Device and method for testing broadband transmission characteristics of vehicle-mounted voltage transformer

Abstract

The invention discloses a device and method for testing the broadband transmission characteristic of a vehicle-mounted voltage transformer, and belongs to the technical field of voltage transformer transmission characteristic testing, and the method comprises a signal main control unit which is used for generating an amplified square pulse signal and injecting the amplified square pulse signal into the voltage transformer; the voltage signal acquisition and storage unit is used for acquiring and storing voltage waveforms of the primary side and the secondary side of the voltage transformer; and the signal processing unit is used for obtaining the broadband transmission characteristic of the voltage transformer by utilizing the principle of an impulse response method according to the voltage waveforms of the primary side and the secondary side of the voltage transformer. The problem that the broadband transmission characteristic of the vehicle-mounted voltage transformer is difficult to master is solved.

Description

Technical Field

[0001] This invention belongs to the field of voltage transformer transfer characteristic testing technology, and particularly relates to a testing device and method for the broadband transfer characteristics of vehicle-mounted voltage transformers. Background Technology

[0002] With the development of my country's science and technology and economic strength, high-speed trains play a vital role in people's travel, making their safe, stable, and punctual operation particularly important. Onboard voltage transformers are crucial high-voltage electrical equipment on high-speed trains, enabling functions such as traction network voltage monitoring and energy metering. When an overvoltage occurs on a high-speed train, the overvoltage on the primary side of the voltage transformer contains many high-frequency components. Due to the influence of the distributed parameters of the voltage transformer, at high frequencies, the amplitude relationship between the primary and secondary sides of the voltage transformer is no longer a linear relationship based on the rated transformation ratio; the transformation ratio changes with frequency. This characteristic inevitably leads to distortion on the secondary side when transmitting broadband waveforms, failing to accurately reflect the actual waveform on the primary side. Therefore, when an overvoltage occurs on a high-speed train, the primary side overvoltage directly obtained from the transformation ratio relationship of the voltage transformer is inaccurate.

[0003] Currently, there is a lack of effective means to test the broadband transfer characteristics of on-board voltage transformers for high-speed trains, making it difficult to grasp the broadband transfer characteristics of on-board voltage transformers. Therefore, testing devices and methods for the broadband transfer characteristics of on-board voltage transformers are needed to test these characteristics. Summary of the Invention

[0004] In view of the above-mentioned shortcomings in the prior art, the present invention provides a test device and method for testing the broadband transfer characteristics of vehicle-mounted voltage transformers, which solves the problem of difficulty in mastering the broadband transfer characteristics of vehicle-mounted voltage transformers.

[0005] To achieve the aforementioned objectives, the present invention employs the following technical solution: a testing device for the broadband transfer characteristics of an on-board voltage transformer, comprising: The signal control unit is used to generate an amplified square pulse signal and inject the amplified square pulse signal into the voltage transformer. The voltage signal acquisition and storage unit is used to acquire and store the voltage waveforms on the primary and secondary sides of the voltage transformer. The signal processing unit is used to obtain the wideband transfer characteristics of the voltage transformer based on the voltage waveforms of the primary and secondary sides of the voltage transformer using the principle of impulse response.

[0006] The beneficial effects of this invention are as follows: the signal control unit can generate square pulse signals with different pulse widths, covering a frequency range from DC to 5MHz, which can measure the wideband transmission characteristics of the voltage transformer; since the pulse signal has high-frequency characteristics, in order to enable it to be transmitted without distortion, the bandwidth of the signal acquisition module meets the bandwidth of the pulse signal, and the input impedance of the signal acquisition module is relatively large, which can reduce the influence of the measurement device and acquire accurate primary and secondary voltage signals of the voltage transformer; thus, accurate testing of the DC-5MHz wideband transmission characteristics of the vehicle-mounted voltage transformer is achieved.

[0007] Furthermore, the signal control unit includes: The pulse signal generation module is used to generate square pulse signals with different pulse widths; The signal amplification module is used to amplify the square pulse signal and inject the amplified signal into the primary side of the voltage transformer through a coaxial cable.

[0008] The beneficial effects of the above-mentioned further solutions are as follows: the pulse signal generation module can flexibly adjust the pulse width of the square pulse signal, covering a frequency range from DC to 5MHz; the signal amplification module increases the signal amplitude; the coaxial cable ensures low-loss transmission and avoids high-frequency distortion; and the whole provides a stable and reliable signal excitation for transmission characteristic testing.

[0009] Furthermore, the expression for the square pulse signal is:

[0010] in, for The value of the square pulse signal at time; For time; It is a step function; The period is the signal period.

[0011] The beneficial effects of the above-mentioned further scheme are: quantifying the characteristics of square pulse signals through mathematical expressions, clarifying the correlation between parameters, ensuring that square pulse signals are standardized and reproducible, and providing a clear theoretical basis for pulse response analysis and Fourier transform of signal processing units.

[0012] Furthermore, the voltage signal acquisition and storage unit includes: The primary side signal acquisition module of the voltage transformer is used to acquire the voltage waveform of the primary side of the voltage transformer. The voltage transformer secondary side signal acquisition module is used to acquire the voltage waveform of the secondary side of the voltage transformer. The signal storage module is used to store the voltage waveforms on the primary side and the secondary side of the voltage transformer.

[0013] The beneficial effects of the above-mentioned further solutions are: to achieve synchronous acquisition and storage of primary and secondary voltage waveforms, to ensure signal timing consistency, and to provide reliable data support for accurate calculation of broadband transmission characteristics.

[0014] Furthermore, the primary side signal acquisition module and the secondary side signal acquisition module of the voltage transformer have the same circuit structure, both including a resistor-capacitor voltage divider circuit and a voltage follower circuit connected to the resistor-capacitor voltage divider circuit.

[0015] The beneficial effects of the above-mentioned further solutions are as follows: both the primary side signal acquisition module and the secondary side signal acquisition module of the voltage transformer adopt the resistor-capacitor voltage divider circuit and the voltage follower circuit structure to ensure the consistency of signal acquisition on both sides and reduce system errors; at the same time, it meets the requirements of wideband signal acquisition and ensures the accuracy of signal acquisition.

[0016] Further, the resistor-capacitor voltage divider circuit includes a voltage acquisition port P1, resistors R1, R2, R3, R4, R5, and R6, and capacitors C1, C2, C3, C4, C5, C6, C7, and C8. Interface 1 of the voltage acquisition port P1 is connected to one end of resistor R1 and one end of capacitor C1, respectively. The other end of resistor R1 is connected to one end of resistor R2. The other end of capacitor C1 is connected to one end of capacitor C2. The other end of resistor R2 is connected to one end of resistor R3. The other end of capacitor C2 is connected to one end of capacitor C3. One end of the resistor R3 is connected to one end of the resistor R4; the other end of the capacitor C3 is connected to one end of the capacitor C4; the other end of the resistor R4 and the other end of the capacitor C4 are respectively connected to one end of the resistor R5, one end of the resistor R6, one end of the capacitor C5, one end of the capacitor C6, one end of the capacitor C7 and one end of the capacitor C8; the interface 2 of the voltage acquisition port P1 is respectively connected to the other end of the resistor R5, the other end of the capacitor C5, the other end of the capacitor C6, the other end of the capacitor C7 and the other end of the capacitor C8 and grounded; the other end of the resistor R6 is connected to the resistor-capacitor voltage divider circuit.

[0017] The beneficial effects of the above-mentioned further solutions are: the multi-resistor-capacitor parallel design optimizes the wideband response, the voltage division ratio is stable in the DC-5MHz range, the grounding structure suppresses interference, and the high-frequency voltage signal is transmitted without distortion.

[0018] Further, the voltage follower circuit includes an integrated operational amplifier chip, a power supply circuit source, a voltage acquisition port P2, a coaxial connector RF1, a resistor R7, and capacitors C9, C10, C11, and C12. The non-inverting input terminal of the integrated operational amplifier chip is connected to the other end of resistor R6 in the RC voltage divider circuit. The positive power supply terminal of the integrated operational amplifier chip is connected to one end of capacitor C9, one end of capacitor C10, and interface 3 of the power supply circuit source. The other ends of capacitors C9 and C10, and interface 4 of the power supply circuit source are all grounded. Interface 1 of ce is connected to interface 2 of power interface P2; interface 2 of the power source circuit is connected to interface 1 of power interface P2; interface 5 of the power source circuit is connected to one end of capacitor C11, one end of capacitor C12, and the negative power supply terminal of the integrated operational amplifier chip; the inverting input and output terminals of the integrated operational amplifier chip are connected to one end of resistor R7 and interface 5 of coaxial connector RF1, respectively; the other end of resistor R7, interface 1, interface 2, interface 3, and interface 4 of coaxial connector RF1 are all grounded.

[0019] The beneficial effects of the above-mentioned further solution are as follows: by using an integrated operational amplifier chip to form a voltage follower circuit, the voltage divider circuit and the coaxial cable are effectively isolated, avoiding interference from parallel impedances in the voltage division ratio and ensuring accurate transmission of voltage signals.

[0020] A method for testing the broadband transfer characteristics of an on-board voltage transformer, characterized in that it includes: Connect the test device for the wideband transfer characteristics of the vehicle voltage transformer to the circuit of the vehicle voltage transformer under test. The main control unit injects the amplified square pulse signal into the primary side of the voltage transformer through a coaxial cable; Based on the voltage waveforms on the primary and secondary sides of the voltage transformer, the signal processing unit obtains the wideband transfer characteristics of the voltage transformer using the principle of impulse response.

[0021] The beneficial effects of this invention are: the test steps are simple, the test device is easy to connect, and the primary and secondary voltage waveforms combined with the pulse response method can accurately obtain the transmission characteristics of the voltage transformer, meeting the test requirements of the wideband transmission characteristics of vehicle-mounted voltage transformers.

[0022] Furthermore, the expression for the wideband transfer characteristic of the voltage transformer is as follows:

[0023] in, For transmission characteristics; The imaginary unit; Angular frequency; The frequency response is obtained by fast Fourier transform of the voltage waveform on the primary side of the voltage transformer. The frequency response obtained by fast Fourier transform of the voltage waveform on the secondary side of the voltage transformer; | represents the amplitude-frequency characteristic; The phase angle symbol; This represents the phase frequency characteristic.

[0024] The beneficial effects of the above-mentioned further scheme are: to quantify the relationship between the wideband transfer characteristics, amplitude-frequency characteristics, and phase-frequency characteristics of the voltage transformer through mathematical expressions, and to achieve accurate conversion from the time domain to the frequency domain through Fourier transform, thus providing accurate calculation basis for signal processing. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the device of the present invention.

[0026] Figure 2 This is a schematic diagram of a pulse signal and its FFT transformation in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the installation of a test device for the broadband transfer characteristics of vehicle-mounted voltage transformers.

[0028] Figure 4 This is a circuit diagram of the signal acquisition module of the present invention.

[0029] Figure 5 This is a flowchart illustrating the test method for the broadband transfer characteristics of voltage transformers. Detailed Implementation

[0030] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0031] Example 1 like Figure 1 and Figure 3 As shown, in one embodiment of the present invention, a test apparatus for the broadband transfer characteristics of an on-board voltage transformer includes: The signal control unit is used to generate an amplified square pulse signal and inject the amplified square pulse signal into the voltage transformer. The voltage signal acquisition and storage unit is used to acquire and store the voltage waveforms on the primary and secondary sides of the voltage transformer. The signal processing unit is used to obtain the wideband transfer characteristics of the voltage transformer based on the voltage waveforms of the primary and secondary sides of the voltage transformer using the principle of impulse response.

[0032] In this embodiment, the device includes: a signal control unit, a voltage signal acquisition and storage unit, and a signal processing unit.

[0033] The signal control unit includes: The pulse signal generation module is used to generate square pulse signals with different pulse widths; The signal amplification module is used to amplify the square pulse signal and inject the amplified signal into the primary side of the voltage transformer through a coaxial cable.

[0034] Pulse signal generation module: used to generate square pulse signals with different pulse widths, and use the square pulse signals as a voltage source; the square pulse signals are rich in frequencies, covering DC to 5MHz; Signal amplification module: used to amplify the square pulse signal from the pulse signal generation module, and the signal is injected into the primary side of the voltage transformer through a 20m coaxial cable.

[0035] The expression for the square pulse signal is:

[0036] in, for The value of the square pulse signal at time; For time; It is a step function; The period is the signal period.

[0037] In this embodiment, the output signal is controlled by the signal master control unit. The output square pulse signal is a voltage signal of 0-100V, which can be used to test the transmission characteristics of the vehicle voltage transformer as a whole. Figure 2 (a) shows a square pulse signal; the range of the square pulse signal is - τ / 2~ τ / 2, and its amplitude is 1, and its period is τ .from Figure 2 As can be clearly seen in (b), the spectrum of the square pulse signal is a sinc signal, and the angular frequency range of its first lobe is -2π / τ ~2π / τ .according to Figure 2 It is known that the spectral width of the square pulse signal after Fourier transform is directly related to the beamwidth of the original signal. Therefore, the signal period can be adjusted by regulating the pulse width. Based on this characteristic, the square pulse signal is selected as the signal source for measuring the transmission characteristics of on-board voltage transformers. Figure 2 middle, The amplitude of the pulse signal in the time domain; The amplitude of the frequency domain square pulse signal.

[0038] The voltage signal acquisition and storage unit includes: The primary side signal acquisition module of the voltage transformer is used to acquire the voltage waveform of the primary side of the voltage transformer. The voltage transformer secondary side signal acquisition module is used to acquire the voltage waveform of the secondary side of the voltage transformer. The signal storage module is used to store the voltage waveforms on the primary side and the secondary side of the voltage transformer.

[0039] like Figure 4 As shown, the primary side signal acquisition module and the secondary side signal acquisition module of the voltage transformer have the same circuit structure, both including a resistor-capacitor voltage divider circuit and a voltage follower circuit connected to the resistor-capacitor voltage divider circuit.

[0040] The resistor-capacitor voltage divider circuit includes a voltage acquisition port P1, resistors R1, R2, R3, R4, R5, and R6, and capacitors C1, C2, C3, C4, C5, C6, C7, and C8. Interface 1 of the voltage acquisition port P1 is connected to one end of resistor R1 and one end of capacitor C1. The other end of resistor R1 is connected to one end of resistor R2. The other end of capacitor C1 is connected to one end of capacitor C2. The other end of resistor R2 is connected to one end of resistor R3. The other end of capacitor C2 is connected to one end of capacitor C3. Connections are made as follows: the other end of resistor R3 is connected to one end of resistor R4; the other end of capacitor C3 is connected to one end of capacitor C4; the other ends of resistor R4 and capacitor C4 are respectively connected to one end of resistor R5, one end of resistor R6, one end of capacitor C5, one end of capacitor C6, one end of capacitor C7, and one end of capacitor C8; interface 2 of voltage acquisition port P1 is connected to the other ends of resistor R5, capacitor C5, capacitor C6, capacitor C7, and capacitor C8 and grounded; the other end of resistor R6 is connected to the resistor-capacitor voltage divider circuit.

[0041] The voltage follower circuit includes an integrated operational amplifier chip, a voltage acquisition port P2, a coaxial connector RF1, a power supply circuit source, a resistor R7, capacitors C9, C10, C11, and C12. The non-inverting input terminal of the integrated operational amplifier chip is connected to the other end of resistor R6 in the RC voltage divider circuit. The positive power supply terminal of the integrated operational amplifier chip is connected to one end of capacitor C9, one end of capacitor C10, and interface 3 of the power supply circuit source. The other ends of capacitors C9 and C10, and interface 4 of the power supply circuit source are all grounded. Interface 1 is connected to interface 2 of power interface P2; interface 2 of the power source circuit is connected to interface 1 of power interface P2; interface 5 of the power source circuit is connected to one end of capacitor C11, one end of capacitor C12, and the negative power supply terminal of the integrated operational amplifier chip; the inverting input and output terminals of the integrated operational amplifier chip are connected to one end of resistor R7 and interface 5 of coaxial connector RF1, respectively; the other end of resistor R7, interface 1, interface 2, interface 3, and interface 4 of coaxial connector RF1 are all grounded.

[0042] In this embodiment, a voltage signal acquisition and storage unit is also included; the voltage signal acquisition and storage unit includes a primary side signal acquisition module of the voltage transformer, a secondary side signal acquisition module of the voltage transformer, and a signal storage module; like Figure 4 As shown, the signal acquisition module consists of a resistor-capacitor (RC) voltage divider circuit, a voltage follower circuit, and a 20m coaxial cable. The input impedance of the RC voltage divider circuit is significantly affected by the impedance of the high-voltage arm. The high-voltage arm is designed using high-resistance resistors and low-capacitance capacitors to increase its input impedance and reduce the impact of the measurement device. Since the circuit uses surface-mount capacitors and resistors, its power is relatively low. To increase the circuit power, multiple components should be used appropriately to increase the overall circuit power. In the RC voltage divider circuit of the primary side signal acquisition module of the voltage transformer, the high-voltage arm resistance is 1MΩ and the capacitance is 2.5pF, and the low-voltage arm resistance is 20kΩ and the capacitance is 66pF, with a transformation ratio of 50:1. In the RC voltage divider circuit of the secondary side signal acquisition module of the voltage transformer, the high-voltage arm resistance is 470kΩ and the capacitance is 17pF, and the low-voltage arm resistance is 470kΩ and the capacitance is 0.5pF, with a transformation ratio of 2:1. A voltage follower circuit composed of an integrated operational amplifier chip is connected to the output of the resistor-capacitor voltage divider circuit. The input impedance of the voltage follower circuit is 6MΩ, and the output impedance gradually increases with frequency, reaching only 0.07Ω at 1MHz and less than 1Ω at 10MHz. This voltage follower circuit provides excellent buffering and isolation. In this embodiment, the primary and secondary voltage measurement points of the on-board voltage transformer on the EMU are far apart. Considering the actual situation, the signal acquisition module is designed with a 20m coaxial cable to transmit the voltage signal, which can simultaneously test the primary and secondary voltage signals of the on-board voltage transformer. The voltage follower circuit has a good isolation effect, and the distributed parameters of the coaxial cable do not affect the transformation ratio of the resistor-capacitor voltage divider circuit, thus achieving distortion-free signal transmission. The primary side signal acquisition module of the voltage transformer receives the output signal U1(t) from the primary side of the vehicle-mounted voltage transformer and transmits it to the signal receiving channel CH1 of the signal storage module; the secondary side signal acquisition module of the voltage transformer receives the output signal U2(t) from the secondary side of the vehicle-mounted voltage transformer and transmits it to the signal receiving channel CH2 of the signal storage module. The signal processing unit is used to calculate the broadband transfer characteristic curve of the vehicle-mounted voltage transformer based on the acquired primary and secondary voltage waveforms and the principle of the impulse response method, thereby realizing the accurate testing of the broadband transfer characteristics of the vehicle-mounted voltage transformer.

[0043] Example 2 like Figure 5 As shown, a method for testing the broadband transfer characteristics of an on-board voltage transformer is characterized by comprising: Connect the test device for the wideband transfer characteristics of the vehicle voltage transformer to the circuit of the vehicle voltage transformer under test. The main control unit injects the amplified square pulse signal into the primary side of the voltage transformer through a coaxial cable; Based on the voltage waveforms on the primary and secondary sides of the voltage transformer, the signal processing unit obtains the wideband transfer characteristics of the voltage transformer using the principle of impulse response.

[0044] In this embodiment, the broadband transfer characteristics of the vehicle voltage transformer are tested using the aforementioned vehicle voltage transformer broadband transfer characteristic testing device, including the following steps: S1: Connect the voltage transformer transfer characteristic testing device to the circuit of the vehicle voltage transformer under test using a connecting wire; wherein, the voltage transformer transfer characteristic testing device is electrically connected to the voltage transformer. S2: After the connection is completed, the signal control unit controls the output signal and outputs square pulse signals with different pulse widths; the square pulse signals are amplified by the signal amplification module and injected into the primary side of the voltage transformer through a 20m coaxial cable. S3: The signal acquisition module acquires the voltage waveforms of the primary and secondary sides of the voltage transformer, and the signal is transmitted to the signal storage module for storage via a 20m coaxial cable. S4: The signal processing unit calculates the wideband transfer characteristics of the voltage transformer based on the stored primary and secondary voltage waveforms of the voltage transformer and the principle of the impulse response method.

[0045] The expression for the wideband transfer characteristic of the voltage transformer is:

[0046] in, For transmission characteristics; The imaginary unit; Angular frequency; The frequency response is obtained by fast Fourier transform of the voltage waveform on the primary side of the voltage transformer. The frequency response obtained by fast Fourier transform of the voltage waveform on the secondary side of the voltage transformer; | represents the amplitude-frequency characteristic; The phase angle symbol; This represents the phase frequency characteristic.

[0047] In this embodiment, based on the actual circuit topology of an on-board voltage transformer, the impulse response method is used to determine the transformer's transfer characteristics. The principle of the impulse response method is to generate a square pulse signal with a suitable amplitude using a signal generating device. This voltage is applied to the primary side of the voltage transformer. Simultaneously, using a signal storage device, the voltage waveforms on both the primary and secondary sides of the voltage transformer are measured. Then, the measured data is transmitted to a signal processing device via the signal storage device for a Fast Fourier Transform to obtain their frequency characteristics. Therefore, the broadband voltage transfer characteristic of the voltage transformer is:

[0048] Due to the injected square pulse signal It possesses rich frequency components, thus enabling the simultaneous acquisition of transfer characteristics at multiple frequency points. However, when the frequency components in the square pulse signal reach excessively high levels, the amplitude of the high-frequency components is relatively small. Furthermore, due to the rated transformation ratio (250:1) of the voltage transformer, the amplitude of the high-frequency components on the secondary side is even smaller, resulting in a larger measurement error. To obtain transfer characteristics over a wide bandwidth, it is necessary to repeatedly change parameters such as the pulse width of the pulse signal to obtain the broadband transfer characteristics.

[0049] To obtain the transmission characteristics over a wide bandwidth, the parameters of the pulse signal (such as pulse width and amplitude) are adjusted to achieve comprehensive measurement of the transmission characteristics within the broadband range. The signal control unit controls the output signal, and the output square pulse signal is a voltage signal of 0-100V, which can be used for overall transmission characteristic testing of the vehicle-mounted voltage transformer. During testing, five pulse signals with different pulse widths are set according to the test requirements: 50μs, 5μs, 1μs, 250ns, and 100ns. In this way, the present invention can achieve a signal frequency range covering DC to 5MHz for square pulse signals with different pulse widths.

[0050] The primary side signal acquisition module of the voltage transformer receives the output signal from the primary side of the vehicle-mounted voltage transformer; the secondary side signal acquisition module of the voltage transformer receives the output signal from the secondary side of the vehicle-mounted voltage transformer; the signal processing unit is used to calculate the broadband transfer characteristics of the vehicle-mounted voltage transformer based on the acquired primary and secondary side voltages and the transfer characteristic algorithm, thereby realizing the accurate testing of the broadband transfer characteristics of the vehicle-mounted voltage transformer.

Claims

1. A testing device for the broadband transfer characteristics of an on-board voltage transformer, characterized in that, include: The signal control unit is used to generate an amplified square pulse signal and inject the amplified square pulse signal into the voltage transformer. The voltage signal acquisition and storage unit is used to acquire and store the voltage waveforms on the primary and secondary sides of the voltage transformer. The signal processing unit is used to obtain the wideband transfer characteristics of the voltage transformer based on the voltage waveforms of the primary and secondary sides of the voltage transformer using the principle of impulse response.

2. The testing device for the broadband transfer characteristics of an on-board voltage transformer according to claim 1, characterized in that, The signal control unit includes: The pulse signal generation module is used to generate square pulse signals with different pulse widths; The signal amplification module is used to amplify the square pulse signal and inject the amplified signal into the primary side of the voltage transformer through a coaxial cable.

3. The testing device for the broadband transfer characteristics of an on-board voltage transformer according to claim 2, characterized in that, The expression for the square pulse signal is: in, for The value of the square pulse signal at time; For time; It is a step function; The period is the signal period.

4. The testing device for the broadband transfer characteristics of an on-board voltage transformer according to claim 1, characterized in that, The voltage signal acquisition and storage unit includes: The primary side signal acquisition module of the voltage transformer is used to acquire the voltage waveform of the primary side of the voltage transformer. The voltage transformer secondary side signal acquisition module is used to acquire the voltage waveform of the secondary side of the voltage transformer. The signal storage module is used to store the voltage waveforms on the primary side and the secondary side of the voltage transformer.

5. The testing device for the broadband transfer characteristics of an on-board voltage transformer according to claim 4, characterized in that, The primary side signal acquisition module and the secondary side signal acquisition module of the voltage transformer have the same circuit structure, both including a resistor-capacitor voltage divider circuit and a voltage follower circuit connected to the resistor-capacitor voltage divider circuit.

6. The testing apparatus for the broadband transfer characteristics of an on-board voltage transformer according to claim 5, characterized in that, The resistor-capacitor voltage divider circuit includes a voltage acquisition port P1, resistors R1, R2, R3, R4, R5, and R6, and capacitors C1, C2, C3, C4, C5, C6, C7, and C8. Interface 1 of the voltage acquisition port P1 is connected to one end of resistor R1 and one end of capacitor C1. The other end of resistor R1 is connected to one end of resistor R2. The other end of capacitor C1 is connected to one end of capacitor C2. The other end of resistor R2 is connected to one end of resistor R3. The other end of capacitor C2 is connected to one end of capacitor C3. Connections are made as follows: the other end of resistor R3 is connected to one end of resistor R4; the other end of capacitor C3 is connected to one end of capacitor C4; the other ends of resistor R4 and capacitor C4 are respectively connected to one end of resistor R5, one end of resistor R6, one end of capacitor C5, one end of capacitor C6, one end of capacitor C7, and one end of capacitor C8; interface 2 of voltage acquisition port P1 is connected to the other ends of resistor R5, capacitor C5, capacitor C6, capacitor C7, and capacitor C8 and grounded; the other end of resistor R6 is connected to the resistor-capacitor voltage divider circuit.

7. The testing device for the wideband transfer characteristics of an on-board voltage transformer according to claim 5, characterized in that, The voltage follower circuit includes an integrated operational amplifier chip, a power supply source, a power interface P2, a coaxial connector RF1, a resistor R7, and capacitors C9, C10, C11, and C12. The non-inverting input terminal of the integrated operational amplifier chip is connected to the other end of resistor R6 in the resistor-capacitor voltage divider circuit. The positive power supply terminal of the integrated operational amplifier chip is connected to one end of capacitor C9, one end of capacitor C10, and interface 3 of the power supply source. The other ends of capacitors C9 and C10, and interface 4 of the power supply source are all grounded. Port 1 is connected to interface 2 of power interface P2; interface 2 of the power source circuit is connected to interface 1 of power interface P2; interface 5 of the power source circuit is connected to one end of capacitor C11, one end of capacitor C12, and the negative power supply terminal of the integrated operational amplifier chip; the inverting input and output terminals of the integrated operational amplifier chip are connected to one end of resistor R7 and interface 5 of coaxial connector RF1, respectively; the other end of resistor R7, interface 1, interface 2, interface 3, and interface 4 of coaxial connector RF1 are all grounded.

8. A method for testing the broadband transfer characteristics of an on-board voltage transformer using a testing device based on the broadband transfer characteristics of an on-board voltage transformer according to any one of claims 1-7, characterized in that, include: Connect the test device for the wideband transfer characteristics of the vehicle voltage transformer to the circuit of the vehicle voltage transformer under test. The main control unit injects the amplified square pulse signal into the primary side of the voltage transformer through a coaxial cable; Based on the voltage waveforms on the primary and secondary sides of the voltage transformer, the signal processing unit obtains the wideband transfer characteristics of the voltage transformer using the principle of impulse response.

9. The test method for the broadband transfer characteristics of an on-board voltage transformer according to claim 8, characterized in that, The expression for the wideband transfer characteristic of the voltage transformer is: in, For transmission characteristics; The imaginary unit; Angular frequency; The frequency response is obtained by fast Fourier transform of the voltage waveform on the primary side of the voltage transformer. The frequency response obtained by fast Fourier transform of the voltage waveform on the secondary side of the voltage transformer; | represents the amplitude-frequency characteristic; The phase angle symbol; This represents the phase frequency characteristic.

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