Battery charging and discharging calibration and monitoring method and system

Abstract

The application discloses a kind of battery charging and discharging calibration and monitoring method, system, first current sensor is measured on the current of connecting line and generates detection signal;Through range selection module, range is selected to enter calibration mode or monitoring mode, corresponding voltage signal is generated based on the current measured by first current sensor;Conversion signal is generated by sampling and converting voltage signal through current sampling conversion module;Conversion signal is monitored by monitoring and calibration control module, alarm signal is generated when conversion signal deviates from preset value and / or the current on the charging and discharging channel is calibrated.The battery charging and discharging calibration and monitoring method and system according to the application can monitor the current accuracy of the charging and discharging channel when the channel is running, and troubleshoot abnormal output of the channel current, so that the battery production or testing process can automatically calibrate the channel current and the calibrated current has high accuracy, which improves the consistency of the produced battery and the measurement accuracy.

Description

Technical Field

[0001] This invention belongs to the field of battery formation and testing equipment current calibration and monitoring technology in the field of control circuits, specifically relating to a battery charging and discharging calibration and monitoring method and system. Background Technology

[0002] With the rapid development of industries such as new energy vehicles and energy storage, the demand for battery formation and testing equipment is enormous, and the requirements for current consistency and control accuracy are constantly increasing. Due to factors such as temperature, humidity, and component aging, the consistency and current control accuracy of battery formation and testing equipment inevitably deviate after long-term use.

[0003] Inconsistencies in current consistency between channels in battery formation equipment result in inconsistent electrical performance of the produced batteries, affecting the stability of battery product quality. This is particularly detrimental to the lifespan of batteries used in series applications, increasing the return rate of battery packs. Deviations in the current control precision of each channel in battery testing equipment lead to inconsistent battery performance data, directly reducing the accuracy and reliability of the tests.

[0004] To ensure the consistency of current in battery formation equipment and the accuracy of current in battery testing equipment, the equipment current needs to be calibrated before leaving the factory, and battery manufacturers need to calibrate the equipment current periodically. Once the charging and discharging system is calibrated, it cannot automatically determine whether the accuracy has drifted after a period of use, and periodic manual measurement is required to determine whether recalibration is needed.

[0005] The current calibration scheme for battery charging and discharging equipment is generally as follows:

[0006] Method 1, Manual Calibration: Using a high-precision ammeter or clamp meter, each channel is calibrated manually one by one. This method is the simplest, but it is labor-intensive, inefficient, and it is difficult to guarantee data consistency.

[0007] Method 2, Single-channel independent sampling online calibration: Each channel uses a high-precision shunt or current sensor to collect data, and the calibration software system automatically calibrates each channel. This method has high real-time current calibration, but each channel requires an independent acquisition system, which is costly.

[0008] Method 3, Automatic Switching Online Calibration: This method uses a single sampling unit and calibrates each channel one by one by switching it on and off. Compared to Method 2, this method reduces costs to some extent and ensures data consistency. However, the switches occupy a lot of space, are complex, difficult to operate in practice, and have the disadvantage of poor contact leading to calibration errors.

[0009] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0010] The purpose of this invention is to provide a battery charging and discharging calibration and monitoring method and system, which can calibrate a single device using only one sensor and without the need for switching.

[0011] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution: a battery charging and discharging calibration and monitoring method, used for calibrating and monitoring charging and discharging equipment, each of the charging and discharging equipment having multiple charging and discharging channels, each of the charging and discharging channels being connected to an external battery via a corresponding connecting line, the calibration and monitoring method comprising:

[0012] A first current sensor is installed in the charging and discharging equipment to measure the current on the connecting wires and generate a detection signal. Part of the connecting wires passes through the first current sensor in the forward direction, and another part of the connecting wires passes through the first current sensor in the reverse direction.

[0013] The range selection module is connected to the first current sensor. The appropriate range is selected through the range selection module to enter the calibration mode or monitoring mode, and a corresponding voltage signal is generated based on the magnitude of the current measured by the first current sensor.

[0014] Connect the current sampling and conversion module to the range selection module to sample and convert the voltage signal to generate a conversion signal.

[0015] The monitoring and calibration control module is connected to the current sampling and conversion module to monitor the conversion signal, generate an alarm signal when the conversion signal deviates from the preset value, and / or calibrate the current on the charging and discharging channel.

[0016] In one or more embodiments of the present invention, when a charging and discharging channel in a single charging and discharging device requires current calibration, the charging and discharging channel to be calibrated is activated in turn by the monitoring and calibration control module to generate current.

[0017] The current generated in the charging and discharging channel is detected by the first current sensor, and the conversion signal is fed back to the corresponding charging and discharging channel by the monitoring and calibration control module.

[0018] The offset value is calculated by the charging and discharging channel based on the current generated by itself and the conversion signal, so as to correct the current output by itself.

[0019] In one or more embodiments of the present invention, multiple charging and discharging devices are divided into multiple groups, and a second current sensor is set for each group. A corresponding connecting line is selected from each charging and discharging device in a group, and the current on the selected connecting line is measured by the second current sensor. In this case, some connecting lines pass through the second current sensor in the forward direction and other connecting lines pass through the second current sensor in the reverse direction.

[0020] Select the appropriate connecting wires from the connecting wires measured by each of the second current sensors, and use the main current sensor to measure the current on the selected connecting wires. In this process, some connecting wires pass through the main current sensor in the forward direction, and other connecting wires pass through the main current sensor in the reverse direction.

[0021] In one or more embodiments of the present invention, for a current group of charging and discharging devices, the charging and discharging channels connected to the connection line passing through the second current sensor are turned on in turn by the monitoring and calibration control module.

[0022] Based on the measurement of the current on the corresponding charging and discharging channels by the main current sensor, the second current sensor, and the first current sensor in one of the current charging and discharging devices in the current group, the calibration of the second current sensor and the corresponding first current sensor by the main current sensor is completed.

[0023] Based on the measurement of the current on the corresponding charging and discharging channel by the second current sensor and the first current sensor in the next charging and discharging device in the current group of charging and discharging devices, the calibration of the second current sensor with the corresponding first current sensor is completed, and so on to complete the calibration.

[0024] In one or more embodiments of the present invention, reserved cables are provided based on the number of first current sensors, and each reserved cable passes through the corresponding first current sensor in the same direction.

[0025] One or more reserved cables are connected in series with the current source using a jumper cable;

[0026] The charging and discharging control system adjusts the current generated by the current source and calibrates the first current sensor when the detected current of the first current sensor deviates from the preset value.

[0027] In one or more embodiments of the present invention, a fixing member is fixedly installed in a first through hole on the first current sensor body, and a plurality of second through holes for the connecting wire to pass through are formed on the fixing member; and / or

[0028] The range selection module includes a first range resistor, a second range resistor, and a switch. The first end of the first range resistor and the first end of the second range resistor are connected to a reference voltage. The second end of the first range resistor is connected to the first end of the switch. The second end of the switch and the second end of the second range resistor are connected to a first current sensor and a current sampling conversion module.

[0029] In one or more embodiments of the present invention, the first current sensor includes a first magnetic ring, a first coil wound on the first magnetic ring, a second magnetic ring, a second coil wound on the second magnetic ring, a third magnetic ring, a third coil wound on the third magnetic ring, a fourth magnetic ring, a fourth coil wound on the fourth magnetic ring, a self-excited oscillation amplifier circuit, an integrating circuit, a filtering circuit, a comparison circuit, a driving circuit, and an amplifying circuit.

[0030] The self-excited oscillation amplifier circuit is connected to the first end and the second end of the first coil. The self-excited oscillation amplifier circuit generates an excitation signal input to the first coil. The integrator circuit is connected to the output end of the self-excited oscillation amplifier circuit and the first end of the second coil to phase-shift and amplify the excitation signal, generating a compensation signal that is sent to the second coil to cancel noise signals on the first coil. The filter circuit is connected to the second end of both the first and second coils to filter the compensation signal output from the second coil. The filtered compensation signal is then superimposed with the excitation signal output from the first coil and filtered again to obtain a DC signal. The comparator circuit is connected to the first end of the third coil and the filter circuit. The second end of the third coil is connected to ground voltage. The comparator circuit compares the signal output from the third coil with the DC signal to generate a control signal. The drive circuit is connected to the comparator circuit to generate a corresponding drive signal based on the control signal. The amplifier circuit is connected to the drive circuit to amplify the signal based on the drive signal, generating an amplified signal. The first end of the fourth coil is connected to the amplifier circuit to receive the amplified signal, and the second end of the fourth coil is used to output a detection signal.

[0031] In one or more embodiments of the present invention, the current sampling conversion module includes a first bias resistor, a second bias resistor, a third bias resistor, a fourth bias resistor, an operational amplifier, an analog-to-digital conversion module, and a first control module;

[0032] The first end of the first bias resistor is connected to the reference voltage. The second end of the first bias resistor is connected to the first end of the third bias resistor and the positive input terminal of the operational amplifier. The first end of the second bias resistor is connected to the range selection module. The second end of the second bias resistor is connected to the negative input terminal of the operational amplifier and the first end of the fourth bias resistor. The second end of the fourth bias resistor is connected to the output terminal of the operational amplifier and the analog-to-digital converter module. The second end of the third bias resistor is connected to the analog-to-digital converter module. The analog-to-digital converter module is connected to the first control module. The first control module is connected to the monitoring and calibration control module.

[0033] In one or more embodiments of the present invention, the current sampling conversion module further includes a first filter capacitor, a second filter capacitor, a third filter capacitor, a fourth filter capacitor, a first filter resistor, and a second filter resistor; the first terminal of the first filter capacitor is connected to the first terminal of the first bias resistor, the second terminal of the first filter capacitor is connected to the second terminal of the second filter capacitor and ground voltage, the first terminal of the second filter capacitor is connected to the first terminal of the second bias resistor, the first terminal of the first filter resistor is connected to the second terminal of the third bias resistor, the second terminal of the first filter resistor is connected to the first terminal of the third filter capacitor and analog-to-digital conversion module, the first terminal of the second filter resistor is connected to the output terminal of the operational amplifier, the second terminal of the second filter resistor is connected to the first terminal of the fourth filter capacitor and analog-to-digital conversion module, and the second terminals of the third filter capacitor and the fourth filter capacitor are connected to ground voltage.

[0034] The present invention also discloses a battery charging and discharging calibration and monitoring system. Based on the battery charging and discharging calibration and monitoring method, the calibration and monitoring system includes a first current sensor, a range selection module, a current sampling and conversion module, and a monitoring and calibration control module installed in the charging and discharging equipment.

[0035] The first current sensor is used to measure the current on the connecting wire and generate a detection signal, wherein part of the connecting wire passes through the first current sensor in the forward direction and part of the connecting wire passes through the first current sensor in the reverse direction;

[0036] The range selection module is connected to the first current sensor. The range selection module enters the calibration mode or monitoring mode based on the selection of the corresponding range, and generates a corresponding voltage signal based on the magnitude of the current measured by the first current sensor.

[0037] The current sampling and conversion module is connected to the range selection module to sample and convert the voltage signal to generate a conversion signal.

[0038] The monitoring and calibration control module is connected to the current sampling and conversion module to monitor the conversion signal, generate an alarm signal when the conversion signal deviates from the preset value, and / or calibrate the current on the charging and discharging channel.

[0039] Compared with the prior art, the battery charging and discharging calibration and monitoring method and system of the present invention uses a high-precision first current sensor in each charging and discharging device. The connection lines of all charging and discharging channels in the charging and discharging device pass through the first current sensor at the same time. There is no need to use a switching switch. After calibration using a preset value as a reference, the output current of all charging and discharging channels has good consistency.

[0040] By passing one half of the connecting wires through the current sensor in the forward direction and the other half in the reverse direction (for example, the connecting wires corresponding to odd-numbered charging and discharging channels are passed in the forward direction, and the connecting wires corresponding to even-numbered charging and discharging channels are passed in the reverse direction), the forward and reverse wires cancel out the magnetic flux under normal operating conditions (simultaneous charging or discharging). In an ideal state, the current sensor operates with zero magnetic flux, which can avoid magnetic flux saturation, reduce the workload of the current sensor, and extend the service life of the current sensor.

[0041] The first current sensor and other devices are embedded in the charging and discharging equipment. When no calibration is required, the system is in standby or monitoring mode. When calibration is required, there is no need to manually connect; calibration can be completed automatically with one click.

[0042] When the charging / discharging channel is in charging / discharging mode, the first current sensor operates in monitoring mode to achieve automatic monitoring and error detection. When a current accuracy deviation or abnormality is detected in the charging / discharging channel, an alarm is issued to prompt the user to recalibrate or troubleshoot.

[0043] The range selection module employs dual-range sampling in conjunction with the two operating conditions described above. The default is the calibration range, using a high-precision range resistor to acquire the current of a single charge / discharge channel, ensuring signal accuracy during calibration. In monitoring mode, another range resistor is connected in parallel to ensure the signal acquisition range, meeting the high current acquisition requirements when multiple charge / discharge channels are operating simultaneously. Similarly, multiple acquisition resistors can be added to meet the needs of multiple ranges. Commands can be sent to the system via the monitoring and calibration control module to automatically switch ranges, enabling more complex operating conditions.

[0044] By using a second-level or multi-level high-precision second current sensor in conjunction with the main current sensor, the first current sensor on multiple charging and discharging devices is automatically calibrated to ensure that the current of each charging and discharging device in the entire production workshop is consistent after calibration.

[0045] The calibration device, including the current sensor, in this invention requires no manual disassembly after assembly and meets the requirements of low cost and automatic calibration. Furthermore, it can monitor the current accuracy of the charging and discharging channel during operation and investigate abnormal current output. This allows for automatic calibration of the channel current during battery production or testing, resulting in high accuracy of the calibrated current, improved battery consistency, and enhanced measurement accuracy. The system is switchless, has low cost, effectively reduces manual wiring operations, and has high execution efficiency. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a perspective view of a current sensor according to an embodiment of the present invention.

[0048] Figure 2 This is a schematic diagram of the first part of the circuit corresponding to the battery charging and discharging calibration and monitoring method and system in one embodiment of the present invention.

[0049] Figure 3 This is a circuit diagram of the self-excited oscillation amplifier circuit and the first coil in one embodiment of the present invention.

[0050] Figure 4 This is a circuit diagram of the integrating circuit and the second coil in one embodiment of the present invention.

[0051] Figure 5 This is a circuit diagram of the filter circuit, the comparator circuit, and the third coil in one embodiment of the present invention.

[0052] Figure 6 This is a circuit diagram of a driving circuit in one embodiment of the present invention.

[0053] Figure 7 This is a circuit diagram of the amplifier circuit and the fourth coil in one embodiment of the present invention.

[0054] Figure 8 This is a circuit diagram of the second part corresponding to the battery charging and discharging calibration and monitoring method and system in one embodiment of the present invention.

[0055] Figure 9 This is a circuit diagram corresponding to a battery charging and discharging calibration and monitoring method and system in another embodiment of the present invention. Detailed Implementation

[0056] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0057] The terms "coupled," "connected," or "linked" in the specification include both direct and indirect connections. An indirect connection is a connection made through an intermediate medium, such as an electrical conduction medium, which may have parasitic inductance or capacitance. Indirect connections may also include connections made through other active or passive devices to achieve the same or similar functional purpose, such as connections through switches, follower circuits, or other circuits or components. Furthermore, in the invention, terms such as "first" and "second" are primarily used to distinguish one technical feature from another, and do not necessarily require or imply any actual relationship, quantity, or order between these technical features.

[0058] In the detailed description of this specification, reference is made to the accompanying drawings, which form a part thereof, wherein like reference numerals always denote like parts, and wherein exemplary embodiments are shown by way of example that may be implemented. It should be understood that other embodiments may be utilized, and structural or logical changes may be made, without departing from the scope of this disclosure. Therefore, the following detailed description should not be considered limiting.

[0059] The various operations in the specification may be described sequentially as multiple discrete actions or operations in a manner most conducive to understanding the claimed subject matter. However, the order of description should not be construed as implying that these operations must be sequentially related. Specifically, these operations may not be performed in the order presented. The described operations may be performed in a different order than in the described embodiments. Various additional operations may be performed in additional embodiments and / or the described operations may be omitted.

[0060] For the purposes of this disclosure, the phrase “A and / or B” means (A), (B), or (A and B). For the purposes of this disclosure, the phrase “A, B and / or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0061] Various components and devices may be referred to or shown in the singular (e.g., “transistor”, “transistor”, “switch”, etc.) in this document, but only for the convenience of discussion, and any element referred to in the singular may include multiple such elements as taught herein.

[0062] The description uses the phrases "in one embodiment," "in other embodiments," or "in some embodiments," each of which may refer to one or more of the same or different embodiments. Furthermore, the terms "comprising," "including," "having," etc., used with respect to embodiments of this disclosure are synonymous.

[0063] A battery charging and discharging calibration and monitoring method according to one embodiment of the present invention is used to calibrate and monitor charging and discharging equipment. Each charging and discharging equipment has multiple charging and discharging channels, and each charging and discharging channel is connected to the positive terminal of an external battery through a corresponding connecting line. The calibration and monitoring method includes:

[0064] A first current sensor is installed within the charging / discharging device. Some connecting wires pass through the first current sensor in the forward direction, while others pass through it in the reverse direction. This method of passing the connecting wires in both directions reduces the load on the first current sensor, preventing it from saturating. In one embodiment, preferably, the number of connecting wires passing through the first current sensor in the forward direction is equal to the number of connecting wires passing through it in the reverse direction. In other embodiments, the number of connecting wires passing through the first current sensor in the forward direction may not be equal to the number of connecting wires passing through it in the reverse direction.

[0065] During normal operation of the charging and discharging channels, the first current sensor is in detection mode to measure the current signal on the connection line and generate a detection signal. When the charging and discharging channels need calibration, each charging and discharging channel is activated sequentially, and the first current sensor measures the current of each charging and discharging channel. The measured current signal is then sent to subsequent modules.

[0066] In one embodiment, the charging and discharging channels can be numbered starting from 1. The connecting lines of even-numbered charging and discharging channels pass through the first current sensor in the forward direction, while the connecting lines of odd-numbered charging and discharging channels pass through the first current sensor in the reverse direction. For example... Figure 1 As shown, in order to better fix the connecting wires and prevent them from being too close together or tangled, which would cause mess and hinder heat dissipation, a fixing member 10 is fixedly installed in the first through hole on the first current sensor body 100. Multiple second through holes 11a and 11b are opened on the fixing member 10 for the connecting wires 20 to pass through. Each second through hole corresponds to a connecting wire 20 passing through, so that each connecting wire 20 passes through the first current sensor in parallel. The second through hole 11a allows the connecting wire 20 to pass through in the forward direction, and the second through hole 11b allows the connecting wire 20 to pass through in the reverse direction. Taking one side of the first current sensor as a reference, the current direction on the connecting wire 20 passing through the second through hole 11a in the forward direction is opposite to the current direction on the connecting wire 20 passing through the second through hole 11b in the reverse direction.

[0067] The range selection module 30 is connected to the first current sensor. Based on the magnitude of the current measured by the first current sensor, the range selection module 30 selects the range (different resistors) and generates a corresponding voltage signal. The range selection module 30 ensures a suitable acquisition range for the subsequent current sampling and conversion module, preventing loss of accuracy due to an excessively large acquisition range, and avoiding saturation output of the current sampling and conversion module due to an excessively small acquisition range. It switches the signal acquisition range in two operating modes: in monitoring mode, the range resistor for increasing the range is engaged, and the large and small range resistors are used together to detect potentially large current ranges when multiple charge / discharge channels are operating simultaneously; in calibration mode, the range resistor for increasing the range is disengaged, and the small range resistor is used alone to accurately calibrate the current of the corresponding charge / discharge channel.

[0068] The current sampling and conversion module 40 is connected to the range selection module 30 to sample and convert the voltage signal to generate a conversion signal (analog to digital signal). The monitoring and calibration control module 50 is connected to the current sampling and conversion module 40 to monitor the conversion signal, generate an alarm signal when the conversion signal deviates from the preset value, and calibrate the current in the charging and discharging channel when calibration is required.

[0069] In one embodiment, the current sampling conversion module 40 acquires the voltage signal on the range selection module 30 and performs amplification, filtering and other operations. The analog-to-digital conversion module of the current sampling conversion module 40 obtains a conversion signal that characterizes the current magnitude of the charging and discharging channel and transmits the conversion signal to the monitoring and calibration control module.

[0070] During normal operation of the charging and discharging channel, the monitoring and calibration control module 50 is in monitoring mode. The monitoring and calibration control module 50 judges the magnitude of the conversion signal transmitted from the current sampling and conversion module 40 in real time and compares it with the actual current of the charging and discharging channel. If a deviation occurs, a warning is issued to the user that the current of the charging and discharging channel may have an error and to suggest calibration.

[0071] In calibration mode, the monitoring and calibration control module 50 sequentially activates the charge and discharge channels that need to be calibrated. The first current sensor measures the detection signal characterizing the actual current magnitude and returns the conversion signal to the current discharge channel through the monitoring and calibration control module 50. The chip inside the current discharge channel calculates the offset value based on the current generated by the current discharge channel and the conversion signal, corrects the output current of the current discharge channel, and completes the current calibration operation.

[0072] like Figure 2As shown, the range selection module 30 includes a first range resistor Rx, a second range resistor Ry, and a switch S1. The first end of the first range resistor Rx and the first end of the second range resistor Ry are connected to the reference voltage Vref. The second end of the first range resistor Rx is connected to the first end of the switch S1. The second end of the switch S1 and the second end of the second range resistor Ry are connected to the first current sensor and the current sampling conversion module 40.

[0073] The current sampling and conversion module 40 includes a first filter capacitor Ca, a second filter capacitor Cb, a third filter capacitor Cc, a fourth filter capacitor Cd, a first bias resistor Ra, a second bias resistor Rb, a third bias resistor Rc, a fourth bias resistor Rd, a first filter resistor Re, a second filter resistor Rf, an operational amplifier EA, an analog-to-digital converter module ADC, and a first control module MCU1.

[0074] The first terminal of the first filter capacitor Ca is connected to the first terminal of the first bias resistor Ra and the reference voltage Vref. The second terminal of the first filter capacitor Ca is connected to the second terminal of the second filter capacitor Cb and the ground voltage GND. The first terminal of the second filter capacitor Cb is connected to the first terminal of the second bias resistor Rb and the second terminal of the second range resistor Ry. The second terminal of the first bias resistor Ra is connected to the first terminal of the third bias resistor Rc and the positive input terminal of the operational amplifier EA. The second terminal of the second bias resistor Rb is connected to the negative input terminal of the operational amplifier EA and the first terminal of the fourth bias resistor Rd. The second terminal of the fourth bias resistor Rd is connected to the output terminal of the operational amplifier EA and the first terminal of the second filter resistor Rf. The second terminal of the third bias resistor Rc is connected to the first terminal of the first filter resistor Re and the reference voltage Vref. The second terminal of the first filter resistor Re is connected to the first terminal of the third filter capacitor Cc and the analog-to-digital converter (ADC). The second terminal of the second filter resistor Rf is connected to the first terminal of the fourth filter capacitor Cd and the ADC. The second terminals of the third filter capacitor Cc and the fourth filter capacitor Cd are connected to the ground voltage GND. The analog-to-digital converter (ADC) module is connected to the first control module (MCU1), and the first control module (MCU1) is connected to the monitoring and calibration control module (50).

[0075] The monitoring and calibration control module 50 communicates with each charging and discharging channel simultaneously. The monitoring and calibration control module 50 is the second control module MCU2.

[0076] The first current sensor includes a first magnetic ring, a first coil L1 wound on the first magnetic ring, a second magnetic ring, a second coil L2 wound on the second magnetic ring, a third magnetic ring, a third coil L3 wound on the third magnetic ring, a fourth magnetic ring, a fourth coil L4 wound on the fourth magnetic ring, a self-excited oscillation amplifier circuit, an integrating circuit, a filtering circuit, a comparison circuit, a driving circuit, and an amplifying circuit.

[0077] The first coil L1 is the excitation coil. The magnetic field on the second coil L2 causes the first magnetic ring to enter a magnetic saturation state. The first coil L1 can sense DC signals. The second coil L2 is a common-mode interference cancellation coil. The magnetic field on the second coil L2 can cancel the noise introduced by the first coil L1. The third coil L3 is an AC zero flux detection coil used to sense high-frequency signals on the connecting line. The fourth coil L4 is a feedback coil used to generate a reverse magnetic field to cancel the primary magnetic field generated by the connecting line passing through the third coil L3.

[0078] The self-excited oscillation amplifier circuit is connected to the first and second ends of the first coil L1. This circuit generates an excitation signal input to the first coil L1, causing the first magnetic ring to repeatedly enter a magnetic saturation state. An integrator circuit is connected to the output of the self-excited oscillation amplifier circuit and the first end of the second coil L2 to phase-shift and amplify the excitation signal, generating a compensation signal that is sent to the second coil L2 to cancel out noise signals generated by common-mode interference on the first coil L1. The filtering circuit is connected to the second end of the first coil L1 and the second end of the second coil L2 to filter the compensation signal output by the second coil L2. The filtered compensation signal is then superimposed with the excitation signal output by the first coil L1 and filtered again to obtain a DC signal. The comparator circuit is connected to the first end of the third coil L3 and the filtering circuit. The second end of the third coil L3 is connected to ground voltage. The comparator circuit is used to compare the signal output by the third coil L3 with the DC signal to generate a control signal. The drive circuit is connected to the comparator circuit to generate a corresponding drive signal based on the control signal. The amplifier circuit is connected to the drive circuit to amplify the signal based on the drive signal control to generate an amplified signal. The first end of the fourth coil L4 is connected to the amplifier circuit to receive the amplified signal. The second end of the fourth coil L4 is used to output a detection signal.

[0079] like Figure 3As shown, the self-excited oscillation amplifier circuit includes: a first operational amplifier OP1A, a first resistor R1, a third resistor R3, a first additional resistor R5A, a second additional resistor R5B, a sixth resistor R6, a third capacitor C3, and a fifth capacitor C5. The first terminals of the third resistor R3 and the sixth resistor R6 are connected to ground. The positive input terminal of the first operational amplifier OP1A is connected to the second terminal of the third resistor R3 and the first terminal of the first resistor R1. The negative input terminal of the first operational amplifier OP1A is connected to the second terminal of the sixth resistor R6 and the second terminal of the first coil L1 to form the first node JP1. The output terminal of the first operational amplifier OP1A is connected to the first terminal of the first additional resistor R5A and the first terminal of the second additional resistor R5B. The second terminals of the first additional resistor R5A and the second additional resistor R5B are connected to the first terminal of the first coil L1 and the second terminal of the first resistor R1 to form the node P1. The third capacitor C3 is connected between the power supply voltage VCC and ground. The fifth capacitor C5 is connected between the first voltage VEE and ground. The power supply voltage VCC and the first voltage VEE are connected to the first operational amplifier OP1A to power the first operational amplifier OP1A. In other embodiments, the first additional resistor R5A, the second additional resistor R5B, the third capacitor C3, and the fifth capacitor C5 may be omitted.

[0080] The first current sensor also includes a fifth diode D5, a second diode D2, a sixth capacitor C6, and a fourth diode D4. The anode of the fifth diode D5 is connected to the first terminal of the first coil L1, and the cathode of the fifth diode D5 is connected to the second terminal of the first coil L1. The cathode of the second diode D2 and the first terminal of the sixth capacitor C6 are connected to node P1, and the anode of the second diode D2 is connected to the anode of the fourth diode D4. The cathode of the fourth diode D4 and the second terminal of the sixth capacitor C6 are connected to ground. The second diode D2 and the fourth diode D4 form a clamping unit to ensure that the output voltage amplitude of the self-excited oscillation amplifier circuit is within the voltage regulation range of the second diode D2 and the fourth diode D4. The fifth diode D5 is used to ensure that the voltage amplitude on the first coil L1 is within 5V or other voltages.

[0081] like Figure 4As shown, the integrating circuit includes: a second operational amplifier OP1B, an eighth resistor R8, a second resistor R2, a twelfth resistor R12, and a first capacitor C1. The first terminal of the eighth resistor R8 is connected to node P1. The second terminal of the eighth resistor R8 is connected to the first terminal of the first capacitor C1, the first terminal of the second resistor R2, and the negative input terminal of the second operational amplifier OP1B. The positive input terminal of the second operational amplifier OP1B is connected to the first terminal of the twelfth resistor R12. The second terminal of the twelfth resistor R12 is connected to ground. The second terminals of the first capacitor C1 and the second terminals of the second resistor R2 are connected to the output terminal of the second operational amplifier OP1B and the first terminal of the second coil L2. The second terminal of the second coil L2 is connected to the first terminal of the bias resistor RS1 to form a second node JP2. The second terminal of the bias resistor RS1 is connected to ground. The first current sensor also includes a first diode D1. The anode of the first diode D1 is connected to the first terminal of the second coil L2, and the cathode of the first diode D1 is connected to the second terminal of the second coil L2. The first diode D1 is used to ensure that the voltage amplitude across the second coil L2 is within a certain range.

[0082] like Figure 5 As shown, the filter circuit includes: a fourth resistor R4, a tenth resistor R10, a fourth capacitor C4, and a second capacitor C2; the first end of the fourth resistor R4 is connected to the first node JP1, the first end of the tenth resistor R10 is connected to the second node JP2, the second end of the tenth resistor R10 is connected to the first end of the fourth capacitor C4, the second end of the fourth capacitor C4 is connected to the second end of the fourth resistor R4, the first end of the second capacitor C2, and the comparator circuit, and the second end of the second capacitor C2 is connected to ground.

[0083] The compensation signal is filtered by the fourth capacitor C4, and the filtered compensation signal is superimposed on the excitation signal. Then, it is filtered by the second capacitor C2 to obtain a smaller and more accurate DC signal.

[0084] like Figure 5 As shown, the comparator circuit includes: a seventh resistor R7, an eleventh resistor R11, a third operational amplifier OP1C, a thirteenth resistor R13, and a seventh capacitor C7. The first terminal of the seventh resistor R7 is connected to the second terminal of the fourth capacitor C4 in the filter circuit. The second terminal of the seventh resistor R7 is connected to the positive input terminal of the third operational amplifier OP1C. The first terminal of the eleventh resistor R11 is connected to the second terminal of the third coil L3, and the first terminal of the third coil L3 is connected to ground. The second terminal of the eleventh resistor R11 is connected to the negative input terminal of the third operational amplifier OP1C. The first terminal of the thirteenth resistor R13 is connected to the negative input terminal of the third operational amplifier OP1C, forming the third node JP3. The second terminal of the thirteenth resistor R13 is connected to the first terminal of the seventh capacitor C7, and the second terminal of the seventh capacitor C7 is connected to the output terminal of the third operational amplifier OP1C, forming node P2.

[0085] The first current sensor also includes a third diode D3, the anode of which is connected to the first end of the third coil L3, and the cathode of which is connected to the second end of the third coil L3.

[0086] The DC signal is compared with the detection signal generated by the third coil L3. If the DC signal is greater than the detection signal generated by the third coil L3, the third operational amplifier OP1C outputs a positive voltage. If the DC signal is less than the detection signal generated by the third coil L3, the third operational amplifier OP1C outputs a negative voltage.

[0087] like Figure 6 As shown, the drive circuit includes: transistor Q1 (first transistor), transistor Q8 (eighth transistor), resistors R14 (fourteenth), R15 (fifteenth), R16 (sixteenth), R40 (fortieth), R41 (forty-first), R42 (forty-second), R17 (seventeenth), R24 (twenty-fourth), R25 (twenty-fifth), R26 (twenty-sixth), R27 (twenty-seventh), R29 (twenty-ninth), R30 (thirtieth), R31 (thirty-first), R32 (thirty-second), and R39 (thirty-ninth). The number of resistors can be increased or decreased as needed.

[0088] The bases of the first transistor Q1 and the eighth transistor Q8 are connected to node P2. The first terminals of the fifteenth resistor R15 and the sixteenth resistor R16 are connected to the collector of the first transistor Q1. The second terminals of the fifteenth resistor R15 and the sixteenth resistor R16 are connected to the first terminal of the fourteenth resistor R14 to form node P31. The second terminal of the fourteenth resistor R14 is connected to the positive power supply voltage (24V). The first terminals of the seventeenth resistor R17, the twenty-fourth resistor R24, the twenty-fifth resistor R25, the twenty-sixth resistor R26, and the twenty-seventh resistor R27 are connected to the emitter of the first transistor Q1. The second terminals of the seventeenth resistor R17, the twenty-fourth resistor R24, the twenty-fifth resistor R25, the twenty-sixth resistor R26, and the twenty-seventh resistor R27 are connected to ground.

[0089] The collector of transistor Q8 is connected to the first terminal of resistors R40 and R41. The second terminals of resistors R40 and R41 are connected to the first terminal of resistor R42 to form node P32. The second terminal of resistor R42 is connected to the negative power supply voltage (-24V). The first terminals of resistors R29, R30, R31, R32, and R39 are connected to the emitter of transistor Q8. The second terminals of resistors R29, R30, R31, R32, and R39 are connected to ground.

[0090] When the third operational amplifier OP1C outputs a positive voltage, node P31 outputs a low level and node P32 outputs a negative high voltage. When the third operational amplifier OP1C outputs a negative voltage, node P32 outputs a low level and node P31 outputs a positive high level.

[0091] like Figure 7 As shown, the amplifier circuit includes: transistors Q2, Q3, Q4, Q5, Q6, Q7, Q9, Q10, Q11, Q12, Q13, Q14, R18, R19, R20, R21, R22, R23, R33, R34, R35, R36, R37, and R38. Multiple transistors are used to improve the driving capability; the number of transistors can be increased or decreased as needed.

[0092] The bases of the second transistor Q2, the third transistor Q3, the fourth transistor Q4, the fifth transistor Q5, the sixth transistor Q6, and the seventh transistor Q7 are connected to node P31. The bases of the ninth transistor Q9, the thirteenth transistor Q10, the eleventh transistor Q11, the tenth diode Q12, the thirteenth transistor Q13, and the fourteenth transistor Q14 are connected to node P32. The emitter of the second transistor Q2 is connected to the first terminal of the eighteenth resistor R18; the emitter of the third transistor Q3 is connected to the first terminal of the nineteenth resistor R19; the emitter of the fourth transistor Q4 is connected to the first terminal of the twentieth resistor R20; the emitter of the fifth transistor Q5 is connected to the first terminal of the twenty-first resistor R21; the emitter of the sixth transistor Q6 is connected to the first terminal of the twenty-second resistor R22; and the emitter of the seventh transistor Q7 is connected to the first terminal of the twenty-third resistor R23. The second terminals of the eighteenth resistor R18, the nineteenth resistor R19, the twentieth resistor R20, the twenty-first resistor R21, the twenty-second resistor R22, and the twenty-third resistor R23 are connected to the positive power supply voltage.

[0093] The emitter of transistor Q9 (9th diode) is connected to the first terminal of resistor R33 (33rd diode); the emitter of transistor Q10 (13th diode) is connected to the first terminal of resistor R34 (34th diode); the emitter of transistor Q11 (11th diode) is connected to the first terminal of resistor R35 (35th diode); the emitter of diode Q12 (10th diode) is connected to the first terminal of resistor R36 (36th diode); the emitter of transistor Q13 (13th diode) is connected to the first terminal of resistor R37 (37th diode); and the emitter of transistor Q14 (14th diode) is connected to the first terminal of resistor R38 (38th diode). The second terminals of resistors R33 (33rd diode), R34 (34th diode), R35 (35th diode), R36 (36th diode), R37 (37th diode), and R38 (38th diode) are connected to the negative power supply voltage.

[0094] The collectors of the second transistor Q2, the third transistor Q3, the fourth transistor Q4, the fifth transistor Q5, the sixth transistor Q6, the seventh transistor Q7, the ninth transistor Q9, the thirteenth transistor Q10, the eleventh transistor Q11, the tenth diode Q12, the thirteenth transistor Q13, and the fourteenth transistor Q14 are connected to the first terminal of the fourth coil L4. The second terminal of the fourth coil L4 is used to output the detection signal.

[0095] The first current sensor also includes a 28th resistor R28, an 8th capacitor C8, a 6th diode D6, an 8th diode D8, a 7th diode D7, and a 9th diode D9. The first terminal of the 28th resistor R28 is connected to the third node JP3, the second terminal of the 28th resistor R28 is connected to the first terminal of the 8th capacitor C8, and the second terminal of the 8th capacitor C8 is connected to the first terminal of the fourth coil L4. The 28th resistor R28 and the 8th capacitor C8 form AC feedback. The cathodes of the 6th diode D6 and the 7th diode D7 are connected to the positive power supply voltage. The anodes of the 6th diode D6 and the 8th diode D8 are connected to the first terminal of the fourth coil L4. The anodes of the 7th diode D7 and the 9th diode D9 are connected to the second terminal of the fourth coil L4. The anodes of the 8th diode D8 and the 9th diode D9 are connected to the negative power supply voltage. The 6th diode D6, the 8th diode D8, the 7th diode D7, and the 9th diode D9 are used to release voltage spikes on the fourth coil L4 caused by accidents, protect other circuits, and keep the signal on the fourth coil L4 within the supply voltage range.

[0096] When node P31 outputs a low level and node P32 outputs a negative high voltage, transistors Q2, Q3, Q4, Q5, Q6, and Q7 are all turned on, powered by the positive power supply voltage, and current flows from the first end of the fourth coil L4 to its second end. When node P32 outputs a low level and node P31 outputs a positive high level, transistors Q9, Q10, Q11, Q12, Q13, and Q14 are all turned on, powered by the negative power supply voltage, and current flows from the second end of the fourth coil L4 to its first end. The different current flows create magnetic fields with different directions on the fourth coil L4.

[0097] The following explanation uses a charging and discharging device with 48 charging and discharging channels and a rated current of 20A, and a fluxgate sensor with a rated current of 20A and a ratio of 2500:1 as the first sensor:

[0098] The fluxgate current sensor module is fixedly installed inside the charging and discharging equipment. The connection wires of all charging and discharging channels to the positive terminal of the battery pass through the fluxgate sensor in the forward direction for even-numbered charging and discharging channels and in the reverse direction for odd-numbered charging and discharging channels, according to the direction of the current detected by the fluxgate sensor.

[0099] According to the magnetic flux density formula And magnetic flux formula The magnetic flux can be obtained from the formula. The direction is determined by the direction of the current I. The relationship between the total magnetic flux measured inside the fluxgate sensor and the magnetic flux on each connecting wire is as follows: When all charging and discharging channels are operating simultaneously and the charging current is 20A, the fluxgate sensor operates according to the formula... The algebraic sum of the induced magnetic flux on each connecting wire and the resulting proportional current is 0A.

[0100] When all odd-numbered charge / discharge channels are operating in charging mode with a charging current of 20A, and all even-numbered charge / discharge channels are operating in discharging mode with a discharging current of 20A, the fluxgate sensor operates according to the formula... The algebraic sum of the magnetic flux detected on each connecting wire and the resulting proportional current is 0.384A. When only the No. 1 charging / discharging channel is charging at its operating position with a charging current of 20A, and the other charging / discharging channels are not operating, the fluxgate sensor operates according to the formula... The algebraic sum of magnetic flux and proportional current induced on each connecting wire is 0.008A.

[0101] In the range selection module 30, based on the operating status of all charging and discharging channels, the first range resistor Rx is switched in and out by controlling the closing and opening of the control switch S1 (in one embodiment, switch S1 is a relay). During normal operation of all charging and discharging channels, the first range resistor Rx with increased range is switched in; when a charging or discharging channel is being calibrated, the first range resistor Rx is switched out. In one embodiment, the resistance of the first range resistor Rx is 1.875Ω, and the resistance of the second range resistor Ry is 90.00Ω. When the charging and discharging channels are operating normally, the maximum current flowing through the parallel connection of the first range resistor Rx and the second range resistor Ry is 0.384A, resulting in a voltage drop of... =0.384A*(1.875Ω / / 90.00Ω)≈0.705V. When calibrating the charge / discharge channel, the current flowing through the second range resistor Ry corresponding to the small range is 0.008A, and the resulting voltage drop is... =0.008A * 90.00Ω = 0.72V, the voltage drops of the two are very close.

[0102] The signal conditioning circuit, composed of the first bias resistor Ra, the second bias resistor Rb, the third bias resistor Rc, the fourth bias resistor Rd, and the operational amplifier EA, amplifies the voltage signal generated by the range selection module 30, with an amplification factor GAIN of [value missing]. In one embodiment, a 2.5x amplification is used to amplify the 0.705V signal by 2.5 times, resulting in a 1.763V voltage signal. After low-pass filtering by the first filter resistor Re, the second filter resistor Rf, the third filter capacitor Cc, and the fourth filter capacitor Cd, the first control module MCU1 (microcontroller) uses the SPI bus to control the analog-to-digital converter module ADC (in one embodiment, an ADS131A04 chip is used as the analog-to-digital converter) to acquire the filtered analog signal. The ADC module converts the signal into a digital signal with a reference voltage Vref of 2.5V. , The number of bits in the analog-to-digital converter (ADC) module. The voltage signal input to the analog-to-digital converter (ADC) is digitally filtered and averaged by the first control module MCU1 using the formula... The algebraic sum of the currents on all the connecting lines passing through the fluxgate sensor is calculated and sent to the monitoring and calibration control module 50 for processing. At the same time, the switch S1 is controlled by the first control module MCU1.

[0103] In one embodiment, when each charging and discharging channel is in normal operating condition, the monitoring and calibration control module 50 automatically monitors and checks for errors. When the equipment is running at full load under the same working conditions (same working mode and current magnitude), since the connection lines of the odd and even number charging and discharging channels are passed in opposite directions, once a fault or current drift occurs in a certain charging and discharging channel, the current sensor can collect the current value and issue an abnormal alarm to the user through the monitoring and calibration control module 50.

[0104] When a charging / discharging channel in a single charging / discharging device needs calibration, the monitoring and calibration control module 50 controls all charging / discharging channels to pause operation and, through the monitoring and calibration control module 50, sequentially starts the charging / discharging channel that needs calibration to generate the corresponding current.

[0105] After the current output from the charging / discharging channel, the first current sensor detects the current generated by the charging / discharging channel and generates a detection signal. This signal is then processed by the range selection module 30 and the current sampling and conversion module 40 to generate a conversion signal. The monitoring and calibration control module 50 feeds the conversion signal back to the corresponding charging / discharging channel. The control chip within the charging / discharging channel calculates the offset value based on the current generated by the channel and the conversion signal to compensate for and correct the current output by the channel to the actual value within the error range. The calibration stops when this charging / discharging channel ends, and then the next channel requiring calibration is started, and so on, completing the automatic calibration process.

[0106] like Figure 8As shown, multiple charging and discharging devices are divided into multiple groups, and each group is equipped with a corresponding second current sensor. Corresponding connecting wires are selected from each charging and discharging device in a group. Preferably, the same number of connecting wires are selected from each charging and discharging device in a group. The current on the selected connecting wires is measured by the second current sensor. Part of the connecting wires pass through the second current sensor in the forward direction, and another part passes through the second current sensor in the reverse direction. Preferably, the number of connecting wires passing through the second current sensor in the forward direction is equal to the number of connecting wires passing through the second current sensor in the reverse direction. In other embodiments, the number of connecting wires passing through the second current sensor in the forward direction and the number of connecting wires passing through the second current sensor in the reverse direction may not be equal. In one embodiment, the structure of the second current sensor is the same as the structure of the first current sensor.

[0107] Select appropriate connecting lines from the connecting lines measured by each of the second current sensors. Preferably, select the same number of connecting lines from the connecting lines measured by each of the second current sensors. Use a main current sensor to measure the current on the selected connecting lines. In this case, some connecting lines pass through the main current sensor in the forward direction and other connecting lines pass through the main current sensor in the reverse direction. Preferably, the number of connecting lines passing through the main current sensor in the forward direction is equal to the number of connecting lines passing through the main current sensor in the reverse direction. In other embodiments, the number of connecting lines passing through the main current sensor in the forward direction and the number of connecting lines passing through the main current sensor in the reverse direction may not be equal.

[0108] In one embodiment, to ensure measurement accuracy, in each charging / discharging device in a group, the connecting line corresponding to the charging / discharging channel with the same sequence number and position is selected to pass through the second current sensor. For example, if there are four charging / discharging devices in a group, the connecting line corresponding to the first charging / discharging channel of each charging / discharging device can be selected to pass through the second current sensor. The form of the connecting line passing through the second current sensor and the main current sensor in both forward and reverse directions is the same as that of the first current sensor. In addition, all second current sensors and main current sensors are connected to a first range selection module and a first current sampling conversion module, and all first current sampling conversion modules are connected to the same first monitoring and calibration control module. The structure of the first range selection module, the first current sampling conversion module, and the first monitoring and calibration control module is the same as the structure of the range selection module 30, the current sampling conversion module 40, and the monitoring and calibration control module 50 connected to the first current sensor as described above. The first current sensor, the second current sensor, and the main current sensor can be sensors with the same structure, and the first current sensor, the second current sensor, and the main current sensor can use the same control system. In one embodiment, the structure of the main current sensor is the same as the structure of the first current sensor.

[0109] For the current set of charging and discharging devices, the charging and discharging channels connected to the connecting wire passing through the second current sensor are turned on in turn by the first monitoring and calibration control module.

[0110] Based on the measurement of the current on the corresponding charging and discharging channels by the main current sensor, the second current sensor, and the first current sensor in one of the current charging and discharging devices in the current group, the calibration of the second current sensor and the corresponding first current sensor by the main current sensor is completed.

[0111] Based on the measurement of the current on the corresponding charging and discharging channel by the second current sensor and the first current sensor in the next charging and discharging device in the current group of charging and discharging devices, the calibration of the second current sensor with the corresponding first current sensor is completed, and so on to complete the calibration.

[0112] In one embodiment, both the second current sensor and the main current sensor are mounted externally on the charging / discharging device. A connection wire is used to connect one charging / discharging channel of each charging / discharging device in each group. Half of the connection wire passes through the corresponding second current sensor in the forward direction, and the other half passes through it in the reverse direction. The number of second current sensors is increased or decreased depending on the number of charging / discharging devices and the maximum number of wires that can pass through a single second current sensor. A second-stage main current sensor is added in addition to the multiple second current sensors, passing through any one connection wire of each second current sensor. Half of the connection wire passes through the main current sensor in the forward direction, and the other half passes through it in the reverse direction. This multi-stage cascaded current sensor setup ensures that all first and second current sensors can ultimately be calibrated by the same main current sensor. The current values ​​measured by the second and main current sensors for each charging / discharging channel are sent to the corresponding first range selection module.

[0113] The first range selection module ensures a suitable acquisition range for the subsequent first current sampling and conversion module. This range is neither too large, leading to a loss of accuracy, nor too small, causing saturation of the first current sampling and conversion module's output. It switches the signal acquisition range between two operating modes: in standby mode, the range resistor for increasing the range is engaged to ensure the second and main current sensors operate safely; in calibration mode, the range resistor for increasing the range is disengaged, allowing a smaller range resistor to be used for precise calibration of the current in the corresponding individual charge / discharge channel.

[0114] The first current sampling and conversion module acquires the signal from the first range selection module, performs a series of operations such as amplification and filtering, and obtains a converted signal representing the actual current magnitude of the charging and discharging channel through the analog-to-digital conversion module of the first current sampling and conversion module, and sends the converted signal to the first monitoring and calibration control module.

[0115] The first monitoring and calibration control module is used to calibrate all current sensors (including the first and second current sensors) based on the main current sensor. First, it turns on the charging and discharging channels connected to the connecting wires passing through the main current sensor in turn, controls the current value generated by the charging and discharging channels, and completes the calibration of the second and first current sensors corresponding to the main current sensor. After the calibration of all the next-level current sensors is completed, the current sensor that has been calibrated will then calibrate the current sensors below it, and so on until the calibration operation of all current sensors is completed.

[0116] Furthermore, such as Figure 8 and Figure 2 As shown, a battery manufacturer has 300 charging and discharging devices, each with a rated current of 20A and 48 charging and discharging channels. The devices are equipped with a first current sensor, a range selection module 30, a current sampling and conversion module 40, and a monitoring and calibration control module 50 to serve as online monitoring and calibration equipment for each charging and discharging device. The automatic calibration process of the first current sensor is detailed using a second current sensor and a main current sensor as examples.

[0117] 300 charging and discharging devices use second current sensors 1-6 and a main current sensor 7, respectively (in one embodiment, both the second current sensor and the main current sensor are fluxgate sensors). The connecting wire of the first charging / discharging channel of each of the 1st to 50th charging / discharging devices passes through the second current sensor 1; the connecting wire of the first charging / discharging channel of each of the 51st to 100th charging / discharging devices passes through the second current sensor 2; and the connecting wire of each charging / discharging channel of each of the 101st to 150th charging / discharging devices... The connection line of the first charging / discharging channel of the device passes through the No. 3 second current sensor; the connection line of the first charging / discharging channel of each charging / discharging device from the 151st to the 200th passes through the No. 4 second current sensor; the connection line of the fifth charging / discharging channel of each charging / discharging device from the 201st to the 250th passes through the No. 1 second current sensor; and the connection line of the first charging / discharging channel of each charging / discharging device from the 251st to the 300th passes through the No. 6 second current sensor.

[0118] The connecting wire can be selected to pass through the first charging / discharging channel of the first charging / discharging device of the first charging / discharging device (second current sensor #1), the first charging / discharging channel of the 51st charging / discharging device (second current sensor #2), the first charging / discharging channel of the 101st charging / discharging device (second current sensor #3), the first charging / discharging channel of the 151st charging / discharging device (second current sensor #4), the first charging / discharging channel of the 201st charging / discharging device (second current sensor #5), and the first charging / discharging channel of the 251st charging / discharging device (second current sensor #6), and then pass through the main gate sensor #7. The wiring method is to run half of the connecting wire forward and half backward. In other embodiments, the selection of the connecting wire can be adjusted as needed.

[0119] The control module in the first current sampling and conversion module controls the first range selection module according to the operating status of the charging and discharging channels, switching the range resistor of the increased range in and out. All charging and discharging channels switch the range resistor of the increased range during normal operation; when a charging or discharging channel is being calibrated, the range resistor of the increased range is switched out. The first current sampling and conversion module amplifies and low-pass filters the voltage signal generated by the first range selection module. The analog-to-digital conversion circuit in the first current sampling and conversion module acquires the filtered analog signal and converts it into a digital signal. The first control module calculates the algebraic sum of the currents passing through all the connection lines of the current sensors and sends it to the first monitoring and calibration control module for processing.

[0120] During normal operation of the charging and discharging channels, all current sensors are in standby mode. When it is necessary to calibrate the first current sensor of a single charging and discharging device, the first charging and discharging channel of the first charging and discharging device is started to generate current. At this time, the second current sensor (No. 1), the main current sensor (No. 7), and the first current sensor in the first device can all monitor the current value on the corresponding connection line.

[0121] The No. 1 second current sensor is calibrated based on the current value measured by the No. 7 main current sensor, and simultaneously the first current sensor in the first device is calibrated. Then, the first charging / discharging channel of the first charging / discharging device is closed, and the first charging / discharging channel of the second charging / discharging device is opened. Since the No. 1 second current sensor has already been calibrated, the first current sensor in the second charging / discharging device can be directly calibrated based on the No. 1 second current sensor. This process is repeated for all the first current sensors in charging / discharging devices from the first to the 50th charging / discharging device, based on the No. 1 second current sensor. Then, the first charging / discharging channel of the 51st charging / discharging device is started, and the above operation is repeated until the first current sensors in all 300 charging / discharging devices are calibrated.

[0122] like Figure 9 As shown, in other embodiments, reserved cables are provided based on the number of first current sensors, and each reserved cable passes through the corresponding first current sensor in the same direction. A jumper cable is used to connect the reserved cables in series with the current source. The number of reserved cables connected can be selected according to the actual number of first current sensors to be tested. The current generated by the current source is adjusted by the charge / discharge control system, and the first current sensor is calibrated when the detected current deviates from a preset value.

[0123] Specifically, for example, there are 300 charging and discharging devices, each with 48 charging and discharging channels. The connecting lines of the 48 charging and discharging channels all pass through a first current sensor, and a reserved cable is installed inside the first current sensor. Each reserved cable passes through the corresponding first current sensor in the same direction. When the first current sensor in the charging and discharging device needs to be calibrated, the reserved cables between the charging and discharging devices are connected by a jumper cable, and finally connected to the current source to form a closed loop. According to Kirchhoff's theorem, the current in the same series branch is equal everywhere. Without activating any charging or discharging channel, the magnetic flux induced on the first current sensor in each charging and discharging device is equal. The current source is connected to the charging and discharging devices and the charging and discharging control system via Ethernet.

[0124] The charging and discharging control system controls the current output of the current source so that the first current sensor can detect it and calibrate it through the range selection module 30, the current sampling and conversion module 40, and the monitoring and calibration control module 50. The first current sensor in each charging and discharging device corrects the deviation value according to the actual output current of the current source, and sequentially completes the calibration of current consistency among multiple charging and discharging devices.

[0125] In practical applications, the first current sensor, second current sensor, and main current sensor used can be other non-contact sensors such as Hall sensors, in addition to fluxgate sensors. The number of current sensors can be selected according to the cost of the sensors, the location of the charging and discharging channels, and the ease of wiring. In practice, they can be divided into multiple groups for data acquisition. For example, 48 charging and discharging channels can be divided into 12 charging and discharging channels in each group and detected by 4 first current sensors.

[0126] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this disclosure. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0127] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for calibrating and monitoring battery charging and discharging, characterized in that, This method is used for calibrating and monitoring charging and discharging equipment. Each charging and discharging equipment has multiple charging and discharging channels, and each charging and discharging channel is connected to an external battery via a corresponding connecting wire. The calibration and monitoring method includes: A first current sensor is installed in the charging and discharging equipment to measure the current on the connecting wire and generate a detection signal. Half of the connecting wire passes through the first current sensor in the forward direction and the other half passes through the first current sensor in the reverse direction. The range selection module is connected to the first current sensor. The appropriate range is selected through the range selection module to enter the calibration mode or monitoring mode, and a corresponding voltage signal is generated based on the magnitude of the current measured by the first current sensor. Connect the current sampling and conversion module to the range selection module to sample and convert the voltage signal to generate a conversion signal. The monitoring and calibration control module is connected to the current sampling and conversion module to monitor the conversion signal, generate an alarm signal when the conversion signal deviates from the preset value, and / or calibrate the current on the charging and discharging channel.

2. The battery charge / discharge calibration and monitoring method according to claim 1, characterized in that, When a charging / discharging channel in a single charging / discharging device requires current calibration, the monitoring and calibration control module sequentially activates the required charging / discharging channel to generate current. The current generated in the charging and discharging channel is detected by the first current sensor, and the conversion signal is fed back to the corresponding charging and discharging channel by the monitoring and calibration control module. The offset value is calculated by the charging and discharging channel based on the current generated by itself and the conversion signal, so as to correct the current output by itself.

3. The battery charge / discharge calibration and monitoring method according to claim 1, characterized in that, Multiple charging and discharging devices are divided into multiple groups, and a second current sensor is set up for each group. The corresponding connection line is selected from each charging and discharging device in the group, and the current on the selected connection line is measured by the second current sensor. Half of the connection line passes through the second current sensor in the forward direction and the other half of the connection line passes through the second current sensor in the reverse direction. Select the appropriate connecting wire from the connecting wires measured by each of the second current sensors, and use the main current sensor to measure the current on the selected connecting wire. In this case, half of the connecting wire passes through the main current sensor in the forward direction and the other half passes through the main current sensor in the reverse direction.

4. The battery charge / discharge calibration and monitoring method according to claim 3, characterized in that, For the current set of charging and discharging devices, the charging and discharging channels connected to the connection line passing through the second current sensor are turned on in turn by the monitoring and calibration control module. Based on the measurement of the current on the corresponding charging and discharging channels by the main current sensor, the second current sensor, and the first current sensor in one of the current charging and discharging devices in the current group, the calibration of the second current sensor and the corresponding first current sensor by the main current sensor is completed. Based on the measurement of the current on the corresponding charging and discharging channel by the second current sensor and the first current sensor in the next charging and discharging device in the current group of charging and discharging devices, the calibration of the second current sensor with the corresponding first current sensor is completed, and so on to complete the calibration.

5. The battery charge / discharge calibration and monitoring method according to claim 1, characterized in that, Pre-reserved cables are set according to the number of first current sensors, and each pre-reserved cable passes through the corresponding first current sensor in the same direction. One or more reserved cables are connected in series with the current source using a jumper cable; The charging and discharging control system adjusts the current generated by the current source and calibrates the first current sensor when the detected current of the first current sensor deviates from the preset value.

6. The battery charge / discharge calibration and monitoring method according to claim 1, characterized in that, A fixing member is fixedly installed in the first through hole on the first current sensor body, and multiple second through holes for the connecting wires to pass through are formed on the fixing member; and / or The range selection module includes a first range resistor, a second range resistor, and a switch. The first end of the first range resistor and the first end of the second range resistor are connected to a reference voltage. The second end of the first range resistor is connected to the first end of the switch. The second end of the switch and the second end of the second range resistor are connected to a first current sensor and a current sampling conversion module.

7. The battery charge / discharge calibration and monitoring method according to claim 1, characterized in that, The first current sensor includes a first magnetic ring, a first coil wound on the first magnetic ring, a second magnetic ring, a second coil wound on the second magnetic ring, a third magnetic ring, a third coil wound on the third magnetic ring, a fourth magnetic ring, a fourth coil wound on the fourth magnetic ring, a self-excited oscillation amplifier circuit, an integrating circuit, a filtering circuit, a comparison circuit, a driving circuit, and an amplifying circuit. The self-excited oscillation amplifier circuit is connected to the first end and the second end of the first coil. The self-excited oscillation amplifier circuit generates an excitation signal input to the first coil. The integrator circuit is connected to the output end of the self-excited oscillation amplifier circuit and the first end of the second coil to phase-shift and amplify the excitation signal, generating a compensation signal that is sent to the second coil to cancel noise signals on the first coil. The filter circuit is connected to the second end of both the first and second coils to filter the compensation signal output from the second coil. The filtered compensation signal is then superimposed with the excitation signal output from the first coil and filtered again to obtain a DC signal. The comparator circuit is connected to the first end of the third coil and the filter circuit. The second end of the third coil is connected to ground voltage. The comparator circuit compares the signal output from the third coil with the DC signal to generate a control signal. The drive circuit is connected to the comparator circuit to generate a corresponding drive signal based on the control signal. The amplifier circuit is connected to the drive circuit to amplify the signal based on the drive signal, generating an amplified signal. The first end of the fourth coil is connected to the amplifier circuit to receive the amplified signal, and the second end of the fourth coil is used to output a detection signal.

8. The battery charge / discharge calibration and monitoring method according to claim 1, characterized in that, The current sampling and conversion module includes a first bias resistor, a second bias resistor, a third bias resistor, a fourth bias resistor, an operational amplifier, an analog-to-digital conversion module, and a first control module; The first end of the first bias resistor is connected to the reference voltage. The second end of the first bias resistor is connected to the first end of the third bias resistor and the positive input terminal of the operational amplifier. The first end of the second bias resistor is connected to the range selection module. The second end of the second bias resistor is connected to the negative input terminal of the operational amplifier and the first end of the fourth bias resistor. The second end of the fourth bias resistor is connected to the output terminal of the operational amplifier and the analog-to-digital converter module. The second end of the third bias resistor is connected to the analog-to-digital converter module. The analog-to-digital converter module is connected to the first control module. The first control module is connected to the monitoring and calibration control module.

9. The battery charge / discharge calibration and monitoring method according to claim 8, characterized in that, The current sampling and conversion module further includes a first filter capacitor, a second filter capacitor, a third filter capacitor, a fourth filter capacitor, a first filter resistor, and a second filter resistor; the first terminal of the first filter capacitor is connected to the first terminal of the first bias resistor, the second terminal of the first filter capacitor is connected to the second terminal of the second filter capacitor and ground voltage, the first terminal of the second filter capacitor is connected to the first terminal of the second bias resistor, the first terminal of the first filter resistor is connected to the second terminal of the third bias resistor, the second terminal of the first filter resistor is connected to the first terminal of the third filter capacitor and analog-to-digital conversion module, the first terminal of the second filter resistor is connected to the output terminal of the operational amplifier, the second terminal of the second filter resistor is connected to the first terminal of the fourth filter capacitor and analog-to-digital conversion module, and the second terminals of the third filter capacitor and the fourth filter capacitor are connected to ground voltage.

10. A battery charge / discharge calibration and monitoring system, characterized in that, Based on the battery charging and discharging calibration and monitoring method according to any one of claims 1 to 9, the calibration and monitoring system includes a first current sensor, a range selection module, a current sampling and conversion module, and a monitoring and calibration control module disposed in the charging and discharging equipment; The first current sensor is used to measure the current on the connecting wire and generate a detection signal, wherein half of the connecting wire passes through the first current sensor in the forward direction and the other half of the connecting wire passes through the first current sensor in the reverse direction. The range selection module is connected to the first current sensor. The range selection module enters the calibration mode or monitoring mode based on the selection of the corresponding range, and generates a corresponding voltage signal based on the magnitude of the current measured by the first current sensor. The current sampling and conversion module is connected to the range selection module to sample and convert the voltage signal to generate a conversion signal. The monitoring and calibration control module is connected to the current sampling and conversion module to monitor the conversion signal, generate an alarm signal when the conversion signal deviates from the preset value, and / or calibrate the current on the charging and discharging channel.

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