The advantages of transformer drive are: the control loop is isolated from the power loop; This has many advantages in power system control. Power electronic equipment, mostly medium and high voltage systems, some even as high as 6000VAC. The transformer is driven in isolation so that the weak current control circuit is electrically isolated from the strong current circuit.

The intermediate circuit between the main circuit and the control circuit for amplifying the control circuit signal (that is, amplifying the control circuit signal to drive the power transistor) is called the driving circuit. The basic task of the driving circuit is to convert the signal from the information electronic circuit into a signal added between the control terminal and the public terminal of the power electronic device, so as to turn it on or off according to the requirements of its control target. For semi-controlled equipment, only on control signals need to be provided, while for fully controlled equipment, both on control signals and off control signals need to be provided at the same time to ensure that the equipment can be reliably turned on or off as required. For safety reasons, the secondary side of the driving circuit is coupled with the main circuit, while the primary side of the driving circuit is connected with the control circuit. The main circuit is the primary circuit and the control circuit is the ELV circuit. The primary circuit and ELV circuit should be basically insulated, and isolation measures such as transformer optocoupler are generally adopted to meet the insulation requirements.