TW201720044A - Driving method for AC motor and motor driving apparatus using the same - Google Patents

Abstract

A driving method for an AC motor and a motor driving apparatus using the same are provided. The driving method for the AC motor includes following steps: generating a three-phase driving voltage to drive the AC motor according to a rotating speed setting and a preset driving parameter; respectively superposing disturbance values with different polarity onto the preset driving parameter during a mechanical period, so as to disturb a phase angle of the three-phase driving voltage; detecting an operational status of the disturbed AC motor, so as to generate an output data; calculating operation efficiencies of the AC motor applied the disturbance values with the different polarity according to the output data; and comparing the operation efficiencies, so as to select the parameter setting corresponding to the higher efficiency as a current setting of the preset driving parameter.

Description

Driving method of AC motor and motor driving device using same

The present invention relates to a motor driving technique, and more particularly to a driving method of an AC motor and a motor driving device using the same.

AC motors have the advantages of low cost, high efficiency and high reliability. Based on these advantages and the rapid development of frequency conversion technology, the variable frequency motor system consisting of AC motor and motor drive/inverter is completely replacing the DC motor system.

In the control of the AC motor, in order to make the AC motor have better working efficiency, the designer will work to optimize the control method of the motor drive device, so that the AC motor can run at most speeds and torques. Good work efficiency.

However, in the current optimization control method of the motor drive device, corresponding optimal efficiency tracking means is required for different types of AC motor applications, and the optimal efficiency tracking means usually requires the designer to spend time making the drive parameters. A lookup table that corresponds to work efficiency or that requires a specific load test equipment. In addition, the existing optimization efficiency tracking methods are usually subject to exchange horses. Tracking errors caused by changes in the specifications of the operating parameters.

The invention provides a driving method of an alternating current motor and a motor driving device using the same, which can dynamically adjust a three-phase driving voltage according to an operating state of the alternating current motor, thereby realizing an optimum working efficiency for any type of alternating current motor. track.

The driving method of the AC motor of the present invention comprises the steps of: generating a three-phase driving voltage according to the rotation speed setting value and the preset driving parameter to drive the AC motor; in a mechanical cycle, respectively, the disturbance amounts of different polarities are superimposed on the preset driving parameters respectively. , by which the phase angle of the three-phase driving voltage is disturbed; detecting the operating state of the disturbed AC motor, and generating output data according to the output data; calculating the working efficiency of the AC motor when applying the disturbance amount of different polarities according to the output data; The working efficiency is used to select the parameter setting value corresponding to the higher one as the setting value of the current preset driving parameter.

In an embodiment of the invention, the driving method of the alternating current motor further comprises: exchanging an application sequence of the disturbance amounts of the different polarities in a next mechanical cycle.

In an embodiment of the invention, the disturbing amounts of different polarities are respectively superimposed on the preset driving parameters, and the step of disturbing the phase angle of the three-phase driving voltage comprises: superimposing the first disturbance amount on the preset driving parameters to generate the first And controlling a parameter; and superimposing a second disturbance amount having a polarity opposite to the first disturbance amount to a preset drive parameter to generate a second control parameter.

In an embodiment of the invention, the step of calculating the working efficiency of the AC motor when applying the disturbance amount of different polarities comprises: calculating the first working efficiency according to the output data corresponding to the first control parameter; and according to the corresponding second control parameter The output data calculates the second work efficiency.

In an embodiment of the present invention, the step of selecting the parameter setting value corresponding to the higher one as the setting value of the current preset driving parameter by comparing the working efficiency includes: when the first working efficiency is greater than the second working efficiency And setting the first control parameter to the preset driving parameter; and setting the second control parameter to the preset driving parameter when the first working efficiency is less than the second working efficiency.

In an embodiment of the invention, the step of generating a three-phase driving voltage to drive the alternating current motor according to the set value of the rotating speed and the preset driving parameter comprises: generating a stator voltage setting value according to the set value of the rotating speed and the rotor speed of the alternating current motor; The parameter and rotor operation information generate a phase angle setting value and convert the DC link voltage and the DC link current into a three-phase driving voltage according to the stator voltage setting value and the phase angle setting value.

In an embodiment of the invention, the step of detecting the operating state of the disturbed AC motor and generating the output data includes: sampling the DC link voltage and the DC link current; receiving a plurality of Hall signals from the AC motor to The plurality of Hall signals define the rotor position of the AC motor; and calculate the rotor speed of the AC motor based on the rotor position.

In an embodiment of the invention, the operating efficiency is calculated based on rotor speed, DC link voltage, and DC link current.

In an embodiment of the invention, the step of sampling the DC link voltage and the DC link current comprises: sampling a current value of the DC link current at a plurality of different time points in the mechanical cycle; and calculating an average of the plurality of current values to As a basis for calculating the efficiency of the work.

In an embodiment of the invention, the AC motor includes a plurality of Hall sensors, and the number of sampling points of the plurality of current values is determined according to the number of pole pairs of the AC motor and the number of the plurality of Hall sensors. .

In an embodiment of the invention, the time point for sampling the plurality of current values is determined according to a pulse edge of the Hall signal emitted by the plurality of Hall sensors.

In an embodiment of the present invention, the driving method of the AC motor further includes: after superimposing the disturbance amount on the preset driving parameter, thereby causing the change of the three-phase driving voltage, delaying the preset period and then detecting the disturbed AC motor. The state of operation.

In an embodiment of the invention, the AC motor is a permanent magnet synchronous motor, and the preset driving parameter is an angle between a stator voltage of the permanent magnet synchronous motor and the rotor.

In an embodiment of the invention, the AC motor is an AC induction motor, and the preset driving parameter is a slip speed between the rotor frequency of the AC induction motor and the stator frequency.

The motor driving device of the present invention is adapted to drive an AC motor and includes a three-phase voltage generator, a drive controller, and a detection circuit. The three-phase voltage generator generates a three-phase driving voltage to drive the AC motor according to the speed setting value and the preset driving parameter. The driving controller is coupled to the three-phase voltage generator for adjusting the three-phase driving voltage according to the operating state of the alternating current motor and the three-phase voltage generator to generate a preset driving parameter. Phase angle. The detecting circuit is coupled to the three-phase voltage generator and the driving controller for detecting the operating state of the AC motor and the three-phase voltage generator, and generating output data accordingly. In a mechanical cycle of the AC motor, the drive controller is superimposed on the preset drive parameters with different polarity disturbances, thereby disturbing the phase angle of the three-phase drive voltage, and calculating the disturbance amount of the AC motor to apply different polarities according to the output data. The working efficiency of the time is compared with the working efficiency, so that the parameter setting value with higher working efficiency is selected as the setting value of the current preset driving parameter.

In an embodiment of the invention, the drive controller exchanges the order of application of the disturbance amounts of the different polarities in the next mechanical cycle.

In an embodiment of the invention, the driving controller superimposes the first disturbance amount to the preset driving parameter to generate the first control parameter, so that the detecting circuit detects the output data corresponding to the first control parameter, and the driving controller according to the corresponding The output data of the first control parameter calculates the first work efficiency.

In an embodiment of the invention, the driving controller superimposes the second disturbance amount having a polarity opposite to the first disturbance amount to the preset driving parameter to generate the second control parameter, so that the detecting circuit detects the output corresponding to the second control parameter. Data, the drive controller calculates the second work efficiency according to the output data corresponding to the second control parameter.

In an embodiment of the invention, when the driving controller determines that the first working efficiency is greater than the second working efficiency, the driving controller sets the first control parameter as the preset driving parameter, and when the driving controller determines that the first working efficiency is less than In the second working efficiency, the drive controller sets the second control parameter as the preset driving parameter.

In an embodiment of the invention, the driving controller is based on the preset driving parameters and The rotor operation information produces a phase angle setting.

In an embodiment of the invention, the three-phase voltage generating device generates the stator voltage setting value according to the speed setting value and the rotor speed of the AC motor, and the three-phase voltage generating device sets the DC link voltage according to the stator voltage setting value and the phase angle setting value. The DC link current is converted to a three-phase drive voltage.

In an embodiment of the invention, the detecting circuit samples the DC link voltage and the DC link current, and receives a plurality of Hall signals from the AC motor to define the rotor position of the AC motor according to the plurality of Hall signals, and calculates the rotor position according to the rotor position. Rotor speed.

In an embodiment of the invention, the drive controller calculates the operating efficiency based on the rotor speed, the DC link voltage, and the DC link current.

In an embodiment of the invention, the detection circuit samples the current value of the DC link current at a plurality of different time points in the mechanical cycle, and then calculates an average of the plurality of current values as a basis for calculating the working efficiency.

In an embodiment of the invention, the detecting circuit superimposes the disturbance state on the preset driving parameter, so that the phase angle of the three-phase driving voltage is changed, and then delays the preset period to detect the operating state of the disturbed AC motor. .

Based on the above, an embodiment of the present invention provides a driving method of an AC motor and a motor driving device using the same, which can calculate a preset driving parameter corresponding to an optimal working efficiency by means of a similar disturbance observation method, and provide control according to the The phase angle of the three-phase drive voltage of the AC motor allows the motor drive to automatically approach optimum operating efficiency during operation. At the same time, the driving method can be applied to any type of AC motor, and the requirements for the load testing device can be omitted and avoided. Eliminating the best efficiency tracking may result in tracking errors caused by changes in the operating parameters of the AC motor.

The above described features and advantages of the invention will be apparent from the following description.

10‧‧‧AC motor

12‧‧‧ Hall sensor

70‧‧‧ Permanent magnet synchronous motor

80‧‧‧AC induction motor

100, 700, 800‧‧‧ motor drive

110, 710, 810 ‧ ‧ three-phase voltage generator

120, 720, 820‧‧‧ drive controller

122‧‧‧Parameter Optimization Tracking Unit

124, 724, 824‧‧‧ phase angle calculation unit

130, 730, 830 ‧ ‧ detection circuit

712, 812‧‧‧Power Control Unit

714, 814‧‧‧Power Conversion Unit

722‧‧‧Efficiency Optimized Angle Tracking Unit

822‧‧‧Efficiency-optimized slip tracking unit

732, 832‧‧‧ power sampling unit

734, 834‧‧‧Speed calculation unit

CP, CP1, CP2, CP3, CP4‧‧‧ control parameters

EFF1, EFF2, EFF3, EFF4‧‧‧ work efficiency

HZ‧‧‧voltage frequency setting

Iin‧‧‧ DC link current

I _P ‧‧‧Sampling current value

MP1, MP2‧‧‧ mechanical cycle

OD, OD1, OD2, OD3, OD4‧‧‧ output data

PDP, PDP', PDP" ‧‧‧Preset drive parameters

Pin‧‧‧DC power supply

RP‧‧‧Rotor position

RI‧‧‧Rotor operation information

RS‧‧‧Rotor speed

S210~S250, S302~S324, S232~S236, S2321~S2322‧‧‧ steps

SA‧‧‧ angle setting parameters

SPD‧‧‧Speed set value

SRDS‧‧‧ slip setting parameters

Sh‧‧‧Hall Signal

VAMP‧‧‧Voltage amplitude setting

VANG‧‧‧ phase angle setting

VTP‧‧‧ three-phase driving voltage

Vin‧‧‧ DC link voltage

V _P ‧‧‧Sampling voltage value

V _U , V _V , V _W ‧‧‧ phase voltage

△D, △D1, △D2, +△D, -△D‧‧‧ disturbance amount

1A and 1B are schematic views of a motor driving device according to an embodiment of the present invention.

2 is a flow chart showing the steps of a driving method of an AC motor according to an embodiment of the present invention.

3 is a flow chart showing the steps of a driving method of an AC motor according to another embodiment of the present invention.

4 is a schematic diagram showing the driving sequence of the driving method of the alternating current motor according to an embodiment of FIG.

FIG. 5 is a flow chart showing the steps of detecting an operating state of an AC motor according to an embodiment of the present invention.

6 is a flow chart showing the steps of sampling a DC link current according to an embodiment of the present invention.

Fig. 7 is a schematic view of a motor driving device applied to a permanent magnet synchronous motor according to an embodiment of the present invention.

Fig. 8 is a schematic view of a motor driving device applied to an AC induction motor according to an embodiment of the present invention.

In order to make the disclosure of the present disclosure easier to understand, the following specific embodiments are examples of the disclosure that can be implemented. In addition, wherever possible, the same elements, components, and steps in the drawings and embodiments are used to represent the same or similar components.

1A is a schematic view of a motor driving device according to an embodiment of the present invention. Referring to FIG. 1A, the motor driving device 100 of the present embodiment is adapted to drive the AC motor 10. The AC motor 10 can be, for example, a permanent magnet synchronous motor (including a surface-mounted permanent magnet synchronous motor and an in-line permanent magnet synchronous motor) or an AC induction motor, and the invention is not limited thereto. In addition, the AC motor 10 includes a Hall sensor 12 that detects a change in the magnetic field of the AC motor and generates a Hall signal Sh accordingly.

The motor driving device 100 is, for example, a variable-frequency driver (VFD), which can be used to generate a three-phase driving voltage VTP (including phase voltages V _U , V _V and V _W ), and according to the speed setting value SPD and other controls The parameters are used to adjust the frequency and amplitude of the generated three-phase driving voltage VTP, and accordingly, the rotational speed and torque of the AC motor 10 are controlled.

In the present embodiment, the motor driving device 100 includes a three-phase voltage generator 110, a drive controller 120, and a detection circuit 130. The three-phase voltage generator 110 receives the DC link voltage Vin and the DC link current Iin from the DC power source Pin, and converts the received DC link voltage Vin and the DC link current Iin into a three-phase drive voltage VTP in the form of an AC to drive the AC motor. 10.

Wherein, the three-phase voltage generator 110 is based on the speed setting value SPD The rotor speed RS of the flow motor 10 generates a certain sub-voltage set value, thereby adjusting the frequency and amplitude of the generated three-phase driving voltage VTP, and adjusting the phase angle of the three-phase driving voltage VTP according to the phase angle setting value, thereby regulating the alternating current. The speed and torque of the motor 10.

Here, the phase angle setting value VANG is generated by the driving controller 120 according to a preset driving parameter PDP. The preset drive parameter PDP may have different definitions depending on the type of the AC motor 10. For example, if the AC motor 10 is a permanent magnet synchronous motor, the preset drive parameter PDP can be, for example, the angle between the stator voltage of the permanent magnet synchronous motor and the rotor. For another example, if the AC motor 10 is an AC induction motor, the preset drive parameter PDP may be, for example, a slip speed between the rotor frequency of the AC induction motor and the stator frequency.

In other words, the three-phase voltage generator 110 of the present embodiment generates the three-phase driving voltage VTP to drive the AC motor 10 in accordance with the rotational speed set value SPD and the phase angle set value VANG.

The driving controller 120 is coupled to the three-phase voltage generator 110, and can be used to calculate and generate a corresponding preset driving parameter PDP according to the operating states of the AC motor 10 and the three-phase voltage generator 110, and according to the preset driving parameter PDP and The rotational speed/rotor position of the AC motor 10 is currently generated to generate a corresponding phase angle set value VANG to adjust the phase angle of the three-phase drive voltage VTP, so that the operation of the AC motor 10 can be stabilized.

The detection circuit 130 is coupled to the three-phase voltage generators 110 and 120 to drive the controller. The detection circuit 130 can be used to detect the AC motor 10 and the three-phase voltage generator 110 The operational state, and accordingly, produces output data OD associated with the operational state. For example, the output data OD may include, for example, power source information of the DC link voltage Vin and the DC link current Iin received by the three-phase voltage generator 110, and calculate the AC motor 10 based on the Hall signal Sh received from the AC motor 10. Rotor operation information such as rotor position and/or rotor speed.

In this embodiment, the driving controller 120 can calculate the current working efficiency according to the operating state of the AC motor 10 in real time without pre-establishing a lookup table associated with the preset driving parameter PDP and the work efficiency correspondence relationship. Then, through a motor drive control mechanism similar to the perturb and observe method, a preset drive parameter PDP corresponding to the optimal working efficiency is calculated, and a corresponding phase angle set value VANG is generated to dynamically control the three phases. The operation of the voltage generator 110 allows the motor drive unit 100 to bring the AC motor 10 closer to optimum operating efficiency during operation.

The motor driving method of the present invention will be specifically described below in conjunction with the embodiment of FIG. 2. 2 is a flow chart showing the steps of a method for driving an AC motor according to an embodiment of the present invention.

Referring to FIG. 1A and FIG. 2 simultaneously, in the motor driving method of the embodiment, first, the three-phase voltage generator 110 generates the phase angle setting value SPD generated according to the preset driving parameter PDP according to the rotation speed setting value SPD. The three-phase driving voltage VTP (step S210). Then, in each mechanical cycle (ie, the time required for the rotor of the AC motor 10 to rotate one revolution), the drive controller 120 superimposes the disturbance driving amount of different polarities on the preset driving parameter PDP, thereby disturbing the three-phase voltage production. The phase angle of the three-phase driving voltage VTP generated by the generator 110 (step S220). During the operation of the AC motor 10, the detecting circuit 130 detects the operating state of the disturbed AC motor 10 in real time, and accordingly generates output data OD (step S230), so that the driving controller 120 can calculate the alternating current according to the output data OD. The operating efficiency of the motor 10 when a disturbance amount of a different polarity is applied (step S240). After calculating the working efficiency, the driving controller 120 compares the calculated working efficiency, so as to select the parameter setting value corresponding to the higher working efficiency as the setting value of the current preset driving parameter (step S250).

With the above-described driving method, the phase angle of the three-phase driving voltage VTP is gradually adjusted in real time toward a trend of higher operating efficiency, so that the motor driving device 100 can achieve automatic optimal efficiency tracking for any type of AC motor 10, and It is no longer necessary for the tester to perform a test in advance to establish a lookup table of the preset drive parameter PDP. In addition, the driving method can also eliminate the requirement for the load testing device, and avoid the tracking error caused by the optimal efficiency tracking that may be changed by the operating parameters of the AC motor.

The above driving method can be implemented by using the functional blocks of the driving controller 320 as shown in FIG. 1B. Referring to FIG. 1B, the drive controller 120 includes a parameter optimization tracking unit 122 and a phase angle calculation unit 124. The parameter optimization tracking unit 122 may superimpose the disturbance amount ΔD to the preset drive parameter PDP to generate the control parameter CP. The phase angle calculation unit 124 calculates a corresponding phase angle setting value VANG according to the control parameter CP and the rotor operation information RI. The parameter optimization tracking unit 122 calculates the interference of the AC motor 10 to apply different polarities according to the output data OD. The operating efficiency at the momentum ΔD, and the polarity of the provided disturbance amount ΔD is determined accordingly. The manner in which the parameter optimization tracking unit 122 calculates the control parameter CP and the generated control parameter CP may vary depending on the type of the AC motor 10 to be applied, which will be further exemplified in the following embodiments.

In the above driving method, the present invention has at least three technical means that can bring about beneficial effects: (1) phase disturbance control to track optimal working efficiency; (2) calculation of working efficiency; and (3) sampling of DC link current . Wherein, the above technical means can be applied individually, partially or collectively in an AC motor driving method, and the present invention does not limit that the above technical means must be simultaneously applied.

In order to more specifically describe the motor driving method and the above-described technical means of the embodiment of the present invention, the structure of the motor driving device 100 of FIGS. 1A and 1B will be described below with reference to the flow chart of FIGS. 3 to 5.

(1) Phase disturbance control to track optimal working efficiency

Please refer to FIG. 1A, FIG. 1B and FIG. 3, wherein FIG. 3 is a flow chart showing the steps of the driving method of the alternating current motor according to another embodiment of the present invention. In the driving method of the present embodiment, first, the three-phase voltage generator 110 generates the three-phase driving voltage VTP in accordance with the rotation speed set value SPD and the phase angle setting value VANG generated based on the preset driving parameter PDP (step S302). Next, the drive controller 120 determines whether or not the activation condition of the optimized efficiency tracking is met in accordance with the operational state of the AC motor 10 (step S304). The starting condition is, for example, that the fluctuation amplitude of the DC link voltage Vin is within a normal interval (which can be defined by the designer).

If the drive controller 120 determines that the operating state of the AC motor 10 does not meet the most After the startup condition of the optimization efficiency tracking, the drive controller 120 does not perform the subsequent optimization efficiency tracking steps S306 to S324, but repeats the step S304 of detecting the activation condition. On the other hand, if the drive controller 120 determines that the operating state of the AC motor 10 meets the activation condition of the optimized efficiency tracking, the drive controller continues to perform steps S306 to S324.

In steps S306-S310, the drive controller 120 superimposes the disturbance amount ΔD1 on the preset drive parameter PDP to generate the control parameter CP1 (step S306), and causes the drive controller 120 to generate a corresponding phase angle according to the control parameter CP1. Set value ANG. Next, the detection circuit 130 detects the output data OD1 corresponding to the control parameter CP1 (step S308), so that the drive controller 120 calculates the corresponding work efficiency EFF1 based on the output data OD1 (step S310).

Similarly, in the subsequent steps S312 to S316, the drive controller 120 changes the disturbance amount ΔD2 whose polarity is opposite to the disturbance amount ΔD1 (that is, if the disturbance amount ΔD1 is the positive disturbance amount, the disturbance amount △ D2 is the negative disturbance amount; if the disturbance amount ΔD1 is the negative disturbance amount, the disturbance amount ΔD2 is the positive disturbance amount) is superimposed on the preset drive parameter PDP to generate the control parameter CP2 (step S312), and the drive control is performed. The device 120 generates a corresponding phase angle set value ANG according to the control parameter CP2. Next, the detection circuit 130 detects the output data OD2 corresponding to the control parameter CP2 (step S314), so that the drive controller 120 calculates the corresponding work efficiency EFF2 based on the output data OD2 (step S316).

Next, the drive controller 120 compares the operating efficiencies EFF1 and EFF2 (step S318). When the drive controller 120 determines that the working efficiency EFF1 is greater than EFF2, The drive controller 120 sets the control parameter CP1 as the preset drive parameter PDP (step S320). On the other hand, when the drive controller 120 determines that the operating efficiency EFF1 is less than EFF2, the drive controller 120 sets the control parameter CP2 as the preset drive parameter PDP (step S322). In other words, the drive controller 120 selects the parameter setting value CP1/CP2 corresponding to the higher working efficiency as the set value of the current preset driving parameter PDP.

The above steps are performed in one mechanical cycle, and upon entering the next mechanical cycle, the drive controller 120 exchanges the order of application of the disturbance amounts ΔD1 and ΔD2 of different polarities (step S324). That is, if in this mechanical cycle, the positive disturbance amount (indicated by "+△D") is applied first and the negative disturbance amount (indicated by "-△D") is applied, then in the next mechanical cycle, Instead, the negative disturbance amount -ΔD is applied first and then the positive disturbance amount +ΔD is applied, and the working efficiency is calculated accordingly and the set value of the preset driving parameter PDP is determined. Through the tracking calculation mechanism of the two-way scanning, the inertia error caused by superimposing the disturbance amount ΔD in the same direction can be avoided, thereby further improving the accuracy of the optimized working efficiency tracking.

In order to more clearly illustrate the tracking calculation mechanism of the two-way scanning, the timing relationship of the step flow of FIG. 3 in different mechanical cycles will be described below with reference to FIG. 4. 4 is a schematic diagram of driving timing of a driving method of an AC motor according to an embodiment of FIG. 3.

Referring to FIG. 1B and FIG. 4, similar to the step flow of the foregoing embodiment of FIG. 3, in the first mechanical period MP1, the parameter optimization tracking unit 122 first superimposes the positive disturbance amount + ΔD on the preset driving parameter PDP. And correspondingly generating a corresponding control parameter CP1 (ie, PDP + ΔD), so that the phase angle calculation unit 124 is based on the control parameter The CP1 generates a corresponding phase angle set value VANG to control the three-phase voltage generator 110. Next, the parameter optimization tracking unit 122 calculates the working efficiency EFF1 of the corresponding control parameter CP1 according to the output data OD1 detected by the detection circuit 130.

After calculating the working efficiency EFF1 corresponding to the control parameter CP1, the parameter optimization tracking unit 122 may change the negative disturbance amount -ΔD to the preset driving parameter PDP, and accordingly generate the corresponding control parameter CP2 (ie, PDP-ΔD) causes the phase angle calculation unit 124 to control the three-phase voltage generator 110 according to the control parameter CP2 to generate a corresponding phase angle set value VANG. Next, the parameter optimization tracking unit 122 calculates the working efficiency EFF2 of the corresponding control parameter CP2 according to the output data OD2 detected by the detection circuit 130.

After calculating the working efficiency EFF1 and EFF2, the parameter optimization tracking unit 122 determines which of the working efficiency EFF1 and EFF2 is higher, and sets the higher one as the preset driving parameter PDP' of the next mechanical period MP2 (ie, PDP). '=PDP+ΔD or PDP'=PDP-△D).

After entering the next mechanical period MP2, the parameter optimization tracking unit 122 may first superimpose the negative disturbance amount -ΔD on the preset driving parameter PDP', and calculate the corresponding working efficiency EFF3 according to the output data OD3, and then The positive disturbance amount + ΔD is superimposed on the preset drive parameter PDP', and the corresponding work efficiency EFF4 is calculated according to the output data OD4. Thereafter, similar to the control of the previous mechanical period MP1, the parameter optimization tracking unit 122 determines which of the operating efficiency EFF3 and EFF4 is higher, and sets the higher one as the preset driving parameter PDP of the next mechanical period (ie, PDP" = PDP' + ΔD or PDP" = PDP' - ΔD).

In the subsequent mechanical cycle, the drive controller 120 continuously exchanges the order of application of the disturbance amount + ΔD / - ΔD of different polarities in the aforementioned control manner, and details are not described herein again.

In other words, in the tracking calculation mechanism of the two-way scanning, the driving controller 120 may perturb the preset driving parameter PDP by using a first addition and then subtraction (or subtraction first) in a mechanical cycle (for example, MP1), and In the next mechanical cycle (for example, MP2), the preset drive parameter PDP' is disturbed by first subtracting and then adding (or adding and then subtracting). Through the tracking calculation mechanism of the two-way scanning, the motor driving device 100 of the present invention can avoid the inertia error caused by superimposing the disturbance amount ΔD in the same direction, thereby further improving the accuracy of the optimized working efficiency tracking.

In addition, in an exemplary embodiment, in order to prevent the output data OD detected by the detecting circuit 130 from being distorted when the preset driving parameter PDP is disturbed, the detecting circuit 130 may superimpose the disturbance amount ΔD on the driving controller 120. The driving parameter PDP is preset, so that the phase angle of the three-phase driving voltage VTP is changed, and the operating state of the disturbed AC motor 10 is detected after a predetermined period of time (which can be defined by the designer).

In addition, it should be noted that the steps of exchanging the application order of the disturbance amounts of different polarities as described in the embodiments of FIG. 3 and FIG. 4 are selectively applicable to the driving method of the present invention, thereby improving the tracking of the optimized working efficiency. Accuracy, but this case does not limit this.

(2) Calculation of work efficiency

Referring to FIG. 1A and FIG. 5, the alternating horse after detecting the disturbance in the embodiment In step S230 of the operational state, first, the detection circuit 130 samples the DC link voltage Vin and the DC link current Iin (step S232), and receives the Hall signal Sh emitted by the Hall sensor 12 from the AC motor 10, The rotor position of the AC motor 10 is defined in accordance with the received Hall signal Sh (step S234). Next, the detecting circuit 130 calculates the rotor speed RS of the AC motor 10 in accordance with the rotor position of the AC motor 10 (step S236). The detecting circuit 130 supplies at least one of the detected DC link voltage Vin, the DC link current Iin, the rotor position of the AC motor 10, and the rotor speed RS as the output data OD to the three-phase voltage generator 110 and the drive controller. 120, as a basis for control.

In the present embodiment, the detection circuit 130 does not use the phase current or line current of the winding of the AC motor 10 as the general constant voltage control means, but uses the sampled DC link voltage Vin and the DC link current Iin as the basis for calculating the working efficiency. Therefore, the complexity of the calculation of the operational efficiency of the drive controller 120 can be reduced.

More specifically, the working efficiency in this embodiment can be expressed by the following formula (1):

η is the working efficiency, P _IN is the input power, and P _OUT is the output power. Among them, the input power P _IN and the output power P _OUT can be expressed by the following equations (2) and (3): P _IN = V _IN × I _IN (2)

P _OUT = ω _g × T _g (3)

Ω _g is the electrical angular frequency of the three-phase driving voltage VTP and T _g is the output torque of the alternating current motor 10. In the present embodiment, since the output torque T _g and can not be directly detected, and therefore in this case the calculation of an exemplary embodiment of the embodiment, so that the output torque T _g based on a short period of time (for example, 100ms) is assumed to be a constant amount , thereby further simplifying the calculation formula of work efficiency.

Based on the above formulas (1) to (3), the work efficiency η can be replaced by the following formula (4):

In an exemplary embodiment of the present application, the driving controller 120 performs the step S240 of calculating the working efficiency of the AC motor 10 by using the above formula (4), thereby avoiding the calculation of the working efficiency too much within a reasonable working efficiency calculation error range. complex.

(3) Sampling of DC link current

The driving controller 120 is based on the DC link voltage Vin and the DC link current Iin sampled by the detecting circuit 130 as a basis for calculating the working efficiency. Therefore, whether the sampled DC link voltage Vin and the DC link current Iin are accurate will affect the calculation of the working efficiency. result. More specifically, in the operation of the AC motor 10, due to the unevenness of the installation of the rotor magnet, the DC link current Iin during the same mechanical period tends to periodically fluctuate, thereby causing the detection circuit 130 to be at a single time point. The sampled DC link current Iin does not reflect the substantial DC link current Iin. As a result, an error occurs in the operation efficiency calculation of the drive controller 120, thereby causing a control error.

Therefore, in an exemplary embodiment of the present invention, a sampling method of a DC link current Iin is proposed, as shown in FIG. 6, wherein FIG. 6 is a flow chart of a step of sampling a DC link current according to an embodiment of the present invention.

Referring to FIG. 1A and FIG. 6 simultaneously, in step S232, the detecting circuit 130 samples the current value of the DC link current Iin at a plurality of different time points in each mechanical cycle (step S2321), and then calculates the sampled value. The average of the current values is used as a basis for calculating the work efficiency (step S2322). In an exemplary embodiment, the number of current value sampling points of the DC link current Iin is determined according to the number of pole pairs of the AC motor 10 and the number of Hall sensors 12 in the AC motor 10.

For example, the number of sampling points can be defined as the number of the rising edge and the falling edge of the Hall signal Sh emitted by each Hall sensor 12 in one electrical cycle. . It is assumed that the AC motor is an 8-pole motor (ie, the number of pole pairs is 4), and the number of Hall sensors 12 is 3. In this aspect, a mechanical cycle will include 4 electrical cycles, and there will be 6 rising and falling edges of the Hall signal Sh in one electrical cycle (each Hall signal Sh has one cycle) A rising edge with a falling edge). Therefore, the number of sampling points in one mechanical cycle will be equal to 4 × 6 total 24 points.

Further, the detecting circuit 130 determines the time point of sampling the current value of the DC link current Iin according to the pulse edge (ie, the rising edge and the falling edge) of the Hall signal Sh emitted by the Hall sensor 12, and The current value sampled at the 24 sampling time points is averaged to calculate a sample current value representative of the actual DC link current Iin. The average operation can be expressed by the following formula (5):

Where I _P is the sampling current value, N is the number of sampling points, and k is the sampling time point.

Through the above method of sampling the DC link current, the detecting circuit 130 can provide a relatively accurate sampling current value of the DC link current I _in to the driving controller 120 as a basis for calculating the working efficiency, thereby improving the accuracy and accuracy of the current sampling.

The hardware structure of the motor driving device 100 of the embodiment of the present invention under different types of AC motors 10 will be specifically described below with reference to the embodiment of FIG. 7 and FIG. 7 is a schematic view of a motor driving device applied to a permanent magnet synchronous motor according to an embodiment of the present invention. Fig. 8 is a schematic view of a motor driving device applied to an AC induction motor according to an embodiment of the present invention.

Referring first to FIG. 7, in the present embodiment, the motor driving device 700 is adapted to provide a three-phase driving voltage VTP to drive the permanent magnet synchronous motor 70. The motor drive device 700 includes a three-phase voltage generator 710, a drive controller 720, and a detection circuit 730.

In the power conversion unit 710, a power control unit 712 and a power conversion unit 714 are included. The power control unit 712 receives the rotational speed set value SPD and the rotor speed RS provided by the detection circuit 730 to generate a voltage amplitude set value VAMP and a voltage frequency set value HZ. The power conversion unit 714 performs power conversion according to the voltage amplitude setting value VAMP, the voltage frequency setting value HZ, and the phase angle setting value VANG provided by the driving controller 720, thereby receiving the DC link voltage Vin. The DC link current Iin is converted into a three-phase driving voltage VTP.

The preset drive parameter of the drive controller 720 is the angle between the stator voltage of the permanent magnet synchronous motor 70 and the rotor (ie, the efficiency optimization angle). The drive controller 720 includes an efficiency optimized angle tracking unit 722 and a phase angle calculation unit 724. The efficiency optimization angle tracking unit 722 can be configured to perform the operation of optimizing the efficiency tracking described in the foregoing FIGS. 2 to 4 according to the sampled voltage value V _P , the sampled current value I _{P ,} and the rotor speed RS received from the detection circuit 730 . And according to the generation of an angle setting parameter SA. The phase angle calculation unit 724 receives the angle setting parameter SA and the rotor position RP provided by the detection circuit 730, and calculates a phase angle setting value VANG corresponding to the rotor position RP according to the angle setting parameter SA.

The detection circuit 730 includes a power supply sampling unit 732 and a rotational speed calculation unit 734. The power sampling unit 732 can sample the DC link voltage Vin and the DC link current Iin, and generate the sampled voltage value V _P and the sampled current value I _P according to the sampled DC link voltage Vin and the DC link current Iin, respectively. The rotational speed calculation unit 734 receives the Hall signal Sh from the permanent magnet synchronous motor 70, and defines the rotor position RP of the permanent magnet synchronous motor 70 in accordance with the received Hall signal Sh. Further, the rotational speed calculation unit 734 also calculates the rotor speed RS of the permanent magnet synchronous motor 70 in accordance with the defined rotor position RP.

Referring to FIG. 8, in the present embodiment, the motor driving device 800 is adapted to provide a three-phase driving voltage VTP to drive the AC induction motor 80. The motor drive device 800 includes a three-phase voltage generator 810, a drive controller 820, and a detection circuit 830.

The power conversion unit 810 of the present embodiment includes a power supply control unit 812 and a power conversion unit 814. The power control unit 812 and the power conversion unit The function and configuration of the 814 are substantially the same as those of the power control unit 712 and the power conversion unit 714 of the embodiment of FIG. 7, and thus will not be described again.

The preset drive parameter of the drive controller 820 is the slip speed between the rotor frequency of the AC induction motor 80 and the stator frequency (ie, efficiency optimized slip). The drive controller 820 includes an efficiency optimized slip tracking unit 822 and a phase angle calculation unit 824. The efficiency-optimized slip tracking unit 822 can be used to perform the optimization efficiency tracking operation described in the foregoing FIGS. 2 to 4 according to the sampled voltage value V _P , the sampled current value I _{P ,} and the rotor speed RS received from the detection circuit 730 . And according to the result of generating a slip setting parameter SRDS. The phase angle calculation unit 724 receives the slip setting parameter SRDS and the rotor speed RS supplied from the detection circuit 730, and calculates a phase angle setting value VANG corresponding to the rotor speed RS according to the slip setting parameter SRDS.

The detection circuit 830 includes a power supply sampling unit 832 and a rotational speed calculation unit 834. The function and configuration of the power sampling unit 832 of this embodiment are substantially the same as those of the power sampling unit 732 of the embodiment of FIG. 7, and thus will not be described herein.

The rotational speed calculation unit 834 receives the Hall signal Sh from the AC induction motor 80, and defines the rotor position of the permanent magnet synchronous motor 80 according to the received Hall signal Sh, and calculates the permanent magnet synchronous motor 70 according to the defined rotor position. Rotor speed RS. Since the efficiency-optimized slip tracking unit 822 of the present embodiment outputs the slip setting parameter SRDS associated with the rotor speed, the phase angle calculating unit 824 only needs to obtain the rotor speed RS to calculate the corresponding phase angle setting value. VANG. In other words, the difference between the rotational speed calculation unit 834 of the present embodiment and the rotational speed calculation unit 734 of the foregoing embodiment of FIG. 7 is that the rotational speed calculation unit 834 of the present embodiment only The signal of the rotor speed RS needs to be output without additionally generating a signal of the rotor position RP.

In summary, the embodiment of the present invention provides a driving method of an AC motor and a motor driving device using the same, which can calculate a preset driving parameter corresponding to an optimal working efficiency through a similar disturbance observation method, and control according to the same. The phase angle of the three-phase drive voltage supplied to the AC motor allows the motor drive to automatically bring the AC motor closer to optimum operating efficiency during operation. At the same time, the driving method can be applied to any type of AC motor, and the requirements for the load testing device can be omitted, and the optimal efficiency tracking can be avoided due to the change of the specification parameters of the AC motor with the operating state. Tracking errors. In addition, the case also proposes phase disturbance control for two-way scanning, simplified work efficiency calculation and high-accuracy DC link current sampling method, which can effectively improve the efficiency and stability of AC motor control.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

S210~S250‧‧‧Steps

Claims (21)

A driving method of an AC motor, comprising: generating a three-phase driving voltage according to a set value of a driving speed and a predetermined driving parameter to drive the AC motor; in a mechanical cycle, respectively, the disturbance amount of different polarities is superimposed on the preset Driving a parameter, thereby disturbing a phase angle of the three-phase driving voltage; detecting an operating state of the disturbed AC motor, and generating an output data; and calculating, according to the output data, the AC motor when applying a disturbance of different polarities The work efficiency; and comparing the work efficiency, by selecting the parameter set value corresponding to the higher one as the set value of the current preset drive parameter. The driving method of the alternating current motor according to claim 1, further comprising: exchanging the order of application of the disturbance amounts of the different polarities in the next mechanical cycle. The driving method of the alternating current motor according to claim 1, wherein the step of disturbing the phase angle of the three-phase driving voltage by superimposing the disturbance amounts of different polarities respectively comprises: first And superimposing the disturbance amount on the preset driving parameter to generate a first control parameter; and superimposing a second disturbance amount having a polarity opposite to the first disturbance amount to the preset driving parameter to generate a second control parameter. The driving method of the alternating current motor according to claim 3, wherein Calculating the working efficiency of the AC motor when applying the disturbance amount of different polarities comprises: calculating a first working efficiency according to the output data corresponding to the first control parameter; and calculating according to the output data corresponding to the second control parameter A second work efficiency. The driving method of the alternating current motor according to claim 4, wherein comparing the working efficiency, the step of selecting a parameter setting value corresponding to the higher one as the setting value of the current preset driving parameter comprises: when When the first working efficiency is greater than the second working efficiency, setting the first control parameter to the preset driving parameter; and when the first working efficiency is less than the second working efficiency, setting the second control parameter to The preset drive parameter. The driving method of the AC motor according to the first aspect of the invention, wherein the step of generating the three-phase driving voltage according to the rotation speed setting value and the preset driving parameter to drive the AC motor comprises: setting the value according to the rotation speed and the A rotor speed of the AC motor generates a certain sub-voltage set value; a phase angle setting value is generated according to the preset driving parameter and a rotor running information, and the current chain voltage is always used according to the stator voltage setting value and the phase angle setting value. The streamline current is converted to the three-phase drive voltage. The method for driving an AC motor according to claim 6, wherein the detecting the operating state of the disturbed AC motor and generating the output data comprises: sampling the DC link voltage and the DC link current; The AC motor receives a plurality of Hall signals to define a rotor position of the AC motor based on the Hall signals; and calculates the rotor speed based on the rotor position. The method for driving an AC motor according to claim 7, wherein the step of sampling the DC link voltage and the DC link current comprises: sampling a current of the DC link current at a plurality of different time points in the mechanical cycle; And calculating an average of the current values as a basis for calculating the operating efficiency. The driving method of the alternating current motor according to claim 8, wherein the alternating current motor comprises a plurality of Hall sensors, and the number of sampling points of the current values is based on the number of poles of the alternating current motor and the plurality of The number of sensors is determined. The method for driving an AC motor according to claim 1, further comprising: after superimposing the disturbance amount on the preset driving parameter, thereby changing a phase angle of the three-phase driving voltage, delaying a predetermined period of time The operating state of the disturbed AC motor is detected. A motor driving device is adapted to drive an AC motor, the motor driving device comprising: a three-phase voltage generator generates a three-phase driving voltage to drive the alternating current motor according to a speed setting value and a preset driving parameter; a driving controller coupled to the three-phase voltage generator for using the alternating current motor And the operating state of the three-phase voltage generator generates the preset driving parameter to adjust a phase angle of the three-phase driving voltage; and a detecting circuit coupled to the three-phase voltage generator and the driving controller for detecting And operating the AC motor and the three-phase voltage generator to generate an output data, wherein, in a mechanical cycle of the AC motor, the drive controller is superimposed on the preset with different polarity disturbances Driving parameters, thereby disturbing a phase angle of the three-phase driving voltage, and calculating an operating efficiency of the alternating current motor when applying a disturbance amount of different polarities according to the output data, and comparing the working efficiency, thereby selecting a parameter with higher working efficiency The set value is used as the set value of the current preset drive parameter. The motor drive device of claim 11, wherein the drive controller exchanges the order of application of the disturbance amounts of the different polarities in a next mechanical cycle. The motor driving device of claim 11, wherein the driving controller superimposes a first disturbance amount on the preset driving parameter to generate a first control parameter, so that the detecting circuit detects the corresponding And controlling output data of the parameter, the driving controller calculating a first working efficiency according to the output data corresponding to the first control parameter. The motor drive device of claim 13, wherein the drive The dynamic controller superimposes a second disturbance amount whose polarity is opposite to the first disturbance amount to the preset driving parameter to generate a second control parameter, so that the detection circuit detects the output data corresponding to the second control parameter, The drive controller calculates a second operating efficiency based on the output data corresponding to the second control parameter. The motor driving device of claim 14, wherein the driving controller sets the first control parameter to the preset driving when the driving controller determines that the first working efficiency is greater than the second working efficiency. a parameter, and when the drive controller determines that the first work efficiency is less than the second work efficiency, the drive controller sets the second control parameter as the preset drive parameter. The motor driving device of claim 11, wherein the driving controller generates a phase angle setting value according to the preset driving parameter and a rotor running information. The motor driving device of claim 16, wherein the three-phase voltage generating device generates a certain sub-voltage setting value according to the rotation speed setting value and a rotor speed of the AC motor, and the three-phase voltage generating device is based on The stator voltage set value and the phase angle set value convert the flow chain voltage and the DC link current into the three-phase drive voltage. The motor driving device of claim 17, wherein the detecting circuit samples the DC link voltage and the DC link current, and receives a plurality of Hall signals from the AC motor to define the AC motor according to the Hall signals. a rotor position and the rotor speed is calculated based on the rotor position. The motor driving device of claim 18, wherein the inspection The measuring circuit samples the current value of the DC link current at a plurality of different time points in the mechanical cycle, and calculates an average of the current values as a basis for calculating the working efficiency. The motor driving device of claim 19, wherein the AC motor comprises a plurality of Hall sensors, and the number of sampling points of the current values is based on a pole number of the AC motor and the sense of Hall The number of detectors is determined. The motor driving device of claim 11, wherein the detecting circuit delays the phase of the three-phase driving voltage after the driving controller superimposes the disturbance amount on the preset driving parameter, thereby delaying one The operating state of the disturbed AC motor is detected again during the preset period.