Phase current detection circuit and clothes treatment equipment
By combining a current sampling module, a resistor voltage divider module, and a filter module, the problem of high cost in traditional phase current detection circuits is solved, achieving low-cost, high-precision phase current signal detection.
Patent Information
- Application Number
- CN202423243103.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2034-12-26
AI Technical Summary
Traditional phase current detection circuits are expensive, and the use of operational amplifier circuits leads to excessively high detection costs.
A combination of current sampling module, resistor voltage divider module, filter module and control module is used to replace the operational amplifier with resistor voltage divider and filter technology to achieve accurate sampling of phase current signal.
It reduces detection costs, improves signal quality and detection accuracy, simplifies circuit structure, and reduces power consumption.
Smart Images
Figure CN223784381U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of current detection, and particularly relates to a phase current detection circuit and a clothes processing device. BACKGROUND
[0002] The electronic commutation device of the direct drive motor and the brushless direct current motor replaces the mechanical commutation device of the brush direct current motor, and improves the defects of the brush motor commutation, such as electric spark, poor reliability, electromagnetic interference and loud noise, and is more and more applied to products such as washing machines or clothes dryers.
[0003] In order to collect the three-phase current of the direct drive motor or the electronic commutation device such as the brushless direct current motor, the traditional phase current detection circuit amplifies and samples the three-phase current through three operational amplifiers. However, the operational amplifier is an integrated chip, which contains multiple transistors, resistors, capacitors and other elements, so that the cost of phase current detection is high. CONTENT OF THE UTILITY MODEL
[0004] The application aims to provide a phase current detection circuit and a clothes processing device, and aims to solve the problem of high detection cost of the traditional phase current detection circuit.
[0005] The application provides a phase current detection circuit, which comprises:
[0006] A current sampling module is used for connecting with a lower bridge arm power device of a motor driving circuit, sampling a phase current signal of a motor, and forming a current sampling signal.
[0007] A resistance voltage dividing module is used for obtaining a power supply voltage signal at a first end, and connecting with the current sampling module at a second end. The resistance voltage dividing module is used for dividing and converting the power supply voltage signal and the current sampling signal to form a voltage detection signal.
[0008] A first filtering module is connected with a third end of the resistance voltage dividing module, and is used for filtering the voltage detection signal to obtain a filtered voltage detection signal.
[0009] A control module is connected with a common connection end of the first filtering module and the third end of the resistance voltage dividing module, and is used for determining the phase current signal according to the filtered voltage detection signal.
[0010] In an embodiment, the phase current detection circuit further comprises:
[0011] A unidirectional protection module, a first end of the unidirectional protection module is connected with a first end of the resistance voltage division module, a second end of the unidirectional protection module is connected with a common connection end of the control module and a third end of the resistance voltage division module, and the unidirectional protection module is used for protecting the control module.
[0012] In one embodiment, the phase current detection circuit further comprises:
[0013] A second filtering module, connected with a common connection end of the current sampling module and a second end of the resistance voltage division module, and used for filtering the current sampling signal.
[0014] In one embodiment, the resistance voltage division module comprises:
[0015] A first sub-voltage division module, a first end of the first sub-voltage division module is used for acquiring the power voltage signal and is connected with a first end of the unidirectional protection module, and a second end of the first sub-voltage division module is connected with a common connection end of the control module and a second end of the unidirectional protection module;
[0016] A second sub-voltage division module, a first end of the second sub-voltage division module is connected with a second end of the first sub-voltage division module, and a second end of the second sub-voltage division module is connected with a common connection end of the current sampling module and the second filtering module.
[0017] In one embodiment, the second filtering module comprises:
[0018] At least one second capacitor, a first end of the second capacitor is connected with a common connection end of the current sampling module and a second end of the resistance voltage division module, and a second end of the second capacitor is grounded.
[0019] In one embodiment, a grounding end of the current sampling module, a grounding end of the first filtering module and a grounding end of the second filtering module are connected to a common grounding end in a single-point grounding mode.
[0020] In one embodiment, the first sub-voltage division module comprises at least one first resistor;
[0021] A first end of the first resistor is used for acquiring a power voltage signal and is connected with a first end of the unidirectional protection module, and a second end of the first resistor is connected with a common connection end of the control module and a second end of the unidirectional protection module;
[0022] The second sub-voltage division module comprises at least one second resistor;
[0023] The first end of the second resistor is connected with the second end of the first resistor, and the second end of the second resistor is connected with a common connection end of the current sampling module and the second filtering module.
[0024] In one embodiment, the unidirectional protection module comprises:
[0025] At least one diode, a cathode end of the diode is connected with the first end of the resistance voltage dividing module, and an anode end of the diode is connected with a common connection end of the control module and the third end of the resistance voltage dividing module.
[0026] In one embodiment, the first filtering module comprises:
[0027] At least one first capacitor, a first end of the first capacitor is connected with a common connection end of the second end of the unidirectional protection module and the third end of the resistance voltage dividing module, and a second end of the first capacitor is grounded.
[0028] In one embodiment, the current sampling module comprises at least one sampling resistor;
[0029] A first end of the sampling resistor is connected with a common connection end of the lower bridge arm power device of the motor driving circuit and the second end of the resistance voltage dividing module, and a second end of the sampling resistor is grounded.
[0030] The present application provides a kind of clothes processing equipment, including at least one phase current detection circuit described in any one of the above embodiments.
[0031] Compared with prior art, the utility model embodiment has the beneficial effects that:
[0032] When the lower bridge arm power device of the motor driving circuit is turned on, the phase current signal of the motor flows out from the motor winding, passes through the lower bridge arm power device, and then flows back to the ground through the current sampling module. The phase current signal of the motor flows through the current sampling module to form a current sampling signal. The current sampling signal is in the form of a voltage signal. The phase current signal of the motor is alternating current, which may include positive current and negative current. After the power voltage signal is divided by the resistance voltage dividing module, a divided voltage is formed, which can provide a DC bias voltage for the current sampling signal, lift the waveform of the current sampling signal as a whole to 0V or above, and convert it into a voltage detection signal, so that the sampling voltage requirement of the control module can be matched, and the back-end control module can collect accurate and complete phase current signals.
[0033] The voltage detection signal converted by the resistance voltage division module contains accurate and complete motor phase current signals. By the first filtering module, the interference signals in the voltage detection signal converted by the resistance voltage division module can be filtered, the signal quality is improved, so that the filtered voltage detection signal can retain the useful signals about the motor phase current signals. Based on the principle of Ohm's law, the control module can calculate and determine the corresponding phase current signal according to the filtered voltage detection signal, so as to obtain the one-way phase current signal of a phase of the motor.
[0034] The current sampling module and the resistance voltage division module in the phase current detection circuit provided by the application both adopt the principle of resistance voltage division, and combine the first filtering module and the control module, so that the phase current signals can be accurately, completely and safely and stably sampled, instead of the operational amplifier circuit in the traditional technology. Compared with the operational amplifier circuit in the traditional technology, the overall circuit structure of the phase current detection circuit provided by the application is simple, low in cost and low in power consumption, can effectively reduce the detection cost, and solves the problem of high detection cost caused by the phase current signal detection by the operational amplifier circuit in the traditional technology. BRIEF DESCRIPTION OF DRAWINGS
[0035] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiments or exemplary technical descriptions will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.
[0036] Figure 1 The structural schematic diagram of the phase current detection circuit in some embodiments provided by the application.
[0037] Figure 2 The structural schematic diagram of the phase current detection circuit in some embodiments provided by the application.
[0038] Figure 3 The structural schematic diagram of the phase current detection circuit in some embodiments provided by the application.
[0039] Figure 4 The structural schematic diagram of the phase current detection circuit in some embodiments provided by the application.
[0040] Figure 5 The structural schematic diagram of the phase current detection circuit in some embodiments provided by the application.
[0041] Figure 6 The structural schematic diagram of the printed circuit board integrated with the intelligent power module and the phase current detection circuit provided by the application.
[0042] Figure 7Fig. 1 shows a schematic diagram of a circuit connection structure of a plurality of phase current detection circuits in a laundry treating apparatus according to some embodiments of the present application. DETAILED DESCRIPTION
[0043] In order to make the technical problems solved by the present application, the technical solutions and the beneficial effects clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present application, and not to limit the present application.
[0044] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.
[0045] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0046] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.
[0047] Please refer to Figure 1 The present application provides a phase current detection circuit 100 for detecting a single-phase current signal of a motor. The phase current detection circuit 100 comprises a current sampling module 10, a resistance voltage division module 20, a first filtering module 30, and a control module 40. The current sampling module 10 is configured to be connected with a lower bridge arm power device of a motor drive circuit. The motor drive circuit comprises a power circuit, a control signal generation circuit, a power supply circuit, a protection circuit, and an interface circuit, etc. The power circuit comprises a three-phase bridge circuit, specifically comprising three upper bridge arms and three lower bridge arms. The motor drive circuit can be integrated in an intelligent power module 200. The intelligent power module 200 (IPM) can be understood as a power module integrating power devices (such as insulated gate bipolar transistors, metal-oxide-semiconductor field effect transistors, etc.) with a drive circuit and a protection circuit.
[0048] When the lower bridge arm power device of the motor driving circuit is turned on, the phase current signal of the motor flows out from the motor winding, passes through the lower bridge arm power device, and then flows back to the ground through the current sampling module 10. The connection of the current sampling module 10 with the lower bridge arm power device of the motor driving circuit realizes the collection of the phase current signal, and the circuit structure is simple and the cost is low. The current sampling module 10 is used for sampling the phase current signal of the motor and forming a current sampling signal. The phase current signal of the motor is an alternating current, and there are positive and negative currents. The phase current signal of the motor flows through the current sampling module 10, forms a current sampling signal, and is expressed in the form of a voltage signal V U .
[0049] The first end of the resistance voltage dividing module 20 is used to obtain a power supply voltage signal VCC. The second end of the resistance voltage dividing module 20 is connected with the current sampling module 10. The resistance voltage dividing module 20 is used to divide and convert the power supply voltage signal VCC and the current sampling signal to form a voltage detection signal V1. After the power supply voltage signal VCC is divided by the resistance voltage dividing module 20, a divided voltage is formed, which can provide a direct current bias voltage for the current sampling signal, so that the sampling voltage requirement of the control module 40 can be matched. By providing a direct current bias voltage for the current sampling signal through the resistance voltage dividing module 20, the waveform of the current sampling signal can be lifted to 0V and above as a whole, and converted into a voltage detection signal V1, so as to facilitate the control module 40 at the rear end to collect accurate and complete phase current signals. The current sampling module 10 and the resistance voltage dividing module 20 both use the principle of resistance voltage division to sample the phase current signal of the motor, so that the overall circuit structure is simple, the cost is low, and the power consumption is low, which can be better applied to different scenes.
[0050] The first filter module 30 is connected with the third end of the resistance voltage dividing module 20. The first filter module 30 is used to filter the voltage detection signal V1 to obtain a filtered voltage detection signal V1. The voltage detection signal V1 converted by the resistance voltage dividing module 20 contains accurate and complete motor phase current signals. Through the first filter module 30, the interference signals (such as power supply noise interference signals, electromagnetic interference signals, and vibration interference signals, etc.) in the voltage detection signal V1 converted by the resistance voltage dividing module 20 can be filtered, and the signal quality is improved, so that the filtered voltage detection signal V1 can retain the useful signals about the motor phase current signal.
[0051] The control module 40 is connected with the common connection end of the first filtering module 30 and the third end of the resistance voltage dividing module 20. The control module 40 is used for determining the phase current signal according to the filtered voltage detection signal V1. The voltage detection signal V1 filtered by the first filtering module 30 retains the useful signal of the phase current signal of the motor and can accurately and completely reflect the phase current signal of the motor. According to the principle of Ohm's law, when the phase current signal flows through the resistor with a known resistance value in the current sampling module 10, the current sampling signal is formed, and the voltage signal V U According to the principle of Ohm's law, the current sampling signal can be converted into the filtered voltage detection signal V1 by the resistance voltage dividing module 20 and the first filtering module 30. The resistance value of the current sampling module 10, the resistance value of the resistance voltage dividing module 20 and the voltage value of the power supply voltage signal VCC are known. According to the principle of Ohm's law, the control module 40 can calculate and determine the corresponding phase current signal according to the filtered voltage detection signal V1, so as to obtain the one-way phase current signal of a phase of the motor.
[0052] The phase current detection circuit 100 provided in the application adopts the principle of resistance voltage division for the current sampling module 10 and the resistance voltage dividing module 20, and combines the first filtering module 30 and the control module 40, so as to accurately, completely and safely sample the phase current signal, instead of the operational amplifier circuit in the traditional technology. Compared with the operational amplifier circuit in the traditional technology, the overall circuit structure of the phase current detection circuit 100 provided in the application is simple, the cost is low and the power consumption is low, which can effectively reduce the detection cost and solve the problem of high detection cost caused by the phase current signal detection by using the operational amplifier circuit in the traditional technology.
[0053] In one embodiment, the control module 40 can be a digital signal processor, a programmable logic controller, a field programmable gate array or a microcontroller, etc. Further, the control module 40 uses a filtering algorithm to further filter the filtered voltage detection signal V1, so as to improve the signal quality and obtain more accurate useful signal containing the phase current signal of the motor. By using the filtering algorithm for filtering processing by the first filtering module 30 in combination with the control module 40, the voltage detection signal V1 can be doubly filtered, so as to further filter out the power supply noise interference signal, the electromagnetic interference signal and the vibration interference signal, etc., and improve the detection accuracy of the phase current signal.
[0054] In one embodiment, the control module 40 uses a median value filtering algorithm or an average value filtering algorithm to filter the filtered voltage detection signal V1, so as to further shield the interference of the useless signal.
[0055] Please refer to Figure 2In one embodiment, the phase current detection circuit 100 further comprises a unidirectional protection module 50. A first end of the unidirectional protection module 50 is connected to a first end of the resistance voltage division module 20. A second end of the unidirectional protection module 50 is connected to a common connection end of the control module 40 and a third end of the resistance voltage division module 20, for protecting the control module 40.
[0056] A first end of the unidirectional protection module 50 is connected to a first end of the resistance voltage division module 20. The first end of the unidirectional protection module 50, the first end of the resistance voltage division module 20, and the power voltage signal VCC form a common connection end. A second end of the unidirectional protection module 50 is connected to a common connection end of the control module 40 and a third end of the resistance voltage division module 20, for protecting the control module 40. The second end of the unidirectional protection module 50, the third end of the resistance voltage division module 20, the first filter module 30, and the control module 40 form a common connection end. The unidirectional protection module 50 has unidirectional conductivity. Through the unidirectional protection module 50, a discharge channel is provided for external current, which can prevent external current from being applied to the control module 40, thereby avoiding damage to the control module 40 and protecting the control module 40, thereby ensuring stable and safe operation of the phase current detection circuit 100. The external current can be understood as a current outside the control module 40.
[0057] Therefore, by using the resistance voltage division principle in the current sampling module 10 and the resistance voltage division module 20 of the phase current detection circuit 100 provided in the present application, and combining the first filter module 30, the unidirectional protection module 50, and the control module 40, the phase current signal can be accurately, completely, and safely and stably sampled, replacing the operational amplifier circuit in the traditional technology. Compared with the operational amplifier circuit in the traditional technology, the overall circuit structure of the phase current detection circuit 100 provided in the present application is simple, low in cost, and low in power consumption, which can effectively reduce the detection cost and solve the problem of high detection cost caused by using the operational amplifier circuit for phase current signal detection in the traditional technology.
[0058] Please refer to Figure 3 In one embodiment, the phase current detection circuit 100 further comprises a second filter module 60. The second filter module 60 is connected to a common connection end of the current sampling module 10 and a second end of the resistance voltage division module 20. The second filter module 60 is used to filter the current sampling signal to obtain a filtered current sampling signal. The resistance voltage division module 20 is used to convert the filtered current sampling signal into a voltage detection signal.
[0059] The second filtering module 60 is connected to the sampling front end of the phase current detection circuit 100. By filtering the current sampling signal directly through the second filtering module 60, the interference signal contained in the current sampling signal is filtered at the initial stage of the propagation of the current sampling signal, which can reduce the interference to other circuit parts in the rear end. Further, by filtering the current sampling signal at the initial stage through the second filtering module 60, it can ensure that the rear-end circuit receives high-quality signals, and the subsequent processing is based on purer signals, which improves the phase current detection accuracy, reliability and stability of the entire circuit. Further, combined with the first filtering module 30 for rear-end filtering, the voltage detection signal V1 filtered by the first filtering module 30 is more in line with the sampling requirements of the control module 40, so that the control module 40 can more accurately and stably obtain the filtered voltage detection signal V1. Therefore, by using the filtering algorithm for multiple filtering processing through the second filtering module 60, the first filtering module 30 and the control module 40, the filtering effect is enhanced, so that the phase current detection circuit 100 can adapt to complex signal environment, improve the stability and reliability of the circuit, and better improve the detection accuracy of the phase current signal.
[0060] See Figure 4 In one embodiment, the resistance voltage division module 20 includes a first sub-voltage division module 210 and a second sub-voltage division module 220. The first end of the first sub-voltage division module 210 is used to obtain a power supply voltage signal and is connected to the first end of the one-way protection module 50. The second end of the first sub-voltage division module 210 is connected to the common connection end of the second end of the control module 40 and the one-way protection module 50. The first end of the second sub-voltage division module 220 is connected to the second end of the first sub-voltage division module 210. The second end of the second sub-voltage division module 220 is connected to the common connection end of the current sampling module 10 and the second filtering module 60.
[0061] The first sub-voltage division module 210 and the second sub-voltage division module 220 form a series circuit structure, which can also be understood as forming a resistance voltage division circuit structure. By forming a series circuit structure of the first sub-voltage division module 210 and the second sub-voltage division module 220, it is convenient to adjust the voltage division ratio, disperse the power loss, and reduce the power requirement of a single sub-voltage division module. Further, during the debugging process of the phase current detection circuit 100, it is convenient for circuit debugging and fault troubleshooting.
[0062] The unidirectional protection module 50 is connected in parallel across the first sub-voltage dividing module 210. The second end of the first sub-voltage dividing module 210, the first end of the second sub-voltage dividing module 220, the first filter module 30, the second end of the unidirectional protection module 50, and the control module 40 form a common connection end. The filtered voltage detection signal V1 collected by the control module 40 can also be understood as the voltage of the common connection end of the second end of the first sub-voltage dividing module 210 and the first end of the second sub-voltage dividing module 220. The first sub-voltage dividing module 210 and the second sub-voltage dividing module 220 each include a resistive element, and the resistance value and the voltage value of the power supply voltage signal VCC are known. Further, based on the principle of Ohm's law, the control module 40 can determine the corresponding phase current signal according to the filtered voltage detection signal V1, thereby obtaining the unidirectional phase current signal of a phase of the motor.
[0063] The resistive voltage dividing structure formed by the first sub-voltage dividing module 210 and the second sub-voltage dividing module 220 is simple and easy to adjust. Different resistance value parameters and voltage value parameters of the power supply voltage signal VCC can be set to adjust the signal range of the current sampling signal and adapt to the signal collection requirements of the control module 40. Further, the resistive voltage dividing structure formed by the first sub-voltage dividing module 210 and the second sub-voltage dividing module 220 can reduce the influence of quantization error, improve signal resolution and accuracy, and make the applicability of the phase current detection circuit 100 more extensive.
[0064] In one embodiment, the first filter module 30 can include a low-pass filter to remove high-frequency noise and retain low-frequency components related to the phase current signal. In one embodiment, the first filter module 30 includes at least one first capacitor 310. The capacitance parameter of the first capacitor 310 can be adjusted according to the actual application scenario. The number of first capacitors 310 can also be adjusted according to the actual application scenario. In one embodiment, the first filter module 30 includes a plurality of first capacitors 310 connected in series.
[0065] The first end of the first capacitor 310 is connected to the common connection end of the second end of the unidirectional protection module 50 and the third end of the resistive voltage dividing module 20. The second end of the first capacitor 310 is grounded. The first end of the first capacitor 310 is connected to the common connection end of the second end of the first sub-voltage dividing module 210 and the first end of the second sub-voltage dividing module 220, for filtering the voltage detection signal V1 of the common connection end to obtain the filtered voltage detection signal V1. The filtered voltage detection signal V1 is transmitted to the control module 40 for subsequent signal processing. The first filter module 30 is implemented by the first capacitor 310, which can filter out noise interference while reducing costs, is simple to use, and reduces the overall circuit cost of the phase current detection circuit 100.
[0066] In an embodiment, the second filtering module 60 comprises at least one second capacitor 610. The capacitance parameter of the second capacitor 610 can be adjusted according to the actual application scenario. The number of the second capacitor 610 can also be adjusted according to the actual application scenario. In an embodiment, the second filtering module 60 comprises a plurality of second capacitors 610, and the plurality of second capacitors 610 are connected in series.
[0067] The first end of the second capacitor 610 is connected with the common connection end of the second end of the current sampling module 10 and the resistance voltage division module 20. The second end of the second capacitor 610 is grounded. The first end of the second capacitor 610 is connected with the second end of the second sub voltage division module 220. The current sampling signal is filtered before being converted by the first sub voltage division module 210 and the second sub voltage division module 220, so that the interference signal contained in the current sampling signal is filtered at the initial stage of the propagation of the current sampling signal, which can ensure that the back-end circuit receives high-quality signals and improves the phase current detection accuracy, reliability and stability of the entire circuit. The second filtering module 60 is realized by the second capacitor 610, which can filter out noise interference while reducing cost, is simple to use, and reduces the overall circuit cost of the phase current detection circuit 100.
[0068] Please refer to Figure 5 In an embodiment, the first sub voltage division module 210 comprises at least one first resistor 211. The first sub voltage division module 210 comprises one first resistor 211 or a plurality of first resistors 211. The number of the first resistor 211 can be adjusted according to the actual application scenario. The resistance value of the first resistor 211 can be set according to the actual application scenario. The first sub voltage division module 210 comprises a plurality of first resistors 211, and the plurality of first resistors 211 are connected in series. The division ratio can be flexibly adjusted by changing the resistance value ratio of the plurality of first resistors 211. Further, by the plurality of first resistors 211, the power loss on each resistor can be dispersed, the power requirement of a single resistor is reduced, the cost and power consumption are reduced, and the reliability of the circuit is improved.
[0069] The first end of the first resistor 211 is used to obtain a power supply voltage signal VCC and is connected with the first end of the unidirectional protection module 50. The second end of the first resistor 211 is connected with the common connection end of the second end of the control module 40 and the unidirectional protection module 50. The first resistor 211 is connected in parallel with the unidirectional protection module 50. The second end of the first resistor 211, the first end of the first capacitor 310, the second end of the unidirectional protection module 50 and the control module 40 form a common connection end.
[0070] In an embodiment, the second sub-voltage division module 220 includes at least one second resistor 221. The second sub-voltage division module 220 includes one second resistor 221 or multiple second resistors 221. The number of second resistors 221 can be adjusted according to the actual application scenario. The resistance value of the second resistor 221 can be adjusted according to the actual application scenario. The second sub-voltage division module 220 includes multiple second resistors 221, and the multiple second resistors 221 are connected in series. By changing the resistance ratio of the multiple second resistors 221, the voltage division ratio can be flexibly adjusted. Further, by the multiple second resistors 221, the power loss on each resistor can be dispersed, the power requirement of a single resistor is reduced, the cost and power consumption are reduced, and the reliability of the circuit is improved.
[0071] The first end of the second resistor 221 is connected with the second end of the first resistor 211. The second end of the second resistor 221 is connected with the common connection end of the current sampling module 10 and the second filter module 60. It can also be understood that the second end of the second resistor 221 is connected with the current sampling module 10 and the first end of the second capacitor 610. After the current sampling signal is filtered by the second capacitor 610, a filtered current sampling signal is formed. After the filtered current sampling signal is divided by the second resistor 221 and the first resistor 211, a voltage detection signal V1 is formed.
[0072] The voltage detection signal V1 is the voltage signal of the common connection end of the first resistor 211 and the second resistor 221. After the voltage detection signal V1 is filtered by the first capacitor 310, a filtered voltage detection signal V1 is formed and transmitted to the control module 40 for signal processing. By the first resistor 211 and the second resistor 221, the voltage division function of the first sub-voltage division module 210 and the second sub-voltage division module 220 is realized, and the cost of the entire circuit is reduced, which is simple and easy to use, and the overall circuit cost of the phase current detection circuit 100 is reduced.
[0073] In an embodiment, the unidirectional protection module 50 includes at least one diode 510. The number of diodes 510 can be adjusted according to the actual application scenario. The parameters of the diode 510 can also be adjusted according to the actual application scenario. The number of diodes 510 can also be set according to the actual application scenario. The cathode end of the diode 510 is connected with the first end of the resistor voltage division module 20. The anode end of the diode 510 is connected with the common connection end of the control module 40 and the third end of the resistor voltage division module 20.
[0074] The diode 510 is connected in parallel between the first resistor 211. The first end of the first capacitor 310, the first end of the second resistor 221, the second end of the first resistor 211, and the control module 40 form a common connection end, and the anode end of the diode 510 is connected to the common connection end. The diode 510 has unidirectional conductivity. Through the diode 510, the function of unidirectional protection of the module 50 can be realized, a discharge channel is provided for external current, and external current can be prevented from being applied to the control module 40, thereby protecting the control module 40.
[0075] In an embodiment, the current sampling module 10 includes at least one sampling resistor 110. The number of sampling resistors 110 can be adjusted according to the actual application scenario. The resistance value of the sampling resistor 110 can also be adjusted according to the actual application scenario. The current sampling module 10 includes a plurality of sampling resistors 110, and the plurality of sampling resistors 110 are connected in series. By changing the resistance ratio of the plurality of sampling resistors 110, the voltage division ratio can be flexibly adjusted. Further, through the plurality of sampling resistors 110, the power loss on each resistor can be dispersed, the power requirement of a single resistor is reduced, the cost and power consumption are reduced, and the reliability of the circuit is improved.
[0076] The first end of the sampling resistor 110 is connected to the common connection end of the lower bridge arm power device of the motor drive circuit and the second end of the resistance voltage division module 20. The second end of the sampling resistor 110 is grounded. It can also be understood that the first end of the sampling resistor 110 is connected to the lower bridge arm power device of the motor drive circuit and the second end of the second resistor 221 and the first end of the second capacitor 610. The phase current signal forms a current sampling signal through the sampling resistor 110, and the voltage signal V U The current sampling signal is filtered through the second capacitor 610 to form a filtered current sampling signal. Through the sampling resistor 110, the collection of the phase current signal is realized, and at the same time the cost of the entire circuit is reduced, which is simple and easy to use, so that the overall circuit cost of the phase current detection circuit 100 is reduced.
[0077] In an embodiment, the control module 40 is a microcontroller unit (MCU). The input pin of the sampling end of the control module 40 can accept a voltage range of 0-3.3V or 0-5V, etc. The control module 40 internally integrates an analog-to-digital conversion module (ADC) or uses an external independent ADC chip. The phase current signal is an alternating current signal, such as a sine wave signal, etc. In order to enable the negative phase current signal to be sampled by the control module 40, a voltage bias corresponding to the time when the phase current signal is zero needs to be set. The maximum current value and the minimum current value of the actual phase current need to be sampled within the range of the control module 40 sampling AD value.
[0078] If the working voltage of the control module 40 needs to be 0V to 3.3V, the range of the phase current signal needs to be set to -9A to 9A. The resistance values R 221 = 172Ω, R 110 = 0.05Ω, and R 211 = 1200Ω. Figure 4 Taking the U phase shown in the figure as an example, the static bias voltage corresponding to the phase current signal of zero is set. If the power voltage signal VCC is 3.3V and the phase current signal is zero, according to the principle of Ohm's law, the static bias voltage collected by the control module 40 = 3.3*(R 221 + R 110 ) / (R 211 + R 221 + R 110 )≈3.3*172 / (172+1200), which is 0.413V. By amplifying the AD value by 4 times by the control module 40, the static bias voltage when the phase current signal is zero is 0.413*4=1.65V.
[0079] If there is a phase current signal, the maximum voltage of the filtered voltage detection signal V1 collected by the control module 40 is 3.3V / 4, then according to the principle of Ohm's law, R 110 *I SU *R 211 / (R 221 + R 211 ) = 3.3 / 4-1.65 / 4 = 0.413, and the phase current signal I SU = 9.43A obtained after solving.
[0080] If there is a phase current signal, the minimum voltage of the filtered voltage detection signal V1 collected by the control module 40 is 0V, then according to the principle of Ohm's law, R 110 *I SU *R 211 / (R 221 + R 211 ) = 0-1.65 / 4 = -0.413, and the phase current signal I SU = -9.43A obtained after solving. By setting the resistance values R 221 = 172Ω, R 110 = 0.05Ω, R 211 = 1200Ω, and the parameters of the power voltage signal VCC, the static bias voltage when the phase current signal is zero and the working voltage of the control module 40 can be met.
[0081] In one embodiment, the resistance values R 221 , R 110 , and R 211The parameters of the circuit elements can be adjusted according to actual application scenarios, and specific parameters are not limited in the present application.
[0082] Referring to Figure 6 In one embodiment, the ground end of the current sampling module 10, the ground end of the first filtering module 30, and the ground end of the second filtering module 60 are connected to a common ground end in a single-point grounding manner. The single-point grounding can be understood as that all circuit parts needing grounding in the phase current detection circuit 100 are connected to a common grounding point, i.e., the common ground end. By grounding the ground end of the current sampling module 10, the ground end of the first filtering module 30, and the ground end of the second filtering module 60 in a single-point grounding manner, a stable ground potential can be ensured for the circuit, and mutual interference between different circuit structures due to ground current can be avoided. Therefore, by grounding the ground end of the current sampling module 10, the ground end of the first filtering module 30, and the ground end of the second filtering module 60 in a single-point grounding manner, common-mode interference in the circuit can be suppressed, ground loop interference can be reduced, and the detection accuracy of the phase current detection circuit 100 is improved.
[0083] As shown in the printed circuit board (PCB) shown in Figure 6 The intelligent power module 200 and the phase current detection circuit 100 are integrated together. The intelligent power module 200 and the phase current detection circuit 100 all adopt a single-point grounding manner to be connected to a common ground end. Further, as can be seen from the PCB wiring shown in Figure 6 It can be seen that the phase current detection circuit 100 provided in the present application for phase current detection has a simple circuit structure and low cost, and the PCB wiring is simpler, without the need to design differential lines required for sampling of an operational amplifier.
[0084] Referring to Figure 7 The present application provides a laundry treatment apparatus. The laundry treatment apparatus includes at least one phase current detection circuit 100 in the above embodiments. The laundry treatment apparatus can be an apparatus for washing laundry, an apparatus for drying laundry, and a washing and drying integrated apparatus that can realize washing and drying of laundry, etc. The laundry treatment apparatus can be a laundry treatment apparatus directly arranged on the ground or a placement surface, or a wall-mounted or table-top laundry treatment apparatus, etc.
[0085] The laundry treatment apparatus can include one phase current detection circuit 100, or two phase current detection circuits 100, or three phase current detection circuits 100 or more. Among them, multiple phase current detection circuits 100 can be used to detect phase current signals of different phases.
[0086] The motor driving circuit comprises a U-phase upper bridge field effect tube, a U-phase lower bridge field effect tube, a V-phase upper bridge field effect tube, a V-phase lower bridge field effect tube, a W-phase upper bridge field effect tube, and a W-phase lower bridge field effect tube.
[0087] In one embodiment, the laundry treating apparatus comprises three phase current detection circuits 100. The current sampling module 10 of the first phase current detection circuit 100 is connected to a lower bridge arm power device, i.e. a U-phase lower bridge field effect tube or a U-phase lower bridge insulated gate bipolar transistor. In one embodiment, the current sampling module 10 of the first phase current detection circuit 100 is connected to the NU pin of the intelligent power module 200. The VSU pin of the intelligent power module 200 is connected to the U-phase of the motor.
[0088] The current sampling module 10 of the second phase current detection circuit 100 is connected to a lower bridge arm power device, i.e. a V-phase lower bridge field effect tube or a V-phase lower bridge insulated gate bipolar transistor. In one embodiment, the current sampling module 10 of the second phase current detection circuit 100 is connected to the NV pin of the intelligent power module 200. The VSV pin of the intelligent power module 200 is connected to the V-phase of the motor.
[0089] The current sampling module 10 of the third phase current detection circuit 100 is connected to a lower bridge arm power device, i.e. a W-phase lower bridge field effect tube or a W-phase lower bridge insulated gate bipolar transistor. In one embodiment, the current sampling module 10 of the third phase current detection circuit 100 is connected to the NW pin of the intelligent power module 200. The VSW pin of the intelligent power module 200 is connected to the W-phase of the motor.
[0090] In one embodiment, the phase current detection circuit 100 provided by the present application can be applied to the phase current detection of the direct driving motor of the laundry treating apparatus, the brushless direct current motor, and the driver of the fan using the brushless direct current motor as a power source. By detecting the phase current of the motor through the phase current detection circuit 100, the phase current signal of each phase can be obtained in real time, and then the vector control, the direct torque control, the variable frequency speed control, and the motor state monitoring and fault diagnosis of the motor are realized, so as to ensure the stable, accurate and safe operation of the motor.
[0091] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction, and do not limit the protection scope of the present application.
[0092] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in a certain embodiment can be referred to the related description of other embodiments. Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present text can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to realize the described functions, but such implementation should not be considered beyond the scope of the present application.
[0093] The division of modules or units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the coupling or direct coupling or communication connection between the displayed or discussed each other can be through some interface, indirect coupling or communication connection of the units or devices, which can be electrical, mechanical or other forms.
[0094] The units described as separate components can or can not be physically separated, and some or all of the units can be selected to achieve the purposes of the present embodiment according to actual needs. In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.
[0095] The integrated module / unit, if realized in the form of a software function unit and sold or used as an independent product, can be stored in a computer-readable storage medium. The computer program includes computer program code, which can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer-readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a U disk, a mobile hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc. It should be noted that the computer-readable medium can include or exclude contents according to the requirements of legislation and patent practice in a jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.
[0096] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.
Claims
1. A phase current detection circuit, characterized in that, include: The current sampling module (10) is used to connect to the lower bridge arm power device of the motor drive circuit to sample the phase current signal of the motor and form a current sampling signal. A resistor voltage divider module (20) is provided. The first end of the resistor voltage divider module (20) is used to acquire the power supply voltage signal. The second end of the resistor voltage divider module (20) is connected to the current sampling module (10). The resistor voltage divider module (20) is used to perform voltage division and conversion based on the power supply voltage signal and the current sampling signal to form a voltage detection signal. The first filtering module (30) is connected to the third terminal of the resistor voltage divider module (20). The first filtering module (30) is used to filter the voltage detection signal to obtain the filtered voltage detection signal. The control module (40) is connected to the common connection terminal of the third terminal of the first filter module (30) and the resistor voltage divider module (20), and is used to determine the phase current signal based on the filtered voltage detection signal.
2. The phase current detection circuit as described in claim 1, characterized in that, The phase current detection circuit also includes: A one-way protection module (50) is provided, wherein the first end of the one-way protection module (50) is connected to the first end of the resistor voltage divider module (20), and the second end of the one-way protection module (50) is connected to the common connection end of the third end of the control module (40) and the resistor voltage divider module (20), for protecting the control module (40).
3. The phase current detection circuit as described in claim 2, characterized in that, The phase current detection circuit also includes: The second filtering module (60) is connected to the common connection terminal of the second end of the current sampling module (10) and the resistor voltage divider module (20). The second filtering module (60) is used to filter the current sampling signal.
4. The phase current detection circuit as described in claim 3, characterized in that, The resistor voltage divider module (20) includes: The first sub-voltage divider module (210) has a first end for acquiring the power supply voltage signal and connecting to the first end of the one-way protection module (50). The second end of the first sub-voltage divider module (210) is connected to the common connection end of the second ends of the control module (40) and the one-way protection module (50). The second sub-voltage divider module (220) has its first end connected to the second end of the first sub-voltage divider module (210), and its second end connected to the common connection terminal of the current sampling module (10) and the second filtering module (60).
5. The phase current detection circuit as described in claim 3, characterized in that, The second filtering module (60) includes: At least one second capacitor (610) is provided, the first end of which is connected to the common connection terminal of the second end of the current sampling module (10) and the resistor voltage divider module (20), and the second end of the second capacitor (610) is grounded.
6. The phase current detection circuit as described in claim 3, characterized in that, The grounding terminals of the current sampling module (10), the first filtering module (30), and the second filtering module (60) are connected to a common grounding terminal using a single-point grounding method.
7. The phase current detection circuit as described in claim 4, characterized in that, The first sub-voltage divider module (210) includes at least one first resistor (211); The first end of the first resistor (211) is used to acquire the power supply voltage signal and is connected to the first end of the one-way protection module (50). The second end of the first resistor (211) is connected to the common connection end of the second end of the control module (40) and the one-way protection module (50). The second sub-voltage divider module (220) includes at least one second resistor (221); The first end of the second resistor (221) is connected to the second end of the first resistor (211), and the second end of the second resistor (221) is connected to the common connection terminal of the current sampling module (10) and the second filtering module (60).
8. The phase current detection circuit as described in any one of claims 2 to 7, characterized in that, The unidirectional protection module (50) includes: At least one diode (510) is provided, the cathode of which is connected to the first end of the resistor divider module (20), and the anode of which is connected to the common connection terminal of the control module (40) and the third end of the resistor divider module (20).
9. The phase current detection circuit as described in any one of claims 2 to 7, characterized in that, The first filtering module (30) includes: At least one first capacitor (310) is provided, the first end of which is connected to the common connection terminal of the second end of the unidirectional protection module (50) and the third end of the resistor voltage divider module (20), and the second end of the first capacitor (310) is grounded.
10. A garment processing device, characterized in that, It includes at least one phase current detection circuit as described in any one of claims 1 to 9.