High-voltage hipot tester YDJ

DCAC

Product introduction
YDJ Series 50–300 kV oil-immersed test transformer consists mainly of a control box and an oil-immersed test transformer. It is designed for power-frequency AC and DC withstand voltage testing (Hipot) of cables, electrical components and insulating materials and can be supplied with higher kV or kVA ratings on request. The design emphasizes compact corona rings, minimized partial discharge and oil-cooling for continuous thermal management.

Product parameters
specifications and models | capacity(kVA) | High Voltage(kV) | high-tension current(mA) | low input voltage(V) | low input current(A) | transformation ratio | temperature rise ℃ (30 minutes)
YDJ-3/50 | 3 | 50 | 60 | 200 | 15 | 500 | 10
YDJ-5/50 | 5 | 50 | 100 | 200 | 25 | 500 | 10
YDJ-10/50 | 10 | 50 | 200 | 200 | 50 | 500 | 10
YDJ-20/50 | 20 | 50 | 400 | 400 | 50 | 500 | 10
YDJ-30/50 | 30 | 50 | 600 | 400 | 50 | 500 | 10
YDJ-50/50 | 50 | 50 | 1000 | 400 | 125 | 500 | 10
YDJ-5/100 | 5 | 100 | 50 | 200 | 25 | 1000 | 10
YDJ-10/100 | 10 | 100 | 100 | 200 | 25 | 1000 | 10
YDJ-10/25 | 10 | 25 | 400 | 400 | 25 | 1000 | 10
YDJ-20/100 | 20 | 100 | 200 | 200 | 50 | 1000 | 10
YDJ-30/100 | 30 | 100 | 300 | 200 | 75 | 1000 | 10
YDJ-50/100 | 50 | 100 | 500 | 200 | 125 | 1000 | 10
YDJ-15/150 | 15 | 150 | 100 | 200 | 37.5 | 1000 | 10
YDJ-20/150 | 20 | 150 | 133 | 200 | 50 | 1000 | 10
YDJ-30/150 | 30 | 150 | 200 | 200 | 75 | 1000 | 10
YDJ-50/150 | 50 | 150 | 333 | 200 | 125 | 1000 | 10
YDJ-100/150 | 100 | 150 | 667 | 200 | 250 | 1000 | 10
YDJ-50/200 | 50 | 200 | 250 | 200 | 125 | 1000 | 10
YDJ-100/200 | 100 | 200 | 500 | 200 | 250 | 1000 | 10
YDJ-150/200 | 150 | 200 | 750 | 200 | 375 | 1000 | 10
YDJ-200/200 | 200 | 200 | 1000 | 200 | 500 | 1000 | 10
YDJ-300/200 | 300 | 200 | 1500 | 200 | 750 | 1000 | 10
YDJ-50/300 | 50 | 300 | 170 | 200 | 125 | 1000 | 10
YDJ-100/300 | 100 | 300 | 333 | 200 | 250 | 1000 | 10
YDJ-150/300 | 150 | 300 | 500 | 200 | 375 | 1000 | 10
YDJ-200/300 | 200 | 300 | 667 | 200 | 500 | 1000 | 10
YDJ-300/300 | 300 | 300 | 3000 | 200 | 750 | 1000 | 10

Visual comparison (summary)
Comparison Dimension | Oil-immersed test transformer | Dry-type (epoxy-cast) test transformer | SF6 inflatable test transformer | Series resonance testing device
Insulating medium | Transformer oil (mineral oil) | Epoxy resin solid | SF6 gas | Dry-type / reactor combination
Maximum voltage per unit | Very high (applications up to several hundred kV or higher) | Lower (generally ≤ 35 kV) | High (up to ~300 kV) | Dependent on resonance setup
Volume and weight | Largest and heaviest (requires oil tank) | Lightweight and compact | Moderate (pressure vessel) | Very light (portable)
Cooling performance | Excellent (oil circulation) | Limited (natural cooling) | Moderate (gas convection) | Limited (intermittent use)
Fire risk | Present (oil is flammable) | Low (non-flammable) | Low (gas non-flammable but decomposition toxic) | Low (oil-free)
Maintenance cost | Higher (oil filtration, testing) | Very low | High (gas monitoring) | Medium

Product characteristics

• Oil-immersed high-voltage design with compact corona rings to reduce partial discharge.
• Advanced insulation materials and optimized windings for reduced size and weight relative to rating.
• Wide voltage range and configurable kV/kVA combinations to match test requirements.

Advantages

• Efficient oil cooling maintains thermal stability under load.
• Transformer oil provides high dielectric strength for short-duration high-voltage testing.
• Designed for long service life with routine maintenance (oil filtration and testing).
• High load capability suited to high-power testing tasks.

Main application areas

• Power system testing: high-voltage tests of transformers, switchgear and distribution equipment.
• Research and laboratories: development and routine testing of high-voltage equipment and insulating materials.
• Insulation testing of cables and components.
• Industrial automation and control: electrical testing and commissioning of equipment.
• Electrical safety verification and compliance testing to national/industry standards.
• Training and vocational education in power engineering.

Frequently asked questions

• Q: Why choose oil-immersed test transformers instead of dry-type for high-voltage testing? A: Oil provides both insulation and effective heat dissipation, allowing the transformer to withstand higher internal field strength and better suppress partial discharges for short-duration high-voltage outputs.
• Q: What is the difference between a 50 Hz test transformer and a series resonance device? A: A test transformer directly steps up voltage and is suitable for short cables and medium test objects; series resonance uses a reactor to compensate capacitive current and reduces required power supply capacity, often preferred for long cables or very large generators.

Technical specifications (summary)

• Series: YDJ oil-immersed high-voltage test transformers.
• Voltage range: typical models 25–300 kV (model-dependent).
• Capacity range: 3–300 kVA (model-dependent).
• Output type: AC and DC withstand voltage testing at power frequency.
• Cooling: oil circulation cooling.
• Typical low input voltage: 200 V or 400 V depending on model; input current varies by model.
• Temperature rise: typical value 10 ℃ at 30 minutes for many models (see model table).