Optimisation of the unit nomenclature and operating modes for a combined photoelectric / diesel DC power supply system

The study considers the development of an algorithm for minimising the cost of electricity production for a combined photoelectric diesel DC power supply system using optimal unit nomenclature selection and operating modes for a hybrid power plant with natural and climatic factors in the area of the electrification facility and its power consumption schedules. An energy balance optimisation model for a photodiesel power supply system was developed in MS Excel using the method of directed enumeration of options for unit nomenclature and operating modes. During the course of the study, various mathematical models were developed for a diesel generator and photoelectric power conversion unit for a direct current system, as well as numerical models of energy conversion processes for a diesel generator with an offset from the external speed characteristics according to the criterion of minimum fuel consumption. In comparison with alternating current systems, direct current approaches allow the effective fractional contribution of photoelectricity to the energy balance of the power system. Although, according to the stability condition for network inverter of a photoelectric power station, the power of the diesel component should exceed 60% of the total generation, when using the direct current, the loading of diesel sources can be reduced to a technical minimum of about 20% of the rated value. For the examples under consideration, the possible saving in terms of diesel fuel is up to 7 tonnes per year. For the middle latitudes of Russia, the minimum production cost of electricity can be achieved by choosing the installed capacity of a photovoltaic power plant generating up to 80% of the power consumption during the hours of maximum insolation in summer. An algorithm for minimising the production cost of electricity demonstrates the possibility of increasing the average annual balance share of photogeneration from a photodiesel energy source (for example, on the territory of Dagestan) to be up to 21.3%. The production cost of the produced electricity equalled to 42.5-43.3 RUB/kWh, i.e. by 30% lower than the existing tariff. The algorithm was used to optimise the main technical and economic characteristics (total production cost of generated electricity, diesel fuel consumption, contribution of DC photo power plant) at electrification facilities in the Irkutsk Oblast and the Republic of Dagestan. The results of the work are applicable in the development of autonomous power supply systems for various objects.

stand-alone DC diesel power supply systems, renewable energy sources, DC and AC power supply systems, photodiesel power supply