**1. Introduction**

The microgrid concept is increasingly being investigated and implemented in military contexts. Research has been conducted on the topic of implementing microgrids at fixed military installations within the United States [1,2]. This paper will focus on the application of microgrid technologies in support of overseas military expeditionary or contingency operations. Specific examples include intermediate staging bases (ISB), forward operating bases (FOB), combat outposts (COP), observation posts (OP), and patrol bases (PB) [3–5]. These may be permanent or temporary bases used by the military while on assignment in foreign countries. This paper will include a demonstration of a COP with a size of 20–40 people, so this type of microgrid will be considered here.

There are several challenges when considering microgrids for military applications. First, the COPs may be somewhat temporary, so equipment that can be easily transported to the location, then moved to future locations is important to consider for equipment selection, but the energy cost of transportation is outside the scope of this paper. Reliability is especially important in military microgrids, since many lives depend on the consistent operation of the electrical equipment at the COP [6]. Minimizing the use of fuel is also critical, as transporting fuel to the COP can cost \$400 per gallon [7], and can be dangerous, resulting in the loss of one life for every 24 fuel convoys in Iraq and Afghanistan in 2007 [8].

Including renewable resources can help reduce the amount of fuel needed, and energy storage can be included to increase the reliability of the system. Assessing the amount of storage needed for energy surety has been previously studied [9,10]. Using the improved droop control methods presented in this paper can allow a military microgrid to utilize as much renewable resources as possible, without relying

on a communication link between the microgrid components—this eliminates the electrical system communications as a single source of failure that would be especially vulnerable in a military setting.

Previous work has demonstrated the use of multidimensional [11] optimal [12] droop control with wind resources, in a residential microgrid setting. This paper expands upon previous work, applying multidimensional optimal droop control with solar resources. A load model for a typical patrol base is presented, and used in simulation of a military microgrid example to demonstrate the proposed controller.
