Energy storage for frequency regulation on the electric grid

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 271-280).Ancillary services such as frequency regulation are required for reliable operation of the electric grid. Currently, the same traditional thermal generators that supply bulk power also perform nearly all frequency regulation. Instead, using high power energy storage resources to provide frequency regulation can allow traditional thermal generators to operate more smoothly. However, using energy storage alone for frequency regulation would require an unreasonably large energy storage capacity. Duration curves for energy capacity and instantaneous ramp rate are used to evaluate the requirements and benefits of using energy storage for a component of frequency regulation. Filtering is used to separate the portion of a frequency regulation control signal suitable for provision by an energy storage unit from the portion suitable for provision by traditional thermal generating resources. Not all frequency regulation signals are equally amenable to the filtering approach used here. Data from two U.S. control areas are used to demonstrate the techniques and the results are compared.by Olivia Leitermann.Ph.D

Radio frequency direct current-direct current converters : device characterization, topology evaluation, and design

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 155-157).High frequency power conversion is attractive for the opportunities it affords for improved performance. Dc-dc converters operating at high frequencies use smaller-valued energy storage elements, which tend to be physically smaller and lower-cost, and this can result in improved transient performance while retaining high efficiency. One way to achieve high switching frequencies is by using resonant inverter and rectifier topologies and regulating voltage via on-off control. This scheme requires a great deal of investigation of design practices appropriate to high frequency power conversion. The design issues were investigated for a 200 W 160-200 V input 33 V output converter. A comparison of resonant inverter topologies for the power stage was made. Appropriate devices were sought, compared, and characterized. A high frequency gate drive scheme for a large vertical MOSFET was developed. Several prototypes were built and these are also presented.by Olivia Leitermann.S.M

Energy Storage for Use in Load Frequency Control

Certain energy storage technologies are well-suited to the high-frequency, high-cycling operation which is required in provision of load frequency control (LFC). To limit the total stored energy capacity required while reducing the cycling burden on traditional thermal generators, the LFC signal may be split between thermal generators and energy storage units. To evaluate the dispatch of energy storage units in concert with thermal generators, this paper presents energy-duration curves and ramp-rate-duration curves as graphical tools. The energy storage requirement and thermal ramping requirement may also be graphically compared to provide insight for cost evaluations.MIT-Portugal ProgramMasdar Institute of Science and Technolog

Resistance Compression Networks for Radio-Frequency Power Conversion

A limitation of many high-frequency resonant inverter topologies is their high sensitivity to loading conditions. This paper introduces a new class of matching networks that greatly reduces the load sensitivity of resonant inverters and radio frequency (RF) power amplifiers. These networks, which we term resistance compression networks, serve to substantially decrease the variation in effective resistance seen by a tuned RF inverter as loading conditions change. We explore the operation, performance characteristics, and design of these networks, and present experimental results demonstrating their performance. Their combination with rectifiers to form RF-to-dc converters having narrow-range resistive input characteristics is also treated. The application of resistance compression in resonant power conversion is demonstrated in a dc-dc power converter operating at 100 MHz

A High-Frequency Resonant Inverter Topology With Low-Voltage Stress

This paper presents a new switched-mode resonant inverter, which we term the inverter, that is well suited to operation at very high frequencies and to rapid on/off control. Features of this inverter topology include low semiconductor voltage stress, small passive energy storage requirements, fast dynamic response, and good design flexibility. The structure and operation of the proposed topology are described, and a design procedure is introduced. Experimental results demonstrating the new topology are also presented. A prototype inverter is described that switches at 30 MHz and provides over 500 W of radio frequency power at a drain efficiency above 92%. It is expected that the inverter will find use as a building block in high-performance dc-dc converters among other applications.General Electric CompanyUnited States. Defense Advanced Research Projects Agency (Robust Integrated Power Electronics

Opportunities and challenges in Very High Frequency power conversion

This paper explores opportunities and challenges in power conversion in the VHF frequency range of 30-300 MHz. The scaling of magnetic component size with frequency is investigated, and it is shown that substantial miniaturization is possible with increased frequencies even considering material and heat transfer limitations. Likewise, dramatic frequency increases are possible with existing and emerging semiconductor devices, but necessitate circuit designs that either compensate for or utilize device parasitics. We outline the characteristics of topologies and control methods that can meet the requirements of VHF power conversion, and present supporting examples from power converters operating at frequencies of up to 110 MHz