Selection of output inverter for microgrid

Abstract

The paper considers the problem of a microgrid output inverter selecting, when information about operating conditions is uncertain. The following factors are considered as sources of uncertainty in information about operating conditions: the possibility of the load increasing in the area, for which the microgrid is being designed, the prospects for its integration into the local power supply system, based on the microgrid, operating in the given region, as well as possible changes in the element base due to import substitution.
 A system of criteria and a methodology for optimal selection have been developed, based on a combination of multi-vector optimization approaches and the hierarchy analysis method. The quality criterion of generated energy, the criterion of reliable operation in conditions of information uncertainty and the criterion of economic indicators were cho- sen as vector criteria. The total number of scalar criteria that are components of the specified vector criteria is seven. At the first stage of selection, an algorithm is used for expert assessment of the importance of vector criteria and their scalar components, as well as values of these criteria for compared alternatives, using of the hierarchy analysis method. At the second stage of selection, considered inverters are ranked according to a global criterion, calculated based on results of the first stage. The technique is demon- strated by choosing between three well-known schemes of autonomous inverters: a voltage inverter with PWM-shaping of the output curve, a current inverter with a variable struc- ture and a group multilevel inverter based on a universal source of levels, when they are operating in autonomous or integrated into the system of other microgrid modes. The de- scribed selection technique can be used, when other microgrid conversion equipment de- vices are selecting.