A high-precision digitized measuring method and measuring system for battery pulse charging

Abstract

The application discloses a high-precision digital measurement method and a measurement system for battery pulse charging, and belongs to the technical field of pulse charging, and comprises the following steps: S1, generating fixed sampling clock signals and adjustable sampling clock signals by using a frequency generator according to pulse charging time; S2, detecting and storing the phase difference between the adjustable sampling clock signals and the fixed sampling clock signals; S3, obtaining and storing the difference between sampling values; S4, obtaining a voltage deviation value and deducing the phase difference corresponding to the voltage deviation value; S5, comparing the sampled digital voltage value with the set lowest battery voltage value, if the voltage values are equal, then the integer number of period times of the sampling clock signal corresponding to the digital voltage value is the stop charging time, and if the voltage values are not equal, then the phase difference is added to the integer number of period times of the fixed sampling clock signal as the stop charging time, and then the duty cycle of pulse charging is measured.

Description

Technical Field

[0001] This invention belongs to the field of pulse charging technology, and in particular relates to a high-precision digital measurement method and system for battery pulse charging. Background Technology

[0002] As is well known, pulse charging breaks the limitations of traditional optimal charging current curves on battery charging. During the pulse charging phase, the large current pulse causes the battery voltage to rise rapidly, while the pause period increases the buffer time for internal chemical reactions, eliminating battery concentration polarization and making subsequent pulse charging smoother. During pulse charging, the battery voltage rises rapidly, and after the set charging time, the voltage gradually decreases. When it drops to the set voltage, the next pulse charging begins. As pulse charging progresses, the pause time gradually lengthens, and the duty cycle of the charging pulses continuously decreases. When the duty cycle reaches a specified value, the battery is considered fully charged.

[0003] Traditional pulse charging controls the charging stop based on changes in the duty cycle. As charging progresses, the stop time gradually increases. When the duty cycle drops to a certain range, the battery is considered fully charged, and charging stops. The duty cycle is calculated as follows:

[0004]

[0005] In the formula, T1 is the pulse charging time and the control system set value, while the charging stop time T2 is a variable value. The measurement of the charging stop cutoff time and the charging stop time is the key to the battery pulse charging method.

[0006] Clearly, the common pulse charging process does not fully utilize the stable phase change characteristics of the clock sampling signal in the digital sampling of battery voltage and the relationship between the digital voltage change value and the phase difference change value, which makes it impossible to further improve the measurement accuracy of the charging stop cutoff time and the charging stop time. Summary of the Invention

[0007] To address the above-mentioned technical deficiencies, this invention provides a high-precision digital measurement method and system for battery pulse charging. By utilizing the periodic changes in the phase difference between two sampling clock signals and the periodic changes in the voltage difference between voltage sampling values, the phase difference and the small frequency difference between the two sampling clock signals are digitally derived. This enables high-precision sampling of the minimum battery voltage value and measurement of the pulse charging duty cycle. The periodic changes in phase difference and voltage difference are used for voltage sampling and pulse charging duty cycle measurement.

[0008] To achieve the above-mentioned technical objectives, the present invention is implemented through the following technical solution:

[0009] The first objective of this invention is to provide a high-precision digital measurement method for battery pulse charging, comprising:

[0010] S1. Based on the pulse charging time, a fixed sampling clock signal and an adjustable sampling clock signal are generated using a frequency generator. The pulse charging time contains an integer number of cycles of the fixed sampling clock signal. Wherein: the frequency f1 of the fixed sampling clock signal is equal to f0 + Δ1; the frequency f2 of the adjustable sampling clock signal is equal to f0 + Δ2; f0 is the nominal frequency value; Δ1 and Δ2 are frequency deviations, and the two are not equal.

[0011] S2. Detect and store the phase difference between the adjustable sampling clock signal and the fixed sampling clock signal;

[0012] S3. Digitally sample the voltage during the charging stop period using an adjustable sampling clock signal and a fixed sampling clock signal, calculate and store the difference between the sampled values, and each difference corresponds to the phase difference between the adjustable sampling clock signal and the fixed sampling clock signal.

[0013] S4. Compare the digital voltage value sampled using the fixed sampling clock signal with the set minimum voltage value for the charging / stopping period, and calculate the voltage deviation value Δu. min And based on the correspondence between phase difference and voltage difference, the voltage deviation value Δu is derived. min The corresponding phase difference Δt min ;

[0014] S5. Compare the digitized voltage values ​​sampled by the fixed sampling clock signal and the adjustable sampling clock signal with the set minimum battery voltage value. If the voltage values ​​are equal, the integer number of cycles of the sampling clock signal corresponding to this digitized voltage value is the charging stop time. If the voltage values ​​are not equal, add a phase difference Δt to the integer number of cycles of the fixed sampling clock signal. min The charging pause time is used to measure the duty cycle of the pulse charging.

[0015] A second objective of this invention is to provide a high-precision digital measurement system for battery pulse charging, comprising:

[0016] A frequency generator is used to generate a fixed sampling clock signal and an adjustable sampling clock signal; the pulse charging time contains an integer number of cycles of the fixed sampling clock signal; wherein: the frequency f1 of the fixed sampling clock signal is equal to f0 + Δ1; the frequency f2 of the adjustable sampling clock signal is equal to f0 + Δ2; f0 is the nominal frequency value; Δ1 and Δ2 are frequency deviations, and the two are not equal;

[0017] A computer is used to control the operating status of the frequency generator;

[0018] The first analog-to-digital converter digitally samples the battery voltage during the off-charging period using a fixed sampling clock signal frequency;

[0019] The second analog-to-digital converter digitally samples the battery voltage during the off-charging period using an adjustable sampling clock signal frequency;

[0020] The voltage deviation calculation module compares the sampled signal from the first analog-to-digital converter with the set minimum voltage value.

[0021] The phase difference detection module between sampling clock signals is used to detect the phase difference between a fixed sampling clock signal and an adjustable sampling clock signal.

[0022] The voltage difference module between voltage sample values ​​is used to compare the voltage sample values ​​of the first analog-to-digital converter and the second analog-to-digital converter.

[0023] The periodic data storage module is used to receive and store the output information from the voltage difference module between voltage sample values ​​and the phase difference detection module between sampling clock signals;

[0024] The phase difference module is derived to receive and analyze data from the voltage difference module between voltage samples and the periodic data storage module.

[0025] The duty cycle measurement module is used to receive data from the phase difference derivation module, the fixed sampling clock signal, and the adjustable sampling clock signal, and to measure the duty cycle based on the data.

[0026] The advantages and technical effects of this invention are:

[0027] This invention utilizes the high-resolution, periodically changing phase difference between a fixed sampling clock signal and an adjustable sampling clock signal to perform high-precision sampling of the voltage during the charging stop period. Then, the phase difference is derived from the sampled digital voltage value to determine the charging stop cutoff time with high precision, thereby obtaining the charging stop time and calculating the duty cycle. This invention has a wide time measurement range and can perform high-precision digital measurement of changing voltage signals.

[0028] The structure of this invention is simple and easy to implement. It utilizes the same nominal frequency value and a small frequency deviation between a fixed sampling clock signal and an adjustable sampling clock signal to generate a stable periodic phase difference. It measures the voltage during the charging / stop period with high resolution and captures the cutoff time of the charging / stop period with high precision. The phase difference is digitally compensated based on the number of whole cycles of the sampling clock signal. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of dual-clock sampling of battery voltage during the off-charging period in a preferred embodiment of the present invention;

[0030] Figure 2This is a system block diagram of a preferred embodiment of the present invention. Detailed Implementation

[0031] To make the above-mentioned objectives, control system design, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0032] This invention utilizes two sampling clock signals to digitally sample the battery voltage. These clock signals have the same nominal frequency and a small frequency difference, resulting in a high-resolution phase difference and its corresponding digital voltage difference change. This invention offers high measurement accuracy, a simple circuit structure, and is easy to implement. It solves the problems in the prior art where the measurement accuracy at the charging cutoff point during the charging stop period is low, leading to low charging stop control accuracy, and also addresses the problem of low pulse duty cycle measurement accuracy.

[0033] Please see Figure 1 and Figure 2 A high-precision digital measurement method for battery pulse charging, comprising:

[0034] ① Based on the pulse charging time, a fixed sampling clock signal and an adjustable sampling clock signal are generated using a frequency generator. This pulse charging time contains an integer number of cycles of the fixed sampling clock signal. The adjustable sampling clock signal and the fixed sampling clock signal have the same nominal frequency value and a slight frequency deviation.

[0035] In the pulse charging method, the charging time of the pulse is set by a computer when calculating the duty cycle, and the frequency of the fixed sampling clock signal can be determined based on the charging time of the pulse.

[0036] ②Detect and store the high-resolution, stable phase difference between the adjustable sampling clock signal and the fixed sampling clock signal.

[0037] In the high-precision digital measurement system of the present invention, the target is to make the adjustable sampling clock signal and the fixed sampling clock signal have the same nominal frequency value and a small frequency deviation during the measurement process. In this case, the phase difference between the two pulse signals changes stably and periodically during the battery charging stop period. Moreover, by changing the small frequency deviation value, the charging stop cutoff time and the charging stop time can be precisely controlled and measured with high precision.

[0038] For example, Figure 1As shown, the rising edges of the adjustable sampling clock signal and the fixed sampling clock signal are used as the comparison points for the phase difference. Assuming a0 and b0 coincide in phase (i.e., the phase difference is 0), this is the initial moment. The phase difference between the two signals is 0 for each subsequent Δt1, Δt2, and Δt3. When the phases of the two signals coincide again, the phase difference changes to 0 for the next Δt1, Δt2, and Δt3. This demonstrates that when the adjustable and fixed sampling clock signals have the same nominal frequency and a small frequency deviation, the phase difference exhibits a monotonic, periodic variation. This provides a technical basis for accurately controlling the charging cutoff time and for high-precision measurement of the charging stop time. The smaller the frequency deviation, the higher the resolution of the phase difference change. Resolution control is achieved through the control of the adjustable sampling clock signal.

[0039] ③ The analog-to-digital converter uses an adjustable sampling clock signal and a fixed sampling clock signal to digitally sample the voltage during the charging and stopping period, calculates the difference between their sampled values ​​and stores them. Each difference corresponds to the phase difference between the adjustable sampling clock signal and the fixed sampling clock signal.

[0040] like Figure 1 As shown, the voltage during the charging / stop period is sampled at the sampling times of the adjustable sampling clock signal and the fixed sampling clock signal, respectively. The phase differences Δt1, Δt2, and Δt3 between the two signals correspond to the sampled voltage differences Δu1, Δu2, and Δu3, respectively.

[0041] ④ Compare the digital voltage value sampled by the fixed sampling clock signal with the set minimum voltage value for the charging / stopping period, and calculate the voltage deviation value Δu. min And based on the correspondence between phase difference and voltage difference, Δu is derived. min The corresponding phase difference Δt min .

[0042] ⑤ Compare the digitized voltage values ​​sampled by the fixed sampling clock signal and the adjustable sampling clock signal with the set minimum battery voltage value. If the voltage values ​​are equal, the integer number of cycles of the sampling clock signal corresponding to this digitized voltage value is the charging stop time. If the voltage values ​​are not equal, add a phase difference Δt to the integer number of cycles of the fixed sampling clock signal. min The charging pause time is used to measure the duty cycle of the pulse charging.

[0043] Because sampling the voltage during the charging stop period using a fixed sampling clock signal may not capture the set minimum battery voltage value, the sampling time of the fixed sampling clock signal cannot be used as the end time of the charging stop period. Furthermore, the charging stop time cannot be precisely determined by measuring the number of cycles of the fixed sampling clock signal. Instead, a phase difference Δt needs to be added to the total number of cycles of the fixed sampling clock signal. min .

[0044] A high-precision digital measurement system for battery pulse charging includes:

[0045] A frequency generator is used to generate a fixed sampling clock signal and an adjustable sampling clock signal; the pulse charging time contains an integer number of cycles of the fixed sampling clock signal; wherein: the frequency f1 of the fixed sampling clock signal is equal to f0 + Δ1; the frequency f2 of the adjustable sampling clock signal is equal to f0 + Δ2; f0 is the nominal frequency value; Δ1 and Δ2 are frequency deviations, and the two are not equal;

[0046] A computer is used to control the operating status of the frequency generator;

[0047] The first analog-to-digital converter digitally samples the battery voltage during the off-charging period using a fixed sampling clock signal frequency;

[0048] The second analog-to-digital converter digitally samples the battery voltage during the off-charging period using an adjustable sampling clock signal frequency;

[0049] The voltage deviation calculation module compares the sampled signal from the first analog-to-digital converter with the set minimum voltage value.

[0050] The phase difference detection module between sampling clock signals is used to detect the phase difference between a fixed sampling clock signal and an adjustable sampling clock signal.

[0051] The voltage difference module between voltage sample values ​​is used to compare the voltage sample values ​​of the first analog-to-digital converter and the second analog-to-digital converter.

[0052] The periodic data storage module is used to receive and store the output information from the voltage difference module between voltage sample values ​​and the phase difference detection module between sampling clock signals;

[0053] The phase difference module is derived to receive and analyze data from the voltage difference module between voltage samples and the periodic data storage module.

[0054] The duty cycle measurement module is used to receive data from the phase difference derivation module, the fixed sampling clock signal, and the adjustable sampling clock signal, and to measure the duty cycle based on the data.

[0055] In the aforementioned high-precision digital measurement system for battery pulse charging, a computer-controlled frequency generator produces a fixed sampling clock signal f1 and an adjustable sampling clock signal f2. The frequency of the fixed sampling clock signal is determined by the pulse charging time, which is an integer number of fixed sampling clock signal cycles. The frequency of the adjustable sampling clock signal is determined based on the fact that the fixed and adjustable sampling clock signals have the same nominal frequency value and a slight frequency deviation. Then, the phase difference between the fixed and adjustable sampling clock signals is detected. The analog-to-digital converter digitally samples the battery voltage during the off-charging period using the fixed sampling clock signal frequency to obtain a voltage sampling value u1, and uses the adjustable sampling clock signal frequency to digitally sample the battery voltage during the off-charging period to obtain a voltage sampling value u2. The voltage difference between voltage sampling values ​​u1 and u2 is then calculated. The computer stores the obtained phase difference and voltage difference, and monitors the periodic changes of the phase difference and voltage difference. The computer monitors the digital voltage value in real time. When the voltage sampling value u1 approaches the preset minimum voltage value during the off-charging period, the voltage deviation value Δu between the voltage sampling value u1 and the minimum voltage value is calculated. min By utilizing the stored correspondence between phase difference and voltage difference, the phase difference Δt between the sampling time of the fixed sampling clock signal and the time of the lowest voltage value during the charging / stop period is derived. min Then, using the integer number of cycles of the sampling clock signal and the phase difference Δt min To measure the duty cycle of pulse charging.

[0056] During the digital sampling of battery voltage in the off-charging period, a stable, periodically changing phase difference arises between the fixed sampling clock signal and the adjustable sampling clock signal, which have the same nominal frequency value but a slight frequency deviation. The smaller the frequency deviation, the higher the resolution of the phase difference change. This invention utilizes the high-resolution periodically changing phase difference between the two sampling clock signals and the corresponding sampling voltage difference to accurately derive the phase difference between the sampling time of the fixed sampling clock signal and the time of the lowest voltage value during the off-charging period. High-precision phase difference compensation is performed based on an integer number of sampling clock signal periods. Furthermore, this invention has a wide measurement range, making it suitable for high-precision measurement of varying off-charging times.

[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-precision digital measurement method for battery pulse charging, characterized in that, include: S1. Based on the pulse charging time, a fixed sampling clock signal and an adjustable sampling clock signal are generated using a frequency generator. The pulse charging time includes an integer number of cycles of the fixed sampling clock signal; wherein: the frequency of the fixed sampling clock signal... f 1 equals f 0+Δ1; the frequency of the adjustable sampling clock signal f 2 equals f 0+Δ2; f 0 represents the nominal frequency value; Δ1 and Δ2 represent the frequency deviations, and the two are not equal. S2. Detect and store the phase difference between the adjustable sampling clock signal and the fixed sampling clock signal; S3. Digitally sample the voltage during the charging stop period using an adjustable sampling clock signal and a fixed sampling clock signal, calculate and store the difference between the sampled values, and each difference corresponds to the phase difference between the adjustable sampling clock signal and the fixed sampling clock signal. S4. Compare the digital voltage value sampled using the fixed sampling clock signal with the set minimum voltage value for the charging / stopping period, and calculate the voltage deviation value Δ. u min And based on the correspondence between phase difference and voltage difference, the voltage deviation value Δ is derived. u min The corresponding phase difference Δ t min ; S5. Compare the digitized voltage values ​​sampled using the fixed sampling clock signal and the adjustable sampling clock signal with the set minimum battery voltage value. If the voltage values ​​are equal, the integer number of cycles of the sampling clock signal corresponding to this digitized voltage value is the charging stop time. If the voltage values ​​are not equal, add a phase difference Δ to the integer number of cycles of the fixed sampling clock signal. t min The charging pause time is used to measure the duty cycle of the pulse charging.

2. A high-precision digital measurement system for battery pulse charging, characterized in that, include: Frequency generator, used to generate fixed sampling clock signals and adjustable sampling clock signals; The pulse charging time includes an integer number of cycles of a fixed sampling clock signal; wherein: the frequency of the fixed sampling clock signal... f 1 equals f 0+Δ1; the frequency of the adjustable sampling clock signal f 2 equals f 0+Δ2; f 0 represents the nominal frequency value; Δ1 and Δ2 represent the frequency deviations, and the two are not equal. A computer is used to control the operating status of the frequency generator; The first analog-to-digital converter digitally samples the battery voltage during the off-charging period using a fixed sampling clock signal frequency; The second analog-to-digital converter digitally samples the battery voltage during the off-charging period using an adjustable sampling clock signal frequency; The voltage deviation calculation module compares the sampled signal from the first analog-to-digital converter with the set minimum voltage value. The phase difference detection module between sampling clock signals is used to detect the phase difference between a fixed sampling clock signal and an adjustable sampling clock signal. The voltage difference module between voltage sample values ​​is used to compare the voltage sample values ​​of the first analog-to-digital converter and the second analog-to-digital converter. The periodic data storage module is used to receive and store the output information from the voltage difference module between voltage sample values ​​and the phase difference detection module between sampling clock signals; The phase difference module is derived to receive and analyze data from the voltage difference module between voltage samples and the periodic data storage module. The duty cycle measurement module receives data from the phase difference derivation module, the fixed sampling clock signal, and the adjustable sampling clock signal, and measures the duty cycle based on the data. Specifically, it derives Δ based on the correspondence between the phase difference and the voltage difference. u min The corresponding phase difference Δ t min The digitized voltage values ​​sampled by both a fixed and adjustable sampling clock signal are compared with the set minimum battery voltage. If the voltage values ​​are equal, the integer number of cycles of the sampling clock signal corresponding to this digitized voltage value is the charging stop time. If the voltage values ​​are not equal, a phase difference Δ is added to the integer number of cycles of the fixed sampling clock signal. t min The charging pause time is used to measure the duty cycle of the pulse charging.

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