The Selection of Energy Storage for a Micro–Gas-Turbine Plant Operating Autonomously in the Conditions of the North

Abstract

On the example of a micro–gas-turbine plant (MGTU) of the C30 Capstone type, an analysis of various options for the use of modern electric energy storage devices as part of a buffer battery was carried out and compared. Gas microturbines with a unit capacity of several tens to hundreds of kilowatts appeared on the market in the 1970s and have become increasingly widely used in autonomous and distributed generation systems. Their competitiveness in comparison with diesel and gas reciprocating power plants is ensured primarily by achieving comparable efficiency values with competitors as a result of the use of a regenerative thermodynamic cycle with highly efficient recuperative heat exchangers and high-speed turbogenerator equipment with air bearings instead of oil bearings. This significantly reduces the operational requirements for the frequency of maintenance of power plants, and also expands the possibilities of using various types of liquid and gaseous fuels (polyfuel) available in the operation area. An important feature of micro–gas-turbine power plants is the DC link and the buffer storage of electrical energy in the power output circuit, which allow one to effectively control the current parameters (regulate them) without changing the engine speed. In traditional versions of such power plants, as a rule, lead-acid batteries are used as a buffer energy storage. The authors considered options for replacing them with supercapacitors and batteries of various types, taking into account such operational factors as the predominance of low ambient temperatures during most of the year (arctic conditions), difficulties in logistics, maintenance conditions for power plants of these batteries, and their considerable cost. The weight and size characteristics of drives are estimated based on different types of elements with an emphasis on products of Russian manufacturers. It is concluded that when operating an MGTU in harsh climatic conditions, it is advisable to use supercapacitor batteries in their buffer storage, despite their low specific energy consumption and high cost.