RU2014110563A - METHOD FOR IDENTIFYING THE TYPE OF DISTORTION OF HARMONIC SIGNALS AND DETERMINING THE DISTORTION PARAMETERS (OPTIONS) - Google Patents

Abstract

1. A method for identifying the type of distortion of harmonic signals and determining distortion parameters, namely, determining the value of X-constant component in electrical signals, in currents and voltages for each phase and in the neutral wire, which consists in the fact that N p is constantly during the period T and at each current point in time t, the current value of the electrical signal x (t) is fixed and the sum R = x (t) + x (t) is calculated with the value of the same electrical signal, which was half a period N / 2 back at time t, then tech comparison the total value of the sum R with the value of the sum R, that is, with the previous measurement of the electrical signal x () at time t, equality over a given interval, for example, a quarter of the period of the values of these sums, that is, the absolute value of their difference | RR | ≤b does not exceed b, where b is the specified accuracy of determining the level of the constant component, is a condition for the presence of the constant X component, the value of which is calculated by the formula X = (x (t) + x (t)) / 2, where x (t) is the current value electrical signal at time tx (t) - the value of this same electrical signal, which was half a period N / 2 back. 2. A method for identifying the type of distortion of harmonic signals and determining the distortion parameters, namely, determining A is the initial value and τ is the decay time constant of the aperiodic component and determining the value of X is the constant component in electrical signals, that is, in currents and voltages for each phase and in zero wire, consisting in the fact that constantly N times during the period T and at each current time t fix the current value of the electric

Claims (3)

1. A method for identifying the type of distortion of harmonic signals and determining distortion parameters, namely, determining the value of X _P - constant component in electrical signals, currents and voltages for each of the phases and in the neutral wire, which consists in the fact that N paz constantly during the period T and at each current point in time t _i fix the current value of the electrical signal x (t _i ) and calculate the sum R _i = x (t _i ) + x (t _{iN / 2} ) with the value of the same electrical signal, which was half the period N / 2 reverse at time t _{iN / 2,} then I realize comparing the sum of the current value of R _i with the value of the sum of R _i-1, i.e. the one that was in the previous measurement of the electrical signal x _(ti-1) at time t _i-1, the equation for a predetermined interval, for example a quarter period values of these sums, that is, the absolute value of their difference | R _i -R _i-1 | ≤b does not exceed b, where b is the specified accuracy of determining the level of the constant component, is a condition for the presence of a constant X _P component, the value of which is calculated by the formula X _P = (x (t _i ) + x (t _{iN / 2} )) / 2, where x (t _i ) is the current value of the electrical signal at time t _i x (t _{iN / 2} ) - the value of the same electrical signal, which was half a period N / 2 ago. 2. A method for identifying the type of distortion of harmonic signals and determining the distortion parameters, namely, determining A is the initial value and τ is the decay time constant of the aperiodic component and determining the value of X _P is the constant component in electrical signals, that is, in currents and voltages for each phase and in the neutral wire, consisting in the fact that constantly N times during the period T and at each current time t _i fix the current value of the electrical signal x (t _i ) and calculate the sum R _i = x (t _i ) + x (t _{iN / 2} ) with using the same electrical signal, which was half a period N / 2 back at the time t _{iN / 2} , then compare the current value of the sum R _i with the value of the sum R _i-1 , that is, with the previous measurement of the electrical signal x (t _i-1 ) at time t _i-1 , constant for a given interval, such as a quarter of a period, the fulfillment of the inequality R _i <R _i-1 , establishes the fact of the presence of a decreasing aperiodic component in the electrical signals, the parameters of which are A ↓. - the initial value and t ↓ is the decay time constant, as well as the value of the constant component X _P are calculated by the expressions: A ↓ = f · N · τ ↓ · exp (τ ↓ · t _{xN / 4} ) (x (t _{xN / 4-1} ) -x (t _{xN / 4 + 1} )) / 2, τ ↓ = 2 · f · ln (| (x (t _{xN / 4-1} ) -x (t _{xN / 4 + 1} )) / (x (t _{x-3N / 4-1} ) -x (t _{x- 3N / 4 + 1} )) |), X _P = x (t _{xN / 2} ) -A ↓ exp (-τ ↓ · t _{xN / 2} ), where is the entry | P | denotes the absolute value of the value of P, And ↓. - the initial value of the decreasing aperiodic component, signal units, B or A, τ ↓ is the decay time constant of the decreasing aperiodic component, s ^-1 , x (t _x ) - the value of the harmonic electrical signal at the time when this signal crosses the abscissa axis, the signal units, B or A, x (t _{xN / 2} ) - the value of the same harmonic electrical signal, which was half a period N / 2 ago, the signal units, V or A, x (t _{xN / 4} ) - the value of the same harmonic electrical signal, which was a quarter of the period N / 4 ago, the signal units, B or A, x (t _{x-3N / 4} ) - the value of the same harmonic electrical signal, which was three-quarters of the period 3 · N / 4 ago, the signal units, B or A, f is the frequency of the harmonic signal, Hz, N is the number of measurements of the harmonic signal during the period. 3. A method for identifying the type of distortion of harmonic signals and determining the distortion parameters, namely, determining A is the initial value and τ is the decay time constant of the aperiodic component and determining the quantity X _P is the constant component in electrical signals, that is, in currents and voltages for each phase and in the neutral wire, consisting in the fact that constantly N times during the period T and at each current time t _i fix the current value of the electrical signal x (t _i ) and calculate the sum R _i = x (t _i ) + x (t _{iN / 2} ) with using the same electrical signal, which was half a period N / 2 back at the time t _{iN / 2} , then compare the current value of the sum R _i with the value of the sum R _i-1 , that is, with the previous measurement of the electrical signal x (t _i-1 ) at time t _i-1 , constant for a given interval, such as a quarter of a period, the fulfillment of the inequality R _i > R _i-1 establishes the fact of the presence of an increasing aperiodic component in electrical signals, the parameters of which are A ↑. - the initial value and τ ↑ is the decay time constant, as well as the value of the constant component X _P , are calculated by the expressions: A ↑ = f · N · τ ↑ · exp (τ ↑ · t _{xN / 4} ) (x (t _{xN / 4 + 1} ) -x (t _{xN / 4-1} )) / 2, τ ↑ = 2 · f · ln (| (x (t _{xN / 4-1} ) -x (t _{xN / 4 + 1} )) / (x (t _{x-3N / 4-1} ) -x (t _{x- 3N / 4 + 1} )) |), X _P = x (t _{xN / 2} ) -A ↑ · (1-exp (-τ ↑ · t _{xN / 2} ), where is the entry | P | denotes the absolute value of the value of P, And ↑ is the initial value of the increasing aperiodic component, signal units, B or A, τ ↑ is the decay time constant of the increasing aperiodic component, s ^-1 , x (t _x ) is the value of the electrical signal at time t ₁ when this signal crosses the abscissa axis, the signal units, B or A, x (t _{xN / 2} ) - the value of the same electrical signal, which was half a period N / 2 ago, the signal units, V or A, x (t _{xN / 4} ) - the value of the same electrical signal, which was a quarter of the period N / 4 ago, the unit of measurement of the signal, B or A, x (t _{x-3N / 4} ) - the value of the same harmonic electrical signal, which was three-quarters of the period 3 · N / 4 ago, the signal units, B or A, f is the frequency of the harmonic signal, Hz, N is the number of measurements of the harmonic signal during the period.