In February 2006 two PSN235 U2 converters were fully assembled at the production facilities of “Transconverter”, they are components for future-proof 2ES4K class electric freight locomotive.

The PSN235 U2 converter is made from modular base blocks, units and modules. Functionally it contains an input contactor, an input filter, a protection unit against pulse spikes in the input voltage, two contactors of input channels, four input single-phase inverters on IGBT transistors with galvanic separation of potentials by power transformers, six AIN1…AIN6 output inverters with single-phase rectifiers, five du/dt-filters, a sine filter, and a microprocessor-based control system (MBCS – МПСУ).

The first output inverter (AIN1) provides three-phase supply voltage for the compressor’s rotary field motor (MK).

The second and fourth output inverter (AIN2 and AIN4) in the standard situation provide single-phase supply voltage to the appropriate excitation converters (PV1 and PV2) which, in their turn, supply DC voltage to the excitation wirings of traction engines in the independent excitation mode. If any of the output inverters AIN1 or AIN6 gets faulty in the auxiliary power supply converter both in its own or a neighbouring section of a locomotive, the power supply to PV1 and PV2 to all sections stops, and the locomotive’s power circuits switch from independent traction engines’ excitation to series excitation. Herein, the AIN2 and AIN4 output inverters, depending on the variant of the redundancy scheme arrangement, provide three-phase supply voltage for the consumers of emergency output inverters, AIN1 or AIN6.

The third output inverter (AIN3) provides single-phase power to the power cabinet of control circuits.

The fifth output inverter (AIN5) provides three-phase supply voltage to the microclimate system, sanitary and technical equipment, etc.

The sixth output inverter (AIN6) provides three-phase supply voltage to two rotary field motors of fans (MV1 and MV2) of the electric locomotive’s traction engines.

The converter’s nominal power of converter PSV235 U2 makes 235 kVA, maximum output power – 320 kVA.