Compressor, control method of compressor, controller and control method of controller

Abstract

The invention discloses a compressor, a control method of the compressor, a controller and a control method of the controller. The control method of the compressor controller comprises the steps that a quadrature-axis current reference value is obtained based on an angular velocity feedback loop according to a target angular velocity and an estimated angular velocity; obtaining the fluctuation amplitude of the quadrature-axis current reference value according to the quadrature-axis current reference value and the estimated angular velocity; a compensation current amplitude is obtained according to the fluctuation amplitude of the quadrature-axis current reference value and the target fluctuation amplitude; generating a quadrature-axis current compensation value according to the compensation current amplitude, the compensation phase angle, the estimated angular velocity and a frequency factor related to the compressor rotor type; generating a quadrature-axis current error signal according to the quadrature-axis current compensation value, the quadrature-axis current reference value and the quadrature-axis current; and generating a PWM control signal according to the quadrature-axis current error signal, the direct-axis current reference value and the direct-axis current. By capturing the fluctuation amplitude of the quadrature-axis current reference value, the following performance of the given electromagnetic torque to the load torque is improved, and then vibration and noise of the compressor are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular, to a compressor and a control method thereof, a controller and a control method thereof. Background Art

[0003] A compressor is a driven fluid mechanical device that boosts low-pressure gas to high-pressure gas. As the heart of the refrigeration system, it is commonly used in household appliances such as air conditioners, refrigerators, and dehumidifiers. The compressor inhales low-temperature, low-pressure refrigerant gas from the suction pipe, compresses it by driving the piston through the motor, and then discharges high-temperature, high-pressure refrigerant gas to the exhaust pipe, providing power for the refrigeration cycle, thereby realizing the refrigeration cycle of compression → condensation (heat release) → expansion → evaporation (heat absorption).

[0004] The torque fluctuation problem of the compressor in the low-frequency stage has always been a difficult point in the control process. The low-frequency operation stage of the compressor refers to the operating state when the angular velocity of the compressor is at a low value. In this state, the load torque fluctuation of the compressor is large. However, the noise, vibration, energy consumption and comfort experience of household appliances such as air conditioners, refrigerators, dehumidifiers, etc. during use are closely related to the torque fluctuation of the compressor in the low-frequency stage.

[0005] Therefore, in order to achieve the control goals of high performance, low noise and low energy consumption of the compressor, it is necessary to provide a reliable and efficient solution to the torque fluctuation problem of the compressor in the low-frequency stage. Summary of the invention

[0006] In view of the above problems, the purpose of the present application is to provide a compressor and a control method thereof, a controller and a control method thereof, so as to achieve the control goal of reducing vibration and noise by compensating for the torque fluctuation of the compressor.

[0007] According to a first aspect of the present application, a control method for a compressor controller is provided. When the compressor is in a low-frequency operation stage, the control method comprises:

[0008] Obtaining a quadrature-axis current reference value according to a target angular velocity and an estimated angular velocity based on an angular velocity feedback loop;

[0009] Obtaining a fluctuation amplitude of a quadrature-axis current reference value according to the quadrature-axis current reference value and the estimated angular velocity;

[0010] Obtaining a compensation current amplitude according to the fluctuation amplitude of the quadrature-axis current reference value and a target fluctuation amplitude;

[0011] generating a quadrature-axis current compensation value according to the compensation current magnitude, the compensation phase angle, the estimated angular velocity, and a frequency factor related to the compressor rotor type;

[0012] generating a quadrature-axis current error signal according to the quadrature-axis current compensation value, the quadrature-axis current reference value and the quadrature-axis current;

[0013] A PWM control signal is generated according to the quadrature-axis current error signal, the direct-axis current reference value and the direct-axis current.

[0014] Optionally, a formula for generating a quadrature-axis current compensation value according to the compensation current amplitude, the compensation phase angle, the estimated angular velocity, and a frequency factor related to the rotor type of the compressor is: ,in, is the quadrature-axis current compensation value, is the compensation current amplitude, is the frequency factor associated with the rotor type of the compressor, is the estimated angular velocity, is the compensation phase angle.

[0015] Optionally, the compensation current amplitude varies with the bandwidth frequency of the angular velocity feedback loop.

[0016] Optionally, the compensation current amplitude is positively correlated with the bandwidth frequency of the angular velocity feedback loop.

[0017] Optionally, it also includes:

[0018] When the bandwidth frequency of the angular velocity feedback loop is constant, different compensation phase angles are obtained based on the initial value of the phase angle and the angle step value, and the compensation phase angle corresponding to the minimum fluctuation amplitude of the angular velocity feedback loop output quadrature-axis current reference value obtained after compensating for the load torque fluctuation at different compensation phase angles is taken as the optimal compensation phase angle.

[0019] Optionally, obtaining a quadrature-axis current reference value according to the target angular velocity and the estimated angular velocity based on the angular velocity feedback loop comprises:

[0020] Subtracting the target angular velocity from the estimated angular velocity to obtain an angular velocity error;

[0021] The angular velocity error is subjected to proportional-integral processing to obtain the quadrature-axis current reference value, wherein the proportional coefficient and the integral coefficient of the proportional-integral processing determine the bandwidth frequency of the angular velocity feedback loop.

[0022] Optionally, obtaining the fluctuation amplitude of the quadrature-axis current reference value according to the quadrature-axis current reference value and the estimated angular velocity includes:

[0023] Performing inverse Fourier transform on the quadrature-axis current reference value and the estimated angular velocity to obtain a real part and an imaginary part;

[0024] An arithmetic square root of the sum of the squares of the real part and the imaginary part is calculated to obtain a fluctuation amplitude of the quadrature-axis current reference value.

[0025] Optionally, obtaining the compensation current amplitude according to the fluctuation amplitude of the quadrature-axis current reference value and the target fluctuation amplitude includes:

[0026] Subtract the target fluctuation amplitude from the fluctuation amplitude of the quadrature-axis current reference value to obtain a difference, and use the difference as an intermediate amplitude;

[0027] The intermediate amplitude is processed by proportional integration to obtain the compensation current amplitude.

[0028] Optionally, generating a quadrature-axis current error signal according to the quadrature-axis current compensation value, the quadrature-axis current reference value and the quadrature-axis current comprises:

[0029] The quadrature-axis current compensation value is superimposed on the quadrature-axis current reference value to compensate the quadrature-axis current reference value, and the quadrature-axis current error signal is generated by subtracting the compensated quadrature-axis current reference value from the quadrature-axis current.

[0030] Optionally, generating a PWM control signal according to the quadrature-axis current error signal, the direct-axis current reference value and the direct-axis current comprises:

[0031] A direct-axis current error signal is generated by subtracting the direct-axis current reference value from the direct-axis current, and the PWM control signal is generated according to the quadrature-axis current error signal and the direct-axis current error signal, wherein the PWM control signal controls the rotation of the compressor.

[0032] According to a second aspect of the present application, a compressor controller is provided, wherein the controller operates when the compressor is in a low-frequency operation stage, and is characterized in that the controller comprises:

[0033] an angular velocity feedback loop, obtaining an estimated angular velocity based on the observation, and obtaining a quadrature-axis current reference value according to the estimated angular velocity and a target angular velocity;

[0034] a torque compensation circuit, obtaining a fluctuation amplitude of the quadrature-axis current reference value according to the quadrature-axis current reference value and the estimated angular velocity, obtaining a compensation current amplitude according to the fluctuation amplitude of the quadrature-axis current reference value and a target fluctuation amplitude, and generating a quadrature-axis current compensation value according to the compensation current amplitude, a compensation phase angle, the estimated angular velocity, and a frequency factor related to the compressor rotor type; and

[0035] A current feedback loop obtains a direct-axis current and a quadrature-axis current according to the received three-phase current, generates a quadrature-axis current error signal according to the quadrature-axis current compensation value, the quadrature-axis current reference value and the quadrature-axis current, and generates a PWM control signal according to the quadrature-axis current error signal, the direct-axis current reference value and the direct-axis current, wherein the PWM control signal controls the rotation of the compressor.

[0036] Optionally, the torque compensation circuit comprises:

[0037] a first calculation unit, for obtaining a fluctuation amplitude of the quadrature-axis current reference value according to the quadrature-axis current reference value and the estimated angular velocity;

[0038] a first processing unit, connected to the first calculation unit, for obtaining a compensation current amplitude according to the fluctuation amplitude of the quadrature-axis current reference value and a target fluctuation amplitude;

[0039] a second calculation unit, connected to the first processing unit, generating a quadrature axis current compensation value according to the compensation current amplitude, the compensation phase angle, the estimated angular velocity, and a frequency factor related to the compressor rotor type;

[0040] Among them, the formula of the second calculation unit is: , is the quadrature-axis current compensation value, is the compensation current amplitude, is the frequency factor associated with the compressor rotor type, is the estimated angular velocity, is the compensation phase angle.

[0041] Optionally, the compensation current amplitude varies with the bandwidth frequency of the angular velocity feedback loop.

[0042] Optionally, the compensation current amplitude is positively correlated with the bandwidth frequency of the angular velocity feedback loop.

[0043] Optionally, when the bandwidth frequency of the angular velocity feedback loop is constant, the controller obtains different compensation phase angles based on the initial phase angle value and the angle step value, and uses the compensation phase angle corresponding to the minimum fluctuation amplitude of the angular velocity feedback loop output cross-axis current reference value obtained after compensating for the load torque fluctuation at different compensation phase angles as the optimal compensation phase angle.

[0044] Optionally, the first computing unit includes:

[0045] a first calculator, performing inverse Fourier transform on the quadrature-axis current reference value and the estimated angular velocity to obtain a real part and an imaginary part;

[0046] The second calculator calculates an arithmetic square root of the sum of the squares of the real part and the imaginary part to obtain a fluctuation amplitude of the quadrature-axis current reference value.

[0047] Optionally, the first processing unit includes:

[0048] a third calculator, which obtains a difference by subtracting the target fluctuation amplitude from the fluctuation amplitude of the quadrature-axis current reference value, and uses the difference as an intermediate amplitude;

[0049] The first regulator performs proportional integration processing on the intermediate amplitude to obtain the compensation current amplitude.

[0050] Optionally, the angular velocity feedback loop comprises:

[0051] An observation unit, used to obtain the rotor position of the motor;

[0052] A differential unit, for obtaining the estimated angular velocity of the motor according to the rotor position of the motor;

[0053] a sixth calculator, which obtains an angular velocity error by subtracting the target angular velocity from the estimated angular velocity; and

[0054] The second regulator performs proportional-integral processing on the angular velocity error to obtain the quadrature-axis current reference value, wherein the proportional coefficient and the integral coefficient of the proportional-integral processing determine the bandwidth frequency of the angular velocity feedback loop.

[0055] Optionally, the current feedback loop includes:

[0056] The third processing unit acquires the three-phase current of the motor and performs coordinate transformation to obtain the direct-axis current and the quadrature-axis current;

[0057] a seventh calculator, which superimposes the quadrature-axis current compensation value and the quadrature-axis current reference value to compensate the quadrature-axis current reference value, and generates the quadrature-axis current error signal by subtracting the compensated quadrature-axis current reference value from the quadrature-axis current;

[0058] A third regulator performs proportional integration processing on the quadrature-axis current error signal to obtain a quadrature-axis voltage reference value;

[0059] an eighth calculator, generating a direct-axis current error signal by subtracting the direct-axis current reference value from the direct-axis current;

[0060] A fourth regulator performs proportional integration processing on the direct-axis current error signal to obtain a direct-axis voltage reference value;

[0061] A second processing unit performs coordinate transformation on the direct-axis voltage reference value and the quadrature-axis voltage reference value to obtain a two-phase control voltage under a stationary coordinate; and

[0062] The fourth processing unit generates the PWM control signal according to the two-phase control voltage under the stationary coordinate.

[0063] According to a third aspect of the present application, a method for controlling a compressor is provided, comprising:

[0064] The compressor is controlled according to the control method of the controller, thereby adjusting the torque of the compressor.

[0065] According to a fourth aspect of the present application, a compressor is provided, comprising the controller as described above.

[0066] The compressor and control method thereof, controller and control method thereof provided by the present application can realize compensation for the torque fluctuation of the compressor by capturing the fluctuation amplitude of the quadrature axis current reference value output by the angular velocity feedback loop and cooperating with the load torque phase angle, thereby improving the followability of the given electromagnetic torque to the load torque, thereby reducing the angular velocity fluctuation, making the motor operation more stable, more efficient, and reducing the vibration and noise of the compressor.

[0067] Furthermore, the present application selects appropriate proportional coefficients and integral coefficients of the regulator in the angular velocity feedback loop so that the torque compensation value (cross-axis current compensation value) meets the actual vibration suppression requirements, thereby improving the followability of the electromagnetic torque of the compressor control system to the load torque.

[0068] Furthermore, the compensation phase angle of the present application is obtained by the fluctuation amplitude of the quadrature axis current reference value output by the minimum angular velocity feedback loop. The fluctuation amplitude output by the angular velocity feedback loop is obtained by a regulator in the angular velocity feedback loop, and the regulator has a low-pass filtering function, which can filter high-frequency interference signals in the angular velocity, and avoid the problem that the angular velocity high-frequency noise directly affects the velocity ripple integral and causes the compensation phase step error. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The above and other objects, features and advantages of the present application will become more apparent through the following description of the embodiments of the present application with reference to the accompanying drawings, in which:

[0070] Figure 1 A schematic diagram of the structure of a compressor control system according to an embodiment of the present application is shown;

[0071] Figure 2 A schematic flow chart of a control method of a compressor controller according to an embodiment of the present application is shown;

[0072] Figure 3 A schematic diagram of a load torque curve according to an embodiment of the present application is shown;

[0073] Figure 4A schematic diagram showing a quadrature-axis current compensation value at different bandwidth frequencies of an angular velocity feedback loop according to an embodiment of the present application is shown;

[0074] Figure 5a A schematic diagram of waveforms of an estimated angular velocity and a target angular velocity is shown;

[0075] Figure 5b A schematic diagram of waveforms of an estimated angular velocity and a target angular velocity according to an embodiment of the present application is shown;

[0076] Figure 6a A waveform diagram of load torque and electromagnetic torque is shown;

[0077] Figure 6b A waveform diagram of load torque and electromagnetic torque according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0078] Various embodiments of the present application will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0079] In this application, the motor in the compressor is described as a permanent magnet synchronous motor, which has the characteristics of high efficiency and high power density and is mainly controlled by vector control technology.

[0080] During the actual operation of the compressor, the load torque applied to the compressor rotor will show mechanical periodic changes due to the influence of the load. The vector control technology of the compressor controls the current by converting it to the rotating coordinate system. Especially in the steady state, the quadrature axis current reference value and the direct axis current reference value are both direct current quantities. The load fluctuation of the compressor will inevitably cause the electromagnetic torque output by the compressor to not match the load torque, that is, the output current of the inverter circuit does not match the current required by the load, thus causing large angular velocity fluctuations.

[0081] On the one hand, when the angular velocity fluctuation of the compressor is large, the bandwidth frequency of the angular velocity feedback loop is low, and the response speed to the angular velocity change is slow, which will cause the quadrature axis current reference value output by the angular velocity feedback loop to fail to reflect the actual angular velocity fluctuation of the compressor. On the other hand, due to the structural limitations of the compressor, it is generally impossible to install a position sensor, so the position and angular velocity of the rotor are obtained using a position-free algorithm. In this case, the angular velocity fluctuation will affect the accuracy of the position and angular velocity estimation, that is, the quadrature axis current reference value output by the angular velocity feedback loop is easily affected by the angular velocity observation error.

[0082] In order to improve the tracking performance of the current feedback loop, the bandwidth frequency of the current feedback loop is increased, which will generate additional torque fluctuations due to the angular velocity observation error. The angular velocity fluctuation will greatly affect the vibration of the compressor system, and in severe cases, it may even cause the connection between the compressor and the system to break.

[0083] The specific implementation of the present application is further described in detail below in conjunction with the drawings and examples.

[0084] Figure 1 A schematic structural diagram of a compressor control system according to an embodiment of the present application is shown. Figure 2 A flow chart of a control method of a compressor controller according to an embodiment of the present application is shown. Figure 3 A schematic diagram of a load torque curve according to an embodiment of the present application is shown. Figure 4 A schematic diagram showing quadrature-axis current compensation values ​​at different bandwidth frequencies of an angular velocity feedback loop according to an embodiment of the present application is shown. Figure 5a A schematic diagram of waveforms of an estimated angular velocity and a target angular velocity is shown. Figure 5b A schematic diagram of waveforms of the estimated angular velocity and the target angular velocity according to an embodiment of the present application is shown. Figure 6a A waveform diagram of load torque and electromagnetic torque is shown. Figure 6b A waveform diagram of load torque and electromagnetic torque according to an embodiment of the present application is shown.

[0085] like Figure 1 As shown, the control system of the compressor includes a controller 100 , an inverter circuit 200 , and a motor 300 .

[0086] The controller 100 provides a PWM control signal SVPWM (Space Vector Pulse Width Modulation) to the inverter circuit 200 to control the inverter circuit 200 to provide a three-phase chopping voltage to the motor 300 for controlling the rotation of the motor 300 .

[0087] The controller 100 of the present application is mainly a dual closed-loop control system, including an angular velocity feedback loop 120 and a current feedback loop 130. The angular velocity feedback loop 120 obtains an estimated angular velocity based on the observation. , and based on the estimated angular velocity and target angular velocity Output quadrature axis current reference value The current feedback loop 130 is based on the quadrature-axis current reference value. and quadrature axis current Generate quadrature-axis voltage reference , according to the direct axis current reference value and direct axis current Generate direct-axis voltage reference , and the direct-axis voltage reference value and quadrature axis voltage reference Perform coordinate transformation (Park inverse transformation) to obtain the two-phase control voltage under the two-phase stationary coordinates and , and according to the two-phase control voltage and Generates a PWM control signal SVPWM to control the inverter circuit 200 to generate a three-phase voltage U a and U b and U c Provided to the motor 300, thereby achieving angular speed and torque control of the compressor.

[0088] The controller 100 further includes a torque compensation circuit 110, which captures the quadrature axis current reference value output by the angular velocity feedback loop 120. The fluctuation amplitude of the compressor torque is adjusted according to the load torque phase angle to achieve the control goal of reducing vibration and noise.

[0089] Furthermore, the load of the compressor presents obvious mechanical characteristics. The main load fluctuation frequency of the single-rotor compressor is single mechanical frequency, and the main load fluctuation frequency of the dual-rotor compressor is double mechanical frequency. Since the mechanical load of the compressor changes relatively slowly, its load fluctuation fitting curve satisfies the Dirichlet convergence theorem. The theoretical torque versus phase angle curve is Fourier expanded to obtain the fundamental wave of the load torque curve, and it is controlled to follow the load fluctuation. Therefore, the first-order Fourier series expansion of the compressor load torque curve can be performed in the time domain, and then the first-order expansion can be decomposed to obtain the fundamental wave of the load torque curve.

[0090] like Figure 3 As shown, the load torque is related to the rotor angle, and the rotor angle is related to the angular velocity.

[0091] Optionally, the fundamental wave of the load torque curve of the compressor is taken as the main object of load fluctuation suppression. After the compressor is finalized, the fundamental wave phase angle of its load torque curve is basically fixed to the initial phase. , its expression can be described as follows:

[0092]

[0093] Among them, TL is the fundamental wave of the load torque curve, is the frequency factor related to the compressor rotor type, is the mechanical angular velocity of the compressor, is the initial phase of the fundamental wave of the load torque curve.

[0094] Since the electromagnetic torque cannot completely follow the load torque, the quadrature-axis current reference value output by the angular velocity feedback loop cannot reflect the actual angular velocity fluctuation of the compressor. It is necessary to compensate the quadrature-axis current reference value to obtain an accurate quadrature-axis current reference value. Since the quadrature-axis current compensation value is linearly related to the fundamental wave of the electromagnetic torque, in an ideal case, the load torque completely follows the electromagnetic torque. That is, in order to obtain the effect that the electromagnetic torque completely follows the load torque, the expression of the quadrature-axis current compensation value can be described as:

[0095]

[0096] in, is the quadrature axis current compensation value, kt is the torque coefficient of the compressor, A is the amplitude of the load torque fundamental wave, and A / kt is recorded as , is the compensation current amplitude, is the mechanical angular velocity of the compressor, is the initial phase of the fundamental wave of the load torque curve, and and The compressor torque fluctuation can be compensated.

[0097] The above theoretical analysis shows that and The quadrature axis current compensation value can be obtained , and then The current is provided to the current feedback loop 130 to compensate the quadrature-axis current Iq to achieve torque compensation.

[0098] In the actual calculation of the prior art, since the current has a linear relationship with the electromagnetic torque (rotation torque formed on the rotor) output by the compressor, and the bandwidth frequency of the angular velocity feedback loop 120 is usually in the range of 1-20 Hz, the current reference value Unable to reflect the true angular velocity of the compressor Fluctuations, therefore, an additional torque compensation circuit 110 is required to suppress the electromagnetic torque fluctuations of the compressor. Specifically, the fluctuation of the real electromagnetic torque can be as high as 50HZ. Since the current is proportional to the electromagnetic torque, the frequency of the current change needs to match the fluctuation of the angular velocity to achieve the electromagnetic torque following the load torque. In actual situations, the bandwidth of the angular velocity feedback loop is low, which makes the current reference value output by the angular velocity feedback loop It cannot accurately reflect the actual angular velocity fluctuation (electromagnetic torque fluctuation).

[0099] like Figure 2 As shown, the control method for the compressor controller includes the following steps:

[0100] Step S510: Based on the angular velocity feedback loop, the target angular velocity and estimated angular velocity Get the quadrature axis current reference value Further, this step includes setting the target angular velocity With the estimated angular velocity The angular velocity error is obtained by differential calculation, and the angular velocity error is proportionally integrated to obtain the quadrature axis current reference value. Among them, the proportional coefficient and integral coefficient of the proportional-integral process determine the bandwidth frequency of the angular velocity feedback loop.

[0101] Step S520: According to the quadrature axis current reference value and estimated angular velocity The fluctuation amplitude of the quadrature axis current reference value is obtained. Further, this step includes performing an inverse Fourier transform on the quadrature axis current reference value and the estimated angular velocity to obtain a real part Real and an imaginary part Img, and calculating the arithmetic square root of the sum of the squares of the real part Real and the imaginary part Img to obtain the quadrature axis current reference value. Ampripple.

[0102] Step S530: Obtain the compensation current amplitude Acomp according to the fluctuation amplitude Ampripple of the cross-axis current reference value and the target fluctuation amplitude. Further, this step includes obtaining a difference by subtracting the target fluctuation amplitude from the fluctuation amplitude Ampripple of the cross-axis current reference value, using the difference as the intermediate amplitude, and performing proportional integration processing on the intermediate amplitude to obtain the compensation current amplitude Acomp. Among them, when the angular velocity fluctuation of the compressor is 0 in an ideal state, the output of the angular velocity feedback loop 120 should also be 0, so the output fluctuation amplitude of the angular velocity feedback loop 120 of 0 can be used as the target fluctuation amplitude. The torque compensation circuit 110 of this embodiment adopts a negative feedback structure design, which cooperates with the cross-axis current reference value output by the angular velocity feedback loop 120, so as to improve the followability of the electromagnetic torque to the load torque.

[0103] Step S540: According to the compensation current amplitude Acomp and the compensation phase angle , estimated angular velocity , frequency factor related to the compressor rotor type Generate quadrature-axis current compensation value To compensate for the load torque fluctuation of the compressor. Further, the formula is: ,in, is the quadrature axis current compensation value, is the compensation current amplitude, is the frequency factor related to the compressor rotor type, To estimate the angular velocity, The embodiments of the present application include but are not limited to torque compensation control of single-rotor and dual-rotor compressors. Take 1, double rotor Take 2.

[0104] Step S550: Based on the quadrature axis current compensation value , quadrature axis current reference value and quadrature axis current Generate a quadrature axis current error signal. Further, the quadrature axis current compensation value With the quadrature axis current reference value The quadrature-axis current reference value is superimposed to compensate the quadrature-axis current reference value, and the compensated quadrature-axis current reference value is added to the quadrature-axis current The difference is then used to generate a quadrature-axis current error signal.

[0105] Step S560: According to the quadrature-axis current error signal and the direct-axis current reference value and the direct axis current Id to generate a PWM control signal. Further, this step includes: converting the direct axis current reference value A direct-axis current error signal is generated by subtracting the direct-axis current Id, and a PWM control signal SVPWM is generated according to the quadrature-axis current error signal and the direct-axis current error signal. The PWM control signal SVPWM controls the rotation of the compressor.

[0106] If the quadrature axis current compensation value is obtained The quadrature axis current compensation value varies with the bandwidth frequency of the angular velocity feedback loop. Positively correlated with the bandwidth frequency of the angular velocity feedback loop. Figure 4 As shown, the bandwidth frequency of the angular velocity feedback loop within 0-1s is greater than the bandwidth frequency of the angular velocity feedback loop within 1-2s, and the amplitude of the corresponding quadrature axis current compensation value, that is, the compensation current amplitude, also decreases with the decrease of the bandwidth frequency. That is, when the bandwidth frequency of the angular velocity feedback loop 120 decreases, the compensation current amplitude and the phase current amplitude will decrease rapidly to adapt to the actual vibration suppression requirements, that is, the technical solution of the present application can change the compensation current amplitude by selecting the proportional coefficient and integral coefficient (bandwidth of the angular velocity feedback loop) of the proportional integral processor in the appropriate angular velocity feedback loop, thereby adjusting the compensation effect of the torque compensation circuit to adapt to different vibration suppression requirements.

[0107] In other embodiments, the torque compensation method further includes, when the bandwidth frequency of the angular velocity feedback loop is constant, based on the initial value and angle step value to obtain different compensation phase angles , and different compensation phase angles The compensation phase angle corresponding to the fluctuation amplitude of the minimum angular velocity feedback loop output quadrature axis current reference value obtained after the load torque fluctuation compensation is performed is used as the optimal compensation phase angle. =0 is the initial value, which is the test value during actual debugging. , when the angular velocity fluctuation is the smallest under the same working conditions, record is the optimal compensation phase angle .

[0108] like Figure 1 As shown, the torque compensation circuit 110 includes a first calculation unit 111 , a first processing unit 112 , and a second calculation unit 113 .

[0109] The first calculation unit 111 obtains the target angular velocity from the angular velocity feedback loop 120 and estimated angular velocity The generated quadrature-axis current reference , and according to the quadrature axis current reference value and estimated angular velocity Obtain the fluctuation amplitude of the quadrature-axis current reference value Exemplarily, the first calculation unit includes a first calculator 114 and a second calculator 115. The first calculator 114 calculates the quadrature-axis current reference value and estimated angular velocity Perform inverse Fourier transform to obtain the real part Real and the imaginary part Img. The second calculator 115 calculates the arithmetic square root of the sum of the squares of the real part Real and the imaginary part Img ( ) to obtain the fluctuation amplitude of the quadrature-axis current reference value .

[0110] The first processing unit 112 is connected to the first calculating unit 111, and calculates the fluctuation amplitude of the quadrature-axis current reference value according to the fluctuation amplitude of the quadrature-axis current reference value. And the target fluctuation amplitude 0 to obtain the compensation current amplitude For example, the first processing unit 112 includes a third calculator A1 and a first regulator 116. The third calculator A1 converts the target fluctuation amplitude 0 and the fluctuation amplitude of the quadrature-axis current reference value into The first regulator 116 performs proportional integration on the intermediate amplitude to obtain the compensation current amplitude. .in, and are the proportional coefficient and the integral coefficient of the first regulator 116 respectively.

[0111] The second calculation unit 113 is connected to the first processing unit 112, and calculates the compensation current amplitude according to the compensation current amplitude. , Compensation phase angle , estimated angular velocity , frequency factor related to compressor rotor type Generate quadrature-axis current compensation value To compensate for the load torque fluctuation of the compressor. The formula of the second calculation unit 113 is: ,in, is the quadrature axis current compensation value, is the compensation current amplitude, is the frequency factor related to the compressor rotor type, To estimate the angular velocity, To compensate the phase angle. Exemplarily, the second calculation unit 113 includes a fourth calculator A2 and a fifth calculator 117. The fifth calculator 117 is based on is the frequency factor related to the compressor rotor type, is the estimated angular velocity, The compensation phase angle is obtained The fourth calculator A2 is, for example, a multiplier to calculate the compensation current amplitude based on and Get the quadrature axis current compensation value .

[0112] It should be noted that the compensation current amplitude Acomp changes with the bandwidth frequency of the angular velocity feedback loop 120. Further, the compensation current amplitude Acomp is positively correlated with the bandwidth frequency of the angular velocity feedback loop 120. In this embodiment, the proportional coefficient and integral coefficient of the regulator in the angular velocity feedback loop 120 determine the bandwidth frequency of the angular velocity feedback loop. The technical solution of the present application needs to select the appropriate proportional coefficient and integral coefficient of the regulator in the angular velocity feedback loop according to the actual vibration suppression requirements.

[0113] Furthermore, the initial value of the compensation phase angle is 0. In practice, it is necessary to fine-tune according to the angular velocity fluctuation to determine the optimal compensation phase angle. . For example, based on the initial value and angle step value to obtain different compensation phase angles Under the same working conditions, the compensation phase angle corresponding to the minimum angular velocity fluctuation (the minimum fluctuation amplitude of the quadrature-axis current reference value output by the angular velocity feedback loop after the compensation phase angle is used to compensate for the load torque fluctuation) is taken as the optimal compensation phase angle. .

[0114] Before compensation: J*dw / dt = Te'–TL.

[0115] After compensation: J*dw / dt = Te'' - TL.

[0116] Wherein, J is the moment of inertia of the compressor, Te' is the electromagnetic torque when the torque compensation method of the present application is not adopted, Te'' is the electromagnetic torque after the torque compensation of the present application, and TL is the load torque. Without compensation, the electromagnetic torque Te' cannot follow the load torque TL well, and the angular velocity fluctuation of the compressor is large. After compensation, the electromagnetic torque Te'' can follow the load torque TL well, and the angular velocity fluctuation of the compressor is significantly reduced.

[0117] That is, the present application compensates the current feedback loop 130 by adding a torque compensation circuit 110, so that the followability of a given electromagnetic torque to the load torque is improved, thereby reducing angular velocity fluctuations, making the motor run more stable and more efficient, and reducing vibration and noise of the compressor.

[0118] Figure 5a is the estimated angular velocity of the control system of the compressor without the torque compensation circuit 110 in the prior art Angular velocity with target The waveform has an offset of 28.862. Figure 5b The estimated angular velocity of the control system of the compressor provided with the torque compensation circuit 110 in the present application Angular velocity with target The waveform has an offset of about 17.539. From the waveform comparison, it can be seen that the embodiment of the present application reduces the offset of the estimated angular velocity with load fluctuation.

[0119] Figure 6a 1 and 2 are waveforms of the electromagnetic torque Te' and the load torque TL of a control system of a compressor in the prior art in which the torque compensation circuit 110 is not provided. Figure 6b The waveforms of the electromagnetic torque Te″ and the load torque TL of the control system of the compressor in which the torque compensation circuit 110 is provided for the present application.

[0120] Combination Figure 5a , Figure 5b , Figure 6a , Figure 6b The electromagnetic torque Te'' after compensation in the embodiment of the present application can better follow the load torque TL, and correspondingly the angular velocity fluctuation of the compressor is significantly reduced.

[0121] This application can achieve compensation for compressor torque fluctuations by capturing the fluctuation amplitude of the quadrature axis circuit reference value output by the angular velocity feedback loop and coordinating it with the load torque phase angle, so as to achieve the control goal of reducing vibration and noise. Especially when the compressor works under low frequency and high power conditions, the technical solution of this application can effectively reduce the risk of compressor overload loss of step.

[0122] Reference Figure 1The angular velocity feedback loop 120 includes a sixth calculator A3, a second regulator 121, a differential unit 122, and an observation unit 123. The observation unit 123 is used to obtain the rotor position of the motor 300. The differential unit 122 is used to determine the rotor position of the motor 300. Get the estimated angular velocity of the motor The sixth calculator A3 converts the target angular velocity With the estimated angular velocity The second regulator 121 is used to perform proportional integration processing on the angular velocity error to obtain a quadrature axis current reference value. .in, .in, and are respectively the proportional coefficient and the integral coefficient of the second regulator 121. The transfer function of the second regulator 121 in the angular velocity feedback loop 120 is The expression is: The bandwidth frequency BW of the angular velocity feedback loop 120 is expressed as: Therefore, the proportional coefficient and integral coefficient of the regulator in the angular velocity feedback loop 120 determine the bandwidth frequency of the angular velocity feedback loop. The technical solution of the present application needs to select appropriate proportional coefficients and integral coefficients of the regulator in the angular velocity feedback loop according to actual vibration suppression requirements.

[0123] The current feedback loop 130 includes a second processing unit 134, a third processing unit 133, a fourth processing unit 135, a seventh calculator A4, an eighth calculator A5, a third regulator 131, and a fourth regulator 132. The third processing unit 133 is a coordinate transformation unit (Clark transformation and Park transformation) for obtaining the three-phase current of the motor 300. and and And perform coordinate transformation to obtain the direct axis current The seventh calculator A4 converts the quadrature axis current compensation value With the quadrature axis current reference value The quadrature-axis current reference value is superimposed to compensate the quadrature-axis current reference value, and the compensated quadrature-axis current reference value is added to the quadrature-axis current The third regulator 131 is used to perform proportional integration processing on the quadrature axis current error signal to obtain a quadrature axis voltage reference value. The eighth calculator A5 converts the direct-axis current reference value With direct axis current The fourth regulator 132 is used to perform proportional integration processing on the direct axis current error signal to obtain a direct axis voltage reference value Among them, the direct axis current reference value is the preset value, usually 0.5A. But when id=0, When the vector control mode is the maximum torque current ratio control (Maximum Torque Per Ampere, MTPA) mode or the weak magnetic control mode, The second processing unit 134 is a coordinate transformation unit (Park inverse transformation) for transforming the direct axis voltage reference value and quadrature axis voltage reference Perform coordinate transformation to obtain the two-phase control voltage under stationary coordinates and The fourth processing unit 135 is a space vector pulse width modulation unit for controlling the voltage according to the two-phase and Generates a control signal SVPWM to control the inverter circuit 200 to generate a three-phase voltage U a and U b and U c Provided to the motor 300, thereby achieving angular speed and torque control of the compressor.

[0124] The present application also provides a compressor, comprising at least the controller of the compressor as described above.

[0125] The present application also provides a method for controlling a compressor, comprising controlling the compressor according to the control method of the controller mentioned above, thereby adjusting the torque of the compressor.

[0126] The compressor and control method thereof, controller and control method thereof provided by the present application can realize compensation for the torque fluctuation of the compressor by capturing the fluctuation amplitude of the quadrature axis circuit reference value output by the angular velocity feedback loop and cooperating with the load torque phase angle, thereby improving the followability of the given electromagnetic torque to the load torque, thereby reducing the angular velocity fluctuation, making the motor operation more stable, more efficient, and reducing the vibration and noise of the compressor.

[0127] Furthermore, the present application selects appropriate proportional coefficients and integral coefficients of the regulator in the angular velocity feedback loop so that the torque compensation value (cross-axis current compensation value) meets the actual vibration suppression requirements, thereby improving the followability of the electromagnetic torque of the compressor control system to the load torque.

[0128] Furthermore, the controller and control method of the compressor provided by the present application, wherein the compensation phase angle is obtained by the fluctuation amplitude of the quadrature axis current reference value output by the minimum angular velocity feedback loop. The fluctuation amplitude output by the angular velocity feedback loop is obtained by the PI regulator in the angular velocity feedback loop, and the PI regulator has a low-pass filtering function, which can filter the high-frequency interference signal in the angular velocity, and avoid the problem that the high-frequency noise of the angular velocity directly affects the velocity ripple integral and causes the compensation phase step error.

[0129] The embodiments of the present application are described above, and these embodiments do not describe all the details in detail, nor do they limit the application to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can make good use of the present application and the modifications based on the present application. The present application is only limited by the claims and their full scope and equivalents.

Claims

1. A control method for a compressor controller, characterized in that: When the compressor is in the low-frequency operation stage, the control method includes: Obtaining a quadrature-axis current reference value according to a target angular velocity and an estimated angular velocity based on an angular velocity feedback loop; Obtaining a fluctuation amplitude of a quadrature-axis current reference value according to the quadrature-axis current reference value and the estimated angular velocity; Obtaining a compensation current amplitude according to the fluctuation amplitude of the quadrature-axis current reference value and a target fluctuation amplitude; generating a quadrature-axis current compensation value according to the compensation current magnitude, the compensation phase angle, the estimated angular velocity, and a frequency factor related to the compressor rotor type; generating a quadrature-axis current error signal according to the quadrature-axis current compensation value, the quadrature-axis current reference value and the quadrature-axis current; A PWM control signal is generated according to the quadrature-axis current error signal, the direct-axis current reference value and the direct-axis current.

2. The control method according to claim 1, characterized in that: The formula for generating the quadrature-axis current compensation value according to the compensation current amplitude, the compensation phase angle, the estimated angular velocity, and the frequency factor related to the rotor type of the compressor is: ,in, is the quadrature-axis current compensation value, is the compensation current amplitude, is the frequency factor associated with the rotor type of the compressor, is the estimated angular velocity, is the compensation phase angle.

3. The control method according to claim 1, characterized in that: The compensation current amplitude varies with the bandwidth frequency of the angular velocity feedback loop.

4. The control method according to claim 3, characterized in that: The compensation current amplitude is positively correlated with the bandwidth frequency of the angular velocity feedback loop.

5. The control method according to claim 1, characterized in that: Also includes: When the bandwidth frequency of the angular velocity feedback loop is constant, different compensation phase angles are obtained based on the initial value of the phase angle and the angle step value, and the compensation phase angle corresponding to the minimum fluctuation amplitude of the angular velocity feedback loop output quadrature-axis current reference value obtained after compensating for the load torque fluctuation at different compensation phase angles is taken as the optimal compensation phase angle.

6. The control method according to claim 1, characterized in that: Obtaining a quadrature-axis current reference value according to the target angular velocity and the estimated angular velocity based on the angular velocity feedback loop includes: Subtracting the target angular velocity from the estimated angular velocity to obtain an angular velocity error; The angular velocity error is subjected to proportional-integral processing to obtain the quadrature-axis current reference value, wherein the proportional coefficient and the integral coefficient of the proportional-integral processing determine the bandwidth frequency of the angular velocity feedback loop.

7. The control method according to claim 1, characterized in that: The fluctuation amplitude of the quadrature-axis current reference value is obtained according to the quadrature-axis current reference value and the estimated angular velocity, including: Performing inverse Fourier transform on the quadrature-axis current reference value and the estimated angular velocity to obtain a real part and an imaginary part; An arithmetic square root of the sum of the squares of the real part and the imaginary part is calculated to obtain a fluctuation amplitude of the quadrature-axis current reference value.

8. The control method according to claim 1, characterized in that: Obtaining the compensation current amplitude according to the fluctuation amplitude of the quadrature-axis current reference value and the target fluctuation amplitude comprises: Subtract the target fluctuation amplitude from the fluctuation amplitude of the quadrature-axis current reference value to obtain a difference, and use the difference as an intermediate amplitude; The intermediate amplitude is processed by proportional integration to obtain the compensation current amplitude.

9. The control method according to claim 1, characterized in that: Generating a quadrature-axis current error signal according to the quadrature-axis current compensation value, the quadrature-axis current reference value and the quadrature-axis current comprises: The quadrature-axis current compensation value is superimposed on the quadrature-axis current reference value to compensate the quadrature-axis current reference value, and the quadrature-axis current error signal is generated by subtracting the compensated quadrature-axis current reference value from the quadrature-axis current.

10. The control method according to claim 9, characterized in that: Generating a PWM control signal according to the quadrature-axis current error signal, the direct-axis current reference value and the direct-axis current comprises: A direct-axis current error signal is generated by subtracting the direct-axis current reference value from the direct-axis current, and the PWM control signal is generated according to the quadrature-axis current error signal and the direct-axis current error signal, wherein the PWM control signal controls the rotation of the compressor.

11. A compressor controller, wherein the controller operates when the compressor is in a low-frequency operation stage, characterized in that: The controller comprises: an angular velocity feedback loop, obtaining an estimated angular velocity based on the observation, and obtaining a quadrature-axis current reference value according to the estimated angular velocity and a target angular velocity; a torque compensation circuit, obtaining a fluctuation amplitude of the quadrature-axis current reference value according to the quadrature-axis current reference value and the estimated angular velocity, obtaining a compensation current amplitude according to the fluctuation amplitude of the quadrature-axis current reference value and a target fluctuation amplitude, and generating a quadrature-axis current compensation value according to the compensation current amplitude, a compensation phase angle, the estimated angular velocity, and a frequency factor related to the compressor rotor type; and A current feedback loop obtains a direct-axis current and a quadrature-axis current according to the received three-phase current, generates a quadrature-axis current error signal according to the quadrature-axis current compensation value, the quadrature-axis current reference value and the quadrature-axis current, and generates a PWM control signal according to the quadrature-axis current error signal, the direct-axis current reference value and the direct-axis current, wherein the PWM control signal controls the rotation of the compressor.

12. The controller according to claim 11, characterized in that: The torque compensation circuit comprises: a first calculation unit, for obtaining a fluctuation amplitude of the quadrature-axis current reference value according to the quadrature-axis current reference value and the estimated angular velocity; a first processing unit, connected to the first calculation unit, for obtaining a compensation current amplitude according to the fluctuation amplitude of the quadrature-axis current reference value and a target fluctuation amplitude; a second calculation unit, connected to the first processing unit, generating a quadrature axis current compensation value according to the compensation current amplitude, the compensation phase angle, the estimated angular velocity, and a frequency factor related to the compressor rotor type; Among them, the formula of the second calculation unit is: , is the quadrature-axis current compensation value, is the compensation current amplitude, is the frequency factor associated with the compressor rotor type, is the estimated angular velocity, is the compensation phase angle.

13. The controller according to claim 11, characterized in that: The compensation current amplitude varies with the bandwidth frequency of the angular velocity feedback loop.

14. The controller according to claim 13, characterized in that: The compensation current amplitude is positively correlated with the bandwidth frequency of the angular velocity feedback loop.

15. The controller according to claim 11, characterized in that: When the bandwidth frequency of the angular velocity feedback loop is constant, the controller obtains different compensation phase angles based on the initial phase angle value and the angle step value, and uses the compensation phase angle corresponding to the minimum fluctuation amplitude of the angular velocity feedback loop output quadrature-axis current reference value obtained after compensating for the load torque fluctuation at different compensation phase angles as the optimal compensation phase angle.

16. The controller according to claim 12, characterized in that: The first computing unit comprises: a first calculator, performing inverse Fourier transform on the quadrature-axis current reference value and the estimated angular velocity to obtain a real part and an imaginary part; The second calculator calculates an arithmetic square root of the sum of the squares of the real part and the imaginary part to obtain a fluctuation amplitude of the quadrature-axis current reference value.

17. The controller according to claim 12, characterized in that: The first processing unit comprises: a third calculator, which obtains a difference by subtracting the target fluctuation amplitude from the fluctuation amplitude of the quadrature-axis current reference value, and uses the difference as an intermediate amplitude; The first regulator performs proportional integration processing on the intermediate amplitude to obtain the compensation current amplitude.

18. The controller according to claim 11, characterized in that: The angular velocity feedback loop includes: An observation unit, used to obtain the rotor position of the motor; A differential unit, for obtaining the estimated angular velocity of the motor according to the rotor position of the motor; a sixth calculator, which obtains an angular velocity error by subtracting the target angular velocity from the estimated angular velocity; and The second regulator performs proportional-integral processing on the angular velocity error to obtain the quadrature-axis current reference value, wherein the proportional coefficient and the integral coefficient of the proportional-integral processing determine the bandwidth frequency of the angular velocity feedback loop.

19. The controller according to claim 11, characterized in that: The current feedback loop includes: The third processing unit acquires the three-phase current of the motor and performs coordinate transformation to obtain the direct-axis current and the quadrature-axis current; a seventh calculator, which superimposes the quadrature-axis current compensation value and the quadrature-axis current reference value to compensate the quadrature-axis current reference value, and generates the quadrature-axis current error signal by subtracting the compensated quadrature-axis current reference value from the quadrature-axis current; A third regulator performs proportional integration processing on the quadrature-axis current error signal to obtain a quadrature-axis voltage reference value; an eighth calculator, generating a direct-axis current error signal by subtracting the direct-axis current reference value from the direct-axis current; A fourth regulator performs proportional integration processing on the direct-axis current error signal to obtain a direct-axis voltage reference value; A second processing unit performs coordinate transformation on the direct-axis voltage reference value and the quadrature-axis voltage reference value to obtain a two-phase control voltage under a stationary coordinate; and The fourth processing unit generates the PWM control signal according to the two-phase control voltage under the stationary coordinate.

20. A method for controlling a compressor, characterized in that: include: The control method according to any one of claims 1 to 10 controls a compressor, thereby adjusting the torque of the compressor.

21. A compressor, characterized in that: include: A controller as claimed in any one of claims 11 to 19.

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