A voltage data processing method and device for zero point detection and a brushless DC motor

Abstract

The present invention relates to the field of voltage data processing, and in particular to a voltage data processing method, device, and brushless DC motor for zero point detection. The method comprises: separately monitoring and acquiring the voltage values ​​of the three phases U, V, and W; if each phase has accumulated voltage values ​​for a preset period, generating a first change graph, and calculating a first deviation value based on the generated first change graph; translating the curve graph in the first change graph to obtain a second change graph, and calculating a second deviation value based on the second change graph; acquiring the first change graph corresponding to a preset number of accumulated preset periods, and calculating a third deviation value based on the acquired first change graph; acquiring a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; and in a preset period following the preset period T, correcting the most recently acquired voltage values ​​of the three phases based on the fourth deviation value to obtain corrected voltage values ​​for the three phases. The present invention solves the problem of insufficient voltage data accuracy.

Description

Technical Field

[0001] The present invention relates to the field of voltage data processing, and in particular to a voltage data processing method and device for zero point detection and a DC brushless motor. Background Art

[0002] Zero-point detection is an essential technology for sensorless control of brushless direct current (BLDC) motors. By precisely capturing the moment when the voltage signal on the motor's stator transitions from a high to a low level, the motor controller can accurately determine the position of the motor's rotor, thereby achieving precise control of the motor's motion.

[0003] For zero point detection, voltage data needs to be collected for detection. The current method is to perform high-frequency voltage sampling on the three phases of the DC brushless motor through a hardware circuit to obtain three-phase voltage data, and then perform software de-bouncing on the burrs of the obtained three-phase voltage data to obtain stable three-phase voltage data.

[0004] In doing so, since the hardware circuit will interfere with the voltage data during the detection or transmission process, the voltage data sampled by the hardware circuit may itself have certain errors. The purpose of software debouncing is to remove abnormal data caused by glitches, but it cannot correct the errors in the voltage data itself. Therefore, there is a problem of insufficient voltage data accuracy. Summary of the Invention

[0005] Based on this, it is necessary to provide a voltage data processing method and device for zero point detection and a DC brushless motor to address the above problems.

[0006] The embodiment of the present invention is implemented as follows: a method for processing voltage data for zero point detection, the method comprising:

[0007] S101, respectively monitor and obtain the voltage values ​​of the U, V, and W phases;

[0008] S102, determining whether each phase has accumulated voltage values ​​for a preset period, and if so, generating a first variation graph based on the most recently accumulated voltage values ​​within the preset period T;

[0009] S103, determining a zero-crossing point of each phase in the first variation graph, and obtaining a first deviation value according to a voltage value corresponding to the zero-crossing point;

[0010] S104, translating the curve graph in the first variation graph to obtain a second variation graph, and obtaining a second deviation value based on the voltage value corresponding to each angle of the second variation graph;

[0011] S105, obtaining a first variation graph corresponding to a preset number of accumulated preset cycles, and obtaining a third deviation value based on a voltage value corresponding to each angle in the obtained first variation graph;

[0012] S106, obtaining a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value;

[0013] S107, in a preset period next to the preset period T, correcting the latest acquired voltage values ​​of the three phases according to the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values;

[0014] S108 , for each preset period after accumulation, executing S102 - S107 to update the fourth deviation value so as to correct the voltage value acquired in the next preset period of the preset period T.

[0015] In one embodiment, the present invention provides a voltage data processing device for zero point detection, the voltage data processing device for zero point detection comprising:

[0016] The voltage monitoring module is used to monitor and obtain the voltage values ​​of the three phases U, V, and W respectively;

[0017] An image generation module is used to determine whether each phase has accumulated a voltage value of a preset cycle, and if so, to generate a first change graph based on the voltage value within the most recently accumulated preset cycle T;

[0018] A first deviation module is used to determine the zero-crossing point of each phase in the first variation diagram, and obtain a first deviation value according to the voltage value corresponding to the zero-crossing point;

[0019] A second deviation module is used to translate the curve graph in the first change graph to obtain a second change graph, and obtain a second deviation value according to the voltage value corresponding to each angle of the second change graph;

[0020] a third deviation module, configured to obtain a first variation graph corresponding to a preset number of accumulated preset cycles, and obtain a third deviation value based on a voltage value corresponding to each angle in the obtained first variation graph;

[0021] a fourth deviation module, configured to obtain a fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value;

[0022] The voltage correction module is used to correct the latest obtained voltage values ​​of the three phases according to the fourth deviation value in the next preset cycle of the preset cycle T to obtain corrected voltage values ​​of the three phases to improve the accuracy of the obtained voltage values.

[0023] In one embodiment, the present invention provides a brushless DC motor, the brushless DC motor comprising a motor device and a control module for controlling the motor device;

[0024] The motor device is used to realize the rotation function to realize the function of a brushless DC motor;

[0025] The control module is used to execute the steps of the voltage data processing method for zero point detection.

[0026] A voltage data processing method for zero point detection provided by an embodiment of the present invention comprises the following steps: monitoring and acquiring voltage values ​​of the three phases U, V, and W; determining whether each phase has accumulated voltage values ​​for a preset period; and if so, generating a first variation graph based on the voltage values ​​within the most recently accumulated preset period T; determining a zero crossing point for each phase in the first variation graph, and obtaining a first deviation value based on the voltage value corresponding to the zero crossing point; translating a curve graph in the first variation graph to obtain a second variation graph, and obtaining a second deviation value based on the voltage value corresponding to each angle in the second variation graph; acquiring the first variation graph corresponding to a preset number of accumulated preset periods, and obtaining a third deviation value based on the voltage value corresponding to each angle in the acquired first variation graph; and obtaining a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; in a preset period following the preset period T, correcting the most recently acquired voltage values ​​of the three phases based on the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values; and repeating the above steps for each accumulated preset period to update the fourth deviation value, thereby correcting the voltage values ​​acquired in the next preset period following the preset period T. In this way, a first deviation value representing the degree of total voltage deviation and a second deviation value representing the degree of voltage deviation of the phase voltage are obtained based on the voltage value of the latest completed accumulated preset period T. A third deviation value representing the degree of voltage deviation at the same moment within a preset period is obtained based on the first change diagram corresponding to a preset number of completed accumulated preset periods, thereby calculating a fourth deviation value representing the correction value, and correcting the latest obtained voltage values ​​of the three phases based on the fourth deviation value. In this way, the error of the voltage data itself is corrected, the error of the voltage data itself sampled by the hardware circuit is eliminated, and the problem of insufficient accuracy of the voltage data is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a flow chart of a voltage data processing method for zero point detection in one embodiment;

[0028] Figure 2 This is the first change diagram under ideal conditions;

[0029] Figure 3 This is the second change diagram under ideal conditions;

[0030] Figure 4 This is a structural block diagram of a voltage data processing device for zero point detection in one embodiment;

[0031] Figure 5 FIG. 4 is a block diagram of the internal structure of a control module in one embodiment. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention 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 only used to explain the present invention and are not intended to limit the present invention.

[0033] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first xx script may be referred to as a second xx script, and similarly, a second xx script may be referred to as a first xx script without departing from the scope of the present invention.

[0034] like Figure 1 As shown, in one embodiment, a voltage data processing method for zero point detection is proposed, which may specifically include the following steps:

[0035] S101, respectively monitor and obtain the voltage values ​​of the U, V, and W phases;

[0036] S102, determining whether each phase has accumulated voltage values ​​for a preset period, and if so, generating a first variation graph based on the most recently accumulated voltage values ​​within the preset period T;

[0037] S103, determining a zero-crossing point of each phase in the first variation graph, and obtaining a first deviation value according to a voltage value corresponding to the zero-crossing point;

[0038] S104, translating the curve graph in the first variation graph to obtain a second variation graph, and obtaining a second deviation value based on the voltage value corresponding to each angle of the second variation graph;

[0039] S105, obtaining a first variation graph corresponding to a preset number of accumulated preset cycles, and obtaining a third deviation value based on a voltage value corresponding to each angle in the obtained first variation graph;

[0040] S106, obtaining a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value;

[0041] S107, in a preset period next to the preset period T, correcting the latest acquired voltage values ​​of the three phases according to the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values;

[0042] S108 , for each preset period after accumulation, executing S102 - S107 to update the fourth deviation value so as to correct the voltage value acquired in the next preset period of the preset period T.

[0043] In this embodiment, the brushless DC motor has three phases: U, V, and W. Each phase is equipped with a corresponding voltage detection circuit to monitor and obtain the voltage values ​​of the three phases, which are referred to as back EMF. The voltage detection circuit detects the phase voltages of the three phases and then extracts the back EMF from the phase voltages. This extraction method can be, for example, to obtain the back EMF from the virtual neutral point voltage.

[0044] In this embodiment, the period length of the preset period of each phase is the same, but the starting point of the preset period of each phase is different, where the starting point refers to the starting angle.

[0045] In this embodiment, the preset period T specifically refers to the latest accumulated preset period, and the accumulated preset period before the preset period T cannot be represented by the preset period T.

[0046] In this embodiment, the first variation graph is essentially a graph showing the voltage value changing with angle. The voltage value here refers to the back electromotive force, and the angle here refers to the electrical angle of the brushless DC motor's rotor, which ranges from 0 to 360 degrees. The rotor's initial position is set to 0. The electrical angle is equal to the mechanical angle multiplied by the number of pole pairs in the brushless DC motor. The mechanical angle is the actual physical angle of rotation of the motor rotor and directly reflects the rotor's spatial position.

[0047] In this embodiment, the horizontal axis of the first change graph is angle, and the vertical axis is voltage. The zero-crossing point here is a point where the voltage value is 0.

[0048] In this embodiment, the translation of the curve graph in the first change graph only involves the horizontal direction, that is, the translation in the horizontal axis direction.

[0049] In this embodiment, the preset number can be set to any value between 10 and 100. If the number of preset cycles completed at this time is less than the preset number, the preset number can be temporarily replaced by the number of preset cycles completed until the number of preset cycles completed is greater than or equal to the preset number.

[0050] In this embodiment, during the accumulation process of the first preset cycle, the third deviation value does not exist and can be regarded as 0. It is even possible not to correct the voltage values ​​in the first few preset cycles, for example, the first 10 cycles.

[0051] In this embodiment, for example, the most recently completed accumulated preset period T is period 1, and the next preset period after period T is period 2. In this case, the fourth deviation value generated in period 1 is only used to correct the voltage value in period 2. When period 2 completes accumulation, period 2 becomes the most recently completed accumulated preset period T. At this point, step S108 is performed, and a new fourth deviation value is generated for period 2. This new fourth deviation value is only used to correct the voltage value in the next preset period after period 2 (i.e., period 3).

[0052] In this embodiment, the corrected voltage value does not affect the monitored and acquired voltage value. The entire process involves correcting the acquired voltage value and transmitting it to the control module so that the control module can more accurately commutate the current. The fourth deviation value used to calibrate the acquired voltage value is derived from the acquired voltage value for each completed accumulation cycle and is unrelated to the corrected voltage value.

[0053] A voltage data processing method for zero point detection provided by an embodiment of the present invention comprises the following steps: monitoring and acquiring voltage values ​​of the three phases U, V, and W; determining whether each phase has accumulated voltage values ​​for a preset period; and if so, generating a first variation graph based on the voltage values ​​within the most recently accumulated preset period T; determining a zero crossing point for each phase in the first variation graph, and obtaining a first deviation value based on the voltage value corresponding to the zero crossing point; translating a curve graph in the first variation graph to obtain a second variation graph, and obtaining a second deviation value based on the voltage value corresponding to each angle in the second variation graph; acquiring the first variation graph corresponding to a preset number of accumulated preset periods, and obtaining a third deviation value based on the voltage value corresponding to each angle in the acquired first variation graph; and obtaining a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; in a preset period following the preset period T, correcting the most recently acquired voltage values ​​of the three phases based on the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values; and repeating the above steps for each accumulated preset period to update the fourth deviation value, thereby correcting the voltage values ​​acquired in the next preset period following the preset period T. In this way, a first deviation value representing the degree of total voltage deviation and a second deviation value representing the degree of voltage deviation of the phase voltage are obtained based on the voltage value of the latest completed accumulated preset period T. A third deviation value representing the degree of voltage deviation at the same moment within a preset period is obtained based on the first change diagram corresponding to a preset number of completed accumulated preset periods, thereby calculating a fourth deviation value representing the correction value, and correcting the latest obtained voltage values ​​of the three phases based on the fourth deviation value. In this way, the error of the voltage data itself is corrected, the error of the voltage data itself sampled by the hardware circuit is eliminated, and the problem of insufficient accuracy of the voltage data is solved.

[0054] In one embodiment, determining whether each phase has accumulated a voltage value for a preset period includes:

[0055] S201, for each phase, determine whether the voltage value of the phase is 0, and if so, record the angle corresponding to the voltage value as a first target angle;

[0056] S202, determining whether the voltage value corresponding to the next angle of the first target angle is greater than 0, if so, marking the first target angle as the starting point of a preset cycle, if not, executing S201;

[0057] S203, after determining the starting point of the preset cycle, determining whether the voltage value of the phase is 0, and if so, recording the angle corresponding to the voltage value as the second target angle;

[0058] S204, determining whether the voltage value corresponding to the next angle of the second target angle is greater than 0, and if so, marking the second target angle as the end point of the preset cycle and the starting point of the next preset cycle;

[0059] S205 , determining whether the start point and the end point of a preset cycle are both marked. If so, the voltage value of the phase is accumulated for a preset cycle.

[0060] In this embodiment, for an ideal first variation diagram, such as Figure 2 As shown, using the U phase as an example, the voltage value first changes from 0 to a positive value. When the rotor angle rotates to 180°, the voltage value returns from a positive value to 0 and then changes to a negative value. When the rotation angle reaches 360° (i.e., 0), the voltage value changes from a negative value to 0, completing a preset cycle. For the V phase, the preset cycle starts at 120° (i.e., the rotor angle is 120°) and ends at 480°. For the W phase, the preset cycle starts at 240° (i.e., the rotor angle is 240°) and ends at 600°. It can be considered that the V phase is delayed by 120° relative to the U phase, and the W phase is delayed by 120° relative to the V phase. The first variation diagram here sets the rotor's initial position to the position when the U phase is energized, at which point the rotor position is set to 0. It is worth noting that the first variation diagram has not yet been generated during the judgment process. The three-phase voltage values ​​are only acquired, and the determination of whether to generate the first variation diagram is based on these three-phase voltage values.

[0061] In this embodiment, Figure 2 、 Figure 3 in It's 180°.

[0062] In this embodiment, the end point of a preset period is also the starting point of the next preset period of the preset period.

[0063] In one embodiment, generating the first variation graph according to the most recently accumulated voltage value within the preset period T includes:

[0064] With the angle as the horizontal axis and the voltage values ​​of the three phases U, V, and W as the vertical axis, three sub-coordinate systems are generated and arranged in the same column to share the horizontal axis, thus establishing a multi-sub coordinate system. Figure 2 dimensional coordinate system;

[0065] For each phase, the voltage value of the phase within the latest accumulated preset period T and its corresponding angle are added to the multi-sub Figure 2 Mark the corresponding sub-coordinate system in the dimensional coordinate system to obtain several coordinate points;

[0066] Connect the adjacent coordinate points to get the phase in the multi-sub Figure 2 Graph on the dimensional coordinate system;

[0067] The three phases in multiple Figure 2 The curve graph on the dimensional coordinate system is recorded as the first change graph.

[0068] In this embodiment, the multiple sub Figure 2 dimensional coordinate system such as Figure 2 、 Figure 3 As shown, they share a horizontal axis. A sub-coordinate system is a two-dimensional coordinate system consisting of a vertical axis and a shared horizontal axis.

[0069] In this embodiment, if Figure 2 As shown, the horizontal axis can be set to cycle from 0 to 360 degrees as an angle cycle, but in fact, for the second 0 (360 degrees), the rotor is at the initial angle of the second circle. Even if the initial angle is the same as the first circle, the time corresponding to these two initial angles is different on the time axis. Of course, the horizontal axis can also be set to cycle from 0 to 720 degrees as an angle cycle, as shown Figure 2 、 Figure 3 Because the preset cycle for the W phase starts at 240° (i.e., the rotor angle is 120°) and ends at 600°, within the angular cycle from 0 to 720°, the voltage value of that phase starting at 240° begins to be counted within the most recently completed preset cycle T. The voltage value after 240° belongs to the previously completed preset cycle (i.e., the preset cycle before preset cycle T). In this case, for the U phase, the voltage value after 360° belongs to the next preset cycle (i.e., the preset cycle after preset cycle T). This embodiment preferably uses the horizontal axis as an angular cycle from 0 to 720°.

[0070] In this embodiment, the first variation diagram includes three curve diagrams, namely, three-phase curve diagrams.

[0071] In one embodiment, determining the zero-crossing point of each phase in the first variation graph and obtaining the first deviation value according to the voltage value corresponding to the zero-crossing point includes:

[0072] For each phase, the angle corresponding to the voltage value of the phase being 0 is recorded as the zero-crossing point;

[0073] For each zero-crossing point, obtain each corresponding voltage value of the zero-crossing point in the first variation graph;

[0074] Depend on Get the voltage offset of the zero crossing point;

[0075] Depend on obtaining a first deviation value;

[0076] Among them, U Uis the voltage value corresponding to the zero crossing point at U, U V is the voltage value corresponding to the zero crossing point at V, U W is the voltage value corresponding to the zero crossing point at W, n is the total number of zero crossing points of the three phases, i is the sequence number of the zero crossing points of the three phases, a i is the voltage offset of the i-th zero-crossing point.

[0077] In this embodiment, each phase has three zero-crossing points, so there are nine zero-crossing points in the first variation diagram, that is, n is 9.

[0078] In this embodiment, for each phase, the third zero-crossing point of the phase is also the first zero-crossing point in the first variation graph generated in the next preset period.

[0079] In this embodiment, when a zero-crossing point occurs, the sum of the three-phase voltage values ​​is ideally 0, so the voltage offset at the zero-crossing point is the absolute value of the difference between the sum of the three-phase voltage values ​​and 0.

[0080] In this embodiment, the first deviation value is an average value of the voltage offsets of all zero-crossing points, and the first deviation value represents the degree of deviation of the total voltage.

[0081] In one embodiment, translating the curve graph in the first change graph to obtain the second change graph, and obtaining the second deviation value according to the voltage value corresponding to each angle of the second change graph includes:

[0082] For each phase, the angle corresponding to the voltage value of the phase being 0 is recorded as the zero-crossing point;

[0083] Determine the first zero-crossing point among the three-phase zero-crossing points according to the time sequence;

[0084] The phase corresponding to the first zero-crossing point is determined as the reference phase;

[0085] Move the curves of the remaining two phases along the horizontal axis so that the starting points of the curves coincide with the starting point of the reference phase;

[0086] The three phases in multiple Figure 2 The curve graph on the dimensional coordinate system is recorded as the second change graph;

[0087] For each angle, obtain each corresponding voltage value of the angle in the second variation graph;

[0088] Depend on Get the voltage offset of the angle;

[0089] Depend on obtaining a second deviation value;

[0090] Among them, u Uis the voltage value corresponding to the angle at U, u V is the voltage value corresponding to the angle at V, u W is the voltage value corresponding to the angle in W, U0 is the reference voltage value corresponding to the angle in the reference phase, m is the total number of angles, j is the serial number of the angle, b j is the voltage offset at the jth angle.

[0091] In this embodiment, generally speaking, since the initialization position of the rotor is set to the position of the rotor when the U phase starts to be energized, the first zero crossing point is the starting point of the preset cycle corresponding to U. At this time, the reference phase is the U phase.

[0092] In this embodiment, the second change diagram under the ideal state is as follows Figure 3 shown.

[0093] In this embodiment, for example, the rotor's starting angle for the V phase is 120°. Ideally, when the rotor rotates 10°, the voltage value of the V phase should be the same as the voltage value of the U phase at 10°. The same applies to the W phase. Therefore, the voltage values ​​of the three phases corresponding to the same angle in the second variation diagram are ideally the same and equal to U0. Otherwise, a voltage offset will occur. U0 can be obtained from a graph showing the ideal voltage value of the reference phase (U phase) as a function of angle. Figure 2 The curve graph shown is the curve graph under ideal conditions.

[0094] In this embodiment, the second deviation value is an average value of the voltage offsets at all angles, and the second deviation value represents the degree of deviation of the single-phase voltage.

[0095] In one embodiment, obtaining the third deviation value according to the voltage value corresponding to each angle in the obtained first variation graph includes:

[0096] For each phase, determining a voltage value corresponding to each angle of the phase in the acquired first variation diagram;

[0097] For each angle of the phase, Obtain the voltage deviation degree of the phase at the angle;

[0098] Depend on Get the voltage offset of the phase;

[0099] Depend on Obtaining a third deviation value;

[0100] Where N is the number of first change graphs obtained, k is the sequence number of the first change graph, and x k is the voltage value corresponding to the angle of the phase in the kth first change diagram, M is the total number of angles, J is the serial number of the angle, c Jis the voltage deviation degree of the Jth angle of the phase, C U is the voltage offset of phase U, C V is the voltage offset of phase V, C W is the voltage offset of phase W.

[0101] In this embodiment, the standard deviation method is used here to calculate the voltage offset degree of the angle of the phase instead of using the average value of the difference between the voltage value corresponding to the angle of the phase in all the first change diagrams and the reference voltage value corresponding to the angle of the phase. This is because there are more reference data, and the voltage fluctuation can be clearly known. The reference voltage value corresponding to the angle of the phase is a value that can only be obtained under an ideal state. In the actual circuit, this value may not be reached, so there is a state value. The voltage value corresponding to the angle of the phase fluctuates around this state value in all the first change diagrams, so it is more appropriate to use the standard deviation method.

[0102] In this embodiment, the voltage offset of a single phase is the voltage deviation degree of the single phase at the same time within a preset period. The third deviation value is the average value of the voltage offsets of the three phases.

[0103] In one embodiment, obtaining the fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value includes:

[0104] Depend on Obtaining a fourth deviation value;

[0105] Among them, K1 is the first coefficient, K2 is the second coefficient, K3 is the third coefficient, the sum of K1, K2 and K3 is 1, d1 is the first deviation value, d2 is the second deviation value, and d3 is the third deviation value.

[0106] In this embodiment, the sum of K1, K2 and K3 is 1, and K1, K2 and K3 can be set to 1 / 3.

[0107] In one embodiment, the step of correcting the latest acquired voltage values ​​of the three phases according to the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values ​​includes:

[0108] For each most recently acquired voltage value of each phase, determine a time difference t between an acquisition time of the most recently acquired voltage value of the phase and an end time of a most recently completed accumulated preset period T of the phase;

[0109] Depend on Get real-time angle;

[0110] Get the reference voltage value corresponding to the real-time angle on the phase;

[0111] Calculate the voltage difference U1 between the latest acquired voltage value of the phase and the reference voltage value corresponding to the real-time angle on the phase;

[0112] Determine whether the voltage difference U1 is greater than 0. If so, Get the corrected voltage value of the latest voltage value of the phase, if not, by Obtaining a corrected voltage value of the most recently acquired voltage value of the phase;

[0113] Wherein, P is the number of pole pairs of the brushless DC motor, v is the rotation speed of the brushless DC motor, U2 is the most recently acquired voltage value of the phase, and d4 is the fourth deviation value.

[0114] In this embodiment, It can also be written as , the two are only different in units. is the formula for calculating the mechanical angle of the rotor, The calculated mechanical angle is constrained within the range of a single circle (i.e. 360°), and the electrical angle of rotation is obtained by multiplying it by the number of pole pairs P, i.e. the real-time angle. The time difference t between the acquisition time of the latest voltage value of the phase and the end time of the latest accumulated preset cycle T of the phase is less than the cycle length of the preset cycle, so it is directly used. That's fine too.

[0115] In this embodiment, the real-time angle is the rotor's rotation angle relative to the initial position (0). For the V phase, although the rotor's initial angle is 120°, when the real-time angle is 120°, the reference voltage value corresponding to the V phase is 0. The same applies to the W phase.

[0116] In this embodiment, the reference voltage value corresponding to the real-time angle on the phase can be obtained from a curve diagram showing the change of the voltage value of the phase with the change of the angle under an ideal state.

[0117] In this embodiment, v is the rotation speed of the brushless DC motor, which may be a rated rotation speed, and the unit is revolutions per minute (RPM).

[0118] like Figure 4 As shown, in one embodiment, a voltage data processing device for zero point detection is provided, which may specifically include:

[0119] The voltage monitoring module is used to monitor and obtain the voltage values ​​of the three phases U, V, and W respectively;

[0120] An image generation module is used to determine whether each phase has accumulated a voltage value of a preset cycle, and if so, to generate a first change graph based on the voltage value within the most recently accumulated preset cycle T;

[0121] A first deviation module is used to determine the zero-crossing point of each phase in the first variation diagram, and obtain a first deviation value according to the voltage value corresponding to the zero-crossing point;

[0122] A second deviation module is used to translate the curve graph in the first change graph to obtain a second change graph, and obtain a second deviation value according to the voltage value corresponding to each angle of the second change graph;

[0123] a third deviation module, configured to obtain a first variation graph corresponding to a preset number of accumulated preset cycles, and obtain a third deviation value based on a voltage value corresponding to each angle in the obtained first variation graph;

[0124] a fourth deviation module, configured to obtain a fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value;

[0125] The voltage correction module is used to correct the latest obtained voltage values ​​of the three phases according to the fourth deviation value in the next preset cycle of the preset cycle T to obtain corrected voltage values ​​of the three phases to improve the accuracy of the obtained voltage values.

[0126] In this embodiment, the various modules of the voltage data processing device for zero point detection are modularized in the method part of the present invention. For the detailed explanation of each module, please refer to the corresponding content of the method part of the present invention, and the embodiment of the present invention will not be repeated here.

[0127] In one embodiment, a brushless DC motor is provided, which may specifically include: a motor module and a control module for controlling the motor module;

[0128] The motor module is used to realize the rotation function to realize the function of the brushless DC motor;

[0129] The control module is used to execute the steps of the above-mentioned voltage data processing method for zero point detection.

[0130] In this embodiment, the motor module includes a stator, a rotor, a position sensor, an electronic commutator, etc.

[0131] In this embodiment, the brushless DC motor further includes a mechanical support module and a heat dissipation module.

[0132] A brushless DC motor provided by an embodiment of the present invention monitors and obtains voltage values ​​of three phases U, V, and W respectively; determines whether each phase has accumulated voltage values ​​for a preset cycle, and if so, generates a first variation graph based on the voltage values ​​within the most recently accumulated preset cycle T; determines the zero crossing point of each phase in the first variation graph, and obtains a first deviation value based on the voltage value corresponding to the zero crossing point; translates the curve graph in the first variation graph to obtain a second variation graph, and obtains a second deviation value based on the voltage value corresponding to each angle in the second variation graph; obtains the first variation graph corresponding to a preset number of accumulated preset cycles, and obtains a third deviation value based on the voltage value corresponding to each angle in the obtained first variation graph; obtains a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; in a preset cycle next to the preset cycle T, corrects the most recently obtained voltage values ​​of the three phases based on the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the obtained voltage values; and repeats the above steps for each accumulated preset cycle to update the fourth deviation value, thereby correcting the voltage values ​​obtained in the next preset cycle of the preset cycle T. In this way, a first deviation value representing the degree of total voltage deviation and a second deviation value representing the degree of voltage deviation of the phase voltage are obtained based on the voltage value of the latest completed accumulated preset period T. A third deviation value representing the degree of voltage deviation at the same moment within a preset period is obtained based on the first change diagram corresponding to a preset number of completed accumulated preset periods, thereby calculating a fourth deviation value representing the correction value, and correcting the latest obtained voltage values ​​of the three phases based on the fourth deviation value. In this way, the error of the voltage data itself is corrected, the error of the voltage data itself sampled by the hardware circuit is eliminated, and the problem of insufficient accuracy of the voltage data is solved.

[0133] Figure 5 FIG. 1 shows an internal structure diagram of a control module in an embodiment. Figure 5 As shown, the control module includes a processor, memory, and a network interface connected via a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the control module stores an operating system and may also store a computer program. When executed by the processor, the computer program enables the processor to implement a voltage data processing method for zero point detection provided in an embodiment of the present invention. The internal memory may also store a computer program. When executed by the processor, the computer program enables the processor to implement a voltage data processing method for zero point detection provided in an embodiment of the present invention.

[0134] Those skilled in the art will understand that Figure 5The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the control module to which the solution of the present invention is applied. The specific control module may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0135] In one embodiment, a voltage data processing device for zero point detection provided by an embodiment of the present invention can be implemented in the form of a computer program. The computer program can be used in Figure 5 The memory of the control module can store various program modules constituting the voltage data processing device for zero point detection, such as: Figure 4 The computer program consisting of the voltage monitoring module, image generation module, first deviation module, second deviation module, third deviation module, fourth deviation module, and voltage correction module shown in the figure enables the processor to execute the steps of the voltage data processing method for zero point detection of various embodiments of the present invention described in this specification.

[0136] For example, Figure 5 The control module shown can be Figure 4 The monitoring voltage module in the voltage data processing device for zero point detection shown in the figure executes step S101; the control module can execute step S102 through the image generation module; the control module can execute step S103 through the first deviation module; the control module can execute step S104 through the second deviation module; the control module can execute step S105 through the third deviation module; the control module can execute step S106 through the fourth deviation module; and the control module can execute step S107 through the voltage correction module.

[0137] In one embodiment, a control module is provided. The control module includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented:

[0138] S101, respectively monitor and obtain the voltage values ​​of the U, V, and W phases;

[0139] S102, determining whether each phase has accumulated voltage values ​​for a preset period, and if so, generating a first variation graph based on the most recently accumulated voltage values ​​within the preset period T;

[0140] S103, determining a zero-crossing point of each phase in the first variation graph, and obtaining a first deviation value according to a voltage value corresponding to the zero-crossing point;

[0141] S104, translating the curve graph in the first variation graph to obtain a second variation graph, and obtaining a second deviation value based on the voltage value corresponding to each angle of the second variation graph;

[0142] S105, obtaining a first variation graph corresponding to a preset number of accumulated preset cycles, and obtaining a third deviation value based on a voltage value corresponding to each angle in the obtained first variation graph;

[0143] S106, obtaining a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value;

[0144] S107, in a preset period next to the preset period T, correcting the latest acquired voltage values ​​of the three phases according to the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values;

[0145] S108 , for each preset period after accumulation, executing S102 - S107 to update the fourth deviation value so as to correct the voltage value acquired in the next preset period of the preset period T.

[0146] In one embodiment, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the processor performs the following steps:

[0147] S101, respectively monitor and obtain the voltage values ​​of the U, V, and W phases;

[0148] S102, determining whether each phase has accumulated voltage values ​​for a preset period, and if so, generating a first variation graph based on the most recently accumulated voltage values ​​within the preset period T;

[0149] S103, determining a zero-crossing point of each phase in the first variation graph, and obtaining a first deviation value according to a voltage value corresponding to the zero-crossing point;

[0150] S104, translating the curve graph in the first variation graph to obtain a second variation graph, and obtaining a second deviation value based on the voltage value corresponding to each angle of the second variation graph;

[0151] S105, obtaining a first variation graph corresponding to a preset number of accumulated preset cycles, and obtaining a third deviation value based on a voltage value corresponding to each angle in the obtained first variation graph;

[0152] S106, obtaining a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value;

[0153] S107, in a preset period next to the preset period T, correcting the latest acquired voltage values ​​of the three phases according to the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values;

[0154] S108 , for each preset period after accumulation, executing S102 - S107 to update the fourth deviation value so as to correct the voltage value acquired in the next preset period of the preset period T.

[0155] It should be understood that, although the various steps in the flow chart of each embodiment of the present invention are shown in sequence according to the indication of the arrows, these steps are not necessarily performed in sequence according to the order indicated by the arrows. Unless otherwise specified herein, the execution of these steps is not strictly limited in order, and these steps can be performed in other orders. Moreover, at least a portion of the steps in each embodiment may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0156] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When executed, the program can include the processes of the above-described method embodiments. Any reference to memory, storage, database, or other media used in the various embodiments provided herein may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct RAMbus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM).

[0157] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0158] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A voltage data processing method for zero point detection, characterized in that: The voltage data processing method for zero point detection includes: S101, respectively monitor and obtain the voltage values ​​of the U, V, and W phases; S102, determining whether each phase has accumulated voltage values ​​for a preset period, and if so, generating a first variation graph based on the most recently accumulated voltage values ​​within the preset period T; S103, determining the zero-crossing point of each phase in the first variation graph, and obtaining a first deviation value based on the voltage value corresponding to the zero-crossing point. The first deviation value is the average of the voltage offsets of all zero-crossing points, and the first deviation value represents the degree of deviation of the total voltage. S104, translating the curve graph in the first variation graph to obtain a second variation graph, and obtaining a second deviation value based on the voltage value corresponding to each angle of the second variation graph; For each phase, the angle corresponding to the voltage value of the phase being 0 is recorded as the zero-crossing point; Determine the first zero-crossing point among the three-phase zero-crossing points according to the time sequence; The phase corresponding to the first zero-crossing point is determined as the reference phase; Move the curves of the remaining two phases along the horizontal axis so that the starting points of the curves coincide with the starting point of the reference phase; The curve diagram of the three phases on the multi-subgraph two-dimensional coordinate system is recorded as the second change diagram; For each angle, obtain each corresponding voltage value of the angle in the second variation graph; Depend on Get the voltage offset of the angle; Depend on obtaining a second deviation value; Among them, u U is the voltage value corresponding to the angle at U, u V is the voltage value corresponding to the angle at V, u W is the voltage value corresponding to the angle in W, U0 is the reference voltage value corresponding to the angle in the reference phase, m is the total number of angles, j is the serial number of the angle, b j is the voltage offset at the jth angle; S105, obtaining a first variation graph corresponding to a preset number of accumulated preset cycles, and obtaining a third deviation value based on a voltage value corresponding to each angle in the obtained first variation graph; For each phase, determining a voltage value corresponding to each angle of the phase in the acquired first variation diagram; For each angle of the phase, Obtain the voltage offset degree of the phase at the angle; Depend on Get the voltage offset of the phase; Depend on Obtaining a third deviation value; Where N is the number of first change graphs obtained, k is the sequence number of the first change graph, and x k is the voltage value corresponding to the angle of the phase in the kth first change diagram, M is the total number of angles, J is the serial number of the angle, c J is the voltage deviation degree of the Jth angle of the phase, C U is the voltage offset of phase U, C V is the voltage offset of phase V, C W is the voltage offset of phase W; S106, obtaining a fourth deviation value based on the first deviation value, the second deviation value, and the third deviation value; S107, in a preset period next to the preset period T, correcting the latest acquired voltage values ​​of the three phases according to the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values; S108, for each preset period after accumulation, executing S102-S107 to update the fourth deviation value so as to correct the voltage value obtained in the next preset period of the preset period T; The angle refers to the electrical angle of the rotor of the brushless DC motor.

2. The voltage data processing method for zero point detection according to claim 1, characterized in that: The determining whether each phase has accumulated a voltage value of a preset cycle includes: S201, for each phase, determine whether the voltage value of the phase is 0, and if so, record the angle corresponding to the voltage value as a first target angle; S202, determining whether the voltage value corresponding to the next angle of the first target angle is greater than 0, if so, marking the first target angle as the starting point of a preset cycle, if not, executing S201; S203, after determining the starting point of the preset cycle, determining whether the voltage value of the phase is 0, and if so, recording the angle corresponding to the voltage value as the second target angle; S204, determining whether the voltage value corresponding to the next angle of the second target angle is greater than 0, and if so, marking the second target angle as the end point of the preset cycle and the starting point of the next preset cycle; S205, determining whether the start and end points of a preset cycle are both marked, if so, the voltage value of the phase accumulated for a preset cycle; The angle refers to the electrical angle of the rotor of the brushless DC motor.

3. The voltage data processing method for zero point detection according to claim 1, characterized in that: The generating of the first variation graph according to the most recently accumulated voltage value within the preset period T includes: With the angle as the horizontal axis and the voltage values ​​of the three phases U, V, and W as the vertical axis, three sub-coordinate systems are generated and arranged in the same column to share the horizontal axis, thus establishing a multi-subgraph two-dimensional coordinate system; For each phase, the voltage value of the phase within the latest accumulated preset period T and its corresponding angle are marked on the corresponding sub-coordinate system to obtain a number of coordinate points; Connecting two adjacent coordinate points to obtain a curve graph of the phase in the multi-subgraph two-dimensional coordinate system; The curve diagram of the three phases on the multi-subgraph two-dimensional coordinate system is recorded as the first change diagram; The angle refers to the electrical angle of the rotor of the brushless DC motor.

4. The voltage data processing method for zero point detection according to claim 1, wherein: Determining the zero-crossing point of each phase in the first variation diagram and obtaining the first deviation value according to the voltage value corresponding to the zero-crossing point includes: For each phase, the angle corresponding to the voltage value of the phase being 0 is recorded as the zero-crossing point; For each zero-crossing point, obtain each corresponding voltage value of the zero-crossing point in the first variation graph; Depend on Get the voltage offset of the zero crossing point; Depend on obtaining a first deviation value; Among them, U U is the voltage value corresponding to the zero crossing point at U, U V is the voltage value corresponding to the zero crossing point at V, U W is the voltage value corresponding to the zero crossing point at W, n is the total number of zero crossing points of the three phases, i is the sequence number of the zero crossing points of the three phases, a i is the voltage offset of the i-th zero-crossing point.

5. The voltage data processing method for zero point detection according to claim 1, wherein: Obtaining the fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value includes: Depend on Obtaining a fourth deviation value; Among them, K1 is the first coefficient, K2 is the second coefficient, K3 is the third coefficient, the sum of K1, K2 and K3 is 1, d1 is the first deviation value, d2 is the second deviation value, and d3 is the third deviation value.

6. The voltage data processing method for zero point detection according to claim 1, wherein: Correcting the latest acquired voltage values ​​of the three phases according to the fourth deviation value to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values ​​includes: For each most recently acquired voltage value of each phase, determine a time difference t between an acquisition time of the most recently acquired voltage value of the phase and an end time of a most recently completed accumulated preset period T of the phase; Depend on Get real-time angle; Get the reference voltage value corresponding to the real-time angle on the phase; Calculate the voltage difference U1 between the latest acquired voltage value of the phase and the reference voltage value corresponding to the real-time angle on the phase; Determine whether the voltage difference U1 is greater than 0. If so, Get the corrected voltage value of the latest voltage value of the phase, if not, by Obtaining a corrected voltage value of the most recently acquired voltage value of the phase; Wherein, P is the number of pole pairs of the brushless DC motor, v is the rotation speed of the brushless DC motor, U2 is the most recently acquired voltage value of the phase, and d4 is the fourth deviation value.

7. A voltage data processing device for zero point detection, characterized in that: The voltage data processing device for zero point detection includes: The voltage monitoring module is used to monitor and obtain the voltage values ​​of the three phases U, V, and W respectively; An image generation module is used to determine whether each phase has accumulated a voltage value of a preset cycle, and if so, to generate a first change graph based on the voltage value within the most recently accumulated preset cycle T; A first deviation module is used to determine the zero-crossing point of each phase in the first variation diagram, and obtain a first deviation value according to the voltage value corresponding to the zero-crossing point. The first deviation value is the average value of the voltage offsets of all zero-crossing points, and the first deviation value represents the degree of deviation of the total voltage; A second deviation module is used to translate the curve graph in the first change graph to obtain a second change graph, and obtain a second deviation value according to the voltage value corresponding to each angle of the second change graph; For each phase, the angle corresponding to the voltage value of the phase being 0 is recorded as the zero-crossing point; Determine the first zero-crossing point among the three-phase zero-crossing points according to the time sequence; The phase corresponding to the first zero-crossing point is determined as the reference phase; Move the curves of the remaining two phases along the horizontal axis so that the starting points of the curves coincide with the starting point of the reference phase; The curve diagram of the three phases on the multi-subgraph two-dimensional coordinate system is recorded as the second change diagram; For each angle, obtain each corresponding voltage value of the angle in the second variation graph; Depend on Get the voltage offset of the angle; Depend on obtaining a second deviation value; Among them, u U is the voltage value corresponding to the angle at U, u V is the voltage value corresponding to the angle at V, u W is the voltage value corresponding to the angle in W, U0 is the reference voltage value corresponding to the angle in the reference phase, m is the total number of angles, j is the serial number of the angle, b j is the voltage offset at the jth angle; a third deviation module, configured to obtain a first variation graph corresponding to a preset number of accumulated preset cycles, and obtain a third deviation value based on a voltage value corresponding to each angle in the obtained first variation graph; For each phase, determining a voltage value corresponding to each angle of the phase in the acquired first variation diagram; For each angle of the phase, Obtain the voltage offset degree of the phase at the angle; Depend on Get the voltage offset of the phase; Depend on Obtaining a third deviation value; Where N is the number of first change graphs obtained, k is the sequence number of the first change graph, and x k is the voltage value corresponding to the angle of the phase in the kth first change diagram, M is the total number of angles, J is the serial number of the angle, c J is the voltage deviation degree of the Jth angle of the phase, C U is the voltage offset of phase U, C V is the voltage offset of phase V, C W is the voltage offset of phase W; a fourth deviation module, configured to obtain a fourth deviation value according to the first deviation value, the second deviation value, and the third deviation value; a voltage correction module, configured to correct the latest acquired voltage values ​​of the three phases according to the fourth deviation value in a preset period next to the preset period T to obtain corrected voltage values ​​of the three phases to improve the accuracy of the acquired voltage values; The angle refers to the electrical angle of the rotor of the brushless DC motor.

8. A brushless DC motor, characterized in that: The brushless DC motor includes a motor device and a control module for controlling the motor device; The motor device is used to realize the rotation function to realize the function of a brushless DC motor; The control module is used to execute the steps of the voltage data processing method for zero point detection according to any one of claims 1 to 6.

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