Design of a Novel Hybrid Energy Storage Configuration Including Control
Abstract
With the increasing age of the power grid and the requirement to maintain continuous electrical power supply required by critical loads, additional power resources are being developed and integrated into the power grid. Most of this generation is in the direct current form, notably renewables, and are characterized by variable power output levels. Not to mention backup power storage for the case of a power outage is becoming increasingly common. Both of those require energy storage systems to store and release power as required. Various configurations are available, and each has its weaknesses. This paper presents a hybrid energy storage topology and control scheme, with the topology being novel to the researcher’s knowledge. There are important requirements that the energy storage must meet; output voltage, reliable control, and quick response time to name a few. Energy Storage in the Hybrid Energy Storage is able to meet each of those requirements. Research here was pursued to design a hybrid energy storage configuration and control to achieve those requirements, with a reduced control structure due to the new topology. Much past research has been invested to determine and characterize how this can be completed, which form the theory governing the system presented here. A characteristic that is critical to the delivery of power to a load is the response time for the system to attain the target voltage. That depends specifically on the sources providing the dc power. While it is not readily apparent, energy storage devices cannot instantly provide the required power flow. This impediment to the implementation of dc-to-ac energy conversion can be critical depending on the application. The research presented here provides an energy storage configuration and complimentary control system characterizing a quick response determined by the load. For this system the configuration of the physical components utilized plays a critical role in the nature of the systems responses to transient loads. The components implemented also impact the efficiency of the system to attain the power output required. With the nature of electron mobility in the energy storage elements to the active and passive elements providing the voltage level change capabilities each play an integral role. The role of the critical components and different configurations will be discussed, with the benefits of the selected configuration reviewed. In addition, without the proper control scheme the active components operation would not access the capabilities of the complementary passive components to achieve the target voltage. This control scheme needs to be able to provide sufficient power demanded. Addressing that requires an analysis of the control system inputs to achieve the output power required. Robustness, reaction time, and consistent voltage control characteristics to be reviewed and addressed. The primary contributions of the researcher for the Hybrid Energy Storage system regard the topology, once more novel to the knowledge of the researcher, and the control scheme implementation achieving bi-directional power flow. Simulation results support the designed system as physical system results were unattainable. The capabilities and limitations of the final system in regards to other choices will be expressed. Accuracy, robustness, target voltage level, and the response to transient load change provide a brief selection of the characteristics characterizing the systems operation.
Degree
M.S.E.C.E.
Advisors
E., Purdue University.
Subject Area
Engineering
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