A 250 VDC power supply was available on site. At this time power bipolar transistors were the best technology available. Design incorporated custom base drives and lossless snubber circuits.
A robust machine was developed that is still in service 20 years after it was built. With newer power devices and topologies, the size and cost of inverters continually decreases. For example, the equivalent of this rack mount inverter can now be easily wall or cabinet mounted.
Application was 500 hp DC traction motors. The nominal supply voltage was 1200 VDC, and peak load current was 1500A. This design used IGBT technology. Existing solutions failed to deliver full load current. Thermal design considerations were critical to solve this problem and ensure a reliable product.
A successful product was developed for a demanding application. This project is an example of the results possible when power electronics are designed specifically for the application as opposed to using generic, off the shelf solutions.
A device was designed and patented to protect motors from damage due to reflected waves caused by fast switching adjustable speed drives. The technology used was power rectifiers and voltage clamping devices.
A new technology was developed that greatly exceeded the performance of the existing technology at significantly lower cost (US Patent# 5784236). This is 1 of several possible solutions to the reflected wave problem. As VFD technology advances, reflected waves paradoxically start developing in systems previously immune. Learn how advances in VFD topologies and filter technology can help if this is happening in your application.