CN102323481A - Measuring apparatus for unstable harmonics and interharmonics - Google Patents

Abstract

The invention discloses a measuring apparatus for unstable harmonics and interharmonics, which is an apparatus for measuring the harmonics and interharmonics generated by a power electronic device. The measuring apparatus mainly comprises an EPLL (Enhanced Phase Locked Loop) logic circuit, a band-pass filter, a homodyne logic circuit and the like, wherein the output end of the homodyne logic circuit is connected with a harmonic display logic circuit; and the output end of the EPLL logic circuit is connected with an interharmonic display logic circuit. According to the measuring apparatus disclosed by the invention, the reference frequency of a power signal is tracked by adopting an EPLL logic circuit so as to determine a reference signal of multiple unstable harmonics; and an input signal is modulated by using the homodyne logic circuit, thereby the multiple unstable harmonic components are measured. The interharmonic component of each frequency is tracked and measured according to the interharmonic frequency range obtained by pre-processing the signal. The measuring apparatus can be used for accurately measuring all unstable harmonic and interharmonic components in the power signal in a real time.

Description

The astable humorous interharmonics measuring meter that involves

Technical field

The present invention relates to be used for the device that a harmonic wave that electronic installation is produced and a harmonic wave are measured, especially for to amplitude in the electric power signal or the time dependent astable harmonic component of frequency and frequency be fundamental frequency non-integral multiple between the fast and accurate measurement instrument of harmonic component.

Background technology

In recent years, on the one hand, being widely used of power electronic equipment brought a large amount of harmonic waves, a harmonic pollution to electric system; On the other hand, the use of a large amount of sensitive equipments is had higher requirement for the measurement and the compensation of harmonic wave, a harmonic wave.High precision harmonic wave, a harmonic measure have crucial meaning for power quality analysis, protecting electrical power system and control.

Be based on the method for time domain-frequency domain at present both at home and abroad mostly about the measurement mechanism of harmonic wave, a harmonic wave.The accuracy of this device mainly by sampling whether synchronously, factors such as the performance of sample window function and frequency resolution determine jointly.

Being widely used of, impact load non-linear along with electric system, mains frequency can not be kept the stationary value of 50Hz, but (generally in 49.5Hz～50.5Hz) fluctuation within the specific limits.For the measurement of astable harmonic wave, a harmonic wave in the system, if adopt current domestic and international widely used square law device, one side needs high as far as possible frequency resolution, on the other hand, and the weak point that sample window length will be tried one's best.At present; The design of these signal measurement apparatus mainly is based on the IEC61000-4-7 standard; This standard recommendation 50Hz systematic sampling length of window is 10 fundamental frequency cycles, in this spectral range, divides into groups to measure the information of harmonic wave, a harmonic component through harmonic wave, a harmonic wave.This standard is to have confirmed this half-way house in requirement aspect frequency resolution and sample window length two after taking all factors into consideration in fact.Under this frequency resolution, be difficult to obtain high-precision measurement result; The method of harmonic component was as harmonic wave group between with the frequency spectrum between 2 harmonic components between the harmonic wave group was measured between the utilization of standard recommendation; The overall effective value of harmonic wave between therefrom obtaining between these two harmonic waves, and can't confirm the specifying information of each harmonic component.Therefore, a kind ofly can avoid contradiction between frequency resolution and the sample window length, accurately the frequency signal measurement mechanism of each component of signal of tracking measurement is necessity very for the measurement of the astable harmonic wave of each time, a harmonic wave.

Summary of the invention

The purpose of this invention is to provide and a kind ofly can measure simultaneously accurately amplitude or the time dependent astable humorous interharmonics measuring meter that involves of frequency.

The objective of the invention is to realize like this: a kind of astable humorous interharmonics measuring meter that involves comprises and contains the signal parameter factor mu ₁, μ ₂And μ ₃The EPLL logical circuit; Input signal module and fundamental frequency harmonics BPF. X0; 3-N odd harmonics BPF. and/or 2-N even harmonics BPF., and harmonic wave BPF. J1 between the 1st, harmonic wave BPF. J2 between the 2nd;, the input end of harmonic wave BPF. Jm is connected between m; The output terminal of fundamental frequency harmonics BPF. X0 is connected with fundamental frequency EPLL logical circuit E0 and fundamental frequency harmonics display logic circuit in order; The output terminal of above-mentioned 3-N odd harmonics BPF. and/or 2-N even harmonics BPF. respectively in order with corresponding homodyne logical circuit L1, L2 ... Ln and corresponding harmonic wave display logic circuit connect; Harmonic wave BPF. J1 between above-mentioned the 1st, harmonic wave BPF. J2 between the 2nd ... The output terminal of harmonic wave BPF. Jm is distinguished in order and harmonic wave EPLL logical circuit E1 between corresponding the 1st between m; Harmonic wave EPLL logical circuit E2 between the 2nd ..., between M harmonic wave EPLL logical circuit Em and corresponding between harmonic wave display logic circuit connect; With above-mentioned homodyne logical circuit L1, L2 ... The gain logical circuit Z1 that Ln is corresponding, Z2;, the input end of Zn all is connected with the corresponding output end of fundamental frequency EPLL logical circuit E0, above-mentioned gain logical circuit Z1; Z2 ..., the output terminal of Zn respectively with corresponding homodyne logical circuit L1; L2 ..., the fixed phase input end of Ln is connected.

Above-mentioned homodyne logical circuit L1, L2 ..., the frequency of the reference signal among the Ln equates that with the frequency of input signal E0 the mixed frequency signal that is produced is made up of the frequency multiplication component of a DC component and a frequency input signal.

In the signal parameter factor of above-mentioned EPLL logical circuit, μ ₁Span be 0＜μ ₁＜1/T, wherein T is the cycle of signal; μ ₂For greater than 1 positive number, μ ₃For less than 1 positive number, and μ ₂With μ ₃Product and μ ₁Be the same order of magnitude.

Above-mentioned μ ₁Be 50, μ ₂Be 1800, μ ₃Be 0.05.

Above-mentioned homodyne logic circuit structure is: the output terminal of fixed phase logical circuit is connected with the input end of sine function logical circuit and cosine function logical circuit respectively; The output terminal of sine function logical circuit is connected with the input end of the 1st multiplier and the input end of the 1st twice gain logical circuit respectively; The output terminal of cosine function logical circuit is connected with the input end of the 2nd multiplier and the input end of the 2nd twice gain logical circuit respectively; Input signal is connected to the input end of the 1st multiplier and the input end of the 2nd multiplier respectively; The output terminal of the 1st multiplier connects the input end of the 1st low-pass filter; The output terminal of the 1st low-pass filter is connected with the input end of the 3rd multiplier and the input end of algorithm logic circuit respectively; The output terminal of the 2nd multiplier connects the input end of the 2nd low-pass filter, and the output terminal of the 2nd low-pass filter is connected with the input end of the 4th multiplier and the input end of algorithm logic circuit respectively, and the algorithm of above-mentioned algorithm logic circuit does

The output terminal of algorithm logic circuit is the amplitude A of measured signal component _R, the output terminal of the output terminal of the 3rd multiplier and the 4th multiplier all is connected with the adder logic circuit, and the output terminal of adder logic circuit is connected with the output display circuit;

In the above-mentioned fixed phase logical circuit, by the phase place ω of signal fundamental component ₁T+ δ ₁Constitute the fixed phase φ of each harmonic _Rk: φ _Rk=k ω ₁T+k δ ₁In the formula, k is a positive integer, expression overtone order, δ ₁Be the first phase place value of signal fundamental component, ω ₁Be fundamental frequency angular frequency value, t is a time variable.

Compared with prior art; The invention has the beneficial effects as follows: the present invention proposes with enhancement mode phaselocked loop (Enhanced Phase Locked Loop; EPLL) logic circuit unit tracking measurement electric power signal fundamental frequency; To determine the reference signal of the astable harmonic wave of each time, with the homodyne logic circuit unit input signal is modulated, thereby obtained the astable harmonic component of each time.The harmonic frequency scope is provided with the initial angle frequency values of EPLL logic circuit unit between the Signal Pretreatment of giving chapter and verse gained, with harmonic component between each frequency of tracking measurement.Propose with the multiple-unit parallel organization all homodyne logic circuit units and the EPLL logic circuit unit astable humorous interharmonics measuring meter that involves of formation that combines, realization is accurately measured to all astable harmonic waves in the electric power signal, harmonic component the time.

The present invention compares the characteristics and the advantage of prior art and will further set forth in the embodiment part.

Description of drawings

Fig. 1 is an EPLL logic circuit structure block diagram.

Fig. 2 is a homodyne logic circuit structure block diagram.

Fig. 3 is the astable humorous harmonic measure circuit structure block diagram that involves of the present invention.

Fig. 3-the 1st, the astable humorous harmonic measure circuit structure block diagram (odd harmonics) that involves of the present invention.

Fig. 4 is 5 subharmonic amplitude curve figure under the amplitude saltus step situation.

Fig. 5 is 3 subharmonic amplitude figure under the noise circumstance.

Fig. 6 is 3 subharmonic amplitude curve figure before and after the fundamental frequency saltus step.

Fig. 7 is 9 subfrequency side-play amount synoptic diagram.

Fig. 8 is the spectrogram of harmonic signal between harmonic wave.

Fig. 9 is the amplitude figure of harmonic signal between harmonic wave.

Figure 10 is the frequency plot of a harmonic signal.

Figure 11 is the amplitude figure of a harmonic signal.

Figure 12 is the frequency plot of a harmonic signal.

Embodiment

The present invention proposes with enhancement mode phaselocked loop (Enhanced Phase Locked Loop; EPLL) logic circuit unit tracking measurement electric power signal fundamental frequency; To determine the reference signal of the astable harmonic wave of each time; With the homodyne logic circuit unit input signal is modulated, thereby obtained the astable harmonic component of each time.The harmonic frequency scope is provided with the initial angle frequency values of EPLL logic circuit unit between the Signal Pretreatment of giving chapter and verse gained, with harmonic component between each frequency of tracking measurement.Propose with the multiple-unit parallel organization all homodyne logic circuit units and the EPLL logic circuit unit astable humorous interharmonics measuring meter that involves of formation that combines, realization is accurately measured to all astable harmonic waves in the electric power signal, harmonic component the time.

The present invention combines homodyne logic circuit unit and EPLL logic circuit unit through the multiple-unit parallel organization; According to the Signal Pretreatment result BPF. (Band Pass Filter is set; The angular frequency initial value of free transmission range BPF) and EPLL logic circuit unit, the output terminal of homodyne logic circuit unit and EPLL logic circuit unit is connected with oscillograph;

The homodyne logical circuit:

A1), receive through the band-pass filter input signal component of single-frequency later;

B1), according to the fixed phase of astable harmonic component in the fundamental frequency structure input signal of fundamental frequency EPLL logic circuit unit output, and further obtain the reference signal of astable harmonic component;

C1), obtain the parameter information of astable harmonic component in the input signal, realize the reconstruct of astable harmonic component through homodyne modulation.

The EPLL logical circuit:

A2), receive through band-pass filter input signal fundamental component later, this fundamental component is carried out tracking measurement, and output maybe time dependent fundamental frequency amplitude, signal parameters such as frequency;

B2), receive through harmonic component between in band-pass filter input signal later, each EPLL logic circuit unit carries out tracking measurement, harmonic signal and corresponding signal parameter thereof between output to harmonic component between specific in the input signal.

The BPF logical circuit:

A3), receiving inputted signal, according to the result of Signal Pretreatment input signal is decomposed, to have only single frequency component in the input signal that guarantees each homodyne logical circuit and EPLL logical circuit.

Multiple-unit parallel circuit structure:

A4), all homodyne logic circuit units and all the EPLL logic circuit units form according to parallel connection is combined, all the astable humorous harmonic components that involve in the input signal are measured simultaneously.

Oscillograph:

A5), accept the output of homodyne logic circuit unit and EPLL logic circuit unit, show the parameter information such as amplitude, frequency of waveform and the component of signal of astable harmonic wave, a harmonic component.

For clearer explanation technical scheme of the present invention, in the face of constituting, logical circuit of the present invention describes down from the principle aspect:

1) principle of EPLL logical circuit can be used as shown in the formula 3 scalariform attitude system of equations shown in (1)～(3) and explain; Wherein,

is the amplitude measurement value of sinusoidal signal;

is the angular frequency measured value of sinusoidal signal, and

is total phase measurement.

The measured value of measured signal component is:

Input with the difference signal e (t) of output is:

Coefficient μ ₁, μ ₂And μ ₃Be the signal parameter regulatory factor of EPLL logical circuit, be used for speed of convergence and the steady-state error of control logic circuit when measuring-signal, wherein, μ ₁The measurement characteristics of major control amplitude; μ ₂And μ ₃The measurement characteristics of controlled frequency and phase place.The value of above-mentioned 3 signal parameter regulatory factors is big more, and speed of convergence is fast more, and simultaneously, it is also serious more that noise and other frequency component are treated the interference of measured frequency component, and measurement result has bigger steady-state error.Otherwise,, need long convergence time though can obtain more accurate result.

EPLL logic circuit structure block diagram among the present invention is as shown in Figure 1, by 2 totalizers (∑), 3 multipliers (*), 3 integrators

1 sine function (sin) and 1 cosine function (cos) logical circuit and μ ₁, μ ₂And μ ₃These 3 gain logical circuits

And

Combine ω ₀Angular frequency initial value for algorithm.Load module is the electric power signal that possibly comprise a plurality of harmonic waves, a harmonic component, output module be in the input signal that measures angular frequency near initial angle frequency values ω ₀Frequency component.

For signal parameter factor mu in the EPLL logical circuit ₁, μ ₂And μ ₃Definite method, in list of references [1],, μ is set usually in order to guarantee convergence ₁Span be 0＜μ ₁＜1/T, wherein T is the cycle of signal, μ ₁After confirming, μ is set ₂Be a bigger positive number, μ ₃For less than 1 positive count and will guarantee μ ₂, μ ₃Product and μ ₁Be the same order of magnitude, restrain simultaneously to guarantee signal amplitude and phase place.In the present invention, for all EPLL logical circuits the identical signal parameter factor is set all, its concrete value is: μ ₁=50, μ ₂=1800, μ ₃=0.05.The signal parameter factor values that provides in the document [1]; The value of the EPLL logical circuit signal parameter factor is relatively large among the present invention; This mainly is to consider when the bigger signal parameter factor is set; The inventive method has speed of convergence faster on the one hand, on the other hand, can not produce tangible steady state measurement error.

2) design philosophy of homodyne logical circuit is similar to the Coherent Detection of optical field.For sinusoidal signal, remove to modulate the input signal of single-frequency with the reference signal of unit amplitude, comprise in the mixed frequency signal of generation frequency equal respectively reference signal and frequency input signal and with 2 kinds of components of difference.In particular cases, reference signal equates with frequency input signal, promptly satisfies the homodyne condition, and the mixed frequency signal of this moment is made up of the frequency multiplication component of a DC component and a frequency input signal.From mixed frequency signal, this frequency multiplication component is filtered out, obtain comprising the DC component of input signal parameter information, it is carried out further computing can realize input signal reconstruct.The structured flowchart of homodyne detection logical circuit is as shown in Figure 2.

Visible by Fig. 2, the internal circuit annexation of homodyne logical circuit is: the output terminal of fixed phase logical circuit 1 is connected with sine function (sin) logical circuit 2 and cosine function (cos) logical circuit 3 respectively.2 are connected with the gain logical circuit 9,10 of 5,6 and 2 times of multiplier (X) logical circuits respectively with 3 output terminal.In 5 and 6, input signal 4 carries out multiplying with 2 and 3 output respectively, and the result of multiplying passes through low-pass filter (LPF) logical circuit 7 and 8 respectively.7 output terminal is connected with algorithm logic circuit 11 and multiplier logical circuit 12 respectively.8 output terminal is connected with 11 and multiplier logical circuit 13 respectively.11 output is the amplitude of measured signal component.12 are connected with totalizer (+) logical circuit 14 with 13 output terminal, and 14 output terminal is connected with output display circuit 15.

The function of homodyne logical circuit is that the function through each inner member in the structure shown in Figure 2 realizes, therefore, just can draw the principle of work of homodyne logical circuit through the function of analyzing inner each element of homodyne logical circuit.Here with the principle of work that example is explained the homodyne logical circuit that is measured as of k subharmonic:

Referring to Fig. 2, narrate with circuit component 1-15 respectively below the label 1-15 among Fig. 2.

The function of circuit component 1 is, according to satisfying ω all the time between the fundamental frequency angular frequency harmonic angular frequency in the signal _k=k ω ₁, ω wherein ₁Be fundamental frequency angular frequency, ω _k(k=2,3 ...) be k subharmonic angular frequency, by the phase place ω of signal fundamental component ₁T+ δ ₁(t is a time variable, δ ₁Initial phase for the fundamental frequency signal component) fixed phase of structure harmonic wave:

φ _rk＝kω ₁t+kδ ₁ (6)

The function of circuit component 2 is, according to the sinusoidal reference signal of the reference signal phase place tectonic unit amplitude of output in 1:

r _s(t)＝sinφ _rk＝sin(kω ₁t+kδ ₁) (7)

The function of circuit component 3 is, according to the cosine reference signal of the reference signal phase place tectonic unit amplitude of output in 1:

r _c(t)＝cosφ _rk＝cos(kω ₁t+kδ ₁) (8)

The function of circuit component 4 is to gather as shown in the formula the input signal shown in (9).In formula (9), A _i, ω _iAnd δ _i(i=1,2 ..., N) represent amplitude, angular frequency and the first phase place value of fundamental frequency and each harmonic component respectively, and satisfy ω _k=k ω ₁(k=1,2 ..., N), N is the frequency component sum in the signal.

$u\left(t\right)=\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{A}_i\sin ({\mathrm{\ω}}_{i}t+{\mathrm{\δ}}_i)---\left(9\right)$

The function of circuit component 5 is, the multiplication modulation operation is carried out in the output in 2 and 4, and its calculating process is as shown in the formula shown in (10):

$u\left(t\right)\×r_s\left(t\right)=\left[\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{A}_i\sin ({\mathrm{\ω}}_{i}t+{\mathrm{\δ}}_i)\right]\sin (k{\mathrm{\ω}}_{1}t+k{\mathrm{\δ}}_1)$

$=A_k\frac{\cos ({\mathrm{\δ}}_k-k{\mathrm{\δ}}_1)-\cos (2k{\mathrm{\ω}}_{1}t+{\mathrm{\δ}}_k+k{\mathrm{\δ}}_1)}{2}+---\left(10\right)$

$\underset{i\≠k}{\overset{N}{\mathrm{\Σ}}}{A}_i\frac{\cos ({\mathrm{\ω}}_{i}t-k{\mathrm{\ω}}_{1}t+{\mathrm{\δ}}_i-k{\mathrm{\δ}}_1)}{2}-\underset{i\≠k}{\overset{N}{\mathrm{\Σ}}}{A}_i\frac{\cos ({\mathrm{\ω}}_{i}t+k{\mathrm{\ω}}_{i}t+{\mathrm{\δ}}_i+k{\mathrm{\δ}}_1)}{2}$

The function of circuit component 6 is, the multiplication modulation operation is carried out in the output in 3 and 4, and its calculating process is as shown in the formula shown in (11):

$u\left(t\right)\×r_c\left(t\right)=\left[\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{A}_i\sin ({\mathrm{\ω}}_{i}t+{\mathrm{\δ}}_i)\right]\cos (k{\mathrm{\ω}}_{1}t+k{\mathrm{\δ}}_1)$

$=A_k\frac{\sin ({\mathrm{\δ}}_k-k{\mathrm{\δ}}_1)+\sin (2k{\mathrm{\ω}}_{1}t+k{\mathrm{\δ}}_1)}{2}+---\left(11\right)$

$\underset{i\≠k}{\overset{N}{\mathrm{\Σ}}}{A}_i\frac{\sin ({\mathrm{\ω}}_{i}t-k{\mathrm{\ω}}_{1}t+{\mathrm{\δ}}_i-k{\mathrm{\δ}}_1)}{2}+\underset{i\≠k}{\overset{N}{\mathrm{\Σ}}}{A}_i\frac{\sin ({\mathrm{\ω}}_{i}t+k{\mathrm{\ω}}_{i}t+{\mathrm{\δ}}_i+k{\mathrm{\δ}}_1)}{2}$

The function of circuit component 7 is to leach the DC component u of output in 5 _1k, obtain:

$u_{1k}=A_k\frac{\cos ({\mathrm{\δ}}_k-k{\mathrm{\δ}}_1)}{2}---\left(12\right)$

The function of circuit component 8 is to leach the DC component u of output in 6 _2k, obtain:

$u_{2k}=A_k\frac{\sin ({\mathrm{\δ}}_k-k{\mathrm{\δ}}_1)}{2}---\left(13\right)$

The function of circuit component 9 is to calculate 2 times the cosine reference signal 2r of unit _c(t).

The function of circuit component 10 is to calculate 2 times the sinusoidal reference signal 2r of unit _s(t).

The function of circuit component 11 is, calculates the amplitude of measured signal component, and concrete calculation expression is as shown in the formula shown in (14):

$A_k=2\sqrt{{\left(u_{1k}\right)}^2+{\left(u_{2k}\right)}^2}---\left(14\right)$

The function of circuit component 12 is, with DC component u _1kCarry out multiplying with 2 times unit sinusoidal reference signal, shown in the formula specific as follows (15):

$u_{1k}\×2\sin (k{\mathrm{\ω}}_{1}t+k{\mathrm{\δ}}_1)=A_k\frac{\cos ({\mathrm{\δ}}_k-k{\mathrm{\δ}}_1)}{2}\×2\sin (k{\mathrm{\ω}}_{1}t+k{\mathrm{\δ}}_1)$ (15)

$=A_k\frac{\sin (k{\mathrm{\ω}}_{1}t+{\mathrm{\δ}}_k)+\sin (k\mathrm{\ω}1t+2k{\mathrm{\δ}}_1-{\mathrm{\δ}}_k)}{2}$

The function of element circuitry 13 is, with DC component u _2kCarry out multiplying with 2 times unit cosine reference signal, shown in the formula specific as follows (16):

$u_{2k}\×2\cos (k{\mathrm{\ω}}_{1}t+k{\mathrm{\δ}}_1)=A_k\frac{\sin ({\mathrm{\δ}}_k-k{\mathrm{\δ}}_1)}{2}\×2\cos (k{\mathrm{\ω}}_{1}t+k{\mathrm{\δ}}_1)$ (16)

$=A_k\frac{\sin ({\mathrm{k\ω}}_{1}t+{\mathrm{\δ}}_k)-\sin (k{\mathrm{\ω}}_{1}t+2k{\mathrm{\δ}}_1-{\mathrm{\δ}}_k)}{2}$

The function of circuit component 14 is, additive operation carried out in the output in 12 and 13 obtained frequency component signal to be measured, specifically calculates as shown in the formula shown in (17):

$A_k\frac{\sin (k{\mathrm{\ω}}_{1}t+{\mathrm{\δ}}_k)+\sin (k{\mathrm{\ω}}_{1}t+2k{\mathrm{\δ}}_1-{\mathrm{\δ}}_k)}{2}+A_k\frac{\sin (k{\mathrm{\ω}}_{1}t+{\mathrm{\δ}}_k)-\sin (k{\mathrm{\ω}}_1+2k{\mathrm{\δ}}_1-{\mathrm{\δ}}_k)}{2}=A_k\sin (k{\mathrm{\ω}}_{1}t+{\mathrm{\δ}}_k)---\left(17\right)$

The function of circuit component 15 is to show the component of signal waveform that measures.

Notice for the astable harmonic component in the distortion electric power signal, still satisfy f _k(t)=kf ₁(t), f wherein ₁(t) and f _k(t) be respectively time dependent fundamental frequency and k subfrequency.So for stable/astable harmonic component, all can utilize the fundamental frequency phase place to construct the fixed phase that satisfies the homodyne condition, just can detect corresponding each harmonic component based on the homodyne logical circuit according to formula (6).

3) the present invention's " the astable humorous interharmonics measuring meter that involves " principle can be explained with logic circuit structure block diagram shown in Figure 3.

Internal circuit annexation at logical circuit of the present invention shown in Figure 3 is: input signal module and BPF. X1, and X2 ... Xn and J1, J2 ... The input end of Jm is connected.The output terminal of BPF. X1 is connected with the signal input part of fundamental frequency EPLL logical circuit E0, X2 ..., Xn successively with homodyne logical circuit L2;, the input end of Ln is connected, J1, J2; Jm successively with EPLL logical circuit E1, E2 ... The input end of Em is connected.Gain logical circuit Z1, Z2 ... Zn, input end be connected with the phase place output terminal of fundamental frequency EPLL logical circuit E0, output terminal successively with homodyne logical circuit L2 ..., Ln fixed phase input end is connected.The output terminal of homodyne logical circuit is connected with harmonic wave display logic circuit, and the output terminal of EPLL logical circuit is connected with a harmonic wave display logic circuit.

Provided a kind of universal architecture of the inventive method among Fig. 3; Comprise odd harmonics, even harmonics and a harmonic measurement unit in this universal architecture, can measure the first-harmonic in the input signal simultaneously, 2 subharmonic;, harmonic component between all m in nth harmonic and the input signal.Wherein m represent in the input signal between harmonic component sum, n representes the harmonic component sum.The inventive method is confirmed the value of m and n according to the spectrum distribution that input signal is carried out FFT pre-service gained according to the frequency resolution of IEC-61000-4-7 standard recommendation in practical application, the value of m and n is that independence is incoherent.

In the measurement structure shown in Figure 3, although the input signal of different homodyne logical circuits is different in all harmonic measurement unit of right side, the inner structure of each homodyne logical circuit all is the same with being provided with; And the left side all between in the harmonic measurement unit, although be provided with the identical signal parameter factor for all EPLL logical circuits, for harmonic component between the input in the different measuring unit, each EPLL logical circuit inner corners frequency initial value ω ₀ω in the different circuit all is set respectively according to harmonic frequency scope between the Signal Pretreatment gained ₀Difference is set.

If the present invention learns that according to Signal Pretreatment the higher hamonic wave that comprises in the signal is the N subharmonic in practical application; Necessity was not provided with N harmonic measurement unit or was provided with 1 times this moment; 2 times, 3 times ... N gain logical circuit doubly, and only need to require to be provided with targetedly harmonic measurement unit and corresponding gain logical circuit according to the spectrogram or the engineering survey of Signal Pretreatment gained.Only do not examine on even-order harmonic or the engineering the bigger odd harmonics of electric system harm if do not contain in the spectrogram, the logical circuit and corresponding harmonic measurement unit of even-multiple gain just need not be set.This does not influence the present invention all has the corresponding with it essence of unique measuring unit for each harmonic wave in the measured signal, a harmonic component, on the contrary, has improved the utilization ratio of device.

The astable humorous function that involves interharmonics measuring meter is that the function through each internal circuit element in the structure shown in Figure 3 realizes; Therefore, the function through inner each element of analysis circuit just can draw the astable humorous principle of work that involves the interharmonics measuring meter logical circuit.Below just the astable humorous function that involves inner each element of interharmonics measuring meter logical circuit is described:

The function of input signal module is to be used to import the electric power signal that possibly comprise a plurality of astable harmonic waves, a harmonic component.

The function of circuit component X1 is other frequency component beyond the filtering fundamental frequency signal.

The function of circuit component X2 is other frequency component beyond filtering 2 subharmonic.

… … …

The function of circuit component Xn is other frequency component beyond the filtering nth harmonic.

The function of circuit component J1 is, other frequency component between the 1st of filtering beyond the harmonic component.

The function of circuit component J2 is, other frequency component between the 2nd of filtering beyond the harmonic component.

… … …

The function of circuit component Jm is other frequency component between filtering m beyond the harmonic component.

The function of circuit component E0 is that the parameter of the signal fundamental component of measured X 1 output is for structure reference signal phase place in the homodyne logical circuit provides the fundamental frequency phase place.

The function of circuit component E1 is harmonic signal parameter between exporting among the measurement J1.

The function of circuit component E2 is harmonic signal parameter between exporting among the measurement J2.

… … …

The function of circuit component Em is harmonic signal parameter between exporting among the measurement Jm.

The function of circuit component L2 is the 2nd astable harmonic signal parameter of output in the measured X 2.

… … …

The function of circuit component Ln is the n time astable harmonic signal parameter exporting among the measured X n.

Fig. 3-1 illustrates, and a kind of astable humorous interharmonics measuring meter that involves comprises and contains the signal parameter factor mu ₁, μ ₂And μ ₃The EPLL logical circuit, input signal module and fundamental frequency harmonics BPF. X0, third harmonic BPF. X1; Quintuple harmonics BPF. X2;, harmonic wave BPF. J1 between odd number N subharmonic BPF. Xn and the 1st, harmonic wave BPF. J2 between the 2nd;, the input end of harmonic wave BPF. Jm is connected between m; The output terminal of fundamental frequency harmonics BPF. X0 is connected with fundamental frequency EPLL logical circuit E0 and fundamental frequency harmonics display logic circuit in order; Above-mentioned third harmonic BPF. X1, quintuple harmonics BPF. X2 ... The output terminal of odd number N subharmonic BPF. Xn respectively in order with corresponding homodyne logical circuit L1; L2 ..., Ln and corresponding harmonic wave display logic circuit connect; Harmonic wave BPF. J1 between above-mentioned the 1st, harmonic wave BPF. J2 between the 2nd ... The output terminal of harmonic wave BPF. Jm is distinguished in order and harmonic wave EPLL logical circuit E1 between corresponding the 1st between m; Harmonic wave EPLL logical circuit E2 between the 2nd ..., between M harmonic wave EPLL logical circuit Em and corresponding between harmonic wave display logic circuit connect; With homodyne logical circuit L1, L2 ..., the gain logical circuit Z1 that Ln is corresponding; Z2 ..., the input end of Zn all is connected with the corresponding output end of fundamental frequency EPLL logical circuit E0, above-mentioned gain logical circuit Z1; Z2 ..., the output terminal of Zn respectively with corresponding homodyne logical circuit L1; L2 ..., the fixed phase input end of Ln is connected.

Further specify characteristics of the present invention and advantage through comparing below with existing method.

1) there is the big deficiency of calculated amount in the astable harmonic measuring method of multiple-unit series connection designated phase based on list of references [1].Compare with this method; The inventive method adopts the homodyne logical circuit to measure the astable harmonic component in the input signal; To modulate and realize through directly signal being carried out homodyne with the nonlinear adaptive process that obtains astable harmonic component in the signal through iterative state equation group; Calculated amount is few, and stable performance.Suppose that input signal u (t) is:

u(t)＝1.00sin(ω ₀t)+0.40sin(3ω ₀t+π/3)+0.20sin(5ω ₀t+π/5)+0.10sin(9ω ₀t+π/9)+0.05sin(11ω ₀t+π/11)

The amplitude saltus step of each harmonic is original 120% among the signal u (t) when t=1.5s.With 5 subharmonic is example, has provided among Fig. 4 with method of the present invention and the amplitude curve that measures based on the designated phase method of document [1].Visible by figure, the method calculated amount that the present invention adopts is few, and efficient is high, can quick and precisely detect the variation of signal amplitude, compares with the designated phase method, and the amplitude curve dynamic process duration that measures has reduced about 80%.

2) measurement result of specific frequency components is received the serious interference of noise and other frequency component based on the astable harmonic measuring method of the multiple-unit of list of references [1] series connection designated phase.Compare with this method, have only a frequency component in the input signal of each measuring unit of the inventive method assurance, effectively suppressed the measurement interference that noise and other frequency component are treated the measured frequency component.

Still with 1) in input signal u (t) be example; In order to verify that the inventive method is to the Noise Suppression effect; (signal noise ratio SNR) is the signal of about 20dB to the white Gaussian noise that in input signal, adds

to obtain signal to noise ratio (S/N ratio).The 3 subharmonic amplitudes that measure with the inventive method and designated phase method under the noise circumstance have been provided among Fig. 5.Visible by figure, the inventive method can effectively suppress the phase mutual interference between noise and each frequency component, and the result who measures is more accurate.

3) the signal parameter regulatory factor based on each measuring unit in the astable harmonic measuring method of multiple-unit series connection designated phase of list of references [1] need require compromise to select according to measuring speed and precision two aspects.Compare with this method, the inventive method has enlarged the span of signal parameter regulatory factor in the EPLL logical circuit, allows the bigger signal parameter regulatory factor of EPLL logical circuit setting can not produce tangible steady state measurement error to improve measuring speed.

Input signal is with 1) in the same, suppose when t=2.8s, the saltus step of the fundamental frequency generation-0.5Hz of input signal, then the frequency hopping amount of i subharmonic is-0.5iHz.In the methods of the invention, the signal parameter regulatory factor of fundamental frequency EPLL logic circuit unit is set to 2 times of relevant parameter regulatory factor in the designated phase method.Fig. 6 has provided the 3 subharmonic amplitude curves that measure with two kinds of methods, and Fig. 7 has provided the 9 subfrequency saltus step discharge curves that measure with two kinds of methods.By Fig. 6; 7 is visible: on the one hand; Owing to be provided with bigger signal parameter regulatory factor for fundamental frequency EPLL1 logic circuit unit, method of the present invention can accurately measure amplitude, the frequency offset of astable harmonic wave in the short period after the fundamental frequency saltus step; On the other hand, owing to effectively suppressed the phase mutual interference between each frequency component, with respect to the true amplitude and the frequency offset of harmonic wave, method of the present invention does not produce tangible steady state measurement error.

4) harmonic wave that can only measure designated phase based on the astable harmonic measuring method of the multiple-unit of list of references [1] series connection designated phase then can't be measured a harmonic wave.Compare with this method; The inventive method can be measured a harmonic component when measuring harmonic wave; Simultaneously; The present invention earlier carries out pre-service to input signal before signal measurement, according to frequencies of harmonic components scope between the pre-service gained angular frequency initial value of EPLL logic circuit unit, the efficiency of measurement of harmonic component and accuracy between having improved are set.

Suppose that fundamental frequency is 50Hz, input signal is:

u(t)＝sin(2π50t+δ ₀)+0.10sin(2π68t+δ ₁)+0.06sin(2π83t+δ ₂)

Wherein, δ ₀, δ ₁And δ ₂Be arbitrary constant.Input signal is carried out the FFT pre-service according to IEC61000-4-7 recommended frequency resolution and sample window length, and the spectrogram that obtains input signal is as shown in Figure 8.Visible by Fig. 8, in the input signal except fundamental component also comprise frequency be positioned at 65～70Hz and 80～85Hz between harmonic component.For this reason, the angular frequency initial value that 2 EPLL logical circuits are set is respectively 140 π rad and 160 π rad, has provided the frequency curve of harmonic component between the component of signal amplitude curve that measured by the inventive method and 2 among Fig. 9 and Figure 10 respectively.

5) based on list of references [2] although a plurality of EPLL measuring units parallel connection astable humorous involve inter-harmonic wave measuring method and adopt parallel-connection structure after overall measurement efficient be improved; But owing to adopt the EPLL method of iterative state equation group to measure the astable harmonic wave of each time, so still there is the big deficiency of calculated amount in this method.Compare with this method, the inventive method adopts the method for homodyne modulation to replace the EPLL method to measure astable harmonic wave, and calculated amount is few, and stable performance.

In list of references [1] through experiment confirm lack rapid dynamic response speed based on the astable harmonic measuring method of designated phase than method calculated amount based on EPLL.So in conjunction with above 1) and 3) in experimental result, be not difficult to draw superiority of the present invention.

6) involve inter-harmonic wave measuring method direct harmonic frequency that the angular frequency initial value is set to and a harmonic frequency is approaching of EPLL measuring unit during harmonic wave between measuring based on a plurality of EPLL measuring units parallel connection of list of references [2] astable humorous; May cause the iterative computation overlong time owing to the harmonic frequency value is too wide in the gap between original frequency value that is provided with and reality like this, even not convergent result occur.Compare with this method; With 4) described in the same, the inventive method is first before signal measurement carries out pre-service to signal, and the angular frequency disposal value of EPLL logic circuit unit is set according to frequencies of harmonic components scope between the pre-service gained; Than method based on document [2]; The angular frequency initial value is more near humorous angular frequency value between reality in the inventive method, thereby can reach convergence quickly, improved efficiency of measurement and accuracy to a harmonic wave.

In order to explain that initial value chooses the influence to EPLL measuring unit constringency performance, below with 4) in input signal be that example is analyzed.With harmonic component between 68Hz is example, in the methods of the invention, according to IEC61000-4-7 signal is carried out pre-service, and the angular frequency initial value that the EPLL unit is set according to pretreated result is 140 π rad.Will be based on the method for document [2] method as a reference, the angular frequency initial value that the EPLL unit is set is 100 π rad.Figure 11 provided with two kinds of methods measure between the harmonic wave amplitude curve, provided the correspondent frequency curve among Figure 12.By Figure 11,12 are not difficult to find out, in the methods of the invention, it is very necessary before measuring signal being carried out pre-service.

7) has higher measuring accuracy based on the prony method of harmonic measure between the harmonic wave of list of references [3] for the input signal of single-frequency; But when having a plurality of frequency components or input signal signal to noise ratio snr low in the input signal, measuring result error is bigger.Compare with the prony method, with 2) described in the same, each measuring unit of the inventive method has only the component to be measured of single-frequency, can effectively suppress the interference between noise and each frequency component, has higher measuring accuracy and anti-interference.

With 2) in used input signal be example, signal to noise ratio snr=20dB analyzes signal respectively with the inventive method and prony method, has provided corresponding amplitude measurement result in the table 1:

Table 1 amplitude measurement value

Tab?1Estimation?of?amplitudes

With 4) in the input signal that contains a harmonic component be example, in the signal that measures with the inventive method and prony method between two the frequency of harmonic component as shown in table 2:

Table 2 frequency measurement

Tab?2Estimation?of?frequencies

Through the frequency measurement in amplitude measurement value and the table 2 in the analysis comparison sheet 1, be not difficult to find that the inventive method can effectively suppress the mutual interference mutually of each frequency component of noise and signal, compare with the prony method, have stronger anti-interference and higher precision.

In sum, the inventive method is all to have bigger advantage aspect calculated amount or the measuring accuracy with respect to existing the whole bag of tricks technology, and engineering practicability is stronger.

List of references

【1】Mcnamara?D?M，Ziarani?A?K，Ortmeyer?T?H.A?new?technique?of?measurement?of?nonstationary?harmonics[J].IEEE?Trans?on?Power?Delivery，2007，22(1)：387-395.

【2】Carvalho?J?R?D，Duque?C?A，Ribeiro?M?V，et?al.A?PLL-Based?Multirate?Structure?for?Time-Varying?Power Systems?Harmonic/Inter-Harmonic?Estimation[J].IEEE?Trans?on?Power?Delivery，2009，24(4)：1789-1800.

[3] Ding Yifeng, Cheng Haozhong, Lv Ganyun, etc. a harmonic wave and a harmonic spectrum based on the prony algorithm are estimated [J]. electrotechnics journal, 2005,20 (10): 94-97.

Ding?Yifeng，Cheng?Haozhong，Lv?Ganyun，et?al.Spectrum?Estimation?of?Harmoincs?and?Interharmonics?Based?on?Prony?Algorithm[J].Transactions?of?China?Electrotechnical?Society，2005，20(10)：94-97.

Claims (5)

1. the astable humorous interharmonics measuring meter that involves comprises, contains the signal parameter factor mu ₁, μ ₂And μ ₃The EPLL logical circuit; It is characterized in that: said input signal module and fundamental frequency harmonics BPF. X0; 3-N odd harmonics BPF. and/or 2-N even harmonics BPF., and harmonic wave BPF. J1 between the 1st, harmonic wave BPF. J2 between the 2nd;, the input end of harmonic wave BPF. Jm is connected between m; The output terminal of fundamental frequency harmonics BPF. X0 is connected with fundamental frequency EPLL logical circuit E0 and fundamental frequency harmonics display logic circuit in order; The output terminal of above-mentioned 3-N odd harmonics BPF. and/or 2-N even harmonics BPF. respectively in order with corresponding homodyne logical circuit L1, L2 ... Ln and corresponding harmonic wave display logic circuit connect; Harmonic wave BPF. J1 between above-mentioned the 1st, harmonic wave BPF. J2 between the 2nd ... The output terminal of harmonic wave BPF. Jm is distinguished in order and harmonic wave EPLL logical circuit E1 between corresponding the 1st between m; Harmonic wave EPLL logical circuit E2 between the 2nd ..., between M harmonic wave EPLL logical circuit Em and corresponding between harmonic wave display logic circuit connect; With above-mentioned homodyne logical circuit L1, L2 ... The gain logical circuit Z1 that Ln is corresponding, Z2;, the input end of Zn all is connected with the corresponding output end of fundamental frequency EPLL logical circuit E0, above-mentioned gain logical circuit Z1; Z2 ..., the output terminal of Zn respectively with corresponding homodyne logical circuit L1; L2 ..., the fixed phase input end of Ln is connected.

2. the astable humorous interharmonics measuring meter that involves according to claim 1; It is characterized in that: said homodyne logical circuit L1; L2;, the frequency of the reference signal among the Ln equates that with the frequency of input signal E0 the mixed frequency signal that is produced is made up of the frequency multiplication component of a DC component and a frequency input signal.

3. the astable humorous interharmonics measuring meter that involves according to claim 1 and 2 is characterized in that: in the signal parameter factor of said EPLL logical circuit, and μ ₁Span be 0＜μ ₁＜1/T, wherein T is the cycle of signal; μ ₂For greater than 1 positive number, μ ₃For less than 1 positive number, and μ ₂With μ ₃Product and μ ₁Be the same order of magnitude.

4. the astable humorous interharmonics measuring meter that involves according to claim 3 is characterized in that: said μ ₁Be 50, μ ₂Be 1800, μ ₃Be 0.05.

5. the astable humorous interharmonics measuring meter that involves according to claim 4; It is characterized in that: said homodyne logic circuit structure is: the output terminal of fixed phase logical circuit (1) is connected with the input end of sine function logical circuit (2) and cosine function logical circuit (3) respectively; The output terminal of sine function logical circuit (2) is connected with the input end of the 1st multiplier (5) and the input end of the 1st twice gain logical circuit (10) respectively; The output terminal of cosine function logical circuit (3) is connected with the input end of the 2nd multiplier (6) and the input end of the 2nd twice gain logical circuit (9) respectively; Input signal (4) is connected to the input end of the 1st multiplier (5) and the input end of the 2nd multiplier (6) respectively; The output terminal of the 1st multiplier (5) connects the input end of the 1st low-pass filter (7); The output terminal of the 1st low-pass filter is connected with the input end of the 3rd multiplier (12) and the input end of algorithm logic circuit (11) respectively; The output terminal of the 2nd multiplier (6) connects the input end of the 2nd low-pass filter (8); The output terminal of the 2nd low-pass filter is connected with the input end of the 4th multiplier (13) and the input end of algorithm logic circuit (11) respectively, and the algorithm of above-mentioned algorithm logic circuit (11) does

The output terminal of algorithm logic circuit (11) is the amplitude A of measured signal component _R, the output terminal of the output terminal of the 3rd multiplier (12) and the 4th multiplier (13) all is connected with adder logic circuit (14), and the output terminal of adder logic circuit (14) is connected with output display circuit (15);

In the above-mentioned fixed phase logical circuit (15), by the phase place ω of signal fundamental component ₁T+ δ ₁Constitute the fixed phase φ of each harmonic _Rk: φ _Rk=k ω ₁T+k δ ₁In the formula, k is a positive integer, expression overtone order, δ ₁Be the first phase place value of signal fundamental component, ω ₁Be fundamental frequency angular frequency value, t is a time variable.

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