage: Three-phase AC 380 V ±10%, 50 Hz
• Rated output power: Single-phase 100 kW
• Output frequency range: 20 Hz–300 Hz (continuously adjustable)
• Rated output voltage: 0–350 V (continuously adjustable)
• Output current: 0–285 A (continuously adjustable)
• Frequency instability: ≤ 0.05%
• Voltage instability: ≤ 1.0%
• Nonlinear distortion: ≤ 1%
• Partial discharge capacity: ≤ 10 pC (measured on high-voltage side of booster)

Features

• Outputs a true sine wave with low waveform distortion (total harmonic distortion < 3%), avoiding the need for peak-value measurements required by shaped wave outputs.
• Fiber-optic control provides full isolation between high- and low-voltage control circuits.
• Compact dimensions and low weight enable flexible handling and on-site use.
• Simple wiring and operation; can improve on-site work efficiency compared with generator-set methods.
• Multiple protection functions: discharge breakdown protection, overvoltage setting protection, output short-circuit protection, startup zero-position protection, bridge-arm amplification protection, power-curve protection. When a protection is triggered the device disconnects the test output and cuts main circuit power.
• Signal source generated by a dedicated chip and managed by a microcontroller; output frequency stability up to 0.01 Hz.
• Variable-frequency output voltage controlled by a high-speed microcontroller; output voltage instability < 1%.

Routine maintenance

• Avoid prolonged operation under severe detuning conditions.
• Regularly inspect internal wiring and fastenings to prevent loosening.
• Store in a dry, clean environment protected from rain; cover with a dust cover when not in use.
• During transport secure the frequency-conversion cabinet with appropriate straps to prevent shifting.
• Do not expose the control-box display to direct sunlight; apply anti-vibration measures during transport.
• Handle connectors carefully to avoid damage and contamination.
• When using fiber-optic cables avoid bending, twisting or crushing; keep away from heat sources and store plugs/cables dry to prevent moisture.

Specifications

• Model / Series: UHV(W) Series
• Rated input voltage: Three-phase AC 380 V ±10%, 50 Hz
• Rated output power: Single-phase 100 kW
• Output frequency range: 20 Hz–300 Hz (continuously adjustable)
• Rated output voltage: 0–350 V (continuously adjustable)
• Output current: 0–285 A (continuously adjustable)
• Frequency instability: ≤ 0.05%
• Voltage instability: ≤ 1.0%
• Nonlinear distortion: ≤ 1%
• Partial discharge capacity: ≤ 10 pC (measured on high-voltage side of booster)
• Waveform distortion rate: < 3%
• Output frequency stability: up to 0.01 Hz
• Integrated protection functions (overvoltage, short circuit, breakdown, startup zero-position, bridge-arm protection, etc.)