This transformer feed a diode rectifier, 6 phase, 12 pulses, which feeds the load with DC voltage 750v, the rectifier is not equipped with smoothing or interphase coil on 750v side, we are responsible of the compatibility of the transformer-rectifier system. The K factor of the transformer is K13, which means the transformer is operating in a heavy harmonic environmental, which is considered by us during design. The transformer is working 20/24 hour, 365 days at -35 to +40 ℃ and 100% humidity. The transformer is able to work at 150% of the rated power with peak of 300% for 20seconds due to peak of voltage every 3 minute without exceeding the temperature of 100℃,the temperature rise is 80℃ max at rated power, the insulation of the copper winding is adopt NOMEX with class H(220℃)

Transnet's traction substations consist of single and double units and in exceptional cases a three unit rectifier configurations.
Each rectifier unit comprises of a set of high voltage AC disconnects, primary circuit breaker, two current transformers and a traction transformer connected for twelve-pulse rectification with its control and protection circuitry.
The rated power of the transformer is 6000 kVA with ONAN cooling, the primary voltage is 22 kV with ±2*2.5% tapping range(NLTC), the secondary voltage is 2 of 1.22 kV, also a tertiary winding is designed to supply a auxiliary 150 KVA 1.22 KV power, they formed a vector group of Y/d11y0y0n.

The rated power of the transformer is 2 x (3635 – 2562/2562) kVA with OFAF cooling, the primary voltage is 22 kV with 462,433,390,346,303,260V tapping range(NLTC), the secondary voltage is 2 of 462 V, they formed a vector group of Yy0y6 & Dy5y11.