A method for quickly eliminating passivation film of clock battery of smart electric energy meter based on dynamic current modulation
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-22
- Publication Date
- 2026-07-03
Smart Images
Figure CN122330732A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of smart energy meter technology, and specifically to a method for rapidly eliminating the passivation film on the clock battery of a smart energy meter based on dynamic current modulation. Background Technology
[0002] As advanced measurement terminals in modern smart grids, the reliable operation of smart meters directly impacts the accuracy of core operations such as electricity consumption data collection, tiered pricing, and line loss analysis. To ensure accurate timing and critical data storage even during grid power outages, smart meters are equipped with long-life clock batteries, with lithium thionyl chloride batteries being the mainstream choice due to their extremely high energy density and low self-discharge rate. However, under prolonged low-current operation or storage conditions, the lithium metal anode surface of this type of battery reacts with thionyl chloride in the electrolyte, forming a dense lithium chloride passivation film. This passivation film remains stable under normal microampere holding current, but when the system requires a large instantaneous current from the battery (such as data upload upon grid restoration or clock calibration), it can cause a momentary drop in battery voltage, leading to microprocessor resets, data loss, and other malfunctions.
[0003] As the deployment scale of smart meters continues to expand and their service life increases, operational reliability issues caused by the passivation film on the clock battery are becoming increasingly prominent, especially after long-term storage or seasonal low electricity consumption. Currently, the industry-standard methods of periodic wake-up and high-current flushing are not only energy-intensive and inefficient, but may also accelerate battery aging. Therefore, there is an urgent need to develop an innovative method that can accurately sense the passivation film status and achieve rapid, adaptive elimination. This is of significant practical importance for improving the overall reliability of smart meters and extending their service life.
[0004] The existing technology has at least the following technical problems: it lacks the ability to accurately quantify and diagnose the state of the passivation film, and can only make a post-event judgment based on macroscopic phenomena such as voltage drops, which leads to the blindness of the elimination process; the elimination strategy with fixed parameters cannot adapt to different battery states and film characteristics, which can easily lead to insufficient or excessive elimination, affecting reliability and potentially damaging battery life; and it is energy-intensive and time-consuming, with constant current discharge requiring tens of minutes or even hours, which is not only inefficient but also consumes a lot of battery energy, resulting in significant deficiencies in the effectiveness, safety and economy of the existing elimination methods. Summary of the Invention
[0005] To address the three technical problems in existing technologies—namely, the lack of precise quantitative diagnostic capabilities for the passivation film state of clock batteries leading to blind elimination processes, the inability to adapt to different battery states due to fixed-parameter elimination strategies, and the high energy consumption and long processing time of traditional constant-current elimination methods—this invention provides a rapid elimination method for the passivation film of smart energy meter clock batteries based on dynamic current modulation, comprising:
[0006] S1. Passivation film state diagnosis: Apply a composite detection signal to the clock battery of the smart energy meter, collect the voltage response of the battery, calculate the asymmetric cross-correlation function between the voltage response and the composite detection signal, and extract the left and right skewness characteristics of the main peak region of the asymmetric cross-correlation function to obtain a film distortion factor for quantifying the thickness and compactness of the passivation film.
[0007] S2. Dynamic Current Elimination: Using the membrane distortion factor as input, a nonlinear oscillator is driven to generate an elimination current and apply it to the clock battery. During the elimination process, the instantaneous power divergence of the battery is continuously calculated, and the driving frequency of the nonlinear oscillator is adjusted in real time according to the instantaneous power divergence to form an inner-loop frequency adaptive control. The inner-loop frequency adaptive process is coupled with the outer-loop parameter setting based on the membrane distortion factor to form a dual closed-loop control system until the membrane distortion factor drops below the preset health threshold, thus completing the elimination of the passivation film.
[0008] Furthermore, in S1, the composite detection signal is a current excitation signal composed of a dual-frequency phase-locked sine wave and Gaussian white noise, and its mathematical expression is:
[0009]
[0010] in, It is the probe current applied to the clock battery at time point t. The fundamental amplitude, To detect the fundamental frequency of the signal, The second harmonic weighting coefficient is used. The parameters represent the intensity of Gaussian white noise. This is a standard Gaussian white noise process.
[0011] Furthermore, in S1, the formula for calculating the asymmetric cross-correlation function is as follows:
[0012]
[0013] in, It is an asymmetric cross-correlation function. Due to time lag, For the fundamental period, This is the battery terminal voltage response signal. It is a symbolic function.
[0014] Further, in S1, the membrane distortion factor is calculated as follows: the global maximum point of the asymmetric cross-correlation function is located to determine the main peak interval; the third-order moment skewness values on the left and right sides within the main peak interval are calculated; the membrane distortion factor is derived from the following formula:
[0015]
[0016] in, It is a membrane distortion factor. It is an index used to adjust the sensitivity to skewness differences, with a value between 1.5 and 2.5.
[0017] Furthermore, in S2, the nonlinear oscillator is a modulated van der Bohr oscillator, and its governing equation is:
[0018]
[0019] in, It eliminates the current; It is the coefficient of the nonlinear damping term. It is the natural angular frequency of the oscillator. It is the magnitude of the external forcing term. It is the angular frequency of the external forcing term.
[0020] Furthermore, the modulation function of the nonlinear damping term coefficient is:
[0021]
[0022] in, and These are the preset minimum and maximum damping coefficients. It is a scaling factor used to adjust right Sensitivity to the impact.
[0023] Furthermore, in S2, the formula for calculating the instantaneous power divergence is:
[0024]
[0025] in, It is the instantaneous power divergence; It is the voltage across the battery terminals.
[0026] Furthermore, in S2, the update law for adjusting the driving frequency of the nonlinear oscillator in real time based on the instantaneous power divergence is as follows:
[0027]
[0028] in, It is the updated angular frequency. It is a preset positive learning rate parameter. It is the expected instantaneous power divergence. It is a sign function of the changing trend of the membrane distortion factor.
[0029] The beneficial effects of this invention are:
[0030] 1. This invention introduces an innovative composite detection signal and asymmetric cross-correlation analysis technique to achieve precise quantitative diagnosis of the passivation film state. Starting from the essence of electrochemical kinetics, it captures the subtle asymmetric relaxation characteristics caused by the passivation film during charging and discharging, thereby extracting a unique quantitative index that can sensitively and accurately characterize the film thickness and compactness, laying a solid foundation for subsequent precise elimination.
[0031] 2. This invention creatively constructs a nonlinear oscillating current generation system that is controlled in real time by the film state quantification index, eliminating the dynamic characteristics of the current, especially its key nonlinear damping behavior. This enables the elimination strategy to form a close and adaptive match with the real-time state of the passivation film, fundamentally avoiding the risks of "under-elimination" or "over-elimination" in traditional constant current or fixed parameter pulse methods. While ensuring the elimination effect, it maximizes the protection of the battery body and prevents performance damage caused by the elimination process itself.
[0032] 3. This invention designs a precise internal and external dual closed-loop collaborative control mechanism. The outer loop is responsible for formulating elimination strategies and adjusting core parameters based on the macroscopic state, while the inner loop monitors the dynamic fluctuations of instantaneous power and makes rapid and precise fine-tuning of the frequency of the elimination current to track the optimal energy injection point of the system. This tight coupling between the inner and outer loops makes the entire system more intelligent and achieves dynamic optimization throughout the elimination process. Attached Figure Description
[0033] Figure 1 This is a flowchart of the present invention. Detailed Implementation
[0034] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, process equipment or devices not specifically specified are all conventional equipment or devices in the art. Unless specifically specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.
[0035] Example 1, combined with Figure 1This embodiment describes a method for rapidly eliminating the passivation film on the clock battery of a smart energy meter based on dynamic current modulation, comprising:
[0036] S1. Passivation film state diagnosis: Apply a composite detection signal to the clock battery of the smart energy meter, collect the voltage response of the battery, calculate the asymmetric cross-correlation function between the voltage response and the composite detection signal, and extract the left and right skewness characteristics of the main peak region of the asymmetric cross-correlation function to obtain a film distortion factor for quantifying the thickness and compactness of the passivation film.
[0037] S2. Dynamic Current Elimination: Using the membrane distortion factor as input, a nonlinear oscillator is driven to generate an elimination current and apply it to the clock battery. During the elimination process, the instantaneous power divergence of the battery is continuously calculated, and the driving frequency of the nonlinear oscillator is adjusted in real time according to the instantaneous power divergence to form an inner-loop frequency adaptive control. The inner-loop frequency adaptive process is coupled with the outer-loop parameter setting based on the membrane distortion factor to form a dual closed-loop control system until the membrane distortion factor drops below the preset health threshold, thus completing the elimination of the passivation film.
[0038] Specifically, a method for rapidly eliminating the passivation film on the clock battery of a smart energy meter based on dynamic current modulation is executed by a hardware platform consisting of the smart energy meter's main control unit, its internal dedicated battery management integrated circuit, and a data acquisition subsystem. The smart energy meter's main control unit refers to the microcontroller or system-on-a-chip integrated within the energy meter, which runs embedded firmware to implement all the logic and control algorithms of this method. The dedicated battery management integrated circuit is a chip directly electrically connected to the clock battery, responsible for accurately outputting the required excitation current signal under the microcontroller's instructions, and possessing necessary load switching functions. The data acquisition subsystem includes an analog-to-digital converter with at least 16-bit resolution and a sampling rate of no less than 10 kSPS, as well as necessary signal conditioning circuitry. Its task is to synchronously and accurately measure and digitize the terminal voltage of the clock battery and / or the excitation current across the calibrated sampling resistor under the timing control of the microcontroller.
[0039] First, the smart meter's main control unit controls the dedicated battery management IC to disconnect all unnecessary loads, putting the clock battery into a static recovery phase. Then, the main control unit instructs the data acquisition subsystem to synchronously acquire baseline open-circuit voltage data of the battery for at least one second at a high sampling rate. Next, the system switches to excitation-response acquisition mode: the main control unit first calculates the digital sequence of the composite micro-current excitation signal and sends it to the dedicated battery management IC via a digital interface. Upon receiving the instruction, the dedicated battery management IC converts the digital sequence into an analog current signal and applies it to the clock battery. Simultaneously, the main control unit triggers the data acquisition subsystem to synchronously and accurately acquire the corresponding battery terminal voltage response signal throughout the entire excitation cycle.
[0040] Furthermore, in S1, the composite detection signal is a current excitation signal composed of a dual-frequency phase-locked sine wave and Gaussian white noise, and its mathematical expression is:
[0041]
[0042] in, It is the probe current applied to the clock battery at time point t. The fundamental amplitude, To detect the fundamental frequency of the signal, The second harmonic weighting coefficient is used. The parameters represent the intensity of Gaussian white noise. This is a standard Gaussian white noise process.
[0043] Specifically, to address the challenge of quantifying and characterizing the nonlinear relaxation response caused by the passivation film, a composite probe signal is needed to simultaneously excite both linear and nonlinear modes of the electrochemical dynamics system within the clock cell. This signal must balance low-frequency dominant excitation with broadband perturbations to comprehensively capture the electrochemical behavior of the passivation film. Specifically, the fundamental sinusoidal component (frequency well below 1 Hz) aims to approximate quasi-static conditions to observe the slow relaxation process of the passivation film; a fixed phase difference is introduced... The purpose of the second harmonic component is to work together with the fundamental wave to construct a specific asymmetry in the current excitation, providing a basis for the subsequent separation of the charging and discharging responses; the superimposed Gaussian white noise is to excite the intrinsic modes of the system in a wide frequency range, to make up for the inadequacy of single or a few frequency detections, and thus to more comprehensively excite the dynamic characteristics related to the passivation film state.
[0044] Furthermore, in S1, the formula for calculating the asymmetric cross-correlation function is as follows:
[0045]
[0046] in, It is an asymmetric cross-correlation function. Due to time lag, For the fundamental period, This is the battery terminal voltage response signal. It is a symbolic function.
[0047] Specifically, after applying the composite detection signal and acquiring the voltage response, the asymmetric cross-correlation function between the two is calculated. The core innovation of this function lies in the introduction of a sign function. The derivative of the probe current is set to +1 when it is positive (charging process) and -1 when it is negative (discharging process). This design amplifies the impedance asymmetry (i.e., different relaxation characteristics) during the charging and discharging processes caused by the presence of the passivation film, making... The peak position, shape, and symmetry can be significantly modulated by the state of the passivation film, thus laying the foundation for subsequent extraction of quantitative features.
[0048] Further, in S1, the membrane distortion factor is calculated as follows: the global maximum point of the asymmetric cross-correlation function is located to determine the main peak interval; the third-order moment skewness values on the left and right sides within the main peak interval are calculated; the membrane distortion factor is derived from the following formula:
[0049]
[0050] in, It is a membrane distortion factor. It is an index used to adjust the sensitivity to skewness differences, with a value between 1.5 and 2.5.
[0051] Specifically, first, position The global maximum point is then used as the center to expand the time window to the left and right. Calculate the barycenter of the asymmetric cross-correlation function The centroid position reflects the overall time shift of the system's relaxation response. Based on the centroid position, the third-order moment skewness values of the asymmetric cross-correlation function on both sides of the main peak interval are further calculated: Then, the third-order moment skewness values on both sides of the main peak interval are calculated: Left skewness... Right skewness ,in for The center of gravity. These two skewness values quantify the degree of asymmetry in the relaxation time distribution during charging and discharging, respectively. Ultimately, the film distortion factor Ψ is given by the normalized difference between the left and right skewness values. A higher Ψ value indicates a thicker or denser passivation film, resulting in more significant ion migration asymmetry (i.e., inconsistency in the charging and discharging process); conversely, a lower Ψ value means that the passivation film is effectively eliminated, and the internal electrochemical kinetics of the battery tend to be symmetrical and healthy. The exponent ξ is used to adjust the sensitivity to skewness differences.
[0052] Furthermore, in S2, the nonlinear oscillator is a modulated van der Bohr oscillator, and its governing equation is:
[0053]
[0054] in, It eliminates the current; It is the coefficient of the nonlinear damping term. It is the natural angular frequency of the oscillator. It is the magnitude of the external forcing term. It is the angular frequency of the external forcing term.
[0055] Specifically, the film distortion factor is used as the core input to drive a nonlinear current generation system. This system is based on a modulated van der Bohr oscillator, and its dynamic characteristics are determined by… Direct regulation. In the equation, The linear restoring force term determines the system's natural frequency; the key nonlinear damping term enables the elimination of dynamic characteristics of the current (such as amplitude and waveform) to adapt to the battery state. This provides continuous drive for the external forcing term. This oscillator can generate rich nonlinear current waveforms, unlike simple constant current or fixed pulses, thus potentially enabling more efficient and adaptive passivation film elimination.
[0056] Furthermore, the modulation function of the nonlinear damping term coefficient is:
[0057]
[0058] in, and These are the preset minimum and maximum damping coefficients. It is a scaling factor used to adjust right Sensitivity to the impact.
[0059] Furthermore, in S2, the formula for calculating the instantaneous power divergence is:
[0060]
[0061] in, It is the instantaneous power divergence; It is the voltage across the battery terminals.
[0062] Specifically, after generating an elimination current modulated by the film distortion factor and applying it to the battery, the voltage across the battery terminals is continuously measured. .based on and Calculate a key instantaneous dynamic feedback quantity—instantaneous power divergence. Essentially, it is the absolute rate of change of power absorbed or released by the battery instantaneously. This physical quantity can sensitively reflect the instantaneous response state of the battery under dynamic current excitation, especially the change in its dynamic impedance. The energy exchange efficiency of the system may be highest when the frequency of the elimination current matches a certain "resonance point" or optimal energy injection point of the battery-passivation film system. It will exhibit specific characteristics. Therefore, It is used as the input signal for rapid and fine adjustment of the inner loop.
[0063] Furthermore, in S2, the update law for adjusting the driving frequency of the nonlinear oscillator in real time based on the instantaneous power divergence is as follows:
[0064]
[0065] in, It is the updated angular frequency. It is a preset positive learning rate parameter. It is the expected instantaneous power divergence. It is a sign function of the changing trend of the membrane distortion factor.
[0066] Specifically, the calculated instantaneous power divergence It is immediately used as the core feedback signal to dynamically adjust the angular frequency of the external forcing term in the nonlinear van der Bohr oscillator. This constitutes a sophisticated inner-loop frequency adaptive mechanism. The direction of angular frequency adjustment is determined by two parts: one is the instantaneous power divergence and the other is the desired value. deviation The driving frequency is directed to make The first is to adjust the direction of the adjustment to approach the expected value in order to track the optimal operating point; the second is to study the changing trend of the membrane distortion factor. This ensures the correctness of the macroscopic direction of the frequency search. When When the trend is declining (elimination is effective), the adjustment tends to maintain the current trend; when... If the frequency does not decrease or even increases, a frequency active search is triggered. Parameters Control and adjust the step size. This inner-loop fine-tuning mechanism is based on the outer-loop... The combination of coarse and fine adjustments constitutes a complete adaptive control system, enabling the elimination process to automatically track the optimal operating point and achieve dynamic optimization of the elimination process.
Claims
1. A method for rapidly eliminating passivation film on the clock battery of a smart energy meter based on dynamic current modulation, characterized in that, include: S1. Passivation film state diagnosis: Apply a composite detection signal to the clock battery of the smart energy meter, collect the voltage response of the battery, calculate the asymmetric cross-correlation function between the voltage response and the composite detection signal, and extract the left and right skewness characteristics of the main peak region of the asymmetric cross-correlation function to obtain a film distortion factor for quantifying the thickness and compactness of the passivation film. S2, Dynamic Current Elimination: Using the membrane distortion factor as input, a nonlinear oscillator is driven to generate an elimination current and apply it to the clock battery; During the elimination process, the instantaneous power divergence of the battery is continuously calculated, and the driving frequency of the nonlinear oscillator is adjusted in real time according to the instantaneous power divergence to form an inner loop frequency adaptive control. The inner loop frequency adaptive process is coupled with the outer loop parameter setting based on the film distortion factor to form a dual closed loop control system until the film distortion factor drops below the preset health threshold, thus completing the elimination of the passivation film.
2. The method for rapid elimination of passivation film in the clock battery of a smart energy meter based on dynamic current modulation according to claim 1, characterized in that... In S1, the composite detection signal is a current excitation signal composed of a dual-frequency phase-locked sine wave and Gaussian white noise superimposed on each other, and its mathematical expression is: in, It is the probe current applied to the clock battery at time point t. The fundamental amplitude, To detect the fundamental frequency of the signal, The second harmonic weighting coefficient is used. The parameters represent the intensity of Gaussian white noise. This is a standard Gaussian white noise process.
3. The method for rapid elimination of passivation film in the clock battery of a smart energy meter based on dynamic current modulation according to claim 2, characterized in that... In S1, the formula for calculating the asymmetric cross-correlation function is: in, It is an asymmetric cross-correlation function. Due to time lag, For the fundamental period, This is the battery terminal voltage response signal. It is a symbolic function.
4. The method for rapid elimination of passivation film in the clock battery of a smart energy meter based on dynamic current modulation according to claim 3, characterized in that, In S1, the membrane distortion factor is calculated as follows: the global maximum point of the asymmetric cross-correlation function is located to determine the main peak interval; the third-order moment skewness values on the left and right sides within the main peak interval are calculated; the membrane distortion factor is derived from the following formula: in, It is a membrane distortion factor. It is an index used to adjust the sensitivity to skewness differences, with a value between 1.5 and 2.
5.
5. The method for rapid elimination of passivation film in the clock battery of a smart energy meter based on dynamic current modulation according to claim 4, characterized in that, In S2, the nonlinear oscillator is a modulated van der Bohr oscillator, and its control equation is: in, It eliminates the current; It is the coefficient of the nonlinear damping term. It is the natural angular frequency of the oscillator. It is the magnitude of the external forcing term. It is the angular frequency of the external forcing term.
6. The method for rapid elimination of passivation film in the clock battery of a smart energy meter based on dynamic current modulation according to claim 5, characterized in that, The modulation function of the nonlinear damping term coefficient is: in, and These are the preset minimum and maximum damping coefficients. It is a scaling factor used to adjust right Sensitivity to the impact.
7. The method for rapid elimination of passivation film in the clock battery of a smart energy meter based on dynamic current modulation according to claim 6, characterized in that, In S2, the formula for calculating the instantaneous power divergence is: in, It is the instantaneous power divergence; It is the voltage across the battery terminals.
8. The method for rapid elimination of passivation film in the clock battery of a smart energy meter based on dynamic current modulation according to claim 7, characterized in that, In S2, the update law for adjusting the driving frequency of the nonlinear oscillator in real time based on the instantaneous power divergence is as follows: in, It is the updated angular frequency. It is a preset positive learning rate parameter. It is the expected instantaneous power divergence. It is a sign function of the changing trend of the membrane distortion factor.