Inverter series I-PTP for traction substations of underground railway

I-PTP-MInvertеr is designed to transfer excessive regeneration power from DC overhead system into AC power supply system at traction substations of underground railways.

 Design features:

  • Forced air cooling of the thyristors is provided with the use of chillers on the basis of heat pipes.
  • Forced blowing of the chillers is provided with the fans installed on the cover of each cabinet.
  • Power busbar is made of copper.
  • Busses are connected to thyristors units with the use of special flexible dampers that allow to compensate heat expansions of the busses due to heating-up and to exclude mechanical stresses in the construction.
  • Control system is located in a separate control cabinet

 Electric circuit:

Inverter is manufactured according to 6-pulse inverter current circuit and is presented in two design   versions:
— as a bridge
— as «two reverse stars with current-balancing reactor»


Thyristors are turned on with pulse shapers via single-turn cable-transformer transmission.

Each thyristor is fitted with conductivity self-diagnostic circuit.

Thyristor diagnostics is based on the measurement of the voltage value, when the control impulse is not available.

Data on conductivity of each thyristor is supplied to microprocessor control system by means of fiber-optic communication.

Current and voltage measurement is ensured with the use of sensors on the basis of Hall effect.
Microprocessor control system is operated on the basis of the controller manufactured by ESTEL and with the use of operator’s control panel with LCD display.

Operating conditions:

Upper maximum value of the ambient temperature, °С +45
Lower maximum value of the ambient temperature, °С – 25
Upper value of the relative air humidity at temperature +25°С, % 98
Altitude above sea level, m 2000


Output parameters
Rated active power, kW 1860
Rated inverted current (phase), А 1600
Overload current relative to rated value and allowable overloads time, s 125 %– 900 sec, 1 time per  2 hours*

150 %– 120 sec, 1 time per  1 hour*

* root mean-square value for every   30 minutes should not exceed rated current value

 Rated voltage at transformer  winding, V 470 
Input parameters
Rated inverted voltage (at substation buses), V 950
Rated input current, А 1960
Rated output frequency, Hz 50
Auxiliary  power supply voltage (50 Hz frequency), V 380
Cooling air, natural
Power factor (design), minimum 0.95
Coefficient of performance (design), minimum 0.98
Ingress protection of:
— power circuit
— control system
 Dimensions (W x H x D), mm 2400 х 2200 х 1000 
 Weight, maximum, kg  1200