Electric motor power computing circuit and method, and electric motor, compressor and vehicle

Abstract

An electric motor power computing circuit and method, and an electric motor, a compressor and a vehicle. The electric motor power computing circuit comprises: a bus voltage sampling unit (10), which is suitable for sampling a bus voltage of an electric motor; a phase voltage sampling unit (20), which is suitable for sampling a phase voltage of any phase of the electric motor; a first current sampling unit (30), which is suitable for sampling a peak value of a bus current of the electric motor; a second current sampling unit (40), which is suitable for sampling an effective value of the bus current; and a control unit (50), which is configured to calibrate a bus voltage sampling value and a phase voltage sampling value to obtain a target voltage value, calibrate the peak value of the bus current and the effective value of the bus current to obtain a target current value, and determine the input power of the electric motor on the basis of the target voltage value and the target current value.

Description

Motor power calculation circuit, method, motor, compressor and vehicle

[0001] Cross-reference to Related Disclosures

[0002] The present application claims priority from the Chinese patent application No. 202410831861.8 filed on June 25, 2024 and entitled "Motor power calculation circuit, method, motor, compressor and vehicle", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of electric machines, and in particular to a motor power calculation circuit, method, motor, compressor and vehicle. BACKGROUND

[0004] In related technologies, in order to accurately calculate the remaining endurance of the battery, the power value feedback from each component is required to be more accurate (the current accuracy is required to be ±0.1A). In terms of motor control, the effective value of the bus voltage and the peak value of the bus current are usually sampled, and then the real-time power value is calculated. However, neither the voltage sampling nor the current sampling is calibrated, especially the peak sampling of the bus current, which will be affected by the circuit parasitic parameters and control algorithm, and the sampling value is unstable, it is difficult to calculate the accurate current, resulting in a large difference between the calculated power and the actual power. SUMMARY

[0005] The present disclosure aims to at least partially solve one of the technical problems in the related art. To this end, the first object of the present disclosure is to provide a motor power calculation circuit, two voltage sampling units and two current sampling units can be calibrated with each other, improve the sampling accuracy, the control unit can perform software calibration on the sampling value, and more accurate target current value and target voltage value can be obtained, so as to obtain accurate input power.

[0006] The second object of the present disclosure is to provide a motor.

[0007] The third object of the present disclosure is to provide a compressor.

[0008] The fourth object of the present disclosure is to provide a vehicle.

[0009] The fifth object of the present disclosure is to provide a motor power calculation method.

[0010] To achieve the above object, according to a first aspect of the present disclosure, a motor power calculation circuit is provided, comprising: a bus voltage sampling unit adapted to sample a bus voltage of a motor to obtain a bus voltage sampling value; a phase voltage sampling unit adapted to sample a phase voltage of any phase of the motor to obtain a phase voltage sampling value; a first current sampling unit adapted to sample a peak value of a bus current of the motor to obtain a bus current peak value; a second current sampling unit adapted to sample a root mean square value of the bus current to obtain a bus current root mean square value; and a control unit configured to calibrate the bus voltage sampling value and the phase voltage sampling value to obtain a target voltage value, calibrate the bus current peak value and the bus current root mean square value to obtain a target current value, and determine an input power of the motor according to the target voltage value and the target current value.

[0011] The motor power calculation circuit according to the embodiments of the present disclosure comprises a bus voltage sampling unit, a phase voltage sampling unit, a first current sampling unit, a second current sampling unit and a control unit, wherein the bus voltage sampling unit is adapted to sample a bus voltage of a motor to obtain a bus voltage sampling value, the phase voltage sampling unit is adapted to sample a phase voltage of any phase of the motor to obtain a phase voltage sampling value, the first current sampling unit is adapted to sample a peak value of a bus current of the motor to obtain a bus current peak value, the second current sampling unit is adapted to sample a root mean square value of the bus current to obtain a bus current root mean square value, and the control unit is configured to calibrate the bus voltage sampling value and the phase voltage sampling value to obtain a target voltage value, calibrate the bus current peak value and the bus current root mean square value to obtain a target current value, and determine an input power of the motor according to the target voltage value and the target current value. Thus, the two voltage sampling units and the two current sampling units can calibrate each other to improve the sampling accuracy, and the risk of sampling abnormality due to circuit damage can be reduced, and the second current sampling unit samples the bus current root mean square value, which is closer to the actual bus current consumption, and then the control unit calibrates the bus voltage sampling value and the phase voltage sampling value and the bus current peak value and the bus current root mean square value to obtain accurate voltage and current values, so that accurate power values can be obtained.

[0012] According to one embodiment of the present disclosure, the second current sampling unit comprises: a current detection resistor connected in series with the DC negative bus; a first operational amplifier module connected with the current detection resistor, the first operational amplifier module being configured to amplify the voltage across the current detection resistor to obtain a first voltage signal; a first filter module having an input end connected with an output end of the first operational amplifier module, the first filter module being configured to filter the first voltage signal to obtain a second voltage signal; and a second filter module having an input end connected with an output end of the first filter module and an output end connected with a first input end of the control unit, the second filter module being configured to filter the second voltage signal to obtain the effective value of the bus current.

[0013] According to one embodiment of the present disclosure, the first current sampling unit comprises: a second operational amplifier module connected with the current detection resistor, the first operational amplifier module being configured to amplify the voltage across the current detection resistor to obtain a third voltage signal; a third filter module having an input end connected with an output end of the second operational amplifier module and an output end connected with a second input end of the control unit, the third filter module being configured to filter the third voltage signal to obtain the peak value of the bus current.

[0014] According to one embodiment of the present disclosure, the amplification factor of the second operational amplifier module is less than the amplification factor of the first operational amplifier module.

[0015] According to one embodiment of the present disclosure, one end of the current detection resistor is grounded, and the other end of the current detection resistor is adapted to be connected with the DC negative bus.

[0016] According to one embodiment of the present disclosure, one end of the current detection resistor is adapted to be connected with one end of a bus capacitor and the DC negative bus, and the other end of the current detection resistor is adapted to be connected with the negative pole of the DC power supply, wherein the bus capacitor filters the DC power supply to generate the bus voltage.

[0017] According to one embodiment of the present disclosure, the input end of the bus voltage sampling unit is adapted to be connected with the positive pole of the DC power supply.

[0018] According to one embodiment of the present disclosure, the bus voltage sampling unit and the phase voltage sampling unit each comprise: a plurality of series-connected voltage dividing resistors, the first ends of the plurality of series-connected voltage dividing resistors being voltage input ends, the second ends of the plurality of series-connected voltage dividing resistors being grounded, the plurality of series-connected voltage dividing resistors having a first node adapted to output a divided input voltage; and a fourth filter module having an input end connected with the first node and an output end being a voltage output end, the fourth filter module being configured to filter the divided input voltage to output a voltage sampling value.

[0019] According to one embodiment of the present disclosure, the control unit is further configured to filter the bus voltage sampling value and the phase voltage sampling value respectively to obtain a phase voltage value and a bus voltage value, and determine an average value of the phase voltage value and the bus voltage value as the target voltage value in a case where an absolute value of a difference between the phase voltage value and the bus voltage value is less than a first preset difference value.

[0020] According to one embodiment of the present disclosure, the control unit is further configured to perform shutdown control on the motor in a case where the absolute value of the difference between the phase voltage value and the bus voltage value is greater than or equal to the first preset difference value.

[0021] According to one embodiment of the present disclosure, the control unit is further configured to filter the bus current peak value to obtain a bus current value, determine a first current value according to a target fitting value and the bus current value in a case where an absolute value of a difference between the bus current value and a bus current effective value is less than a second preset difference value, filter the bus current effective value to obtain a second current value, and determine a target current value according to a difference between the first current value and the second current value, wherein the target fitting value is obtained by looking up a pre-established motor parameter table according to the bus voltage sampling value and the phase voltage sampling value.

[0022] According to one embodiment of the present disclosure, the control unit is further configured to determine the target fitting value as the first current value in a case where an absolute value of a difference between the target fitting value and the bus current value is less than or equal to a third preset difference value, or determine the bus current value as the first current value in a case where the absolute value of the difference between the target fitting value and the bus current value is greater than the third preset difference value.

[0023] According to one embodiment of the present disclosure, the control unit is further configured to determine the second current value as the target current value in a case where an absolute value of a difference between the first current value and the second current value is greater than a fourth preset difference value, or determine the first current value as the target current value in a case where the absolute value of the difference between the first current value and the second current value is less than or equal to the fourth preset difference value.

[0024] According to one embodiment of the present disclosure, the control unit is further configured to perform shutdown control on the motor in a case where the absolute value of the difference between the bus current value and the bus current effective value is greater than or equal to the second preset difference value.

[0025] To achieve the above object, according to a second aspect of the present disclosure, a motor is provided, which comprises the motor power calculation circuit of any one of the preceding embodiments.

[0026] According to the motor of the embodiment of the present disclosure, by adopting the motor power calculation circuit, the two voltage sampling units and the two current sampling units can be calibrated with each other, the sampling precision is improved, the control unit performs software calibration on the sampling values, the target current value and the target voltage value can be obtained more accurately, and thus the input power can be obtained accurately.

[0027] To achieve the above object, the compressor according to the third aspect of the present disclosure is provided, which comprises the motor power calculation circuit of any one of the foregoing embodiments or the motor.

[0028] According to the compressor of the embodiment of the present disclosure, by adopting the motor power calculation circuit or the motor, the two voltage sampling units and the two current sampling units can be calibrated with each other, the sampling precision is improved, the control unit performs software calibration on the sampling values, the target current value and the target voltage value can be obtained more accurately, and thus the input power can be obtained accurately.

[0029] To achieve the above object, the vehicle according to the fourth aspect of the present disclosure is provided, which comprises the compressor.

[0030] According to the vehicle of the embodiment of the present disclosure, by adopting the compressor, the two voltage sampling units and the two current sampling units can be calibrated with each other, the sampling precision is improved, the control unit performs software calibration on the sampling values, the target current value and the target voltage value can be obtained more accurately, and thus the input power can be obtained accurately.

[0031] To achieve the above object, the motor power calculation method according to the fifth aspect of the present disclosure is provided, which is applied to a motor power calculation circuit, the motor power calculation circuit comprises a bus voltage sampling unit, a phase voltage sampling unit, a first current sampling unit and a second current sampling unit, the bus voltage sampling unit is adapted to sample a bus voltage of a motor to obtain a bus voltage sampling value, the phase voltage sampling unit is adapted to sample a phase voltage of any phase of the motor to obtain a phase voltage sampling value, the first current sampling unit is adapted to sample a peak value of a bus current of the motor to obtain a bus current peak value, and the second current sampling unit is adapted to sample a root mean square value of the bus current to obtain a bus current root mean square value, the method comprises: calibrating the bus voltage sampling value and the phase voltage sampling value to obtain a target voltage value, and calibrating the bus current peak value and the bus current root mean square value to obtain a target current value; and determining an input power of the motor according to the target voltage value and the target current value.

[0032] According to the motor power calculation method provided in the embodiments of the present disclosure, the bus voltage sampling value, the phase voltage sampling value of any phase, the bus current peak value and the bus current effective value of the motor are obtained, the bus voltage sampling value and the phase voltage sampling value are calibrated to obtain a target voltage value, the bus current peak value and the bus current effective value are calibrated to obtain a target current value, and the input power of the motor is determined according to the target voltage value and the target current value. In this way, the two voltage sampling units and the two current sampling units can be calibrated with each other, the sampling accuracy is improved, the risk of sampling abnormality caused by circuit damage can be reduced, and the second current sampling unit samples the bus current effective value, which is closer to the actual bus current consumption, and then the control unit calibrates the bus voltage sampling value and the phase voltage sampling value and the bus current peak value and the bus current effective value to obtain accurate voltage value and current value, so that the accurate power value can be obtained.

[0033] According to one embodiment of the present disclosure, the bus voltage sampling value and the phase voltage sampling value are calibrated to obtain a target voltage value, including: filtering the bus voltage sampling value and the phase voltage sampling value respectively to obtain a phase voltage value and a bus voltage value; in the case that the absolute value of the difference between the phase voltage value and the bus voltage value is less than a first preset difference value, the average value of the phase voltage value and the bus voltage value is determined as the target voltage value.

[0034] According to one embodiment of the present disclosure, in the case that the absolute value of the difference between the phase voltage value and the bus voltage value is greater than or equal to the first preset difference value, the method further comprises: performing shutdown control on the motor.

[0035] According to one embodiment of the present disclosure, the bus current peak value and the bus current effective value are calibrated to obtain a target current value, including: filtering the bus current peak value to obtain a bus current value; in the case that the absolute value of the difference between the bus current value and the bus current effective value is less than a second preset difference value, determining a first current value according to a target fitting value and the bus current value, and filtering the bus current effective value to obtain a second current value, wherein the target fitting value is obtained from a pre-established motor parameter table according to the bus voltage sampling value and the phase voltage sampling value; and determining the target current value according to the difference between the first current value and the second current value.

[0036] According to one embodiment of the present disclosure, determining the first current value according to the target fitting value and the bus current value includes: in the case that the absolute value of the difference between the target fitting value and the bus current value is less than or equal to a third preset difference value, determining the target fitting value as the first current value; or in the case that the absolute value of the difference between the target fitting value and the bus current value is greater than the third preset difference value, determining the bus current value as the first current value.

[0037] According to one embodiment of the present disclosure, determining the target current value according to the difference between the first current value and the second current value comprises: determining the second current value as the target current value in a case that the absolute value of the difference between the first current value and the second current value is greater than a fourth preset difference value; or determining the first current value as the target current value in a case that the absolute value of the difference between the first current value and the second current value is less than or equal to the fourth preset difference value.

[0038] According to one embodiment of the present disclosure, in a case that the absolute value of the difference between the bus current value and the bus current effective value is greater than or equal to the second preset difference value, the method further comprises: performing shutdown control on the motor.

[0039] Additional aspects and advantages of the present disclosure will be partially given in the following description, partially become obvious from the following description, or be understood by practice of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0040] FIG. 1 is a circuit diagram of a bus voltage sampling unit in the related art;

[0041] FIG. 2 is a circuit diagram of 3-way current sampling in the related art;

[0042] FIG. 3 is a circuit diagram of a bus current sampling unit in the related art;

[0043] FIG. 4 is a structural schematic diagram of a motor power calculation circuit according to one embodiment of the present disclosure;

[0044] FIG. 5 is a circuit diagram of a second current sampling unit according to one embodiment of the present disclosure;

[0045] FIG. 6 is a waveform schematic diagram of a second voltage signal according to one embodiment of the present disclosure;

[0046] FIG. 7 is a waveform schematic diagram of a bus current effective value according to one embodiment of the present disclosure;

[0047] FIG. 8 is a waveform schematic diagram of a bus current peak value according to one embodiment of the present disclosure;

[0048] FIG. 9 is a circuit diagram of a power filter circuit according to one embodiment of the present disclosure;

[0049] FIG. 10 is a circuit diagram of a first current sampling unit according to one embodiment of the present disclosure;

[0050] FIG. 11 is a circuit diagram of a second current sampling unit according to another embodiment of the present disclosure;

[0051] FIG. 12 is a circuit diagram of a phase voltage sampling unit according to one embodiment of the present disclosure;

[0052] FIG. 13 is a flowchart of voltage sampling calibration according to one embodiment of the present disclosure;

[0053] FIG. 14 is a flowchart of current sampling calibration according to one embodiment of the present disclosure;

[0054] FIG. 15 is a circuit diagram of 4-way current sampling according to one embodiment of the present disclosure;

[0055] FIG. 16 is a system diagram of a motor according to one embodiment of the present disclosure;

[0056] FIG. 17 is a system diagram of a compressor according to one embodiment of the present disclosure;

[0057] FIG. 18 is a system diagram of a compressor according to another embodiment of the present disclosure;

[0058] FIG. 19 is a system diagram of a vehicle according to one embodiment of the present disclosure;

[0059] FIG. 20 is a flowchart of a motor power calculation method according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0060] Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings, in which the same or similar components have the same or similar designations and functions throughout various figures and embodiments, and a description of the same or similar components is not repeated. Embodiments described below are examples for explaining the present disclosure and are not intended to be limiting of the present disclosure.

[0061] It should be noted that the present disclosure is made by the inventors' understanding and research on the following problems:

[0062] In the related art, the voltage sampling of the motor is usually only provided with one bus voltage sampling unit 10 as shown in FIG. 1, and the current sampling of the motor is usually provided with 3-way current sampling as shown in FIG. 2, i.e., a first sampling resistor Rs1 is arranged at the U-phase lower bridge arm and the V-phase lower bridge arm, and a second sampling resistor Rs2 is arranged at the DC negative bus, so as to sample the U-phase phase current, the V-phase phase current and the bus current peak value, and the bus current peak value is obtained according to the voltage across the second sampling resistor by the bus current sampling unit as shown in FIG. 3, and then the input power of the motor is calculated according to the bus current peak value and the bus voltage sampling value.

[0063] However, the above motor voltage sampling scheme and motor current sampling scheme have the following defects:

[0064] 1. Because the bus voltage and the bus current both have only one sampling unit, when the sampling unit is abnormal, it is impossible to determine whether the bus voltage sampling value and the bus current peak value are correct. If the bus voltage sampling value or the bus current peak value is incorrect, the motor power value will also be incorrect. Therefore, the control unit will make incorrect control based on the incorrect motor power value, which will cause the motor to be prone to failure.

[0065] 2. The bus current peak value will be affected by the circuit parasitic parameters and the control algorithm, and the sampling value is unstable.

[0066] 3. The bus current peak value needs to be converted into the effective value, which will cause the error to become larger, thereby causing the precision to decrease.

[0067] Therefore, based on this, the embodiment of the present disclosure provides a motor power calculation circuit, method, motor, compressor and vehicle. Two voltage sampling units and two current sampling units can be calibrated with each other, the sampling precision is improved, the control unit performs software calibration on the sampling value, the target current value and the target voltage value can be obtained more accurately, and the input power can be obtained accurately.

[0068] The motor power calculation circuit, method, motor, compressor and vehicle of the embodiment of the present disclosure are described below with reference to the accompanying drawings.

[0069] FIG. 4 is a structural schematic diagram of a motor power calculation circuit according to one embodiment of the present disclosure. As shown in FIG. 4, the motor power calculation circuit comprises a bus voltage sampling unit 10, a phase voltage sampling unit 20, a first current sampling unit 30, a second current sampling unit 40 and a control unit 50.

[0070] The bus voltage sampling unit 10 is adapted to sample the bus voltage of the motor to obtain a bus voltage sampling value. The phase voltage sampling unit 20 is adapted to sample the phase voltage of any phase of the motor to obtain a phase voltage sampling value. The first current sampling unit 30 is adapted to sample the peak value of the bus current of the motor to obtain a bus current peak value. The second current sampling unit 40 is adapted to sample the effective value of the bus current to obtain a bus current effective value. The control unit 50 is configured to calibrate the bus voltage sampling value and the phase voltage sampling value to obtain a target voltage value, calibrate the bus current peak value and the bus current effective value to obtain a target current value, and determine the input power of the motor according to the target voltage value and the target current value.

[0071] Specifically, in the case that the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are not faulty, the difference between the bus voltage sampling value and the phase voltage sampling value is small, so the bus voltage sampling unit 10 and the phase voltage sampling unit 20 can be calibrated with each other according to the bus voltage sampling value and the phase voltage sampling value. Similarly, in the case that the first current sampling unit 30 and the second current sampling unit 40 are not faulty, the difference between the bus current peak value and the bus current effective value is also small, so the first current sampling unit 30 and the second current sampling unit 40 can be calibrated with each other according to the bus current peak value and the bus current effective value. The second current sampling unit 40 samples the bus current effective value, which is closer to the actual bus current consumption, and then the control unit 50 calibrates the bus voltage sampling value and the phase voltage sampling value and the bus current peak value and the bus current effective value to obtain accurate target voltage value and target current value, and calculates the product of the target voltage value and the target current value to obtain the input power.

[0072] In the above embodiment, the two voltage sampling units and the two current sampling units can be calibrated with each other, which not only improves the sampling accuracy, but also reduces the risk of sampling abnormality caused by circuit damage, and the second current sampling unit samples the bus current effective value, which is closer to the actual bus current consumption and has smaller error, and then the control unit performs software calibration to obtain accurate voltage value and current value, so that accurate power value can be obtained.

[0073] In some embodiments, as shown in FIG. 5, the second current sampling unit 40 includes a current detection resistor Rs, a first operational amplifier module 41, a first filter module 42 and a second filter module 43. The current detection resistor Rs is connected in series to the DC negative bus HVDC-. The first operational amplifier module 41 is connected to the current detection resistor Rs, and is configured to amplify the voltage across the current detection resistor Rs to obtain a first voltage signal. The input end of the first filter module 42 is connected to the output end of the first operational amplifier module 41, and the first filter module 42 is configured to filter the first voltage signal to obtain a second voltage signal. The input end of the second filter module 43 is connected to the output end of the first filter module 42, and the output end of the second filter module 43 is connected to the first input end I_ADC1 of the control unit 50. The second filter module 43 is configured to filter the second voltage signal to obtain the bus current effective value.

[0074] Specifically, the current detection resistor Rs is connected in series with the DC negative bus HVDC-, to convert the bus current into a voltage signal, the first operational amplification module 41 amplifies the voltage across the current detection resistor Rs to obtain a first voltage signal, and then inputs the first voltage signal to the first filter module 42, the first filter module 42 filters the first voltage signal into a smooth second voltage signal, but there are still glitches in the second voltage signal (as shown in FIG. 6), therefore, the second filter module 43 filters out the glitches in the second voltage signal to obtain an accurate bus current effective value as shown in FIG. 7.

[0075] It should be noted that the lower curve in FIG. 6 is an enlargement of the white area in the upper curve; the sinusoidal curve in FIG. 7 is the phase current, the straight line curve is the bus current effective value, and the two lower curves are enlargements of the white area in the upper curve.

[0076] In an alternative embodiment, as shown in FIG. 5, the first operational amplification module 41 is a differential amplification circuit, and the first operational amplification module 41 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a first operational amplifier OP1, wherein one end of the first resistor R1 is connected with the current detection resistor Rs, the other end of the first resistor R1 is connected with the negative input terminal of the first operational amplifier OP1 and has a second node J2, one end of the second resistor R2 is grounded, the other end of the second resistor R2 is connected with the positive input terminal of the first operational amplifier OP1 and has a third node J3, one end of the third resistor R3 is connected with the second node J2, the other end of the third resistor R3 is connected with the output terminal O of the first operational amplifier OP1, the fourth resistor R4 is connected in parallel with the third resistor R3, one end of the fifth resistor R5 is adapted to input a preset power supply, the other end of the fifth resistor R5 is connected with the third node J3, one end of the sixth resistor R6 is connected with the other end of the fifth resistor R5, and the other end of the sixth resistor R6 is grounded.

[0077] The first filter module 42 and the second filter module 43 are low-pass filter circuits respectively, and the capacitance of the second filter module 43 is smaller than that of the first filter module 42. The first filter module 42 includes a seventh resistor R7, a first capacitor C1, a second capacitor C2 and a third capacitor C3, wherein the seventh resistor R7 is connected to the output terminal of the first operational amplifier OP1, the other end of the seventh resistor R7 is connected to one end of the first capacitor C1, the other end of the first capacitor C1 is grounded, and the second capacitor C2 and the third capacitor C3 are connected in parallel and then connected in parallel with the first capacitor C1. The second filter module 43 includes an eighth resistor R8, a fourth capacitor C4 and a fifth capacitor C5, wherein one end of the eighth resistor R8 is connected to the other end of the seventh resistor R7, the other end of the eighth resistor R8 is connected to the first input terminal I_ADC1 of the control unit 50 and one end of the fourth capacitor C4 respectively, the other end of the fourth capacitor C4 is grounded, and the fifth capacitor C5 is connected in parallel with the fourth capacitor C4.

[0078] It should be noted that the bus current effective value and the bus current peak value are voltage signals, and the control unit 50 can calculate the current value corresponding to the bus current effective value and the current value corresponding to the bus current peak value according to the bus current effective value, the bus current peak value and the resistance value of the current detection resistor Rs after receiving the bus current effective value and the bus current peak value.

[0079] In the above embodiment, the first operational amplifier module amplifies the voltage across the current detection resistor, and the first voltage signal is filtered through two-stage filter circuits, so that a more accurate bus current effective value can be obtained.

[0080] In some embodiments, as shown in FIG. 3, the first current sampling unit 30 includes a second operational amplifier module 31 and a third filter module 32, wherein the second operational amplifier module 31 is connected to the current detection resistor Rs, the first operational amplifier module 41 is configured to amplify the voltage across the current detection resistor Rs to obtain a third voltage signal; the input terminal of the third filter module 32 is connected to the output terminal of the second operational amplifier module 31, the output terminal of the third filter module 32 is connected to the second input terminal I_ADC2 of the control unit 50, and the third filter module 32 is configured to filter the third voltage signal to obtain the bus current peak value.

[0081] Specifically, the first current sampling unit 30 and the second current sampling unit 40 adopt the same current detection resistor Rs, so that the input signals of the two current sampling units are the same, to avoid the influence on the motor control caused by the different signals obtained by the two current sampling units. Because the first current sampling unit 30 also samples the bus current peak value, the circuit structure of the first current sampling unit 30 can be the same as that of the bus current sampling unit in the related art. The second operational amplifier module 31 amplifies the voltage across the current detection resistor Rs to obtain a third voltage signal, and the third filtering module 32 filters the third voltage signal to output the bus current peak value as shown in FIG. 8.

[0082] As can be seen from FIG. 8, the sampling time of the first current sampling unit 30 will deviate, and is not at the peak value every time, and the amplitude of the bus current peak value obtained by sampling every time will change, so that the bus current peak value has a large error, and therefore the second current sampling unit 40 is needed to sample the bus current effective value.

[0083] It should be noted that the curve below in FIG. 8 is an enlarged view of the white area in the curve above.

[0084] In an optional embodiment, as shown in FIG. 3, the second operational amplifier module 31 is a differential amplification circuit, and the second operational amplifier module 31 includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a second operational amplifier OP2, wherein one end of the ninth resistor R9 is connected with the current detection resistor Rs, the other end of the ninth resistor R9 is connected with the negative input terminal of the second operational amplifier OP2 and has a fourth node J4, one end of the tenth resistor R10 is grounded, the other end of the tenth resistor R10 is connected with the positive input terminal of the second operational amplifier OP2 and has a fifth node J5, one end of the eleventh resistor R11 is connected with the fourth node J4, the other end of the eleventh resistor R11 is connected with the output terminal O of the second operational amplifier OP2, one end of the twelfth resistor R12 is adapted to input a preset power supply, the other end of the twelfth resistor R12 is connected with the fifth node J5, one end of the thirteenth resistor R13 is connected with the other end of the twelfth resistor R12, and the other end of the thirteenth resistor R13 is grounded.

[0085] The third filtering module 32 is also a low-pass filter circuit, and the third filtering module 32 includes a fourteenth resistor R14 and a sixth capacitor C6, wherein one end of the fourteenth resistor R14 is connected with the output terminal O of the second operational amplifier OP2, the other end of the fourteenth resistor R14 is connected with the second input terminal I_ADC2 of the control unit 50 and one end of the sixth capacitor C6 respectively, and the other end of the sixth capacitor C6 is grounded.

[0086] In some embodiments, the amplification factor of the second operational amplification module 31 is less than the amplification factor of the first operational amplification module 41.

[0087] It can be understood that the amplification factor of the second operational amplification module 31 is less than the amplification factor of the first operational amplification module 41, that is, the amplification factor of the second current sampling unit 40 is greater than the amplification factor of the first current sampling unit 30. The greater the amplification factor, the smaller the corresponding full load current, and the higher the sampling accuracy. For example, when the amplification factor is 30.3, the corresponding full load current is 108.9A, when the amplification factor is 77.27, the corresponding full load current is 21.4A, and the maximum digital quantity sampled by the control unit is 4096. When the full load current is 108.9A, a single digital quantity 1 corresponds to 108.9 / 4096=0.0265A, and when the full load current is 21.4A, a single digital quantity 1 corresponds to 21.4 / 4096=0.0052A. Therefore, the greater the amplification factor, the higher the sampling accuracy.

[0088] It should be noted that because the amplification factor of the first operational amplification module 41 is greater than the amplification factor of the second operational amplification module 31, the upper limit of the sampling value of the first operational amplification module 41 is less than the upper limit of the sampling value of the second operational amplification module 31. Therefore, the upper limit of the sampling value of the first operational amplification module 41 is 20-30A, and the upper limit of the sampling value of the second operational amplification module 31 is greater than 100A.

[0089] In some embodiments, as shown in FIG. 2, one end of the current detection resistor Rs is grounded, and the other end of the current detection resistor Rs is adapted to be connected to the DC negative bus HVDC-.

[0090] That is, the current detection resistor Rs can be arranged after the bus capacitor C, and the three-phase lower bridge arms of the inverter of the motor are connected to the ground after being connected. One end of the current detection resistor Rs is connected to the three-phase lower bridge arms and grounded, and the other end of the current detection resistor Rs is adapted to be connected to the DC negative bus HVDC-.

[0091] In some embodiments, as shown in FIG. 9, one end of the current detection resistor Rs is adapted to be connected to one end of the bus capacitor C and the DC negative bus HVDC-, and the other end of the current detection resistor Rs is adapted to be connected to the negative electrode of the DC power supply. The bus capacitor C filters the DC power supply to generate a bus voltage.

[0092] Specifically, when the current detection resistor Rs is arranged after the bus capacitor C, the bus capacitor C will interfere with current sampling when charging and discharging, thereby reducing the sampling accuracy. Therefore, the current detection resistor Rs can also be arranged in front of the bus capacitor C.

[0093] Taking FIG. 9 as an example, the power supply filter circuit of the motor adopts a differential mode filter circuit, and the power supply filter circuit includes a first inductor L1, a second inductor L2, and a bus capacitor C. One end of the first inductor L1 is adapted to be connected to a positive pole HV+ of a high-voltage power supply, and the other end of the first inductor L1 is a positive pole of a direct-current power supply, that is, a direct-current positive bus HVDC+. One end of the second inductor L2 is adapted to be connected to a negative pole HV- of the high-voltage power supply, and the other end of the second inductor L2 is a negative pole of the direct-current power supply. The other end of the current detection resistor Rs is connected to the other end of the second inductor L2, and one end of the current detection resistor Rs is connected to one end of the bus capacitor C. The other end of the bus capacitor C is connected to the other end of the first inductor L1, and one end of the bus capacitor C is a direct-current negative bus HVDC-.

[0094] When the current detection resistor Rs is arranged in front of the bus capacitor C, as shown in FIGS. 10 and 11, one end of the first resistor R1 of the first operational amplifier module 41 is connected to the other end of the current detection resistor Rs, one end of the second resistor R2 of the first operational amplifier module 41 is connected to one end of the current detection resistor Rs, one end of the ninth resistor R9 of the second operational amplifier module 31 is connected to the other end of the current detection resistor Rs, and one end of the tenth resistor R10 of the second operational amplifier module 31 is connected to one end of the current detection resistor Rs.

[0095] In the above embodiment, the bus current sampling point is arranged in front of the bus capacitor, so that the charging and discharging of the bus capacitor can avoid interfering with current sampling, thereby further improving the accuracy of current sampling.

[0096] In some embodiments, as shown in FIGS. 1 and 12, the bus voltage sampling unit 10 and the phase voltage sampling unit 20 each include a plurality of series-connected voltage dividing resistors R and a fourth filter module 11. The first end of the plurality of series-connected voltage dividing resistors R is a voltage input end, the second end of the plurality of series-connected voltage dividing resistors R is grounded, the plurality of series-connected voltage dividing resistors R has a first node J1 adapted to output a divided input voltage, the input end of the fourth filter module 11 is connected to the first node J1, and the output end of the fourth filter module 11 is a voltage output end. The fourth filter module 11 is configured to filter the divided input voltage to output a voltage sampling value.

[0097] Specifically, the circuit structures of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are the same, so that the voltage dividing ratios of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are the same, and the difference between the bus voltage sampling value and the phase voltage sampling value will not increase. If the circuit structures of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are different, the difference between the bus voltage sampling value and the phase voltage sampling value will increase, thereby affecting motor control.

[0098] The bus voltage sampling unit 10 can adopt a sampling circuit in the related art. For example, as shown in FIG. 1, the voltage input end of the bus voltage sampling unit 10 is adapted to be connected to the positive DC bus HVDC+, there are eight voltage dividing resistors R, the first node J1 is the connection point of the sixth voltage dividing resistor R and the seventh voltage dividing resistor R, the fourth filter module 11 of the bus voltage sampling unit 10 filters the voltage dividing voltage of the positive DC bus HVDC+ to obtain a bus voltage sampling value, and the fourth filter module 11 of the bus voltage sampling unit 10 is connected to the third input end VDC_AD3 of the control unit 50 to provide the bus voltage sampling value to the control unit 50.

[0099] For example, as shown in FIG. 12, the voltage input end of the phase voltage sampling unit 20 is adapted to be connected to the midpoint of the W-phase bridge arm of the inverter. Because the circuit structure of the phase voltage sampling unit 20 is the same as that of the bus voltage sampling unit 10, the phase voltage sampling unit 20 also includes eight voltage dividing resistors R, the first node J1 is the connection point of the sixth voltage dividing resistor R and the seventh voltage dividing resistor R, the fourth filter module 11 of the phase voltage sampling unit 20 filters the voltage dividing voltage of the W-phase phase voltage to obtain a phase voltage sampling value, and the fourth filter module 11 of the phase voltage sampling unit 20 is connected to the fourth input end VDC_AD4 of the control unit 50 to provide the phase voltage sampling value to the control unit 50.

[0100] It should be noted that the bus voltage sampling value and the phase voltage sampling value are voltage values after voltage division, and the control unit 50 can calculate the bus voltage corresponding to the bus voltage sampling value and the phase voltage corresponding to the phase voltage sampling value according to the voltage dividing resistors R, the bus voltage sampling value and the phase voltage sampling value.

[0101] In an optional embodiment, as shown in FIG. 1 and FIG. 12, the fourth filter module 11 includes a fifteenth resistor R15 and a seventh capacitor C7, one end of the fifteenth resistor R15 is connected to the first node J1, the other end of the fifteenth resistor R15 is the output end of the fourth filter module 11, one end of the seventh capacitor C7 is connected to the other end of the fifteenth resistor R15, and the other end of the seventh capacitor C7 is grounded.

[0102] In some embodiments, the input end of the bus voltage sampling unit 10 is adapted to be connected to the positive electrode of the DC power supply.

[0103] Specifically, when the sampling point of the bus voltage is set after the bus capacitor C, that is, the bus voltage sampling unit 10 is adapted to sample the positive DC bus HVDC+, the interference of the power supply input end on the bus voltage sampling can be avoided, but the inverter will interfere with the bus voltage sampling when working. Therefore, the bus voltage sampling point can also be set in front of the bus capacitor C, closer to the input end, so as to avoid the interference when the inverter works.

[0104] For example, as shown in FIG. 9, the input end of the bus voltage sampling unit 10 is adapted to be connected to the positive pole HV+ of the high-voltage power supply.

[0105] In the above embodiment, the bus voltage sampling point can also be arranged in front of the bus capacitor to avoid the interference of the inverter on the bus voltage sampling, thereby improving the accuracy of the bus voltage sampling.

[0106] In some embodiments, as shown in FIG. 13, the control unit 50 is further configured to filter the bus voltage sampling value and the phase voltage sampling value respectively to obtain a phase voltage value and a bus voltage value, and determine the average value of the phase voltage value and the bus voltage value as the target voltage value in a case where the absolute value of the difference between the phase voltage value and the bus voltage value is less than a first preset difference value.

[0107] Specifically, the control unit 50 performs software low-pass filtering on the bus voltage sampling value and the phase voltage sampling value to obtain the phase voltage value and the bus voltage value. If the absolute value of the difference between the phase voltage value and the bus voltage value is less than the first preset difference value, it indicates that the difference between the phase voltage sampling value and the bus voltage sampling value is relatively small, the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are working normally, and the sampling values of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are reliable. Therefore, the average value of the phase voltage value and the bus voltage value can be determined as the target voltage value.

[0108] In some embodiments, as shown in FIG. 13, the control unit 50 is further configured to perform shutdown control on the motor in a case where the absolute value of the difference between the phase voltage value and the bus voltage value is greater than or equal to the first preset difference value.

[0109] That is, if the absolute value of the difference between the phase voltage value and the bus voltage value is greater than or equal to the first preset difference value, it indicates that the difference between the phase voltage sampling value and the bus voltage sampling value is relatively large, the bus voltage sampling unit 10 and / or the phase voltage sampling unit 20 is faulty, and the motor cannot be controlled according to the sampling values of the bus voltage sampling unit 10 and the phase voltage sampling unit 20. Therefore, the motor is controlled to stop.

[0110] In the above embodiment, the absolute value of the difference between the phase voltage value and the bus voltage value can be used to determine whether the bus voltage sampling unit 10 and / or the phase voltage sampling unit 20 is faulty. When the bus voltage sampling unit 10 and / or the phase voltage sampling unit 20 is faulty, the motor can be controlled to stop in time, thereby improving the safety of the motor. When the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are working normally, an accurate target voltage value can be calculated, thereby improving the accuracy of the motor control.

[0111] In some embodiments, as shown in FIG. 14, the control unit 50 is further configured to filter the bus current peak value to obtain a bus current value, determine a first current value according to the target fitting value and the bus current value in a case where an absolute value of a difference between the bus current value and the bus current effective value is less than a second preset difference, filter the bus current effective value to obtain a second current value, and determine the target current value according to a difference between the first current value and the second current value, wherein the target fitting value is obtained by looking up a motor parameter table established in advance according to the bus voltage sampling value and the phase voltage sampling value.

[0112] Specifically, the control unit 50 performs software low-pass filtering on the bus current peak value to obtain a bus current value. If an absolute value of a difference between the bus current value and the bus current effective value is less than a second preset difference, it indicates that the first current sampling unit 30 and the second current sampling unit 40 are working normally, and control can be performed based on the bus current value and the bus current effective value. The control unit 50 looks up a target fitting value corresponding to the bus voltage sampling value and the phase voltage sampling value from a motor parameter table established in advance, determines a first current value according to the target fitting value and the bus current value, and performs software low-pass filtering on the bus current effective value to obtain a second current value, and then determines the target current value according to the first current value and the second current value.

[0113] It should be noted that the motor parameter table established in advance is constructed according to motor speeds, bus voltages, phase voltages, phase currents, bus current peak values, bus current effective values and powers in a plurality of operating states, wherein the bus current peak values, the bus current effective values and the powers are calculated based on the relationship between the bus voltage and the bus current of the motor at different motor speeds.

[0114] In an alternative embodiment, the motor phase current can be sampled by a double-resistance sampling scheme as shown in FIG. 2, or can be sampled by a three-resistor (Rs1, Rs2, Rs3) sampling scheme as shown in FIG. 15.

[0115] In some embodiments, as shown in FIG. 14, the control unit 50 is further configured to determine the target fitting value as the first current value in a case where an absolute value of a difference between the target fitting value and the bus current value is less than or equal to a third preset difference, or determine the bus current value as the first current value in a case where the absolute value of the difference between the target fitting value and the bus current value is greater than the third preset difference.

[0116] Specifically, if the absolute value of the difference between the target fitting value and the bus current value is less than or equal to a third preset difference value, it indicates that the bus current value conforms to the relationship between the bus voltage and the bus current in the pre-established motor parameter table, and thus the target fitting value can be taken as the first current value; if the absolute value of the difference between the target fitting value and the bus current value is greater than the third preset difference value, it indicates that the bus current value does not conform to the relationship between the bus voltage and the bus current in the pre-established motor parameter table, and thus the actual sampled current value is taken as the first current value.

[0117] In some embodiments, as shown in FIG. 14, the control unit 50 is further configured to determine the second current value as the target current value if the absolute value of the difference between the first current value and the second current value is greater than a fourth preset difference value, or determine the first current value as the target current value if the absolute value of the difference between the first current value and the second current value is less than or equal to the fourth preset difference value.

[0118] It can be understood that if the absolute value of the difference between the first current value and the second current value is greater than the fourth preset difference value (for example, 1A), the filtered bus current effective value is more accurate, and thus the second current value is taken as the target current value; if the absolute value of the difference between the first current value and the second current value is less than or equal to the fourth preset difference value, the difference between the first current value and the second current value is small, and thus the first current value can be taken as the target current value.

[0119] It should be noted that the smaller the fourth preset difference value is, the more accurate the target current value is.

[0120] In some embodiments, as shown in FIG. 14, the control unit 50 is further configured to perform shutdown control on the motor if the absolute value of the difference between the bus current value and the bus current effective value is greater than or equal to a second preset difference value.

[0121] That is, if the absolute value of the difference between the bus current value and the bus current effective value is greater than or equal to the second preset difference value, it indicates that the difference between the bus current peak value and the bus current effective value is relatively large, and the first current sampling unit 30 and / or the second current sampling unit 40 fails to perform motor control according to the sampling values of the first current sampling unit 30 and the second current sampling unit 40, and thus the motor is subjected to shutdown control.

[0122] In the above embodiment, the absolute value of the difference between the bus current peak value and the bus current effective value can be used to determine whether the first current sampling unit and / or the second current sampling unit is malfunctioning, and when the first current sampling unit and / or the second current sampling unit is malfunctioning, the motor can be controlled to stop in time, thereby improving the safety of the motor, and when the first current sampling unit and the second current sampling unit are working normally, an accurate target current value can be calculated, thereby improving the accuracy of motor control.

[0123] In summary, the motor power calculation circuit according to the embodiments of the present disclosure includes a bus voltage sampling unit, a phase voltage sampling unit, a first current sampling unit, a second current sampling unit, and a control unit, wherein the bus voltage sampling unit is adapted to sample the bus voltage of the motor to obtain a bus voltage sampling value, the phase voltage sampling unit is adapted to sample the phase voltage of any phase of the motor to obtain a phase voltage sampling value, the first current sampling unit is adapted to sample the peak value of the bus current of the motor to obtain a bus current peak value, the second current sampling unit is adapted to sample the effective value of the bus current to obtain a bus current effective value, the control unit is configured to calibrate the bus voltage sampling value and the phase voltage sampling value to obtain a target voltage value, and calibrate the bus current peak value and the bus current effective value to obtain a target current value, and determine the input power of the motor according to the target voltage value and the target current value. Thus, the two voltage sampling units and the two current sampling units can be calibrated with each other to improve the sampling accuracy, and the risk of sampling abnormality due to circuit damage can be reduced, and the second current sampling unit samples the bus current effective value, which is closer to the actual bus current consumption, and then the control unit calibrates the bus voltage sampling value and the phase voltage sampling value and the bus current peak value and the bus current effective value to obtain accurate voltage and current values, so that accurate power values can be obtained.

[0124] Corresponding to the above embodiment, the embodiments of the present disclosure also provide a motor. As shown in FIG. 16, the motor 200 includes the motor power calculation circuit 100 of any of the preceding embodiments.

[0125] The motor according to the embodiments of the present disclosure adopts the above motor power calculation circuit, the two voltage sampling units and the two current sampling units can be calibrated with each other to improve the sampling accuracy, and the control unit can calibrate the sampling values by software to obtain more accurate target current values and target voltage values, thereby obtaining accurate input power.

[0126] Corresponding to the above embodiment, the embodiments of the present disclosure also provide a compressor. As shown in FIG. 17 and FIG. 18, the compressor 300 includes the motor power calculation circuit 100 of any of the preceding embodiments or the motor 200 described above.

[0127] According to the compressor of the embodiment of the present disclosure, by adopting the motor power calculation circuit or the motor, the two voltage sampling units and the two current sampling units can be calibrated with each other, the sampling accuracy is improved, the control unit performs software calibration on the sampling values, and more accurate target current values and target voltage values can be obtained, so that accurate input power can be obtained.

[0128] Corresponding to the above-mentioned embodiments, the embodiment of the present disclosure also provides a vehicle. As shown in FIG. 19, the vehicle 1000 comprises the aforementioned compressor 300.

[0129] The vehicle 1000 according to the embodiment of the present disclosure comprises the compressor 300 described in any of the above-mentioned embodiments. Here, the vehicle can be a new energy vehicle, and in some embodiments, the new energy vehicle can be a pure electric vehicle using a motor as the main driving force, and in other embodiments, the new energy vehicle can also be a hybrid vehicle using an internal combustion engine and a motor as the main driving force. As mentioned in the above-mentioned embodiments, the internal combustion engine and the motor that provide driving force for the new energy vehicle, wherein the internal combustion engine can use gasoline, diesel, hydrogen, etc. as fuel, and the way to provide power for the motor can use power battery, hydrogen fuel cell, etc. Here, no special limitation is made. It should be noted that here is only an exemplary description of the structure of the new energy vehicle, and is not a limitation on the protection scope of the present disclosure.

[0130] According to the vehicle of the embodiment of the present disclosure, by adopting the above-mentioned compressor, the two voltage sampling units and the two current sampling units can be calibrated with each other, the sampling accuracy is improved, the control unit performs software calibration on the sampling values, and more accurate target current values and target voltage values can be obtained, so that accurate input power can be obtained.

[0131] Corresponding to the above-mentioned embodiments, the embodiment of the present disclosure also provides a motor power calculation method, which is applied to the motor power calculation circuit as shown in FIG. 4. The motor power calculation circuit comprises a bus voltage sampling unit 10, a phase voltage sampling unit 20, a first current sampling unit 30 and a second current sampling unit 40. The bus voltage sampling unit 10 is adapted to sample the bus voltage of the motor to obtain a bus voltage sampling value. The phase voltage sampling unit 20 is adapted to sample the phase voltage of any phase of the motor to obtain a phase voltage sampling value. The first current sampling unit 30 is adapted to sample the peak value of the bus current of the motor to obtain a bus current peak value. The second current sampling unit 40 is adapted to sample the effective value of the bus current to obtain a bus current effective value. As shown in FIG. 20, the method comprises:

[0132] S101, calibrating the bus voltage sampling value and the phase voltage sampling value to obtain a target voltage value, and calibrating the bus current peak value and the bus current effective value to obtain a target current value.

[0133] Specifically, in the case that the bus voltage sampling unit and the phase voltage sampling unit are not faulty, the difference between the bus voltage sampling value and the phase voltage sampling value is small, so the bus voltage sampling unit and the phase voltage sampling unit can be calibrated with each other according to the bus voltage sampling value and the phase voltage sampling value. Similarly, in the case that the first current sampling unit and the second current sampling unit are not faulty, the difference between the bus current peak value and the bus current effective value is also small, so the first current sampling unit and the second current sampling unit can be calibrated with each other according to the bus current peak value and the bus current effective value. The bus current effective value sampled by the second current sampling unit is closer to the actual bus current, and then the control unit calibrates the bus voltage sampling value and the phase voltage sampling value and the bus current peak value and the bus current effective value to obtain accurate target voltage value and target current value

[0134] S102, determine the input power of the motor according to the target voltage value and the target current value.

[0135] Specifically, the product of the target voltage value and the target current value can be calculated to obtain the input power.

[0136] In the above embodiment, the two voltage sampling units and the two current sampling units can be calibrated with each other, which not only improves the sampling accuracy, but also reduces the risk of sampling abnormality caused by circuit damage, and the bus current effective value sampled by the second current sampling unit is closer to the actual bus current, with smaller error, and then the control unit is calibrated by software to obtain accurate voltage value and current value, so that accurate power value can be obtained.

[0137] In some embodiments, as shown in FIG. 5, the second current sampling unit 40 includes a current detection resistor Rs, a first operational amplifier module 41, a first filter module 42 and a second filter module 43. The current detection resistor Rs is connected in series with the DC negative bus HVDC-. The first operational amplifier module 41 is connected with the current detection resistor Rs, and is configured to amplify the voltage across the current detection resistor Rs to obtain a first voltage signal. The input end of the first filter module 42 is connected with the output end of the first operational amplifier module 41, and the first filter module 42 is configured to filter the first voltage signal to obtain a second voltage signal. The input end of the second filter module 43 is connected with the output end of the first filter module 42, and the output end of the second filter module 43 is connected with the first input end I_ADC1 of the control unit 50. The second filter module 43 is configured to filter the second voltage signal to obtain the bus current effective value.

[0138] Specifically, the current detection resistor Rs is connected in series with the DC negative bus HVDC-, to convert the bus current into a voltage signal, the first operational amplifier module 41 amplifies the voltage across the current detection resistor Rs to obtain a first voltage signal, and then inputs the first voltage signal into the first filter module 42, the first filter module 42 filters the first voltage signal into a smooth second voltage signal, but there are still glitches in the second voltage signal (as shown in FIG. 6), therefore, the second filter module 43 filters out the glitches in the second voltage signal to obtain an accurate bus current effective value as shown in FIG. 7.

[0139] In an alternative embodiment, as shown in FIG. 5, the first operational amplifier module 41 is a differential amplification circuit, and the first operational amplifier module 41 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a first operational amplifier OP1, wherein one end of the first resistor R1 is connected with the current detection resistor Rs, the other end of the first resistor R1 is connected with the negative input terminal of the first operational amplifier OP1 and has a second node J2, one end of the second resistor R2 is grounded, the other end of the second resistor R2 is connected with the positive input terminal of the first operational amplifier OP1 and has a third node J3, one end of the third resistor R3 is connected with the second node J2, the other end of the third resistor R3 is connected with the output terminal O of the first operational amplifier OP1, the fourth resistor R4 is connected in parallel with the third resistor R3, one end of the fifth resistor R5 is adapted to input a preset power supply, the other end of the fifth resistor R5 is connected with the third node J3, one end of the sixth resistor R6 is connected with the other end of the fifth resistor R5, and the other end of the sixth resistor R6 is grounded.

[0140] The first filter module 42 and the second filter module 43 are low-pass filter circuits respectively, and the capacitance of the second filter module 43 is smaller than that of the first filter module 42. The first filter module 42 includes a seventh resistor R7, a first capacitor C1, a second capacitor C2, and a third capacitor C3, wherein the seventh resistor R7 is connected with the output terminal O of the first operational amplifier OP1, the other end of the seventh resistor R7 is connected with one end of the first capacitor C1, the other end of the first capacitor C1 is grounded, and the second capacitor C2 and the third capacitor C3 are connected in parallel and then connected in parallel with the first capacitor C1. The second filter module 43 includes an eighth resistor R8, a fourth capacitor C4, and a fifth capacitor C5, wherein one end of the eighth resistor R8 is connected with the other end of the seventh resistor R7, the other end of the eighth resistor R8 is connected with the first input terminal I_ADC1 of the control unit 50 and one end of the fourth capacitor C4 respectively, the other end of the fourth capacitor C4 is grounded, and the fifth capacitor C5 is connected in parallel with the fourth capacitor C4.

[0141] It should be noted that the bus current effective value and the bus current peak value are voltage signals, and the control unit 50 can calculate the current value corresponding to the bus current effective value and the current value corresponding to the bus current peak value according to the bus current effective value, the bus current peak value and the resistance value of the current detection resistor Rs after receiving the bus current effective value and the bus current peak value.

[0142] In the above embodiment, the first operational amplification module amplifies the voltage across the current detection resistor, and the first voltage signal is filtered through the two-stage filter circuit, so that a more accurate bus current effective value can be obtained.

[0143] In some embodiments, as shown in FIG. 3, the first current sampling unit 30 includes a second operational amplification module 31 and a third filter module 32, wherein the second operational amplification module 31 is connected with the current detection resistor Rs, and the first operational amplification module 41 is configured to amplify the voltage across the current detection resistor Rs to obtain a third voltage signal; the input end of the third filter module 32 is connected with the output end of the second operational amplification module 31, the output end of the third filter module 32 is connected with the second input end I_ADC2 of the control unit 50, and the third filter module 32 is configured to filter the third voltage signal to obtain the bus current peak value.

[0144] Specifically, the first current sampling unit 30 and the second current sampling unit 40 use the same current detection resistor Rs, which ensures that the input signals of the two current sampling units are the same, so as to avoid the influence on the motor control caused by the different signals of the two current sampling units. Because the first current sampling unit 30 also samples the bus current peak value, the circuit structure of the first current sampling unit 30 can be the same as that of the bus current sampling unit in the related art. The second operational amplification module 31 amplifies the voltage across the current detection resistor Rs to obtain a third voltage signal, and the third filter module 32 filters the third voltage signal to output the bus current peak value as shown in FIG. 8.

[0145] As can be seen from FIG. 8, the sampling time of the first current sampling unit 30 will deviate, and it is not at the peak time every time, and the amplitude of the bus current peak value obtained by sampling every time will change, so that the bus current peak value has a large error, and therefore the second current sampling unit 40 is needed to sample the bus current effective value.

[0146] It should be noted that FIGS. 6 to 8 are software interfaces of waveform display software.

[0147] In an alternative embodiment, as shown in FIG. 3, the second operational amplification module 31 is a differential amplification circuit, and the second operational amplification module 31 comprises a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a second operational amplifier OP2, wherein one end of the ninth resistor R9 is connected with the current detection resistor Rs, the other end of the ninth resistor R9 is connected with the negative input terminal of the second operational amplifier OP2 and has a fourth node J4, one end of the tenth resistor R10 is grounded, the other end of the tenth resistor R10 is connected with the positive input terminal of the second operational amplifier OP2 and has a fifth node J5, one end of the eleventh resistor R11 is connected with the fourth node J4, the other end of the eleventh resistor R11 is connected with the output terminal O of the second operational amplifier OP2, one end of the twelfth resistor R12 is adapted to input a preset power supply, the other end of the twelfth resistor R12 is connected with the fifth node J5, one end of the thirteenth resistor R13 is connected with the other end of the twelfth resistor R12, and the other end of the thirteenth resistor R13 is grounded.

[0148] The third filter module 32 is also a low-pass filter circuit, and the third filter module 32 comprises a fourteenth resistor R14 and a sixth capacitor C6, wherein one end of the fourteenth resistor R14 is connected with the output terminal O of the second operational amplifier OP2, the other end of the fourteenth resistor R14 is connected with the second input terminal I_ADC2 of the control unit 50 and one end of the sixth capacitor C6 respectively, and the other end of the sixth capacitor C6 is grounded.

[0149] In some embodiments, the amplification multiple of the second operational amplification module 31 is less than the amplification multiple of the first operational amplification module 41.

[0150] It can be understood that the amplification multiple of the second operational amplification module 31 is less than the amplification multiple of the first operational amplification module 41, i.e., the amplification multiple of the second current sampling unit 40 is greater than the amplification multiple of the first current sampling unit 30. The greater the amplification multiple, the smaller the corresponding full load current, and the higher the sampling accuracy. For example, when the amplification multiple is 30.3, the corresponding full load current is 108.9A, when the amplification multiple is 77.27, the corresponding full load current is 21.4A, and the maximum digital quantity sampled by the control unit is 4096, then when the full load current is 108.9A, a single digital quantity 1 corresponds to 108.9 / 4096=0.0265A, when the full load current is 21.4A, a single digital quantity 1 corresponds to 21.4 / 4096=0.0052A, therefore, the greater the amplification multiple, the higher the sampling accuracy.

[0151] It should be noted that because the amplification multiple of the first operational amplification module 41 is greater than the amplification multiple of the second preamplification module 31, the sampling upper limit value of the first operational amplification module 41 is less than the sampling upper limit value of the second operational amplification module 31, and thus the sampling upper limit value of the first operational amplification module 41 is 20-30A, and the sampling upper limit value of the second operational amplification module 31 is greater than 100A.

[0152] In some embodiments, as shown in FIG. 2, one end of the current detection resistor Rs is grounded, and the other end of the current detection resistor Rs is adapted to be connected to the DC negative bus HVDC-.

[0153] That is, the current detection resistor Rs can be arranged after the bus capacitor C, and the three-phase lower bridge arms of the inverter of the motor are connected to the ground, one end of the current detection resistor Rs is connected to the three-phase lower bridge arms respectively and grounded, and the other end of the current detection resistor Rs is adapted to be connected to the DC negative bus HVDC-.

[0154] In some embodiments, as shown in FIG. 9, one end of the current detection resistor Rs is adapted to be connected to one end of the bus capacitor C and the DC negative bus HVDC-, and the other end of the current detection resistor Rs is adapted to be connected to the negative electrode of the DC power supply, wherein the bus capacitor C filters the DC power supply to generate a bus voltage.

[0155] Specifically, when the current detection resistor Rs is arranged after the bus capacitor C, the bus capacitor C will interfere with current sampling during charging and discharging, thereby reducing the sampling accuracy, and thus the current detection resistor Rs can also be arranged in front of the bus capacitor C.

[0156] For example, as shown in FIG. 9, the power supply filter circuit of the motor uses a differential mode filter circuit, and the power supply filter circuit includes a first inductor L1, a second inductor L2, and a bus capacitor C, one end of the first inductor L1 is adapted to be connected to the positive electrode HV+ of the high-voltage power supply, the other end of the first inductor L1 is the positive electrode of the DC power supply, which is also the DC positive bus HVDC+, one end of the second inductor L2 is adapted to be connected to the negative electrode HV- of the high-voltage power supply, the other end of the second inductor L2 is the negative electrode of the DC power supply, the other end of the current detection resistor Rs is connected to the other end of the second inductor L2, one end of the current detection resistor Rs is connected to one end of the bus capacitor C, the other end of the bus capacitor C is connected to the other end of the first inductor L1, and one end of the bus capacitor C is the DC negative bus HVDC-.

[0157] When the current detection resistor Rs is arranged in front of the bus capacitor C, as shown in FIGS. 10 and 11, one end of the first resistor R1 of the first operational amplifier module 41 is connected to the other end of the current detection resistor Rs, one end of the second resistor R2 of the first operational amplifier module 41 is connected to one end of the current detection resistor Rs, one end of the ninth resistor R9 of the second operational amplifier module 31 is connected to the other end of the current detection resistor Rs, and one end of the tenth resistor R10 of the second operational amplifier module 31 is connected to one end of the current detection resistor Rs.

[0158] In the above embodiment, the bus current sampling point is arranged in front of the bus capacitor, which can avoid the interference of the charging and discharging of the bus capacitor on the current sampling, thereby further improving the accuracy of the current sampling.

[0159] In some embodiments, as shown in FIGS. 1 and 12, the bus voltage sampling unit 10 and the phase voltage sampling unit 20 each include a plurality of series-connected voltage dividing resistors R and a fourth filtering module 11, wherein a first end of the plurality of series-connected voltage dividing resistors R is a voltage input end, a second end of the plurality of series-connected voltage dividing resistors R is grounded, the plurality of series-connected voltage dividing resistors R has a first node J1 adapted to output a divided input voltage, an input end of the fourth filtering module 11 is connected to the first node J1, and an output end of the fourth filtering module 11 is a voltage output end. The fourth filtering module 11 is configured to filter the divided input voltage to output a voltage sampling value.

[0160] Specifically, the circuit structures of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are the same, so that the voltage dividing ratios of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are the same, and the difference between the bus voltage sampling value and the phase voltage sampling value will not increase. If the circuit structures of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are different, the difference between the bus voltage sampling value and the phase voltage sampling value will increase, thereby affecting the motor control.

[0161] The bus voltage sampling unit 10 can use a sampling circuit in the related art. For example, as shown in FIG. 1, the voltage input end of the bus voltage sampling unit 10 is adapted to be connected to the DC positive bus HVDC+, there are eight voltage dividing resistors R, the first node J1 is the connection point of the sixth voltage dividing resistor R and the seventh voltage dividing resistor R, the fourth filtering module 11 of the bus voltage sampling unit 10 filters the divided voltage of the DC positive bus HVDC+ to obtain a bus voltage sampling value, and the fourth filtering module 11 of the bus voltage sampling unit 10 is connected to the third input end VDC_AD3 of the control unit 50 to provide the bus voltage sampling value to the control unit 50.

[0162] Taking the sampling of the W-phase phase voltage by the phase voltage sampling unit 20 as an example, as shown in FIG. 12, the voltage input end of the phase voltage sampling unit 20 is adapted to be connected to the midpoint of the W-phase bridge arm of the inverter. Since the circuit structure of the phase voltage sampling unit 20 is the same as that of the bus voltage sampling unit 10, the phase voltage sampling unit 20 also includes eight voltage dividing resistors R, and the first node J1 is the connection point of the sixth voltage dividing resistor R and the seventh voltage dividing resistor R. The fourth filter module 11 of the phase voltage sampling unit 20 filters the voltage dividing voltage of the W-phase phase voltage to obtain a phase voltage sampling value. The fourth filter module 11 of the phase voltage sampling unit 20 is connected to the fourth input end VDC_AD4 of the control unit 50 to provide the phase voltage sampling value to the control unit 50.

[0163] It should be noted that the bus voltage sampling value and the phase voltage sampling value are voltage values after voltage division. The control unit 50 can calculate the bus voltage corresponding to the bus voltage sampling value and the phase voltage corresponding to the phase voltage sampling value according to the voltage dividing resistors R, the bus voltage sampling value and the phase voltage sampling value.

[0164] In an optional embodiment, as shown in FIG. 1 and FIG. 12, the fourth filter module 11 includes a fifteenth resistor R15 and a seventh capacitor C7. One end of the fifteenth resistor R15 is connected to the first node J1, and the other end of the fifteenth resistor R15 is the output end of the fourth filter module 11. One end of the seventh capacitor C7 is connected to the other end of the fifteenth resistor R15, and the other end of the seventh capacitor C7 is grounded.

[0165] In some embodiments, the input end of the bus voltage sampling unit 10 is adapted to be connected to the positive pole of the direct current power supply.

[0166] Specifically, when the sampling point of the bus voltage is set after the bus capacitor C, i.e., the bus voltage sampling unit 10 is adapted to sample the direct current positive bus HVDC+, the interference of the power supply input end on the bus voltage sampling can be avoided. However, the inverter will interfere with the bus voltage sampling when working. Therefore, the bus voltage sampling point can also be set in front of the bus capacitor C, closer to the input end, so as to avoid the interference of the inverter when working.

[0167] Taking FIG. 9 as an example, the input end of the bus voltage sampling unit 10 is adapted to be connected to the positive pole HV+ of the high-voltage power supply.

[0168] In the above embodiments, the bus voltage sampling point can also be set in front of the bus capacitor to avoid the interference of the inverter on the bus voltage sampling, so as to improve the accuracy of the bus voltage sampling.

[0169] In some embodiments, as shown in FIG. 13, the bus voltage sampling value and the phase voltage sampling value are calibrated to obtain the target voltage value, including: filtering the bus voltage sampling value and the phase voltage sampling value respectively to obtain the phase voltage value and the bus voltage value; and in a case where an absolute value of a difference between the phase voltage value and the bus voltage value is less than a first preset difference, determining an average value of the phase voltage value and the bus voltage value as the target voltage value.

[0170] Specifically, the bus voltage sampling value and the phase voltage sampling value are software low-pass filtered to obtain the phase voltage value and the bus voltage value. If the absolute value of the difference between the phase voltage value and the bus voltage value is less than the first preset difference, it indicates that the difference between the phase voltage sampling value and the bus voltage sampling value is relatively small, and the bus voltage sampling unit and the phase voltage sampling unit are working normally, and the sampling values of the bus voltage sampling unit and the phase voltage sampling unit are reliable. Therefore, the average value of the phase voltage value and the bus voltage value can be the target voltage value.

[0171] In some embodiments, as shown in FIG. 13, in a case where the absolute value of the difference between the phase voltage value and the bus voltage value is greater than or equal to the first preset difference, the method further includes: performing shutdown control on the motor.

[0172] That is, if the absolute value of the difference between the phase voltage value and the bus voltage value is greater than or equal to the first preset difference, it indicates that the difference between the phase voltage sampling value and the bus voltage sampling value is relatively large, and the bus voltage sampling unit and / or the phase voltage sampling unit fails, and the motor cannot be controlled according to the sampling values of the bus voltage sampling unit and the phase voltage sampling unit. Therefore, the motor is controlled to shut down.

[0173] In the above embodiments, the absolute value of the difference between the phase voltage value and the bus voltage value can be used to determine whether the bus voltage sampling unit and / or the phase voltage sampling unit fails. When the bus voltage sampling unit and / or the phase voltage sampling unit fails, the motor can be controlled to shut down in time, thereby improving the safety of the motor. When the bus voltage sampling unit and the phase voltage sampling unit are working normally, an accurate target voltage value can be calculated, thereby improving the accuracy of the motor control.

[0174] In some embodiments, as shown in FIG. 14, the bus current peak value and the bus current effective value are calibrated to obtain the target current value, including: filtering the bus current peak value to obtain a bus current value; in a case where an absolute value of a difference between the bus current value and the bus current effective value is less than a second preset difference value, determining a first current value according to a target fitting value and the bus current value, and filtering the bus current effective value to obtain a second current value, wherein the target fitting value is obtained from a pre-established motor parameter table according to a bus voltage sampling value and a phase voltage sampling value; and determining the target current value according to a difference between the first current value and the second current value.

[0175] Specifically, the control unit performs software low-pass filtering on the bus current peak value to obtain a bus current value. If an absolute value of a difference between the bus current value and the bus current effective value is less than a second preset difference value, it indicates that the first current sampling unit and the second current sampling unit are working normally, and control can be performed based on the bus current value and the bus current effective value. The control unit looks up a target fitting value corresponding to the bus voltage sampling value and the phase voltage sampling value from a pre-established motor parameter table, and determines a first current value according to the target fitting value and the bus current value, and performs software low-pass filtering on the bus current effective value to obtain a second current value, and then determines the target current value according to the first current value and the second current value.

[0176] It should be noted that the pre-established motor parameter table is constructed according to motor speeds, bus voltages, phase voltages, phase currents, bus current peak values, bus current effective values and powers in multiple operating states, wherein the bus current peak values, the bus current effective values and the powers are calculated based on the relationship between the bus voltage and the bus current of the motor at different motor speeds.

[0177] In an alternative embodiment, the motor phase current can be sampled by a double-resistance sampling scheme as shown in FIG. 2, or can be sampled by a three-resistor (Rs1, Rs2, Rs3) sampling scheme as shown in FIG. 15.

[0178] In some embodiments, as shown in FIG. 14, determining the first current value according to the target fitting value and the bus current value includes: in a case where an absolute value of a difference between the target fitting value and the bus current value is less than or equal to a third preset difference value, determining the target fitting value as the first current value; or in a case where the absolute value of the difference between the target fitting value and the bus current value is greater than the third preset difference value, determining the bus current value as the first current value.

[0179] Specifically, if the absolute value of the difference between the target fitting value and the bus current value is less than or equal to a third preset difference value, it indicates that the bus current value conforms to the relationship between the bus voltage and the bus current in the pre-established motor parameter table, and therefore the target fitting value can be taken as the first current value; if the absolute value of the difference between the target fitting value and the bus current value is greater than the third preset difference value, it indicates that the bus current value does not conform to the relationship between the bus voltage and the bus current in the pre-established motor parameter table, and therefore the actual sampled current value is taken as the reference, and therefore the bus current value is taken as the first current value.

[0180] In some embodiments, as shown in FIG. 14, the target current value is determined according to the difference between the first current value and the second current value, including: in the case that the absolute value of the difference between the first current value and the second current value is greater than a fourth preset difference value, the second current value is determined as the target current value; or in the case that the absolute value of the difference between the first current value and the second current value is less than or equal to the fourth preset difference value, the first current value is determined as the target current value.

[0181] It can be understood that if the absolute value of the difference between the first current value and the second current value is greater than the fourth preset difference value (for example, 1A), the filtered bus current effective value is more accurate, and therefore the second current value is taken as the target current value; if the absolute value of the difference between the first current value and the second current value is less than or equal to the fourth preset difference value, the difference between the first current value and the second current value is small, and therefore the first current value can be taken as the target current value.

[0182] It should be noted that the smaller the fourth preset difference value is, the more accurate the target current value is.

[0183] In some embodiments, as shown in FIG. 14, in the case that the absolute value of the difference between the bus current value and the bus current effective value is greater than or equal to the second preset difference value, the method further includes: performing shutdown control on the motor.

[0184] That is, if the absolute value of the difference between the bus current value and the bus current effective value is greater than or equal to the second preset difference value, it indicates that the difference between the bus current peak value and the bus current effective value is relatively large, and the first current sampling unit and / or the second current sampling unit is faulty, and the motor control cannot be performed according to the sampling values of the first current sampling unit and the second current sampling unit, and therefore the shutdown control is performed on the motor.

[0185] In the above embodiment, the absolute value of the difference between the bus current peak value and the bus current effective value can be used to determine whether the first current sampling unit and / or the second current sampling unit is malfunctioning. When the first current sampling unit and / or the second current sampling unit is malfunctioning, the motor can be controlled to stop in time, thereby improving the safety of the motor. When the first current sampling unit and the second current sampling unit are working normally, an accurate target current value can be calculated, thereby improving the accuracy of motor control.

[0186] To sum up, according to the motor power calculation method of the embodiment of the present disclosure, the bus voltage sampling value, the phase voltage sampling value of any phase, the bus current peak value and the bus current effective value of the motor are obtained, the bus voltage sampling value and the phase voltage sampling value are calibrated to obtain a target voltage value, the bus current peak value and the bus current effective value are calibrated to obtain a target current value, and the input power of the motor is determined according to the target voltage value and the target current value. Thus, the two voltage sampling units and the two current sampling units can be calibrated with each other to improve the sampling accuracy, and the risk of sampling abnormality caused by circuit damage can be reduced. Moreover, the second current sampling unit samples the bus current effective value, which is closer to the actual bus current consumption, and then the control unit calibrates the bus voltage sampling value and the phase voltage sampling value and the bus current peak value and the bus current effective value to obtain accurate voltage and current values, so that an accurate power value can be obtained.

[0187] It is to be appreciated that the above description and the examples that follow are intended to be illustrative only and that changes can be made to the description and examples without departing from the spirit and scope of the disclosure. Note also that the use of particular brand names in the description is solely for illustration and should not be construed as an endorsement of such brands.

[0188] It should be understood that aspects of the present disclosure can be implemented in hardware, software, firmware or a combination thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, and in another embodiment, any of the following techniques, which are well known in the art, can be used to implement the various techniques and procedures: discrete logic circuitry having logic gates for implementing logic functions upon an application of data signals; application specific integrated circuits having appropriate combinational logic gates; programmable gate arrays (PGA), field programmable gate arrays (FPGA), and other implementations known to those with skill in the art.

[0189] In the description of the present disclosure, reference has been made to descriptive terms such as "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" meant to

[0190] In addition, the terms "first", "second", and the like used in the embodiments of the present disclosure are only used for descriptive purposes, and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated in the embodiments. Therefore, the features defined with the terms "first", "second", and the like in the embodiments of the present disclosure can explicitly or implicitly indicate that at least one of the features is included in the embodiments. In the description of the present disclosure, the meaning of the word "plurality" is at least two or two or more, such as two, three, four, etc., unless otherwise specifically limited in the embodiments.

[0191] In the present disclosure, unless otherwise specifically defined or limited in the embodiments, the terms "mounting", "connecting", "connecting" and "fixing" and the like appearing in the embodiments should be understood broadly, for example, the connection can be fixed connection, or detachable connection, or integral, which can be understood, or mechanical connection, electrical connection, etc. Of course, it can also be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements, or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific implementation.

[0192] Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limiting the present disclosure, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A motor power calculation circuit, comprising: The bus voltage sampling unit is suitable for sampling the bus voltage of the motor to obtain the bus voltage sampling value; A phase voltage sampling unit is adapted to sample the phase voltage of any phase of the motor to obtain a phase voltage sample value; The first current sampling unit is adapted to sample the peak value of the bus current of the motor to obtain the peak value of the bus current; The second current sampling unit is adapted to sample the effective value of the bus current to obtain the effective value of the bus current; A control unit is configured to calibrate the bus voltage sample value and the phase voltage sample value to obtain a target voltage value, and to calibrate the peak value of the bus current and the effective value of the bus current to obtain a target current value, and to determine the input power of the motor based on the target voltage value and the target current value.

2. The motor power calculation circuit according to claim 1, wherein, The second current sampling unit includes: A current-sensing resistor, which is connected in series with the DC negative bus; A first operational amplifier module is connected to the current sensing resistor and is configured to amplify the voltage across the current sensing resistor to obtain a first voltage signal. A first filtering module, the input of which is connected to the output of the first operational amplifier module, is configured to filter the first voltage signal to obtain a second voltage signal. The second filtering module has its input terminal connected to the output terminal of the first filtering module, and its output terminal connected to the first input terminal of the control unit. The second filtering module is configured to filter the second voltage signal to obtain the effective value of the bus current.

3. The motor power calculation circuit according to claim 2, wherein, The first current sampling unit includes: The second operational amplifier module is connected to the current sensing resistor, and the first operational amplifier module is configured to amplify the voltage across the current sensing resistor to obtain a third voltage signal. The third filtering module has its input terminal connected to the output terminal of the second operational amplifier module and its output terminal connected to the second input terminal of the control unit. The third filtering module is configured to filter the third voltage signal to obtain the peak value of the bus current.

4. The motor power calculation circuit according to claim 3, wherein, The amplification factor of the second operational amplifier module is less than that of the first operational amplifier module.

5. The motor power calculation circuit according to claim 2, wherein, One end of the current sensing resistor is grounded, and the other end of the current sensing resistor is adapted to be connected to the DC negative bus.

6. The motor power calculation circuit according to claim 2, wherein, One end of the current sensing resistor is adapted to connect one end of the bus capacitor and the DC negative bus, and the other end of the current sensing resistor is adapted to connect to the negative terminal of the DC power supply. The bus capacitor filters the DC power supply to generate the bus voltage.

7. The motor power calculation circuit according to claim 6, wherein, The input terminal of the bus voltage sampling unit is adapted to be connected to the positive terminal of the DC power supply.

8. The motor power calculation circuit according to any one of claims 1-7, wherein, The bus voltage sampling unit and the phase voltage sampling unit each include: Multiple voltage divider resistors connected in series, wherein the first terminal of the multiple voltage divider resistors connected in series is a voltage input terminal, the second terminal of the multiple voltage divider resistors connected in series is grounded, and the multiple voltage divider resistors connected in series have a first node, the first node being adapted to output the voltage-divided input voltage; The fourth filtering module has its input terminal connected to the first node and its output terminal being a voltage output terminal. The fourth filtering module is configured to filter the input voltage after voltage division to output a sampled voltage value.

9. The motor power calculation circuit according to any one of claims 1-7, wherein, The control unit is further configured to filter the bus voltage sample value and the phase voltage sample value respectively to obtain the phase voltage value and the bus voltage value, and to determine the average value of the phase voltage value and the bus voltage value as the target voltage value if the absolute value of the difference between the phase voltage value and the bus voltage value is less than a first preset difference.

10. The motor power calculation circuit according to claim 9, wherein, The control unit is also configured to stop the motor if the absolute value of the difference between the phase voltage value and the bus voltage value is greater than or equal to a first preset difference.

11. The motor power calculation circuit according to claim 1, wherein, The control unit is further configured to filter the peak value of the bus current to obtain a bus current value. If the absolute value of the difference between the bus current value and the effective value of the bus current is less than a second preset difference, a first current value is determined based on a target fitting value and the bus current value. The effective value of the bus current is then filtered to obtain a second current value. The target current value is determined based on the difference between the first current value and the second current value. The target fitting value is obtained by looking up the bus voltage sample value and the phase voltage sample value from a pre-established motor parameter table.

12. The motor power calculation circuit according to claim 11, wherein, The control unit is also configured to, If the absolute value of the difference between the target fitted value and the bus current value is less than or equal to a third preset difference, the target fitted value is determined to be the first current value. or If the absolute value of the difference between the target fitted value and the bus current value is greater than the third preset difference, the bus current value is determined to be the first current value.

13. The motor power calculation circuit according to claim 11, wherein, The control unit is also configured to, If the absolute value of the difference between the first current value and the second current value is greater than a fourth preset difference, the second current value is determined to be the target current value; or If the absolute value of the difference between the first current value and the second current value is less than or equal to the fourth preset difference, the first current value is determined to be the target current value.

14. The motor power calculation circuit according to claim 11, wherein, The control unit is further configured to stop the motor if the absolute value of the difference between the bus current value and the effective value of the bus current is greater than or equal to the second preset difference.

15. An electric motor, comprising a motor power calculation circuit according to any one of claims 1-14.

16. A compressor comprising a motor power calculation circuit according to any one of claims 1-14 or a motor according to claim 15.

17. A vehicle comprising the compressor according to claim 16.

18. A method for calculating motor power, applied to a motor power calculation circuit, the motor power calculation circuit including a bus voltage sampling unit, a phase voltage sampling unit, a first current sampling unit, and a second current sampling unit, wherein the bus voltage sampling unit is adapted to sample the bus voltage of the motor to obtain a bus voltage sample value, the phase voltage sampling unit is adapted to sample the phase voltage of any phase of the motor to obtain a phase voltage sample value, the first current sampling unit is adapted to sample the peak value of the bus current of the motor to obtain a bus current peak value, and the second current sampling unit is adapted to sample the effective value of the bus current to obtain an effective value of the bus current, the method comprising: The bus voltage sample value and the phase voltage sample value are calibrated to obtain the target voltage value, and the peak value of the bus current and the effective value of the bus current are calibrated to obtain the target current value; The input power of the motor is determined based on the target voltage value and the target current value.

19. The method according to claim 18, wherein, The bus voltage sample value and the phase voltage sample value are calibrated to obtain the target voltage value, including: The bus voltage sample value and the phase voltage sample value are filtered respectively to obtain the phase voltage value and the bus voltage value; If the absolute value of the difference between the phase voltage value and the bus voltage value is less than a first preset difference, the average value of the phase voltage value and the bus voltage value is determined as the target voltage value.

20. The method according to claim 19, wherein, If the absolute value of the difference between the phase voltage value and the bus voltage value is greater than or equal to a first preset difference, the method further includes: The motor is stopped.

21. The method according to claim 18, wherein, The peak value and effective value of the bus current are calibrated to obtain the target current value, including: The peak value of the bus current is filtered to obtain the bus current value; If the absolute value of the difference between the bus current value and the effective value of the bus current is less than a second preset difference, a first current value is determined based on the target fitting value and the bus current value, and the effective value of the bus current is filtered to obtain a second current value. The target fitting value is obtained by looking up the bus voltage sampling value and the phase voltage sampling value from a pre-established motor parameter table. The target current value is determined based on the difference between the first current value and the second current value.

22. The method according to claim 21, wherein, Determining the first current value based on the target fitted value and the bus current value includes: If the absolute value of the difference between the target fitted value and the bus current value is less than or equal to a third preset difference, the target fitted value is determined to be the first current value; or If the absolute value of the difference between the target fitted value and the bus current value is greater than the third preset difference, the bus current value is determined to be the first current value.

23. The method according to claim 21, wherein, Determining the target current value based on the difference between the first current value and the second current value includes: If the absolute value of the difference between the first current value and the second current value is greater than a fourth preset difference, the second current value is determined to be the target current value; or If the absolute value of the difference between the first current value and the second current value is less than or equal to the fourth preset difference, the first current value is determined to be the target current value.

24. The method according to claim 21, wherein, If the absolute value of the difference between the bus current value and the effective value of the bus current is greater than or equal to the second preset difference, the method further includes: The motor is stopped.

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