Wideband impedance real-time calculation method, system and equipment based on disturbance injection method and storage medium

Abstract

The invention discloses a broadband impedance real-time calculation method, system and equipment based on a disturbance injection method, and a storage medium. The method comprises the following steps: obtaining a current disturbance frequency through communication with a broadband disturbance injection device; carrying out clark conversion on the three-phase line voltage and the three-phase current; constructing an improved second-order generalized integrator with a narrow bandwidth according to the current disturbance injection frequency; positive and negative sequence separation of orthogonal signal construction is achieved through a generalized integrator, positive and negative sequence voltage and current are obtained respectively, and the phase of impedance of the system at the current frequency is obtained through calculation according to the positive and negative sequence voltage and current; compared with a traditional band-pass filter amplitude calculation method, the band-pass filter amplitude calculation method has the advantages that the bandwidth is narrower, the precision is higher, and the excellence is more obvious under the condition that the sampling frequency is limited.

Description

Technical Field

[0001] The present invention relates to the technical field of broadband impedance, and in particular to a broadband impedance real-time calculation method, system, device and storage medium based on a disturbance injection method. Background Art

[0002] With the large-scale grid connection of new energy equipment and the access of power electronic equipment, the behavior characteristics of the power system have become more complex. Many oscillation accidents caused by power electronic equipment have occurred around the world. The oscillation has shown new characteristics such as wide bandwidth and time-varying, which seriously affects the effective absorption level of new energy. At present, injecting broadband disturbances into the system and calculating the system impedance curve is the main method to evaluate system stability and realize oscillation prediction. The traditional Fourier algorithm has a large amount of calculation and cannot realize real-time calculation, which restricts the rapidity of oscillation prediction and suppression. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a method, system, device and storage medium for real-time calculation of broadband impedance based on the disturbance injection method, which can perform real-time calculation of impedance at any frequency.

[0004] Technical solution: The method for real-time calculation of broadband impedance based on disturbance injection method described in the present invention comprises the following steps: obtaining the current disturbance frequency by communicating with a broadband disturbance injection device; performing Clark transformation on the three-phase line voltage and current to obtain the two-phase orthogonal components of voltage and current respectively; constructing an improved second-order generalized integrator with narrow bandwidth according to the current disturbance frequency and the two-phase orthogonal components of voltage and current; realizing positive and negative sequence separation of orthogonal signal construction through the improved second-order generalized integrator, obtaining positive and negative sequence voltage and current respectively, and obtaining the phase of the impedance of the system at the current frequency by calculation according to the positive and negative sequence voltage and current.

[0005] Furthermore, the three-phase line voltage and current are transformed by Clark, and the calculation method is:

[0006]

[0007]

[0008] Among them, V α 、V β is the aβ component of the voltage, V ab 、V bc 、V ca are the line voltages of the three-phase voltages. α ,I β is the aβ component of the current, I ab ,I bc ,I ca They are the three-phase current components respectively.

[0009] Furthermore, the improved second-order generalized integrator formula is as follows:

[0010]

[0011]

[0012] Among them, ω r is the disturbance injection frequency, k is the gain coefficient, ω c is the cut-off frequency;

[0013] The formula of the improved second-order generalized integrator after discretization is as follows:

[0014]

[0015]

[0016] in,

[0017] Further simplification gives

[0018]

[0019] Among them, x(n) is the input at the current moment, y(n) is the output at the current moment, x(n-1), y(n-1) represent the input and output at the previous moment, x(n-2), y(n-2) represent the input and output of x(n-1), y(n-1) at the previous moment, and T is the sampling time.

[0020] Furthermore, the positive and negative sequence separation method includes the following steps: inputting the α and β components of the voltage into an integrator to obtain the current disturbance frequency component V Dα , V Dβ and V with a lag of one quarter cycle Qα ,V Qβ , and further obtain the expression of its positive and negative sequence components

[0021]

[0022] Among them, V pα Yes V α The positive sequence component, V pβ Yes V β The positive sequence component, V nα Yes V α The negative sequence component, V nβ Yes V β The negative sequence component of V p is the amplitude of the positive sequence component of the voltage, V n is the amplitude of the negative sequence component of the voltage. is the phase angle of the positive sequence voltage, is the phase angle of the negative sequence voltage; similarly, the amplitude and phase angle of the positive and negative sequence components of the current are obtained; the impedance of the positive sequence voltage is obtained by the ratio of the positive sequence components of the voltage and the current, and the impedance of the negative sequence voltage is obtained by the ratio of the negative sequence components of the voltage and the current. The amplitude and phase angle of the positive and negative sequence impedance are expressed as:

[0023] X p =V p / I p

[0024] X n =V n / I n

[0025]

[0026] Among them, Z p , Z n are the magnitudes of the positive-sequence impedance and the negative-sequence impedance, I p ,I n are the amplitudes of the positive and negative sequence components of the current, respectively. are the phases of the positive-sequence impedance and the negative-sequence impedance, are the phases of the positive and negative sequence components of the current, respectively.

[0027] The invention discloses a broadband impedance real-time calculation system based on a disturbance injection method, comprising:

[0028] Disturbance frequency acquisition module: used to obtain the current disturbance frequency by communicating with the broadband disturbance injection device; perform Clark transformation on the three-phase line voltage and current to obtain the two-phase orthogonal components of the voltage and current respectively;

[0029] Integrator module: used to obtain the two-phase orthogonal components of voltage and current according to the current disturbance frequency, and construct an improved second-order generalized integrator with narrow bandwidth;

[0030] Impedance module: It is used to realize the positive and negative sequence separation of orthogonal signal construction through the improved second-order generalized integrator, and obtain the positive and negative sequence voltage and current respectively. The phase of the impedance of the system at the current frequency is calculated based on the positive and negative sequence voltage and current.

[0031] Furthermore, in the integrator module, the three-phase line voltage and current are transformed by Clark, and the calculation method is:

[0032]

[0033]

[0034] Among them, V α 、V β is the aβ component of the voltage, V ab、V bc 、V ca are the line voltages of the three-phase voltages. α ,I β is the aβ component of the current, I ab ,I bc ,I ca They are the three-phase current components respectively.

[0035] Furthermore, the improved second-order generalized integrator formula is as follows:

[0036]

[0037]

[0038] Among them, ω r is the disturbance injection frequency, k is the gain coefficient, ω c is the cut-off frequency;

[0039] The formula of the improved second-order generalized integrator after discretization is as follows:

[0040]

[0041]

[0042] in,

[0043] Further simplification gives

[0044]

[0045] y Q (n) = c[1-cos(bT)e -aT -sin(bT)e -aT a / b]x(n-1)+c[e -2aT +sin(bT)e -aT a / b-cos(bT)e -aT ]x(n-2)

[0046] +2e -aT cos(bT)y(n-1)-e -2aT y(n-2)

[0047] Among them, x(n) is the input at the current moment, y(n) is the output at the current moment, x(n-1), y(n-1) represent the input and output at the previous moment, x(n-2), y(n-2) represent the input and output of x(n-1), y(n-1) at the previous moment, and T is the sampling time.

[0048] Furthermore, in the impedance module, the positive and negative sequence separation method includes the following steps:

[0049] Input the α and β components of the voltage into the integrator to obtain the current disturbance frequency component V Dα , V Dβ and V with a lag of one quarter cycle Qα ,V Qβ , and further obtain the expression of its positive and negative sequence components

[0050]

[0051] Among them, V pα Yes V α The positive sequence component, V pβ Yes V β The positive sequence component, V nα Yes V α The negative sequence component, V nβ Yes V β The negative sequence component of V p is the amplitude of the positive sequence component of the voltage, V n is the amplitude of the negative sequence component of the voltage. is the phase angle of the positive sequence voltage, is the phase angle of the negative sequence voltage; similarly, the amplitude and phase angle of the positive and negative sequence components of the current are obtained; the impedance of the positive sequence voltage is obtained by the ratio of the positive sequence components of the voltage and the current, and the impedance of the negative sequence voltage is obtained by the ratio of the negative sequence components of the voltage and the current. The amplitude and phase angle of the positive and negative sequence impedance are expressed as

[0052] X p =V p / I p

[0053] X n =V n / I n

[0054]

[0055] Among them, Z p , Z n are the magnitudes of the positive-sequence impedance and the negative-sequence impedance, I p ,I n are the amplitudes of the positive and negative sequence components of the current, respectively. are the phases of the positive-sequence impedance and the negative-sequence impedance, are the phases of the positive and negative sequence components of the current, respectively.

[0056] An electronic device described in the present invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the computer program is loaded into the processor, any one of the methods for real-time calculation of broadband impedance based on a disturbance injection method is implemented.

[0057] A storage medium described in the present invention stores a computer program, and when the computer program is executed by a processor, any one of the methods for real-time calculation of broadband impedance based on a disturbance injection method is implemented.

[0058] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) Compared with the fast Fourier method, the amount of calculation is small and real-time calculation can be achieved; (2) Compared with the single-frequency Fourier algorithm, the accuracy is greatly improved. (3) Compared with the traditional bandpass filter amplitude calculation method, the bandwidth is narrower, the accuracy is higher, and the superiority is more obvious when the sampling frequency is limited. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a simulation signal in the embodiment of the present invention.

[0060] Figure 2 1 is a Bode diagram of a generalized integrator in an embodiment of the present invention.

[0061] Figure 3 It is the output signal of the generalized integrator in the embodiment of the present invention.

[0062] Figure 4 It is the calculation result of the disturbance amplitude in the embodiment of the present invention.

[0063] Figure 5 Calculation results of impedance and phase in the embodiment of the present invention. DETAILED DESCRIPTION

[0064] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0065] like Figure 1 As shown, an embodiment of the present invention provides a broadband impedance real-time calculation based on a disturbance injection method, comprising the following steps:

[0066] S1, Clark transformation

[0067] For ease of explanation, a three-phase voltage and three-phase current simulation signal is generated, including a 50Hz positive sequence component of 100V and a negative sequence component of 10V, and a 1000Hz positive sequence component of 100V and a negative sequence component of 10V. The current amplitude is one tenth of the voltage. The simulation signal is as follows Figure 1 shown.

[0068] S2, constructing a generalized integrator

[0069] The transfer function is as follows:

[0070]

[0071]

[0072] where ω r is the disturbance injection frequency, k is the gain coefficient, ω c is the cut-off frequency.

[0073] The discretized improved second-order generalized integrator expression is further obtained:

[0074]

[0075]

[0076] In the formula

[0077] Further information is available

[0078]

[0079] y Q (n) = c[1-cos(bT)e -aT -sin(bT)e -aT a / b]x(n-1)+c[e -2aT +sin(bT)e -aT a / b-cos(bT)e -aT ]x(n-2)

[0080] +2e -aT cos(bT)y(n-1)-e -2aT y(n-2)

[0081] Where x(n) is the input at the current moment, y(n) is the output at the current moment, x(n-1) and y(n-1) represent the input and output at the previous moment, and the same is true for x(n-2) and y(n-2). T is the sampling time.

[0082] Compared with the traditional second-order generalized integrator Figure 2 As shown, the disturbance frequencies are 50 Hz and 1000 Hz, the sampling frequency is 9000 Hz, and k is 1.414. It can be seen that the integrator proposed in the present invention has a narrower bandwidth, especially around 50 Hz, and will not receive power frequency interference when calculating the disturbance component, so the calculation is more accurate.

[0083] S3, calculate positive and negative sequence components

[0084] The α and β components of the voltage are input into the integrator to obtain V Dα , V Dβ and V with a lag of one quarter cycle Qα ,V Qβ , and further obtain the expression of its positive and negative sequence components. The calculation results are as follows Figure 3 As shown, the same is true for current.

[0085]

[0086] S4, calculate amplitude

[0087] The amplitude is calculated according to the following formula

[0088]

[0089] Where V pα Yes V α The positive sequence component, V pβ Yes V β The positive sequence component, V nα Yes V α The negative sequence component, V nβ Yes V β The negative sequence component of V p is the amplitude of the positive sequence component of the voltage, V n is the amplitude of the negative sequence component of the voltage. is the phase angle of the positive sequence voltage, is the phase angle of the negative sequence voltage. The calculation speed can be adjusted by changing the gain factor k. The calculation results are as follows: Figure 4 shown.

[0090] S5, calculate impedance and phase

[0091] The impedance and its phase angle are calculated according to the following formula.

[0092] X p =V p / I p

[0093] X n =V n / I n

[0094]

[0095] The calculation results are as follows Figure 5 shown.

[0096] The embodiment of the present invention further provides a broadband impedance real-time calculation system based on a disturbance injection method, comprising the following steps:

[0097] Disturbance frequency acquisition module: used to obtain the current disturbance frequency by communicating with the broadband disturbance injection device; perform Clark transformation on the three-phase line voltage and current to obtain the two-phase orthogonal components of the voltage and current respectively; perform Clark transformation on the three-phase line voltage and current, and the calculation method is

[0098]

[0099]

[0100] Among them, V α 、V β is the aβ component of the voltage, V ab 、V bc 、V ca are the line voltages of the three-phase voltages. α ,I β is the aβ component of the current, I ab ,I bc ,I ca They are the three-phase current components respectively.

[0101] Integrator module: It is used to obtain the two-phase orthogonal components of voltage and current according to the current disturbance frequency, and construct an improved second-order generalized integrator with narrow bandwidth; the formula of the improved second-order generalized integrator is as follows:

[0102]

[0103] Among them, ω r is the disturbance injection frequency, k is the gain coefficient, ω c is the cut-off frequency;

[0104] The formula of the improved second-order generalized integrator after discretization is as follows:

[0105]

[0106]

[0107] in,

[0108] Further simplification gives

[0109]

[0110] y Q (n) = c[1-cos(bT)e -aT -sin(bT)e -aT a / b]x(n-1)+c[e -2aT +sin(bT)e -aT a / b-cos(bT)e -aT ]x(n-2)

[0111] +2e -aT cos(bT)y(n-1)-e -2aT y(n-2)

[0112] Among them, x(n) is the input at the current moment, y(n) is the output at the current moment, x(n-1), y(n-1) represent the input and output at the previous moment, x(n-2), y(n-2) represent the input and output of x(n-1), y(n-1) at the previous moment, and T is the sampling time.

[0113] Impedance module: used for improved second-order generalized integrator to realize orthogonal signal construction and positive and negative sequence separation, and obtain positive and negative sequence voltage and current respectively. According to the positive and negative sequence voltage and current, the phase of the impedance of the system at the current frequency is calculated. The positive and negative sequence separation method includes the following steps:

[0114] Input the α and β components of the voltage into the integrator to obtain the current disturbance frequency component V Dα , V Dβ and V with a lag of one quarter cycle Qα ,V Qβ , and further obtain the expression of its positive and negative sequence components

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123] Among them, V pα Yes V α The positive sequence component, V pβ Yes V β The positive sequence component, V nα Yes V α The negative sequence component, V nβ Yes V β The negative sequence component of V p is the amplitude of the positive sequence component of the voltage, V n is the amplitude of the negative sequence component of the voltage. is the phase angle of the positive sequence voltage, is the phase angle of the negative sequence voltage; similarly, the amplitude and phase angle of the positive and negative sequence components of the current are obtained; the impedance of the positive sequence voltage is obtained by the ratio of the positive sequence components of the voltage and the current, and the impedance of the negative sequence voltage is obtained by the ratio of the negative sequence components of the voltage and the current. The amplitude and phase angle of the positive and negative sequence impedance are expressed as

[0124] X p =V p / I p

[0125] X n =V n / I n

[0126]

[0127] Among them, Z p , Z n are the magnitudes of the positive-sequence impedance and the negative-sequence impedance, I p ,I n are the amplitudes of the positive and negative sequence components of the current, respectively. are the phases of the positive-sequence impedance and the negative-sequence impedance, are the phases of the positive and negative sequence components of the current, respectively.

[0128] An embodiment of the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is loaded into the processor, any one of the methods for real-time calculation of broadband impedance based on a disturbance injection method is implemented.

[0129] An embodiment of the present invention further provides a storage medium storing a computer program. When the computer program is executed by a processor, any one of the methods for real-time calculation of broadband impedance based on a disturbance injection method is implemented.

Claims

1. A broadband impedance real-time calculation method based on disturbance injection method, characterized in that: The following steps are involved: The current disturbance frequency is obtained by communicating with a wideband disturbance injection device; Clark transformation is performed on the three-phase line voltage and current to obtain the two-phase orthogonal components of the voltage and current respectively; an improved second-order generalized integrator with a narrow bandwidth is constructed according to the current disturbance frequency and the obtained two-phase orthogonal components of the voltage and current; the orthogonal signal construction positive and negative sequence separation is realized through the improved second-order generalized integrator, and the positive and negative sequence voltage and current are obtained respectively, and the phase of the impedance of the system at the current frequency is calculated according to the positive and negative sequence voltage and current.

2. The method for real-time calculation of broadband impedance based on disturbance injection method according to claim 1, characterized in that: The Clark transformation is performed on the three-phase line voltage and current, and the calculation method is: Among them, V α 、V β is the aβ component of the voltage, V ab 、V bc 、V ca are the line voltages of the three-phase voltages; I α ,I β is the aβ component of the current, I ab ,I bc ,I ca They are the three-phase current components respectively.

3. The method for real-time calculation of broadband impedance based on disturbance injection method according to claim 1, characterized in that: The improved second-order generalized integrator formula is as follows: Among them, ω r is the disturbance injection frequency, k is the gain coefficient, ω c is the cut-off frequency; The formula of the improved second-order generalized integrator after discretization is as follows: in, Further simplification gives y Q (n)=c[1-cos(bT)e -aT -sin(bT)e -aT a / b]x(n-1)+c[e -2aT +sin(bT)e -aT a / b-cos(bT)e -aT ]x(n-2)+2e -aT cos(bT)y(n−1)−e -2aT y(n−2) Among them, x(n) is the input at the current moment, y(n) is the output at the current moment, x(n-1), y(n-1) represent the input and output at the previous moment, x(n-2), y(n-2) represent the input and output of x(n-1), y(n-1) at the previous moment, and T is the sampling time.

4. The method for real-time calculation of broadband impedance based on disturbance injection method according to claim 1, characterized in that: The positive and negative sequence separation method includes the following steps: Input the α and β components of the voltage into the integrator to obtain the current disturbance frequency component V Dα , V Dβ and V with a lag of one quarter cycle Qα ,V Qβ , and further obtain the expression of its positive and negative sequence components Among them, V pα Yes V α The positive sequence component, V pβ Yes V β The positive sequence component, V nα Yes V α The negative sequence component, V nβ Yes V β The negative sequence component of V p is the amplitude of the positive sequence component of the voltage, V n is the amplitude of the negative sequence component of the voltage; is the phase angle of the positive sequence voltage, is the phase angle of the negative sequence voltage; similarly, the amplitude and phase angle of the positive and negative sequence components of the current are obtained; the impedance of the positive sequence voltage is obtained by the ratio of the positive sequence components of the voltage and the current, and the impedance of the negative sequence voltage is obtained by the ratio of the negative sequence components of the voltage and the current. The amplitude and phase angle of the positive and negative sequence impedance are expressed as: Z p =V p / I p Z n =V n / I n Among them, Z p , Z n are the magnitudes of the positive-sequence impedance and the negative-sequence impedance, I p ,I n are the amplitudes of the positive and negative sequence components of the current, respectively. are the phases of the positive-sequence impedance and the negative-sequence impedance, are the phases of the positive and negative sequence components of the current, respectively.

5. A broadband impedance real-time calculation system based on disturbance injection method, characterized in that: include: Disturbance frequency acquisition module: used to obtain the current disturbance frequency by communicating with the broadband disturbance injection device; perform Clark transformation on the three-phase line voltage and current to obtain the two-phase orthogonal components of the voltage and current respectively; Integrator module: used to construct an improved second-order generalized integrator with narrow bandwidth according to the current disturbance frequency and the obtained two-phase orthogonal components of voltage and current; Impedance module: It is used to realize the positive and negative sequence separation of orthogonal signal construction through the improved second-order generalized integrator, and obtain the positive and negative sequence voltage and current respectively. The phase of the impedance of the system at the current frequency is calculated based on the positive and negative sequence voltage and current.

6. A broadband impedance real-time calculation system based on disturbance injection method according to claim 5, characterized in that: In the integrator module, the three-phase line voltage and current are transformed by Clark, and the calculation method is: Among them, V α 、V β is the aβ component of the voltage, V ab 、V bc 、V ca are the line voltages of the three-phase voltages; I α ,I β is the aβ component of the current, I ab ,I bc ,I ca They are the three-phase current components respectively.

7. A broadband impedance real-time calculation system based on disturbance injection method according to claim 5, characterized in that: The improved second-order generalized integrator formula is as follows: Among them, ω r is the disturbance injection frequency, k is the gain coefficient, ω c is the cut-off frequency; The formula of the improved second-order generalized integrator after discretization is as follows: in, Further simplification gives y Q (n)=c[1-cos(bT)e -aT -sin(bT)e -aT a / b]x(n-1)+c[e -2aT +sin(bT)e -aT a / b-cos(bT)e -aT ]x(n-2)+2e -aT cos(bT)y(n−1)−e -2aT y(n−2) Among them, x(n) is the input at the current moment, y(n) is the output at the current moment, x(n-1), y(n-1) represent the input and output at the previous moment, x(n-2), y(n-2) represent the input and output of x(n-1), y(n-1) at the previous moment, and T is the sampling time.

8. The broadband impedance real-time calculation system based on disturbance injection method according to claim 5, characterized in that: In the impedance module, the positive and negative sequence separation method includes the following steps: Input the α and β components of the voltage into the integrator to obtain the current disturbance frequency component V Dα , V Dβ and V with a lag of one quarter cycle Qα ,V Qβ , and further obtain the expression of its positive and negative sequence components Among them, V pα Yes V α The positive sequence component, V pβ Yes V β The positive sequence component, V nα Yes V α The negative sequence component, V nβ Yes V β Negative sequence component; V p is the amplitude of the positive sequence component of the voltage, V n is the amplitude of the negative sequence component of the voltage; is the phase angle of the positive sequence voltage, is the phase angle of the negative sequence voltage; similarly, the amplitude and phase angle of the positive and negative sequence components of the current are obtained; the impedance of the positive sequence voltage is obtained by the ratio of the positive sequence components of the voltage and the current, and the impedance of the negative sequence voltage is obtained by the ratio of the negative sequence components of the voltage and the current. The amplitude and phase angle of the positive and negative sequence impedance are expressed as: X p =V p / I p X n =V n / I n Among them, Z p , Z n are the magnitudes of the positive-sequence impedance and the negative-sequence impedance, I p ,I n are the amplitudes of the positive and negative sequence components of the current, respectively. are the phases of the positive-sequence impedance and the negative-sequence impedance, are the phases of the positive and negative sequence components of the current, respectively.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the computer program is loaded into a processor, a real-time calculation method for broadband impedance based on a disturbance injection method according to any one of claims 1 to 4 is implemented.

10. A storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, a real-time calculation method for broadband impedance based on a disturbance injection method according to any one of claims 1 to 4 is implemented.

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