Control method and driving system of high-speed magnetic suspension fan

Abstract

The invention provides a control method and a driving system of a high-speed magnetic suspension fan. The control method comprises the following steps: starting a magnetic suspension bearing active controller; acquiring three-phase current, rotating speed and rotor position signals of the high-speed magnetic suspension fan; determining a target phase current when two phases of the permanent magnet motor are conducted according to the three-phase current and the rotor position signal; the direct-current side voltage is converted into a rotating speed given value according to the direct-current side voltage-power curve relation, the difference value between the rotating speed given value and the rotating speed of the high-speed magnetic suspension draught fan is a first error value, and a current given value is output after the first error value passes through a first PI regulator; a difference value between the target phase current and the current given value is a second error value, the second error value passes through a second PI regulator, a duty ratio is output, the duty ratio is compared with the triangular carrier wave, and a PWM pulse signal is generated according to a comparison result; the PWM pulse signal controls on and off of a power switch device of the machine side medium voltage power converter; therefore, acceleration and deceleration operation of the high-speed magnetic suspension fan is controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of high-power AC speed regulation, and in particular to a control method and a drive system for a high-speed magnetic suspension fan. Background Art

[0002] A high-speed magnetic levitation blower is a mechanical device for conveying gas. It utilizes core technologies such as magnetic bearings, a three-dimensional flow impeller, a high-speed permanent magnet synchronous motor, efficient inverter speed regulation, and intelligent monitoring and control. Upon startup, the blower first levitates before rotating, making it a high-tech, green, energy-saving, and environmentally friendly product. Using contactless, frictionless magnetic bearings and a high-speed, high-power permanent magnet synchronous motor, the blower directly drives a high-efficiency fluid impeller. This overcomes the shortcomings of traditional blowers and air suspension blowers, offering advantages such as high efficiency, low noise, minimal failure, and the absence of a lubrication system. Even if the magnetic bearing fails, the protective bearing in the system can still safely shut down the high-speed rotor without causing serious damage to the equipment.

[0003] However, existing high-speed magnetic levitation fans require complex control systems to maintain stable suspension and high-speed operation of the rotor. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a simple and efficient control method and drive system for a high-speed magnetic levitation fan.

[0005] In order to solve the above problems, the present invention provides a simple and efficient control method for a high-speed magnetic levitation fan, comprising the following steps: S10, starting the magnetic suspension bearing active controller to realize magnetic suspension of the high-speed magnetic suspension fan bearing; S20, collecting three-phase current, speed and rotor position signals of the high-speed magnetic suspension fan; S30, determining the target phase current when two phases of the permanent magnet motor are turned on according to the three-phase current and the rotor position signal; The DC side voltage is converted into a speed set value according to the DC side voltage-power curve relationship. The difference between the speed set value and the speed of the high-speed magnetic levitation fan is a first error value. The first error value is output as a current set value after passing through a first PI regulator. S40: The difference between the target phase current and the current set value is a second error value, and the second error value is output as a duty cycle after passing through a second PI regulator; The duty cycle is compared with the triangular carrier, and a PWM pulse signal is generated based on the comparison result; S50, PWM pulse signal controls the on and off of the power switch device of the medium voltage power converter on the machine side; S60, the on and off of the power switching device of the machine-side medium-voltage power converter controls the acceleration and deceleration operation of the high-speed magnetic levitation fan.

[0006] The technical effect achieved by adopting this technical solution is as follows: magnetic levitation of the bearing is achieved by activating the active magnetic bearing controller, and three-phase current, speed, and rotor position signals are collected, combined with a PI regulator for precise control. Specifically, the target phase current is determined based on the three-phase current and rotor position signals. The DC voltage is converted into a speed setpoint using the DC voltage-power curve. The difference between the speed setpoint and the actual speed is used to output a current setpoint via the PI regulator. Furthermore, the difference between the target phase current and the current setpoint is used to output a duty cycle via the PI regulator, generating a PWM pulse signal that controls the on and off of the power switching devices of the medium-voltage power converter on the generator side, thereby achieving acceleration and deceleration of the wind turbine. This method has the advantages of fast dynamic response, high control accuracy, and high energy utilization. The active magnetic bearing controller also reduces mechanical friction, improving system stability and lifespan. It is applicable to a variety of operating conditions and significantly improves the operating performance and control effectiveness of high-speed magnetic levitation wind turbines.

[0007] Optionally, in step S50, when determining the on and off state of the upper arm switching device of the machine-side medium-voltage power converter, the upper and lower amplitudes of the triangular carrier are 1 and 0; when determining the on and off state of the lower arm switching device of the machine-side medium-voltage power converter, the upper and lower amplitudes of the triangular carrier are 0 and -1.

[0008] The technical effect achieved after adopting this technical solution is as follows: by setting the upper and lower amplitudes of the triangular carrier to 1 and 0 respectively to control the upper arm switching device and 0 and -1 to control the lower arm switching device, the logic of PWM signal generation is simplified, the complexity of the control algorithm is reduced, and the PWM signal can be generated more accurately. At the same time, the risk of the upper and lower arm switching devices being turned on at the same time is avoided, thereby achieving precise control of the conduction and shutdown of the power switching devices of the medium-voltage power converter on the machine side.

[0009] Optionally, in step S30 , within one switching cycle, each 1 / 6 rotation of the permanent magnet motor is recorded as a conduction sector (S_phase=1, 2, 3, 4, 5, 6).

[0010] The technical effects achieved after adopting this technical solution are: First, sector division simplifies the calculation and control logic of the target phase current, improving the real-time performance and efficiency of the control algorithm; second, by precisely matching the rotation position of the permanent magnet motor with the conduction sector, it can more accurately control the target phase current when the two phases are turned on, optimize the motor torque output, reduce torque pulsation, and improve the smoothness and dynamic response performance of the motor operation.

[0011] The present invention also provides a drive system for a high-speed magnetic levitation fan, which is applicable to any of the above-mentioned high-speed magnetic levitation fan control methods, comprising: A generator-side medium-voltage power converter, wherein the input end of the generator-side medium-voltage power converter is connected to the grid-side voltage; A high-speed magnetic levitation fan is connected to the output end of the medium-voltage power converter on the machine side; A magnetic bearing active controller, the magnetic bearing active controller is connected to a high-speed magnetic bearing fan; The signal acquisition and processing unit has an input end connected to the high-speed magnetic levitation fan, and an output end connected to the input end of the machine-side medium-voltage power converter.

[0012] The technical effects achieved by adopting this technical solution are as follows: the grid-side voltage provides power input for the drive system, and the generator-side medium-voltage power converter converts the grid-side voltage into a voltage and current suitable for the high-speed magnetic levitation fan, ensuring efficient and stable operation of the high-speed magnetic levitation fan. The magnetic bearing active controller achieves magnetic levitation of the high-speed magnetic levitation fan bearing, reducing mechanical friction and wear, and improving the operating life and stability of the drive system. The signal acquisition and processing unit collects the three-phase current, speed, rotor position signal, and DC-side voltage of the high-speed magnetic levitation fan in real time, and generates PWM signals through a precise control algorithm. The PWM signals control the power switching devices of the generator-side medium-voltage power converter. Through the coordinated operation of the generator-side medium-voltage power converter, the high-speed magnetic levitation fan, the magnetic bearing active controller, and the signal acquisition and processing unit, precise speed regulation and rapid dynamic response of the high-speed magnetic levitation fan are achieved.

[0013] Optionally, the signal acquisition and processing unit in the drive system includes: AC information sampling and conditioning board, which is responsible for collecting AC signals from high-speed magnetic levitation fans; Main control board, which processes the AC signal from the AC information sampling and conditioning board; The pulse signal driver board converts the PWM pulse signal into a drive signal to control the on and off of the power switching devices of the medium-voltage power converter on the machine side.

[0014] The technical effects achieved by adopting this technical solution are: the AC information sampling and conditioning board 31 is responsible for collecting the AC signals of the high-speed magnetic levitation fan, ensuring the accuracy and real-time performance of signal acquisition, and providing a reliable data foundation for subsequent control. The main control board processes the signals from the AC information sampling and conditioning board 31 and calculates the target phase current, speed setpoint, duty cycle, and PWM pulse signal through a built-in control algorithm. The pulse signal driver board receives the PWM pulse signal from the main control board and converts it into a drive signal to control the conduction and shutdown of the power switching devices of the medium-voltage power converter on the machine side, thereby achieving precise control of the speed and magnetic levitation state of the high-speed magnetic levitation fan. Through high-precision signal acquisition, efficient signal processing, and precise pulse signal generation, the signal acquisition and processing unit 3 significantly improves the control accuracy, dynamic response speed, and system stability of the high-speed magnetic levitation fan.

[0015] Optionally, a medium-voltage transformer is connected between the machine-side medium-voltage power converter and the grid-side voltage, and the medium-voltage transformer converts the grid-side voltage into a medium-voltage voltage used by the drive system of the high-speed magnetic levitation wind turbine.

[0016] The technical effect achieved after adopting this technical solution is: the medium-voltage transformer converts the grid-side voltage into a medium-voltage voltage suitable for use in the high-speed magnetic levitation wind turbine drive system. Through the voltage conversion of the medium-voltage transformer, the drive system can adapt to different grid-side voltage levels, expanding the applicability of the system and enabling it to be flexibly applied to various power grid environments.

[0017] Optionally, a grid-side inductor is connected between the generator-side medium-voltage power converter and the grid-side voltage. The grid-side inductor is used to filter and stabilize the current and reduce high-frequency noise in the current.

[0018] The technical effect achieved after adopting this technical solution is: the grid-side inductor can filter out high-frequency noise and harmonics in the current, suppress current mutations, smooth the current waveform, and reduce current fluctuations, thereby stabilizing the input current of the machine-side medium-voltage power converter and reducing the stress of the power switching devices.

[0019] Optionally, a grid-side medium-voltage power converter is connected between the generator-side medium-voltage power converter and the grid-side voltage, and the grid-side medium-voltage power converter converts alternating current into direct current.

[0020] The technical effect achieved after adopting this technical solution is: the grid-side medium-voltage power converter converts the grid-side AC power into DC power, providing a stable DC power supply for the machine-side medium-voltage power converter. By converting AC power into DC power, the grid-side medium-voltage power converter optimizes the energy transmission process and reduces energy loss.

[0021] Optionally, a DC side capacitor is connected between the generator-side medium voltage power converter and the grid-side voltage, and the DC side capacitor is used to smooth the DC voltage and reduce voltage fluctuations.

[0022] The technical effect achieved after adopting this technical solution is: the DC side capacitor can effectively absorb and release energy, smooth the DC side voltage fluctuations, and reduce voltage ripple. By reducing the DC side voltage fluctuations, the DC side capacitor reduces the operating pressure of the machine-side medium-voltage power converter and reduces the risk of failure caused by voltage fluctuations.

[0023] Optionally, the main control board uses a digital signal processor to work in conjunction with a field programmable gate array to achieve real-time interaction between control signals and feedback data.

[0024] The technical effect achieved after adopting this technical solution is: the digital signal processor DSP can quickly execute complex control algorithms such as PI adjustment and coordinate transformation, combined with the high-precision PWM signal generation capability of the field programmable gate array FPGA, to achieve precise control of high-speed magnetic levitation fans and optimize the adjustment performance of speed, torque and magnetic levitation state.

[0025] Compared with the prior art, the drive system of the high-speed magnetic levitation fan of the present invention has the following beneficial effects: (1) Using active magnetic bearing controller to realize magnetic suspension function, which can effectively reduce the friction generated during high-speed (greater than 10,000 r / min) rotation; (2) The use of permanent magnet motors has the advantages of high efficiency and low energy consumption; (3) Using medium voltage power converter, it can achieve medium voltage and high power occasions, such as DC1500V; (4) The medium-voltage power converter on the machine side adopts a three-level topology as the drive system of the high-speed active magnetic levitation wind turbine. The output waveform is closer to a sine wave, which improves the voltage utilization rate; (5) The square wave modulation-two-phase conduction control method can reduce the power switching device loss at high fundamental frequency and high carrier frequency, and improve the working efficiency of the wind turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flow chart of the control method steps of the high-speed magnetic levitation fan according to an embodiment of the present application; Figure 2 This is a control diagram of a high-speed magnetic levitation fan drive system according to an embodiment of the present application; Figure 3 A schematic diagram of a high-speed magnetic levitation fan drive system according to an embodiment of the present application; Figure 4 This is a schematic diagram of a two-phase conduction determination and phase current calculation module according to an embodiment of the present application; Figure 5 This is a simulation diagram of the acceleration and deceleration speed of the high-speed magnetic levitation fan in an embodiment of the present application.

[0027] Figure 6 This is a simulation diagram of the AC side line voltage of the high-speed magnetic levitation fan in an embodiment of the present application. Description of the drawings: 1- High-speed magnetic levitation fan; 11- Active magnetic levitation bearing controller; 12- Permanent magnet motor; 2- Generator-side medium-voltage power converter; 3- Signal acquisition and processing unit; 31- AC information sampling and conditioning board; 32- Main control board; 33- Pulse signal driver board; 4- Grid-side voltage; 5- Medium-voltage transformer; 6- Grid-side inductor; 7- Grid-side medium-voltage power converter, 8- DC-side capacitor; PI 1- First PI regulator; PI 2- Second PI regulator. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] The present application provides a method for controlling a high-speed magnetic levitation fan. Figure 1 As shown, the specific steps include: S10, starting the magnetic suspension bearing active controller 11 to realize magnetic suspension of the high-speed magnetic suspension fan 1 bearing; S20, collecting three-phase current, speed and rotor position signals of the high-speed magnetic suspension fan 1; S30, determining the target phase current when two phases of the permanent magnet motor are turned on according to the three-phase current and the rotor position signal; The DC side voltage is converted into a speed set value according to the DC side voltage-power curve relationship. The difference between the speed set value and the speed of the permanent magnet motor is a first error value. The first error value is output as a current set value after passing through a first PI regulator PI1; S40: The difference between the target phase current and the current set value is a second error value. After the second error value passes through the second PI regulator PI2, the duty cycle is output; The duty cycle is compared with the triangular carrier, and a PWM pulse signal is generated based on the comparison result; S50, PWM pulse signal controls the on and off of the power switch device of the machine-side medium-voltage power converter 2; S60 , the power switch device of the machine-side medium-voltage power converter 2 is turned on and off to control the acceleration and deceleration operation of the high-speed magnetic levitation wind turbine 1 .

[0031] This control method achieves magnetic levitation of the bearing by activating an active magnetic bearing controller 11, collecting three-phase current, speed, and rotor position signals, and combining them with a PI regulator for precise control. Specifically, the target phase current is determined based on the three-phase current and rotor position signals. The DC voltage is converted into a set speed value using the DC voltage-power curve. The difference between the set speed value and the actual speed is then used to output a current set value via a first PI regulator (PI 1). Furthermore, the difference between the target phase current and the set current value is used to output a duty cycle via a second PI regulator (PI 2), generating a PWM pulse signal that controls the on and off of the power switching devices of the medium-voltage power converter 2 on the generator side, thereby achieving acceleration and deceleration of the wind turbine. This method has the advantages of fast dynamic response, high control accuracy, and high energy utilization. Furthermore, the active magnetic bearing controller 11 reduces mechanical friction, improves system stability and lifespan, and is applicable to a variety of operating conditions, significantly improving the operating performance and control effectiveness of the high-speed magnetic levitation wind turbine 1.

[0032] Specifically, if Figure 2 As shown, the magnetic suspension bearing active controller 11 is started to make the high-speed magnetic suspension fan 1 magnetically suspended. The two-phase conduction judgment and phase current calculation module calculates the three-phase current i a 、i b 、i c The target phase current i when the permanent magnet motor is two-phase turned on is determined by the rotor position signal. The DC side voltage u is adjusted in the voltage-power regulation module according to the DC side voltage-power curve relationship. dc It is converted into a speed set value n*. The difference between the speed set value n* and the permanent magnet motor speed n is a first error value. The first error value is output as a current set value i* after passing through the first PI regulator PI 1; the difference between the target phase current i and the current set value i* is a second error value. The second error value is output as a duty cycle after passing through the second PI regulator PI 2. The duty cycle is compared with the triangular carrier, and a PWM pulse signal is generated according to the comparison result; the PWM pulse signal controls the conduction and shutdown of the power switching device of the machine-side medium-voltage power converter 2; the conduction and shutdown of the power switching device of the machine-side medium-voltage power converter 2 control the acceleration and deceleration operation of the high-speed magnetic levitation fan 1.

[0033] Furthermore, in step S50, when determining the on and off state of the upper-arm switching device of the generator-side medium-voltage power converter 2, the upper and lower amplitudes of the triangular carrier are 1 and 0; when determining the on and off state of the lower-arm switching device of the generator-side medium-voltage power converter 2, the upper and lower amplitudes of the triangular carrier are 0 and -1. By setting the upper and lower amplitudes of the triangular carrier to 1 and 0 to control the upper-arm switching device and 0 and -1 to control the lower-arm switching device, respectively, the logic for generating the PWM signal is simplified, the complexity of the control algorithm is reduced, and the PWM signal can be generated more accurately. At the same time, the risk of simultaneous on-state of the upper and lower-arm switching devices is avoided, thereby achieving precise control over the on and off state of the power switching devices of the generator-side medium-voltage power converter 2.

[0034] Furthermore, in step S30, within one switching cycle, the rotation of the permanent magnet motor is precisely divided into six conduction sectors (S_phase=1, 2, 3, 4, 5, 6), as shown in FIG. Figure 4 As shown, each sector corresponds to 1 / 6 of a motor rotor rotation (60 degrees). During each switching cycle, carriers 1 and 2 (represented by blue and red waveforms, respectively) serve as high-frequency triangular wave carrier signals, providing a reference for pulse-width modulation (PWM). Within each on-sector, the PI output is compared with carriers 1 and 2 to generate a precise PWM signal. This control scheme enables precise switching of the corresponding permanent magnet motor phase within each sector based on the binary modulation signal and the current sector position, generating the desired torque. As the rotor moves from one sector to the next, the sector signal is updated, and the PWM signal is adjusted accordingly, ensuring continuous and precise motor control. Sectoring the permanent magnet motor simplifies the calculation and control logic for the target phase current, improving the real-time and efficiency of the control algorithm. By precisely matching the permanent magnet motor's rotational position with the on-sector, the target phase current can be more accurately controlled when both phases are on, optimizing motor torque output, reducing torque ripple, and enhancing motor smoothness and dynamic response.

[0035] An embodiment of the present application provides a drive system for a high-speed magnetic levitation wind turbine 1, comprising a machine-side medium-voltage power converter 2, a grid-side voltage 4, a high-speed magnetic levitation wind turbine 1, a magnetic levitation bearing active controller 11, and a signal acquisition and processing unit 3, wherein the input end of the machine-side medium-voltage power converter 2 is connected to the grid-side voltage 4, the high-speed magnetic levitation wind turbine 1 is connected to the output end of the machine-side medium-voltage power converter 2, the magnetic levitation bearing active controller 11 is connected to the high-speed magnetic levitation wind turbine 1, the input end of the signal acquisition and processing unit 3 is connected to the high-speed magnetic levitation wind turbine 1, and the output end of the signal acquisition and processing unit 3 is connected to the input end of the machine-side medium-voltage power converter 2. The grid-side voltage 4 provides electrical energy input for the drive system, and the machine-side medium-voltage power converter 2 converts the grid-side voltage 4 into a voltage and current suitable for the operation of the high-speed magnetic levitation fan 1, ensuring the efficient and stable operation of the high-speed magnetic levitation fan 1; the magnetic levitation bearing active controller 11 realizes the magnetic levitation state of the bearing of the high-speed magnetic levitation fan 1, reduces mechanical friction and wear, and improves the service life and stability of the drive system; the signal acquisition and processing unit 3 collects the three-phase current, speed, and rotor position signals of the high-speed magnetic levitation fan 1 in real time, and generates a PWM signal through a precise control algorithm. The PWM signal controls the power switching device of the machine-side medium-voltage power converter 2. Through the coordinated work of the machine-side medium-voltage power converter 2, the high-speed magnetic levitation fan 1, the magnetic levitation bearing active controller 11 and the signal acquisition and processing unit 3, the precise adjustment of the speed and rapid dynamic response of the high-speed magnetic levitation fan 1 are achieved.

[0036] Furthermore, the signal acquisition and processing unit 3 in the driving system includes: an AC information sampling and conditioning board 31 , a main control board 32 and a pulse signal driving board 33 .

[0037] AC information sampling and conditioning board 31, high-speed magnetic levitation fan 1 three-phase current i a 、i b 、i c , electrical angular velocity ω e and the rotor speed n; The main control board 32 includes a two-phase conduction judgment and phase current calculation module and a voltage-power regulation module, which calculates and processes the AC signal from the AC information sampling and conditioning board 31. The specific processing process is as follows: a 、i b 、i c and electrical angular velocity ω e Calculate the target phase current i when the two phases of the permanent magnet motor are turned on, and convert the DC side voltage u dc Converted to speed given value n * The difference between the speed setting value n* and the permanent magnet motor speed n is the first error value. The first error value outputs the current setting value i after passing through the first PI regulator PI1. *; Target phase current i and current given value i * The difference is the second error value, and the second error value is output as a duty cycle after passing through the second PI regulator PI2. The duty cycle is compared with the triangular carrier, and a PWM pulse signal is generated according to the comparison result; The pulse signal driving board 33 receives the PWM pulse signal from the main control board 32 , converts the PWM pulse signal into a driving signal, and controls the on and off of the power switching device of the generator-side medium-voltage power converter 2 .

[0038] The AC information sampling and conditioning board 31 is responsible for collecting the AC signals from the high-speed magnetic levitation fan 1, ensuring the accuracy and real-time nature of signal acquisition and providing a reliable data foundation for subsequent control. The main control board 32 processes the signals from the AC information sampling and conditioning board 31 and calculates the target phase current, speed setpoint, duty cycle, and PWM pulse signal using a built-in control algorithm. The pulse signal driver board 33 receives the PWM pulse signal from the main control board 32 and converts it into a drive signal to control the on and off state of the power switching devices of the medium-voltage power converter 2 on the machine side, thereby achieving precise control of the speed and magnetic levitation state of the high-speed magnetic levitation fan 1. Through high-precision signal acquisition, efficient signal processing, and precise pulse signal generation, the signal acquisition and processing unit 3 significantly improves the control accuracy, dynamic response speed, and system stability of the high-speed magnetic levitation fan 1.

[0039] Furthermore, a medium-voltage transformer 5 is connected between the generator-side medium-voltage power converter 2 and the grid-side voltage 4. This transformer converts the grid-side voltage 4 into a medium-voltage voltage for use by the drive system of the high-speed magnetic levitation wind turbine 1. Through voltage conversion by the medium-voltage transformer 5, the drive system can adapt to different grid-side voltage levels 4, expanding the system's applicability and enabling its flexible application in various power grid environments.

[0040] Furthermore, a grid-side inductor 6 is connected between the generator-side medium-voltage power converter 2 and the grid-side voltage 4. This inductor is used to filter and stabilize the current, reducing high-frequency noise in the current. This inductor can filter out high-frequency noise and harmonics in the current, suppress sudden current fluctuations, smooth the current waveform, and reduce current fluctuations, thereby stabilizing the input current of the generator-side medium-voltage power converter 2 and reducing stress on the power switching components.

[0041] Furthermore, a grid-side medium-voltage power converter 7 is connected between the generator-side medium-voltage power converter 2 and the grid-side voltage 4 to convert AC power into DC power. By converting the grid-side AC power into DC power, the grid-side medium-voltage power converter 7 provides a stable DC power supply for the generator-side medium-voltage power converter 2. By converting AC power into DC power, the grid-side medium-voltage power converter 7 optimizes the energy transmission process and reduces energy loss.

[0042] Furthermore, a DC-side capacitor 8 is connected between the generator-side medium-voltage power converter 2 and the grid-side voltage 4. This capacitor is used to smooth the DC voltage and reduce voltage fluctuations. The DC-side capacitor 8 effectively absorbs and releases energy, smoothing DC-side voltage fluctuations and reducing voltage ripple. By reducing DC-side voltage fluctuations, the DC-side capacitor 8 reduces the operating pressure of the generator-side medium-voltage power converter 2 and reduces the risk of failures caused by voltage fluctuations.

[0043] Furthermore, the main control board 32 uses a digital signal processor (DSP) and a field-programmable gate array (FPGA) to work together to achieve real-time interaction between control signals and feedback data. The DSP can rapidly execute complex control algorithms such as PI regulation and coordinate transformation. Combined with the high-precision PWM signal generation capabilities of the FPGA, this enables precise control of the high-speed magnetic levitation fan 1, optimizing the regulation of speed, torque, and magnetic levitation state.

[0044] The specific connection method of the drive system components of the high-speed magnetic levitation fan 1 is as follows: Figure 3 As shown, the grid-side voltage 4 is connected to the medium-voltage transformer 5, the medium-voltage transformer 5 is connected to the grid-side voltage 4, the grid-side voltage 4 is connected to the grid-side medium-voltage power converter 7, the grid-side medium-voltage power converter 7 is connected to the DC-side capacitor 8, the DC-side capacitor 8 is connected to the machine-side medium-voltage power converter 2, the machine-side medium-voltage power converter 2 is connected to the high-speed magnetic levitation fan 1, the high-speed magnetic levitation fan 1 is connected to the magnetic bearing active controller 11, the high-speed magnetic levitation fan 1 is connected to the AC information sampling and conditioning board 31, the AC information sampling and conditioning board 31 is connected to the main control board 32, the main control board 32 is connected to the pulse signal driving board 33, and the pulse signal driving board 33 is connected to the machine-side medium-voltage power converter 2, completing the square wave modulation-two-phase conduction control method algorithm calculation.

[0045] Next, the drive system of the high-speed magnetic levitation fan 1 is tested and simulated.

[0046] When the given speed is 10000r / min within 0~1.0s; the given speed is 20000r / min within 1.0~2.0s; the given speed is 30000r / min within 2.0~3.0s; the given speed is 36000r / min within 3.0~4.0s; the given speed is 30000r / min within 4.0~5.0s; the given speed is 27000r / min within 5.0~6.0s, as shown in the following example: Figure 5 As shown, the speed ranges from 10000 r / min to 36000 r / min, and the given speed is basically consistent with the actual speed, which reflects the dynamic response capability, control accuracy and system stability of the high-speed magnetic levitation fan 1 at different speeds.

[0047] When the given speed is 27000r / min, the voltage waveform of the AB line on the AC side is as follows Figure 6 As shown, the frequency of the AB line voltage is 1350 Hz. The high-speed magnetic levitation fan 1 completes 1350 high-low level conversions in the voltage signal per second to form a PWM signal. When the given speed is 27,000 r / min, the control system accurately controls the speed of the high-speed magnetic levitation fan by adjusting the duty cycle of the PWM signal. The change in the duty cycle directly affects the average voltage of the permanent magnet motor winding of the high-speed magnetic levitation fan 1, thereby controlling the torque and speed of the permanent magnet motor of the high-speed magnetic levitation fan 1 to reach or maintain the required 27,000 r / min. The use of this high-frequency PWM signal not only achieves precise control of the speed of the high-speed magnetic levitation fan 1, but also provides better dynamic response, allowing the high-speed magnetic levitation fan 1 to quickly adapt to changes in load or speed instructions.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A control method for a high-speed magnetic levitation fan, characterized in that: The following steps are involved: S10, starting the magnetic suspension bearing active controller (11) to achieve magnetic suspension of the bearing of the high-speed magnetic suspension fan (1); S20, collecting three-phase current, rotation speed and rotor position signals of the high-speed magnetic levitation fan (1); S30, determining a target phase current when two phases of the permanent magnet motor are turned on according to the three-phase current and the rotor position signal; converting the DC side voltage into a speed set value according to a DC side voltage-power curve relationship, wherein the difference between the speed set value and the speed of the high-speed magnetic levitation fan is a first error value, and the first error value is output as a current set value after passing through a first PI regulator (PI 1); S40, the difference between the target phase current and the current set value is a second error value, and the second error value is output as a duty cycle after passing through a second PI regulator (PI 2); The duty cycle is compared with the triangular carrier, and a PWM pulse signal is generated according to the comparison result; S50, the PWM pulse signal controls the on and off of the power switch device of the machine-side medium-voltage power converter (2); S60, the on and off of the power switch device of the machine-side medium-voltage power converter (2) controls the acceleration and deceleration operation of the high-speed magnetic suspension fan (1).

2. The control method of a high-speed magnetic levitation fan according to claim 1, characterized in that: In the step S50, when determining the on and off of the upper bridge arm switching device of the machine-side medium-voltage power converter (2), the upper and lower amplitudes of the triangular carrier are 1 and 0; when determining the on and off of the lower bridge arm switching device of the machine-side medium-voltage power converter (2), the upper and lower amplitudes of the triangular carrier are 0 and -1.

3. The control method of a high-speed magnetic levitation fan according to claim 1, characterized in that: In the step S30, within one switching cycle, each 1 / 6 cycle of rotation of the permanent magnet motor is recorded as one conducting sector.

4. A high-speed magnetic levitation fan drive system, wherein the high-speed magnetic levitation fan drive system is applicable to the high-speed magnetic levitation fan control method according to any one of claims 1 to 3, characterized in that: include: A machine-side medium-voltage power converter (2), wherein an input end of the machine-side medium-voltage power converter (2) is connected to a grid-side voltage (4); A high-speed magnetic levitation fan (1), the high-speed magnetic levitation fan (1) is connected to the output end of the machine-side medium-voltage power converter (2); A magnetic suspension bearing active controller (11), the magnetic suspension bearing active controller (11) being connected to the high-speed magnetic suspension fan (1); A signal acquisition and processing unit (3), wherein the input end of the signal acquisition and processing unit (3) is connected to the high-speed magnetic levitation fan (1), and the output end of the signal acquisition and processing unit (3) is connected to the input end of the machine-side medium-voltage power converter (2).

5. The driving system of the high-speed magnetic levitation fan according to claim 4, characterized in that: The signal acquisition and processing unit (3) comprises: An AC information sampling and conditioning board (31), the AC information sampling and conditioning board (31) is responsible for collecting the AC signal of the high-speed magnetic levitation fan (1); A main control board (32), the main control board (32) processes the AC signal from the AC information sampling and conditioning board (31); A pulse signal driving board (33) receives the PWM pulse signal from the main control board (32), converts the PWM pulse signal into a driving signal, and controls the on and off of the power switch device of the machine-side medium-voltage power converter (2).

6. The driving system of the high-speed magnetic levitation fan according to claim 4, characterized in that: A medium-voltage transformer (5) is connected between the machine-side medium-voltage power converter (2) and the grid-side voltage (4), and the medium-voltage transformer (5) converts the grid-side voltage (4) into a medium-voltage voltage used by the drive system of the high-speed magnetic levitation fan (1).

7. The driving system of the high-speed magnetic levitation fan according to claim 4, characterized in that: A grid-side inductor (6) is connected between the machine-side medium-voltage power converter (2) and the grid-side voltage (4), and the grid-side inductor (6) is used to filter and stabilize current and reduce high-frequency noise in the current.

8. The driving system of the high-speed magnetic levitation fan according to claim 4, characterized in that: A grid-side medium-voltage power converter (7) is connected between the generator-side medium-voltage power converter (2) and the grid-side voltage (4), and the grid-side medium-voltage power converter (7) converts alternating current into direct current.

9. The driving system of the high-speed magnetic levitation fan according to claim 4, characterized in that: A DC side capacitor (8) is connected between the machine-side medium voltage power converter (2) and the grid-side voltage (4), and the DC side capacitor (8) is used to smooth the DC voltage and reduce voltage fluctuations.

10. The driving system of the high-speed magnetic levitation fan according to claim 5, characterized in that: The main control board (32) uses a digital signal processor and a field programmable gate array to work together to achieve real-time interaction between control signals and feedback data.

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