Motor power calculation circuits, methods, motors, compressors, and vehicles

Abstract

This invention discloses a motor power calculation circuit, method, motor, compressor, and vehicle. The motor power calculation circuit includes: a bus voltage sampling unit adapted to sample the motor's bus voltage to obtain a sampled bus voltage value; a phase voltage sampling unit adapted to sample the phase voltage of any phase of the motor to obtain a sampled phase voltage value; a first current sampling unit adapted to sample the peak value of the motor's bus current to obtain a peak bus current value; a second current sampling unit adapted to sample the effective value of the bus current to obtain an effective bus current value; and a control unit configured to calibrate the sampled bus voltage values ​​and phase voltage values ​​to obtain a target voltage value, calibrate the peak bus current value and the effective bus current value to obtain a target current value, and determine the motor's input power based on the target voltage value and target current value. This motor power calculation circuit can obtain accurate input power.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a motor power calculation circuit, method, motor, compressor, and vehicle. Background Technology

[0002] In related technologies, to accurately calculate the remaining battery range, the power values ​​fed back by each component require greater precision (current accuracy within ±0.1A). In motor control, the effective value of the bus voltage and the peak value of the bus current are typically sampled, and then the real-time power value is calculated. However, neither the voltage nor the current sampling is calibrated. In particular, the peak bus current sampling is affected by circuit parasitic parameters and control algorithms, resulting in unstable sampled values ​​and making it difficult to calculate accurate current. This leads to a significant discrepancy between the calculated and actual power. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, the first objective of this invention is to propose a motor power calculation circuit in which two voltage sampling units and two current sampling units can be mutually calibrated to improve sampling accuracy. The control unit performs software calibration on the sampled values ​​to obtain more accurate target current and target voltage values, thereby obtaining precise input power.

[0004] The second objective of this invention is to provide an electric motor.

[0005] The third objective of this invention is to provide a compressor.

[0006] The fourth objective of this invention is to provide a vehicle.

[0007] The fifth objective of this invention is to provide a method for calculating motor power.

[0008] To achieve the above objectives, a motor power calculation circuit is provided according to a first aspect embodiment of the present invention, comprising: a bus voltage sampling unit adapted to sample the bus voltage of the motor to obtain a bus voltage sample value; a phase voltage sampling unit adapted to sample the phase voltage of any phase of the motor to obtain a phase voltage sample value; a first current sampling unit adapted to sample the peak value of the bus current of the motor to obtain a peak value of the bus current; a second current sampling unit adapted to sample the effective value of the bus current to obtain an effective value of the bus current; and a control unit 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.

[0009] According to an embodiment of the present invention, a motor power calculation circuit 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. 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 motor's bus current to obtain a peak bus current; the second current sampling unit is adapted to sample the effective value of the bus current to obtain an effective bus current 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 to calibrate the peak bus current and the effective bus current value 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. Therefore, the two voltage sampling units and the two current sampling units can be mutually calibrated to improve sampling accuracy and reduce the risk of sampling abnormalities due to circuit damage. The second current sampling unit samples the effective value of the bus current, which is closer to the actual current consumed by the bus. Then, the control unit calibrates the bus voltage sampling value, the phase voltage sampling value, the peak value of the bus current, and the effective value of the bus current to obtain accurate voltage and current values, thereby obtaining accurate power values.

[0010] According to one embodiment of the present invention, the second current sampling unit includes: a current-sensing resistor connected in series with the DC negative bus; a first operational amplifier module connected to the current-sensing resistor, configured to amplify the voltage across the current-sensing resistor to obtain a first voltage signal; a first filtering module, the input terminal of which is connected to the output terminal of the first operational amplifier module, configured to filter the first voltage signal to obtain a second voltage signal; and a second filtering module, the input terminal of which is connected to the output terminal of the first filtering module, the output terminal of which is connected to a first input terminal of the control unit, configured to filter the second voltage signal to obtain the effective value of the bus current.

[0011] According to one embodiment of the present invention, the first current sampling unit includes: a second operational amplifier module connected to a current sensing resistor, the first operational amplifier module being configured to amplify the voltage across the current sensing resistor to obtain a third voltage signal; and a third filtering module, the input terminal of the third filtering module being connected to the output terminal of the second operational amplifier module, the output terminal of the third filtering module being connected to the second input terminal of the control unit, the third filtering module being configured to filter the third voltage signal to obtain the peak value of the bus current.

[0012] According to one embodiment of the present invention, the amplification factor of the second operational amplifier module is less than that of the first operational amplifier module.

[0013] According to one embodiment of the present invention, 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.

[0014] According to one embodiment of the present invention, 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, wherein the bus capacitor filters the DC power supply to generate the bus voltage.

[0015] According to one embodiment of the present invention, the input terminal of the bus voltage sampling unit is adapted to be connected to the positive terminal of a DC power supply.

[0016] According to one embodiment of the present invention, the bus voltage sampling unit and the phase voltage sampling unit respectively include: a plurality of series-connected voltage divider resistors, the first end of the plurality of series-connected voltage divider resistors being a voltage input terminal, the second end of the plurality of series-connected voltage divider resistors being grounded, the plurality of series-connected voltage divider resistors having a first node, the first node being adapted to output the voltage-divided input voltage; and a fourth filtering module, the input terminal of the fourth filtering module being connected to the first node, the output terminal of the fourth filtering module being a voltage output terminal, the fourth filtering module being configured to filter the voltage-divided input voltage to output a voltage sampling value.

[0017] According to one embodiment of the present invention, 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 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.

[0018] According to one embodiment of the present invention, the control unit is further configured to perform a shutdown control on the motor when 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.

[0019] According to one embodiment of the present invention, the control unit is further configured to filter the peak value of the bus current to obtain a bus current value, and 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, determine a first current value based on a target fitted value and the bus current value, filter the effective value of the bus current to obtain a second current value, and determine a target current value based on the difference between the first current value and the second current value, wherein the target fitted value is obtained by looking up the bus voltage sample value and the phase voltage sample value from a pre-established motor parameter table.

[0020] According to one embodiment of the present invention, the control unit is further configured to determine the target fitted value as a first current value when 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; or, to determine the bus current value as a first current value when the absolute value of the difference between the target fitted value and the bus current value is greater than the third preset difference.

[0021] According to one embodiment of the present invention, the control unit is further configured to determine the second current value as a 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; or to determine the first current value as a 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.

[0022] According to one embodiment of the present invention, the control unit is further configured to perform a shutdown control on the motor when 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 a second preset difference.

[0023] To achieve the above objectives, a motor is provided according to a second aspect of the present invention, including the motor power calculation circuit of any of the foregoing embodiments.

[0024] According to the present invention, by employing the above-described motor power calculation circuit, the two voltage sampling units and the two current sampling units can be mutually calibrated to improve sampling accuracy. The control unit performs software calibration on the sampled values ​​to obtain more accurate target current and target voltage values, thereby obtaining precise input power.

[0025] To achieve the above objectives, a compressor is provided according to a third aspect of the present invention, including the motor power calculation circuit of any of the foregoing embodiments or the foregoing motor.

[0026] According to the compressor of the present invention, by employing the above-described motor power calculation circuit or motor, the two voltage sampling units and the two current sampling units can be mutually calibrated to improve sampling accuracy. The control unit performs software calibration on the sampled values ​​to obtain more accurate target current and target voltage values, thereby obtaining precise input power.

[0027] To achieve the above objectives, a vehicle comprising the aforementioned compressor is provided according to a fourth aspect of the present invention.

[0028] According to the vehicle of the present invention, by employing the above-described compressor, the two voltage sampling units and the two current sampling units can be mutually calibrated to improve sampling accuracy. The control unit performs software calibration on the sampled values ​​to obtain more accurate target current and target voltage values, thereby obtaining precise input power.

[0029] To achieve the above objectives, a motor power calculation method is proposed according to a fifth aspect embodiment of the present invention. This method is applied to a motor power calculation circuit, which includes 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 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 peak bus current. The second current sampling unit is adapted to sample the effective value of the bus current to obtain an effective bus current value. The method includes: calibrating the bus voltage sample value and the phase voltage sample value to obtain a target voltage value; calibrating the peak bus current and the effective bus current value to obtain a target current value; and determining the input power of the motor based on the target voltage value and the target current value.

[0030] According to the motor power calculation method of this invention, the bus voltage sampling value, the phase voltage sampling value of any phase, the peak value of the bus current, and the effective value of the bus current are obtained. The bus voltage sampling value and the phase voltage sampling value are calibrated to obtain a target voltage value, and the peak value of the bus current and the effective value of the bus current are calibrated to obtain a target current value. The input power of the motor is determined based on the target voltage value and the target current value. Thus, the two voltage sampling units and the two current sampling units can mutually calibrate, improving sampling accuracy and reducing the risk of sampling abnormalities due to circuit damage. Furthermore, the second current sampling unit samples the effective value of the bus current, which is closer to the actual current consumed by the bus. Then, the control unit calibrates the bus voltage sampling value, the phase voltage sampling value, the peak value of the bus current, and the effective value of the bus current to obtain accurate voltage and current values, thereby obtaining a precise power value.

[0031] According to one embodiment of the present invention, calibrating the bus voltage sample value and the phase voltage sample value to obtain a target voltage value includes: filtering the bus voltage sample value and the phase voltage sample value respectively to obtain the phase voltage value and the bus voltage value; and determining the average value of the phase voltage value and the bus voltage value as the target voltage value when the absolute value of the difference between the phase voltage value and the bus voltage value is less than a first preset difference.

[0032] According to one embodiment of the present invention, when 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: controlling the motor to stop.

[0033] According to one embodiment of the present invention, calibrating the peak value and effective value of the bus current to obtain a target current value includes: filtering 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, determining a first current value based on a target fitted value and the bus current value, and filtering the effective value of the bus current to obtain a second current value, wherein the target fitted value is obtained by looking up the bus voltage sample value and the phase voltage sample value from a pre-established motor parameter table; and determining the target current value based on the difference between the first current value and the second current value.

[0034] According to one embodiment of the present invention, determining a first current value based on a target fitted value and a bus current value includes: determining the target fitted value as the first current value when 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; or determining the bus current value as the first current value when the absolute value of the difference between the target fitted value and the bus current value is greater than a third preset difference.

[0035] According to one embodiment of the present invention, determining a target current value based on the difference between a first current value and a second current value includes: determining the second current value as the target current value when the absolute value of the difference between the first current value and the second current value is greater than a fourth preset difference; or, determining the first current value as the target current value when the absolute value of the difference between the first current value and the second current value is less than or equal to a fourth preset difference.

[0036] According to one embodiment of the present invention, when 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 a second preset difference, the method further includes: controlling the motor to stop.

[0037] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0038] Figure 1 This is a circuit diagram of a bus voltage sampling unit in related technologies;

[0039] Figure 2 This is a circuit diagram for 3-channel current sampling in related technologies;

[0040] Figure 3 This is a circuit diagram of a bus current sampling unit in related technologies;

[0041] Figure 4 This is a schematic diagram of a motor power calculation circuit according to an embodiment of the present invention;

[0042] Figure 5This is a circuit diagram of a second current sampling unit according to an embodiment of the present invention;

[0043] Figure 6 This is a waveform diagram of the second voltage signal according to an embodiment of the present invention;

[0044] Figure 7 This is a waveform diagram of the effective value of the bus current according to an embodiment of the present invention;

[0045] Figure 8 This is a waveform diagram of the peak bus current according to an embodiment of the present invention;

[0046] Figure 9 This is a circuit diagram of a power supply filtering circuit according to an embodiment of the present invention;

[0047] Figure 10 This is a circuit diagram of a first current sampling unit according to an embodiment of the present invention;

[0048] Figure 11 This is a circuit diagram of a second current sampling unit according to another embodiment of the present invention;

[0049] Figure 12 This is a circuit diagram of a phase voltage sampling unit according to an embodiment of the present invention;

[0050] Figure 13 This is a schematic diagram of a voltage sampling calibration process according to an embodiment of the present invention;

[0051] Figure 14 This is a schematic diagram of the current sampling calibration process according to an embodiment of the present invention;

[0052] Figure 15 This is a circuit diagram of a 4-channel current sampling according to an embodiment of the present invention;

[0053] Figure 16 This is a schematic diagram of a motor system according to an embodiment of the present invention;

[0054] Figure 17 This is a schematic diagram of a compressor system according to an embodiment of the present invention;

[0055] Figure 18 This is a system schematic diagram of a compressor according to another embodiment of the present invention;

[0056] Figure 19 This is a schematic diagram of a vehicle system according to an embodiment of the present invention;

[0057] Figure 20 This is a schematic flowchart of a motor power calculation method according to an embodiment of the present invention. Detailed Implementation

[0058] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0059] It should be noted that this application is based on the inventor's understanding and research into the following issues:

[0060] In related technologies, the voltage sampling of a motor is usually set to only one, such as... Figure 1 The bus voltage sampling unit 10 shown typically includes a motor current sampling unit such as... Figure 2 The three-channel current sampling shown involves setting a first sampling resistor Rs1 in the lower arm of phase U and phase V, and a second sampling resistor Rs2 in the DC negative bus, to sample the peak values ​​of the phase current of phase U, phase current of phase V, and bus current, and then sampling them using methods such as... Figure 3 The bus current sampling unit shown obtains the peak value of the bus current based on the voltage across the second sampling resistor, and then calculates the input power of the motor based on the peak value of the bus current and the sampled value of the bus voltage.

[0061] However, the above-mentioned motor voltage sampling scheme and motor current sampling scheme have the following drawbacks:

[0062] 1. Because there is only one sampling unit for both bus voltage and bus current, when the sampling unit malfunctions, 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 make the motor prone to failure.

[0063] 2. The peak value of the bus current is affected by circuit parasitic parameters and control algorithm, and the sampled value is unstable.

[0064] 3. The peak value of the bus current needs to be converted into an effective value, which increases the error and thus reduces the accuracy.

[0065] Based on this, embodiments of the present invention provide a motor power calculation circuit, method, motor, compressor, and vehicle. Two voltage sampling units and two current sampling units can be mutually calibrated to improve sampling accuracy. The control unit performs software calibration on the sampled values ​​to obtain more accurate target current and target voltage values, thereby obtaining precise input power.

[0066] The following description, with reference to the accompanying drawings, describes an embodiment of the present invention, including a motor power calculation circuit, a method, a motor, a compressor, and a vehicle.

[0067] Figure 4 This is a schematic diagram of a motor power calculation circuit according to an embodiment of the present invention, as shown below. Figure 4 As shown, the motor power calculation circuit includes: 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.

[0068] 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 the peak value of the bus current; the second current sampling unit 40 is adapted to sample the effective value of the bus current to obtain the effective value of the bus current; 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, 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.

[0069] Specifically, when the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are functioning correctly, the difference between the bus voltage sampling value and the phase voltage sampling value is small. Therefore, the bus voltage sampling unit 10 and the phase voltage sampling unit 20 can be mutually calibrated based on the bus voltage sampling value and the phase voltage sampling value. Similarly, when the first current sampling unit 30 and the second current sampling unit 40 are functioning correctly, the difference between the peak value of the bus current and the effective value of the bus current is also relatively small. Therefore, the first current sampling unit 30 and the second current sampling unit 40 can be mutually calibrated based on the peak value of the bus current and the effective value of the bus current. The second current sampling unit 40 samples the effective value of the bus current, which is closer to the actual current consumed by the bus. Then, the control unit 50 calibrates the bus voltage sampling value and the phase voltage sampling value, as well as the peak value of the bus current and the effective value of the bus current, to obtain accurate target voltage and target current values. The product of the target voltage and target current values ​​is then calculated to obtain the input power.

[0070] In the above embodiment, the two voltage sampling units and the two current sampling units can be calibrated with each other, which can not only improve the sampling accuracy, but also reduce the risk of sampling abnormalities due to circuit damage. Furthermore, the second current sampling unit samples the effective value of the bus current, which is closer to the actual current consumed by the bus with a smaller error. Then, the control unit performs software calibration to obtain accurate voltage and current values, thereby obtaining accurate power values.

[0071] In some embodiments, such as Figure 5As shown, the second current sampling unit 40 includes: a current sensing resistor Rs, a first operational amplifier module 41, a first filter module 42, and a second filter module 43. The current sensing resistor Rs is connected in series with the DC negative bus HVDC-. The first operational amplifier module 41 is connected to the current sensing resistor Rs and is configured to amplify the voltage across the current sensing resistor Rs to obtain a first voltage signal. The input terminal of the first filter module 42 is connected to the output terminal 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 terminal of the second filter module 43 is connected to the output terminal of the first filter module 42, and the output terminal of the second filter module 43 is connected to the first input terminal I_ADC1 of the control unit 50. The second filter module 43 is configured to filter the second voltage signal to obtain the effective value of the bus current.

[0072] Specifically, the current-sensing 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-sensing resistor Rs to obtain a first voltage signal. This first voltage signal is then input to the first filter module 42, which filters the first voltage signal into a stable second voltage signal. However, glitches still exist in the second voltage signal (such as...). Figure 6 As shown), therefore, the second filtering module 43 filters out the glitches in the second voltage signal to obtain the signal as shown. Figure 7 The accurate RMS value of the bus current is shown.

[0073] It should be noted that, Figure 6 The lower middle curve is a magnified version of the white area in the upper curve; Figure 7 The sine curve in the image represents the phase current, the straight line curve represents the effective value of the bus current, and the two curves below are magnified versions of the white area in the curve above.

[0074] In one alternative implementation, such as Figure 5As shown, the first operational amplifier module 41 is a differential amplifier circuit. 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. One end of the first resistor R1 is connected to the current sensing resistor Rs, and the other end of the first resistor R1 is connected to 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, and the other end of the second resistor R2 is connected to 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 to the second node J2, and the other end of the third resistor R3 is connected to 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, and the other end of the fifth resistor R5 is connected to the third node J3. One end of the sixth resistor R6 is connected to the other end of the fifth resistor R5, and the other end of the sixth resistor R6 is grounded.

[0075] The first filter module 42 and the second filter module 43 are both low-pass filter circuits, and the capacitance value 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. The seventh resistor R7 is connected to the output terminal of the first operational amplifier OP1, and 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. 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. 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. The other end of the fourth capacitor C4 is grounded. The fifth capacitor C5 is connected in parallel with the fourth capacitor C4.

[0076] It should be noted that the effective value and peak value of the bus current are voltage signals. After receiving the effective value and peak value of the bus current, the control unit 50 can calculate the current value corresponding to the effective value of the bus current and the current value corresponding to the peak value of the bus current based on the effective value, the peak value of the bus current and the resistance value of the current sensing resistor Rs.

[0077] In the above embodiment, after the first operational amplifier module amplifies the voltage across the current sensing resistor, the first voltage signal is filtered by a two-stage filter circuit to obtain a more accurate effective value of the bus current.

[0078] In some embodiments, such as Figure 3As shown, the first current sampling unit 30 includes a second operational amplifier module 31 and a third filter module 32. The second operational amplifier module 31 is connected to the current sensing resistor Rs. The first operational amplifier module 41 is configured to amplify the voltage across the current sensing 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, and the output terminal of the third filter module 32 is connected to the second input terminal I_ADC2 of the control unit 50. The third filter module 32 is configured to filter the third voltage signal to obtain the peak value of the bus current.

[0079] Specifically, the first current sampling unit 30 and the second current sampling unit 40 use the same current sensing resistor Rs, ensuring that the input signals of the two current sampling units are the same. This avoids the impact on motor control caused by different current samples obtained from different signal sources. Since the first current sampling unit 30 also samples the peak value of the bus current, its circuit structure can be the same as that of the bus current sampling unit in related technologies. The second operational amplifier module 31 amplifies the voltage across the current sensing resistor Rs to obtain a third voltage signal, and the third filter module 32 filters the third voltage signal, outputting as shown. Figure 8 The peak value of the bus current is shown.

[0080] from Figure 8 As can be seen, the sampling time of the first current sampling unit 30 will be deviated, and it is not always at the peak time. Moreover, the amplitude of the peak value of the bus current obtained by each sampling will change. Therefore, there is a large error in the peak value of the bus current. So the second current sampling unit 40 is needed to sample the effective value of the bus current.

[0081] It should be noted that, Figure 8 The lower middle curve is a magnified version of the white area in the upper curve.

[0082] In one alternative implementation, such as Figure 3As shown, the second operational amplifier module 31 is a differential amplifier circuit. 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. One end of the ninth resistor R9 is connected to the current sensing resistor Rs, and the other end of the ninth resistor R9 is connected to 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, and the other end of the tenth resistor R10 is connected to 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 to the fourth node J4, and the other end of the eleventh resistor R11 is connected to 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, and the other end of the twelfth resistor R12 is connected to the fifth node J5. One end of the thirteenth resistor R13 is connected to the other end of the twelfth resistor R12, and the other end of the thirteenth resistor R13 is grounded.

[0083] The third filter module 32 is also a low-pass filter circuit. The third filter module 32 includes a fourteenth resistor R14 and a sixth capacitor C6. One end of the fourteenth resistor R14 is connected to the output terminal O of the second operational amplifier OP2. The other end of the fourteenth resistor R14 is connected to the second input terminal I_ADC2 of the control unit 50 and one end of the sixth capacitor C6. The other end of the sixth capacitor C6 is grounded.

[0084] In some embodiments, the amplification factor of the second operational amplifier module 31 is less than the amplification factor of the first operational amplifier module 41.

[0085] It is understandable that the amplification factor of the second operational amplifier module 31 is less than that of the first operational amplifier module 41, meaning the amplification factor of the second current sampling unit 40 is greater than that of the first current sampling unit 30. A higher amplification factor corresponds to a smaller full-load current and higher 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. The maximum digital value sampled by the control unit is 4096. Therefore, when the full-load current is 108.9A, a single digital value of 1 corresponds to 108.9 / 4096 = 0.0265A; when the full-load current is 21.4A, a single digital value of 1 corresponds to 21.4 / 4096 = 0.0052A. Thus, a higher amplification factor results in higher sampling accuracy.

[0086] It should be noted that because the amplification factor of the first operational amplifier module 41 is greater than that of the second operational amplifier module 31, the upper limit of sampling of the first operational amplifier module 41 is less than that of the second operational amplifier module 31. Therefore, the upper limit of sampling of the first operational amplifier module 41 is 20-30A, and the upper limit of sampling of the second operational amplifier module 31 is greater than 100A.

[0087] In some embodiments, such as Figure 2 As shown, one end of the current sensing resistor Rs is grounded, and the other end of the current sensing resistor Rs is suitable for connecting to the DC negative bus HVDC-.

[0088] In other words, the current sensing resistor Rs can be set after the bus capacitor C, and the three-phase lower bridge arms of the motor inverter are connected and grounded. One end of the current sensing resistor Rs is connected to the three-phase lower bridge arms and grounded, and the other end of the current sensing resistor Rs is suitable for connecting to the DC negative bus HVDC-.

[0089] In some embodiments, such as Figure 9 As shown, one end of the current sensing resistor Rs is adapted to connect one end of the bus capacitor C and the DC negative bus HVDC-, and the other end of the current sensing resistor Rs is adapted to connect to the negative terminal of the DC power supply. The bus capacitor C filters the DC power supply to generate the bus voltage.

[0090] Specifically, when the current sensing resistor Rs is set after the bus capacitor C, the bus capacitor C will interfere with the current sampling during charging and discharging, thereby reducing the sampling accuracy. Therefore, the current sensing resistor Rs can also be set before the bus capacitor C.

[0091] by Figure 9 As shown in the example, the power supply filtering circuit of the motor adopts a differential mode filtering circuit. The power supply filtering circuit includes a first inductor L1, a second inductor L2, and a bus capacitor C. One end of the first inductor L1 is suitable for connecting to the positive terminal HV+ of the high-voltage power supply, and the other end of the first inductor L1 is the positive terminal of the DC power supply, which is also the DC positive bus HVDC+. One end of the second inductor L2 is suitable for connecting to the negative terminal HV- of the high-voltage power supply, and the other end of the second inductor L2 is the negative terminal of the DC power supply. The other end of the current sensing resistor Rs is connected to the other end of the second inductor L2. One end of the current sensing resistor Rs is connected to one end of the bus capacitor C, and the other end of the bus capacitor C is connected to the other end of the first inductor L1. One end of the bus capacitor C is the DC negative bus HVDC-.

[0092] Furthermore, when the current sensing resistor Rs is set before the bus capacitor C, such as Figure 10 and Figure 11As shown, one end of the first resistor R1 of the first operational amplifier module 41 is connected to the other end of the current sensing resistor Rs, one end of the second resistor R2 of the first operational amplifier module 41 is connected to one end of the current sensing 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 sensing 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 sensing resistor Rs.

[0093] In the above embodiments, setting the bus current sampling point in front of the bus capacitor can avoid interference from the charging and discharging of the bus capacitor on the current sampling, thereby further improving the accuracy of the current sampling.

[0094] In some embodiments, such as Figure 1 and Figure 12 As shown, the bus voltage sampling unit 10 and the phase voltage sampling unit 20 respectively include: a plurality of series-connected voltage divider resistors R and a fourth filter module 11, wherein the first end of the plurality of series-connected voltage divider resistors R is a voltage input terminal, the second end of the plurality of series-connected voltage divider resistors R is grounded, the plurality of series-connected voltage divider resistors R have a first node J1, the first node J1 is adapted to output the input voltage after voltage division; the input terminal of the fourth filter module 11 is connected to the first node J1, the output terminal of the fourth filter module 11 is a voltage output terminal, and the fourth filter module 11 is configured to filter the input voltage after voltage division to output a voltage sampling value.

[0095] Specifically, the circuit structures of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are the same, so the voltage division 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.

[0096] The bus voltage sampling unit 10 can employ a sampling circuit from related technologies to... Figure 1 As shown in the example, the voltage input terminal of the bus voltage sampling unit 10 is suitable for connecting to the DC positive bus HVDC+. There are 8 voltage divider resistors R. The first node J1 is the connection point of the sixth voltage divider resistor R and the seventh voltage divider resistor R. The fourth filter module 11 of the bus voltage sampling unit 10 filters the voltage divider voltage of the DC positive bus HVDC+ to obtain the bus voltage sampling value. The fourth filter module 11 of the bus voltage sampling unit 10 is connected to the third input terminal VDC_AD3 of the control unit 50 to provide the bus voltage sampling value to the control unit 50.

[0097] Taking the sampling of phase voltage of phase W by phase voltage sampling unit 20 as an example, such as Figure 12As shown, the voltage input terminal of the phase voltage sampling unit 20 is adapted to connect to the midpoint of the W-phase bridge arm of the inverter. Because the phase voltage sampling unit 20 has the same circuit structure as the bus voltage sampling unit 10, the phase voltage sampling unit 20 also includes 8 voltage divider resistors R, and the first node J1 is the connection point of the sixth voltage divider resistor R and the seventh voltage divider resistor R. The fourth filter module 11 of the phase voltage sampling unit 20 filters the voltage divider voltage of the W-phase phase voltage to obtain the phase voltage sampling value. The fourth filter module 11 of the phase voltage sampling unit 20 is connected to the fourth input terminal VDC_AD4 of the control unit 50 to provide the phase voltage sampling value to the control unit 50.

[0098] It should be noted that the bus voltage sample value and the phase voltage sample value are voltage values ​​after voltage division. The control unit 50 can calculate the bus voltage corresponding to the bus voltage sample value and the phase voltage corresponding to the phase voltage sample value based on the voltage dividing resistor R, the bus voltage sample value and the phase voltage sample value.

[0099] In one alternative implementation, such as Figure 1 and Figure 12 As shown, 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 terminal 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.

[0100] In some embodiments, the input terminal of the bus voltage sampling unit 10 is adapted to be connected to the positive terminal of a DC power supply.

[0101] Specifically, when the bus voltage sampling point is set after the bus capacitor C, that is, the bus voltage sampling unit 10 is suitable for sampling the DC positive bus HVDC+, it can avoid interference from the power input terminal to the bus voltage sampling. However, the inverter will interfere with the bus voltage sampling when it is working. Therefore, the bus voltage sampling point can also be set before the bus capacitor C, closer to the input terminal, so as to avoid interference when the inverter is working.

[0102] Furthermore, with Figure 9 As shown in the example, the input terminal of the bus voltage sampling unit 10 is adapted to be connected to the positive terminal HV+ of the high voltage power supply.

[0103] In the above embodiments, the bus voltage sampling point can also be set in front of the bus capacitor to avoid interference from the inverter to the bus voltage sampling, thereby improving the accuracy of the bus voltage sampling.

[0104] In some embodiments, such as Figure 13As shown, the control unit 50 is also 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 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.

[0105] Specifically, the control unit 50 performs software low-pass filtering on the bus voltage sample value and the phase voltage sample 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 a first preset difference, it indicates that the difference between the phase voltage sample value and the bus voltage sample value is relatively small. In this case, the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are working normally, and the sampled 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 used as the target voltage value.

[0106] In some embodiments, such as Figure 13 As shown, the control unit 50 is also configured to stop the motor when 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.

[0107] In other words, 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. In this case, the bus voltage sampling unit 10 and / or the phase voltage sampling unit 20 are faulty and cannot control the motor based on the sampling values ​​of the bus voltage sampling unit 10 and the phase voltage sampling unit 20. Therefore, the motor is stopped.

[0108] 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 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 stopped 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, the accurate target voltage value can be calculated, thereby improving the accuracy of motor control.

[0109] In some embodiments, such as Figure 14As shown, the control unit 50 is also configured to filter the peak value of the bus current 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 fitted value and the bus current value. The effective value of the bus current is then filtered to obtain a second current value. A target current value is determined based on the difference between the first current value and the second current value. The target fitted value is obtained by looking up the bus voltage sample value and the phase voltage sample value from a pre-established motor parameter table.

[0110] Specifically, the control unit 50 performs software low-pass filtering on the peak value of the bus current 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, 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 effective value of the bus current. The control unit 50 looks up the target fitted values ​​corresponding to the bus voltage sample value and the phase voltage sample value from the pre-established motor parameter table, determines the first current value based on the target fitted value and the bus current value, performs software low-pass filtering on the effective value of the bus current to obtain the second current value, and then determines the target current value based on the first current value and the second current value.

[0111] It should be noted that the pre-established motor parameter table is constructed based on the motor speed, bus voltage, phase voltage, phase current, peak bus current, effective bus current, and power under multiple operating conditions. Among them, the peak bus current, effective bus current, and power are calculated based on the relationship between bus voltage and bus current at different motor speeds.

[0112] In one alternative implementation, the motor phase current can be determined by means of... Figure 2 The sampling is obtained using the dual-resistance sampling scheme shown, or it can be obtained through methods such as... Figure 15 The sampling was obtained using the three resistors (Rs1, Rs2, Rs3) sampling scheme shown.

[0113] In some embodiments, such as Figure 14 As shown, the control unit 50 is further configured to determine the target fitted value as the first current value when 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; or, to determine the bus current value as the first current value when the absolute value of the difference between the target fitted value and the bus current value is greater than the third preset difference.

[0114] Specifically, if the absolute value of the difference between the target fitted value and the bus current value is less than or equal to the third preset difference, it indicates that the bus current value conforms to the relationship between bus voltage and bus current in the pre-established motor parameter table. Therefore, the target fitted value can be used as the first current value. If the absolute value of the difference between the target fitted value and the bus current value is greater than the third preset difference, it indicates that the bus current value does not conform to the relationship between bus voltage and bus current in the pre-established motor parameter table. In this case, the actual sampled current value is used as the standard, and the bus current value is set as the first current value.

[0115] In some embodiments, such as Figure 14 As shown, 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; or to 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 a fourth preset difference.

[0116] Understandably, if the absolute value of the difference between the first current value and the second current value is greater than the fourth preset difference (e.g., 1A), the effective value of the filtered bus current is more accurate, and therefore the second current value is used 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, the difference between the first current value and the second current value is small, and the first current value can be used as the target current value.

[0117] It should be noted that the smaller the fourth preset difference, the more accurate the target current value.

[0118] In some embodiments, such as Figure 14 As shown, the control unit 50 is also configured to stop the motor when 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 a second preset difference.

[0119] In other words, 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, it indicates that the difference between the peak value of the bus current and the effective value of the bus current is relatively large. In this case, the first current sampling unit 30 and / or the second current sampling unit 40 are faulty and cannot control the motor based on the sampling values ​​of the first current sampling unit 30 and the second current sampling unit 40. Therefore, the motor is stopped.

[0120] In the above embodiments, the absolute value of the difference between the peak value of the bus current and the effective value of the bus current can be used to determine whether the first current sampling unit and / or the second current sampling unit has malfunctioned. When the first current sampling unit and / or the second current sampling unit malfunctions, the motor can be stopped in time, thereby improving the safety of the motor. When the first current sampling unit and the second current sampling unit are working normally, the accurate target current value can be calculated, thereby improving the accuracy of motor control.

[0121] In summary, the motor power calculation circuit according to an embodiment of the present invention 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. 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 motor's bus current to obtain a peak bus current; the second current sampling unit is adapted to sample the effective value of the bus current to obtain an effective bus current 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, and to calibrate the peak bus current and the effective bus current value 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. Therefore, the two voltage sampling units and the two current sampling units can be mutually calibrated to improve sampling accuracy and reduce the risk of sampling abnormalities due to circuit damage. The second current sampling unit samples the effective value of the bus current, which is closer to the actual current consumed by the bus. Then, the control unit calibrates the bus voltage sampling value, the phase voltage sampling value, the peak value of the bus current, and the effective value of the bus current to obtain accurate voltage and current values, thereby obtaining accurate power values.

[0122] Corresponding to the above embodiments, embodiments of the present invention also provide a motor. For example... Figure 16 As shown, the motor 200 includes the motor power calculation circuit 100 of any of the foregoing embodiments.

[0123] According to the present invention, by employing the above-described motor power calculation circuit, the two voltage sampling units and the two current sampling units can be mutually calibrated to improve sampling accuracy. The control unit performs software calibration on the sampled values ​​to obtain more accurate target current and target voltage values, thereby obtaining precise input power.

[0124] Corresponding to the above embodiments, embodiments of the present invention also provide a compressor. For example... Figure 17 and Figure 18As shown, the compressor 300 includes the motor power calculation circuit 100 of any of the foregoing embodiments or the motor 200 described above.

[0125] According to the compressor of the present invention, by employing the above-described motor power calculation circuit or motor, the two voltage sampling units and the two current sampling units can be mutually calibrated to improve sampling accuracy. The control unit performs software calibration on the sampled values ​​to obtain more accurate target current and target voltage values, thereby obtaining precise input power.

[0126] Corresponding to the above embodiments, embodiments of the present invention also provide a vehicle. For example... Figure 19 As shown, vehicle 1000 includes the aforementioned compressor 300.

[0127] The vehicle 1000 according to an embodiment of the present invention includes the compressor 300 described in any of the above embodiments. Here, the vehicle can be a new energy vehicle. In some embodiments, the new energy vehicle can be a pure electric vehicle with an electric motor as the main driving force. In other embodiments, the new energy vehicle can also be a hybrid vehicle with both an internal combustion engine and an electric motor as the main driving force. Regarding the internal combustion engine and electric motor mentioned in the above embodiments that provide driving power for the new energy vehicle, the internal combustion engine can use gasoline, diesel, hydrogen, etc. as fuel, and the method of providing electrical energy to the electric motor can be a power battery, hydrogen fuel cell, etc., without special limitation. It should be noted that this is merely an exemplary description of the structure of new energy vehicles, etc., and is not intended to limit the scope of protection of the present invention.

[0128] According to the vehicle of the present invention, by employing the above-described compressor, the two voltage sampling units and the two current sampling units can be mutually calibrated to improve sampling accuracy. The control unit performs software calibration on the sampled values ​​to obtain more accurate target current and target voltage values, thereby obtaining precise input power.

[0129] Corresponding to the above embodiments, embodiments of the present invention also provide a method for calculating motor power, applicable to, for example... Figure 4 The motor power calculation circuit shown includes 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 motor's bus voltage to obtain a sampled bus voltage value. The phase voltage sampling unit 20 is adapted to sample the voltage of any phase of the motor to obtain a sampled phase voltage value. The first current sampling unit 30 is adapted to sample the peak value of the motor's bus current to obtain the peak bus current value. The second current sampling unit 40 is adapted to sample the effective value of the bus current to obtain the effective value of the bus current. Figure 20 As shown, the method includes:

[0130] S101 calibrates the bus voltage sampling value and the phase voltage sampling value to obtain the target voltage value, and calibrates the peak value of the bus current and the effective value of the bus current to obtain the target current value.

[0131] Specifically, assuming no faults in the bus voltage sampling unit and phase voltage sampling unit, the difference between the bus voltage sample value and the phase voltage sample value is small. Therefore, the bus voltage sampling unit and the phase voltage sampling unit can be mutually calibrated based on the bus voltage sample value and the phase voltage sample value. Similarly, assuming no faults in the first current sampling unit and the second current sampling unit, the difference between the peak value and the effective value of the bus current is also relatively small. Therefore, the first current sampling unit and the second current sampling unit can be mutually calibrated based on the peak value and the effective value of the bus current. The second current sampling unit samples the effective value of the bus current, which is closer to the actual current consumed by the bus. Then, the control unit calibrates the bus voltage sample value and the phase voltage sample value, as well as the peak value and the effective value of the bus current, to obtain accurate target voltage and target current values.

[0132] S102 determines the input power of the motor based on the target voltage and target current values.

[0133] Specifically, the input power can be obtained by calculating the product of the target voltage value and the target current value.

[0134] In the above embodiment, the two voltage sampling units and the two current sampling units can be calibrated with each other, which can not only improve the sampling accuracy, but also reduce the risk of sampling abnormalities due to circuit damage. Furthermore, the second current sampling unit samples the effective value of the bus current, which is closer to the actual current consumed by the bus with a smaller error. Then, the control unit performs software calibration to obtain accurate voltage and current values, thereby obtaining accurate power values.

[0135] In some embodiments, such as Figure 5As shown, the second current sampling unit 40 includes: a current sensing resistor Rs, a first operational amplifier module 41, a first filter module 42, and a second filter module 43. The current sensing resistor Rs is connected in series with the DC negative bus HVDC-. The first operational amplifier module 41 is connected to the current sensing resistor Rs and is configured to amplify the voltage across the current sensing resistor Rs to obtain a first voltage signal. The input terminal of the first filter module 42 is connected to the output terminal 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 terminal of the second filter module 43 is connected to the output terminal of the first filter module 42, and the output terminal of the second filter module 43 is connected to the first input terminal I_ADC1 of the control unit 50. The second filter module 43 is configured to filter the second voltage signal to obtain the effective value of the bus current.

[0136] Specifically, the current-sensing 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-sensing resistor Rs to obtain a first voltage signal. This first voltage signal is then input to the first filter module 42, which filters the first voltage signal into a stable second voltage signal. However, glitches still exist in the second voltage signal (such as...). Figure 6 As shown), therefore, the second filtering module 43 filters out the glitches in the second voltage signal to obtain the signal as shown. Figure 7 The accurate RMS value of the bus current is shown.

[0137] In one alternative implementation, such as Figure 5 As shown, the first operational amplifier module 41 is a differential amplifier circuit. 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. One end of the first resistor R1 is connected to the current sensing resistor Rs, and the other end of the first resistor R1 is connected to 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, and the other end of the second resistor R2 is connected to 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 to the second node J2, and the other end of the third resistor R3 is connected to 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, and the other end of the fifth resistor R5 is connected to the third node J3. One end of the sixth resistor R6 is connected to the other end of the fifth resistor R5, and the other end of the sixth resistor R6 is grounded.

[0138] The first filter module 42 and the second filter module 43 are both low-pass filter circuits, and the capacitance value 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. The seventh resistor R7 is connected to the output terminal O of the first operational amplifier OP1, and 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. 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. 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. The other end of the fourth capacitor C4 is grounded. The fifth capacitor C5 is connected in parallel with the fourth capacitor C4.

[0139] It should be noted that the effective value and peak value of the bus current are voltage signals. After receiving the effective value and peak value of the bus current, the control unit 50 can calculate the current value corresponding to the effective value of the bus current and the current value corresponding to the peak value of the bus current based on the effective value, the peak value of the bus current and the resistance value of the current sensing resistor Rs.

[0140] In the above embodiment, after the first operational amplifier module amplifies the voltage across the current sensing resistor, the first voltage signal is filtered by a two-stage filter circuit to obtain a more accurate effective value of the bus current.

[0141] In some embodiments, such as Figure 3 As shown, the first current sampling unit 30 includes a second operational amplifier module 31 and a third filter module 32. The second operational amplifier module 31 is connected to the current sensing resistor Rs. The first operational amplifier module 41 is configured to amplify the voltage across the current sensing 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, and the output terminal of the third filter module 32 is connected to the second input terminal I_ADC2 of the control unit 50. The third filter module 32 is configured to filter the third voltage signal to obtain the peak value of the bus current.

[0142] Specifically, the first current sampling unit 30 and the second current sampling unit 40 use the same current sensing resistor Rs, ensuring that the input signals of the two current sampling units are the same. This avoids the impact on motor control caused by different current samples obtained from different signal sources. Since the first current sampling unit 30 also samples the peak value of the bus current, its circuit structure can be the same as that of the bus current sampling unit in related technologies. The second operational amplifier module 31 amplifies the voltage across the current sensing resistor Rs to obtain a third voltage signal, and the third filter module 32 filters the third voltage signal, outputting as shown. Figure 8 The peak value of the bus current is shown.

[0143] from Figure 8 As can be seen, the sampling time of the first current sampling unit 30 will be deviated, and it is not always at the peak time. Moreover, the amplitude of the peak value of the bus current obtained by each sampling will change. Therefore, there is a large error in the peak value of the bus current. So the second current sampling unit 40 is needed to sample the effective value of the bus current.

[0144] It should be noted that, Figures 6 to 8 This is the software interface for waveform display software.

[0145] In one alternative implementation, such as Figure 3 As shown, the second operational amplifier module 31 is a differential amplifier circuit. 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. One end of the ninth resistor R9 is connected to the current sensing resistor Rs, and the other end of the ninth resistor R9 is connected to 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, and the other end of the tenth resistor R10 is connected to 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 to the fourth node J4, and the other end of the eleventh resistor R11 is connected to 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, and the other end of the twelfth resistor R12 is connected to the fifth node J5. One end of the thirteenth resistor R13 is connected to the other end of the twelfth resistor R12, and the other end of the thirteenth resistor R13 is grounded.

[0146] The third filter module 32 is also a low-pass filter circuit. The third filter module 32 includes a fourteenth resistor R14 and a sixth capacitor C6. One end of the fourteenth resistor R14 is connected to the output terminal O of the second operational amplifier OP2. The other end of the fourteenth resistor R14 is connected to the second input terminal I_ADC2 of the control unit 50 and one end of the sixth capacitor C6. The other end of the sixth capacitor C6 is grounded.

[0147] In some embodiments, the amplification factor of the second operational amplifier module 31 is less than the amplification factor of the first operational amplifier module 41.

[0148] It is understandable that the amplification factor of the second operational amplifier module 31 is less than that of the first operational amplifier module 41, meaning the amplification factor of the second current sampling unit 40 is greater than that of the first current sampling unit 30. A higher amplification factor corresponds to a smaller full-load current and higher 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. The maximum digital value sampled by the control unit is 4096. Therefore, when the full-load current is 108.9A, a single digital value of 1 corresponds to 108.9 / 4096 = 0.0265A; when the full-load current is 21.4A, a single digital value of 1 corresponds to 21.4 / 4096 = 0.0052A. Thus, a higher amplification factor results in higher sampling accuracy.

[0149] It should be noted that because the amplification factor of the first operational amplifier module 41 is greater than that of the second operational amplifier module 31, the upper limit of sampling of the first operational amplifier module 41 is less than that of the second operational amplifier module 31. Therefore, the upper limit of sampling of the first operational amplifier module 41 is 20-30A, and the upper limit of sampling of the second operational amplifier module 31 is greater than 100A.

[0150] In some embodiments, such as Figure 2 As shown, one end of the current sensing resistor Rs is grounded, and the other end of the current sensing resistor Rs is suitable for connecting to the DC negative bus HVDC-.

[0151] In other words, the current sensing resistor Rs can be set after the bus capacitor C, and the three-phase lower bridge arms of the motor inverter are connected and grounded. One end of the current sensing resistor Rs is connected to the three-phase lower bridge arms and grounded, and the other end of the current sensing resistor Rs is suitable for connecting to the DC negative bus HVDC-.

[0152] In some embodiments, such as Figure 9 As shown, one end of the current sensing resistor Rs is adapted to connect one end of the bus capacitor C and the DC negative bus HVDC-, and the other end of the current sensing resistor Rs is adapted to connect to the negative terminal of the DC power supply. The bus capacitor C filters the DC power supply to generate the bus voltage.

[0153] Specifically, when the current sensing resistor Rs is set after the bus capacitor C, the bus capacitor C will interfere with the current sampling during charging and discharging, thereby reducing the sampling accuracy. Therefore, the current sensing resistor Rs can also be set before the bus capacitor C.

[0154] by Figure 9 As shown in the example, the power supply filtering circuit of the motor adopts a differential mode filtering circuit. The power supply filtering circuit includes a first inductor L1, a second inductor L2, and a bus capacitor C. One end of the first inductor L1 is suitable for connecting to the positive terminal HV+ of the high-voltage power supply, and the other end of the first inductor L1 is the positive terminal of the DC power supply, which is also the DC positive bus HVDC+. One end of the second inductor L2 is suitable for connecting to the negative terminal HV- of the high-voltage power supply, and the other end of the second inductor L2 is the negative terminal of the DC power supply. The other end of the current sensing resistor Rs is connected to the other end of the second inductor L2. One end of the current sensing resistor Rs is connected to one end of the bus capacitor C, and the other end of the bus capacitor C is connected to the other end of the first inductor L1. One end of the bus capacitor C is the DC negative bus HVDC-.

[0155] Furthermore, when the current sensing resistor Rs is set before the bus capacitor C, such as Figure 10 and Figure 11 As shown, one end of the first resistor R1 of the first operational amplifier module 41 is connected to the other end of the current sensing resistor Rs, one end of the second resistor R2 of the first operational amplifier module 41 is connected to one end of the current sensing 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 sensing 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 sensing resistor Rs.

[0156] In the above embodiments, setting the bus current sampling point in front of the bus capacitor can avoid interference from the charging and discharging of the bus capacitor on the current sampling, thereby further improving the accuracy of the current sampling.

[0157] In some embodiments, such as Figure 1 and Figure 12 As shown, the bus voltage sampling unit 10 and the phase voltage sampling unit 20 respectively include: a plurality of series-connected voltage divider resistors R and a fourth filter module 11, wherein the first end of the plurality of series-connected voltage divider resistors R is a voltage input terminal, the second end of the plurality of series-connected voltage divider resistors R is grounded, the plurality of series-connected voltage divider resistors R have a first node J1, the first node J1 is adapted to output the input voltage after voltage division; the input terminal of the fourth filter module 11 is connected to the first node J1, the output terminal of the fourth filter module 11 is a voltage output terminal, and the fourth filter module 11 is configured to filter the input voltage after voltage division to output a voltage sampling value.

[0158] Specifically, the circuit structures of the bus voltage sampling unit 10 and the phase voltage sampling unit 20 are the same, so the voltage division 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.

[0159] The bus voltage sampling unit 10 can employ a sampling circuit from related technologies to... Figure 1 As shown in the example, the voltage input terminal of the bus voltage sampling unit 10 is suitable for connecting to the DC positive bus HVDC+. There are 8 voltage divider resistors R. The first node J1 is the connection point of the sixth voltage divider resistor R and the seventh voltage divider resistor R. The fourth filter module 11 of the bus voltage sampling unit 10 filters the voltage divider voltage of the DC positive bus HVDC+ to obtain the bus voltage sampling value. The fourth filter module 11 of the bus voltage sampling unit 10 is connected to the third input terminal VDC_AD3 of the control unit 50 to provide the bus voltage sampling value to the control unit 50.

[0160] Taking the sampling of phase voltage of phase W by phase voltage sampling unit 20 as an example, such as Figure 12 As shown, the voltage input terminal of the phase voltage sampling unit 20 is adapted to connect to the midpoint of the W-phase bridge arm of the inverter. Because the phase voltage sampling unit 20 has the same circuit structure as the bus voltage sampling unit 10, the phase voltage sampling unit 20 also includes 8 voltage divider resistors R, and the first node J1 is the connection point of the sixth voltage divider resistor R and the seventh voltage divider resistor R. The fourth filter module 11 of the phase voltage sampling unit 20 filters the voltage divider voltage of the W-phase phase voltage to obtain the phase voltage sampling value. The fourth filter module 11 of the phase voltage sampling unit 20 is connected to the fourth input terminal VDC_AD4 of the control unit 50 to provide the phase voltage sampling value to the control unit 50.

[0161] It should be noted that the bus voltage sample value and the phase voltage sample value are voltage values ​​after voltage division. The control unit 50 can calculate the bus voltage corresponding to the bus voltage sample value and the phase voltage corresponding to the phase voltage sample value based on the voltage dividing resistor R, the bus voltage sample value and the phase voltage sample value.

[0162] In one alternative implementation, such as Figure 1 and Figure 12 As shown, 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 terminal 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.

[0163] In some embodiments, the input terminal of the bus voltage sampling unit 10 is adapted to be connected to the positive terminal of a DC power supply.

[0164] Specifically, when the bus voltage sampling point is set after the bus capacitor C, that is, the bus voltage sampling unit 10 is suitable for sampling the DC positive bus HVDC+, it can avoid interference from the power input terminal to the bus voltage sampling. However, the inverter will interfere with the bus voltage sampling when it is working. Therefore, the bus voltage sampling point can also be set before the bus capacitor C, closer to the input terminal, so as to avoid interference when the inverter is working.

[0165] Furthermore, with Figure 9 As shown in the example, the input terminal of the bus voltage sampling unit 10 is adapted to be connected to the positive terminal HV+ of the high voltage power supply.

[0166] In the above embodiments, the bus voltage sampling point can also be set in front of the bus capacitor to avoid interference from the inverter to the bus voltage sampling, thereby improving the accuracy of the bus voltage sampling.

[0167] In some embodiments, such as Figure 13 As shown, the bus voltage sample value and phase voltage sample value are calibrated to obtain the target voltage value, including: filtering the bus voltage sample value and phase voltage sample value respectively to obtain the phase voltage value and 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.

[0168] Specifically, the bus voltage sample value and the phase voltage sample value are subjected to software low-pass filtering 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, it indicates that the difference between the phase voltage sample value and the bus voltage sample value is relatively small. In this case, the bus voltage sampling unit and the phase voltage sampling unit are working normally, and the sampled 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 used as the target voltage value.

[0169] In some embodiments, such as Figure 13 As shown, when 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: controlling the motor to stop.

[0170] In other words, 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 sample value and the bus voltage sample value is relatively large. In this case, the bus voltage sampling unit and / or the phase voltage sampling unit is faulty and cannot control the motor based on the sampled values ​​of the bus voltage sampling unit and the phase voltage sampling unit. Therefore, the motor is stopped.

[0171] 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 is faulty. When the bus voltage sampling unit and / or the phase voltage sampling unit is faulty, the motor can be stopped in time, thereby improving the safety of the motor. When the bus voltage sampling unit and the phase voltage sampling unit are working normally, the accurate target voltage value can be calculated, thereby improving the accuracy of motor control.

[0172] In some embodiments, such as Figure 14 As shown, the calibration of the peak bus current and the effective bus current to obtain the target current value includes: filtering the peak bus current to obtain the bus current value; if the absolute value of the difference between the bus current value and the effective bus current value is less than a second preset difference, determining a first current value based on the target fitted value and the bus current value, and filtering the effective bus current value to obtain a second current value, wherein the target fitted value is obtained by looking up the bus voltage sample value and the phase voltage sample value from a pre-established motor parameter table; and determining the target current value based on the difference between the first current value and the second current value.

[0173] Specifically, the control unit performs software low-pass filtering on the peak value of the bus current 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, it indicates that the first and second current sampling units are working normally, and control can be performed based on the bus current value and the effective value of the bus current. The control unit looks up the target fitted values ​​corresponding to the bus voltage sampling value and the phase voltage sampling value from the pre-established motor parameter table, and determines the first current value based on the target fitted value and the bus current value. It also performs software low-pass filtering on the effective value of the bus current to obtain the second current value, and then determines the target current value based on the first and second current values.

[0174] It should be noted that the pre-established motor parameter table is constructed based on the motor speed, bus voltage, phase voltage, phase current, peak bus current, effective bus current, and power under multiple operating conditions. Among them, the peak bus current, effective bus current, and power are calculated based on the relationship between bus voltage and bus current at different motor speeds.

[0175] In one alternative implementation, the motor phase current can be determined by means of... Figure 2 The sampling is obtained using the dual-resistance sampling scheme shown, or it can be obtained through methods such as... Figure 15 The sampling was obtained using the three resistors (Rs1, Rs2, Rs3) sampling scheme shown.

[0176] In some embodiments, such as Figure 14 As shown, determining the first current value based on the target fitted value and the bus current value includes: determining the target fitted value as the first current value when 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; or determining the bus current value as the first current value when the absolute value of the difference between the target fitted value and the bus current value is greater than the third preset difference.

[0177] Specifically, if the absolute value of the difference between the target fitted value and the bus current value is less than or equal to the third preset difference, it indicates that the bus current value conforms to the relationship between bus voltage and bus current in the pre-established motor parameter table. Therefore, the target fitted value can be used as the first current value. If the absolute value of the difference between the target fitted value and the bus current value is greater than the third preset difference, it indicates that the bus current value does not conform to the relationship between bus voltage and bus current in the pre-established motor parameter table. In this case, the actual sampled current value is used as the standard, and the bus current value is set as the first current value.

[0178] In some embodiments, such as Figure 14 As shown, determining the target current value based on the difference between the first current value and the second current value includes: determining the second current value as the target current value when the absolute value of the difference between the first current value and the second current value is greater than a fourth preset difference; or, determining the first current value as the target current value when 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.

[0179] Understandably, if the absolute value of the difference between the first current value and the second current value is greater than the fourth preset difference (e.g., 1A), the effective value of the filtered bus current is more accurate, and therefore the second current value is used 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, the difference between the first current value and the second current value is small, and the first current value can be used as the target current value.

[0180] It should be noted that the smaller the fourth preset difference, the more accurate the target current value.

[0181] In some embodiments, such as Figure 14 As shown, when 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: stopping the motor.

[0182] In other words, 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, it indicates that the difference between the peak value of the bus current and the effective value of the bus current is relatively large. In this case, the first current sampling unit and / or the second current sampling unit is faulty and cannot control the motor based on the sampling values ​​of the first current sampling unit and the second current sampling unit. Therefore, the motor is stopped.

[0183] In the above embodiments, the absolute value of the difference between the peak value of the bus current and the effective value of the bus current can be used to determine whether the first current sampling unit and / or the second current sampling unit has malfunctioned. When the first current sampling unit and / or the second current sampling unit malfunctions, the motor can be stopped in time, thereby improving the safety of the motor. When the first current sampling unit and the second current sampling unit are working normally, the accurate target current value can be calculated, thereby improving the accuracy of motor control.

[0184] In summary, the motor power calculation method according to embodiments of the present invention acquires the sampled values ​​of the motor's bus voltage, the sampled values ​​of the phase voltage of any phase, the peak value of the bus current, and the effective value of the bus current. The sampled values ​​of the bus voltage and phase voltage are calibrated to obtain a target voltage value, and the peak value and effective value of the bus current are calibrated to obtain a target current value. The input power of the motor is then determined based on the target voltage and target current values. Thus, the two voltage sampling units and the two current sampling units can mutually calibrate, improving sampling accuracy and reducing the risk of sampling anomalies due to circuit damage. Furthermore, the second current sampling unit samples the effective value of the bus current, which is closer to the actual current consumed by the bus. The control unit then calibrates the sampled values ​​of the bus voltage and phase voltage, as well as the peak value and effective value of the bus current, to obtain accurate voltage and current values, thereby yielding a precise power value.

[0185] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0186] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0187] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0188] Furthermore, the terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this invention can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this invention, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.

[0189] In this invention, unless otherwise explicitly specified or limited in the embodiments, the terms "installation," "connection," "joining," and "fixing" appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific implementation.

[0190] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A motor power calculation circuit, characterized in that, include: 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, Includes the motor power calculation circuit according to any one of claims 1-14.

16. A compressor, characterized in that, Includes the motor power calculation circuit according to any one of claims 1-14 or the motor according to claim 15.

17. A vehicle, characterized in that, Includes the compressor according to claim 16.

18. A method for calculating motor power, characterized in that, An application is made in 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. 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. 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 includes: 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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, characterized in that, 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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