Driving board overcurrent protection circuit, control method, driving board and storage medium

Abstract

The invention relates to a driver board overcurrent protection circuit, a control method, a driver board and a storage medium. The driver board overcurrent protection circuit comprises a current acquisition module and a plurality of current discharge modules. Wherein the current acquisition module is arranged on at least two current output paths, and the current acquisition module is used for acquiring current values on the at least two current output paths; the current discharge module is arranged on the current output path in series, and the current discharge module comprises multiple stages of discharge paths; the current acquisition module and each current discharge module are electrically connected with the control module, the control module is used for determining whether an overcurrent current output path exists or not according to the current value acquired by the current acquisition module, and the current discharge modules are electrically connected with the control module under the condition that the overcurrent current output path exists currently. And controlling the current discharge module corresponding to the overcurrent output path to perform graded discharge. In this way, accurate control over the output current of the driving board can be achieved, and the stability and reliability of the motor driving system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit protection, in particular to a drive board overcurrent protection circuit, a control method, a drive board and a storage medium. BACKGROUND

[0002] In a motor drive system, the drive board bears the important function of converting the main control signal into high-power output to drive the motor. In the actual working process, the drive board is prone to overcurrent failure due to factors such as load mutation, short circuit or control abnormality, thereby causing the power device on the drive board to be damaged.

[0003] In the prior art, when the overcurrent of the drive board is detected, the current output of the drive board is usually directly turned off, or the current is inhibited through a single discharge path. However, in the face of different levels of overcurrent, due to the single processing method, precise control cannot be achieved, thereby easily leading to the problems of reduced stability and reliability of the motor drive system. Therefore, how to precisely control the drive board overcurrent has become a technical problem to be solved. SUMMARY

[0004] The present application provides a drive board overcurrent protection circuit, a control method, a drive board and a storage medium to solve the problem that the prior art cannot precisely control the drive board overcurrent, thereby reducing the stability and reliability of the motor drive system.

[0005] In a first aspect, the embodiments of the present application provide a drive board overcurrent protection circuit applied to a drive board, wherein the drive board includes a control module and an inverter circuit for providing working power to a motor, and the drive board overcurrent protection circuit includes a current collection module and a plurality of current discharge modules. The inverter circuit includes a plurality of current output terminals, and a plurality of current output paths are formed between the plurality of current output terminals and the motor. The current collection module is arranged on at least two current output paths, and is configured to collect current values on the at least two current output paths. The current discharge module is arranged in one-to-one correspondence with the current output path, and is arranged in series on the current output path. The current discharge module includes a plurality of discharge paths. The current collection module and each current discharge module are electrically connected to the control module. The control module is configured to determine whether there is an overcurrent current output path according to the current values collected by the current collection module, and control the current discharge module corresponding to the overcurrent current output path to discharge in stages in the case that there is an overcurrent current output path.

[0006] Optionally, each of the current leakage modules comprises a first switch unit, a second switch unit, a third switch unit, a first load unit and a second load unit. The first switch unit is arranged in series between a current output end of the inverter circuit and the motor, the second switch unit, the first load unit and the third switch unit are arranged in series and in parallel with the first switch unit, and the second load unit is arranged in parallel with the third switch unit. The first switch unit, the second switch unit and the third switch unit are electrically connected to the control module, and the control module is configured to control the switching states of the first switch unit, the second switch unit and the third switch unit to perform hierarchical leakage in the case that there is a current output path with overcurrent.

[0007] Optionally, the first load unit comprises an inductor and an absorption capacitor. The absorption capacitor is arranged in series between the second switch unit and the third switch unit, and the inductor is arranged in parallel with the absorption capacitor.

[0008] Optionally, the second load unit comprises a buffer resistor. The buffer resistor is arranged in parallel with the third switch unit.

[0009] Optionally, the current collection module comprises a first sampling resistor and a second sampling resistor. The first sampling resistor and the second sampling resistor are arranged in series on two current output paths respectively.

[0010] In a second aspect, the embodiments of the present application further provide a control method of a drive board overcurrent protection circuit, applied to the drive board overcurrent protection circuit of the first aspect, and the method comprises: determining whether there is a current output path with overcurrent according to the current value collected by the current collection module; controlling the current leakage module corresponding to the current output path with overcurrent to perform hierarchical leakage in the case that there is a current output path with overcurrent.

[0011] Optionally, the controlling the current leakage module corresponding to the current output path with overcurrent to perform hierarchical leakage comprises: in the case that the current value corresponding to the current output path with overcurrent is greater than a first preset threshold, controlling the second switch unit and the third switch unit in the current leakage module corresponding to the current output path with overcurrent to be turned on, and the first switch unit to be turned off; In a case where the current value corresponding to the current output path in overcurrent is greater than the second preset threshold, the second switch unit in the current discharge module corresponding to the current output path in overcurrent is controlled to be turned on, and the first switch unit and the third switch unit are controlled to be turned off, wherein the second preset threshold is greater than the first preset threshold. In a case where the current value corresponding to the current output path in overcurrent is greater than the third preset threshold, the control module itself is controlled to stop outputting the pulse control signal to the inverter circuit, so as to stop the inverter circuit from outputting current, wherein the third preset threshold is greater than the second preset threshold.

[0012] Optionally, the control of the current discharge module corresponding to each current output path is hierarchical discharge, comprising: In a case where the current value corresponding to the current output path in overcurrent is greater than the first preset threshold, and the change rate of the current value is greater than the fourth preset threshold, the second switch unit in the current discharge module corresponding to the current output path in overcurrent is controlled to be turned on, and the first switch unit and the third switch unit are controlled to be turned off. In a case where the current value corresponding to the current output path in overcurrent is greater than the second preset threshold, and the change rate of the current value is greater than the fourth preset threshold, the control module itself is controlled to stop outputting the pulse control signal to the inverter circuit, so as to stop the inverter circuit from outputting current.

[0013] Optionally, the method further comprises: In a case where there is no current output path in overcurrent at present, the first switch unit in each current discharge module is controlled to be turned on, and the second switch unit and the third switch unit are controlled to be turned off.

[0014] Optionally, the determination of whether the current output path is in overcurrent according to the current value collected by the current collection module comprises: The current value corresponding to each current output path is determined according to the first current value collected by the first sampling resistor and the second current value collected by the second sampling resistor, wherein the sum of the current values corresponding to each current output path is zero. The current value corresponding to each current output path is compared with the first preset threshold respectively, to determine whether there is a current output path in overcurrent at present.

[0015] In a third aspect, the embodiments of the present application further provide a drive board, which comprises a control module, an inverter circuit for providing working power supply for a motor, and a drive board overcurrent protection circuit as described in the first aspect. The drive board overcurrent protection circuit is arranged in series between the inverter circuit and the motor, the drive board overcurrent protection circuit is electrically connected with the control module, and the control module is configured to perform overcurrent protection by using the drive board overcurrent protection circuit in the case that the output current of the inverter circuit is overcurrent.

[0016] In a fourth aspect, the embodiments of the present application further provide a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the control method of the drive board overcurrent protection circuit according to the second aspect.

[0017] The drive board overcurrent protection circuit provided by the embodiments of the present application has the following advantages compared with the prior art: the drive board overcurrent protection circuit provided by the embodiments of the present application is applied to a drive board, the drive board includes a control module and an inverter circuit for providing working power supply for a motor, and the drive board overcurrent protection circuit includes a current collection module and a plurality of current discharge modules; the inverter circuit includes a plurality of current output terminals, a plurality of current output paths are formed between the plurality of current output terminals and the motor; the current collection module is arranged on at least two current output paths, and the current collection module is configured to collect current values on the at least two current output paths; the current discharge modules are arranged in one-to-one correspondence with the current output paths, and the current discharge modules are arranged in series on the current output paths, the current discharge modules include a plurality of discharge paths; the current collection module and each current discharge module are electrically connected with the control module, and the control module is configured to determine whether there is an overcurrent current output path according to the current values collected by the current collection module, and control the current discharge module corresponding to the overcurrent current output path to discharge in stages in the case that there is an overcurrent current output path. In this way, the drive board overcurrent protection circuit can determine whether there is an overcurrent current output path according to the current values collected by the current collection module, and control the current discharge module corresponding to the overcurrent current output path to discharge in stages in the case that there is an overcurrent current output path, so as to realize accurate control of current discharge on the overcurrent current output path, avoid directly shutting down the current output of the drive board, or suppressing current through a single discharge path, and thus improve the stability and reliability of the motor drive system. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles behind the application.

[0019] 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, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without any creative effort.

[0020] One or more embodiments are illustrated by the pictures in the drawings corresponding thereto, which do not constitute a limitation on the embodiments, and elements with the same reference numerals in the drawings represent similar elements, unless otherwise specified. The drawings in the drawings do not constitute a proportional limit.

[0021] Figure 1 A schematic diagram of a drive board overcurrent protection circuit provided by an embodiment of the present application; Figure 2 A flowchart of a control method of a drive board overcurrent protection circuit provided by an embodiment of the present application; Figure 3 A schematic diagram of another drive board overcurrent protection circuit provided by an embodiment of the present application; Figure 4 A flowchart of a control method of another drive board overcurrent protection circuit provided by an embodiment of the present application; Figure 5 A structural schematic diagram of a drive board provided by an embodiment of the present application.

[0022] Explanation of reference numerals: 100, control module; 200, inverter circuit; 300, drive board overcurrent protection circuit; 400, motor; 310, current acquisition module; 320, current discharge module; 3201, first switch unit; 3202, second switch unit; 3203, third switch unit; 3204, first load unit; 3205, second load unit. DETAILED DESCRIPTION

[0023] 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 a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort fall within the scope of protection of the present application.

[0024] The disclosure below provides many different embodiments or examples for implementing different structures of the application. For the sake of simplicity, the description below of a particular embodiment or example does not include a discussion of alternative or about other embodiments or examples. But it should be understood that all of these different embodiments and examples can be combined with each other, unless stated otherwise. In other words, each and every possible combination of the features described below is covered by this application. The description below is merely exemplary and is not intended to be limiting.

[0025] To solve the problem that the prior art cannot control the precision when the drive board overflows, resulting in the reduction of the stability and reliability of the motor drive system, the application provides a drive board overcurrent protection circuit, a control method, a drive board and a storage medium, which can control the precision when the drive board overflows.

[0026] Referring to Figure 1 , Figure 1 A schematic diagram of a drive board overcurrent protection circuit provided by an embodiment of the application is shown. As Figure 1 shown, the drive board overcurrent protection circuit is applied to a drive board, the drive board includes a control module 100 and an inverter circuit 200 for providing working power to a motor 400, and the drive board overcurrent protection circuit 300 includes a current collection module 310 and a plurality of current discharge modules 320. The inverter circuit 200 includes a plurality of current output terminals, and a plurality of current output paths are formed between the plurality of current output terminals and the motor 400. The current collection module 310 is arranged on at least two current output paths, and the current collection module 310 is used to collect the current values on the at least two current output paths. The current discharge module 320 is arranged one-to-one with the current output path, and the current discharge module 320 is arranged in series on the current output path, and the current discharge module 320 includes a plurality of discharge paths. The current collection module 310 and each current discharge module 320 are electrically connected with the control module 100, and the control module 100 is used to determine whether there is an overcurrent current output path according to the current values collected by the current collection module 310, and in the case that there is an overcurrent current output path, the control module 100 controls the current discharge module 320 corresponding to the overcurrent current output path to discharge in stages.

[0027] Specifically, the drive board can include a control module 100 and an inverter circuit 200 for providing operating power to the motor 400, wherein the control module 100 can collect the current value output by the drive board, which can be obtained by using a current collection module 310. The control module 100 can also determine whether overcurrent occurs according to the size of the collected current value, and select a corresponding protection strategy according to a preset threshold. In addition, the control module 100 can output six pulse width modulation (PWM) signals to the inverter circuit 200. The control module 100 controls the amplitude, frequency and phase of the three-phase voltage of the motor 400 by adjusting the duty ratio and phase of the six PWM signals, thereby realizing the control of the speed and torque of the motor 400. The inverter circuit 200 can include six power switching tubes, and its main function is to convert direct current (DC) into adjustable frequency / amplitude three-phase alternating current (AC) for the motor 400. Of course, the drive board can also include rectifier circuit (for converting mains into DC), filter circuit (for filtering the DC input to the inverter circuit 200) and other structures.

[0028] In an optional embodiment, the number of current output paths and current discharge modules 320 can be three, corresponding to the U phase, V phase and W phase of the three-phase alternating current, as shown in Figure 1 Of course, as other optional embodiments, the number of current output paths and current discharge modules 320 can be adjusted according to the type of motor 400, and the embodiments of the present application are not limited.

[0029] The current collection module 310 can be used to collect the current value on two or all current output paths. Since the sum of three-phase currents is usually 0, in order to reduce hardware cost and occupied space, only the current value of two phases can be collected to determine the current value of the other phase. The current collection module 310 can be a sampling resistor or a current collection instrument (such as an ammeter, etc.). The current discharge module 320 can include multiple discharge paths, such as two-stage discharge path, three-stage discharge path, four-stage discharge path, etc. Since the loads on different discharge paths are different, different discharge paths can be used for hierarchical discharge according to the size of the current value.

[0030] In this way, the drive board overcurrent protection circuit 300 can determine whether there is an overcurrent current output path at present according to the current value collected by the current collection module 310, and control the current discharge module 320 corresponding to the overcurrent current output path to perform hierarchical discharge in the case that there is an overcurrent current output path at present, so as to realize accurate control of current discharge on the overcurrent current output path, avoid directly closing the current output of the drive board, or suppressing current through a single discharge path, thereby improving the stability and reliability of the motor driving system.

[0031] In an optional embodiment, each current discharge module 320 includes a first switch unit 3201, a second switch unit 3202, a third switch unit 3203, a first load unit 3204, and a second load unit 3205. The first switch unit 3201 is arranged in series between the current output end of the inverter circuit 200 and the motor 400, the second switch unit 3202, the first load unit 3204, and the third switch unit 3203 are arranged in series in turn and in parallel with the first switch unit 3201, and the second load unit 3205 is arranged in parallel with the third switch unit 3203. The first switch unit 3201, the second switch unit 3202, and the third switch unit 3203 are electrically connected with the control module 100, and the control module 100 is configured to control the switching states of the first switch unit 3201, the second switch unit 3202, and the third switch unit 3203 to perform hierarchical discharge in the case that there is an overcurrent current output path at present.

[0032] Specifically, the current discharge module 320 includes two-pole discharge paths, wherein the first-stage discharge path is from the first switch unit 3201→the first load unit 3204→the second switch unit 3202, that is, the load on the first-stage discharge path is the load corresponding to the first load unit 3204. The second-stage discharge path is from the first switch unit 3201→the first load unit 3204→the second load unit 3205, that is, the load on the second-stage discharge path is the sum of the loads corresponding to the first load unit 3204 and the second load unit 3205. As can be seen, the load on the second-stage discharge path is greater than the load on the first-stage discharge path.

[0033] In this way, the control module 100 can control the switching states of the first switching unit 3201, the second switching unit 3202 and the third switching unit 3203 to perform hierarchical discharge in the case that the current output path in which overcurrent currently exists. Specifically, the control module 100 can control the second switching unit 3202 and the third switching unit 3203 in the corresponding current discharge module 320 to be turned on and the first switching unit 3201 to be turned off in the case that the current value corresponding to the overcurrent current output path is greater than the first preset threshold, so as to discharge through the first-level discharge path. In the case that the current value corresponding to the overcurrent current output path is greater than the second preset threshold (greater than the first preset threshold), the control module 100 can control the second switching unit 3202 in the current discharge module 320 to be turned on and the first switching unit 3201 and the third switching unit 3203 to be turned off, so as to discharge through the second-level discharge path. In addition, in the case that the current value corresponding to the overcurrent current output path is greater than the third preset threshold (greater than the second preset threshold), the control module 100 can control itself to stop outputting the pulse control signal to the inverter circuit 200, so as to stop the inverter circuit 200 from outputting current.

[0034] In this way, the control module 100 can utilize different discharge paths in the current discharge module 320 to perform hierarchical discharge according to the current value on the current output path, so as to realize accurate control of current discharge on the overcurrent current output path, avoid directly shutting down the current output of the drive board, or suppressing current through a single discharge path, and thus improve the stability and reliability of the motor driving system.

[0035] In an optional embodiment, the first load unit 3204 includes an inductor and an absorption capacitor. The absorption capacitor is connected in series between the second switching unit 3202 and the third switching unit 3203, and the inductor is connected in parallel with the absorption capacitor.

[0036] Specifically, the inductance value of the inductor and the capacitance value of the absorption capacitor can be set according to actual needs, which are not specifically limited herein.

[0037] The inductor and the absorption capacitor are connected in parallel to form a filter, and the filter can be utilized to discharge the current on the corresponding current output path, so as to reduce the current value on the current output path.

[0038] In an optional embodiment, the second load unit 3205 includes a buffer resistor. The buffer resistor is connected in parallel with the third switching unit 3203.

[0039] Specifically, the second load unit 3205 can be a buffer resistor, and the resistance value of the buffer resistor can be set according to actual needs, which is not specifically limited herein.

[0040] In this way, the buffer resistor can be used to further reduce the current value on the corresponding current output path, and the current on the current output path can be further discharged.

[0041] In an optional embodiment, the current collection module 310 includes a first sampling resistor and a second sampling resistor. The first sampling resistor and the second sampling resistor are respectively arranged in series on the two current output paths.

[0042] Specifically, the resistance values of the first sampling resistor and the second sampling resistor can be set according to actual needs, which are not limited here.

[0043] In this way, the first sampling resistor and the second sampling resistor can be used to obtain the current values on the two current output paths, and then the principle that the sum of the three-phase currents is generally 0 can be used to determine the current value on the other current output path, so that the current values on the current output paths can be obtained. Compared with the method of using three sampling resistors to sample the current values on the three current output paths, the hardware cost can be reduced and the occupied space of the protection circuit can be reduced.

[0044] Referring to Figure 2 , Figure 2 A flowchart of a control method of a drive board overcurrent protection circuit provided by an embodiment of the present application is shown in FIG. 7. As shown in FIG. 7, the control method of the drive board overcurrent protection circuit is applied to the drive board overcurrent protection circuit in any of the foregoing embodiments. The control method of the drive board overcurrent protection circuit can include the following steps. Figure 2 Step S201: determining whether there is a current output path with overcurrent according to the current values collected by the current collection module.

[0045] Specifically, since the control module is electrically connected to the current collection module, the control module can obtain the current values on the at least two current output paths from the current collection module, and then determine the current values on the current output paths based on the current values on the at least two current output paths. Then, the current values on the current output paths are compared with the first preset threshold to determine whether there is a current output path with overcurrent. If there is a current output path with overcurrent, step S202 is performed; if there is no current output path with overcurrent, step S201 is continued.

[0046] Step S202: controlling the current discharge module corresponding to the current output path with overcurrent to discharge in stages in the case that there is a current output path with overcurrent.

[0047] ​After determining that the current output path is in overcurrent, the control module can control the current discharge module corresponding to the overcurrent current output path to discharge in stages based on the current value on the overcurrent current output path.

[0048] In this way, the drive board overcurrent protection circuit can determine whether the current output path is in overcurrent according to the current value collected by the current collection module, and control the current discharge module corresponding to the overcurrent current output path to discharge in stages in the case that the current output path is in overcurrent, so as to realize accurate control of current discharge on the overcurrent current output path, avoid directly shutting down the current output of the drive board or suppressing current through a single discharge path, and thus improve the stability and reliability of the motor drive system.

[0049] In an optional embodiment, the step S202 of controlling the current discharge module corresponding to the overcurrent current output path to discharge in stages includes: In the case that the current value corresponding to the overcurrent current output path is greater than the first preset threshold, the second switch unit and the third switch unit in the current discharge module corresponding to the overcurrent current output path are controlled to be turned on, and the first switch unit is controlled to be turned off. In the case that the current value corresponding to the overcurrent current output path is greater than the second preset threshold, the second switch unit in the current discharge module corresponding to the overcurrent current output path is controlled to be turned on, and the first switch unit and the third switch unit are controlled to be turned off, wherein the second preset threshold is greater than the first preset threshold. In the case that the current value corresponding to the overcurrent current output path is greater than the third preset threshold, the control module itself is controlled to stop outputting the pulse control signal to the inverter circuit to stop the inverter circuit from outputting current, wherein the third preset threshold is greater than the second preset threshold.

[0050] Specifically, the sizes of the first preset threshold, the second preset threshold and the third preset threshold can be set according to actual needs, which are not limited here. It should be emphasized that the first preset threshold < the second preset threshold < the third preset threshold. The current discharge module includes two-stage discharge paths, wherein the first-stage discharge path is from the first switch unit → the first load unit → the second switch unit, that is, the load on the first-stage discharge path is the load corresponding to the first load unit. The second-stage discharge path is from the first switch unit → the first load unit → the second load unit, that is, the load on the second-stage discharge path is the sum of the loads corresponding to the first load unit and the second load unit. As can be seen, the load on the second-stage discharge path is greater than the load on the first-stage discharge path.

[0051] The control module can compare the current value corresponding to the overcurrent current output path with the first preset threshold value, the second preset threshold value and the third preset threshold value respectively when controlling the current discharge module corresponding to the overcurrent current output path to discharge in stages. If the current value corresponding to the overcurrent current output path is greater than the first preset threshold value, the control module can control the second switch unit and the third switch unit in the current discharge module corresponding to the overcurrent current output path to be conductive, and the first switch unit to be disconnected, so as to discharge through the first-stage discharge path. If the current value corresponding to the overcurrent current output path is greater than the second preset threshold value, the control module can control the second switch unit in the current discharge module corresponding to the overcurrent current output path to be conductive, and the first switch unit and the third switch unit to be disconnected, so as to discharge through the second-stage discharge path. If the current value corresponding to the overcurrent current output path is greater than the third preset threshold value, the control module can control itself to stop outputting the pulse control signal to the inverter circuit, so as to stop the inverter circuit from outputting current, to prevent the drive board from being burnt out.

[0052] In this way, the control module can utilize different discharge paths in the current discharge module to discharge in stages according to the current value on the current output path, so as to realize accurate control of current discharge on the overcurrent current output path, avoid directly shutting down the current output of the drive board, or suppressing current through a single discharge path, and thus improve the stability and reliability of the motor driving system.

[0053] In an optional embodiment, the step S202 of controlling the current discharge module corresponding to each current output path to discharge in stages includes: In the case where the current value corresponding to the overcurrent current output path is greater than the first preset threshold value and the change rate of the current value is greater than the fourth preset threshold value, the control module controls the second switch unit in the current discharge module corresponding to the overcurrent current output path to be conductive, and the first switch unit and the third switch unit to be disconnected. In the case where the current value corresponding to the overcurrent current output path is greater than the second preset threshold value and the change rate of the current value is greater than the fourth preset threshold value, the control module controls itself to stop outputting the pulse control signal to the inverter circuit, so as to stop the inverter circuit from outputting current.

[0054] Specifically, the fourth preset threshold value can be set according to actual needs, which is not limited herein.

[0055] As another optional implementation, the control module can control the second switch unit in the current discharge module corresponding to the overcurrent current output path to be conductive, and the first switch unit and the third switch unit to be disconnected when the current value corresponding to the overcurrent current output path is greater than the first preset threshold and the change rate of the current value is greater than the fourth preset threshold, so as to directly discharge through the second-stage discharge path. When the current value corresponding to the overcurrent current output path is greater than the second preset threshold and the change rate of the current value is greater than the fourth preset threshold, the control module controls itself to stop outputting the pulse control signal to the inverter circuit to stop the inverter circuit from outputting current, thereby preventing the drive board from being burned out.

[0056] In this way, the control module can perform hierarchical discharge according to the current value on the current output path and the change rate of the current, avoid accidental current fluctuation from causing the discharge path to frequently switch, and further improve the stability and reliability of the motor driving system.

[0057] In an optional embodiment, the method further includes: In the case where there is no overcurrent current output path at present, the control module controls the first switch unit in each current discharge module to be conductive, and the second switch unit and the third switch unit to be disconnected.

[0058] Specifically, when it is determined that there is no overcurrent current output path at present, the control module can control the first switch unit in each current discharge module to be conductive, and the second switch unit and the third switch unit to be disconnected.

[0059] In this way, when the current value of each current output path is in a normal range, the current value can be directly output to the motor through the first switch unit without being discharged through any load unit.

[0060] In an optional embodiment, the step S201 of determining whether the current output path is overcurrent according to the current value collected by the current collection module includes: According to the first current value collected by the first sampling resistor and the second current value collected by the second sampling resistor, the current value corresponding to each current output path is determined, wherein the sum of the current values corresponding to each current output path is zero. The current value corresponding to each current output path is compared with the first preset threshold respectively to determine whether there is an overcurrent current output path at present.

[0061] Specifically, when determining whether the current output path is overcurrent according to the current values collected by the current collection module, the control module can first determine the current values corresponding to each current output path according to the first current value collected by the first sampling resistor and the second current value collected by the second sampling resistor, and then compare the current values corresponding to each current output path with the first preset threshold value respectively, so as to accurately determine whether there is an overcurrent current output path at present. In this way, subsequent control of the current bleed module corresponding to the overcurrent current output path can be facilitated when the overcurrent current output path exists at present, so as to realize the overcurrent protection function of the drive board.

[0062] In an optional embodiment, the structure of the drive board overcurrent protection circuit can be as shown in Figure 3 which includes three current bleed modules for performing current bleed on the U phase, V phase and W phase of the three-phase alternating current M respectively. Among them, R1 and R2 are sampling resistors, which function to collect the currents of the U and V phases. The sum of the three-phase currents is usually 0, so only two-phase currents need to be collected. R3, R4 and R5 are buffer resistors, which, in combination with the absorption capacitors C1, C2 and C3, increase the load of the circuit when the three-phase current is too large, so as to reduce the current flowing through the three phases. The control flow of the drive board overcurrent protection circuit can be as shown in Figure 4 which can include the following steps: Step S401, obtain the actual output current value A of the drive board.

[0063] Step S402, determine whether the actual current value A is greater than the current protection value A1 (i.e., the first preset threshold value in the foregoing).

[0064] If the actual current value A is greater than the current protection value A1, step S403 is performed; if the actual current value A is less than or equal to the current protection value A1, step S410 is performed.

[0065] Step S403, determine whether the current change rate is greater than a.

[0066] If the current change rate is greater than a, step S407 is performed; if the current change rate is less than or equal to a, step S404 is performed.

[0067] Step S404, open the switches S1, S4, S 7， and close the switches S2, S3, S5, S6, S8 and S9.

[0068] The control module triggers the first-stage bleed path, i.e., closes S2, S3, S5, S6, S8 and S9, and opens S1, S4 and S7. In this way, the current can be guided to the bleed path, so that the current flows to the motor through the filter circuit composed of the inductor and the absorption capacitor. If the current is reduced after being discharged through the first-stage bleed path, the circuit is switched back to the original path.

[0069] Step S405, judge whether the actual current value A is greater than the current protection value A2 (i.e. the second preset threshold in the above).

[0070] If the actual current value A is greater than the current protection value A2, step S406 is executed; if the actual current value A is less than or equal to the current protection value A2, step S404 is returned.

[0071] Step S406, judge whether the current change rate is greater than a (i.e. the fourth preset threshold in the above).

[0072] If the current change rate is greater than a, step S409 is executed; if the current change rate is less than or equal to a, step S407 is continued to be executed.

[0073] Step S407, open the switches S1, S3, S4, S6, S7 and S9, and close the switches S2, S5 and S8.

[0074] The control module starts the second stage discharge path, i.e. closes the switches S2, S5 and S8, and opens the switches S1, S3, S4, S6, S7 and S9, so that the current flows through the buffer resistor and then flows to the motor, to prevent the power device from being overloaded. If the current is reduced after being discharged through the second stage discharge path, the circuit is cut back to the first stage discharge path.

[0075] Step S408, judge whether the actual current value A is greater than the current protection value A3 (i.e. the third preset threshold in the above).

[0076] If the actual current value A is greater than the current protection value A3, step S409 is executed; if the actual current value A is less than or equal to the current protection value A3, step S407 is returned.

[0077] Step S409, report an overcurrent protection fault.

[0078] The control module directly triggers the overcurrent protection, disables the PWM wave and shuts down.

[0079] Step S410, normal operation.

[0080] When it is detected that the current value is in the normal range (i.e. lower than the first preset threshold), the control module controls the switches to remain in the original path, i.e. closes the switches S1, S4 and S7, and opens the switches S2, S3, S5, S6, S8 and S9.

[0081] By executing the above steps S401 to S410, the optimal discharge path is selected from the current discharge module according to the size of the real-time detected current value for discharge, which can effectively reduce the burden of a single discharge circuit, improve the protection response speed and reliability, and achieve the technical effects of prolonging the service life of the drive board, improving the system stability and safety.

[0082] Referring to Figure 5 , Figure 5 A structural schematic diagram of a drive board provided by the embodiment is shown in the figure. The drive board 500 includes a control module 100, an inverter circuit 200 for providing working power supply to the motor 400, and a drive board overcurrent protection circuit 300; The drive board overcurrent protection circuit 300 is electrically connected with the control module 100, and the control module 100 is configured to perform overcurrent protection by using the drive board overcurrent protection circuit 300 in the case that the output current of the inverter circuit 200 is overcurrent.

[0083] It should be noted that the drive board overcurrent protection circuit 300 has the same function as the drive board overcurrent protection circuit in the foregoing embodiment, and will not be described here.

[0084] In addition, the embodiment of the application further provides a computer readable storage medium, which stores a computer program. The computer program is executed by a processor to implement the control method of the drive board overcurrent protection circuit provided by any one of the foregoing method embodiments.

[0085] The device embodiments described above are only schematic, wherein the units shown as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0086] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be implemented by means of software plus a general hardware platform, and of course can also be implemented by hardware. Based on such understanding, the above technical solutions essentially or in other words the part that contributes to the related art can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.

[0087] It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order

[0088] The above description is that of current embodiments of the application. Various modifications and changes can be made thereto without departing from the spirit and scope of the application as set forth. The scope of the application is not to be limited to the exact details shown above.

Claims

1. A drive board overcurrent protection circuit, characterized by, The application is applied to a drive board, the drive board comprises a control module and an inverter circuit for providing working power supply for a motor, and the drive board over-current protection circuit comprises a current collection module and a plurality of current discharge modules; The inverter circuit comprises a plurality of current output ends, and a plurality of current output paths are formed between the plurality of current output ends and the motor; The current collection module is arranged on at least two current output paths, and the current collection module is used for collecting current values on the at least two current output paths; The current discharge module is arranged in one-to-one correspondence with the current output path, the current discharge module is arranged in series on the current output path, and the current discharge module comprises a plurality of discharge paths; The current collection module and each current discharge module are electrically connected with the control module, the control module is used for determining whether there is an over-current current output path at present according to the current values collected by the current collection module, and in the case that there is an over-current current output path at present, the control module controls the current discharge module corresponding to the over-current current output path to be discharged in stages.

2. The drive board overcurrent protection circuit of claim 1, wherein, Each current discharge module comprises a first switch unit, a second switch unit, a third switch unit, a first load unit and a second load unit; The first switch unit is arranged in series between the current output end of the inverter circuit and the motor, the second switch unit, the first load unit and the third switch unit are arranged in series and in parallel with the first switch unit, and the second load unit is arranged in parallel with the third switch unit; The first switch unit, the second switch unit and the third switch unit are electrically connected with the control module, and the control module is used for controlling the switching states of the first switch unit, the second switch unit and the third switch unit to be discharged in stages in the case that there is an over-current current output path at present.

3. The drive board overcurrent protection circuit of claim 2, wherein, The first load unit comprises an inductor and an absorption capacitor; The absorption capacitor is arranged in series between the second switch unit and the third switch unit, and the inductor is arranged in parallel with the absorption capacitor.

4. The drive board overcurrent protection circuit of claim 2, wherein, The second load unit comprises a buffer resistor; The buffer resistor is arranged in parallel with the third switch unit.

5. The drive board overcurrent protection circuit of claim 1, wherein, The current collection module comprises a first sampling resistor and a second sampling resistor; The first sampling resistor and the second sampling resistor are arranged in series on two current output paths respectively.

6. A control method of a drive board overcurrent protection circuit, characterized by, The method is applied to the drive board over-current protection circuit in any one of claims 1-5, and the method comprises: According to the current values collected by the current collection module, it is determined whether there is an over-current current output path at present; In the case that there is an over-current current output path at present, the current discharge module corresponding to the over-current current output path is controlled to be discharged in stages.

7. The control method of claim 6, wherein, The control of the current discharge module corresponding to the over-current current output path to be discharged in stages comprises: In a case where the current value corresponding to the current output path in overcurrent is greater than a first preset threshold, the second switch unit and the third switch unit in the current discharge module corresponding to the current output path in overcurrent are controlled to be turned on, and the first switch unit is turned off. In a case where the current value corresponding to the current output path in overcurrent is greater than a second preset threshold, the second switch unit in the current discharge module corresponding to the current output path in overcurrent is controlled to be turned on, and the first switch unit and the third switch unit are turned off, wherein the second preset threshold is greater than the first preset threshold. In a case where the current value corresponding to the current output path in overcurrent is greater than a third preset threshold, the control module itself is controlled to stop outputting a pulse control signal to the inverter circuit, so as to stop the inverter circuit from outputting current, wherein the third preset threshold is greater than the second preset threshold.

8. The control method of claim 7, wherein, The control of the current discharge module corresponding to each current output path for hierarchical discharge comprises: In a case where the current value corresponding to the current output path in overcurrent is greater than the first preset threshold, and the change rate of the current value is greater than a fourth preset threshold, the second switch unit in the current discharge module corresponding to the current output path in overcurrent is controlled to be turned on, and the first switch unit and the third switch unit are turned off. In a case where the current value corresponding to the current output path in overcurrent is greater than the second preset threshold, and the change rate of the current value is greater than the fourth preset threshold, the control module itself is controlled to stop outputting a pulse control signal to the inverter circuit, so as to stop the inverter circuit from outputting current.

9. The control method of claim 7, wherein, The method further comprises: In a case where there is no current output path in overcurrent at present, the first switch unit in each current discharge module is controlled to be turned on, and the second switch unit and the third switch unit are turned off.

10. The control method of claim 7, wherein, The determination of whether there is a current output path in overcurrent at present according to the current value collected by the current collection module comprises: The current value corresponding to each current output path is determined according to a first current value collected by a first sampling resistor and a second current value collected by a second sampling resistor, wherein the sum of the current values corresponding to each current output path is zero; The current value corresponding to each current output path is compared with the first preset threshold respectively, to determine whether there is a current output path in overcurrent at present.

11. A drive plate, characterized by The drive board comprises a control module, an inverter circuit for providing working power supply to a motor, and the drive board overcurrent protection circuit according to any one of claims 1-5; The drive board overcurrent protection circuit is connected in series between the inverter circuit and the motor, the drive board overcurrent protection circuit is electrically connected with the control module, and the control module is used for performing overcurrent protection by using the drive board overcurrent protection circuit in a case where the output current of the inverter circuit is in overcurrent.

12. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by a processor to implement the control method of the drive board overcurrent protection circuit according to any one of claims 6-10.

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