Preventing battery short circuit

Power Short circuit refers to a circuit in which the current does not flow through the electrical appliances, but directly connects the positive and negative poles of the power supply. According to ohm's law I=U/R, since the resistance of the wire is very small the current on the circuit will be very large when the power is short. Such a large current, the battery or other power supply cannot withstand, will cause power damage. What's more, because the current is too large, it will raise the temperature of the wire, which may cause a fire.

That is, the current does not pass through any electrical appliances, and flows directly from the positive electrode to the negative electrode through the wire. It is especially easy to burn out the power supply. Since the internal resistance Ro of the power supply is small, the short-circuit current is large, and the terminal voltage of the power supply is 0, and the electromotive force of the power supply is all lowered to the internal resistance. Short-circuit current may cause mechanical damage and damage to the power supply. When the short circuit occurs, the power generated by the power supply is completely consumed by internal resistance. Short circuit is usually a serious accident and should be prevented as much as possible.

In order to ensure the safe and reliable operation of the system and mitigate the effects of short circuit, in addition to all the reasons that may cause short circuit in operation and maintenance, the short circuit fault should be removed as soon as possible to restore the system voltage in a short period of time to normal value. For this purpose, fast-acting relay protection and circuit breakers, as well as automatic installation of excitation devices for generators can be used. In addition, measures to limit the short-circuit current should be considered, such as reasonable selection of the form or operation mode of the electrical main wiring to increase the system impedance and reduce the short circuit current value; install a current-limiting reactor; use a split low-voltage winding transformer.

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