Method and system for rapid observation of air conditioner compressor rotation speed

Abstract

The application belongs to the technical field of motor control, and relates to a kind of air conditioner compressor rotating speed fast observation method and system, the method comprises: three-phase current of motor is transformed into dq axis current actual value;PI is carried out PI adjustment to the difference between motor rotating speed given value and motor rotating speed actual value, and q axis current given value is obtained, and the difference between q axis current given value and q axis current actual value is carried out PI adjustment to obtain q axis voltage given value;The difference between d axis current given value and d axis current actual value is carried out PI adjustment to obtain d axis voltage given value;Dq axis voltage given value is transformed into alpha axis voltage given value;Based on alpha axis voltage given value and the output voltage of frequency as motor rotating speed observation value, the updated motor rotating speed observation value is obtained.The application can realize stable observation of motor rotating speed in full speed range, and the observation result is accurate, especially when motor rotating speed dynamically changes, excellent dynamic tracking effect can be realized.

Description

Technical Field

[0001] This invention belongs to the field of motor control technology, and relates to air conditioning compressor control technology. Specifically, it relates to a method and system for rapid observation of air conditioning compressor speed. Background Technology

[0002] In the drive control of high-performance air conditioning compressors, the performance of closed-loop speed control depends on the accurate control of motor speed. Traditional solutions use physical speed sensors to acquire speed data. While the principle is intuitive, this significantly increases system hardware costs, overall size, and wiring complexity. Furthermore, under harsh operating conditions such as high temperature, strong vibration, and high humidity in air conditioning compressors, sensors are prone to drift and failure, making it difficult to meet long-term stable operation requirements. Therefore, sensorless motor observation technology has become the mainstream solution in the industry. Sensorless motor observation technology eliminates the need for physical speed sensors. It acquires voltage and current signals from the motor stator and reconstructs rotor speed information using advanced algorithms or observer models, significantly improving system robustness and economy while maintaining drive control performance. Early sensorless observation strategies were mostly based on idealized steady-state models of the motor, such as analyzing and calculating the fundamental component of the back electromotive force. These solutions are simple in structure, require little computation, are easy to implement digitally, and can achieve relatively stable observation results in the high-speed operating range of the motor. However, due to the limitations of the theoretical model, the amplitude of the back EMF is directly proportional to the motor speed. Therefore, when operating in the low-speed range, the back EMF signal is weak and easily affected by measurement noise and nonlinear distortion of the inverter. This ultimately leads to a deterioration in observation accuracy and a narrowing of the system's effective speed regulation range, making it difficult to meet the stringent requirements of high-performance wide-speed regulation application scenarios.

[0003] To overcome the limitations of idealized steady-state models, sensorless control technology has shifted towards advanced observer design based on the dynamic equations of the motor. Among these, model reference adaptive observers (MRA) and sliding mode variable structure observer control are two mainstream approaches. The MRA scheme estimates the rotor speed by constructing a parallel structure of a reference model and an adjustable model, using the output deviation to adjust the adaptive rate in real time. This method has a clear physical concept and is easy to implement in engineering. The sliding mode variable structure observer employs a discontinuous feedback control strategy, forcing the system state trajectory to converge and remain on the sliding hyperplane within a finite time, thereby accurately reconstructing implicit state information such as back electromotive force. It possesses natural resistance to parameter perturbations and external disturbances. While these dynamic observers effectively extend the low-speed operating boundary of the system, they also introduce new design challenges. The accuracy of the MRA is closely coupled to internal parameters such as motor inductance and resistance. Factors such as temperature rise and magnetic saturation effects during actual operation can easily cause parameter drift, leading to deterioration in observation performance. Furthermore, global stability analysis and parameter tuning are quite difficult. The high-frequency chattering phenomenon inherent in sliding mode variable structure observers can be smoothed by low-pass filtering or continuous functions, but this often comes at the cost of sacrificing system bandwidth and dynamic tracking performance. The introduction of filters inevitably causes phase lag, which restricts their application in scenarios requiring fast response (such as rapid load changes and wideband speed regulation).

[0004] Furthermore, traditional frequency-locked loop (FLL) speed observers have received widespread attention in motor speed observation due to their excellent harmonic suppression capabilities and adaptive tracking characteristics to the fundamental frequency. However, since the frequency of the signal to be measured is unknown in practical applications, it is impossible to pre-tune the optimal damping coefficient to match the entire frequency band. When the damping coefficient is too large, the FLL has a faster dynamic response to high-frequency signals, but for low-frequency signals, the tracking time will be longer due to the large overshoot. Conversely, when the damping coefficient is too small, the FLL has a better dynamic response to low-frequency signals, but the response time to high-frequency signals will be longer. Therefore, speed observers based on traditional FLLs struggle to maintain full-band dynamic tracking performance in scenarios with rapid frequency changes, and cannot meet the actual operating requirements of frequent speed changes and wide-range speed regulation of air conditioning compressors.

[0005] In summary, existing sensorless speed monitoring technology for air conditioning compressor motors has significant shortcomings in low-speed accuracy, parameter robustness, and full-frequency dynamic response. Traditional frequency-locked loop (LLL) observers also cannot achieve rapid and accurate tracking under frequency abrupt changes. There is an urgent need for an effective motor speed monitoring solution that, while retaining the advantages of FLL harmonic suppression and fundamental frequency tracking, overcomes the performance imbalance across the entire frequency band caused by a fixed damping coefficient, and achieves excellent dynamic tracking characteristics when the motor frequency changes rapidly. This would meet the control requirements of high-performance variable frequency air conditioning compressors for wide speed range, high reliability, and rapid response. Summary of the Invention

[0006] This invention addresses the aforementioned problems in existing technologies, such as the inability to adaptively track signals with rapidly changing frequencies. It provides a method and system for rapidly observing the speed of an air conditioning compressor, which can achieve stable and accurate observation of motor speed across the entire speed range, and especially achieves excellent dynamic tracking performance when the motor speed changes dynamically.

[0007] In a first aspect, the present invention provides a method for rapidly observing the speed of an air conditioner compressor, comprising:

[0008] Rotation transformation steps: Based on the motor rotor position angle, transform the three-phase current of the motor into the actual value of the dq axis current;

[0009] PI control steps: The difference between the motor speed setpoint and the actual motor speed is used to obtain the q-axis current setpoint; the difference between the q-axis current setpoint and the actual q-axis current is used to obtain the q-axis voltage setpoint; the difference between the d-axis current setpoint and the actual d-axis current is used to obtain the d-axis voltage setpoint.

[0010] Two-phase stationary transformation steps: Based on the motor rotor position angle, transform the dq-axis voltage setpoint to the α-axis voltage setpoint;

[0011] Speed ​​observation steps: Based on the given α-axis voltage value and the output voltage with frequency equal to the observed motor speed value, the updated observed motor speed value is obtained;

[0012] Methods for obtaining observed motor speed values ​​include:

[0013] The first difference is obtained by subtracting the output voltage from the given α-axis voltage value.

[0014] The first intermediate value is obtained by integrating the output voltage and multiplying it by the observed motor speed.

[0015] Multiply the first difference by the first median value to get the second median value;

[0016] Multiply the second intermediate value by the negative damping coefficient to obtain the third intermediate value;

[0017] Add the square of the output voltage to the square of the first intermediate value, and take the reciprocal to obtain the fourth intermediate value;

[0018] Multiply the third intermediate value by the fourth intermediate value, then multiply by the square of the observed motor speed, and integrate to obtain the updated observed motor speed.

[0019] In conjunction with the first aspect, in some embodiments, the method for obtaining the q-axis current setpoint by PI adjustment of the difference between the motor speed setpoint and the actual motor speed in the PI adjustment step includes:

[0020] The first setpoint is obtained by multiplying the difference between the motor speed setpoint and the actual motor speed by the proportional coefficient of the speed loop PI regulator.

[0021] The difference between the setpoint motor speed and the actual motor speed is multiplied by the integral coefficient of the speed loop PI regulator, and then integrated to obtain the second setpoint.

[0022] Add the first given value to the second given value to obtain the q-axis current given value.

[0023] In conjunction with the first aspect, in some embodiments, the method for obtaining the q-axis voltage setpoint by PI adjustment of the difference between the q-axis current setpoint and the actual q-axis current value in the PI adjustment step includes:

[0024] The third setpoint is obtained by multiplying the difference between the q-axis current setpoint and the actual q-axis current value by the proportional coefficient of the q-axis current loop PI regulator.

[0025] Multiply the difference between the q-axis current setpoint and the actual q-axis current by the integral coefficient of the q-axis current loop PI regulator, and then integrate to obtain the fourth setpoint.

[0026] Adding the third given value to the fourth given value yields the q-axis voltage given value.

[0027] In conjunction with the first aspect, in some embodiments, the method for obtaining the d-axis voltage setpoint by PI adjustment of the difference between the d-axis current setpoint and the actual d-axis current value in the PI adjustment step includes:

[0028] The fifth setpoint is obtained by multiplying the difference between the d-axis current setpoint and the actual d-axis current value by the proportional coefficient of the d-axis current loop PI regulator.

[0029] Multiply the difference between the d-axis current setpoint and the actual d-axis current value by the integral coefficient of the d-axis current loop PI regulator, and then integrate to obtain the sixth setpoint.

[0030] Add the fifth given value to the sixth given value to obtain the d-axis voltage given value.

[0031] In conjunction with the first aspect, in some embodiments, the method for correcting the output voltage includes:

[0032] Multiply the first difference by a set scaling factor, and then subtract the first intermediate value to obtain the fifth intermediate value;

[0033] Multiply the fifth intermediate value by the observed motor speed to obtain the sixth intermediate value;

[0034] Integrating the sixth intermediate value yields the corrected output voltage.

[0035] In conjunction with the first aspect, in some embodiments, the method further includes:

[0036] Rotational inverse transformation steps: Based on the motor rotor position angle, transform the given dq axis voltage values ​​into three-phase voltages in the abc coordinate system;

[0037] Compressor drive modulation steps: Determine the projection area based on the magnitude of the three-phase voltage; calculate the initial duty cycle of the three phases based on the three-phase voltage and the preset coefficient group corresponding to the area; generate a three-phase modulation wave based on the initial duty cycle of the three phases, the DC bus voltage, and the switching cycle; generate the drive signal for the switching devices in the compressor motor control circuit based on the magnitude of the three-phase modulation wave and the triangular carrier wave.

[0038] In conjunction with the first aspect, in some embodiments, the method for determining the projection area based on the magnitude of the three-phase voltage in the compressor drive modulation step includes:

[0039] Compare the magnitudes of the three voltages: phase a voltage, phase b voltage, and phase c voltage.

[0040] If phase a voltage is the largest, then the projection area is determined as region 1; if phase b voltage is the largest, then the projection area is determined as region 2; if phase c voltage is the largest, then the projection area is determined as region 3.

[0041] The preset coefficient group corresponding to region 1 is: , , , , , , , , The preset coefficient group corresponding to region 2 is: , , , , , , , , The preset coefficient group corresponding to region 3 is: , , , , , , , , ;

[0042] The formula for calculating the initial duty cycle of the three phases is expressed as follows:

[0043]

[0044]

[0045]

[0046] In the formula, Let a be the initial duty cycle of phase a. The initial duty cycle of phase b. This represents the initial duty cycle of phase c.

[0047] In conjunction with the first aspect, in some embodiments, the method for generating a three-phase modulation wave in the compressor drive modulation step includes: multiplying the reciprocal of the DC bus voltage by the switching period, and then multiplying by the initial duty cycle of phase i to obtain the phase i modulation wave, i=a,b,c.

[0048] In conjunction with the first aspect, in some embodiments, the method for generating drive signals for the switching devices in the compressor motor control circuit during the compressor drive modulation step includes:

[0049] Compare the magnitudes of the i-phase modulated wave and the triangular carrier wave;

[0050] When the i-phase modulation wave is less than or equal to the triangular carrier wave, the drive signal of the first switching device in the i-phase of the motor control circuit is high; by inverting the drive signal of the first switching device, the drive signal of the second switching device in the i-phase of the motor control circuit is low; when the i-phase modulation wave is greater than the triangular carrier wave, the drive signal of the first switching device in the i-phase of the motor control circuit is low; by inverting the drive signal of the first switching device, the drive signal of the second switching device in the i-phase of the motor control circuit is high.

[0051] In a second aspect, the present invention provides a rapid air conditioning compressor speed observation system for implementing the rapid air conditioning compressor speed observation method described in the first aspect of the present invention, comprising:

[0052] The acquisition module is used to acquire the three-phase current of the air conditioner compressor motor, the DC bus voltage, the actual value of the motor speed, and the motor rotor position angle;

[0053] The setting module is used to set the triangular carrier wave, switching cycle, motor speed setpoint, and preset coefficient group;

[0054] The rotation conversion module converts the three-phase current of the motor into the actual value of the dq axis current based on the rotor position angle of the motor.

[0055] The PI control module adjusts the difference between the motor speed setpoint and the actual motor speed to obtain the q-axis current setpoint, adjusts the difference between the q-axis current setpoint and the actual q-axis current to obtain the q-axis voltage setpoint, and adjusts the difference between the d-axis current setpoint and the actual d-axis current to obtain the d-axis voltage setpoint.

[0056] The two-phase stationary conversion module transforms the dq-axis voltage setpoint into the α-axis voltage setpoint based on the motor rotor position angle.

[0057] The speed observation module obtains updated motor speed observation values ​​based on the α-axis voltage setpoint and the output voltage with a frequency equal to the motor speed observation value.

[0058] The rotational inverse transformation module transforms the given dq-axis voltage into three-phase voltages in the abc coordinate system based on the motor rotor position angle.

[0059] The compressor drive modulation module determines the projection area based on the magnitude of the three-phase voltage, calculates the initial duty cycle of the three phases based on the three-phase voltage and the preset coefficient group corresponding to the area, generates a three-phase modulation wave based on the initial duty cycle of the three phases, the DC bus voltage and the switching cycle, and generates the drive signal of the switching device in the compressor motor control circuit based on the magnitude of the three-phase modulation wave and the triangular carrier wave.

[0060] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0061] (1) The method and system for rapid observation of air conditioning compressor speed provided by the present invention, through the frequency adaptive closed-loop observation mechanism based on α-axis voltage, breaks through the limitation of traditional back EMF observers that the back EMF is weak and cannot be effectively observed in the low-speed region. It can cover the entire speed range of air conditioning compressor motor from low speed zero speed to high speed operation. It is especially suitable for application scenarios of frequent start-stop and wide operating condition speed adjustment of air conditioning compressor, realizes stable and accurate observation of speed in the full speed range, significantly expands the effective speed regulation range of the system, and meets the requirements of high-performance full-speed range drive control.

[0062] (2) The method and system for rapid observation of air conditioning compressor speed provided by the present invention does not rely on motor body parameters such as stator resistance, rotor flux linkage, and inductance. The speed reconstruction can be completed by voltage calculation, integral and proportional coefficient adjustment. It effectively avoids the problem of decreased observation accuracy caused by motor temperature rise, magnetic saturation and parameter drift in traditional model reference adaptive and sliding mode observer schemes. It has strong robustness to parameter perturbation and external interference. The observation results are stable, reliable and highly accurate.

[0063] (3) The method and system for rapid observation of air conditioning compressor speed provided by the present invention adopts a speed update mechanism based on difference calculation, integral link and damping coefficient adjustment. It can still converge quickly and accurately track the actual speed under the conditions of rapid change of motor speed and sudden change of frequency. It effectively overcomes the problem of imbalance of high and low frequency dynamic performance caused by fixed damping coefficient of traditional frequency lock ring. It has small overshoot, fast response and no obvious tracking lag, which greatly improves the control dynamic quality of compressor when running at variable speed. Attached Figure Description

[0064] Figure 1This is a circuit diagram of the main topology circuit of the air conditioner compressor according to an embodiment of the present invention;

[0065] Figure 2 This is a flowchart of the method for rapid observation of air conditioner compressor speed according to an embodiment of the present invention;

[0066] Figure 3 This is a schematic diagram illustrating the principle of obtaining the q-axis current and q-axis voltage setpoints using PI control in an embodiment of the present invention.

[0067] Figure 4 This is a schematic diagram illustrating the principle of obtaining the d-axis voltage setpoint through PI regulation in an embodiment of the present invention.

[0068] Figure 5 This is a schematic diagram illustrating the principle of obtaining observed motor speed values ​​according to an embodiment of the present invention.

[0069] Figure 6 This is a flowchart of the air conditioner compressor drive control method according to an embodiment of the present invention;

[0070] Figure 7 This is a schematic diagram illustrating the generation of a three-phase modulated wave and the driving signal for the three-phase switching devices in the compressor motor control circuit, as described in an embodiment of the present invention.

[0071] Figure 8 In this embodiment of the invention, phase a current flows out of the motor, phase b current and phase c current flow into the motor, and the Si-Mos transistor... S a1 Si-Mos tube S b2 Si-Mos tube S c2 Conduction, Si-Mos transistor S a2 Si-Mos tube S b1 Si-Mos tube S c1 A schematic diagram of the current path when disconnected;

[0072] Figure 9 In this embodiment of the invention, phase a current flows out of the motor, phase b current and phase c current flow into the motor, and the Si-Mos transistor... S a1 Si-Mos tube S b1 Si-Mos tube S c1 Disconnect, Si-Mos tube S a2 Si-Mos tube S b2 Si-Mos tube S c2 A schematic diagram of the current path when the circuit is on;

[0073] Figure 10 In this embodiment of the invention, phase b current flows out of the motor, phase a current and phase c current flow into the motor, and the Si-Mos transistor... S a1 Si-Mos tube S b2 Si-Mos tube S c1 Disconnect, Si-Mos tube S a2 Si-Mos tube S b1 Si-Mos tube S c2 A schematic diagram of the current path when the circuit is on;

[0074] Figure 11 In this embodiment of the invention, phase b current flows out of the motor, phase a current and phase c current flow into the motor, and the Si-Mos transistor... S a1 Si-Mos tube S b1 Si-Mos tube S c1 Disconnect, Si-Mos tube S a2 Si-Mos tube S b2 Si-Mos tube S c2 A schematic diagram of the current path when the circuit is on;

[0075] Figure 12 In this embodiment of the invention, phase c current flows out of the motor, phase a current and phase b current flow into the motor, and the Si-Mos transistor... S a1 Si-Mos tube S b1 Si-Mos tube S c2 Disconnect, Si-Mos tube S a2 Si-Mos tube S b2 Si-Mos tube S c1 A schematic diagram of the current path when the circuit is on;

[0076] Figure 13 In this embodiment of the invention, phase c current flows out of the motor, phase a current and phase b current flow into the motor, and the Si-Mos transistor... S a1 Si-Mos tube S b1Si-Mos tube S c1 Disconnect, Si-Mos tube S a2 Si-Mos tube S b2 Si-Mos tube S c2 A schematic diagram of the current path when the circuit is on;

[0077] Figure 14 This is a structural block diagram of the air conditioner compressor speed rapid observation system according to an embodiment of the present invention;

[0078] Figure 15 A schematic diagram showing the actual motor speed and the observed motor speed using a traditional frequency-locked loop;

[0079] Figure 16 This diagram illustrates the actual and observed motor speed values ​​obtained using the rapid observation method and system for air conditioner compressor speed described in this invention.

[0080] In the diagram, 1 is the acquisition module, 2 is the setting module, 3 is the rotation transformation module, 4 is the PI adjustment module, 5 is the two-phase static transformation module, 6 is the speed observation module, 7 is the rotation inverse transformation module, and 8 is the compressor drive modulation module. Detailed Implementation

[0081] The present invention will now be described in detail with reference to the accompanying drawings through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0082] Figure 1 The main topology circuit of the air conditioner compressor shown includes a permanent magnet synchronous motor and a motor control circuit. The input of the motor control circuit is connected to the DC bus voltage, and the output of the motor control circuit is connected to the permanent magnet synchronous motor. In the main topology circuit, This is the DC bus voltage. S a1 , S a2 The silicon-oxide-semiconductor field-effect transistor (Si-MoS transistor) is used in phase a of the motor control circuit. D a1 , D a2 The diode in phase a of the motor control circuit. L aFor the small inductance of phase a in the motor control circuit, i ra Let a be the current in phase a of the motor; S b1 , S b2 For the Si-Mos transistor in phase b of the motor control circuit, D b1 , D b2 This is a diode in phase b of the motor control circuit. L b For the small inductance of phase b in the motor control circuit, i rb This refers to the b-phase current of the motor. S c1 , S c2 For the Si-Mos transistor in phase c of the motor control circuit, D c1 , D c2 The diode is for phase c of the motor control circuit. L c For the small inductance of phase c in the motor control circuit, i rc is the c-phase current of the motor; M is the permanent magnet synchronous motor.

[0083] Since the three-phase bridge arms of the electrode control circuit in the main topology are completely symmetrical, the connection method is explained using phase a as an example. (Si-Mos transistor) S a1 source and diode D a2 The anode of the diode is connected to the negative terminal of the DC bus voltage. D a1 cathode and Si-Mos tube S a2 The drain of the Si-Mos transistor is connected to the positive terminal of the DC bus voltage. S a1 Drain and diode D a1 The anode is connected to A Point 1, diode D a2 Cathode and Si-Mos tube S a2 The source is connected to A 2 points, inductance L a The two ends are respectively with A 1 point draw A Connect the two points. APoint 2 is connected to phase a winding of permanent magnet synchronous motor M. The connection method of phase b and phase c bridge arms is the same as that of phase a bridge arm, and will not be described again here.

[0084] For the aforementioned air conditioning compressor, this invention provides a method and system for rapid observation of air conditioning compressor speed. Based on the α-axis voltage setpoint and the output voltage with frequency as the observed motor speed value, the speed reconstruction can be completed through voltage calculation, integration, and proportional coefficient adjustment. This effectively avoids the problem of decreased observation accuracy caused by motor temperature rise, magnetic saturation, and parameter drift in traditional model reference adaptive and sliding mode observer schemes. It has strong robustness to parameter perturbations and external interference, and the observation results are stable, reliable, and highly accurate.

[0085] The following describes in detail the method and system for rapid observation of air conditioner compressor speed according to the present invention, with reference to the accompanying drawings and embodiments.

[0086] See Figure 2 The first aspect of the present invention provides a method for rapid observation of the speed of an air conditioner compressor, comprising:

[0087] S1. Rotation transformation steps: Transform the three-phase current of the motor into the actual value of the dq axis current.

[0088] Specifically, the method for transforming the three-phase current of the motor into the actual value of the dq-axis current includes: the three-phase current of the motor is transformed into the actual value of the dq-axis current through a first transformation matrix and a second transformation matrix, and the actual value of the dq-axis current is expressed as:

[0089]

[0090] in: , ;

[0091] In the formula, This represents the actual value of the d-axis current. This is the actual value of the q-axis current. Let a be the current of phase a of the motor. This refers to the phase current of the motor. Let A be the c-phase current of the motor, A be the first transformation matrix, and B be the second transformation matrix. This is the rotor position angle of the motor.

[0092] S2, PI adjustment steps: See [link / reference] Figure 3 The setpoint for motor speed Actual value of motor speed The difference is used to obtain the q-axis current setpoint through PI regulation. For the q-axis current given value Compared with the actual value of q-axis current The difference is used to obtain the q-axis voltage setpoint through PI regulation. See also Figure 4 For the d-axis current given value Compared with the actual value of d-axis current The difference is used to obtain the d-axis voltage setpoint through PI regulation. .

[0093] Specifically, in one embodiment of the present invention, see further... Figure 3 The setpoint for motor speed Actual value of motor speed The difference is used to obtain the q-axis current setpoint through PI regulation. The methods include:

[0094] Set the motor speed to a set value Actual value of motor speed The difference multiplied by the proportional coefficient of the speed ring PI regulator The first given value is obtained;

[0095] Set the motor speed to a set value Actual value of motor speed The difference multiplied by the integral coefficient of the speed loop PI controller Then, integrate to obtain the second given value;

[0096] Adding the first given value to the second given value yields the q-axis current given value. .

[0097] In this embodiment of the invention, the deviation between the given motor speed and the actual motor speed is calculated proportionally and integrally, and then superimposed to obtain the q-axis current setpoint, achieving precise closed-loop adjustment of the outer speed loop. Specifically, the proportional loop rapidly outputs the adjustment amount based on the instantaneous speed deviation, providing a rapid dynamic response and effectively suppressing speed fluctuations and overshoot. The integral loop continuously accumulates and adjusts the speed deviation, completely eliminating steady-state speed error, enabling the motor speed to accurately and stably follow the given speed. By generating the q-axis current setpoint through PI regulation of the outer speed loop, a hierarchical closed-loop coordination between the speed loop and the current loop is achieved, precisely controlling the motor torque component, effectively reducing speed fluctuations caused by load disturbances and changes in operating conditions, and improving the compressor's operating speed stability and anti-disturbance capability.

[0098] Specifically, in one embodiment of the present invention, see further... Figure 3 For the q-axis current given value Compared with the actual value of q-axis current The difference is used to obtain the q-axis voltage setpoint through PI regulation. The methods include:

[0099] Set the q-axis current value Compared with the actual value of q-axis current The difference multiplied by the proportional coefficient of the q-axis current loop PI controller The third given value is obtained;

[0100] Set the q-axis current value Compared with the actual value of q-axis current The difference multiplied by the integral coefficient of the q-axis current loop PI controller Then, by integration, the fourth given value is obtained;

[0101] Adding the third given value to the fourth given value yields the q-axis voltage given value. .

[0102] Specifically, in one embodiment of the present invention, see further... Figure 4 For the d-axis current given value Compared with the actual value of d-axis current The difference is used to obtain the d-axis voltage setpoint through PI regulation. The methods include:

[0103] Set the d-axis current value Compared with the actual value of d-axis current The difference multiplied by the proportional coefficient of the d-axis current loop PI controller The fifth given value is obtained;

[0104] Set the d-axis current value Compared with the actual value of d-axis current The difference multiplied by the integral coefficient of the d-axis current loop PI controller Then, by integration, the sixth given value is obtained;

[0105] Adding the fifth given value to the sixth given value yields the d-axis voltage given value. .

[0106] In this embodiment of the invention, the d-axis current is precisely controlled in a closed loop by performing proportional and integral calculations on the current deviation between the given and actual d-axis current values, and then superimposing these calculations to obtain the given d-axis voltage value. Specifically, the proportional stage can quickly output the adjustment amount based on the real-time current deviation, with a fast response speed, which can promptly suppress current fluctuations and improve the dynamic tracking capability of the current. The integral stage accumulates the current deviation, which can completely eliminate the steady-state error of the current and ensure that the d-axis current tracks the given value without deviation in a steady state. This enables precise decoupled closed-loop control of the d-axis current, stabilizes the motor excitation component, reduces the impact of parameter fluctuations and load disturbances on the current control accuracy, improves the motor's operating stability, and effectively reduces torque pulsation and electromagnetic noise.

[0107] S3. Two-phase stationary transformation steps: Based on the motor rotor position angle This transforms the dq-axis voltage setpoint into the α-axis voltage setpoint.

[0108] Specifically, the method for transforming the dq-axis voltage setpoint into the α-axis voltage setpoint includes: based on the motor rotor position angle The dq-axis voltage setpoint is transformed into the α-axis voltage setpoint through the third transformation matrix. The α-axis voltage setpoint is expressed as:

[0109]

[0110] in: ;

[0111] In the formula, Let C be the given value of the α-axis voltage, and C be the third transformation matrix. The given value for the d-axis voltage. This is the given value for the q-axis voltage.

[0112] In this embodiment of the invention, the real-time motor rotor position angle is used as the transformation reference. A third transformation matrix converts the dq-axis voltage setpoint into the α-axis voltage setpoint, achieving precise coordinate mapping from the synchronously rotating dq coordinate system to the two-phase stationary αβ coordinate system. The transformation process follows the motor vector space constraint rules, resulting in high transformation accuracy, accurate phase matching, and complete preservation of the dq-axis voltage decoupling control characteristics. The coordinate transformation can be dynamically and adaptively completed according to the motor rotor position angle, adapting to the compressor's full speed range and variable load operating conditions. This provides an accurate and reliable α-axis voltage reference for subsequent speed observation and voltage correction, ensuring the overall stability and dynamic response performance of sensorless speed observation and drive control.

[0113] S4. Speed ​​observation steps: Based on the given value of the α-axis voltage and the output voltage with the frequency of the observed motor speed, the updated observed motor speed value is obtained.

[0114] Specifically, in one embodiment of the present invention, see [link to relevant documentation]. Figure 5 Methods for obtaining observed motor speed values ​​include:

[0115] Set the α-axis voltage value Reduce output voltage Obtain the first difference ;

[0116] Output voltage After integration, the motor speed observation value is compared with the observed value. Multiply to obtain the first intermediate value ;

[0117] The first difference Multiply by the first intermediate value Obtain the second intermediate value ;

[0118] The second intermediate value Multiply by negative damping coefficient Obtain the third intermediate value ;

[0119] Output voltage The square of the first median value After adding the squares together, take the reciprocal to get the fourth intermediate value;

[0120] The third intermediate value Multiply by the fourth intermediate value, then multiply by the observed motor speed. Integrate the squared value to obtain the updated motor speed observation. .

[0121] Specifically, in this embodiment of the invention, the damping coefficient can be 2, and can be set according to the actual situation.

[0122] In this embodiment of the invention, on the one hand, the difference between the given α-axis voltage and the output voltage is used as the input for observation error. An intermediate computational quantity is constructed by combining the output voltage integral term with the observed motor speed, enabling accurate extraction of motor frequency-related features and providing a reliable computational basis for speed observation. On the other hand, the introduction of a negative damping coefficient for amplitude constraint adjustment effectively suppresses oscillations, overshoot, and steady-state fluctuations during speed observation, improving the convergence and steady-state stability of the observation system. Furthermore, normalization is achieved by summing the square of the output voltage and the first intermediate value and taking the reciprocal, weakening the interference of voltage amplitude fluctuations on observation accuracy and giving the observation algorithm good anti-interference capability against operating condition fluctuations and sampling noise. Moreover, by combining the square of the observed motor speed for weighted integration and iterative speed updates, the algorithm avoids the problems of observation accuracy degradation caused by temperature rise, magnetic saturation, and parameter drift, without relying on motor body parameters such as stator resistance, inductance, and rotor flux linkage, demonstrating strong parameter robustness.

[0123] Specifically, in one embodiment of the present invention, see further... Figure 5 The methods for correcting the output voltage include:

[0124] The first difference Multiply by the set ratio factor Subtract the first intermediate value. Obtain the fifth intermediate value ;

[0125] The fifth intermediate value Multiply by the observed motor speed The sixth intermediate value is obtained. ;

[0126] For the sixth intermediate value After integration, the corrected output voltage is obtained. .

[0127] Specifically, in the embodiments of the present invention, the scaling factor Pick The specific settings can be adjusted according to the actual situation.

[0128] In this embodiment of the invention, on the one hand, a set proportional coefficient is introduced to adjust the amplitude of the first difference, and then combined with the speed observation value for dynamic weighted calculation, which can compensate for voltage observation deviation in real time, effectively suppress the influence of sampling noise and inverter nonlinear disturbance on the output voltage, and improve the voltage reconstruction accuracy. On the other hand, the intermediate calculation quantity is accumulated and smoothed by the integral link, so that the corrected output voltage is continuous and stable without sudden fluctuations, avoiding speed observation jitter caused by voltage oscillation, and improving the steady-state stability of the entire speed observation system.

[0129] The air conditioning compressor speed prediction method of the present invention, on the one hand, overcomes the defects of weak low-speed back EMF signals and observation failure of traditional observers based on the frequency adaptive closed-loop observation mechanism of α-axis voltage. It can achieve accurate observation of the entire speed range of the motor from zero speed to high speed, adapting to the frequent start-stop and wide-condition speed regulation requirements of air conditioning compressors and effectively expanding the speed regulation range. On the other hand, it does not rely on motor parameters such as stator resistance, inductance, and rotor flux linkage. Speed ​​reconstruction can be completed only through voltage calculation and integral adjustment. It is not affected by motor temperature rise, magnetic saturation, and parameter drift. It has strong resistance to parameter perturbation and external interference, and has high observation accuracy and good stability. Furthermore, by adaptively updating the speed through difference calculation, integral link, and damping coefficient, it solves the problem of high and low frequency dynamic performance imbalance caused by the fixed damping coefficient of traditional frequency-locked loop. When the speed changes abruptly, the convergence speed is fast, the overshoot is small, and the tracking lag is low, which significantly improves the dynamic control performance of the compressor under variable speed conditions.

[0130] See Figure 6 A second aspect of the present invention provides an air conditioner compressor drive control method, comprising:

[0131] S1. Rotation Transformation Step: Transform the three-phase current of the motor into the actual value of the dq-axis current. The specific method for transforming the three-phase current of the motor into the actual value of the dq-axis current is the same as that in the first aspect embodiment of the present invention, and will not be repeated here.

[0132] S2, PI Adjustment Steps: Set the motor speed setpoint. Actual value of motor speed The difference is used to obtain the q-axis current setpoint through PI regulation. For the q-axis current given value Compared with the actual value of q-axis current The difference is used to obtain the q-axis voltage setpoint through PI regulation. ; for the d-axis current setpoint Compared with the actual value of d-axis current The difference is used to obtain the d-axis voltage setpoint through PI regulation. The q-axis voltage setpoint is obtained by performing PI regulation. and d-axis voltage setpoint The specific method is the same as that in the first aspect of the present invention, and will not be repeated here.

[0133] S3. Rotational Inverse Transformation Steps: Based on the Motor Rotor Position Angle The given dq-axis voltage is transformed into the three-phase voltage in the abc coordinate system.

[0134] Specifically, methods for transforming the dq-axis voltage setpoint into three-phase voltages in the abc coordinate system include: based on the motor rotor position angle The given dq-axis voltage is transformed into three-phase voltages in abc coordinates using the fourth and fifth transformation matrices. The three-phase voltages are expressed as follows:

[0135]

[0136] in: , ;

[0137] In the formula, Let a be the phase voltage. This is the voltage of phase b. Let E be the phase c voltage, E be the fourth transformation matrix, and F be the fifth transformation matrix.

[0138] In this embodiment of the invention, the given value of the dq-axis voltage is converted into a three-phase voltage in the abc coordinate system by using the real-time acquired motor rotor position angle and the fourth and fifth transformation matrices. This enables a precise orthogonal transformation from a synchronous rotating coordinate system to a three-phase stationary coordinate system, resulting in high coordinate transformation accuracy and good phase matching. Simultaneously, the coordinate transformation can be dynamically and adaptively completed according to the motor rotor position angle, adapting to the compressor's full speed range and variable load operating conditions. This effectively reduces motor torque ripple and current harmonics, improving the overall machine's operational stability and control robustness.

[0139] S4. Compressor drive modulation steps: Determine the projection area based on the magnitude of the three-phase voltage; calculate the initial duty cycle of the three phases based on the three-phase voltage and the preset coefficient group corresponding to the area; generate a three-phase modulation wave based on the initial duty cycle of the three phases, the DC bus voltage and the switching cycle; generate the drive signal of the switching device in the compressor motor control circuit based on the magnitude of the three-phase modulation wave and the triangular carrier wave.

[0140] Specifically, in one embodiment of the present invention, the method for determining the projection area based on the magnitude of the three-phase voltage includes:

[0141] Compare the magnitudes of the three voltages: phase a voltage, phase b voltage, and phase c voltage.

[0142] If phase a voltage is the largest, then the projection area is determined as region 1; if phase b voltage is the largest, then the projection area is determined as region 2; if phase c voltage is the largest, then the projection area is determined as region 3.

[0143] The preset coefficient group corresponding to region 1 is: , , , , , , , , The preset coefficient group corresponding to region 2 is: , , , , , , , , The preset coefficient group corresponding to region 3 is: , , , , , , , , ;

[0144] The formula for calculating the initial duty cycle of the three phases is expressed as follows:

[0145]

[0146]

[0147]

[0148] In the formula, Let a be the initial duty cycle of phase a. The initial duty cycle of phase b. This represents the initial duty cycle of phase c.

[0149] Specifically, in one embodiment of the present invention, the method for generating a three-phase modulated wave includes: multiplying the reciprocal of the DC bus voltage by the switching period, and then multiplying by the initial duty cycle of phase i to obtain the phase i modulated wave, i=a,b,c.

[0150] In this embodiment of the invention, on the one hand, the reciprocal of the DC bus voltage is introduced into the modulation wave calculation, which can compensate for the impact of DC bus voltage fluctuations on the output modulation waveform in real time. When the DC bus voltage drops or fluctuates, the modulation wave amplitude can still be automatically corrected, suppressing the distortion of the motor output voltage caused by DC bus voltage disturbances and improving the operating stability of the compressor motor. On the other hand, through the normalization conversion between the switching cycle and the DC bus voltage, a precise quantitative mapping from the initial duty cycle to the modulation wave is achieved, and the modulation wave amplitude is accurately calibrated. Furthermore, the three phases a, b, and c are generated with the same operational logic, resulting in a regular and unified three-phase modulation logic with high phase and amplitude matching, effectively reducing the three-phase current asymmetry, reducing compressor motor torque pulsation and electromagnetic noise, and improving motor operation smoothness.

[0151] Specifically, see Figure 7 Methods for generating phase a modulated wave include: DC bus voltage Reciprocal of the switching period Then multiply by the initial duty cycle of phase a. The phase a modulated wave is obtained. .

[0152] Specifically, see [link to relevant documentation] Figure 7 Methods for generating phase b modulated waves include: DC bus voltage Reciprocal of the switching period Then multiply by the initial duty cycle of phase b. The phase b modulated wave is obtained. .

[0153] Specifically, see [link to relevant documentation] Figure 7 Methods for generating c-phase modulated waves include: DC bus voltage Reciprocal of the switching period Then multiply by the initial duty cycle of phase c. The c-phase modulated wave is obtained. .

[0154] Specifically, in one embodiment of the present invention, the method for generating drive signals for switching devices in a compressor motor control circuit includes:

[0155] Compare the magnitudes of the i-phase modulated wave and the triangular carrier wave;

[0156] When the i-phase modulation wave is less than or equal to the triangular carrier wave, the drive signal of the first switching device in the i-phase of the motor control circuit is high; by inverting the drive signal of the first switching device, the drive signal of the second switching device in the i-phase of the motor control circuit is low; when the i-phase modulation wave is greater than the triangular carrier wave, the drive signal of the first switching device in the i-phase of the motor control circuit is low; by inverting the drive signal of the first switching device, the drive signal of the second switching device in the i-phase of the motor control circuit is high.

[0157] In this embodiment of the invention, by comparing the amplitudes of the modulation waves of each phase with the triangular carrier wave, and based on the relative magnitudes of the modulation waves and the triangular carrier wave, the drive levels of the upper and lower bridge arm switching devices are directly generated, and complementary drive signals are obtained using inversion logic. On the one hand, this strictly ensures that the drive levels of the upper and lower bridge arms of the same phase are complementary, with strong logical constraints, effectively avoiding conduction abnormalities caused by control logic errors. On the other hand, relying on the regularized generation method of comparing the modulation waves and the triangular carrier wave, PWM pulse waveforms can be accurately generated, resulting in low harmonic content in the inverter output voltage and good sinusoidal waveform of the motor stator current. This effectively reduces compressor motor operating torque pulsation, electromagnetic noise, and operating losses, improving motor operating stability. Furthermore, using the instantaneous amplitudes of the modulation waves and the triangular carrier wave as the decision criteria, the switching time of the switching device drive levels is precisely controllable, with fast dynamic response speed. It can quickly update the PWM drive state following the modulation wave command, meeting the dynamic speed regulation control requirements of the compressor under variable speed and load conditions.

[0158] Specifically, see [link to relevant documentation] Figure 7 The method for generating drive signals for the switching devices in phase a of the compressor motor control circuit includes:

[0159] Comparison of phase a modulated wave With triangular carrier Size;

[0160] In phase a modulated wave Less than or equal to triangular carrier At that time, the drive signal of the first switching device in phase a of the motor control circuit is obtained. The signal is high; it is the drive signal for the first switching device. Inverting the signal yields the drive signal for the second switching device in phase a of the motor control circuit. Low level; in phase a modulated wave Greater than triangular carrier At that time, the drive signal of the first switching device in phase a of the motor control circuit is obtained. Low level; drive signal for the first switching device. Inverting the signal yields the drive signal for the second switching device in phase a of the motor control circuit. It is a high level.

[0161] Specifically, see [link to relevant documentation] Figure 7 The method for generating drive signals for the switching devices in phase b of the compressor motor control circuit includes:

[0162] Comparison of phase b modulated waves With triangular carrier Size;

[0163] In phase b modulation wave Less than or equal to triangular carrier At that time, the drive signal of the first switching device in phase b of the motor control circuit is obtained. The signal is high; it is the drive signal for the first switching device. Inverting the signal yields the drive signal for the second switching device in phase b of the motor control circuit. Low level; in phase b modulated wave Greater than triangular carrier At that time, the drive signal of the first switching device in phase b of the motor control circuit is obtained. Low level; drive signal for the first switching device. Inverting the signal yields the drive signal for the second switching device in phase b of the motor control circuit. It is a high level.

[0164] Specifically, see [link to relevant documentation] Figure 7 The methods for generating drive signals for the switching devices in phase c of the compressor motor control circuit include:

[0165] Comparison of C-phase modulated waves With triangular carrier Size;

[0166] In phase c modulated wave Less than or equal to triangular carrier At that time, the drive signal of the first switching device in phase c of the motor control circuit is obtained. The signal is high; it is the drive signal for the first switching device. Inverting the signal yields the drive signal for the second switching device in phase c of the motor control circuit. Low level; in the c-phase modulated wave Greater than triangular carrier At that time, the drive signal of the first switching device in phase c of the motor control circuit is obtained. Low level; drive signal for the first switching device. Inverting the signal yields the drive signal for the second switching device in phase c of the motor control circuit. It is a high level.

[0167] When the wide-frequency-range air conditioner compressor is controlled to operate using the above-described drive control method, the motor control circuit in the main topology circuit of the air conditioner compressor outputs three-phase AC, and the direction of the motor current can be one of the following: phase a current flows out of the motor, and phase b and phase c currents flow into the motor; phase b current flows out of the motor, and phase a and phase c currents flow into the motor; phase c current flows out of the motor, and phase a and phase b currents flow into the motor; phase a current flows into the motor, and phase b and phase c currents flow out of the motor; phase b current flows into the motor, and phase a and phase c currents flow out of the motor; phase c current flows into the motor, and phase a and phase b currents flow out of the motor. The following example demonstrates the relationship between current flow direction and switching device operation under six different switching states.

[0168] See Figure 8 Phase a current flows out of the motor, while phase b and phase c currents flow into the motor. At this time, the Si-Mos transistor in the phase a bridge arm... S a1 Conductive, Si-Mos transistor S a2 Disconnect; Si-Mos transistor in phase b bridge arm S b1 Disconnect, Si-Mos tube S b2 Conductive; Si-Mos transistor in phase c bridge arm S c1 Disconnect, Si-Mos tube S c2 Conduction. In phase a bridge arm, current flows through the inductor. L a Si-Mos tube S a1 The series path; in the b-phase bridge arm, current flows through the Si-Mos transistor. S b2 The path; in the c-phase bridge arm, current flows through the Si-Mos transistor. S c2 The path.

[0169] See Figure 9 The direction of the motor current is Figure 8 The current flows out of the motor in phase a, while the current flows into the motor in phases b and c. At this time, the Si-Mos transistor in the phase a bridge arm... S a1 Disconnect, Si-Mos tube S a2 Conductive; Si-Mos transistor in phase b bridge arm S b1 Disconnect, Si-Mos tube S b2 Conductive; Si-Mos transistor in phase c bridge arm Sc1 Disconnect, Si-Mos tube S c2 Conduction. In phase a bridge arm, current flows through the inductor. L a ,diode D a1 The series path flows through the Si-Mos tube simultaneously. S a2 The path; in phase b arm, current flows through the Si-Mos transistor. S b2 The path; in the c-phase bridge arm, current flows through the Si-Mos transistor. S c2 The path.

[0170] See Figure 10 Phase b current flows out of the motor, while phase a and phase c currents flow into the motor. At this time, the Si-Mos transistor in the phase a bridge arm... S a1 Disconnect, Si-Mos tube S a2 Conductive; Si-Mos transistor in phase b bridge arm S b1 Conductive, Si-Mos transistor S b2 Disconnect; Si-MoS tube in phase c bridge arm S c1 Disconnect, Si-Mos tube S c2 Conduction. In phase a bridge arm, current flows through the Si-Mos transistor. S a2 The path; in phase b bridge arm, current flows through the inductor L b Si-Mos tube S b1 The series path; in the c-phase bridge arm, current flows through the Si-Mos transistor. S c2 The path.

[0171] See Figure 11 The direction of the motor current is Figure 10 The current flows out of the motor in phase b, while phase a and phase c currents flow into the motor. At this time, the Si-Mos transistor in phase a bridge arm... S a1 Disconnect, Si-Mos tube S a2 Conductive; Si-Mos transistor in phase b bridge arm S b1 Disconnect, Si-Mos tube S b2 Conductive; Si-Mos transistor in phase c bridge armS c1 Disconnect, Si-Mos tube S c2 Conduction. In phase a bridge arm, current flows through the Si-Mos transistor. S a2 The path; in phase b bridge arm, current flows through the inductor L b ,diode D b1 The series path flows through the Si-Mos tube simultaneously. S b2 The path; in the c-phase bridge arm, current flows through the Si-Mos transistor. S c2 The path.

[0172] See Figure 12 Phase c current flows out of the motor, while phase a and phase b currents flow into the motor. At this time, the Si-Mos transistor in the phase a bridge arm... S a1 Disconnect, Si-Mos tube S a2 Conductive; Si-Mos transistor in phase b bridge arm S b1 Disconnect, Si-Mos tube S b2 Conductive; Si-Mos transistor in phase c bridge arm S c1 Conductive, Si-Mos transistor S c2 Disconnected. In phase a bridge arm, current flows through the Si-Mos transistor. S a2 The path; in phase b arm, current flows through the Si-Mos transistor. S b2 The path; in the c-phase bridge arm, current flows through the inductor. L c Si-Mos tube S c1 The serial path.

[0173] See Figure 13 The direction of the motor current is Figure 12 The currents are the same, meaning that phase c current flows out of the motor, while phase a current and phase b current flow into the motor. At this time, the Si-Mos transistor in the phase a bridge arm... S a1 Disconnect, Si-Mos tube S a2 Conductive; Si-Mos transistor in phase b bridge arm S b1 Disconnect, Si-Mos tube S b2Conductive; Si-Mos transistor in phase c bridge arm S c1 Disconnect, Si-Mos tube S c2 Conduction. In phase a bridge arm, current flows through the Si-Mos transistor. S a2 The path; in phase b arm, current flows through the Si-Mos transistor. S b2 The path; in the c-phase bridge arm, current flows through the inductor. L c ,diode D c2 The series path flows through the Si-Mos tube simultaneously. S c2 The path.

[0174] A third aspect of this invention provides a rapid air conditioner compressor speed observation system, used to implement the rapid air conditioner compressor speed observation method described in the first aspect of this invention. See also... Figure 14 The control system includes:

[0175] Module 1 is used to acquire the three-phase motor current, DC bus voltage, actual motor speed, and motor rotor position angle of the air conditioner compressor.

[0176] Setting module 2 is used to set the triangular carrier wave, switching cycle, motor speed setpoint, and preset coefficient group;

[0177] Rotation conversion module 3, based on the motor rotor position angle, converts the three-phase current of the motor into the actual value of the dq axis current;

[0178] PI control module 4 performs PI adjustment on the difference between the motor speed setpoint and the actual motor speed to obtain the q-axis current setpoint; performs PI adjustment on the difference between the q-axis current setpoint and the actual q-axis current to obtain the q-axis voltage setpoint; and performs PI adjustment on the difference between the d-axis current setpoint and the actual d-axis current to obtain the d-axis voltage setpoint.

[0179] The two-phase static conversion module 5 converts the dq-axis voltage setpoint to the α-axis voltage setpoint based on the motor rotor position angle.

[0180] The speed observation module 6 obtains the updated motor speed observation value based on the α-axis voltage setpoint and the output voltage with the frequency of the motor speed observation value.

[0181] The rotational inverse transformation module 7 transforms the given value of the dq axis voltage into the three-phase voltage in the abc coordinate system based on the rotor position angle of the motor.

[0182] The compressor drive modulation module 8 determines the projection area based on the magnitude of the three-phase voltage, calculates the initial duty cycle of the three phases based on the three-phase voltage and the preset coefficient group corresponding to the area, generates a three-phase modulation wave based on the initial duty cycle of the three phases, the DC bus voltage and the switching cycle, and generates the drive signal of the switching device in the compressor motor control circuit based on the magnitude of the three-phase modulation wave and the triangular carrier wave.

[0183] In this embodiment of the invention, the acquisition module uniformly collects multiple key operating parameters such as the three-phase current of the motor, the DC bus voltage, the actual value of the motor speed, and the rotor position angle of the motor. The signal dimensions are complete and the information coverage is comprehensive, providing accurate and real-time raw data support for subsequent coordinate transformation, closed-loop regulation, speed observation and modulation calculation, and ensuring the accuracy of the calculation basis of the entire control logic.

[0184] In this embodiment of the invention, the setting module centrally configures the triangular carrier wave, switching cycle, motor speed setpoint and preset coefficient group. The parameters are centralized and well-organized, and the configuration is flexible. It can adapt to the control requirements of different models and power air conditioning compressors, which facilitates parameter calibration and portability and reuse, and improves the generalization and engineering adaptability of the control system.

[0185] In this embodiment of the invention, relying on the rotation transformation module, the two-phase stationary transformation module, and the rotation inverse transformation module, and taking the real-time motor rotor position angle as the reference, the abc / dq, dq / α, and dq / abc multi-coordinate system precise transformations are realized in sequence. The transformation strictly follows the spatial vector law of motor vector control, fully preserves the current-voltage decoupling characteristics of the dq axis, and has no additional error in the transformation process, providing standardized coordinate domain calculation conditions for closed-loop regulation and speed observation.

[0186] In this embodiment of the invention, the PI control module constructs a dual closed-loop control architecture of speed outer loop + current inner loop, and independently adjusts the speed deviation and dq axis current deviation respectively. It can quickly track the speed and current setpoint, suppress dynamic fluctuations, and completely eliminate steady-state error. It can accurately realize the decoupled control of motor excitation and torque components, effectively reduce torque pulsation and electromagnetic noise, and improve the smoothness of compressor operation.

[0187] In this embodiment of the invention, the speed observation module updates the speed observation value by iterative calculation based on the given value of the α-axis voltage and the output voltage. It does not rely on motor body parameters such as stator resistance, inductance, and rotor flux linkage, thus avoiding the accuracy degradation caused by temperature rise, magnetic saturation, and parameter drift. It breaks through the bottleneck of low-speed observation failure of traditional observers and can achieve accurate observation across the entire speed range from zero speed, low speed to high speed. It has fast convergence, small overshoot, low tracking lag, and strong anti-interference ability when the speed changes dynamically.

[0188] In this embodiment of the invention, the compressor drive modulation module outputs a switching drive signal by matching a preset coefficient group through regional projection, calculating the duty cycle, generating a three-phase modulation wave, and comparing the carrier. The logic link is complete and well-organized. It generates a modulation wave in real time by combining the DC bus voltage and the switching cycle, and has the ability to adaptively compensate for DC bus voltage fluctuations. The PWM waveform generation accuracy is high, and the upper and lower bridge arm drive signals are complementary and reliable, effectively reducing inverter harmonic losses and adapting to the actual drive requirements of compressors under wide operating conditions, frequent start-stop, and full-speed range regulation.

[0189] To verify the effectiveness of the above-mentioned method and control system for rapid observation of air conditioner compressor speed, a simulation model of the rapid observation system for air conditioner compressor speed was built in Matlab / Simulink. DC bus voltage The voltage is 540V, and the air conditioner compressor speed rapid observation module is located in [location missing]. The size is , The size is 2. The parameters of the permanent magnet synchronous motor M are as follows: stator resistance is 0.63Ω, direct-axis inductance is 0.00268H, quadrature-axis inductance is 0.0347H, flux linkage is 0.142Wb, and moment of inertia is 0.00057kg·m. 2 The number of pole pairs is 3, the initial speed of the motor is 300 rpm, which increases by 300 rpm at 1s and 2s respectively, and the load torque is 7.5 N·m. Figure 15 The actual value of motor speed observed using a traditional frequency-locked loop. and motor speed observation value It can be seen that the speed tracking speed is slow when the speed changes abruptly. Figure 16 To use a rapid observation method for air conditioner compressor speed and the actual value of motor speed observed by the system. and motor speed observation value The simulation results show that the motor speed can be accurately tracked when there are sudden changes in motor speed. These results demonstrate the effectiveness of the present invention.

[0190] The above embodiments are used to explain the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A method for rapid observation of air conditioner compressor speed, characterized in that, include: Rotation transformation steps: Based on the motor rotor position angle, transform the three-phase current of the motor into the actual value of the dq axis current; PI control steps: The difference between the motor speed setpoint and the actual motor speed is used to obtain the q-axis current setpoint; the difference between the q-axis current setpoint and the actual q-axis current is used to obtain the q-axis voltage setpoint; the difference between the d-axis current setpoint and the actual d-axis current is used to obtain the d-axis voltage setpoint. Two-phase stationary transformation steps: Based on the motor rotor position angle, transform the dq-axis voltage setpoint to the α-axis voltage setpoint; Speed ​​observation steps: Based on the given α-axis voltage value and the output voltage with frequency equal to the observed motor speed value, the updated observed motor speed value is obtained; Methods for obtaining observed motor speed values ​​include: The first difference is obtained by subtracting the output voltage from the given α-axis voltage value. The first intermediate value is obtained by integrating the output voltage and multiplying it by the observed motor speed. Multiply the first difference by the first median value to get the second median value; Multiply the second intermediate value by the negative damping coefficient to obtain the third intermediate value; Add the square of the output voltage to the square of the first intermediate value, and take the reciprocal to obtain the fourth intermediate value; Multiply the third intermediate value by the fourth intermediate value, then multiply by the square of the observed motor speed, and integrate to obtain the updated observed motor speed.

2. The method for rapid observation of air conditioner compressor speed as described in claim 1, characterized in that, In the PI control step, the method for obtaining the q-axis current setpoint by PI adjustment of the difference between the motor speed setpoint and the actual motor speed includes: The first setpoint is obtained by multiplying the difference between the motor speed setpoint and the actual motor speed by the proportional coefficient of the speed loop PI regulator. The difference between the setpoint motor speed and the actual motor speed is multiplied by the integral coefficient of the speed loop PI regulator, and then integrated to obtain the second setpoint. Add the first given value to the second given value to obtain the q-axis current given value.

3. The method for rapid observation of air conditioner compressor speed as described in claim 1, characterized in that, In the PI control step, the method for obtaining the q-axis voltage setpoint by PI adjustment of the difference between the q-axis current setpoint and the actual q-axis current value includes: The third setpoint is obtained by multiplying the difference between the q-axis current setpoint and the actual q-axis current value by the proportional coefficient of the q-axis current loop PI regulator. Multiply the difference between the q-axis current setpoint and the actual q-axis current by the integral coefficient of the q-axis current loop PI regulator, and then integrate to obtain the fourth setpoint. Adding the third given value to the fourth given value yields the q-axis voltage given value.

4. The method for rapid observation of air conditioner compressor speed as described in claim 1, characterized in that, In the PI control step, the method for obtaining the d-axis voltage setpoint by PI adjustment of the difference between the d-axis current setpoint and the actual d-axis current value includes: The fifth setpoint is obtained by multiplying the difference between the d-axis current setpoint and the actual d-axis current value by the proportional coefficient of the d-axis current loop PI regulator. Multiply the difference between the d-axis current setpoint and the actual d-axis current value by the integral coefficient of the d-axis current loop PI regulator, and then integrate to obtain the sixth setpoint. Add the fifth given value to the sixth given value to obtain the d-axis voltage given value.

5. The method for rapid observation of air conditioner compressor speed as described in claim 1, characterized in that, Methods for correcting output voltage include: Multiply the first difference by a set scaling factor, and then subtract the first intermediate value to obtain the fifth intermediate value; Multiply the fifth intermediate value by the observed motor speed to obtain the sixth intermediate value; Integrating the sixth intermediate value yields the corrected output voltage.

6. The method for rapid observation of air conditioner compressor speed as described in claim 1, characterized in that, The method further includes: Rotational inverse transformation steps: Based on the motor rotor position angle, transform the given dq axis voltage values ​​into three-phase voltages in the abc coordinate system; Compressor drive modulation steps: Determine the projection area based on the magnitude of the three-phase voltage; calculate the initial duty cycle of the three phases based on the three-phase voltage and the preset coefficient group corresponding to the area; generate a three-phase modulation wave based on the initial duty cycle of the three phases, the DC bus voltage, and the switching cycle; generate the drive signal for the switching devices in the compressor motor control circuit based on the magnitude of the three-phase modulation wave and the triangular carrier wave.

7. The method for rapid observation of air conditioner compressor speed as described in claim 6, characterized in that, In the compressor drive modulation step, the method for determining the projection area based on the magnitude of the three-phase voltage includes: Compare the magnitudes of the three voltages: phase a voltage, phase b voltage, and phase c voltage. If phase a voltage is the largest, then the projection area is determined as region 1; if phase b voltage is the largest, then the projection area is determined as region 2; if phase c voltage is the largest, then the projection area is determined as region 3. The preset coefficient group corresponding to region 1 is: , , , , , , , , The preset coefficient group corresponding to region 2 is: , , , , , , , , The preset coefficient group corresponding to region 3 is: , , , , , , , , ; The formula for calculating the initial duty cycle of the three phases is expressed as follows: In the formula, Let a be the initial duty cycle of phase a. The initial duty cycle of phase b. This represents the initial duty cycle of phase c.

8. The method for rapid observation of air conditioner compressor speed as described in claim 6, characterized in that, In the compressor drive modulation step, the method for generating a three-phase modulation wave includes: multiplying the reciprocal of the DC bus voltage by the switching period, and then multiplying by the initial duty cycle of phase i to obtain the phase i modulation wave, i=a,b,c.

9. The method for rapid observation of air conditioner compressor speed as described in claim 6, characterized in that, In the compressor drive modulation step, the method for generating drive signals for the switching devices in the compressor motor control circuit includes: Compare the magnitudes of the i-phase modulated wave and the triangular carrier wave; When the i-phase modulation wave is less than or equal to the triangular carrier wave, the drive signal of the first switching device in the i-phase of the motor control circuit is high; by inverting the drive signal of the first switching device, the drive signal of the second switching device in the i-phase of the motor control circuit is low; when the i-phase modulation wave is greater than the triangular carrier wave, the drive signal of the first switching device in the i-phase of the motor control circuit is low; by inverting the drive signal of the first switching device, the drive signal of the second switching device in the i-phase of the motor control circuit is high.

10. A rapid air conditioning compressor speed observation system, used to implement the rapid air conditioning compressor speed observation method as described in any one of claims 1 to 9, characterized in that, include: The acquisition module is used to acquire the three-phase current of the air conditioner compressor motor, the DC bus voltage, the actual value of the motor speed, and the motor rotor position angle; The setting module is used to set the triangular carrier wave, switching cycle, motor speed setpoint, and preset coefficient group; The rotation conversion module converts the three-phase current of the motor into the actual value of the dq axis current based on the rotor position angle of the motor. The PI control module adjusts the difference between the motor speed setpoint and the actual motor speed to obtain the q-axis current setpoint, adjusts the difference between the q-axis current setpoint and the actual q-axis current to obtain the q-axis voltage setpoint, and adjusts the difference between the d-axis current setpoint and the actual d-axis current to obtain the d-axis voltage setpoint. The two-phase stationary conversion module transforms the dq-axis voltage setpoint into the α-axis voltage setpoint based on the motor rotor position angle. The speed observation module obtains updated motor speed observation values ​​based on the α-axis voltage setpoint and the output voltage with a frequency equal to the motor speed observation value. The rotational inverse transformation module transforms the given dq-axis voltage into three-phase voltages in the abc coordinate system based on the motor rotor position angle. The compressor drive modulation module determines the projection area based on the magnitude of the three-phase voltage, calculates the initial duty cycle of the three phases based on the three-phase voltage and the preset coefficient group corresponding to the area, generates a three-phase modulation wave based on the initial duty cycle of the three phases, the DC bus voltage and the switching cycle, and generates the drive signal of the switching device in the compressor motor control circuit based on the magnitude of the three-phase modulation wave and the triangular carrier wave.

Images