Efficient brushless motor sampling circuit
By designing an efficient brush -free motor sampling circuit containing diode and capacitors, the problem of the traditional FOC control circuit requires the need to calculate the amplifier under low signal conditions, and achieve the effect of reducing costs and enhancing competitive advantages.
Patent Information
- Application Number
- CN202420680214.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-03
- Publication Date
- 2025-01-28
- Estimated Expiration
- 2034-04-03
AI Technical Summary
The traditional FOC control circuit has weak signals when the motor is no load or low speed, and requires an operational amplifier to amplify the signal. The cost is high and limited by the motor-specific chip, so the competitive advantage is not obvious.
Design a high -efficiency brush -free motor sampling circuit, through the combination of diodes D1 and D2, resistance R18, R16, R19, R17, and capacitor C2, C3 , And process the signal through RC filtering.
The cost is reduced and the dependence on the computing amplifier has been avoided. The MCU selection is no longer limited by special chips for motor, and has obvious competitive advantages.
Smart Images
Figure CN222420353U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of brushless motor sampling circuit design, in particular to a high-efficiency brushless motor sampling circuit. Background Art
[0002] FOC control is a motor control technology, the full name is Field Oriented Control, also known as vector control. This technology can improve the efficiency, control stability and accuracy of the motor, and is widely used in motor drive systems. FOC control requires the collection of three-phase current information (IU, IV, IW), and then obtains motor speed, position and other information through software algorithm processing, so as to realize the start and operation of the motor.
[0003] Traditional FOC control circuit such as Figure 2 The phase current shown is converted into a voltage signal through sampling resistors RS1 and RS2. Since the signal is relatively weak when the motor is unloaded or at a low speed, the signal is usually amplified by a certain multiple through an operational amplifier and then sampled by the ADC module to obtain the current value.
[0004] The FOC motor control solution is basically implemented using a dedicated motor control chip, which is tied to the chip manufacturer, has a high procurement cost, and has no obvious competitive advantage. After the circuit improvement, it is no longer limited to the dedicated motor chip, reducing the solution cost and having a clear competitive advantage. Utility Model Content
[0005] In view of the above situation, in order to overcome the defects of the prior art, the utility model provides a high-efficiency brushless motor sampling circuit.
[0006] The technical solution adopted by the utility model is as follows: the utility model is a high-efficiency brushless motor sampling circuit, including a phase current sampling improvement circuit 1, the phase current sampling improvement circuit 1 includes a diode D1, a resistor R18, a resistor R16 and a capacitor C2, the cathode of the diode D1 is connected to the sampling point U, one end of the resistor R18 is connected to the anode of the diode D1, the resistor R16 is connected to the other end of the resistor R18, the other end of the resistor R16 is connected to the VREF end, one end of the capacitor C2 is connected to the resistor R16 and the resistor R1 8 is connected, the other end of the capacitor C2 is grounded, and also includes a phase current sampling improvement circuit 2, the phase current sampling improvement circuit 2 includes a diode D2, a resistor R19, a resistor R17 and a capacitor C3, the cathode of the diode D2 is connected to the sampling point V, one end of the resistor R19 is connected to the anode of the diode D2, the resistor R17 is connected to the other end of the resistor R19, the other end of the resistor R17 is connected to the VREF end, one end of the capacitor C3 is connected to the resistor R17 and the resistor R19, and the other end of the capacitor C3 is grounded.
[0007] Furthermore, the connection point between the resistor R18, the resistor R16 and the capacitor C2 outputs a signal U-AD to the MCU collection pin.
[0008] Furthermore, the connection point between the resistor R19, the resistor R17 and the capacitor C3 outputs a signal V-AD to the MCU collection pin.
[0009] Furthermore, the diode D1 and the diode D2 prevent high voltage from being connected to the MCU collection pin.
[0010] The beneficial effects achieved by the utility model using the above structure are as follows:
[0011] Low cost, can save operational amplifiers, and MCU selection is no longer limited to motor-specific chips. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 This is an overall schematic circuit diagram of a high-efficiency brushless motor sampling circuit proposed by the utility model;
[0013] Figure 2 A circuit diagram of an improved phase current sampling circuit 1 in a high-efficiency brushless motor sampling circuit proposed by the utility model;
[0014] Figure 3 The utility model discloses a circuit diagram of a second improved phase current sampling circuit in a high-efficiency brushless motor sampling circuit. DETAILED DESCRIPTION
[0015] like Figure 1 to Figure 3 As shown, the utility model is a high-efficiency brushless motor sampling circuit, including a phase current sampling improvement circuit 1, the phase current sampling improvement circuit 1 includes a diode D1, a resistor R18, a resistor R16 and a capacitor C2, the cathode of the diode D1 is connected to the sampling point U, one end of the resistor R18 is connected to the anode of the diode D1, the resistor R16 is connected to the other end of the resistor R18, the other end of the resistor R16 is connected to the VREF end, one end of the capacitor C2 is connected to the resistor R16 and the resistor R18, and the other end of the capacitor C2 is grounded, and also includes a phase current sampling improvement circuit 2, the phase current sampling improvement circuit 2 includes a diode D2, a resistor R19, a resistor R17 and a capacitor C3, the cathode of the diode D2 is connected to the sampling point V, one end of the resistor R19 is connected to the anode of the diode D2, the resistor R17 is connected to the other end of the resistor R19, the other end of the resistor R17 is connected to the VREF end, one end of the capacitor C3 is connected to the resistor R17 and the resistor R19, and the other end of the capacitor C3 is grounded.
[0016] The connection point of resistor R18, resistor R16 and capacitor C2 outputs signal U-AD to the MCU collection pin; the connection point of resistor R19, resistor R17 and capacitor C3 outputs signal V-AD to the MCU collection pin; diode D1 and diode D2 prevent high voltage from entering the MCU collection pin.
[0017] When used specifically: Traditional circuits use sampling resistors to convert current signals, and weak signals require an operational amplifier. Since the internal resistance of the MOS tube itself is relatively large, it is equivalent to the signal after operational amplification of the traditional solution. In this circuit, diodes D1 and D2 are used to prevent high voltage from entering the ADC module in the high-voltage motor, causing chip damage, and play a protective role; since the phase current direction is positive and negative, the MCU does not support the collection of negative current, so R16, R18 and R17, R19 are required to divide the voltage and raise the static bias point to ensure that the collected current is positive. At the same time, the resistor and capacitor form an RC filter to filter the signal.
[0018] It should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.
Claims
1. A high-efficiency brushless motor sampling circuit, characterized in that: The invention comprises a first phase current sampling improvement circuit, wherein the first phase current sampling improvement circuit comprises a diode D1, a resistor R18, a resistor R16 and a capacitor C2, wherein the cathode of the diode D1 is connected to the sampling point U, one end of the resistor R18 is connected to the anode of the diode D1, the resistor R16 is connected to the other end of the resistor R18, the other end of the resistor R16 is connected to the VREF end, one end of the capacitor C2 is connected to the resistor R16 and the resistor R18, and the other end of the capacitor C2 is grounded, and further comprises a second phase current sampling improvement circuit, wherein the second phase current sampling improvement circuit comprises a diode D2, a resistor R19, a resistor R17 and a capacitor C3, wherein the cathode of the diode D2 is connected to the sampling point V, one end of the resistor R19 is connected to the anode of the diode D2, the resistor R17 is connected to the other end of the resistor R19, the other end of the resistor R17 is connected to the VREF end, one end of the capacitor C3 is connected to the resistor R17 and the resistor R19, and the other end of the capacitor C3 is grounded.
2. The high-efficiency brushless motor sampling circuit according to claim 1, characterized in that: The connection point between the resistor R18, the resistor R16 and the capacitor C2 outputs a signal U-AD to the MCU collection pin.
3. The high-efficiency brushless motor sampling circuit according to claim 1, characterized in that: The connection point among the resistor R19, the resistor R17 and the capacitor C3 outputs a signal V-AD to the MCU collection pin.
4. The high-efficiency brushless motor sampling circuit according to claim 1, characterized in that: The diode D1 and the diode D2 prevent high voltage from being connected to the MCU collection pin.