CN-121978392-A - ID voltage multistage filtering method, system, storage medium and electric automobile

CN121978392ACN 121978392 ACN121978392 ACN 121978392ACN-121978392-A

Abstract

The application discloses an ID voltage multistage filtering method, an ID voltage multistage filtering system, a storage medium and an electric automobile, wherein the ID voltage multistage filtering method comprises the steps of periodically sampling an ID voltage analog signal through an analog-to-digital converter to obtain original ADC data, filtering the original ADC data by adopting a median filter with a fixed window size to obtain a filtering output value, performing voltage calibration and linear conversion on the filtering output value to convert the filtering output value into a millivolt voltage value, performing grading judgment according to a preset voltage interval where the millivolt voltage value is located, outputting a corresponding current connection state, starting a timing anti-shake mechanism when the current connection state is a normal connection state and the state changes, only confirming state update after the state changes last for a preset time, performing accumulated count on the continuously occurring abnormal connection state when the current connection state is an abnormal connection state, triggering protection processing when the accumulated number reaches a preset threshold, and resetting count after the voltage is recovered to be normal.

Inventors

WANG QING

Assignees

奇鲸信息科技(上海)有限公司

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (10)

1. An ID voltage multistage filtering method, characterized by comprising: periodically sampling the ID voltage analog signal through an analog-to-digital converter to obtain original ADC data; Filtering the original ADC data by adopting a median filter with a fixed window size to obtain a filtering output value; Performing voltage calibration and linear conversion on the filtered output value, and converting the filtered output value into a millivolt level voltage value; performing grading judgment according to a preset voltage interval in which the millivolt-level voltage value is positioned, and outputting a corresponding current connection state; when the current connection state is a normal connection state and the state is changed, starting a timing anti-shake mechanism, and only confirming state update after the state change lasts for a preset time; when the current connection state is an abnormal connection state, carrying out accumulated count on the continuously-occurring abnormal connection state, triggering protection processing when the accumulated times reach a preset threshold value, and clearing the count after the voltage is recovered to be normal.
2. The ID voltage multistage filtering method of claim 1, wherein said voltage calibrating and linearly scaling said filtered output value to a millivolt level voltage value comprises: And carrying out numerical conversion on the filtered output value by adopting a fixed calibration coefficient according to the characteristics of a hardware circuit to obtain a millivolt voltage value, wherein the conversion relation is adc_value_id= (id_filtered/0.61) +0.5, wherein id_filtered is a median filtered output value, 0.61 is a calibration coefficient related to resistance voltage division and ADC reference voltage, +0.5 is used for realizing rounding processing, and adc_value_id is an output millivolt voltage value.
3. The ID voltage multistage filtering method of claim 1, wherein the step of performing a step decision according to a preset voltage interval in which the millivolt-level voltage value is located, outputting a corresponding current connection state, comprises: comparing the millivolt voltage value with a plurality of preset voltage intervals to determine the current connection state; when the millivolt voltage value falls into any one of the preset voltage intervals, outputting a corresponding normal connection state; and outputting an abnormal connection state when the millivolt-level voltage value exceeds all the preset voltage intervals.
4. The ID voltage multistage filtering method of claim 3, wherein the preset voltage interval and its corresponding normal connection state comprise: 0-100mV corresponds to the unconnected STATE ID_STATE_ UNMATED, 740-1370mV corresponds to the connected STATE ID_STATE_ MATED, 8.4-32V corresponds to the connected and electric automobile auxiliary power supply STATE ID_STATE_ MATED _ EVAUX, and 21-26.4V corresponds to the connected and charging pile auxiliary power supply STATE ID_STATE_ MATED _ EVSEAUX.
5. The ID voltage multistage filtering method of claim 1, wherein when the current connection state is a normal connection state and a state change occurs, starting a timing anti-shake mechanism, and confirming a state update only after the state change continues for a preset time, comprising: When the current connection state is a normal connection state, comparing the current connection state with a historical connection state at the last moment; Triggering an anti-shake confirmation process when the current connection state is inconsistent with the historical connection state; Starting a software timer and setting anti-shake confirmation time; continuously monitoring the current connection state in the anti-shake confirmation time; If the current connection state is always kept to be a new state after the change in the anti-shake confirmation time, confirming that the state change is effective after the timer is overtime, and updating the system state to be the new state; If the current connection state is jumped back or changed again in the anti-shake confirmation time, canceling the current state change, stopping the timer and resetting the anti-shake flow.
6. The ID voltage multistage filtering method according to claim 1, wherein when the current connection state is an abnormal connection state, performing cumulative count on continuously occurring abnormal connection states, triggering protection processing when the cumulative number reaches a preset threshold, and clearing the count after the voltage is restored to normal, comprises: When the current connection state is an abnormal connection state, executing 1 adding operation on an abnormal counter; when the current connection state is restored to the normal connection state, executing zero clearing operation on the abnormal counter; After each time the anomaly counter is increased by 1, comparing the current value of the anomaly counter with a preset threshold value; If the current value of the abnormal counter is smaller than a preset threshold value, continuously maintaining the monitoring state, and not triggering the protection processing; Triggering protection processing if the current value of the anomaly counter reaches or exceeds a preset threshold value, wherein the protection processing comprises the steps of outputting an alarm signal or executing a charging stopping operation; And after triggering the protection processing, continuously monitoring the current connection state, and resetting an abnormal counter after the current connection state is restored to a normal connection state and is stable, so that the system is restored to normal monitoring.
7. The ID voltage multistage filtering method of claim 1, wherein filtering the raw ADC data with a median filter of a fixed window size to obtain a filtered output value comprises: storing original ADC data obtained by the last N times of sampling by adopting a circulating buffer area, wherein N is a preset fixed window size; Each time a new original ADC data is obtained, storing the new original ADC data into the circular buffer area and covering the target original ADC data in the fixed window; performing sorting operation on N original ADC data currently stored in the circular buffer area to obtain a sorted data sequence; and selecting the data value at the middle position from the ordered data sequence as a filtering output value.
8. An ID voltage multistage filtering system, comprising: the signal acquisition module is used for periodically sampling the ID voltage analog signal through the analog-to-digital converter to acquire original ADC data; The primary filtering module is used for filtering the original ADC data by adopting a median filter with a fixed window size to obtain a filtering output value; the voltage calibration module is used for carrying out voltage calibration and linear conversion on the filtering output value and converting the filtering output value into a millivolt level voltage value; The grading judgment module is used for carrying out grading judgment according to a preset voltage interval in which the millivolt voltage value is positioned and outputting a corresponding current connection state; The anti-shake confirmation module is used for starting a timing anti-shake mechanism when the current connection state is a normal connection state and the state is changed, and confirming state update only after the state change lasts for a preset time; And the abnormal protection module is used for carrying out accumulated count on the continuously-occurring abnormal connection state when the current connection state is the abnormal connection state, triggering protection processing when the accumulated number reaches a preset threshold value, and clearing the count after the voltage is recovered to be normal.
9. A storage medium storing a plurality of instructions adapted to be loaded by a processor to perform the ID voltage multistage filtering method of any of claims 1-7.
10. An electric vehicle, characterized by comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the ID voltage multistage filtering method according to any one of claims 1-7 when executing the computer program.

Description

ID voltage multistage filtering method, system, storage medium and electric automobile Technical Field The embodiment of the application relates to the technical field of electric vehicle charging, in particular to an ID voltage multistage filtering method, an ID voltage multistage filtering system, a storage medium and an electric vehicle. Background With the continuous increase of the electric vehicle conservation amount and the rapid evolution of the high-power rapid charging technology, the megawatt charging system (MEGAWATT CHARGING SYSTEM, MCS) gradually becomes an important development direction of the electric vehicle charging technology of the next stage by virtue of the extremely high charging power and remarkable commercial application prospect. In the MCS charging process, the system needs to operate under extremely high voltage and high current conditions, so that whether the physical connection state between the charging connector and the vehicle charging interface can be accurately, real-time and reliably detected directly relates to the safety, stability and efficiency of the whole charging process. If the detection signal has deviation, poor contact is easily caused, so that electric arcs, local overheating and even fire disasters and other serious potential safety hazards are generated. In MCS charging systems, detection of the connection status typically relies on monitoring an ID voltage signal that is generated by a detection circuit within the charging interface, the voltage value of which can reflect the physical connection status between the connector and the vehicle interface. However, due to the influence of the complexity of the MCS charging application scene, the ID voltage signal is inevitably interfered by various external factors in the acquisition process, including strong electromagnetic environment, mechanical vibration, environmental temperature and humidity change and the like, and the interference is superimposed on the original detection signal, so that signal fluctuation and noise are caused, and the difficulty of accurately judging the real connection state is increased. At present, filtering processing is generally required to be performed on the ID voltage detection signal so as to weaken the interference component and obtain a relatively stable judgment basis. However, existing filtering schemes have significant drawbacks. Firstly, the filter with fixed parameters cannot be optimally adjusted according to the actual noise level and signal characteristics, in the MCS charging process, the noise characteristic difference is obvious in different stages and working conditions, strong transient interference exists at the moment of charging starting and when the load suddenly changes, continuous random interference exists at the stage of stable charging, the filter with fixed parameters cannot conduct differential processing aiming at the different working conditions, so that the accuracy of judgment is affected by insufficient filtering and residual noise under certain conditions, and the real state change is possibly excessively smoothed and covered under other conditions. Secondly, there is inherent contradiction between the filtering effect and the response speed, the larger the filtering depth is, the larger the response delay is, the smaller the filtering depth is, the quicker the response is, but the worse the filtering effect is, the fixed filtering parameters are adopted in the existing scheme, the dynamic balance can not be obtained between the condition that the noise is required to be suppressed by strong filtering and the condition that the condition is required to be responded quickly, and particularly, the condition detection delay can be caused when the connection condition is changed quickly, so that the timely response of the system to the abnormal condition is influenced. Thirdly, the existing scheme lacks a time dimension confirmation mechanism for state change, only carries out smooth processing on signals from amplitude dimension, cannot effectively distinguish short-time transient fluctuation from real connection state change, and is easy to cause frequent state jump due to single interference, so that the stability and reliability of a system are affected. Disclosure of Invention The embodiment of the application provides an ID voltage multistage filtering method, an ID voltage multistage filtering system, a storage medium and an electric automobile, which can effectively inhibit the influence of electromagnetic interference and transient noise on an ID voltage signal, simultaneously maintain the quick response capability on the change of a connection state, and improve the accuracy of detection of a charging connection state and the reliability of system operation. In a first aspect, an embodiment of the present application provides an ID voltage multistage filtering method, including: periodically sampling the ID voltage analog signal through an