The primary objective of this Technical Report is to provide guidelines in planning and design of the interconnected power system (IPS) and consequently achieve the delivery of reliable supply service. The guidelines for the design of interconnected power systems within this document will enhance system reliability, mitigate many of the adverse impacts associated with the loss of a major portion of the system or unintentional separation of a major portion of the system, and will not be consequential because of normal design contingencies.
In the context of this Technical Report, interconnected power system means an entity’s (control area or a system operator) high-voltage transmission system that can adversely impact other connected systems due to faults and disturbances within its area. In the case of large areas, the system operator may define a subset of its area to keep the adverse impact contained within a smaller portion of its system.
This Technical Report specifies the recommended techniques for securing an IPS to ensure a high level of reliability. Generally, interconnected power systems are synchronously connected or asynchronously connected through DC interconnections. This document aims to ensure that the interconnections are designed and operated consistently on both ends. The recommendations include design and operation requirements to withstand the primary contingencies specified in this document.
It is recommended that each entity ensures that its portion of the high voltage IPS is designed and operated in unison with these guidelines. This precaution is recommended, otherwise additional system interconnections can cause significant adverse impacts on reliability of the connected entities. Each entity is also encouraged to make use of committees, task forces, working groups, interregional studies and other methods in order to ensure their IPS is constantly updated/enhanced and maintained, in such a way that it is in agreement with these guidelines.
NOTE The application of this guide is for high voltage transmission systems (generally over 50 kV). However, mitigation measures for certain system conditions, such as under frequency load shedding (UFLSh), are frequently required for low voltage distribution systems; hence, for the purpose of this transmission guide, interconnected control areas and/or system operators can establish the voltage level, as required. In addition, the design guidelines in this document are intended only for those elements of the IPS (not the entire high voltage transmission system) that can adversely impact other connected system(s) due to faults and disturbances within an area or a predefined subset of a large area. This document also provides guidance to determine such elements of the IPS.