A Triangular Modular Multilevel DC-DC Converter with Multiple-input Multiple-output Power Flow Capability

There has been recent interest in expansion of direct-current (dc) networks, motivated mainly by proliferation of renewable energy sources, electrical energy storage, and electronic loads which operate with dc power. One of the key challenges hindering the adoption of dc networks is the lack of high performance dc-dc converter topologies to accommodate energy exchange, at high power levels, between dc buses of different voltage levels. Conventional dc-dc power converters such as the boost or the flyback face a fundamental limitation in operating at high power levels and/or voltage conversion ratios. As these topologies utilize a single semiconductor switch, their maximum attainable power and voltage rating is dependent on the highest power rated semiconductors available. Moreover, regardless of the operating power, these topologies suffer from high losses and ringing when operated at high conversion ratios. In recognizing the shortcomings of conventional topologies for employment in high power and/or conversion ratio applications, a new topology is proposed that provides an efficient and cost-effective solution. The proposed modular topology is constructed from identical converter cells which may be connected in parallel and series to share the overall power stress. As a result, the dependency of the topology's power and conversion ratio on existing semiconductor technology is insignificant. Moreover, the topology is capable of supporting bidirectional power flow exchange between multiple sources and loads which makes it suitable for a wide range of power conversion applications. The proposed topology can achieve a conversion ratio of six with half of its switches operating at a duty cycle value 25% lower and the other half of its switches operating at a duty cycle value 40% lower than that of the conventional boost converter while requiring only 15% higher switch volt-ampere rating. The proposed converter's operating mechanism is described, and its analytical steady-state and dynamic models are derived. In investigating the topology's dynamic model, a modular control algorithm is devised for closed-loop operation of the topology. The ability of the topology to operate as a multiple-input multiple-output converter is also investigated through similar analytical and control studies. Simulation and experimental studies are carried out to evaluate the converter's performance under both steady-state and dynamic operation.Ph.D

Prometheus Home Control System [power line communications]

The Prometheus system from Nexus Technologies will provide users with a practical low cost implementation of a smart home. Our smart home design will allow users to control the lights of their house from either a local computer, or any computer connected to the internet. The building controller determines what device the user intends to control by the data received and sends control signals to the Power Line Communication Modem (PLCM). The control signals are processed by the PLCM and sent through the electrical grid. These control signals are then recovered from the electrical grid by another PLCM located near the corresponding light that is to be controlled