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This paper addresses the challenge of integrating multiple energy sources into a single-domain microgrid, commonly found in urban buildings, while also providing a platform for energy management. A Lyapunov stability analysis of a simple boost converter was used as a basis for designing the dual control loop of the grid. The versatility of the developed control structure allows for the incorporation of an arbitrary number of sources hence achieving scalability. Next, the energy in the microgrid was separated into exogenous energy and actuator energy. This yielded a description of the system that quantified the condition of stability independent of the decision made by a would-be energy management system. This, in turns, liberates the process of designing an optimized energy management system from stability concerns. The acquired theoretical findings were then translated to a simulation model, where multiple components of the grid were simulated under a typical scenario of operation. Once the simulation phase was concluded, a prototype of the designed grid was constructed to emulate the theoretical results. The prototype exhibited promising performance, matching the simulation predictions to a reasonable degree. [ABSTRACT FROM AUTHOR]

This paper addresses the challenge of integrating multiple energy sources into a single-domain microgrid, commonly found in urban buildings, while also providing a platform for energy management. A Lyapunov stability analysis of a simple boost converter was used as a basis for designing the dual control loop of the grid. The versatility of the developed control structure allows for the incorporation of an arbitrary number of sources hence achieving scalability. Next, the energy in the microgrid was separated into exogenous energy and actuator energy. This yielded a description of the system that quantified the condition of stability independent of the decision made by a would-be energy management system. This, in turns, liberates the process of designing an optimized energy management system from stability concerns. The acquired theoretical findings were then translated to a simulation model, where multiple components of the grid were simulated under a typical scenario of operation. Once the simulation phase was concluded, a prototype of the designed grid was constructed to emulate the theoretical results. The prototype exhibited promising performance, matching the simulation predictions to a reasonable degree.

Abstract: This paper proposes an optimal real-time energy management strategy based on the Pontryagin's Minimal Principle (PMP) targeting at minimizing operation cost for a plug in proton electrolyte membrane (PEM) fuel cell city bus. The Dynamic Programming (DP) and PMP strategies are firstly deduced. Influences of the initial co-state value on the PMP strategy are analyzed. The DP, PMP, Charge Depleting Charge Sustaining (CDCS) and Blended strategies are compared in a simulation model. Results show that, major factors that influent the operation cost are the end value of battery State of Charge (SoC), the SoC trajectory curve, and the distribution of the working points of the fuel cell system. From a statistic viewpoint, the operation cost increases almost linearly with the end value of the SoC with a gradient of 1.41 Yuan.%−1. Compared with a CDCS strategy, the operation cost can be reduced by 7.2% through taking the DP strategy, and by 5.9% through taking the PMP strategy. The PMP strategy leads to an operation cost that is 1.4% higher than the DP, but it is applicable in the real-time control system. An online energy management strategy based on PMP was set up and applied to an embedded controller. Tests in the 30 “China city bus typical cycles” showed that, the fuel economy was 5.8 kg (100 km)−1, and the operation cost was 271.3 Yuan (100 km)−1. [Copyright &y& Elsevier]