HCTT-2x400kV/400kVA AC Test Transformer

Mode: HCTT 2x400KV/400KVA
Cylinder type, two modules,       Single phase
Frequency: 50Hz
Rated Capacitance: LV Capacitance: 400kVA HV Capacitance: 400kVA
Rated Voltage: LV Voltage: 2*0.6kV;      HV Voltage: 2*400kV
Rated Current: LV Current: 2*333.3A   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%
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 (880kV) for 60s., then it shall not happened any insulation damage for the testing transformer.
Insulation Level:18kV/1min(low voltage terminal to earth)
Noise: ≤60dB
PD Level: <5pC at 100%UH of complete test system; <3pC at 80%UH of complete test system;
Unevenness at 2 transformer in series: ≤±5%
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.
Dimension: Dia. 2780* Height 7130mm(grading ring dia. 2780mm)
Weight: 23500kg
Upper Stage Transformer
Mode: HCTT-200kVA/400kV-II
Cylinder type                Single phase       
Rated Capacitance: 200kVA    Frequency: 50Hz
Rated Voltage: LV Voltage: 0.6kV, HV Voltage: 400kV
Rated Current: Exciting current: 333.3A, HV Current: 0.5A
Impedance Voltage ≤4%   Waveform deviation ≤3%
Dividing Ratio of Measurement Winding:1000:1
Noise level ≤60dB (Measure in 4 meters distance)
Cooling: ONAN
Over Voltage Ability: Continuous working for 60S minutes under 110% rated voltage (440kV), then thermal damage or distortion of the winding shall not be occurred.
PD Level: <5pC at 100%UH of complete test system; <3pC at 80%UH of complete test system;

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: 18kV/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
Dimension: Dia. 2200* Height 3200mm
Weight:10500kg

Sub-Stage Transformer
Type: HCTT-400kVA/400kV-I
Single phase    Cylinder Type   Frequency: 50Hz
Rated Capacity: LV capacitance: 400kVA
HV Capacitance: 200kVA Transfer capacitance: 200kVA
Rated Voltage: exciting volt: 2*0.6kV
HV Volt.:400kV transfer volt: 0.6kV
Rated Current: exciting current:2*333.3A,HV Current: 0.5A, transfer current: 333.3A
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; <3pC at 80%UH of complete test system;
Over Voltage: Continuous working for 60S minutes under 110% rated voltage (440kV), 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: 18kV/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

Structure: 
Inside Structure:
① Use CRGO Steel Model 30Q130 to make iron core and cover with insulated painting as well as glass fiber glass cloth.
② isolated screens are mounted and grounded well among LV winding, iron core, measurement winding and HV winding.
Outside Structure:
① The casing is constructed to be insulated barrel and be flange connected on its both ends which has the features of low leakage current, low PD level and large strength. The surface color will be painted in red.
② The welding portion of the whole structure can bear Max. 20kP air pressure test and without oil leakage and structure damage.
③ The sealing rings will use a high quality rubber which is good to endure oil materials and high temperature conditions.
Dimension: Dia.2200* Height3200mm              
Weight:13000kg

Principle Diagram: