Circuit for driving single degree of freedom of rotor and magnetic suspension bearing control system

Abstract

The invention discloses a circuit for driving a single degree of freedom of a rotor and a magnetic suspension bearing control system, the circuit for driving the single degree of freedom of the rotor comprises a bridge type power amplifier and two inductance coils, the bridge type power amplifier comprises a first midpoint and a second midpoint, the bridge type power amplifier is used for providing driving current, and the two inductance coils are connected with the first midpoint and the second midpoint. And the two inductance coils are connected in series and arranged between the first midpoint and the second midpoint, and the two inductance coils are used for generating driving force to the rotor under the action of the driving current. By adopting the circuit, the condition that the two power amplifiers have adjustment competition when the rotor is adjusted to be at the position of the same degree of freedom can be avoided, and the cost of the circuit is effectively reduced.

Description

Technical Field

[0001] The invention relates to the field of bearing control, and in particular to a circuit for driving a single degree of freedom of a rotor and a magnetic suspension bearing control system. Background Art

[0002] Related technology: The existing circuit for driving a single degree of freedom of the rotor uses two inductors, and each inductor is configured with a power amplifier to control the inductor to generate current to adjust the position of the rotor in a single degree of freedom. However, the circuit requires a corresponding power amplifier to be set for each inductor, which leads to regulation competition between the two power amplifiers and increases circuit costs. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the first object of the present invention is to provide a circuit for driving a single degree of freedom of a rotor, which can avoid the regulation competition between two power amplifiers when adjusting the position of the rotor in the same degree of freedom, and effectively reduce the cost of the circuit.

[0004] The second object of the present invention is to provide a magnetic bearing control system.

[0005] In order to achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes a circuit for driving a single degree of freedom of a rotor, including a bridge power amplifier, the bridge power amplifier including a first midpoint and a second midpoint, the bridge power amplifier is used to provide a driving current; two inductors, the two inductors are connected in series and arranged between the first midpoint and the second midpoint, the two inductors are used to generate a driving force for the rotor under the action of the driving current.

[0006] According to the circuit for driving a single degree of freedom of the rotor according to an embodiment of the present invention, based on a circuit connection structure in which two inductors are connected in series and arranged between the first midpoint and the second midpoint of a bridge power amplifier, a bridge power amplifier is used to provide driving current for the two inductors, and the two inductors generate driving force in the same degree of freedom direction on the rotor under the action of the driving current, thereby reducing the driving current applied when adjusting the rotor position. Therefore, compared with the existing circuit for driving a single degree of freedom of the rotor using two inductors and two power amplifiers, in the present application, two inductors and a bridge power amplifier are used to provide driving current for the two inductors through one bridge power amplifier, instead of providing driving current for the two inductors through two power amplifiers, thereby avoiding adjustment competition between the two power amplifiers when adjusting the position of the rotor with the same degree of freedom, effectively reducing the cost of the circuit.

[0007] In some embodiments of the present invention, the two inductors include a first inductor and a second inductor, and the bridge power amplifier includes: a first power tube, a drain of the first power tube is connected to a first power supply terminal of a power supply, and a source of the first power tube is connected to a first end of the first inductor; a second power tube, a drain of the second power tube is connected to a first end of the first inductor and a source of the first power tube, and a source of the second power tube is connected to a second power supply terminal of the power supply; a third power tube, a drain of the third power tube is connected to the first power supply terminal of the power supply and the drain of the first power tube, and a source of the third power tube is connected to a first end of the second inductor; a fourth power tube, a drain of the fourth power tube is connected to a first end of the second inductor and a source of the third power tube, and a source of the fourth power tube is connected to a second power supply terminal of the power supply and a source of the second power tube.

[0008] The second aspect of the present invention proposes a magnetic bearing control system, comprising: N circuits for driving a single degree of freedom of the rotor as described in the above embodiments, the circuits are used to drive the rotor in the magnetic bearing, wherein N is equal to the number of degrees of freedom of the rotor.

[0009] According to the magnetic bearing control system of the embodiment of the present invention, the circuit for driving a single degree of freedom of the rotor in the above embodiment can avoid the adjustment competition between the two power amplifiers when adjusting the position of the rotor with the same degree of freedom, thereby effectively reducing the cost of the circuit. In addition, by expanding two PWM control signals through the CPLD controller, the DSP controller only needs to output ten PWM control signals. Therefore, compared with the existing magnetic bearing control system that only uses the DSP controller, the demand for PWM hardware channels is reduced from forty channels to ten channels, thereby avoiding the problem of insufficient DSP controller drive channels and reducing the difficulty of selecting the DSP controller.

[0010] In some embodiments of the present invention, the magnetic bearing control system also includes: N current sensors, each current sensor is arranged in a one-to-one correspondence with each circuit for driving a single degree of freedom of the rotor, and the current sensor is used to collect the driving current in the circuit for driving a single degree of freedom of the rotor.

[0011] In some embodiments of the present invention, each circuit for driving a single degree of freedom of the rotor includes two inductance coils, and the magnetic bearing control system also includes: 2N position sensors, each position sensor is arranged in a one-to-one correspondence with each inductance coil, and the position sensor is used to collect position information of the rotor.

[0012] In some embodiments of the present invention, the magnetic bearing control system also includes: a DSP controller, which is used to generate two PWM control signals and a current direction control signal corresponding to each circuit for driving a single degree of freedom of the rotor according to the position information of each circuit for driving a single degree of freedom of the rotor; a CPLD controller, which is connected to the DSP controller and each circuit for driving a single degree of freedom of the rotor, and is used to receive the two PWM control signals and the current direction control signal, and generate another two PWM control signals according to the current direction control signal, so as to drive each circuit for driving a single degree of freedom of the rotor through four PWM control signals.

[0013] In some embodiments of the present invention, the magnetic bearing control system also includes: a signal processing module, a first end of the signal processing module is connected to each position sensor and each current sensor, and is used to perform signal processing on the position information of the rotor in each degree of freedom to obtain the position state parameters of the rotor in each degree of freedom, and to perform signal processing on the driving current in each circuit for driving a single degree of freedom of the rotor to obtain the current state parameters corresponding to each circuit for driving a single degree of freedom of the rotor; an A / D conversion module, a first end of the A / D conversion module is connected to the second end of the signal processing module, and a second end of the A / D conversion module is connected to the DSP controller, and is used to convert the position state parameters of the rotor in each degree of freedom into position digital signals, and convert the current state parameters corresponding to each circuit for driving a single degree of freedom of the rotor into current digital signals, and send the position digital signals and the current digital signals to the DSP controller.

[0014] In some embodiments of the present invention, the magnetic bearing control system also includes: a current fault protection circuit, a first end of the current fault protection circuit is connected to the third end of the signal processing module, and a second end of the current fault protection circuit is connected to the DSP controller and the CPLD controller, and is used to obtain a first drive protection signal corresponding to each circuit for driving a single degree of freedom of the rotor according to a current state parameter corresponding to each circuit for driving a single degree of freedom of the rotor.

[0015] In some embodiments of the present invention, the magnetic bearing control system also includes: a position fault protection circuit, a first end of the position fault protection circuit is connected to the fourth end of the signal processing module, and a second end of the position fault protection circuit is connected to the DSP controller and the CPLD controller, and is used to obtain a second drive protection signal according to the position state parameters of the rotor in each degree of freedom.

[0016] In some embodiments of the present invention, the DSP controller includes: a communication interface, which is used to connect to a host computer of the magnetic bearing control system to feed back working status information of the magnetic bearing control system to the host computer.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 A circuit diagram of a circuit for driving a single degree of freedom of a rotor according to an embodiment of the present invention; Figure 2 is a structural block diagram of a magnetic bearing control system according to an embodiment of the present invention; Figure 3 A schematic diagram of a PWM control signal waveform and a current direction control signal waveform when a magnetic bearing control system outputs a positive current according to an embodiment of the present invention; Figure 4 It is a schematic diagram of the waveforms of four-channel PWM control signals after expansion when the magnetic bearing control system outputs positive current according to an embodiment of the present invention; Figure 5 A schematic diagram of a PWM control signal waveform and a current direction control signal waveform when a magnetic bearing control system outputs a negative current according to an embodiment of the present invention; Figure 6 It is a schematic diagram of the waveforms of four expanded PWM control signals when the magnetic bearing control system outputs negative current according to an embodiment of the present invention.

[0019] Reference numerals: A circuit 10 for driving a single degree of freedom of the rotor; Magnetic bearing control system 100; Bridge power amplifier 1; power supply 3; controller power supply 4; The first midpoint is 11; the second midpoint is 12; A first inductor coil L1; a second inductor coil L2; Current sensor 20; position sensor 30; DSP controller 40; CPLD controller 50; signal processing module 60; A / D conversion module 70; current fault protection circuit 80; position fault protection circuit 90; A first power tube 101; a second power tube 102; a third power tube 103; a fourth power tube 104; Communication interface 401; host computer 402. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0021] In order to solve the above problems, an embodiment of the first aspect of the present invention provides a circuit for driving a single degree of freedom of a rotor. The circuit can avoid adjustment competition between two power amplifiers when adjusting the position of the rotor in the same degree of freedom, thereby effectively reducing the cost of the circuit.

[0022] Reference below Figure 1 A circuit 10 for driving a single degree of freedom of a rotor according to an embodiment of the present invention is described. Figure 1 As shown, the circuit includes a bridge power amplifier 1 and two inductors (not shown in the figure).

[0023] The bridge power amplifier 1 includes a first midpoint 11 and a second midpoint 12. The bridge power amplifier 1 is used to provide a driving current. The bridge power amplifier 1 may be an H-bridge power amplifier. Two inductors are connected in series and arranged between the first midpoint 11 and the second midpoint 12. The two inductors are used to generate a driving force on the rotor under the action of the driving current. The rotor may be a rotor of a motor. The magnitude of the driving current provided by the bridge power amplifier 1 determines the magnitude of the driving force generated by the two inductors, thereby determining the position change of the rotor in a single degree of freedom.

[0024] Specifically, in order to solve this problem, in the present application, two inductors are connected in series and arranged between the first midpoint 11 and the second midpoint 12 of the bridge power amplifier 1, so that the driving current is provided to the two inductors through one bridge power amplifier 1, instead of providing the driving current to the two inductors through two power amplifiers, thereby effectively reducing the cost of the circuit. Specifically, the two inductors are inductors in the positive and negative directions of the same degree of freedom, and the winding directions of the two inductors are the same. By connecting one end of the two inductors that control the rotor in the same degree of freedom in series to form a circuit 10 for driving a single degree of freedom of the rotor, when the bridge power amplifier 1 provides driving current to the two inductors, according to Faraday's law of electromagnetic induction, since the directions of the currents flowing through the two inductors at the same time are opposite, the driving forces of the two inductors are in the same direction, that is, when one of the inductors generates thrust on the rotor, the other inductor generates suction on the rotor, so that the rotor moves in the same direction of the degree of freedom. Based on this, the same force is applied when controlling the rotor to move in one degree of freedom. When driving current, the two inductors will generate a driving force equivalent to twice the driving current. Therefore, compared with the existing circuit for driving a single degree of freedom of the rotor using two inductors and two power amplifiers, in the present application, two inductors are connected in series and arranged between the first midpoint 11 and the second midpoint 12 of the bridge power amplifier 1, so that the driving current is provided to the two inductors through one bridge power amplifier 1, instead of providing the driving current to the two inductors through two power amplifiers, thereby avoiding adjustment competition between the two power amplifiers when adjusting the position of the rotor with the same degree of freedom, effectively reducing the cost of the circuit, reducing the driving current applied when adjusting the rotor position, and reducing the driving power and heat generation of the bridge power amplifier 1.

[0025] According to the circuit 10 for driving a single degree of freedom of the rotor according to an embodiment of the present invention, based on a circuit connection structure in which two inductors are connected in series and arranged between a first midpoint 11 and a second midpoint 12 of a bridge power amplifier 1, a bridge power amplifier 1 is used to provide driving current for the two inductors, and the two inductors generate driving force in the same degree of freedom direction on the rotor under the action of the driving current, thereby reducing the driving current applied when adjusting the rotor position. Therefore, compared with the existing circuit for driving a single degree of freedom of the rotor using two inductors and two power amplifiers, the present application uses two inductors and a bridge power amplifier 1 to provide driving current for the two inductors through a bridge power amplifier 1, instead of using two power amplifiers to provide driving current for the two inductors, thereby avoiding adjustment competition between the two power amplifiers when adjusting the position of the rotor with the same degree of freedom, effectively reducing the cost of the circuit.

[0026] In some embodiments of the present invention, the two inductors include a first inductor and a second inductor, wherein the first inductor L1 and the second inductor L2 are as follows: Figure 1 As shown, the bridge power amplifier 1 includes: a first power tube 101 , a second power tube 102 , a third power tube 103 and a fourth power tube 104 .

[0027] Among them, the second end of the first inductor L1 is connected to the second end of the second inductor L2, the drain of the first power tube 101 is connected to the first power end of the power supply 3, the source of the first power tube 101 is connected to the first end of the first inductor L1, the drain of the second power tube 102 is connected to the first end of the first inductor L1 and the source of the first power tube 101, the source of the second power tube 102 is connected to the second power end of the power supply 3, the drain of the third power tube 103 is connected to the first power end of the power supply 3 and the drain of the first power tube 101, the source of the third power tube 103 is connected to the first end of the second inductor L2, the drain of the fourth power tube 104 is connected to the first end of the second inductor L2 and the source of the third power tube 103, and the source of the fourth power tube 104 is connected to the second power end of the power supply 3 and the source of the second power tube 102.

[0028] Specifically, the first power tube 101, the second power tube 102, the third power tube 103 and the fourth power tube 104 in the bridge power amplifier 1 are controlled to be turned on and off, so as to control the direction of the driving current provided by the bridge power amplifier 1 to the first inductor L1 and the second inductor L2, thereby adjusting the direction of the driving force generated by the first inductor L1 and the second inductor L2, so as to make the rotor move along the positive direction or the negative direction of a single degree of freedom. For example, when the first power tube 101 and the fourth power tube 104 are controlled to be turned on according to the direction of the driving current, and the second power tube 102 and the third power tube 103 are controlled to be turned off, at this time, the current flows from the first inductor L1 to the second inductor L2, and the direction of the driving force generated by the first inductor L1 and the second inductor L2 is the negative direction X1- of the single degree of freedom, so as to make the rotor move along the negative direction X1- of the single degree of freedom; when the second power tube 102 and the third power tube 103 are controlled to be turned on according to the direction of the driving current, and the first power tube 101 and the fourth power tube 104 are controlled to be turned off, When 104 is cut off, the current flows from the second inductor L2 to the first inductor L1, and the direction of the driving force generated by the first inductor L1 and the second inductor L2 is the positive direction X1+ of the single degree of freedom, so that the rotor moves along the positive direction X1+ of the single degree of freedom, and the magnitude of the driving force is equal to twice the driving force generated by the driving current. Therefore, compared with the existing circuit for driving a single degree of freedom of the rotor using two inductors and two power amplifiers, in the present application, two inductors are connected in series and arranged between the first midpoint 11 and the second midpoint 12 of the bridge power amplifier 1, so as to provide driving current for the two inductors through one bridge power amplifier 1, instead of providing driving current for the two inductors through two power amplifiers, thereby avoiding adjustment competition between the two power amplifiers when adjusting the position of the rotor in the same degree of freedom, effectively reducing the cost of the circuit, reducing the driving current applied when adjusting the rotor position, and reducing the driving power and heat generation of the bridge power amplifier 1.

[0029] A second aspect of the present invention provides a magnetic bearing control system 100, such as Figure 2 As shown, the circuit 10 for driving a single degree of freedom of a rotor includes N of the above-mentioned embodiments.

[0030] Among them, the circuit 10 for driving a single degree of freedom of the rotor is used to drive the rotor in the magnetic bearing, wherein N is equal to the number of degrees of freedom of the rotor, and N can be 1, 2, 3, 4 or 5. That is, the number of degrees of freedom of the rotor can be 1, 2, 3, 4 or 5, and the corresponding number of circuits 10 for driving a single degree of freedom of the rotor is 1, 2, 3, 4 or 5.

[0031] The magnetic bearing control system 100 is a control device that uses the magnetic principle to achieve rotor suspension. Its working principle is to support and suspend the rotor through electromagnetic force, and has the advantages of high speed, high precision, no contact and low energy consumption.

[0032] Specifically, the magnetic bearing control system 100 provides control signals to N circuits 10 for driving a single degree of freedom of the rotor, so that the N circuits 10 for driving a single degree of freedom of the rotor control the rotor to move in the positive or negative direction of the N degrees of freedom, thereby realizing the position change of the rotor in the N degrees of freedom.

[0033] For example, Figure 2 As shown, the magnetic bearing control system 100 includes five circuits 10 for driving a single degree of freedom of the rotor. The five circuits 10 for driving a single degree of freedom of the rotor are used to drive the rotor in the magnetic bearing to change its position in five degrees of freedom, such as Figure 2 As shown, the five degrees of freedom can be expressed as X1, X2, Y1, Y2, and Z, the positive direction of X1 is X1+, the negative direction of X1 is X1-, the positive direction of X2 is X2+, the negative direction of X2 is X2-, the positive direction of Y1 is Y1+, the negative direction of Y1 is Y1-, the positive direction of Y2 is Y2+, the negative direction of Y2 is Y2-, the positive direction of Z is Z+, and the negative direction of Z is Z-, and the five circuits 10 for driving a single degree of freedom of the rotor connect two inductors of the same degree of freedom in series to realize the position change of the rotor in five degrees of freedom, reducing the number of controls on the inductors from ten to five, effectively reducing the cost of the magnetic bearing control system 100, and the system reduces the original amount of data to be processed by half.

[0034] According to the magnetic bearing control system 100 of the embodiment of the present invention, the circuit 10 for driving a single degree of freedom of the rotor in the above embodiment can avoid the regulation competition between the two power amplifiers when adjusting the position of the rotor in the same degree of freedom, thereby effectively reducing the circuit cost.

[0035] In some embodiments of the present invention, Figure 2 As shown, the magnetic bearing control system 100 further includes a current sensor 20 .

[0036] The number of current sensors 20 is N, and each current sensor 20 is set in one-to-one correspondence with each circuit 10 for driving a single degree of freedom of the rotor, and the current sensor 20 is used to collect the driving current in the circuit 10 for driving a single degree of freedom of the rotor. The current sensor 20 is connected in series to the circuit 10 for driving a single degree of freedom of the rotor.

[0037] Specifically, each current sensor 20 may be respectively disposed at any position of each circuit 10 for driving a single degree of freedom of the rotor, and is used to collect the driving current of the circuit 10 for driving a single degree of freedom of the rotor.

[0038] For example, when the existing magnetic bearing control system drives the rotor to change position in five degrees of freedom, the number of circuits included for driving a single degree of freedom of the rotor is 10, and the number of current sensors is also 10, which increases the cost of the magnetic bearing control system. In order to solve this problem, the circuit 10 for driving a single degree of freedom of the rotor in the present application can realize the position change of the rotor in a single degree of freedom through two inductors and a bridge power amplifier 1. Based on this, the magnetic bearing control system 100 of the present application is provided with five circuits 10 for driving a single degree of freedom of the rotor, and the five circuits 10 for driving a single degree of freedom of the rotor only need to be provided with five current sensors 20, so that the number of current sensors 20 is reduced from ten to five, thereby effectively reducing the cost of the magnetic bearing control system 100 and reducing the processing amount of current sensor 20 data.

[0039] In some embodiments of the present invention, each circuit 10 for driving a single degree of freedom of the rotor includes two inductance coils, and the magnetic bearing control system 100 further includes 2N position sensors 30 .

[0040] Among them, each position sensor 30 is arranged in a one-to-one correspondence with each inductor coil, and each position sensor 30 and the inductor coil are installed in the same way and are sleeved on the same rotor shaft. The position sensor 30 is used to collect the position information of the rotor, that is, each position sensor 30 collects the position information of the rotor in the corresponding degree of freedom.

[0041] In addition, since the rotor's operating stroke is very small, about 2 mm, and considering that electromagnetic interference and heat generation in the process of driving the inductor coil will affect the signal collected by the position sensor 30, the position sensor 30 can be placed independently.

[0042] In some embodiments, Figure 2 As shown, the magnetic bearing control system 100 further includes a DSP controller 40 and a CPLD controller 50 .

[0043] Among them, the DSP (high-speed digital signal processor) controller 40 is used to generate two PWM control signals and a current direction control signal corresponding to each circuit 10 for driving a single degree of freedom of the rotor according to the position information of each circuit 10 for driving a single degree of freedom of the rotor, and the CPLD (Complex Programmable logic device) controller 50 is connected to the DSP controller 40 and each circuit 10 for driving a single degree of freedom of the rotor, and is used to receive the two PWM control signals and the current direction control signal, and generate another two PWM control signals according to the current direction control signal, so as to drive each circuit 10 for driving a single degree of freedom of the rotor through four PWM control signals.

[0044] Existing magnetic bearing control systems mostly use DSP controllers as magnetic levitation controllers. However, due to the limited hardware resources and algorithm processing capabilities of DSP controllers, when DSP controllers are applied to magnetic bearing control systems that control the position changes of the rotor in five degrees of freedom, the speed of signal acquisition, filtering, calculation and analysis of multi-channel displacement information and current information is low, affecting the control accuracy and real-time performance of the DSP controller. In addition, since a magnetic bearing control system that controls the position changes of the rotor in five degrees of freedom usually requires ten inductors, and each inductor needs to be configured with a position sensor, a current sensor and a power amplifier, and each power amplifier requires four PWM control signals to drive it, ten power amplifiers require at least forty PWM control signals, resulting in the problem of insufficient DSP controller drive channels, thereby increasing the difficulty of selecting a DSP controller.

[0045] To this end, the prior art uses a dual controller to calculate the PWM control signal, that is, different inductance coils are controlled separately by a DSP controller and a CPLD controller. However, there are disadvantages such as asynchronous control, information interaction delay, and asynchronous protection action, which increases the failure rate of the magnetic bearing control system.

[0046] In order to solve this problem, the magnetic bearing control system 100 in the present application is provided with a CPLD controller 50 and a DSP controller 40. The DSP controller 40 outputs two PWM control signals and a current direction control signal for driving the circuit 10 of a single degree of freedom of the rotor to the CPLD controller 50. The CPLD controller 50 expands the other two PWM control signals of the circuit 10 for driving a single degree of freedom of the rotor according to the current direction control signal, thereby obtaining four PWM control signals, and then outputs the four PWM control signals to the circuit 10 for driving a single degree of freedom of the rotor, that is, the four PWM control signals are respectively output to the four power tubes of the bridge power amplifier 1. Therefore, compared with the existing magnetic bearing control system that only adopts the DSP controller, the magnetic bearing control system 100 in the present application expands two PWM control signals through the CPLD controller 50. At this time, when controlling the rotor to change position in five degrees of freedom, twenty PWM control signals are required, and the DSP controller 40 only needs to output ten PWM control signals, that is, the number of PWM hardware channels required is reduced from forty to ten, thereby avoiding the problem of insufficient driving channels of the DSP controller 40 and reducing the difficulty of selecting the DSP controller 40. In addition, when the DSP controller 40 and the CPLD controller 50 control the same inductor, problems such as asynchronous control, information interaction delay, and asynchronous protection action are avoided, thereby reducing the failure rate of the magnetic bearing control system 100.

[0047] In addition, the specific process of the CPLD controller 50 expanding the other two PWM control signals according to the current direction control signal is as follows: the CPLD controller 50 acts as a PWM wave processor. If the offset displacement between the displacement information and the target position is positive, the current direction is positive, that is, the current flowing from the first inductor coil L1 to the second inductor coil L2 is positive. The DSP controller 40 sends the current direction control signal and the two PWM control signals to the CPLD controller 50. The current direction control signal GPIO and the two PWM control signals PWMH and PWML are as follows: Figure 3 As shown, the level of the current direction control signal GPIO is high level, specifically, as Figure 4The waveform of the expanded PWM control signal is shown. The logic processing unit of the CPLD controller 50 inverts the current direction control signal GPIO, and uses the inverted current direction control signal GPIO as the PWMBH control signal, and directly outputs the current direction control signal GPIO as the PWMBL control signal, and directly outputs one PWMH control signal output by the DSP controller 40 as the PWMAH control signal, and directly outputs another PWML control signal output by the DSP controller 40 as the PWMAL control signal. Then, according to the driving principle of the bridge power amplifier 1, the current flowing from the first inductor L1 to the second inductor L2 can be obtained; if the offset displacement between the displacement information and the target position is negative, the current direction is negative, that is, the current flowing from the second inductor L2 to the first inductor L1 is negative, and the DSP controller 40 sends the current direction control signal GPIO and the two PWM control signals to the CPLD controller 50, wherein the level of the current direction control signal GPIO is low, and the current direction control signal GPIO and the two PWM control signals PWMH and PWML are as shown in FIG. Figure 5 As shown, when the CPLD controller 50 receives the current direction control signal GPIO sent by the DSP controller 40, the level is low, such as Figure 6 The waveform of the expanded four-way PWM control signal is shown. The logic processing unit of the CPLD controller 50 inverts the current direction control signal GPIO, and uses the inverted current direction control signal GPIO as the PWMAL control signal, and directly outputs the current direction control signal GPIO as the PWMAH control signal, and directly outputs one PWMH control signal output by the DSP controller 40 as the PWMBH control signal, and directly outputs another PWML control signal output by the DSP controller 40 as the PWMBL control signal. Then, according to the driving principle of the bridge power amplifier 1, the current flowing from the second inductor coil L2 to the first inductor coil L1 can be obtained.

[0048] Based on this, when the CPLD controller 50 inputs the PWMAH control signal to the gate of the first power tube 101 to control the first power tube 101 to be alternately turned on or off, or to control the first power tube 101 to be normally closed or normally open, and inputs the PWMAL control signal to the gate of the second power tube 102 to control the second power tube 102 to be alternately turned on or off, or to control the second power tube 102 to be normally open or normally closed, and inputs the PWMBH control signal to the gate of the third power tube 103 to control the third power tube 103 to be normally closed or normally open, or to control the third power tube 103 to be alternately turned on or off, and inputs the PWMBL control signal to the gate of the fourth power tube 104 to control the fourth power tube 104 to be normally closed or normally open, or to control the fourth power tube 104 to be alternately turned on or off, current direction control is achieved.

[0049] For example, Figure 4 As shown, the magnetic bearing control system 100 outputs a positive current. When the PWMAH control signal is high, the PWMAL control signal is low, the PWMBL control signal is high, and the PWMBH control signal is low, the first power tube 101 is turned on, the fourth power tube 104 is normally open, the second power tube 102 is turned off, and the third power tube 103 is normally closed, then the current flows from the first inductor coil L1 to the second inductor coil L2; or, as Figure 6 As shown, the magnetic bearing control system 100 outputs a negative current. When the PWMAH control signal is at a low level, the PWMAL control signal is at a high level, the PWMBH control signal is at a high level, and the PWMBL control signal is at a low level, the first power tube 101 is normally closed, the fourth power tube 104 is cut off, the second power tube 102 is normally open, and the third power tube 103 is turned on, the current flows from the second inductor coil L2 to the first inductor coil L1, thereby realizing current direction control.

[0050] In an embodiment, Figure 2 As shown, the magnetic bearing control system 100 further includes a controller power supply 4 , which is connected to the CPLD controller 50 and the DSP controller 40 and is used to supply power to the CPLD controller 50 and the DSP controller 40 .

[0051] In some embodiments of the present invention, Figure 2 As shown, the magnetic bearing control system 100 further includes a signal processing module 60 and an A / D conversion module 70 .

[0052] Among them, the first end of the signal processing module 60 is connected to each position sensor 30 and each current sensor 20, and is used to perform signal processing on the position information of the rotor in each degree of freedom to obtain the position state parameters of the rotor in each degree of freedom, and to perform signal processing on the driving current in each circuit 10 for driving a single degree of freedom of the rotor to obtain the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor. The first end of the A / D conversion module 70 is connected to the second end of the signal processing module 60, and the second end of the A / D conversion module 70 is connected to the DSP controller 40, and is used to convert the position state parameters of the rotor in each degree of freedom into position digital signals, and convert the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor into current digital signals, and send the position digital signals and current digital signals to the DSP controller 40.

[0053] Specifically, each current sensor 20 collects the driving current corresponding to the circuit 10 for driving a single degree of freedom of the rotor, and sends the driving current of each circuit 10 for driving a single degree of freedom of the rotor to the signal processing module 60. The signal processing module 60 performs signal processing on the driving current in each circuit 10 for driving a single degree of freedom of the rotor to obtain the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor, and then sends the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor to the A / D conversion module 70. The A / D conversion module 70 converts the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor into current digital signals, and then sends the current digital signals corresponding to each circuit 10 for driving a single degree of freedom of the rotor to the DSP controller 40, so as to provide the DSP controller 40 with the driving current change status of each circuit 10 for driving a single degree of freedom of the rotor.

[0054] Alternatively, each position sensor 30 collects position information of the rotor in five degrees of freedom and sends the position information to the signal processing module 60. The signal processing module 60 performs signal processing on the position information of the rotor in each degree of freedom to obtain the position state parameters of the rotor in each degree of freedom, and then sends the position state parameters of the rotor in each degree of freedom to the A / D conversion module 70. The A / D conversion module 70 converts the position state parameters of the rotor in each degree of freedom into a position digital signal so as to provide the DSP controller 40 with the position change status of the rotor in each degree of freedom.

[0055] In the embodiment, the signal processing module 60 is optimized by adding hardware such as digital potentiometers and filters, and the fixed errors of the hardware loop and the inductor are processed and offset, thereby reducing the signal processing tasks of the DSP controller 40 and further improving the signal processing speed of the DSP controller 40.

[0056] In some embodiments of the present invention, Figure 2 As shown, the magnetic bearing control system 100 further includes a current fault protection circuit 80 .

[0057] Among them, the first end of the current fault protection circuit 80 is connected to the third end of the signal processing module 60, and the second end of the current fault protection circuit 80 is connected to the DSP controller 40 and the CPLD controller 50, which is used to obtain the first drive protection signal corresponding to each circuit 10 for driving a single degree of freedom of the rotor according to the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor.

[0058] Specifically, the signal processing module 60 sends the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor to the current fault protection circuit 80. The current fault protection circuit 80 obtains the first drive protection signal corresponding to each circuit 10 for driving a single degree of freedom of the rotor according to the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor. That is to say, the current fault protection circuit 80 compares the current state parameters corresponding to the circuit 10 for driving a single degree of freedom of the rotor with the set current protection threshold. When the current state parameters corresponding to each circuit 10 for driving a single degree of freedom of the rotor exceed the corresponding set current protection threshold, the current fault protection circuit 80 sends a signal to the DSP controller 40, The CPLD controller 50 sends a first drive protection signal corresponding to each circuit 10 for driving a single degree of freedom of the rotor, that is, sends current fault information of each circuit 10 for driving a single degree of freedom of the rotor to the DSP controller 40 and the CPLD controller 50. The DSP controller 40 first calculates the duty cycle of the PWM control signal of each circuit 10 for driving a single degree of freedom of the rotor according to the digital signal of the rotor position at each degree of freedom and the target position, and then adjusts the duty cycle of the PWM control signal according to the first drive protection signal corresponding to each circuit 10 for driving a single degree of freedom of the rotor to determine the PWM control signal of each circuit 10 for driving a single degree of freedom of the rotor. In the present application, the PWM control signal is adjusted by the first drive protection signal output by the current fault protection circuit 80, so as to avoid failure of the circuit 10 used to drive a single degree of freedom of the rotor. In addition, the first drive protection signal is simultaneously input into the DSP controller 40 and the CPLD controller 50, so that the CPLD controller 50 can send a backup first drive protection signal to the DSP controller 40, so that the DSP controller 40 can make corresponding adjustments to the PWM control signal through the first drive protection signal. Thus, the PWM control signal is doubly protected by the CPLD controller 50 and the DSP controller 40.

[0059] In addition, the larger the duty cycle of the PWM control signal is, the larger the driving current provided by the bridge power amplifier 1 is.

[0060] In some embodiments of the present invention, Figure 2 As shown, the magnetic bearing control system 100 further includes a position fault protection circuit 90 .

[0061] Among them, the first end of the position fault protection loop 90 is connected to the fourth end of the signal processing module 60, and the second end of the position fault protection loop 90 is connected to the DSP controller 40 and the CPLD controller 50, which are used to obtain the second drive protection signal according to the position state parameters of the rotor in each degree of freedom.

[0062] Specifically, the signal processing module 60 sends the position state parameters of the rotor at each degree of freedom to the position fault protection circuit 90, and the position fault protection circuit 90 compares the position state parameters of the rotor at each degree of freedom with the corresponding set position protection threshold. When the position state parameters of the rotor at each degree of freedom exceed the corresponding set position protection threshold, the second drive protection signal corresponding to each circuit 10 for driving a single degree of freedom of the rotor is sent to the DSP controller 40 and the CPLD controller 50 at the same time, that is, the position fault information of each circuit 10 for driving a single degree of freedom of the rotor is sent to the DSP controller 40 and the CPLD controller 50. The DSP controller 40 first calculates the duty cycle of the PWM control signal of each circuit 10 for driving a single degree of freedom of the rotor according to the position digital signal of the rotor at each degree of freedom and the target position, and then adjusts the duty cycle of the PWM control signal according to the second drive protection signal corresponding to each circuit 10 for driving a single degree of freedom of the rotor to determine the PWM control signal of each circuit 10 for driving a single degree of freedom of the rotor. In the present application, the PWM control signal is adjusted by the second drive protection signal output by the position fault protection circuit 90, so as to avoid the failure of the circuit 10 used to drive a single degree of freedom of the rotor. In addition, the second drive protection signal is simultaneously input into the DSP controller 40 and the CPLD controller 50, so that the CPLD controller 50 can send a backup second drive protection signal to the DSP controller 40, so that the DSP controller 40 can make corresponding adjustments to the PWM control signal through the second drive protection signal. Thus, the PWM control signal is doubly protected by the CPLD controller 50 and the DSP controller 40.

[0063] In some embodiments of the present invention, Figure 2 As shown, the DSP controller 40 includes a communication interface 401 .

[0064] The communication interface 401 is used to connect to the host computer of the magnetic bearing control system 100 to feed back the working status information of the magnetic bearing control system 100 to the host computer. The working status information may be information fed back by the sensor, and the host computer may be a PC (Personal Computer).

[0065] Specifically, the DSP controller 40 feeds back the working status information of the magnetic bearing control system 100 to the host computer through the communication interface 401 , and the host computer 402 displays the working status information on the host computer interface so that the user can know the working status information of the magnetic bearing control system 100 in time.

[0066] Exemplarily, the communication interface 401 can be RJ45 (Registered Jack 45), and the DSP controller 40 uses the Modbus TCP communication protocol to exchange information with the host computer 402. The host computer 402 can also control the DSP controller 40 through the Modbus TCP communication protocol. In addition, the user can set the working parameters of the magnetic bearing control system 100 through the interface of the host computer 402.

[0067] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0068] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A circuit for driving a single degree of freedom of a rotor, characterized in that: include A bridge power amplifier, the bridge power amplifier comprising a first midpoint and a second midpoint, the bridge power amplifier being used to provide a driving current; Two inductors are connected in series and arranged between the first midpoint and the second midpoint, and the two inductors are used to generate driving force for the rotor under the action of the driving current.

2. The circuit for driving a single degree of freedom of a rotor according to claim 1, characterized in that: The two inductors include a first inductor and a second inductor, and the bridge power amplifier includes: A first power tube, wherein a drain of the first power tube is connected to a first power supply terminal of a power supply, and a source of the first power tube is connected to a first end of a first inductor; a second power tube, wherein a drain of the second power tube is connected to a first end of the first inductor coil and a source of the first power tube, and a source of the second power tube is connected to a second power supply end of a power supply; a third power tube, wherein a drain of the third power tube is connected to a first power supply end of a power supply and a drain of the first power tube, and a source of the third power tube is connected to a first end of a second inductor; A fourth power tube, wherein the drain of the fourth power tube is connected to the first end of the second inductor coil and the source of the third power tube, and the source of the fourth power tube is connected to the second power supply end of the power supply and the source of the second power tube.

3. A magnetic bearing control system, characterized in that: include: N circuits for driving a single degree of freedom of a rotor as claimed in claim 1 or 2, wherein the circuit is used to drive a rotor in a magnetic bearing, wherein N is equal to the number of degrees of freedom of the rotor.

4. The magnetic bearing control system according to claim 3, characterized in that: Also includes: N current sensors, each current sensor is arranged in one-to-one correspondence with each circuit for driving a single degree of freedom of the rotor, and the current sensor is used to collect the driving current in the circuit for driving a single degree of freedom of the rotor.

5. The magnetic bearing control system according to claim 4, characterized in that: Each circuit for driving a single degree of freedom of the rotor includes two inductor coils, and the magnetic bearing control system also includes: 2N position sensors, each position sensor is arranged in one-to-one correspondence with each inductor coil, and the position sensor is used to collect the position information of the rotor.

6. The magnetic bearing control system according to claim 5, characterized in that: Also includes: A DSP controller, the DSP controller is used to generate two PWM control signals and a current direction control signal corresponding to each circuit for driving a single degree of freedom of the rotor according to the position information of each circuit for driving a single degree of freedom of the rotor; A CPLD controller is connected to the DSP controller and each circuit for driving a single degree of freedom of the rotor, and is used to receive the two PWM control signals and the current direction control signal, and generate another two PWM control signals according to the current direction control signal, so as to drive each circuit for driving a single degree of freedom of the rotor through four PWM control signals.

7. The magnetic bearing control system according to claim 6, characterized in that: Also includes: a signal processing module, wherein a first end of the signal processing module is connected to each position sensor and each current sensor, and is used to perform signal processing on the position information of the rotor in each degree of freedom to obtain the position state parameter of the rotor in each degree of freedom, and to perform signal processing on the driving current in each circuit for driving a single degree of freedom of the rotor to obtain the current state parameter corresponding to each circuit for driving a single degree of freedom of the rotor; An A / D conversion module, wherein the first end of the A / D conversion module is connected to the second end of the signal processing module, and the second end of the A / D conversion module is connected to the DSP controller, for converting the position state parameter of the rotor at each degree of freedom into a position digital signal, and converting the current state parameter corresponding to each circuit for driving a single degree of freedom of the rotor into a current digital signal, and sending the position digital signal and the current digital signal to the DSP controller.

8. The magnetic bearing control system according to claim 7, characterized in that: Also includes: A current fault protection circuit, wherein a first end of the current fault protection circuit is connected to a third end of the signal processing module, and a second end of the current fault protection circuit is connected to the DSP controller and the CPLD controller, and is used to obtain a first drive protection signal corresponding to each circuit for driving a single degree of freedom of the rotor according to a current state parameter corresponding to each circuit for driving a single degree of freedom of the rotor.

9. The magnetic bearing control system according to claim 7, characterized in that: Also includes: A position fault protection circuit, wherein a first end of the position fault protection circuit is connected to a fourth end of the signal processing module, and a second end of the position fault protection circuit is connected to the DSP controller and the CPLD controller, and is used to obtain a second drive protection signal according to a position state parameter of the rotor in each degree of freedom.

10. The magnetic bearing control system according to any one of claims 6 to 9, characterized in that: The DSP controller comprises: A communication interface, wherein the communication interface is used to connect to a host computer of a magnetic bearing control system so as to feed back working status information of the magnetic bearing control system to the host computer.

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