Method for detecting rectifier circuit bias voltage and air conditioning system

Abstract

The application provides a method for detecting a bias voltage of a rectifier circuit and an air conditioning system, and the method comprises the following steps: in the case that the rectifier circuit is powered on and a PWM signal is turned off, detecting an AD signal of an input voltage and converting the AD signal of the input voltage into a phase signal through a three-phase phase-locked loop algorithm; identifying a time when the amplitude of an input phase current corresponding to the phase signal of the input voltage is 0 based on the corresponding relationship between the phase signal of the input voltage and the amplitude of the input phase current, so as to obtain a detection time; and detecting the bias voltage of the rectifier circuit at the moment when the detection time reaches the detection time. According to the inherent characteristics of the rectifier circuit, the phase of the input voltage is tracked through the three-phase phase-locked loop algorithm, the detection time when the current amplitude is 0 is accurately locked, and finally the current detection accuracy is improved, so that the stability and reliability of the variable frequency control system in the starting stage are ensured. The rectifier circuit can be a Vienna rectifier circuit.

Description

Technical Field

[0001] This invention relates to the field of air conditioner control technology, and in particular to a method for detecting the bias voltage of a rectifier circuit and an air conditioning system. Background Technology

[0002] In the frequency converter control system of power electronic equipment such as air conditioner outdoor units, the accuracy of current detection during the startup phase directly determines the stability and reliability of subsequent control. However, the hardware characteristics of current sensors and output current detection circuits are easily affected by factors such as manufacturing processes and ambient temperature fluctuations, resulting in inherent errors that can lead to zero-point drift and decreased control accuracy. Therefore, current microcontroller units (MCUs) generally perform bias voltage sampling calibration. For example, when the air conditioning system is powered on and the pulse width modulation (PWM) wave is not output, the MCU first shuts down the power devices and then acquires the analog-to-digital (AD) bias voltage signal of the current signal to calculate a reference value. After the load devices start up, subtracting this reference value from the real-time detected bias voltage AD signal eliminates zero-point drift and ensures control accuracy.

[0003] However, in controllable rectifier circuits such as the Vienna rectifier topology used in air conditioning systems, the aforementioned bias voltage detection method has significant limitations. For example, after the rectifier circuit is powered on, even if the pulse width modulation signal is off, the inherent power consumption of various load devices in the air conditioning system will still generate a small current that flows through the current sensor, causing interference to the bias voltage sampling and making it impossible to obtain an accurate reference value. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a method and air conditioning system for detecting the bias voltage of a rectifier circuit that overcomes or at least partially solves the above problems, and can solve the adverse effect of the inherent power consumption of the load device on the bias voltage detection accuracy, thereby improving the bias voltage detection accuracy.

[0005] Specifically, the present invention provides a method for detecting the bias voltage of a rectifier circuit, comprising:

[0006] When the rectifier circuit is powered on and the PWM signal is turned off, the AD signal of the input voltage is detected, and the AD signal of the input voltage is converted into a phase signal through a three-phase phase-locked loop algorithm.

[0007] Based on the correspondence between the phase signal of the input voltage and the amplitude of the input phase current, the timing when the amplitude of the input phase current corresponding to the phase signal of the input voltage is 0 is identified, thus obtaining the detection timing;

[0008] The bias voltage of the rectifier circuit is detected in response to the moment when the detection time reaches the detection opportunity.

[0009] Optionally, the input voltage's AD signal is converted into a phase signal using a three-phase phase-locked loop algorithm, including:

[0010] By performing a Clark transform on the AD signal of the input voltage, we obtain... Two-phase equivalent signals in a coordinate system;

[0011] Perform a Park transform on the two equivalent signals to obtain d q Error correlation signals of the coordinate system;

[0012] The error-correlated signal is sequentially subjected to error closed-loop correction processing and integral operation processing to obtain the phase signal.

[0013] Optionally, the formula used to perform the Clark transformation is:

[0014] , ,

[0015] Among them, V alfa Indicates the In coordinate system shaft equivalent voltage signal, V beta express In coordinate system shaft equivalent voltage signal, V a V represents the input voltage r Phase voltage value, V b V represents the input voltage s Phase voltage value.

[0016] Optionally, the formula used to perform the Park transformation is: ,

[0017] Among them, V q Indicates the d q The error correlation signal of the coordinate system, θ represents the d q Phase reference of the coordinate system, V alfa Indicates the In coordinate system shaft equivalent voltage signal, V beta express In coordinate system Shaft equivalent voltage signal.

[0018] Optionally, the error-correlated signal is sequentially subjected to error closed-loop correction processing and integral operation processing to obtain the phase signal, including:

[0019] The error-correlated signal is subjected to error closed-loop correction processing to obtain the phase-corrected voltage;

[0020] The phase correction voltage is integrated over time to obtain the phase signal to be verified.

[0021] Determine whether the phase signal to be verified exceeds a preset reset threshold;

[0022] If the threshold is exceeded, the integration process is repeated until the phase signal to be verified does not exceed the preset reset threshold.

[0023] Optionally, the step after determining whether the phase signal to be verified exceeds a preset reset threshold further includes:

[0024] If the value is not exceeded, the phase signal to be verified is used as the phase signal of the input voltage.

[0025] Optionally, the step after detecting the bias voltage of the rectifier circuit further includes:

[0026] Obtain multiple detection values ​​of the bias voltage;

[0027] The target value of the bias voltage is calculated based on the detected values ​​of multiple bias voltages.

[0028] The present invention also provides an air conditioning system, including a rectifier circuit, a detection circuit, a control module, and a load circuit. The rectifier circuit is used to supply power to the load circuit at least. The detection circuit is used to detect electrical signals in the rectifier circuit and feed them back to the control module at least. The control module includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of the method described in any of the above embodiments.

[0029] Optionally, at least one input terminal of the rectifier circuit is connected to a current sensor;

[0030] The detection circuit includes a voltage sampling terminal, a bias sub-circuit, an operational amplifier sub-circuit, and a filter sub-circuit. The voltage sampling terminal is used to collect the voltage across the current sensor. The bias sub-circuit adopts a resistor voltage divider structure. The operational amplifier sub-circuit is used to amplify the voltage signal output by the bias sub-circuit. The filter sub-circuit is used to filter the voltage signal output by the operational amplifier sub-circuit.

[0031] The present invention also provides an air conditioning system, including a rectifier circuit, a detection circuit, a control module, and a load circuit. The rectifier circuit is used at least to supply power to the load circuit. The detection circuit is used at least to detect electrical signals in the rectifier circuit and feed them back to the control module. The control module includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of the method described in any of the above embodiments.

[0032] The control module also includes a Clark transform module, a Park transform module, a PI controller, and a resettable integrator module connected in sequence.

[0033] The present invention relates to a method for detecting the bias voltage of a rectifier circuit and an air conditioning system. Based on the inherent characteristics of the rectifier circuit, it uses a three-phase phase-locked loop algorithm to track the phase of the input voltage and accurately lock the detection timing when the current amplitude is 0. This eliminates the traditional method of calculating the bias voltage theoretically, solving the sampling interference problem caused by the small current generated by the inherent power consumption of the load in traditional bias voltage calibration. This also eliminates factors such as the inherent differences in electronic components or the influence of temperature, making sampling more accurate and ultimately improving the accuracy of current detection, thus ensuring the stability and reliability of the frequency converter control system during startup.

[0034] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0035] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0036] Figure 1 This is a schematic diagram of a motor control system in the prior art;

[0037] Figure 2 This is a schematic flowchart of a method for detecting the bias voltage of a rectifier circuit according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic flowchart of a method for detecting the bias voltage of a rectifier circuit according to an embodiment of the present invention;

[0039] Figure 4 This is a schematic flowchart of a method for detecting the bias voltage of a rectifier circuit according to an embodiment of the present invention;

[0040] Figure 5 This is a schematic flowchart of a method for detecting the bias voltage of a rectifier circuit according to an embodiment of the present invention;

[0041] Figure 6 This is a comparison diagram of input voltage Vr and voltage phase in a method for detecting the bias voltage of a rectifier circuit according to an embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram of the input voltage and input phase current in a method for detecting the bias voltage of a rectifier circuit according to an embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the input phase current bias voltage sampling area in a method for detecting the bias voltage of a rectifier circuit according to an embodiment of the present invention;

[0044] Figure 9 This is a schematic diagram of a control module in an air conditioning system according to an embodiment of the present invention;

[0045] Figure 10 This is a topology diagram of a rectifier circuit in an air conditioning system according to an embodiment of the present invention;

[0046] Figure 11 This is a schematic diagram of a detection circuit in an air conditioning system according to an embodiment of the present invention. Detailed Implementation

[0047] The following reference Figures 1 to 11 This invention describes a method for detecting the bias voltage of a rectifier circuit and an air conditioning system according to embodiments of the present invention. In this description, it should be understood that 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. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.

[0048] Unless otherwise expressly specified and limited, the terms "set up," "install," "connect," "link," "fix," and "couple" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "below" of the second feature can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0050] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] In power electronic systems, such as rectifiers, frequency converters, and inverters, bias voltage detection is a core technology ensuring system accuracy and reliability. Its importance lies primarily in: control accuracy. The electrical components used in current sensors and current detection circuits are affected by factors such as manufacturing processes and ambient temperature, leading to variations. Inaccurate bias voltage can even cause excessive DC injection signals, affecting normal control and triggering protective shutdowns. Furthermore, abnormal bias voltage is an early indicator of detection circuit failure. In the fields of new energy and home appliances, such as Haier's inverter air conditioners, a system lifespan of over 10 years is required. Real-time bias voltage tracking can prevent progressive failures caused by drift. Therefore, accurate bias voltage detection is crucial. Figure 1 The diagram shows a schematic of a conventional motor control system. Traditionally, the bias voltage is detected when power devices VT1 to VT6 are off, meaning no current flows through phases U, V, and W (zero current). The average bias voltage collected at this time is used as a reference. Subtracting this reference value from the collected signal after operation gives the actual current. In the diagram, 1 represents the DC bus voltage, 2 represents the power module, VT1 to VT6 are transistors, VD1 to VD6 are diodes, 3 is the current sensor, and 4 represents the motor. However, the inherent power consumption of the load in the rectifier circuit generates a small current, causing the current sensor to output a non-zero signal, resulting in a deviation in the reference value calculation. Current technologies generally use theoretical calculations to obtain the bias value. This approach cannot account for errors in the detection circuit or current sensor, making precise control difficult.

[0052] To address the problem of inaccurate measurement of the bias voltage in a rectifier circuit, this invention provides a method for detecting the bias voltage of a rectifier circuit, such as... Figure 2 As shown, and with reference Figures 3 to 11 The methods include:

[0053] Step S100: When the rectifier circuit is powered on and the PWM signal is turned off, the AD signal of the input voltage is detected, and the AD signal of the input voltage is converted into a phase signal through a three-phase phase-locked loop algorithm.

[0054] Step S200: Based on the correspondence between the phase signal of the input voltage and the amplitude of the input phase current, identify the timing when the amplitude of the input phase current corresponding to the phase signal of the input voltage is 0, and obtain the detection timing.

[0055] In step S300, in response to the moment when the detection time reaches the detection opportunity, the bias voltage of the rectifier circuit is detected.

[0056] This embodiment addresses the inherent characteristics of rectifier circuits by employing a three-phase phase-locked loop (PLL) algorithm to track the input voltage phase and precisely pinpoint the detection opportunity when the current amplitude is zero. It abandons the traditional method of theoretically calculating the bias, thus resolving the sampling interference problem caused by the minute current generated by the inherent power consumption of the load in traditional bias voltage calibration. This eliminates factors such as variations in electronic components or temperature effects, resulting in more accurate sampling and ultimately improving current detection precision, ensuring the stability and reliability of the frequency converter control system during startup. The rectifier circuit here can be a Vienna rectifier circuit.

[0057] Figure 7 and Figure 8 This invention provides a theoretical reference for detecting the bias voltage of a rectifier circuit, clarifying the sampling timing when no current flows through waveform characteristics, and providing a judgment standard for accurate acquisition of the bias voltage. Among other things, Figure 7 The top graph shows the voltage waveform, and the bottom graph shows the current waveform. Figure 8 The time frame indicated by the Chinese square indicates the sampling time.

[0058] In some embodiments of the present invention, such as Figure 3 and Figure 6 As shown, the input voltage AD signal is converted into a phase signal using a three-phase phase-locked loop algorithm, including:

[0059] Step S110: Obtain the input voltage signal by performing a Clark transformation. Two-phase equivalent signals in a coordinate system;

[0060] Step S120: Perform Park transform on the two-phase equivalent signals to obtain d qError correlation signals of the coordinate system;

[0061] Step S130: The error-correlated signal is sequentially processed by error closed-loop correction and integral operation to obtain the phase signal.

[0062] Through a combination of Clark transform, Park transform, error closed-loop correction, and integral operation, the three-phase phase-locked loop algorithm can accurately extract and output a phase signal synchronized with the grid voltage from the AD sampling signal of the input voltage. This provides a basis for subsequent detection of the input phase current amplitude being 0, ultimately ensuring the accuracy of bias voltage sampling and solving the problem of zero-point drift calibration in rectifier circuits. Figure 6 The synchronization relationship between the input voltage Vr and the phase is presented intuitively, verifying the accuracy of the three-phase phase-locked loop algorithm. Among other things, Figure 6 The upper middle figure shows the voltage diagram of Vr, and the lower figure shows the voltage phase comparison diagram. From the figures, it can be directly observed that the sinusoidal waveform change of Vr through phase-locked loop is synchronized with the phase. For example, when Vr reaches its peak value, the phase corresponds to a specific value, and when Vr crosses zero, the phase also corresponds to a specific value.

[0063] Furthermore, in some embodiments of the present invention, the formula for performing the Clark transformation is:

[0064] , , where V alfa express In coordinate system shaft equivalent voltage signal, V beta express In coordinate system shaft equivalent voltage signal, V a V represents the input voltage r Phase voltage value, V b V represents the input voltage s Phase voltage value.

[0065] The Clark transform only requires two phase voltage values ​​from the three-phase input voltage to perform the calculation. The purpose of the Clark transform is to convert the AD signal of the three-phase input voltage into a digital signal. Equivalent signal in coordinate system. Due to the phase difference between three-phase signals, direct analysis is difficult. Clark transform reduces the three-dimensional signal to a two-dimensional signal, reducing the computational load of subsequent algorithms and adapting to the computing power of MCUs.

[0066] In some embodiments of the present invention, the formula used for performing the Park transformation is: , where V q d q Error correlation signal of coordinate system, θ represents dq Phase reference of the coordinate system, V alfa express In coordinate system shaft equivalent voltage signal, V beta express In coordinate system Shaft equivalent voltage signal.

[0067] The purpose of performing the Park transformation is to... The signal in the coordinate system is converted into an error-related signal in the dq coordinate system, which rotates synchronously with the grid voltage. Through synchronous rotation transformation, the originally periodically changing AC voltage signal is converted into a stable DC signal and a zero-mean AC signal, which greatly reduces the difficulty of phase error detection.

[0068] In some embodiments of the present invention, such as Figure 4 As shown, in step S130, the error-correlated signal is sequentially subjected to error closed-loop correction processing and integral operation processing to obtain the phase signal, including:

[0069] Step S131: Perform error closed-loop correction processing on the error-correlated signal to obtain the phase correction voltage;

[0070] Step S132: Perform integration calculation on the accumulation of time according to the phase correction voltage to obtain the phase signal to be verified;

[0071] Step S133: Determine whether the phase signal to be verified exceeds the preset reset threshold.

[0072] If the threshold is exceeded, step S134 is executed to repeat the integration operation until the phase signal to be verified does not exceed the preset reset threshold.

[0073] Error closed-loop correction processing is performed on the d-value of the Park transform output. q The coordinate system error correlation signal is used for closed-loop adjustment to output a precise phase correction voltage. The integral operation process integrates the phase correction voltage over time, converting the voltage signal into a continuous phase signal to be verified.

[0074] The preset reset threshold here is 2π. The phase signal usually has a period of 0 to 2π. Long-term integration may cause the phase value to exceed the effective range due to accumulated errors. If it is greater than 2π, the threshold verification can reset it in time. Boundary verification is performed on the phase signal to be verified by the integration output. If it exceeds the preset reset threshold, the integration is restarted to ensure that the phase signal is always within the effective range.

[0075] In some embodiments of the present invention, such as Figure 4As shown, step S130 involves sequentially performing error closed-loop correction and integration processing on the error-correlated signal to obtain the phase signal, and also includes:

[0076] If the error does not exceed the limit, proceed to step S135, using the phase signal to be verified as the phase signal of the input voltage.

[0077] Specifically, in some embodiments of the present invention, such as Figure 5 As shown, in the formula for integral processing, u(n) is the input variable, y(n) is the output variable, y(n-1) is the output variable of the previous control cycle, and T is the control cycle time.

[0078] In some embodiments of the present invention, such as Figure 1 As shown, the steps after detecting the bias voltage of the rectifier circuit also include:

[0079] Step S400: Obtain the detection values ​​of multiple bias voltages;

[0080] Step S500: Calculate the target value of the bias voltage based on the detected values ​​of multiple bias voltages.

[0081] The target value of the bias voltage can be the average of multiple detected bias voltage values. Preferably, 128 detected bias voltage values ​​are obtained, and the average of the 128 detected bias voltage values ​​is calculated. This average value is the target value of the bias voltage.

[0082] This invention also provides an air conditioning system, including a rectifier circuit, a detection circuit, a control module, and a load circuit. The rectifier circuit is used to supply power to the load circuit at least. The detection circuit is used to detect electrical signals in the rectifier circuit and feed them back to the control module. The control module includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of the method in any of the above embodiments.

[0083] Figure 10 This is a topology diagram of the rectifier circuit in an air conditioning system according to an embodiment of the present invention. 5 is a three-phase input power supply, 6 is a three-phase input reactor, 8 is a diode rectifier bridge, 9 is a power device, 10 is a bus capacitor, 11 is an equivalent load, and 7 is an input current sensor. The detection circuit of the air conditioning system detects the electrical signal in the rectifier circuit and feeds it back to the control module, executing a computer program to achieve the method described in any of the above embodiments. This method can accurately pinpoint the detection timing when the current amplitude is 0, solving the sampling interference problem caused by the small current generated by the inherent power consumption of the load in traditional bias voltage calibration. Ultimately, this improves the accuracy of current detection and ensures the stability and reliability of the frequency converter control system during startup.

[0084] In some embodiments of the invention, at least one input terminal of the rectifier circuit is connected to a current sensor. For example... Figure 11 As shown, the detection circuit includes a voltage sampling terminal 14, a bias sub-circuit 15, an operational amplifier sub-circuit 16, and a filter sub-circuit 17. The voltage sampling terminal is used to collect the voltage across the current sensor. The bias sub-circuit adopts a resistor voltage divider structure. The operational amplifier sub-circuit is used to amplify the voltage signal output by the bias sub-circuit. The filter sub-circuit is used to filter the voltage signal output by the operational amplifier sub-circuit.

[0085] The detection circuit achieves accurate acquisition of the voltage signal from the current sensor through a four-step process: voltage sampling, bias adjustment, signal amplification, and filtering / noise reduction. Specifically, the bias sub-circuit 15 employs a resistor voltage divider structure, using two precision resistors connected in series to output a bias voltage from the divider node. This generates a reference bias voltage, such as 2.5V, that matches the MCU's sampling voltage range, adapting to the 0-5V sampling voltage range and preventing the signal from exceeding the sampling voltage range. The operational amplifier sub-circuit 16 enhances the signal amplitude, and the filter sub-circuit 17 eliminates interference signals.

[0086] This invention also provides an air conditioning system, including a rectifier circuit, a detection circuit, a control module, and a load circuit. The rectifier circuit is used to supply power to the load circuit at least once. The detection circuit is used to detect electrical signals in the rectifier circuit and feed them back to the control module at least once. The control module includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of the method described in the above embodiments. The control module further includes a Clark converter module 18, a Park converter module 19, a PI controller 20, and a resettable integrator module 21 connected in sequence. The PI controller 20 is used to implement error closed-loop correction processing.

[0087] The detection circuit is used to detect the electrical signals of the rectifier circuit, such as... Figure 9 As shown, the control module performs Clark transformation, Park transformation, error closed-loop correction, and integration on the electrical signal to obtain the phase signal. It then detects the bias voltage of the rectifier circuit when the amplitude of the input phase current corresponding to the phase signal of the input voltage is zero. This solves the sampling interference problem caused by the small current generated by the inherent power consumption of the load in traditional bias voltage calibration, ultimately improving the accuracy of current detection and ensuring the stability and reliability of the frequency converter control system during startup.

[0088] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A method for detecting the bias voltage of a rectifier circuit, characterized in that, include: When the rectifier circuit is powered on and the PWM signal is turned off, the AD signal of the input voltage is detected, and the AD signal of the input voltage is converted into a phase signal through a three-phase phase-locked loop algorithm. Based on the correspondence between the phase signal of the input voltage and the amplitude of the input phase current, the timing when the amplitude of the input phase current corresponding to the phase signal of the input voltage is 0 is identified, thus obtaining the detection timing; The bias voltage of the rectifier circuit is detected in response to the moment when the detection time reaches the detection opportunity.

2. The method according to claim 1, characterized in that, The input voltage's AD signal is converted into a phase signal using a three-phase phase-locked loop algorithm, including: By performing a Clark transform on the AD signal of the input voltage, the following is obtained: Two-phase equivalent signals in a coordinate system; Perform a Park transform on the two equivalent signals to obtain d q Error correlation signals of the coordinate system; The error-correlated signal is sequentially subjected to error closed-loop correction processing and integral operation processing to obtain the phase signal.

3. The method according to claim 2, characterized in that, The formula used to perform the Clark transformation is: ， ， Among them, V alfa Indicates the In coordinate system shaft equivalent voltage signal, V beta express In coordinate system shaft equivalent voltage signal, V a V represents the input voltage r Phase voltage value, V b V represents the input voltage s Phase voltage value.

4. The method according to claim 2, characterized in that, The formula used to perform the Park transformation is: , Among them, V q Indicates the d q The error correlation signal of the coordinate system, θ represents the d q Phase reference of the coordinate system, V alfa Indicates the In coordinate system shaft equivalent voltage signal, V beta express In coordinate system Shaft equivalent voltage signal.

5. The method according to claim 2, characterized in that, The error-correlated signal is sequentially subjected to error closed-loop correction processing and integral operation processing to obtain the phase signal, including: The error-correlated signal is subjected to error closed-loop correction processing to obtain the phase-corrected voltage; The phase correction voltage is integrated over time to obtain the phase signal to be verified. Determine whether the phase signal to be verified exceeds a preset reset threshold; If the threshold is exceeded, the integration process is repeated until the phase signal to be verified does not exceed the preset reset threshold.

6. The method according to claim 5, characterized in that, The steps following determining whether the phase signal to be verified exceeds the preset reset threshold also include: If the value is not exceeded, the phase signal to be verified is used as the phase signal of the input voltage.

7. The method according to claim 1, characterized in that, The steps following detecting the bias voltage of the rectifier circuit further include: Obtain multiple detection values ​​of the bias voltage; The target value of the bias voltage is calculated based on the detected values ​​of multiple bias voltages.

8. An air conditioning system, characterized in that, The method includes a rectifier circuit, a detection circuit, a control module, and a load circuit. The rectifier circuit is used to supply power to the load circuit at least. The detection circuit is used to detect electrical signals in the rectifier circuit and feed them back to the control module at least. The control module includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

9. The air conditioning system according to claim 8, characterized in that, At least one input terminal of the rectifier circuit is connected to a current sensor; The detection circuit includes a voltage sampling terminal, a bias sub-circuit, an operational amplifier sub-circuit, and a filter sub-circuit. The voltage sampling terminal is used to collect the voltage across the current sensor. The bias sub-circuit adopts a resistor voltage divider structure. The operational amplifier sub-circuit is used to amplify the voltage signal output by the bias sub-circuit. The filter sub-circuit is used to filter the voltage signal output by the operational amplifier sub-circuit.

10. An air conditioning system, characterized in that, The system includes a rectifier circuit, a detection circuit, a control module, and a load circuit. The rectifier circuit is used to supply power to the load circuit at least once. The detection circuit is used to detect electrical signals in the rectifier circuit and feed them back to the control module at least once. The control module includes a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps of the method described in claim 2. The control module also includes a Clark transform module, a Park transform module, a PI controller, and a resettable integrator module connected in sequence.

Images