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Directionalized relays are relays that use a polarizing circuit to determine which "direction" (in the zone of protection, or out of the zone protection) a fault is. There are many different types and different polarizing methods - ground polarizing, voltage polarizing, zero sequence voltage polarizing, negative sequence polarizing, etc.
The basic operation of this relay is just like any nondirectional relay, but with an added torque control - the directionalizing element. This element allows the relay to operate when it is satisfied that the fault is within the zone of protection (ie not behind where the relay is looking).
What else can I help you with?
What is difference between reverse power relay and directional relay in electrical protection?
A reverse power relay is a directional overcurrent relay. Directional relays are relays that sense power flow in one direction, and include (directional) overcurrent relays, reverse power, and impedance based relays. So a reverse power relay is a directional relay, but a directional relay is not necessarily a reverse power relay.
What is the difference between directional and non directional over current protection?
The directional part. Directional relays will operate for events "in front of" them, but will not operate for events "behind" them. Typically directional relays are used in non radial situations such as on the bulk electric system. Non-directional overcurrents are commonly used on radial lines.
What is LBB protection Relay?
LBB is local breaker protection
How Directional overcurrent relay works?
I don't know how you got this posted in the Dodge forum but I will explain. The directional overcurrent relay is a relay that will provide overcurrent protection in a directional manner. I know this sounds simplistic but let me give you a scenario. A large industrial company has its own electrical generation provided by a few generators. One might think that the company would have no outside connection to a public utility because they generate their own electricity. However this is not the case as having a tie to the utility affords a few advantages. Some advantages are that synchronization of the industrial companies generators can easily be maintained at 60Hz. Additional inrush current can be easily provided by the utility, whereas should the industrial company only rely on their generators a larger voltage swing might occur when a large motor is started. The industrial customer can also be provided with backup power levels in case of some failure with their own generation. So you do want to provide a tie to the utility. You must protect the tie against overcurrents. However, if something were to happen to cause the utility power to fail you certainly do NOT want to try to power all the utilities other customers. Thats where the directional overcurrent relay comes into play. It will allow power to flow and protect a circuit as long as power is coming into a plant by a tie line. However should power try to flow out of the utility tie the directional overcurrent relay will trip. A mechanical directional overcurrent relay is actually a combination of a directional relay and an overcurrent relay. The directional portion is closely resembles a watt-hour meter. A potential transformer is required to provide a reference and if current is flowing one direction then a positive torque is placed on a mechanical disk. If current is flowing in the other direction then a negative torque is placed on the disk. Should the CT and PT connections be made such that positive torque is placed on the disk when current is flowing out of the industrial customer and to the utility then the disk will rotate and cause a contact to close. The closing contact will operate a breaker trip coil. However if current is flowing from the utility to the industrial customer then negative torque will be placed on the disk and it will be stopped by mechanical stops and the breaker will continue to remain closed. Of course you can use normally open or closed contacts to make the relays operate when and how you want. Other applications are as a reverse power relay for a generator and for line protection in a grid type system.
What is 50G protection relay mean?
50 is the ANSI device number for an instantaneous overcurrent relay. The G suffix stands for "ground." A 50G protection relay trips the circuit breaker without time delay when it detects a ground fault on the circuit.
What is difference between reverse power relay and directional relay in electrical protection?
A reverse power relay is a directional overcurrent relay. Directional relays are relays that sense power flow in one direction, and include (directional) overcurrent relays, reverse power, and impedance based relays. So a reverse power relay is a directional relay, but a directional relay is not necessarily a reverse power relay.
What is directional relay and its advantages and disadvantages?
A directional relay is a type of protective relay that determines the direction of fault current flow in a power system, enabling it to operate only when a fault occurs in a specific direction. Advantages include improved protection for transmission lines and the ability to distinguish between faults and load conditions, enhancing system reliability. However, disadvantages include increased complexity in settings and coordination, as well as the possibility of misoperation if the directional settings are not correctly configured. Additionally, directional relays can be more costly compared to non-directional relays.
Is feeder protection relay and ring main unit protection relay same?
No there not same
What is the difference between directional and non directional over current protection?
The directional part. Directional relays will operate for events "in front of" them, but will not operate for events "behind" them. Typically directional relays are used in non radial situations such as on the bulk electric system. Non-directional overcurrents are commonly used on radial lines.
What the three types of over current protection relay and describe the principles of operation?
over current protection relay
What is LBB protection Relay?
LBB is local breaker protection
Non-directional over current relay?
The synchronous generator when act as a motor that relay is operated. or reverse power relay is acted. mainly it sence thet direction of power flow direction
What are the directional characteristics of an over current relay?
Directional relay opeartes +/- 90degree of MTA (maxumum torque angle). Relay is set either forward or reverse depending on the direction of current flow. 180 degree to MTA is always restraint region. Some relay has chareteristic of +/- 85 degree to MTA.
Would a bad blinker relay wont let start the car?
No, the flasher relay has nothing to do with starting the vehicle. It only controls the flash of the directional lights.
Which relay is used to protect generators and motors?
differential protection relay
What is defrential protection relay?
I am going to assume that you are asking about a differential relay. It is basically just that- it compare two different sources and will trip at a set value value of the difference. These can be directional as well. A couple of examples are transformer protective relays and bus differential. A transformer relay will measure the amount of current coming into the transformer and the amount of current going out. If there is a disparity due to an internal fault the relay will trip the supply source and deenergize the transformer. Same for the Bus differential.
What is the use of reactance relay?
reactance relay is used for distance protection of the transmission line....
