HCTT-2x500KV/300KVA AC Test Transformer

Mode: HCTT 2x500KV/300KVA

Cylinder type, modules structure
Single phase
Frequency: 50Hz
Rated Capacity: 300kVA                                   
Rated Voltage: excitation winding: 2*0.6kV;        HV winding: 1000kV
Rated Current: excitation current:  2*250A        HV Current: 0.3A
(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%
Voltage Ratio of Measurement Winding: 2000:1
Over Current Ability: Continuous working for 300S at 125% rated current (0.375A), then thermal damage or distortion of the winding shall not be occurred.
Over Voltage Ability: Over voltage at 110% UH (1100kV) for 60s, then it shall not happened any insulation damage for the testing transformer.
Insulation Level: 5kV/1min(low voltage terminal to earth)
Noise: ≤60dB
PD Level: <3pC at 50%UH of complete test system.
Unevenness at 2 transformers in series: ≤±5%
 

Operating Time: Working for 60 minutes allowed at 100% rated current & voltage; 5min on, 10min off at 760kV, 0.2A everyday 5 cycle; 5min on, 5min off, at 460kV 0.1A, 10 cycle per day; and temperature rise of transformer winding is less than 65K, temperature rise of oil surface is less than 55K.
Protection: The 0.6kV surge arrestors 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 300KVA/500KV 
Cylinder type
Single phase
Frequency: 50Hz
Rated exciting capacity: 150kVA
HV capacitance: 150kVA                       
Rated exciting voltage: 0.6kV        
HV Voltage: 500kV
Rated exciting current: 250A      
HV Current: 0.3A
Impedance Voltage ≤4%
Waveform deviation ≤3%
Dielectric loss <0.5%
Noise level ≤60dB (Measure in 4 meters distance)
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 (550kV) for 60s., then it shall not happened any insulation damage for the testing transformer.
Partial discharge level: <3pC at 50%UH(250kV)
Working for 60 minutes allowed at 100% rated current & voltage; and temperature rise of transformer winding is less than 65K, temperature rise of oil surface is less than 55K.
Winding to ground insulation:HV Winding to LV winding, measuring winding and ground >2500MΩ
                                                     LV Winding to HV winding, measuring winding and ground >2500MΩ
                                                      Measuring Winding to LV winding, HV winding and ground >2500MΩ
Insulation level: test transformer LV input winding to ground withstanding level: 10kV/1min; Test transformer measuring winding to LV, HV winding and shell withstanding level: 5kV/1min

Lower Stage Transformer
Type: HCTT 250KVA/500KV
Single phase
Type: Insulated cylinder, fixed structure
Frequency: 50Hz                           
Rated Capacity: Exiting capacity: 250kVA
HV Capacity: 250kVA
Transfer capacity: 100kVA
Rated Voltage: Exciting volt: 2*3kV  
HV Volt.:500kV   
Transfer volt.: 3kV
Rated Current: Exciting current: 2*166.7A  
HV Current: 0.5A  
Transfer current: 166.7A
No-load current <10%
Waveform deviation ≤3%
Dividing Ratio of Measurement Winding: 1000:1
Over Current Ability: Continuous working for 300S at 120% rated current, then thermal damage or distortion of the winding shall not be occurred.
Over Voltage Ability: Over voltage at 110% UH (1100kV) for 60s, then it shall not happened any insulation damage for the testing transformer.
Winding to ground insulation:
HV Winding to LV winding, measuring winding and ground >2500MΩ
LV Winding to HV winding, measuring winding and ground >2500MΩ
Measuring Winding to LV winding, HV winding and ground >2500MΩ
Insulation level: test transformer LV input winding to ground withstanding level: 5kV/1min; Test transformer measuring winding to LV, HV winding and shell withstanding level: 5kV/1min  

Principle Diagram: