CIRCUIT BREAKERS AND CIRCUIT BREAKER OPERATIONAL METHODS (iEdison No. 0685901-22-0217)
For seamless integration of offshore renewable generation with onshore grid using LF-HVac network it is essential to develop a robust protection system. Under low frequency transmission, the transmission line impedance is reduced that helps to increase the power transfer capability of the system. Power transfer capabilities are almost comparable to HVdc systems under very low frequencies. The key difference between developing a protection scheme for LF-HVac compared to a HVdc system is the essential zero-crossing of the ac current/voltage. Some literature's have proposed the use of conventional ac breakers to interrupt faults on the LF-HVac transmission side. Reduction of system impedance on the low-frequency ac side results in higher fault current. In our study we have worked on and improved a previously proposed low-frequency circuit breaker (US 9,263,880 B2). Our design and operation shows a faster interruption of the fault current. Along with that we proposed a new hybrid circuit breaker design that has a serial operating structure contrary to the parallel operating one as was previously proposed. We have extensively tested the operational characteristics of the modified design and the newly proposed serial circuit breaker design.
Method and Apparatus for Smart Battery Charging
Unlike most electric loads, electric vehicles are mobile. Consequently, one cannot necessarily know that an electric vehicle will be configured safely for any of the charging stations at which it might try to charge. Limitations might be imposed by any of the components, including battery packs, power electronic chargers, premise plug and wiring infrastructure. Furthermore, preferences (and perhaps hard limits) will be imposed by the electric utility, which might insist, for example, that electric vehicles charge off peak, or by vehicle owners, each of whom might wish to assert preferences that will affect charging costs and convenience. This invention describes a fuzzy approach for accommodating such limits and preferences from numerous sources.
Battery Charging Control Methods, Electric Vehicle Charging Methods, Battery Charging Apparatus and Rechargeable Battey Systems
The invention represents an algorithm to provide a form of regulation up and down services to the electric power grid using a plug-in electric hybrid vehicle (PHEV/EV) or electric vehicle (EV). The basis for this regulation will come from frequency measurements of the power grid. The actual charge rate of the PHEV/EV charger will be adjusted using this regulation signal and information about any charging constraints imposed upon the charger (such as a desired finish time).
Methods and Electrolytes for Electrodeposition of Smooth Films
Electrolytes which can effectively enhance the smoothness of deposited films during electroplating process are provided. The electrolyte contains a solvent, a metal (M1) salt containing a metal to be deposited, and an additive metal (M2) salt. The cations of the additive salt can be preferentially adsorbed, but cannot be deposited on the protruded region of the deposited film, therefore forms a positively charged electrical shield which covers the protruded region. This self-assembled electrical shield (SAES) will prevent further deposition of metal (M1) in the protruded region so metal (M1) will be preferentially deposited onto the non-protruded region. This self-smoothing process will effectively improve the smoothness of deposited films during electroplating process.
Medical Radioisotopes and Methods for Producing the Same (Incorporates 14348-B, 14402-B, 14398-B, 14399-B & 14795-B)
Methods for producing radioisotopes required for nuclear-medicine procedures using particle accelerators with small dimensions that can easily be located within a standard-sized laboratory are described. In particular, a method for producing Mo-99 from a target consisting of Zr-96 via an (a, n) reaction has several advantages over current methods used to produce Mo-99. The Zr-96 target contains a stable isotope and does not have the proliferation or RDD implications of the U-235 targets that are currently used. A nuclear reactor is not required to produce the Mo-99. The Mo-99 can be isolated from the target material without interference from multiple fission products. The separation of Mo-99 from Zr-96 is straightforward. In addition, rotation of a thin circular target disk or spooling of a metallic wire target that provides for maximum use of the a-particles and quick dissolution of the target material is novel, to the best of our knowledge. The method should be applicable to the production of many other medical radioisotopes by using the appropriate targets and separation procedures.
CURRENT LIMITING CONTROL STRATEGY FOR SINGLE-LOOP DROOP-CONTROLLED-GRID-FORMING INVERTERS (iEdison No. 0685901-22-0109)
Existing studies of current limiting control for grid-forming inverters mostly focus on grid-forming inverters that use the multi-loop control structure. This paper describes a current limiting control for grid-forming inverters that use the single-loop control structure. The proposed current limiting control is implemented at the PWM control layer to guarantee the fast response. Once detecting the overcurrent caused by severe faults, the proposed control strategy immediately blocks relevant IGBTs using a hysteresis loop, ensuring the overcurrent can be limited within a few PWM cycles. After the fault is cleared, the inverter seamlessly transfers back to the droop control mode to maintain the stability. The current limiting control has been tested in a microgrid environment in the OPAL-RT platform. Study results show that the control strategy can effectively limit the overcurrent under both balanced and unbalanced faults, and the system transient stability can be maintained after the fault is cleared.
IN-SITU HEALTH MONITORING SYSTEM FOR REDOX FLOW BATTERIES (iEdison No. 0685901-22-0242)
We designed an acoustic monitoring system to detect hydrogen bubbles in the analyte solution of all-vanadium redox flow batteries (AVFBs). The system has a specially designed ultrasonic probing cell made of borosilicate glass that can be integrated into the flow system on the analyte side (Figure 1). The analyte solution firstly flows through the negative electrode, where the chemical reaction occurs and hydrogen bubbles are generated, and then flows into the ultrasonic probing cell. The ultrasonic transducer transmits signals into the probing cell and collects echoes that propagate through the electrolyte solution in the probing cell. Details about how the signals are transmitted and received are included in Appendix A. The echoes are collected by the ultrasonic receiver and sent to the computer for data analysis. The sound speed and the acoustic attenuation coefficient are calculated from these echoes, with the detailed methods given in Appendix B and C. Bubbles that flow through the acoustic path are reflected as abnormal values in the measurements of the sound speed and the attenuation coefficient. This method not only can detect bubbles in the analyte solution, but also can estimate the bubble flow speed. The monitoring system can continuously monitor bubble amounts in negative electrolytes without interrupting the battery operation, and thus provides a real-time noninvasive surveillance of the health status of flow battery systems. Figure 1. Schematic of the in-situ battery health monitoring system for hydrogen detection in an all-vanadium redox flow battery.
Forward Looking Transactive Pricing Schemes for Use in a Market-Based Resource Allocation System
This is an extension of the Invention Disclosure for the Olympic Peninsula Demonstration Project. In this project, a rolling window of 24 hours was used to determine average price and standard deviations. The new method uses day ahead pricing to calculate similar values.
Novel Composite Solid Oxide Fuel Cell Anode Based on Ceria and Strontium Titanate
Rare earth-doped ceria possesses mixed ionic and electronic conductivity and is considered to be a promising anode material for SOFCs operating on methane. They exhibit excellent activity for hydrogen oxidation and high resistively to carbon deposition when exposed to hydrocarbons. It has been reported that gadolinia-doped ceria anodes are able to tolerate redox cycling without degradation in their performance. At the same time, an electronic conductivity of gadolinia- and samaria-doped cerates of 0.1 S/cm is rather low and limits their use to the electrolyte-based SOFCs only. Doping with the pentavalent V2O5 showed a slight increase in Oe compared to pure CeO2. This suggested to be attributed to the introduction of cation vacancies, which react with oxide vacancies and shift Eq. 1 to the right. Consequently, this increases electronic and decrease ionic conductivity.
COORDINATION OF THERMOSTATICALLY CONTROLLED LOADS WITH UNKNOWN PARAMETERS
Apparatus and methods are disclosed for coordination of a population of Thermostatically Controlled Loads (TCLs) with unknown parameters to achieve group objectives including bidding and market clearing strategies designed to motivate self-interested users to realize efficient energy allocation subject to a peak power constraint. In one examples of the disclosed technology, a method of operating a load includes estimating a set of values for unmeasured parameters of the load's thermal environment based on output measurements of the thermal environment, determining an energy response based on the estimated set of values for the unmeasured parameters, and transmitting a bid for power for a finite time period based on the determined energy response to the coordinator. A clearing price is received from the coordinator responsive to the transmitted bid and power is sent to the load responsive to the received clearing price.