SYNERGEE 4.0 FAULT LOCATION APPLICATION TUTORIALS AND GUIDE

SYNERGEE 4.0 FAULT LOCATION APPLICATION TUTORIALS AND GUIDE
Fault Location using Synergee simulation software version 4.0

SynerGEE has an application to help find probable fault locations when the magnitude of fault current is known for a specific location. If fault values are known from electronic relay readings, fault meter values, or other sources then SynerGEE can help track down the location of the fault. This application is part of the SynerGEE Protection Module.

Application approach
The fault location application uses SynerGEE’s Fault Flow Analysis and detailed by-phase models to calculate fault current values at various locations in the model. For each location, SynerGEE determines the current that is seen at the metering device. In a radial, semi-homogeneous, grounded system, the type of fault can be easily determined from the fault levels seen at the point of metering. The fault type becomes more difficult to determine when some of these complexities are introduced:

• Transformers with phase coupling connections
• Ungrounded regulator banks
• Significant line-line loads
• Large loads
• Strong electromagnetic coupling between phases
• Substantial error or variation in recorded fault values
• Incomplete fault data
• Loops
• Wandering laterals
• Generators

SynerGEE distribution models deal with all of these complexities and more. The fundamental applications like load-flow, fault, and fault-flow also deal with these issues. The fault location application leverages those capabilities by faulting all reasonable locations downstream from the metering point (or protective device operating point) and evaluating the results. It does not attempt to identify the fault type based on the metered values but instead measures the fit for all fault types. This approach is likely inefficient for small simple models but it gains efficiency and practicality as models grow in size and complexity. In most realistic circuit models, manually determining fault location from recorded values is not an easy task. Fault Location analysis automates the job and gives the engineer scored zones where the fault will likely be found.

Fault Sequence
Fault sequence analysis is a new application (under further development) within the SynerGEE Protection Module that helps the engineer understand the time-domain switching sequences of protective devices and automated switches.

This application has settings which allow the engineer to specify fault values at a specific location. Once run, the application estimates the operation of relays, reclosers, fuses, and auto-transfer switches in response to the fault. The real-world interaction of these devices is very complex and this SynerGEE application is designed to be a good estimate of that real-world behaviour. There are some things that are not addressed in the application:

• Relay cooling
• Time dial reset delay (disk ‘heating’ and ‘cooling’)
• Stochastic handling of fuse blowing (we blow our fuses at maximum clear)

The application does include settings for recloser fast and slow curve reset time and for auto-transfer switching delays.