Power supply prototype using SiC MOSFETs for energization of electrostatic precipitators

Sønderskov, Simon Dyhr ; Jørgensen, Asger Bjørn

4. term

Energy Engineering, Master

2016

2016-05-31

119 pages

Electrostatic precipitators (ESPs) are used in industrial processes to remove particles from fumes. They require high-voltage power supplies. The commonly adopted technologies are based on silicon thyristor or IGBT switching sets. The emergence of Silicon Carbide (SiC) offers potential benefits in the power supply design for ESPs. The synchronous boost converter topology is chosen, and by operation in discontinuous conduction mode (DCM) turn-on losses are eliminated. The topology requires voltage balancing of series connected SiC MOSFETs, for which only limited research currently exists. Many serialization techniques turn on/off all switches simultaneously. The fast switching and high blocking voltages of SiC devices, tend to cause overshoot, ringing and difficulty in voltage balancing. A circuit structure is chosen which features a cascaded switching sequence. The circuit is designed using a modular layout and is tested in the laboratory in a double pulse test. Compared with existing research, the number of series connected devices is extended and voltage balancing is improved. However, during DCM operation with a switching frequency of 50 kHz, the voltage balancing of the circuit is degraded. The origin of voltage imbalances is investigated and future improvements are suggested.

Silicon Carbide ; SiC ; serialization ; electrostatic precipitator ; ESP ; MOSFET ; series connection

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