A compressor compensation device, method, and compressor system

Abstract

The compressor compensation device is a device for torque compensation based on multiple parameters, comprising an input module, a calculation module and a limiting module. The input module inputs speed-related values, electric power-related values and electric angular speed-related values. The calculation module calculates compensation coefficients for each input in the input module respectively, multiplies the obtained compensation coefficients to obtain a speed compensation coefficient Kb, and superimposes a compensation base value Kj to obtain a total compensation coefficient Kc. The limiting module limits the total compensation coefficient Kc to obtain a final compensation coefficient Kd.

Description

Technical Field

[0001] This invention relates to the field of refrigerator compressor control technology, and in particular to a compressor compensation device, method, and compressor system. Background Technology

[0002] When a compressor is running, the motor's mechanical torque constantly fluctuates as it drives the cylinders to compress and draw in gas. Traditional speed-loop PI control ignores the influence of load torque (TL) and tunes its parameters to be a linear time-invariant system, making it unable to adapt to dynamic load changes. Furthermore, torque fluctuations cause speed fluctuations, which in turn lead to system instability due to proportional-integral saturation under fixed PI parameters (Kp, Ki), and also introduce problems such as system noise and vibration.

[0003] Patent Document 1 describes a torque compensation method that calculates the compensation amount based on the speed error and superimposes it onto the given q-axis current Iq. Although Patent Document 1 conceives of compensating for speed fluctuations to suppress vibration, this method only compensates in parallel with the stage following the speed loop and does not consider other compressor parameters (such as electrical power, electrical angular velocity, etc.).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Chinese Patent Application No. 201610029247.5 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] The present invention aims to provide a compressor compensation device, method, and compressor system, which effectively solves the problems of unstable startup and system noise generated during operation caused by oscillation and loss of synchronization when the load of the refrigerator compressor increases in the prior art.

[0009] Technical means for solving technical problems

[0010] To address the aforementioned issues, the inventors first conceived of setting a torque compensation gain after the speed PI calculation to suppress torque fluctuations. Specifically, in the speed PI calculation, torque fluctuations are determined by the speed fluctuations during compressor operation. Using a speed reference value as a benchmark, when the speed is greater than the benchmark, the speed is high and the torque is low, so the values ​​of Kp and Ki are correspondingly decreased; conversely, when the speed is less than the benchmark, the speed is slow and the torque is high, so the values ​​of Kp and Ki are correspondingly increased. Furthermore, the fluctuation value for each current calculation cycle varies depending on the speed and power at which it occurs. Therefore, different torque compensation coefficients are set based on different speed and power values.

[0011] One embodiment of the present invention provides a compressor compensation device, which is a device for torque compensation based on multiple parameters, comprising:

[0012] The input module takes as input at least two of the following: a speed setpoint Wn and a speed reference value Wnref as speed-related values; a calculated electric power value Pe and an electric power reference value Peref as electric power-related values; and an estimated electric angular velocity value We and an electric angular velocity reference value Weref as electric angular velocity-related values; and...

[0013] The calculation module includes a compensation coefficient calculation unit, a speed compensation coefficient calculation unit, and a total compensation coefficient calculation unit.

[0014] The compensation coefficient calculation unit calculates the compensation coefficient for each input in the input module to obtain at least two of the following: rotational speed compensation coefficient: Kn=Wn / Wnref; power compensation coefficient: Ka=Pe / Peref; and electrical angular velocity error: Weerr=Weref-We.

[0015] The speed compensation coefficient calculation unit multiplies the compensation coefficient obtained by the compensation coefficient calculation unit to obtain the speed compensation coefficient Kb.

[0016] The total compensation coefficient calculation unit superimposes the compensation base value Kj on the speed compensation coefficient Kb to obtain the total compensation coefficient Kc.

[0017] The compressor compensation device also includes:

[0018] The limiting module limits the total compensation coefficient Kc through a compensation limiter to obtain the final compensation coefficient Kd.

[0019] The compressor compensation device according to the present invention performs quantitative compensation based on multiple parameters (such as speed deviation, power deviation, and electrical angular velocity error), and comprehensively derives the compensation coefficient Kd, which can achieve accurate compensation for torque fluctuations and improve the system control accuracy.

[0020] In the compressor compensation device of the present invention, optionally, the limiting module operates after the calculation module.

[0021] In the compressor compensation device of the present invention, optionally, the input module inputs all of the speed-related values, the electrical power-related values ​​and the electrical angular velocity-related values, and the speed compensation coefficient Kb = Ka × Kn × Weerr.

[0022] Another embodiment of the present invention provides a compressor compensation method, which performs: a speed control step, a torque compensation step, and a current loop output step.

[0023] The speed control step obtains the current loop reference value.

[0024] The torque compensation step multiplies the final compensation coefficient Kd obtained from the compressor compensation device by the current loop reference value to obtain the corrected current loop reference value.

[0025] The current loop output step performs a current loop PI calculation on the current loop error value, which is the difference between the corrected current loop reference value and the current loop measurement value, and outputs the voltage amplitude.

[0026] The compressor compensation method of the present invention can be applied to scenarios requiring high-precision dynamic adjustment (such as motor control, power system optimization, etc.). Through comprehensive compensation, it can achieve precise adjustment of the output voltage, improve the stability and control performance of the system, reduce fluctuations, and thus suppress the noise generated by the compressor.

[0027] In the compressor compensation method of the present invention, optionally, in the speed control step, the speed error value Rerr, which is the difference between the speed setpoint nref and the speed estimate Rest, is subjected to PI operation to generate the current loop Iq reference value Iqmref, and the current loop Id reference value Idref and the current loop Iq reference value Iqref are generated by the field weakening control module.

[0028] In the torque compensation step, the final compensation coefficient Kd is multiplied by the current loop reference value Iqref and the current loop reference value Idref to obtain the corrected current loop reference value Iqref′ and the corrected current loop reference value Idref′.

[0029] In the current loop output step, the measured values ​​Iq and Id of the current loop, which are used as current measurement values, are compared with the corrected reference values ​​Iqref′ and Idref′ of the current loop, respectively, to obtain the error values ​​Iqerr=Iqref′-Iq and Id error values ​​Iderr=Idref′-Id of the current loop. After current loop PI calculation, the output voltage amplitudes Vq and Vd are obtained.

[0030] In the compressor compensation method of the present invention, optionally, in the speed control step, the PI calculation is dynamically adjusted by updating the proportional coefficient Kp and integral coefficient Ki in real time according to the deviation between the actual speed and the reference speed.

[0031] In the compressor compensation method of the present invention, optionally, when the actual rotational speed is higher than the reference rotational speed, the proportional coefficient Kp and the integral coefficient Ki are increased. When the actual rotational speed is lower than the reference rotational speed, the proportional coefficient Kp and the integral coefficient Ki are decreased.

[0032] According to the compressor compensation method of the present invention, by dynamically adjusting the PI parameters, speed fluctuations can be suppressed, control failures caused by integral saturation can be avoided, and system stability can be improved. Simultaneously, noise and vibration can be reduced, extending equipment lifespan. Furthermore, adaptive control under load fluctuations can be achieved by setting different coefficients according to differences in speed and power, enhancing system robustness and adapting to various application scenarios requiring dynamic load compensation, such as variable frequency compressors and motor drives operating under multiple conditions.

[0033] Another embodiment of the present invention provides a compressor system for performing the above-described compressor compensation method, comprising:

[0034] The aforementioned compressor compensation device;

[0035] The speed control loop is configured to obtain reference values ​​from the current loop.

[0036] A torque compensation loop is configured to perform torque compensation on the current loop reference value through the aforementioned compressor compensation device to obtain a corrected current loop reference value.

[0037] A current control loop is configured to perform a current loop PI operation on the current loop error value, which is the difference between the corrected current loop reference value and the current loop measurement value, and output the voltage amplitude.

[0038] The position and angle observation section is configured to obtain at least the electric angular velocity We;

[0039] The coordinate transformation section is configured to perform Clarke transformation, Park transformation, and inverse Park transformation; and

[0040] The pulse width modulation section is configured to generate inverter control signals via SVPWM.

[0041] According to the compressor system of the present invention, in the speed-current dual closed-loop system, the current reference value is dynamically adjusted by combining the torque compensation device, and the inverter is precisely driven by coordinate transformation and SVPWM technology to achieve precise driving of loads such as compressors, thereby improving system stability and torque control performance.

[0042] In the compressor system of the present invention, optionally, the compressor compensation device is disposed between the speed control loop and the current control loop to form a series compensation structure.

[0043] In the compressor system of the present invention, optionally, the torque compensation loop compensates the current loop reference value based on the electrical angular velocity We obtained from the position and angle observation portion and the calculation based on the reference rotational speed nref.

[0044] According to the compressor system of the present invention, by introducing a compensation coefficient Kd between the speed loop and the current loop, the current reference value is dynamically corrected. The compensation device optimizes the input reference of the current loop. Essentially, it combines information such as power and speed deviation during system operation to adjust the current control target in advance, thereby improving the response accuracy of the current loop to actual load changes and ultimately improving the control performance of the entire speed-current dual closed-loop system.

[0045] The effects of the invention

[0046] Therefore, the present invention provides a compressor compensation device, method, and compressor system that adapts to load changes, enables stable compressor operation, and enhances the robustness of program operation.

[0047] According to the compressor compensation device, method, and compressor system of the present invention, by calculating the speed error and adaptively adjusting the PI parameters based on the operating power, speed fluctuations can be suppressed. This effectively suppresses situations where increased load and torque pulsation cause system oscillations, leading to compressor loss of synchronization and shutdown. Furthermore, the reduction in fluctuations also suppresses vibration and noise generated by the compressor. Attached Figure Description

[0048] Figure 1 This is a flowchart of the compensation device of the present invention.

[0049] Figure 2 This is a flowchart illustrating the location of the compensation device in the system and the compensation method of the present invention.

[0050] Figure 3 This is a system control block diagram of the compensation device described above in this invention.

[0051] Figure 4 This is a block diagram of the PI algorithm for the parallel motor structure of the present invention.

[0052] Figure 5 This is a graph showing the speed fluctuation when the reference speed is 30 rpm.

[0053] Figure 6 This is a graph showing the speed fluctuations at a reference speed of 75 rpm.

[0054] Figure 7 This is a flowchart of a compensation device according to a modified example of the present invention. Detailed Implementation

[0055] Figure 1 This is a flowchart of the compensation device of the present invention.

[0056] The compensation device of the present invention is a multi-parameter compensation coefficient calculation device, which calculates the compensation coefficient Kd for adjusting the system control parameters by integrating the actual values ​​of rotational speed, electric power, and electric angular velocity with the reference values.

[0057] Specifically, the compensation device includes the following input module, calculation module, and limiting module.

[0058] [Input Module]

[0059] The compensation device of the present invention includes the following input parameters.

[0060] Speed-related: Speed ​​setpoint Wn, Speed ​​reference value Wnref;

[0061] Electric power related: Calculated electric power value Pe, reference electric power value Peref;

[0062] Related to electric angular velocity: estimated electric angular velocity We, reference electric angular velocity Weref.

[0063] The compensation device of the present invention calculates the final compensation coefficient through the following calculation steps.

[0064] [Calculation Module]

[0065] Speed ​​compensation coefficient calculation: Kn=Wn / Wnref, which reflects the ratio of the speed set value to the reference value;

[0066] Power compensation factor calculation: Ka = Pe / Peref, which reflects the ratio of the calculated power value to the reference value;

[0067] Calculation of electric angular velocity error: Weerr = Weref - We, calculate the deviation of electric angular velocity;

[0068] Speed ​​compensation coefficient calculation: Kb=Ka×Kn×Weerr, which is the comprehensive compensation amount that integrates power, speed, and electrical angular velocity errors;

[0069] Total compensation coefficient calculation: Kc=Kj+Kb (Kj is the compensation base value), which is adjusted by superimposing the compensation base value and the above comprehensive compensation amount.

[0070] In addition, such as Figure 1 As shown, in the calculation of speed compensation coefficient and power compensation coefficient, the compensation coefficients obtained from the calculation of speed compensation coefficient: Kn'=Wn / Wnref and the calculation of power compensation coefficient: Ka'=Pe / Peref can be limited by a limiter to obtain the speed compensation coefficient Kn and the power compensation coefficient Ka.

[0071] [Amplitude Limiting Module]

[0072] Compensation Limiting: Kc is processed by the compensation limiter to output the final compensation coefficient Kd, ensuring that the value is within a reasonable range.

[0073] Based on the aforementioned compensation device, quantitative compensation is performed on deviations of multiple physical quantities (such as speed deviation, power deviation, and electrical angular velocity error). The compensation coefficient Kd is comprehensively derived through mathematical calculations, which enables precise compensation for torque fluctuations and improves the system control accuracy.

[0074] Furthermore, since the aforementioned compensation device dynamically adjusts the compensation coefficient by combining real-time operating parameters (such as the calculated electric power value We, the estimated electric angular velocity value Pe, etc.), it can adapt to changes in the system under different operating conditions.

[0075] In addition, the aforementioned compensation device also constrains the range of compensation coefficients through a limiter, thereby avoiding overcompensation, ensuring stable system operation, and preventing abnormal parameter fluctuations from affecting the equipment.

[0076] Figure 2 This is a flowchart illustrating the location of the compensation device in the system and the compensation method of the present invention.

[0077] Specifically, the compensation method performs the following speed control steps, torque compensation steps, and current loop output steps.

[0078] [Speed ​​Control Procedure]

[0079] By calculating the difference between the setpoint speed nref and the estimated speed Rest, the speed error value Rerr = nref - Rest is obtained. This error is then used in a speed loop PI calculation to generate a current loop reference value Iqmref. The field weakening control module (field weakening controller) then generates a current loop reference value Iqref as the q-axis reference value and a current loop reference value Idref as the d-axis reference value. Specifically, under high-speed conditions, by adjusting the current loop reference value Idref to a negative value, the motor's magnetic field is weakened, preventing inverter output voltage saturation due to excessively high back EMF, thus allowing for higher speeds.

[0080] [Torque Compensation Steps]

[0081] Using the compensation coefficient Kd derived from the compensation device of the present invention, the reference values ​​Iqref and Idref of the current loop Iq are compensated to obtain the corrected reference values ​​Iqref′=Iqref×Kd and Idref′=Idref×Kd of the current loop Iq.

[0082] [Current Loop Output Steps]

[0083] The measured values ​​of current loop Iq and Id, which are used as current measurement values, are compared with the corrected reference values ​​of current loop Iq ref′ and Id ref′, respectively, to obtain the error values ​​of current loop Iq Iq Ierr = Iqref′ - Iq and current loop Id Iderr = Idref′ - Id. After current loop PI operation (including current loop (Id) PI operation and current loop (Iq) PI operation), the output voltage amplitudes Vq and Vd are obtained.

[0084] The above compensation method can be applied to scenarios requiring high-precision dynamic adjustment (such as motor control, power system optimization, etc.). Through comprehensive compensation, the output voltage can be precisely adjusted, improving the stability and control performance of the system, reducing fluctuations, and thus suppressing the noise generated by the compressor.

[0085] Figure 3 This is a system control block diagram of the compensation device described above in this invention.

[0086] The present invention is a closed-loop starting system, which includes a torque compensation device to suppress fluctuations in rotational speed.

[0087] First, the speed setpoint nref, used as the reference speed, is input and compared with the speed estimate Rest, used as the feedback speed. The difference is taken as the speed error value Rerr, which is then output as the quadrature-axis current reference value Iqmref by the PI controller of the speed control loop. The direct-axis current reference values ​​Idref and Iqref are generated by the field weakening control module. Idref and Iqref are calculated by superimposing the compensation coefficient Kd through the compensation device to obtain the corrected Idref′ and Iqref′. Then, Idref′ and Iqref′ are compared with the actual current feedback values ​​id and iq, respectively. The difference is processed by the PI controller of the current control loop, which outputs the direct-axis voltage vd and the quadrature-axis voltage vq. The current itase is first transformed by Clarke transformation into iα and iβ in the two-phase stationary coordinate system, and then transformed by Park to obtain id and iq; vd and vq are transformed by Park inverse transformation to vα and vβ. vα and vβ are used to generate six PWM signals through SVPWM to control the inverter and drive the compressor. The position and angle observation unit estimates the rotor position θe and the electrical angular velocity We for coordinate transformation. The position and angle observation unit performs position and angle observations based on the static compensation voltage observation unit, ensuring stable and efficient system operation.

[0088] The following is about Figure 3 The functions and roles of each part in the control block diagram of the closed-loop starting system including the torque compensation device are explained respectively.

[0089] [Input Section]

[0090] Reference speed nref: The desired motor speed value of the system, which serves as the target input for the entire speed control loop.

[0091] The reference speed nref is divided into two paths: one path compares with the feedback speed signal (derived from the electric angular velocity We: (We / (2*pi)) / n (n=3), which will be described in detail later) to generate a speed error. After calculation by the PI regulator, the output current loop q-axis reference value Iqref (corresponding to the torque current reference value) is generated; the other path calculates nref*6*pi, which is used as one of the inputs for the compensation coefficient calculation.

[0092] [Speed ​​Control Loop]

[0093] PI controller: Receives the difference between the reference speed nref and the feedback speed (the actual speed measured and estimated by the position and angle observation unit described later), and outputs a quadrature-axis current reference value Iqmref through a proportional-integral control algorithm. The function of the PI controller is to eliminate steady-state error and ensure that the actual speed tracks the reference speed.

[0094] [Magnetic Weakening Control Loop]

[0095] The field weakening control module generates a direct-axis current reference value Idref (corresponding to the excitation current reference value) to adjust the field weakening state of the motor; and a quadrature-axis current reference value Iqref (corresponding to the torque current reference value) to control the output torque.

[0096] Torque compensation loop

[0097] As the core module of a closed-loop starting system that includes a torque compensation device, the inputs include electrical angular velocity We, speed-related parameters (nref*6*pi), etc. Based on the calculation of the compensation coefficient Kd using the aforementioned torque compensation device, Iqref and Idref are compensated to obtain the corrected current reference values ​​Idref′ and Iqref′.

[0098] [Current Control Loop]

[0099] Two PI controllers control the direct-axis current id and the quadrature-axis current iq, respectively. The difference between the corrected current reference values ​​(Idref′ and Iqref′) and the actual current feedback values ​​(id and iq) is calculated using a proportional-integral (PI) operation to output the direct-axis voltage vd and the quadrature-axis voltage vq.

[0100] [Coordinate Transformation Section]

[0101] Clarke transformation: Converts the current isample in a three-phase stationary coordinate system (abc) into the currents iα and iβ in a two-phase stationary coordinate system (αβ).

[0102] Park transformation: Converts the current isample in a three-phase stationary coordinate system (abc) into the currents id and iq in a two-phase rotating coordinate system (dq).

[0103] Inverse Park transformation: Converts voltages vd and vq in a two-phase rotating coordinate system (dq) into voltages vα and vβ in a two-phase stationary coordinate system (αβ).

[0104] [Pulse Width Modulation Section]

[0105] SVPWM (Space Vector Pulse Width Modulation): Based on the voltages vα and vβ in the two-phase stationary coordinate system (αβ), six PWM signals (va, vb, vc) are generated to control the switching state of the inverter, thereby adjusting the input voltage and current of the motor.

[0106] [Output and Feedback Section]

[0107] Inverter: Receives the PWM signal generated by SVPWM and converts DC power into three-phase AC power to drive the compressor (motor load).

[0108] [Position and Angle Observation Section]

[0109] Position and angle observation unit: By outputting current, voltage, and other signals to the motor, it estimates the electrical angle θe and electrical angular velocity We of the motor as the rotor position. The electrical angle θe provides parameters to each coordinate transformation section. Park transformation and inverse Park transformation are performed based on the electrical angle θe measured by the position and angle observation unit, realizing decoupled control of the current. The electrical angular velocity We is calculated as We / (2*pi) / n, where n is the number of electrode pole pairs, as the actual rotational speed measured and estimated by the position and angle observation unit, and is compared with the reference rotational speed nref for PI control to achieve speed control. In this embodiment, the number of electrode pole pairs n can be 3.

[0110] In the position and angle observation unit of the embodiment of the present invention, the position and electrical angular velocity of the rotor are estimated based on the following calculation formula.

[0111] ed=vd-RSH*id+We*Lq*iq……(1)

[0112] eq=vq-RSH*iq-We*Ld*id……(2)

[0113] α=α0+2*λ*fabs(We)……(3)

[0114]

[0115] θe + =T*We……(5)

[0116] while(θe>π)θe - =2*π……(6)

[0117] while(θe<-π)θe + =2*π……(7)

[0118] Where ed and eq are the back electromotive forces along the dq axis, RSH is the phase resistance, We is the rotor electric angular velocity, Ld and Lq are the inductances along the dq axis, vd and vq are the voltages along the dq axis, id and iq are the currents along the dq axis, α and λ are the two gains of the observation unit, and T is the operating period of the system current loop. θe represents the rotor flux linkage, and θe represents the system operating angle.

[0119] Specifically, firstly, the back electromotive forces ed and eq of the dq axis are calculated using equations (1) and (2). This step is based on the motor's voltage equation, combined with parameters such as the dq axis voltage, current, phase resistance, and inductance to obtain the back electromotive force.

[0120] Next, the observation unit gain α is calculated using equation (3), which is related to the initial gain α0, another gain λ, and the absolute value of the rotor electric angular velocity We.

[0121] Then, the rotor electric angular velocity We is updated by equation (4). This formula takes into account factors such as back electromotive force, gain, rotor flux linkage, and inductance difference to achieve dynamic adjustment of We.

[0122] Then, the system operating angle θ is calculated using equation (5), which reflects the change of the angle with time (determined by the current loop operating period T) and electric angular velocity.

[0123] Finally, by using equations (6) and (7) and two while loops, we ensure that the system operating angle θ is always within the range of -π to π, so as to facilitate the system's handling and control of the angle.

[0124] These formulas work together to provide estimates of rotor position and electrical angular velocity for the control of the compressor motor, which is a crucial step in achieving precise control.

[0125] Furthermore, because traditional speed loop PI control ignores the influence of load torque (TL) and is tuned as a linear time-invariant system, it cannot adapt to dynamic load changes. Fixed PI parameters (Kp, Ki) are prone to integral saturation and control failure when the load fluctuates, leading to system instability, noise, and vibration problems.

[0126] In this regard, in the compressor system of the present invention, when performing proportional-integral (PI) control in the above-mentioned [speed control loop], the PI parameters can be dynamically adjusted to suppress torque fluctuations.

[0127] Figure 4 This is a block diagram of the PI algorithm for the parallel motor structure of the present invention.

[0128] Specifically, such as Figure 4 As shown, the PI algorithm for parallel motor structure is adopted based on the following calculation formula.

[0129] Errr(t)=nref(t)-Wn(t)……(8)

[0130] utput(t)=Kp*Errr(t)+Ki∫Errr(t)……(9)

[0131] Where nref(t) represents the baseline value at time t, Wn(t) represents the estimated value at time t, Errr(t) represents the error at time t, utput(t) represents the error at time t, and Kp and Ki represent the proportional coefficient and integral coefficient of the proportional-integral operation, respectively.

[0132] Error is calculated using equation (8), and then output adjustment is performed using equation (9). In this control algorithm, speed fluctuations are monitored (as described below). Figure 5 , Figure 6 (As shown) The torque fluctuation trend is determined, and Kp and Ki are updated in real time to achieve dynamic parameter adjustment.

[0133] Figure 5 This is a graph showing the speed fluctuation when the reference speed is 30 rpm.

[0134] Figure 6 This is a graph showing the speed fluctuations at a reference speed of 75 rpm.

[0135] Figure 5 The curve represents the actual fluctuation of the electrical angular velocity (approximately 565.4867 radians / second) when the compressor is running at a reference speed of 30 rpm. The straight line represents the reference value, and the curve represents the actual fluctuation.

[0136] Figure 6 The curve represents the actual fluctuation of the electrical angular velocity (approximately 1413.717 radians / second) when the compressor is running at a reference speed of 75 rpm. The straight line represents the reference value, and the curve represents the actual fluctuation.

[0137] Figure 5 and Figure 6 The diagram shows that the actual rotational speed (curve) fluctuates around the reference value (straight line), verifying the existence of torque fluctuations.

[0138] Using a reference speed value (such as 30 rpm or 75 rpm), Kp and Ki are dynamically adjusted according to the deviation between the actual speed and the reference value.

[0139] When the actual speed (Wn(t)) is higher than the reference value (nref(t)), decrease Kp and Ki to reduce the control response; when the actual speed is lower than the reference value, increase Kp and Ki.

[0140] Therefore, different adjustment coefficients are set for different speed and power conditions (such as 30 rpm or 75 rpm) to improve the system's adaptability under different operating conditions.

[0141] In addition, combined Figure 2 Flowcharts and Figure 3 The control block diagram shows that the system forms a closed loop through speed feedback → fluctuation judgment → parameter adjustment → PI control output.

[0142] By dynamically adjusting the PI parameters in this way, speed fluctuations can be suppressed, control failures caused by integral saturation can be avoided, and system stability can be improved. At the same time, noise and vibration can be reduced, and equipment life can be extended. Furthermore, adaptive control under load fluctuations can be achieved by setting different coefficients according to the differences in speed and power, enhancing system robustness and adapting to various application scenarios requiring dynamic load compensation, such as variable frequency compressors and motor drives under multiple operating conditions.

[0143] In the compressor system of this invention, by introducing a compensation coefficient Kd between the speed loop and the current loop, the current reference value is dynamically corrected. The compensation device optimizes the input reference of the current loop. Essentially, it combines information such as power and speed deviation during system operation to adjust the current control target in advance, thereby improving the response accuracy of the current loop to actual load changes and ultimately improving the control performance of the entire speed-current dual closed-loop system.

[0144] Overall, based on the aforementioned speed-current dual closed-loop system, combined with the torque compensation device to dynamically adjust the current reference value, the inverter is precisely driven through coordinate transformation and SVPWM technology, thereby achieving precise drive of loads such as compressors and improving system stability and torque control performance.

[0145] As described above, in the compressor compensation device, method, and compressor system of the present invention, speed fluctuations can be suppressed by calculating based on the speed error and adapting the PI parameters according to the operating power. This effectively suppresses situations where increased load and torque pulsation cause system oscillations, leading to compressor loss of synchronization and shutdown. Furthermore, the reduction in fluctuations also suppresses vibrations and noise generated by the compressor.

[0146] Furthermore, although the present invention has been specifically described above in conjunction with the accompanying drawings and embodiments, it is to be understood that the above description does not limit the present invention in any way. For example, as Figure 7As shown, in a modified embodiment of the present invention, the input module of the compensation device may only input the calculated electric power value Pe and the reference electric power value Peref, which are related values ​​of electric power; and the estimated electric angular velocity value We and the reference electric angular velocity value Weref, which are related values ​​of electric angular velocity, without inputting the speed setting value Wn and the speed reference value Wnref, which are related values ​​of speed. In a modified embodiment of the present invention, the speed compensation coefficient calculation is correspondingly changed to Kb = Ka * Weerr. However, the modified embodiment of the present invention can still achieve the above-mentioned beneficial effects of the present invention. In other words, the input module only needs to input at least two of the following: the speed setting value Wn and the speed reference value Wnref, which are related values ​​of speed; the calculated electric power value Pe and the reference electric power value Peref, which are related values ​​of electric power; and the estimated electric angular velocity value We and the reference electric angular velocity value Weref, which are related values ​​of electric angular velocity. Those skilled in the art can make modifications and changes to the present invention as needed without departing from the essential spirit and scope of the present invention, and all such modifications and changes fall within the scope of the present invention.

Claims

1. A compressor compensation device, characterized in that, It is a device for torque compensation based on multiple parameters. include: The input module takes as input at least two of the following: a speed setpoint Wn and a speed reference value Wnref as speed-related values; a calculated electric power value Pe and an electric power reference value Peref as electric power-related values; and an estimated electric angular velocity value We and an electric angular velocity reference value Weref as electric angular velocity-related values; and... The calculation module includes a compensation coefficient calculation unit, a speed compensation coefficient calculation unit, and a total compensation coefficient calculation unit. The compensation coefficient calculation unit calculates the compensation coefficient for each input in the input module, obtaining at least two of the following: speed compensation coefficient: Kn = Wn / Wnref; power compensation coefficient: Ka = Pe / Peref; and electrical angular velocity error: Weerr = Weref - We. The speed compensation coefficient calculation unit multiplies the compensation coefficients obtained by the compensation coefficient calculation unit to obtain the speed compensation coefficient Kb. The total compensation coefficient calculation unit superimposes the compensation base value Kj onto the speed compensation coefficient Kb to obtain the total compensation coefficient Kc. The compressor compensation device also includes: The limiting module limits the total compensation coefficient Kc through a compensation limiter to obtain the final compensation coefficient Kd.

2. The compressor compensation device according to claim 1, characterized in that, The limiting module runs after the calculation module.

3. The compressor compensation device according to claim 1 or 2, characterized in that, The input module inputs all of the rotational speed related values, the electric power related values, and the electric angular velocity related values. The speed compensation coefficient Kb = Ka × Kn × Weerr.

4. A compressor compensation method, characterized in that, Execution steps: speed control, torque compensation, and current loop output. The speed control step obtains the current loop reference value. The torque compensation step involves multiplying the final compensation coefficient Kd obtained from the compressor compensation device of claim 1 with the current loop reference value to obtain the corrected current loop reference value. The current loop output step performs a current loop PI calculation on the current loop error value, which is the difference between the corrected current loop reference value and the current loop measurement value, and outputs the voltage amplitude.

5. The compressor compensation method according to claim 4, characterized in that, In the speed control step, the speed error value Rerr, which is the difference between the speed setpoint nref and the speed estimate Rest, is subjected to PI calculation to generate a current loop Iq reference value Iqmref. Furthermore, the field weakening control module generates current loop Id reference values ​​Idref and Iq reference values ​​Iqref. In the torque compensation step, the final compensation coefficient Kd is multiplied by the current loop reference values ​​Iqref and Idref to obtain the corrected current loop reference values ​​Iqref′ and Idref′. In the current loop output step, the measured values ​​Iq and Id of the current loop, which are used as current measurement values, are compared with the corrected reference values ​​Iqref′ and Idref′ of the current loop, respectively, to obtain the error values ​​Iqerr=Iqref′-Iq and Id error values ​​Iderr=Idref′-Id of the current loop. After current loop PI calculation, the output voltage amplitudes Vq and Vd are obtained.

6. The compressor compensation method according to claim 5, characterized in that, In the speed control step, the PI calculation is dynamically adjusted by updating the proportional coefficient Kp and integral coefficient Ki in real time based on the deviation between the actual speed and the reference speed.

7. The compressor compensation method according to claim 6, characterized in that, When the actual rotational speed is higher than the reference rotational speed, decrease the proportional coefficient Kp and the integral coefficient Ki. When the actual rotational speed is lower than the reference rotational speed, the proportional coefficient Kp and the integral coefficient Ki are increased.

8. A compressor system for performing the compressor compensation method according to any one of claims 4 to 7, characterized in that, include: The compressor compensation device according to claim 1; The speed control loop is configured to obtain reference values ​​from the current loop. A torque compensation loop is configured to perform torque compensation on the current loop reference value through the compressor compensation device to obtain a corrected current loop reference value. A current control loop is configured to perform a current loop PI operation on the current loop error value, which is the difference between the corrected current loop reference value and the current loop measurement value, and output the voltage amplitude. The position and angle observation section is configured to obtain at least the electric angular velocity We; The coordinate transformation section is configured to perform Clarke transformation, Park transformation, and inverse Park transformation; and The pulse width modulation section is configured to generate inverter control signals via SVPWM.

9. The compressor system according to claim 8, characterized in that, The compressor compensation device is configured between the speed control loop and the current control loop to form a series compensation structure.

10. The compressor system according to claim 8 or 9, characterized in that, The torque compensation loop compensates for the reference value of the current loop based on the electric angular velocity We obtained from the position and angle observation section and the calculation based on the reference rotational speed nref.

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