A Floating Double Buck-Boost Converter as Driver for a Permanent Exited DC Machine

Every year still hundreds of millions of DC drives are built in the low voltage area because of the simplicity of the machine. But only very few papers are published concerning converters for them. Here a floating double buck-boost converter is treated with some interesting features (reduced voltage stress across the devices and higher voltage transformation ratio). The converter is explained and important connections between the voltages and the currents are derived. The design is presented, the large signal and the small signal models are given, the transfer function derived and a simple feedforward-controller is designed and verified by simulations.