Resistance voltage divider calibration system, method and equipment based on self-calibration frequency counter and medium

Abstract

The invention discloses a resistance voltage divider calibration system, method and device based on a self-calibration frequency counter and a medium, and relates to the technical field of metering calibration. The system comprises a stabilized voltage source, a resistance voltage divider, a high-speed electronic switch, a voltage-frequency converter, a self-calibration frequency counter, a satellite signal receiver, an electric energy metering chip and a CPU. According to the invention, the output signal of the voltage divider is connected to the voltage-frequency conversion channel through a specific time sequence, the pulse sequence in proportion to the voltage is generated by using the inherent linear characteristic of the output signal, then the pulse sequence is subjected to high-precision counting and comparative analysis through the self-calibration frequency counter, and finally the dynamic correction of the voltage division ratio parameter is realized. According to the technical path, an external reference source and high-precision voltage measurement equipment do not need to be introduced, in-situ calibration of the characteristic parameters of the voltage divider can be completed in a remote mode, and the long-term stability of the high-voltage electric energy metering device in a complex electromagnetic environment is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of metrology and calibration technology, and in particular to a resistance voltage divider calibration system, method, device and medium based on a self-calibrating frequency counter. Background Technology

[0002] As the core sampling unit of the energy metering module, the resistive voltage divider continuously collects the high-voltage side voltage in real time and converts it into a low-voltage signal according to a preset voltage division ratio, which is then input to a dedicated metering chip to calculate energy parameters. However, during long-term operation in a high-voltage environment, the actual voltage division ratio of the resistive voltage divider may experience unpredictable drift due to complex operating conditions such as temperature fluctuations and insulation aging. If the initial calibration value is continued to be used for voltage conversion, it will directly lead to distortion of the sampling signal amplitude, causing systematic deviations in key parameters such as active power and reactive energy output by the metering chip. Traditional calibration schemes are always limited by the bottlenecks of reference signal error transmission and insufficient frequency band coverage, requiring an external high-precision voltage source as a reference standard and a professional high-precision voltmeter to measure the voltage value to ensure the accuracy of the measurement results. However, smart meters and other terminal devices usually do not have such standard sources and high-precision voltage measurement equipment inside. Summary of the Invention

[0003] The purpose of this invention is to provide a resistor voltage divider calibration system, method, device and medium based on a self-calibrating frequency counter, which aims to solve or improve at least one of the above-mentioned technical problems.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] A resistor divider calibration system based on a self-calibrating frequency counter includes:

[0006] Regulated voltage source, resistive voltage divider, high-speed electronic switch, voltage-to-frequency converter, self-calibrating frequency counter, satellite signal receiver, power metering chip and CPU;

[0007] The regulated voltage source is connected to the input terminals of the resistor divider and the high-speed electronic switch, respectively. The output terminal of the resistor divider is also connected to the input terminals of the high-speed electronic switch and the power metering chip, respectively. The output terminal of the high-speed electronic switch is connected to the input terminal of the voltage-to-frequency converter. The output terminals of the voltage-to-frequency converter and the satellite signal receiver are both connected to the input terminal of the self-calibrating frequency counter. The output terminal of the self-calibrating frequency counter is connected to the input terminal of the CPU. The output terminal of the CPU is connected to the power metering chip.

[0008] Optionally, the resistor divider includes a voltage sampling module and a current sampling module.

[0009] Optionally, the voltage sampling module consists of a high-voltage arm resistor R1 and a low-voltage arm resistor R2 connected in series; the current sampling module consists of a shunt and a PGA.

[0010] This invention also provides a resistor divider calibration method based on a self-calibrating frequency counter, applied to the calibration system described above, comprising:

[0011] A steady-state voltage is input to a resistor divider and a high-speed electronic switch using a regulated voltage source, and a sampling voltage is obtained using the resistor divider. The steady-state voltage and the sampling voltage are then switched at high frequency using the high-speed electronic switch to form two single-channel signals with alternating timing.

[0012] A voltage-to-frequency linear conversion is performed on a single signal using a voltage-to-frequency converter to obtain a frequency signal;

[0013] The satellite second pulse signal is received using a satellite signal receiver, and the frequency signal is measured using the satellite second pulse signal as a reference in a self-calibrating frequency counter to obtain two measurement signals;

[0014] The two measurement signals are input into the CPU to calculate the frequency ratio, thereby obtaining the voltage division ratio of the resistor voltage divider. The voltage division ratio is then input into the power metering chip for deviation correction, thus completing the voltage calibration.

[0015] Optionally, the formula for calculating the partial pressure ratio is:

[0016]

[0017] Among them, R1 实际 R2 is the actual value of the high-voltage arm resistance. 实际 λ is the actual value of the low-voltage arm resistance, Ui is the steady-state voltage, Uo is the sampling voltage, fi is the frequency of the steady-state voltage, fo is the frequency of the sampling voltage, and λ is the voltage-to-frequency conversion coefficient.

[0018] Optionally, the voltage division ratio input to the power metering chip is corrected for deviation, specifically including:

[0019] In the power metering chip, the initial voltage signal is reconstructed based on the sampled voltage and the voltage division ratio.

[0020] The present invention also provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to cause the electronic device to perform the resistor divider calibration method based on the self-calibrating frequency counter described above.

[0021] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the resistor divider calibration method based on a self-calibrating frequency counter as described above.

[0022] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0023] This invention discloses a resistor voltage divider calibration system, method, device, and medium based on a self-calibrating frequency counter. The system includes a regulated voltage source, a resistor voltage divider, a high-speed electronic switch, a voltage-to-frequency converter, a self-calibrating frequency counter, a satellite signal receiver, an energy metering chip, and a CPU. This invention utilizes the device's built-in voltage-to-frequency conversion module and a frequency counter with self-calibration function to construct a closed-loop calibration system: the voltage divider output signal is input to the voltage-to-frequency conversion channel through a specific timing sequence, utilizing its inherent linear characteristics to generate a pulse sequence proportional to the voltage. Then, the self-calibrating frequency counter performs high-precision counting and comparison analysis of the pulse sequence, ultimately achieving dynamic correction of the voltage divider ratio parameter. This technical approach eliminates the need for an external reference source and high-precision voltage measurement equipment, enabling in-situ calibration of the voltage divider's characteristic parameters remotely, significantly improving the long-term stability of high-voltage energy metering devices in complex electromagnetic environments. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the resistor divider calibration system in this embodiment;

[0026] Figure 2 This is a schematic diagram of the direct counting method in this embodiment;

[0027] Figure 3 This is a schematic diagram of the remote calibration circuit for the resistor divider in this embodiment;

[0028] Figure 4 This is a flowchart illustrating the resistor divider calibration method in this embodiment. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The purpose of this invention is to provide a resistor voltage divider calibration system, method, device and medium based on a self-calibrating frequency counter, which aims to solve or improve at least one of the above-mentioned technical problems.

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, the present invention provides a resistor voltage divider calibration system based on a self-calibrating frequency counter, comprising: a regulated voltage source, a resistor voltage divider, a high-speed electronic switch, a voltage-to-frequency converter, a self-calibrating frequency counter, a satellite signal receiver, an energy metering chip, and a CPU.

[0033] The regulated voltage source is connected to the input terminals of the resistor divider and the high-speed electronic switch, respectively. The output terminal of the resistor divider is also connected to the input terminals of the high-speed electronic switch and the power metering chip, respectively. The output terminal of the high-speed electronic switch is connected to the input terminal of the voltage-to-frequency converter. The output terminals of the voltage-to-frequency converter and the satellite signal receiver are both connected to the input terminal of the self-calibrating frequency counter. The output terminal of the self-calibrating frequency counter is connected to the input terminal of the CPU. The output terminal of the CPU is connected to the power metering chip.

[0034] Based on the aforementioned calibration system, a remote calibration method is provided. Its core principle lies in using a high-speed electronic switch to frequently switch the input voltage and the sampled output voltage of a resistor divider, forming a time-interleaved single-channel signal. This signal is then transmitted to a voltage-to-frequency converter, which utilizes its linear voltage-to-frequency conversion characteristic to convert the two voltage signals into their corresponding frequency signals within a short time. This process achieves the transformation from voltage to frequency, providing a signal carrier with stronger anti-interference capabilities for subsequent measurements.

[0035] Furthermore, the frequency counter with self-calibration function accurately measures the converted frequency signal using the satellite second pulse signal as a reference. The voltage division ratio of the resistor divider is then calculated by comparing the frequencies of the two signals. Because the measurement process is entirely based on frequency signal comparison and uses a high-precision satellite second pulse signal as a reference, it avoids dependence on high-precision physical voltage references and high-precision voltage measurement equipment. Combined with the frequency counter's built-in self-calibration algorithm, environmental interference and instrument errors can be corrected in real time, ultimately achieving remote, high-precision resistor divider calibration without the need for a standard voltage source and voltmeter.

[0036] As a more specific implementation method, the following application process is provided.

[0037] To improve the remote calibration and metering system and enhance the accuracy of voltage sampling by the resistive voltage divider during power metering, thereby enabling the resistive voltage divider to operate normally and measure more accurate voltage values, this invention combines multiple modules to realize a resistive voltage divider calibration system based on a self-calibrating frequency counter. The entire system hardware consists of a regulated voltage source, a resistive voltage divider, a high-speed electronic switch, a voltage-to-frequency converter, a self-calibrating frequency counter, a satellite signal receiver, and a CPU.

[0038] A regulated voltage source inputs a large voltage signal at its voltage terminal. A resistive voltage divider outputs a small sampled voltage signal at its sampling terminal through voltage division. A high-frequency electronic switch rapidly switches the input and output voltages of the voltage divider to form a single-channel signal. A voltage-to-frequency conversion module then linearly converts the voltage amplitude information in this signal into a digital frequency pulse sequence. This process achieves precise voltage-to-frequency mapping through the charging and discharging control of semiconductor devices, ensuring a strict proportional relationship between the output frequency and the input voltage. This converts a susceptible analog quantity into a more robust digital frequency quantity. The converted frequency signal is measured by a frequency counter with self-calibration capabilities and then input to the CPU for comparison and calculation of the ratio between the two frequency signals. This ratio allows for the recalibration of the resistive voltage divider, completing the calibration process. This method is entirely based on digital comparison of frequency signals, completely eliminating the reliance on high-precision physical voltage references. With the built-in intelligent calibration algorithm of the counter, the optimal measurement method for the frequency signal can be selected in real time. Ultimately, remote automated calibration of the resistor divider parameters can be achieved without manual intervention or external reference sources, significantly improving the reliability and maintenance efficiency of the metering system.

[0039] Working principle:

[0040] (1) Satellite signal receiver

[0041] The core of satellite signal receivers receiving second pulse signals lies in generating second pulse signals that are strictly synchronized with UTC time using atomic clocks onboard the satellite. After the receiver antenna captures this signal, it first decodes it to obtain the precise time information contained in the navigation message. This process involves analyzing the moment the satellite transmits the second pulse; by extracting key data such as the timestamp, the receiver can determine the absolute reference of the satellite time. Subsequently, the receiver compares its local clock with the satellite time, measures the time difference of signal propagation from the satellite to the receiver, and calculates its own geographical location using triangulation. Through the convergence of signals from at least three satellites, the receiver can achieve high-precision positioning and simultaneously complete initial synchronization with the satellite clock.

[0042] During signal processing, the receiver needs to apply a correction factor to compensate for the propagation delay caused by the atmosphere. When electromagnetic waves pass through the troposphere, atmospheric refraction causes a significant delay, the impact of which increases as the satellite's elevation angle decreases. The receiver uses a built-in tropospheric delay correction model, combined with real-time meteorological parameters, to accurately correct for both dry and wet delays. Furthermore, the receiver employs techniques such as phase-locked loops to further eliminate minute deviations between the local clock and the satellite clock. Ultimately, the rising edge error of the receiver's output second pulse signal is controlled to an extremely low level, typically less than 1 microsecond. This high-precision time standard can be widely used in fields such as communication base station synchronization and power system time-frequency unification, ensuring time consistency in distributed systems.

[0043] (2) Resistor voltage divider

[0044] A resistor divider is a voltage measurement device based on the principle of series resistor voltage division. Essentially, it converts the input voltage (Ui) into a measurable output voltage (Uo) according to a preset ratio by connecting the high-voltage arm resistor (R1) and the low-voltage arm resistor (R2) in series. The output voltage strictly follows the formula shown below. By precisely adjusting the resistance ratio of R1 and R2, a linear conversion from high voltage to low voltage can be achieved. This device is wound with resistor materials with extremely low temperature coefficients, ensuring output voltage stability better than ±0.01% / ℃ over a wide temperature range of -55℃ to 200℃. Simultaneously, its optimized response characteristics through a compressive resistor divider structure enable nanosecond-level rise times, capturing rapid transient voltage changes. Its unique shielding design effectively suppresses stray capacitance to ground and external electromagnetic interference, resulting in a measurement error as low as ±0.1%. Modern resistor dividers integrate high-precision operational amplifiers to construct differential amplifier circuits, further reducing noise interference through optimized common-mode rejection ratio and low-pass filter networks.

[0045]

[0046] (3) High-speed electronic switch

[0047] A high-speed electronic switch is an electronic device capable of rapidly switching the on / off state of a circuit. Its core lies in utilizing the physical properties of semiconductor materials such as silicon and silicon carbide. The conductivity of semiconductor materials is described by conductivity σ, which is related to carrier concentration n, mobility μ, and charge e as follows:

[0048] σ=n*e*μ

[0049] By precisely controlling the electric field or current, the distribution of charge carriers inside the semiconductor can be rapidly changed, thereby completing the switching from a high-resistivity state to a low-resistivity state or vice versa in a very short time. Through this process, high-speed switching output of two voltage signals can be achieved.

[0050] High-speed electronic switches typically have two voltage input ports, Vin1 and Vin2, one voltage output port, Vout, and one control port, C. Their operation can be divided into two stages: triggering and response.

[0051] Triggering Phase: An external control signal pulse voltage Vcontrol is applied to control port C. This signal is decoded into a switching command by the internal logic circuit or drive circuit of the switch. If the control signal is high (Vcontrol = VOH), the switch selects the input voltage signal Vin1.

[0052] The signal is transmitted to the output port Vout; if the control signal is low (Vcontrol = VOL), then the input voltage signal Vin2 is selected. This process can be represented by a switching function:

[0053]

[0054] Wherein, VOH and VOL represent the high-level threshold and low-level threshold of the control signal, respectively.

[0055] Response Phase: Based on the control signal, the internal semiconductor structure of the switch rapidly adjusts its conduction state. When switching to Vin1 is required, the switch channel corresponding to Vin1 quickly turns on (resistance Ron1≈0), while the channel corresponding to Vin2 remains off (resistance Roff2→∞), thus achieving interference-free switching of the voltage signal. Its switching speed can be quantified by the rise time tr and fall time tf, and satisfies tr+tf<<T (T is the signal period). High-speed electronic switches are widely used in applications requiring rapid switching between two voltage signals due to their extremely low switching losses and high-frequency operation capabilities.

[0056] (4) Voltage-to-frequency conversion technology

[0057] A voltage-to-frequency converter (V / F converter) is an electronic device that converts a continuous analog voltage signal into a digital frequency pulse signal proportional to its amplitude. Its core principle is based on the charging and discharging characteristics of semiconductor materials and the linear mapping mechanism of a voltage-controlled oscillator. The conductivity σ of the semiconductor material is determined by the carrier concentration n, mobility μ, and charge e. When the input voltage Vin charges the capacitor C through the resistor R, the charging current I decreases as the voltage increases, resulting in a slower voltage rise slope. When the capacitor voltage reaches the comparator threshold Vref, it triggers the monostable circuit to flip and discharge rapidly, completing one charge-discharge cycle. Its time constant T directly determines the output frequency fout, thus achieving a linear voltage-to-frequency conversion and a voltage-to-frequency conversion ratio.

[0058]

[0059] The voltage-to-frequency converter (VDC) consists of an analog voltage input port (Vin), a frequency pulse output port (fout), and an optional calibration port. Internally, it comprises an integrator, comparator, monostable multivibrator (MSF), and feedback network forming a closed-loop control system. During operation, the input voltage is converted into a periodic trigger signal through a charging and discharging circuit. The pulses output from the MSF circuit are fed back through the feedback network to adjust the integrator gain, compensating for temperature drift or component parameter deviations, ensuring that the output frequency strictly tracks changes in the input voltage. With its high-precision linear conversion, strong electromagnetic interference resistance, and long-distance transmission capabilities, the VDC is widely used in analog-to-digital converters (ADCs), telemetry systems, and motor control. In ADCs, it converts sensor voltages into digital pulses for microcontroller processing; in telemetry systems, the frequency signal is transmitted via fiber optic or wireless links, avoiding analog signal attenuation; in motor control, it converts the speed setting voltage into a PWM signal to drive the frequency converter for precise speed regulation. Its semiconductor monolithic integration further meets the requirements of portable devices and industrial systems for low power consumption and high reliability.

[0060] (5) Self-calibrating frequency counter

[0061] like Figure 2 As shown, the direct counting method, a classic frequency measurement technique, is widely used in the field of electronic measurement. This method is mainly divided into two types: frequency measurement and period measurement. The frequency measurement method sets a fixed gate time T, during which the rising or falling edges of the signal under test are counted, and the frequency fx of the signal under test is calculated by the ratio of the count value N to the gate time T. The period measurement method takes the opposite approach; it measures the time required for one complete cycle of the signal under test. Specifically, it counts a standard frequency within the period of the signal under test, and uses the product of the count value N0 and the standard frequency fc to deduce the frequency fx of the signal under test. Its core principle is based on the reciprocal relationship between period and frequency.

[0062] However, direct counting methods also have significant limitations. Both frequency and period methods are affected by an error of ±1 counting unit, which originates from the quantization process of signal edge detection. Frequency measurement performs well at high frequencies, but as the measured frequency decreases, the number of counts N per unit time decreases, leading to an increase in relative error. Conversely, period measurement is advantageous at low frequencies; however, as the measured frequency increases and approaches the standard frequency fc, the number of counts N per single period becomes very small, significantly amplifying the error. Although both methods can achieve high measurement accuracy within their respective applicable frequency bands, neither can completely eliminate the ±1 unit error of the reference signal, and both are difficult to cover the entire frequency band, thus limiting their measurement accuracy.

[0063] To overcome the limitations of traditional direct counting methods, this invention proposes an innovative high-precision frequency measurement method based on second pulse self-calibration. The design of a high-precision frequency meter based on the STM32 microcontroller utilizes the high-speed and accurate characteristics of the STM32H750 series microcontroller, combined with the second pulse signal received from an external satellite positioning module for self-calibration. This effectively eliminates the ±1-digit counting error found in traditional frequency and period measurement methods. Precise frequency measurement is performed using the microcontroller's internal timer / counter, and the measured frequency is corrected using the second pulse signal as a reference frequency, thus significantly improving measurement accuracy. Experimental verification shows that this design achieves an accuracy of 10⁻⁶ digits in low-frequency measurements. -8 With a magnitude of 100,000 and extremely small relative error, the accuracy remains high even with a slight decrease at high frequencies. At the same time, the design has advantages such as small size, high speed, high accuracy, low cost, and wide measurable frequency bandwidth, which greatly reduces the design cost and implementation complexity. It is suitable for occasions requiring high-precision frequency measurement, such as universities, research institutes, and testing institutions, and has high practical value and cost performance.

[0064] (6) Electricity metering

[0065] In DC power metering systems, precise control of the voltage divider ratio error is crucial for ensuring metering accuracy. Essentially, it represents the relative deviation between the actual and theoretical voltage divider ratios. The theoretical voltage divider ratio is determined by the nominal resistance value, and its expression is:

[0066]

[0067] Where R1 and R2 are the resistance values ​​of the high-voltage arm and low-voltage arm of the voltage divider resistor, respectively. However, actual resistors have manufacturing precision errors and temperature drift errors, causing the actual voltage division ratio to deviate from the theoretical value. Manufacturing precision errors are typically ±1%, directly causing deviations in the voltage division ratio calculation; temperature drift errors, due to the change in resistance value with temperature, may introduce additional errors of more than 0.1% in a wide temperature range. The actual voltage division ratio can be expressed as:

[0068] K 实际 =K理论 ×(1+δ)

[0069] Where δ is the relative error of the partial pressure ratio, and its definition is:

[0070]

[0071] Without correction, the voltage restoration formula is:

[0072] V 初始，未修正 =V 采样 ×K 理论

[0073] The actual voltage should be:

[0074] V 实际 =V 采样 ×K 实际 =V 采样 ×K 理论 ×(1+δ)

[0075] Therefore, the voltage deviation can be expressed as:

[0076] ΔV=V 实际 -V 初始,未修正 =V 采样 ×K 理论 ×δ=V 初始,未修正 ×δ

[0077] This deviation indicates that the voltage division ratio error δ is directly transmitted to the voltage signal, causing the sampled voltage to deviate from the true voltage after being amplified by the voltage division ratio. This voltage deviation further affects power calculation; the uncorrected power formula is:

[0078] P 未修正 =V 初始,未修正 ×I

[0079] The actual power should be:

[0080] P 实际 =V 实际 ×I=V 采样 ×K 实际 ×I

[0081] The error between the two is:

[0082] ΔP=P 实际 -P 未修正

[0083] The relative error between the two is:

[0084]

[0085] That is, the relative error in power calculation is equal to the voltage division ratio error:

[0086]

[0087] The cumulative error of electrical energy increases linearly with time, and its expression is:

[0088]

[0089] Under long-term operation, the power error of the uncorrected system may deviate completely from the true value. Especially in application scenarios that require high-precision metering, such cumulative error will lead to unreliable metering results.

[0090] To eliminate voltage division ratio errors, the system introduces a high-precision self-calibration mechanism based on satellite second pulses. This mechanism alternately switches two voltage signals, Ui and Uo, using a high-speed electronic switch. These signals are then converted into frequency signals fi and fo by a voltage-to-frequency converter, and compared using the satellite second pulse as a frequency reference. The satellite second pulse has excellent periodic stability, ensuring the accuracy of frequency measurements. The switching frequency of the high-speed electronic switch is typically set in the kHz range to ensure synchronous sampling of the two voltage signals. The voltage-to-frequency converter converts the voltage signals into frequency signals. By comparing the ratios fi and fo of the two frequency signals, the system can accurately calculate the actual voltage division ratio, thereby correcting the deviation from the theoretical value. This step reduces the relative error of the voltage division ratio to zero, significantly improving the accuracy of voltage restoration.

[0091] The corrected partial pressure ratio is:

[0092]

[0093] The corrected relative error of the partial pressure ratio is δ = 0.

[0094] The corrected voltage restoration formula is:

[0095] V 初始,修正后 =V 采样 ×K 实际

[0096] This formula incorporates the actual voltage division ratio into the calculation, eliminating the deviation of the theoretical voltage division ratio. The corrected voltage signal is closer to the true value, providing an accurate basis for subsequent power calculations. The power calculation formula becomes:

[0097] P 修正后 =V 初始,修正后 ×I

[0098] Its relative error is:

[0099]

[0100] Since the voltage division ratio error has been significantly reduced, the relative error in power calculation has also been reduced to a negligible level. The formula for cumulative energy error then becomes:

[0101]

[0102] Its error ΔE = 0. The comparison before and after correction shows that the power error increases linearly with time when it is not corrected, while the error after correction is strictly controlled within the range required by the metering accuracy and can usually be ignored.

[0103] By dynamically correcting the voltage division ratio, the system achieves end-to-end error control from voltage sampling to power output. The core of the self-calibration mechanism lies in real-time correction of the voltage division ratio through frequency comparison, ensuring accurate voltage restoration. This process not only eliminates the effects of resistor manufacturing errors and temperature drift but also achieves continuous optimization of the voltage division ratio through a closed-loop feedback mechanism. The corrected system maintains high stability even in complex environments, providing reliable technical support for fields such as power monitoring, smart meters, and new energy metering.

[0104] Based on the above technical solution, the following is provided: Figures 3-4 The example shown.

[0105] like Figure 3 The diagram shows the circuit structure of a remote calibration system for a resistive voltage divider. This system integrates a resistive voltage divider, a high-speed electronic switch, a voltage-to-frequency conversion module, a self-calibrating frequency counter, a satellite signal receiver, and a central processing unit (CPU). Its working principle is as follows: A high-speed electronic switch enables high-frequency, rapid switching between two voltage signals, forming a single-channel alternating output; subsequently, the voltage signal is converted into a frequency signal by the voltage-to-frequency converter and input to the self-calibrating frequency counter; using the second pulse signal synchronously acquired by the satellite receiver as the frequency reference, the measured frequency is calibrated and accurately measured; the CPU calculates the ratio of the frequency signals corresponding to the two voltages, thereby deriving the actual voltage division ratio of the resistive voltage divider and completing the self-calibration process. Finally, the energy metering chip accurately reconstructs the original voltage signal based on the updated voltage division ratio parameters and the sampled voltage data, ensuring the accuracy of the energy metering results.

[0106] like Figure 4 The diagram shows the system calibration flowchart, which describes the calibration process of this resistor divider calibration system based on a self-calibrating frequency counter and the conversion relationships between various parameters. The specific calibration process is as follows:

[0107] (1) Connect the calibration circuit and start calibration.

[0108] Complete the hardware connection of the resistor divider, voltage-to-frequency converter, high-speed electronic switch and self-calibrating frequency counter.

[0109] Start the calibration procedure and perform system initialization operations, including microcontroller self-test, satellite positioning module signal synchronization, and timer / counter clock calibration.

[0110] (2) Uo channel calibration and data acquisition

[0111] A high-speed electronic switch turns on the Uo channel, inputting the input voltage signal into the voltage-to-frequency converter, whose output frequency fo is proportional to Uo.

[0112] The self-calibrating frequency counter simultaneously captures the fo and satellite second pulse signals, calculates and stores the fo value in the CPU data storage unit.

[0113] (3) UI channel switching and frequency measurement

[0114] Close the Uo channel, switch to the Ui channel, repeat the voltage-frequency conversion and frequency counting process, and obtain the frequency value fi corresponding to the measured voltage Ui.

[0115] CPU based on formula Calculate the voltage division ratio and compensate for the error in the voltage division ratio of the resistor voltage divider.

[0116] (4) Voltage reconstruction and calibration completed

[0117] The power metering chip restores the initial voltage signal based on the sampled voltage Uo and the calibrated voltage division ratio K, and the calibration process ends.

[0118] In summary, this embodiment has the following beneficial effects:

[0119] This self-calibration module for a resistor voltage divider constructs a closed-loop resistor voltage divider ratio correction system through the synergistic action of a voltage-to-frequency converter and a self-calibrating frequency counter. The system performs high-frequency switching and comparison between the input voltage and the sampled output voltage of the resistor voltage divider, generating a corresponding frequency signal using the voltage-to-frequency converter, and then achieving high-precision frequency measurement through the self-calibrating frequency counter. Based on the linear relationship between the frequency ratio and the voltage divider ratio, the algorithm module can calculate the voltage divider ratio drift in real time and dynamically adjust the voltage divider network parameters, forming a fully automatic calibration cycle. This technology overcomes the dependence of traditional voltage dividers on external reference sources and high-precision voltage measurement equipment, achieving accurate voltage divider ratio correction without physical contact based on high-precision satellite second pulse signals, significantly improving the long-term stability of high-voltage sampling systems and power metering.

[0120] This self-calibration module for resistive voltage dividers exhibits three key technological advantages: First, it eliminates the reliance on external reference sources and high-precision voltage measurement equipment found in traditional voltage divider calibration methods. Instead, it utilizes high-precision satellite second pulse signals and frequency signal comparison to achieve accurate correction of the voltage division ratio, significantly improving the long-term stability of high-voltage sampling systems and power metering in industrial settings. Furthermore, it eliminates the need for manual intervention in the measurement process and high-precision equipment, making remote high-precision measurement simple and efficient. Second, through high-frequency switching and frequency domain comparison technology, it effectively suppresses the impact of environmental factors such as temperature drift and electromagnetic interference on the voltage division ratio, significantly reducing sampling signal distortion and meeting high-precision metering requirements. Third, the module's built-in predictive maintenance algorithm monitors the voltage divider network status in real time, providing early warnings of component aging trends and significantly extending equipment maintenance cycles. This technology has enabled multi-node remote calibration, significantly reducing operation and maintenance costs compared to traditional solutions and providing highly reliable raw data support for upper-level applications such as power trading and load forecasting.

[0121] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0122] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A resistor voltage divider calibration system based on a self-calibrating frequency counter, characterized in that, include: Regulated voltage source, resistive voltage divider, high-speed electronic switch, voltage-to-frequency converter, self-calibrating frequency counter, satellite signal receiver, power metering chip and CPU; The regulated voltage source is connected to the input terminals of the resistor divider and the high-speed electronic switch, respectively. The output terminal of the resistor divider is also connected to the input terminals of the high-speed electronic switch and the power metering chip, respectively. The output terminal of the high-speed electronic switch is connected to the input terminal of the voltage-to-frequency converter. The output terminals of the voltage-to-frequency converter and the satellite signal receiver are both connected to the input terminal of the self-calibrating frequency counter. The output terminal of the self-calibrating frequency counter is connected to the input terminal of the CPU. The output terminal of the CPU is connected to the power metering chip.

2. The resistor voltage divider calibration system based on a self-calibrating frequency counter according to claim 1, characterized in that, The resistor divider includes a voltage sampling module and a current sampling module.

3. The resistor divider calibration system based on a self-calibrating frequency counter according to claim 2, characterized in that, The voltage sampling module consists of a high-voltage arm resistor R1 and a low-voltage arm resistor R2 connected in series; the current sampling module consists of a shunt and a PGA.

4. A method for calibrating a resistor divider based on a self-calibrating frequency counter, applied to the calibration system as described in any one of claims 1-3, characterized in that, include: A steady-state voltage is input to a resistor divider and a high-speed electronic switch using a regulated voltage source, and a sampling voltage is obtained using the resistor divider. The steady-state voltage and the sampling voltage are then switched at high frequency using the high-speed electronic switch to form two single-channel signals with alternating timing. A voltage-to-frequency linear conversion is performed on a single signal using a voltage-to-frequency converter to obtain a frequency signal; The satellite second pulse signal is received using a satellite signal receiver, and the frequency signal is measured using the satellite second pulse signal as a reference in a self-calibrating frequency counter to obtain two measurement signals; The two measurement signals are input into the CPU to calculate the frequency ratio, thereby obtaining the voltage division ratio of the resistor voltage divider. The voltage division ratio is then input into the power metering chip for deviation correction, thus completing the voltage calibration.

5. The resistor divider calibration method based on a self-calibrating frequency counter according to claim 4, characterized in that, The formula for calculating the partial pressure ratio is: Among them, R1 实际 R2 is the actual value of the high-voltage arm resistance. 实际 λ is the actual value of the low-voltage arm resistance, Ui is the steady-state voltage, Uo is the sampling voltage, fi is the frequency of the steady-state voltage, fo is the frequency of the sampling voltage, and λ is the voltage-to-frequency conversion coefficient.

6. The resistor divider calibration method based on a self-calibrating frequency counter according to claim 4, characterized in that, The deviation correction of the voltage division ratio input to the power metering chip specifically includes: In the power metering chip, the initial voltage signal is reconstructed based on the sampled voltage and the voltage division ratio.

7. An electronic device, characterized in that, The device includes a memory and a processor, the memory being used to store a computer program, and the processor running the computer program to cause the electronic device to perform the resistor divider calibration method based on a self-calibrating frequency counter according to any one of claims 4-6.

8. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the resistor divider calibration method based on a self-calibrating frequency counter as described in any one of claims 4-6.

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