The voltage regulating rectifier transformers used in the graphite electrode (carbon) industry currently mostly use 35kV, 66kV and 110kV for power supply, and the maximum DC current is more than 300kA.The DC no-load voltage is about 100-200V, and the capacity of a single set of voltage regulating rectifier transformer can reach 40MVA, without standby. The voltage regulating transformer and the rectifier transformer can be of separate structure or can share the same oil tank.Forced oil-water cooling or forced oil-air cooling can be used.

The secondary voltage regulation of the voltage regulating transformer is mostly step-down voltage regulation, which is generally continuous voltage regulation, with 79 levels, 95 levels or 107 levels at most. The on-load tap changer is mostly made in China.

When the voltage regulator is separated from the main transformer, the primary side of the rectifier transformer is connected with the secondary side of the voltage regulator transformer through the bushing outside the oil tank.The phase shift angle of the primary side of the rectifier transformer is calculated according to the pulse number of 12N formed by the total number of units. The single unit group forms 12 pulse waves, and the phase shift angle difference within the single unit group is 30 ° configuration.The phase shift angle of the primary side of the rectifier transformer is calculated according to the pulse number of 12N formed by the total number of units. The single unit group forms 12 pulse waves, and the phase shift angle difference within the single unit group is 30 ° configuration. The valve side adopts the structure of double inverted star in phase and inverse parallel connection, and mostly adopts the structure of five-column unbalanced reactor.The load is resistive.