HPLC (High Performance Liquid Chromatography) noise measuring device and method considering impedance matching influence

Abstract

The invention discloses an HPLC (High Performance Liquid Chromatography) noise measuring device and method considering impedance matching influence. The device comprises a three-winding transformer, a signal injection circuit, a noise acquisition circuit and a digital signal processor. A primary winding of the three-winding transformer is connected with a power line, a secondary winding and a tertiary winding of the three-winding transformer are respectively connected with the signal injection circuit and the noise acquisition circuit, the signal injection circuit and the noise acquisition circuit are completely mirrored, and an injection circuit signal source is superposed through the digital signal processor to generate an input signal in a required noise measurement range. Injecting into a power line through a signal injection circuit; utilizing a digital signal processor to extract amplitude-frequency characteristics of the input voltage and the injection voltage, calculating to obtain amplitude-frequency characteristics of power line impedance, and calculating a voltage reflection coefficient; and the noise acquisition circuit acquires noise information and adjusts the measured noise signal according to the power reflection coefficient of each frequency to obtain the power line noise. According to the invention, the noise of the low-voltage power line can be measured more accurately.

Description

Technical Field

[0001] The invention belongs to the technical field of power line carrier communication, and relates to a HPLC noise measurement device and method taking impedance matching influence into account. Background Art

[0002] HPLC high-speed power line carrier communication has become an important local communication technology in my country's smart power consumption. Using low-voltage power lines as communication lines has the advantages of low investment and low maintenance costs. However, low-voltage power lines are not dedicated communication lines. The characteristics of large impedance changes, large interference noise, and drastic signal level attenuation on the lines make it very difficult to achieve high-quality communication on power lines. Among them, complex, diverse, and time-varying channel noise will increase the system bit error rate during the communication process, which is a key factor affecting the quality of power line communication. Therefore, how to accurately measure low-voltage power line noise is of great significance to the design and operation and maintenance of HPLC.

[0003] In the prior art, patent application CN201410566690.7 discloses a method for detecting and suppressing periodic pulse noise of power line carrier based on OFDM. First, it is determined whether there is periodic pulse noise, the frequency band of the periodic pulse noise is statistically located, and then the filter is modulated to perform targeted periodic pulse noise suppression.

[0004] Patent application CN201911232799.6 discloses a low-voltage power line noise recording and injection system, including a power line interface, a power module, a power line coupling filter, a power amplifier, an arbitrary waveform generator, and a power line communication signal detector and analyzer. This system records and stores on-site noise, and restores the on-site noise signal in the laboratory through an arbitrary signal generator to verify the working characteristics of the power line carrier communication module under the on-site noise environment; the high-voltage mains is isolated by the power line coupling filter, so that the measuring instrument is isolated from the strong electricity, ensuring the safety of the measuring equipment, filtering the noise outside the test frequency band, and reducing useless signal interference.

[0005] Patent application CN201910338336.1 discloses a device and method for measuring idle noise power of a power line communication network, the device comprising an analog front end unit, an automatic gain control unit, a frame synchronization unit, a demodulation and decoding unit, a main control unit, and a sending unit. The analog front end unit is used to amplify, filter, and perform analog-to-digital conversion on the received power line carrier signal; the automatic gain control unit is used to perform power measurement and gain control on the signal input by the analog front end unit; the frame synchronization unit is used to perform frame synchronization, bit synchronization, and timing control on the physical layer frame of the power line carrier signal; the demodulation and decoding unit is used to perform frequency domain processing and bit-level processing on the signal input by the frame synchronization unit; the main control unit is used to schedule the automatic gain control unit, the frame synchronization unit, and the demodulation and decoding unit; the sending unit is used to send signals.

[0006] However, the above patented technical solutions do not take into account the influence of power line impedance matching, do not consider the influence of injected signals during the test process, and can only input a sinusoidal signal of the frequency point to be measured, thus causing the technical problem of inaccurate measurement of HPLC noise signals. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the present invention provides an HPLC noise measurement device and method taking into account the influence of impedance matching, which mainly solves the problem that impedance mismatch affects the low-voltage power line noise collection accuracy in the prior art. The device comprises a three-winding transformer, a signal injection circuit, a noise collection circuit and a digital signal processor. The three-winding transformer is used to isolate strong electricity, the primary winding is connected to the power line, the secondary winding and the tertiary winding are respectively connected to the signal injection circuit and the noise collection circuit, the signal injection circuit and the noise collection circuit are completely mirrored, and are composed of the same high-pass filter circuit, low-pass filter circuit and impedance matching circuit, which can improve the power line noise collection accuracy, thereby improving the accuracy of noise measurement.

[0008] The present invention adopts the following technical solution.

[0009] The first aspect of the present invention provides an HPLC noise measurement device taking into account the influence of impedance matching, characterized in that it includes: a three-winding transformer, a signal injection circuit, a noise collection circuit and a digital signal processor; wherein the primary winding of the three-winding transformer is connected to the HPLC power line, and the secondary winding and the tertiary winding are respectively connected to the signal injection circuit and the noise collection circuit; the noise collection power is used to collect power line noise; the signal injection circuit is used to inject the input voltage signal generated by the digital signal processor within the noise measurement range into the power line, and the signal injection circuit and the noise collection circuit are completely mirrored, and are composed of the same high-pass filter circuit, low-pass filter circuit and impedance matching circuit. The digital signal processor performs Fourier operation on the input voltage signal and the injected voltage signal to obtain the amplitude-frequency characteristics of the input voltage signal and the injected voltage signal respectively, and calculates the frequency information and voltage emission coefficient of the power line impedance based on the coupling circuit impedance; wherein the coupling circuit includes a transformer, a high-pass filter circuit, a low-pass filter circuit and an impedance matching circuit; the HPLC noise value is calculated based on the power line noise value collected by the noise collection circuit and the voltage reflection coefficient.

[0010] Preferably, the transformation ratio of the three-winding transformer is 1:1:1.

[0011] The second aspect of the present invention provides a HPLC noise measurement method taking into account the influence of impedance matching using the above-mentioned HPLC noise measurement device taking into account the influence of impedance matching, comprising the following steps:

[0012] Step 1: The digital signal processor adopts a one-time multi-frequency input signal superposition generation technology to generate input data information of each frequency point to be measured at one time according to the noise measurement frequency range, generates an input voltage signal according to the input data information, and injects the input voltage signal into the power line through a signal injection circuit via a three-winding transformer;

[0013] Step 2: collecting the input voltage signal and the injected power line voltage signal between the signal injection circuit and the coupling circuit, and sending them to the digital signal processor through analog-to-digital conversion. The digital signal processor uses data processing technology to extract the amplitude-frequency characteristics of the input voltage and the injected voltage;

[0014] Step 3: According to the amplitude-frequency characteristics of the input voltage and the injected voltage obtained in step 2, the amplitude-frequency characteristics of the power line impedance, including the amplitude and phase, are calculated, and the voltage reflection coefficient is calculated;

[0015] Step 4: The noise collection circuit collects the power line noise signal and sends it to the digital signal processor through analog-to-digital conversion. The digital signal processor filters the input voltage signal and adjusts the measured noise signal according to the voltage reflection coefficient of each frequency to obtain the HPLC noise value taking into account the influence of impedance matching.

[0016] Preferably, in step 1, input data information of each frequency point to be measured is generated at one time according to the noise measurement frequency range, and generating an input voltage signal according to the input data information includes:

[0017] The sinusoidal signals of all noise frequency points to be measured are superimposed according to the following formula to obtain input data information containing all frequency information to be measured:

[0018]

[0019] in,

[0020] u is the input data information containing all the frequency information to be tested.

[0021] f i is the frequency of the i-th noise frequency point to be measured,

[0022] u i is the amplitude of the input signal at the i-th noise frequency point to be measured,

[0023] θ i is the phase of the input signal at the i-th noise frequency point to be measured;

[0024] n is the number of noise frequency points to be measured;

[0025] Encode the input data information to obtain an encoding result;

[0026] Perform fast Fourier transform (IFFT) operation according to the encoding result to generate a discrete signal in the time domain;

[0027] The time-domain discrete signal is converted from digital to analog and power amplified to generate an input voltage signal.

[0028] Preferably, in step 1, the input voltage signal is used to measure the impedance characteristics of the low-voltage power line channel, and the input voltage signal can cover a bandwidth range of 100 KHz to 12 MHz.

[0029] Preferably, in step 2, the input voltage u 输入 and the injected voltage u 注入 , perform Fourier FFT operation to extract the corresponding amplitude-frequency characteristics and

[0030] Preferably, in step 3, the frequency domain information of the power line impedance and the voltage reflection coefficient are calculated according to the following formula:

[0031]

[0032] in,

[0033] Z 耦合 is the known coupling circuit impedance,

[0034] is the amplitude-frequency characteristic of the injected voltage,

[0035] is the amplitude-frequency characteristic of the input voltage,

[0036] Z x is the frequency domain information of the power line impedance,

[0037] Γ is the voltage reflection coefficient.

[0038] Preferably, in step 4, the measured noise signal is adjusted according to the following formula to obtain the HPLC noise value taking into account the influence of impedance matching:

[0039] PSD 噪声 =PSD 噪采集 / (1-Γ) 2

[0040] in,

[0041] PSD 噪声 is the HPLC noise value to be measured, that is, the noise power spectrum density,

[0042] PSD 噪采集 is the noise power spectral density collected directly,

[0043] Γ is the voltage reflection coefficient.

[0044] The third aspect of the present invention provides an electronic device, comprising 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, the method for measuring HPLC noise taking into account the influence of impedance matching is implemented.

[0045] A fourth invention of the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the above-mentioned HPLC noise measurement method taking into account the influence of impedance matching.

[0046] Compared with the prior art, the beneficial effects of the present invention include at least:

[0047] 1. The present invention adopts a signal injection circuit that is completely mirrored with the noise acquisition circuit. On the one hand, it can conveniently and effectively filter out the influence of the injected signal on the noise signal. On the other hand, the signal injection and noise acquisition are carried out simultaneously, which can ensure that the measurement line impedance is the impedance at the current noise acquisition moment, so as to adjust the collected noise, effectively solve the adverse effects caused by the coupling circuit impedance mismatch, and improve the noise acquisition accuracy.

[0048] 2. The present invention adopts a one-time multi-frequency test signal generation technology, which effectively ensures the synchronization of signal injection and noise collection, and improves measurement efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0050] Figure 1 It is a schematic diagram of a principle diagram of a HPLC noise measurement device taking into account the influence of impedance matching provided by an embodiment of the present invention;

[0051] Figure 2 It is a schematic flow chart of a HPLC noise measurement method taking into account the influence of impedance matching provided by an embodiment of the present invention;

[0052] Figure 3 It is a schematic diagram of a signal injection equivalent circuit diagram of a noise acquisition system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described below; obviously, the following description is only a part of the embodiments, and for ordinary technicians in the field, the technical solution of the present invention can also be applied to other similar scenarios based on these without creative work; in order to more clearly illustrate the technical solution of the present invention, the technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:

[0054] like Figure 1 and Figure 3As shown, embodiment 1 of the present invention provides an HPLC noise measurement device taking into account the influence of impedance matching, including a three-winding transformer, a signal injection circuit, a noise collection circuit and a digital signal processor. Among them, the three-winding transformer is used to isolate strong electricity, the primary winding is connected to the power line, the secondary winding and the tertiary winding are respectively connected to the signal injection circuit and the noise collection circuit, and the noise collection circuit is used to collect power line noise; the signal injection circuit is used to inject the input voltage signal generated by the digital signal processor within the noise measurement range into the power line; the signal injection circuit and the noise collection circuit are completely mirrored, and are composed of the same high-pass filter circuit, low-pass filter circuit and impedance matching circuit. The digital signal processor performs Fourier operation on the input voltage signal and the injected voltage signal injected into the HPLC power line through the coupling circuit to obtain the amplitude-frequency characteristics of the input voltage signal and the injected voltage signal, and calculates the frequency information and voltage emission coefficient of the power line impedance based on the coupling circuit impedance; wherein, the coupling circuit includes a transformer, a high-pass filter circuit, a low-pass filter circuit and an impedance matching circuit; according to the power line noise value collected by the noise collection circuit, the HPLC noise value is calculated in combination with the voltage reflection coefficient.

[0055] In this embodiment, the signal injection circuit that is completely mirrored with the noise acquisition circuit can, on the one hand, conveniently and effectively filter out the influence of the injected signal on the noise signal; on the other hand, the signal injection and noise acquisition are performed simultaneously, which can ensure that the measurement line impedance is the impedance at the current noise acquisition moment, so as to adjust the collected noise, effectively solve the adverse effects caused by the coupling circuit impedance mismatch, and improve the noise acquisition accuracy.

[0056] Preferably, a three-winding transformer with a transformation ratio of 1:1:1 is used in the device; the signal injection circuit and the noise collection circuit are mirrored, and the topology and parameters are exactly the same to ensure that the input signal is collected by the noise collection device without reflection; the signal processor uses data processing technology to process all collected voltage signals, extract frequency domain characteristics, and calculate accurate power line noise.

[0057] Based on the device provided in Example 1, combined with Figure 2 As shown, embodiment 2 of the present invention provides a HPLC noise measurement method taking into account the influence of impedance matching, comprising the following steps:

[0058] Step 1: Use a one-time multi-frequency input signal superposition generation technology through a digital signal processor to generate input data information of each frequency point to be measured at one time according to the noise measurement frequency range, generate an input voltage signal according to the input data information, and inject the input voltage signal into the power line through a signal injection circuit via a three-winding transformer.

[0059] Preferably, in step 1, a one-time multi-frequency input signal superposition generation technology is adopted to generate input data information of each frequency point to be measured at one time according to the noise measurement frequency range, and an input voltage signal is generated according to the input data information, including:

[0060] The sinusoidal signals of all noise frequency points to be measured are superimposed according to the following formula to obtain input data information containing all frequency information to be measured:

[0061]

[0062] in,

[0063] u is the input data information containing all the frequency information to be tested.

[0064] f i is the frequency of the i-th noise frequency point to be measured,

[0065] u i is the amplitude of the input signal at the i-th noise frequency point to be measured,

[0066] θ i is the phase of the input signal at the i-th noise frequency point to be measured;

[0067] n is the number of noise frequency points to be measured;

[0068] Encode the input data information to obtain an encoding result;

[0069] Perform fast Fourier transform (IFFT) operation according to the encoding result to generate a discrete signal in the time domain;

[0070] The time-domain discrete signal is converted from digital to analog and power amplified to generate an input voltage signal.

[0071] Encode the input data information to obtain the encoding result. The specific process is:

[0072] The input data information is sampled, and the number of frequency domain information samples is calculated according to the sampling frequency and sampling time, and the frequency domain information outside the noise frequency point to be measured is supplemented, and its amplitude is set to 0, including the zero frequency point information, and the single-sided frequency domain information is transformed into double-sided frequency domain information to construct a complete and uniformly distributed double-sided frequency domain information, extract the real and imaginary parts of the frequency domain signal, construct the input voltage signal complex sample array, and obtain the encoding result. The purpose of encoding the input data information is to provide input information for the IFFT operation.

[0073] Specifically, in step 1, a one-time multi-frequency test signal generation technology is used to generate a test signal for measuring the impedance characteristics of a low-voltage power line channel, and the test signal can cover a bandwidth of 100 KHz to 12 MHz.

[0074] This embodiment is different from the general sweep signal input method. It superimposes the waveform required for the test and performs IFFT operation to generate a time domain discrete signal at one time. Therefore, only one signal input is required to measure the impedance information of all frequency points, which effectively ensures the synchronization of signal injection and noise collection, and improves measurement efficiency and accuracy.

[0075] Step 2: Collect the input voltage signal and the injected power line voltage signal between the signal injection circuit and the coupling circuit, send them to the digital signal processor through analog-to-digital conversion, and use data processing technology to extract the amplitude-frequency characteristics of the input voltage and the injected voltage.

[0076] Specifically, in step 2, the analog signal is converted into a digital signal by the analog-to-digital conversion unit, which is completed by the ADC control module controlling the analog-to-digital conversion unit. The input voltage signal u can be obtained. 输入 And the injected voltage signal u 注入 , and perform FFT operation on it to obtain its amplitude-frequency characteristics, that is and

[0077] Step 3: According to the amplitude-frequency characteristics of the input voltage and the injected voltage obtained in step 2, the amplitude-frequency characteristics of the power line impedance, including the amplitude and phase, are calculated, and the voltage reflection coefficient is calculated.

[0078] Specifically, in step 3, based on the data calculated in step 2, when the coupling circuit impedance Z is known 耦合 If accurate measurement is possible, Figure 3 The equivalent circuit shown in FIG. 1 is used to calculate the frequency domain information of the power line impedance and the voltage reflection coefficient according to the following formula:

[0079]

[0080] in,

[0081] Z 耦合 is the known coupling circuit impedance,

[0082] is the amplitude-frequency characteristic of the injected voltage,

[0083] is the amplitude-frequency characteristic of the input voltage,

[0084] Z x is the frequency domain information of the power line impedance,

[0085] Γ is the voltage reflection coefficient.

[0086] Step 4: The noise collection circuit collects the power line noise signal and sends it to the digital signal processor through analog-to-digital conversion. The digital signal processor filters out the input voltage signal information and adjusts the measured noise signal according to the voltage reflection coefficient of each frequency to obtain the HPLC noise value taking into account the influence of impedance matching.

[0087] Since the device adopts a completely mirrored noise collection circuit and signal injection circuit, the input voltage signal can be superimposed on the noise signal without reflection. In step 4, the input voltage signal is directly filtered out by applying digital signal processing technology, and the measured noise signal is adjusted according to the voltage reflection coefficient of each frequency to obtain the accurate power line noise taking into account the influence of impedance matching.

[0088] Preferably, in step 4, the measured noise signal is adjusted according to the following formula to obtain the HPLC noise value taking into account the influence of impedance matching:

[0089] PSD 噪声 =PSD 噪采集 / (1-Γ) 2

[0090] in,

[0091] PSD 噪声 is the HPLC noise value to be measured, that is, the noise power spectrum density,

[0092] PSD 噪采集 is the noise power spectral density collected directly,

[0093] Γ is the voltage reflection coefficient.

[0094] Embodiment 3 of the present invention provides an electronic device, comprising 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, the HPLC noise measurement method taking into account the influence of impedance matching described in Embodiment 1 is implemented.

[0095] Embodiment 4 of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the HPLC noise measurement method taking into account the influence of impedance matching according to Embodiment 1 is implemented.

[0096] Compared with the prior art, the beneficial effects of the present invention include at least:

[0097] 1. The present invention adopts a signal injection circuit that is completely mirrored with the noise acquisition circuit. On the one hand, it can conveniently and effectively filter out the influence of the injected signal on the noise signal. On the other hand, the signal injection and noise acquisition are carried out simultaneously, which can ensure that the measurement line impedance is the impedance at the current noise acquisition moment, so as to adjust the collected noise, effectively solve the adverse effects caused by the coupling circuit impedance mismatch, and improve the noise acquisition accuracy.

[0098] 2. The present invention adopts a one-time multi-frequency test signal generation technology, which effectively ensures the synchronization of signal injection and noise collection, and improves measurement efficiency and accuracy.

[0099] The applicant of the present invention has made a detailed explanation and description of the implementation examples of the present invention in conjunction with the drawings in the specification. However, those skilled in the art should understand that the above implementation examples are only preferred implementation schemes of the present invention, and the detailed description is only to help readers better understand the spirit of the present invention, but not to limit the scope of protection of the present invention. On the contrary, any improvements or modifications based on the inventive spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. A HPLC noise measurement device taking into account the influence of impedance matching, characterized in that: include: Three-winding transformer, signal injection circuit, noise collection circuit and digital signal processor; among them, The primary winding of the three-winding transformer is connected to the HPLC power line, and the secondary winding and tertiary winding are connected to the signal injection circuit and the noise collection circuit respectively; The noise collection circuit is used to collect power line noise; The signal injection circuit is used to inject the input voltage signal generated by the digital signal processor within the noise measurement range into the power line. The signal injection circuit is completely mirrored with the noise acquisition circuit and is composed of the same high-pass filter circuit, low-pass filter circuit and impedance matching circuit. The digital signal processor performs Fourier operation on the input voltage signal and the injected voltage signal injected into the HPLC power line through the coupling circuit to obtain the amplitude-frequency characteristics of the input voltage signal and the injected voltage signal respectively, and calculates the frequency information and voltage emission coefficient of the power line impedance based on the coupling circuit impedance; wherein the coupling circuit includes a transformer, a high-pass filter circuit, a low-pass filter circuit and an impedance matching circuit; The HPLC noise value is calculated based on the power line noise value collected by the noise collection circuit and the voltage reflection coefficient.

2. The HPLC noise measurement device taking into account the influence of impedance matching according to claim 1, characterized in that: The transformation ratio of the three-winding transformer is 1:1:

1.

3. A method for measuring HPLC noise taking into account the influence of impedance matching using the HPLC noise measurement device taking into account the influence of impedance matching according to claim 1 or 2, characterized in that: The method comprises: Step 1: The digital signal processor generates input data information of each frequency point to be measured at one time according to the noise measurement frequency range, generates an input voltage signal according to the input data information, and injects the input voltage signal into the power line through the signal injection circuit via the three-winding transformer; Step 2: collecting the input voltage signal and the injected power line voltage signal between the signal injection circuit and the coupling circuit, and sending them to the digital signal processor through analog-to-digital conversion. The digital signal processor performs data processing to extract the amplitude-frequency characteristics of the input voltage and the injected voltage; Step 3: According to the amplitude-frequency characteristics of the input voltage and the injected voltage obtained in step 2, the amplitude-frequency characteristics of the power line impedance, including the amplitude and phase, are calculated, and the voltage reflection coefficient is calculated; Step 4: The noise collection circuit collects the power line noise signal and sends it to the digital signal processor through analog-to-digital conversion. The digital signal processor filters the input voltage signal and adjusts the measured noise signal according to the voltage reflection coefficient of each frequency to obtain the HPLC noise value taking into account the influence of impedance matching.

4. The HPLC noise measurement method taking into account the influence of impedance matching according to claim 3, characterized in that: In step 1, input data information of each frequency point to be measured is generated at one time according to the noise measurement frequency range, and the input voltage signal is generated according to the input data information, including: The sinusoidal signals of all noise frequency points to be measured are superimposed according to the following formula to obtain input data information containing all frequency information to be measured: in, u is the input data information containing all the frequency information to be tested. f i is the frequency of the i-th noise frequency point to be measured, u i is the amplitude of the input signal at the i-th noise frequency point to be measured, θ i is the phase of the input signal at the i-th noise frequency point to be measured; n is the number of noise frequency points to be measured; Encode the input data information to obtain an encoding result; Perform fast Fourier transform (IFFT) operation according to the encoding result to generate a discrete signal in the time domain; The time-domain discrete signal is converted from digital to analog and power amplified to generate an input voltage signal.

5. The HPLC noise measurement method taking into account the influence of impedance matching according to claim 4, characterized in that: In step 1, the input voltage signal is used to measure the impedance characteristics of the low-voltage power line channel, and the input voltage signal can cover a bandwidth range of 100KHz to 12MHz.

6. The HPLC noise measurement method taking into account the influence of impedance matching according to claim 5, characterized in that: In step 2, the input voltage u 输入 and the injected voltage u 注入 , perform Fourier FFT operation to extract the corresponding amplitude-frequency characteristics and 7. The HPLC noise measurement method taking into account the influence of impedance matching according to claim 6, characterized in that: In step 3, the frequency domain information of the power line impedance and the voltage reflection coefficient are calculated according to the following formula: in, Z 耦合 is the known coupling circuit impedance, is the amplitude-frequency characteristic of the injected voltage, is the amplitude-frequency characteristic of the input voltage, Z x is the frequency domain information of the power line impedance, Γ is the voltage reflection coefficient.

8. The HPLC noise measurement method taking into account the influence of impedance matching according to claim 7, characterized in that: In step 4, the measured noise signal is adjusted according to the following formula to obtain the HPLC noise value taking into account the influence of impedance matching: PSD 噪声 =PSD 噪采集 / (1-Γ) 2 in, PSD 噪声 is the HPLC noise value to be measured, that is, the noise power spectrum density, PSD 噪采集 is the noise power spectral density collected directly, Γ is the voltage reflection coefficient.

9. An electronic device, comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the HPLC noise measurement method taking into account the influence of impedance matching according to any one of claims 3 to 8.

10. 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 HPLC noise measurement method taking into account the influence of impedance matching as claimed in any one of claims 3 to 8 are implemented.

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