Design of Smart MVDC Power Grid Protection

Abstract

Improved reliability and safety of the medium-voltage dc power distribution systems on board of all electric ships are the objectives of this paper. The authors propose the integration of the self-healing capability against faults of the measurement system in power system fault detection and protection systems. While most of previous work in the literature focuses on either one aspect independently, here, the two are integrated. On one hand, our approach addresses also the case of concurrent power system fault and measurement system fault. On the other hand, the proposed approach must be capable of distinguishing between the two types of failure. The proposed architecture is based on exchange of information between energy conversion and measurement devices. This makes the impact of communication delays critical, so its analysis is provided for the proposed case study. The impact on the performance of the measurement validation and protection systems is derived and can provide hints on the design. The protection method used as case study consists in controlling power converters to ride through the power system fault while maintaining power supply to the vital loads. To overcome failures of the measurement system, invalid data were detected and reconstructed through their expected value.