At the Electric Power Transmission and High Voltage Laboratory of ETHZ the New Switchgear Technology NST has been developed. Objective of this project is to search for alternatives in medium-voltage current breaking principles. The research includes investigations of fault-current-limiting medium-voltage switchgears based on a hybrid system.
In this semester thesis an integrated controller for such a switch has been implemented. It enables fast detection of overcurrents by applying an extrapolation algorithm.
The ASIC realizes all required digital signal processing, e.g. a serial QSPI interface controller for the analog- to-digital converter, a display controller, generation of the power switch control signals, arithmetic functions such as numerical differentiation and integration, and approximation of trigonometric functions. Parameters are set over the chip's RS-232 interface or with a simple user interface. Reasonable defaults can be pre-loaded. Parameters that do not affect the internal structure of the ASIC can be updated online