Fuel Consumption Minimization of a Microgrid

Abstract

Abstract-A cost optimization scheme for a microgrid is presented. Prior to the optimization of the microgrid itself, several schemes for sharing power between two generators are compared. The minimization of fuel use in a microgrid with a variety of power sources is then discussed. The optimization of a small power system has important differences from the case of a large system and its traditional economic dispatch problem. Among the most important differences is the presence of a local heat demand which adds another dimension to the optimization problem. The microgrid considered in this paper consists of two reciprocating gas engines, a combined heat and power plant, a photovoltaic array and a wind generator. The optimization is aimed at reducing the fuel consumption rate of the system while constraining it to fulfil the local energy demand (both electrical and thermal) and provide a certain minimum reserve power. A penalty is applied for any heat produced in excess of demand. The solution of the optimization problem strongly supports the idea of having a communication infrastructure operating between the power sources.

Conditions for stability of droop-controlled inverter-based microgrids

“…However, it has been argued in [7] that system operators may not always seek to achieve a power sharing in proportion to the power ratings of the units. Instead they may also wish to take into account other technical, economic or environmental criteria, such as fuel consumption, generation costs or emission costs, see also [19].…”

On power sharing and stability in autonomous inverter-based microgrids

“…Second, the design allows to specify a range for the droop gains, rather than a fixed value. In this way, the power sharing characteristics could then be adjusted e.g., by market mechanisms similar to the present implementation in many large power systems [18], [19], while preserving stability. Opposed to standard droop control our approach does guarantee zero steady-state frequency deviation.…”

A Review of Power Electronics Based Microgrids

“…A further problem is the resistive nature in low-voltage distribution networks, which results in a coupling between active power and system voltage, and consequently complicates the controls of power flows and microgrid voltage profile [64]. Furthermore, the whole energy system in the context of microgrid is expected to be interactive, intelligent and distributed [61]. Advanced supervisory control architectures for the energy management are therefore needed [62].…”