Auto Re-close Function for Transmission System

Auto Re-close Function for Transmission System

Ultra-high voltage transmission System lines transmit a large amount of electricity. Therefore, it is always desirable that the continuation of the flow of energy through the lines is not interrupted for a long time. There may be a temporary or permanent line error. Temporary errors are automatically removed and require no attempt to correct them. It is normal practice for operators to close the line after each defective initial journey on the line. If the error is temporary, the line is maintained after the second attempt to close the switch, but if the error persists, the protection system disconnects the line again and a permanent error is declared.

Electricity distribution networks are generally of two types, radial or interconnected. A radial network organizes the station and branches like a tree without connection to any other supply. This is typical of long rural lines with isolated

But since the further high voltage transmission lines bring high power, if there is a delay due to manual operation to close the circuit, there will be a great loss of system in view of costs and stability. By introducing the automatic reclosing scheme in additional high voltage transmission system, we can avoid unwanted delays due to human operation. We classify failures in the electrical transmission system in three ways,

Transitional failure

Semi-permanent bankruptcy

Permanent bankruptcy

auto reclosing scheme of transmission system

But since the further high voltage transmission system lines bring high power, Transitional failure

Semi-permanent bankruptcy

Permanent bankruptcy

if there is a delay due to manual operation to close the circuit, there will be a great loss of system in view of costs and stability. By introducing the automatic reclosing scheme in additional high voltage transmission system

Temporary errors are those that are automatically removed for a moment. Semi-permanent faults are also transient in nature, but it takes a few minutes to eliminate them. Semi-permanent failures can occur due to drops in active conductors. Semi-permanent faults are removed after burning out the cause of the faults. During the two aforementioned faults, the line trips, but the line can be reset if the switches associated with the line are closed.

The automatic reclosing or automatic reclosing scheme does exactly that. In an overhead transmission system, 80% of failures are transient and 12% of failures are semi-permanent. In the automatic reclosing scheme, if the fault is not eliminated on the first attempt, there will be short or triple closing short circuits until the fault is eliminated. If the error still persists, this scheme permanently opens the circuit breaker. A prescribed delay can be imposed on the automatic reclosing system to allow the elimination of the semi-permanent fault from the circuit.

A prescribed delay can be imposed on the automatic reclosing system to allow the elimination of the semi-permanent fault from the circuit.

Electricity distribution networks are generally of two types, radial or interconnected. A radial network organizes the station and branches like a tree without connection to any other supply. This is typical of long rural lines with isolated loading areas. In general, the radial distribution network has more power outages than the interconnected distribution networks.

In a secondary network, transformers are distributed over an area (eg on roads) and have multiple supplies. The transformers are connected to each other on the secondary side. The system is organized in such a way that neighboring transformers do not use the same power supply. In case of problems with a power supply (or transformer), the load is powered by nearby transformers, so there is no interruption, although there may be a voltage drop for that load. Usually a mistake on the secondary side is not a big deal as the drivers will destroy themselves.

A point network is basically a secondary network condensed in a point. Several transformers have multiple supplies and their secondaries are connected together. In addition to a power outage across the region, they are vulnerable to bus failure, which is extremely rare. The simplest case is that in which each transformer connects to a power supply and vice versa (“unit system”). High voltage switching can be used to manage multiple cases, for example transformer in operation but power supply defective or vice versa.

Urban network transformation substations (spots) can be used to create interconnected distribution networks to serve a single installation. Examples of such individual facilities include airports, hospitals, major data centers (especially those that use uninterrupted power supplies) and sports stadiums that regularly broadcast national television events.

In large cities, many utility companies use power supplies to create interconnected distribution networks to serve the city center. The interconnected network has multiple connections to the supply points.

Network protections (reverse current relays) are used to detect any open circuit that allows electric current to flow to its source.

In electricity distribution, automatic circuit reclosers (ACR) are a class of switchboards designed for use in air power distribution networks to detect and stop momentary faults. Also known as automatic reclosers or automatic reclosers, ACRs are essentially high voltage rated circuit breakers with integrated current and voltage sensors and a protection relay, optimized for use as a protection resource for the distribution of the air network. Commercial ACRs are regulated by the ANSI / IEEE C37.60, IEC 62271-111 and IEC 62271-200 standards. The three main operating voltage classes are 15.5 kV, 27 kV and 38 kV.

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While the original designs of hydraulic reclosers had rudimentary protection capabilities, modern semiconductor-controlled devices feature sophisticated control systems that allow the configuration of variable responses to different types of faults in the distribution network. The number of reclosure 

In electricity distribution, automatic circuit reclosers (ACR) are a class of switchboards designed for use in air power distribution networks to detect and stop momentary faults. Also known as automatic reclosers or automatic reclosers, ACRs are essentially high voltage rated circuit breakers with integrated current and voltage sensors and a protection relay, optimized for use as a protection attempts is limited to a maximum of four by the Imprisonment Standards. The basic philosophy of reclosing is to actively consider bankruptcy cases and provide an effective response based on the type of failure, this is done in a probabilistic methodology together with the detection of the type of failure.

The most common type of failure in an air distribution network is lightning. Overvoltages cause an increase in voltage which can cause localized breakdown of the insulation, allowing arcs to form on the insulators. Reclosers can detect this as an overcurrent or ground fault (depending on the asymmetry of the fault). The flashes flash very quickly (decrease by 50 ms), therefore the first reclosing operation of a reclosing can be configured to trigger and close quickly. This first reclosing allows the interruption of the electric arc caused by lightning, but quickly restores power.

If the recloser closes on a failure, the failure is likely to be a secondary class of failure, contact with vegetation, or equipment failure. An overcurrent error would indicate a line to line class error, which can be confirmed by a negative phase sequence overcurrent protection, while a ground fault can indicate a line to ground or double line to ground fault. The reclosers can apply a fuse burnt policy, in which they remain closed for a short period to allow the fuses to burn on the side lines, isolating the fault. If the error is not eliminated, the recloser reopens. The same policy can be used to supply power to error sites to burn the line error. It could be a cross between several lines or a wildlife (birds, snakes, etc.) that comes into contact with drivers.

Automatic closure in action

Residential customers in areas powered by affected overhead power lines may occasionally see the effects of an automatic reclosure in action. If the error concerns the customer’s distribution circuit, one or more short and complete interruptions followed by normal operation may be displayed (since automatic reclosing can restore the power supply after a temporary error has been resolved) or a interruption completes the service (like automatic reclosing) exhausts your attempts). If the fault is in an adjacent circuit, the customer can see several short voltage drops when the heavy fault current flows into the adjacent circuit and is interrupted one or more times. A typical manifestation would be the fall, or intermittent blackout, of home lighting during an electrical storm. The action of automatic reclosing can cause loss of time settings of electronic devices, loss of data in volatile memory, shutdown, restart or damage due to a power failure. Owners of such equipment may need to protect electronic devices from the consequences of power outages and even surges. 

In electricity distribution, automatic circuit reclosers (ACR) are a class of switchboards designed for use in air power distribution networks to detect and stop momentary faults. Also known as automatic reclosers or automatic reclosers, ACRs are essentially high voltage rated circuit breakers with integrated current and voltage sensors and a protection relay, optimized for use as a protection Fire and forest fire safety

The risk of fire is an innate risk of an air distribution network. Regardless of the choice of distribution protection switchboards, the risk of fire is always greater with overhead conductors than with underground cross-linking. 

The Royal Victorian Commission on fires in 2009 indicated that reconnection should be disabled on high fire risk days, however on low risk days it should be applied for the reliability of the offer. If the recloser closes on a failure, the failure is likely to be a secondary class of failure, contact with vegetation, or equipment failure. An overcurrent error would indicate a line to line class error, which can be confirmed by a negative phase sequence overcurrent protection, while a ground fault can indicate a line to ground or double line to ground fault. The reclosers can apply a fuse burnt policy, in which they remain closed for a short period to allow the fuses to burn on the side lines, isolating the fault. If the error is not eliminated, the recloser reopens. The same policy can be used to supply power to error sites to burn the line error. It could be a cross between several lines or a wildlife (birds, snakes, etc.) that comes into contact with drivers.

Wrong or previous model reclosers have been implicated in the activation or spread of forest fires. Research on Black Saturday fires in Australia in 2009 indicated that reclosers that function as single-click circuit breakers with a sensitive earth fault protection set to 500 mA would reduce the risk of fire by 80%. Any form of reclosure should be eliminated on days with a high risk of fire and reclosure in general should not apply to ground faults. The most common type of failure in an air distribution network is lightning. Overvoltages cause an increase in voltage which can cause localized breakdown of the insulation, allowing arcs to form on the insulators. Reclosers can detect this as an overcurrent or ground fault (depending on the asymmetry of the fault). The flashes flash very quickly (decrease by 50 ms), therefore the first reclosing operation of a reclosing can be configured to trigger and close quickly. This first reclosing allows the interruption of the electric arc caused by lightning, but quickly restores power

Victorian public services responded to the Royal Commission by converting part of their air network into high-risk areas into underground cables, replacing exposed air conductors with insulated cables and replacing old reclosers with modern ACRs with remote communications to ensure that the configuration can be regular in case of forest fire. risk days

Temporary errors are those that are automatically removed for a moment. Semi-permanent faults are also transient in nature, but it takes a few minutes to eliminate them. Semi-permanent failures can occur due to drops in active conductors. Semi-permanent faults are removed after burning out the cause of the faults. During the two aforementioned faults, the line trips, but the line can be reset if the switches associated with the line are closed.

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