Modular approach in building auxiliary supplies for traction

The paper describes a modular concept for building auxiliary supplies for traction. The main building blocks-modules are described. The merits of such approach are outlined: short development time, easy maintenance and redundant operation. The concept of two types of IGBT drive circuits used in modules is presented. In one type of drive circuit, the short circuit protection is not realized in the driver. Instead, the current is measured with conventional current sensor and the control circuits terminate the on signal. Measured results that illustrate the effectiveness of this method are shown. Mechanical design and cooling strategy is also presented. Measured characteristics of a supply, now in prototype production, are shown.