Bus current determination method and device of motor controller, equipment and medium

Abstract

The invention provides a bus current determination method and device of a motor controller, equipment and a medium, and the method comprises the steps: calculating and obtaining a conduction duty ratio corresponding to each phase of bridge arm according to the conduction duration of space vector pulse width modulation read from a control chip; according to the conduction duty ratio corresponding to each phase of bridge arm and the current corresponding to each phase of bridge arm, the first bus end current of the motor controller is determined, the bus end current of the motor controller can be obtained without additional hardware facilities, the vehicle manufacturing cost is reduced, and the vehicle reliability is improved. Determining a loss current according to the loss power of the motor controller and the bus end voltage of the motor controller; the difference between the first bus end current and the loss current is obtained to obtain the second bus end current of the motor controller, and the loss current corresponding to the loss is considered, so that the calculation precision of the bus current can be improved, and a current sensor can be completely replaced to calculate power for energy management; and a basis can be provided for energy required for starting an engine of a hybrid power automobile power system.

Description

Technical Field

[0001] The present application relates to the field of automobiles, and particularly to a method, device, equipment and medium for determining the bus current of a motor controller. Background Art

[0002] The permanent magnet synchronous motor has advantages such as high power density and wide speed regulation range, and is a favorable choice for the drive motor of current electric vehicles. In order to control and monitor it stably and effectively, it is necessary to accurately obtain the control variable information of each part of the system, so as to ensure the safety of driving and the accuracy of control and reduce risks.

[0003] In terms of battery energy management, such as vehicle energy efficiency calculation, etc., the power at the bus terminal of the motor controller is required, that is, the bus current must be obtained. However, the common method for obtaining the bus current is to collect it through external hardware facilities such as Hall sensors, which will increase the system cost, and cost reduction and efficiency improvement are the current important trends. At the same time, the hardware facilities have the risk of damage and are easily affected by external interference, resulting in a decrease in its accuracy, losing its original high-resolution and high-precision functions, and the accuracy of the obtained bus terminal current is poor. Summary of the Invention

[0004] In view of this, the purpose of the present application is to provide a method, device, equipment and medium for determining the bus current of a motor controller, which can obtain the bus terminal current of the motor controller without external hardware facilities, can reduce the vehicle manufacturing cost, and improve the calculation accuracy of the bus terminal current. The specific scheme is as follows:

[0005] On the one hand, the present application provides a method for determining the bus current of a motor controller, including:

[0006] Calculating the conduction duty ratio corresponding to each phase bridge arm according to the on-time of the space vector pulse width modulation read from the control chip;

[0007] Determining the first bus terminal current of the motor controller according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm;

[0008] Determining the loss current according to the loss power of the motor controller and the bus terminal voltage of the motor controller;

[0009] Subtracting the loss current from the first bus terminal current to obtain the second bus terminal current of the motor controller.

[0010] Specifically, before determining the loss current according to the loss power of the motor controller and the bus terminal voltage of the motor controller, the method further includes:

[0011] Determine the switching loss power according to the bus terminal voltage, collector current, and device junction temperature of the motor controller;

[0012] Determine the loss power according to the switching loss power.

[0013] Specifically, the determining the loss power according to the switching loss power includes:

[0014] Determine the conduction loss power according to the conduction duty cycle of the switching device, the conduction voltage drop of the switching device, and the collector current of the motor controller;

[0015] Sum the switching loss power and the conduction loss power to obtain the loss power.

[0016] Specifically, before the method determines the first bus terminal current of the motor controller according to the conduction duty cycle corresponding to each phase leg and the current corresponding to each phase leg, the method further includes:

[0017] Align the timings of the conduction duty cycles corresponding to each phase leg and the timings of the currents corresponding to each phase leg.

[0018] Specifically, the aligning the timings of the conduction duty cycles corresponding to each phase leg and the timings of the currents corresponding to each phase leg includes:

[0019] Align the timings of the conduction duty cycles corresponding to each phase leg and the timings of the currents corresponding to each phase leg by using park transformation, vpark transformation, and clark transformation.

[0020] In another aspect, an embodiment of the present application further provides a device for determining the bus current of a motor controller, including:

[0021] A first determining unit, configured to calculate the conduction duty cycle corresponding to each phase leg according to the turn-on duration of the space vector pulse width modulation read from the control chip;

[0022] A second determining unit, configured to determine the first bus terminal current of the motor controller according to the conduction duty cycle corresponding to each phase leg and the current corresponding to each phase leg;

[0023] A third determining unit, configured to determine the loss current according to the loss power of the motor controller and the bus terminal voltage of the motor controller;

[0024] A fourth determining unit, configured to subtract the loss current from the first bus terminal current to obtain the second bus terminal current of the motor controller.

[0025] Specifically, the device further includes:

[0026] A fifth determination unit, configured to determine the switching loss power according to the bus terminal voltage, collector current, and device junction temperature of the motor controller;

[0027] A sixth determination unit, configured to determine the loss power according to the switching loss power.

[0028] Specifically, the sixth determination unit is configured to:

[0029] Determine the conduction loss power according to the conduction duty ratio of the switching device, the conduction voltage drop of the switching device, and the collector current of the motor controller;

[0030] Sum the switching loss power and the conduction loss power to obtain the loss power.

[0031] In another aspect, an embodiment of the present application provides a computer device, which includes a processor and a memory:

[0032] The memory is used to store program codes and transmit the program codes to the processor;

[0033] The processor is configured to execute the method described in the above aspect according to the instructions in the program codes.

[0034] In another aspect, an embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program, and the computer program is used to execute the method described in the above aspect.

[0035] An embodiment of the present application provides a method, device, equipment, and medium for determining the bus current of a motor controller. According to the on-time of space vector pulse width modulation read from a control chip, the conduction duty ratio corresponding to each phase bridge arm is calculated; according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm, the first bus terminal current of the motor controller is determined. In this way, the bus terminal current of the motor controller can be obtained without additional hardware facilities, which can reduce the vehicle manufacturing cost. Then, according to the loss power of the motor controller and the bus terminal voltage of the motor controller, the loss current is determined; the difference between the first bus terminal current and the loss current is calculated to obtain the second bus terminal current of the motor controller. Considering the loss current corresponding to the loss can improve the calculation accuracy of the bus current. The second bus terminal current is more accurate than the first bus terminal current and can completely replace the current sensor to calculate the power for energy management, further perform health diagnosis of the motor controller, and can also provide a basis for the energy required for the engine startup of the hybrid vehicle power system. Description of the Drawings

[0036] 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 required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 Fig. 4 shows a schematic flowchart of a method for determining the bus current of a motor controller provided by an embodiment of the present application;

[0038] Figure 2 Fig. 8 shows a schematic connection diagram of an inverter and a motor provided by an embodiment of the present application;

[0039] Figure 3 Fig. 12 shows a voltage vector time distribution diagram provided by an embodiment of the present application;

[0040] Figure 4 Fig. 16 shows a schematic flowchart of a method for calculating the current at the first bus end provided by an embodiment of the present application;

[0041] Figure 5 Fig. 20 shows a schematic comparison diagram of the actual current and the estimated current provided by an embodiment of the present application;

[0042] Figure 6 Fig. 24 shows a schematic flowchart of another method for determining the bus current of a motor controller provided by an embodiment of the present application;

[0043] Figure 7 Fig. 28 is a structural block diagram of a device for determining the bus current of a motor controller provided by an embodiment of the present application;

[0044] Figure 8 Fig. 32 is a structural diagram of a computer device provided by an embodiment of the present application. Detailed Embodiments

[0045] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will provide a detailed description of the specific embodiments of the present application with reference to the drawings.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0047] For ease of understanding, the following will provide a detailed description of a method, device, equipment, and medium for determining the bus current of a motor controller provided by an embodiment of the present application with reference to the drawings.

[0048] Reference Figure 1 As shown, it is a schematic flowchart of a method for determining the bus current of a motor controller provided by an embodiment of the present application. This method may include the following steps.

[0049] S101, calculate the conduction duty ratio corresponding to each phase bridge arm according to the on-time of space vector pulse width modulation read from the control chip.

[0050] Specifically, a voltage can be input at the bus end, and switching is performed through different switching combinations of switching devices to realize the flow of the bus current from the DC end to the AC end. That is to say, in order to obtain the bus current, analysis can be carried out from the three-phase currents and their corresponding switching states.

[0051] Reference Figure 2 As shown, it is a schematic connection diagram of an inverter and a motor provided by an embodiment of the present application. The motor controller includes an inverter. The inverter includes 2 capacitors and 6 switching devices. By controlling the opening and closing of three bridge arms, the current input to the motor is controlled. Referring to the following table, where S A , S B , S C respectively control the opening and closing of the three bridge arms. Table 1 shows the flow direction of the bus current I DC under different switch closures.

[0052] Table 1

[0053] <![CDATA[S A > <![CDATA[S B > <![CDATA[S C > <![CDATA[Busbar current I DC Flowing]]> 0 0 0 0 0 0 1 <![CDATA[i w <!-- 3 -->]]> 0 1 0 <![CDATA[i v > 0 1 1 <![CDATA[i v +i w > 1 0 0 <![CDATA[i u > 1 0 1 <![CDATA[i u +i w > 1 1 0 <![CDATA[i u +i v > 1 1 1 0

[0054] Since the sum of the three-phase currents i w , i v and i u is 0, Table 1 can be transformed to obtain Table 2, in which the bus current is transformed.

[0055] Table 2

[0056] <![CDATA[S A > <![CDATA[S B > <![CDATA[S C > <![CDATA[Busbar current I DC > 0 0 0 0 0 0 1 <![CDATA[i w > 0 1 0 <![CDATA[i v > 0 1 1 <![CDATA[-i u > 1 0 0 <![CDATA[i u > 1 0 1 <![CDATA[-i v > 1 1 0 <![CDATA[-i w > 1 1 1 0

[0057] The on-time of space vector pulse width modulation (SVPWM) can be obtained by reading back the control chip information. SVPWM makes appropriate switching with different switching modes of a three-phase inverter, thereby forming a PWM (pulse width modulation) wave. Specifically, referring to Figure 3 as shown, it is a voltage vector time allocation diagram provided by an embodiment of the present application, showing a period T SInside, the voltage vectors of the three-phase bridge arms change. The on-time of SVPWM can be the duration of the switch in the closed conduction stage, such as the high-level time period in the figure. According to the on-time of SVPWM, the conduction duty ratio corresponding to each phase bridge arm of the three-phase inverter can be calculated.

[0058] Specifically, when the software calculates the PWM switch time instruction, the software and hardware cooperate to capture, for example, Figure 3 in which the rising and falling edges of the three-phase PWM coexist in the timer register. The result is read out in the next cycle, the on-time is calculated, and then combined with the PWM period, the ratio of the on-time to the period duration is used as the conduction duty ratio. The corresponding conduction duty ratio can be obtained for each phase bridge arm.

[0059] S102. Determine the first bus terminal current of the motor controller according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm.

[0060] Specifically, for each phase bridge arm, multiply the conduction duty ratio by the corresponding current, and then add the product results of each bridge arm to obtain the first bus terminal current of the motor controller. The first bus terminal current can be expressed as:

[0061] I DC =i u t u +i v t v +i w t w

[0062] wherein, i u 、i v 、i w represent the current corresponding to each phase bridge arm, and t u 、t v 、t w represent the conduction duty ratio corresponding to each phase bridge arm.

[0063] In a possible implementation manner, before determining the first bus terminal current of the motor controller according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm, the timings of the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm can also be aligned.

[0064] Specifically, since the readback conduction time is located in the monitoring layer, there are voltage coordinate transformation delay and reading delay. It is necessary to compensate the current and duty ratio timings to ensure their synchronization. If they are not synchronized, compensation can be performed through coordinate transformation to align the two timings, which can avoid the non-correspondence between the current and the duty ratio and improve the calculation accuracy of the first bus terminal current.

[0065] Specifically, when aligning the duty cycle timing and the current timing, the timing of the conduction duty cycle corresponding to each phase bridge arm and the timing of the current corresponding to each phase bridge arm can be aligned using park transformation, vpark transformation (inverse park transformation) and clark transformation.

[0066] Since the PWM switch is calculated by the voltage command, the voltage command is converted from ud and uq to uα and uβ by vpark. However, the vpark conversion generally causes a delay of 1.5 cycles, and the readback mechanism will cause the voltage to lag behind the current. At the same time, the monitoring layer generally has a slightly poor angle accuracy, and the speed and angle deviation fluctuate more. It is necessary to eliminate the influence of the angle on the current during the conversion process to ensure the stability and reliability of the current.

[0067] Therefore, an algorithm for directly transforming from a two-phase stationary coordinate system to a new sequential two-phase stationary coordinate system is proposed. Figure 4 As shown in FIG. 1 , a schematic diagram of a flow chart of calculating the current at the first bus terminal provided in an embodiment of the present application is shown. The current i corresponding to each phase bridge arm is w 、i v 、i u After uvw / αβ transformation, the two-phase currents iα and iβ in the stationary coordinate system are obtained. The two-phase currents iα and iβ are transformed by αβ / dq to obtain the two-phase currents id and iq in the rotating coordinate system. The two-phase currents id and iq are output through the PI regulator to output the two-phase voltages ud and uq. The two-phase voltages ud and uq are transformed by dq / αβ and compensated for 1.5 cycles to obtain the two-phase voltages uα and uβ. The two-phase voltages uα and uβ are processed by SVPWM to obtain the duty cycle instruction, and the conduction duty cycle t corresponding to each phase bridge arm is obtained by reading back. u ,t v ,t w .

[0068] Correspondingly, the delay of the two-phase current from the moment of reading the conduction duty cycle to the moment of generating the duty cycle instruction is the time difference between the read-back moment and the instruction moment, which is generally 2 cycles. Figure 4 The delay module is used, and then the current is transformed by αβ / αβ*, that is, Vpark_new(n*ωT)=Park(θ)+Vpark(θ+n*ωT). Only the vpark transformation related to time but not angle can be performed from the two-phase stationary coordinate system to the new sequential stationary coordinate system to obtain the new two-phase currents iα* and iβ*, which makes up for the 1.5-cycle delay caused by the voltage vpark transformation. Then the two-phase currents iα* and iβ* are transformed by αβ* / uvw* to obtain the corresponding current i u *、i v *、i w *, so that i u *、iv *, i w * and t u , t v , t w Timing alignment with...

[0069] That is, after performing new vpark on the currents iα and iβ, the new compensated two-phase stationary coordinate system currents iα* and iβ* can be obtained. Then, through the Clark transformation, the three-phase currents i u *, i v *, i w * can be obtained.

[0070] S103. Determine the loss current based on the loss power of the motor controller and the bus voltage of the motor controller.

[0071] Specifically, there are some losses in the motor controller. To improve the accuracy of the bus current and achieve the function of replacing the current Hall sensor, it is necessary to compensate for the current corresponding to the power loss from the front end of the motor controller input to the controller switching device after switching. This part of the loss includes line loss, PEB loss, etc. The loss power P of the motor controller L and the bus voltage U of the motor controller DC The ratio is used as the bus current corresponding to the controller loss, that is, the loss current. The loss current I DC1 can be expressed as:

[0072]

[0073] In a possible implementation, before determining the loss current, the loss power can be determined. Since the loss of the motor controller is mainly PEB loss, the PEB loss can include the switching loss of the switching device. The switching loss is the loss when the switching device is turned on and off. The switching loss can be obtained through double-pulse testing. Furthermore, the switching loss is related to the bus voltage, current, and device junction temperature.

[0074] Specifically, based on the bus voltage U of the motor controller dc , the collector current I, and the device junction temperature T j , the switching loss power Ex(U, T j , I) can be determined and can be expressed using the following formula:

[0075] Ex(U, T j , I) = (a0 + b0×U + c0×U 2 )×(a1 + b1×I + c1×I 2 )

[0076] Among them, c0 is set to a fixed value, which can be the value under the highest crystallization, and the relationships of a0, b0, and T j are as follows:

[0077] a0 = a2 + b2 × T j

[0078] b0 = a3 + b3 × T j

[0079] Next, the loss power can be determined according to the switching loss power. The switching loss power can be used as the loss power, and other loss powers can also be calculated. The sum of the switching loss power and other loss powers is used as the loss power.

[0080] Specifically, in order to further improve the calculation accuracy of the bus current, not only the switching loss can be considered, but also the conduction loss can be considered. The conduction loss is the loss generated by the switching device in the conduction state. That is, the PEB loss can include the switching loss and conduction loss of the switching device. For a general Insulate-Gate Bipolar Transistor (IGBT) and diode system, the conduction loss is divided into IGBT conduction loss and diode conduction loss, and the switching loss is divided into IGBT turn-on loss, IGBT turn-off loss, and diode reverse recovery loss.

[0081] Specifically, determining the loss power according to the switching loss power can be based on the duty cycle D of the switching device conduction, the conduction voltage drop and the collector current I of the motor controller to determine the conduction loss power. The conduction loss power can be expressed as:

[0082]

[0083] Then, the switching loss power and the conduction loss power are summed to obtain the loss power. The loss power is:

[0084] P L = Ex(U, T j , I) + Ex(V, T j , I)

[0085] S104. Subtract the loss current from the first bus terminal current to obtain the second bus terminal current of the motor controller.

[0086] After calculating the loss current, the loss current can be subtracted from the first bus terminal current to obtain the true bus terminal current of the motor controller, denoted as the second bus terminal current. The second bus terminal current is expressed as:

[0087] I DC2 = I DC - IDC1

[0088] It can be seen that this solution can obtain the bus terminal current of the motor controller without additional hardware facilities, which can reduce the vehicle manufacturing cost. Moreover, by taking into account the loss current corresponding to the loss, the calculation accuracy of the bus current can be improved. The second bus terminal current is more accurate than the first bus terminal current, and it can completely replace the current sensor to calculate power for energy management, further perform motor controller health diagnosis, and can also provide a basis for the energy required for the engine startup of the hybrid vehicle power system.

[0089] Specifically, since the second bus current fluctuates, the second bus current can be input into a low-pass filter to obtain the filtered second bus terminal current, which can make the current change more stable. Refer to Figure 5 As shown, the figure shows the comparison between the actual current and the estimated current calculated by this solution, and the estimated current fits well with the actual current.

[0090] In the embodiment of the present application, refer to Figure 6 As shown, the duty cycle can be read back to compensate for the current time, synchronize the current with the duty cycle, then calculate the preliminary current (the first bus terminal current), calculate the inverter loss, and further calculate the loss current. The compensated current is calculated based on the loss current and the preliminary current, and then the current after passing through the filter is calculated to obtain the final bus current (the second bus terminal current).

[0091] The embodiment of the present application provides a method for determining the bus current of a motor controller. According to the on-time of the space vector pulse width modulation read from the control chip, the conduction duty cycle corresponding to each phase bridge arm is calculated; according to the conduction duty cycle corresponding to each phase bridge arm and the current corresponding to each phase bridge arm, the first bus terminal current of the motor controller is determined. In this way, the bus terminal current of the motor controller can be obtained without additional hardware facilities, which can reduce the vehicle manufacturing cost. Then, according to the loss power of the motor controller and the bus terminal voltage of the motor controller, the loss current is determined; the difference between the first bus terminal current and the loss current is calculated to obtain the second bus terminal current of the motor controller. By taking into account the loss current corresponding to the loss, the calculation accuracy of the bus current can be improved. The second bus terminal current is more accurate than the first bus terminal current, and it can completely replace the current sensor to calculate power for energy management, further perform motor controller health diagnosis, and can also provide a basis for the energy required for the engine startup of the hybrid vehicle power system.

[0092] Based on the above method for determining the bus current of a motor controller, the embodiment of the present application further provides a device for determining the bus current of a motor controller. Refer to Figure 7As shown in the figure, it is a structural block diagram of a bus current determination device for a motor controller provided by an embodiment of the present application. The device may include:

[0093] A first determination unit 201, configured to calculate the conduction duty ratio corresponding to each phase bridge arm according to the on-duration of space vector pulse width modulation read from a control chip;

[0094] A second determination unit 202, configured to determine the first bus terminal current of the motor controller according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm;

[0095] A third determination unit 203, configured to determine a loss current according to the loss power of the motor controller and the bus terminal voltage of the motor controller;

[0096] A fourth determination unit 204, configured to subtract the loss current from the first bus terminal current to obtain the second bus terminal current of the motor controller.

[0097] Specifically, the device further includes:

[0098] A fifth determination unit, configured to determine a switching loss power according to the bus terminal voltage, collector current, and device junction temperature of the motor controller;

[0099] A sixth determination unit, configured to determine the loss power according to the switching loss power;

[0100] Specifically, the sixth determination unit is configured to:

[0101] Determine a conduction loss power according to the conduction duty ratio of the switching device, the conduction voltage drop of the switching device, and the collector current of the motor controller;

[0102] Sum the switching loss power and the conduction loss power to obtain the loss power.

[0103] Specifically, the device further includes:

[0104] An alignment unit, configured to align the timings of the conduction duty ratios corresponding to each phase bridge arm and the timings of the currents corresponding to each phase bridge arm.

[0105] Specifically, the alignment unit is configured to:

[0106] Align the timings of the conduction duty ratios corresponding to each phase bridge arm and the timings of the currents corresponding to each phase bridge arm by using park transformation, vpark transformation, and clark transformation.

[0107] An embodiment of the present application provides a device for determining the bus current of a motor controller. The first determination unit is configured to calculate the conduction duty ratio corresponding to each phase bridge arm according to the on-duration of space vector pulse width modulation read from a control chip. The second determination unit is configured to determine the current of the first bus terminal of the motor controller according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm. In this way, the bus terminal current of the motor controller can be obtained without additional hardware facilities, which can reduce the vehicle manufacturing cost. Then, the third determination unit is configured to determine the loss current according to the loss power of the motor controller and the bus terminal voltage of the motor controller. The fourth determination unit is configured to subtract the loss current from the first bus terminal current to obtain the second bus terminal current of the motor controller. Considering the loss current corresponding to the loss can improve the calculation accuracy of the bus current. The second bus terminal current is more accurate than the first bus terminal current and can completely replace the current sensor to calculate power for energy management, further perform health diagnosis of the motor controller, and can also provide a basis for the energy required for the engine startup of the hybrid vehicle power system.

[0108] In another aspect, an embodiment of the present application provides a computer device. Refer to Figure 8 As shown, it is a structural diagram of a computer device provided by an embodiment of the present application. The computer device includes a processor 310 and a memory 320:

[0109] The memory 320 is configured to store program codes and transmit the program codes to the processor 310;

[0110] The processor 310 is configured to execute the method provided by the above embodiment according to the instructions in the program codes.

[0111] This computer device may include a terminal device or a server, and the foregoing device may be configured in this computer device.

[0112] In another aspect, an embodiment of the present application further provides a storage medium. The storage medium is configured to store a computer program, and the computer program is configured to execute the method provided by the above embodiment.

[0113] Those of ordinary skill in the art can understand that all or part of the steps for implementing the above method embodiment can be completed by program instruction hardware. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps including the above method embodiment; and the foregoing storage medium may be at least one of the following media: read-only memory (English: Read-only Memory, abbreviation: ROM), RAM, magnetic disk, or optical disc, etc., which can store program codes.

[0114] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiments.

[0115] The above is only the preferred embodiment of the present application. Although the present application has been disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present application by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present application, or modify it into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of protection of the technical solution of the present application.

Claims

1. A method for determining the bus current of a motor controller, characterized in that Including: Calculating the conduction duty ratio corresponding to each phase bridge arm according to the on-duration of space vector pulse width modulation read from the control chip; Determining the first bus terminal current of the motor controller according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm; Determining the loss current according to the loss power of the motor controller and the bus terminal voltage of the motor controller; Subtracting the loss current from the first bus terminal current to obtain the second bus terminal current of the motor controller.

2. The method according to claim 1, characterized in that Before determining the loss current according to the loss power of the motor controller and the bus terminal voltage of the motor controller, the method further includes: Determining the switching loss power according to the bus terminal voltage, collector current and device junction temperature of the motor controller; Determining the loss power according to the switching loss power.

3. The method according to claim 2, characterized in that, The determining the loss power according to the switching loss power includes: Determining the conduction loss power according to the conduction duty ratio of the switching device, the conduction voltage drop of the switching device and the collector current of the motor controller; Summing the switching loss power and the conduction loss power to obtain the loss power.

4. The method according to claim 1, wherein Before determining the first bus terminal current of the motor controller according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm, the method further includes: Aligning the timing of the conduction duty ratio corresponding to each phase bridge arm with the timing of the current corresponding to each phase bridge arm.

5. The method according to claim 4, wherein The aligning the timing of the conduction duty ratio corresponding to each phase bridge arm with the timing of the current corresponding to each phase bridge arm includes: Aligning the timing of the conduction duty ratio corresponding to each phase bridge arm with the timing of the current corresponding to each phase bridge arm by using park transformation, vpark transformation and clark transformation.

6. A device for determining the bus current of a motor controller, characterized in that, Including: A first determination unit, configured to calculate the conduction duty ratio corresponding to each phase bridge arm according to the on-duration of space vector pulse width modulation read from the control chip; A second determination unit, configured to determine the first bus terminal current of the motor controller according to the conduction duty ratio corresponding to each phase bridge arm and the current corresponding to each phase bridge arm; A third determination unit, configured to determine the loss current according to the loss power of the motor controller and the bus terminal voltage of the motor controller; A fourth determination unit, configured to subtract the loss current from the first bus terminal current to obtain the second bus terminal current of the motor controller.

7. The device according to claim 6, characterized in that, The device further includes: A fifth determination unit, configured to determine the switching loss power according to the bus terminal voltage, collector current and device junction temperature of the motor controller; A sixth determination unit, configured to determine the loss power according to the switching loss power.

8. The device according to claim 7, characterized in that, The sixth determination unit is configured to: Determine the conduction loss power according to the conduction duty ratio of the switching device, the conduction voltage drop of the switching device and the collector current of the motor controller; Sum the switching loss power and the conduction loss power to obtain the loss power.

9. A computer device, characterized in that, The computer device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the method according to any one of claims 1-5 based on the instructions in the program code.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is configured to store a computer program, and the computer program is configured to execute the method according to any one of claims 1-5.

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