Sampling circuit and motor

Abstract

The utility model provides a sampling circuit and a motor. The sampling circuit comprises a first MOS tube, the first end of the first MOS tube is connected with a first power supply, and the second end of the first MOS tube is grounded; the output end of the current injection module is connected with the first end of the first MOS tube, and the current injection module is used for injecting first current with a first current value into the first MOS tube; the first end of the detection module is connected with the first end of the first MOS tube, the second end of the detection module is connected with the second end of the first MOS tube, and the detection module is used for collecting a first voltage value and a second voltage value at the first MOS tube. According to the invention, the accuracy of collecting the current value of the first MOS tube is improved, and the problem of inaccurate current sampling is solved.

Description

Technical Field

[0001] The present application relates to the technical field of electric motors, and more particularly, to a sampling circuit and an electric motor. Background Art

[0002] In the controller topology of a three-phase six-bridge electric motor, resistance sampling and Hall current sensors are usually used for sampling the phase current.

[0003] In the related art, to reduce costs, MOS (Metal-Oxide-Semiconductor) tube internal resistance sampling is often used in the industry for vector control. The internal resistance of the MOS tube increases with the increase of the MOS temperature, so that the voltage collected by the controller cannot reflect the magnitude of the real current in real time, resulting in low current sampling accuracy. Summary of the Utility Model

[0004] The present application aims to solve one of the technical problems existing in the prior art or related technologies.

[0005] To this end, a first aspect of the present application provides a sampling circuit.

[0006] A second aspect of the present application provides an electric motor.

[0007] In view of this, according to a first aspect of the present application, a sampling circuit is provided, including: a first MOS tube, a first end of the first MOS tube is electrically connected to a first power supply, and a second end of the first MOS tube is grounded; a current injection module, an output end of the current injection module is connected to the first end of the first MOS tube, and the current injection module is configured to inject a first current with a first current value into the first MOS tube; a detection module, a first end of the detection module is connected to the first end of the first MOS tube, and a second end of the detection module is connected to the second end of the first MOS tube, and the detection module is configured to collect a first voltage value and a second voltage value at the first MOS tube; wherein, the first voltage value includes a voltage value when the current injection module injects the first current into the first MOS tube, and the second voltage value includes a voltage value when the current injection module does not inject the first current into the first MOS tube.

[0008] In this technical solution, the first MOS transistor is the MOS transistor on the lower bridge arm of the three-phase six-bridge arm, and current sampling is performed through the internal resistance of the first MOS transistor. The current injection module is used to inject a first current into the first end of the first MOS transistor. The first current injected by the current injection module is an accurate current, and this first current is a current for which a specific first current value can be read. The detection module can detect the voltage value at the internal resistance of the first MOS transistor. During the process of sampling the current value of the first MOS transistor, the sampled second current value can be determined based on the internal resistance value of the first MOS transistor and the voltage value of the first MOS transistor obtained by sampling. The second current value is the sampled current value of the first MOS transistor.

[0009] In this technical solution, when injecting the first current into the first MOS transistor through the current injection module, the detection module collects the first voltage value. Then, when the current injection module stops injecting the second current into the first MOS transistor, the detection module collects the second voltage value. The internal resistance value of the first MOS transistor can be calculated based on the first current value, the first voltage value, and the second voltage value.

[0010] Specifically, the current injection module injects a first current Ia into the first MOS transistor. The first current Ia flows through the first MOS transistor. The detection module collects the first voltage value V1. Then, the injection of current into the first MOS transistor is stopped, and the detection module collects the second voltage value V2.

[0011] In the technical solution of this application, by setting a current injection module in the sampling circuit, and during the process of sampling the current of the first MOS transistor, injecting a first current into the first MOS transistor through the current injection module and then stopping injecting the first current into the first MOS transistor, the internal resistance value of the first MOS transistor can be determined based on the first voltage value and the second voltage value collected by the detection module twice respectively. Thus, the accuracy of collecting the current value of the first MOS transistor is improved, and the problem of inaccurate current sampling is solved.

[0012] In some technical solutions, optionally, the current injection module includes: a switch element, the first end of the switch element is used to receive current; a first resistor, the first end of the first resistor is connected to the second end of the switch element, and the second end of the first resistor is connected to the first end of the first MOS transistor.

[0013] In this technical solution, the current injection module includes a switch element and a first resistor. The first end of the switch element is used to receive current, the second end of the switch element is used to output current, and the switch element can switch the on-off state between the first end and the second end of the diode, thereby controlling whether the current injection module injects current into the first MOS transistor.

[0014] In this technical solution, the first resistor is a current-limiting resistor. The first resistor is connected in series between the switching element and the first end of the first MOS transistor. The first resistor can prevent the current value transmitted to the first MOS transistor from being too large, which may impact the first MOS transistor, thereby improving the safety and stability of the current injection module injecting current into the first MOS transistor.

[0015] In the technical solution of this application, the first end of the switching element is the input end of the current injection module, and the second end of the first resistor is the output end of the current injection module. By providing a switching element in the current injection module, it is possible to control whether the current injection module injects current into the first MOS transistor through the switching element. The first resistor can play a role in current limiting and protection for the first MOS transistor, improving the overall safety of the circuit.

[0016] In some technical solutions, optionally, the first end of the switching element is connected to the first power supply.

[0017] In this technical solution, the first power supply is the power supply in the motor, and the first power supply is reused to supply power to the DC injection module. Specifically, the current output by the first power supply flows through the first MOS transistor, and the current output by the first power supply also flows through the switching element and the first resistor to supply power to the current injection module. When the first power supply supplies power to the current injection module, it is possible to control whether the current injection module injects a first current into the first MOS transistor through the switching element.

[0018] In the technical solution of this application, by reusing the first power supply in the motor to supply power to the current injection module through the first power supply, the switching element can control whether the current output by the first power supply passes through the first resistor and is output to the first end of the first MOS transistor, eliminating the need to separately configure a power supply for the current injection module and simplifying the circuit structure of the sampling circuit.

[0019] In some technical solutions, optionally, the current injection module further includes: a second power supply, and the output end of the second power supply is connected to the first end of the switching element.

[0020] In this technical solution, the current injection module includes a second power supply. The second power supply is used to output current to the first end of the switching element. When the switching element is in the conducting state, the current output by the second power supply flows through the switching element and the first resistor and is injected into the first end of the first MOS transistor.

[0021] It should be noted that the second power supply is a power supply separately provided in the current injection module, and the output current value of the second power supply is a fixed current value. Specifically, the output current value of the second power supply is a first current value.

[0022] In the technical solution of this application, by setting an additional second power supply in the current injection module, the second power supply can be used as the power supply for the current injection module, and the current value output by the second power supply is the first current value. By separately setting the second power supply in the current injection module, the accuracy of the first current output by the current injection module can be improved, and the fluctuation of the current value of the first current can be reduced.

[0023] In some technical solutions, optionally, the current injection module further includes:

[0024] A second resistor, the first end of the second resistor is connected to the first end of the switching element;

[0025] A third resistor, the first end of the third resistor is connected to the second end of the second resistor, and the second end of the third resistor is grounded;

[0026] Wherein, the first end of the third resistor is a voltage sampling terminal, and the voltage sampling terminal is used to collect a third voltage value, and the third voltage value is used to determine the first current value.

[0027] In this technical solution, a second resistor and a third resistor are provided in the current injection module. The second resistor and the third resistor are voltage-dividing resistors, and the second resistor and the third resistor are connected in series between the first end of the switching element and the ground terminal.

[0028] In this technical solution, the common terminal of the second resistor and the third resistor is a voltage sampling terminal. By collecting the third voltage value between the second resistor and the third resistor, and based on the resistance values of the second resistor and the third resistor, and the third voltage value, the first current value can be calculated.

[0029] Specifically, by setting a second resistor and a third resistor in the current injection module, and using the common terminal of the second resistor and the third resistor as the voltage sampling terminal, the voltage value of the first current output by the current injection module can be collected at the voltage sampling terminal, so as to determine the first current value of the first MOS transistor output by the current injection module.

[0030] In the technical solution of this application, by collecting the third voltage value at the common terminal of the second resistor and the third resistor, the first current value of the first current output by the current injection module can be accurately calculated, realizing continuous monitoring of the first current value output by the current injection module, further improving the accuracy of determining the internal resistance value of the first MOS transistor, and thus improving the accuracy of current sampling.

[0031] In some technical solutions, optionally, the detection module includes: an operational amplifier, the output terminal of the operational amplifier is used to output a first voltage value and a second voltage value; a fourth resistor, the first end of the fourth resistor is connected to the first end of the first MOS transistor, and the second end of the fourth resistor is connected to the first end of the operational amplifier; a fifth resistor, the first end of the fifth resistor is connected to the second end of the operational amplifier, and the second end of the fifth resistor is connected to the second end of the first MOS transistor.

[0032] In this technical solution, the detection module includes an operational amplifier, a fourth resistor, and a fifth resistor. The operational amplifier is used to collect the first voltage value and the second voltage value of the first MOS transistor through the fourth resistor and the fifth resistor.

[0033] Specifically, the first end of the operational amplifier is connected to the first end of the first MOS transistor through the fourth resistor, the second end of the operational amplifier is connected to the second end of the first MOS transistor through the fifth resistor, and the operational amplifier can continuously monitor the voltage values at both ends of the first MOS transistor through the fourth resistor and the fifth resistor.

[0034] In the technical solution of the present application, by arranging an operational amplifier in the detection module, and the fourth resistor and the fifth resistor connected to the first end and the second end of the operational amplifier, the first voltage value and the second voltage value at both ends of the first MOS transistor can be accurately detected, further improving the accuracy of current sampling of the sampling circuit.

[0035] In some technical solutions, optionally, the detection module further includes: a diode, the first end of the diode is connected to the second end of the fourth resistor, and the second end of the diode is connected to the first end of the fifth resistor, wherein the diode conducts unidirectionally from the first end to the second end.

[0036] In this technical solution, the detection module further includes a diode. The diode is arranged between the fourth resistor and the fifth resistor. The diode can enable the current to flow through the fourth resistor and the fifth resistor in sequence, and cut off in the reverse direction between the fourth resistor and the fifth resistor.

[0037] Specifically, the first end and the second end of the diode are respectively connected to the fourth resistor and the resistor, that is, the diode can enable the current to flow from the fourth resistor to the fifth resistor, and prevent the current at the fifth resistor from flowing reversely through the fourth resistor.

[0038] In the technical solution of the present application, by arranging an anti-reverse diode between the fourth resistor and the fifth resistor, the impact of reverse current on the operational amplifier can be avoided, further improving the stability of the detection module.

[0039] In some technical solutions, optionally, the detection module further includes: a sixth resistor, the first end of the sixth resistor is used to receive a fourth voltage value, the second end of the sixth resistor is connected to the first end of the operational amplifier, and the fourth voltage value includes the reference voltage value of the operational amplifier; a seventh resistor, the first end of the seventh resistor is connected to the second end of the operational amplifier, and the second end of the seventh resistor is connected to the output end of the operational amplifier.

[0040] In this technical solution, the detection module further includes a sixth resistor and a seventh resistor. The sixth resistor is used to receive the fourth voltage value of the reference voltage of the operational amplifier, that is, the reference voltage value is transmitted to the operational amplifier through the sixth resistor. The seventh resistor is connected between the output end and the second end of the operational amplifier, and the seventh resistor is used to adjust the amplification factor of the operational amplifier.

[0041] In the technical solution of the present application, by setting the sixth resistor and the seventh resistor in the detection module, the first end of the operational amplifier can receive a stable reference voltage value, and the amplification factor of the operational amplifier can be adjusted by adjusting the resistance value of the seventh resistor.

[0042] In some technical solutions, the sampling circuit further includes: a second MOS transistor, the first end of the second MOS transistor is connected to the first power supply, and the second end of the second MOS transistor is connected to the first end of the first MOS transistor.

[0043] In the technical solution of the present application, the second MOS transistor is connected between the first MOS transistor and the first power supply. Among them, the second MOS transistor is the MOS transistor of the upper bridge arm, and the first MOS transistor is the MOS transistor of the lower bridge arm. By connecting the detection module across the first MOS transistor, the accuracy of the vector control of the motor can be improved.

[0044] According to a second aspect of the present application, a motor is provided, including: a sampling circuit and a controller, and the controller is connected to the sampling circuit. The sampling circuit is the sampling circuit in any of the above technical solutions, and thus has all the beneficial technical effects of the sampling circuit in any of the above technical solutions, which will not be elaborated here too much.

[0045] The additional aspects and advantages of the present application will become obvious in the following description part, or will be understood through the practice of the present application. Description of the Drawings

[0046] The above and / or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the technical solutions in conjunction with the following drawings, where:

[0047] Figure 1 One of the circuit diagrams of the sampling circuit provided in some embodiments of the present application is shown;

[0048] Figure 2Shows the relationship diagram between the temperature and the internal resistance value of the first MOS transistor provided in some embodiments of the present application;

[0049] Figure 3 Shows the second circuit diagram of the sampling circuit provided in some embodiments of the present application;

[0050] Figure 4 Shows the structural block diagram of the motor provided by some technical solutions of the present application.

[0051] Figure 1 and Figure 3 The reference numerals of are as follows:

[0052] 100 Sampling circuit, 120 Current injection module, 140 Detection module, BT1 First power supply, SW Switching element, VBAT Second power supply, R1 First resistor, R2 Second resistor, R3 Third resistor, R4 Fourth resistor, R5 Fifth resistor, R6 Sixth resistor, R7 Seventh resistor, D1 Diode, OPA Operational amplifier, Q1 First MOS transistor, Q2 Second MOS transistor. Detailed implementation manners

[0053] In order to be able to more clearly understand the above objects, features and advantages of the present application, the present application will be further described in detail below with reference to the drawings and specific implementation manners. It should be noted that, without conflict, the features in this embodiment and the embodiments can be combined with each other.

[0054] Many specific details are set forth in the following description in order to fully understand the present application. However, the present application may be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0055] Next, refer to Figures 1 to 4 Describe the sampling circuit and the motor according to some embodiments of the present application.

[0056] According to an embodiment of the present application, Figure 1 Shows the first circuit diagram of the sampling circuit provided in some embodiments of the present application. As Figure 1 shown, a sampling circuit 100 is proposed. The sampling circuit 100 includes: a first MOS transistor Q1, a current injection module 120, and a detection module 140.

[0057] The first end of the first MOS transistor Q1 is electrically connected to the first power supply BT1, and the second end of the first MOS transistor Q1 is grounded; the output end of the current injection module 120 is connected to the first end of the first MOS transistor Q1, and the current injection module 120 is used to inject a first current with a first current value into the first MOS transistor Q1; the first end of the detection module 140 is connected to the first end of the first MOS transistor Q1, and the second end of the detection module 140 is connected to the second end of the first MOS transistor Q1, and the detection module 140 is used to collect a first voltage value and a second voltage value at the first MOS transistor Q1; wherein, the first voltage value includes the voltage value when the current injection module injects the first current into the first MOS transistor Q1, and the second voltage value includes the voltage value when the current injection module does not inject the first current into the first MOS transistor Q1.

[0058] In this embodiment, the first MOS transistor Q1 is a MOS transistor on the lower bridge arm of the three-phase six-bridge arm, and current sampling is performed through the internal resistance of the first MOS transistor Q1. The current injection module 120 is used to inject a first current into the first end of the first MOS transistor Q1. The first current injected by the current injection module 120 is an accurate current, and the first current is a current that can read a specific first current value. The detection module 140 can detect the voltage value at the internal resistance of the first MOS transistor Q1. During the process of sampling the current value of the first MOS transistor Q1, the second current value obtained by sampling can be determined according to the internal resistance value of the first MOS transistor Q1 and the voltage value of the first MOS transistor Q1 obtained by sampling, and the second current value is the sampling current value of the first MOS transistor Q1.

[0059] In this embodiment, when the current injection module 120 injects the first current into the first MOS transistor Q1, the detection module 140 is used to collect the first voltage value. When the current injection module 120 stops injecting the second current into the first MOS transistor Q1, the detection module 140 is used to collect the second voltage value. The internal resistance value of the first MOS transistor Q1 can be calculated according to the first current value, the first voltage value, and the second voltage value.

[0060] Specifically, the current injection module 120 injects a first current Ia into the first MOS transistor Q1. The first current Ia flows through the first MOS transistor Q1. The detection module 140 is used to collect the first voltage value V1. The current injection into the first MOS transistor Q1 is stopped, and the detection module 140 is used to collect the second voltage value V2.

[0061] Exemplarily, from the above content, the relational expression (1) when the first current Ia flows through the first MOS transistor Q1 and the relational expression (2) when the first current Ia does not flow through the first MOS transistor Q1 can be known:

[0062] V1 = I1 × Rdson × A + Vref; (1)

[0063] V2 = I2×Rdson×A + Vref; (2)

[0064] Wherein, V1 is the first voltage value, V2 is the second voltage value, I1 is the current value when the first current Ia flows through the first MOS transistor Q1, I2 is the current value when the first current Ia does not flow through the first MOS transistor Q1, Rdson is the internal resistance value of the first MOS transistor Q1, A is the amplification factor, and Vref is the reference voltage value.

[0065] The following relational expression (3) is determined through the above relational expressions (1) and (2):

[0066] Ia×Rdson = V2 - V1; (3)

[0067] Wherein, Ia is the first current value, Rdson is the internal resistance value of the first MOS transistor Q1, V2 is the second voltage value, and V1 is the first voltage value.

[0068] Through the above relational expression (3), the internal resistance value of the first MOS transistor Q1 can be determined, and then the second current value can be calculated according to the collected second voltage value and the internal resistance value. This second current value is the sampling current value of the first MOS transistor Q1.

[0069] Figure 2 The graph showing the relationship between the temperature and the internal resistance value of the first MOS transistor provided in some embodiments of the present application is as follows Figure 2 As shown, as the temperature of the first MOS transistor Q1 increases, the internal resistance value of the first MOS transistor Q1 gradually increases.

[0070] In the embodiments of the present application, by setting the current injection module 120 in the sampling circuit 100, and during the process of current sampling of the first MOS transistor Q1, injecting a first current into the first MOS transistor Q1 through the current injection module 120, and stopping injecting the first current into the first MOS transistor Q1, the internal resistance value of the first MOS transistor Q1 can be determined according to the first voltage value and the second voltage value respectively collected by the detection module 140 twice, thereby improving the accuracy of the collection of the current value of the first MOS transistor Q1 and solving the problem of inaccurate current sampling.

[0071] In some embodiments, optionally, the current injection module 120 includes: a switch SW, the first end of the switch SW is used to receive the current; a first resistor R1, the first end of the first resistor R1 is connected to the second end of the switch SW, and the second end of the first resistor R1 is connected to the first end of the first MOS transistor Q1.

[0072] In this embodiment, the current injection module 120 includes a switch SW and a first resistor R1. The first end of the switch SW is used to receive current, and the second end of the switch SW is used to output current. The switch SW can switch the on-off state between the first end and the second end of the diode, so as to control whether the current injection module 120 injects current into the first MOS transistor Q1.

[0073] In this embodiment, the first resistor R1 is a current limiting resistor. The first resistor R1 is connected in series between the switch SW and the first end of the first MOS transistor Q1. The first resistor R1 can prevent the current value transmitted to the first MOS transistor Q1 from being too large, causing an impact on the first MOS transistor Q1, and improving the safety and stability of the current injection module 120 injecting current into the first MOS transistor Q1.

[0074] In the embodiment of the present application, the first end of the switch SW is the input end of the current injection module 120, and the second end of the first resistor R1 is the output end of the current injection module 120. By setting the switch SW in the current injection module 120, it is possible to control whether the current injection module 120 injects current into the first MOS transistor Q1 through the switch SW. The first resistor R1 can play a role in current limiting and protection for the first MOS transistor Q1, improving the overall safety of the circuit.

[0075] Figure 3 Figure 2 shows the circuit diagram of the sampling circuit provided in some embodiments of the present application, as Figure 3 shown. In some embodiments, optionally, the first end of the switch SW is connected to the first power supply BT1.

[0076] In this embodiment, the first power supply BT1 is the power supply in the motor, and the first power supply BT1 is reused to supply power to the DC injection module. Specifically, the current output by the first power supply BT1 flows through the first MOS transistor Q1, and the current output by the first power supply BT1 also flows through the switch SW and the first resistor R1 to supply power to the current injection module 120. When the first power supply BT1 supplies power to the current injection module 120, it is possible to control whether the current injection module 120 injects the first current into the first MOS transistor Q1 through the switch SW.

[0077] In the embodiment of the present application, by reusing the first power supply BT1 in the motor and using the first power supply BT1 to supply power to the current injection module 120, the switch SW can control whether the current output by the first power supply BT1 passes through the first resistor R1 and is output to the first end of the first MOS transistor Q1, without separately configuring a power supply for the current injection module 120, simplifying the circuit structure of the sampling circuit 100.

[0078] In some embodiments, optionally, the current injection module 120 further includes: a second power supply VBAT, and an output terminal of the second power supply VBAT is connected to a first end of the switch SW.

[0079] In this embodiment, the current injection module 120 includes a second power supply VBAT. The second power supply VBAT is used to output current to the first end of the switch SW. When the switch SW is in the on state, the current output by the second power supply VBAT flows through the switch SW and the first resistor R1 and is injected into the first end of the first MOS transistor Q1.

[0080] It should be noted that the second power supply VBAT is a power supply separately provided in the current injection module 120, and the output current value of the second power supply VBAT is a fixed current value. Specifically, the output current value of the second power supply VBAT is a first current value.

[0081] In the embodiments of the present application, by providing an additional second power supply VBAT in the current injection module 120, the second power supply VBAT can be used as the power supply of the current injection module 120, and the output current value of the second power supply VBAT is the first current value. By separately providing the second power supply VBAT in the current injection module 120, the accuracy of the first current output by the current injection module 120 can be improved, and the fluctuation of the current value of the first current can be reduced.

[0082] In some embodiments, optionally, the current injection module 120 further includes:

[0083] a second resistor R2, and a first end of the second resistor R2 is connected to the first end of the switch SW;

[0084] a third resistor R3, a first end of the third resistor R3 is connected to a second end of the second resistor R2, and a second end of the third resistor R3 is grounded;

[0085] Wherein, the first end of the third resistor R3 is a voltage sampling terminal, and the voltage sampling terminal is used to collect a third voltage value, and the third voltage value is used to determine the first current value.

[0086] In this embodiment, the current injection module 120 is provided with a second resistor R2 and a third resistor R3. The second resistor R2 and the third resistor R3 are voltage dividing resistors, and the second resistor R2 and the third resistor R3 are connected in series between the first end of the switch SW and the ground terminal.

[0087] In this embodiment, the common end of the second resistor R2 and the third resistor R3 is the voltage sampling terminal. By collecting the third voltage value between the second resistor R2 and the third resistor R3, and based on the resistance values of the second resistor R2 and the third resistor R3, and the third voltage value, the first current value can be calculated.

[0088] Specifically, by setting a second resistor R2 and a third resistor R3 in the current injection module 120, and using the common terminal of the second resistor R2 and the third resistor R3 as the voltage sampling terminal, the voltage value of the first current output by the current injection module 120 can be collected at the voltage sampling terminal, thereby determining the first current value of the first MOS transistor Q1 output by the current injection module 120.

[0089] In the embodiment of the present application, by collecting the third voltage value at the common terminal of the second resistor R2 and the third resistor R3, the first current value of the first current output by the current injection module 120 can be accurately calculated, realizing continuous monitoring of the first current value output by the current injection module 120, further improving the accuracy of determining the internal resistance value of the first MOS transistor Q1, and thus improving the accuracy of current sampling.

[0090] In some embodiments, optionally, the detection module 140 includes: an operational amplifier OPA, the output terminal of the operational amplifier OPA is used to output a first voltage value and a second voltage value; a fourth resistor R4, the first end of the fourth resistor R4 is connected to the first end of the first MOS transistor Q1, and the second end of the fourth resistor R4 is connected to the first end of the operational amplifier OPA; a fifth resistor R5, the first end of the fifth resistor R5 is connected to the second end of the operational amplifier OPA, and the second end of the fifth resistor R5 is connected to the second end of the first MOS transistor Q1.

[0091] In this embodiment, the detection module 140 includes an operational amplifier OPA, a fourth resistor R4, and a fifth resistor R5. The operational amplifier OPA is used to collect the first voltage value and the second voltage value of the first MOS transistor Q1 through the fourth resistor R4 and the fifth resistor R5.

[0092] Specifically, the first end of the operational amplifier OPA is connected to the first end of the first MOS transistor Q1 through the fourth resistor R4, the second end of the operational amplifier OPA is connected to the second end of the first MOS transistor Q1 through the fifth resistor R5, and the operational amplifier OPA can continuously monitor the voltage value across the first MOS transistor Q1 through the fourth resistor R4 and the fifth resistor R5.

[0093] Exemplarily, when the current injection module 120 injects a first current into the first end of the first MOS transistor Q1, the voltage value collected by the operational amplifier OPA is the first voltage value. When the current injection module 120 stops injecting the first current into the first end of the first MOS transistor Q1, the voltage value collected by the operational amplifier OPA is the second voltage value.

[0094] In the embodiments of the present application, by providing an operational amplifier OPA in the detection module 140, and a fourth resistor R4 and a fifth resistor R5 connected to the first end and the second end of the operational amplifier OPA respectively, it is possible to accurately detect the first voltage value and the second voltage value across the first MOS transistor Q1, further improving the accuracy of current sampling of the sampling circuit 100.

[0095] In some embodiments, optionally, the detection module 140 further includes: a diode D1, a first end of the diode D1 is connected to a second end of the fourth resistor R4, and a second end of the diode D1 is connected to a first end of the fifth resistor R5, wherein the current conducts unidirectionally from the first end to the second end of the diode D1.

[0096] In this embodiment, the detection module 140 further includes a diode D1. The diode D1 is disposed between the fourth resistor R4 and the fifth resistor R5. The diode D1 enables current to flow through the fourth resistor R4 and the fifth resistor R5 in sequence, and provides reverse cut-off between the fourth resistor R4 and the fifth resistor R5.

[0097] Specifically, the first end and the second end of the diode D1 are connected to the fourth resistor R4 and the resistor respectively, that is, the diode D1 enables current to flow from the fourth resistor R4 to the fifth resistor R5, and prevents the current at the fifth resistor R5 from flowing reversely through the fourth resistor R4.

[0098] In the embodiments of the present application, by providing an anti-reverse diode D1 between the fourth resistor R4 and the fifth resistor R5, it is possible to avoid the impact of reverse current on the operational amplifier OPA, further improving the stability of the detection module 140.

[0099] In some embodiments, optionally, the detection module 140 further includes: a sixth resistor R6, a first end of the sixth resistor R6 is configured to receive a fourth voltage value, a second end of the sixth resistor R6 is connected to a first end of the operational amplifier OPA, and the fourth voltage value includes a reference voltage value of the operational amplifier OPA; a seventh resistor R7, a first end of the seventh resistor R7 is connected to a second end of the operational amplifier OPA, and a second end of the seventh resistor R7 is connected to an output end of the operational amplifier OPA.

[0100] In this embodiment, the detection module 140 further includes a sixth resistor R6 and a seventh resistor R7. The sixth resistor R6 is used to receive the fourth voltage value of the reference voltage of the operational amplifier OPA, that is, the reference voltage value is transmitted to the operational amplifier OPA through the sixth resistor R6. The seventh resistor R7 is connected between the output end and the second end of the operational amplifier OPA, and the seventh resistor R7 is used to adjust the amplification factor of the operational amplifier OPA.

[0101] Exemplarily, the amplification factor A of the operational amplifier OPA in the above relationship (1) and the above relationship (2) can be adjusted by the seventh resistor R7.

[0102] In the embodiment of the present application, by setting the sixth resistor R6 and the seventh resistor R7 in the detection module 140, the first end of the operational amplifier OPA can receive a stable reference voltage value, and the amplification factor of the operational amplifier OPA can be adjusted by adjusting the resistance value of the seventh resistor R7.

[0103] In some embodiments, the sampling circuit 100 further includes: a second MOS transistor Q2, a first end of the second MOS transistor Q2 is connected to the first power supply BT1, and a second end of the second MOS transistor Q2 is connected to a first end of the first MOS transistor Q1.

[0104] In the embodiment of the present application, the second MOS transistor Q2 is connected between the first MOS transistor Q1 and the first power supply BT1, where the second MOS transistor Q2 is the MOS transistor of the upper bridge arm, and the first MOS transistor Q1 is the MOS transistor of the lower bridge arm. By connecting the detection module 140 across the two ends of the first MOS transistor Q1, the accuracy of the vector control of the motor can be improved.

[0105] Figure 4 The structural block diagram of a motor provided by some embodiments of the present application is shown, as Figure 4 shown. According to an embodiment of the present application, a motor 200 is proposed, including: a sampling circuit 100 and a controller 202, and the controller 202 is connected to the sampling circuit. The sampling circuit 100 is the sampling circuit 100 in any of the above embodiments, and thus has all the beneficial technical effects of the sampling circuit 100 in any of the above embodiments, and will not be elaborated here too much.

[0106] In some embodiments, optionally, the controller is connected to the output end of the detection module.

[0107] In some embodiments, optionally, the controller is connected to the voltage sampling end of the current injection module.

[0108] It should be clear that in the claims, the specification and the drawings of the present application, the term "a plurality of" means two or more, unless otherwise explicitly defined. The orientation or positional relationship indicated by terms such as "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings. This is only for more convenient description of the present application and to simplify the description process, rather than to indicate or imply that the device or element referred to must have the specific orientation described, be constructed and operate in a specific orientation. Therefore, these descriptions should not be construed as limitations on the present application; terms such as "connection", "installation", "fixation", etc. should all be understood in a broad sense. For example, "connection" can be a fixed connection between multiple objects, a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances of the above data.

[0109] In the claims, the specification and the drawings of the present application, the description of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the claims, the specification and the drawings of the present application, the schematic expressions of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0110] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A sampling circuit, characterized in that: include: A first MOS transistor, wherein a first end of the first MOS transistor is electrically connected to a first power supply, and a second end of the first MOS transistor is grounded; a current injection module, wherein an output end of the current injection module is connected to a first end of the first MOS transistor, and the current injection module is used to inject a first current of a first current value into the first MOS transistor; a detection module, wherein a first end of the detection module is connected to a first end of the first MOS tube, a second end of the detection module is connected to a second end of the first MOS tube, and the detection module is used to collect a first voltage value and a second voltage value at the first MOS tube; The first voltage value includes a voltage value when the current injection module injects the first current into the first MOS transistor, and the second voltage value includes a voltage value when the current injection module does not inject the first current into the first MOS transistor.

2. The sampling circuit according to claim 1, characterized in that: The current injection module comprises: A switch element, wherein a first end of the switch element is used to receive current; A first resistor, wherein a first end of the first resistor is connected to a second end of the switch element, and a second end of the first resistor is connected to a first end of the first MOS tube.

3. The sampling circuit according to claim 2, characterized in that: The first end of the switch element is connected to the first power source.

4. The sampling circuit according to claim 2, characterized in that: The current injection module also includes: A second power supply, wherein an output end of the second power supply is connected to the first end of the switch element.

5. The sampling circuit according to any one of claims 2 to 4, characterized in that: The current injection module also includes: a second resistor, wherein a first end of the second resistor is connected to a first end of the switch element; a third resistor, a first end of the third resistor being connected to a second end of the second resistor, and a second end of the third resistor being grounded; Among them, the first end of the third resistor is a voltage sampling end, and the voltage sampling end is used to collect a third voltage value, and the third voltage value is used to determine the first current value.

6. The sampling circuit according to any one of claims 1 to 4, characterized in that: The detection module comprises: an operational amplifier, wherein an output terminal of the operational amplifier is used to output the first voltage value and the second voltage value; a fourth resistor, wherein a first end of the fourth resistor is connected to a first end of the first MOS tube, and a second end of the fourth resistor is connected to a first end of the operational amplifier; A fifth resistor, wherein a first end of the fifth resistor is connected to the second end of the operational amplifier, and a second end of the fifth resistor is connected to the second end of the first MOS tube.

7. The sampling circuit according to claim 6, characterized in that: The detection module further includes: A diode, wherein the first end of the diode is connected to the second end of the fourth resistor, and the second end of the diode is connected to the first end of the fifth resistor, wherein the first end of the diode is unidirectionally conductive to the second end of the diode.

8. The sampling circuit according to claim 6, characterized in that: The detection module further includes: a sixth resistor, wherein a first end of the sixth resistor is used to receive a fourth voltage value, a second end of the sixth resistor is connected to the first end of the operational amplifier, and the fourth voltage value includes a reference voltage of the operational amplifier; A seventh resistor, wherein a first end of the seventh resistor is connected to the second end of the operational amplifier, and a second end of the seventh resistor is connected to the output end of the operational amplifier.

9. The sampling circuit according to any one of claims 1 to 4, characterized in that: Also includes: A second MOS tube, wherein a first end of the second MOS tube is connected to the first power source, and a second end of the second MOS tube is connected to the first end of the first MOS tube.

10. An electric motor, characterized in that: include: The sampling circuit according to any one of claims 1 to 9; A controller is connected to the sampling circuit.

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