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Negative sequence current is defined as 3I2 = (phase 1)*(1angle 0) + (phase 2)*(1angle 240) + (phase 3)*(1angle 120) Negative sequence current is seen in three phase power systems due to natural system imbalance. Also during unbalanced fault conditions such as line to line, Line to ground, and line to line to ground faults. It is not seen in purely balanced three phase faults.
Negative Phase Sequence is Phenomena generally found in motors,the formula for positive phase sequence is : Ip= Ir + a * Iy + a^2*Ibthe formula for negative phase sequence is : In= Ir + a ^2* Iy + a*IbAs the name suggest the sequence of current or the mmf is in reverse order, a reverse order current in stator will produce a reverse order mmf, now this reverse order mmf is rotating in direction opposite to the rotor of the motor, thus the mmf cut is very high and so current induced in stator is considerably high; as for normal mmf it is in direction of rotor so mmf cut is very small thus current induced is very small.this high current in your rotor leads to overheating of your motor and finally burning of your windings.CommentNegative phase sequence is not 'generally found in motors'. But one of the effects of negative phase sequence would be to cause a three-phase motor to reverse direction.
Zero sequence is part of symmetrical components; it's a way of looking at three phase power that simplifies the math involved. In general zero sequence current is synonymous with ground fault current.
In symmetrical components, there are three types of impedances - positive sequence (balanced), negative sequence (unbalanced), and zero sequence (ground). In a transformer, positive and negative are equal. Ground impedance is determined by the (same factors as the) positive sequence and is based on the flux paths available through the transformer core that can induce ground current.
When a capacitor is discharging, current is flowing out of the capacitor to other elements in the circuit, similar to a battery. Current flowing out of an element, by convention, is defined as negative current, while current flowing into an element, such as a resistor, is defined as positive current. Thus a discharging capacitor will always have a negative current.
4/4+4*4=20 is it correct by any means or not ? No this garbage has got nothing to do with negative phase sequence current in 3 phase electrical systems.
A negative sequence relay is looking at unbalanced current, such as what would result from a line to line or line to ground fault. I'm not sure what you're meaning by "mechanism". Please explain if the above doesn't answer your question.
Negative sequence current is defined as 3I2 = (phase 1)*(1angle 0) + (phase 2)*(1angle 240) + (phase 3)*(1angle 120) Negative sequence current is seen in three phase power systems due to natural system imbalance. Also during unbalanced fault conditions such as line to line, Line to ground, and line to line to ground faults. It is not seen in purely balanced three phase faults.
Negative Phase Sequence is Phenomena generally found in motors,the formula for positive phase sequence is : Ip= Ir + a * Iy + a^2*Ibthe formula for negative phase sequence is : In= Ir + a ^2* Iy + a*IbAs the name suggest the sequence of current or the mmf is in reverse order, a reverse order current in stator will produce a reverse order mmf, now this reverse order mmf is rotating in direction opposite to the rotor of the motor, thus the mmf cut is very high and so current induced in stator is considerably high; as for normal mmf it is in direction of rotor so mmf cut is very small thus current induced is very small.this high current in your rotor leads to overheating of your motor and finally burning of your windings.CommentNegative phase sequence is not 'generally found in motors'. But one of the effects of negative phase sequence would be to cause a three-phase motor to reverse direction.
A negative current only signifies direction.
Is called AC voltage or current.
What is the significance of negative values of voltage and current?Negative values show direction and that is the significance
Zero sequence is part of symmetrical components; it's a way of looking at three phase power that simplifies the math involved. In general zero sequence current is synonymous with ground fault current.
In symmetrical components, there are three types of impedances - positive sequence (balanced), negative sequence (unbalanced), and zero sequence (ground). In a transformer, positive and negative are equal. Ground impedance is determined by the (same factors as the) positive sequence and is based on the flux paths available through the transformer core that can induce ground current.
Electron flow is from negative to positive. Conventional current flow is from positive to negative.
When a capacitor is discharging, current is flowing out of the capacitor to other elements in the circuit, similar to a battery. Current flowing out of an element, by convention, is defined as negative current, while current flowing into an element, such as a resistor, is defined as positive current. Thus a discharging capacitor will always have a negative current.
Conventional current flow is from positive to negative. Electron flow is from negative to positive