Motor energy consumption braking large heat consumption braking pipe current sharing circuit and method

Abstract

The invention relates to a motor energy consumption braking large heat consumption brake pipe current sharing circuit and method. The circuit comprises a positive voltage current sampling circuit, a negative voltage current sampling circuit, a three-phase upper bridge driving unit, a three-phase lower bridge driving unit, a motor and a controller. Each phase of upper and lower bridge driving unit comprises a plurality of upper and lower bridge MOSFET driving circuits which are connected in parallel; one end of the positive voltage and current sampling circuit is connected with a positive power supply, the other end of the positive voltage and current sampling circuit is connected with one end of each upper bridge MOSFET driving circuit, and the other end of each upper bridge MOSFET driving circuit is connected with a phase winding of the motor; one end of the negative voltage current sampling circuit is connected with a negative power supply, the other end of the negative voltage current sampling circuit is connected with one end of each lower bridge MOSFET driving circuit, and the other end of each lower bridge MOSFET driving circuit is connected with a phase winding of the motor; a winding common point of the motor is connected with the ground; the positive and negative voltage current sampling circuits are respectively used for collecting current signals of each driving circuit and sending the current signals to the controller; the controller is used for outputting different driving signals based on the current signals. The output current and the output power of the circuit can be greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic circuit, in particular to a motor energy consumption braking large heat consumption braking tube current sharing circuit and method. BACKGROUND

[0002] In order to realize high precision and low power consumption control, the motor driving circuit generally uses power tubes to realize energy consumption control at high speed. When energy consumption control is needed, the power tube works in the linear region. Since the triode has better linear control characteristics than the power MOSFET, the driving circuit is simpler and easier to implement in parallel, so when the motor driving circuit output current is small and the output power is low, a triode is generally used for energy consumption control. However, as the motor operating current gradually increases, the triode cannot meet the demand of the motor for large current and high power output. Therefore, a power MOSFET tube is needed for energy consumption control.

[0003] However, although the power MOSFET tube has the advantages of small size, easy heat dissipation, small power loss, large maximum current, and high maximum voltage. On the one hand, the drain-source voltage of the MOSFET tube is large, and its drain operating current is small due to the limitation of its power loss. On the other hand, the MOSFET tube has large individual differences, and is prone to system oscillation when switching the working state. Therefore, in order to overcome the above-mentioned defects of the MOSFET tube in application, so as to meet the application requirements of the large current and high power motor driving circuit, a motor energy consumption braking large heat consumption braking tube current sharing circuit is needed to solve the above-mentioned problems. SUMMARY

[0004] The motor energy consumption braking large heat consumption braking tube current sharing circuit and method provided by the embodiment of the present application can greatly improve the output current and output power of the circuit, and meet the demand of the motor for large current and high power output.

[0005] In a first aspect, the embodiment of the present application provides a motor energy consumption braking large heat consumption braking tube current sharing circuit, comprising: A positive voltage current sampling circuit, a negative voltage current sampling circuit, a three-phase upper bridge driving unit, a three-phase lower bridge driving unit, a motor and a controller; wherein each phase upper bridge driving unit comprises a plurality of parallel upper bridge MOSFET driving circuits, and each phase lower bridge driving unit comprises a plurality of parallel lower bridge MOSFET driving circuits. One end of the positive voltage current sampling circuit is connected with a positive power supply, and the other end is connected with one end of each of the upper bridge MOSFET drive circuits, and the other end of each of the upper bridge MOSFET drive circuits is connected with a winding of a motor; one end of the negative voltage current sampling circuit is connected with a negative power supply, and the other end is connected with one end of each of the lower bridge MOSFET drive circuits, and the other end of each of the lower bridge MOSFET drive circuits is connected with a winding of the motor; and the winding common point of the motor is connected with the ground. The positive voltage current sampling circuit and the negative voltage current sampling circuit are respectively used for collecting current signals of the upper bridge MOSFET drive circuits and the lower bridge MOSFET drive circuits, and sending the collected current signals to the controller; and the controller is used for outputting different drive signals based on the received current signals, so as to control each MOSFET drive circuit.

[0006] In a second aspect, the embodiment of the present application further provides a motor energy consumption braking large heat consumption braking pipe current sharing method, comprising: The current signal of the upper bridge MOSFET drive circuit is collected by using the positive voltage current sampling circuit, and the collected current signal is sent to the controller; The current signal of the lower bridge MOSFET drive circuit is collected by using the negative voltage current sampling circuit, and the collected current signal is sent to the controller; The controller outputs different drive signals based on the received current signals, so as to control each MOSFET drive circuit.

[0007] In the embodiment of the present application, the positive power supply and the negative power supply are respectively used for current control of the upper bridge and the lower bridge, the upper bridge drive circuit and the lower bridge drive circuit are independent of each other, and any bridge failure will not cause system failure. The positive voltage current sampling circuit and the negative voltage current sampling circuit are respectively used for current signal collection of the upper bridge and the lower bridge, the controller outputs different control signals for MOSFET control on the upper bridge and the lower bridge by collecting the current signals of the upper bridge and the lower bridge; the power MOSFET in the upper bridge MOSFET drive circuit and the lower bridge MOSFET drive circuit works in a linear amplification state by adopting closed-loop negative feedback, so as to realize hardware closed-loop control of the working current of the power MOSFET. In addition, the MOSFET drive circuit is used in parallel, so that the working current can be greatly improved. As can be seen, the circuit provided in the present application can greatly improve the output current and the output power of the circuit. BRIEF DESCRIPTION OF DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present application, and the other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0009] Figure 1 is a structural schematic diagram of a motor energy consumption braking large heat consumption braking pipe current sharing circuit provided by an embodiment of the present application. Figure 2 is a structural schematic diagram of a positive voltage current sampling circuit provided by an embodiment of the present application. Figure 3 is a structural schematic diagram of a negative voltage current sampling circuit provided by an embodiment of the present application. Figure 4 is a structural schematic diagram of an upper bridge MOSFET driving circuit provided by an embodiment of the present application. Figure 5 is a structural schematic diagram of a lower bridge MOSFET driving circuit provided by an embodiment of the present application.

[0010] Reference signs: 1-positive voltage current sampling circuit; 2-negative voltage current sampling circuit; 3-upper bridge MOSFET driving circuit; 4-lower bridge MOSFET driving circuit. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative effort are within the protection scope of the present application.

[0012] Figure 1 is a structural schematic diagram of a motor energy consumption braking large heat consumption braking pipe current sharing circuit provided by an embodiment of the present application. As shown in Figure 1 , the motor energy consumption braking large heat consumption braking pipe current sharing circuit comprises: a positive voltage current sampling circuit 1, a negative voltage current sampling circuit 2, a three-phase upper bridge driving unit, a three-phase lower bridge driving unit, a motor and a controller; wherein each phase upper bridge driving unit comprises a plurality of parallel upper bridge MOSFET driving circuits 3, and each phase lower bridge driving unit comprises a plurality of parallel lower bridge MOSFET driving circuits 4. One end of the positive voltage current sampling circuit 1 is connected with the positive power supply, and the other end is connected with one end of each upper bridge MOSFET drive circuit 3 respectively, and the other end of each upper bridge MOSFET drive circuit 3 is connected with one phase winding of the motor respectively; one end of the negative voltage current sampling circuit 2 is connected with the negative power supply, and the other end is connected with one end of each lower bridge MOSFET drive circuit 4 respectively, and the other end of each lower bridge MOSFET drive circuit 4 is connected with one phase winding of the motor respectively; the winding common point of the motor is connected with the ground; The positive voltage current sampling circuit 1 and the negative voltage current sampling circuit 2 are respectively used for collecting the current signals of each upper bridge MOSFET drive circuit 3 and each lower bridge MOSFET drive circuit 4, and sending the collected current signals to the controller; the controller is used for outputting different drive signals based on the received current signals, so as to control each MOSFET drive circuit respectively.

[0013] In this embodiment, the positive and negative power supplies are respectively used for the current control of the upper and lower bridges, and the upper and lower bridge drive circuits are independent of each other, and any bridge failure will not cause system failure. The positive voltage current sampling circuit 1 and the negative voltage current sampling circuit 2 are respectively used for the current signal collection of the upper and lower bridges, and the controller outputs different control signals for the MOSFET control on the upper and lower bridges by collecting the current signals of the upper and lower bridges; by adopting closed loop negative feedback, the power MOSFET in the upper bridge MOSFET drive circuit 3 and the lower bridge MOSFET drive circuit 4 works in the linear amplification state, and the working current closed loop control of the power MOSFET is realized, in addition, by using the parallel connection of the MOSFET drive circuit, the working current can be greatly improved. As can be seen, the circuit provided by the application can greatly improve the output current and output power of the circuit.

[0014] The specific structure of each module in the circuit will be introduced in detail as follows: 1. Positive voltage current sampling circuit As shown in Figure 2 , the positive voltage current sampling circuit 1 comprises: a resistor 10, a resistor 11A, a resistor 11B, a resistor 12A, an operational amplifier 13A, a resistor 13B, a resistor 14A, a resistor 14B, a resistor 14C, an operational amplifier 14D and a resistor 14F.

[0015] In the above positive voltage current sampling circuit 1, the positive power supply is output to the upper bridge MOSFET drive circuit 3 through the resistor 10, the voltage across the resistor 10 is reduced through the resistors 11A, 11B, 12A and 13B and is input to the operational amplifier 13A, 13B is the feedback resistor, the two ends of 13B are connected to the input negative terminal of 13A and the output of 13A respectively, the output signal of 13A is input to the positive terminal of 14D through the resistor 14A, the negative terminal of 14D is connected to the ground through the resistor 14B, 14C is the feedback resistor, the two ends of 14C are connected to the input negative terminal of 14D and the upper bridge current signal respectively, and the output of 14D is input to the upper bridge current signal through the resistor 14F.

[0016] By using the above positive voltage current sampling circuit 1, the current of each upper bridge MOSFET drive circuit 3 can be collected in real time and sent to the controller as a current feedback signal.

[0017] In addition, the positive voltage current sampling circuit 1 also includes capacitors 11C, 13C and 14E. Among them, the capacitor 11C is connected in parallel with the resistor 11B, the capacitor 13C is connected in parallel with the resistor 13B, and the capacitor 14E is connected in parallel with the resistor 14C. By setting the above three capacitors, low-frequency noise in the corresponding circuit can be effectively filtered out.

[0018] 2, negative voltage current sampling circuit As shown in Figure 3 , the negative voltage current sampling circuit 2 includes resistors 20, 21A, 21B, 22A, 23A, 23B, 24A, 24B, 24C, 24D and 24F.

[0019] In the above negative voltage current sampling circuit 2, the output of the lower bridge MOSFET drive circuit 4 enters the negative power supply through the resistor 20, the voltage across the resistor 20 is reduced through the resistors 21A, 21B, 22A and 23B and is input to the operational amplifier 23A, 23B is the feedback resistor, the two ends of 23B are connected to the input negative terminal of 23A and the output of 23A respectively, the output signal of 23A is input to the positive terminal of 24D through the resistor 24A, the negative terminal of 24D is connected to the ground through the resistor 24B, 24C is the feedback resistor, the two ends of 24C are connected to the input negative terminal of 24D and the lower bridge current signal respectively, and the output of 24D is input to the lower bridge current signal through the resistor 24F.

[0020] By using the above negative voltage current sampling circuit 2, the current of each lower bridge MOSFET drive circuit 4 can be collected in real time and sent to the controller as a current feedback signal.

[0021] In addition, the negative voltage current sampling circuit 2 also includes capacitors 21C, 23C, and 24E. Capacitor 21C is connected in parallel with resistor 21B, capacitor 23C is connected in parallel with resistor 23B, and capacitor 24E is connected in parallel with resistor 24C. By setting these three capacitors, low-frequency noise in the corresponding circuit can be effectively filtered out.

[0022] 3. Upper Bridge MOSFET Drive Circuit like Figure 4 As shown, the motor is a three-phase motor, including three phases A, B, and C. Each phase corresponds to an upper bridge drive unit, and each upper bridge drive unit includes multiple parallel upper bridge MOSFET drive circuits 3. Each upper bridge MOSFET drive circuit 3 includes: resistor 30, resistor 31A, resistor 31B, capacitor 31C, operational amplifier 31D, resistor 31E, resistor 31F, capacitor 31G, resistor 32A, capacitor 32B, resistor 32C, resistor 33A, operational amplifier 33B, resistor 33C, capacitor 33D, capacitor 33E, resistor 34A, resistor 34B, resistor 34C, transistor 34D, Zener diode 34E, resistor 34F, MOSFET 35, and diode 36.

[0023] In each upper-bridge MOSFET drive circuit 3, the positive voltage current sampling circuit 1 is connected to the motor winding via resistor 30, MOSFET 35, and diode 36, with the other end of the motor winding grounded. The voltage across resistor 30 is stepped down by resistors 31A, 31B, 31E, and 31F to serve as the input signal for operational amplifier 31D. 31F is a feedback resistor, with its two ends connected to the negative input terminal and the output terminal of operational amplifier 31D, respectively. Capacitors 31C and 31G are used to filter out low-frequency noise and are connected in parallel with resistors 31B and 31F, respectively. The output signal of operational amplifier 31D is input to the negative terminal of operational amplifier 33B via resistor 33A. The upper-bridge drive signal output by the controller is input to the positive terminal of operational amplifier 33B via resistor 32A. The positive terminal of operational amplifier 33B is grounded via resistor 32C, with capacitor 32B connected in parallel with resistor 32C. The two ends of capacitor 33E are connected to the negative terminal and the output terminal of operational amplifier 33B, respectively. The negative terminal of op-amp 33B is connected to its output via resistor 33C and capacitor 33D. The output of op-amp 33B drives transistor 34D via resistor 34A. 34C limits the operating state of 34D, keeping it in amplification mode. 34B provides a turn-off path for 34D. When 34D is on, current flows through resistor 30 into the gate-source (GS) terminals of MOSFET 35, turning it on. When 34D is off, resistor 34F provides a discharge path for the GS terminals of MOSFET 35. As the GS voltage of MOSFET 35 decreases, MOSFET 35 turns off. Zener diode 34E limits the GS voltage of MOSFET 35.

[0024] From the above connection relationship, the positive and negative terminals of the operational amplifier 33B are inputted with the driving signal sent by the controller and the negative feedback signal outputted by the operational amplifier 31D respectively, and the output signal of the operational amplifier 33B is obtained after the driving signal is compared with the negative feedback signal. The output signal controls the triode 34D to adjust the working current of the MOSFET tube 35, forming a closed loop to make the working current of the MOSFET tube 35 linearly related to the driving signal. In this way, the MOSFET tube 35 can work in a linear amplification state by controlling the driving signal, and the working current closed loop control of the power MOSFET is realized. In addition, since each upper bridge MOSFET driving circuit 3 is controlled respectively, the independent regulation and control of the current can be realized, the individual differences between the MOSFET tubes are eliminated, and the current sharing effect is obtained.

[0025] In addition, the current sharing circuit further comprises a diode 37, the anode of the diode 37 is connected to the ground, and the cathode is connected to the positive power supply; When the motor is in the energy consumption braking state, the current flows out from the ground, sequentially passes through the diode 37, the positive voltage current sampling circuit 1, the resistor 30, the MOSFET tube 35 and the diode 36, and then flows through the motor winding and is grounded.

[0026] 4. Lower bridge MOSFET driving circuit Similarly, as shown in Figure 5 The motor is a three-phase motor, which includes three phases A, B and C, and each phase corresponds to a lower bridge driving unit, and each lower bridge driving unit includes a plurality of parallel lower bridge MOSFET driving circuits 4. Each lower bridge MOSFET driving circuit 4 includes a resistor 40, a resistor 41A, a resistor 41B, a capacitor 41C, an operational amplifier 41D, a resistor 41E, a resistor 41F, a capacitor 41G, a resistor 42A, a capacitor 42B, a resistor 42C, a resistor 43A, an operational amplifier 43B, a resistor 43C, a capacitor 43D, a capacitor 43E, a resistor 44A, a resistor 44B, a resistor 44C, a triode 44D, a voltage stabilizing tube 44E, a resistor 44F, a MOSFET tube 45 and a diode 46.

[0027] In each lower bridge MOSFET drive circuit 4, one end of the motor winding is grounded, and the other end is connected to the negative power supply through diode 46, MOSFET tube 45, resistor 40 and positive voltage current sampling circuit 1. The voltage across resistor 40 is reduced through resistors 41A, 41B, 41E and 41F, and then used as the input signal of operational amplifier 41D. 41F is a feedback resistor, and the two ends of 41F are connected to the input negative terminal of operational amplifier 41D and the output of 41D, respectively. Capacitors 41C and 41G are used to filter out low-frequency noise and are connected in parallel with resistors 41B and 41F, respectively. The output signal of operational amplifier 41D is input to the positive terminal of operational amplifier 43B through resistor 43A. The lower bridge drive signal output by the controller is input to the negative terminal of operational amplifier 43B through resistor 42A. The negative terminal of operational amplifier 43B is connected to ground through resistor 42C, and capacitor 42B is connected in parallel with resistor 42C. Capacitor 43E is connected to the negative terminal and the output of operational amplifier 43B, respectively. The negative terminal of operational amplifier 43B is connected to the output of 43B through resistor 43C and capacitor 43D. The output of operational amplifier 43B drives transistor 44D to work through resistor 44A. 44C is used to limit the working state of 44D, so that it works in the amplification state. 44B provides a turn-off path for 44D. When 44D is turned on, the current flows through resistor 40 and is injected into the GS terminal of MOSFET tube 45, causing MOSFET tube 45 to conduct. When 44D is turned off, resistor 44F provides a discharge path for the GS terminal of MOSFET tube 45. As the voltage at the GS terminal of 45 decreases, 45 turns off. Zener diode 44E is used to limit the voltage at the GS terminal of 45.

[0028] Similarly, from the above connection relationship, it can be seen that the positive and negative terminals of operational amplifier 43B are input with the negative feedback signal output by operational amplifier 41D and the drive signal output by the controller, respectively. After comparing the drive signal with the negative feedback signal, the output signal of operational amplifier 43B is obtained. This output signal controls transistor 44D to adjust the working current of MOSFET tube 45, forming a closed loop, so that the working current of MOSFET tube 45 is linearly related to the drive signal. In this way, by controlling the drive signal, MOSFET tube 45 can work in the linear amplification state, realizing the closed-loop control of the working current of the power MOSFET. In addition, since each upper bridge MOSFET drive circuit 3 controls independently, the current can be independently regulated and controlled, eliminating the individual differences between the MOSFET tubes and achieving the effect of current sharing.

[0029] In addition, the current sharing circuit also includes diode 47; the anode of diode 47 is connected to the negative power supply, and the cathode is connected to the ground; When the motor is in the energy consumption braking state, the current flows from the ground through the motor winding, and then flows back to the ground through diode 46, MOSFET tube 45, resistor 40, negative voltage current sampling circuit 2 and diode 47.

[0030] In summary, the current sharing circuit can form an upper bridge drive loop and a lower bridge drive loop, and the upper bridge drive loop and the lower bridge drive loop work independently. The upper bridge drive loop is composed of the positive voltage current sampling circuit 1, the three-phase upper bridge drive unit, the motor and the controller. The lower bridge drive loop is composed of the negative voltage current sampling circuit 2, the three-phase lower bridge drive unit, the motor and the controller.

[0031] By adopting the above two drive loops, the acceleration and energy consumption braking of the motor can be realized.

[0032] 1. When the motor needs to accelerate, the acceleration can be realized by any one of the following circuits or a combination of the following two circuits: (1) The positive power supply enters the motor winding through the resistance 10 in the positive voltage current sampling circuit 1, the resistance 30 in the upper bridge MOSFET drive circuit 3, the MOSFET tube 35 and the diode 36, and then to the power supply ground.

[0033] (2) The current flows out from the motor winding to the negative power supply through the diode 46, the MOSFET tube MOSFET 45, the resistance 40 in the lower bridge MOSFET drive circuit 4 and the resistance 20 in the negative voltage current sampling circuit 2.

[0034] By using the above circuit, the control of the motor winding current can be realized by adjusting the upper and lower bridge drive signals.

[0035] 2. When the motor needs energy consumption braking, the positive power supply and the negative power supply are in the output off state, and the motor winding is used as the power supply. At this time, the energy consumption braking can be realized by any one of the following circuits: (1) When the winding voltage is negative, the lower bridge works, and the current flows back to the winding through the power supply ground in sequence through the diode 46, the MOSFET tube 45, the resistance 40 in the lower bridge MOSFET drive circuit 4, the resistance 20 in the negative voltage current sampling circuit 2 and the diode 47.

[0036] (2) When the winding voltage is positive, the upper bridge works, and the current enters the motor winding through the diode 37, the resistance 10 in the positive voltage current sampling circuit 1, the resistance 30 in the upper bridge MOSFET drive circuit 3, the MOSFET tube 35 and the diode 36.

[0037] By using the above circuit, the control of the motor winding current can be realized by adjusting the upper and lower bridge drive signals.

[0038] It should be noted that as the kinetic energy of the motor rotor gradually decreases, when the back electromotive force generated by the motor winding is not enough to maintain the current required for energy consumption braking, the positive and negative power supplies can be turned on, and at this time the working mode is the same as that during acceleration.

[0039] It should be further noted that,Figure 1 The parallel number of the upper bridge MOSFET driving circuit 3 and the lower bridge MOSFET driving circuit 4 is two only for example, and in actual application, the user can independently select the parallel number according to the need, and the application is not limited specifically.

[0040] The motor energy consumption braking large heat consumption braking pipe current sharing method also comprises the following steps of: The positive voltage current sampling circuit 1 is used to collect the current signal of the upper bridge MOSFET driving circuit 3, and the collected current signal is sent to the controller; The negative voltage current sampling circuit 2 is used to collect the current signal of the lower bridge MOSFET driving circuit 4, and the collected current signal is sent to the controller; The controller outputs different driving signals according to the received current signals, so as to control each MOSFET driving circuit.

[0041] In some embodiments, the positive voltage current sampling circuit 1, the three-phase upper bridge driving unit, the motor and the controller constitute an upper bridge driving loop; The negative voltage current sampling circuit 2, the three-phase lower bridge driving unit, the motor and the controller constitute a lower bridge driving loop; The upper bridge driving loop and the lower bridge driving loop work independently.

[0042] It can be understood that the motor energy consumption braking large heat consumption braking pipe current sharing method has the same technical effects as the motor energy consumption braking large heat consumption braking pipe current sharing circuit, and the detailed description is not repeated here.

[0043] It should be noted that in this document, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the element limited by the statement "including one" does not exclude the existence of other same elements in the process, method, article or equipment including the element.

[0044] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A current-sharing circuit for a high-energy-consumption and high-heat-consumption braking tube in a motor, characterized in that, include: Positive voltage current sampling circuit (1), negative voltage current sampling circuit (2), three-phase upper bridge drive unit, three-phase lower bridge drive unit, motor and controller; wherein, each phase upper bridge drive unit includes multiple parallel upper bridge MOSFET drive circuits (3), and each phase lower bridge drive unit includes multiple parallel lower bridge MOSFET drive circuits (4). One end of the positive voltage current sampling circuit (1) is connected to the positive power supply, and the other end is connected to one end of each of the upper bridge MOSFET driving circuits (3). The other end of each of the upper bridge MOSFET driving circuits (3) is connected to one phase winding of the motor. One end of the negative voltage current sampling circuit (2) is connected to the negative power supply, and the other end is connected to one end of each of the lower bridge MOSFET driving circuits (4). The other end of each of the lower bridge MOSFET driving circuits (4) is connected to one phase winding of the motor. The common point of the motor windings is connected to ground. The positive voltage current sampling circuit (1) and the negative voltage current sampling circuit (2) are used to collect the current signals of the upper bridge MOSFET driving circuit (3) and the lower bridge MOSFET driving circuit (4), respectively, and send the collected current signals to the controller. The controller is used to output different drive signals based on the received current signal, so as to control each MOSFET drive circuit respectively.

2. The current sharing circuit for the high-heat-consumption braking tube of the motor according to claim 1, characterized in that, The positive voltage current sampling circuit (1), the three-phase upper bridge drive unit, the motor and the controller constitute the upper bridge drive circuit; The negative voltage current sampling circuit (2), the three-phase lower bridge drive unit, the motor and the controller constitute the lower bridge drive circuit; The upper bridge drive circuit and the lower bridge drive circuit operate independently.

3. The current sharing circuit for the high-heat-consumption braking tube of the motor according to claim 1, characterized in that, The positive voltage current sampling circuit (1) includes: resistor 10, resistor 11A, resistor 11B, resistor 12A, operational amplifier 13A, resistor 13B, resistor 14A, resistor 14B, resistor 14C, operational amplifier 14D and resistor 14F; Among them, one end of resistor 10 is connected to the positive power supply, and the other end is connected to each upper bridge MOSFET driving circuit (3) and one end of resistor 12A; one end of resistor 11A is connected to the positive power supply, and the other end is connected to one end of resistor 11B and the positive terminal of operational amplifier 13A respectively, and the other end of resistor 11B is grounded; the other end of resistor 12A is connected to the negative terminal of operational amplifier 13A; the two ends of resistor 13B are connected to the negative terminal and the output terminal of operational amplifier 13A respectively; the two ends of resistor 14A are connected to the output terminal of operational amplifier 13A and the positive terminal of operational amplifier 14D respectively; one end of resistor 14B is grounded, and the other end is connected to the negative terminal of operational amplifier 14D; the output terminal of operational amplifier 14D is connected to one end of resistor 14F, and the other end is connected to the controller; one end of resistor 14C is connected to the negative terminal of operational amplifier 14D, and the other end is connected to the connection line between resistor 14F and the controller.

4. The current sharing circuit for the high-heat-consumption braking tube of the motor according to claim 1, characterized in that, The negative voltage current sampling circuit (2) includes: resistor 20, resistor 21A, resistor 21B, resistor 22A, operational amplifier 23A, resistor 23B, resistor 24A, resistor 24B, resistor 24C, operational amplifier 24D and resistor 24F; Among them, one end of resistor 20 is connected to the negative power supply, and the other end is connected to each lower bridge MOSFET driving circuit (4) and one end of resistor 21A; the other end of resistor 21A is connected to the positive terminal of operational amplifier 23A and one end of resistor 21B respectively, and the other end of resistor 21B is grounded; one end of resistor 22A is connected to the negative power supply, and the other end is connected to the negative terminal of operational amplifier 23A; the two ends of resistor 23B are connected to the negative terminal and the output terminal of operational amplifier 23A respectively; the two ends of resistor 24A are connected to the output terminal of operational amplifier 23A and the positive terminal of operational amplifier 24D respectively; one end of resistor 24B is grounded, and the other end is connected to the negative terminal of operational amplifier 24D; the output terminal of operational amplifier 24D is connected to one end of resistor 24F, and the other end is connected to the controller; one end of resistor 24C is connected to the negative terminal of operational amplifier 24D, and the other end is connected to the connection line between resistor 24F and the controller.

5. The current sharing circuit for the high-heat-consumption braking tube of the motor according to claim 3, characterized in that, Each of the aforementioned upper bridge MOSFET drive circuits (3) includes: resistor 30, resistor 31A, resistor 31B, capacitor 31C, operational amplifier 31D, resistor 31E, resistor 31F, capacitor 31G, resistor 32A, capacitor 32B, resistor 32C, resistor 33A, operational amplifier 33B, resistor 33C, capacitor 33D, capacitor 33E, resistor 34A, resistor 34B, resistor 34C, transistor 34D, Zener diode 34E, resistor 34F, MOSFET 35, and diode 36; In this circuit, one end of resistor 30 is connected to resistor 10, and the other end is connected to the source of MOSFET 35. The drain of MOSFET 35 is connected to the anode of diode 36. The cathode of diode 36 is connected to one end of the motor winding, and the other end of the motor winding is grounded. One end of resistor 31A is connected to the connection line between resistors 10 and 30, and the other end is connected to the positive terminal of operational amplifier 31D. One end of resistor 31B is connected to the positive terminal of operational amplifier 31D, and the other end is grounded. Capacitor 31C is connected in parallel with resistor 31B. The two ends of resistor 31E are connected to the negative terminal of operational amplifier 31D and the source of MOSFET 35, respectively. The two ends of resistor 31F are connected to the output and negative terminals of operational amplifier 31D, respectively. Capacitor 31G is connected in parallel with resistor 31F. One end of resistor 33A is connected to the output terminal of operational amplifier 31D, and the other end is connected to the negative terminal of operational amplifier 33B and one end of resistor 33C, respectively. The other end of resistor 33C is connected to capacitor 31B. One end of capacitor 33D is connected to the output terminal of operational amplifier 33B and one end of resistor 34A, respectively. The other end of resistor 34A is connected to the base of transistor 34D and one end of resistor 34B, respectively. The other end of resistor 34B is connected to the negative signal power supply. The emitter of transistor 34D is connected to one end of resistor 34C, and the collector is connected to the anode of Zener diode 34E and the gate of MOSFET 35, respectively. The other end of resistor 34C is connected to the negative signal power supply. The cathode of Zener diode 34E is connected to the source of MOSFET 35. The two ends of resistor 34F are connected to the source and gate of MOSFET 35, respectively. The two ends of capacitor 33E are connected to the negative terminal and the output terminal of operational amplifier 33B, respectively. The positive terminal of operational amplifier 33B is connected to one end of resistor 32A and one end of resistor 32C, respectively. The other end of resistor 32A is connected to the controller. The other end of resistor 32C is grounded. Capacitor 32B and resistor 32C are connected in parallel.

6. The current sharing circuit for the high-heat-consumption braking tube of the motor according to claim 5, characterized in that, It also includes diode 37, whose anode is grounded and cathode is connected to the positive power supply; When the motor is in regenerative braking state, the current flows out from the ground, passes through diode 37, positive voltage current sampling circuit (1), resistor 30, MOSFET 35 and diode 36 in sequence, and then flows through the motor winding and ground.

7. The current sharing circuit for the high-heat-consumption braking tube of the motor according to claim 4, characterized in that, Each of the lower bridge MOSFET drive circuits (4) includes: resistor 40, resistor 41A, resistor 41B, capacitor 41C, op-amp 41D, resistor 41E, resistor 41F, capacitor 41G, resistor 42A, capacitor 42B, resistor 42C, resistor 43A, op-amp 43B, resistor 43C, capacitor 43D, capacitor 43E, resistor 44A, resistor 44B, resistor 44C, transistor 44D, Zener diode 44E, resistor 44F, MOSFET 45, and diode 46; In this circuit, one end of resistor 40 is connected to resistor 20, and the other end is connected to the drain of MOSFET 45. The source of MOSFET 45 is connected to the cathode of diode 46. The anode of diode 46 is connected to one end of the motor winding, and the other end of the motor winding is grounded. One end of resistor 41A is connected to the connection line between resistors 20 and 40, and the other end is connected to the negative terminal of operational amplifier 41D. One end of resistor 41B is connected to the positive terminal of operational amplifier 41D, and the other end is grounded. Capacitor 41C is connected in parallel with resistor 41B. The two ends of resistor 41E are connected to the positive terminal of operational amplifier 41D and the drain of MOSFET 45, respectively. The two ends of resistor 41F are connected to the output and negative terminals of operational amplifier 41D, respectively. Capacitor 41G is connected in parallel with resistor 41F. The two ends of resistor 43A are connected to the positive terminal of operational amplifier 43B and the output terminal of operational amplifier 41D, respectively. One end of resistor 43C is connected to the negative terminal of operational amplifier 43B, and the other end is connected to capacitor 43A. One end of capacitor 43D is connected to the output of operational amplifier 43B; the two ends of resistor 44A are connected to the output of operational amplifier 43B and the base of transistor 44D respectively; the two ends of resistor 44B are connected to the base of transistor 44D and the positive signal power supply respectively; the emitter of transistor 44D is connected to one end of resistor 44C, and the collector is connected to the cathode of Zener diode 44E and the gate of MOSFET 45 respectively; the other end of resistor 44C is connected to the positive signal power supply; the anode of Zener diode 44E is connected to the drain of MOSFET 45; the two ends of resistor 44F are connected to the drain and gate of MOSFET 45 respectively; the two ends of capacitor 43E are connected to the negative terminal and the output of operational amplifier 43B respectively; the negative terminal of operational amplifier 43B is connected to one end of resistor 42A and one end of resistor 42C respectively, and the other end of resistor 42A is connected to the controller; the other end of resistor 42C is grounded; capacitor 42B and resistor 42C are connected in parallel.

8. The current sharing circuit for the high-heat-consumption braking tube of the motor according to claim 7, characterized in that, It also includes diode 47; the anode of diode 47 is connected to the negative power supply, and the cathode is connected to ground; When the motor is in the energy-consumption braking state, the current flows out from the ground through the motor windings, and then flows back to the ground through diode 46, MOSFET 45, resistor 40, negative voltage current sampling circuit (2) and diode 47 in sequence.

9. A current sharing method for a high-heat-dissipation braking tube in a motor, applied to the current sharing circuit of the high-heat-dissipation braking tube in a motor as described in any one of claims 1-8, characterized in that, include: The positive voltage current sampling circuit (1) is used to collect the current signal of the upper bridge MOSFET driving circuit (3) and the collected current signal is sent to the controller; The negative voltage current sampling circuit (2) is used to collect the current signal of the lower bridge MOSFET driving circuit (4) and the collected current signal is sent to the controller; The controller outputs different drive signals based on the received current signal to control each MOSFET drive circuit separately.

10. The current sharing method for high heat loss braking tubes in motors according to claim 9, characterized in that, The positive voltage current sampling circuit (1), the three-phase upper bridge drive unit, the motor and the controller constitute the upper bridge drive circuit; The negative voltage current sampling circuit (2), the three-phase lower bridge drive unit, the motor and the controller constitute the lower bridge drive circuit; The upper bridge drive circuit and the lower bridge drive circuit operate independently.

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