Voltage regulating method and voltage regulating device of alternating current magnetic control transformer

Abstract

The invention provides a voltage regulating method and a voltage regulating device of an alternating current magnetic control transformer. The alternating-current magnetic control transformer comprises a magnetic control transformer body and a magnetic control circuit, the magnetic control transformer body comprises a primary winding, a secondary winding and an auxiliary winding, the primary winding is used for accessing power grid input voltage, the secondary winding provides output voltage of the transformer, and the alternating-current output end of the magnetic control circuit is connected to the two ends of the auxiliary winding. The method comprises the steps of collecting a power grid input voltage and an output voltage of an alternating-current magnetic control transformer; obtaining a pre-compensation fundamental wave voltage of the output voltage; extracting harmonic wave and negative sequence voltage of the power grid input voltage; the magnetic control circuit calculates the required compensation voltage of the auxiliary winding based on the pre-compensation fundamental wave voltage and the harmonic wave and negative sequence voltage of the power grid input voltage; adjusting the voltage of the auxiliary winding based on the compensation voltage of the auxiliary winding; and the output voltage of the alternating-current magnetic control transformer is changed through the voltage of the auxiliary winding. According to the invention, continuous fundamental wave voltage regulation and harmonic and negative sequence voltage treatment can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transformers, and particularly relates to a voltage regulating method of an AC magnetic control transformer and a voltage regulating device thereof. BACKGROUND

[0002] In modern power systems, the fluctuation of grid voltage and the non-ideal factors such as harmonics and negative sequence components contained therein have a significant impact on power transmission and distribution equipment and power quality. The traditional on-load voltage regulating transformer realizes voltage regulation through winding ratio, but since the grid voltage input to the primary side (i.e. the primary winding) of the transformer usually contains harmonics and negative sequence components, the non-ideal voltage (such as harmonics and negative sequence components) of the primary side will be transmitted to the secondary side (i.e. the secondary winding) of the transformer through electromagnetic coupling, resulting in that the output voltage of the secondary side of the transformer superimposes harmonics and negative sequence components, and further affecting the output voltage quality of the transformer. SUMMARY

[0003] The present application aims to provide a voltage regulating method of an AC magnetic control transformer and a voltage regulating device thereof, which can solve at least one technical problem mentioned in the prior art.

[0004] One aspect of the present application provides a voltage regulating method of an AC magnetic control transformer. The AC magnetic control transformer comprises a magnetic control transformer body and a magnetic control circuit, the magnetic control transformer body comprises a primary winding, a secondary winding and an auxiliary winding, the primary winding is used for inputting grid voltage, the secondary winding is used for providing output voltage of the AC magnetic control transformer, and the AC output end of the magnetic control circuit is connected to both ends of the auxiliary winding. The method comprises: collecting grid input voltage and output voltage of the AC magnetic control transformer; obtaining pre-compensation fundamental voltage of the output voltage; extracting harmonic and negative sequence voltage of the grid input voltage; calculating required compensation voltage of the auxiliary winding based on the pre-compensation fundamental voltage and the harmonic and negative sequence voltage of the grid input voltage by the magnetic control circuit; adjusting voltage of the auxiliary winding based on the compensation voltage of the auxiliary winding; and changing the output voltage of the AC magnetic control transformer through the voltage of the auxiliary winding.

[0005] Further, the method further comprises: pre-processing the collected grid input voltage and output voltage of the AC magnetic control transformer to obtain pre-processed grid input voltage and pre-processed output voltage.

[0006] Furthermore, obtaining the pre-compensated fundamental voltage of the output voltage includes: using a phase-locked loop to obtain the phase of the grid input voltage; using the phase of the grid input voltage to perform Clarke transform and Park transform on the output voltage to extract the fundamental voltage and phase of the output voltage; and obtaining the pre-compensated fundamental voltage of the output voltage based on the fundamental voltage and phase of the output voltage and the target voltage.

[0007] Furthermore, the AC magnetic control transformer also includes a host computer, which is communicatively connected to the magnetic control circuit. The method also includes: receiving a target voltage set by a user through the host computer; and sending the target voltage to the magnetic control circuit by the host computer, wherein the magnetic control circuit adjusts the output voltage of the AC magnetic control transformer in response to the target voltage.

[0008] Furthermore, the extraction of the harmonics and negative-sequence voltage of the grid input voltage includes: using a phase-locked loop to obtain the phase of the grid input voltage; using the phase of the grid input voltage to perform Clarke transform and Park transform on the grid input voltage to obtain the voltage in the +1st synchronous rotating coordinate system; passing the voltage in the +1st synchronous rotating coordinate system through a low-pass filter to extract the fundamental voltage and phase of the grid input voltage; subtracting the fundamental voltage of the grid input voltage from the voltage in the +1st synchronous rotating coordinate system to obtain the harmonic voltage; multiplying the phase of the extracted grid input voltage by k-1, and using it to perform Park transform on the obtained harmonic voltage to obtain the voltage in the kth synchronous rotating coordinate system; passing the voltage in the kth synchronous rotating coordinate system through a low-pass filter to extract the effective value and phase of the kth harmonic of the grid input voltage; performing inverse Park transform and inverse Clarke transform based on the effective value and phase of the kth harmonic of the grid input voltage to extract the harmonics and negative-sequence voltage of the grid input voltage.

[0009] Furthermore, the calculation of the required compensation voltage of the auxiliary winding by the magnetic control circuit based on the pre-compensation fundamental voltage and the harmonics and negative sequence voltage of the grid input voltage includes: calculating and determining the physical relationship between the voltage of the auxiliary winding, the grid input voltage and the output voltage in combination with the structural characteristics of the AC magnetic control transformer; and calculating the compensation voltage of the auxiliary winding according to the control target of the output voltage, the physical relationship and the calculated pre-compensation fundamental voltage and the harmonics and negative sequence voltage of the grid input voltage.

[0010] Furthermore, the structural characteristics of the AC magnetically controlled transformer include the turns ratio, magnetic saturation curve and leakage inductance of the primary winding, the secondary winding and the auxiliary winding. The control target of the output voltage is to make the fundamental voltage of the output voltage follow the target voltage set by the user and minimize the harmonics and negative sequence voltage of the output voltage.

[0011] Furthermore, the magnetic control circuit includes a power electronic converter, and adjusting the voltage of the auxiliary winding based on the compensation voltage of the auxiliary winding includes: controlling the on and off of the power device in the power electronic converter based on the compensation voltage of the auxiliary winding to change the voltage of the auxiliary winding.

[0012] Furthermore, controlling the on and off of the power device in the power electronic converter based on the compensation voltage of the auxiliary winding includes: generating a PWM signal of the power device in the power electronic converter according to the compensation voltage of the auxiliary winding through a pulse width modulation or space vector pulse width modulation method; and controlling the power device based on the PWM signal of the power device.

[0013] Furthermore, the method further includes: adding a predetermined dead time to the generated PWM signal of the power device according to the switching characteristics of the power device.

[0014] Furthermore, the method further includes: comparing the output voltage with a target voltage, and performing error correction using PID closed-loop control.

[0015] Another aspect of the present application provides a voltage regulating device for an AC magnetically controlled transformer. The voltage regulating device includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the voltage regulating method for an AC magnetically controlled transformer as described above.

[0016] The voltage regulation method and voltage regulation device of the AC magnetically controlled transformer of one or more embodiments of the present application can adaptively respond to grid voltage fluctuations, fluctuations of various harmonics in the grid, etc. during the actual operation of the transformer, and can perform adaptive adjustments according to the real-time state of the grid to maintain output voltage stability. At the same time, it can compensate for harmonics and negative sequence content, realize continuous fundamental voltage regulation and harmonic and negative sequence control, and optimize the output power quality of the transformer at a relatively low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall structure of an AC magnetically controlled transformer according to an embodiment of the present application.

[0018] Figure 2 This is a flow chart of a voltage regulation method for an AC magnetically controlled transformer according to one embodiment of the present application.

[0019] Figure 3 This is a diagram of the steps for obtaining the pre-compensated fundamental voltage of the output voltage according to one embodiment of the present application.

[0020] Figure 4 This is a diagram of the steps for extracting harmonics and negative sequence voltage from the grid input voltage according to one embodiment of the present application.

[0021] Figure 5 This is a schematic structural block diagram of extracting harmonics and negative sequence voltage of grid input voltage according to an embodiment of the present application.

[0022] Figure 6 The experimental result diagram of the voltage waveform of the AC magnetic control transformer when the user sets the output voltage of the AC magnetic control transformer from 380V to 420V.

[0023] Figure 7 This is the experimental result diagram of the related voltage waveform of the AC magnetic control transformer when the grid input voltage has a -5th frequency signal and a +7th frequency signal and the user sets the output voltage of the AC magnetic control transformer to 380V.

[0024] Figure 8 This is a schematic block diagram of a voltage regulating device for an AC magnetically controlled transformer according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of devices consistent with certain aspects of the present application, as detailed in the appended claims.

[0026] The voltage regulation method and voltage regulation device of the AC magnetically controlled transformer of the present application will be described in detail below with reference to the accompanying drawings. The features of the following embodiments and implementations may be combined with each other unless there is a conflict.

[0027] Figure 1 The overall structure diagram of an AC magnetic control transformer 100 according to an embodiment of the present application is disclosed. Figure 1As shown, an AC magnetic control transformer 100 according to one embodiment of the present application includes a magnetic control transformer body 110 and a magnetic control circuit 120. The magnetic control transformer body 110 includes a primary winding 111, a secondary winding 112, and an auxiliary winding 113. The primary winding 111 of the magnetic control transformer body 110 is connected to the power grid for receiving the power grid input voltage. The secondary winding 112 is connected to the load for providing the output voltage of the AC magnetic control transformer 100 to the load. The input end of the magnetic control circuit 120 is connected to the secondary winding 112 of the magnetic control transformer body 110, and the AC output end of the magnetic control circuit 120 is connected to both ends of the auxiliary winding 113.

[0028] The AC magnetic control transformer 100 of the present application incorporates an additional core branch and auxiliary winding 113 in the body 110 of the magnetic control transformer, compared to a conventional three-phase transformer. In this structure, the magnetic flux coupled by the secondary winding 112 is affected by both the primary winding 111 and the auxiliary winding 113. The voltage of the primary winding 111 is determined by the power grid, while the voltage of the auxiliary winding 113 is determined by the magnetic control circuit 120. The voltage of the auxiliary winding 113 can influence the magnetic flux distribution of the AC magnetic control transformer 100, enabling precise regulation of the magnetic flux coupled to the secondary winding 112 and, therefore, precise regulation of the transformer output voltage within a certain range.

[0029] The magnetic control circuit 120 can control the voltage of the auxiliary winding 113 to inject AC magnetic flux into the transformer, change the magnetic flux distribution of the transformer core, offset the harmonics and negative sequence magnetic flux generated by the primary winding 111, reduce the harmonics and negative sequence magnetic flux coupled by the secondary winding 112, and optimize the quality of the output voltage of the AC magnetic control transformer 100.

[0030] In some embodiments, the magnetic control circuit 120 may include a modular power electronic converter including power devices.

[0031] The AC magnetically controlled transformer 100 of the present application combines a traditional transformer with a magnetically controlled circuit 120, so that it has the capability of continuous fundamental voltage regulation and harmonic and negative sequence control, thereby optimizing the output power quality of the transformer at a relatively low cost.

[0032] The present application provides a voltage regulation method for the AC magnetically controlled transformer 100 , which can achieve fundamental wave voltage regulation and harmonic and negative sequence voltage compensation voltage regulation. Figure 2 The flowchart of the voltage regulation method of the AC magnetic controlled transformer according to one embodiment of the present application is disclosed. Figure 2 As shown, a voltage regulation method for an AC magnetically controlled transformer according to an embodiment of the present application may include steps S1 to S6.

[0033] In step S1 , the grid input voltage and the output voltage of the AC magnetic-controlled transformer 100 are collected.

[0034] A voltage sensor is used to sample the grid input voltage and the output voltage of the AC magnetic control transformer 100 in real time. The sampled signal is then digitized by an analog-to-digital converter (ADC) and input into a microprocessor or digital signal processor (DSP) for calculation to obtain relevant information about the grid input voltage and the output voltage of the AC magnetic control transformer 100.

[0035] In some embodiments, to improve data sampling accuracy, the voltage regulation method of the AC magnetically controlled transformer of the present application may further include step S7 when performing signal sampling.

[0036] In step S7, the collected grid input voltage and the output voltage of the AC magnetic-controlled transformer 100 may be preprocessed to obtain a preprocessed grid input voltage and a preprocessed output voltage. Therefore, the grid input voltage and output voltage mentioned in the following steps may refer to the preprocessed grid input voltage and the preprocessed output voltage, respectively. The preprocessing of the grid input voltage and output voltage may, for example, include anti-aliasing filtering to eliminate high-frequency noise and fine-tuning the timing to ensure that the sampling frequency meets the Nyquist sampling criterion.

[0037] In step S2 , the pre-compensated fundamental voltage of the output voltage is obtained.

[0038] Since the fundamental voltage and phase of the output voltage of the AC magnetic control transformer 100 need to be controlled, it is necessary to extract the fundamental voltage and phase of the output voltage of the AC magnetic control transformer 100 and calculate the difference between the output voltage and the target voltage.

[0039] Figure 3 The present invention discloses a step diagram for obtaining a pre-compensated fundamental voltage of an output voltage according to an embodiment of the present invention. Figure 3 As shown, the step S2 of obtaining the pre-compensated fundamental voltage of the output voltage may further include steps S21 to S24.

[0040] Since the output of the AC magnetically controlled transformer 100 needs to be controlled to have the same phase as the grid input voltage, a phase-locked loop is used to obtain the phase of the grid input voltage in step S21 .

[0041] In step S22 , the output voltage of the AC magnetic-controlled transformer 100 is subjected to Clarke transformation and Park transformation using the phase of the grid input voltage to extract the fundamental voltage and phase of the output voltage.

[0042] In step S23 , the fundamental voltage and phase of the output voltage are compared with the target voltage.

[0043] In step S24 , a pre-compensated fundamental voltage of the output voltage is obtained.

[0044] Return to reference Figure 2 ,In step S3, the harmonics and negative sequence voltage of the grid input voltage are extracted.

[0045] Figure 4 The present invention discloses a step diagram for extracting harmonics and negative sequence voltage of the grid input voltage according to an embodiment of the present invention. Figure 5 The schematic structural block diagram of extracting harmonics and negative sequence voltage of grid input voltage according to one embodiment of the present application is disclosed. Figure 4 and Figure 5 As shown, taking the kth harmonic as an example, where k can be any integer except 0 and 1, in some embodiments, extracting the harmonics and negative sequence voltage of the grid input voltage in step S3 can further include steps S31 to S37.

[0046] In step S31, a phase-locked loop is used to obtain the grid input voltage V ABC_in The phase Φ in .

[0047] In step S32, the grid input voltage V ABC_in The phase Φ in Input voltage to the grid V ABC_in Perform Clarke transformation and Park transformation to obtain the voltage V in the +1 synchronous rotating coordinate system. dq_in .

[0048] Specifically, the grid input voltage V ABC_in Perform Clarke transformation and convert the grid input voltage V ABC_in Transform from the three-phase stationary (ABC) coordinate system to the two-phase stationary (α-β) coordinate system, and thus the voltage V in the two-phase stationary coordinate system can be obtained αβ_in ; Then, using the phase of the grid input voltage Φ in The voltage V in the two-phase stationary coordinate system αβ_in Perform Park transformation and transform the voltage V in the two-phase stationary coordinate system αβ_in Transform the two-phase stationary (α-β) coordinate system to the two-phase synchronous rotating (dq) coordinate system, and then obtain the voltage V in the +1 synchronous rotating coordinate system. dq_in .

[0049] In step S33, the voltage in the +1 synchronous rotating coordinate system is passed through a low-pass filter to extract the fundamental voltage V of the grid input voltage. dq1_in and phase.

[0050] In step S34, the voltage V in the +1st synchronous rotation coordinate system is used. dq_in Subtract the fundamental voltage V of the grid input voltage dq1_in Get the harmonic voltage.

[0051] In step S35, the extracted grid input voltage V ABC_in The phase Φ in Multiply by k to get the phase Φ of the kth harmonic of the grid input voltage k =kΦ in , and use Φ k -Φ in The phase after (that is, the grid input voltage V ABC_in The phase Φ in Multiply by k-1), that is, (k-1)Φ in Perform Park transformation on the obtained harmonic voltage to obtain the voltage in the k-th synchronous rotating coordinate system.

[0052] In step S36, the voltage in the kth order synchronous rotating coordinate system is passed through a low-pass filter to extract the kth order harmonic effective value V of the grid input voltage. dqk_in and phase Φ k .

[0053] In step S37, based on the grid input voltage kth harmonic effective value V dqk_in and phase Φ k Perform inverse Park transformation to convert the grid input voltage kth harmonic effective value V dqk_in Transform from the two-phase synchronous rotating coordinate system to the two-phase stationary coordinate system, so that the kth harmonic voltage V in the two-phase stationary coordinate system can be obtained αβk_in , the kth harmonic voltage V in the two-phase stationary coordinate system αβk_in Perform inverse Clarke transformation to convert the kth harmonic voltage V in the two-phase stationary coordinate system into αβk_in By transforming from a two-phase stationary coordinate system to a three-phase stationary coordinate system, the harmonics of the grid input voltage and the negative sequence voltage V can be extracted. ABCk_in .

[0054] It is understandable that the above is an example of the kth harmonic, but the present application is not limited thereto. The present application can realize the extraction of any harmonic and negative sequence voltage.

[0055] Return to reference Figure 2 In step S4, the magnetic control circuit 120 calculates the required compensation voltage of the auxiliary winding 113 based on the pre-compensated fundamental voltage obtained in step S2 and the harmonics and negative sequence voltage of the grid input voltage extracted in step S3.

[0056] In some embodiments, step S4 of calculating the required compensation voltage of the auxiliary winding 113 by the magnetic control circuit 120 based on the pre-compensated fundamental voltage and the harmonics and negative sequence voltage of the grid input voltage may further include steps S41 and S42 .

[0057] In step S41, the physical relationship among the voltage of the auxiliary winding 113, the input voltage of the power grid and the output voltage can be calculated and determined in combination with the structural characteristics of the AC magnetic control transformer 100.

[0058] In step S42, the compensation voltage of the auxiliary winding 113 can be calculated according to the control target of the output voltage, the physical relationship among the voltage of the auxiliary winding 113, the input voltage of the power grid and the output voltage calculated in step S41, and the pre-compensation fundamental voltage and the harmonic and negative sequence voltage of the input voltage of the power grid calculated in step S2 and step S3.

[0059] The structural characteristics of the AC magnetic control transformer 100 can include, for example, the turn ratio of the primary winding 111, the secondary winding 112 and the auxiliary winding 113, the magnetic saturation curve and the leakage inductance, etc. The control target of the output voltage is to make the fundamental voltage of the output voltage follow the target voltage set by the user, and to minimize the harmonic and negative sequence voltage of the output voltage, i.e. to reduce the harmonic and negative sequence voltage content in the output voltage as much as possible.

[0060] In step S5, the voltage of the auxiliary winding 113 can be adjusted based on the compensation voltage of the auxiliary winding 113.

[0061] In some embodiments, the conduction and turn-off of the power devices in the power electronic converter can be controlled based on the compensation voltage of the auxiliary winding 113, so as to change the voltage of the auxiliary winding 113.

[0062] The PWM signal of the power devices in the power electronic converter can be generated according to the compensation voltage of the auxiliary winding 113 by the pulse width modulation (PWM) or space vector pulse width modulation (SVPWM) method; then, the power devices in the power electronic converter can be controlled based on the PWM signal of the power devices.

[0063] Considering the switching characteristics of the power devices, such as hardware delay, turn-on and turn-off loss, therefore, in some embodiments, appropriate dead time can be added to the generated PWM signal of the power devices according to the switching characteristics of the power devices.

[0064] In step S6, the output voltage of the AC magnetic control transformer 100 can be changed by the voltage of the auxiliary winding 113.

[0065] In some embodiments, the AC magnetic control transformer 100 further comprises a host computer, and the host computer is in communication connection with the magnetic control circuit 120. The voltage regulating method of the AC magnetic control transformer of the present application can further comprise steps S81 and S82.

[0066] In step S81, the target voltage set by the user can be received by the host computer.

[0067] In step S82, the target voltage is sent to the magnetic control circuit 120 by the host computer.

[0068] The magnetic control circuit 120 can adjust the output voltage of the magnetic control transformer 100 in response to the target voltage sent by the host computer, so as to achieve the purpose of harmonic and negative sequence voltage management.

[0069] Due to the sampling delay and control delay of the magnetic control circuit 120, the actual compensation voltage takes effect later than the sampling time, and this delay will cause a phase difference between the actual compensation voltage and the target compensation voltage, and the larger the harmonic frequency, the larger the phase difference. Therefore, in some embodiments, the voltage regulating method of the magnetic control transformer of the present application can further include step S9.

[0070] In step S9, the output voltage of the magnetic control transformer 100 is compared with the target voltage, and the error is corrected by PID (Proportional Integral Derivative) closed loop control, so as to further optimize the compensation performance.

[0071] It can be understood that the division of each step and its order shown in the drawings of the present application is only a schematic illustration of the present application, however, the steps involved in the voltage regulating method of the magnetic control circuit of the present application are not limited to the illustration, and other splitting and / or merging or adjusting the order of execution of each step can be performed according to the actual situation, and these minor or equivalent changes will be covered within the protection scope of the present application.

[0072] The voltage regulating method of the magnetic control transformer of the present application can adaptively cope with grid voltage fluctuations, harmonic fluctuations in the grid and other situations during actual operation of the transformer, and can adaptively adjust according to the real-time state of the grid to maintain stable output voltage, while compensating for harmonics and negative sequence content, realizing continuous fundamental voltage regulation and harmonic and negative sequence management, optimizing the output power quality of the transformer at relatively low cost.

[0073] To verify the voltage regulating method of the magnetic control transformer of the present application, a 200kVA 10kV / 380V±10% magnetic control transformer is built, and the designed magnetic control transformer can adjust the output voltage according to the user set value, Figure 6 The experimental results of the transformer related voltage waveform when the user set output voltage of the magnetic control transformer is increased from 380V to 420V are disclosed. From Figure 6 It can be seen that the magnetic control circuit can quickly adjust the voltage across the auxiliary winding according to the target voltage, and the output voltage of the magnetic control transformer follows the set value change within 100ms.

[0074] The voltage regulation method of the AC magnetically controlled transformer of the present application can achieve the control of harmonics and negative sequence while regulating the voltage. Figure 7 The experimental results reveal that the grid input voltage has -5th frequency signal and +7th frequency signal, and when the user sets the output voltage of the AC magnetic control transformer to 380V, the voltage waveform of the AC magnetic control transformer is related. Figure 7 It can be seen that when the grid input voltage has harmonics and negative sequence content, the traditional transformer output voltage will also have harmonics and negative sequence content. However, the magnetically controlled AC transformer of the present application can significantly reduce the harmonic content of the output voltage while maintaining the output voltage at the set 380V.

[0075] The present application also provides a voltage regulating device 800 for an AC magnetically controlled transformer. Figure 8 The schematic block diagram of a voltage regulating device 800 for an AC magnetically controlled transformer according to an embodiment of the present application is disclosed. Figure 8 As shown, an AC magnetically controlled transformer voltage regulating device 800 according to an embodiment of the present application includes a processor 801, an internal bus 802, a network interface 803, a memory 804, and a non-volatile memory 805. Of course, it may also include hardware required for other services. The processor 801 can read the corresponding computer program from the non-volatile memory 805 into the memory 804 and then run it to implement the steps of the AC magnetically controlled transformer voltage regulating method described above. Of course, in addition to software implementation, this application does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic components.

[0076] The voltage regulating device 800 of the AC magnetically controlled transformer of the present application can have similar beneficial technical effects as the voltage regulating method of the AC magnetically controlled transformer described above, so it will not be described in detail here.

[0077] The above is a detailed introduction to the voltage regulation method and voltage regulation device of the AC magnetic control transformer provided in the embodiment of the present application. This article uses specific examples to illustrate the voltage regulation method and voltage regulation device of the AC magnetic control transformer in the embodiment of the present application. The description of the above embodiment is only used to help understand the core idea of ​​the present application and is not intended to limit the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the spirit and principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications should also fall within the scope of protection of the claims attached to the present application.

Claims

1. A voltage regulation method for an AC magnetron transformer, characterized in that: The AC magnetic control transformer includes a magnetic control transformer body and a magnetic control circuit. The magnetic control transformer body includes a primary winding, a secondary winding, and an auxiliary winding. The primary winding is used to connect to the grid input voltage. The secondary winding is used to provide the output voltage of the AC magnetic control transformer. The AC output end of the magnetic control circuit is connected to both ends of the auxiliary winding. The method includes: Collecting the grid input voltage and the output voltage of the AC magnetic control transformer; Obtaining a pre-compensated fundamental voltage of the output voltage; extracting harmonics and negative sequence voltage of the grid input voltage; The magnetic control circuit calculates the required compensation voltage of the auxiliary winding based on the pre-compensation fundamental voltage and the harmonics and negative sequence voltage of the grid input voltage; adjusting a voltage of the auxiliary winding based on a compensation voltage of the auxiliary winding; The output voltage of the AC magnetic control transformer is changed by the voltage of the auxiliary winding.

2. The voltage regulation method according to claim 1, wherein: Also includes: The collected grid input voltage and the output voltage of the AC magnetic control transformer are preprocessed to obtain a preprocessed grid input voltage and a preprocessed output voltage.

3. The voltage regulation method according to claim 1, wherein: The obtaining of the pre-compensated fundamental voltage of the output voltage comprises: Obtaining the phase of the grid input voltage using a phase-locked loop; Performing Clarke transformation and Park transformation on the output voltage using the phase of the grid input voltage to extract the fundamental voltage and phase of the output voltage; A pre-compensated fundamental voltage of the output voltage is obtained based on the fundamental voltage and phase of the output voltage and a target voltage.

4. The voltage regulation method according to claim 3, wherein: The AC magnetic control transformer further includes a host computer, the host computer being communicatively connected to the magnetic control circuit, and the method further includes: Receiving a target voltage set by a user through the host computer; The host computer sends the target voltage to the magnetron circuit. The magnetic control circuit adjusts the output voltage of the AC magnetic control transformer in response to the target voltage.

5. The voltage regulation method according to claim 1, wherein: Extracting the harmonics and negative sequence voltage of the grid input voltage includes: Obtaining the phase of the grid input voltage using a phase-locked loop; Performing Clarke transformation and Park transformation on the grid input voltage using the phase of the grid input voltage to obtain a voltage in a +1-order synchronous rotating coordinate system; Pass the voltage in the +1 synchronous rotating coordinate system through a low-pass filter to extract the fundamental voltage and phase of the grid input voltage; The harmonic voltage is obtained by subtracting the fundamental voltage of the grid input voltage from the voltage in the +1st synchronous rotating coordinate system; Multiplying the extracted phase of the grid input voltage by k-1, and using the multiplication factor to perform Park transformation on the obtained harmonic voltage to obtain the voltage in the k-th synchronous rotating coordinate system; The voltage in the kth order synchronous rotating coordinate system is passed through a low-pass filter to extract the effective value and phase of the kth order harmonic of the grid input voltage; An inverse Park transform and an inverse Clarke transform are performed based on the effective value and phase of the kth harmonic of the grid input voltage to extract the harmonics and negative sequence voltage of the grid input voltage.

6. The voltage regulation method according to claim 1, wherein: The calculation of the required compensation voltage of the auxiliary winding by the magnetic control circuit based on the pre-compensation fundamental voltage and the harmonics and negative sequence voltage of the grid input voltage includes: In combination with the structural characteristics of the AC magnetic control transformer, calculating and determining the physical relationship between the voltage of the auxiliary winding, the grid input voltage, and the output voltage; The compensation voltage of the auxiliary winding is calculated according to the control target of the output voltage, the physical relationship, and the calculated pre-compensation fundamental voltage and the harmonics and negative sequence voltage of the grid input voltage.

7. The voltage regulation method according to claim 6, wherein: The structural characteristics of the AC magnetic control transformer include the turns ratio, magnetic saturation curve and leakage inductance of the primary winding, the secondary winding and the auxiliary winding. The control target of the output voltage is to make the fundamental voltage of the output voltage follow the target voltage set by the user and minimize the harmonics and negative sequence voltage of the output voltage.

8. The voltage regulation method according to claim 1, wherein: The magnetic control circuit includes a power electronic converter, and adjusting the voltage of the auxiliary winding based on the compensation voltage of the auxiliary winding includes: The on / off state of a power device in the power electronic converter is controlled based on the compensation voltage of the auxiliary winding to change the voltage of the auxiliary winding.

9. The voltage regulation method according to claim 8, wherein: The controlling the on and off of the power devices in the power electronic converter based on the compensation voltage of the auxiliary winding includes: Generate a PWM signal for a power device in the power electronic converter according to the compensation voltage of the auxiliary winding by pulse width modulation or space vector pulse width modulation; The power device is controlled based on the PWM signal of the power device.

10. The voltage regulating method according to claim 9, wherein: Also includes: According to the switching characteristics of the power device, a predetermined dead time is added to the generated PWM signal of the power device.

11. The voltage regulating method according to any one of claims 1 to 10, characterized in that: Also includes: The output voltage is compared with the target voltage, and the error is corrected using PID closed-loop control.

12. A voltage regulating device for an AC magnetically controlled transformer, comprising a memory, a processor, and a computer program stored in the memory, wherein: The processor executes the computer program to implement the steps of the voltage regulation method for an AC magnetically controlled transformer according to any one of claims 1 to 11.

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