WO2018077019A1 - Capacitance miniaturized motor driving system, and overvoltage prevention control method and device therefor - Google Patents

Abstract

Disclosed are a capacitance miniaturized motor driving system, and an overvoltage prevention control method and device therefor. The method comprises the following steps of: acquiring a mechanical angle of a compressor motor, and performing, according to the mechanical angle, torque compensation on the compressor motor so as to obtain an initial torque compensation amount of the compressor motor (S1); acquiring a direct current bus voltage of the compressor motor, and correcting, according to the direct current bus voltage, the initial torque compensation amount so as to obtain a corrected torque compensation amount of the compressor motor (S2); calculating a given value of a total peak torque of the compressor motor according to a given rotational speed of the compressor motor, a rotational speed estimation value of a rotor of the compressor motor and the corrected torque compensation amount (S3); and controlling, according to the given value of the total peak torque, the compressor motor (S4). The method corrects, according to the direct current bus voltage, the initial torque compensation amount of the compressor motor, and thus can effectively avoid an overvoltage phenomenon caused by performing torque compensation on the compressor motor.

Description

Capacitor miniaturized motor drive system and anti-overvoltage control method and device thereof Technical field

The invention relates to the technical field of electric motors, in particular to an anti-overvoltage control method for a capacitor miniaturized motor drive system, an anti-overvoltage control device for a capacitor miniaturized motor drive system, and a capacitor miniaturized motor drive system.

Background technique

With the improvement of energy-saving requirements, the proportion of inverter compressors is increasing, and it has gradually become the mainstream of the market. The speed control of the inverter compressor needs to be realized by the driver, so the performance of the driver has a great influence on the compressor control system. The DC bus voltage of the conventional compressor driver is in a stable state, and the inverter part is relatively independent from the input AC voltage, which is convenient for the realization of the speed control. However, this design method requires an electrolytic capacitor having a large capacitance value, so that the size of the driver becomes large and the cost increases. In addition, the life of electrolytic capacitors is limited, and its effective working time is often the bottleneck of the life of the drive.

To this end, in the related art, a capacitor miniaturized driver is proposed, which eliminates the PFC (Power Factor Correction) circuit portion and the small capacitance film capacitor compared with the conventional AC orthogonal driving circuit. Or ceramic capacitors replace electrolytic capacitors with large capacitance values. Therefore, both the cost can be reduced and the service life bottleneck caused by the electrolytic capacitor can be eliminated.

However, when the compressor is driven by a capacitor miniaturized driver, if the compressor has a characteristic that the load fluctuates with the rotor angle (for example, a single-rotor compressor), it tends to cause large rotational speed fluctuations at low frequency operation. Torque compensation is required, but the capacitance in the miniaturized driver is greatly reduced. The negative torque generated by the torque compensation causes the DC bus voltage to rise rapidly. At this time, the device is easily damaged due to overvoltage.

Summary of the invention

The present invention aims to solve at least one of the technical problems in the related art to some extent.

Therefore, an object of the present invention is to provide an overvoltage prevention control method for a capacitor miniaturized motor drive system, which can effectively prevent the compression of the compressor by correcting the initial torque compensation amount of the compressor motor according to the DC bus voltage. The machine motor performs overvoltage phenomenon caused by torque compensation.

Another object of the present invention is to provide an overvoltage prevention control device for a capacitive miniaturized motor drive system.

Still another object of the present invention is to provide a capacitor miniaturized motor drive system.

To achieve the above object, an embodiment of the present invention provides an overvoltage prevention control method for a capacitor miniaturized motor drive system, comprising the steps of: acquiring a mechanical angle of a compressor motor, and compressing the compressor according to the mechanical angle The machine motor performs torque compensation to obtain an initial torque compensation amount of the compressor motor; acquires a DC bus voltage of the compressor motor, and corrects the initial torque compensation amount according to the DC bus voltage to obtain a corrected torque compensation amount of the compressor motor; calculating according to a given rotational speed of the compressor motor, an estimated rotor rotational speed of the compressor motor, and the corrected torque compensation amount a total peak torque setpoint of the compressor motor; and controlling the compressor motor based on the total peak torque setpoint.

According to the anti-overvoltage control method of the capacitor miniaturized motor drive system according to the embodiment of the invention, first, the mechanical angle of the compressor motor is obtained, and the compressor motor is torque compensated according to the mechanical angle to obtain the initial torque of the compressor motor. The compensation amount is then obtained, the DC bus voltage of the compressor motor is obtained, and the initial torque compensation amount is corrected according to the DC bus voltage to obtain the corrected torque compensation amount of the compressor motor, and finally, according to the given rotational speed of the compressor motor, The rotor speed estimation value of the compressor motor and the corrected torque compensation amount calculate the total peak torque reference value of the compressor motor, and control the compressor motor according to the total peak torque reference value. The method corrects the initial torque compensation amount of the compressor motor according to the DC bus voltage, thereby effectively avoiding an overvoltage phenomenon caused by torque compensation of the compressor motor.

According to an embodiment of the invention, the initial torque compensation amount of the compressor motor is obtained by the following formula:

Where T _p is the initial torque compensation amount of the compressor motor, T _com is a preset torque compensation amplitude, and θ _m is a mechanical angle of the compressor motor.

The offset phase angle for the preset torque compensation.

According to an embodiment of the present invention, the initial torque compensation amount is corrected according to the DC bus voltage to obtain a corrected torque compensation amount of the compressor motor, including: a preset maximum DC bus voltage Subtracting from the DC bus voltage to obtain a voltage difference, and performing a first limiting process on the voltage difference to obtain a first value; One value is multiplied by a preset anti-overpressure proportional coefficient to obtain a second value; a preset initial torque compensation limit value is added to the second value, and a second limiting process is performed to obtain a third value And performing a third limiting process on the initial torque compensation amount according to the third value to obtain the corrected torque compensation amount.

According to an embodiment of the present invention, the calculating a total peak torque of the compressor motor according to a given rotational speed of the compressor motor, an estimated rotor rotational speed of the compressor motor, and the corrected torque compensation amount And a predetermined value, comprising: performing PI (Proportional Integral) adjustment on a difference between the given rotational speed and the rotor rotational speed estimation value to obtain a first torque reference value of the compressor motor; The first torque set value and the corrected torque compensation amount are added to obtain the total peak torque reference value.

According to an embodiment of the invention, the controlling the compressor motor according to the total peak torque reference value comprises: acquiring a voltage phase value of the AC input power source, and generating a waveform variable according to the voltage phase value Multiplying the waveform variable by the total peak torque setpoint and dividing by the torque coefficient of the compressor motor to obtain a q-axis given current of the compressor motor; according to the q-axis A constant current controls the compressor motor.

According to an embodiment of the invention, the waveform variable is generated by the following formula:

Where W _f (θ _g ) is the waveform variable, θ _d is the dead zone angle when the current of the AC input power source is zero, and θ _g is the voltage phase value of the AC input power source.

According to an embodiment of the present invention, the overvoltage prevention control method further includes: calculating a d-axis given current of the compressor motor according to a maximum output voltage of the inverter circuit and an output voltage amplitude of the inverter circuit; Obtaining a q-axis given voltage and a d-axis given voltage of the compressor motor according to the q-axis given current, the d-axis given current, the q-axis actual current, and the d-axis actual current, and according to the q A shaft given voltage, the d-axis given voltage, the rotor angle estimate generates a control signal, and the compressor motor is controlled by the inverter circuit according to the control signal.

In order to achieve the above object, an overvoltage prevention control device for a capacitor miniaturized motor drive system according to another embodiment of the present invention includes: a torque compensation module for acquiring a mechanical angle of a compressor motor, and according to the a mechanical angle for torque compensation of the compressor motor to obtain an initial torque compensation amount of the compressor motor; a correction module for acquiring a DC bus voltage of the compressor motor, and according to the DC bus voltage pair The initial torque compensation amount is corrected to obtain a corrected torque compensation amount of the compressor motor; and a torque given module is configured to: according to a given rotational speed of the compressor motor, a rotor speed of the compressor motor Estimating a value and the corrected torque compensation amount to calculate a total peak torque reference value of the compressor motor; and a control module, the control module being coupled to the torque reference module, the control module for The total peak torque setpoint controls the compressor motor.

An overvoltage prevention control device for a capacitor miniaturized motor drive system according to an embodiment of the present invention obtains a mechanical angle of a compressor motor through a torque compensation module, and torque compensates the compressor motor according to a mechanical angle to obtain a compressor motor The initial torque compensation amount, and then the DC bus voltage of the compressor motor is obtained through the correction module, and according to the DC bus voltage Correcting the initial torque compensation amount to obtain the corrected torque compensation amount of the compressor motor. Finally, the torque reference module is based on the given rotational speed of the compressor motor, the estimated rotor speed of the compressor motor, and the corrected torque compensation amount. The total peak torque reference value of the compressor motor is calculated, and the control module controls the compressor motor according to the total peak torque reference value. The device corrects the initial torque compensation amount of the compressor motor according to the DC bus voltage, thereby effectively avoiding an overvoltage phenomenon caused by torque compensation of the compressor motor.

According to an embodiment of the invention, the torque compensation module obtains an initial torque compensation amount of the compressor motor by the following formula:

Where T _p is the initial torque compensation amount of the compressor motor, T _com is a preset torque compensation amplitude, and θ _m is a mechanical angle of the compressor motor.

The offset phase angle for the preset torque compensation.

According to an embodiment of the present invention, the correction module includes: a first subtracter configured to subtract a first preset maximum DC bus voltage from the DC bus voltage to obtain a voltage difference; a processor, configured to perform a first limiting process on the voltage difference to obtain a first value; a multiplier, configured to multiply the first value by a preset anti-overvoltage proportional coefficient to obtain a second value a first adder for adding a preset initial torque compensation limit value to the second value; a second limiter processor configured to compensate the preset initial torque compensation limit value Performing a second limiting process with the sum of the second values to obtain a third value; and a third limiting processor configured to perform a third limiting process on the initial torque compensation amount according to the third value The corrected torque compensation amount is obtained.

According to an embodiment of the invention, the torque reference module comprises: a speed regulator, And performing PI adjustment on a difference between the given rotational speed and the rotor rotational speed estimation value to obtain a first torque reference value of the compressor motor; and a second adder for using the first A torque reference value and the corrected torque compensation amount are added to obtain the total peak torque reference value.

According to an embodiment of the present invention, the overvoltage prevention control device further includes: a waveform generator for acquiring a voltage phase value of the AC input power source, and generating a waveform variable according to the voltage phase value; q-axis current given a module for multiplying the waveform variable by the total peak torque reference value and dividing by a torque coefficient of the compressor motor to obtain a q-axis given current of the compressor motor; And a module for controlling the compressor motor according to the q-axis given current.

According to an embodiment of the invention, the waveform generator generates the waveform variable by the following formula:

Where W _f (θ _g ) is the waveform variable, θ _d is the dead zone angle when the current of the AC input power source is zero, and θ _g is the voltage phase value of the AC input power source.

According to an embodiment of the present invention, the overvoltage prevention control device further includes: a d-axis current given module, configured to calculate the maximum output voltage of the inverter circuit and the output voltage amplitude of the inverter circuit The d-axis of the compressor motor is given a current; the control module is configured to acquire the compressor motor according to the q-axis given current, the d-axis given current, the q-axis actual current, and the d-axis actual current Q axis given voltage and d axis given electricity Pressing, and generating a control signal according to the q-axis given voltage, the d-axis given voltage, the rotor angle estimation value, and controlling the compressor motor through the inverter circuit according to the control signal .

In addition, embodiments of the present invention also provide a capacitor miniaturized motor drive system including the above-described anti-overvoltage control device for a capacitive miniaturized motor drive system.

The capacitor miniaturized motor drive system according to the embodiment of the present invention can correct the initial torque compensation amount of the compressor motor according to the DC bus voltage by the above-mentioned anti-overvoltage control device, thereby effectively avoiding the rotation of the compressor motor Overvoltage phenomenon caused by moment compensation.

DRAWINGS

1 is a circuit diagram of a capacitor miniaturized motor driver in accordance with one embodiment of the present invention;

2 is a schematic view of a load characteristic of a compressor according to an embodiment of the present invention;

3 is a flow chart of a method for preventing overvoltage prevention of a capacitor miniaturized motor drive system according to an embodiment of the present invention;

4 is a structural diagram of correcting an initial torque compensation amount according to a DC bus voltage according to an embodiment of the present invention;

5 is a block diagram showing an overvoltage prevention control device for a capacitor miniaturized motor drive system according to an embodiment of the present invention;

6 is a waveform diagram of a waveform variable W _f (θ _g ) and an AC input voltage V _ac according to an embodiment of the present invention;

Figure 7 is a waveform comparison diagram before and after anti-overvoltage control according to an embodiment of the present invention.

detailed description

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.

Hereinafter, a capacitor miniaturized motor drive system and an overvoltage prevention control method and apparatus thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a circuit diagram of a capacitor miniaturized motor driver in accordance with one embodiment of the present invention. As shown in FIG. 1, the circuit eliminates the PFC circuit portion and replaces the electrolytic capacitor with a large capacitance value with a small-capacity film capacitor or a ceramic capacitor as compared with the conventional AC-DC drive circuit. Therefore, both the cost can be reduced and the service life bottleneck caused by the electrolytic capacitor can be eliminated.

2 is a schematic diagram of load characteristics of a compressor in accordance with one embodiment of the present invention. It can be seen from Fig. 2 that the load torque of the compressor fluctuates periodically with the rotor angle, and there is a significant difference in the amplitude of the load fluctuation under different working conditions. When the system pressure is in equilibrium, the load torque can be expressed by the following formula (1):

Where T _l is the load torque of the compressor, T _l0 is the DC component of the load torque T _l , and T _lk (k=1, 2, . . . ) is the kth harmonic component of the load torque T _l Amplitude,

For the angular deviation corresponding to the kth harmonic component, ω _m is the mechanical angular velocity of the compressor, and t is time.

Under the action of the load torque T _l , the compressor will produce obvious speed fluctuations. If the torque compensation is not performed for the load fluctuation, it will cause the compressor motor to lose the step fault. When the compressor is applied to the air conditioner, it will also cause Excessive vibration of the piping affects the service life of the piping and reduces the safety and reliability of the air conditioner. To this end, embodiments of the present invention provide an overvoltage prevention method and apparatus for a capacitor miniaturized motor drive system and a capacitor miniaturized motor drive system.

3 is a flow chart of an overvoltage prevention control method of a capacitor miniaturized motor drive system according to an embodiment of the present invention. As shown in FIG. 3, the overvoltage prevention control method of the capacitor miniaturized motor drive system may include the following steps:

S1: Obtain a mechanical angle of the compressor motor, and perform torque compensation on the compressor motor according to the mechanical angle to obtain an initial torque compensation amount of the compressor motor.

According to an embodiment of the present invention, the initial torque compensation amount of the compressor motor can be obtained by the following formula (2):

Where T _p is the initial torque compensation amount of the compressor motor, T _com is the preset torque compensation amplitude, which can be obtained according to the commissioning, and θ _m is the mechanical angle of the compressor motor.

The offset phase angle for the preset torque compensation.

S2: Obtain a DC bus voltage of the compressor motor, and correct the initial torque compensation amount according to the DC bus voltage to obtain a corrected torque compensation amount of the compressor motor.

Specifically, when the load torque fluctuation increases, the magnitude of the initial torque compensation amount T _p of the compressor motor also increases, and after the torque compensation of the compressor motor, the torque reference value may be Negative, a certain negative power will be generated at this time. Moreover, since the capacitance of the film capacitor or the ceramic capacitor is small (generally 5 to 20 μF), the negative power will cause the DC bus voltage to rise rapidly, and the DC bus voltage may exceed the withstand voltage of the power device or capacitor in a short time. Causes damage to the power device or capacitor. For this purpose, in the embodiment of the present invention, the initial correction torque compensation amount T _p the DC link voltage, in order to avoid the initial magnitude of the torque compensation amount T _p is too large due to overvoltage.

According to an embodiment of the present invention, as shown in FIG correcting the initial torque compensation amount T _p 4 The DC bus voltage V _dc to obtain a corrected compressor motor torque compensation amount T _p1, comprising: a preset The maximum DC bus voltage V _{dcmax is subtracted} from the DC bus voltage V _dc to obtain a voltage difference, and the voltage difference is subjected to a first limiting process to obtain a first value ΔV; the first value ΔV and a preset overvoltage prevention The proportional coefficient K _{v is} multiplied to obtain a second value ΔT _pmax ; the preset initial torque compensation limit value T _{pmax0 is added} to the second value ΔT _pmax , and the second limiting process is performed to obtain the third value T _pmax And performing a third limiting process on the initial torque compensation amount T _p according to the third value T _pmax to obtain the corrected torque compensation amount T _p1 . Wherein, the preset anti-overpressure proportional coefficient K _v >0.

It should be noted that, in FIG. 4, when V _dc ≤ V _dcmax , the first value ΔV is 0 after the first limiting process, and the first value ΔV=V _dcmax -V when V _dc >V _{dcmax Dc} . When T _pmax0 ≤|ΔT _pmax |, the third value T _pmax =0 after the second clipping process; and when T _pmax0 >|ΔT _pmax |, the third value T _pmax =T _pmax0 +ΔT _pmax . When -T _pmax <T _p <T _pmax , the torque compensation amount T _p1 =T _{p is} corrected; when T _p ≤-T _pmax , the torque compensation amount T _p1 =-T _{pmax is} corrected; when T _p ≥T _pmax , Correct the torque compensation amount T _p1 =T _pmax .

Specifically, when the DC bus voltage does not overvoltage, that is, V _dc ≤ V _dcmax , and the third value T _pmax = T _pmax0 + (V _dcmax - V _dc ) * K _v = T _pmax0 + 0 * K _v =T _pmax0 , T _{p is} between [-T _pmax0 , T _pmax0 ], at this time, the initial torque compensation amount T _{p is} not corrected for torque; when the DC bus voltage is overvoltage, ie V _dc >V _dcmax , this When the third value T _pmax =T _pmax0 +(V _dcmax -V _dc )*K _v , the third value T _pmax will decrease, so that the initial torque compensation amount T _p decreases proportionally until V _{dc is} close to V _Dcmax . When the PI adjustment is adopted in the circuit, the closed-loop regulation can ensure a sufficiently fast response speed, thereby quickly and effectively suppressing the overvoltage of the DC bus voltage.

It should be noted that since the PI adjustment cannot make the error converge to zero, the setting of V _dcmax should leave a certain margin, that is, the value is smaller than the actual withstand voltage value of the power device.

S3. Calculate a total peak torque reference value of the compressor motor according to a given rotation speed of the compressor motor, an estimated rotor speed of the compressor motor, and a corrected torque compensation amount.

According to an embodiment of the present invention, the total peak torque reference value T of the compressor motor is calculated according to a given rotational speed ω _ref of the compressor motor, a rotor rotational speed estimated value ω _{est of the} compressor motor, and a corrected torque compensation amount T _p1 . _t , comprising: performing PI adjustment on the difference between the given rotational speed ω _ref and the rotor rotational speed estimated value ω _est to obtain a first torque reference value T _{0 of the} compressor motor; and setting the first torque reference value T _{0 is} added to the corrected torque compensation amount T _p1 to obtain a total peak torque reference value T _t .

Specifically, the compressor motor may be obtained by the method Flux Observer rotor speed estimate ω _est, to be concrete (3) by the following formula - (5) to obtain the estimated value of the rotor speed ω _est:

among them,

with

They are the effective flux estimates of the compressor motor on the αβ axis, s is the Laplace transform coefficient, v _α and v _β are the voltages of the compressor motor on the αβ axis, respectively, and i _α and i _β are compression respectively. The current of the machine motor on the αβ axis, R is the stator resistance of the compressor motor, and L _q is the q-axis inductance of the compressor motor.

Where θ _err is the estimated value of the deviation angle θ-θ _est , θ is the actual rotor angle of the compressor motor, θ _est is the rotor angle estimation value of the compressor motor, L _d is the d-axis inductance of the compressor motor, I _dref For the d-axis current of the compressor motor, K _e is the back EMF coefficient of the compressor motor.

Where K _{p_pll} and K _{i_pll} are the proportional and integral coefficients of PI regulation, ω _est is the estimated rotor speed of the compressor motor, and ω _f is the speed low-pass filter bandwidth.

Then, calculating the difference between the given rotational speed ω _ref and the estimated rotor rotational speed ω _est , and performing PI adjustment on the difference, the first torque reference value T _{0 of the} compressor motor can be obtained in real time, which will be the first The torque set value T ₀ and the corrected torque compensation amount T _p1 are added to obtain a total peak torque reference value T _t .

S4, the compressor motor is controlled according to the total peak torque reference value.

According to an embodiment of the present invention, as shown in FIG. 5, controlling the compressor motor according to the total peak torque reference value T _t includes: obtaining a voltage phase value θ _{g of the} AC input power source, and according to the voltage phase value θ _g generates a waveform variable W _f (θ _g ); multiplies the waveform variable W _f (θ _g ) by the total peak torque set value T _t and divides it by the torque coefficient K _t of the compressor motor to obtain the compressor motor The q-axis gives the current I _qref ; the compressor motor is controlled according to the q-axis given current I _qref .

According to an embodiment of the present invention, a waveform variable can be generated by the following formula (6):

Where W _f (θ _g ) is the waveform variable, and θ _d is the dead zone angle when the current of the AC input power source is zero, generally 0.1 to 0.2 rad, and θ _g is the voltage phase value of the AC input power source.

6 is a waveform diagram and the AC input voltage V _ac waveform according to a variable W _f (θ _g) of a embodiment of the present invention. As can be seen from Figure 6, the waveform of W _f (θ _g ) is close to a sine wave.

Further, according to one embodiment of the present invention, the above-described method for preventing overvoltage control capacitor miniaturized motor drive system further comprises: calculating the magnitude of the output voltage V _max and the maximum output voltage of the inverter circuit V ₁ of the inverter circuit The d-axis given current I _{dref of the} compressor motor; the q-axis of the compressor motor is _obtained according to the q-axis given current I _qref , the d-axis given current I _dref , the q-axis actual current I _q and the d-axis actual current I _d The constant voltage V _qref and the d-axis give a voltage V _dref , and generate a control signal according to the q-axis given voltage V _qref , the d-axis given voltage V _dref , the rotor angle estimated value θ _est , and the inverter circuit pair according to the control signal The compressor motor is controlled.

Specifically, the output voltage amplitude V _{1 of the} inverter circuit and the maximum output voltage V _max of the inverter circuit can be calculated by the following formula (7):

Where V _d and V _q are the d-axis actual voltage and the q-axis actual voltage of the compressor motor, respectively.

Then, the integral feedback type field weakening control algorithm can be used to calculate the d-axis given current I _dref of the compressor motor, as shown in the following formula (8):

Where K _i is the integral coefficient and I _demag is the demagnetization current limit value of the compressor motor.

Then, by obtaining the three-phase current of the compressor motor and performing coordinate transformation on the three-phase current to obtain the q-axis actual current I _q and the d-axis actual current I _{d of the} compressor motor, and according to the q-axis of the compressor motor The current I _qref , the d-axis given current I _dref , the q-axis actual current I _q and the d-axis actual current I _d calculate the q-axis given voltage V _qref and the d-axis given voltage V _dref of the compressor motor in real time, as follows Formula (9):

Where K _pd is the d-axis current control proportional gain, K _id is the d-axis current control integral gain, K _pq is the q-axis current control proportional gain, and K _iq is the q-axis current control integral gain.

Finally, coordinate transformation is performed on the d-axis given voltage V _dref and the q-axis given voltage V _qref of the compressor motor according to the rotor angle estimation value θ _est of the compressor motor to obtain a given voltage of the compressor motor on the αβ axis. V _α and V _{β are} as shown in the following formula (10):

Then, based on V _α , V _β and the DC bus voltage V _dc , the duty ratios of the U, V and W phases in the inverter circuit are calculated by the following equations (11) and (12):

Where D _u, D _v and D _w are the duty ratios of the three phases of U, V and W in the inverter circuit, respectively.

After obtaining the duty ratios of the three phases of U, V and W in the inverter circuit, the on and off of the power devices in the inverter circuit can be controlled in real time, thereby realizing the control of the compressor motor.

7 is a waveform comparison diagram before and after anti-overvoltage control according to a specific example of the present invention, wherein FIG. 7(a) is a waveform diagram without anti-overvoltage control, and FIG. 7(b) is an anti-overvoltage control. Waveform. As can be seen in FIG. 7 (a), prior to addition of the anti-overpressure is not controlled, the q-axis torque compensation will cause the compressor motor to a constant current I _qref instantaneous negative, thereby causing the DC link voltage V _dc rises. By comparing the waveforms of the q-axis given current I _qref and the DC bus voltage V _dc in Fig. 7(a) and Fig. 7(b), it can be seen that when V _dc >V _dcmax appears after the overvoltage prevention control is added, The current of the negative q-axis can be quickly reduced, thereby effectively preventing the DC bus voltage V _{dc from} further increasing. Before the anti-overvoltage control is added, the DC bus voltage V _dc may exceed 450V, and after the anti-overvoltage control is added, the maximum value of the DC bus voltage V _dc is lower than 400V, and the capacitor miniaturized motor proposed by the embodiment of the present invention can be seen. The overvoltage prevention method of the drive system can effectively avoid the problem of DC bus voltage overvoltage.

In summary, according to the anti-overvoltage control method of the capacitor miniaturized motor drive system according to the embodiment of the present invention, first, the mechanical angle of the compressor motor is obtained, and the compressor motor is torque compensated according to the mechanical angle to obtain a compressor. The initial torque compensation amount of the motor is then obtained, and the DC bus voltage of the compressor motor is obtained, and the initial torque compensation amount is corrected according to the DC bus voltage to obtain the corrected torque compensation amount of the compressor motor, and finally, according to the compressor motor The given rotational speed, the estimated rotor speed of the compressor motor, and the corrected torque compensation amount are used to calculate the total peak torque reference value of the compressor motor, and the compressor motor is controlled according to the total peak torque reference value. The method corrects the initial torque compensation amount of the compressor motor according to the DC bus voltage, thereby effectively avoiding an overvoltage phenomenon caused by torque compensation of the compressor motor.

Figure 5 is a block schematic diagram of an overvoltage prevention control device for a capacitive miniaturized motor drive system in accordance with one embodiment of the present invention. As shown in FIG. 5, the overvoltage prevention control device of the capacitor miniaturized motor drive system includes a torque compensation module 10, a correction module 20, a torque reference module 30, and a control module 40.

The torque compensation module 10 is configured to acquire a mechanical angle of the compressor motor, and perform torque compensation on the compressor motor according to the mechanical angle to obtain an initial torque compensation amount of the compressor motor. The correction module 20 is configured to obtain a DC bus voltage of the compressor motor, and correct the initial torque compensation amount according to the DC bus voltage to obtain a corrected torque compensation amount of the compressor motor. The torque reference module 30 is configured to calculate the total compressor motor based on a given rotational speed of the compressor motor, an estimated rotor speed of the compressor motor, and a corrected torque compensation amount. Peak torque reference. The control module 40 is coupled to a torque reference module 30 for controlling the compressor motor based on a total peak torque setpoint.

Embodiment, a torque compensation module 10 may obtain the initial torque compensation amount T _p of the compressor motor by the above formula (2) in accordance with one embodiment of the present invention.

According to an embodiment of the present invention, as shown in FIG. 4, the correction module 20 may include: a first subtractor 21, a first limiter processor 22, a multiplier 23, a first adder 24, and a second limiter processor. 25 and a third limiter processor 26. The first subtractor 21 is configured to subtract the first maximum DC bus voltage V _dcmax from the DC bus voltage V _dc to obtain a voltage difference. The first limiting processor 22 is configured to perform a first limiting process on the voltage difference to obtain a first value ΔV. The multiplier 23 is for multiplying the first value ΔV by a preset anti-overvoltage proportional coefficient K _v to obtain a second value ΔT _pmax . A first adder 24 for compensating the preset initial torque limit value and the second value _T pmax0 adding ΔT _pmax. Second limiter processor 25 for a preset initial torque limit value _T pmax0 compensation value ΔT _pmax and a second sum of the second clip processing to obtain a third value T _pmax. The third limit processor 26 is configured to perform a third limiting process on the initial torque compensation amount T _p according to the third value T _pmax to obtain the corrected torque compensation amount T _p1 .

According to an embodiment of the present invention, as shown in FIG. 5, the torque reference module 30 may include a speed adjuster 31 and a second adder 32. The speed regulator 31 is configured to perform PI adjustment on the difference between the given rotational speed ω _ref and the rotor rotational speed estimated value ω _est to obtain a first torque reference value T _{0 of the} compressor motor. The second adder 32 is configured to add the first torque set value T ₀ and the corrected torque compensation amount T _p1 to obtain a total peak torque reference value T _t .

According to an embodiment of the present invention, as shown in FIG. 5, the overvoltage prevention control device of the above-described capacitive miniaturized motor drive system may further include: a waveform generator 50 and a q-axis current giving module 60. The waveform generator 50 is configured to acquire a voltage phase value θ _{g of the} AC input power source, and generate a waveform variable W _f (θ _g ) according to the voltage phase value θ _g . The q-axis current reference module 60 is configured to multiply the waveform variable W _f (θ _g ) by the total peak torque reference value T _t and divide it by the torque coefficient K _t of the compressor motor to obtain the q-axis of the compressor motor. Given current I _qref . The control module 40 is configured to control the compressor motor according to the q-axis given current I _qref .

According to an embodiment of the present invention, the waveform generator 50 can generate the waveform variable W _f (θ _g ) by the above formula (6).

According to an embodiment of the present invention, the overvoltage prevention control device of the capacitor miniaturized motor drive system may further include: a d-axis current given module 70. The d-axis current given module 70 is configured to calculate a d-axis given current I _{dref of the} compressor motor according to the maximum output voltage V _{max of the} inverter circuit and the output voltage amplitude V _{1 of the} inverter circuit. The control module 40 is configured to obtain a q-axis given voltage V _qref and a d-axis of the compressor motor according to the q-axis given current I _qref , the d-axis given current I _dref , the q-axis actual current I _{q ,} and the d-axis actual current I _d . The voltage V _{dref is} given, and a control signal is generated according to the q-axis given voltage V _qref , the d-axis given voltage V _dref , the rotor angle estimated value θ _est , and the compressor motor is controlled by the inverter circuit according to the control signal.

It should be noted that, in the undisclosed details of the overvoltage prevention control device of the capacitor miniaturized motor drive system according to the embodiment of the present invention, please refer to the overvoltage prevention control method of the capacitor miniaturized motor drive system according to the embodiment of the present invention. The details of the disclosure are not detailed here.

An overvoltage prevention control device for a capacitor miniaturized motor drive system according to an embodiment of the present invention obtains a mechanical angle of a compressor motor through a torque compensation module, and torque compensates the compressor motor according to a mechanical angle to obtain a compressor motor The initial torque compensation amount, and then the DC bus voltage of the compressor motor is obtained through the correction module, and according to the DC bus voltage Correcting the initial torque compensation amount to obtain the corrected torque compensation amount of the compressor motor. Finally, the torque reference module is based on the given rotational speed of the compressor motor, the estimated rotor speed of the compressor motor, and the corrected torque compensation amount. The total peak torque reference value of the compressor motor is calculated, and the control module controls the compressor motor according to the total peak torque reference value. The device corrects the initial torque compensation amount of the compressor motor according to the DC bus voltage, thereby effectively avoiding an overvoltage phenomenon caused by torque compensation of the compressor motor.

In addition, embodiments of the present invention also provide a capacitor miniaturized motor drive system including the above-described anti-overvoltage control device for a capacitive miniaturized motor drive system.

The capacitor miniaturized motor drive system according to the embodiment of the present invention can correct the initial torque compensation amount of the compressor motor according to the DC bus voltage by the above-mentioned anti-overvoltage control device, thereby effectively avoiding the rotation of the compressor motor Overvoltage phenomenon caused by moment compensation.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " After, "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axial", The orientation or positional relationship of the "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is merely for convenience of description of the present invention and simplified description, and does not indicate or imply the indicated device or component. It must be constructed and operated in a particular orientation, and is not to be construed as limiting the invention.

Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may explicitly or implicitly include at least one of feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless specifically defined otherwise.

In the present invention, the terms "installation", "connected", "connected", "fixed" and the like shall be understood broadly, and may be either a fixed connection or a detachable connection, unless explicitly stated and defined otherwise. , or integrated; can be mechanical or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction of two elements, unless otherwise specified Limited. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

In the present invention, the first feature "on" or "under" the second feature may be a direct contact of the first and second features, or the first and second features may be indirectly through an intermediate medium, unless otherwise explicitly stated and defined. contact. Moreover, the first feature "above", "above" and "above" the second feature may be that the first feature is directly above or above the second feature, or merely that the first feature level is higher than the second feature. The first feature "below", "below" and "below" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely that the first feature level is less than the second feature.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means a specific feature described in connection with the embodiment or example. A structure, material or feature is included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, and materials described Or features may be combined in any suitable manner in any one or more embodiments or examples. In addition, various embodiments or examples described in the specification, as well as features of various embodiments or examples, may be combined and combined.

Although the embodiments of the present invention have been shown and described, it is understood that the above-described embodiments are illustrative and are not to be construed as limiting the scope of the invention. The embodiments are subject to variations, modifications, substitutions and variations.

Claims (18)

1. An overvoltage prevention control method for a capacitor miniaturized motor drive system, characterized in that the method comprises the following steps:

   Obtaining a mechanical angle of the compressor motor, and performing torque compensation on the compressor motor according to the mechanical angle to obtain an initial torque compensation amount of the compressor motor;

   Obtaining a DC bus voltage of the compressor motor, and correcting the initial torque compensation amount according to the DC bus voltage to obtain a corrected torque compensation amount of the compressor motor;

   Calculating a total peak torque reference value of the compressor motor according to a given rotational speed of the compressor motor, an estimated rotor rotational speed of the compressor motor, and the corrected torque compensation amount;

   The compressor motor is controlled based on the total peak torque setpoint.
2. The overvoltage prevention control method according to claim 1, wherein the initial torque compensation amount of the compressor motor is obtained by the following formula:

   

   Where T _p is the initial torque compensation amount of the compressor motor, T _com is a preset torque compensation amplitude, and θ _m is a mechanical angle of the compressor motor.

   

   The offset phase angle for the preset torque compensation.
3. The overvoltage prevention control method according to claim 1, wherein said correcting said initial torque compensation amount according to said DC bus voltage to obtain a corrected torque compensation amount of said compressor motor, including :

   And dividing a preset maximum DC bus voltage with the DC bus voltage to obtain a voltage difference, and performing a first limiting process on the voltage difference to obtain a first value;

   Multiplying the first value by a preset anti-overpressure proportional coefficient to obtain a second value;

   Adding a preset initial torque compensation limit value to the second value, and performing a second limiting process to obtain a third value;

   And performing third limiting processing on the initial torque compensation amount according to the third value to obtain the corrected torque compensation amount.
4. The overvoltage prevention control method according to claim 1, wherein said calculation is based on a given rotational speed of said compressor motor, said rotor rotational speed estimated value of said compressor motor, and said corrected torque compensation amount The total peak torque reference value of the compressor motor, including:

   Performing a PI adjustment on a difference between the given rotational speed and the rotor rotational speed estimate to obtain a first torque reference value of the compressor motor;

   The first torque set value and the corrected torque compensation amount are added to obtain the total peak torque reference value.
5. The overvoltage prevention control method according to claim 1, wherein said controlling said compressor motor according to said total peak torque reference value comprises:

   Obtaining a voltage phase value of the AC input power source, and generating a waveform variable according to the voltage phase value;

   Multiplying the waveform variable by the total peak torque reference value and dividing by the torque coefficient of the compressor motor to obtain a q-axis given current of the compressor motor;

   The compressor motor is controlled according to the q-axis given current.
6. The overvoltage prevention control method according to claim 2, wherein the controlling the compressor motor according to the total peak torque reference value comprises:

   Obtaining a voltage phase value of the AC input power source, and generating a waveform variable according to the voltage phase value;

   Multiplying the waveform variable by the total peak torque reference value and dividing by the torque coefficient of the compressor motor to obtain a q-axis given current of the compressor motor;

   The compressor motor is controlled according to the q-axis given current.
7. The overvoltage prevention control method according to claim 6, wherein the waveform variable is generated by the following formula:

   

   Where W _f (θ _g ) is the waveform variable, θ _d is the dead zone angle when the current of the AC input power source is zero, and θ _g is the voltage phase value of the AC input power source.
8. The overvoltage prevention control method according to claim 6, further comprising:

   Calculating a d-axis given current of the compressor motor according to a maximum output voltage of the inverter circuit and an output voltage amplitude of the inverter circuit;

   Obtaining a q-axis given voltage and a d-axis given voltage of the compressor motor according to the q-axis given current, the d-axis given current, the q-axis actual current, and the d-axis actual current, and And generating a control signal according to the q-axis given voltage, the d-axis given voltage, the rotor angle estimation value, and controlling the compressor motor through the inverter circuit according to the control signal.
9. An overvoltage prevention control device for a capacitor miniaturized motor drive system, comprising:

   a torque compensation module, configured to acquire a mechanical angle of the compressor motor, and perform torque compensation on the compressor motor according to the mechanical angle to obtain an initial torque compensation amount of the compressor motor;

   a correction module, configured to acquire a DC bus voltage of the compressor motor, and correct the initial torque compensation amount according to the DC bus voltage to obtain a corrected torque compensation amount of the compressor motor;

   a torque reference module, configured to calculate a total peak torque reference of the compressor motor according to a given rotational speed of the compressor motor, an estimated rotor rotational speed of the compressor motor, and the corrected torque compensation amount Value;

   And a control module, wherein the control module is connected to the torque reference module, and the control module is configured to control the compressor motor according to the total peak torque reference value.
10. The overvoltage prevention control device according to claim 9, wherein the torque compensation module obtains an initial torque compensation amount of the compressor motor by the following formula:

    

    Where T _p is the initial torque compensation amount of the compressor motor, T _com is a preset torque compensation amplitude, and θ _m is a mechanical angle of the compressor motor.

    

    The offset phase angle for the preset torque compensation.
11. The overvoltage prevention control device according to claim 9, wherein the correction module comprises:

    a first subtracter, configured to subtract a first predetermined maximum DC bus voltage from the DC bus voltage to obtain a voltage difference;

    a first limiting processor, configured to perform a first limiting process on the voltage difference to obtain a first value;

    a multiplier for multiplying the first value by a preset anti-overvoltage proportional coefficient to obtain a second value;

    a first adder for adding a preset initial torque compensation limit value to the second value;

    a second limiting processor, configured to perform a second limiting process on the sum of the preset initial torque compensation limiting value and the second value to obtain a third value;

    And a third limiting processor, configured to perform third limiting processing on the initial torque compensation amount according to the third value to obtain the corrected torque compensation amount.
12. The overvoltage prevention control device according to claim 9, wherein the torque reference module comprises:

    a speed regulator for performing PI adjustment on a difference between the given rotational speed and the rotor rotational speed estimate to obtain a first torque reference value of the compressor motor;

    And a second adder for adding the first torque set value and the corrected torque compensation amount to obtain the total peak torque reference value.
13. The anti-overvoltage control device according to claim 9, further comprising:

    a waveform generator, configured to obtain a voltage phase value of the AC input power source, and generate a waveform variable according to the voltage phase value;

    a q-axis current given module for multiplying the waveform variable by the total peak torque reference value and dividing by a torque coefficient of the compressor motor to obtain a q-axis reference of the compressor motor Current

    The control module is configured to control the compressor motor according to the q-axis given current.
14. The anti-overvoltage control device according to claim 12, further comprising:

    a waveform generator, configured to obtain a voltage phase value of the AC input power source, and generate a waveform variable according to the voltage phase value;

    a q-axis current given module for multiplying the waveform variable by the total peak torque reference value and dividing by a torque coefficient of the compressor motor to obtain a q-axis reference of the compressor motor Current

    The control module is configured to control the compressor motor according to the q-axis given current.
15. The overvoltage prevention control apparatus according to claim 13, wherein said waveform generator generates said waveform variable by the following formula:

    

    Where W _f (θ _g ) is the waveform variable, θ _d is the dead zone angle when the current of the AC input power source is zero, and θ _g is the voltage phase value of the AC input power source.
16. The anti-overvoltage control device according to claim 13, further comprising:

    a d-axis current given module, configured to calculate a d-axis given current of the compressor motor according to a maximum output voltage of the inverter circuit and an output voltage amplitude of the inverter circuit;

    The control module is configured to obtain a q-axis given voltage and a d-axis of the compressor motor according to the q-axis given current, the d-axis given current, the q-axis actual current, and the d-axis actual current And generating a control signal according to the q-axis given voltage, the d-axis given voltage, the rotor angle estimation value, and controlling the compressor motor through the inverter circuit according to the control signal .
17. A capacitor miniaturized motor drive system characterized by comprising an overvoltage prevention control device for a capacitor miniaturized motor drive system according to claim 9.
18. A capacitor miniaturized motor drive system characterized by comprising an overvoltage prevention control device for a capacitor miniaturized motor drive system according to claim 10.

Images