HCTT-2×350kV /250kVA AC Test Transformer

Mode: HCTT 2x350KV/250KVA
Cylinder type, two modules,    Single phase,   Frequency: 50Hz
Rated Capacitance:LV Capacitance: 250kVA, HV Capacitance: 700kVA
Rated Voltage:LV Voltage: 2*0.6kV; HV Voltage: 2*350kV
Rated Current:LV Current: 2*208.3A, HV Current: 0.375A
(HV terminal of the transformer will be earthed through a current transformer 5/5 so as to check the current value of HV side and ensure safety of the operators and equipment.)
Waveform deviation ≤3%           Unload Current: IO<10%
Impedance voltage ≤15%
Voltage Ratio of Measurement Winding: 2000:1
Over Current Ability: Continuous working for 300S under 125% rated current, then thermal damage or distortion of the winding shall not be occurred.
Over Voltage Ability: Over voltage at 110% UH (770kV) for 60s., then it shall not happened any insulation damage for the testing transformer.
Insulation Level:10kV/1min(low voltage terminal to earth)
Noise: ≤60dB
PD Level: <5pC at 100%UH of complete test system;
Unevenness at 2 transformer in series: ≤±5%
Transformer Oil: 25# China made
Operating Time: (starting from environment temperature)

Working for 60 minutes allowed at 100% rated current & voltage;
Continuous working allowed at 80% rated current & voltage; and temperature rise of transformer winding is less than 65K, temperature rise of oil surface is less than 55K.
Protection: The surge arrestors 3kV shall be installed among excitation winding of the transformer and transfer winding for protection purpose.
Injection and release valve for transformer oil are available.

Upper Stage Transformer
Mode: HCTT-125kVA/350kV-II
Cylinder type,  Single phase,  Frequency: 50Hz
Rated Capacitance: 125kVA
Rated Voltage: LV Voltage: 0.6kV, HV Voltage: 350kV
Rated Current: Exciting current: 208.3A ,HV Current: 0.375A
Impedance Voltage ≤4.5%        Waveform deviation ≤3%
Dividing Ratio of Measurement Windings:1000:1
Noise level ≤60dB (Measure in 4 meters distance)
Cooling: ONAN
Over Voltage Ability: Continuous working for 60S minutes under 110% rated voltage, then thermal damage or distortion of the winding shall not be occurred.
PD Level: <5pC at 100%UH of complete test system;

Insulation of Winding to Earth:
>2500MΩ (HV winding to LV winding to earth);
>2500MΩ (LV winding to HV winding to earth);
Insulation Level: 10kV/1min (LV winding to HV winding and transformer housing)
Insulation Level: 5kV/1min (measurement winding to LV winding, HV winding and transformer housing)

Electric Strength of Transformer Oil:
- Breakdown Voltage>60kV/2.5mm Moisture<10ppm
- Dielectric Loss<0.5%(at 90℃)
- Without acetylene in oil; Solidifying point>40

Sub-Stage Transformer
Tyoe: HCTT-250kVA/350kV-I
Single phase,  Cylinder Type,  Frequency: 50Hz
Rated Capacity: LV capacitance: 250kVA, HV Capacitance: 125kVA,Transfer capacitance: 125kVA
Rated Voltage: HV Volt.:350kV, Transfer volt: 0.6kV
Rated Current: HV Current: 0.375A,Transfer current: 208.3A
Impedance Voltage: ≤4.5%         Waveform deviation ≤3%
Dividing Ratio of Measurement Windings:1000:1
Noise level ≤60dB (Measure in 4 meter distance)
Cooling: ONAN
PD Level: <5pC at 100%UH of complete test system;
Over Voltage: Continuous working for 60S minutes under 110% rated voltage, then thermal  damage or distortion of the winding shall not be occurred.

Insulation of Winding to Earth:
>2500MΩ (HV winding to LV winding and measurement winding to earth);
>2500MΩ (LV winding to HV and measurement winding to earth);
>2500MΩ (measurement winding to HV and LV winding to earth)
Insulation Level: 10kV/1min (LV winding to HV winding and transformer housing)
Insulation Level: 5kV/1min (measurement winding to LV winding, HV winding and transformer housing)    Electric Strength of Transformer Oil:
- Breakdown Voltage>60kV/2.5mm Moisture<10ppm
- Dielectric Loss<0.5%(at 90℃)
- Without acetylene in oil; Solidifying point>40 

Principle Diagram: