Electric locomotive power supply quality monitoring system and locomotive

Abstract

The utility model provides an electric locomotive power supply quality monitoring system and a locomotive, according to the method, a sensor is used for collecting a pantograph analog signal, the pantograph analog signal is transmitted to a signal conditioning module, the signal conditioning module is used for conditioning the pantograph analog signal, such as signal gain, signal filtering, etc. The method comprises the following steps: receiving a pantograph analog signal, conditioning the pantograph analog signal to obtain a conditioned pantograph analog signal, transmitting the conditioned pantograph analog signal to a data acquisition card, receiving the conditioned pantograph analog signal by the data acquisition card, sampling the conditioned pantograph analog signal at a preset frequency to obtain a pantograph digital signal, and transmitting the pantograph digital signal to the data acquisition card. The preset frequency is in positive correlation with the frequency of a high-frequency component needing to be studied, the pantograph digital signal is transmitted to the main control module, and the main control module performs spectral analysis on the pantograph digital signal based on Fourier transform to obtain a fundamental wave and harmonic waves with different frequencies.

Description

Technical Field

[0001] The utility model relates to the technical field of power quality monitoring, in particular to a power supply quality monitoring system for an electric locomotive and a locomotive. Background Art

[0002] In the field of power quality monitoring technology, many standards and research focus on monitoring power quality within the public grid or common connection points, while research on power quality within electrified railways is relatively lacking. In electrified railway traction power supply systems, mismatched train-grid electrical parameters can lead to a range of power quality issues, such as harmonic resonance, low-frequency oscillation, and harmonic instability. These issues often damage onboard or ground equipment, shortening their lifespan and even causing train shutdowns, posing significant challenges to the safe and stable operation of electrified railways. Therefore, monitoring traction network power quality is crucial.

[0003] Currently, voltage RMS recording devices have been installed in railway traction substations or locomotives for monitoring. However, these devices are designed for fundamental signals and have a low sampling frequency, making them unable to analyze high-frequency components or effectively capture abnormal data. Utility Model Content

[0004] Based on this, it is necessary to provide an electric locomotive power supply quality monitoring system and locomotive to address the above technical issues.

[0005] An electric locomotive power supply quality monitoring system comprises: a signal conditioning module, a data acquisition module and a main control module connected in sequence, wherein the signal conditioning module is used to connect to a sensor for collecting pantograph analog signals; wherein,

[0006] The signal conditioning module is used to receive the pantograph analog signal output by the sensor, condition the pantograph analog signal to obtain the conditioned pantograph analog signal, and transmit the conditioned pantograph analog signal to the data acquisition module;

[0007] The data acquisition module is used to receive the conditioned pantograph analog signal, sample the conditioned pantograph analog signal at a preset frequency to obtain a pantograph digital signal, and transmit the pantograph digital signal to the main control module;

[0008] The main control module is used to receive the pantograph digital signal, perform spectrum analysis on the pantograph digital signal based on Fourier transform, and obtain pantograph high-order harmonics.

[0009] In one embodiment, the main control module includes a signal analysis chip and a signal monitoring chip that are electrically connected, and the signal analysis chip is electrically connected to the data acquisition module;

[0010] The signal analysis chip is used to receive the pantograph digital signal, perform spectrum analysis on the pantograph digital signal based on Fourier transform, obtain pantograph higher harmonics, and output the pantograph higher harmonics to the signal monitoring chip;

[0011] The signal monitoring chip is used to receive the pantograph high-order harmonics and monitor the pantograph high-order harmonics.

[0012] In one embodiment, the signal analysis chip includes a programmable logic chip; and / or the signal monitoring chip includes a central processing unit.

[0013] In one embodiment, the signal conditioning module includes a preamplifier circuit, a filter circuit, a zero adjustment circuit, and a postamplifier circuit electrically connected in sequence; wherein,

[0014] The preamplifier circuit is used to connect to a sensor for collecting pantograph analog signals, the preamplifier circuit is used to receive the pantograph analog signal output by the sensor, perform gain adjustment on the pantograph analog signal to obtain the adjusted pantograph analog signal, and output the adjusted pantograph analog signal to the filter circuit;

[0015] The filtering circuit is used to receive the adjusted pantograph analog signal, filter the adjusted pantograph analog signal to obtain the filtered pantograph analog signal, and output the filtered pantograph analog signal to the zeroing circuit;

[0016] The zeroing circuit is used to receive the filtered pantograph analog signal, eliminate the offset signal in the filtered pantograph analog signal, obtain the zeroed pantograph analog signal, and output the zeroed pantograph analog signal to the post-amplification circuit;

[0017] The post-amplification circuit is used to adjust the pantograph analog signal after zeroing, perform gain adjustment on the pantograph analog signal after zeroing to obtain the gained pantograph analog signal, and output the gained pantograph analog signal to the data acquisition module.

[0018] In one embodiment, the preamplifier circuit includes a first resistor, a second resistor and a first operational amplifier; wherein, the non-inverting input terminal of the first operational amplifier is connected to a sensor for collecting pantograph analog signals, the reverse input terminal of the first operational amplifier is used to be grounded through the second resistor, the first end of the first resistor is connected to the non-inverting input terminal of the first operational amplifier, the second end of the first resistor is used to be grounded, and the output terminal of the first operational amplifier is connected to the filter circuit.

[0019] In one embodiment, the filtering circuit includes a filtering capacitor, a first end of the filtering capacitor is respectively connected to the output end of the preamplifier circuit and an input end of the zero adjustment circuit, and a second end of the filtering capacitor is respectively connected to the input end of the preamplifier circuit and another input end of the zero adjustment circuit.

[0020] In one embodiment, the zero adjustment circuit includes a third resistor and a voltage-stabilizing reference source component; wherein, the first end of the third resistor is connected to the first output end of the filter circuit, the second end of the third resistor is connected to the first input end of the voltage-stabilizing reference source component, the second input end of the voltage-stabilizing reference source component is connected to the second output end of the filter circuit, and the output end of the voltage-stabilizing reference source component is connected to the post-amplification circuit.

[0021] In one embodiment, the post-amplification circuit includes a fourth resistor and a second operational amplifier; wherein, the non-inverting input terminal of the second operational amplifier is connected to the output terminal of the zero adjustment circuit, the output terminal of the second operational amplifier is connected to the input terminal of the data acquisition module, the reverse input terminal of the second operational amplifier is connected to the input terminal of the data acquisition module, the first end of the fourth resistor is connected to the non-inverting input terminal of the second operational amplifier, and the second end of the fourth resistor is grounded.

[0022] A power quality monitoring chassis includes the power quality monitoring system described in any one of the above embodiments.

[0023] A locomotive comprises the power quality monitoring system described in any one of the above embodiments.

[0024] The above-mentioned power quality monitoring system, power quality monitoring chassis and train collect pantograph analog signals through sensors, such as voltage analog signals and / or current analog signals of pantographs, transmit the pantograph analog signals to signal conditioning modules, and the signal conditioning modules condition the pantograph analog signals, such as signal gain, signal filtering, etc., to obtain the conditioned pantograph analog signals, and transmit the conditioned pantograph analog signals to the data acquisition module, which receives the conditioned pantograph analog signals and processes the conditioned pantograph analog signals at a preset frequency. The signal is sampled to obtain a pantograph digital signal. The preset frequency is positively correlated with the frequency of the high-frequency component to be studied. When the frequency of the high-frequency component to be studied is high, the sampling frequency of the conditioned pantograph analog signal, that is, the preset frequency, is higher. The pantograph digital signal is transmitted to the main control module. The main control module performs spectrum analysis on the pantograph digital signal based on Fourier transform to obtain the fundamental wave and harmonics of different frequencies, such as pantograph higher harmonics. The maximum frequency in the harmonics is positively correlated with the preset frequency. Therefore, the high-frequency component in the pantograph analog signal can be collected by controlling the preset frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 1 is a schematic structural diagram of a power quality monitoring system according to an embodiment;

[0026] Figure 2 is a structural block diagram of a signal conditioning module in one embodiment;

[0027] Figure 3 FIG. 4 is a diagram showing the internal structure of a main control module in an embodiment.

[0028] Reference numerals: R1, first resistor; R2, second resistor; OPA1, first operational amplifier; C, filter capacitor; R3, third resistor; R4, fourth resistor; OPA2, second operational amplifier. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0030] Currently, most existing standards and research focus on power quality issues within the public grid or common connection points, while research on power quality within the traction grid has been relatively lacking. In electrified railway traction power supply systems, power quality issues caused by mismatched train-grid electrical parameters are becoming increasingly prominent. These issues include harmonic resonance, low-frequency oscillation, large traction grid voltage losses, and low power factor. These problems often result in damage to onboard or ground equipment, shortened service life, and even train shutdowns, posing significant challenges to the safe and stable operation of electrified railways. Traditionally, detecting abnormal train-grid mismatch involves installing RMS voltage detectors or watt-hour meters in some substations or electric locomotives. While some substations and locomotives also have RMS voltage recorders or watt-hour meters installed, their waveform recording functions are often designed for fundamental signals, resulting in low sampling frequencies and an inability to analyze high-frequency components or effectively capture abnormal data.

[0031] Therefore, in order to solve the above problems, it is necessary to study an electrified railway catenary power supply quality inspection device to achieve high-precision collection, processing and analysis of catenary electrical data, and accurately identify power quality problems caused by abnormal vehicle-grid matching, so as to provide data support for the safe and stable operation of electric locomotives.

[0032] Example 1

[0033] In this embodiment, Figure 1As shown, a power supply quality monitoring system for electric locomotives is provided, which includes: a signal conditioning module, a data acquisition module and a main control module electrically connected in sequence, the signal conditioning module is used to connect to a sensor for collecting pantograph analog signals; wherein,

[0034] The signal conditioning module is used to receive the pantograph analog signal output by the sensor, condition the pantograph analog signal to obtain the conditioned pantograph analog signal, and transmit the conditioned pantograph analog signal to the data acquisition module;

[0035] The data acquisition module is used to receive the conditioned pantograph analog signal, sample the conditioned pantograph analog signal at a preset frequency, obtain the pantograph digital signal, and transmit the pantograph digital signal to the main control module;

[0036] The main control module is used to receive the pantograph digital signal, perform spectrum analysis on the pantograph digital signal based on Fourier transform, obtain the pantograph high-order harmonics, and monitor the pantograph high-order harmonics.

[0037] In this embodiment, the sensor may be a voltage sensor and / or a current sensor. The voltage sensor collects the voltage signal at the pantograph as one type of pantograph analog signal, and the current sensor collects the current signal at the pantograph as another type of pantograph analog signal. The voltage sensor and / or current sensor are installed at a test point on the pantograph inside the locomotive to detect the voltage and current at the pantograph. The voltage and current at the pantograph with a larger signal amplitude range are converted into voltage and current with a smaller signal amplitude range as the pantograph analog signal. The pantograph analog signal is then transmitted to the power quality monitoring system via a signal cable. The signal conditioning module of the power quality monitoring system receives the pantograph analog signal output by the sensor and conditions the pantograph analog signal, for example, by using existing signal conditioning methods such as signal gain adjustment, signal amplification, and signal noise reduction to obtain a conditioned pantograph analog signal. The conditioned pantograph analog signal is a standard signal, so that the conditioned pantograph analog signal more accurately reflects changes in the voltage and current at the pantograph. The signal conditioning module transmits the conditioned pantograph analog signal to the data acquisition module, which can be a data acquisition card. The data acquisition module samples the conditioned pantograph analog signal at a preset frequency. The preset frequency is related to the frequency of the harmonic to be studied. For example, to study the 50th harmonic, the preset frequency can be set to 5kHz, increasing the sampling frequency so that the 50th harmonic can be obtained in subsequent signal decomposition. After sampling, the data acquisition module obtains the pantograph digital signal and transmits the pantograph digital signal to the main control module. The main control module receives the pantograph digital signal, performs spectrum analysis on the pantograph digital signal based on Fourier transform, and performs signal decomposition on the pantograph digital signal. Fourier transform is an existing signal decomposition technology. Its basic idea is to decompose a continuous signal into a weighted sum of several sine waves, that is, any periodic signal can be expressed as the sum of single-frequency sine functions or cosine functions. The frequency, amplitude, and phase of these sine waves can characterize the characteristics of the original signal. The Fourier transform can analyze signals in the frequency domain to detect signal components at specific frequencies. Therefore, the Fourier transform can be used to decompose and identify pantograph harmonics for monitoring. Existing power quality monitoring methods can be used to detect pantograph harmonics, such as the fluctuation range or rate of change of the detected value.

[0038] In this embodiment, a pantograph analog signal, such as a voltage analog signal and / or a current analog signal of the pantograph, is collected by a sensor, and the pantograph analog signal is transmitted to a signal conditioning module. The signal conditioning module conditions the pantograph analog signal, such as signal gain, signal filtering, etc., to obtain a conditioned pantograph analog signal, and the conditioned pantograph analog signal is transmitted to a data acquisition module. The data acquisition module receives the conditioned pantograph analog signal, samples the conditioned pantograph analog signal at a preset frequency, and obtains a pantograph digital signal. The preset frequency is positively correlated with the frequency of the high-frequency component to be studied. When the frequency of the high-frequency component to be studied is high, the sampling frequency of the conditioned pantograph analog signal, i.e., the preset frequency, is higher. The pantograph digital signal is transmitted to a main control module. The main control module performs spectrum analysis on the pantograph digital signal based on Fourier transform to obtain a fundamental wave and harmonics of different frequencies, such as higher harmonics of the pantograph. The maximum frequency in the harmonics is positively correlated with the preset frequency. Therefore, the high-frequency component in the pantograph analog signal can be collected by controlling the preset frequency. The main control module monitors the pantograph's high-order harmonics.

[0039] In one embodiment, the signal conditioning module includes a preamplifier circuit, a filter circuit, a zero adjustment circuit, and a postamplifier circuit electrically connected in sequence; wherein,

[0040] The preamplifier circuit is used to connect to a sensor for collecting pantograph analog signals, the preamplifier circuit is used to receive the pantograph analog signal output by the sensor, perform gain adjustment on the pantograph analog signal to obtain the adjusted pantograph analog signal, and output the adjusted pantograph analog signal to the filter circuit;

[0041] The filtering circuit is used to receive the adjusted pantograph analog signal, filter the adjusted pantograph analog signal to obtain the filtered pantograph analog signal, and output the filtered pantograph analog signal to the zeroing circuit;

[0042] The zeroing circuit is used to receive the filtered pantograph analog signal, eliminate the offset signal in the filtered pantograph analog signal, obtain the zeroed pantograph analog signal, and output the zeroed pantograph analog signal to the post-amplification circuit;

[0043] The post-amplification circuit is used to adjust the pantograph analog signal after zeroing, perform gain adjustment on the pantograph analog signal after zeroing to obtain the gained pantograph analog signal, and output the gained pantograph analog signal to the data acquisition module.

[0044] In this embodiment, before filtering and zeroing, the pantograph analog signal is first received through a preamplifier circuit. Since the amplitude of the pantograph analog signal and the amplitude of the noise signal present therein are both relatively small, in order to preserve more effective information in the pantograph analog signal, the preamplifier circuit amplifies the signal and then filters it through a filter circuit. The amplification of the preamplifier circuit does not lead to saturated output, and the original signal is preserved to the greatest extent. The pantograph analog signal is then filtered through a filter circuit to reduce the noise signal in the pantograph analog signal. The offset signal present in the pantograph analog signal is then eliminated through a zeroing circuit to obtain a pantograph analog signal that more accurately reflects the power quality of the pantograph. In order to make the monitoring more sensitive, the pantograph analog signal output by the zeroing circuit is amplified through a postamplifier circuit to increase the signal fluctuation amplitude of the pantograph analog signal, making it easier to monitor whether there are abnormal changes in the pantograph analog signal.

[0045] In practical applications, operational amplifiers (OPA) need to amplify small input signals by tens or hundreds of times. Even the differential amplifier in an OPA struggles to completely cancel the differential input voltage, resulting in an offset voltage or signal. To improve the accuracy and stability of OPA circuits, a nulling circuit can be used to eliminate this offset signal. A nulling circuit generates a current equal to and in the opposite direction of the OPA's output voltage, thereby canceling the OPA's output offset voltage.

[0046] See also Figure 2In one embodiment, the preamplifier circuit includes a first resistor R1, a second resistor R2, and a first operational amplifier OPA1. The non-inverting input of the first operational amplifier OPA1 is connected to a sensor that collects pantograph analog signals, and the inverting input of the first operational amplifier OPA1 is grounded via the second resistor R2. The first end of the first resistor R1 is connected to the non-inverting input of the first operational amplifier OPA1, and the second end of the first resistor R1 is grounded. The output of the first operational amplifier OPA1 is connected to the filter circuit. In this embodiment, the first operational amplifier OPA1, with the first resistor R1 between the non-inverting and inverting inputs of the first operational amplifier OPA1, limits the current flowing into and out of the first operational amplifier OPA1 for the pantograph analog signal. A larger resistance value for the first resistor R1 increases the equivalent input impedance, reducing the input current, thereby minimizing the circuit's bandwidth impact and Gaussian noise. Excessively large or small resistance values ​​for the first resistor R1 can affect the performance of the first operational amplifier OPA1. If the resistance of first resistor R1 is too small, excessive current will flow in, increasing input current bias and noise interference. Conversely, if the resistance of first resistor R1 is too large, the impedance of the input circuit will be too high, affecting signal transmission and regulation. Furthermore, first resistor R1 is a variable resistor, and its resistance can be flexibly adjusted to meet the current inflow and outflow requirements of first operational amplifier OPA1. The inverting input terminal of first operational amplifier OPA1 is grounded through second resistor R2 to maintain input resistance balance and reduce drift of first operational amplifier OPA1.

[0047] In one embodiment, the filter circuit includes a filter capacitor C. A first end of the filter capacitor C is connected to the output of the preamplifier circuit and one input of the zeroing circuit, respectively. A second end of the filter capacitor C is connected to the input of the preamplifier circuit and another input of the zeroing circuit, respectively. In this embodiment, the filter capacitor C filters out AC components mixed in the pantograph analog signal, outputting a purer DC power. The first end of the filter capacitor C is connected to the output of the first operational amplifier OPA1 of the preamplifier circuit, and the second end of the filter capacitor C is connected to the inverting input of the first operational amplifier OPA1 of the preamplifier circuit.

[0048] In one embodiment, the zeroing circuit includes a third resistor R3 and a voltage-stabilizing reference source; wherein the first end of the third resistor R3 is connected to the first output end of the filter circuit, the second end of the third resistor R3 is connected to the first input end of the voltage-stabilizing reference source, the second input end of the voltage-stabilizing reference source is connected to the second output end of the filter circuit, and the output end of the voltage-stabilizing reference source is connected to the post-amplifier circuit. In this embodiment, the voltage-stabilizing reference source can be a three-terminal adjustable shunt shunt regulator, such as the integrated circuit TL431, which is used to adjust the reference level of the pantograph analog signal to ensure the zero point of the pantograph analog signal is accurate. The third resistor R3 divides the voltage of the voltage-stabilizing reference source to protect the voltage-stabilizing reference source. In this embodiment, the first end of the filter capacitor C is connected to the first end of the third resistor R3 as the first output end of the filter circuit, and the second end of the filter capacitor C is connected to the second input end of the voltage-stabilizing reference source as the second output end of the filter circuit.

[0049] In one embodiment, the post-amplification circuit includes a fourth resistor R4 and a second operational amplifier OPA2; wherein the non-inverting input of the second operational amplifier OPA2 is connected to the output of the zeroing circuit, the output of the second operational amplifier OPA2 is connected to the input of the data acquisition module, the inverting input of the second operational amplifier OPA2 is connected to the input of the data acquisition module, the first end of the fourth resistor R4 is connected to the non-inverting input of the second operational amplifier OPA2, and the second end of the fourth resistor R4 is grounded. In this embodiment, the non-inverting input of the second operational amplifier OPA2 is connected to the output of the voltage-stabilizing reference source of the zeroing circuit. The second operational amplifier OPA2 amplifies the pantograph analog signal output by the voltage-stabilizing reference source, allowing the main control module to more sensitively monitor whether the pantograph analog signal is abnormal. Because operational amplifiers are voltage-sensitive, the second operational amplifier OPA2 may experience zero-point drift. The fourth resistor R4 is connected to the non-inverting input of the second operational amplifier OPA2 and to ground to reduce noise and prevent zero-point drift.

[0050] In one embodiment, the main control module includes a signal analysis chip and a signal monitoring chip that are electrically connected, and the signal analysis chip is electrically connected to the data acquisition module;

[0051] The signal analysis chip is used to receive the pantograph digital signal, perform spectrum analysis on the pantograph digital signal based on Fourier transform, obtain pantograph higher harmonics, and output the pantograph higher harmonics to the signal monitoring chip;

[0052] The signal monitoring chip is used to receive and monitor the pantograph's higher harmonics. In this embodiment, to improve the signal analysis efficiency of the main control module, two electrically connected chips are provided to process the pantograph's digital signals: a signal analysis chip and a signal monitoring chip. The signal analysis chip primarily uses Fourier transform to perform spectral analysis and signal decomposition on the pantograph's digital signals, obtaining the pantograph's higher harmonics of interest and outputting these harmonics to the signal monitoring chip. The signal monitoring chip is used to monitor the pantograph's higher harmonics, for example, by monitoring the effective value of the pantograph's higher harmonics and comparing them with a preset warning threshold. When the effective value of the pantograph's higher harmonics exceeds the preset warning threshold, a warning signal is output. The decomposition of the pantograph's digital signals by the signal analysis chip and the monitoring of the pantograph's higher harmonics by the signal monitoring chip can occur simultaneously, enabling the main control module to more timely monitor power quality.

[0053] See also Figure 3 In one embodiment, the signal analysis chip includes a programmable logic chip; and / or the signal monitoring chip includes a central processing unit. In this embodiment, the programmable logic chip has the characteristics of flexibility and reusability. In order to flexibly adapt to the research needs of different pantograph high-order harmonics, a programmable logic chip is used to decompose the pantograph digital signal so as to flexibly obtain pantograph high-order harmonics of different orders. The programmable logic chip is, for example, an FPGA (Field-Programmable Gate Array). In addition to monitoring the pantograph high-order harmonics, the signal monitoring chip may also need to interact with other electronic components and require higher data processing performance. Therefore, a central processing unit such as a CPU is used for signal monitoring. The signal monitoring chip can be, for example, a digital signal processor (DSP).

[0054] See also Figure 1 In one embodiment, the system further includes a human-computer interaction module electrically connected to the main control module. In this embodiment, the human-computer interaction module may be a display screen with a touch function. The human-computer interaction module obtains pantograph digital signals or pantograph higher harmonics from the main control module, decodes and processes the pantograph digital signals or pantograph higher harmonics, and displays real-time monitored power quality data.

[0055] See also Figure 1 In one embodiment, the system further includes a data storage module electrically connected to the main control module. In this embodiment, the data storage module may be a hard disk, and the data storage module stores relevant data calculation results, waveform files, and log files provided by the main control module.

[0056] In one embodiment, the system further comprises: an alarm module, the alarm module being electrically connected to the main control module. Figure 1 In this embodiment, the alarm module can be an audible and visual alarm, which obtains operating parameters such as the equipment power supply status, external temperature and humidity parameters, and communication status from the main control module. When the operating parameters are monitored to exceed or fall below the set threshold range, it is judged as an abnormal situation and an alarm needs to be triggered.

[0057] See also Figure 1 In one embodiment, the system further includes a communication module electrically connected to the main control module. In this embodiment, the communication module may be a 4G antenna and a DTU communication module. The main control module monitors the pantograph's higher harmonics and, when abnormal pantograph higher harmonics are detected, sends a text message to notify a technician.

[0058] Furthermore, the resistance of the first resistor is 500Ω; the resistance of the second resistor is 22kΩ; the resistance of the third resistor is 10kΩ; the resistance of the fourth resistor is 12kΩ; and the capacitance of the filter capacitor is 0.1μF.

[0059] The technical solution provided by the utility model is a power supply quality inspection device for an electrified railway contact network, which is characterized by comprising: voltage and current sensors, a signal conditioning module, a data acquisition module, a data storage module, an alarm module, a power supply module, a human-computer interaction module, a communication module and a main control module.

[0060] The voltage sensor utilizes electromagnetic induction between the iron core and the primary and secondary coils to achieve isolated measurement and electrical protection of the primary voltage. The current sensor operates by passing a high current through the primary coil, generating a magnetic field that induces a much smaller current in the secondary coil, enabling high current measurement and protection. The voltage and current sensors are installed at the pantograph inside the locomotive, converting the high voltage and current signals at the pantograph into small signals that are then transmitted to the transmission device via a signal cable.

[0061] The signal conditioning module receives the analog voltage and current signals output by the voltage and current sensors and performs signal conditioning and filtering. The signal conditioning module uses an amplifier circuit, a zeroing circuit, and a filter circuit to adjust the gain, amplify, and reduce noise on the analog signals, converting the small sensor output signals into standard signals. The signal conditioning module consists of four components: a preamplifier circuit, a filter circuit, a zeroing circuit, and a postamplifier circuit. The input signal Ui enters the LM358 operational amplifier through resistors R1 (500Ω) and R2 (22kΩ). The operational amplifier performs preliminary amplification on the input signal, and the amplified signal is transmitted to the filter circuit through resistor R3 (10kΩ). The filter circuit consists of a capacitor C (0.1μF) and a resistor R3 (10kΩ). This circuit removes high-frequency noise from the signal, ensuring signal purity. The filtered signal is then passed to the zeroing circuit, which uses the TL431 integrated circuit. This circuit adjusts the signal's reference level to ensure an accurate zero point. The zeroed signal is then passed to the postamplifier circuit. The post-amplification circuit uses another LM358 operational amplifier. Resistors R4 (12kΩ) and R5 (12kΩ) form a feedback circuit, further amplifying the signal and ultimately outputting a stable signal, Uo. The current signal processing process is similar to the voltage signal. The analog signal, processed by the signal conditioning module, is input into the A / D converter for conversion to a digital signal. The A / D converter samples and quantizes the analog signal, converting it into digital data for subsequent digital signal processing.

[0062] The data acquisition module includes a data acquisition card that converts the standard voltage or current signal output by the signal conditioning module into a digital signal. To meet the measurement requirements of up to the 50th harmonic, the sampling rate is generally set to 5kHz. The main control module processes the digital signal through spectrum analysis and pattern recognition, as well as effective value calculation.

[0063] The data storage module includes a hard disk that can store relevant data calculation results, waveform files, and log files provided by the main control module. The data storage module stores the data processed by the main control module in the form of files or databases on the device's hard disk to ensure data persistence.

[0064] The alarm module includes an audible and visual alarm, which can remind the administrator to take appropriate actions when the device fails or the communication status is abnormal. The alarm module can monitor the operating parameters of the device regularly or in real time. These parameters include the device power supply status, external temperature and humidity parameters, and communication status, and set a series of thresholds. If the monitored status exceeds or falls below the set threshold range, it is judged as an abnormal situation and an alarm needs to be triggered. The alarm module receives the device operating parameters sent by the main control module and sets its own thresholds for judgment. Once an abnormal situation is detected, the alarm module will trigger an alarm, send an alarm signal, and notify relevant personnel or systems.

[0065] The power supply module includes a switching power supply, which can provide power to all other modules.

[0066] The human-computer interaction module includes a touchscreen display that displays data in real time and supports touch operations. The display module decodes the digital signals received from the main control module, converting the data into a format that meets the display device's requirements for accurate display on the screen. The display screen accepts manually entered parameter configuration information, including sensor ratio parameters and channel calibration parameters. The main control module receives this data and uses it to calculate the real-time values ​​of the pantograph voltage and current.

[0067] The communication module, which includes a 4G antenna and a DTU communication module, sends a text message to technicians when it detects voltage exceeding the standard or other abnormalities. The main control module performs real-time spectrum analysis and pattern recognition to determine whether there is an abnormality in the vehicle-grid matching. If an abnormality is present, it transmits the relevant abnormality parameters to the communication module, which then sends the abnormality parameters to ground technicians via text message. The communication module forwards the vehicle-grid matching abnormality parameters sent by the main control module, ensuring that the abnormality parameters are promptly transmitted to ground technicians.

[0068] The main control module uses the TMS320C6416T as a microprocessor, which has the advantages of low power consumption, high performance, high peripheral integration, and high precision, and can well meet the functions of data sampling and data upload. The digital signal after AD conversion is transmitted to the FPGA for processing. The FPGA performs preliminary processing such as fast Fourier transform, and then passes it to the CPU (TMS320C6416T) for further processing via the EMIFA interface. Ultimately, the entire signal processing process is completed by auxiliary modules such as memory, clock circuit, and reset circuit. Fast Fourier transform can obtain the high-frequency component of the signal. The CPU can then analyze the low-frequency and high-frequency components obtained by FPGA processing, and ultimately capture power supply anomaly data.

[0069] Traditional monitoring devices generally have a low sampling rate, are unable to measure high-order harmonics, and data cannot be effectively shared. The present invention can achieve effective measurement of electrical quantities in the traction network and reliable evaluation of power quality such as vehicle-grid matching, and can achieve efficient management, sharing and storage of monitoring data, overcoming the limitations of traditional devices. The present application provides a contact network power supply quality inspection device with multiple functions such as data acquisition, preprocessing, storage, real-time analysis and communication, including: voltage and current sensors, signal conditioning modules, data acquisition modules, data storage modules, alarm modules, power supply modules, human-computer interaction modules, communication modules and main control modules, to achieve effective measurement of electrical quantities in the contact network and reliable evaluation of power quality. The utility model can provide a more effective means for the problem of monitoring the quality of contact network power supply. The data acquisition module converts the voltage and current analog signals of the signal conditioning module into digital signals, and transmits them to the CPU main control module for analysis and calculation.

[0070] A second aspect of the present application provides a power quality monitoring chassis, which includes the power quality monitoring system described in any of the above embodiments.

[0071] A third aspect of the present application provides a locomotive, which includes the power quality monitoring system described in any one of the above embodiments.

[0072] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An electric locomotive power supply quality monitoring system, characterized in that: include: A signal conditioning module, a data acquisition module and a main control module are electrically connected in sequence, wherein the signal conditioning module is used to connect to a sensor for collecting pantograph analog signals; wherein, The signal conditioning module is used to receive the pantograph analog signal output by the sensor, condition the pantograph analog signal to obtain the conditioned pantograph analog signal, and transmit the conditioned pantograph analog signal to the data acquisition module; The data acquisition module is used to receive the conditioned pantograph analog signal, sample the conditioned pantograph analog signal at a preset frequency to obtain a pantograph digital signal, and transmit the pantograph digital signal to the main control module; The main control module is used to receive the pantograph digital signal, perform spectrum analysis on the pantograph digital signal based on fast Fourier transform, and obtain pantograph high-order harmonics.

2. The monitoring system according to claim 1, characterized in that The main control module includes a signal analysis chip and a signal monitoring chip that are electrically connected, and the signal analysis chip is electrically connected to the data acquisition module; The signal analysis chip is used to receive the pantograph digital signal, perform spectrum analysis on the pantograph digital signal based on fast Fourier transform to obtain pantograph higher harmonics, and output the pantograph higher harmonics to the signal monitoring chip; The signal monitoring chip is used to receive the pantograph high-order harmonics and monitor the pantograph high-order harmonics.

3. The monitoring system according to claim 2, characterized in that The signal analysis chip includes a programmable logic chip; and / or the signal monitoring chip includes a central processing unit.

4. The monitoring system according to claim 1, wherein: The signal conditioning module includes a preamplifier circuit, a filter circuit, a zero adjustment circuit and a post-amplifier circuit that are electrically connected in sequence, the input end of the preamplifier circuit is used to connect to a sensor that collects pantograph analog signals, the output end of the preamplifier circuit is connected to the input end of the filter circuit, the output end of the filter circuit is connected to the input end of the zero adjustment circuit, the output end of the zero adjustment circuit is connected to the input end of the post-amplifier circuit, and the output end of the post-amplifier circuit is connected to the input end of the data acquisition module; wherein, The preamplifier circuit is used to connect to a sensor for collecting pantograph analog signals, the preamplifier circuit is used to receive the pantograph analog signal output by the sensor, perform gain adjustment on the pantograph analog signal to obtain the adjusted pantograph analog signal, and output the adjusted pantograph analog signal to the filter circuit; The filtering circuit is used to receive the adjusted pantograph analog signal, filter the adjusted pantograph analog signal to obtain the filtered pantograph analog signal, and output the filtered pantograph analog signal to the zeroing circuit; The zeroing circuit is used to receive the filtered pantograph analog signal, eliminate the offset signal in the filtered pantograph analog signal, obtain the zeroed pantograph analog signal, and output the zeroed pantograph analog signal to the post-amplification circuit; The post-amplification circuit is used to adjust the pantograph analog signal after zeroing, perform gain adjustment on the pantograph analog signal after zeroing to obtain the gained pantograph analog signal, and output the gained pantograph analog signal to the data acquisition module.

5. The monitoring system according to claim 4, characterized in that: The preamplifier circuit includes a first resistor, a second resistor and a first operational amplifier; wherein, the non-inverting input terminal of the first operational amplifier is connected to the sensor for collecting the pantograph analog signal, the reverse input terminal of the first operational amplifier is used to be grounded through the second resistor, the first end of the first resistor is connected to the non-inverting input terminal of the first operational amplifier, the second end of the first resistor is used to be grounded, and the output terminal of the first operational amplifier is connected to the filter circuit.

6. The monitoring system according to claim 4, characterized in that The filtering circuit includes a filtering capacitor, a first end of the filtering capacitor is respectively connected to the output end of the preamplifier circuit and an input end of the zero adjustment circuit, and a second end of the filtering capacitor is respectively connected to the input end of the preamplifier circuit and another input end of the zero adjustment circuit.

7. The monitoring system according to claim 4, characterized in that The zero adjustment circuit includes a third resistor and a voltage-stabilizing reference source component; wherein, the first end of the third resistor is connected to the first output end of the filter circuit, the second end of the third resistor is connected to the first input end of the voltage-stabilizing reference source component, the second input end of the voltage-stabilizing reference source component is connected to the second output end of the filter circuit, and the output end of the voltage-stabilizing reference source component is connected to the post-amplification circuit.

8. The monitoring system according to claim 4, characterized in that The post-amplifier circuit includes a fourth resistor and a second operational amplifier; wherein, the non-inverting input terminal of the second operational amplifier is connected to the output terminal of the zero adjustment circuit, the output terminal of the second operational amplifier is connected to the input terminal of the data acquisition module, the inverting input terminal of the second operational amplifier is connected to the input terminal of the data acquisition module, the first end of the fourth resistor is connected to the non-inverting input terminal of the second operational amplifier, and the second end of the fourth resistor is grounded.

9. A locomotive, characterized in that: A monitoring system comprising any one of claims 1 to 8.

Images