HCTT-2×500kV/500kVA AC Test Transformer

Mode: HCTT 2x500KV/500KVA
Cylinder type, two modules
Single phase      Frequency: 50Hz
Rated Capacitance: LV Capacitance: 500kVA    HV Capacitance: 500kVA
Rated Voltage:    LV Voltage: 2*3kV;         HV Voltage: 2x500kV
Rated Current:    LV Current: 2*83.3A        HV Current: 0.5A
（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 ≤12%
Over Current Ability: Continuous working for 300S under 125% rated current (0.625A) no thermal damage or distortion to the winding.
Over Voltage Ability: Over voltage at 110% UH (1100kV) for 60s no any insulation damage for the testing transformer.
Noise: ≤65dB (Measure in 4meter distance with full load.)
PD Level: <5pC at 100%UH of complete test system; <2pC at 80%UH of complete test system;
Unevenness at 2 transformers in series: ≤±5%
 

Operating Time: (starting from environment temperature)
15min on, 15min off, 8 cycle per day at 100%UH, 100%IH, 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-250kVA/500kV
Cylinder type
Single phase
Frequency: 50Hz
Rated Capacitance: 250kVA                       
Rated Voltage: LV Voltage: 3kV        
HV Voltage: 500kV
Rated Current: exciting current: 83.3A      
HV Current: 0.5A
Impedance Voltage ≤4%
Waveform deviation ≤3%
Noise level ≤60dB (Measure in 4 meters distance)
Cooling: ONAN
Over Voltage Ability: Continuous working for 60S minutes under 110% rated voltage (550kV), then thermal damage or distortion of the winding shall not be occurred.
PD Level: <5pC at 100%UH of complete test system; <2pC at 80%UH of complete test system;
15min on, 15min off, 8 cycle per day at 100%UH, 100%IH, and temperature rise of transformer winding is less than 65K, temperature rise of oil surface is less than 55K.

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

 Lower Transformer
Type: HCTT-500kVA/500kV
Single phase
Type: Insulated Barrel, fixed structure
Frequency: 50Hz                           
Rated Capacity: LV capacitance: 500kVA                    
HV Capacitance: 2500kVA; Transfer capacitance: 250kVA
Rated Voltage: LV volt: 2*3kV  
HV Volt.:500kV   transfer volt: 3kV
Rated Current: LV Current: 2*83.3A  
HV Current: 0.5A   transfer current: 83.3A
Impedance Voltage: ≤4%
Waveform deviation ≤3%
Dividing Ratio of Measurement Winding: 1000:1
Noise level ≤60dB (Measure in 4 meter distance)
Cooling: ONAN
PD Level: <5pC at 100%UH of complete test system; <2pC at 80%UH of complete test system;
Over Voltage: Continuous working for 60S minutes under 110% rated voltage (550kV), 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:
5kV/1min (HV winding to LV winding measuring winding and transformer shell)
10kV/1min (LV winding to HV winding and transformer shell)
5kV/1min (measurement winding to LV winding, HV winding and transformer shell)

Electric Strength of Transformer Oil: 
- Dielectric Loss<0.5%（at 90℃）
- Without acetylene in oil; Solidifying point>40
Working time: 15min on, 15min off, 8 cycle per day at 100%UH, 100%IH, and temperature rise of transformer winding is less than 65K, temperature rise of oil surface is less than 55K.

Principle Diagram: