Control system and control method

Abstract

Embodiments of the present application provide a control system and a control method. The control system comprises: an initialization control module configured to determine a first time required for a motor control unit to complete initialization from power up of a supply voltage; a charging control module configured to determine a second time required for an output capacitor of the motor control unit to complete charging from the start of the charging, wherein the output capacitor starts charging when the motor control unit enters an initialization state; and a total time determination module configured to use a greater one of the first time and the second time as a total time spent on the initialization of the motor control unit and the charging of the output capacitor.

Description

Control system and control method Technical Field

[0001] The present application relates to the field of circuit technology, and more specifically, to a control system and a control method. Background Art

[0002] In the design of automotive motor control circuits, rectifier circuits convert AC power into DC power. A large-capacity output capacitor is required after the rectifier circuit. Its charge-discharge characteristics transform the rectified pulsed DC voltage into a stable DC voltage, eliminating harmful AC components and discharging them into the ground. Furthermore, the energy stored in the large-capacity output capacitor is used to release the high current required during motor startup, ensuring a more immediate transient response and smoother motor operation.

[0003] As motor power increases, the required output capacitor increases, and charging time increases. After the motor control unit (MCU) is powered on, it must undergo initialization and self-tests for system fault diagnosis before the downstream system can function properly. Furthermore, as automotive electronics become increasingly complex, the system's self-tests are becoming more complex, increasing the time it takes to boot up the MCU. This accumulated time can exceed system requirements, causing the system to malfunction.

[0004] Summary of the Invention

[0005] In one aspect, an embodiment of the present application provides a control system, including: an initialization control module, configured to determine a first time required for a motor control unit to power on a supply voltage and complete initialization; a charging control module, configured to determine a second time required for an output capacitor of the motor control unit to start charging and be fully charged, wherein the output capacitor starts charging when the motor control unit enters initialization; and a total time determination module, configured to use the larger of the first time and the second time as the total time spent on initializing the motor control unit and charging the output capacitor.

[0006] In some implementations, the charging control module includes: a charging module, configured to utilize the body diode of the power tube of the charging control module to initially charge the output capacitor with the power supply voltage and charge it to a first threshold voltage; and a boost module, configured to boost the charging voltage of the output capacitor by the charging module to obtain a boosted voltage when the output capacitor is charged to the first threshold voltage, wherein the boosted voltage causes the power tube to be fully turned on; and the charging module is further configured to utilize the fully turned-on power tube to continue charging the output capacitor with the power supply voltage from the first threshold voltage until it is fully charged, wherein the sum of the initial charging time and the continued charging time is a second time, and wherein the power supply voltage is greater than or equal to the conduction voltage of the body diode of the power tube, but less than the fully turned-on voltage of the power tube, and the boosted voltage is greater than or equal to the fully turned-on voltage of the power tube.

[0007] In some implementations, the charging module includes: a first power tube, serving as a power tube, having a first end, a second end, and a third end, wherein the first end of the first power tube is used to receive a supply voltage, the second end of the first power tube provides a charging voltage to the output capacitor, and the third end of the first power tube is used to receive the boosted voltage; a first resistor and a first diode connected in parallel, connected between the first end and the third end of the first power tube, wherein the positive electrode of the first diode is connected to the first end of the first power tube, and the negative electrode of the first diode is connected to the third end of the first power tube; and a second resistor, connected between the second end and the third end of the first power tube.

[0008] In some implementations, the first power tube is a metal oxide semiconductor (MOS) tube, the first end of the first power tube is the source of the MOS tube, the second end of the first power tube is the drain of the MOS tube, and the third end of the first power tube is the gate of the MOS tube.

[0009] In some implementations, the first power transistor is an NMOS transistor.

[0010] In some implementations, the boost module includes: an input end configured to receive a charging voltage provided by the second end of the first power tube; a conversion module configured to perform a boost conversion on the charging voltage; and an output end configured to output the boosted voltage to the third end of the first power tube.

[0011] In some implementations, the first threshold voltage is a minimum operating voltage of the conversion module.

[0012] In some implementations, the initialization control module includes: a second power tube having a first end, a second end, and a third end, wherein the first end of the second power tube is used to receive a power supply voltage, and the second end of the second power tube provides a signal indicating that the motor control unit has completed initialization via a second diode and a third resistor; and a third power tube having a first end, a second end, and a third end, wherein the first end of the third power tube is connected to the third end of the second power tube via a fourth resistor, the second end of the third power tube is grounded, and the third end of the third power tube receives a signal indicating that the motor control unit has started via a fifth resistor.

[0013] In some implementations, the second power tube is a PNP tube, wherein the first end of the second power tube is the emitter of the PNP tube, the second end of the second power tube is the collector of the PNP tube, and the third end of the second power tube is the base of the PNP tube.

[0014] In some implementations, the third power tube is an NPN tube, wherein the first end of the third power tube is the collector of the NPN tube, the second end of the third power tube is the emitter of the NPN tube, and the third end of the third power tube is the base of the NPN tube.

[0015] In some implementations, the output capacitor includes: a first capacitor and a second capacitor connected in parallel between the second end of the first power transistor and ground.

[0016] In some implementations, when the charging voltage is greater than or equal to a second threshold voltage, the output capacitor is completely charged, where the second threshold voltage is higher than the first threshold voltage.

[0017] In one aspect, an embodiment of the present application provides a motor control unit, comprising: any one of the control systems described above.

[0018] In one aspect, an embodiment of the present application provides a control method, including: determining a first time required for a motor control unit to be powered on with a supply voltage and to complete initialization; determining a second time required for the output capacitor of the motor control unit to be fully charged from the beginning, wherein the output capacitor starts to be charged when the motor control unit enters initialization; and using the larger of the first time and the second time as the total time spent on initializing the motor control unit and charging the output capacitor.

[0019] In some implementations, determining the second time includes: utilizing the body diode of the power tube of the charging control module to initially charge the output capacitor with the power supply voltage and charge it to a first threshold voltage; when the output capacitor is charged to the first threshold voltage, boosting the charging voltage of the charging module to the output capacitor to obtain a boosted voltage, wherein the boosted voltage causes the power tube to be fully turned on; and utilizing the fully turned-on power tube to continue charging the output capacitor with the power supply voltage from the first threshold voltage until it is fully charged, wherein the sum of the initial charging time and the continued charging time is the second time, and wherein the power supply voltage is greater than or equal to the conduction voltage of the body diode of the power tube, but less than the fully turned-on voltage of the power tube, and the boosted voltage is greater than or equal to the fully turned-on voltage of the power tube.

[0020] In some implementations, the control method of the embodiment of the present application further includes: determining whether the charging of the output capacitor is completed based on a comparison of the charging voltage and a second threshold voltage, wherein the second threshold voltage is higher than the first threshold voltage.

[0021] According to the control system and control method of the embodiments of the present application, during the initialization process of the motor control unit, the body diode of the power transistor in the charging module is used to charge the output capacitor. When the output capacitor is charged to a predetermined value, the peripheral excitation signal is controlled to fully turn on the power transistor, and the output capacitor continues to be charged until it is fully charged. Based on this solution, the total time for initializing the motor control unit and charging the output capacitor can be reduced, thereby meeting system requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly describes the drawings involved in the embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without creative work. In the drawings:

[0023] FIG1 shows a schematic circuit diagram of a conventional control system.

[0024] FIG2 shows a control timing diagram of the conventional control system in FIG1 ;

[0025] FIG3 shows a schematic block diagram of a control system according to an embodiment of the present application;

[0026] FIG4 shows a schematic block diagram of a charging control module according to an embodiment of the present application;

[0027] FIG5 shows a schematic circuit diagram of a control system according to an embodiment of the present application;

[0028] FIG6 shows a control timing diagram of a control system according to an embodiment of the present application;

[0029] FIG7 shows an equivalent diagram of a charging circuit for an output capacitor;

[0030] FIG8 shows a flow chart of a control method according to an embodiment of the present application; and

[0031] FIG9 shows a flow chart of a control method for determining the charging time of an output capacitor according to an embodiment of the present application. DETAILED DESCRIPTION

[0032] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, scheme, and advantages of the present application clearer, the details of the present application are further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. For those skilled in the art, the present application can be implemented without some of the details in these specific details. The following description of the embodiments is only for providing a better understanding of the present application by illustrating the examples of the present application.

[0033] It should be noted that, in this article, relational terms such as first, second, third, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. In addition, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, and the process, method, article or equipment including a series of elements includes not only these elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of additional elements in the process, method, article or equipment including the elements.

[0034] As mentioned earlier, automotive motor control circuit designs often require the use of large-capacity output capacitors for voltage regulation and immediate transient response. Therefore, the output capacitors must be pre-charged. However, the long charge time of the output capacitors may not meet system requirements.

[0035] In view of this, the present application provides a control system and a control method, which are described in detail below with reference to the accompanying drawings.

[0036] FIG1 shows a schematic circuit diagram of a conventional control system. As shown in FIG1 , the conventional control system 100 includes an initialization control module 11 and a charging control module 12 .

[0037] The initialization control module 11 includes: a first power transistor Q1 having a first terminal, a second terminal, and a third terminal. The first terminal of the first power transistor Q1 is used to receive the power supply voltage VBAT of the motor control unit. The second terminal of the first power transistor Q1 provides a first control signal via a first diode D1 and a first resistor R1, which instructs the motor control unit to complete initialization. A second power transistor Q2 having a first terminal, a second terminal, and a third terminal. The first terminal of the second power transistor Q2 is connected to the third terminal of the first power transistor Q1 via a second resistor R2. The second terminal of the second power transistor Q2 is grounded GND. The third terminal of the second power transistor Q2 receives a second control signal MCU_Start via a third resistor R3, which instructs the motor control unit to start. It should be understood that in FIG1 , two small resistors are shown near the first power transistor Q1 and the second power transistor Q2. These are the internal resistors of the respective power transistors. The first power transistor Q1 is a PNP transistor, and the second power transistor Q2 is an NPN transistor.

[0038] The charging control module 12 includes a switch module 121 having a first terminal, a second terminal, and a third terminal. The first terminal of the switch module 121 is configured to receive a first control signal V_FLRT_BATT provided by the initialization control module 11, the second terminal of the switch module 121 provides a charging voltage V_FLRT_BATT_PD for the output capacitors (C1, C2), and the third terminal of the switch module 121 is configured to receive a third control signal Control_Signal for turning on the switch module 121. Furthermore, a fourth resistor R4 and a second diode D2 are connected in parallel between the first and third terminals of the switch module 121. The switch module 121 can be implemented using devices such as relays, MOSFETs, and transistors.

[0039] Figure 2 shows a control timing diagram for the conventional control system shown in Figure 1. In Figure 2, the horizontal axis represents time, and the vertical axis represents voltage. In Figure 2, u0 represents the MCU's operating voltage, and u1 represents the undervoltage threshold set by the system. The control operations implemented by the conventional control system shown in Figure 1 will be described below in conjunction with Figure 2.

[0040] As shown in FIG2 , the control operation implemented by the conventional control system shown in FIG1 includes the following stages S1 to S5:

[0041] In phase S1 (indicated by ① in the figure), the MCU is powered up by the supply voltage VBAT (e.g., from a vehicle's power supply) and then begins initialization. Initialization takes time t1. During initialization, various MCU components (such as registers and interfaces) are configured.

[0042] In stage S2, the MCU completes interface configuration, causing the control signal MCU_Start to output a high level. This forward-biased saturation turns on the second power transistor Q2, which in turn reverse-biased saturates the first power transistor Q1. Based on the supply voltage VBAT, the control signal V_FLTR_BATT is energized via the first diode D1 and the first resistor R1, indicating that initialization is complete.

[0043] In phase S3 (indicated by ② in the figure): the control signal V_FLTR_BATT powers the switch module 121 in the charging control module 12. The control signal Control_Signal turns on the switch module 121, thereby providing a charging voltage V_FLTR_BATT_PD to charge the output capacitors C1 and C2. The charging time is t2.

[0044] In stage S4 (indicated by ③ in the figure): When the output capacitor is fully charged (determined by checking that the charging voltage V_FLTR_BATT_PD is not lower than the undervoltage threshold u1 set by the system), the system enters fault self-test. The system self-test time is t3.

[0045] In stage S5 (indicated by ④ in the figure): when the fault self-check is completed and there are no other faults, the system operates normally.

[0046] In this process, the processing time of stage S2 can be ignored. Based on this, the total startup time T1 from MCU power-on to normal system operation can be expressed as: T1 = t1 + t2 + t3

[0047] Due to the increasing functional safety requirements of the international standard ISO26262, initialization time t1 can be reduced by selecting an MCU with a high core frequency. For circuits with high bus current, the inverter circuit has high ripple current, requiring larger output capacitors to absorb the ripple, which in turn increases the charging duration t2. Furthermore, during system redundancy, the system self-test content increases and the redundant systems undergo mutual verification, which results in a longer self-test time t3. When automotive systems require the first frame of a message to be sent via CAN, the system response time must be less than 500ms (using 500ms as an example, but response times vary among OEMs). If the total startup time T1 exceeds the system requirement, initialization time t1 cannot be changed. The only way to reduce charging duration t2 is to cycle the system power to charge the output capacitors, retaining some charge. Normal operation can only be resumed when the total startup time meets the system requirement. This technical solution does not meet practical requirements in complex automotive electronic components and can only be applied to simple electronic systems.

[0048] FIG3 is a schematic block diagram of a control system according to an embodiment of the present application. As shown in FIG3 , the control system 300 according to the embodiment of the present application includes: an initialization control module 301 configured to determine a first time required for a motor control unit to complete initialization after being powered on with a supply voltage; a charging control module 302 configured to determine a second time required for an output capacitor of the motor control unit to be fully charged, wherein charging of the output capacitor begins when the motor control unit enters initialization; and a total time determination module 303 configured to use the greater of the first time and the second time as the total time required for initializing the motor control unit and charging the output capacitor.

[0049] According to the control system 300 of the embodiment of the present application, since the output capacitor starts to charge when the motor control unit enters initialization, the total time spent on initializing the motor control unit and charging the output capacitor is reduced, thereby meeting system requirements.

[0050] FIG4 is a schematic block diagram of a charging control module according to an embodiment of the present application. As shown in FIG4 , the charging control module 302 according to the embodiment of the present application includes: a charging module 3021 configured to utilize the body diode of the power transistor of the charging control module 302 to initially charge the output capacitor with the supply voltage and charge the output capacitor to a first threshold voltage; and a boost module 3022 configured to, when the output capacitor is charged to the first threshold voltage, boost the charging voltage of the charging module 302 on the output capacitor to obtain a boosted voltage, wherein the boosted voltage fully turns on the power transistor; and the charging module 3021 is further configured to utilize the fully turned-on power transistor to continue charging the output capacitor with the supply voltage from the first threshold voltage until the output capacitor is fully charged, wherein the sum of the initial charging time and the continued charging time is a second time, wherein the supply voltage is greater than or equal to the forward voltage of the body diode of the power transistor but less than the fully forward voltage of the power transistor, and the boosted voltage is greater than or equal to the fully forward voltage of the power transistor.

[0051] According to the charging control module 302 of the embodiment of the present application, the charging of the output capacitor is divided into two stages: initial charging using the body diode of the power tube and continued charging using the fully turned-on diode. The sum of the charging time of these two stages is the total charging duration.

[0052] FIG5 shows a schematic circuit diagram of a control system according to an embodiment of the present application. As shown in FIG5 , the control system 500 according to the embodiment of the present application includes: an initialization control module 501 configured to determine a first time required for a motor control unit to complete initialization after being powered on with a supply voltage. The control system 500 according to the embodiment of the present application also includes: a charging module 502 configured to utilize the body diode of a power transistor to initially charge the output capacitor with the supply voltage to a first threshold voltage; and a boost module 503 configured to, when the output capacitor is charged to the first threshold voltage, boost the charging voltage of the charging module 502 on the output capacitor to obtain a boosted voltage, wherein the boosted voltage causes the power transistor to fully conduct. The charging module 502 is further configured to utilize the fully conducting power transistor to continue charging the output capacitor with the supply voltage from the first threshold voltage until the output capacitor is fully charged, wherein the sum of the initial charging time and the continued charging time is a second time, wherein the supply voltage is greater than or equal to the conduction voltage of the body diode of the power transistor but less than the fully conducting voltage of the power transistor, and the boosted voltage is greater than or equal to the fully conducting voltage of the power transistor. The charging module 502 and the boost module 503 may implement the charging control module 302 shown in FIG. 3 and FIG. 4 .

[0053] More specifically, as shown in FIG5 , the charging module 502 includes: a first power tube Q1, serving as a power tube, having a first end, a second end, and a third end, wherein the first end of the first power tube is used to receive a power supply voltage VBAT, the second end of the first power tube provides a charging voltage V_FLTR_BATT to the output capacitor, and the third end of the first power tube is used to receive a boosted voltage Charge_VCP; a first resistor R1 and a first diode D1 connected in parallel, connected between the first end and the third end of the first power tube Q1, wherein the anode of the first diode D1 is connected to the first end of the first power tube Q1, and the cathode of the first diode D1 is connected to the third end of the first power tube Q1; and a second resistor R2, connected between the second end and the third end of the first power tube Q1.

[0054] In some implementations, the first power transistor Q1 is a metal oxide semiconductor (MOS) transistor, wherein a first terminal of the first power transistor Q1 is a source of the MOS transistor, a second terminal of the first power transistor Q1 is a drain of the MOS transistor, and a third terminal of the first power transistor Q1 is a gate of the MOS transistor. In some implementations, the first power transistor Q1 is an NMOS transistor.

[0055] As shown in FIG5 , the boost module 503 includes an input terminal VIN configured to receive a charging voltage V_FLTR_BATT provided by the second terminal of the first power tube Q1; a conversion module Charge_up configured to perform a boost conversion on the charging voltage V_FLTR_BATT; and an output terminal VOUT configured to output a boosted voltage Charge_VCP to the third terminal of the first power tube Q1.

[0056] In some implementations, the first threshold voltage may be a minimum operating voltage of the conversion module Charge_up.

[0057] As shown in Figure 5, the initialization control module 501 includes: a second power tube Q2, having a first end, a second end and a third end, wherein the first end of the second power tube Q2 is used to receive the power supply voltage VBAT, and the second end of the second power tube Q2 provides a signal V_FLTR_BATT_PD indicating that the motor control unit has completed initialization via a second diode D2 and a third resistor R3; and a third power tube Q3, having a first end, a second end and a third end, wherein the first end of the third power tube Q3 is connected to the third end of the second power tube Q2 via a fourth resistor R4, the second end of the third power tube Q3 is grounded GND, and the third end of the third power tube Q3 receives a signal MCU_Start indicating that the motor control unit is started via a fifth resistor R5.

[0058] In some implementations, the second power tube Q2 is a PNP tube, wherein the first end of the second power tube Q2 is the emitter of the PNP tube, the second end of the second power tube Q2 is the collector of the PNP tube, and the third end of the second power tube Q2 is the base of the PNP tube.

[0059] In some implementations, the third power tube Q3 is an NPN tube, wherein the first end of the third power tube Q3 is the collector of the NPN tube, the second end of the third power tube Q3 is the emitter of the NPN tube, and the third end of the third power tube Q3 is the base of the NPN tube.

[0060] In some implementations, as shown in FIG5 , the output capacitor may include a first capacitor C1 and a second capacitor C2 connected in parallel between the second terminal of the first power transistor Q1 and ground. It should be understood that the output capacitor is not limited thereto and may include more or fewer capacitors, or may employ other connection methods.

[0061] In FIG. 5 , when the charging voltage V_FLTR_BATT is greater than or equal to a second threshold voltage, the output capacitor is completely charged, where the second threshold voltage is higher than the first threshold voltage.

[0062] It should be understood that although the charging of the output capacitor begins at the time of initialization in order to save time to the greatest extent possible, it is also conceivable to start the charging at any point in the initialization process. This can reduce the total time required for initialization and charging compared to traditional control systems.

[0063] Figure 6 shows a control timing diagram for a control system according to an embodiment of the present application. In Figure 6, the horizontal axis represents time, and the vertical axis represents voltage. u0' represents the minimum operating voltage of the Charge_up conversion module of the boost module 503, u1' represents the operating voltage of the MCU, and u2' represents the undervoltage threshold set by the system. The control operations implemented by the control system shown in Figure 5 will be described below in conjunction with Figure 6.

[0064] As shown in FIG6 , the control operation implemented by the control system in FIG5 includes the following stages S1-S4:

[0065] In stage S1 (indicated by ① in the figure): the MCU is powered on by the power supply voltage VBAT (for example, through the vehicle power supply), and then starts initialization. The initialization time is t1. During the initialization period, the various components of the MCU (such as registers and interfaces, etc.) are configured. After the MCU configures the interface, the control signal MCU_Start outputs a high level, the third power tube Q3 is forward biased and saturated and turned on, and then the second power tube Q2 is reverse biased and saturated and turned on, and then through the second diode D2 and the third resistor R3, the control signal V_FLTR_BATT_PD is energized, indicating that the initialization is complete. At the same time, the charging module 502 initially charges the output capacitors C1 and C2 based on the power supply voltage VBAT via the body diode of the first power tube Q1. In this stage, the charging time of the output capacitor is t 21 .

[0066] In stage S2 (indicated by ② in the figure): When the output capacitors C1 and C2 are charged to a certain threshold voltage (i.e., the minimum operating voltage of the conversion module of the boost module 503) u0', the charging voltage V_FLRT_BATT of the output capacitors by the charging module 502 is provided to the boost module 503. The boost module 503 performs a step-up conversion on the received charging voltage V_FLRT_BATT and outputs a stepped-up voltage signal Charge_VCP. The stepped-up voltage signal Charge_VCP is received by the charging module 502, causing the first power transistor Q1 to be fully turned on, so as to continue to charge the output capacitors C1 and C2 for a period of time t 22 .

[0067] The total charging time of the output capacitor is therefore t2 ≈ t 21 +t 22, which is determined by the current passing capability of the body diode of the first power tube Q1.

[0068] Specifically, the charging and discharging process of the output capacitor is nonlinear. In the system, the charging circuit can be equivalent to that shown in Figure 7. In Figure 7, VBAT represents the supply voltage, SW represents the switch, ESR represents the equivalent impedance in the circuit, C represents the capacitor, and Uc represents the voltage across the output capacitor C. As in the pre-charge circuit model described above, the voltage across the output capacitor can be obtained by solving a first-order linear nonhomogeneous differential equation. Here, it is assumed that the output capacitor C has no charge in its initial state. When the switch SW is closed, the following KVL (Kirchhoff's law) equation can be listed:

[0069] Solving the differential equation, we get: Where, τ = ESR*C.

[0070] The equivalent equation is:

[0071] This is the general equation corresponding to the exponential change in the instantaneous voltage during the output capacitor charging, where Uc represents the voltage across the instantaneous output capacitor and VBAT represents the supply voltage.

[0072] To simplify subsequent calculations and analysis:

[0073] When τ=ESR*C,U c =0.63*V BAT ;

[0074] When τ=2ESR*C,U c =0.86*V BAT ;

[0075] When τ=3ESR*C,U c =0.95*V BAT ;

[0076] When τ=4ESR*C,U c =0.98*V BAT ;

[0077] When τ=5ESR*C,U c =0.99*V BAT ;

[0078] The results show that after a period of (3 to 5)τ, the charging process is basically completed.

[0079] In stage S3 (indicated by ③ in the figure): When the output capacitor is detected to be fully charged (determined by checking that the charging voltage V_FLTR_BATT is not less than the system-set undervoltage threshold u2') and there are no other faults, the system enters fault self-test. The system self-test time is t3.

[0080] In stage S4 (indicated by ④ in the figure): when the fault self-check is completed and there are no other faults, the MCU operates normally.

[0081] In the above process, during the MCU initialization, the output capacitor is also charged through the body diode of the first power transistor Q1, and the two events are connected in parallel. The output capacitor charging process is divided into two parts. The first part uses the body diode of the first power transistor Q1 to charge, and the second part is charged after the first power transistor Q1 is fully turned on. The total charging time of the output capacitor is t 21 +t 22 Therefore, the total startup time T2 from MCU power-on to MCU normal operation can be expressed as: T2 = MAX{t1, t 21 +t 22}+t3<T1

[0082] This means that the total startup time is shortened compared to traditional solutions. As systems become more complex, this approach will save significant startup time, thereby meeting system requirements.

[0083] The control system according to the embodiments of the present application features a simple circuit, minimal hardware changes, and ease of implementation. It is independent of the MCU's timing control and is implemented in hardware, reducing software resource usage. Furthermore, the control system according to the embodiments of the present application can be used in circuits containing high-capacity output capacitors and is highly compatible, making it suitable for a wide range of applications.

[0084] FIG8 shows a flow chart of a control method according to an embodiment of the present application. As shown in FIG8 , a control method 800 according to an embodiment of the present application includes:

[0085] Step S801, determining a first time required for the motor control unit to be powered on with a supply voltage and to complete initialization;

[0086] Step S802 , determining a second time required for the output capacitor of the motor control unit to be fully charged from the start of charging, wherein the output capacitor starts to be charged when the motor control unit enters initialization; and

[0087] Step S803 : The larger of the first time and the second time is used as the total time taken for the motor control unit to be initialized and the output capacitor to be charged.

[0088] According to the control method 800 of the embodiment of the present application, since the output capacitor starts to charge when the motor control unit enters initialization, the total time spent on initializing the motor control unit and charging the output capacitor is reduced, so that system requirements can be met.

[0089] FIG9 shows a flow chart of a control method for determining the charging time of the output capacitor according to an embodiment of the present application. As shown in FIG9 , in some embodiments, the control method 800 shown in FIG8 according to an embodiment of the present application for determining the second time (i.e., the charging time of the output capacitor) may include:

[0090] Step S901, using the body diode of the power transistor of the charging control module to enable the supply voltage to initially charge the output capacitor and charge it to a first threshold voltage;

[0091] Step S902 , when the output capacitor is charged to a first threshold voltage, boosting the charging voltage of the output capacitor by the charging module to obtain a boosted voltage, wherein the boosted voltage enables the power transistor to be fully turned on; and

[0092] Step S903: Using the fully turned-on power transistor to continuously charge the output capacitor with the supply voltage from the first threshold voltage until the output capacitor is fully charged.

[0093] The sum of the initial charging time and the continued charging time is the second time, and the supply voltage is greater than or equal to the conduction voltage of the body diode of the power tube, but less than the full conduction voltage of the power tube, and the boosted voltage is greater than or equal to the full conduction voltage of the power tube.

[0094] In some implementations, the control method 800 according to the embodiment of the present application may further include: determining whether charging of the output capacitor is completed based on a comparison of the charging voltage and a second threshold voltage, where the second threshold voltage is higher than the first threshold voltage.

[0095] According to the output capacitor charging control method of an embodiment of the present application, during the control system initialization process, the output capacitor is charged using the body diode of the power transistor of the switching module. When the output capacitor is charged to a predetermined value, the peripheral excitation signal is controlled to fully turn on the power transistor of the switching module, and the output capacitor continues to be charged until it is fully charged. Based on this solution, the time for system initialization and output capacitor charging can be reduced, thereby reducing the startup time of the control system, so that system requirements can be met.

[0096] According to an embodiment of the present application, the above-mentioned control systems 300 , 400 , 500 and control methods 800 , 900 may be incorporated into a motor control unit.

[0097] Those skilled in the art will understand that the present application is not limited to the specific structures and steps described above and shown in the accompanying drawings. For the sake of simplicity, the description of known structures and methods is omitted herein. In the above embodiments, several specific steps are described and shown as examples. However, the method of the present application is not limited to the specific steps described and shown. Without departing from the scope of the present application, those skilled in the art can make various changes, modifications and additions to the embodiments of the present application, or change the order between the steps.

[0098] The above disclosures are only some specific implementation methods of the present application. Those skilled in the art will understand that the scope of protection of the present application is not limited thereto. Rather, various equivalent modifications or replacements can be conceived within the technical scope disclosed in the present application, and these equivalent modifications or replacements are all covered by the scope of protection of the present application.

Claims

1. A control system, comprising: An initialization control module is configured to determine a first time required for the motor control unit to complete initialization from being powered on with a supply voltage; A charging control module is configured to determine a second time required for the output capacitor of the motor control unit to be fully charged from the beginning of charging, wherein the output capacitor starts to be charged when the motor control unit enters initialization; as well as The total time determination module is configured to use the greater of the first time and the second time as the total time taken for initializing the motor control unit and charging the output capacitor.

2. The control system according to claim 1, wherein: The charging control module comprises: a charging module configured to utilize the body diode of the power tube of the charging control module to enable the supply voltage to initially charge the output capacitor and charge it to a first threshold voltage; and a boost module, configured to boost the charging voltage of the output capacitor by the charging module to obtain a boosted voltage when the output capacitor is charged to the first threshold voltage, wherein the boosted voltage makes the power tube fully turned on; and The charging module is further configured to utilize the fully turned-on power tube to allow the supply voltage to continue charging the output capacitor from the first threshold voltage until the output capacitor is fully charged. The sum of the initial charging time and the continued charging time is the second time, and the supply voltage is greater than or equal to the conduction voltage of the body diode of the power tube, but less than the full conduction voltage of the power tube, and the boosted voltage is greater than or equal to the full conduction voltage of the power tube.

3. The control system according to claim 2, wherein: The charging module comprises: a first power tube, used as the power tube, having a first end, a second end and a third end, wherein the first end of the first power tube is used to receive the supply voltage, the second end of the first power tube provides a charging voltage to the output capacitor, and the third end of the first power tube is used to receive the boosted voltage; A first resistor and a first diode connected in parallel are connected between the first end and the third end of the first power tube, wherein the anode of the first diode is connected to the first end of the first power tube. The cathode of the first diode is connected to the third end of the first power tube; and The second resistor is connected between the second end and the third end of the first power tube.

4. The control system according to claim 3, wherein: The first power tube is a metal oxide semiconductor (MOS) tube, the first end of the first power tube is the source of the MOS tube, the second end of the first power tube is the drain of the MOS tube, and the third end of the first power tube is the gate of the MOS tube.

5. The control system according to claim 4, wherein: The first power tube is an NMOS tube.

6. The control system according to claim 3, wherein: The boost module comprises: An input end, configured to receive the charging voltage provided by the second end of the first power tube; a conversion module configured to perform a boost conversion on the charging voltage; and The output end is configured to output the boosted voltage to the third end of the first power tube.

7. The control system according to claim 6, wherein: The first threshold voltage is the minimum operating voltage of the conversion module.

8. The control system according to claim 6, wherein: The initialization control module comprises: A second power tube having a first end, a second end and a third end, wherein the first end of the second power tube is used to receive the power supply voltage, and the second end of the second power tube provides a signal indicating that the motor control unit has completed initialization via a second diode and a third resistor; and The third power tube has a first end, a second end and a third end, wherein the first end of the third power tube is connected to the third end of the second power tube via a fourth resistor, the second end of the third power tube is grounded, and the third end of the third power tube receives a signal indicating that the motor control unit is started via a fifth resistor.

9. The control system according to claim 8, wherein: The second power tube is a PNP tube, wherein the first end of the second power tube is the emitter of the PNP tube, the second end of the second power tube is the collector of the PNP tube, and the third end of the second power tube is the base of the PNP tube.

10. The control system according to claim 8, wherein: The third power tube is an NPN tube, wherein the first end of the third power tube is the collector of the NPN tube, the second end of the third power tube is the emitter of the NPN tube, and the third end of the third power tube is the base of the NPN tube.

11. The control system according to claim 3, wherein: The output capacitor includes: a first capacitor and a second capacitor connected in parallel between the second end of the first power tube and the ground.

12. The control system according to claim 2, wherein: When the charging voltage is greater than or equal to a second threshold voltage, the output capacitor is completely charged, wherein the second threshold voltage is higher than the first threshold voltage.

13. A motor control unit, comprising: A control system according to any one of claims 1 to 12.

14. A control method, comprising: Determine a first time required for the motor control unit to complete initialization after being powered on with a supply voltage; Determine a second time required for the output capacitor of the motor control unit to be fully charged from the beginning of charging, wherein the output capacitor starts to be charged when the motor control unit enters initialization; as well as The larger one of the first time and the second time is taken as the total time taken for initializing the motor control unit and charging the output capacitor.

15. The control method according to claim 14, wherein: Determining the second time includes: Using the body diode of the power tube of the charging control module to enable the supply voltage to initially charge the output capacitor and charge it to a first threshold voltage; When the output capacitor is charged to the first threshold voltage, boosting the charging voltage of the output capacitor by the charging module to obtain a boosted voltage, wherein the boosted voltage enables the power tube to be fully turned on; and Using the fully turned-on power tube, starting from the first threshold voltage, the supply voltage continues to charge the output capacitor until it is fully charged. The sum of the initial charging time and the continued charging time is the second time, and the supply voltage is greater than or equal to the conduction current of the body diode of the power tube. voltage, but less than the fully-on voltage of the power tube, and the boosted voltage is greater than or equal to the fully-on voltage of the power tube.

16. The control method according to claim 15, further comprising: Whether the charging of the output capacitor is completed is determined based on a comparison of the charging voltage with a second threshold voltage, wherein the second threshold voltage is higher than the first threshold voltage.

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