Gerald J. FitzPatrick

NIST interoperability framework and action plans

The 2007 Energy Independence and Security Act gave NIST the role of coordinating with industry and government stakeholders the development of an interoperability framework for Smart Grid (SG) devices and systems, including standards and protocols. The goal is to achieve seamless interoperability of SG devices and systems across the power system from generator to consumer. With the collaboration of many smart grid stakeholders who provided input through a series of workshops, domain expert working group activities, and other direct interactions, NIST has published the “NIST Framework and Roadmap for Smart Grid Interoperability Standards Release 1.0” document. It includes a conceptual reference model for the SG, standards identified for implementation, a set of standards priority action plans (PAPs), and a cyber security risk management framework and strategy. In 2009, a SG Interoperability Panel (SGIP) that comprises representatives from SG stakeholders across the board was established to further the development of the Interoperability Framework, support the development of new and revised PAPs, and coordination with the Standards Development Organizations (SDOs). This paper reports on progress made in the development and implementation of the Interoperability Framework, the SGIP activities, and on the progress on tasks for standards harmonization and development defined in the PAPs.

Calibration of dissipation factor standards

Dissipation factor (DF) standards obtained by connecting a shielded three-terminal capacitor in series with a shielded resistor have been developed for calibration purposes. An analysis of these DF standards, including precautions in their construction and use, is presented and calibration procedures using the NIST high voltage capacitance bridge is discussed.

Comparative high voltage impulse measurement

A facility has been developed for the determination of the ratio of pulse high voltage dividers over the range from 10 kV to 300 kV using comparative techniques with Kerr electro-optic voltage measurement systems and reference resistive voltage dividers. Pulse voltage ratios of test dividers can be determined with relative expanded uncertainties of 0.4 % (coverage factor k = 2 and thus a two standard deviation estimate) or less using the complementary resistive divider/Kerr cell reference systems. This paper describes the facility and specialized procedures used at NIST for the determination of test voltage divider ratios through comparative techniques. The error sources and special considerations in the construction and use of reference voltage dividers to minimize errors are discussed, and estimates of the measurement uncertainties are presented.

Pressure effects on partial discharges in hexane under DC voltage

The pressure dependence of partial discharges (PD) has been experimentally investigated at a needle electrode in hexane from subatmospheric pressure (near hexane vapor pressure) to several atmospheres. Each PD produces a phase transition in the liquid near the needle, which is photographed in synchronism with a characteristic pattern of current pulses. An image-preserving optical delay allows photography to commence just before or at inception of the discharge. Individual current pulses comprising a characteristic pattern are resolved. The cathode event consists of a short pressure-insensitive inception phase, a pressure-sensitive growth at a decreasing rate, and finally a detachment and dissipation, sometimes with noticeable contraction before detachment; increased pressure reduces the growth rate and lifetime. The accompanying characteristic current pulse pattern always ceases during the growth of the PD. For the anode event, less extensive data similarly show slowing of growth with increased pressure and a (different) characteristic current pulse pattern.<<ETX>>

Extension of voltage range for power and energy calibrations

A special purpose ac voltage divider system having voltage ratios of 600 V, 480 V, 360 V, and 240 V to 120 V has been developed to extend the voltage range of primary electric power calibrations from 120 volts to 600 volts at power frequencies of 50 and 60 Hz. The system consists of a special two-stage resistive divider compensated with an active circuit, thereby reducing the error contributions to below 1 /spl mu/V/V. The developmental goal to realize ac voltage scaling within 5 /spl mu/V/V uncertainty in a device verifiable with dc resistance ratio measurements has been attained.

Transient errors in a precision resistive divider

Resistive dividers have the advantages of DC response and stability. However unlike capacitive dividers, they inevitably involve power dissipation and also generally involve an appreciable inductance. These aspects of a resistive divider result in transient errors, i.e., errors which are a function of the applied waveform. This paper discusses transient measurement errors of precision high voltage resistive dividers such as the one developed by NIST.

Application of a 10 V Programmable Josephson Voltage Standard in Direct Comparison With Conventional Josephson Voltage Standards

This paper briefly describes the working principle of the 10 V programmable Josephson voltage standard (PJVS) that was developed at the National Institute of Standards and Technology and how to use it in a direct comparison with a conventional Josephson voltage standard (CJVS). Manual and automatic comparison methods were developed to verify the agreement between the two types of Josephson standards. A 10 V PJVS provided by the National Aeronautics and Space Administration (NASA) was used as a transfer standard in the 2014 Josephson voltage standard Interlaboratory Comparison that is organized by the National Conference of Standards Laboratories International. The results of automatic direct comparisons between a NASA PJVS and three CJVSs are reported. Allan variance is applied to analyze the large number of correlated data for Type A uncertainty.

NIST role in the interoperable Smart Grid

The 2007 Energy Independence and Security Act (EISA) gave NIST the role of coordinating with industry and government stakeholders the development of an interoperability framework for Smart Grid (SG) devices and systems, including standards and protocols. The goal is to achieve seamless interoperability across the power system from generator to consumer. NIST is in the process of identifying the standards necessary to achieve interoperability.

Smart Sensors and Standard-Based Interoperability in Smart Grids

Smart grids (SGs) are electrical power grids that apply information, advanced networking, and real-time monitoring and control technologies to lower costs, save energy, and improve security, interoperability, and reliability. Smart sensors (SSs) can provide real-time data and status of the grids for real-time monitoring, protection, and control of grid operations. Sensor data exchange and interoperability are major challenges for the SGs. This paper describes sensing, timing, intelligence, and communication requirements of sensors for the SGs and proposes a general model of the SSs for SGs based on these requirements. Then it illustrates, how the model works with phasor measurement unit (PMU)- and merging unit-based SSs deployed in the SGs with standardized interfaces to support the interoperability of the SSs. Furthermore, to address the interoperability issues, this paper describes sensor interface standards used in the SGs and the need for interoperability testing, and proposes a passive interoperability test method for the SSs to achieve and assure sensor data interoperability. To verify this test method, an interoperability test system for the PMU-based SSs was developed and presented. Interoperability test results of eight commercial PMU-based SSs are provided to show that the proposed interoperability test method works.

NIST coordination of smart grid interoperability standards

The National Institute of Standards and Technology has efforts underway to accelerate the development of interoperability standards to support the future modernized “Smart Grid” electric grid or energy delivery network characterized by a two-way flow of electricity and information, capable of monitoring and responding to changes in everything from power plants to customer preferences to individual appliances. Through a high-visibility, rapid, and open process that brought together the Smart Grid community, including utilities, equipment suppliers, government and consumers of electricity, NIST has developed and published its Framework and Roadmap for Smart Grid Interoperability Standards, Release 1.0 [1], to create the basis for prioritizing, coordinating and accelerating the development of standards in private-sector standards setting organizations, including international standards development organizations such as the International Electrotechnical Commission (IEC) and the IEEE.