A broadband injection signal optimization distribution method and system for impedance measurement

Abstract

The present invention discloses a method and system for optimizing the allocation of broadband injection signals for impedance measurement. The method comprises: determining an initial frequency matrix based on determining the frequency domain starting point, frequency ending point, and frequency interval of each frequency segment; calculating the minimum signal duration of each frequency segment based on the initial frequency matrix, generating a discrete interval binary sequence DIBS signal for each frequency segment, and connecting them end to end to generate a DIBS signal with the minimum duration of the full frequency domain point; obtaining the three-phase voltage signal and three-phase current signal of each frequency segment and performing positive sequence calculation to determine the positive sequence voltage and positive sequence current of each frequency segment; extracting the amplitude of the frequency point of the positive sequence voltage and positive sequence current of each frequency segment through FFT to determine the voltage amplitude and current amplitude, and calculating the impedance and signal injection degree of each frequency point based on the voltage amplitude and current amplitude; and executing a frequency allocation strategy based on the signal injection degree of each frequency point.

Description

Technical Field

[0001] The present invention relates to the technical field of broadband impedance measurement, and more particularly to a broadband injection signal optimization distribution method and system for impedance measurement. Background Art

[0002] The single-sine frequency sweep method is used for broadband impedance measurement. The wider the bandwidth and the more frequency points, the longer the measurement time. It is basically unsuitable for broadband impedance measurement in actual engineering, but it can be used to improve the measurement accuracy of individual frequency points. The multi-sine signal, obtained by superimposing multiple sinusoidal signals, can reduce the measurement time, but is prone to large time-domain peaks. The discrete interval binary sequence (DIBS) is a signal that can be optimized by a computer. The optimization goal is to input as much power as possible into the specified harmonic frequency without increasing the signal's time-domain amplitude. DIBS has a large harmonic component at the set frequency. The more frequency points there are, the smaller the harmonic component. The denser the frequency points, the smaller the component. Therefore, the frequency points need to be reasonably distributed. In addition, the injection time needs to be reasonably designed, considering the actual frequency interval. Summary of the Invention

[0003] According to the present invention, a method for optimizing the distribution of broadband injection signals for impedance measurement is provided to solve the technical problem of how to reasonably distribute frequency points.

[0004] According to a first aspect of the present invention, there is provided a method for optimizing distribution of broadband injection signals for impedance measurement, comprising:

[0005] Determine an initial frequency matrix based on the frequency domain starting point, frequency end point, and frequency interval of each frequency segment;

[0006] Based on the initial frequency matrix, the minimum signal duration of each frequency segment is calculated to generate a discrete interval binary sequence DIBS signal for each frequency segment, and the DIBS signals of each frequency segment are connected end to end to generate a DIBS signal with the minimum duration of the full frequency domain point;

[0007] Based on the DIBS signal with the minimum duration at the full-frequency point, the three-phase voltage signal and the three-phase current signal of each frequency segment are obtained, and the positive sequence calculation is performed on the three-phase voltage and three-phase current signals of each frequency segment to determine the positive sequence voltage and positive sequence current of each frequency segment;

[0008] Extracting the amplitude of the frequency point from the positive sequence voltage and positive sequence current of each frequency segment through Fourier transform, determining the voltage amplitude and current amplitude, and calculating the impedance and signal injection degree at each frequency point based on the voltage amplitude and current amplitude;

[0009] A frequency allocation strategy is executed based on the signal injection degree of each frequency point.

[0010] Optionally, determining an initial frequency matrix based on a frequency domain starting point, a frequency end point, and a frequency interval of each frequency segment includes:

[0011] Measure the frequency segment N and determine the frequency domain starting point f of each frequency segment ns , frequency end point f ne and the frequency interval Δf n , n∈[1,N], determine the initial frequency matrix as:

[0012]

[0013] Where, f0={f1 f2…f N}.

[0014] Optionally, based on the initial frequency matrix, the minimum signal duration of each frequency segment is calculated, a discrete interval binary sequence DIBS signal of each frequency segment is generated, and the DIBS signals of each frequency segment are connected end to end to generate a DIBS signal with the minimum duration of the full frequency domain point, including:

[0015] Based on the initial frequency matrix, the minimum signal duration of each frequency segment is calculated to generate a discrete interval binary sequence DIBS signal for each frequency segment;

[0016] Connect the discrete interval binary sequence DIBS signals of each frequency band end to end and generate the signals with a duration of t n DIBS signal of each frequency band, t n =1 / Δf n , the signal of each segment is recorded as signal_n, and the DIBS signal with the minimum duration of the full frequency domain point is generated as

[0017] signal=[signal_1signal_2...signal_N].

[0018] Optionally, based on the DIBS signal with the minimum duration of the full-frequency point, three-phase voltage signals and three-phase current signals of each frequency segment are obtained, and positive sequence calculation is performed on the three-phase voltage and three-phase current signals of each frequency segment to determine the positive sequence voltage and positive sequence current of each frequency segment, including:

[0019] Based on the DIBS signal with the lowest duration at the full frequency domain point, the three-phase voltage signal and the three-phase current signal are obtained on the high-voltage side. According to the time sequence and duration of the injected DIBS signal, the three-phase voltage signal and the three-phase current signal U in each frequency band are intercepted. an 、U bn 、U cn , I an , Ibn , I cn , where the three-phase voltage signal and three-phase current signal with a duration of t0 before the injection signal are intercepted and recorded as U a0 、U b0 、U c0 , I a0 , I b0 , I c0 , t0=max(t1 t2…t N );

[0020] Perform positive sequence calculation on the three-phase voltage and three-phase current signals of each frequency band to determine the positive sequence voltage and positive sequence current of each frequency band;

[0021] U m =1 / 3(U am +a·U bm +a 2 ·U cm )

[0022] I m =1 / 3(I am +a·I bm +a 2 I cm )

[0023] Among them, m∈[0,N], 0 represents the time before the injection signal, a=e j120o .

[0024] Optionally, extracting the amplitude of the frequency point from the positive-sequence voltage and the positive-sequence current of each frequency segment by Fourier transform, determining the voltage amplitude and the current amplitude, and calculating the impedance and the signal injection degree at each frequency point based on the voltage amplitude and the current amplitude, including:

[0025] The positive sequence voltage and positive sequence current of each frequency band are extracted by Fourier transform to obtain the amplitude of the frequency point and determine the voltage amplitude U m_fm and the current amplitude I m_fm ;

[0026] Based on the voltage amplitude U m_fm and the current amplitude I m_fm , calculate the impedance Z at each frequency point fn and signal injection level r_I fm :

[0027]

[0028] Among them, I 0_f1 Refers to the background harmonic current value under the f1 frequency matrix; I 0_50 is the background harmonic current value at the fundamental frequency.

[0029] Optionally, executing a frequency allocation strategy based on the signal injection degree of each frequency point includes:

[0030] Determine whether the signal injection degree of each frequency point is greater than or equal to a set threshold;

[0031] If the signal injection level of each frequency point is greater than or equal to the set threshold, then end;

[0032] If there is a frequency point where the signal injection degree of each frequency point is less than the set threshold, the frequency allocation strategy is executed to redefine the initial frequency matrix until the signal injection degree of each frequency point is greater than or equal to the set threshold.

[0033] According to another aspect of the present invention, there is also provided a broadband injection signal optimization distribution system for impedance measurement, comprising:

[0034] The frequency segment measurement module is used to determine the initial frequency matrix based on the frequency domain starting point, frequency end point and frequency interval of each frequency segment;

[0035] A DIBS signal generation module is used to calculate the minimum signal duration of each frequency segment based on the initial frequency matrix, generate a discrete interval binary sequence DIBS signal for each frequency segment, and connect the DIBS signals of each frequency segment end to end to generate a DIBS signal with the minimum duration of the full frequency domain point;

[0036] A positive-sequence voltage and current determination module is used to obtain the three-phase voltage signal and the three-phase current signal of each frequency segment based on the DIBS signal with the minimum duration of the full-frequency domain point, and perform positive-sequence calculation on the three-phase voltage and the three-phase current signal of each frequency segment to determine the positive-sequence voltage and positive-sequence current of each frequency segment; a signal injection degree calculation module is used to extract the amplitude of the frequency point by Fourier transform of the positive-sequence voltage and the positive-sequence current of each frequency segment, determine the voltage amplitude and the current amplitude, and calculate the impedance and signal injection degree of each frequency point based on the voltage amplitude and the current amplitude;

[0037] The frequency allocation strategy execution module is used to execute the frequency allocation strategy based on the signal injection degree of each frequency point. Optionally, the frequency segment measurement module includes:

[0038] The frequency segment measurement submodule is used to measure the frequency segment N and determine the frequency domain starting point f of each frequency segment. ns , frequency end point f ne and the frequency interval Δf n , n∈[1,N], determine the initial frequency matrix as:

[0039]

[0040] Where, f0={f1 f2…f N}.

[0041] Optionally, a DIBS signal generation module is provided, including:

[0042] A DIBS signal generation submodule is used to calculate the minimum signal duration of each frequency segment based on the initial frequency matrix and generate a discrete interval binary sequence DIBS signal for each frequency segment;

[0043] Connect the discrete interval binary sequence DIBS signals of each frequency segment end to end, and generate the DIBS signals of each frequency segment with a duration of t n =1 / Δf n , the signal of each segment is recorded as signal_n, and the DIBS signal with the minimum duration of the full frequency domain point is generated as

[0044] signal=[signal_1signal_2...signal_N].

[0045] Optionally, determining a positive sequence voltage and current module includes:

[0046] The voltage and current acquisition submodule is used to obtain the three-phase voltage signal and the three-phase current signal on the high-voltage side based on the DIBS signal with the lowest duration at the full-frequency domain point, and intercept the three-phase voltage signal and the three-phase current signal U in each frequency band according to the time sequence and duration of the injected DIBS signal. an 、U bn 、U cn , I an , I bn , I cn , where the three-phase voltage signal and three-phase current signal with a duration of t0 before the injection signal are intercepted and recorded as U a0 、U b0 、U c0 , I a0 , I b0 , I c0 , t0=max(t1 t2…t N );

[0047] The positive sequence voltage and current determination submodule is used to perform positive sequence calculation on the three-phase voltage and three-phase current signals of each frequency band to determine the positive sequence voltage and positive sequence current of each frequency band;

[0048] U m =1 / 3(U am +a·U bm +a 2 ·U cm )

[0049] I m =1 / 3(Iam +a·I bm +a 2 I cm )

[0050] Among them, m∈[0,N], 0 represents the time before the injection signal, a=e j120o .

[0051] Optionally, the signal injection degree calculation module includes:

[0052] The voltage and current amplitude determination submodule is used to extract the amplitude of the frequency point through Fourier transform of the positive sequence voltage and positive sequence current in each frequency band to determine the voltage amplitude U m_fm and the current amplitude I m_fm ;

[0053] The impedance calculation accuracy submodule is used to calculate the impedance based on the voltage amplitude U m_fm and the current amplitude I m_fm , calculate the impedance Z at each frequency point fn and signal injection level r_I fm :

[0054]

[0055] Among them, I 0_f1 Refers to the background harmonic current value under the f1 frequency matrix; I 0_50 is the background harmonic current value at the fundamental frequency.

[0056] Optionally, executing a frequency allocation strategy module includes:

[0057] The impedance calculation accuracy determination submodule is used to determine whether the impedance calculation accuracy of each frequency point passes a certain frequency point or certain frequency points;

[0058] The frequency allocation strategy end submodule is used to determine whether the signal injection degree of each frequency point is greater than or equal to a set threshold;

[0059] An end submodule, configured to end the process if the signal injection levels at each frequency point are greater than or equal to a set threshold;

[0060] The allocation strategy execution submodule is used to execute the frequency allocation strategy if there is a frequency point where the signal injection degree of each frequency point is less than the set threshold, and redetermine the initial frequency matrix until the signal injection degree of each frequency point is greater than or equal to the set threshold.

[0061] Thus, based on the frequency domain starting point, frequency end point and frequency interval of each frequency segment, the initial frequency matrix is determined, the minimum signal duration of each frequency segment is calculated, the discrete interval binary sequence DIBS signal of each frequency segment is generated, and the DIBS signals of each frequency segment are connected end to end to generate the DIBS signal with the minimum duration of the full frequency domain point; the three-phase voltage signal and three-phase current signal of each frequency segment are obtained, and the positive sequence calculation of the three-phase voltage and three-phase current signals of each frequency segment is performed to determine the positive sequence voltage and positive sequence current of each frequency segment. The amplitude of the frequency point is extracted from the positive sequence voltage and positive sequence current of each frequency segment through Fourier transform, and the voltage amplitude and current amplitude are determined. Based on the voltage amplitude and current amplitude, the impedance and signal injection degree of each frequency point are calculated. Based on the signal injection degree of each frequency point, the frequency allocation strategy is executed. Thus, the actual frequency interval is taken into consideration, the injection time is reasonably designed, and the frequency points are reasonably allocated. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0063] Figure 1 Schematic diagram of a flow chart of a method for optimizing distribution of broadband injection signals for impedance measurement according to this embodiment;

[0064] Figure 2 Schematic diagram of a method for optimizing distribution of broadband injection signals for impedance measurement according to this embodiment;

[0065] Figure 3 Schematic diagram of a broadband injection signal optimization distribution system for impedance measurement according to this embodiment. DETAILED DESCRIPTION

[0066] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments shown in the accompanying drawings is not intended to limit the present invention. In the accompanying drawings, identical elements are denoted by the same reference numerals.

[0067] Unless otherwise specified, the terms used herein (including technical terms) have the meanings commonly understood by those skilled in the art. In addition, it is understood that terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0068] According to a first aspect of the present invention, a broadband injection signal optimization distribution method 100 for impedance measurement is provided. Figure 1 As shown, the method 100 includes:

[0069] S101: Determine an initial frequency matrix based on the frequency domain starting point, frequency end point, and frequency interval of each frequency segment;

[0070] S102: Based on the initial frequency matrix, calculate the minimum signal duration of each frequency segment, generate a discrete interval binary sequence DIBS signal for each frequency segment, and connect the DIBS signals of each frequency segment end to end to generate a DIBS signal with the minimum duration of the full frequency domain point;

[0071] S103: Based on the DIBS signal with the minimum duration at the full-frequency point, obtain the three-phase voltage signal and the three-phase current signal of each frequency segment, and perform positive sequence calculation on the three-phase voltage and three-phase current signals of each frequency segment to determine the positive sequence voltage and positive sequence current of each frequency segment;

[0072] S104: extracting the amplitude of the frequency point from the positive-sequence voltage and positive-sequence current of each frequency segment through Fourier transform, determining the voltage amplitude and current amplitude, and calculating the impedance and signal injection degree at each frequency point based on the voltage amplitude and current amplitude;

[0073] S105: Execute a frequency allocation strategy based on the signal injection degree of each frequency point.

[0074] Specifically, refer to Figure 2 As shown, the initial frequency matrix is obtained; a DIBS signal with the minimum duration across all frequency domain points is generated; the DIBS signal is injected into Iqreq via SVG to obtain voltage and current signals on the high-voltage side; positive sequence calculations are performed on the voltage and current signals in each frequency band; the amplitudes of the positive sequence voltage and current in each frequency band are extracted using Fourier transform; the impedance and harmonic current injection level at each frequency point are calculated; and the frequency allocation strategy is executed based on whether the harmonic current injection accuracy at each frequency point meets the set requirements.

[0075] 1) Obtain the initial frequency matrix;

[0076] According to the actual measurement requirements, divide the frequency band N and determine the frequency domain starting point f of each frequency band ns , frequency end point f ne and the frequency interval Δf n , n∈[1,N]; then the initial frequency matrix is:

[0077]

[0078] In addition, f0={f1 f2…f N}

[0079] 2) Generate the DIBS signal with the lowest duration in the entire frequency domain;

[0080] Calculate the minimum signal duration of each frequency band, generate the DIBS signal of each frequency band, connect the DIBS signals of each frequency band end to end to obtain the final injected DIBS signal; generate the duration t in sequence n DIBS signal of each frequency band, t n =1 / Δf n , the signal of each segment is recorded as signal_n, then the DIBS signal with the minimum duration of the full frequency domain point is generated as

[0081] signal=[signal_1signal_2...signal_N].

[0082] 3) Inject DIBS signal on Iqreq through SVG, obtain three-phase voltage and current signals on the high-voltage side, and intercept the three-phase voltage and current signals U in each frequency band according to the time sequence and duration of the injected DIBS signal. an 、U bn 、U cn , I an , I bn , I cn ; In addition, the three-phase voltage and current signals with a duration of t0 before the injection signal are intercepted and recorded as U a0 、U b0 、U c0 , I a0 , I b0 , I c0 ; t0=max(t1t2…t N );

[0083] 4) Perform positive sequence calculation on the three-phase voltage and current signals of each frequency band;

[0084] U m =1 / 3(U am +a·U bm +a 2 ·U cm )

[0085] I m =1 / 3(I am +a·I bm +a 2 I cm ), where m∈[0, N], 0 represents the value before the signal is injected. a=e j120o .

[0086] 5) The amplitude of the positive sequence voltage and current of each frequency band is extracted by Fourier transform, which is recorded as U m_fm, I m_fm , referring to U m The signal is extracted by Fourier transform f m The amplitude below

[0087] 6) Calculate the impedance Z at each frequency point fn and signal injection level r_I fm ;

[0088]

[0089] I 0_f1 Refers to the background harmonic current value under the f1 frequency matrix; I 0_50 is the background harmonic current value at the fundamental frequency.

[0090] 7) Execute the frequency allocation strategy according to whether the accuracy meets the requirements until it is met.

[0091] If the signal injection level in 6) is less than the set threshold at a certain frequency point or some frequency points, the frequency allocation strategy is executed for the frequency segment where the frequency point is located; the allocation strategy is detailed in 5. Repeat 2) to 7) until the condition is satisfied.

[0092] The initial frequency matrix [f start :Δf:f end ), f start is the frequency starting point, f end is the frequency end point, Δf is the frequency interval, and the frequency allocation strategy is implemented to divide the system into k groups. The frequency matrix of each group is as follows:

[0093]

[0094] in,

[0095] Measure broadband impedance from 2.5Hz to 1000Hz, with a step size of 0.1Hz from 2.5Hz to 10Hz, a step size of 1Hz from 10Hz to 100Hz, and a step size of 10Hz from 100Hz to 1000Hz, with an accuracy of no less than 5%.

[0096] 1) The initial frequency matrix is [2.5:0.1:10), [10:1:100), [100:10:1000).

[0097] 2) The first segment is a DIBS signal with a frequency of [2.5:0.1:10) and a duration of 10 seconds, denoted as signal_1;

[0098] The second segment is a DIBS signal with a frequency of [10:1:100) and a duration of 1s, denoted as signal_2;

[0099] The third segment is a DIBS signal with a frequency of [100:10:1000) and a duration of 0.1s, denoted as signal_3;

[0100] The final signal is composed of three segments connected end to end to form signal: [signal_1signal_2signal_3]

[0101] 3) Inject DIBS signal on Iqreq through SVG, obtain three-phase voltage and current signals on the high-voltage side, intercept the three-phase voltage and current signals 10s before the injection signal as U a0 、U b0 、U c0 , I a0 , I b0 , I c0 ; intercept the 10s data after the injection signal as U a1 、U b1 、U c1 , I a1 , I b1 , I c1 ; Intercept the data between 10s and 11s after the injection signal as U a2 、U b2 、U c2 , I a2 , I b2 , I c2 ; intercept the data between 11s and 11.1s after the injection signal as U a3 、U b3 、U c3 , I a3 , I b3 , I c3 ;

[0102] 4) Perform positive sequence calculation on the voltage and current signals of each frequency band;

[0103] U0=1 / 3(U a0 +a·U b0 +a 2 ·U c0 )U1=1 / 3(U a1 +a·U b1 +a 2 ·U c1 )

[0104] I0=1 / 3(I a0 +a·I b0 +a 2 I c0 ), I1=1 / 3(I a1 +a·I b1 +a 2 Ic1 ),

[0105] U2=1 / 3(U a2 +a·U b2 +a 2 ·U c2 )U3=1 / 3(U a3 +a·U b3 +a 2 ·U c3 )

[0106] I2=1 / 3(I a2 +a·I b2 +a 2 I c2 ), I3=1 / 3(I a3 +a·I b3 +a 2 I c3 ),

[0107] 5) Extract the amplitude U of U0 and I0 at the frequency f0∈{[2.5:0.1:10)[10:1:100)[100:10:1000)} through Fourier transform 0_f0 , I 0_f0 ; Extract the amplitude U of U1 and I1 at the frequency of f1∈{[2.5:0.1:10)} 1_f1 , I 1_f1 ;right

[0108] U2, I2 extract the amplitude U at the frequency of f2∈{[10:1:100)} 2_f2 , I 2_f2 ; Extract the amplitude U of U3 and I3 at the frequency of f3∈{[100:10:1000)} 3_f3 , I 3_f3 ;

[0109] 6) Calculate the impedance Z at each frequency point fi and signal injection level r_I fm ;

[0110]

[0111]

[0112] 7) The second and third segments meet the accuracy requirements, but the first segment does not. Execute the frequency allocation strategy for the first segment, and k is 10, so the first segment is divided into 10 groups.

[0113] The first set of frequency points is [2.5:1:9.5],

[0114] The second set of frequency points is [2.6:1:9.6],

[0115] The third set of frequency points is [2.7:1:9.7],…,

[0116] The frequency points of the ninth group are [3.3:1:10),

[0117] The frequency points of the tenth group are [3.4:1:10). Repeat 2)-7). until the accuracy meets the requirements.

[0118] Optionally, determining an initial frequency matrix based on a frequency domain starting point, a frequency end point, and a frequency interval of each frequency segment includes:

[0119] Measure the frequency segment N and determine the frequency domain starting point f of each frequency segment ns , frequency end point f ne and the frequency interval Δf n , n∈[1,N], determine the initial frequency matrix as:

[0120]

[0121] Where, f0={f1 f2…f N}.

[0122] Optionally, based on the initial frequency matrix, the minimum signal duration of each frequency segment is calculated, a discrete interval binary sequence DIBS signal of each frequency segment is generated, and the DIBS signals of each frequency segment are connected end to end to generate a DIBS signal with the minimum duration of the full frequency domain point, including:

[0123] Based on the initial frequency matrix, the minimum signal duration of each frequency segment is calculated to generate a discrete interval binary sequence DIBS signal for each frequency segment;

[0124] Connect the discrete interval binary sequence DIBS signals of each frequency band end to end and generate the signals with a duration of t n DIBS signal of each frequency band, t n =1 / Δf n , the signal of each segment is recorded as signal_n, and the DIBS signal with the minimum duration of the full frequency domain point is generated as

[0125] signal=[signal_1signal_2...signal_N].

[0126] Optionally, based on the DIBS signal with the minimum duration of the full-frequency point, three-phase voltage signals and three-phase current signals of each frequency segment are obtained, and positive sequence calculation is performed on the three-phase voltage and three-phase current signals of each frequency segment to determine the positive sequence voltage and positive sequence current of each frequency segment, including:

[0127] Based on the DIBS signal with the lowest duration at the full frequency domain point, the three-phase voltage signal and the three-phase current signal are obtained on the high-voltage side. According to the time sequence and duration of the injected DIBS signal, the three-phase voltage signal and the three-phase current signal U in each frequency band are intercepted. an 、U bn 、U cn , I an , I bn , I cn , where the three-phase voltage signal and three-phase current signal with a duration of t0 before the injection signal are intercepted and recorded as U a0 、U b0 、U c0 , I a0 , I b0 , I c0 , t0=max(t1 t2…t N );

[0128] Perform positive sequence calculation on the three-phase voltage and three-phase current signals of each frequency band to determine the positive sequence voltage and positive sequence current of each frequency band;

[0129] U m =1 / 3(U am +a·U bm +a 2 ·U cm )

[0130] I m =1 / 3(I am +a·I bm +a 2 I cm )

[0131] Among them, m∈[0,N], 0 represents the time before the injection signal, a=e j120o .

[0132] Optionally, extracting the amplitude of the frequency point from the positive-sequence voltage and the positive-sequence current of each frequency segment by Fourier transform, determining the voltage amplitude and the current amplitude, and calculating the impedance and the signal injection degree at each frequency point based on the voltage amplitude and the current amplitude, including:

[0133] The positive sequence voltage and positive sequence current of each frequency band are extracted by Fourier transform to obtain the amplitude of the frequency point and determine the voltage amplitude U m_fm and the current amplitude I m_fm ;

[0134] Based on the voltage amplitude U m_fm and the current amplitude I m_fm , calculate the impedance Z at each frequency point fn and signal injection level r_I fm :

[0135] Among them, I 0_f1 Refers to the background harmonic current value under the f1 frequency matrix; I 0_50 is the background harmonic current value at the fundamental frequency.

[0136] Optionally, executing a frequency allocation strategy based on the signal injection degree of each frequency point includes:

[0137] Determine whether the signal injection degree of each frequency point is greater than or equal to a set threshold;

[0138] If the signal injection level of each frequency point is greater than or equal to the set threshold, then end;

[0139] If there is a frequency point where the signal injection degree of each frequency point is less than the set threshold, the frequency allocation strategy is executed and the initial frequency matrix is re-determined until the signal injection degree of each frequency point is greater than or equal to the set threshold. According to another aspect of the present invention, a broadband injection signal optimization allocation system 300 for impedance measurement is also provided, referring to Figure 3 As shown, the system 300 includes:

[0140] The frequency segment measurement module is used to determine the initial frequency matrix based on the frequency domain starting point, frequency end point and frequency interval of each frequency segment;

[0141] A DIBS signal generation module is used to calculate the minimum signal duration of each frequency segment based on the initial frequency matrix, generate a discrete interval binary sequence DIBS signal for each frequency segment, and connect the DIBS signals of each frequency segment end to end to generate a DIBS signal with the minimum duration of the full frequency domain point;

[0142] A positive-sequence voltage and current determination module is configured to obtain the three-phase voltage signal and the three-phase current signal of each frequency segment based on the DIBS signal with the minimum duration of the full-frequency point, and perform positive-sequence calculation on the three-phase voltage and the three-phase current signal of each frequency segment to determine the positive-sequence voltage and the positive-sequence current of each frequency segment;

[0143] A signal injection degree calculation module is used to extract the amplitude of the frequency point of the positive sequence voltage and positive sequence current of each frequency segment through Fourier transform, determine the voltage amplitude and current amplitude, and calculate the impedance and signal injection degree of each frequency point based on the voltage amplitude and current amplitude;

[0144] The frequency allocation strategy execution module is used to execute the frequency allocation strategy based on the signal injection degree of each frequency point. Optionally, the frequency segment measurement module includes:

[0145] The frequency segment measurement submodule is used to measure the frequency segment N and determine the frequency domain starting point f of each frequency segment.ns , frequency end point f ne and the frequency interval Δf n , n∈[1,N], determine the initial frequency matrix as:

[0146]

[0147] Where, f0={f1 f2…f N}.

[0148] Optionally, a DIBS signal generation module is provided, including:

[0149] A DIBS signal generation submodule is used to calculate the minimum signal duration of each frequency segment based on the initial frequency matrix and generate a discrete interval binary sequence DIBS signal for each frequency segment;

[0150] Connect the discrete interval binary sequence DIBS signals of each frequency segment end to end, and generate the DIBS signals of each frequency segment with a duration of t n =1 / Δf n , the signal of each segment is recorded as signal_n, and the DIBS signal with the minimum duration of the full frequency domain point is generated as

[0151] signal=[signal_1signal_2...signal_N].

[0152] Optionally, determining a positive sequence voltage and current module includes:

[0153] The voltage and current acquisition submodule is used to obtain the three-phase voltage signal and the three-phase current signal on the high-voltage side based on the DIBS signal with the lowest duration at the full-frequency domain point, and intercept the three-phase voltage signal and the three-phase current signal U in each frequency band according to the time sequence and duration of the injected DIBS signal. an 、U bn 、U cn , I an , I bn , I cn , where the three-phase voltage signal and three-phase current signal with a duration of t0 before the injection signal are intercepted and recorded as U a0 、U b0 、U c0 , I a0 , I b0 , I c0 , t0=max(t1 t2…t N );

[0154] The positive sequence voltage and current determination submodule is used to perform positive sequence calculation on the three-phase voltage and three-phase current signals of each frequency band to determine the positive sequence voltage and positive sequence current of each frequency band;

[0155] U m =1 / 3(U am +a·U bm +a 2 ·U cm )

[0156] I m =1 / 3(I am +a·I bm +a 2 I cm )

[0157] Among them, m∈[0,N], 0 represents the time before the injection signal, a=e j120o .

[0158] Optionally, the signal injection degree calculation module includes:

[0159] The voltage and current amplitude determination submodule is used to extract the amplitude of the frequency point through Fourier transform of the positive sequence voltage and positive sequence current in each frequency band to determine the voltage amplitude U m_fm and the current amplitude I m_fm ;

[0160] The impedance calculation accuracy submodule is used to calculate the impedance based on the voltage amplitude U m_fm and the current amplitude I m_fm , calculate the impedance Z at each frequency point fn and signal injection level r_I fm :

[0161]

[0162] Among them, I 0_f1 Refers to the background harmonic current value under the f1 frequency matrix; I 0_50 is the background harmonic current value at the fundamental frequency.

[0163] Optionally, executing a frequency allocation strategy module includes:

[0164] The impedance calculation accuracy determination submodule is used to determine whether the impedance calculation accuracy of each frequency point passes a certain frequency point or certain frequency points;

[0165] The frequency allocation strategy end submodule is used to determine whether the signal injection degree of each frequency point is greater than or equal to a set threshold;

[0166] An end submodule, configured to end the process if the signal injection levels at each frequency point are greater than or equal to a set threshold;

[0167] The allocation strategy execution submodule is used to execute the frequency allocation strategy if there is a frequency point where the signal injection degree of each frequency point is less than the set threshold, and redetermine the initial frequency matrix until the signal injection degree of each frequency point is greater than or equal to the set threshold.

[0168] A broadband injection signal optimization distribution system 300 for impedance measurement according to an embodiment of the present invention corresponds to a broadband injection signal optimization distribution method 100 for impedance measurement according to another embodiment of the present invention, and details thereof will not be repeated herein.

[0169] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal translation scripting language JavaScript, etc.

[0170] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0171] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0172] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0173] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0174] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for optimizing the distribution of broadband injection signals for impedance measurement, characterized in that: include: Determine an initial frequency matrix based on the frequency domain starting point, frequency end point, and frequency interval of each frequency segment; Based on the initial frequency matrix, the minimum signal duration of each frequency segment is calculated to generate a discrete interval binary sequence DIBS signal for each frequency segment, and the DIBS signals of each frequency segment are connected end to end to generate a DIBS signal with the minimum duration of the full frequency domain point; Based on the DIBS signal with the minimum duration at the full-frequency point, the three-phase voltage signal and the three-phase current signal of each frequency segment are obtained, and the positive sequence calculation is performed on the three-phase voltage and three-phase current signals of each frequency segment to determine the positive sequence voltage and positive sequence current of each frequency segment; Extracting the amplitude of the frequency point from the positive sequence voltage and positive sequence current of each frequency segment through Fourier transform, determining the voltage amplitude and current amplitude, and calculating the impedance and signal injection degree at each frequency point based on the voltage amplitude and current amplitude; A frequency allocation strategy is executed based on the signal injection degree of each frequency point.

2. The method according to claim 1, characterized in that Based on the frequency domain start point, frequency end point, and frequency interval of each frequency segment, an initial frequency matrix is determined, including: Measure the frequency segment N and determine the frequency domain starting point f of each frequency segment ns , frequency end point f ne and the frequency interval Δf n , n∈[1,N], determine the initial frequency matrix as: Where, f0={f1 f2…f N }.

3. The method according to claim 1, characterized in that Based on the initial frequency matrix, the minimum signal duration of each frequency segment is calculated, a discrete interval binary sequence DIBS signal of each frequency segment is generated, and the DIBS signals of each frequency segment are connected end to end to generate a DIBS signal with the minimum duration of the full frequency domain point, including: Based on the initial frequency matrix, the minimum signal duration of each frequency segment is calculated to generate a discrete interval binary sequence DIBS signal for each frequency segment; Connect the discrete interval binary sequence DIBS signals of each frequency band end to end and generate the signals with a duration of t n DIBS signal of each frequency band, t n =1 / Δf n , the signal of each segment is recorded as signal_n, and the DIBS signal with the minimum duration of the full frequency domain point is generated as signal=[signal_1signal_2...signal_N].

4. The method according to claim 1, wherein Based on the DIBS signal with the minimum duration at the full-frequency point, the three-phase voltage signal and the three-phase current signal of each frequency segment are obtained, and the positive sequence calculation is performed on the three-phase voltage and three-phase current signals of each frequency segment to determine the positive sequence voltage and positive sequence current of each frequency segment, including: Based on the DIBS signal with the lowest duration at the full frequency domain point, the three-phase voltage signal and the three-phase current signal are obtained on the high-voltage side. According to the time sequence and duration of the injected DIBS signal, the three-phase voltage signal and the three-phase current signal U in each frequency band are intercepted. an 、U bn 、U cn , I an , I bn , I cn , where the three-phase voltage signal and three-phase current signal with a duration of t0 before the injection signal are intercepted and recorded as U a0 、U b0 、U c0 , I a0 , I b0 , I c0 , t0=max(t1 t2…t N ); Perform positive sequence calculation on the three-phase voltage and three-phase current signals of each frequency band to determine the positive sequence voltage and positive sequence current of each frequency band; U m =1 / 3(U am +a·U bm +a 2 ·U cm ) I m =1 / 3(I am +a·I bm +a 2 ·I cm ) Among them, m∈[0,N], 0 represents the time before the injection of the signal, a=e j120o .

5. The method according to claim 1, wherein The positive sequence voltage and positive sequence current of each frequency segment are subjected to Fourier transform to extract the amplitude of the frequency point, determine the voltage amplitude and current amplitude, and calculate the impedance and signal injection degree of each frequency point based on the voltage amplitude and current amplitude, including: The positive sequence voltage and positive sequence current of each frequency band are extracted by Fourier transform to obtain the amplitude of the frequency point and determine the voltage amplitude U m_fm and the current amplitude I m_fm ; Based on the voltage amplitude U m_fm and the current amplitude I m_fm , calculate the impedance Z at each frequency point fn and signal injection level r_I fm : Among them, I 0_f1 Refers to the background harmonic current value under the f1 frequency matrix; I 0_50 is the background harmonic current value at the fundamental frequency.

6. The method according to claim 1, characterized in that Executing a frequency allocation strategy based on the signal injection degree of each frequency point includes: Determine whether the signal injection degree of each frequency point is greater than or equal to a set threshold frequency point; If the signal injection degree of each frequency point is greater than or equal to the set threshold frequency point, then end; If there is a frequency point where the signal injection degree of each frequency point is less than the set threshold, the frequency allocation strategy is executed to redefine the initial frequency matrix until the signal injection degree of each frequency point is greater than or equal to the set threshold.

7. A broadband injection signal optimization distribution system for impedance measurement, characterized in that: include: The frequency segment measurement module is used to determine the initial frequency matrix based on the frequency domain starting point, frequency end point and frequency interval of each frequency segment; A DIBS signal generation module is used to calculate the minimum signal duration of each frequency segment based on the initial frequency matrix, generate a discrete interval binary sequence DIBS signal for each frequency segment, and connect the DIBS signals of each frequency segment end to end to generate a DIBS signal with the minimum duration of the full frequency domain point; A positive-sequence voltage and current determination module is configured to obtain the three-phase voltage signal and the three-phase current signal of each frequency segment based on the DIBS signal with the minimum duration of the full-frequency point, and perform positive-sequence calculation on the three-phase voltage and the three-phase current signal of each frequency segment to determine the positive-sequence voltage and the positive-sequence current of each frequency segment; A signal injection degree calculation module is used to extract the amplitude of the frequency point of the positive sequence voltage and positive sequence current of each frequency segment through Fourier transform, determine the voltage amplitude and current amplitude, and calculate the impedance and signal injection degree of each frequency point based on the voltage amplitude and current amplitude; The frequency allocation strategy execution module is used to execute the frequency allocation strategy based on the signal injection degree of each frequency point.

8. The system according to claim 7, characterized in that Measurement frequency band module, including: The frequency segment measurement submodule is used to measure the frequency segment N and determine the frequency domain starting point f of each frequency segment. ns , frequency end point f ne and the frequency interval Δf n , n∈[1,N], determine the initial frequency matrix as: Where, f0={f1 f2…f N }.

9. The system according to claim 7, wherein: Generate DIBS signal module, including: A DIBS signal generation submodule is used to calculate the minimum signal duration of each frequency segment based on the initial frequency matrix and generate a discrete interval binary sequence DIBS signal for each frequency segment; Connect the discrete interval binary sequence DIBS signals of each frequency segment end to end, and generate the DIBS signals of each frequency segment with a duration of t n =1 / Δf n , the signal of each segment is recorded as signal_n, and the DIBS signal with the minimum duration of the full frequency domain point is generated as signal=[signal_1signal_2...signal_N].

10. The system according to claim 7, wherein: Determine the positive sequence voltage and current module, including: The voltage and current submodule is used to obtain the three-phase voltage signal and the three-phase current signal on the high-voltage side based on the DIBS signal with the lowest duration at the full-frequency domain point, and intercept the three-phase voltage signal and the three-phase current signal U under each frequency band according to the time sequence and duration of the injected DIBS signal. an 、U bn 、U cn , I an , I bn , I cn , where the three-phase voltage signal and three-phase current signal with a duration of t0 before the injection signal are intercepted and recorded as U a0 、U b0 、U c0 , I a0 , I b0 , I c0 , t0=max(t1 t2…t N ); The positive sequence voltage and current determination submodule is used to perform positive sequence calculation on the three-phase voltage and three-phase current signals of each frequency band to determine the positive sequence voltage and positive sequence current of each frequency band; U m =1 / 3(U am +a·U bm +a 2 ·U cm ) I m =1 / 3(I am +a·I bm +a 2 ·I cm ) Among them, m∈[0,N], 0 represents the time before the injection of the signal, a=e j120o .

11. The system according to claim 7, wherein: Module for calculating signal injection degree, including: The voltage and current amplitude determination submodule is used to extract the amplitude of the frequency point through Fourier transform of the positive sequence voltage and positive sequence current in each frequency band to determine the voltage amplitude U m_fm and the current amplitude I m_fm ; The impedance calculation accuracy submodule is used to calculate the impedance based on the voltage amplitude U m_fm and the current amplitude I m_fm , calculate the impedance Z at each frequency point fn and signal injection level r_I fm : Among them, I 0_f1 Refers to the background harmonic current value under the f1 frequency matrix; I 0_50 is the background harmonic current value at the fundamental frequency.

12. The system according to claim 7, wherein: Execute frequency allocation strategy module, including: The impedance calculation accuracy determination submodule is used to determine whether the signal injection degree of each frequency point is greater than or equal to a set threshold; An end submodule, configured to end the process if the signal injection levels at each frequency point are greater than or equal to a set threshold; The allocation strategy execution submodule is used to execute the frequency allocation strategy if there is a frequency point where the signal injection degree of each frequency point is less than the set threshold, and redetermine the initial frequency matrix until the signal injection degree of each frequency point is greater than or equal to the set threshold.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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