A ventilation therapy device and its BLDC square wave drive control method and apparatus

Abstract

This invention provides a ventilation therapy device and its BLDC square wave drive control method and apparatus. By controlling the closing of the power logic switch unit of the continuously conducting phase and performing pulse width modulation on the power logic switch unit of the commutated phase winding, this invention effectively alleviates torque pulsation caused by commutation in the BLDC drive, providing stable torque and achieving better pressure control.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a ventilation therapy device and its BLDC square wave drive control method and apparatus. Background Technology

[0002] A ventilator is a vital medical device that can prevent and treat respiratory failure, reduce complications, and save and prolong patients' lives.

[0003] Currently, ventilators can be driven using brushless direct current motors (BLDC) via square waves. However, in existing technologies, BLDC square wave drive uses a fixed-phase conduction scheme of PWM_ON, meaning that in a three-phase half-bridge, one phase is fixed on and off, one phase is fixed off via pulse width modulation (PWM), and the remaining phase is on and off. This results in significant torque ripple, which can easily affect pressure control performance. Summary of the Invention

[0004] In view of the above problems, embodiments of the present invention are proposed to provide a ventilation therapy device and its BLDC square wave drive control method and apparatus that overcome or at least partially solve the above problems.

[0005] According to a first aspect of the present invention, a BLDC square wave drive control method for a ventilation therapy device is provided. The motor body of the ventilation therapy device includes a stator and a rotor. The stator is composed of three-phase windings symmetrically connected in a Y-shape. The stator is connected to a DC power supply through a commutation circuit device. The commutation circuit device adopts a three-phase bridge circuit, which consists of three half-bridges formed by connecting six power logic switch units in pairs. The output terminals of each half-bridge are respectively connected to the corresponding phase windings in the motor stator. The method includes:

[0006] Obtain the rotor's position information;

[0007] Based on the location information, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction are determined; wherein, the continuously conducting phase winding is the winding that is conducting both before and after the commutation, and the commutated phase winding is the winding that is different from the winding before the commutation among the two conducting phase windings after the current commutation.

[0008] Based on the current direction, the power logic switch unit of the continuously conducting phase winding is controlled to close, the power logic switch unit of the commutated phase winding is controlled to open, and the power logic switch unit of the commutated phase winding is controlled to perform pulse width modulation.

[0009] According to a second aspect of the present invention, a BLDC square wave drive control device for a ventilation therapy device is provided. The motor body of the ventilation therapy device includes a stator and a rotor. The stator is composed of three-phase windings symmetrically connected in a Y-shape. The stator is connected to a DC power supply through a commutation circuit device. The commutation circuit device adopts a three-phase bridge circuit, which consists of three half-bridges formed by connecting six power logic switch units in pairs. The output terminals of each half-bridge are respectively connected to the corresponding phase windings in the motor stator. The device includes:

[0010] The acquisition module is used to acquire the rotor's position information;

[0011] The determining module is used to determine the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction based on the position information; wherein, the continuously conducting phase winding is the winding that is conducting both before and after the commutation, and the commutated phase winding is the winding that is different from the winding before the commutation among the two conducting phase windings after the current commutation.

[0012] The control module is used to control the power logic switch unit of the continuously conducting phase winding to close, control the power logic switch unit of the commutated phase winding to open, and control the power logic switch unit of the commutated phase winding to perform pulse width modulation according to the current direction.

[0013] According to a third aspect of the present invention, a ventilation therapy device is provided, the ventilation therapy device comprising a BLDC square wave drive control device as described in the second aspect.

[0014] According to a fourth aspect of the present invention, a terminal device is provided, the terminal device including a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the method described in the first aspect.

[0015] According to a fifth aspect of the invention, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect.

[0016] The embodiments of the present invention have the following advantages:

[0017] The rotor's position information is acquired. Based on this position information, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction are determined. The continuously conducting phase winding is the winding that is conducting both before and after commutation. The commutated phase winding is the winding that is different from the one before commutation among the two conducting phase windings after current commutation. According to the current direction, the power logic switch unit of the continuously conducting phase winding is controlled to close, the power logic switch unit of the commutated phase winding is controlled to open, and the power logic switch unit of the commutated phase winding is controlled to perform pulse width modulation. By controlling the power logic switch unit of the continuously conducting phase to close and the power logic switch unit of the commutated phase winding to perform pulse width modulation, the torque pulsation caused by commutation in the BLDC drive can be effectively alleviated, providing stable torque and achieving a better pressure control effect. Attached Figure Description

[0018] Figure 1 This is a flowchart of a BLDC square wave drive control method for a ventilation therapy device provided in an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the motor drive for implementing the ventilation therapy device in this embodiment of the invention;

[0020] Figure 3 This is a block diagram of a BLDC square wave drive control device for a ventilation therapy device provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1

[0023] Reference Figure 1 The diagram shows a flowchart of a BLDC square wave driven control method for a ventilation therapy device. The method is applied to a ventilation therapy device driven by a BLDC square wave and may specifically include the following steps 101 to 103.

[0024] The BLDC square wave drive control method provided in this invention is applied to ventilation therapy equipment, such as... Figure 2 As shown, the motor body of the ventilation therapy device includes a stator and a rotor. The stator is composed of three-phase (ABC) windings connected in a symmetrical Y-shape. The stator is connected to a DC power supply through a commutation circuit device. The commutation circuit device adopts a three-phase bridge circuit, which consists of three half-bridges formed by connecting six power logic switch units in pairs. The output terminals of each half-bridge are respectively connected to the corresponding phase windings in the motor stator.

[0025] Specifically, the aforementioned six power logic switching units include power logic switching unit Q1, power logic switching unit Q2, power logic switching unit Q3, power logic switching unit Q4, power logic switching unit Q5, and power logic switching unit Q6. Power logic switching unit Q1 and power logic switching unit Q2 are connected to form a first half-bridge with their output terminals connected to the A-phase winding; power logic switching unit Q3 and power logic switching unit Q4 serve as the high-side switch and low-side switch, respectively. Power logic switching unit Q5 and power logic switching unit Q6 are connected to form a second half-bridge with their output terminals connected to the B-phase winding; power logic switching unit Q1 and power logic switching unit Q2 serve as the high-side switch and low-side switch, respectively. Power logic switching unit Q3 and power logic switching unit Q4 are connected to form a third half-bridge with their output terminals connected to the C-phase winding; power logic switching unit Q5 and power logic switching unit Q6 serve as the high-side switch and low-side switch, respectively. Optionally, the aforementioned power logic switching units can be power transistors or field-effect transistors.

[0026] When the motor is running, two phases of the three-phase winding are conducting, and in one of the conducting phases, the high-side switch is closed and the low-side switch is open, and in another of the conducting phases, the low-side switch is closed and the high-side switch is open.

[0027] In practical applications, the aforementioned ventilation therapy equipment can specifically be a ventilator or an oxygen therapy device.

[0028] Step 101: Obtain the rotor position information.

[0029] In this step, the aforementioned position information refers to the rotation angle or phase of the rotor in each electrical cycle.

[0030] Optionally, in one embodiment, the motor body further includes a position detection device for detecting the rotor position in the motor body.

[0031] Step 101 above specifically includes:

[0032] The rotor's position information is obtained based on the detection signal from the position detection device.

[0033] In this embodiment, the position detection device is installed on the motor body and is fixed relative to the stator, and is electrically connected to the motor controller; when the rotor rotates to different angles, the position detection device can be triggered to generate different detection signals, so the rotor position information can be determined based on the detection information.

[0034] The rotor position of a BLDC motor can be sensed by a position sensor or a position observer, i.e., sensor-equipped square wave drive and sensorless square wave drive.

[0035] Optionally, in one specific embodiment, the position detection device employs three or six Hall sensors, which are evenly spaced.

[0036] For example, when the position detection device uses three Hall sensors, these three sensors are installed at different locations on the motor to detect the rotor position relative to the three windings (ABC). During motor operation, when a positive magnetic field line passes through a Hall sensor, the sensor outputs "1," and vice versa, it outputs "0." Since the three Hall sensors are evenly distributed over a 360-degree electrical angle, each Hall sensor's voltage level will flip twice during one electrical cycle (360 degrees), resulting in a total of six voltage level flips. Because the sensors are evenly distributed, each flip occurs exactly 60 degrees electrically, which is precisely the electrical angle difference between two commutation phases of the motor. By continuously reading the different voltage level flip times of the Hall sensors and then energizing the corresponding windings, the motor can operate smoothly.

[0037] For example, when the position detection device uses six Hall sensors, these six sensors are installed at different locations on the motor to detect the rotor position relative to the three windings (ABC). During motor operation, when a positive magnetic field line passes through a Hall sensor, the sensor outputs "1," and vice versa, it outputs "0." Since the six Hall sensors are evenly distributed across a 360-degree electrical angle, the voltage level of each Hall sensor flips once during one electrical cycle (360 degrees) of the motor operation, resulting in a total of six voltage level flips. Because the sensors are evenly distributed, each flip occurs exactly 60 degrees of electrical angle, which is precisely the electrical angle difference between two commutation phases of the motor. By continuously reading the different voltage level flip times of the Hall sensors and then energizing the corresponding windings, the motor can operate smoothly.

[0038] Step 102: Based on the position information, determine the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction; wherein, the continuously conducting phase winding is the winding that is conducting before and after the commutation, and the commutated phase winding is the winding that is different from the winding before the commutation among the two conducting phase windings after the current commutation.

[0039] In this step, the BLDC motor adopts a two-phase working mode, where only two phases are conducting at any given time, and the other phase is disconnected. The selection of which two phases to conduct is determined by the rotor position. Therefore, after determining the rotor position information, it is possible to determine which two phases are conducting and which phase is disconnected. Since only two phases are conducting at any given time, and there are only three phases in total, one phase must be the same as the two phases that were conducting before commutation. This same phase is the continuously conducting phase winding, while the different phase winding is the commutated phase winding, and the remaining phase winding is the commutated phase winding.

[0040] Since each phase winding is connected to the output of a half-bridge formed by two power logic switching units connected in pairs, in order to maintain the normal and continuous rotation of the motor rotor, after determining the two phase windings that are conducting at each moment, it is also necessary to determine the current direction so that the rotor can continue to rotate in the positive direction after commutation.

[0041] Step 103: According to the current direction, control the power logic switch unit of the continuously conducting phase winding to close, control the power logic switch unit of the commutated phase winding to open, and control the power logic switch unit of the commutated phase winding to perform pulse width modulation.

[0042] In this step, according to the aforementioned current direction requirements, the first power logic switch unit in the half-bridge connected to the continuously conducting phase winding is closed, and the second power logic switch unit in the half-bridge connected to the commutated phase winding is closed, while other power logic switch units are opened. This allows the current after conduction to flow from the power supply through the two conducting phase windings according to the aforementioned current direction, enabling the rotor to continue rotating forward after entering the current commutation angle range from the angle range after the previous commutation. Simultaneously, after the rotor enters the current commutation angle range, this embodiment of the invention controls the first power logic switch unit to remain closed, while controlling the second power logic switch unit to close in a PWM manner. This effectively improves the torque pulsation caused by commutation in BLDC drives, provides stable torque, and achieves better pressure control.

[0043] The specific proof process is as follows:

[0044] Three-phase winding port voltage u A ,u B ,u C The midpoint voltage is u0;

[0045] Three-phase winding current i A i B i C The positive direction of the current is the inflow port;

[0046] Three-phase winding back EMF e A ,e B ,e C The positive direction of the electric potential is from the midpoint to the port;

[0047] The self-inductance of the phase winding is L, and the mutual inductance between the windings is M;

[0048] Simplifying the analysis by neglecting winding resistance, the equation is derived from the phase voltage equation of the BLDC motor:

[0049]

[0050] Let phase A be the continuously conducting phase, phase B be the commutation-in phase, and phase C be the commutation-out phase.

[0051] For the sinusoidal back electromotive force BLDCM, according to the commutation strategy, the average back electromotive force within the commutation interval satisfies:

[0052] e B =-0.5e A e C =-0.5e A

[0053] From the characteristics of the three-phase symmetrical winding, we can know that:

[0054] M = -0.5L

[0055] make By rearranging the terms, we obtain a system of four linear equations in four variables:

[0056]

[0057] Solving for the given information yields the following results:

[0058]

[0059] Analysis of the rate of change of on-phase current

[0060] Let V = 3*e A -2*u A +u B +u C It can be seen that the smaller the absolute value of V, the smaller the fluctuation of the phase A current.

[0061] Let the bus voltage be U. Bus The output voltage is U out Because the resistance is negligible, the voltage is balanced before commutation, and the voltage does not change abruptly, because e B =-0.5e A e C =-0.5e A e A =E, and because when conduction occurs, a voltage is applied between A and B, which needs to overcome e. A and e B The pressure drop, then U out =e A -e B =1.5E, where E is the positive peak value of the back electromotive force.

[0062] The following analysis covers eight different scenarios.

[0063] (1) Assuming low-side commutation, phase A is on, phase B is PWM, and phase C is off, the motor is running, and before commutation, the actual current flows into phase A and out of phase C:

[0064] Analysis shows that

[0065] e A =E,u A =U Bus u B =U Bus -U out =U Bus -1.5E, u C =U Bus

[0066] Substitution

[0067] V = 3 * E - 2 * U Bus +U Bus -1.5E+U Bus =1.5E

[0068] (2) Assume that the low side is commutated, phase A is PWM, phase B is On, and phase C is commutated to run the motor. Before commutation, the current actually flows into phase A and out of phase C.

[0069] e A =E,u A =U out =1.5E, u B =0, u C =U Bus

[0070] Substitution

[0071] V = 3 * E - 2 * 1.5 E + 0 + U Bus =U Bus

[0072] (3) Assume that the high side is commutated, phase A is on, phase B is PWM, and phase C is commutated to run the motor. Before commutation, the current actually flows into phase C and out of phase A.

[0073] Analysis shows that

[0074] e A =-E,u A =0, u B =U out =1.5E, u C =0

[0075] Substitution

[0076] V = -3*E - 2*0 + 1.5E - 0 = -1.5E

[0077] (4) Assume that the high side is commutated, phase A is PWM, phase B is On, phase C is commutated, and the motor is running. Before the commutation, the current actually flows into phase C and out of phase A.

[0078] Analysis shows that

[0079] eA =-E,u A =U Bus -U out =U Bus -1.5E, u B =U Bus u C =0

[0080] Substitution

[0081] V = -3 * E - 2 * (U) Bus -1.5E)+U Bus +0=-U Bus

[0082] (5) Assume low-side commutation, phase A is on, phase B is PWM, and phase C is commutated, operating as a generator. Before commutation, the actual current flows into phase C and out of phase A.

[0083] Analysis shows that

[0084] e A =E,u A =U Bus u B =U Bus -U out =U Bus -1.5E, u C =0

[0085] Substitution

[0086] V = 3 * E - 2 * U Bus +U Bus -1.5E+0=1.5EU Bus

[0087] (6) Assume that the low-side commutation is performed, phase A is PWM, phase B is On, and phase C is commutated, and the generator is running. Before the commutation, the current actually flows into phase C and out of phase A.

[0088] e A =E,u A =U out =1.5E, u B =0, u C =0

[0089] Substitution

[0090] V = 3 * E - 2 * 1.5 E + 0 + 0 = 0

[0091] (7) Assume that the high side is commutated, phase A is on, phase B is PWM, and phase C is commutated to operate as a generator. Before commutation, the current actually flows into phase A and out of phase C.

[0092] Analysis shows that

[0093] e A =-E,u A =0, u B =U out =1.5E, u c =U Bus

[0094] Substitution

[0095] V = -3*E - 2*0 + 1.5E + U Bus =-1.5E+U Bus

[0096] (8) Assume high-side commutation, phase A is PWM, phase B is On, phase C is commutated, and the generator is running. Before commutation, the current actually flows into phase A and out of phase C.

[0097] Analysis shows that

[0098] e A =-E,u A =U Bus -U out =U Bus -1.5E, u B =U Bus u C =U Bus

[0099] Substitution

[0100] V = -3 * E - 2 * (U) Bus -1.5E)+U Bus +U Bus =0

[0101] To ensure current injection, U needs to be satisfied. Bus >1.5E, it can be seen that the conduction phase current fluctuation in case (1) is smaller than that in case (2), the conduction phase current fluctuation in case (3) is smaller than that in case (4), the conduction phase current fluctuation in case (6) is smaller than that in case (5), and the conduction phase current fluctuation in case (8) is smaller than that in case (7).

[0102] In summary, for motor operation, continuously conducting the On phase and switching to the PWM phase results in smaller current fluctuations.

[0103] The embodiments of the present invention have the following advantages:

[0104] The rotor's position information is acquired. Based on this position information, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction are determined. The continuously conducting phase winding is the winding that is conducting both before and after commutation. The commutated phase winding is the winding that is different from the one before commutation among the two conducting phase windings after current commutation. According to the current direction, the power logic switch unit of the continuously conducting phase winding is controlled to close, the power logic switch unit of the commutated phase winding is controlled to open, and the power logic switch unit of the commutated phase winding is controlled to perform pulse width modulation. By controlling the power logic switch unit of the continuously conducting phase to close and the power logic switch unit of the commutated phase winding to perform pulse width modulation, the torque pulsation caused by commutation in the BLDC drive can be effectively alleviated, providing stable torque and achieving a better pressure control effect.

[0105] Optionally, in one embodiment, step 102 includes steps 201 to 202.

[0106] Step 201: When the rotor reaches the commutation angle based on the position information, determine the two-phase conducting windings and the current direction after current commutation.

[0107] In this step, since the position of the rotor determines the two conducting windings in the BLDC motor, and the rotor needs to update the two conducting windings every 60 degrees after the windings are commutated, and replace one of the two conducting windings with the other non-conducting winding, when the rotor rotates to the next commutation angle based on the obtained rotor position information, the two conducting windings that can make the rotor continue to rotate in the positive direction and the corresponding current direction can be determined according to the rotor rotation direction and winding distribution law.

[0108] Step 202: Determine the continuously conducting phase winding and the commutated phase winding from the two-phase conducting windings after current commutation, and determine the windings other than the two-phase conducting windings in the three-phase windings as the commutated phase windings.

[0109] In this step, the two-phase conducting windings before and after commutation are compared. The windings that conduct current before and after commutation are determined as the continuously conducting windings, which are the same as the windings before commutation among the two-phase conducting windings after commutation. The windings that are different from the windings before commutation among the two-phase conducting windings after commutation are designated as the commutation-in windings. The windings that conduct current before commutation but no longer conduct after commutation are designated as the commutation-out windings, which are the windings other than the two-phase conducting windings among the three-phase windings after commutation.

[0110] Optionally, in one specific embodiment, step 102 above further includes step 203.

[0111] Step 203: When it is determined from the position information that the rotor has not rotated to the commutation angle, keep the continuously conducting phase winding, the commutated phase winding, the commutated phase winding and the current direction unchanged.

[0112] In this step, based on the obtained rotor position information, it is determined that the rotor has not rotated to the commutation angle. This indicates that the current winding conduction state can continue to drive the rotor to rotate with a larger torque. Therefore, there is no need to update the conducting winding. Thus, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction remain unchanged.

[0113] In the above embodiments, when the BLDC motor driving the ventilation therapy device is running, the conducting phase is updated only when the rotor rotates to a new commutation angle. That is, the new continuous conducting phase winding, the commutated phase winding, and the commutated phase winding are determined. This ensures the smooth rotation of the rotor and reduces the computational load of the system.

[0114] For example, when the position detection device uses 6 Hall sensors evenly distributed along the winding, the conduction sequence of the 6 power logic switch units is shown in Table 1.

[0115] In this context, 0 represents open and 1 represents closed.

[0116] Table 1

[0117] HALL 1 2 3 4 5 6 Q1 pwm 1 0 0 0 0 Q2 0 0 0 pwm 1 0 Q3 0 0 pwm 1 0 0 Q4 1 0 0 0 0 pwm Q5 0 0 0 0 pwm 1 Q6 0 pwm 1 0 0 0

[0118] As shown in Table 1, when the rotor rotates to Hall sensor 1, the control power logic switch unit Q4 is closed, the control power logic switch unit Q1 is closed in PWM mode, and the control other power logic switch units are opened.

[0119] When the rotor rotates to Hall sensor 2, control power logic switch unit Q1 closes, control power logic switch unit Q6 closes in PWM mode, and control other power logic switch units open.

[0120] When the rotor rotates to Hall sensor 3, the control power logic switch unit Q6 closes, the control power logic switch unit Q3 closes in PWM mode, and the control other power logic switch units open.

[0121] When the rotor rotates to Hall sensor 4, the control power logic switch unit Q3 closes, the control power logic switch unit Q2 closes in PWM mode, and the control other power logic switch units open.

[0122] When the rotor rotates to Hall sensor 5, control power logic switch unit Q2 closes, control power logic switch unit Q5 closes in PWM mode, and control other power logic switch units open.

[0123] When the rotor rotates to Hall sensor 6, the control power logic switch unit Q5 closes, the control power logic switch unit Q4 closes in PWM mode, and the control other power logic switch units open.

[0124] By controlling the conduction of each phase winding and outputting control waveforms according to the corresponding order in Table 1, the torque pulsation during BLDC operation can be reduced, and the stability of pressure control in ventilation therapy equipment can be improved.

[0125] Example 2

[0126] Reference Figure 3 A block diagram of a BLDC square wave drive control device for a ventilation therapy equipment is shown. The motor body of the ventilation therapy equipment includes a stator and a rotor. The stator is composed of three-phase windings symmetrically connected in a Y-shape. The stator is connected to a DC power supply through a commutation circuit device. The commutation circuit device adopts a three-phase bridge circuit, which consists of three half-bridges formed by connecting six power logic switch units in pairs. The output terminals of each half-bridge are respectively connected to the corresponding phase windings in the motor stator. Specifically, the device may include:

[0127] The acquisition module 31 is used to acquire the rotor's position information;

[0128] The determining module 32 is used to determine the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction based on the position information; wherein, the continuously conducting phase winding is the winding that is conducting both before and after the commutation, and the commutated phase winding is the winding that is different from the winding before the commutation among the two conducting phase windings after the current commutation.

[0129] The control module 33 is used to control the power logic switch unit of the continuously conducting phase winding to close, control the power logic switch unit of the commutated phase winding to open, and control the power logic switch unit of the commutated phase winding to perform pulse width modulation according to the current direction.

[0130] The embodiments of the present invention have the following advantages:

[0131] The acquisition module 31 acquires the rotor's position information; the determination module 32, based on this position information, determines the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction. The continuously conducting phase winding is the winding that is conducting both before and after commutation, while the commutated phase winding is the winding that is different from the one before commutation among the two conducting phase windings after current commutation. Then, the control module 33, based on the current direction, controls the power logic switch unit of the continuously conducting phase winding to close, controls the power logic switch unit of the commutated phase winding to open, and controls the power logic switch unit of the commutated phase winding to perform pulse width modulation. By controlling the power logic switch unit of the continuously conducting phase to close and the power logic switch unit of the commutated phase winding to perform pulse width modulation, the torque pulsation caused by commutation in the BLDC drive can be effectively alleviated, providing stable torque and achieving better pressure control.

[0132] Optionally, in the device, the determining module 32 includes:

[0133] The first determining unit is used to determine the two-phase conducting windings and the current direction after current commutation when the rotor is determined to have rotated to the commutation angle based on the position information.

[0134] The second determining unit is used to determine the continuously conducting phase winding and the commutated phase winding from the two-phase conducting windings after current commutation, and to determine the windings other than the two-phase conducting windings in the three-phase windings as the commutated phase windings.

[0135] Optionally, in the device, the determining module 32 further includes:

[0136] When it is determined, based on the position information, that the rotor has not rotated to the commutation angle, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction remain unchanged.

[0137] In another embodiment of the present invention, a ventilation therapy device is also provided, including a motor and the aforementioned BLDC square wave drive control device.

[0138] As the embodiments of ventilation therapy equipment and devices are basically similar to those of method embodiments, the description is relatively simple, and relevant parts can be referred to in the description of the method embodiments.

[0139] In another embodiment of the present invention, a terminal device is also provided, including a processor, a memory, and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, it implements the steps in the ventilation control method and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0140] In another embodiment of the present invention, a readable storage medium is also provided, on which a computer program is stored. When the computer program is executed by a processor, it implements the various processes of the ventilation control method and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0141] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0142] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, embodiments of the present invention can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0143] In a typical configuration, the computer device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory. Memory may include non-persistent memory in computer-readable media, random access memory (RAM), and / or non-volatile memory such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media. Computer-readable media includes both permanent and non-persistent, removable and non-removable media that can store information by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device. As defined in this article, computer-readable media do not include transient media, such as modulated data signals and carrier waves.

[0144] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0145] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0146] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0147] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0148] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0149] The above provides a detailed description of the BLDC square wave drive control method, device, and ventilation therapy device provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A BLDC square wave drive control method for a ventilation therapy device, characterized in that, When the ventilation therapy device is in motor operation mode, the motor body of the ventilation therapy device includes a stator and a rotor. The stator is composed of three-phase windings symmetrically connected in a Y-shape. The stator is connected to a DC power supply through a commutation circuit device. The commutation circuit device adopts a three-phase bridge circuit, which consists of three half-bridges formed by connecting six power logic switch units in pairs. The output terminals of each half-bridge are respectively connected to the corresponding phase windings in the motor stator. The method includes: Obtain the rotor's position information; Based on the location information, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction are determined; wherein, the continuously conducting phase winding is the winding that is conducting both before and after the commutation, and the commutated phase winding is the winding that is different from the winding before the commutation among the two conducting phase windings after the current commutation. Based on the current direction, the power logic switch unit of the continuously conducting phase winding is controlled to close, the power logic switch unit of the commutated phase winding is controlled to open, and the power logic switch unit of the commutated phase winding is controlled to perform pulse width modulation.

2. The BLDC square wave drive control method according to claim 1, characterized in that, Based on the location information, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction are determined, including: Based on the position information, when the rotor reaches the commutation angle, the two-phase conducting windings and current direction after current commutation are determined. The continuously conducting phase winding and the commutated phase winding are determined from the two conducting phase windings after current commutation, and the windings other than the two conducting phase windings in the three-phase windings are determined as the commutated phase windings.

3. The BLDC square wave drive control method according to claim 2, characterized in that, Based on the location information, determining the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction also includes: When it is determined, based on the position information, that the rotor has not rotated to the commutation angle, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction remain unchanged.

4. The BLDC square wave drive control method according to claim 1, characterized in that, The motor body also includes a position detection device for detecting the rotor position in the motor body; Obtaining rotor position information includes: The rotor's position information is obtained based on the detection signal from the position detection device.

5. The BLDC square wave drive control method according to claim 4, characterized in that, The position detection device uses three or six Hall sensors, which are evenly spaced.

6. The BLDC square wave drive control method according to claim 1, characterized in that, The power logic switching unit is a power transistor or a field-effect transistor.

7. A BLDC square wave drive control device for a ventilation therapy equipment, characterized in that, When the ventilation therapy device is in motor operation mode, the motor body of the ventilation therapy device includes a stator and a rotor. The stator is composed of three-phase windings symmetrically connected in a Y-shape. The stator is connected to a DC power supply through a commutation circuit device. The commutation circuit device adopts a three-phase bridge circuit, which consists of three half-bridges formed by connecting six power logic switch units in pairs. The output terminals of each half-bridge are respectively connected to the corresponding phase windings in the motor stator. The device includes: The acquisition module is used to acquire the rotor's position information; The determining module is used to determine the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction based on the position information; wherein, the continuously conducting phase winding is the winding that is conducting both before and after the commutation, and the commutated phase winding is the winding that is different from the winding before the commutation among the two conducting phase windings after the current commutation. The control module is used to control the power logic switch unit of the continuously conducting phase winding to close, control the power logic switch unit of the commutated phase winding to open, and control the power logic switch unit of the commutated phase winding to perform pulse width modulation according to the current direction.

8. The BLDC square wave drive control device according to claim 7, characterized in that, The determining module includes: The first determining unit is used to determine the two-phase conducting windings and the current direction after current commutation when the rotor is determined to have rotated to the commutation angle based on the position information. The second determining unit is used to determine the continuously conducting phase winding and the commutated phase winding from the two-phase conducting windings after current commutation, and to determine the windings other than the two-phase conducting windings in the three-phase windings as the commutated phase windings.

9. The BLDC square wave drive control device according to claim 8, characterized in that, The determining module further includes: When it is determined, based on the position information, that the rotor has not rotated to the commutation angle, the continuously conducting phase winding, the commutated phase winding, the commutated phase winding, and the current direction remain unchanged.

10. A ventilation therapy device, characterized in that, Includes the apparatus as described in any one of claims 7 to 9.

11. A terminal device, the terminal device comprising a processor, a memory, and a program or instructions stored in the memory and executable on the processor, characterized in that, When the program or instructions are executed by the processor, they implement the steps of the method as described in any one of claims 1 to 6.

12. A readable storage medium on which a program or instructions are stored, characterized in that, When the program or instructions are executed by the processor, they implement the steps of the method as described in any one of claims 1 to 6.

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