Energy control system and electrical equipment

Abstract

The invention discloses an energy control system and electrical equipment, and relates to the technical field of energy control. The energy control system comprises a motor driving circuit and an energy release circuit; the motor driving circuit comprises a direct current motor and a controller, and the controller outputs a variable control signal, so that the direct current motor converts mechanical energy into first electric energy during braking, and the bus voltage of the direct current motor is increased by the first electric energy; the energy release circuit comprises a detection circuit and a step-down circuit, the detection circuit is used for comparing the bus voltage of the direct current motor with a preset threshold value and conducting the step-down circuit when the bus voltage of the direct current motor is larger than the preset threshold value, the first end of the step-down circuit is connected with a bus of the direct current motor, and the second end of the step-down circuit is grounded. The energy control system disclosed by the invention can give consideration to response speed and stability in the braking process of the direct current motor.

Description

Technical Field

[0001] The present application relates to the field of energy control technology, and in particular to an energy control system and electrical equipment. Background Art

[0002] Motor braking refers to the process of taking certain technical measures to quickly stop the motor from rotating after completing its motion task during the operation of DC motors, AC motors, and other electric motors. Common motor braking methods include mechanical braking, motor short-circuit braking, and power resistor energy consumption braking. Among them, motor short-circuit braking achieves braking by directly consuming the kinetic energy of the motor on the stator winding of the motor. Power resistor energy consumption braking achieves braking by converting the kinetic energy of the motor into electrical energy and consuming it on an externally set braking resistor.

[0003] However, motor short-circuit braking can cause the motor temperature to rise rapidly, and in severe cases may even cause motor damage. The power resistor energy consumption braking response speed is slow and may be difficult to meet the requirements in scenarios that require rapid starting and stopping.

[0004] Therefore, how to balance the response speed and stability of motor braking is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of this, the present application discloses an energy control system and electrical equipment, which enable the system to take into account both response speed and stability during the DC motor braking process.

[0006] In the first aspect, the present application discloses an energy control system, including a motor drive circuit and an energy release circuit; the motor drive circuit includes a DC motor and a controller, the controller outputs a variable control signal to enable the DC motor to convert mechanical energy into a first electrical energy during braking, and to enable the first electrical energy to increase the bus voltage of the DC motor; the energy release circuit includes a detection circuit and a step-down circuit, the detection circuit is used to compare the bus voltage of the DC motor with a preset threshold, and to turn on the step-down circuit when the bus voltage of the DC motor is greater than the preset threshold, the first end of the step-down circuit is connected to the bus of the DC motor, and the second end of the step-down circuit is grounded.

[0007] Optionally, the motor drive circuit includes a first path and a second path, the first path includes a path from the bus to the DC motor, and the second path includes a path from the DC motor to the bus; the controller closes the first path and turns on the second path when the DC motor brakes.

[0008] Optionally, the motor drive circuit also includes a third path, which includes a path from the DC motor to the ground terminal; when the DC motor is braked, the controller turns on the third path in a first time period, and the controller turns off the third path in a second time period, and the first time period and the second time period are in the same cycle.

[0009] Optionally, the third path includes a braking resistor, and the DC motor is grounded through the braking resistor; when the third path is turned on, the DC motor converts mechanical energy into second electrical energy, and converts the second electrical energy into heat energy for release through the braking resistor; when the third path is closed, the DC motor converts mechanical energy into first electrical energy.

[0010] Optionally, the control signal includes a pulse width modulation signal; the duty cycle of the pulse width modulation signal is a preset width, or the controller dynamically sets the duty cycle of the pulse width modulation signal based on an external signal.

[0011] Optionally, the step-down circuit includes a semiconductor switch element, a first end of the semiconductor switch element is connected to a bus bar of the DC motor, a second end of the semiconductor switch element is connected to the detection circuit, and a third end of the semiconductor switch element is grounded.

[0012] Optionally, when the bus voltage of the DC motor is greater than a preset threshold, the detection circuit outputs a conduction signal to the second end of the semiconductor switch element to turn on the buck circuit.

[0013] Optionally, the energy release circuit further includes a cement resistor, which is connected between the busbar of the DC motor and the semiconductor switch element and is configured to convert the electrical energy of the busbar into heat energy for release.

[0014] Optionally, the detection circuit includes a transient suppression diode and a processing chip, the first end of the transient suppression diode is connected to the bus of the DC motor, and the second end of the transient suppression diode is connected to the processing chip, so that the processing chip outputs a conduction signal to the second end of the semiconductor switching element when the bus voltage of the DC motor is greater than a preset threshold.

[0015] In a second aspect, the present application discloses an electrical device, comprising the energy control system disclosed in the first aspect above.

[0016] In summary, the energy control system and electrical equipment disclosed in this application have at least the following beneficial effects: (1) By clamping the bus voltage of the DC motor, damage to the hardware system caused by raising the bus voltage during energy release can be avoided; (2) The bus voltage during braking can be automatically detected by building a hardware circuit. When the bus voltage exceeds the preset threshold of the detection circuit, the hardware automatically turns on the step-down circuit in the energy release circuit to consume the energy. (3) The braking force can be flexibly adjusted through software to achieve the switching of energy release paths. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following is a brief introduction to the drawings used in describing the embodiments of the present application: Figure 1This is a diagram of the change of motor short-circuit braking current in the prior art.

[0018] Figure 2 This is a structural example diagram of an energy control system provided in an embodiment of the present application.

[0019] Figure 3 This is a structural example diagram of another energy control system provided in an embodiment of the present application.

[0020] Figure 4 This is a structural example diagram of another energy control system provided in an embodiment of the present application.

[0021] Figure 5 This is a structural example diagram of another energy control system provided in an embodiment of the present application.

[0022] Figure 6 This is a structural example diagram of another energy control system provided in an embodiment of the present application.

[0023] Figure 7 This is a structural example diagram of another energy control system provided in an embodiment of the present application.

[0024] Figure 8 This is a structural example diagram of another energy control system provided in an embodiment of the present application.

[0025] Fig. 9 This is a parameter change schematic diagram provided in an embodiment of the present application.

[0026] Fig.10 This is another parameter change schematic diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the specific implementation methods of the present application will be described below with reference to the accompanying drawings. The accompanying drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other accompanying drawings and other implementation methods can be obtained based on these drawings without creative work. Adjustments and improvements made without departing from the concept of the present application are all within the scope of protection of the present application.

[0028] In order to simplify the drawings, only the parts related to the corresponding embodiments are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, only part of the components with the same structure or function in some figures are schematically drawn, and there may be more or fewer components with the same structure or function in reality.

[0029] In this application, unless otherwise clearly specified and limited, ordinal numbers, such as "first", "second", etc., are only used to distinguish and describe associated objects, and cannot be understood as indicating or implying the relative importance or order between associated objects; in addition, they do not represent the number of associated objects. "Multiple" includes two or more, and other quantifiers are similar. " / " is used to describe the relationship between associated objects, which indicates the "or" relationship between associated objects. "And / or" is used to describe the relationship between associated objects, which includes any combination relationship between associated objects, such as "a and / or b" includes: "alone a", "alone b", or "a and b". "One or more" or "at least one" in multiple objects refers to any object or any combination of multiple objects, such as "one or more of a1, a2, a3" or "at least one of a1, a2, a3" includes: "alone a1", "alone a2", "alone a3", "a1 and a2", "a1 and a3", "a2 and a3", or "a1, a2 and a3".

[0030] A motor is an electrical device that converts electrical energy into mechanical energy. It is widely used in industries, transportation, household appliances, and other fields, providing power support for various mechanical devices. According to different working principles and structures, motors can be divided into two categories: DC motors and AC motors. Among them, DC motors are widely used in scenarios that require precise control because of their excellent speed regulation performance and large starting torque. DC motors can be further divided into brushed DC motors and brushless DC motors. Among them, brushless DC motors have become the mainstream choice in modern industry and consumer electronics due to their high efficiency, low maintenance, and long life. In particular, the three-phase brushless DC motor (BLDC) replaces the mechanical commutator with an electronic commutator, and cooperates with three-phase windings and position sensors to achieve high-precision and high-efficiency conversion of electrical energy to mechanical energy. It has important application value in automation equipment, electric vehicles, and drones. The busbar (or power busbar) of a DC motor refers to the wire or electrical system that provides power to the motor. It connects the armature (or stator) of the motor and the power supply. In the operation of DC motors, the busbar plays a vital role. It transmits electrical energy from the external power supply to the motor to drive the motor. Depending on the different structures and control methods of the DC motor, the specific design and configuration of the busbar will be different.

[0031] During the operation of the motor, in order to ensure the safety of the equipment or achieve precise control, it is usually necessary to quickly stop the rotation of the motor through braking. Motor braking is the process of converting mechanical energy into other forms of energy to achieve braking. Common braking methods include mechanical braking, motor short-circuit braking, and power resistor energy consumption braking. Among them, motor short-circuit braking consumes the kinetic energy of the motor on the stator winding. Although the implementation method is simple, it is easy to cause overheating inside the motor and affect the reliability of the motor. Power resistor energy consumption braking converts kinetic energy into heat dissipation through an external braking resistor, avoiding the problem of overheating of the motor body, and is suitable for long-term braking needs of high-power equipment.

[0032] Figure 1 This is a graph showing the current variation of a motor short-circuit braking current in the prior art. Please refer to Figure 1 , the relevant waveforms represent the bus voltage, motor phase voltage and motor phase current respectively. At the moment of braking, the internal current of the motor reaches 61.2A, which is much larger than the current at the working moment. This will cause the motor to heat up seriously. Repeated operations may damage the motor or shorten the motor life. It can also be seen from the image that the motor phase current will change significantly during braking, resulting in reduced system stability.

[0033] In order to reduce the high current generated by motor braking, there is a method in the prior art to control the current through pulse width modulation (PWM) signals. However, the disadvantage is that the motor generates a higher voltage than the bus, and a power tube device with a higher voltage resistance needs to be selected. The motor is an inductive element (equivalent to an inductor). When the PWM controls the power tube to continuously close and open for braking, the power device and the motor form a boost, which will raise the bus voltage. The increase in bus voltage may cause damage to some devices in the system. For example, electrical equipment and electronic components have a strict tolerance range for operating voltage. Exceeding this range may cause a variety of problems, including insulation breakdown, component overheating, and even failure.

[0034] It is crucial to take into account the response speed and stability of motor braking, as these two factors directly affect the performance, safety and service life of the system. In practical applications, different scenarios have different requirements for response speed and stability. The response speed of motor braking determines whether the system can decelerate or stop quickly. For example, in electric vehicles, emergency braking requires a quick response to avoid collisions. If the braking response is too slow, it may cause safety accidents. During braking, the motor needs to decelerate smoothly to avoid vibration, shock or excessive torque fluctuations. Insufficient stability may cause mechanical damage, personal discomfort or misoperation of precision equipment. Therefore, the idea of ​​this application is to design an energy control system that takes into account the response speed and stability during motor braking.

[0035] The following is a description with reference to the accompanying drawings.

[0036] Figure 2 This is a structural example diagram of an energy control system provided in an embodiment of the present application. Please refer to Figure 2 The energy control system disclosed in the present application includes a motor drive circuit 200 and an energy release circuit 210; the motor drive circuit 200 includes a DC motor 202 and a controller 204, the controller 204 outputs a variable control signal to enable the DC motor 202 to convert mechanical energy into a first electrical energy during braking, and to enable the first electrical energy to increase the voltage of the bus 206 of the DC motor; the energy release circuit 210 includes a detection circuit 212 and a step-down circuit 214, the detection circuit 212 is used to compare the bus voltage of the DC motor with a preset threshold, and to turn on the step-down circuit 214 when the bus voltage of the DC motor is greater than the preset threshold, the first end of the step-down circuit 214 is connected to the bus 206 of the DC motor, and the second end of the step-down circuit 214 is grounded.

[0037] From the perspective of energy conversion, the DC motor 202 mainly involves the conversion process of mechanical energy, electrical energy and thermal energy before and after braking. Before the DC motor 202 is braked, the DC motor 202 is in operation, and the power supply transmits electrical energy to the DC motor 202 through the bus 206. The electrical energy of the DC motor 202 is converted into mechanical energy to drive the load to do work. In other words, most of the input electrical energy is converted into mechanical energy, and a small part is converted into thermal energy due to losses such as resistance, iron loss and mechanical friction in the motor. The essence of motor braking is to reduce the mechanical energy of the motor and its load by some means, thereby reducing the speed or stopping the movement. During the braking process of the DC motor 202, the operation mode of the DC motor 202 is reversed, and the DC motor 202 becomes a generator, converting mechanical energy into electrical energy, which is finally converted into thermal energy for release. For example, in motor short-circuit braking, electrical energy is consumed in the winding resistance and eventually dissipated in the form of heat energy; in power resistor energy consumption braking, electrical energy is converted into thermal energy dissipation through an external braking resistor. In the present application, the DC motor 202 converts mechanical energy into two parts of electrical energy during braking. For the sake of distinction, they are referred to as the first electrical energy and the second electrical energy. Among them, the first electrical energy is transmitted to the bus 206, so that the voltage of the bus 206 increases; the second electrical energy is converted into heat energy and released through the braking resistor set in the motor drive circuit 200. After the braking is completed, the speed of the DC motor 202 drops to zero or stabilizes at the target speed, and the mechanical energy of the system is basically zero. In summary, before braking, the DC motor 202 converts electrical energy into mechanical energy, and the mechanical energy is dominant; during the braking process. The mechanical energy of the DC motor 202 is gradually converted into electrical energy and thermal energy, the mechanical energy decreases rapidly, the electrical energy increases briefly, and finally most of the electrical energy is dissipated in the form of thermal energy; after braking, the mechanical energy of the DC motor 202 is basically zero, the output of electrical energy and thermal energy gradually stops, and the system enters a static or low energy consumption state.

[0038] In the above energy conversion process, the first electric energy generated by the DC motor 202 during the braking process will increase the voltage of the bus 206, and the over-raised bus voltage may cause damage to some components in the circuit. Therefore, the energy control system disclosed in the present application also includes an energy release circuit 210, which uses hardware equipment to detect in real time whether the bus voltage exceeds a preset threshold, and when the bus voltage exceeds the preset threshold, the buck circuit 214 is turned on to reduce the bus voltage so that the bus voltage is clamped within a certain range. In this way, the components in the circuit are no longer damaged due to excessive bus voltage. During the braking process, the detection action of the detection circuit 212 is implemented by hardware to achieve a higher response speed, that is, once the bus voltage exceeds the preset threshold, the detection circuit 212 can respond to this state. For example, the detection circuit 212 can output a start signal for turning on the buck circuit 214. The first end of the buck circuit 214 is connected to the bus 206, and the second end is grounded, which can convert the electric energy in the bus 206 into heat energy dissipation, thereby realizing energy release.

[0039] Through the above energy control system, the bus voltage of the DC motor can be clamped to avoid damage to the hardware system due to the increase of the bus voltage during the energy release process; and the bus voltage during braking can be automatically detected by building a hardware circuit. When the bus voltage exceeds the preset threshold of the detection circuit, the hardware automatically opens the step-down circuit in the energy release circuit to consume the energy (electrical energy in the bus).

[0040] In some embodiments of the present application, the motor drive circuit includes a first path and a second path, the first path includes a path from the bus to the DC motor, and the second path includes a path from the DC motor to the bus; the controller closes the first path and turns on the second path when the DC motor brakes.

[0041] Figure 3 This is a structural example diagram of another energy control system provided in the embodiment of the present application. Please refer to Figure 3 The motor driving circuit 300 includes a first path (i.e. Figure 3 The circled "1" in the figure) and the second path (that is, Figure 3The circled "2" in the figure). The first path includes the path from the bus 306 to the DC motor 302, and the second path includes the path from the DC motor 302 to the bus 306. During the braking process of the DC motor 302, the controller 304 outputs a control signal to close the first path and turn on the second path. For example, the first path includes a plurality of semiconductor switching elements, and an NMOS tube is used as an example for illustration. In this way, during the braking process of the DC motor 302, the control signal output by the controller to the first path is a low-level signal, so that the NMOS tube cannot be turned on, thereby achieving the goal of closing the first path. After the first path is closed, the electric energy of the bus cannot be transmitted to the DC motor 302 via the first path. Similarly, after the second path is turned on, the electric energy in the DC motor 302 can be superimposed on the bus 306 through the internal diode of the NMOS tube.

[0042] Please continue to refer to Figure 3 The motor driving circuit 300 also includes a third path (i.e. Figure 3 The circled "3" in the figure) is shown in the figure. The third path includes the path from the DC motor 302 to the ground terminal. When the DC motor is braked, the controller 304 turns on the third path in the first time period, and the controller 304 turns off the third path in the second time period. The first time period and the second time period are in the same cycle. In some embodiments of the present application, the third path includes a braking resistor 308, and the DC motor 302 is grounded through the braking resistor 308. When the third path is turned on, the DC motor 302 converts mechanical energy into second electrical energy, and converts the second electrical energy into heat energy for release through the braking resistor 308. When the third path is turned off, the DC motor 302 converts mechanical energy into first electrical energy.

[0043] During the braking process, the mechanical energy of the DC motor 302 is first converted into electrical energy, and the electrical energy leaves the DC motor 302 through different paths. For the convenience of distinction, the electrical energy is divided into the first electrical energy and the second electrical energy. Among them, the first electrical energy enters the bus 306 through the second path; the second electrical energy is converted into heat energy and released through the braking resistor 308 in the third path. By setting the third path, part of the electrical energy generated during the braking process can be guided to the area outside the bus 306 to reduce the pressure of the bus 306. In addition, the braking resistor 308 can also be set in the third path to prevent the circuit from being directly damaged by a large current during the braking process. During the braking process, the third path can also be set to a time-sharing conduction mode by a control signal. For example, a cycle is divided into a first time period and a second time period. In the first time period, the control signal output by the controller 304 conducts the third path, and in the second time period, the control signal output by the controller 304 closes the third path. Through the time-sharing conduction mode, not only the pressure of the bus 306 is shared, but also the risk of circuit damage caused by long-term conduction of the third path can be reduced. The length of the first time period and the length of the second time period can be equal or different. In some embodiments of the present application, the control signal includes a pulse width modulation signal; the duty cycle of the pulse width modulation signal is a preset width, or the controller dynamically sets the duty cycle of the pulse width modulation signal based on an external signal. The third path may include an NMOS tube for receiving a pulse width modulation signal. For example, the duty cycle of the pulse width modulation signal may be set to 50% so that the length of the first time period and the second time period are equal. For another example, the duty cycle of the pulse width modulation signal may be set to 30% so that the length of the first time period is less than the length of the second time period. Alternatively, the controller 304 may dynamically set the duty cycle of the pulse width modulation signal based on an external signal so that its duty cycle is variable. For example, it may be a duty cycle of 10%, increasing by 1% every 1ms, and gradually increasing. The specific setting of the duty cycle can be set according to actual needs, and the present application does not limit this. In this way, the braking force can be freely adjusted by combining the software with different PWM duty cycles to avoid the motor being completely short-circuited and causing excessive braking, which would bring a bad experience to the user. In addition, by outputting different PWM duty cycles through the software to control the braking force, the current generated during motor short-circuit braking can be reduced, thus avoiding large current damaging the power tube and avoiding excessive heating of the motor and burning out the motor.

[0044] In some embodiments of this application, please continue to refer to Figure 3, the step-down circuit 314 includes a semiconductor switch element, a first end of the semiconductor switch element is connected to the bus 306 of the DC motor, a second end of the semiconductor switch element is connected to the detection circuit 312, and a third end of the semiconductor switch element is grounded. Take the semiconductor switch element as an NMOS tube as an example for explanation. The first end of the semiconductor switch element is the drain of the NMOS tube, the second end of the semiconductor switch element is the gate of the NMOS tube, and the third end of the semiconductor switch element is the source of the NMOS tube. When the bus voltage of the DC motor is greater than the preset threshold, the detection circuit 312 outputs a conduction signal to the second end of the semiconductor switch element to turn on the step-down circuit 314. For example, when the bus voltage is greater than the preset threshold, the detection circuit 312 outputs a high-level signal, which is transmitted to the gate of the NMOS tube to turn on the step-down circuit 314. When the bus voltage of the DC motor is less than the preset threshold, the detection circuit 312 outputs a low-level signal, which is transmitted to the gate of the NMOS tube, and the step-down circuit 314 is not turned on.

[0045] In some embodiments of this application, please continue to refer to Figure 3 , the energy release circuit 310 also includes a cement resistor 316, which is connected between the bus 306 of the DC motor and the semiconductor switch element, and is configured to convert the electrical energy of the bus into thermal energy for release. Similar to the braking resistor 308, the cement resistor 316 can also prevent the circuit from being directly damaged by a large current during the braking process. The difference between the braking resistor 308 and the cement resistor 316 is that the trigger conditions for converting electrical energy into thermal energy are different. When the third path is turned on, the braking resistor 308 begins to convert the second electrical energy into thermal energy for release; when the bus voltage is greater than the preset threshold, the cement resistor 316 converts the electrical energy of the bus (related to the first electrical energy) into thermal energy for release.

[0046] In some embodiments of the present application, the detection circuit includes a transient voltage suppressor diode (TVS tube) and a processing chip, the first end of the transient voltage suppressor diode is connected to the bus of the DC motor, and the second end of the transient voltage suppressor diode is connected to the processing chip, so that the processing chip outputs a conduction signal to the second end of the semiconductor switching element when the bus voltage of the DC motor is greater than a preset threshold.

[0047] Figures 4 to 8 This is another example diagram of the structure of an energy control system provided in the embodiment of the present application. Figures 4 to 8 , the overall logical architecture of the energy control system they show is the same, the difference lies in the specific implementation of the energy release circuit, and the bus voltage in the figure is represented by BAT. Figure 4In the embodiment, the EG3001 chip is used as a processing chip, and the second end of the TVS tube is connected to the second pin of the EG3001 chip through a resistor; correspondingly, the seventh pin of the EG3001 chip is connected to the gate of the NMOS tube in the buck circuit through a resistor. When the motor is subjected to PWM control braking, the bus will be lifted. When the BAT voltage is greater than D1 (the preset threshold set by the TVS tube), D1 is turned on, and the front-end voltage of R3 reaches a certain voltage and is input to the second pin IN of the chip EG3001. The seventh pin of the chip EG3001 outputs a high level to drive the NMOS tube (Q1) to turn on, and the bus voltage releases energy through R2 and Q1, which can reduce the bus voltage. When the bus voltage drops to a certain value, D1 (TVS tube) is cut off, the seventh pin of EG3001 is closed, the sixth pin outputs a low level, Q1 is closed, and the bus voltage remains in its original state, which will not affect the normal operation of the system. In the specific implementation, it is not limited to using the EG3001 chip as a processing chip. Other similar processing chips can also be used as the processing chip of this application for signal processing. Figure 5-Figure 8 In the embodiment, the processing chips are UCC37322, 1EDI60N12, 1EDI20N12AF and TC4420 chips. For different types of processing chips, the connection method of the circuit is also different, and the connection method in the attached figure can be referred to for setting. In addition to the above enumerated chip types, other chips that can realize the functions of the processing chip in this application can also be used as processing chips, and this application will not list them one by one.

[0048] In this application, the function of the processing chip is to classify and process the signals output by the TVS tube: when the TVS tube is turned on, the processing chip outputs a conduction signal (such as a high-level signal) to the step-down circuit to complete the energy release and reduce the bus voltage. When the TVS tube is not turned on, no signal is output or an invalid signal (such as a low-level signal) is output to the step-down circuit so that the step-down circuit is not in working state. When the bus voltage is greater than the preset threshold of the TVS tube, the TVS tube will turn on quickly to play the role of overvoltage protection. The preset threshold can be changed by changing the TVS tube specification or model. TVS tube (transient voltage suppressor) is a device used to protect circuits from transient overvoltage shocks. It is turned on at a preset breakdown voltage threshold (commonly referred to as reverse breakdown voltage or clamping voltage) to limit the excessive voltage to a safe range, thereby protecting the subsequent circuit. Under normal circumstances, the bus voltage is lower than the breakdown voltage of the TVS tube, and the TVS tube is equivalent to an open circuit, which is basically not turned on and has no effect on the system. In the case of overvoltage, the bus voltage exceeds the preset threshold of the TVS tube, and the TVS tube quickly breaks down and conducts, shunting the excess voltage to the ground or other paths to prevent the bus voltage from continuing to rise. Since the TVS tube has an extremely fast response speed (usually in the picosecond to nanosecond level), it is suitable for protecting equipment that is sensitive to transient voltages.

[0049] Fig. 9 and Fig.10 This is a schematic diagram of parameter changes provided in the embodiment of this application. Please refer to Fig. 9 and Fig.10 When the motor is braked, the PWM signal output can be controlled to control the motor braking current (phase current) to gradually increase, and the bus voltage is also controlled to a certain value to avoid excessive rise. And compared with the prior art, the phase current change amplitude of the energy control system of the present application during braking is relatively stable, and will not produce a large change like short-circuit braking. Fig.10 In the example, when the bus voltage exceeds the preset threshold, the conduction signal output by the processing chip to the semiconductor switch element (such as the gate of the NMOS tube) jumps to a high level, which can quickly turn on the buck circuit so that the bus voltage no longer rises, and after the energy is released, when the bus voltage begins to decrease, the signal output by the processing chip quickly jumps to a low level, turning off the buck circuit. As can be seen from the figure, when performing energy control, the system has a good response speed and can better realize the energy release during motor braking.

[0050] Based on similar technical concepts, the present application discloses an electrical device, including an energy control system as disclosed in the above embodiments. The electrical device may be, for example, electric vehicles and rail transportation equipment (electric vehicles, electric bicycles, hybrid vehicles, subway trains, high-speed trains, etc.), industrial automation equipment (CNC machine tools, industrial robots, cranes, conveyor belt systems, port automation equipment, etc.), consumer electronics and household appliances (cordless vacuum cleaners, drones, smart home appliances, etc.).

[0051] It should be noted that in this application, the meanings of the labels with the same suffix in different drawings are consistent. For example, 202, 302, 402...802 are all DC motors; 204, 304, 404...804 are all controllers; 212, 312, 412...812 are all detection circuits; 214, 314, 414...814 are all step-down circuits. The parameters of each electronic component (such as resistors, capacitors, etc.) in the drawings of this application can be set according to actual needs.

[0052] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. In addition, the above embodiments can be freely combined as needed.

Claims

1. An energy control system, characterized in that: It includes a motor driving circuit and an energy releasing circuit; The motor drive circuit includes a DC motor and a controller, wherein the controller outputs a variable control signal so that the DC motor converts mechanical energy into first electrical energy during braking, and the first electrical energy increases the bus voltage of the DC motor; The energy release circuit includes a detection circuit and a step-down circuit. The detection circuit is used to compare the bus voltage of the DC motor with a preset threshold value, and to turn on the step-down circuit when the bus voltage of the DC motor is greater than the preset threshold value. The first end of the step-down circuit is connected to the bus of the DC motor, and the second end of the step-down circuit is grounded.

2. The energy control system according to claim 1, characterized in that: The motor drive circuit includes a first path and a second path, the first path includes a path from the bus to the DC motor, and the second path includes a path from the DC motor to the bus; The controller closes the first path and opens the second path when the DC motor is braking.

3. The energy control system according to claim 2, characterized in that: The motor drive circuit further includes a third path, wherein the third path includes a path from the DC motor to the ground terminal; When the DC motor is braking, the controller turns on the third path in a first time period and turns off the third path in a second time period, and the first time period and the second time period are in the same cycle.

4. The energy control system according to claim 3, characterized in that: The third path includes a braking resistor, and the DC motor is grounded through the braking resistor; When the third path is turned on, the DC motor converts mechanical energy into second electrical energy, and converts the second electrical energy into heat energy for release through the braking resistor; When the third path is closed, the DC motor converts mechanical energy into the first electrical energy.

5. The energy control system according to any one of claims 2 to 4, characterized in that: The control signal comprises a pulse width modulation signal; The duty cycle of the pulse width modulation signal is a preset width, or the controller dynamically sets the duty cycle of the pulse width modulation signal based on an external signal.

6. The energy control system according to claim 1, characterized in that: The step-down circuit includes a semiconductor switch element, a first end of the semiconductor switch element is connected to the busbar of the DC motor, a second end of the semiconductor switch element is connected to the detection circuit, and a third end of the semiconductor switch element is grounded.

7. The energy control system according to claim 6, characterized in that: When the bus voltage of the DC motor is greater than the preset threshold, the detection circuit outputs a conduction signal to the second end of the semiconductor switch element to turn on the buck circuit.

8. The energy control system according to claim 6 or 7, characterized in that: The energy release circuit also includes a cement resistor, which is connected between the bus bar of the DC motor and the semiconductor switch element and is configured to convert the electrical energy of the bus bar into heat energy for release.

9. The energy control system according to claim 7, characterized in that: The detection circuit includes a transient suppression diode and a processing chip, wherein the first end of the transient suppression diode is connected to the bus of the DC motor, and the second end of the transient suppression diode is connected to the processing chip, so that the processing chip outputs the conduction signal to the second end of the semiconductor switch element when the bus voltage of the DC motor is greater than the preset threshold.

10. An electrical device, characterized in that: Comprising an energy control system as described in any one of claims 1-9.

Images