• Rainbow Technologies
  • Rainbow Technologies
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  • Rainbow Technologies
  • Rainbow Technologies
  • Rainbow Technologies
  • Rainbow Technologies
  • Rainbow Technologies
  • Rainbow Technologies

Protection

The primary functions of a Protection System have remained unchanged through the decades and advance of Technology. The main functions of the Protection System are detailed below (in order of importance)
 
I= Fault Current (constant value, governed by system impedance)
R = Fault Resistance
t = Time (determinate value which can be reduced by adequate Protection Design and Implementation)
 
To safeguard the entire system to ensure continuity of supply in the event of a fault
Discrimination is key here (effective isolation of faulted portion of network whilst keeping healthy portion live).
 
To minimise damage and repair costs
This relates to IRt as arc flash can render equipment irreparable and can also erode upstream components due to thermal damage (i.e. upstream transformers in the fault path)
In order for these criteria to be satisfied, the following basic requirements are necessary.

BASIC REQUIREMENTS

Selectivity -To detect and isolate only the faulty item
Reliability - Dependability of operation - security that the system will remain solid for transient events such as inrush currents during motor starts.
Sensitivity - Isolate small fault currents that could result in further damage e.g. an earth fault resulting in a 3phase fault
Speed - Minimise damage to plant and personnel
 
Rainbow Technologies makes use of ERACS Power System Simulation tools (checked using basic principles) to ensure effective Protection Design in order for the 4 basic requirements to be met as detailed above.
Rainbow has extensive experience in the 21 years of operation in the following protection areas;

• Protection philosophy – essential to meet the BASIC REQUIREMENTS while ensuring that the protection integrates with existing supply utility systems and in-situ protection
• Protection Troubleshooting – investigating nuisance tripping/protection failure and rectifying problems with revised and optimised settings
• Protection studies and Grading – complete system studies and Grading to ensure correct grading with sufficient margins. Specialising in co-generation applications with islanding settings (frequency, rate-of-change of frequency, voltage deviations, reverse power etc).
• Audits and Commissioning – Injection testing, Application of settings, Certification of systems (important for insurance purposes), QA and Documentation Control etc
 
An abbreviated list of protection studies carried out is shown below:
 
protection
  • Rainbow Technologies
  • Rainbow Technologies
  • Rainbow Technologies
  • Rainbow Technologies
  • ECSA
  • SAIEE
  • UKZN
  • Millenium Power