Smart Grid - The New and Improved Power Grid:

Phasor Measurement Techniques.- Phasor Estimation of Nominal Frequency Inputs.- Phasor Estimation at Off-Nominal Frequency Inputs.- Frequency Estimation.- Phasor Measurement Units and Phasor Data Concentrators.- Transient Response of Phasor Measurement Units.- Phasor Measurement Applications.- State Estimation.- Control with Phasor Feedback.- Protection Systems with Phasor Inputs.- Electromechanical Wave Propagation.

Synchronized Phasor Measurements and Their Applications

In this article, we present the security, agility, and robustness/survivability of a large-scale power delivery infrastructure that faces new threats and unanticipated conditions. By way of background, we present a brief overview of the past work on the challenges faced in online parameter estimation and real-time adaptive control of a damaged F-15 aircraft. This work, in part, provided the inspiration and laid the foundation in the 1990s for the flight testing of a fast parameter estimation/modeling and reconfigurable aircraft control system that allowed the F-15 to become self-healing in the face of damaged equipment.

Toward a smart grid: power delivery for the 21st century

On August 14, 2003, a cascading outage of transmission and generation facilities in the North American Eastern Interconnection resulted in a blackout of most of New York state as well as parts of Pennsylvania, Ohio, Michigan, and Ontario, Canada. On September 23, 2003, nearly four million customers lost power in eastern Denmark and southern Sweden following a cascading outage that struck Scandinavia. Days later, a cascading outage between Italy and the rest of central Europe left most of Italy in darkness on September 28. These major blackouts are among the worst power system failures in the last few decades. The Power System Stability and Power System Stability Controls Subcommittees of the IEEE PES Power System Dynamic Performance Committee sponsored an all day panel session with experts from around the world. The experts described their recent work on the investigation of grid blackouts. The session offered a unique forum for discussion of possible root causes and necessary steps to reduce the risk of blackouts. This white paper presents the major conclusions drawn from the presentations and ensuing discussions during the all day session, focusing on the root causes of grid blackouts. This paper presents general conclusions drawn by this Committee together with recommendations based on lessons learned.

Causes of the 2003 major grid blackouts in North America and Europe, and recommended means to improve system dynamic performance

Synchronized phasor measurements have become a mature technology with several international manufacturers offering commercial phasor measurement units (PMUs) which meet the prevailing industry standard for synchrophasors. With the occurrence of major blackouts in many power systems around the world, the value of data provided by PMUs has been recognized, and installation of PMUs on power transmission networks of most major power systems has become an important current activity. This paper provides a brief introduction to the PMU and wide-area measurement system (WAMS) technology and discusses the uses of these measurements for improved monitoring, protection, and control of power networks.

Synchronized Phasor Measurement Applications in Power Systems

??????????? ????? Stanley Horowitz H Power System Relaying May 13th, 2020 With emphasis on power system protection from the network operator perspective this classic textbook explains the fundamentals of relaying and power system phenomena including stability protection and reliability The fourth edition brings coverage up to date with important advancements in protective relaying due to significant changes in the conventional electric power system that will

Power System Relaying

IEEE Standard 1344, Synchrophasors for Power Systems, was completed in 1995. It sets parameters required to ensure that phasor measurement will be made and communicated in a consistent manner. It specifies requirements for the timing signal used for phasor synchronization and the time code needed for input to a measurement unit. GPS is the recommended time source and IRIG-B is the basic format used for time communication. The standard requires correlating phasors computed from unsynchronized and synchronized sampling to a common basis. Timetagging accurately and consistently is essential for wide area comparison of phase. The standard specifies information exchange and control message formats. These include data output, configuration, and command messages. It includes 7 annexes that discuss the concepts covered in the body of the standard.

IEEE Standard for Synchrophasors for Power Systems

The use of digital techniques to adapt transmission system protection and control to real-time power system changes is investigated. The discussion covers transmission system protection philosophy, transmission line protection, relay settings, transformer protection, and automatic reclosing. The tradeoff between dependability and security is examined, as well as the various conflicting criteria embodied in transmission line protection. Adaptive strategies that minimize the compromises required and thereby optimize system performance are presented. >

Adaptive transmission system relaying

Major blackouts of electric power systems in which many customers are left without power are rare events. However, the effects of blackouts, for instance, can be catastrophic. It has been observed that protective system failures are a contributing factor in a large proportion of these blackouts. The most troublesome protection system failures are hidden failures, which remain dormant during normal system conditions, and are exposed during system disturbances. A study of hidden failures of the protective systems is undertaken to uncover their modes of failures, and to determine means of supervising their actions in times of highly stressed power system operations. The main contribution of this paper is to develop and document a method of quantitative analysis of the significance of hidden failures of protection systems. A complete protection system was designed for the New England 39-bus system and the hidden failure modes were used to develop regions of vulnerability and a vulnerability index. Through this analysis, critical protection systems, whose hidden failures would have a major impact on cascading failures or blackouts of the power system, can be identified These protection systems are candidates for increased monitoring and control, which would help alleviate the problems posed by hidden failures.

Anatomy of power system blackouts: preventive relaying strategies

The application of microprocessor-based phasor measurements to novel adaptive protection schemes is presented. The concepts of digital adaptive protection in which relay characteristics are modified in response to external signals and conditions in the system, are examined. The importance of real-time phasor measurements in adaptive protection systems is illustrated by two examples. The first involves obtaining synchronizing information about phasor measurements to be used for current differential protection of a multithermal line. By estimating the reference angles for the phasor measurements the effect of synchronized sampling can be obtained without the expense of synchronizing equipment. The second use is the adaptive setting of out-of-step blocking and tripping. Traditional approaches experience problems because the settings are, of necessity, compromises based on offline studies. By reacting to real-time phasor measurements from selected buses in interconnection, it is shown that improved out-of-step blocking and tripping is possible. >

Stanley H. Horowitz

Papers

Power System Relaying

IEEE Standard for Synchrophasors for Power Systems

Adaptive transmission system relaying

Anatomy of power system blackouts: preventive relaying strategies

Some applications of phasor measurements to adaptive protection