CN105158558B - The frequency detecting method and system of electric power signal - Google Patents

The frequency detecting method and system of electric power signal Download PDF

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CN105158558B
CN105158558B CN201510600974.8A CN201510600974A CN105158558B CN 105158558 B CN105158558 B CN 105158558B CN 201510600974 A CN201510600974 A CN 201510600974A CN 105158558 B CN105158558 B CN 105158558B
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sequence
frequency
phase
initial phase
zero initial
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CN105158558A (en
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李军
陈世和
万文军
罗嘉
庞志强
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Electric Power Research Institute of Guangdong Power Grid Co Ltd
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Electric Power Research Institute of Guangdong Power Grid Co Ltd
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Abstract

The present invention relates to a kind of frequency detecting method of electric power signal and system.The present invention obtains zero initial phase cosine function modulation sequence and zero initial phase SIN function modulation sequence by sequence of operations, then selects the larger modulation sequence of average amplitude as zero initial phase modulation sequence for the signal sequence of any initial phase.The zero initial phase modulation sequence avoids the influence of any initial phase problem of signal sequence, zero initial phase modulation sequence carries the larger signal sequence all phase difference information of numerical value simultaneously, can significantly improve the degree of accuracy of sine parameter calculating, improve anti-harmonic wave and noise jamming.The frequency accuracy for the electric power signal that the present invention obtains according to the zero initial phase modulation sequence can reach 10‑10Magnitude, the degree of accuracy that frequency calculates are higher.

Description

The frequency detecting method and system of electric power signal
Technical field
The present invention relates to technical field of electric power, more particularly to a kind of frequency detecting method of electric power signal, electric power signal Frequency detection system.
Background technology
The measurement of the sine parameter of power system includes frequency measurement, phase measurement, amplitude measurement etc..Fourier transformation is The basic skills of sine parameter measurement is realized, is widely used in power system.But with sine parameter e measurement technology Development, the problem of Fourier transformation is present also more aobvious protrusion, it is difficult to further meet power system to sine parameter high precision Spend the requirement calculated.
In terms of power system sine parameter measurement, there are some improved measurement method of parameters, such as zero hands over method, based on filter The mensuration of ripple, the mensuration based on Wavelet Transform, based on neutral net, based on DFT (Discrete Fourier Transform, discrete Fourier transform) conversion mensuration etc..The specified power frequency of operation of power networks belongs near 50Hz (hertz) The relatively low sinusoidal frequency of frequency.Due to the complexity that the limitation and signal of actual signal treatment technology are formed, such as signal discrete Data quantization ambient noise caused by sampling influences, and signal sequence blocks caused spectrum leakage problem and is objectively difficult to avoid that, The influence of any initial phase problem of signal, the influence of direct current and subharmonic and subharmonic problem in signal etc., these algorithms Measurement accuracy it is relatively low, and anti-harmonic wave and noise jamming are poor.
The content of the invention
Based on this, it is necessary in view of the above-mentioned problems, providing the frequency detecting method and system of a kind of electric power signal, Neng Gouti The degree of accuracy, the anti-harmonic wave of raising and the noise jamming that high sine parameter calculates.
In order to solve the above technical problems, the present invention adopts the following technical scheme that：
A kind of frequency detecting method of electric power signal, including step：
According to the lower limit of frequency power signal scope, preset sample frequency and default integer signal period number, obtain preliminary Sample sequence length；
The electric power signal is tentatively sampled according to the preliminary sample sequence length, obtains the electric power signal Preliminary sample sequence；
Line frequency preliminary survey is entered to the preliminary sample sequence, the preliminary frequency of the electric power signal is obtained, according to described first Synchronizing frequency determines reference frequency；
According to the preset sample frequency and the reference frequency, the unit period sequence length of the electric power signal is obtained Degree；
According to the default integer signal period number and the unit period sequence length, predetermined sequence length is obtained；
According to the predetermined sequence length, positive sequence is obtained from the preliminary sample sequence；
The positive sequence is reversely exported, obtains the anti-pleat sequence of the positive sequence；
The positive sequence is added with the anti-pleat sequence, obtains zero initial phase cosine function modulation sequence；
The positive sequence and the anti-pleat sequence are subtracted each other, obtain zero initial phase SIN function modulation sequence；
Integral operation is carried out to the absolute value of the zero initial phase cosine function modulation sequence, obtained more than zero initial phase First average amplitude of string FUNCTION MODULATION sequence；
Integral operation is carried out to the absolute value of the zero initial phase SIN function modulation sequence, is obtaining zero initial phase just Second average amplitude of string FUNCTION MODULATION sequence；
Judge whether first average amplitude is more than or equal to second average amplitude, if so, by zero initial phase Cosine function modulation sequence is as zero initial phase modulation sequence, otherwise using the zero initial phase SIN function modulation sequence as zero Initial phase modulation sequence；
The zero initial phase modulation sequence is truncated, obtains truncated sequence；
The cosine function of the reference frequency and the SIN function of the reference frequency are adjusted with zero initial phase respectively Sequence processed is multiplied, and obtains the first real frequency sequence vector and the first empty frequency sequence vector；
By the cosine function of the reference frequency and the SIN function of the reference frequency respectively with the truncated sequence phase Multiply, obtain the second real frequency sequence vector and the second empty frequency sequence vector；
Digital notch is carried out to the described first real frequency sequence vector and the first empty frequency sequence vector respectively, obtains first Real frequently vectorial trap sequence and the first empty vectorial trap sequence of frequency；
Integral operation is carried out to the described first real vectorial trap sequence of frequency and the first empty vectorial trap sequence of frequency respectively, Obtain the first real frequently vectorial integrated value and the first empty vectorial integrated value of frequency；
Digital notch is carried out to the described second real frequency sequence vector and the second empty frequency sequence vector respectively, obtains the Two real frequently vectorial trap sequences and the second empty vectorial trap sequence of frequency；
Integral operation is carried out to the described second real vectorial trap sequence of frequency and the second empty vectorial trap sequence of frequency respectively, Obtain the second real frequently vectorial integrated value and the second empty vectorial integrated value of frequency；
According to default phase transition rule, the described first empty vectorial integrated value of frequency and the described first real frequency vector are integrated Value is converted to first phase；The described second empty vectorial integrated value of frequency and the described second real vectorial integrated value of frequency are converted into the second phase Position；
According to default cut-off phase transition rule, the first phase and the second phase are converted at the beginning of described zero The initial phase of phase modulation sequence；
According to default all phase difference transformation rule, the initial phase of the zero initial phase modulation sequence is converted into the electricity The all phase of force signal is poor；
According to default sinusoidal frequency transformation rule, all phase difference of the electric power signal is converted into the electric power signal Frequency.
A kind of frequency detection system of electric power signal, including：
Preliminary sample sequence length determination modul, for the lower limit according to frequency power signal scope, preset sample frequency With default integer signal period number, preliminary sample sequence length is obtained；
Preliminary sample sequence acquisition module, for being carried out just to the electric power signal according to the preliminary sample sequence length Step sampling, obtain the preliminary sample sequence of the electric power signal；
Reference frequency determining module, for entering line frequency preliminary survey to the preliminary sample sequence, obtain the electric power signal Preliminary frequency, reference frequency is determined according to the preliminary frequency；
Unit period sequence length determining module, for according to the preset sample frequency and the reference frequency, obtaining The unit period sequence length of the electric power signal；
Predetermined sequence length determination modul, for according to the default integer signal period number and the unit period sequence Length, obtain predetermined sequence length；
Positive retrieval module, for according to the predetermined sequence length, being obtained just from the preliminary sample sequence To sequence；
Anti- pleat retrieval module, for the positive sequence reversely to be exported, obtain the anti-pleat sequence of the positive sequence Row；
Cosine function modulation sequence determining module, for the positive sequence to be added with the anti-pleat sequence, obtain zero Initial phase cosine function modulation sequence；
SIN function modulation sequence determining module, for the positive sequence and the anti-pleat sequence to be subtracted each other, obtain zero Initial phase SIN function modulation sequence；
First average amplitude determining module, for being accumulated to the absolute value of the zero initial phase cosine function modulation sequence Partite transport is calculated, and obtains the first average amplitude of the zero initial phase cosine function modulation sequence；
Second average amplitude determining module, for being accumulated to the absolute value of the zero initial phase SIN function modulation sequence Partite transport is calculated, and obtains the second average amplitude of the zero initial phase SIN function modulation sequence；
Average amplitude judge module, for judging whether first average amplitude is more than or equal to the described second average width Value, when first average amplitude is more than or equal to second average amplitude, the zero initial phase cosine function is modulated into sequence Row are used as zero initial phase modulation sequence, when first average amplitude is less than second average amplitude, by zero first phase Position SIN function modulation sequence is as zero initial phase modulation sequence；
Truncated sequence acquisition module, for the zero initial phase modulation sequence to be truncated, obtain truncated sequence；
Primary vector sequence determining module, for by the sine of the cosine function of the reference frequency and the reference frequency Function is multiplied with the zero initial phase modulation sequence respectively, obtains the first real frequency sequence vector and the first empty frequency sequence vector；
Secondary vector sequence determining module, for by the sine of the cosine function of the reference frequency and the reference frequency Function is multiplied with the truncated sequence respectively, obtains the second real frequency sequence vector and the second empty frequency sequence vector；
First trap sequence determining module, for respectively to the described first real frequency sequence vector and the first empty frequency vector Sequence carries out digital notch, obtains the first real frequently vectorial trap sequence and the first empty vectorial trap sequence of frequency；
First integral value determining module, the described first real vectorial trap sequence of frequency and the first empty frequency vector are fallen into respectively Wave train carries out integral operation, obtains the first real frequently vectorial integrated value and the first empty vectorial integrated value of frequency；
Second trap sequence determining module, for respectively to the described second real frequency sequence vector and the second empty frequency vector Sequence carries out digital notch, obtains the second real frequently vectorial trap sequence and the second empty vectorial trap sequence of frequency；
Second integral value determining module, for respectively to the described second real vectorial trap sequence of frequency and the second empty frequency Vectorial trap sequence carries out integral operation, obtains the second real frequently vectorial integrated value and the second empty vectorial integrated value of frequency；
Phase determination module, for regular according to default phase transition, by the described first empty frequently vectorial integrated value and institute State the first real vectorial integrated value of frequency and be converted to first phase；By the described second empty vectorial integrated value of frequency and the described second real frequency vector Integrated value is converted to second phase；
Initial phase determining module, for according to default cut-off phase transition rule, by the first phase and described the Two phase is converted to the initial phase of the zero initial phase modulation sequence；
All phase difference determining module, for according to default all phase difference transformation rule, zero initial phase to be modulated into sequence The all phase that the initial phase of row is converted to the electric power signal is poor；
Frequency detection module, it is for according to default sinusoidal frequency transformation rule, all phase of the electric power signal is poor Be converted to the frequency of the electric power signal.
The frequency detecting method and system of electric power signal of the present invention, for the signal sequence of any initial phase, pass through a system Row operation obtains zero initial phase cosine function modulation sequence and zero initial phase SIN function modulation sequence, then selects average amplitude Larger modulation sequence is as zero initial phase modulation sequence.The zero initial phase modulation sequence avoids any first phase of signal sequence The influence of position problem, while zero initial phase modulation sequence carries the larger signal sequence all phase difference information of numerical value, can be notable Improve the degree of accuracy that sine parameter calculates, improve anti-harmonic wave and noise jamming.The present invention modulates sequence according to zero initial phase 10 can be reached by arranging the frequency accuracy of obtained electric power signal-10Magnitude, the degree of accuracy that frequency calculates are higher.
Brief description of the drawings
Fig. 1 is the schematic flow sheet of the frequency detecting method embodiment of electric power signal of the present invention；
Fig. 2 is the schematic diagram of positive sequence of the invention and anti-pleat sequence length；
Fig. 3 is the experimental result schematic diagram that the signal fundamental frequency obtained using the inventive method detects relative error；
Fig. 4 is the structural representation of the frequency detection system embodiment of electric power signal of the present invention；
Fig. 5 is the structural representation of phase determination module embodiment one of the present invention；
Fig. 6 is the structural representation of phase determination module embodiment two of the present invention.
Embodiment
In order to which the technical scheme for being better understood from the technical problem to be solved in the present invention, taking and the technology reached are imitated Fruit, the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.
As shown in figure 1, a kind of frequency detecting method of electric power signal, including step：
S101, according to the lower limit of frequency power signal scope, preset sample frequency and default integer signal period number, obtain Preliminary sample sequence length；
S102, according to the preliminary sample sequence length electric power signal is tentatively sampled, obtain the electric power The preliminary sample sequence of signal；
S103, line frequency preliminary survey is entered to the preliminary sample sequence, the preliminary frequency of the electric power signal is obtained, according to institute State preliminary frequency and determine reference frequency；
S104, according to the preset sample frequency and the reference frequency, obtain the unit period sequence of the electric power signal Row length；
S105, according to the default integer signal period number and the unit period sequence length, obtain predetermined sequence length Degree；
S106, according to the predetermined sequence length, obtain positive sequence from the preliminary sample sequence；
S107, the positive sequence reversely exported, obtain the anti-pleat sequence of the positive sequence；
S108, the positive sequence is added with the anti-pleat sequence, obtains zero initial phase cosine function modulation sequence；
S109, the positive sequence and the anti-pleat sequence subtracted each other, obtain zero initial phase SIN function modulation sequence；
S110, the absolute value to the zero initial phase cosine function modulation sequence carry out integral operation, obtain at the beginning of described zero First average amplitude of phase cosine FUNCTION MODULATION sequence；
S111, the absolute value to the zero initial phase SIN function modulation sequence carry out integral operation, obtain at the beginning of described zero Second average amplitude of phase sinusoidal FUNCTION MODULATION sequence；
S112, judge whether first average amplitude is more than or equal to second average amplitude, if so, by the beginning of described zero Otherwise phase cosine FUNCTION MODULATION sequence is made the zero initial phase SIN function modulation sequence as zero initial phase modulation sequence It is zero initial phase modulation sequence；
S113, the zero initial phase modulation sequence truncated, obtain truncated sequence；
S114, by the cosine function of the reference frequency and the SIN function of the reference frequency respectively with zero first phase Position modulation sequence is multiplied, and obtains the first real frequency sequence vector and the first empty frequency sequence vector；
S115, by the cosine function of the reference frequency and the SIN function of the reference frequency respectively with the truncation sequence Row are multiplied, and obtain the second real frequency sequence vector and the second empty frequency sequence vector；
S116, digital notch is carried out to the described first real frequency sequence vector and the first empty frequency sequence vector respectively, obtained To the first real frequently vectorial trap sequence and the first empty vectorial trap sequence of frequency；
S117, the described first real vectorial trap sequence of frequency and the first empty vectorial trap sequence of frequency are integrated respectively Computing, obtain the first real frequently vectorial integrated value and the first empty vectorial integrated value of frequency；
S118, digital notch is carried out to the described second real frequency sequence vector and the second empty frequency sequence vector respectively, obtained To the second real frequently vectorial trap sequence and the second empty vectorial trap sequence of frequency；
S119, the described second real vectorial trap sequence of frequency and the second empty vectorial trap sequence of frequency are integrated respectively Computing, obtain the second real frequently vectorial integrated value and the second empty vectorial integrated value of frequency；
S120, according to default phase transition rule, will the described first empty vectorial integrated value of frequency with described first it is real frequently to Amount integrated value is converted to first phase；The described second empty vectorial integrated value of frequency and the described second real vectorial integrated value of frequency are converted to Second phase；
S121, according to it is default cut-off phase transition rule, the first phase and the second phase are converted into institute State the initial phase of zero initial phase modulation sequence；
S122, according to default all phase difference transformation rule, the initial phase of the zero initial phase modulation sequence is converted to The all phase of the electric power signal is poor；
S123, according to default sinusoidal frequency transformation rule, all phase difference of the electric power signal is converted into the electricity The frequency of force signal.
Electric power signal is the sinusoidal signal based on a kind of fundamental wave component.Sinusoidal signal extensively criticizes string function signal and cosine letter Number signal.Frequency power signal scope is generally 45Hz~55Hz.So lower limit f of frequency power signal scopeminIt can be taken as 45Hz.Default integer signal period number C2πIt can be configured according to being actually needed, for example, being set to 11 etc..In one embodiment In, preliminary sample sequence length N can be determined according to formula (1)start：
Wherein, (int) represents to round；fnFor preset sample frequency, unit Hz；NstartUnit dimensionless, C2πList Position dimensionless, fminUnit be Hz.
After obtaining preliminary sample sequence length, electric power signal is tentatively sampled according to preliminary sample sequence length.Example Such as, the electric power signal is single fundamental frequency sinusoidal signal, according to preliminary sample sequence length to single fundamental frequency sinusoidal signal Tentatively sampled, the preliminary sample sequence X of the electric power signal of acquisitionstart(n) it is formula (2)：
Wherein, A is signal amplitude, and unit can be v；ω is signal frequency, unit rad/s；TnFor sampling interval, list Position is s；fnFor preset sample frequency, unit Hz；N is series of discrete number, unit dimensionless；For signal initial phase, unit For rad；NstartFor preliminary sample sequence length, unit dimensionless.
After obtaining preliminary sample sequence, method, the algorithm based on filtering can be handed over, based on Wavelet Transformation Algorithm, base by zero Algorithm in neutral net, the frequency algorithm based on DFT transform or frequency algorithm based on phase difference etc. are to preliminary sample sequence Enter line frequency preliminary survey, obtain preliminary frequency ωo, preliminary frequency ωoUnit be rad/s.In one embodiment, can should Preliminary frequency is as reference frequency, i.e. reference frequency ωs=ωo.Reference frequency ωsUnit is rad/s.
After obtaining reference frequency, in one embodiment, unit period sequence length N can be determined according to formula (3)2π：
Wherein, (int) is round numbers；fnFor preset sample frequency, unit Hz；fsFor the reference frequency of Hz units, ωs For the reference frequency of rad/s units；N2πUnit dimensionless.Unit period sequence length integer was present in 1 sampling interval Error.
After obtaining unit period sequence length, in one embodiment, predetermined sequence length N is determined according to formula (4)：
N=(int) (C2πN2π) (4)
Wherein, (int) is round numbers；N unit dimensionless.From formula (4) as can be seen that predetermined sequence length N and integer Signal period number C2πIt is corresponding.Predetermined sequence length N can the periodic sequence length N in units of2π11 times.Due to error be present, institute It is about to state the signal period integer that predetermined sequence length is included.
After obtaining default series length N, according to predetermined sequence length, positive sequence is obtained from the preliminary sample sequence Row.In one embodiment, the preliminary sample sequence obtained based on formula (2), the positive sequence X that the present invention obtainsi(n) it is formula (5)：
Wherein, Xstart(n) it is preliminary sample sequence；A is signal amplitude, and unit can be v；ω is signal frequency, unit For rad/s；TnFor sampling interval, unit s；N is series of discrete number, unit dimensionless；φ is signal initial phase, and unit is rad；N is positive sequence length, that is to say predetermined sequence length, unit dimensionless.
The positive sequence obtained based on formula (5), anti-pleat sequence X of the invention-i(- n) is formula (6)：
X-i(- n)=Xi(N-n)=Acos (- ω Tnn+β)
(6)
N=0,1,2,3 ... .., N-1
Wherein, β is anti-pleat sequence initial phase, and anti-pleat sequence initial phase is the cut-off phase of positive sequence, i.e., described electric power The cut-off phase of signal, unit rad；N is anti-pleat sequence length, as shown in Fig. 2 anti-pleat sequence length and positive sequence length It is identical, unit dimensionless.
The anti-pleat sequence that positive sequence and formula (6) based on formula (5) obtain, the zero initial phase cosine function that the present invention obtains Modulation sequence Xcos(n) it is formula (7)：
Wherein,For cosine function modulation sequence amplitude, unit can be v；To be remaining String FUNCTION MODULATION sequence initial phase, unit rad.The zero initial phase cosine function modulation sequence carriesInformation.
It is reference frequency error correspondingly to preset integer signal period number to have one of error, reason due to predetermined sequence length Caused error, the two of reason is the integer error of predetermined sequence length.If described error is zero, cosine function is adjusted Sequence initial phase processedIt is zero, on the contrary cosine function modulation sequence initial phaseNear zero.The first phase PositionError compared with null value and be proportional relation between the error of the default integer signal period number.
The anti-pleat sequence that positive sequence and formula (6) based on formula (5) obtain, the zero initial phase SIN function that the present invention obtains Modulation sequence Xsin(n) it is formula (8)：
Wherein,It is the amplitude of zero initial phase SIN function modulation sequence, unit can be v；It is the initial phase of zero initial phase SIN function modulation sequence, unit rad.
It is that reference frequency error causes because predetermined sequence length corresponds to integer signal period number to have one of error, reason Error, the two of reason is the integer error of the predetermined sequence length.If described error is zero, zero initial phase is just The initial phase of string FUNCTION MODULATION sequenceIt is zero, on the contrary initial phaseNear zero.The initial phaseError compared with null value and be proportional relation between the error of the integer signal period number.
When signal initial phase arbitrarily changes, sequence XcosAnd X (n)sin(n) and the situation of null is likely to occur, due to AmplitudeWithBetween be a kind of complementary relation, therefore can be from sequence Xcos And sequence X (n)sin(n) selection amplitude the greater is as zero initial phase modulation sequence in, if the amplitude of 2 sequences is identical, By sequence Xcos(n) it is used as zero initial phase modulation sequence.
In one embodiment, the first average amplitude V is obtained according to formula (9)cos-avg：
Wherein, the first average amplitude Vcos-avgUnit can be v；N is predetermined sequence length, Xcos(n) it is zero initial phase Cosine function modulation sequence.
In one embodiment, the second average amplitude V is obtained according to formula (10)sin-vag：
Wherein, the second average amplitude Vsin-vagUnit can be v；N is predetermined sequence length, Xsin(n) it is zero initial phase SIN function modulation sequence.
Obtain the first average amplitude Vcos-avgWith the second average amplitude Vsin-vagAfterwards, both sizes are compared.Such as formula (11) institute Show, as the first average amplitude Vcos-avgMore than or equal to the second average amplitude Vsin-vagWhen, by zero initial phase cosine function modulation sequence As zero initial phase modulation sequence；As the first average amplitude Vcos-avgLess than the second average amplitude Vsin-vagWhen, by zero initial phase just String FUNCTION MODULATION sequence is as zero initial phase modulation sequence.
Wherein, in formula, Xout(n) it is zero initial phase modulation sequence.
After obtaining zero initial phase modulation sequence, the zero initial phase modulation sequence is truncated, as shown in formula (12), obtained Truncated sequence is obtained, wherein, the length of truncation can be the unit period sequence length N2π0.25 times：
Xs(n)=Xout(n)
Ns=N-Ms (12)
Ms=0.25N2π
Wherein, Xs(n) it is truncated sequence；N is zero initial phase modulation sequence length of dimensionless unit, that is to say default sequence Row length；NsFor the truncated sequence length of dimensionless unit；MsFor the shortening value of Relative Zero initial phase modulation sequence length, unit Dimensionless；N2πFor the unit period sequence length of dimensionless unit.
So that zero initial phase modulation sequence is zero initial phase cosine function modulation sequence as an example, do not considering to be mixed interfering frequency During composition, obtained the first real frequency sequence vector R1And the first empty frequency sequence vector I (n)1(n) it is formula (13)：
In formula, AcosIt is the amplitude of zero initial phase cosine function modulation sequence, unit can be v.
So that zero initial phase modulation sequence is zero initial phase cosine function modulation sequence as an example, do not considering to be mixed interfering frequency During composition, obtained the second real frequency sequence vector R2And the second empty frequency sequence vector I (n)2(n) it is formula (14)：
In formula, AcosIt is the amplitude of zero initial phase cosine function modulation sequence, unit can be v.
Mixing interfering frequency is included in real frequency sequence vector and empty frequency sequence vector.When in input signal include direct current into Point, subharmonic composition and during subharmonic composition, the mixing interfering frequency will be more complicated, and these mixing interfering frequencies will be tight Ghost image rings the degree of accuracy that frequency calculates.Although window function and integral operation have good decay to mixing interfering frequency in itself Effect, but there is no specific aim, it is impossible to the inhibitory action of depth is produced to the mixing interfering frequency of complexity, it is impossible to meet sinusoidal ginseng Several high accuracies, which calculates, to be needed.
In order to targetedly suppress to be mixed the influence of interfering frequency, the present invention uses a kind of digital trap.Preferable feelings Under condition, the null Frequency point of digital trap just corresponds to the mixing interfering frequency point, to the mixing interfering frequency tool There is complete inhibitory action.In one embodiment, digital notch specifically uses digital averaging filtering algorithm, i.e., connects several Continuous centrifugal pump is added, and then takes its arithmetic mean of instantaneous value to be exported as this filter value.Digital notch needs to set digital notch to join Number, the digital notch parameter refer to the length N that several continuous centrifugal pumps are addedD.In digital notch parameter NDValue is unit week At 1.5 times of phase sequence length, it can suppress to being mixed interfering frequency caused by 1/3 subharmonic.And NDValue is single At 2 times of bit period sequence length, can to direct current, 1/2 by several times, 1 time, 2 times, 3 times, 4 times, mixing caused by 5 subharmonic etc. Interfering frequency is suppressed.Therefore, digital notch is made up of the digital trap of 2 kinds of parameters, it is contemplated that physical presence error Deng factor, influenceed in order to which depth suppresses mixing interfering frequency, the digital trap of every kind of parameter is by the series of parameter identical three Word trap is formed, and totally six grades of arithmetic mean of instantaneous value digital notch are formed.In one embodiment, six grades of arithmetic mean of instantaneous value numerals are fallen into Waves can be formula (15)：
To X (n) n=0,1,2,3 ..., N-1
To XD(n) n=0,1,2,3 ..., N-3ND1-3ND2-1
Wherein, X (n) is digital notch list entries, sequence length N；XD(n) it is digital notch output sequence, sequence length Spend N-3ND1-3ND2；ND1For notch parameter 1, i.e., continuous centrifugal pump is added quantity；ND2For notch parameter 2, i.e. continuous centrifugal pump phase Addend amount.
In one embodiment, notch parameter ND1Value is 1.5 times of the unit period sequence length of the reference frequency, Notch parameter ND2Value is 2 times of the unit period sequence length of the reference frequency, and six grades of arithmetic mean of instantaneous value digital notch need To use 10.5 times of unit period sequence lengths.
So that zero initial phase modulation sequence is zero initial phase cosine function modulation sequence as an example, it is described mixing interfering frequency into Divide under the premise of being completely suppressed, the described first real vectorial trap sequence of frequency and the first empty vectorial trap sequence of frequency are (16)：
To R1(n) I1(n) n=0,1,2,3 ..., N-1
To RD1(n) ID1(n) n=0,1,2,3 ..., N-3ND1-3ND2-1
Wherein, RD1(n) it is the first real vectorial trap sequence of frequency；ID1(n) it is the first empty vectorial trap sequence of frequency；K (Ω) is Dimensionless gain of the digital notch in frequency difference Ω；α (Ω) is rad unit phase shift of the digital filtering in frequency difference Ω.
Equally, so that zero initial phase modulation sequence is zero initial phase cosine function modulation sequence as an example, in mixing interfering frequency Under the premise of composition is completely suppressed, the described second real vectorial trap sequence of frequency and the second empty vectorial trap sequence of frequency are formula (17)：
To R2(n) I2(n) n=0,1,2,3 ..., Ns-1
To RD2(n) ID2(n) n=0,1,2,3 ..., Ns-3ND1-3ND2-1
Wherein, RD2(n) it is the described second real vectorial trap sequence of frequency；ID2(n) it is the described second empty vectorial trap sequence of frequency Row；K (Ω) is dimensionless gain of the digital filtering in frequency difference Ω；α (Ω) is phase shift of the digital filtering in frequency difference Ω, and unit is rad。
In one embodiment, the present invention carries out integral operation using existing integrator in the prior art.With zero first phase Exemplified by position modulation sequence is zero initial phase cosine function modulation sequence, using integrator to the described first real vectorial trap sequence of frequency Integral operation is carried out with the described first empty vectorial trap sequence of frequency, obtains the first real frequently vectorial integrated value and the first empty frequency vector product Score value is formula (18)：
Wherein, R1For the first real vectorial integrated value of frequency；I1For the first empty vectorial integrated value of frequency；L1 is integral and calculating length 1, Unit dimensionless, L1 is minimum to be generally 0.5 times of unit period sequence length.
Equally, so that zero initial phase modulation sequence is zero initial phase cosine function modulation sequence as an example, distinguished using integrator Integral operation is carried out to the described second real vectorial trap sequence of frequency and the second empty vectorial trap sequence of frequency, obtains the second real frequency Vectorial integrated value and the second empty vectorial integrated value of frequency are formula (19)：
Wherein, R2For the second real vectorial integrated value of frequency；I2For the second empty vectorial integrated value of frequency.L2 is integral and calculating length 2, Unit dimensionless, L2 is minimum to be generally 0.25 times of unit period sequence length.
, it is necessary to consider that zero initial phase modulates sequence when obtaining first phase and second phase according to default phase transition rule Row are zero initial phase cosine function modulation sequence or zero initial phase SIN function modulation sequence.If zero initial phase modulates sequence The zero initial phase cosine function modulation sequence is classified as, step S120 can include：
Determine the first ratio of the described first empty vectorial integrated value of frequency and the described first real vectorial integrated value of frequency；
Using the opposite number of the arctan function value of first ratio as the first phase；
Determine the second ratio of the described second empty vectorial integrated value of frequency and the described second real vectorial integrated value of frequency；
Using the opposite number of the arctan function value of second ratio as the second phase.
As shown in formula (20) and formula (21), when the zero initial phase modulation sequence is modulated for the zero initial phase cosine function During sequence, obtained first phase and second phase are respectively：
Wherein, PH1For first phase, unit rad；R1For the first real vectorial integrated value of frequency；I1For the first empty frequency vector product Score value；PH2For second phase, unit rad；R2For the second real vectorial integrated value of frequency；I2For the second empty vectorial integrated value of frequency.
If the zero initial phase modulation sequence is the zero initial phase SIN function modulation sequence, step S120 can be wrapped Include：
Determine the 3rd ratio of the described first real vectorial integrated value of frequency and the described first empty vectorial integrated value of frequency；
Using the arctan function value of the 3rd ratio as the first phase；
Determine the 4th ratio of the described second real vectorial integrated value of frequency and the described second empty vectorial integrated value of frequency；
Using the arctan function value of the 4th ratio as the second phase.
It should be noted that above-mentioned first ratio, the second ratio, the 3rd ratio and the 4th ratio are each just to distinguish Ratio, not the order of reduced value be limited.
As shown in formula (22) and formula (23), when the zero initial phase modulation sequence is modulated for the zero initial phase SIN function During sequence, obtained first phase and second phase are respectively：
After obtaining first phase and second phase, in one embodiment, it can determine that zero initial phase is adjusted according to formula (24) The initial phase of sequence processed
The all phase difference of electric power signal is signal sinusoidal frequency and the product of zero initial phase modulation sequence time span.Quan Xiang Potential difference Δ PH and initial phaseRelation be：Initial phaseSubstantially represent described in the predetermined sequence length correspondence The error amount of integer signal period number, if error amount is zero, all phase difference is 2 π integral multiples, otherwise all phase The non-2 π integral multiples of difference, initial phase2 times of opposite number just reflects the error amount of 2 π integral multiples and non-2 π integral multiples.
In one embodiment, all phase difference Δ PH of electric power signal can be determined according to formula (25)：
Wherein, 2 π C2πAll phase for 2 π integral multiples is poor；Work as C2πWhen=11,2 π C2π=22 π, then Δ PH scope is in 22 π Left and right, unit rad.
It is the relation of the product of signal sinusoidal frequency and zero initial phase modulation sequence time span according to all phase difference, can be with Draw：Signal sinusoidal frequency is the ratio of all phase difference and zero initial phase modulation sequence time span.It is so true according to formula (26) Determine the frequencies omega of electric power signal：
Wherein, ω is the frequency of the electric power signal of rad/s units；TnN is the modulation sequence time span of s units.
In order to be better understood from the technique effect that technical solution of the present invention reaches, carried out with reference to a specific embodiment Explanation.
Assuming that the experimental signal provided is formula (27)：
Signal fundamental frequency excursion is in 45Hz-55Hz, and round numbers signal period number is about 11, any first phase of signal Position, the sample frequency of signal are 10kHz, the discrete data quantization digit 24bit of signal, frequency preliminary survey relative error<|± 0.25% |, obtain signal fundamental frequency detection absolute relative error | Ferr(f) | with the reality of signal fundamental frequency f variation characteristics It is as shown in Figure 3 to test result.According to Fig. 3 as can be seen that the experimental signal fundamental frequency accuracy in detection of the invention provided is 10-10 Magnitude, the degree of accuracy are higher.
Based on same inventive concept, the present invention also provides a kind of frequency detection system of electric power signal, below in conjunction with the accompanying drawings Embodiments of systems of the invention are described in detail.
As shown in figure 4, a kind of frequency detection system of electric power signal, including：
Preliminary sample sequence length determination modul 101, for the lower limit according to frequency power signal scope, default sampling frequency Rate and default integer signal period number, obtain preliminary sample sequence length；
Preliminary sample sequence acquisition module 102, for being entered according to the preliminary sample sequence length to the electric power signal The preliminary sampling of row, obtain the preliminary sample sequence of the electric power signal；
Reference frequency determining module 103, for entering line frequency preliminary survey to the preliminary sample sequence, obtain the electric power letter Number preliminary frequency, reference frequency is determined according to the preliminary frequency；
Unit period sequence length determining module 104, for according to the preset sample frequency and the reference frequency, obtaining To the unit period sequence length of the electric power signal；
Predetermined sequence length determination modul 105, for according to the default integer signal period number and the unit period Sequence length, obtain predetermined sequence length；
Positive retrieval module 106, for according to the predetermined sequence length, being obtained from the preliminary sample sequence Positive sequence；
Anti- pleat retrieval module 107, for the positive sequence reversely to be exported, obtain the anti-pleat of the positive sequence Sequence；
Cosine function modulation sequence determining module 108, for the positive sequence to be added with the anti-pleat sequence, obtain Zero initial phase cosine function modulation sequence；
SIN function modulation sequence determining module 109, for the positive sequence and the anti-pleat sequence to be subtracted each other, obtain Zero initial phase SIN function modulation sequence；
First average amplitude determining module 110, for entering to the absolute value of the zero initial phase cosine function modulation sequence Row integral operation, obtain the first average amplitude of the zero initial phase cosine function modulation sequence；
Second average amplitude determining module 111, for entering to the absolute value of the zero initial phase SIN function modulation sequence Row integral operation, obtain the second average amplitude of the zero initial phase SIN function modulation sequence；
Average amplitude judge module 112, for judging it is average whether first average amplitude is more than or equal to described second Amplitude, when first average amplitude is more than or equal to second average amplitude, the zero initial phase cosine function is modulated Sequence is as zero initial phase modulation sequence, when first average amplitude is less than second average amplitude, by the beginning of described zero Phase sinusoidal FUNCTION MODULATION sequence is as zero initial phase modulation sequence；
Truncated sequence acquisition module 113, for the zero initial phase modulation sequence to be truncated, obtain truncated sequence；
Primary vector sequence determining module 114, for by the cosine function of the reference frequency and the reference frequency SIN function is multiplied with the zero initial phase modulation sequence respectively, obtains the first real frequency sequence vector and the first empty vectorial sequence of frequency Row；
Secondary vector sequence determining module 115, for by the cosine function of the reference frequency and the reference frequency SIN function is multiplied with the truncated sequence respectively, obtains the second real frequency sequence vector and the second empty frequency sequence vector；
First trap sequence determining module 116, for respectively to the described first real frequency sequence vector and the first empty frequency Sequence vector carries out digital notch, obtains the first real frequently vectorial trap sequence and the first empty vectorial trap sequence of frequency；
First integral value determining module 117, respectively the vectorial trap sequence of frequency real to described first and the first empty frequency to Measure trap sequence and carry out integral operation, obtain the first real frequently vectorial integrated value and the first empty vectorial integrated value of frequency；
Second trap sequence determining module 118, for respectively to the described second real frequency sequence vector and the second empty frequency Sequence vector carries out digital notch, obtains the second real frequently vectorial trap sequence and the second empty vectorial trap sequence of frequency；
Second integral value determining module 119, for respectively to the described second real vectorial trap sequence of frequency and second void Frequently vectorial trap sequence carries out integral operation, obtains the second real frequently vectorial integrated value and the second empty vectorial integrated value of frequency；
Phase determination module 120, for according to default phase transition rule, will the vectorial integrated value of the described first empty frequency and The described first real vectorial integrated value of frequency is converted to first phase；By the described second empty vectorial integrated value of frequency and the described second real frequency to Amount integrated value is converted to second phase；
Initial phase determining module 121, for according to default cut-off phase transition rule, by the first phase and described Second phase is converted to the initial phase of the zero initial phase modulation sequence；
All phase difference determining module 122, for according to default all phase difference transformation rule, zero initial phase to be modulated The all phase that the initial phase of sequence is converted to the electric power signal is poor；
Frequency detection module 123, for according to default sinusoidal frequency transformation rule, by all phase of the electric power signal Difference is converted to the frequency of the electric power signal.
Frequency power signal scope is generally 45Hz~55Hz.So lower limit f of frequency power signal scopeminIt can take For 45Hz.Default integer signal period number C2πIt can be configured according to being actually needed, for example, being set to 11 etc..In an implementation In example, the preliminary sample sequence length determination modul 101 can basisIt is determined that preliminary sampling Sequence length Nstart, wherein (int) represents to round, fnFor preset sample frequency.
After the preliminary sample sequence length determination modul 101 obtains preliminary sample sequence length, preliminary sample sequence obtains Modulus block 102 is tentatively sampled according to preliminary sample sequence length to electric power signal.For example, the electric power signal is single fundamental wave frequency Rate sinusoidal signal, preliminary sample sequence acquisition module 102 are carried out according to preliminary sample sequence length to single fundamental frequency sinusoidal signal Preliminary sampling, the preliminary sample sequence X of the electric power signal of acquisitionstart(n) it is： Wherein, A is signal amplitude；ω is signal frequency；For the sampling interval；fnFor preset sample frequency；N=0,1,2, 3,.....,Nstart- 1, it is series of discrete number；For signal initial phase；NstartFor preliminary sample sequence length.
After preliminary sample sequence acquisition module 102 obtains preliminary sample sequence, reference frequency determining module 103 can pass through Zero hands over method, the algorithm based on filtering, the algorithm based on Wavelet Transformation Algorithm, based on neutral net, the frequency based on DFT transform to calculate Method or frequency algorithm based on phase difference etc. enter line frequency preliminary survey to preliminary sample sequence, obtain preliminary frequency ωo.In a reality Apply in example, reference frequency determining module 103 can be using the preliminary frequency as reference frequency, i.e. reference frequency ωs=ωo。
After reference frequency determining module 103 obtains reference frequency, in one embodiment, unit period sequence length determines Module 104 can basisDetermine unit period sequence length N2π.Wherein (int) is round numbers, fnFor Preset sample frequency,fsFor the reference frequency of Hz units, ωsFor the reference frequency of rad/s units.Unit week The error in 1 sampling interval be present in phase sequence length integer.
After unit period sequence length determining module 104 obtains unit period sequence length, in one embodiment, preset Sequence length determining module 105 is according to N=(int) (C2πN2π) determine predetermined sequence length N.Wherein (int) is round numbers, C2π For default integer signal period number, N2πFor unit periodic sequence length.Predetermined sequence length N and integer are can be seen that from the formula Signal period number C2πIt is corresponding.Predetermined sequence length N can the periodic sequence length N in units of2π11 times.Due to error be present, institute It is about to state the signal period integer that predetermined sequence length is included.
After predetermined sequence length determination modul 105 obtains default series length N, positive retrieval module 106 is according to pre- If sequence length, positive sequence is obtained from the preliminary sample sequence.In one embodiment, based on above-mentioned preliminary sampling sequence The preliminary sample sequence that row acquisition module 102 obtains, the positive sequence X that positive retrieval module 106 obtainsi(n) it is：Wherein, Xstart(n) it is preliminary sample sequence；A is signal amplitude； ω is signal frequency；TnFor the sampling interval；N=0,1,2,3 ... .., N-1, it is series of discrete number；N≤Nstart；For signal Initial phase；N is positive sequence length, that is to say predetermined sequence length.
The positive sequence obtained based on above-mentioned positive retrieval module 106, anti-pleat retrieval module 107 obtains anti- Pleat sequence X-i(- n) is：X-i(- n)=Xi(N-n)=Acos (- ω Tnn+β).Wherein n=0,1,2,3 ... .., N-1；β is anti- Pleat sequence initial phase, anti-pleat sequence initial phase are the cut-off phases of positive sequence, i.e., the cut-off phase of described electric power signal；N is Anti- pleat sequence length, as shown in Fig. 2 anti-pleat sequence length is identical with positive sequence length.
What the positive sequence and anti-pleat retrieval module 107 obtained based on above-mentioned positive retrieval module 106 was obtained Anti- pleat sequence, the zero initial phase cosine function modulation sequence X that cosine function modulation sequence determining module 108 obtainscos(n) it is：
Wherein,For cosine function modulation sequence amplitude；Sequence is modulated for cosine function Row initial phase.The zero initial phase cosine function modulation sequence carriesInformation.
What the positive sequence and anti-pleat retrieval module 107 obtained based on above-mentioned positive retrieval module 106 was obtained Anti- pleat sequence, the zero initial phase SIN function modulation sequence X that SIN function modulation sequence determining module 109 obtainssin(n) it is：
Wherein,It is the amplitude of zero initial phase SIN function modulation sequence, unit v； It is the initial phase of zero initial phase SIN function modulation sequence, unit rad.
When signal initial phase arbitrarily changes, sequence XcosAnd X (n)sin(n) and the situation of null is likely to occur, due to AmplitudeWithBetween be a kind of complementary relation, therefore can be from sequence Xcos And sequence X (n)sin(n) selection amplitude the greater is as zero initial phase modulation sequence in, if the amplitude of 2 sequences is identical, By sequence Xcos(n) it is used as zero initial phase modulation sequence.
In one embodiment, the first average amplitude determining module 110 can basis Obtain the first average amplitude Vcos-avg, wherein n=0,1,2N, -3, N is predetermined sequence length 1.
In one embodiment, the second average amplitude determining module 111 can basis Obtain the second average amplitude Vsin-vag, wherein n=0,1,2,3 ... .., N-1, N are predetermined sequence length, Xsin(n) it is Zero initial phase SIN function modulation sequence.
First average amplitude determining module 110 obtains the first average amplitude Vcos-avgWith the second average amplitude determining module 111 second average amplitude Vsin-vagAfterwards, the average amplitude judge module 112 compares both sizes.When the first average amplitude Vcos-avgMore than or equal to the second average amplitude Vsin-vagWhen, zero initial phase cosine function is modulated sequence by average amplitude judge module 112 Row are used as zero initial phase modulation sequence；As the first average amplitude Vcos-avgLess than the second average amplitude Vsin-vagWhen, average amplitude is sentenced Disconnected module 112 is using zero initial phase SIN function modulation sequence as zero initial phase modulation sequence.
After average amplitude judge module 112 obtains zero initial phase modulation sequence, truncated sequence acquisition module 113 is by described zero Initial phase modulation sequence is truncated, and is shown below, and obtains truncated sequence：
Xs(n)=Xout(n)
Ns=N-Ms
Ms=0.25N2π
Wherein, Xs(n) it is truncated sequence；N is zero initial phase modulation sequence length of dimensionless unit, that is to say default sequence Row length；NsFor the truncated sequence length of dimensionless unit；MsFor the shortening value of Relative Zero initial phase modulation sequence length, unit Dimensionless；N2πFor the unit period sequence length of dimensionless unit.
As shown in figure 5, in one embodiment, the phase determination module 120 can include：
First ratio determining unit 1201, for being the zero initial phase cosine function in the zero initial phase modulation sequence During modulation sequence, the first ratio of the described first empty vectorial integrated value of frequency and the described first real vectorial integrated value of frequency is determined；
First phase determining unit 1202, for using the opposite number of the arctan function value of first ratio as described in First phase；
Second ratio determining unit 1203, for being the zero initial phase cosine function in the zero initial phase modulation sequence During modulation sequence, the second ratio of the described second empty vectorial integrated value of frequency and the described second real vectorial integrated value of frequency is determined；
Second phase determining unit 1204, for using the opposite number of the arctan function value of second ratio as described in Second phase.
It is shown below, when the zero initial phase modulation sequence is the zero initial phase cosine function modulation sequence, institute State first phase that phase determination module 120 obtains and second phase is respectively：
Wherein, PH1For first phase, unit rad；R1For the first real vectorial integrated value of frequency；I1For the first empty frequency vector product Score value；PH2For second phase, unit rad；R2For the second real vectorial integrated value of frequency；I2For the second empty vectorial integrated value of frequency.
As shown in fig. 6, in another embodiment, the phase determination module 120 can also include：
3rd ratio determining unit 1205, for being the zero initial phase SIN function in the zero initial phase modulation sequence During modulation sequence, the 3rd ratio of the described first real vectorial integrated value of frequency and the described first empty vectorial integrated value of frequency is determined；
First phase detection unit 1206, for using the arctan function value of the 3rd ratio as first phase Position；
4th ratio determining unit 1207, for being the zero initial phase SIN function in the zero initial phase modulation sequence During modulation sequence, the 4th ratio of the described second real vectorial integrated value of frequency and the described second empty vectorial integrated value of frequency is determined；
Second phase detection unit 1208, for using the arctan function value of the 4th ratio as second phase Position.
It should be noted that above-mentioned first ratio, the second ratio, the 3rd ratio and the 4th ratio are each just to distinguish Ratio, not the order of reduced value be limited.
It is shown below, when the zero initial phase modulation sequence is the zero initial phase SIN function modulation sequence, institute State first phase that phase determination module 120 obtains and second phase is respectively：
In one embodiment, the basis of initial phase determining module 121 Determine the initial phase of zero initial phase modulation sequenceWherein, PH1For first phase, PH2For second phase, N is predetermined sequence Length, NsFor truncated sequence length.
In one embodiment, all phase difference determining module 122 can basis The all phase difference Δ PH of the electric power signal is determined, wherein, C2πTo preset integer signal period number,For zero first phase The initial phase of position modulation sequence.
In one embodiment, the basis of frequency detection module 123Determine the electric power signal Frequencies omega, wherein, N is predetermined sequence length,For preset sample frequency.
Each technical characteristic of embodiment described above can be combined arbitrarily, to make description succinct, not to above-mentioned reality Apply all possible combination of each technical characteristic in example to be all described, as long as however, the combination of these technical characteristics is not deposited In contradiction, the scope that this specification is recorded all is considered to be.
Embodiment described above only expresses the several embodiments of the present invention, and its description is more specific and detailed, but simultaneously Can not therefore it be construed as limiting the scope of the patent.It should be pointed out that come for one of ordinary skill in the art Say, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to the protection of the present invention Scope.Therefore, the protection domain of patent of the present invention should be determined by the appended claims.

Claims (10)

1. a kind of frequency detecting method of electric power signal, it is characterised in that including step：
According to the lower limit of frequency power signal scope, preset sample frequency and default integer signal period number, tentatively sampled Sequence length；
The electric power signal is tentatively sampled according to the preliminary sample sequence length, obtains the preliminary of the electric power signal Sample sequence；
Line frequency preliminary survey is entered to the preliminary sample sequence, obtains the preliminary frequency of the electric power signal, according to the just cadence Rate determines reference frequency；
According to the preset sample frequency and the reference frequency, the unit period sequence length of the electric power signal is obtained；
According to the default integer signal period number and the unit period sequence length, predetermined sequence length is obtained；
According to the predetermined sequence length, positive sequence is obtained from the preliminary sample sequence；
The positive sequence is reversely exported, obtains the anti-pleat sequence of the positive sequence；
The positive sequence is added with the anti-pleat sequence, obtains zero initial phase cosine function modulation sequence；
The positive sequence and the anti-pleat sequence are subtracted each other, obtain zero initial phase SIN function modulation sequence；
Integral operation is carried out to the absolute value of the zero initial phase cosine function modulation sequence, obtains the zero initial phase cosine letter First average amplitude of number modulation sequence；
Integral operation is carried out to the absolute value of the zero initial phase SIN function modulation sequence, obtains the zero initial phase sine letter Second average amplitude of number modulation sequence；
Judge whether first average amplitude is more than or equal to second average amplitude, if so, by the zero initial phase cosine FUNCTION MODULATION sequence is as zero initial phase modulation sequence, otherwise using the zero initial phase SIN function modulation sequence as zero first phase Position modulation sequence；
The zero initial phase modulation sequence is truncated, obtains truncated sequence；
The cosine function of the reference frequency and the SIN function of the reference frequency are modulated into sequence with zero initial phase respectively Row are multiplied, and obtain the first real frequency sequence vector and the first empty frequency sequence vector；
The cosine function of the reference frequency and the SIN function of the reference frequency are multiplied with the truncated sequence respectively, obtained To the second real frequency sequence vector and the second empty frequency sequence vector；
Digital notch is carried out to the described first real frequency sequence vector and the first empty frequency sequence vector respectively, obtains the first real frequency Vectorial trap sequence and the first empty vectorial trap sequence of frequency；
Integral operation is carried out to the described first real vectorial trap sequence of frequency and the first empty vectorial trap sequence of frequency respectively, obtained First real frequently vectorial integrated value and the first empty vectorial integrated value of frequency；
Digital notch is carried out to the described second real frequency sequence vector and the second empty frequency sequence vector respectively, obtains the second real frequency Vectorial trap sequence and the second empty vectorial trap sequence of frequency；
Integral operation is carried out to the described second real vectorial trap sequence of frequency and the second empty vectorial trap sequence of frequency respectively, obtained Second real frequently vectorial integrated value and the second empty vectorial integrated value of frequency；
According to default phase transition rule, by the described first empty vectorial integrated value of frequency and the described first real vectorial integrated value of frequency The arctan function value of first ratio obtains first phase after entering row coefficient amendment；By the described second empty vectorial integrated value of frequency and the The arctan function value of second ratio of the two real vectorial integrated values of frequency obtains second phase after entering row coefficient amendment；
According to default initial phase transformation rule, first phase and second phase are entered into row coefficient amendment respectively and ask poor, by institute State and ask the value of difference to enter the initial phase that row coefficient amendment obtains zero initial phase modulation sequence；
According to default all phase difference transformation rule, the initial phase of the zero initial phase modulation sequence is linearly calculated, obtained The all phase of power taking force signal is poor；
According to default sinusoidal frequency transformation rule, obtained after all phase difference is taken into ratio with zero initial phase modulation sequence time span Take the frequency power signal.
2. the frequency detecting method of electric power signal according to claim 1, it is characterised in that if zero initial phase is modulated Sequence is the zero initial phase cosine function modulation sequence, according to default phase transition rule, by the described first empty frequency vector Integrated value is converted to first phase with the described first real vectorial integrated value of frequency；By the described second empty vectorial integrated value of frequency and described the The step of two real vectorial integrated values of frequency are converted to second phase includes：
Determine the first ratio of the described first empty vectorial integrated value of frequency and the described first real vectorial integrated value of frequency；
Using the opposite number of the arctan function value of first ratio as the first phase；
Determine the second ratio of the described second empty vectorial integrated value of frequency and the described second real vectorial integrated value of frequency；
Using the opposite number of the arctan function value of second ratio as the second phase.
3. the frequency detecting method of electric power signal according to claim 1, it is characterised in that if zero initial phase is modulated Sequence is the zero initial phase SIN function modulation sequence, according to default phase transition rule, by the described first empty frequency vector Integrated value is converted to first phase with the described first real vectorial integrated value of frequency；By the described second empty vectorial integrated value of frequency and described the The step of two real vectorial integrated values of frequency are converted to second phase includes：
Determine the 3rd ratio of the described first real vectorial integrated value of frequency and the described first empty vectorial integrated value of frequency；
Using the arctan function value of the 3rd ratio as the first phase；
Determine the 4th ratio of the described second real vectorial integrated value of frequency and the described second empty vectorial integrated value of frequency；
Using the arctan function value of the 4th ratio as the second phase.
4. the frequency detecting method of electric power signal according to claim 1, it is characterised in that according toDetermine the initial phase of the zero initial phase modulation sequenceWherein, PH1For first Phase, PH2For second phase, N is predetermined sequence length, NsFor truncated sequence length.
5. the frequency detecting method of electric power signal according to claim 1, it is characterised in that according toThe all phase difference △ PH of the electric power signal are determined, wherein, C2πTo preset integer Signal period number,For the initial phase of the zero initial phase modulation sequence；
According toThe frequencies omega of the electric power signal is determined, wherein, N is predetermined sequence length,fn For preset sample frequency.
A kind of 6. frequency detection system of electric power signal, it is characterised in that including：
Preliminary sample sequence length determination modul, for the lower limit according to frequency power signal scope, preset sample frequency and pre- If integer signal period number, preliminary sample sequence length is obtained；
Preliminary sample sequence acquisition module, for tentatively being adopted to the electric power signal according to the preliminary sample sequence length Sample, obtain the preliminary sample sequence of the electric power signal；
Reference frequency determining module, for entering line frequency preliminary survey to the preliminary sample sequence, obtain the first of the electric power signal Synchronizing frequency, reference frequency is determined according to the preliminary frequency；
Unit period sequence length determining module, for according to the preset sample frequency and the reference frequency, obtaining described The unit period sequence length of electric power signal；
Predetermined sequence length determination modul, for according to the default integer signal period number and unit period sequence length Degree, obtains predetermined sequence length；
Positive retrieval module, for according to the predetermined sequence length, positive sequence to be obtained from the preliminary sample sequence Row；
Anti- pleat retrieval module, for the positive sequence reversely to be exported, obtain the anti-pleat sequence of the positive sequence；
Cosine function modulation sequence determining module, for the positive sequence to be added with the anti-pleat sequence, obtain zero first phase Position cosine function modulation sequence；
SIN function modulation sequence determining module, for the positive sequence and the anti-pleat sequence to be subtracted each other, obtain zero first phase Position SIN function modulation sequence；
First average amplitude determining module, for carrying out integration fortune to the absolute value of the zero initial phase cosine function modulation sequence Calculate, obtain the first average amplitude of the zero initial phase cosine function modulation sequence；
Second average amplitude determining module, for carrying out integration fortune to the absolute value of the zero initial phase SIN function modulation sequence Calculate, obtain the second average amplitude of the zero initial phase SIN function modulation sequence；
Average amplitude judge module, for judging whether first average amplitude is more than or equal to second average amplitude, When first average amplitude is more than or equal to second average amplitude, using the zero initial phase cosine function modulation sequence as Zero initial phase modulation sequence, it is when first average amplitude is less than second average amplitude, zero initial phase is sinusoidal FUNCTION MODULATION sequence is as zero initial phase modulation sequence；
Truncated sequence acquisition module, for the zero initial phase modulation sequence to be truncated, obtain truncated sequence；
Primary vector sequence determining module, for by the SIN function of the cosine function of the reference frequency and the reference frequency It is multiplied respectively with the zero initial phase modulation sequence, obtains the first real frequency sequence vector and the first empty frequency sequence vector；
Secondary vector sequence determining module, for by the SIN function of the cosine function of the reference frequency and the reference frequency It is multiplied respectively with the truncated sequence, obtains the second real frequency sequence vector and the second empty frequency sequence vector；
First trap sequence determining module, for respectively to the described first real frequency sequence vector and the first empty frequency sequence vector Digital notch is carried out, obtains the first real frequently vectorial trap sequence and the first empty vectorial trap sequence of frequency；
First integral value determining module, respectively to the described first real vectorial trap sequence of frequency and the first empty vectorial trap sequence of frequency Row carry out integral operation, obtain the first real frequently vectorial integrated value and the first empty vectorial integrated value of frequency；
Second trap sequence determining module, for respectively to the described second real frequency sequence vector and the second empty frequency sequence vector Digital notch is carried out, obtains the second real frequently vectorial trap sequence and the second empty vectorial trap sequence of frequency；
Second integral value determining module, for being fallen into respectively to the described second real vectorial trap sequence of frequency and the second empty frequency vector Wave train carries out integral operation, obtains the second real frequently vectorial integrated value and the second empty vectorial integrated value of frequency；
Phase determination module, will the vectorial integrated value of the described first empty frequency and described for according to default phase transition rule The arctan function value of first ratio of the one real vectorial integrated value of frequency obtains first phase after entering row coefficient amendment；By described second The empty vectorial integrated value of frequency and the arctan function value of the second ratio of the second real vectorial integrated value of frequency obtain after entering row coefficient amendment Second phase；
Initial phase determining module, for according to default initial phase transformation rule, first phase and second phase to be carried out respectively Coefficient amendment simultaneously asks poor, and the value for seeking difference is entered to the initial phase of row coefficient amendment zero initial phase modulation sequence of acquisition；
All phase difference determining module, for according to default all phase difference transformation rule, by the zero initial phase modulation sequence Initial phase is linearly calculated, and all phase for obtaining electric power signal is poor；
Frequency detection module, for according to default sinusoidal frequency transformation rule, by all phase difference and zero initial phase modulation sequence Time span obtains the frequency power signal after taking ratio.
7. the frequency detection system of electric power signal according to claim 6, it is characterised in that the phase determination module bag Include：
First ratio determining unit, for being the zero initial phase cosine function modulation sequence in the zero initial phase modulation sequence When, determine first void the first ratio of vectorial integrated value and the described first real vectorial integrated value of frequency frequently；
First phase determining unit, for using the opposite number of the arctan function value of first ratio as first phase Position；
Second ratio determining unit, for being the zero initial phase cosine function modulation sequence in the zero initial phase modulation sequence When, determine second void the second ratio of vectorial integrated value and the described second real vectorial integrated value of frequency frequently；
Second phase determining unit, for using the opposite number of the arctan function value of second ratio as second phase Position.
8. the frequency detection system of electric power signal according to claim 6, it is characterised in that the phase determination module bag Include：
3rd ratio determining unit, for being the zero initial phase SIN function modulation sequence in the zero initial phase modulation sequence When, determine the 3rd ratio of the described first real vectorial integrated value of frequency and the described first empty vectorial integrated value of frequency；
First phase detection unit, for using the arctan function value of the 3rd ratio as the first phase；
4th ratio determining unit, for being the zero initial phase SIN function modulation sequence in the zero initial phase modulation sequence When, determine the 4th ratio of the described second real vectorial integrated value of frequency and the described second empty vectorial integrated value of frequency；
Second phase detection unit, for using the arctan function value of the 4th ratio as the second phase.
9. the frequency detection system of electric power signal according to claim 6, it is characterised in that the initial phase determining module According toDetermine the initial phase of the zero initial phase modulation sequenceWherein, PH1For First phase, PH2For second phase, N is predetermined sequence length, NsFor truncated sequence length.
10. the frequency detection system of electric power signal according to claim 6, it is characterised in that all phase difference determines Module according toThe all phase difference △ PH of the electric power signal are determined, wherein, C2πFor Default integer signal period number,For the initial phase of the zero initial phase modulation sequence；
The frequency detection module according toThe frequencies omega of the electric power signal is determined, wherein, N is predetermined sequence Length,fnFor preset sample frequency.
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