Actuator Circuits for the Complete Small Signal Characterization of DC/DC Power Converters

摘要

An essential feature of modern power networks is their ability to efficiently manage the flow of power, e.g. for a better exploitation of renewable energy sources, for the load balancing in home automation systems, etc. To achieve those benefits smart power electronic interfaces - often working in DC - are needed. The interaction of multiple DC/DC power converters can give rise to complex stability issues. To evaluate the influence of a converter on the whole power system, an experimental characterization is needed. While techniques for the loop gain measurement are well established and usually adopted in test procedures, the characterization of input and output closed loop frequency responses is rarely performed, because it imply to inject small signals upon the steady state values in high voltage or with high current, as depicted in Fig. A. In those cases, the use of a power amplifiers has to be considered. Requirements of large bandwidth, high voltage and high current capability force to use top level instruments, not always accessible to all laboratories. As an alternative, the paper proposes to use some actuator circuits for the signal injection, giving some hints about how to design such circuits, and providing experimental proof of their use.