Brake chopper, control board, bus voltage control method, equipment and medium

Abstract

The embodiment of the invention discloses a brake chopper, a control panel, a bus voltage control method, equipment and a medium. The brake chopper comprises a resistor module which is electrically connected with a direct current bus to form an energy discharge loop of the direct current bus; the control module is used for determining a difference value between the voltage value of the direct current bus and a preset first threshold value, and generating a first switch control signal based on the difference value; and the switch module is used for controlling the conduction time of the energy discharge loop based on the first switch control signal, and the conduction time and the difference value have an increasing relationship. The conduction time of the energy discharge loop is precisely controlled based on the difference value between the voltage value of the DC bus and the first threshold value, and the energy utilization rate of the DC bus is improved. The brake chopper is onboard, and the installation space and the assembly cost are reduced. When the temperature of the resistor module is too high, the energy discharge loop is disconnected to provide protection. Multiple switch protection is realized through the multi-stage field effect transistors, and the safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic devices, in particular to a brake chopper, a control board, a bus voltage control method, a device and a medium. Background Art

[0002] Motor control is usually adopted in a motion system configured with single-axis motion or multi-axis motion. During the stop or braking process of the motor, the back electromotive force of the motor feeds back energy, causing the DC bus voltage to rise and resulting in overvoltage, which may damage the motor driver. By using a brake chopper to consume this part of energy in the form of heat, the DC bus voltage can be kept stable.

[0003] How to improve the performance of the brake chopper is a technical problem to be solved. Summary of the Invention

[0004] Embodiments of the present invention provide a brake chopper, a control board, a bus voltage control method, a device and a medium.

[0005] A brake chopper includes:

[0006] A resistor module electrically connected to the DC bus to form an energy discharge circuit of the DC bus;

[0007] A control module configured to determine a difference between a voltage value of the DC bus and a preset first threshold, and generate a first switch control signal based on the difference;

[0008] A switch module configured to control an on-time of the energy discharge circuit based on the first switch control signal, where the on-time has an increasing relationship with the difference.

[0009] It can be seen that embodiments of the present invention precisely control the on-time of the energy discharge circuit by using the difference between the voltage value of the DC bus and a preset threshold, where the on-time has an increasing relationship with the difference. Therefore, when the difference is larger (correspondingly, the voltage value of the DC bus is larger), the on-time is longer, so as to ensure that the energy is fully discharged; when the difference is smaller (correspondingly, the voltage value of the DC bus is smaller), the on-time is shorter, preventing excessive energy discharge. Therefore, embodiments of the present invention can adaptively control the on-time based on the voltage value of the DC bus, improving the energy utilization rate of the DC bus.

[0010] In one embodiment, it includes:

[0011] A temperature sensor close to the resistor module;

[0012] The control module is configured to obtain the temperature detection value of the temperature sensor, and generate a second switch control signal when the temperature detection value is greater than or equal to a preset second threshold; the switch module is configured to disconnect the energy discharge circuit based on the second switch control signal; or

[0013] The temperature sensor is configured to generate a third switch control signal when the temperature detection value is greater than or equal to a preset second threshold; the switch module is configured to disconnect the energy discharge circuit based on the third switch control signal.

[0014] Therefore, in the embodiment of the present invention, the temperature sensor is arranged close to the resistor module. When the temperature of the resistor module is too high, the energy discharge circuit can be automatically disconnected to protect the resistor module and improve safety.

[0015] In one embodiment, it includes:

[0016] A switch driving module is arranged between the control module and the switch module, and is configured to drive the switch module based on the first switch control signal, the second switch control signal, and / or the third switch control signal.

[0017] It can be seen that based on the switch driving module, multiple signals are used to drive the switch module.

[0018] In one embodiment, the control module is configured to determine the connection state of the resistor module based on a second difference between the low-side potential value of the resistor module and the voltage value of the DC bus when the energy discharge circuit is in an off state.

[0019] Therefore, in the embodiment of the present invention, the self-check function for the resistor module is realized by the difference between the low-side potential value of the resistor module and the voltage value of the DC bus.

[0020] In one embodiment, the switch module includes a first Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) and a second MOSFET;

[0021] The drain of the first MOSFET is connected to the resistor module, the source of the first MOSFET is connected to the drain of the second MOSFET, and the gate of the first MOSFET is connected to the control module; the gate of the second MOSFET is connected to the control module, and the source of the second MOSFET is grounded;

[0022] The first switch control signal is adapted to continuously turn on the second MOSFET and turn on the first MOSFET during the on time.

[0023] Therefore, multiple switch protections are achieved through multi - stage field - effect transistors, improving safety.

[0024] A control board, comprising:

[0025] A base material;

[0026] A DC bus, arranged on the base material;

[0027] A resistor module, arranged on the base material and electrically connected to the DC bus to form an energy discharge circuit of the DC bus;

[0028] A motor drive module, arranged on the base material, for driving a motor based on the DC bus;

[0029] A control module, arranged on the base material, for controlling the motor drive module, determining the difference between the voltage value of the DC bus and a preset first threshold, and generating a first switch control signal based on the difference;

[0030] A switch module, arranged on the base material, for controlling the conduction time of the energy discharge circuit based on the first switch control signal, wherein the conduction time has an increasing relationship with the difference.

[0031] Therefore, integrating the braking chopper into the control board realizes an on - board braking chopper, which can reduce the installation space and assembly cost of the braking chopper.

[0032] In one embodiment, the switch module includes a first MOSFET and a second MOSFET;

[0033] The drain of the first MOSFET is connected to the resistor module, the source of the first MOSFET is connected to the drain of the second MOSFET, and the gate of the first MOSFET is connected to the control module; the gate of the second MOSFET is connected to the control module, and the source of the second MOSFET is grounded;

[0034] The first switch control signal is adapted to continuously turn on the second MOSFET and turn on the first MOSFET during the conduction time.

[0035] Therefore, multiple switch protections are achieved through multi - stage field - effect transistors, improving safety.

[0036] In one embodiment, it includes: a heat dissipation layer, arranged at the bottom of the base material, for dissipating heat from the DC bus, the resistor module, the motor drive module, the control module, and the switch module.

[0037] Therefore, by sharing the heat dissipation layer of the control board, there is no need to additionally set up heat dissipation equipment for the braking chopper, which saves costs and improves the integration of the control board.

[0038] A bus voltage control method includes:

[0039] Determine the voltage value of the DC bus;

[0040] Determine the difference between the voltage value of the DC bus and a preset first threshold;

[0041] Generate a first switch control signal based on the difference;

[0042] Control the conduction time of the energy discharge circuit based on the first switch control signal, where the conduction time has an increasing relationship with the difference.

[0043] It can be seen that the embodiment of the present invention utilizes the difference between the voltage value of the DC bus and a preset threshold to precisely control the conduction time of the energy discharge circuit, where the conduction time has an increasing relationship with the difference. Therefore, when the difference is larger (correspondingly, the voltage value of the DC bus is larger), the conduction time is longer, so as to ensure that the energy is fully discharged; when the difference is smaller (correspondingly, the voltage value of the DC bus is smaller), the conduction time is shorter, preventing excessive energy discharge. Therefore, the embodiment of the present invention can adaptively control the conduction time based on the voltage value of the DC bus, improving the energy utilization rate of the DC bus.

[0044] In one embodiment, it includes:

[0045] Obtain a temperature detection value from a temperature sensor close to the resistor module;

[0046] When the temperature detection value is greater than or equal to a preset second threshold, generate a second switch control signal;

[0047] Disconnect the energy discharge circuit based on the second switch control signal.

[0048] Therefore, in the embodiment of the present invention, a temperature sensor is arranged close to the resistor module. When the temperature of the resistor module is too high, the energy discharge circuit can be automatically disconnected to protect the resistor module, improving safety.

[0049] In one embodiment, the generating the first switch control signal based on the difference includes:

[0050] Generate a Pulse Width Modulation (PWM) signal based on the difference, and the duty cycle of the PWM signal has an increasing relationship with the difference.

[0051] Therefore, based on the duty cycle setting of the PWM signal, the conduction time can be flexibly controlled.

[0052] In one embodiment, it includes:

[0053] Obtain the low-side potential value of the resistor module when the energy discharge circuit is in the off state;

[0054] Determine the connection state of the resistor module based on the difference between the low-side potential value of the resistor module and the voltage value of the DC bus; wherein when the second difference is zero, it is determined that the connection state of the resistor module is qualified, and when the second difference is not zero, it is determined that the connection state of the resistor module is unqualified.

[0055] Therefore, the embodiment of the present invention realizes the self-check function for the resistor module through the difference between the low-side potential value of the resistor module and the voltage value of the DC bus.

[0056] An electronic device includes:

[0057] A processor;

[0058] A memory for storing the executable instructions of the processor;

[0059] The processor is configured to read the executable instructions from the memory and execute the executable instructions to implement the bus voltage control method as described above.

[0060] A computer-readable storage medium stores computer instructions thereon, and when the computer instructions are executed by a processor, the bus voltage control method as described above is implemented. Description of the Drawings

[0061] The following will make the above and other features and advantages of the present invention clearer to those of ordinary skill in the art by referring to the accompanying drawings in detail. In the drawings:

[0062] Figure 1 is a schematic structural diagram of a braking chopper according to an embodiment of the present invention.

[0063] Figure 2 is a schematic circuit diagram of a braking chopper according to an embodiment of the present invention.

[0064] Figure 3 is a schematic diagram of the correspondence between the bus voltage and the switch control signal according to an embodiment of the present invention.

[0065] Figure 4 is a schematic structural diagram of a control board according to an embodiment of the present invention.

[0066] Figure 5It is a schematic flowchart of a bus voltage control method according to an embodiment of the present invention.

[0067] Figure 6 It is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

[0068] Among them, the reference numerals are as follows:

[0069]

[0070] Detailed implementation manners

[0071] To make the objectives, technical solutions and advantages of the present invention clearer, the following examples are given to further elaborate on the present invention in detail. In this patent application, nouns and pronouns related to people are not limited to specific genders.

[0072] For the sake of simplicity and intuitiveness in description, the solutions of the present invention are elaborated below by describing several representative embodiments. A large number of details in the embodiments are only used to help understand the solutions of the present invention. However, it is obvious that the implementation of the technical solutions of the present invention may not be limited to these details. To avoid unnecessarily obscuring the solutions of the present invention, some embodiments are not described in detail but only the frameworks are given. Hereinafter, "including" means "including but not limited to", and "according to..." means "at least according to..., but not limited to only according to...". Due to the language habits of Chinese, when the quantity of a component is not specifically indicated hereinafter, it means that the component may be one or more, or can be understood as at least one.

[0073] In a variable frequency speed regulation system, the given frequency of the motor is gradually reduced to achieve motor speed reduction. However, when the inertia of the motor drive system is large, the actual speed of the motor is higher than its synchronous speed. The direction in which the rotor winding of the motor cuts the magnetic force lines of the rotating magnetic field is opposite to that when the motor runs at a constant speed, and the direction of the induced electromotive force and current in the rotor winding is also opposite. The motor appears negative torque, and the kinetic energy of the drive system is fed back to the DC bus of the frequency converter, resulting in continuous increase of the DC bus voltage, which may damage the frequency converter. By consuming the feedback kinetic energy of the drive system in the form of heat through a braking chopper, the stability of the DC bus voltage can be maintained.

[0074] The applicant has found that in the braking choppers of the prior art, a fixed switching control signal is used to control the conduction time of the energy discharge circuit. However, the voltage value of the DC bus is usually variable, and it is difficult for a fixed switching control signal to adapt to the change in the voltage value, making it difficult to ensure the energy utilization rate of the DC bus. Moreover, the braking choppers of the prior art are generally implemented as independent products external to the motor control board, which requires a large amount of installation space and assembly cost. In addition, the braking choppers of the prior art usually lack switch protection and resistance over-temperature protection. Furthermore, the braking choppers of the prior art usually lack a self-check function for the resistance.

[0075] In the embodiments of the present invention, by using the difference between the voltage value of the DC bus and a preset threshold value, the conduction time of the energy discharge circuit is precisely controlled, thereby improving the energy utilization rate of the DC bus. Moreover, in the embodiments of the present invention, the braking chopper is integrated into the control board. The on-board braking chopper can reduce the installation space and assembly cost, and can also reduce the heat dissipation cost. In addition, a temperature sensor is arranged close to the resistance module. When the temperature of the resistance module is too high, the energy discharge circuit can be automatically disconnected to improve the safety of the resistance module. Furthermore, in the embodiments of the present invention, multiple switch protections are achieved through multiple levels of field effect transistors, improving the safety of the switches. Additionally, in the embodiments of the present invention, a self-check function for the resistance is also achieved by comparing the low-side potential value of the resistance with the voltage value of the DC bus.

[0076] The above disclosure details the technical defects existing in the prior art, the reasons for these technical defects, and the thought analysis process for overcoming these technical defects. In fact, the recognition of the above technical defects is not common knowledge in the field, but a novel discovery by the applicant in the research. In addition, the reason tracing of the technical defects and the thought analysis process for overcoming these technical defects are also the gradual analysis results of the applicant in the actual research process, and none of them are common knowledge in the field.

[0077] Figure 1 It is a schematic structural diagram of a braking chopper according to an embodiment of the present invention. As Figure 1 shown, the braking chopper 10 includes;

[0078] A resistor module 12 is electrically connected to a DC bus 11 to form an energy discharge circuit of the DC bus 11; a control module 13 is configured to determine a difference between a voltage value of the DC bus 11 and a preset first threshold, and generate a first switch control signal based on the difference; a switch module 14 is configured to control an on-time of the energy discharge circuit based on the first switch control signal, where the on-time has an increasing relationship with the difference. The increasing relationship between the on-time and the difference can be a linear increasing relationship or a non-linear increasing relationship. For example, when the increasing relationship is a linear increasing relationship, the on-time linearly increases as the difference increases; when the increasing relationship is a non-linear increasing relationship, the on-time non-linearly increases as the difference increases.

[0079] In one embodiment, the resistor module 12 can be implemented as a plurality of resistors with small resistance values connected in parallel, or as one or more resistors with large resistance values connected in series, or as a hybrid connection structure including one or more parallel resistors and one or more series resistors. The DC bus 11 and the resistor module 12 are electrically connected to form an energy discharge circuit of the DC bus 11 (as shown by the arrow S in Figure 1 ). The switch module 14 is arranged in the energy discharge circuit and is configured to turn on or off the energy discharge circuit of the DC bus 11.

[0080] A first threshold is set in the control module 13. The value of the first threshold can be fixed or adjustable. Preferably, the value of the first threshold is adjustable. The control module 13 detects the voltage value of the DC bus 11, calculates the difference between the voltage value of the DC bus 11 and the first threshold, and generates a first switch control signal based on the difference. The first switch control signal generated by the control module 13 is adapted to control the switch module 14, thereby controlling the on-time of the energy discharge circuit, where the on-time represented by the first switch control signal has an increasing relationship with the difference. Therefore, the embodiment of the present invention uses the difference between the voltage value of the DC bus and the first threshold to precisely control the on-time of the energy discharge circuit. When the difference is larger (correspondingly, the voltage value of the DC bus is larger), the on-time of the energy discharge circuit is longer, so as to ensure that the energy is fully discharged; when the difference is smaller (correspondingly, the voltage value of the DC bus is smaller), the on-time of the energy discharge circuit is shorter, preventing excessive energy discharge. The embodiment of the present invention can adaptively control the on-time of the energy discharge circuit based on the voltage value of the DC bus, improving the energy utilization rate of the DC bus.

[0081] In one embodiment, the braking chopper 10 includes: a temperature sensor 16 close to the resistor module 12; a control module 13 configured to obtain a temperature detection value of the temperature sensor 16, and generate a second switch control signal when the temperature detection value is greater than or equal to a preset second threshold; a switch module 14 configured to disconnect the energy discharge circuit based on the second switch control signal.

[0082] Therefore, in the embodiment of the present invention, the temperature sensor 16 is disposed close to the resistor module 12. When the temperature of the resistor module 12 is too high, the control module 13 generates a second switch control signal adapted to disconnect the energy discharge circuit, and the switch module 14 disconnects the energy discharge circuit based on the second switch control signal, thereby protecting the resistor module 12 and improving safety. In this embodiment, the control module 13 generates a control signal for disconnecting the energy discharge circuit, which improves the control ability of the control module 13.

[0083] In one embodiment, the braking chopper 10 includes: a temperature sensor 16 disposed close to the resistor module 12; the temperature sensor 16 is configured to generate a third switch control signal when the temperature detection value is greater than or equal to a preset second threshold; a switch module 14 configured to disconnect the energy discharge circuit based on the third switch control signal.

[0084] Therefore, in the embodiment of the present invention, the temperature sensor 16 is disposed close to the resistor module 12. When the temperature of the resistor module 12 is too high, the temperature sensor 16 generates a third switch control signal adapted to disconnect the energy discharge circuit, and the switch module 14 disconnects the energy discharge circuit based on the third switch control signal, thereby protecting the resistor module 12 and improving safety. In this embodiment, the temperature sensor 16 is used to generate a control signal for disconnecting the energy discharge circuit, which reduces the response time and improves the circuit disconnection efficiency.

[0085] In one embodiment, the braking chopper 10 includes: a switch driving module 15 disposed between the control module 13 and the switch module 14, and configured to drive the switch module 14 based on the first switch control signal, the second switch control signal, and / or the third switch control signal. For example, the switch driving module 15 can amplify the power of the first switch control signal, the second switch control signal, and / or the third switch control signal, so as to be sufficient to drive the switch module 14.

[0086] In one embodiment, the control module 13 is configured to determine the connection state of the resistor module 12 based on a second difference between the low-side potential value of the resistor module 12 and the voltage value of the DC bus 11 when the energy discharge circuit is in a disconnected state. Wherein: when the second difference is zero (i.e., the low-side potential value of the resistor module 12 is the same as the voltage value of the DC bus 11), it is determined that the connection state of the resistor module 12 is qualified; when the second difference is not zero (i.e., the low-side potential value of the resistor module 12 is different from the voltage value of the DC bus 11), it is determined that the connection state of the resistor module 12 is unqualified.

[0087] For example, when the braking chopper is started, the energy dissipation circuit is in an open state. At this time, the connection state of the resistor module 12 is determined based on the second difference between the low-side potential value of the resistor module 12 and the voltage value of the DC bus 11. Therefore, in the embodiment of the present invention, the self-check function for the resistor module 12 is realized by the difference between the low-side potential value of the resistor module 12 and the voltage value of the DC bus 11.

[0088] In one embodiment, the switch module 14 includes a first MOSFET and a second MOSFET; the drain of the first MOSFET is connected to the resistor module 12, the source of the first MOSFET is connected to the drain of the second MOSFET, and the gate of the first MOSFET is connected to the control module 13; the gate of the second MOSFET is connected to the control module 13, and the source of the second MOSFET is grounded; the first switch control signal is adapted to continuously conduct the second MOSFET and conduct the first MOSFET during the conduction time. For example, the first MOSFET and the second MOSFET can be implemented as N-type MOSFETs. Therefore, multiple switch protections are achieved through multiple field-effect transistors, improving safety.

[0089] The above describes the typical structure of the switch module 14 by taking two MOSFETs as an example. Those skilled in the art can realize that this description is only exemplary and is not used to limit the protection scope of the embodiments of the present invention. For example, the switch module 14 can also be implemented as a junction field-effect transistor (JFET), or include a larger number of MOSFETs, or use P-type MOSFETs, etc. The embodiments of the present invention are not limited thereto.

[0090] Next, the exemplary circuit structure of the braking chopper according to the embodiment of the present invention will be specifically described. Figure 2 It is an exemplary circuit diagram of the braking chopper according to the embodiment of the present invention.

[0091] In Figure 2 , the resistor module 11 includes a plurality of power resistors R1 to R4 connected in parallel with each other. The high side of the resistor module 11 is connected to the DC bus 11 (for example, the rated voltage of the DC bus 11 is 48 volts). The high side of the resistor module 11 is also connected to the control module 13 via a high-impedance operational amplifier 20. The low side of the resistor module 11 is connected to the switch module 14. The low side of the resistor module 11 is also connected to the control module 13 via a high-impedance operational amplifier 21. The switch module 14 is grounded (GND). The DC bus 11 and the resistor module 12 form an energy dissipation circuit for the DC bus 11. The switch module 14 is arranged in the energy dissipation circuit and is used to conduct or cut off the energy dissipation circuit of the DC bus 11.

[0092] When the braking chopper is started, the energy dissipation circuit is in an open state. At this time, the control module 13 obtains the low-side potential value of the resistor module 11 via the high-impedance operational amplifier 21. Moreover, the control module 13 obtains the voltage value of the DC bus 11 via the high-impedance operational amplifier 20. The control module 13 determines the connection state of the resistor module 12 based on the difference between the low-side potential value of the resistor module and the voltage value of the DC bus 11. Among them: when the difference is zero (that is, when both the low-side potential value and the voltage value of the DC bus 11 are 48 volts), it is determined that the connection state of the resistor module 12 is qualified; when the difference 12 is not zero, it is determined that the connection state of the resistor module is unqualified. Therefore, the embodiment of the present invention realizes the self-check function for the resistor module 12 through the difference between the low-side potential value of the resistor module 12 and the voltage value of the DC bus 11.

[0093] A first threshold is set in the control module 13. The first threshold is usually greater than the voltage value of the DC bus 11. For example, the first threshold can be set to 60 volts. The control module 13 obtains the voltage value of the DC bus 11 via the high-impedance operational amplifier 20. The control module 13 determines the difference between the voltage value of the DC bus and the first threshold, and generates a first switch control signal adapted to the conduction time of the control switch module 14 based on this difference, where the conduction time has an increasing relationship with the difference. The switch module 14 controls the conduction time of the energy dissipation circuit based on the first switch control signal.

[0094] The temperature sensor 16 is close to the resistor module 12. The temperature sensor 16 continuously collects the temperature detection value of the surrounding environment of the resistor module 12. The temperature sensor 16 can send the collected temperature detection value to the control module 13.

[0095] In one embodiment, a second threshold can be set in the control module 13. The second threshold can be fixed or adjustable. Preferably, the value of the second threshold is adjustable. When the control module 13 determines that the temperature detection value is greater than or equal to the second threshold, the control module 13 generates a second switch control signal, and the second switch control signal is adapted to disconnect the energy dissipation circuit. Optionally, a second threshold is set in the temperature sensor 16. When the temperature sensor 16 determines that the temperature detection value is greater than or equal to the preset second threshold, the temperature sensor 16 generates a third switch control signal, and the third switch control signal is adapted to disconnect the energy dissipation circuit.

[0096] Compared with the situation where the control module 13 generates the second switch control signal, the temperature sensor 16 generates the third switch control signal, which can directly control the disconnection of the energy dissipation circuit, reduces the response time, improves the circuit disconnection efficiency, and also reduces the processing pressure of the control module 13.

[0097] A switch driving module 15 is provided between the control module 13 and the switch module 12. The input end of the switch driving module 15 includes an HI terminal and an LI terminal. The output end of the switch driving module 15 includes an HO terminal and an LO terminal. The switch driving module 15 receives a first switch control signal or a second switch control signal from the control module 13 via the HI terminal and the LI terminal, or receives a third switch control signal from the temperature sensor 16 via the HI terminal and the LI terminal. The switch driving module 15 performs power amplification processing on the first switch control signal, the second switch control signal or the third switch control signal, so as to drive the switch module 14.

[0098] The temperature sensor 16 is connected to the inverter 16. The output of the inverter 16 is connected to the HI terminal and the LI terminal. The inverter 16 is grounded via the grounding resistors R5 and R6. For example, the inverter 16 flips the high-level third switch control signal generated by the temperature sensor 16 into a low-level signal, so that the switch driving module 15 can drive the switch module 14 to disconnect the energy discharge circuit based on the low-level third switch control signal.

[0099] The switch module 14 includes a first MOSFET (Q1) and a second MOSFET (Q2). Both the first MOSFET (Q1) and the second MOSFET (Q2) are N-type. The drain of the first MOSFET (Q1) is connected to the resistor module 12, the source of the first MOSFET (Q1) is connected to the drain of the second MOSFET (Q2), and the gate of the first MOSFET (Q1) is connected to the HO terminal of the switch driving module 15. The gate of the second MOSFET (Q2) is connected to the LO terminal of the switch driving module 15, and the source of the second MOSFET (Q2) is grounded (GND). At the connection point between the source of the first MOSFET and the drain of the second MOSFET (Q2), the bootstrap terminal (HS) in the switch driving module 15 is further connected. The switch driving module 15 provides a bootstrap signal for the switch module 14 via the bootstrap terminal (HS), so that the output signal of the switch module 14 is sufficient to offset the influence of the feedback signal.

[0100] When a high level is input to the HI terminal, a high level is output from the HO terminal, and the first MOSFET (Q1) is turned on. When a low level is input to the HI terminal, a low level is output from the HO terminal, and the first MOSFET (Q1) is turned off. When a high level is input to the LI terminal, a high level is output from the LO terminal, and the second MOSFET (Q2) is turned on. When a low level is input to the LI terminal, a low level is output from the LO terminal, and the second MOSFET (Q2) is turned off.

[0101] The first switch control signal is adapted to continuously turn on the second MOSFET (Q2) and turn on the first MOSFET (Q1) during the on-time. For example, the first switch control signal includes a high-level HI signal (preferably a PWM signal with a duty cycle having an increasing relationship with the difference value) and a high-level LI signal (preferably a continuously high-level signal, such as a PWM signal with a duty cycle of 100%). The switch driving module 15 amplifies the power of the first switch control signal and outputs a high-level HO signal (preferably a PWM signal with the same duty cycle as that of the LI signal) and a high-level LO signal (preferably a continuously high-level signal, such as a PWM signal with a duty cycle of 100%). At this time, the first MOSFET (Q1) is turned on during the on-time represented by the duty cycle of the HO signal and turned off during the non-on-time, while the second MOSFET (Q2) is continuously turned on.

[0102] The second switch control signal is adapted to turn off the first MOSFET (Q1) and the second MOSFET (Q2). For example, the second switch control signal includes a low-level HI signal and a low-level LI signal, and the switch driving module 15 outputs a low-level HO signal and a low-level LO signal. At this time, both the first MOSFET (Q1) and the second MOSFET (Q2) are turned off.

[0103] The third switch control signal is adapted to turn off the first MOSFET (Q1) and the second MOSFET (Q2).

[0104] For example, the third switch control signal includes a low-level HI signal and a low-level LI signal, and the switch driving module 15 outputs a low-level HO signal and a low-level LO signal. At this time, both the first MOSFET (Q1) and the second MOSFET (Q2) are turned off. Table 1 is the truth table of the HI signal, the LI signal, the HI signal, and the HO signal. Wherein: the meaning of X is no signal.

[0105]

[0106] Table 1

[0107] When the HI signal has an input, the HO signal has the same state as the HI signal; when the LI signal has an input, the LO signal has the same state as the LI signal. When the HI signal has no input, the HO signal outputs a low level; when the HI signal has no input, the LO signal outputs a low level.

[0108] Figure 3 It is a schematic diagram showing the correspondence between the bus voltage and the switch control signal according to the embodiment of the present invention. In Figure 3In the coordinate system shown, the abscissa is time (T) and the ordinate is voltage (V). Assume that the rated voltage (v1) of the DC bus is 48 volts; the first threshold (v2) is 60 volts; the maximum voltage (v3) of the DC bus is 70 volts. Based on the DC bus voltage curve 31, it can be seen that the voltage of the DC bus may change.

[0109] (1): When the voltage of the DC bus is at the rated voltage (v1) (corresponding to the 0 - t1 interval on the horizontal axis), both the HI signal curve 31 and the LI signal curve 32 are at a low level. Correspondingly, the HO signal curve 33 and the LO signal curve are at a low level. Therefore, both the first MOSFET (Q1) and the second MOSFET (Q2) are turned off, and the energy discharge circuit is disconnected.

[0110] (2): When the voltage of the DC bus is greater than the rated voltage (v1) and less than the first threshold (v2) (corresponding to the t1 - t2 interval on the horizontal axis), at this time both the HI signal curve 31 and the LI signal curve 32 are at a low level. Correspondingly, the HO signal curve 33 and the LO signal curve are at a low level. Therefore, both the first MOSFET (Q1) and the second MOSFET (Q2) are turned off, and the energy discharge circuit is disconnected.

[0111] (3): When the voltage of the DC bus is greater than the first threshold (v2) and less than the maximum voltage (corresponding to the t2 - t3 interval on the horizontal axis), the LI signal curve 32 and the LO signal curve 34 remain at a high level, so the second MOSFET (Q2) remains closed. The HI signal curve 31 includes the first waveform 51, the second waveform 52, the third waveform 53, and the fourth waveform 54. Among them, as the voltage of the DC bus gradually increases, the duty cycle of the fourth waveform 54 is greater than that of the third waveform 53, the duty cycle of the third waveform 53 is greater than that of the second waveform 52, and the duty cycle of the second waveform 53 is greater than that of the first waveform 52. The HO signal curve 33 includes the fifth waveform 61, the sixth waveform 62, the seventh waveform 63, and the eighth waveform 64. Among them, as the voltage of the DC bus gradually increases, the duty cycle of the eighth waveform 64 is greater than that of the seventh waveform 63, the duty cycle of the seventh waveform 63 is greater than that of the sixth waveform 62, and the duty cycle of the sixth waveform 62 is greater than that of the fifth waveform 61. Therefore, the second MOSFET (Q2) remains closed, and the first MOSFET (Q1) conducts when the HO signal is at a high level and turns off when the HO signal is at a low level.

[0112] (4): When the voltage of the DC bus starts to drop from the maximum voltage and the voltage value of the DC bus is still greater than the first threshold (v2) (corresponding to the interval t3 - t4 on the horizontal axis), the HI signal curve 31, the LI signal curve 32, the HO signal curve 33, and the LO signal curve 34 remain at a high level. Therefore, the first MOSFET (Q1) and the second MOSFET (Q2) remain closed, and the energy discharge circuit remains conducting.

[0113] (5): When the voltage value of the DC bus drops below the first threshold (v2) (corresponding to the interval t4 - t5 on the horizontal axis), the HI signal curve 31, the LI signal curve 32, the HO signal curve 33, and the LO signal curve 34 remain at a low level. Therefore, the first MOSFET (Q1) and the second MOSFET (Q2) remain open, and the energy discharge circuit remains open.

[0114] An embodiment of the present invention also proposes a control board. For example, the control board is implemented as a motor control board for controlling a motor. Figure 4 It is a schematic structural diagram of the control board according to the embodiment of the present invention.

[0115] The control board 50 includes: a substrate 40; a DC bus 11 disposed on the substrate 40; a resistor module 12 disposed on the substrate 40 and electrically connected to the DC bus 11 to form an energy discharge circuit of the DC bus 11; a motor drive module 41 disposed on the substrate 40 for driving a motor based on the DC bus 11; a control module 13 disposed on the substrate 40 for controlling the motor drive module 41, determining the difference between the voltage value of the DC bus 11 and a preset first threshold, and generating a first switch control signal based on the difference; a switch module 14 disposed on the substrate 40 for controlling the conduction time of the energy discharge circuit based on the first switch control signal, wherein the conduction time has an increasing relationship with the difference.

[0116] In one embodiment, the control board 50 can be implemented as a rigid circuit board or a flexible circuit board. When the control board 50 is implemented as a rigid circuit board, the substrate 40 can include a phenolic paper layer, an epoxy paper layer, a polyester glass felt layer, or an epoxy glass cloth layer, etc. When the control board 50 is implemented as a flexible circuit board, the substrate 40 can include a polyester film or a polyimide film, etc.

[0117] Therefore, integrating the braking chopper into the control board realizes an on-board braking chopper, which can reduce the installation space and assembly cost of the braking chopper.

[0118] In one embodiment, the switching module 14 includes a first MOSFET and a second MOSFET; the drain of the first MOSFET is connected to the resistor module 12, the source of the first MOSFET is connected to the drain of the second MOSFET, and the gate of the first MOSFET is connected to the control module 13; the gate of the second MOSFET is connected to the control module 13, and the source of the second MOSFET is grounded; a first switching control signal is adapted to continuously turn on the second MOSFET and turn on the first MOSFET during the on-time.

[0119] In one embodiment, the control board 50 includes: a heat dissipation layer 42 disposed at the bottom of the base material 40 for dissipating heat from the DC bus 11, the resistor module 12, the motor drive module 41, the control module 13, and the switching module 14.

[0120] Therefore, by sharing the heat dissipation layer of the control board, there is no need to additionally provide a heat dissipation device for the braking chopper, which saves costs and improves the integration of the control board.

[0121] The embodiment of the present invention also proposes a method for controlling the bus voltage. Figure 5 It is a schematic flowchart of the bus voltage control method according to the embodiment of the present invention. As Figure 5 shown, the method includes:

[0122] Step 501: Determine the voltage value of the DC bus.

[0123] Step 502: Determine the difference between the voltage value of the DC bus and a preset first threshold.

[0124] Step 503: Generate a first switching control signal based on the difference.

[0125] Step 504: Control the on-time of the energy discharge circuit based on the first switching control signal, where the on-time has an increasing relationship with the difference.

[0126] In one embodiment, the method includes: obtaining a temperature detection value from a temperature sensor close to the resistor module; when the temperature detection value is greater than or equal to a preset second threshold, generating a second switching control signal; and disconnecting the energy discharge circuit based on the second switching control signal.

[0127] In one embodiment, step 503 specifically includes: generating a PWM signal based on the difference, and the duty cycle of the PWM signal has an increasing relationship with the difference.

[0128] In one embodiment, the method includes: obtaining the low-side potential value of the resistance module when the energy discharge circuit is in an open state; determining the connection state of the resistance module based on the difference between the low-side potential value of the resistance module and the voltage value of the DC bus; wherein when the second difference is zero, it is determined that the connection state of the resistance module is qualified, and when the second difference is not zero, it is determined that the connection state of the resistance module is unqualified.

[0129] An embodiment of the present invention also provides an electronic device with a processor-memory architecture. Figure 6 It is a structural diagram of an electronic device according to an embodiment of the present invention. As Figure 6 shown, the electronic device 600 includes a processor 601, a memory 602, and a computer program stored on the memory 602 and executable on the processor 601. When the computer program is executed by the processor 601, it implements any one of the above bus voltage control methods. Among them, the memory 602 can be specifically implemented as various storage media such as electrically erasable programmable read-only memory (EEPROM), flash memory, programmable read-only memory (PROM), etc. The processor 601 can be implemented as including one or more central processing units or one or more field programmable gate arrays, where the field programmable gate array integrates one or more central processing unit cores. Specifically, the central processing unit or central processing unit core can be implemented as a CPU, MCU, or DSP, etc.

[0130] It should be noted that not all steps and modules in the above-mentioned processes and structural diagrams are necessary, and some steps or modules can be ignored according to actual needs. The execution order of each step is not fixed and can be adjusted according to needs. The division of each module is only for the convenience of description in terms of function. In actual implementation, one module can be implemented by multiple modules, and the functions of multiple modules can also be implemented by the same module. These modules can be located in the same device or in different devices.

[0131] The hardware modules in each embodiment can be implemented mechanically or electronically. For example, a hardware module can include specially designed permanent circuits or logic devices (such as dedicated processors, such as FPGA or ASIC) for performing specific operations. The hardware module can also include programmable logic devices or circuits (such as including a general-purpose processor or other programmable processors) temporarily configured by software for performing specific operations. As for whether to specifically adopt a mechanical method, or a dedicated permanent circuit, or a temporarily configured circuit (such as configured by software) to implement the hardware module, it can be determined according to cost and time considerations.

[0132] The above are only the preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A braking chopper (10), characterized in that, Comprising; A resistor module (12) electrically connected to a DC bus (11) to form an energy discharge circuit of the DC bus (11); A control module (13) for determining a difference between a voltage value of the DC bus (11) and a preset first threshold, and generating a first switch control signal based on the difference; A switch module (14) for controlling an on-time of the energy discharge circuit based on the first switch control signal, wherein the on-time has an increasing relationship with the difference.

2. The braking chopper (10) according to claim 1, characterized in that, Including: A temperature sensor (16) close to the resistor module (12); The control module (13) for obtaining a temperature detection value of the temperature sensor (16), and generating a second switch control signal when the temperature detection value is greater than or equal to a preset second threshold; the switch module (14) for disconnecting the energy discharge circuit based on the second switch control signal; or The temperature sensor (16) for generating a third switch control signal when the temperature detection value is greater than or equal to a preset second threshold; the switch module (14) for disconnecting the energy discharge circuit based on the third switch control signal.

3. The braking chopper (10) according to claim 2, characterized in that, Including: A switch driving module (15) arranged between the control module (13) and the switch module (14) for driving the switch module (14) based on the first switch control signal, the second switch control signal, and / or the third switch control signal.

4. The braking chopper (10) according to claim 1, characterized in that The control module (13) for determining a connection state of the resistor module (12) based on a second difference between a low-side potential value of the resistor module (12) and a voltage value of the DC bus (11) when the energy discharge circuit is in an off state.

5. The braking chopper (10) according to any one of claims 1-4, characterized in that The switch module (14) includes a first metal-oxide-semiconductor field-effect transistor MOSFET and a second MOSFET; The drain of the first MOSFET is connected to the resistor module (12), the source of the first MOSFET is connected to the drain of the second MOSFET, and the gate of the first MOSFET is connected to the control module (13); the gate of the second MOSFET is connected to the control module (13), and the source of the second MOSFET is grounded; The first switch control signal is adapted to continuously turn on the second MOSFET and turn on the first MOSFET during the on-time.

6. A control board (50), characterized in that, Including: A substrate (40); A DC bus (11) arranged on the substrate (40); A resistor module (12) arranged on the substrate (40) and electrically connected to the DC bus (11) to form an energy discharge circuit of the DC bus (11); A motor drive module (41) arranged on the substrate (40) for driving a motor based on the DC bus (11). A control module (13), arranged on the substrate (40), for controlling the motor drive module (41), determining a difference between the voltage value of the DC bus (11) and a preset first threshold, and generating a first switch control signal based on the difference; A switch module (14), arranged on the substrate (40), for controlling the conduction time of the energy dissipation circuit based on the first switch control signal, wherein the conduction time has an increasing relationship with the difference.

7. The control board (50) according to claim 6, characterized in that the switch module (14) includes a first MOSFET and a second MOSFET; the drain of the first MOSFET is connected to the resistor module (12), the source of the first MOSFET is connected to the drain of the second MOSFET, and the gate of the first MOSFET is connected to the control module (13); the gate of the second MOSFET is connected to the control module (13), and the source of the second MOSFET is grounded; the first switch control signal is adapted to continuously conduct the second MOSFET and conduct the first MOSFET during the conduction time.

8. The control board (50) according to claim 6 or 7, characterized in that, Comprising: A heat dissipation layer (42), arranged at the bottom of the substrate (40), for dissipating heat from the DC bus (11), the resistor module (12), the motor drive module (41), the control module (13) and the switch module (14).

9. A bus voltage control method, characterized in that, Comprising: Determine the voltage value of the DC bus (501); Determine the difference between the voltage value of the DC bus and a preset first threshold (502); Generate a first switch control signal based on the difference (503); Control the conduction time of the energy dissipation circuit based on the first switch control signal, wherein the conduction time has an increasing relationship with the difference (504).

10. The method according to claim 9, characterized in that Comprising: Obtain a temperature detection value from a temperature sensor close to the resistor module; When the temperature detection value is greater than or equal to a preset second threshold, generate a second switch control signal; Disconnect the energy dissipation circuit based on the second switch control signal.

11. The method according to claim 9, wherein The generating the first switch control signal based on the difference (503) includes: Generate a pulse width modulation signal based on the difference, and the duty cycle of the pulse width modulation signal has an increasing relationship with the difference.

12. The method according to claim 9, characterized in that Comprising: Obtain the low-side potential value of the resistor module when the energy dissipation circuit is in the off state; Determine the connection state of the resistor module based on the difference between the low-side potential value of the resistor module and the voltage value of the DC bus; wherein when the second difference is zero, determine that the connection state of the resistor module is qualified, and when the second difference is not zero, determine that the connection state of the resistor module is unqualified.

13. An electronic device, characterized in that, Comprising: A processor (601); A memory (602), for storing executable instructions of the processor (601); The processor (601) is configured to read the executable instructions from the memory (602) and execute the executable instructions to implement the bus voltage control method according to any one of claims 9-12.

14. A computer-readable storage medium having computer instructions stored thereon, characterized in that, When the computer instructions are executed by a processor, the bus voltage control method according to any one of claims 9-12 is implemented.

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