SLD Preparation
What is the need of single line diagram in power system?
It shows a correct power distribution path from the incoming power source to each downstream load – including the ratings and sizes of each piece of electrical equipment, their circuit conductors, and their protective devices.
The Single Line Diagram (SLD) is considered as an essential tool for the electrical professional. The SLD is the blueprint for electrical system analysis. It represents a three-phase power system. It is a form of the block diagram which conveys the paths for power flow between different entities of the system.
Uses of an SLD
It works differently in a balanced and unbalanced system.
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In a three-phase power system, each phase is considered separately as long as the load is balanced separately in each phase. There can be asymmetric faults on one or two phases. So, here the SLD is used along with notational simplification.
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When using the symmetrical components method, separate one-line diagrams are made for each of the positive, negative, and zero-sequence systems.
What We Do?
Creating and Maintaining an SLD
After the construction of a building is completed, engineers and the builder work together to eliminate hazards related to power supply. The process goes step by step.
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A design engineer lays out the components and devices to be installed.
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The engineer creates assumptions used to estimate fault-current calculations and selective coordination needs.
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A contractor installs an SLD, marking-up the SLD as changes are made.
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The original design drawings revised to reflect changes made in the field are created.
The Importance of an SLD
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It is the primary resource to calculate short-circuit currents, determine selective coordination and, ultimately, calculate incident energy.
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Serving as a map of the electrical distribution system, an SLD documents conductors, transformers, overcurrent protective devices (OCPDs) and other electrical devices and safety mechanisms to aid in many areas of design and maintenance while reducing confusion.
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The simpler diagram leaves more space for non-electrical to be included.
Vidhyut Engineering
Shree Krishna Park Society,
Himalaya Mall Road,
Bhavnagar-364001,
Gujarat, India