An air conditioning control system

Abstract

The present disclosure provides an air conditioner control system, and relates to the technical field of motor control. The air conditioner control system comprises a repetitive controller and a motor. The repetitive controller is connected with the motor. The repetitive controller is used for adjusting the rotating speed of the motor. The repetitive controller comprises a low-pass filter, a compensator, a rotating speed regulator and a discrete transfer; the compensator is connected with the low-pass filter and the rotating speed regulator respectively, and the rotating speed regulator is connected with the discrete transfer; the repetitive controller is configured to meet: the air conditioner control system provided by the present disclosure can suppress the rotating speed fluctuation of the compressor.

Description

Technical Field

[0001] This disclosure relates to the field of motor control technology, and in particular to an air conditioning control system. Background Technology

[0002] Inverter air conditioners use an inverter to adjust the compressor's operating frequency, thereby changing the compressor speed and controlling room temperature. When the room temperature reaches the set temperature, the inverter air conditioner's compressor enters a low-frequency operating mode. This effectively reduces the air conditioner's power consumption, minimizes room temperature fluctuations, avoids frequent compressor starts, and extends the compressor's lifespan.

[0003] However, at low speeds, the air conditioner compressor exhibits significant pulse-like fluctuations in speed. This is because the quadrature-axis current controlling the motor's electromagnetic torque cannot change with the sudden changes in load torque, resulting in an imbalance between the electromagnetic torque and the load torque. Consequently, the air conditioner cannot operate stably at low frequencies, leading to severe vibrations.

[0004] Therefore, how to suppress compressor speed fluctuations is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] Embodiments of this disclosure provide an air conditioning control system for suppressing compressor speed fluctuations.

[0006] To achieve the above objectives, the embodiments of this disclosure adopt the following technical solutions:

[0007] In a first aspect, an air conditioning control system is provided, comprising a repetitive controller and a motor; the repetitive controller is connected to the motor; the repetitive controller is used to regulate the speed of the motor. The repetitive controller includes a low-pass filter, a compensator, a speed regulator, and a discrete transmitter; the compensator is connected to both the low-pass filter and the speed regulator, and the speed regulator is connected to the discrete transmitter.

[0008] The repeat controller is configured to satisfy:

[0009] Where Q(Z) is a function of the low-pass filter, S(Z) is a function of the compensator in the discrete domain, Gpi(Z) is a function of the speed regulator, and Gp(Z) is a discrete transfer function of the discrete transmitter.

[0010] In some embodiments, the low-pass filter is configured to pass signals below the cutoff frequency and filter signals above the cutoff frequency; the low-pass filter is also configured to have a filter function in the discrete domain as: q(Z)=(K1*Z+K2) / (Z 2–K3*Z+K4), where q(Z) is the filtering function of the low-pass filter in the discrete domain, Z is the discrete variable in the discrete domain, K1 is the first preset filtering parameter, K2 is the first preset filtering parameter, K3 is the first preset filtering parameter, K4 is the first preset filtering parameter, and K1, K2, K3, and K4 are all greater than 0; the compensator is configured such that its input and output in the discrete domain satisfy:

[0011] Y(Z) = (1 / 1 + t) * Z -1 *Y(Z)+(t / 1+t)*U(Z), where Y(Z) is the input of the compensator in the discrete domain, U(Z) is the output of the compensator in the discrete domain, t is the time of a single step in the discretization process, and Z is the discrete variable in the discrete domain.

[0012] In some embodiments, the low-pass filter is further configured such that its function in the discrete domain is: Q(Z) = q(Z)*Z n Where Q(Z) is the function of the low-pass filter in the discrete domain, q(Z) is the filtering function of the low-pass filter in the discrete domain, and Z... n This is the compensation function for the low-pass filter.

[0013] In some embodiments, the compensator is further configured to function in the discrete domain as: S(Z) = q(Z)*Z m Where S(Z) is the function of the compensator in the discrete domain, q(Z) is the filtering function of the low-pass filter, and Z... m This is the lead function of the compensator.

[0014] In some embodiments, the transfer function of the compensator in the discrete domain satisfies: Where G(Z) is the transfer function of the compensator in the discrete domain, t is the time of a single step in the discretization process, and Z is the discrete variable in the discrete domain.

[0015] In some embodiments, the repetitive controller further includes a periodic delay element Z. -N .

[0016] In some embodiments, Z n In this context, n takes the value 16, K1 takes the value 0.006302, K2 takes the value 0.004977, K3 takes the value 1.48, and K4 takes the value 0.4915.

[0017] In some embodiments, the low-pass filter is a second-order Butterworth low-pass filter or a first-order low-pass filter.

[0018] In some embodiments, the cutoff frequency of the low-pass filter is 1 Hz.

[0019] This disclosure provides an air conditioning control system, which brings the following beneficial effects: A repetitive controller is added to the air conditioning control system. The repetitive controller includes a low-pass filter, a compensator, a speed regulator, and a discrete transmitter. The compensator is connected to both the low-pass filter and the speed regulator, and the speed regulator is connected to the discrete transmitter. The repetitive controller is configured to satisfy the following:

[0020] Where Q(Z) is a function of the low-pass filter, S(Z) is a function of the compensator in the discrete domain, Gpi(Z) is a function of the speed regulator, and Gp(Z) is a discrete transfer function of the discrete transmitter.

[0021] Thus, by configuring a repetitive controller, the transfer function of the repetitive controller reaches the stability condition of the air conditioning control system, thereby ensuring the stability of the air conditioning control system, stabilizing the motor speed, suppressing compressor speed fluctuations, and ensuring stable operation of the air conditioning control system.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0023] Figure 1 One of the structural schematic diagrams of an air conditioning control system provided as an embodiment of this disclosure;

[0024] Figure 2 A second schematic diagram of the structure of an air conditioning control system provided as an embodiment of this disclosure;

[0025] Figure 3 A third schematic diagram of an air conditioning control system provided as an embodiment of this disclosure;

[0026] Figure 4 A fourth schematic diagram of an air conditioning control system provided as an embodiment of this disclosure;

[0027] Figure 5 A phase-frequency waveform diagram is provided for embodiments of this disclosure;

[0028] Figure 6 An amplitude-frequency waveform diagram is provided for embodiments of this disclosure;

[0029] Figure 7 Fifth schematic diagram of an air conditioning control system provided as an embodiment of this disclosure;

[0030] Figure 8 One of the schematic diagrams of an electric motor provided for embodiments of this disclosure;

[0031] Figure 9A second schematic diagram of an electric motor provided as an embodiment of this disclosure;

[0032] Figure 10 A speed waveform diagram without adding a repetitive controller is provided for an embodiment of this disclosure;

[0033] Figure 11 A speed waveform diagram with an added repetitive controller is provided for embodiments of this disclosure;

[0034] Figure 12 This is the sixth schematic diagram of an air conditioning control system provided as an embodiment of the present disclosure. Detailed Implementation

[0035] The technical solutions of the embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0036] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" and its other forms, such as the third-person singular "comprising" and the present participle "comprising," are interpreted as open-ended and inclusive, meaning "including, but not limited to." That is, words such as "comprising" or "including" indicate that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0037] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0038] In the description of this disclosure, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone.

[0039] As used herein, depending on the context, the term “if” may optionally be interpreted as meaning “when”, “in the event of”, “in response to determination”, or “in response to detection”. Similarly, depending on the context, the phrase “if it is determined that…” or “if [the stated condition or event] is detected” may optionally be interpreted as meaning “in the event of determination that…”, “in response to determination that…”, “when [the stated condition or event] is detected”, or “in response to the detection of [the stated condition or event]”.

[0040] The use of “applies to” or “configured to” in this article implies an open and inclusive language that does not preclude applicability to or configuration to devices that perform additional tasks or steps.

[0041] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0042] First, a brief introduction to the relevant elements involved in this disclosure.

[0043] The cutoff frequency, when the input signal amplitude remains constant and the frequency is changed to reduce the output signal to 0.707 times its maximum value, is expressed in terms of frequency response characteristics at the -3dB point. It is a special frequency used to describe frequency characteristics. The cutoff frequency also refers to the boundary frequency at which the output signal energy of a system begins to decrease significantly or, in a band-stop filter, increases significantly (generally defined as -3dB).

[0044] A low-pass filter is an electronic filter that allows signals below the cutoff frequency to pass through, but blocks signals above the cutoff frequency.

[0045] The transfer function is the ratio of the Laplace transform (or z-transform) of the response (output) of a linear system under zero initial conditions to the Laplace transform of the excitation (input). It is denoted as G(s) = Y(s) / U(s), where Y(s) and U(s) are the Laplace transforms of the output and input, respectively.

[0046] A proportional-integral controller (PI controller) is a linear controller that uses the control deviation between a given value and the actual output value as a basis. It then combines the proportional and integral components of this deviation linearly to form the control quantity, thereby controlling the controlled object.

[0047] A permanent magnet synchronous motor (PMSM) is a type of synchronous motor in which the rotor uses permanent magnets instead of wound wires.

[0048] Secondly, a brief introduction to the application scenarios involved in this disclosure will be given.

[0049] Inverter air conditioners use an inverter to adjust the compressor's operating frequency, thereby changing the compressor speed and controlling room temperature. When the room temperature reaches the set temperature, the inverter air conditioner's compressor enters a low-frequency operating mode. This effectively reduces the air conditioner's power consumption, minimizes room temperature fluctuations, avoids frequent compressor starts, and extends the compressor's lifespan.

[0050] However, at low speeds, the air conditioner compressor exhibits significant pulse-like fluctuations in speed. This is because the quadrature-axis current controlling the motor's electromagnetic torque cannot change with the sudden changes in load torque, resulting in an imbalance between the electromagnetic torque and the load torque. Consequently, the air conditioner cannot operate stably at low frequencies, leading to severe vibrations.

[0051] Specifically, the compressor controls temperature by exchanging heat through air intake and exhaust. At high frequencies, the compressor's cycle is relatively smooth due to its short cycle length. However, at low speeds, the cycle length is also short, resulting in more noticeable fluctuations throughout the compression cycle. This not only makes the internal piping of the air conditioner more susceptible to damage, reducing its lifespan, but also generates significant noise during low-frequency operation, negatively impacting the user experience.

[0052] Therefore, how to suppress compressor speed fluctuations is a technical problem that urgently needs to be solved.

[0053] To address the aforementioned problems, this disclosure provides an air conditioning control system, which includes a repetitive controller and a motor. The repetitive controller is connected to the motor and is used to regulate the motor speed. The repetitive controller includes a low-pass filter, a compensator, a speed regulator, and a discrete transmitter. The compensator is connected to both the low-pass filter and the speed regulator, and the speed regulator is connected to the discrete transmitter. The repetitive controller is configured to satisfy:

[0054] Where Q(Z) is a function of the low-pass filter, S(Z) is a function of the compensator in the discrete domain, Gpi(Z) is the function of the speed regulator, and Gp(Z) is the discrete transfer function of the discrete transmitter.

[0055] Thus, by configuring a repetitive controller, the transfer function of the repetitive controller reaches the stability condition of the air conditioning control system, thereby ensuring the stability of the air conditioning control system, stabilizing the motor speed, suppressing compressor speed fluctuations, and ensuring stable operation of the air conditioning control system.

[0056] Finally, a brief introduction is given to the implementation environment (implementation architecture) involved in the methods provided in this disclosure.

[0057] The air conditioning control system provided in this embodiment of the disclosure Figure 1 A schematic diagram of one structure of the air conditioning control system is shown. For example... Figure 1 As shown, the air conditioning control system 10 includes a motor 101 and a repeater controller 102. The motor 101 is connected to the repeater controller 102.

[0058] It should be noted that the air conditioning control system 10 may also include other devices, such as speed regulators, current regulators, Parker converters, and three-phase thin-film capacitor drivers. The air conditioning control system will not be described in detail here, but can be referred to in the following embodiments.

[0059] Specifically, such as Figure 2 As shown, the repetitive controller includes a low-pass filter Q(Z), a compensator S(Z), a speed regulator Gpi(Z), and a discrete transmitter Gp(Z). The compensator is connected to the low-pass filter and the speed regulator, respectively, and the speed regulator is connected to the discrete transmitter.

[0060] In some embodiments, such as Figure 2 As shown, the low-pass filter Q(Z) also includes a periodic delay element Z. -N .

[0061] In a design, combining Figure 2 ,like Figure 3 As shown, the repetitive controller 102 also includes a periodic delay element Z. -N Periodic delay element Z -N It is connected to the low-pass filter Q(Z) and the compensator S(Z) respectively.

[0062] Specifically, in Figure 3 In the process, the repetitive controller receives the input speed difference r(Z) (the difference between the given value of the motor's electric angular velocity and the feedback value of the motor's electric angular velocity), and outputs the target speed signal y(Z) through the transfer function in the repetitive controller 102.

[0063] exist Figure 3 In this diagram, Gp(Z) is the discrete transfer function of the compressor's dual closed-loop control system. Gpi(Z) is the speed regulator, employing a PI controller. GRP(z) is a function of the basic repetitive controller in the repetitive controller. The repetitive controller adjusts the input speed to eventually equal the desired speed value (i.e., the target speed signal y(Z)) when the speed feedback value is not zero.

[0064] For example, when the speed feedback value is greater than 0, the repetitive controller outputs a positive value, the system command value increases, and the output increases under the action of the PI controller. At this time, although the speed feedback value still exists, it gradually tends to 0 under the action of the repetitive controller 102, eventually achieving speed stability.

[0065] Combination Figure 3 ,exist Figure 4 It also includes the input noise d(z) and the preset noise transfer function Gd(Z).

[0066] It should be noted that the repetitive controller, low-pass filter, compensator, speed regulator, discrete transmitter, and periodic delay element in the embodiments of this disclosure are not logic controllers. The repetitive controller can be regarded as a control algorithm.

[0067] To better illustrate the repeat controller in this disclosure, in conjunction with the above... Figures 1-4 This disclosure provides an air conditioning control system including a repetitive controller and a motor. A speed regulator is connected to the motor; the repetitive controller is used to regulate the motor speed. The repetitive controller includes a low-pass filter, a compensator, a speed regulator, and a discrete transmitter; the compensator is connected to both the low-pass filter and the speed regulator, and the speed regulator is connected to the discrete transmitter; the repetitive controller is configured to satisfy:

[0068] Where Q(Z) is a function of the low-pass filter, S(Z) is a function of the compensator in the discrete domain, Gpi(Z) is the function of the speed regulator, and Gp(Z) is the discrete transfer function of the discrete transmitter.

[0069] Specifically, the transfer function of the repetitive controller system is as shown in Formula 1 below:

[0070]

[0071] Where y(Z) is the output target speed signal, Grp(Z) is the function of the basic repetitive controller, Gpi(Z) is the speed regulator, Gp(Z) is the discrete transfer function of the discrete transmitter, r(Z) is the input speed difference, and Gd(Z) is the preset noise transfer function.

[0072] The specific formula for Grp(Z) in Formula 1 is shown in Formula 2 below:

[0073]

[0074] Where Grp(Z) is the function of the basic repetitive controller, Z -N For the periodic delay element, S(Z) is a function of the compensator, and Q(Z) is a function of the low-pass filter.

[0075] The necessary and sufficient condition for the stability of an air conditioning control system is that the poles of the closed-loop transfer function are located inside the unit circle, that is, the roots of Equation 3 are located inside the unit circle, as described in Equation 3 below:

[0076]

[0077] Where Grp(Z) is the function of the basic repetitive controller, Gpi(Z) is the speed regulator, and Gp(Z) is the discrete transfer function of the discrete transmitter.

[0078] Substituting Formula 3 into Formula 1, we get Formula 4:

[0079]

[0080] Among them, Z -N For the periodic delay element, S(Z) is the function of the compensator, Q(Z) is the function of the low-pass filter, Gpi(Z) is the function of the speed regulator, and Gp(Z) is the discrete transfer function of the discrete transmitter.

[0081] The condition for a stable air conditioning control system is that it meets Formula 5:

[0082]

[0083] Where Q(Z) is a function of the low-pass filter, S(Z) is a function of the compensator in the discrete domain, Gpi(Z) is the speed regulator, and Gp(Z) is the discrete transfer function of the discrete transmitter.

[0084] It is evident that, based on the repetitive controller designed in this disclosure, when the repetitive controller satisfies Formula 5, it can control the stable operation of the air conditioning control system, thereby stabilizing the motor running speed and suppressing the compressor speed fluctuation.

[0085] Furthermore, the air conditioning control system provided in this embodiment adds a logic control module: a repeater controller, to suppress compressor speed fluctuations. Thus, without increasing costs, compressor speed fluctuations are suppressed, preventing severe air conditioner vibration and improving the user experience.

[0086] Furthermore, based on Formula 5 above, the stability of the air conditioning control system with a repetitive controller depends on the parameter design of Q(z) and S(z) (only the parameter design of these two is considered, because the other two factors are known and fixed). The configuration methods of each component in the repetitive controller are described in detail below.

[0087] First, regarding low-pass filters.

[0088] When configuring a low-pass filter, two aspects need to be considered: first, to ensure the stability of the air conditioning control system, and second, to improve the accuracy of the air conditioning control system.

[0089] Specifically, in the low-frequency range of system operation, when |Q(Z)-Gp(Z)S(Z)|<1, the air conditioning control system is stable. At this time, the amplitude of the low-pass filter should be as close as possible to 1 (i.e., converted according to equation (1-5)) to ensure that the error signal is sufficiently attenuated at the repetition frequency, thereby ensuring the steady-state characteristics of the system. In the high-frequency range where |1-Gp(Z)S(Z)|>1, the amplitude of the low-pass filter should be attenuated to a value much less than 1 to ensure system stability.

[0090] In some designs, Butterworth low-pass filters are chosen to improve response speed and system stability; filters of appropriate order should be selected.

[0091] Since the low-pass filter Q(Z) has an approximately linear phase-frequency response in the low-frequency range, a phase-leading element is needed to compensate for the lagging phase. Therefore, the structure of the low-pass filter Q(Z) is shown in Formula 6:

[0092] Q(Z)=q(Z)*Z n Formula Six

[0093] Where Q(Z) is a function of the low-pass filter, q(Z) is the filter function, and Z is the value of Z. n This is the compensation function.

[0094] In some embodiments, the low-pass filter can be a second-order Butterworth low-pass filter.

[0095] In other embodiments, the low-pass filter can be a first-order low-pass filter.

[0096] It should be noted that any low-pass filter in this disclosure can represent low-pass characteristics, and the embodiments of this disclosure do not limit the low-pass filter.

[0097] Since the discrete transfer function Gp(Z) yields its amplitude-frequency response and phase-frequency response diagrams, the function of Gp(Z) in the complex frequency domain is as shown in Equation 7:

[0098]

[0099] Where Gp(s) is the discrete transfer function in the complex frequency domain, Kp is the current loop proportionality coefficient, T is the current loop operation period, L is the dq-axis equivalent inductance, and s is the complex variable in the complex domain.

[0100] The discrete transfer function Gp(Z) in the discrete domain is shown in Equation 8 below:

[0101]

[0102] Where Gp(z) is the discrete transfer function in the discrete domain, Kp is the current loop scaling factor, T is the current loop operation period, L is the dq-axis equivalent inductance, and Z is the discrete variable in the discrete domain.

[0103] like Figure 5 and Figure 6 As shown, Figure 5 A Bode plot is shown, illustrating the relationship between phase and frequency. Figure 6 The relationship between amplitude (mignatude) and frequency (frequency) is shown.

[0104] Combination Figure 5 and Figure 6 It can be seen that the phase frequency decreases as the frequency increases, and the amplitude frequency also decreases as the frequency increases. That is, both the phase frequency and amplitude frequency are negatively correlated with the frequency.

[0105] As can be seen from the Bode plot of the transfer function in the complex frequency domain, the amplitude of the system transfer function is basically 0 in the low frequency range. The conversion formula from the complex frequency domain to the discrete domain is shown in Formula Nine below:

[0106] Z = e T Formula Nine

[0107] Where Z is a discrete variable in the discrete domain, e is a natural constant, and T is the current loop operation period.

[0108] Since the discrete transfer function of the air conditioning control system has an amplitude of approximately 1 in the low-frequency range, based on the phase frequency and amplitude frequency characteristics of the discrete transfer function, the filtering function of the low-pass filter in the discrete domain is determined in this embodiment: q(Z)=(K1*Z+K2) / (Z 2 –K3*Z+K4).

[0109] Specifically, when K1 is 0.006302, K2 is 0.004977, K3 is 1.48, and K4 is 0.4915, the filtering function of the low-pass filter in the discrete domain is as shown in Formula 10 below:

[0110]

[0111] Where q(Z) is the filter function, and Z is the discrete variable in the discrete domain (i.e., the discrete domain operator).

[0112] Compensation function Z n In the case of n=16.

[0113] Thus, the configured low-pass filter Q(Z) can ensure that the error signal is sufficiently attenuated at the repetition frequency, thereby ensuring the steady-state characteristics of the system.

[0114] The compensator is configured as follows.

[0115] The design of the compensator S(Z) must consider the amplitude and phase of the compensator Gp(Z). Compensation must be applied to both the amplitude and phase of Gp(Z) to improve the stability and disturbance rejection capability of the air conditioning control system. The air conditioning control system exhibits the best dynamic and static characteristics when |1-Gp(Z)S(Z)|=1. However, since Gp(Z) is a function with low-pass characteristics, the compensator S(Z) cannot have the inverse characteristics of Gp(Z) across the entire frequency band. Considering all factors, the compensator S(Z) adopts the following structure, as shown in Formula 11:

[0116] S(Z)=s(Z)*Z m Formula Eleven

[0117] Where S(Z) is the function of the compensator, s(Z) is the function of the low-pass filter in the discrete Z-domain, and Z... m This is a function for the leading element.

[0118] Let the current complex frequency domain S-domain transfer function be Equation XII as follows:

[0119]

[0120] Where G(s) is the transfer function in the S-domain, Y(s) is the input of the compensator in the S-domain, U(s) is the output of the compensator in the S-domain, and s is a complex variable in the complex domain (also called a function in the complex domain).

[0121] If the low-pass filter is a second-order low-pass filter, then s is the symbolic value of the second-order system representation in the complex domain.

[0122] By discretizing it using the forward difference method, we obtain the following formula thirteen:

[0123]

[0124] Where s is a complex variable in the complex field, Z is a discrete variable in the discrete field, and t is the time of a single step in the discretization process.

[0125] Thus, the transfer function of the compensator in the discrete Z-domain is determined as shown in Formula Fourteen below:

[0126]

[0127] Where G(Z) is the transfer function of the compensator in the discrete domain, Y(Z) is the input of the compensator, U(Z) is the output of the compensator, t is the time of a single step in the discretization process, and Z is the discrete variable in the discrete domain.

[0128] Simplifying and integrating Formula 14 above yields the relationship between input and output, as shown in Formula 15 below:

[0129]

[0130] Where Y(Z) is the input of the compensator, U(Z) is the output of the compensator, t is the single step time in the discretization process, and Z is the discrete variable in the discrete domain. It should be noted that in the embodiments of this disclosure, taking S(Z) = 1 is sufficient to meet the requirements of Gp(Z) in the low-frequency band.

[0131] Additionally, in some examples, to make ∠Gp(Z)S(Z)Z m ≈0. In this embodiment, the advance compensation amount is taken as m=13, where m and n are opposites and have the same meaning, both representing the order.

[0132] To better stabilize the air conditioning control system, a periodic delay element Z is also configured in this embodiment. -N .

[0133] Since the repetitive controller in this embodiment of the present disclosure is configured with a periodic delay element, the error signal of one control cycle can only affect the control quantity of the next control cycle. Therefore, the control response of the repetitive controller is delayed by one cycle.

[0134] Once the permanent magnet synchronous motor reaches its given speed and operates stably, the speed command on the speed control loop of the air conditioning control system becomes constant, while the feedback speed caused by the periodic fluctuations in the load becomes an alternating variable. Both can be considered as periodically changing repetitive quantities, thus allowing for regulation using a repetitive control system. However, the delay element also affects the response speed, causing control lag, which requires compensation. Furthermore, the periodic delay element is also necessary for achieving phase lead compensation.

[0135] In some embodiments, the cutoff frequency of the low-pass filter is 1 Hz.

[0136] In some embodiments, the damping of the low-pass filter is greater than a preset threshold.

[0137] Understandably, the damping ratio of a low-pass filter can be appropriately increased to reduce speed overshoot.

[0138] The air conditioning control system provided in this embodiment of the present disclosure has the following beneficial effects: by configuring a repetitive controller, the transfer function of the repetitive controller reaches the stability condition of the air conditioning control system, so that the air conditioning control system meets the stability condition, thereby stabilizing the motor running speed and suppressing the speed fluctuation of the compressor, so that the air conditioning control system can operate stably.

[0139] To further illustrate the repeater controller in the embodiments of this disclosure, this disclosure also discloses an air conditioning control system, such as... Figure 7 As shown. In Figure 7 The air conditioning control system includes a repetitive controller, a speed regulator, a q-axis current controller, a d-axis current controller, a space vector pulse width modulation (SVPWM) operation unit, a PMSM, a rotor position observer, a Clarke transform unit, a Parker transform unit, a capacitor driver, and an inverse Parker transform module.

[0140] Specifically, the q-axis current command I is calculated through the speed regulator. q *, d-axis current command I d * and q-axis current command I q *The d-axis voltage command U is obtained through the current regulator. d * and q-axis voltage command U q * .

[0141] d-axis voltage command U d * and q-axis voltage command U q *The α-axis voltage U is obtained through the inverse Park transformation unit. α and β-axis voltage U β The input is used to drive and control the system via the SVPWM arithmetic unit.

[0142] In addition, i a Let i be the phase a current in a three-phase stationary coordinate system. b Let i be the phase b current in a three-phase stationary coordinate system. c Let I be the c-phase current in a three-phase stationary coordinate system. α Let I be the α-axis current in a two-phase stationary coordinate system. β I represents the β-axis current in a two-phase stationary coordinate system. d * represents the direct-axis current setpoint. I q * represents the quadrature-axis current setpoint. U d U is the d-axis voltage output value. q This is the q-axis voltage output value. ω * m The given value is the electric angular velocity of the motor. This is the feedback value of the motor's electrical angular velocity. I represents the rotor's position angle. d I is the direct-axis current value. q This is the quadrature-axis current value.

[0143] PMSMs are classified into surface-mounted PMSMs and built-in PMSMs based on the structure of the rotor magnetic poles. Figure 8A surface-mount PMSM is shown. Figure 9 A built-in PMSM is shown. The types of PMSMs are not specifically limited in this disclosure embodiment.

[0144] Understandable, Figure 7 In the air conditioning control system, the repeating controller obtains the difference between the given value of the motor's electric angular velocity and the feedback value of the motor's electric angular velocity, and outputs the target speed signal value through the transfer function of the repeating controller.

[0145] Based on the above technical solution, the repeat controller in the embodiments of this disclosure is verified. Figure 10 This is a speed fluctuation diagram without a repeater controller. Figure 11 The diagram shows the speed fluctuation with the addition of a repetitive controller. It can be seen that under the action of the repetitive controller in this embodiment, the speed fluctuation of the air conditioning control system is narrowed. That is, the motor operating speed is stabilized, thereby suppressing the speed fluctuation of the compressor and enabling the air conditioning control system to meet stability conditions.

[0146] In addition, in related technologies, air conditioning control systems, such as Figure 12 As shown, the repeat controller is not included. Figure 12 The configuration can be found in the documentation. Figure 7 The details of the previous section will not be repeated here. It is evident that the repetitive controller with added logic to the air conditioning control system in this embodiment of the present disclosure suppresses compressor speed fluctuations without increasing costs, thereby ensuring the stability of the air conditioning control system.

[0147] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer-executable instructions. When these computer-executable instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this disclosure is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer-executable instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer-executable instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs).

[0148] Although this disclosure has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed disclosure. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0149] Although this disclosure has been described in conjunction with specific features and embodiments, it will be apparent that various modifications and combinations can be made therein without departing from the spirit and scope of this disclosure. Accordingly, this specification and drawings are merely exemplary illustrations of the disclosure as defined by the appended claims and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this disclosure. It is obvious that those skilled in the art can make various alterations and modifications to this disclosure without departing from its spirit and scope. Thus, this disclosure is also intended to include any such modifications and modifications that fall within the scope of the claims of this disclosure and their equivalents.

[0150] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any changes or substitutions within the technical scope disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. An air conditioning control system, characterized in that, The air conditioning control system includes a repetitive controller and a motor; the repetitive controller is connected to the motor; the repetitive controller is used to adjust the speed of the motor; The repetitive controller includes a low-pass filter, a compensator, a speed regulator, and a discrete transmitter; the compensator is connected to the low-pass filter and the speed regulator, and the speed regulator is connected to the discrete transmitter. The repeat controller is configured to satisfy: in, Let be a function of the low-pass filter in the discrete domain. Let be a function of the compensator in the discrete domain. Let be a function of the speed regulator in the discrete domain. Let be the discrete transfer function of the discrete transferor in the discrete domain; The low-pass filter is configured to allow signals below the cutoff frequency to pass through while filtering signals above the cutoff frequency. The low-pass filter is further configured with the following filtering function in the discrete domain: q (Z) = (K1 Z+ K2) / (Z 2 – K3 (Z + K4) Wherein, q(Z) is the filtering function of the low-pass filter in the discrete domain, Z is the discrete variable in the discrete domain, K1 is the first preset filtering parameter, K2 is the first preset filtering parameter, K3 is the first preset filtering parameter, K4 is the first preset filtering parameter, and K1, K2, K3 and K4 are all greater than 0; The compensator is configured such that its input and output in the discrete domain satisfy: Y(Z) = (1 / 1+ t) Z -1 Y(Z) + (t / 1+t) U(Z) Where Y(Z) is the input of the compensator in the discrete domain, U(Z) is the output of the compensator in the discrete domain, t is the time of a single step in the discretization process, and Z is the discrete variable in the discrete domain.

2. The air conditioning control system according to claim 1, characterized in that, The low-pass filter is also configured to function as follows in the discrete domain: Q(Z)= q (Z) Z n wherein Q(Z) is a function of the low-pass filter in the discrete domain, q(Z) is a filter function of the low-pass filter in the discrete domain, and Z n is a compensation function of the low-pass filter.

3. The air conditioning control system according to claim 1, characterized in that, The compensator is also configured to function as follows in the discrete domain: S(Z)= q (Z) Z m Where S(Z) is the function of the compensator in the discrete domain, q(Z) is the filtering function of the low-pass filter, and Z m This is the lead function of the compensator.

4. The air conditioning control system according to claim 1, characterized in that, The transfer function of the compensator in the discrete domain satisfies: in, Let t be the transfer function of the compensator in the discrete domain, t be the time of a single step in the discretization process, and Z be the discrete variables in the discrete domain.

5. The air conditioning control system according to claim 1, characterized in that, The repetitive controller also includes a periodic delay element Z. -N .

6. The air conditioning control system according to claim 2, characterized in that, The Z n In this context, n takes the value of 16, K1 takes the value of 0.006302, K2 takes the value of 0.004977, K3 takes the value of 1.48, and K4 takes the value of 0.4915.

7. The air conditioning control system according to any one of claims 1-6, characterized in that, The low-pass filter is a second-order Butterworth low-pass filter or a first-order low-pass filter.

8. The air conditioning control system according to any one of claims 1-6, characterized in that, The cutoff frequency of the low-pass filter is 1 Hz.

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