The Busbar working principle is based on electrical conduction. Because busbars have a large cross-sectional area, they can safely carry high current without excessive. Bus bars appear to be simple and low glamour in comparison to many other active and even passive components, and in some ways, they are. However, they are also sophisticated structures that require an understanding of voltage drop due to conductor resistance, materials science, thermal issues. Percentage differential relays, also known as low-impedance differential relays, provide similar operating speed, and can provide a similar level of security, as high-impedance differential relays. In addition, low-impedance relays are simple to apply, as there are no special requirements for CT. Busbar differential protection is the primary method for detecting and isolating faults within the busbar zone of electrical substations using Kirchhoff's current law principle. This part looks at these situations, as well as testing of high-current/voltage bus bars.
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