Herman Lucas Norbert Wiegman

A resonant pulse gate drive for high frequency applications

The analysis and implementation of a resonant pulse gate drive are discussed. The resonant gate drive is based on a simple charge pulse circuit which has conduction and logic losses. The pulse charging and discharging instances are controlled by the user, and hence this circuit is applicable to pulse width modulation (PWM) schemes as well as resonant converters. Theoretical analysis of the circuit shows its operation. Detailed equations are presented which describe the inherent losses of the circuit. Experimental results are shown to verify the operation and loss mechanisms.<<ETX>>

Utility energy storage life degradation estimation method

Energy Storage installations have been used in electric utilities for a few decades now. The primary applications of energy storage in utilities include grid stabilization, back-up power and peak shaving, while other potential applications include arbitrage, reduction in renewable variability and frequency regulation. Selection of the appropriate energy storage system for each of the above applications depends on the power/energy ratio requirement, along with the cost, lifetime and other technical challenges. This paper presents a matrix that evaluates the state-of-art energy storage technologies for various utility applications. The characteristics of energy storage systems required for these applications and challenges inherent in the design of such systems are also summarized in this paper. A specific methodology used for analyzing and optimizing the size of the battery energy storage system for frequency regulation is discussed in detail. The same methodology can be extended to the selection of the most optimum technology for other utility applications.

Sodium-metal halide batteries in diesel-battery hybrid telecom applications

GE is commercializing the Durathon™* sodium-metal halide battery for stationary power and electrified transportation applications. Attributes of the technology, which include high energy capacity, long cycle life, safe failure modes, and compatibility with extreme operating environments, make it particularly suitable for applications such as stationary back up power in areas where the electrical grid is unavailable. In off-grid or weak-grid telecom applications, cell towers that rely on backup generators and batteries can operate more fuel-efficiently by utilizing Durathon batteries instead of lead acid batteries for energy storage, reducing fuel usage and associated emissions. This manuscript describes the battery technology, performance in hybrid telecom applications and demonstrates the value Durathon batteries bring to off-grid and weak-grid telecom customers.

Optimal day-ahead scheduling for microgrid participation in frequency regulation markets

As microgrid installations are steadily growing in the United States and around the world, widespread adoption of commercial microgrids would rely upon the economic benefit to the owners and operators. With the introduction of new market mechanisms and growing penetration of non-traditional generation assets, there is an increasing need and interest in allowing distributed assets to participate in traditional grid services such as frequency regulation. This paper considers the problem of determining the optimal balance of energy and ancillary services for individual microgrid generation assets to participate in such markets. An optimization framework that maximizes the predicted performance of the microgrid over a day-ahead time horizon while accounting for individual asset constraints is proposed. Simulation results on a realistic test system with practical considerations are presented.

Energy and power savings assessment in buildings via conservation voltage reduction

This paper evaluates the potential energy and power savings from application of Conservation Voltage Reduction to buildings with load diversity. Slow and fast voltage change experiments were performed to develop regression models with which the conservation voltage reduction energy and power factors were evaluated on a subject building. Least mean squares algorithm was used for the estimation of these parameters. The experimental results of 6 months of recordings captures not only the enforced voltage changes but also the existing voltage deviations on a feeder, weather conditions and load patterns.