What you mean by positive sequence, negative sequence and zero sequence of voltage?

What you mean by positive sequence, negative sequence and zero sequence of voltage?
by

1 Answer

Answer :

Positive phase sequence

A system of vectors is said to have positive sequence if they are all of equal magnitude and are displaced by 120° with same time interval to arrive at fixed axis of reference as that of generated voltage. The positive phase sequence is represented below and the vectors arrive along X-axis in order 1, 2, 3 and conscript P has been used to designate as positive sequence.


image 


Negative phase sequence  

A system of vectors is said to have a negative phase sequence if they are of equal magnitude displaced at an angle of 120° but arrive at the axis of reference at the regular interval same as that of positive phase sequence but in order of 1, 3, 2. That is the order is reversed.

image 


Zero sequence  

A system of vectors in a phase system is said to have zero phase sequence if all the three vectors are not displaced from each other and there will be no phase sequence in such cases. The current or voltages in the 3-phase circuit vary simultaneously in all the 3- phases. Such phase sequence is zero phase sequence.


image

by

Related questions

What is meant by positive, negative and zero sequence reactance.

Description : What is meant by positive, negative and zero sequence reactance.

Last Answer : The reactance diagram of a power system, when formed using positive, negative and zero sequence reactances are called positive, negative and zero sequence reactance diagram resp.

What is meant by positive, negative and zero sequence impedance.

Description : What is meant by positive, negative and zero sequence impedance.

Last Answer : The impedance of the circuit element for positive, negative and zero sequence component currents are called positive, negative and zero sequence impedances resp.

If a 6 volt battery were connected in series with a 24 volt battery by putting their negative terminals together, what would be the result? A. 'Zero' volts B. 12 volts of the opposite polarity C. 18 volts, positive on the 24 volt battery D. 30 volts, negative on the 24 volt battery

Description : If a 6 volt battery were connected in series with a 24 volt battery by putting their negative terminals together, what would be the result? A. 'Zero' volts B. 12 volts of the opposite polarity C. 18 volts, positive on the 24 volt battery D. 30 volts, negative on the 24 volt battery

Last Answer : Answer: C

What is the calculated voltage at the positive and negative terminals of the battery shown in the illustration if each cell has a voltage of 1.5 volts? EL-0034 A. 1.5 volts B. 3.0 volts C. 6.0 volts D. 12.0 volts

Description : What is the calculated voltage at the positive and negative terminals of the battery shown in the illustration if each cell has a voltage of 1.5 volts? EL-0034 A. 1.5 volts B. 3.0 volts C. 6.0 volts D. 12.0 volts

Last Answer : Answer: A

An open occurring within the field rheostat of an AC generator can be detected by short circuiting its terminals and observing a ____________. A. negative deflection of the wattmeter pointer B. positive deflection of the wattmeter pointer C. buildup of alternator voltage D. low, but constant alternator voltage

Description : An open occurring within the field rheostat of an AC generator can be detected by short circuiting its terminals and observing a ____________. A. negative deflection of the wattmeter pointer B. ... of the wattmeter pointer C. buildup of alternator voltage D. low, but constant alternator voltage

Last Answer : Answer: C

If the electricity represented by the wave form in 'B' were applied to the left side of the illustrated circuit, the output on the right side would be ____________. EL-0064 A. direct current with the top lead positive with repect to the lower lead B. direct current, half wave rectified with a ripple frequency of 60 hz C. direct current with the top lead negative with repect to the lower lead D. clipped to a value equal to the square root of 3 times the input voltage value

Description : If the electricity represented by the wave form in 'B' were applied to the left side of the illustrated circuit, the output on the right side would be ____________. EL-0064 A. direct current with the ... lower lead D. clipped to a value equal to the square root of 3 times the input voltage value

Last Answer : Answer: C

In a simple series circuit, the entire source voltage will drop across ______________. A. the resistor next to the negative terminal B. a short circuit C. the resistor next to the positive terminal D. an open circuit

Description : In a simple series circuit, the entire source voltage will drop across ______________. A. the resistor next to the negative terminal B. a short circuit C. the resistor next to the positive terminal D. an open circuit

Last Answer : Answer: D

What is the polarity of voltage at point 'Z' in the circuit shown in the illustration? EL-0085 A. It will always be positive. B. It will always be negative. C. It depends on the instantaneous polarity at point 'W'. D. It cannot be determined without a voltmeter.

Description : What is the polarity of voltage at point 'Z' in the circuit shown in the illustration? EL-0085 A. It will always be positive. B. It will always be negative. C. It depends on the instantaneous polarity at point 'W'. D. It cannot be determined without a voltmeter.

Last Answer : Answer: A

A transformer has negative voltage regulation when its load power factor is- (a) Zero (b) Unity (c) Leading (d) Lagging

Description : A transformer has negative voltage regulation when its load power factor is- (a) Zero (b) Unity (c) Leading (d) Lagging

Last Answer : Ans: C

Define negative sequence component.

Description : Define negative sequence component.

Last Answer : It has 3 vectors equal in magnitude and displaced from each other by an angle 120 degrees and has the phase sequence in opposite to its original phasors.

What are negative sequence components?

Description : What are negative sequence components?

Last Answer : The negative sequence components of a three phase unbalanced vectors consists of three vectors of equal magnitude displaced from each other by 120 degree in phase and having the phase sequence opposite to that of the original vectors.

When the negative sequence reactance arises?

Description : When the negative sequence reactance arises?

Last Answer : Negative sequence arises whenever there is any unbalance present in the system. Their effect is to set up a field rotating in opposite direction to the main field.

What is Negative sequence reactance?

Description : What is Negative sequence reactance?

Last Answer : Negative sequence can arise whenever there is any unbalance present in the system. Their effect is to setup a field rotating in opposite direction to the main field. 

What is the negative sequence capability?

Description : What is the negative sequence capability?

Last Answer : I2 = 5% max,  I2 2 t = 7

Va and Vb are negative sequence component voltages the difference angle between Va and Vb with respect to Va is a) 240 b) 120 c) 180 d) 360

Description : Va and Vb are negative sequence component voltages the difference angle between Va and Vb with respect to Va is a) 240 b) 120 c) 180 d) 360

Last Answer : Ans: 120

Define positive sequence component.

Description : Define positive sequence component.

Last Answer : -has 3 vectors equal in magnitude and displaced from each other by an angle 120 degrees and having the phase sequence as original vectors.

What are positive sequence components?

Description : What are positive sequence components?

Last Answer : The positive sequence components of a three phase unbalanced vectors consists of three vectors of equal magnatude, displased from each other by 120 in phase and having the same phase sequence as the original vectors.

Define zero sequence component.

Description : Define zero sequence component.

Last Answer : They has 3 vectors having equal magnitudes and displaced from each other by an angle zero degrees.

What are zero sequence components?

Description : What are zero sequence components?

Last Answer : The zero sequence components of a three phase unbalanced vectors consists of 3 vectors of equal magnitude and with zero phase displacement from each other.

When the Zero sequence reactance arises?

Description : When the Zero sequence reactance arises? 

Last Answer : If a machine is operating with an earthed neutral, a system earth fault will give rise to zero sequence current in the machine. 

What is Zero sequence reactance?

Description : What is Zero sequence reactance? 

Last Answer : If a machine is operating with an earthed neutral, a system earth fault will give rise to zero sequence current in the machine. 

Q: Is zero a positive or a negative number? -General Knowledge

Description : Q: Is zero a positive or a negative number? -General Knowledge

Last Answer : None of the two mentioned above

A particle of mass m is moving along a straight path through the origin of coordinates with a velocity v. The angular momentum of the particle about the origin (a) mv (b) Depends on its distance from origin (c) Is zero (d) Changes from positive to negative as it passes through the origin

Description : A particle of mass m is moving along a straight path through the origin of coordinates with a velocity v. The angular momentum of the particle about the origin (a) mv (b) Depends on its distance from origin (c) Is zero (d) Changes from positive to negative as it passes through the origin

Last Answer : Ans:(c)

The electron affinity for the inert gases is (a) Zero (b) High (c) Negative (d) Positive

Description : The electron affinity for the inert gases is (a) Zero (b) High (c) Negative (d) Positive

Last Answer : Ans:(a)

If two commodities are complements, then their crossprice elasticity is- (1) zero (2) positive (3) negative (4) imaginary number

Description : If two commodities are complements, then their crossprice elasticity is- (1) zero (2) positive (3) negative (4) imaginary number

Last Answer : (4) imaginary number Explanation: In economics, the cross elasticity of demand or cross-price elasticity of demand measures the responsiveness of the demand for a good to a change in ... denotes two products that are complements, while a positive cross elasticity denotes two substitute products.

Cross elasticity of demand between petrol and car is - (1) infinite (2) positive (3) zero (4) negative

Description : Cross elasticity of demand between petrol and car is - (1) infinite (2) positive (3) zero (4) negative

Last Answer : (4) negative Explanation: In economics, the cross elasticity of demand or cross-price elasticity of demand measures the responsiveness of the demand for a good to a change in the ... denotes two products that are complements, while a positive cross elasticity denotes two substitute products

In the case of an inferior good, the income elasticity of demand is : (1) Zero (2) Negative (3) Infinite (4) Positive

Description : In the case of an inferior good, the income elasticity of demand is : (1) Zero (2) Negative (3) Infinite (4) Positive

Last Answer : (2) Negative Explanation: A negative income elasticity of demand is associated with inferior goods; an increase in income will lead to a fall in the demand and may lead to changes to more luxurious ... demand is associated with normal goods; an increase in income will lead to a rise in demand.

If total utility is maximum at a point, then marginal utility is - (1) positive (2) zero (3) negative (4) positive but decreasing

Description : If total utility is maximum at a point, then marginal utility is - (1) positive (2) zero (3) negative (4) positive but decreasing

Last Answer : (2) zero Explanation: Marginal utility of a good or service is the gain (or loss) from an increase (or decrease) in the consumption of that good or service. As the rate ... increase in consumption of units of commodities causes marginal utility to become negative; this signifies dissatisfaction.

The total energy of revolving electron in an atom – (1) cannot be negative (2) can have any value above zero (3) can never be positive (4) will always be positive

Description : The total energy of revolving electron in an atom – (1) cannot be negative (2) can have any value above zero (3) can never be positive (4) will always be positive

Last Answer : (3) can never be positive Explanation: The total energy of a revolving electron in any orbit is the sum of its kinetic and potential energies. Energy of an electron at infinite distance from the ... and the energy of electron decreases and thus becomes negative. Thus, it can never be positive.

The focal length of a plane mirror is (1) Positive (2) Negative (3) Zero (4) Infinity

Description : The focal length of a plane mirror is (1) Positive (2) Negative (3) Zero (4) Infinity

Last Answer : (4) Infinity Explanation: A plane mirror is a mirror with a flat reflective surface. The focal length of a plane mirror is infinity. Its optical power is zero.

Gravitational potential is always A. infinite B. zero C. positive D. negative

Description : Gravitational potential is always A. infinite B. zero C. positive D. negative

Last Answer : negative

In frequency modulation, amplitude of modulated wave is A. positive B. negative C. constant D. zero

Description : In frequency modulation, amplitude of modulated wave is A. positive B. negative C. constant D. zero

Last Answer : constant

If frequency of modulated wave is less than frequency of carrier wave, then input signal is A. negative B. positive C. zero D. infinite

Description : If frequency of modulated wave is less than frequency of carrier wave, then input signal is A. negative B. positive C. zero D. infinite

Last Answer : negative

Speed is unchanged because work done on an object is A. zero B. positive C. negative D. infinite

Description : Speed is unchanged because work done on an object is A. zero B. positive C. negative D. infinite

Last Answer : zero

If the plates of capacitor are oppositely charged then the total charge is equal to A. negative B. positive C. zero D. infinite

Description : If the plates of capacitor are oppositely charged then the total charge is equal to A. negative B. positive C. zero D. infinite

Last Answer : zero

If we have a positive and a negative charge, then force between them is A. positive B. negative C. zero D. infinite

Description : If we have a positive and a negative charge, then force between them is A. positive B. negative C. zero D. infinite

Last Answer : . negative

Gravitational potential is always A. positive B. negative C. zero D. infinity

Description : Gravitational potential is always A. positive B. negative C. zero D. infinity

Last Answer : negative

If the gradient of a graph is negative, then the acceleration is A. positive B. negative C. zero D. 1

Description : If the gradient of a graph is negative, then the acceleration is A. positive B. negative C. zero D. 1

Last Answer : negative

Price movement between two Information Technology stocks would generally have a co-variance. A. zero B. positive C. negative

Description : Price movement between two Information Technology stocks would generally have a  co-variance. A. zero B. positive C. negative

Last Answer : B. positive

In_______encoding, we use three levels: positive, zero, and negative. A) unipolar B) bipolar C) polar D) none of the above

Description : In_______encoding, we use three levels: positive, zero, and negative. A) unipolar B) bipolar C) polar D) none of the above

Last Answer : bipolar

The magnetic susceptibility in a superconductor will be a) Positive b) Negative c) Zero d) Infinity

Description : The magnetic susceptibility in a superconductor will be a) Positive b) Negative c) Zero d) Infinity

Last Answer : b) Negative

The potential taken between two points across a resistor will be a) Positive b) Negative c) Zero d) Infinity

Description : The potential taken between two points across a resistor will be a) Positive b) Negative c) Zero d) Infinity

Last Answer : b) Negative

When total product remains constant the marginal product will be a. Zero b. Negative c. Positive d. Constant

Description : When total product remains constant the marginal product will be a. Zero b. Negative c. Positive d. Constant

Last Answer : a. Zero

Joule-Thomson co-efficient for a perfect gas is (A) Zero (B) Positive (C) Negative(D) None of these

Description : Joule-Thomson co-efficient for a perfect gas is (A) Zero (B) Positive (C) Negative (D) None of these

Last Answer : (A) Zero

firm's marginal revenue A.is always negative B.can be positive C.is always positive D.is zero at point at which the total revenue is maximum

Description : firm's marginal revenue A.is always negative B.can be positive C.is always positive D.is zero at point at which the total revenue is maximum

Last Answer : D.is zero at point at which the total revenue is maximum

According to principle of moments (A) If a system of coplanar forces is in equilibrium, then their algebraic sum is zero (B) If a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero (C) The algebraic sum of the moments of any two forces about any point is equal to moment of their resultant about the same point (D) Positive and negative couples can be balanced

Description : According to principle of moments  (A) If a system of coplanar forces is in equilibrium, then their algebraic sum is zero  (B) If a system of coplanar forces is in equilibrium, then the ... of  their resultant about the same point  (D) Positive and negative couples can be balanced

Last Answer : (C) The algebraic sum of the moments of any two forces about any point is equal to moment of  their resultant about the same point 

. Free energy change at equilibrium is (A) Zero (B) Positive (C) Negative (D) Indeterminate

Description : . Free energy change at equilibrium is (A) Zero (B) Positive (C) Negative (D) Indeterminate

Last Answer : (A) Zero

The change in Gibbs free energy for vaporisation of a pure substance is (A) Positive (B) Negative (C) Zero (D) May be positive or negative

Description : The change in Gibbs free energy for vaporisation of a pure substance is (A) Positive (B) Negative (C) Zero (D) May be positive or negative

Last Answer : (C) Zero

A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is (A) Zero (B) Positive (C) Negative (D) None of these

Description : A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is (A) Zero (B) Positive (C) Negative (D) None of these

Last Answer : (C) Negative