Battery module power control method, device and system

Abstract

The invention discloses a battery module power control method, device and system. Only the controller and the converter are needed, and low-cost and simple-layout battery module power control is achieved. And the controller obtains a pulse width modulation (PWM) signal according to duty ratio modulation related to the power of the battery module, and sends the PWM signal to the converter. And the transmission delay of the PWM signal is small, the signal is continuous, and no jump exists, so that the timeliness and the stability of power control are improved. And the converter demodulates the PWM signal, and controls the power of the battery module according to the obtained duty ratio, so that the charging and discharging power of the battery module is balanced, and the circulating current problem is inhibited. For example, data calibration can be realized according to the PWM signal, so that the precision of the duty ratio obtained by demodulation is improved. And the on-off command of the converter can be realized according to the PWM signal, and the charging and discharging power of the battery module can be flexibly changed.

Description

Technical Field

[0001] This application relates to the technical field of energy storage systems, and particularly to a method, device, and system for controlling the power of battery modules. Background Art

[0002] In an energy storage system, multiple battery modules are usually configured to perform charging and discharging operations. However, when multiple battery modules work simultaneously, it is difficult to balance the charging and discharging powers of each battery module, and a circulating current problem is likely to occur, that is, the current flows between the battery modules instead of all flowing to the load or the power grid, resulting in power loss and instability of the energy storage system.

[0003] In the prior art, there is a method of using the 485 communication protocol (Recommended Standard 485, RS485) or the Controller Area Network (CAN) to send commands to the converters corresponding to each battery module to adjust the charging and discharging powers of the battery modules. However, it is necessary to configure communication-related components in the energy storage system, which not only incurs costs but also increases the complexity of the energy storage system. Summary of the Invention

[0004] Based on the above problems, this application provides a method, device, and system for controlling the power of battery modules to simply control the charging and discharging powers of the battery modules.

[0005] This application discloses a method for controlling the power of a battery module, which is applied to a converter corresponding to the battery module. The method includes:

[0006] Receiving a Pulse Width Modulation (PWM) signal from a controller; the PWM signal is modulated by the controller according to a duty cycle related to the power of the battery module;

[0007] Demodulating the PWM signal to obtain the duty cycle;

[0008] Controlling the power of the battery module according to the duty cycle.

[0009] Optionally, the demodulating the PWM signal to obtain the duty cycle includes:

[0010] Filtering the PWM signal to obtain an analog signal;

[0011] Converting the analog signal into a sampled voltage value;

[0012] Calculating the ratio of the sampled voltage value to the supply voltage value of the battery module to obtain the duty cycle.

[0013] Optionally, the duty cycle includes a control value, a first calibration value, and a second calibration value for calibrating the power control of the battery module. Controlling the power of the battery module according to the duty cycle includes:

[0014] Demodulate the PWM signal at a first moment to obtain a first duty cycle;

[0015] When the first duty cycle is within a first range, record the first duty cycle as the first calibration value;

[0016] Demodulate the PWM signal at a second moment to obtain a second duty cycle; the second moment is after the first moment;

[0017] When the second duty cycle is within a second range, record the second duty cycle as the second calibration value;

[0018] Calculate a calibration parameter based on the first duty cycle, the second duty cycle, the first calibration value, and the second calibration value;

[0019] Demodulate the PWM signal at a third moment to obtain the control value; the third moment is after the second moment;

[0020] Calibrate the control value based on the calibration parameter, and control the power of the battery module according to the calibrated control value.

[0021] Optionally, calculating the calibration parameter based on the first duty cycle, the second duty cycle, the first calibration value, and the second calibration value includes:

[0022] Calculate the calibration parameter according to the following formula:

[0023]

[0024] In the formula, y1 is the first duty cycle, a is the gain in the calibration parameter, p1 is the first calibration value, b is the offset of the calibration parameter, y2 is the second duty cycle, and p2 is the second calibration value.

[0025] Optionally, calibrating the control value based on the calibration parameter includes:

[0026] Calibrate the control value according to the following formula:

[0027]

[0028] In the formula, x is the calibrated control value, and y is the control value.

[0029] Optionally, controlling the power of the battery module according to the duty cycle includes:

[0030] When the first duty ratio reaches the first calibration value, stop the converter from controlling the power of the battery module;

[0031] When the second duty ratio reaches the second calibration value, start the converter to control the power of the battery module.

[0032] Optionally, controlling the power of the battery module according to the duty ratio includes:

[0033] When the duty ratio is within the third range, control the battery module to charge and control the charging power of the battery module according to the value of the duty ratio;

[0034] When the duty ratio is within the fourth range, control the battery module to discharge and control the discharging power of the battery module according to the value of the duty ratio;

[0035] When the duty ratio is at the intersection of the third range and the fourth range, control the battery module neither to charge nor to discharge.

[0036] Optionally, the PWM signal is demodulated by a low-pass filter, and the low-pass filter is a resistor-capacitor (RC) circuit.

[0037] Based on the above method for controlling the power of a battery module, the present application also discloses a device for controlling the power of a battery module, which is applied to a converter corresponding to the battery module. The device includes: a receiving unit, a demodulating unit, and a controlling unit;

[0038] The receiving unit is configured to receive a pulse width modulation (PWM) signal from a controller; the PWM signal is modulated by the controller according to a duty ratio related to the power of the battery module;

[0039] The demodulating unit is configured to demodulate the PWM signal to obtain the duty ratio;

[0040] The controlling unit is configured to control the power of the battery module according to the duty ratio.

[0041] Optionally, the demodulating unit includes:

[0042] A filtering subunit configured to filter the PWM signal to obtain an analog signal;

[0043] A converting subunit configured to convert the analog signal into a sampled voltage value;

[0044] A calculating subunit configured to calculate the ratio of the sampled voltage value to the supply voltage value of the battery module to obtain the duty ratio.

[0045] Optionally, the duty cycle includes a control value, as well as a first calibration value and a second calibration value for calibrating the power control of the battery module. The control unit includes:

[0046] A first demodulation sub-unit for demodulating the PWM signal at a first moment to obtain a first duty cycle;

[0047] A first recording sub-unit for recording the first duty cycle as the first calibration value when the first duty cycle is within a first range;

[0048] A second demodulation sub-unit for demodulating the PWM signal at a second moment to obtain a second duty cycle; the second moment is after the first moment;

[0049] A second recording sub-unit for recording the second duty cycle as the second calibration value when the second duty cycle is within a second range;

[0050] A parameter calculation sub-unit for calculating a calibration parameter based on the first duty cycle, the second duty cycle, the first calibration value, and the second calibration value;

[0051] A control value acquisition sub-unit for demodulating the PWM signal at a third moment to obtain the control value; the third moment is after the second moment;

[0052] A calibration sub-unit for calibrating the control value based on the calibration parameter and controlling the power of the battery module according to the calibrated control value.

[0053] Optionally, the parameter calculation sub-unit is used for:

[0054] Calculating the calibration parameter according to the following formula:

[0055]

[0056] In the formula, y1 is the first duty cycle, a is the gain in the calibration parameter, p1 is the first calibration value, b is the offset of the calibration parameter, y2 is the second duty cycle, and p2 is the second calibration value.

[0057] Optionally, the calibration sub-unit is used for:

[0058] Calibrating the control value according to the following formula:

[0059]

[0060] In the formula, x is the calibrated control value and y is the control value.

[0061] Optionally, the control unit includes:

[0062] A stop subunit, configured to stop the converter from controlling the power of the battery module when the first duty cycle is the first calibration value;

[0063] A start subunit, configured to start the converter to control the power of the battery module when the second duty cycle is the second calibration value.

[0064] Optionally, the control unit includes:

[0065] A charging subunit, configured to control the battery module to charge when the duty cycle is within the third range, and control the charging power of the battery module according to the value of the duty cycle;

[0066] A discharging subunit, configured to control the battery module to discharge when the duty cycle is within the fourth range, and control the discharging power of the battery module according to the value of the duty cycle;

[0067] A waiting subunit, configured to control the battery module neither to charge nor to discharge when the duty cycle is at the intersection of the third range and the fourth range.

[0068] Optionally, the PWM signal is demodulated by a low-pass filter, and the low-pass filter is a resistor-capacitor RC circuit.

[0069] Based on the above method for controlling the power of a battery module, the present application also discloses a system for controlling the power of a battery module, configured to implement the above method. The system includes: a controller, a battery module, and a converter corresponding to the battery module;

[0070] The controller is configured to modulate a duty cycle related to the power of the battery module into a pulse width modulation (PWM) signal;

[0071] The converter is configured to receive the PWM signal from the controller, demodulate the PWM signal to obtain a duty cycle, and control the power of the battery module according to the duty cycle.

[0072] The present application discloses a method, device and system for power control of a battery module. Only a controller and a converter are required to achieve low-cost and simple-layout power control of the battery module. The controller modulates a duty cycle related to the power of the battery module to obtain a pulse width modulation (PWM) signal, and sends it to the converter. The PWM signal has a small transmission delay, the signal is continuous and there is no jump, thereby improving the timeliness and stability of power control. The converter demodulates the PWM signal and controls the power of the battery module according to the obtained duty cycle, thereby balancing the charging and discharging powers of the battery module and suppressing the circulating current problem. For example, data calibration can be implemented according to the PWM signal to improve the accuracy of the demodulated duty cycle. The on / off command of the converter can also be implemented according to the PWM signal, and the charging and discharging powers of the battery module can be flexibly changed, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0074] Figure 1a It is a schematic flowchart of a method for power control of a battery module disclosed in an embodiment of the present application;

[0075] Figure 1b It is a schematic diagram of the calibration principle disclosed in an embodiment of the present application;

[0076] Figure 1c It is a schematic diagram of the charging / discharging power of the converter disclosed in an embodiment of the present application;

[0077] Figure 2 It is a schematic flowchart of another method for power control of a battery module disclosed in an embodiment of the present application;

[0078] Figure 3 It is a schematic structural diagram of a device for power control of a battery module disclosed in an embodiment of the present application;

[0079] Figure 4 It is a schematic structural diagram of a system for power control of a battery module disclosed in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0080] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts belong to the scope of protection of the present application.

[0081] Embodiment 1: The present application discloses a method for controlling the power of a battery module.

[0082] Specifically, please refer to Figure 1a , a method for controlling the power of a battery module disclosed in this embodiment includes the following steps:

[0083] Step 101: Receive a Pulse Width Modulation (PWM) signal from a controller.

[0084] In the method of this embodiment, the controller can first preset the duty cycle according to the information to be transmitted. This duty cycle is related to the power of the battery module, so that the controller can accurately instruct relevant operations and achieve fine control of the battery module or the converter. Subsequently, the controller modulates the duty cycle to obtain a Pulse Width Modulation (PWM) signal. As an alternative method, the selection of the PWM frequency can be based on the impedance and bandwidth of the hardware circuit, such as 1 MHz. By flexibly selecting an appropriate PWM frequency, the quality of signal transmission can be optimized, signal distortion can be reduced, and at the same time, compatibility with the hardware circuit can be ensured. Moreover, the PWM signal is easy to generate and process. By adopting the PWM control strategy, the number of components used can be reduced, the circuit design can be simplified, and thus the cost can be reduced.

[0085] Specifically, the Micro Controller Unit (MCU) in the controller is responsible for scheduling the charging, discharging, neither charging nor discharging of the battery module, controlling the operation and stop of the converter, calibrating the control of the battery module, etc. These operations are all related to the power of the battery module and respectively correspond to the duty cycles for controlling the power of the battery module. The corresponding relationship can be shown in the following table:

[0086] Table 1 Pulse Width Decoding Information

[0087]

[0088]

[0089] In the method of this embodiment, the controller may include an MCU, a PWM modulator, and a signal driving and amplifying device. The PWM modulator may also be integrated in the MCU to reduce the complexity of the energy storage system and efficiently utilize resources. In the controller, the MCU is used to flexibly preset the duty cycle according to control requirements and send the duty cycle to the PWM modulator. The PWM modulator is used to modulate the duty cycle into a PWM signal, and the signal driving and amplifying device is used to increase the signal driving ability, enhance the anti-interference ability of the PWM signal, ensure the stability and reliability of the signal, and at the same time improve the transmission distance of the PWM signal, which is beneficial to applications in larger energy storage systems.

[0090] In the method of this embodiment, the controller efficiently and directly sends the PWM signal to the converter corresponding to the battery module to be controlled, uses the PWM signal to transmit information to the converter, and instructs the operation of the converter and the battery module, so that the battery module can perform operations such as charging and discharging in a timely manner. Among them, the PWM signal can be transmitted through the battery charge and discharge control communication line, avoiding complex wiring and reducing the cost of the energy storage system.

[0091] In the method of this embodiment, after receiving the PWM signal, the converter can perform preprocessing on it. Specifically, the signal isolation device in the converter receives the PWM signal and isolates it, which can effectively block or reduce the influence of external electromagnetic interference on the PWM signal, thereby improving the anti-interference ability of the energy storage system. At the same time, after isolating the noise or interference carried in the PWM signal, the safe operation of the subsequent circuit can be protected, making the transmission of the PWM signal more reliable and stable.

[0092] Step 102: Demodulate the PWM signal to obtain the duty cycle.

[0093] In the method of this embodiment, the converter can demodulate the PWM signal to obtain the duty cycle therein, that is, the duty cycle sent by the controller for indicating relevant operations, so as to understand and execute the intention of the controller. Specifically, the low-pass filter in the converter filters the PWM signal to obtain an analog signal. Among them, the low-pass filter can be implemented by a resistor-capacitance (RC) circuit with a simple structure, low cost, and easy implementation. By selecting appropriate RC values, the bandwidth of the RC circuit is made lower than the PWM frequency, such as 500 kHz. Thereby effectively filtering out the high-frequency components in the PWM signal and obtaining a stable analog signal.

[0094] Subsequently, the analog-to-digital converter (ADC) in the converter samples the analog signal and converts it into a specific voltage value, i.e., the sampled voltage value. The MCU in the converter calculates the ratio of the sampled voltage value to the supply voltage value of the current battery module, which is the duty cycle. As an alternative method, the ADC in the converter can also be integrated into the MCU to reduce the number of components and lower the cost.

[0095] Step 103: Control the power of the battery module according to the duty cycle.

[0096] In the method of this embodiment, the converter flexibly controls the power of the battery module according to the demodulated duty cycle to ensure the stable operation of the battery module and meet the control requirements. Due to sampling errors, the duty cycles demodulated by each converter may not be the same, which may also lead to unbalanced charge and discharge power and the generation of circulating current. Then, as an alternative method, the sampling error, that is, the power control of the battery module, can be calibrated first. Generally, the sampling error is a linear error, and two calibration points are required for calibration.

[0097] In the method of this embodiment, the duty cycle includes a control value for adjusting the power of the battery module, as well as a first calibration value and a second calibration value for calibrating the power control of the battery module, etc. The converter first demodulates the PWM signal at the first moment to obtain the first duty cycle. When the first duty cycle is within the first range, record the first duty cycle as the first calibration value. Among them, the first range can be 0% to 20%. For example, when the first duty cycle is between 0% and 20%, record the first duty cycle as 10%, that is, the first calibration value in Table 1.

[0098] Correspondingly, the converter then demodulates the PWM signal at the second moment after the first moment to obtain the second duty cycle. When the second duty cycle is within the second range, record the second duty cycle as the second calibration value. Among them, the second range can be 80% to 100%. For example, when the second duty cycle is between 80% and 100%, record the second duty cycle as 90%, that is, the second calibration value in Table 1.

[0099] In the method of this embodiment, calibration parameters are calculated based on the first duty cycle, the second duty cycle, the first calibration value, and the second calibration value. Figure 1b Schematic diagram of the calibration principle disclosed in the embodiments of this application, for Figure 1bThe content is taken as an example. Among them, the PWM duty cycle obtained by demodulating the PWM signal is used as the abscissa, and the sampled voltage value is used as the ordinate. v1 is the first sampled voltage value, and the ratio of it to the supply voltage value Vcc of the battery module is the first duty cycle, which is recorded as the first calibration value of 10%. v2 is the second sampled voltage value, and the ratio of it to the supply voltage value Vcc of the battery module is the second duty cycle, which is recorded as the second calibration value of 90%. It is necessary to restore it to the duty cycle preset by the controller, that is, the restored duty cycle on the left side of the figure.

[0100] Specifically, it can be calculated according to the following formula:

[0101]

[0102] In the formula, y1 is the first duty cycle, a is the gain in the calibration parameters, p1 is the first calibration value, b is the offset of the calibration parameters, y2 is the second duty cycle, and p2 is the second calibration value.

[0103] According to formula (1), the gain and offset can be calculated respectively as:

[0104]

[0105] In the method of this embodiment, after calibration, the duty cycle reduction degree obtained by demodulating each converter is relatively high, that is, it can be close to the same as the duty cycle preset by the controller, so as to balance the power of each battery module. Specifically, continue to demodulate the PWM signal at the third moment after the second moment, and the obtained value is the control value for controlling the power of the battery module. After calibrating the control value based on the calibration parameters, the power of the battery module can be controlled according to the calibrated control value. Specifically, the control value can be calibrated according to the following formula:

[0106]

[0107] In the formula, x is the calibrated control value, and y is the control value.

[0108] In the method of this embodiment, the calibrated control value accurately restores the duty cycle preset by the controller, thereby realizing the precise regulation of the power of the battery module, effectively reducing the unstable factors caused by sampling errors, and improving the reliability of the energy storage system.

[0109] In the method of this embodiment, the on / off command of the converter can also be executed according to the duty cycle to accurately control the operating state of the converter and realize the flexible control of the converter. Specifically, as shown in Table 1, when the first duty cycle is the first calibration value, the converter stops controlling the power of the battery module. When the second duty cycle is the second calibration value, the converter starts to control the power of the battery module. At this time, the converter starts but does not control the battery module to charge or discharge.

[0110] In the method of this embodiment, when the duty cycle is in the third range (30% - 50% as shown in Table 1), the battery module is controlled to charge, and the charging power of the battery module is controlled according to the value of the duty cycle. When the duty cycle is in the fourth range (50% - 70% as shown in Table 1), the battery module is controlled to discharge, and the discharging power of the battery module is controlled according to the value of the duty cycle. When the duty cycle is at the intersection of the third range and the fourth range (50% as shown in Table 1), the battery module is controlled neither to charge nor to discharge. When the duty cycle is in the third range and the fourth range, the converter can control the power of the battery module according to the Figure 1c charging / discharging power shown.

[0111] The method described in this embodiment realizes efficient power control of the battery module through a converter and a controller with lower cost and simpler layout. At the same time, the control process is precisely calibrated, which can balance the charging / discharging power of the battery module and effectively suppress the occurrence of the circulating current problem. In addition, using PWM signals for communication between the controller and the converter has the advantages of small signal transmission delay and continuous signal without jumps, further improving the stability and reliability of the energy storage system.

[0112] Embodiment 2: The present application discloses another method for controlling the power of a battery module. Please refer to Figure 2 This embodiment describes the entire process of controlling the power of the battery module.

[0113] Step 201: Demodulate the PWM signal from the controller to obtain the first duty cycle.

[0114] Step 202: When the first duty cycle is in the first range, record the first duty cycle as the first calibration value.

[0115] Step 203: Demodulate the PWM signal from the controller to obtain the second duty cycle.

[0116] Step 204: When the second duty cycle is in the second range, record the second duty cycle as the second calibration value.

[0117] Step 205: Calculate the calibration parameter according to the first duty cycle, the second duty cycle, the first calibration value, and the second calibration value.

[0118] Step 206: Demodulate the PWM signal from the controller to obtain the control value.

[0119] Step 207: Calibrate the control value based on the calibration parameter.

[0120] Step 208: When the control value is in the third range, control the battery module to charge, and control the charging power of the battery module according to the value of the control value.

[0121] Step 209: When the control value is within the fourth range, control the battery module to discharge, and control the discharge power of the battery module according to the value of the control value.

[0122] Based on the method for controlling the power of a battery module disclosed in the above embodiments, this embodiment correspondingly discloses a device for controlling the power of a battery module, which is applied to a converter corresponding to the battery module. Please refer to Figure 3 The device for controlling the power of a battery module includes: a receiving unit 301, a demodulating unit 302, and a control unit 303;

[0123] The receiving unit 301 is configured to receive a pulse width modulation PWM signal from a controller; the PWM signal is modulated by the controller according to a duty cycle related to the power of the battery module;

[0124] The demodulating unit 302 is configured to demodulate the PWM signal to obtain the duty cycle;

[0125] The control unit 303 is configured to control the power of the battery module according to the duty cycle.

[0126] Optionally, the demodulating unit 302 includes:

[0127] A filtering subunit, configured to filter the PWM signal to obtain an analog signal;

[0128] A conversion subunit, configured to convert the analog signal into a sampled voltage value;

[0129] A calculating subunit, configured to calculate a ratio of the sampled voltage value to the supply voltage value of the battery module to obtain the duty cycle.

[0130] Optionally, the duty cycle includes a control value, as well as a first calibration value and a second calibration value for calibrating the power control of the battery module. The control unit 303 includes:

[0131] A first demodulating subunit, configured to demodulate the PWM signal at a first moment to obtain a first duty cycle;

[0132] A first recording subunit, configured to record the first duty cycle as the first calibration value when the first duty cycle is within a first range;

[0133] A second demodulating subunit, configured to demodulate the PWM signal at a second moment to obtain a second duty cycle; the second moment is after the first moment;

[0134] A second recording subunit, configured to record the second duty cycle as the second calibration value when the second duty cycle is within a second range;

[0135] A parameter calculation subunit, configured to calculate a calibration parameter according to the first duty ratio, the second duty ratio, the first calibration value, and the second calibration value;

[0136] A control value acquisition subunit, configured to demodulate the PWM signal at a third moment to obtain the control value; the third moment is after the second moment;

[0137] A calibration subunit, configured to calibrate the control value based on the calibration parameter and control the power of the battery module according to the calibrated control value.

[0138] Optionally, the parameter calculation subunit is configured to:

[0139] Calculate the calibration parameter according to the following formula:

[0140]

[0141] In the formula, y1 is the first duty ratio, a is the gain in the calibration parameter, p1 is the first calibration value, b is the offset of the calibration parameter, y2 is the second duty ratio, and p2 is the second calibration value.

[0142] Optionally, the calibration subunit is configured to:

[0143] Calibrate the control value according to the following formula:

[0144]

[0145] In the formula, x is the calibrated control value, and y is the control value.

[0146] Optionally, the control unit 303 includes:

[0147] A stop subunit, configured to stop the control of the power of the battery module by the converter when the first duty ratio is the first calibration value;

[0148] A start subunit, configured to start the control of the power of the battery module by the converter when the second duty ratio is the second calibration value.

[0149] Optionally, the control unit 303 includes:

[0150] A charging subunit, configured to control the charging of the battery module when the duty ratio is within the third range and control the charging power of the battery module according to the value of the duty ratio;

[0151] A discharging subunit, configured to control the discharging of the battery module when the duty ratio is within the fourth range and control the discharging power of the battery module according to the value of the duty ratio;

[0152] A waiting subunit, configured to control the battery module to neither charge nor discharge when the duty ratio is at the intersection of the third range and the fourth range.

[0153] Optionally, the PWM signal is demodulated by a low-pass filter, and the low-pass filter is a resistor-capacitor (RC) circuit.

[0154] Based on the above method for controlling the power of a battery module, the present application also discloses a system for controlling the power of a battery module, which is used to implement the above method. Please refer to Figure 4 , the system includes: a controller, a battery module (Battery 1, Battery 2, and Battery 3), and converters (Converter 1, Converter 2, and Converter 3) corresponding to the battery module;

[0155] The controller is configured to modulate a duty ratio related to the power of the battery module into a pulse width modulation (PWM) signal;

[0156] The converter is configured to receive the PWM signal from the controller, demodulate the PWM signal to obtain a duty ratio, and control the power of the battery module according to the duty ratio.

[0157] The embodiments in this specification are described in a progressive manner. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For related parts, please refer to the description in the method part.

[0158] It should also be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprises", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0159] The steps of the methods or algorithms described in connection with the embodiments disclosed herein may be implemented directly in hardware, in software modules executed by a processor, or in a combination thereof. The software modules may be located in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0160] The features described in the embodiments of this specification may be replaced or combined with each other, enabling those skilled in the art to implement or use this application.

[0161] The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling battery module power, characterized in that: Applied to a converter corresponding to a battery module, the method comprises: Receiving a pulse width modulation (PWM) signal from a controller; the PWM signal is modulated by the controller according to a duty cycle related to the power of the battery module; Demodulating the PWM signal to obtain the duty cycle; The power of the battery module is controlled according to the duty cycle.

2. The method according to claim 1, characterized in that The demodulating the PWM signal to obtain the duty cycle includes: Filtering the PWM signal to obtain an analog signal; Converting the analog signal into a sampled voltage value; The duty cycle is obtained by calculating a ratio of the sampled voltage value to a power supply voltage value of the battery module.

3. The method according to claim 1, characterized in that The duty cycle includes a control value, and a first calibration value and a second calibration value for calibrating power control of the battery module, and controlling the power of the battery module according to the duty cycle includes: Demodulating the PWM signal at a first moment to obtain a first duty cycle; When the first duty cycle is in a first range, recording the first duty cycle as the first calibration value; Demodulating the PWM signal at a second moment to obtain a second duty cycle; the second moment is after the first moment; When the second duty cycle is in a second range, recording the second duty cycle as the second calibration value; Calculate a calibration parameter according to the first duty cycle, the second duty cycle, the first calibration value, and the second calibration value; Demodulating the PWM signal at a third moment to obtain the control value; the third moment is after the second moment; The control value is calibrated based on the calibration parameter, and the power of the battery module is controlled according to the calibrated control value.

4. The method according to claim 3, characterized in that The calculating and obtaining a calibration parameter according to the first duty cycle, the second duty cycle, the first calibration value, and the second calibration value includes: The calibration parameters are calculated according to the following formula: In the formula, y1 is the first duty cycle, a is the gain in the calibration parameter, p1 is the first calibration value, b is the offset of the calibration parameter, y2 is the second duty cycle, and p2 is the second calibration value.

5. The method according to claim 4, characterized in that The calibrating the control value based on the calibration parameter comprises: The control value is calibrated according to the following formula: Wherein, x is the calibrated control value, and y is the control value.

6. The method according to claim 3, characterized in that: The controlling the power of the battery module according to the duty cycle includes: When the first duty cycle is the first calibration value, stopping the converter from controlling the power of the battery module; When the second duty cycle is the second calibration value, the converter is started to control the power of the battery module.

7. The method according to claim 1, characterized in that The controlling the power of the battery module according to the duty cycle includes: When the duty cycle is within the third range, controlling the battery module to charge, and controlling the charging power of the battery module according to the value of the duty cycle; When the duty cycle is within the fourth range, controlling the battery module to discharge, and controlling the discharge power of the battery module according to the value of the duty cycle; When the duty ratio is at an intersection of the third range and the fourth range, the battery module is controlled neither to be charged nor to be discharged.

8. The method according to any one of claims 1 to 7, characterized in that: The PWM signal is demodulated by a low-pass filter, which is a resistor-capacitor RC circuit.

9. A battery module power control device, characterized in that: Applied to a converter corresponding to a battery module, the device comprises: a receiving unit, a demodulation unit and a control unit; The receiving unit is used to receive a pulse width modulation (PWM) signal from a controller; the PWM signal is modulated by the controller according to a duty cycle related to the power of the battery module; The demodulation unit is used to demodulate the PWM signal to obtain the duty cycle; The control unit is used to control the power of the battery module according to the duty cycle.

10. A battery module power control system, characterized in that: For implementing the method according to any one of claims 1 to 8, the system comprises: a controller, a battery module, and a converter corresponding to the battery module; The controller is used to modulate a duty cycle related to the power of the battery module into a pulse width modulation (PWM) signal; The converter is used to receive the PWM signal from the controller, demodulate the PWM signal to obtain a duty cycle, and control the power of the battery module according to the duty cycle.

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