SES-Shield is a complement to the considerably more powerful SESShield-3D package, providing optimized lightning shielding system heights for substations, shielding performance estimates for substations and transmission lines, and detailed risk assessments in accordance with IEC 62305-2.
The substation and transmission line shielding analyses are based on the electrogeometric model (frequently called “the rolling sphere method”) specified in the IEEE 998, IEEE 1243 and IEC 62305 standards.
The main purpose of the design component of this software package is to assist the user in optimizing the location and configuration of shield wires and masts in order to prevent the exposure of energized conductors, busses and equipment to direct lightning strikes of excessive magnitude. The risk assessment module, for its part, provides a formal assessment of the risk of different types of loss pertaining to vulnerable structures.
Main Interface – Optimal Position of the Protection System
The design component of SES-Shield is particularly suited to shielding substations made up of parallel bays. See the following figure, for example, which shows a substation bay, along which shield wires (dotted red lines) and masts (points a1,…,an and c1,…,cn) are installed. SES-Shield can handle such systems, whether shield wires or masts are to be used for protection. For more complex configurations, use SESShield-3D.
Example of Substation for Which Shielding Can Be Designed with SES-Shield
SES-Shield also explores two lightning protection failure mechanisms associated with transmission lines:
- Back Flashover: SES-Shield calculates the probability that a flashover will occur across the line insulators as a result of a lightning strike to transmission line structures or to shield wires to which they are connected.
- Shielding Failures: SES-Shield also calculates the probability that a large magnitude lightning strike will miss the shield wires or transmission line structures and terminate directly on the phase conductors. SES-Shield can help you by computing the optimal position of each transmission line shield wire for effective shielding of each phase conductor. The corresponding shielding angles between shield wires and phase conductors are also computed.
Main Interface – Fluctuation of Critical Stroke Current
The risk assessment module integrated into SES-Shield allows you to assess the risks related to lightning strikes on a structure, based on a formal procedure set forth in IEC 62305. The risks include damage to the structure itself, its components and contents, and may also extend to the surroundings of the structure and even involve the local environment. This type of analysis can help in selecting appropriate protection measures that reduce risks associated with lightning to a tolerable level.
Input data for the characteristics of the structure
Whereas SES-Shield allows you to rapidly design shielding systems for simple substation and transmission line geometries and carry out formal risk assessments, SESShield-3D provides you with the ability to model complex 3D systems and design lightning shielding systems for them.