Power electronic transformer control circuit, device and control method

Abstract

The application relates to a power electronic transformer control circuit, which comprises a sampling circuit, a load detection circuit and a main control circuit, wherein the sampling circuit is used for collecting circuit parameters, the circuit parameters include real-time voltage values and real-time current values; the load detection circuit is connected with the sampling circuit and is used for generating a load calculation value according to the real-time voltage values and an output voltage reference value; the main control circuit is connected with the sampling circuit and the load detection circuit and is used for generating a phase shift angle control signal according to the real-time current values, the load calculation value and a phase shift angle reference value, so as to control the power electronic transformer to output a voltage value in a preset range. In the power electronic transformer control circuit of the above embodiment, the slope change value of the load curve is obtained through the load detection circuit to predict the change of the load in advance, and then the phase shift angle control signal generated through the main control circuit can timely reflect the real-time change of the load, and then the output voltage of the power electronic transformer controlled through the modulation wave can be kept relatively stable.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and in particular to a power electronic transformer control circuit, device and control method. Background Technology

[0002] With the rapid development of urban construction, the construction and renovation of power distribution networks need to be continuously strengthened. Due to line relocation or equipment failure, the number of power outages requiring regular maintenance is increasing, inevitably leading to longer and more irregular power outages, which seriously affects the reliability of power supply and the safety of residents' electricity use. To address this, a low-voltage mobile portable switchgear for bypass live-line work has emerged, which can temporarily supply power to low-voltage distribution lines during maintenance operations.

[0003] However, due to the complexity and variability of power grid systems, they are difficult to model. Therefore, load parameters in traditional closed-loop control are often inaccurately obtained, leading to the control circuit's inability to quickly track disturbance responses and resulting in unstable switchgear output voltage. Thus, designing a control circuit capable of accurately and quickly predicting load changes is crucial to ensuring the stable operation of the switchgear's main circuitry. Summary of the Invention

[0004] Therefore, it is necessary to provide a power electronic transformer control circuit, device, and control method to address the aforementioned technical problems, thereby solving the problem that traditional closed-loop control methods cannot quickly respond to load changes, leading to unstable output voltage.

[0005] This application provides a power electronic transformer control circuit, including a sampling circuit, a load detection circuit, and a main control circuit. The sampling circuit collects circuit parameters, including real-time voltage and current values. The load detection circuit, connected to the sampling circuit, generates a calculated load value based on the real-time voltage value and an output voltage reference value. The load detection circuit obtains the load change value based on the slope change of the load curve, causing a corresponding change in the calculated load value. The main control circuit, connected to both the sampling circuit and the load detection circuit, generates a phase shift angle control signal based on the real-time current value, the calculated load value, and a phase shift angle reference value to control the power electronic transformer to output a voltage value within a preset range.

[0006] In the power electronic transformer control circuit described in the above embodiments, load changes are tracked in real time through a load detection circuit, and the slope change value of the load curve is further obtained to predict load changes in advance. By transmitting the load change trend information to the main control circuit, the generated phase shift angle control signal can reflect the real-time changes of the load in a timely manner, and thus the output voltage of the power electronic transformer can be kept relatively stable through modulation wave control. Compared with traditional closed-loop control, the output voltage can be effectively controlled even when the load is unknown, eliminating the impact of load changes on system stability. Furthermore, as the load continues to change, the next change in the load can be predicted in advance and controlled, improving the robustness of the system.

[0007] In one embodiment, the load detection circuit includes:

[0008] The first subtractor has its non-inverting input connected to the sampling circuit. The first subtractor is used to generate a voltage error signal based on the real-time voltage value and the output voltage reference value.

[0009] A first proportional amplifier has its input terminal connected to the output terminal of the first subtractor. The first proportional amplifier is used to generate a load curve slope value based on the voltage error signal.

[0010] The multiplier has a first input terminal connected to the output terminal of the first subtractor and a second input terminal connected to the output terminal of the first proportional amplifier. The multiplier is used to generate a first corrected load curve slope value based on the voltage error signal and the load curve slope value.

[0011] The second proportional amplifier has its input terminal connected to the output terminal of the multiplier. The second proportional amplifier is used to generate an amplified second corrected load curve slope value based on the first corrected load curve slope value.

[0012] An integrator, whose input is connected to the output of the second proportional amplifier, is used to generate the calculated load value based on the slope value of the second corrected load curve.

[0013] In one embodiment, the main control circuit includes:

[0014] The second subtractor has its non-inverting input connected to the sampling circuit and its inverting input connected to the output of the integrator. The second subtractor is used to generate a first load error signal based on the real-time current value and the calculated load value.

[0015] The third proportional amplifier has its input terminal connected to the output terminal of the second subtractor. The third proportional amplifier is used to generate an amplified second load error signal based on the load error signal.

[0016] The third subtractor has its inverting input connected to the third proportional amplifier and its non-inverting input connected to the phase shift angle reference value. The third subtractor is used to generate the phase shift angle control signal based on the second load error signal and the phase shift angle reference value.

[0017] In one embodiment, the phase shift control signal is a linear function of the change in the load, so that the output phase shift angle is dynamically adjusted to follow the load change.

[0018] In one embodiment, it further includes:

[0019] The output voltage reference value acquisition circuit is connected to the second input terminal of the first subtractor and is used to generate the output voltage reference value signal.

[0020] A second aspect of this application provides a power electronic transformer control device, comprising:

[0021] The control circuit described in any of the foregoing embodiments.

[0022] A second aspect of this application provides a power electronic transformer control method, implemented based on the control circuit described in any of the foregoing embodiments, the method comprising:

[0023] The control load detection circuit generates a calculated load value based on the real-time voltage value and the output voltage reference value.

[0024] The main control circuit generates a phase shift angle control signal based on the real-time current value, the calculated load value, and the phase shift angle reference value, and controls the power electronic transformer to output a voltage value within a preset range.

[0025] In one embodiment, the load detection circuit includes at least one of a first subtractor, a first proportional amplifier, a multiplier, a second proportional amplifier, and an integrator. The step of generating the load calculation value based on the real-time voltage value and the output voltage reference value includes:

[0026] The first subtractor is controlled to generate a voltage error signal based on the real-time voltage value and the output voltage reference value;

[0027] The first proportional amplifier is controlled to generate a load curve slope value based on the voltage error signal;

[0028] The multiplier is controlled to generate a first corrected load curve slope value based on the voltage error signal and the load curve slope value;

[0029] The second proportional amplifier is controlled to generate an amplified second correction load curve slope value based on the first correction load curve slope value;

[0030] The integrator is controlled to generate the calculated load value based on the slope value of the second corrected load curve.

[0031] In one embodiment, the main control circuit includes at least one of a second subtractor, a third proportional amplifier, and a third subtractor. The step of generating a phase-shift control signal based on the real-time current value, the calculated load value, and the phase-shift angle reference value includes:

[0032] The second subtractor is controlled to generate a first load error signal based on the real-time current value and the calculated load value.

[0033] The third proportional amplifier is controlled to generate an amplified second load error signal based on the load error signal;

[0034] The third subtractor is controlled to generate the phase shift angle control signal based on the second load error signal and the phase shift angle reference value.

[0035] In one embodiment, it further includes:

[0036] The control circuit acquires an output voltage reference value signal; the control circuit controls the error between the output voltage of the power electronic transformer and the output voltage reference value to be within a preset range. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 A schematic diagram of the power electronic transformer control circuit in one embodiment provided in this application;

[0039] Figure 2 A schematic diagram of the power electronic transformer control circuit provided in one embodiment of this application;

[0040] Figure 3 A schematic diagram of the power electronic transformer control circuit in another embodiment provided in this application;

[0041] Figure 4 A flowchart of a power electronic transformer control method provided in one embodiment of this application;

[0042] Figure 5 A flowchart illustrating the power electronic transformer control method in yet another embodiment provided in this application;

[0043] Figure 6A flowchart illustrating the power electronic transformer control method in another embodiment provided in this application. Detailed Implementation

[0044] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0046] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

[0047] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. Furthermore, in the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if there is transmission of electrical signals or data between the connected objects.

[0048] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0049] Live-line bypass work refers to bypassing and connecting a transfer line to the normal power supply line, allowing the transfer line to temporarily replace the normal power supply line, thus achieving power outage maintenance of the normal power supply line without interrupting the power supply to users. Specialized vehicles such as bypass cable trucks, mobile transformer substation vehicles (or power load transfer vehicles), load switch vehicles, bypass tool vehicles, insulated tool vehicles, and insulated bucket trucks may be used during this process. Compared with traditional power outage maintenance methods, this method not only accomplishes the task of fault diagnosis but also does not affect the normal power supply to users during maintenance, improving the reliability of power supply. It is one of the most advanced live-line working methods currently available both domestically and internationally.

[0050] Because many urban low-voltage power distribution rooms are located in underground basements, and the surrounding environment of low-voltage power distribution rooms is often obstructed and has limited space, bypassing low-voltage switchgear can be difficult due to the difficulty of load transfer vehicles entering and the difficulty of transferring connection lines, resulting in significant construction impact and low safety. Therefore, a low-voltage mobile portable switchgear for bypassing live work has been developed to temporarily supply power to low-voltage power distribution lines during maintenance operations.

[0051] However, due to the complexity and variability of power grid systems, they are difficult to model. Therefore, load parameters in traditional closed-loop control are often inaccurately obtained, leading to the control circuit's inability to quickly track disturbance responses and resulting in unstable switchgear output voltage. Thus, designing a control circuit capable of accurately and quickly predicting load changes is crucial to ensuring the stable operation of the switchgear's main circuitry.

[0052] Therefore, it is necessary to provide a power electronic transformer control circuit, device, and control method to address the aforementioned technical problems, thereby solving the problem that traditional closed-loop control methods cannot quickly respond to load changes, leading to unstable output voltage.

[0053] In one embodiment of this application, such as Figure 1 As shown, a power electronic transformer control circuit is provided, including a sampling circuit 100, a load detection circuit 200, and a main control circuit 300. The sampling circuit 100 is used to collect circuit parameters, including real-time voltage and real-time current values. The load detection circuit 200 is connected to the sampling circuit 100 and is used to generate a calculated load value based on the real-time voltage value and an output voltage reference value. The load detection circuit 200 obtains the load change value based on the slope change value of the load curve, causing a corresponding change in the calculated load value. The main control circuit 300 is connected to both the sampling circuit 100 and the load detection circuit 200, and is used to generate a phase shift angle control signal based on the real-time current value, the calculated load value, and the phase shift angle reference value to control the power electronic transformer to output a voltage value within a preset range.

[0054] In the power electronic transformer control circuit of the above embodiment, the load change is tracked in real time by a load detection circuit, and the slope change value of the load curve is further obtained to predict the load change in advance. By transmitting the load change trend information to the main control circuit, the generated phase shift angle control signal can reflect the real-time load change in a timely manner, and thus the output voltage of the power electronic transformer can be kept relatively stable by modulating the wave. Compared with traditional closed-loop control, the output voltage can be effectively controlled even when the load is unknown, eliminating the impact of load change on system stability. Furthermore, as the load continues to change, the next change of the load can be predicted in advance and controlled, thus improving the robustness of the system.

[0055] In one embodiment provided in this application, such as Figure 2 As shown, the load detection circuit 200 includes a first subtractor 210, a first proportional amplifier 220, a multiplier 230, a second proportional amplifier 240, and an integrator 250.

[0056] The non-inverting input of the first subtractor 210 is connected to the sampling circuit 100. The first subtractor 210 is used to generate a voltage error signal based on the real-time voltage value and the output voltage reference value.

[0057] Specifically, as an example, the first subtractor 210 includes a first operational amplifier A1 and a twelfth resistor R. 12 The thirteenth resistor R 13 Fourteenth resistor R 14 and the fifteenth resistor R 15 In this circuit, the non-inverting input of the first operational amplifier A1 is connected to the thirteenth resistor R. 13 Connected to sampling circuit 100, the non-inverting input of the first operational amplifier A1 is also connected to the twelfth resistor R. 12 Grounded, the inverting input of the first operational amplifier A1 is connected to the fourteenth resistor R. 14 With the output voltage reference value V ref The inverting input of the first operational amplifier A1 is also connected through the fifteenth resistor R. 15 Connected to the output of the first operational amplifier A1, the real-time voltage value V o The input voltage is fed into the non-inverting input of the first subtractor 210, and the output voltage reference value V is obtained. ref The voltage error signal e1, which is fed into the inverting input of the first subtractor 210 and calculated by the first subtractor, is calculated according to the following formula:

[0058]

[0059] The voltage error signal e1 reflects the difference between the real-time voltage and the output reference voltage. It should be noted that the specific settings of the first subtractor 210 can be adjusted accordingly. Figure 2 The embodiments shown may differ, but as long as they can achieve the above functions, they are acceptable, and this application does not impose any limitations.

[0060] Furthermore, such as Figure 2 As shown, the input terminal of the first proportional amplifier 220 is connected to the output terminal of the first subtractor 210. The first proportional amplifier 220 is used to generate the load curve slope value based on the voltage error signal.

[0061] Specifically, as an example, the first proportional amplifier 220 includes a second operational amplifier A2 and a nineteenth resistor R. 19 The twentieth resistor R 20 and the twenty-first resistor R 21In this case, the non-inverting input of the second operational amplifier A2 is connected to the nineteenth resistor R. 19 The output of the first subtractor 210 is connected to the inverting input of the second operational amplifier A2, which is connected to the twentieth resistor R. 20 Grounded, the inverting input of the second operational amplifier A2 is also connected to the twenty-first resistor R. 21 Connected to the output of the second operational amplifier A2, the voltage error signal e1 is processed by the first proportional amplifier 220 to generate the load curve slope value e1, which is calculated according to the following formula:

[0062]

[0063] The load curve slope value e2 is the value of the voltage error signal e1 after being amplified by a non-inverting proportional amplifier. Through proper configuration of the operational amplifier's peripheral circuitry, e2 is made to reflect the slope of the load change curve. It should be noted that the specific settings of the first proportional amplifier 220 can be compared with... Figure 2 The embodiments shown may differ, but as long as they can achieve the above functions, they are acceptable, and this application does not impose any limitations.

[0064] Furthermore, such as Figure 2 As shown, the first input terminal of the multiplier 230 is connected to the output terminal of the first subtractor 210, and the second input terminal is connected to the output terminal of the first proportional amplifier 220. The multiplier 230 is used to generate a first corrected load curve slope value based on the voltage error signal and the load curve slope value.

[0065] Specifically, as an example, the two input terminals of multiplier 230 are connected to the output terminals of first subtractor 210 and first proportional amplifier 220, respectively, and the first corrected load curve slope value e3 is calculated according to the following formula:

[0066] e3 = e1e2;

[0067] It should be noted that the specific settings of multiplier 230 can be compared with... Figure 2 The embodiments shown may differ, but as long as they can achieve the above functions, they are acceptable, and this application does not impose any limitations.

[0068] Furthermore, such as Figure 2 As shown, the input terminal of the second proportional amplifier 240 is connected to the output terminal of the multiplier 230. The second proportional amplifier 240 is used to generate an amplified second corrected load curve slope value based on the first corrected load curve slope value.

[0069] Specifically, as an example, the second proportional amplifier 240 includes a third operational amplifier A3 and a sixteenth resistor R. 16 The seventeenth resistor R 17 and the eighteenth resistor R 18 The non-inverting input of the third operational amplifier A3 is connected to the sixteenth resistor R.16 Connected to the output of multiplier 230, the inverting input of the third operational amplifier A3 is connected to the seventeenth resistor R. 17 Grounded, the inverting input of the third operational amplifier A3 is also connected to the eighteenth resistor R. 18 Connected to the output of the third operational amplifier A3, the slope value e3 of the first corrected load curve is amplified by the second proportional amplifier 240 to generate the slope value E4 of the second corrected load curve, which is calculated according to the following formula:

[0070]

[0071] It should be noted that the specific settings of the second proportional amplifier 240 can be compared with... Figure 2 The embodiments shown may differ, but as long as they can achieve the above functions, they are acceptable, and this application does not impose any limitations.

[0072] Furthermore, such as Figure 2 As shown, the input terminal of the integrator 250 is connected to the output terminal of the second proportional amplifier 240. The integrator 250 is used to generate a load calculation value based on the slope value of the second corrected load curve.

[0073] Specifically, as an example, integrator 250 includes a fourth operational amplifier A4 and a twenty-second resistor R. 22 The twenty-third resistor R 23 and the first capacitor C1, wherein the non-inverting input of the fourth operational amplifier A4 is connected to the twenty-third resistor R. 23 Grounded, the inverting input of the fourth operational amplifier A4 is connected to the twenty-second resistor R. 22 The output of the second proportional amplifier 240 is connected to the output of the fourth operational amplifier A4, which is also connected to the output of the fourth operational amplifier A4 through the first capacitor C1. The slope value e4 of the second corrected load curve is used by the integrator 250 to generate the load calculation value e5, which is calculated according to the following formula:

[0074]

[0075] The calculated load value e5 reflects the future trend of the load. It should be noted that the specific settings for integrator 250 can be adjusted accordingly. Figure 2 The embodiments shown may differ, but as long as they can achieve the above functions, they are acceptable, and this application does not impose any limitations.

[0076] In one embodiment provided in this application, such as Figure 3 As shown, the main control circuit 300 includes a second subtractor 310, a third proportional amplifier 320, and a third subtractor 330.

[0077] The second subtractor 310 is configured such that its non-inverting input is connected to the sampling circuit 100 and its inverting input is connected to the output of the integrator 250. The second subtractor 310 is used to generate a first load error signal based on the real-time current value and the calculated load value.

[0078] Specifically, as an example, the second subtractor 310 includes a fifth operational amplifier A5, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. The non-inverting input of the fifth operational amplifier A5 is connected to the sampling circuit 100 via the second resistor R2. The non-inverting input of the fifth operational amplifier A5 is also grounded via the first resistor R1. The inverting input of the fifth operational amplifier A5 is connected to the calculated load value e5 via the third resistor R3. The inverting input of the fifth operational amplifier A5 is also connected to the output terminal of the fifth operational amplifier A5 via the fourth resistor R4. The real-time current value I... in The load calculation value e5 is fed into the non-inverting input of the second subtractor 310, and the load error signal e6 is fed into the inverting input of the second subtractor 310. The second subtractor 310 outputs the first load error signal e6 according to the following formula:

[0079]

[0080] The voltage error signal e6 reflects the difference between the real-time load value and the predicted load value. It should be noted that the specific settings of the second subtractor 310 can be adjusted accordingly. Figure 2 The embodiments shown may differ, but as long as they can achieve the above functions, they are acceptable, and this application does not impose any limitations.

[0081] Furthermore, such as Figure 3 As shown, the input terminal of the third proportional amplifier 320 is connected to the output terminal of the second subtractor 310. The third proportional amplifier 320 is used to generate an amplified second load error signal based on the load error signal.

[0082] As an example, the third proportional amplifier 320 includes a sixth operational amplifier A6, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The non-inverting input of the sixth operational amplifier A6 is connected to the output of the second subtractor 310 via the fifth resistor R5, the inverting input of the sixth operational amplifier A6 is grounded via the sixth resistor R6, and the inverting input of the sixth operational amplifier A6 is also connected to its output via the seventh resistor R7. The first load error signal e6, after being amplified by the third proportional amplifier 320, generates an amplified second load error signal e7, which is calculated according to the following formula:

[0083]

[0084] It should be noted that the specific settings of the third proportional amplifier 320 can be compared with... Figure 2The embodiments shown may differ, but as long as they can achieve the above functions, they are acceptable, and this application does not impose any limitations.

[0085] Furthermore, such as Figure 3 As shown, the inverting input of the third subtractor 330 is connected to the third proportional amplifier 320, and the non-inverting input is connected to the phase shift angle reference value. The third subtractor 330 is used to generate a phase shift angle control signal based on the second load error signal and the phase shift angle reference value.

[0086] Specifically, as an example, the third subtractor 330 includes a seventh operational amplifier A7, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R 10 and the eleventh resistor R 11 In this case, the non-inverting input of the seventh operational amplifier A7 is connected to the tenth resistor R. 10 Connected to the phase shift reference value α, the non-inverting input of the seventh operational amplifier A7 is also grounded through the ninth resistor R9. The inverting input of the seventh operational amplifier A7 is connected to the output of the third proportional amplifier 320 through the eighth resistor R8. The inverting input of the seventh operational amplifier A7 is also connected to the eleventh resistor R... 11 Connected to the output of the seventh operational amplifier A7, the phase shift angle reference value α is fed into the non-inverting input of the third subtractor 330, and the second load error signal e7 is fed into the inverting input of the third subtractor 330. The phase shift angle control signal e8 output by the third subtractor 330 is calculated according to the following formula:

[0087]

[0088] The phase shift angle control signal e8 is a linear function of the load change value, reflecting the real-time trend of the load change. By dynamically adjusting the output phase shift angle according to the load change, the error between the output voltage of the power electronic transformer and the output voltage reference value is kept within a preset range. It should be noted that the specific settings of the third subtractor 330 can be compared with... Figure 2 The embodiments shown may differ, but as long as they can achieve the above functions, they are acceptable, and this application does not impose any limitations.

[0089] In one embodiment provided in this application, it further includes:

[0090] The output voltage reference value acquisition circuit is connected to the second input terminal of the first subtractor 210 and is used to generate the output voltage reference value signal.

[0091] In one embodiment of this application, a power electronic transformer control device is also provided, including the control circuit of any of the foregoing embodiments, specifically including a sampling circuit 100, a load detection circuit 200, and a main control circuit 300. The sampling circuit 100 is used to collect circuit parameters, including real-time voltage and real-time current values. The load detection circuit 200 is connected to the sampling circuit 100 and is used to generate a calculated load value based on the real-time voltage value and an output voltage reference value. The load detection circuit 200 obtains the load change value based on the slope change value of the load curve, causing the calculated load value to change accordingly. The main control circuit 300 is connected to both the sampling circuit 100 and the load detection circuit 200 and is used to generate a phase shift angle control signal based on the real-time current value, the calculated load value, and the phase shift angle reference value to control the power electronic transformer to output a voltage value within a preset range.

[0092] In one embodiment of this application, such as Figure 4 As shown, a power electronic transformer control method is provided, implemented based on the control circuit described in any of the foregoing embodiments. The method includes:

[0093] Step 22: Control the load detection circuit to generate a load calculation value based on the real-time voltage value and the output voltage reference value;

[0094] Step 24: The main control circuit generates a phase shift angle control signal based on the real-time current value, the calculated load value, and the phase shift angle reference value, and controls the power electronic transformer to output a voltage value within a preset range.

[0095] In one embodiment provided in this application, such as Figure 5 As shown, the load detection circuit includes at least one of a first subtractor, a first proportional amplifier, a multiplier, a second proportional amplifier, and an integrator. Step 22 involves generating a calculated load value based on the real-time voltage value and the output voltage reference value, including:

[0096] Step 222: Control the first subtractor to generate a voltage error signal based on the real-time voltage value and the output voltage reference value;

[0097] Step 224: Control the first proportional amplifier to generate a load curve slope value based on the voltage error signal;

[0098] Step 226: Control the multiplier to generate a first corrected load curve slope value based on the voltage error signal and the load curve slope value;

[0099] Step 228: Control the second proportional amplifier to generate an amplified second correction load curve slope value based on the first correction load curve slope value;

[0100] Step 2210: Control the integrator to generate the calculated load value based on the slope value of the second corrected load curve.

[0101] In one embodiment provided in this application, such as Figure 6 As shown, the main control circuit includes at least one of a second subtractor, a third proportional amplifier, and a third subtractor. The step of generating a phase-shift angle control signal based on the real-time current value, the calculated load value, and the phase-shift angle reference value includes:

[0102] Step 242: Control the second subtractor to generate a first load error signal based on the real-time current value and the calculated load value;

[0103] Step 244: Control the third proportional amplifier to generate an amplified second load error signal based on the load error signal;

[0104] Step 246: Control the third subtractor to generate the phase shift angle control signal based on the second load error signal and the phase shift angle reference value.

[0105] In one embodiment provided in this application, it further includes:

[0106] The control circuit acquires an output voltage reference value signal; the control circuit controls the error between the output voltage of the power electronic transformer and the output voltage reference value to be within a preset range.

[0107] It should be noted that, in the embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The system embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection can be through some interfaces; the indirect coupling or communication connection between units or modules can be electrical or other forms.

[0108] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0109] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit described above can be implemented in hardware.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A power electronic transformer control circuit, characterized in that, include: A sampling circuit is used to collect circuit parameters, including real-time voltage and real-time current values. A load detection circuit, connected to the sampling circuit, is used to generate a load calculation value based on the real-time voltage value and the output voltage reference value; wherein, the load detection circuit obtains the load change value based on the slope change value of the load curve, so that the load calculation value changes accordingly; The main control circuit is connected to both the sampling circuit and the load detection circuit. It is used to generate a phase shift angle control signal based on the real-time current value, the calculated load value, and the phase shift angle reference value, so as to control the power electronic transformer to output a voltage value within a preset range. The load detection circuit includes: The first subtractor includes a first operational amplifier, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, and a fifteenth resistor. Its non-inverting input is connected to the sampling circuit. The first subtractor is used to generate a voltage error signal based on the real-time voltage value and the output voltage reference value. Where e1 is the voltage error signal, V ref V is the output voltage reference value. o R is the real-time voltage value. 12 The resistance value R represents the twelfth resistor. 13 The resistance value R represents the thirteenth resistor. 14 The resistance value R represents the fourteenth resistor. 15 The resistance value that characterizes the fifteenth resistor; A first proportional amplifier, including a second operational amplifier, a nineteenth resistor, a twentieth resistor, and a twenty-first resistor, has its input terminal connected to the output terminal of the first subtractor. The first proportional amplifier is used to generate a load curve slope value based on the voltage error signal. Where e2 is the slope value of the load curve, R 20 The resistance value R represents the twentieth resistor. 21 The resistance value that characterizes the twenty-first resistor; The multiplier has its first input connected to the output of the first subtractor and its second input connected to the output of the first proportional amplifier. The multiplier is used to generate a first corrected load curve slope value based on the voltage error signal and the load curve slope value. e3 = e1e2; Where e3 is the slope value of the first corrected load curve; The second proportional amplifier includes a third operational amplifier, a sixteenth resistor, a seventeenth resistor, and an eighteenth resistor. Its input is connected to the output of the multiplier. The second proportional amplifier is used to generate an amplified second corrected load curve slope value based on the first corrected load curve slope value. Where e4 is the slope value of the second corrected load curve, R 17 The resistance value R represents the seventeenth resistor. 18 The resistance value that characterizes the eighteenth resistor; The integrator, comprising a fourth operational amplifier, a twenty-second resistor, a twenty-third resistor, and a first capacitor, has its input terminal connected to the output terminal of the second proportional amplifier. The integrator is used to generate the calculated load value based on the slope value of the second corrected load curve. Where e5 is the calculated load value, R 22 C1 represents the resistance value of the twenty-second resistor, and C2 represents the capacitance value of the first capacitor. The main control circuit includes: The second subtractor includes a fifth operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor. Its non-inverting input is connected to the sampling circuit, and its inverting input is connected to the output of the integrator. The second subtractor is used to generate a first load error signal based on the real-time current value and the calculated load value. Where e6 is the first load error signal, I in R1 represents the resistance value of the first resistor, R2 represents the resistance value of the second resistor, R3 represents the resistance value of the third resistor, and R4 represents the resistance value of the fourth resistor. The third proportional amplifier includes a sixth operational amplifier, a fifth resistor, a sixth resistor, and a seventh resistor. Its input terminal is connected to the output terminal of the second subtractor. The third proportional amplifier is used to generate an amplified second load error signal based on the first load error signal. Where e7 is the second load error signal, R6 represents the resistance value of the sixth resistor, and R7 represents the resistance value of the seventh resistor. The third subtractor includes a seventh operational amplifier, an eighth resistor, a ninth resistor, a tenth resistor, and an eleventh resistor. Its inverting input is connected to the third proportional amplifier, and its non-inverting input is connected to the phase shift angle reference value. The third subtractor is used to generate the phase shift angle control signal based on the second load error signal and the phase shift angle reference value. Where e8 is the phase shift angle control signal, R8 represents the resistance value of the eighth resistor, R9 represents the resistance value of the ninth resistor, and R... 10 The resistance value R that characterizes the tenth resistor 11 The resistance value of the eleventh resistor is represented by α, which is the reference value for the phase shift angle.

2. The control circuit according to claim 1, characterized in that, The phase shift angle control signal is a linear function of the load change value, so that the output phase shift angle is dynamically adjusted to follow the load change.

3. The control circuit according to claim 1, characterized in that, Also includes: The output voltage reference value acquisition circuit is connected to the second input terminal of the first subtractor and is used to generate the output voltage reference value signal.

4. A power electronic transformer control device, characterized in that, include: The control circuit according to any one of claims 1-3.

5. A control method for a power electronic transformer, characterized in that, Based on the control circuit according to any one of claims 1-3, the method includes: The control load detection circuit generates a calculated load value based on the real-time voltage value and the output voltage reference value. The main control circuit generates a phase shift angle control signal based on the real-time current value, the calculated load value, and the phase shift angle reference value, and controls the power electronic transformer to output a voltage value within a preset range; The load detection circuit includes a first subtractor, a first proportional amplifier, a multiplier, a second proportional amplifier, and an integrator. The step of generating the load calculation value based on the real-time voltage value and the output voltage reference value includes: The first subtractor is controlled to generate a voltage error signal based on the real-time voltage value and the output voltage reference value as follows: Where e1 is the voltage error signal, V ref V is the output voltage reference value. o R is the real-time voltage value. 12 The resistance value R represents the twelfth resistor. 13 The resistance value R represents the thirteenth resistor. 14 The resistance value R represents the fourteenth resistor. 15 The resistance value that characterizes the fifteenth resistor; The first proportional amplifier is controlled to generate a load curve slope value based on the voltage error signal: Where e2 is the slope value of the load curve, R 20 The resistance value R represents the twentieth resistor. 21 The resistance value that characterizes the twenty-first resistor; The multiplier is controlled to generate a first corrected load curve slope value based on the voltage error signal and the load curve slope value: e3 = e1e2; Where e3 is the slope value of the first corrected load curve; The second proportional amplifier is controlled to generate an amplified second corrected load curve slope value based on the slope value of the first corrected load curve: Where e4 is the slope value of the second corrected load curve, R 17 The resistance value R represents the seventeenth resistor. 18 The resistance value that characterizes the eighteenth resistor; The integrator is controlled to generate the calculated load value based on the slope value of the second corrected load curve: Where e5 is the calculated load value, R 22 C1 represents the resistance value of the twenty-second resistor, and C2 represents the capacitance value of the first capacitor. The main control circuit includes a second subtractor, a third proportional amplifier, and a third subtractor. The generation of the phase shift control signal based on the real-time current value, the calculated load value, and the phase shift angle reference value includes: The second subtractor is controlled to generate a first load error signal based on the real-time current value and the calculated load value as follows: Where e6 is the first load error signal, I in R1 represents the resistance value of the first resistor, R2 represents the resistance value of the second resistor, R3 represents the resistance value of the third resistor, and R4 represents the resistance value of the fourth resistor. The third proportional amplifier is controlled to generate an amplified second load error signal based on the first load error signal as follows: Where e7 is the second load error signal, R6 represents the resistance value of the sixth resistor, and R7 represents the resistance value of the seventh resistor. The third subtractor is controlled to generate the phase shift control signal based on the second load error signal and the phase shift angle reference value as follows: Where e8 is the phase shift angle control signal, R8 represents the resistance value of the eighth resistor, R9 represents the resistance value of the ninth resistor, and R... 10 The resistance value R that characterizes the tenth resistor 11 The resistance value of the eleventh resistor is represented by α, which is the reference value for the phase shift angle.

6. The method according to claim 5, characterized in that, Also includes: Obtain the output voltage reference signal; The control circuit controls the error between the output voltage of the power electronic transformer and the output voltage reference value to be within a preset range.

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