Uninterruptible Power Supply Design (Spring 2021)
For my final project in my power electronics course, a power electronics system was to be designed in the MATLAB Simulink environment. The chosen system was an uninterruptible power supply capable of supporting up to a 6kW load for the intended purpose of supporting a sensitive machine in a local outage, such as a large server. A heatsink was chosen for the transistors used with cost in mind.
The inverting stage of the UPS consisted of four IGBTs configured in an H-bridge. The gates of the respective IGBTs were driven by a designed SPWM controller. Each IGBT was protected by connecting an RC snubber network to minimize dv/dt, di/dt, and switching losses. A low-cost heatsink was applied to each IGBT by calculating the sink-to-ambient thermal resistance with datasheet values and maximum theoretical power draw.
For the output stage, an LC filter stage was constructed to minimize total harmonic distortion for the sensitive load. The under 10 percent THD goal was achieved in all load tests in Simulink, resulting in a successful project!
