Power conversion device, control method, wireless power transfer system and rail vehicle

Abstract

This invention provides a power converter, a control method, a wireless power transmission system, and a rail vehicle. The power converter includes an uncontrolled rectifier circuit, a boost circuit, and a control circuit. The uncontrolled rectifier circuit converts an input AC voltage into a DC voltage. The boost circuit is connected to the uncontrolled rectifier circuit and includes a first boost chopper circuit and a second boost chopper circuit, which are connected in parallel and alternately. The current in either the first or second boost chopper circuit is a first current. The boost circuit boosts the DC voltage to obtain a first voltage. The control circuit adjusts the first voltage based on the first current and a set voltage of the boost circuit to stabilize the first voltage. This invention effectively reduces the size of the power converter and lowers power device losses and heat generation.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and more specifically, to a converter, a control method, a wireless power transmission system, and a rail vehicle. Background Technology

[0002] In wireless power transmission systems for rail transit, on-board converters are a crucial component. In existing technologies, on-board converters generally consist of compensation devices, rectifiers, and DC-DC converters. Their working principle is as follows: the high-frequency induced voltage on the receiving coil of the wireless power transmission system is used as the input voltage, which is then rectified into a DC voltage by the rectifier, and finally boosted by the DC-DC converter to become the bus voltage of the on-board power supply system, providing power to the train's internal systems. On-board converters are one of the most important devices in wireless power transmission systems for rail transit.

[0003] However, due to the high power demand of rail transit train power supply systems and the dynamic changes in the input voltage and load of on-board converters in wireless power transmission systems, existing on-board converters face problems such as difficulty in selecting power devices, high losses in main circuit devices, and large size of energy storage devices when the input current is large. Summary of the Invention

[0004] The present invention aims to solve at least one of the above-mentioned technical problems.

[0005] Therefore, the first objective of the present invention is to provide a converter.

[0006] A second objective of this invention is to provide a control method for a converter device.

[0007] A third objective of this invention is to provide a wireless power transmission system.

[0008] The fourth objective of this invention is to provide a rail vehicle.

[0009] To achieve the first objective of this invention, the technical solution of this invention provides a converter device, comprising: an uncontrolled rectifier circuit, a boost circuit, and a control circuit; the uncontrolled rectifier circuit is used to convert the input AC voltage into DC voltage; the boost circuit is connected to the uncontrolled rectifier circuit, the boost circuit includes a first boost chopper circuit and a second boost chopper circuit, the first boost chopper circuit and the second boost chopper circuit are connected in parallel alternately, the current of the first boost chopper circuit or the second boost chopper circuit is a first current, the boost circuit boosts the DC voltage to obtain a first voltage; the control circuit adjusts the first voltage according to the first current of the boost circuit and the set voltage to stabilize the first voltage.

[0010] In this technical solution, an uncontrolled rectifier circuit is used as the front-end rectifier, and a boost circuit with the first boost chopper circuit and the second boost chopper circuit connected in parallel is used as the back-end boost circuit. This can effectively reduce the size of the converter and reduce power device losses and heat generation.

[0011] In addition, the technical solution provided by this invention may also have the following additional technical features:

[0012] In the above technical solution, the uncontrolled rectifier circuit includes a first branch and a second branch. The first branch includes two diodes, and the second branch includes two diodes. The first branch and the second branch are connected in parallel. The middle of the two diodes in the first branch is connected to the first phase of the AC voltage, and the middle of the two diodes in the second branch is connected to the second phase of the AC voltage.

[0013] In this technical solution, the uncontrolled rectifier circuit serves as the front-stage rectifier device, which has a simple circuit structure and low loss.

[0014] In any of the above technical solutions, the uncontrolled rectifier circuit includes: a first diode, a second diode, a third diode, and a fourth diode; the cathode of the second diode is connected to the anode of the first diode, and the second diode and the first diode are connected in series to form a first branch; the cathode of the fourth diode is connected to the anode of the third diode, and the fourth diode and the third diode are connected in series to form a second branch; wherein, the anode of the first diode is connected to the first phase of the AC voltage, the anode of the third diode is connected to the second phase of the AC voltage, the cathodes of the first diode and the third diode are connected, and the first branch and the second branch are connected in parallel.

[0015] In this technical solution, the uncontrolled rectifier circuit has a simple circuit structure and low loss, which can effectively reduce the size of the converter device.

[0016] In any of the above technical solutions, the boost circuit includes a first boost chopper circuit, a second boost chopper circuit, a first voltage regulator component, and a second voltage regulator component. The first boost chopper circuit includes a first switching device, a first inductor, and a first commutation component. The first switching device controls the connection or disconnection of the first commutation component, which enables commutation of the first boost chopper circuit. The second boost chopper circuit includes a second switching device, a second inductor, and a second commutation component. The second switching device controls the connection or disconnection of the second commutation component, which enables commutation of the second boost chopper circuit. The first boost chopper circuit and the second boost chopper circuit are connected in parallel. The first voltage regulator component is connected to the input terminals of the first and second boost chopper circuits and is used to regulate the DC voltage output by the uncontrolled rectifier circuit. The second voltage regulator component is connected to the output terminals of the first and second boost chopper circuits and is used to regulate the first voltage output by the boost circuit.

[0017] In this technical solution, the first boost chopper circuit and the second boost chopper circuit shunt the current, reducing the current flowing through a single switching device, thereby reducing the loss of the switching device, reducing the heat generation of the power device, and thus extending the service life of the converter.

[0018] In any of the above technical solutions, the boost circuit includes: a first capacitor, a first switching device, a first inductor, a second capacitor, a fifth diode, a second inductor, a sixth diode, and a second switching device; the first capacitor is connected in parallel with the uncontrolled rectifier circuit; the first switching device is connected in parallel with the first capacitor; the first inductor is connected in series between the first capacitor and the first switching device, and the first inductor is connected to the drain of the first switching device; the second capacitor is connected in parallel with the first switching device; the fifth diode is connected in series between the second capacitor and the first switching device, and the drain of the first switching device is connected to the anode of the fifth diode, and the fifth diode is connected in series with the first inductor to form a third branch; the anode of the sixth diode is connected to the second inductor, and the sixth diode is connected in series with the second inductor to form a fourth branch, and the fourth branch is connected in parallel with the third branch; the drain of the second switching device is connected to the anode of the sixth diode, and the source of the second switching device is connected to the source of the first switching device; wherein, the first capacitor, the first inductor, the first switching device, the fifth diode, and the second capacitor form a first boost chopper circuit, and the first capacitor, the second inductor, the second switching device, the sixth diode, and the second capacitor form a second boost chopper circuit.

[0019] This technical solution reduces the size of inductors and capacitors, thereby reducing the overall size of the converter and improving the applicability of on-board converters.

[0020] In any of the above technical solutions, the boost circuit further includes: a voltage sensor and a current sensor; the voltage sensor is connected in parallel with the second capacitor to measure the first voltage; the current sensor is connected in series with the first inductor or the second inductor to measure the first current.

[0021] This technical solution uses voltage and current sensors to obtain the first voltage and first current of the boost circuit in a timely and accurate manner.

[0022] In any of the above technical solutions, the value of the first capacitor satisfies:

[0023]

[0024] Where C0 represents the value of the first capacitor, P o_max r represents the maximum output power of the converter. v The ripple rate of the DC voltage is represented by η, the efficiency of the converter is represented by f0, and the frequency of the input AC voltage is represented by V. in V represents the peak value of the DC voltage. th-diode This represents the forward voltage drop of the first diode.

[0025] The value of the second capacitor satisfies:

[0026]

[0027] Where C1 represents the value of the second capacitor, I o_max The maximum output current of the converter is represented by , D represents the rated duty cycle of the converter, Δu represents the ripple of the first voltage, and f represents the rated switching frequency of the converter.

[0028] The value of the first inductor or the second inductor satisfies:

[0029]

[0030] Where L represents the value of the first inductance or the value of the second inductance, V in Indicates the value of the first inductor or the value of the second inductor, I L This represents the sum of the currents of the first and second inductors.

[0031] This technical solution provides the value requirements for the first capacitor, the second capacitor, the first inductor, and the second inductor. The above parameters can be set according to the actual situation, which facilitates the design of the converter.

[0032] In any of the above technical solutions, the control circuit includes: a voltage loop control module, a current loop control module, a carrier module, and a comparison output module; the voltage loop control module obtains a first output value based on a first voltage and a set voltage; the current loop control module obtains a second output value based on the first output value and a first current; the carrier module outputs a carrier to the comparison output module; the comparison output module obtains a first gate drive signal and a second gate drive signal based on the second output value and the carrier, and outputs them to the boost circuit.

[0033] This technical solution incorporates a voltage loop control module and a current loop control module, achieving constant voltage dual closed-loop control, which offers better dynamic response performance compared to single closed-loop control methods.

[0034] In any of the above technical solutions, the voltage loop control module includes: a voltage loop adder, a voltage loop proportional-integral controller, and a voltage loop limiter; the voltage loop adder obtains a first error value between a first voltage and a set voltage; the voltage loop proportional-integral controller adjusts the first error value; and the voltage loop limiter limits the adjusted first error value to obtain a first output value.

[0035] The voltage loop control module of this technical solution realizes the first closed-loop control of the first voltage.

[0036] In any of the above technical solutions, the current loop control module includes: a current loop adding unit, a current loop proportional-integral controller, and a current loop limiting unit; the current loop adding unit obtains a second error value between a first output value and a first current; the current loop proportional-integral controller adjusts the second error value; and the current loop limiting unit limits the adjusted second error value to obtain a second output value.

[0037] The current loop control module of this technical solution implements a second closed-loop control of the first output value.

[0038] In any of the above technical solutions, the carrier module outputs a triangular wave.

[0039] This technical solution uses a triangular wave, which is simple and easy to implement.

[0040] In any of the above technical solutions, the comparison output module includes: a first comparator, a second comparator, and an inverter; the first comparator is used for a first difference and a carrier wave, the first difference being the difference between 1 and a second output value; the second comparator is used to receive the second output value and the carrier wave, and the second comparator outputs a second gate drive signal to the gate of the second switching device of the boost circuit; the inverter inverts the output signal of the first comparator to obtain a first gate drive signal, and the first gate drive signal is output to the gate of the first switching device of the boost circuit.

[0041] This technical solution outputs a first gate drive signal and a second gate drive signal through a first comparator, a second comparator, and an inverter, thereby controlling the first and second switching devices of the boost circuit and maintaining the stability of the first voltage output by the converter.

[0042] To achieve the second objective of this invention, the technical solution of this invention provides a control method for a converter device. The converter device adopting any embodiment of this technical solution includes: acquiring a first voltage and a first current of a boost circuit; and adjusting the first voltage according to a set voltage and a first current.

[0043] This technical solution features a simple control method and a rapid response.

[0044] In addition, the technical solution provided by this invention may also have the following additional technical features:

[0045] In the above technical solution, adjusting the first voltage according to the set voltage and the first current specifically includes: obtaining a first error value between the first voltage and the set voltage; performing proportional-integral adjustment on the first error value; limiting the adjusted first error value to obtain a first output value; obtaining a second error value between the first output value and the first current; performing proportional-integral adjustment on the second error value; limiting the adjusted second error value to obtain a second output value; obtaining a first difference; comparing the first difference with a carrier wave to obtain an output signal; inverting the output signal to obtain a first gate drive signal, which is output to the gate of the first switching device, wherein the first difference is the difference between 1 and the second output value; comparing the second output value with a carrier wave to obtain a second gate drive signal, which is output to the gate of the second switching device; and adjusting the duty cycle of the first and second switching devices through the first and second gate drive signals to maintain the stability of the first voltage.

[0046] In this technical solution, by processing the first output value and the second output value, a constant voltage dual closed-loop control is achieved, which has better dynamic response performance compared with the single closed-loop control method.

[0047] To achieve the third objective of this invention, the technical solution of this invention provides a wireless power transmission system, comprising: a receiving coil and a converter as described in any technical solution of this invention; the receiving coil outputs an AC voltage to the converter, the converter converts the input AC voltage into a DC voltage, and boosts the DC voltage before outputting it.

[0048] The rail vehicle provided by the technical solution of the present invention includes the converter device of any technical solution of the present invention, and therefore has all the beneficial effects of the converter device of any technical solution of the present invention, which will not be repeated here.

[0049] To achieve the fourth objective of this invention, the technical solution of this invention provides a rail vehicle, including: a wireless power transmission system; the wireless power transmission system includes a receiving coil and a converter as described in any technical solution of this invention, the receiving coil outputs an AC voltage to the converter, the converter converts the input AC voltage into a DC voltage, and boosts the DC voltage before outputting it to the rail vehicle.

[0050] The rail vehicle provided by the technical solution of the present invention includes the rail vehicle of any technical solution of the present invention, and therefore has all the beneficial effects of the converter device of any technical solution of the present invention, which will not be repeated here.

[0051] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0052] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0053] Figure 1 This is one of the schematic diagrams of a converter device according to an embodiment of the present invention;

[0054] Figure 2 This is a schematic diagram of a control circuit according to an embodiment of the present invention;

[0055] Figure 3 This is one of the flowcharts for a control method of a converter according to an embodiment of the present invention;

[0056] Figure 4 This is a second flowchart of a control method for a converter according to an embodiment of the present invention;

[0057] Figure 5 This is a schematic block diagram of a wireless power transmission system according to an embodiment of the present invention;

[0058] Figure 6 This is a schematic block diagram of a rail vehicle according to an embodiment of the present invention;

[0059] Figure 7 This is a schematic diagram illustrating the control effect according to an embodiment of the present invention.

[0060] in, Figures 1 to 7 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0061] 100: Converter; 200: Uncontrolled rectifier circuit; 210: First diode; 220: Second diode; 230: First branch; 240: Third diode; 250: Fourth diode; 260: Second branch; 300: Boost circuit; 310: First capacitor; 320: First switching device; 330: First inductor; 340: Second capacitor; 350: Fifth diode; 360: Third branch; 370: Second inductor; 380: Sixth diode; 390: Second switching device; 400: Voltage sensor; 410: Current sensor; 42 0: Fourth branch; 500: Control circuit; 510: Voltage loop control module; 512: Voltage loop adder unit; 514: Voltage loop proportional-integral controller; 516: Voltage loop limiting unit; 520: Current loop control module; 522: Current loop adder unit; 524: Current loop proportional-integral controller; 526: Current loop limiting unit; 530: Carrier module; 540: Comparison output module; 542: First comparator; 544: Second comparator; 546: Inverter; 600: Wireless power transmission system; 610: Receiving coil; 700: Rail vehicle. Detailed Implementation

[0062] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0063] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0064] The following reference Figures 1 to 7 The present invention describes some embodiments of a converter, control method, wireless power transmission system, and rail vehicle.

[0065] Example 1:

[0066] like Figure 1 As shown, this embodiment provides a converter device 100, including: an uncontrolled rectifier circuit 200, a boost circuit 300, and a control circuit 500; the uncontrolled rectifier circuit 200 is used to convert the input AC voltage into DC voltage; the boost circuit 300 is connected to the uncontrolled rectifier circuit 200, and the boost circuit 300 includes a first boost chopper circuit and a second boost chopper circuit, which are connected in parallel and alternately. The current of the first boost chopper circuit or the second boost chopper circuit is a first current. The boost circuit 300 boosts the DC voltage to obtain the first voltage; the control circuit 500 adjusts the first voltage according to the first current of the boost circuit 300 and the set voltage to stabilize the first voltage.

[0067] The converter 100 of this embodiment can be applied in rail transit wireless power transmission systems, such as on-board power supply networks for high-speed maglev trains, subways, etc.

[0068] In existing rail transit train power supply systems, power demand is high, and the input voltage and load of the on-board converter in the wireless power transmission system are dynamically changing, resulting in large input current. Related technical solutions typically use typical boost chopper circuits, which have the problem of large current flow in the switching devices. Due to device losses, the switching frequency is low, and the reactive power devices are large in size, with a limited range of power device selection.

[0069] Currently, with the increasing power demand in rail transit train power supply systems, the power of onboard power supply devices is growing, while the induced voltage in the receiving coil is relatively small. This results in a large current flowing through the input terminal of the onboard converter. This large input current leads to difficulties in selecting power devices, high losses in main circuit components, and large size of energy storage devices.

[0070] In this embodiment, an uncontrolled rectifier circuit 200 is used as the front-end rectifier, and a boost circuit 300 consisting of a first boost chopper circuit and a second boost chopper circuit connected in parallel is used as the rear-end DC-DC boost device. This can effectively reduce the size of the converter device 100 and reduce power device losses and heat generation.

[0071] The converter 100 in this embodiment has a strong current carrying capacity. The two boost circuits are connected in parallel and interleaved. Each boost circuit shunts the current, so the current flowing through a single switch is reduced, reducing the loss of the switch. This can further increase the switching frequency of the switch, reduce the size of reactive components, and expand the selection range of switch, making design and selection easier, thereby improving the applicability and reliability of the vehicle-mounted converter.

[0072] Example 2:

[0073] like Figure 1 As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0074] The uncontrolled rectifier circuit 200 includes: a first branch 230 and a second branch 260. The first branch 230 includes two diodes, and the second branch 260 includes two diodes. The first branch 230 and the second branch 260 are connected in parallel. The middle of the two diodes in the first branch 230 is connected to the first phase of the AC voltage, and the middle of the two diodes in the second branch 260 is connected to the second phase of the AC voltage.

[0075] In this embodiment, the uncontrolled rectifier circuit 200 serves as a front-stage rectifier device, with a simple circuit structure and low loss.

[0076] Example 3:

[0077] like Figure 1 As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0078] The uncontrolled rectifier circuit 200 includes: a first diode 210, a second diode 220, a third diode 240, and a fourth diode 250; the cathode of the second diode 220 is connected to the anode of the first diode 210, and the second diode 220 and the first diode 210 are connected in series to form a first branch 230; the cathode of the fourth diode 250 is connected to the anode of the third diode 240, and the fourth diode 250 and the third diode 240 are connected in series to form a second branch 260; wherein, the anode of the first diode 210 is connected to the first phase of the AC voltage, the anode of the third diode 240 is connected to the second phase of the AC voltage, the cathodes of the first diode 210 and the third diode 240 are connected, and the first branch 230 and the second branch 260 are connected in parallel.

[0079] In this embodiment, the first and second phases of the AC voltage are input to the uncontrolled rectifier circuit 200. The uncontrolled rectifier circuit 200 serves as a front-end rectifier device, with a simple circuit structure and low loss.

[0080] In this embodiment, the forward voltage drops of the first diode 210, the second diode 220, the third diode 240, and the fourth diode 250 are the same.

[0081] Example 4:

[0082] like Figure 1 As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0083] The boost circuit 300 includes: a first boost chopper circuit, a second boost chopper circuit, a first voltage regulator, and a second voltage regulator. The first boost chopper circuit includes a first switching device 320, a first inductor 330, and a first commutation component. The first switching device 320 controls the connection or disconnection of the first commutation component, which enables commutation of the first boost chopper circuit. The second boost chopper circuit includes a second switching device 390, a second inductor 370, and a second commutation component. The second switching device 390 controls the connection or disconnection of the second commutation component, which enables commutation of the second boost chopper circuit. The first and second boost chopper circuits are connected in parallel. The first voltage regulator is connected to the input terminals of the first and second boost chopper circuits and is used to regulate the DC voltage output by the uncontrolled rectifier circuit 200. The second voltage regulator is connected to the output terminals of the first and second boost chopper circuits and is used to regulate the first voltage output by the boost circuit 300.

[0084] In this embodiment, the first commutation component can be a fifth diode 350, the second commutation component can be a sixth diode 380, the first voltage regulator component can be a first capacitor 310, and the second voltage regulator component can be a second capacitor 340.

[0085] In this embodiment, the duty cycle of the first switching device 320 and the second switching device 390 is determined according to the required voltage gain. By connecting the two boost chopper circuits in parallel, the ripple rate of the output first voltage can be effectively reduced.

[0086] In this embodiment, the first boost chopper circuit and the second boost chopper circuit shunt the current, reducing the current flowing through each switching device, thereby reducing the losses of the switching devices, reducing the heat generated by the power devices, and thus extending the service life of the converter 100. Furthermore, because the current of each switching device is reduced, the range of switching device models that can be selected is expanded, which facilitates design and selection and improves the applicability and reliability of the converter 100.

[0087] This embodiment uses a first boost chopper circuit and a second boost chopper circuit connected in parallel, which reduces the current of a single switching device, can further increase the switching frequency of the switching device, reduce the size of the inductor, and thus reduce the overall size of the converter 100, improving the applicability of the vehicle-mounted converter.

[0088] Example 5:

[0089] like Figure 1 As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0090] The boost circuit 300 includes: a first capacitor 310, a first switching device 320, a first inductor 330, a second capacitor 340, a fifth diode 350, a second inductor 370, a sixth diode 380, and a second switching device 390; the first capacitor 310 is connected in parallel with the uncontrolled rectifier circuit 200; the first switching device 320 is connected in parallel with the first capacitor 310; the first inductor 330 is connected in series between the first capacitor 310 and the first switching device 320, and the first inductor 330 is connected to the drain of the first switching device 320; the second capacitor 340 is connected in parallel with the first switching device 320; the fifth diode 350 is connected in series between the second capacitor 340 and the first switching device 320, and the drain of the first switching device 320 is connected to the anode of the fifth diode 350. 350 is connected in series with the first inductor 330 to form the third branch 360; the anode of the sixth diode 380 is connected to the second inductor 370, and the sixth diode 380 and the second inductor 370 are connected in series to form the fourth branch 420, which is connected in parallel with the third branch 360; the drain of the second switching device 390 is connected to the anode of the sixth diode 370, and the source of the second switching device 390 is connected to the source of the first switching device 320; wherein, the first capacitor 310, the first inductor 330, the first switching device 320, the fifth diode 350 and the second capacitor 340 form the first boost chopper circuit, and the first capacitor 310, the second inductor 370, the second switching device 390, the sixth diode 380 and the second capacitor 340 form the second boost chopper circuit.

[0091] In this embodiment, the fifth diode 350 is the first commutation component, the sixth diode 380 is the second commutation component, the first capacitor 310 is the first voltage regulator component, and the second capacitor 340 is the second voltage regulator component.

[0092] In this embodiment, the boost circuit 300 has two interleaved parallel boost circuits, which shunt the current. This reduces the current flowing through each individual switching device, lowering losses and heat generation in the power devices, thereby extending the lifespan of the converter 100. Furthermore, the reduced current in each switching device expands the range of switch device models available, facilitating design and selection, and improving the applicability and reliability of the converter 100.

[0093] In this embodiment, by using two boost circuits connected in parallel in an alternating manner, the current of a single switching device is reduced, which can further increase the switching frequency of the switching device, reduce the size of the inductor and capacitor, and thus reduce the overall size of the converter 100, thereby improving the applicability of the vehicle-mounted converter.

[0094] Example 6:

[0095] like Figure 1As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0096] The boost circuit 300 also includes a voltage sensor 400 and a current sensor 410; the voltage sensor 400 is connected in parallel with the second capacitor 340 to measure the first voltage; the current sensor 410 is connected in series with the first inductor 330 or the second inductor 370 to measure the first current.

[0097] In this embodiment, the voltage sensor 400 is connected in parallel across the second capacitor 340 to measure the first voltage, which is the output voltage of the boost circuit 300. The first voltage can be output to the vehicle power supply system, and the value of the output voltage is the bus voltage value of the vehicle power supply system.

[0098] In this embodiment, the current sensor 410 can be set at the terminal connection line of the first inductor 330 to measure the first current of the first inductor 330.

[0099] In this embodiment, by setting a voltage sensor 400 and a current sensor 410, the first voltage and the first current of the boost circuit 300 are obtained in a timely and accurate manner. Based on the first voltage and the first current, the output voltage is controlled to ensure that the control can be responded to in a timely and accurate manner.

[0100] Example 7:

[0101] This embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0102] The value of the first capacitor 310 satisfies:

[0103]

[0104] Where C0 represents the value of the first capacitor 310, P o_max r represents the maximum output power of converter 100. v The ripple rate of the DC voltage is represented by η, the efficiency of the converter 100 is represented by f0, and the frequency of the input AC voltage is represented by V. in V represents the peak value of the DC voltage. th-diode This indicates the forward voltage drop of the first diode 210;

[0105] The value of the second capacitor 340 satisfies:

[0106]

[0107] Where C1 represents the value of the second capacitor 340, I o_maxThe maximum output current of converter 100 is represented by Δu, the rated duty cycle of converter 100 is represented by D, the ripple of the first voltage is represented by Δu, and the rated switching frequency of converter 100 is represented by f.

[0108] The values ​​of the first inductor 330 or the second inductor 370 satisfy the following:

[0109]

[0110] Where L represents the value of the first inductance 330 or the value of the second inductance 370, V in I represents the peak input voltage of converter 100. L This represents the sum of the current in the first inductor 330 and the current in the second inductor 370.

[0111] In this embodiment, the forward voltage drops of the first diode 210, the second diode 220, the third diode 240, and the fourth diode 250 are the same.

[0112] In this embodiment, the rated value of the switching duty cycle of the converter 100 is set according to the voltage transformation requirements of the converter 100 under specific operating conditions. The rated value of the switching frequency of the converter 100 is set according to the frequency requirements of the converter's operating conditions.

[0113] This embodiment provides the value requirements for the first capacitor 310, the second capacitor 340, the first inductor 330, and the second inductor 370. The above parameters can be set according to the actual situation, which facilitates the design of the converter 100.

[0114] Example 8:

[0115] like Figure 2 As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0116] The control circuit 500 includes: a voltage loop control module 510, a current loop control module 520, a carrier module 530, and a comparison output module 540; the voltage loop control module 510 obtains a first output value based on a first voltage and a set voltage; the current loop control module 520 obtains a second output value based on the first output value and a first current; the carrier module 530 outputs a carrier wave to the comparison output module 540; the comparison output module 540 obtains a first gate drive signal and a second gate drive signal based on the second output value and the carrier wave, and outputs them to the boost circuit 300.

[0117] In wireless power transmission systems, the ground transmitting coil and the on-board receiving coil experience a certain positional misalignment during train movement, leading to dynamic changes in the peak value of the induced voltage in the receiving coil. Furthermore, the on-board power supply load also undergoes dynamic changes; therefore, the converter 100 needs to possess excellent regulation performance. To meet this requirement, the control circuit 500 employs a constant output voltage dual closed-loop control.

[0118] In this embodiment, a voltage loop control module 510 and a current loop control module 520 are provided to realize constant voltage dual closed-loop control, which has better dynamic response performance compared with the single closed-loop control method.

[0119] In this embodiment, the first gate drive signal and the second gate drive signal are output to the gates of the first switching device 320 and the second switching device 390 in the boost circuit 300, which can adjust the duty cycle of the first switching device 320 and the second switching device 390 to maintain the stability of the first voltage. When the voltage of the voltage sensor 400 is too high or the load is suddenly unloaded, the conduction duty cycle of the first switching device 320 and the second switching device 390 is reduced. When the voltage of the voltage sensor 400 is too low or the load is suddenly increased, the conduction duty cycle of the first switching device 320 and the second switching device 390 is increased, so that the converter 100 has good dynamic response performance.

[0120] In this embodiment, the principle of controlling the stability of the first voltage is as follows: the difference between the collected first voltage and the set voltage is adjusted by the voltage loop control module 510 and the current loop control module 520, and then the square wave is output by the comparison output module 540. By adjusting the duty cycle of the square wave, the final adjustment of the first voltage is achieved.

[0121] Example 9:

[0122] like Figure 2 As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0123] The voltage loop control module 510 includes: a voltage loop adder unit 512, a voltage loop proportional-integral controller 514, and a voltage loop limiter unit 516; the voltage loop adder unit 512 acquires a first error value between a first voltage and a set voltage; the voltage loop proportional-integral controller 514 adjusts the first error value; and the voltage loop limiter unit 516 limits the adjusted first error value to obtain a first output value.

[0124] The voltage loop proportional-integral controller 514 in this embodiment can be a digital PI controller.

[0125] In this embodiment, the voltage loop control module 510 implements the first closed-loop control of the first voltage, performing the first adjustment by comparing the first voltage with the set voltage. The second adjustment is achieved by the current loop control module 520. This embodiment adopts a constant voltage dual closed-loop control, which has better dynamic response performance compared to the single closed-loop control method.

[0126] Example 10:

[0127] like Figure 2 As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0128] The current loop control module 520 includes: a current loop adder 522, a current loop proportional-integral controller 524, and a current loop limiter 526; the current loop adder 522 acquires a second error value between a first output value and a first current; the current loop proportional-integral controller 524 adjusts the second error value; and the current loop limiter 526 limits the adjusted second error value to obtain a second output value.

[0129] The current loop proportional-integral controller 524 in this embodiment can be a digital PI controller.

[0130] In this embodiment, the current loop control module 520 implements a second closed-loop control of the first output value, performing a second adjustment by comparing the first current with the first output value. The voltage loop control module 510 implements the first adjustment. This embodiment employs a constant voltage dual closed-loop control, which has better dynamic response performance compared to the single closed-loop control method.

[0131] Example 11:

[0132] This embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0133] The carrier module 530 outputs a triangular wave as its carrier.

[0134] In this embodiment, as Figure 2 As shown, the carrier module 530 provides a carrier for the first comparator 542 and the second comparator 544. The carrier can be a triangular wave, which is simple and easy to implement.

[0135] Example 12:

[0136] like Figure 2 As shown, this embodiment provides a converter 100, which, in addition to the technical features of the above embodiments, further includes the following technical features:

[0137] The comparison output module 540 includes a first comparator 542, a second comparator 544, and an inverter 546. The first comparator 542 is used to receive a first difference and a carrier wave, where the first difference is the difference between 1 and a second output value. The second comparator 544 is used to receive the second output value and a carrier wave, and outputs a second gate drive signal to the gate of the second switching device 390 of the boost circuit 300. The inverter 546 inverts the output signal of the first comparator 542 to obtain a first gate drive signal, which is output to the gate of the first switching device 320 of the boost circuit 300.

[0138] In this embodiment, 1 is subtracted from the second output value output by the current loop limiting unit 526 to obtain a first difference. In the first comparator 542, the first difference is compared with the carrier wave. If the first difference is greater than the carrier wave, the first comparator 542 outputs 1; if the first difference is less than the carrier wave, the first comparator 542 outputs 0. In the second comparator 544, the second output value is compared with the carrier wave. If the second output value is greater than the carrier wave, the second comparator 544 outputs 1; if the second output value is less than the carrier wave, the second comparator 544 outputs 0.

[0139] In this embodiment, the output first gate drive signal and second gate drive signal control two first switching devices 320 and second switching devices 390, respectively. Since the first switching devices 320 and second switching devices 390 are connected in parallel, the first gate drive signal and the second gate drive signal need to be phase-shifted by 180 degrees. This is achieved through a first difference and an inverter, ultimately realizing the 180-degree phase shift between the two drive signals. The first difference is the difference between 1 and the second output value. This first difference allows the inputs of the two comparators to be complementary. In this embodiment, both the first gate drive signal and the second gate drive signal are square wave signals with the same amplitude and frequency but different phases.

[0140] In this embodiment, the first gate drive signal and the second gate drive signal are output through the first comparator 542, the second comparator 544 and the inverter 546, thereby realizing the control of the first switching device 320 and the second switching device 390 of the boost circuit 300 and maintaining the stability of the first voltage output by the converter 100.

[0141] Example 13:

[0142] like Figure 3 As shown, this embodiment provides a control method for a converter device. The control method for a converter device 100 using any embodiment of this technical solution includes the following steps:

[0143] Step S102: Collect the first voltage and first current of the boost circuit;

[0144] Step S104: Adjust the first voltage according to the set voltage and the first current to stabilize the first voltage.

[0145] In this embodiment, firstly, the first voltage and first current in the boost circuit are collected, and then the first voltage is adjusted based on the first voltage and first current. The control method is simple and the response is rapid.

[0146] Example 14:

[0147] like Figure 4 As shown, this embodiment provides a control method for a converter device. In addition to the technical features of the above embodiments, this embodiment further includes the following technical features:

[0148] Adjusting the first voltage based on the set voltage and the first current involves the following steps:

[0149] Step S202: Obtain the first error value between the first voltage and the set voltage, perform proportional-integral adjustment on the first error value, limit the adjusted first error value, and obtain the first output value;

[0150] Step S204: Obtain the second error value between the first output value and the first current, perform proportional-integral adjustment on the second error value, limit the adjusted second error value, and obtain the second output value;

[0151] Step S206: Obtain the first difference, compare the first difference with the carrier wave to obtain the output signal, invert the output signal to obtain the first gate drive signal, and output it to the gate of the first switching device;

[0152] The first difference is the difference between 1 and the second output value;

[0153] Step S208: By comparing the second output value with the carrier wave, a second gate drive signal is obtained and output to the gate of the second switching device;

[0154] In step S210, the duty cycle of the first switching device and the second switching device is adjusted by the first gate drive signal and the second gate drive signal to maintain the stability of the first voltage.

[0155] To ensure good regulation performance, the control method adopts constant output voltage dual closed-loop control.

[0156] In this embodiment, by processing the first output value and the second output value, a constant voltage dual closed-loop control is achieved, which has better dynamic response performance compared with the single closed-loop control method.

[0157] In this embodiment, the first gate drive signal and the second gate drive signal are output to the gates of the first switching device 320 and the second switching device 390 in the boost circuit 300, which can adjust the duty cycle of the first switching device 320 and the second switching device 390 to maintain the stability of the first voltage. When the voltage of the voltage sensor 400 is too high or the load is suddenly unloaded, the duty cycle of the first switching device 320 and the second switching device 390 is reduced. When the voltage of the voltage sensor 400 is too low or the load is suddenly increased, the duty cycle of the first switching device 320 and the second switching device 390 is increased, so that the converter 100 has good dynamic response performance.

[0158] In this embodiment, firstly, a first error value between a first voltage and a set voltage is obtained. This first error value is then subjected to proportional-integral (PI) adjustment, and the adjusted first error value is limited to obtain a first output value, thus achieving the first closed-loop control of the first voltage. A first adjustment is performed by comparing the first voltage with the set voltage. Next, a second error value between the first output value and a first current is obtained. This second error value is then subjected to PI adjustment, and the adjusted second error value is limited to obtain a second output value, thus achieving the second closed-loop control of the first output value. A second adjustment is performed by comparing the first current with the first output value. This embodiment employs a constant voltage dual-closed-loop control, which offers better dynamic response performance compared to a single-closed-loop control method.

[0159] Example 15:

[0160] like Figure 5 As shown, this embodiment provides a wireless power transmission system 600, including: a receiving coil 610 and a converter 100 as described in any technical solution of the present invention; the receiving coil 610 outputs an AC voltage to the converter 100, the converter 100 converts the input AC voltage into a DC voltage, and boosts the DC voltage before outputting it.

[0161] Example 16:

[0162] like Figure 6 As shown, this embodiment provides a rail vehicle 700, including: a wireless power transmission system 600; the wireless power transmission system 600 includes a receiving coil 610 and a converter 100 as described in any technical solution of the present invention, the receiving coil 610 outputs an AC voltage to the converter 100, the converter 100 converts the input AC voltage into a DC voltage, and boosts the DC voltage before outputting it to the rail vehicle 700. Specific implementation examples:

[0164] like Figure 1 and Figure 2As shown, this embodiment provides a converter 100 and a control method. The converter 100 has a strong current-carrying capacity, and the control method of the converter 100 has a rapid response, which can improve the applicability and reliability of the vehicle-mounted converter (converter 100). This embodiment has two interleaved parallel boost circuits. Each boost circuit shunts the current, so the current flowing through a single switching transistor (switching device) is reduced, reducing the loss of the switching transistor. This can further increase the switching frequency of the switching transistor, reduce the size of reactive power components, and expand the selection range of switching transistors, making design and selection easier. Figure 1 In this diagram, AC represents alternating current, Vout is the output voltage (i.e., the first voltage), S1 and S2 are both MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), specifically S1 is the first switching device 320 and S2 is the second switching device 390. L1 and L2 are both energy storage inductors, specifically L1 is the first inductor 330 and L2 is the second inductor 370. C0 and C1 are DC support capacitors, specifically C0 is the first capacitor 310 and C1 is the second capacitor 340. D1 and D2 are commutation diodes, specifically D1 is the first diode 210, D2 is the second diode 220, D3 is the third diode 240, D4 is the fourth diode 250, D5 is the fifth diode 350, and D6 is the sixth diode 380. TV1 is a voltage sensor 400 and TV2 is a current sensor 410. GS1 V is the first gate drive signal. GS2 This is the second gate drive signal.

[0165] The technical solution and working principle of this embodiment are as follows:

[0166] The train's onboard power supply has a high power output, but the induced voltage in the receiving coil is relatively low, resulting in a large current flowing through the input terminal of the onboard converter. This large input current leads to difficulties in selecting power devices, high losses in the main circuit components, and large size of the energy storage devices. To reduce the size of the converter and decrease power device losses and heat generation, this embodiment uses an uncontrolled rectifier circuit as the front-stage rectifier and an interleaved parallel Boost circuit as the rear-stage DC-DC boost converter.

[0167] The converter 100 includes an uncontrolled rectifier circuit 200 and a boost circuit 300 (DC / DC boost circuit). The uncontrolled rectifier circuit 200 includes diodes D1, D2, D3, and D4. The DC / DC boost circuit includes an input DC support capacitor C0, switching devices S1 and S2, commutation diodes D5 and D6, energy storage inductors L1 and L2, and an output filter capacitor C1. A voltage sensor TV1 is connected in parallel across the output filter capacitor C1, and a current sensor TA1 is located at the terminal connection of the energy storage inductor L1.

[0168] In wireless power transmission systems, the ground transmitting coil and the onboard receiving coil experience a certain positional misalignment during train movement, leading to dynamic changes in the peak value of the induced voltage in the receiving coil. Furthermore, the onboard power supply load also undergoes dynamic changes; therefore, the onboard converter needs to possess excellent regulation performance. To meet this requirement, a constant output voltage dual closed-loop control method is employed.

[0169] The control method is as follows: The voltage (first voltage) of the output voltage sensor TV1 is collected and the difference is calculated with the given voltage. The error value is then passed through a digital PI controller (voltage loop proportional-integral controller 514). After passing through a limiting circuit, the obtained value is compared with the inductance current (first current) measured by the current sensor TA1. The error value is then passed through a digital PI circuit (current loop proportional-integral controller 524). The control loop outputs a gate drive signal V with a phase difference of 180°. GS1 V GS2 The controller (control circuit 500) maintains a constant output voltage sensor TV1 by adjusting the duty cycle of the switches. When the voltage sensor TV1 is too high or the load is suddenly removed, the duty cycle of switches S1 and S2 is reduced; when the voltage sensor TV1 is too low or the load is suddenly increased, the duty cycle of switches S1 and S2 is increased. Compared to a single closed-loop control method, this control method has better dynamic response performance.

[0170] like Figure 7 As shown, S1 and S2 are the gate drive signals of the switching transistor, I L The sum of the current values ​​of inductors L1 and L2, I L1 I is the current in the inductor L1 branch. L2 The current in the L2 branch of inductor flows through... Figure 7 It can be seen that S1 and S2 are related to I L I L1 I L2 It allows for good control and has better dynamic response performance.

[0171] In summary, the beneficial effects of the embodiments of the present invention are as follows:

[0172] The converter 100 in this embodiment has a strong current carrying capacity. The two boost circuits are connected in parallel and interleaved. Each boost circuit shunts the current, so the current flowing through a single switch is reduced, reducing the loss of the switch. This can further increase the switching frequency of the switch, reduce the size of reactive components, and expand the selection range of switch, making design and selection easier, thereby improving the applicability and reliability of the vehicle-mounted converter.

[0173] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0174] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0175] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is 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.

[0176] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A current conversion device (100), characterized in that include: An uncontrolled rectifier circuit (200) is used to convert an input AC voltage into a DC voltage; A boost circuit (300) is connected to the uncontrolled rectifier circuit (200). The boost circuit (300) includes a first boost chopper circuit and a second boost chopper circuit, which are connected in parallel in an alternating manner. The current of the first boost chopper circuit or the second boost chopper circuit is a first current. The boost circuit (300) boosts the DC voltage to obtain the first voltage. The control circuit (500) adjusts the first voltage according to the first current and the set voltage of the boost circuit (300) to stabilize the first voltage; The control circuit (500) includes: A voltage loop control module (510) obtains a first output value based on the first voltage and a set voltage; A current loop control module (520) obtains a second output value based on the first output value and the first current; Carrier module (530), which outputs a carrier to comparison output module (540); The comparison output module (540) obtains a first gate drive signal and a second gate drive signal based on the second output value and the carrier wave, and outputs them to the boost circuit (300). The voltage loop control module (510) includes: A voltage loop adder (512) acquires a first error value between the first voltage and the set voltage; A voltage loop proportional-integral controller (514) adjusts the first error value; A voltage loop limiting unit (516) limits the adjusted first error value to obtain the first output value; The current loop control module (520) includes: A current loop adder (522) acquires a second error value between the first output value and the first current. A current loop proportional-integral controller (524) adjusts the second error value; The current loop limiting unit (526) limits the adjusted second error value to obtain the second output value.

2. The current conversion device (100) according to claim 1, characterized in that The uncontrolled rectifier circuit (200) includes: The first branch (230) includes two diodes; The second branch (260) includes two diodes; The first branch (230) and the second branch (260) are connected in parallel. The middle of the two diodes in the first branch (230) is connected to the first phase of the AC voltage, and the middle of the two diodes in the second branch (260) is connected to the second phase of the AC voltage.

3. The current conversion device (100) according to claim 1, characterized in that The uncontrolled rectifier circuit (200) includes: First diode (210); The second diode (220) has its cathode connected to the anode of the first diode (210), and the second diode (220) and the first diode (210) are connected in series to form the first branch (230). Third diode (240); A fourth diode (250) is connected to the cathode of the third diode (240), and the fourth diode (250) and the third diode (240) are connected in series to form a second branch (260). Wherein, the anode of the first diode (210) is connected to the first phase of the AC voltage, the anode of the third diode (240) is connected to the second phase of the AC voltage, the cathode of the first diode (210) is connected to the cathode of the third diode (240), and the first branch (230) is connected in parallel with the second branch (260).

4. The converter (100) according to claim 1, characterized in that, The boost circuit (300) includes: The first boost chopper circuit includes a first switching device (320), a first inductor (330), and a first commutation component. The first switching device (320) controls the first commutation component to be connected or disconnected, and the first commutation component realizes the commutation of the first boost chopper circuit. The second boost chopper circuit includes a second switching device (390), a second inductor (370), and a second commutation component. The second switching device (390) controls the connection or disconnection of the second commutation component, and the second commutation component realizes the commutation of the second boost chopper circuit. The first boost chopper circuit and the second boost chopper circuit are connected in parallel. The first voltage regulator is connected to the input terminals of the first boost chopper circuit and the second boost chopper circuit. The first voltage regulator is used to regulate the DC voltage output by the uncontrolled rectifier circuit (200). The second voltage regulator is connected to the output terminals of the first boost chopper circuit and the second boost chopper circuit. The second voltage regulator is used to regulate the first voltage output by the boost circuit (300).

5. The converter (100) according to claim 1, characterized in that, The boost circuit (300) includes: The first capacitor (310) is connected in parallel with the uncontrolled rectifier circuit (200); The first switching device (320) is connected in parallel with the first capacitor (310); The first inductor (330) is connected in series between the first capacitor (310) and the first switching device (320), and the first inductor (330) is connected to the drain of the first switching device (320); The second capacitor (340) is connected in parallel with the first switching device (320); The fifth diode (350) is connected in series between the second capacitor (340) and the first switching device (320). The drain of the first switching device (320) is connected to the anode of the fifth diode (350). The fifth diode (350) is connected in series with the first inductor (330) to form a third branch (360). Second inductor (370); A sixth diode (380) is connected to the anode of the sixth diode (380) and the second inductor (370) in series to form a fourth branch (420), which is connected in parallel with the third branch (360). The drain of the second switching device (390) is connected to the anode of the sixth diode (380), and the source of the second switching device (390) is connected to the source of the first switching device (320). The first capacitor (310), the first inductor (330), the first switching device (320), the fifth diode (350) and the second capacitor (340) form the first boost chopper circuit, and the first capacitor (310), the second inductor (370), the second switching device (390), the sixth diode (380) and the second capacitor (340) form the second boost chopper circuit.

6. The current conversion device (100) according to claim 4, characterized in that The boost circuit (300) also includes: A voltage sensor (400) is connected in parallel with a second capacitor (340) to measure the first voltage; A current sensor (410) is connected in series with the first inductor (330) or the second inductor (370), and the current sensor (410) measures the first current.

7. The current conversion device (100) according to claim 5, characterized in that The value of the first capacitor (310) satisfies: ； in, This indicates the value of the first capacitor (310). This indicates the maximum output power of the converter (100). This represents the ripple rate of the DC voltage. This indicates the efficiency of the converter (100). Indicates the frequency of the input AC voltage. This indicates the peak value of the DC voltage. This represents the forward voltage drop of the first diode (210); The value of the second capacitor (340) satisfies: ； in, This indicates the value of the second capacitor (340). This indicates the maximum output current of the converter (100). This indicates the rated duty cycle value of the converter (100). This represents the ripple of the first voltage. This indicates the rated switching frequency of the converter (100); The values ​​of the first inductor (330) or the second inductor (370) satisfy: ； in, This indicates the value of the first inductor (330) or the value of the second inductor (370). This indicates the peak value of the input voltage of the converter (100). This represents the sum of the current in the first inductor (330) and the current in the second inductor (370).

8. The current conversion device (100) according to claim 1, characterized in that The carrier module (530) outputs a triangular wave as its carrier.

9. The current conversion device (100) according to claim 1, characterized in that The comparison output module (540) includes: A first comparator (542) is configured to receive a first difference and the carrier, wherein the first difference is the difference between 1 and the second output value; The second comparator (544) is used to receive the second output value and the carrier wave, and the second comparator (544) outputs the second gate drive signal to the gate of the second switching device (390) of the boost circuit (300); Inverter (546) inverts the output signal of the first comparator (542) to obtain the first gate drive signal, which is output to the gate of the first switching device (320) of the boost circuit (300).

10. A control method for a converter, employing a converter (100) as described in any one of claims 1 to 9, characterized in that, The control method includes: Collect the first voltage and first current of the boost circuit; Adjust the first voltage according to the set voltage and the first current to stabilize the first voltage.

11. The control method of a variable flow device according to claim 10, wherein The step of adjusting the first voltage according to the set voltage and the first current specifically includes: Obtain a first error value between the first voltage and the set voltage, perform proportional-integral adjustment on the first error value, limit the adjusted first error value, and obtain the first output value; Obtain the second error value between the first output value and the first current, perform proportional-integral adjustment on the second error value, limit the adjusted second error value, and obtain the second output value; A first difference is obtained, and an output signal is obtained by comparing the first difference with the carrier wave. The output signal is inverted to obtain the first gate drive signal, which is then output to the gate of the first switching device. The first difference is the difference between 1 and the second output value. The second output value is compared with the carrier wave to obtain the second gate drive signal, which is then output to the gate of the second switching device. The duty cycle of the first switching device and the second switching device is adjusted by the first gate drive signal and the second gate drive signal to maintain the stability of the first voltage.

12. A wireless power transfer system (600), characterized by include: Receiver coil (610); In the converter (100) as described in any one of claims 1 to 9, the receiving coil (610) outputs an AC voltage to the converter (100), the converter (100) converts the input AC voltage into a DC voltage, and boosts the DC voltage before outputting it.

13. A rail vehicle (700), characterized by include: A wireless power transmission system (600) includes a receiving coil (610) and a converter (100) as described in any one of claims 1 to 9. The receiving coil (610) outputs an AC voltage to the converter (100), which converts the input AC voltage into a DC voltage and boosts the DC voltage before outputting it to the rail vehicle (700).

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