CONTROL AND PROTECTION OF AC/DC HYBRID MICROGRIDS

Future trends in electrical power engineering predict the development of dispersed generation, accumulation and microgrids. Besides many of the various benefits and efficiency increase, the operation of hybrid AC/DC networks brings also specific requirements for control and protection. This paper analyses the key challenges of hybrid AC/DC network operation. The paper deals with operation and protection issues respecting different levels of short-circuit power in different operating states and focuses on specific properties of short circuit current shutdown in terms of protection of hybrid microgrids. Specific issue of line to ground fault detection and tripping in microgrid are verified using laboratory experiment. The paper provides a comprehensive view on some specific requirements for the protection and control of AC/DC hybrid microgrids.