Integrated Centralized Substation Protection

Substation cyber assets are mission critical for protection and control of substations. Managing and ensuring their secure operation is of paramount importance. A known vulnerability is hidden failures which are responsible for about 10% of mis-operations and their detrimental effects on system reliability. The paper presents an integrated centralized substation protection approach that is based on the recently developed setting-less relays which are integrated into a centralized substation protection scheme with the following features: (a) fast, dependable and secure protection of each substation protection zone by a settingless relay, (b) supervision of each settingless relay by validating relay input data by a substation wide state estimator, (c) self-healing against hidden failures by detecting and identifying compromised data and replacing them with estimated values, thus ensuring that the settingless relays will always operate on validated data. The paper provides a summary review of the settingless protective relay and introduces the Integrated Centralized Substation Protection Scheme (ICSP) which uses the data from all settingless relays in the substation to perform a substation wide state estimation. The state estimator uses a hypothesis testing algorithm to determine whether (a) data are valid with no faults or hidden failures, (b) data are valid and a fault exists in the system, or (c) some data are invalid due to hidden failures. In the last case, the state estimator uses the substation state and model to replace the compromised data with estimated values and thus enabling self-immunization against hidden failures. A byproduct of the method is the substation state estimate which is transmitted to the control center where it is used with the state from all substations to synthesize the system wide state estimate and model. Architectural issues are addressed as well as migration issues of existing systems into the proposed ICSP

Breaker to Control Center Integrated Protection, Control and Operations Model

Technological advances in electric energy system data acquisition systems, time synchronization, and cyber assets used in power system substations, distribution systems, and control centers offer new opportunities to dramatically improve the practice of monitoring, protection, control, and operation of the system. We can make the computer based new technologies smarter and more intelligent to fully automate the basic protection and control functions. The challenges posed to the system from the continuous deployment of renewable resources that are typically inverter interface resources require monitoring of the system at much higher rates and development of protection and control systems that can respond in much faster rates than for conventional systems and they are immune to the characteristics of the new system, namely reduced fault currents and suppressed negative and zero sequence components of the fault currents. We propose a new system that provides validated data at fast rates (once per cycle), protective relays that are immune to the effects of inverter interfaced generation, detect anomalies, and enable the continuous operation of relays and other functions even in the presence of hidden failures in instrumentation. This system will be able to enable the operators to meet the challenges posed by the evolving power system and provides robust solutions to the new requirements

Role of Protective Relaying in the Smart Grid

This paper discusses the role of protective relaying in a Smart Grid. It outlines the definition, attributes, and benefits of a Smart Grid. The role that protective relays can play in implementing Smart Grid functionality and the impact that a Smart Grid design may have on modern protective relays is discussed. Specific examples of Smart Grid applications that may be implemented using modern protective relays and other intelligent electronic devices are provided