AC / DC Converter, Energy Conversion System, THD Optimization Method, Electronic Device and Vehicle

Abstract

The present application provides an AC / DC converter, an energy conversion system, a THD optimization method, an electronic device, and a vehicle, which relate to the field of power supply technology and are intended to solve the problem of poor total harmonic distortion of input current in a single-stage AC / DC converter. The AC / DC converter includes: an output port, an output port, a main power converter, and an auxiliary power converter, wherein the input port is used to connect to an AC power source, the output port is used to connect to a battery, the main power converter and the auxiliary power converter are connected in parallel and connected between the input port and the output port, the auxiliary power converter is configured to operate when the voltage of the AC signal received at the input port is within a preset voltage range to convert the AC signal into a DC signal and output it to the battery, and the main power converter is configured to operate when the voltage of the AC signal received at the input port is outside the preset voltage range to convert the AC signal into a DC signal and output it to the battery.

Description

Technical Field

[0001] The present application relates to the field of power supply technology, and in particular to an AC / DC converter, an energy conversion system, a THD optimization method, an electronic device, and a vehicle. Background Art

[0002] As a key component of electric vehicles, the on-board charger (OBC) converts AC power to DC to charge the vehicle's battery. The OBC can use a two-stage converter for AC / DC conversion, or a single-stage alternating current (AC) / direct current (DC) converter.

[0003] A single-stage AC / DC converter implements a two-stage converter with a single-stage AC / DC converter. Compared to a two-stage converter, this eliminates the intermediate bus electrolytic capacitor and some electronic components, thereby increasing the power density of the onboard charger. To achieve power factor correction in a single-stage AC / DC converter, a sinusoidal control strategy is required. However, while achieving power factor correction, a single-stage AC / DC converter must also achieve output voltage matching. When the AC input voltage is near zero, the duty cycle of the switching transistor must be controlled.

[0004] However, the converter's duty cycle is difficult to control at the input voltage's zero-crossing point. This can cause AC current distortion and increase the AC current distortion rate. Consequently, single-stage AC / DC converters suffer from poor input current total harmonic distortion (THD). Summary of the Invention

[0005] The purpose of this application is to provide an AC / DC converter, an energy conversion system, a THD optimization method, an electronic device and a vehicle, aiming to solve the problem of how to improve the input current THD of a single-stage AC / DC converter.

[0006] In a first aspect, an AC / DC converter is provided, comprising: an input port, an output port, a main power converter and an auxiliary power converter; the input port is used to connect to an AC power source, and the output port is used to connect to a battery; the main power converter and the auxiliary power converter are connected between the input port and the output port, and the main power converter and the auxiliary power converter are connected in parallel; wherein the auxiliary power converter is configured to operate when the voltage of the AC signal received by the input port is within a preset voltage range, so as to convert the AC signal into a DC signal and output it to the battery; the two endpoint values of the preset voltage range are a first voltage value and a second voltage value, respectively, the first voltage value is less than 0, and the second voltage value is greater than 0; the main power converter is configured to operate when the voltage of the AC signal received by the input port is outside the preset voltage range, so as to convert the AC signal into a DC signal and output it to the battery.

[0007] Optionally, the main power converter includes: a first rectifier circuit, a first transformer and an inverter circuit; the first rectifier circuit is connected to the input port, the first rectifier circuit, the first transformer and the inverter circuit are connected in sequence, and the inverter circuit is connected to the output port; the first rectifier circuit is configured to receive an AC signal through the input port, convert the AC signal into a first AC signal, and output the first AC signal to the first transformer; the first transformer is configured to receive the first AC signal, convert the first AC signal into a second AC signal, and output the second AC signal to the inverter circuit; the inverter circuit is configured to receive the second AC signal, convert the second AC signal into a DC signal, and output the DC signal to the battery.

[0008] Optionally, the main power converter also includes: a first filtering circuit; the first filtering circuit is connected between the input port and the first rectifier circuit, or between the first rectifier circuit and the first transformer; the first filtering circuit is configured to filter the AC signal from the input port, or the first AC signal output by the first rectifier circuit.

[0009] Optionally, the first rectifier circuit includes: a first bridge arm, a second bridge arm and a third bridge arm; the first ends of the first bridge arm, the second bridge arm and the third bridge arm are connected, and the second ends of the first bridge arm, the second bridge arm and the third bridge arm are connected; the midpoint of the first bridge arm and the midpoint of the second bridge arm are both connected to the positive end of the input port, and the midpoint of the third bridge arm is connected to the negative end of the input port; the midpoint of the first bridge arm is also connected to the first end of the first transformer, and the midpoint of the second bridge arm is also connected to the second end of the first transformer; the midpoint of the bridge arm is the connection end of the upper half bridge and the lower half bridge of the bridge arm.

[0010] Optionally, the first filtering circuit includes: a first inductor, a second inductor and a first capacitor; the first end of the first inductor is connected to the positive terminal of the input port, the second end of the first inductor is connected to the midpoint of the first bridge arm, and is connected to the first end of the first transformer; the first end of the second inductor is connected to the positive terminal of the input port, the second end of the second inductor is connected to the midpoint of the second bridge arm, and is connected to the second end of the first transformer; the first end of the first capacitor is connected to the first ends of the first bridge arm, the second bridge arm and the third bridge arm, and the second end of the first capacitor is connected to the second ends of the first bridge arm, the second bridge arm and the third bridge arm.

[0011] Optionally, the first rectifier circuit includes: a fourth bridge arm, a fifth bridge arm, a sixth bridge arm and a seventh bridge arm; the first end of the fourth bridge arm is connected to the first end of the fifth bridge arm and is connected to the positive terminal of the input port; the second end of the fourth bridge arm is connected to the first end of the sixth bridge arm and is connected to the first end of the first transformer; the second end of the fifth bridge arm is connected to the first end of the seventh bridge arm and is connected to the second end of the first transformer; the second end of the sixth bridge arm is connected to the second end of the seventh bridge arm and is connected to the negative terminal of the input port.

[0012] Optionally, the first filtering circuit includes: a third inductor; a first end of the third inductor is connected to the second end of the fourth bridge arm and the first end of the sixth bridge arm, and a second end of the third inductor is connected to the first end of the first transformer.

[0013] Optionally, the first rectifier circuit includes: an eighth bridge arm and a ninth bridge arm; the first ends of the eighth bridge arm and the ninth bridge arm are connected; the second ends of the eighth bridge arm and the ninth bridge arm are connected; the midpoint of the eighth bridge arm is connected to the positive end of the input port, and the midpoint of the eighth bridge arm is also connected to the first end of the first transformer; the midpoint of the ninth bridge arm is connected to the positive end of the input port.

[0014] Optionally, the first filtering circuit includes: a fourth inductor, a fifth inductor, a second capacitor, and a third capacitor; the first end of the fourth inductor is connected to the positive end of the input port; the second end of the fourth inductor is connected to the midpoint of the eighth bridge arm; the first end of the fifth inductor is connected to the midpoint of the eighth bridge arm, and the first end of the fifth inductor is also connected to the second end of the fourth inductor; the second end of the fifth inductor is connected to the first end of the first transformer; the first end of the second capacitor is connected to the first ends of the eighth bridge arm and the ninth bridge arm; the second end of the second capacitor is connected to the first end of the third capacitor, and the second end of the second capacitor is also connected to the second end of the first transformer; the second end of the third capacitor is connected to the second ends of the eighth bridge arm and the ninth bridge arm.

[0015] Optionally, the first rectifier circuit includes: a tenth bridge arm, an eleventh bridge arm, and a first switch tube, a second switch tube, a third switch tube, and a fourth switch tube; the first end of the first switch tube, the third switch tube, the tenth bridge arm, and the first end of the eleventh bridge arm are connected;

[0016] The second ends of the second switching tube, the fourth switching tube, the tenth bridge arm, and the eleventh bridge arm are connected; the second end of the first switching tube is connected to the first end of the second switching tube and to the positive end of the input port; the second end of the third switching tube is connected to the first end of the fourth switching tube and to the negative end of the input port; the midpoint of the tenth bridge arm is connected to the first end of the first transformer; the midpoint of the eleventh bridge arm is connected to the second end of the first transformer; the midpoint of the bridge arm is the connection end of the upper half bridge and the lower half bridge of the bridge arm.

[0017] Optionally, the first filtering circuit includes: a fourth capacitor and a sixth inductor; the first end of the fourth capacitor is connected to the first end of the first switch tube, the third switch tube, the tenth bridge arm and the eleventh bridge arm; the second end of the fourth capacitor is connected to the second end of the second switch tube, the fourth switch tube, the tenth bridge arm and the eleventh bridge arm; the first end of the sixth inductor is connected to the midpoint of the tenth bridge arm; the second end of the sixth inductor is connected to the first end of the first transformer.

[0018] Optionally, the inverter circuit includes: a twelfth bridge arm and a thirteenth bridge arm; the first ends of the twelfth bridge arm and the thirteenth bridge arm are connected and connected to the positive end of the output port; the second ends of the twelfth bridge arm and the thirteenth bridge arm are connected and connected to the negative end of the output port; the midpoint of the twelfth bridge arm is connected to the fourth end of the first transformer; the midpoint of the thirteenth bridge arm is connected to the third end of the first transformer; the midpoint of the bridge arm is the connection end of the upper half bridge and the lower half bridge of the bridge arm.

[0019] Optionally, the main power converter also includes: a second filtering circuit; the second filtering circuit is connected between the inverter circuit and the output port; the second filtering circuit is configured to filter the DC signal output by the inverter circuit; the second filtering circuit includes: a fifth capacitor; the first end of the fifth capacitor is connected to the first end of the twelfth bridge arm and the thirteenth bridge arm, and the fifth capacitor is also connected to the positive terminal of the output port; the second end of the fifth capacitor is connected to the second end of the twelfth bridge arm and the thirteenth bridge arm, and the fifth capacitor is also connected to the negative terminal of the output port.

[0020] Optionally, the auxiliary power converter includes: a second rectifier circuit, a second transformer and a rectifier filter circuit; the second rectifier circuit is connected to the input port, the second rectifier circuit, the second transformer and the rectifier filter circuit are connected in sequence, and the rectifier filter circuit is connected to the output port; the second rectifier circuit is configured to receive an AC signal through the input port, convert the AC signal into a first AC signal, and output the first AC signal to the second transformer; the second transformer is configured to receive the first AC signal, convert the first AC signal into a second AC signal, and output the second AC signal to the output rectifier filter circuit; the output rectifier filter circuit is configured to receive the second AC signal, convert the second AC signal into a DC signal, and output the DC signal to the battery.

[0021] Optionally, the second rectifier circuit includes: a first diode, a second diode, a third diode and a fourth diode; the first ends of the first diode and the third diode are connected to each other and to the first end of the second transformer; the second end of the first diode is connected to the first end of the second diode and to the positive end of the input port; the second end of the third diode is connected to the first end of the fourth diode and to the negative end of the input port; the second ends of the second diode and the fourth diode are connected and to the second end of the second transformer.

[0022] Optionally, the rectifier and filtering circuit includes: a fifth diode and a sixth capacitor; the first end of the fifth diode is connected to the third end of the second transformer; the second end of the fifth diode is connected to the first end of the sixth capacitor, and the second end of the fifth diode is also connected to the positive end of the output port; the second end of the sixth capacitor is connected to the fourth end of the second transformer, and the second end of the sixth capacitor is also connected to the negative end of the output port.

[0023] Optionally, the auxiliary power converter further includes: a fifth switching tube; a first end of the fifth switching tube is connected to the second end of the second transformer; and a second end of the fifth switching tube is connected to the second ends of the second diode and the fourth diode.

[0024] Optionally, the auxiliary power converter also includes: an absorption circuit, the absorption circuit including: a seventh capacitor, a sixth diode and a resistor; the first end of the seventh capacitor is connected to the resistor, and is connected to the second end of the second diode and the fourth diode, and is also connected to the first end of the second transformer; the second end of the seventh capacitor is connected to the resistor, and is connected to the first end of the sixth diode; the second end of the sixth diode is connected to the first end of the fifth switching tube; the absorption circuit is configured to absorb voltage spikes in the first AC signal to protect the fifth switching tube.

[0025] Optionally, the auxiliary power converter also includes: an eighth capacitor; the first end of the eighth capacitor is connected to the first end of the first diode and the third diode, and the first end of the eighth capacitor is also connected to the first end of the second transformer; the second end of the eighth capacitor is connected to the second end of the second diode and the fourth diode, and the eighth capacitor is also connected to the second end of the fifth switching tube.

[0026] Optionally, the auxiliary power converter further includes: a sixth switching tube; a first end of the sixth switching tube is connected to the first end of the second transformer; and a second end of the sixth switching tube is connected to the second end of the second transformer.

[0027] Optionally, the auxiliary power converter also includes: a seventh inductor and a ninth capacitor; the first end of the seventh inductor is connected to the first ends of the first diode and the third diode; the second end of the seventh inductor is connected to the first end of the sixth switching tube; the first end of the ninth capacitor is connected to the first end of the sixth switching tube, and the first end of the ninth capacitor is also connected to the second end of the seventh inductor; the second end of the ninth capacitor is connected to the first end of the second transformer.

[0028] Optionally, the auxiliary power converter is also configured to operate when the voltage of the AC signal received at the input port is outside a preset voltage range, so as to convert the AC signal into a DC signal and output it to the battery; the sum of the output power of the auxiliary power converter and the output power of the main power converter is the same as the rated output power.

[0029] In a second aspect, an energy conversion system is provided, comprising: a controller, and an AC / DC converter as described in the first aspect; the controller is configured to sample the voltage of an AC signal input to the AC / DC converter, and control the operation of a main power converter and / or an auxiliary power converter in the AC / DC converter according to the voltage of the AC signal.

[0030] In a third aspect, a vehicle is provided, comprising the AC / DC converter as described in the first aspect, and / or the energy conversion system as described in the second aspect.

[0031] In a fourth aspect, a THD optimization method is provided, comprising: sampling the voltage of an AC signal input to an AC / DC converter; controlling an auxiliary power converter to operate when the voltage of the AC signal is within a preset voltage range; and controlling a main power converter to operate when the voltage of the AC signal is outside the preset voltage range; the two endpoint values of the preset voltage range are a first voltage value and a second voltage value, respectively, the first voltage value is less than 0, and the second voltage value is greater than 0.

[0032] Optionally, the THD optimization method also includes: when the voltage of the AC signal is outside a preset voltage range, controlling the auxiliary power converter to operate, and making the sum of the output power of the auxiliary power converter and the output power of the main power converter the same as the rated output power.

[0033] In a fifth aspect, an electronic device is provided, comprising a processor and a memory, wherein the memory stores computer program instructions suitable for execution by the processor, and the computer program instructions are executed by the processor to execute the THD optimization method as described in the fourth aspect when the processor is running.

[0034] In a sixth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer program instructions. When the computer program instructions are executed by a processor, the THD optimization method as described in the fourth aspect is executed.

[0035] In a seventh aspect, a computer program product is provided, the computer program product comprising: a computer program or instructions, which, when the computer program or instructions are run on an electronic device, enables the electronic device to execute the THD optimization method as described in the fourth aspect.

[0036] It should be noted that the above computer instructions may be stored in whole or in part on a computer-readable storage medium, which is not limited in the present embodiment.

[0037] The descriptions of the second, third, fourth, fifth, sixth and seventh aspects of this application can refer to the detailed description of the first aspect.

[0038] The technical solution provided by this application brings at least the following beneficial effects:

[0039] Based on the above-mentioned first aspect, the AC / DC converter provided in the embodiment of the present application includes a main power converter and an auxiliary power converter. When the voltage of the AC signal received by the input port is near the zero-crossing voltage, that is, when the voltage of the AC signal received by the input port is within a preset voltage range, the auxiliary power converter is controlled to operate. Since there are fewer power devices in the auxiliary power converter, it is easy to control. The present application can control the auxiliary power converter within the preset voltage range, better control the duty cycle of the AC / DC converter, and thus reduce the problem of current distortion on the AC side.

[0040] The beneficial effects of the first, second, third, fourth, fifth, sixth and seventh aspects of this application can all be referred to the analysis of the above beneficial effects and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0042] Figure 1 A waveform diagram of an AC signal on the AC side of the prior art;

[0043] Figure 2 A schematic diagram of the structure of an energy conversion system provided in an embodiment of the present application;

[0044] Figure 3 A schematic diagram of the structure of an AC / DC converter provided in an embodiment of the present application;

[0045] Figure 4A schematic structural diagram of a bridge arm provided in an embodiment of the present application;

[0046] Figure 5 A schematic structural diagram of a main power converter provided in an embodiment of the present application;

[0047] Figure 6 A schematic structural diagram of another main power converter provided in an embodiment of the present application;

[0048] Figure 7 A schematic structural diagram of another main power converter provided in an embodiment of the present application;

[0049] Figure 8 A schematic structural diagram of another main power converter provided in an embodiment of the present application;

[0050] Figure 9 A schematic structural diagram of an auxiliary power converter provided in an embodiment of the present application;

[0051] Figure 10 A schematic structural diagram of another auxiliary power converter provided in an embodiment of the present application;

[0052] Figure 11 A schematic structural diagram of another AC / DC converter provided in an embodiment of the present application;

[0053] Figure 12 A schematic diagram of a preset voltage range provided in an embodiment of the present application;

[0054] Figure 13 A control signal timing diagram provided in an embodiment of the present application;

[0055] Figure 14 A schematic flow chart of a THD optimization method provided in an embodiment of the present application;

[0056] Figure 15 A flowchart of another THD optimization method provided in an embodiment of the present application.

[0057] Reference numerals:

[0058] 1. Energy conversion system;

[0059] 10. Controller; 20. AC / DC converter;

[0060] 201, input port; 202, main power converter; 203, auxiliary power converter; 204, output port;

[0061] Q1, first switch tube; Q2, second switch tube; Q3, third switch tube; Q4, fourth switch tube; Q5, fifth switch tube; Q6, sixth switch tube; Q7, seventh switch tube; Q8, eighth switch tube; Q9, ninth switch tube; Q10, tenth switch tube;

[0062] D1, first diode; D2, second diode; D3, third diode; D4, fourth diode; D5, fifth diode; D6, sixth diode; D7, seventh diode; D8, eighth diode; D9, ninth diode; D10, tenth diode;

[0063] M1, first transformer; M2, second transformer;

[0064] S1, first bridge arm; S2, second bridge arm; S3, third bridge arm; S4, fourth bridge arm; S5, fifth bridge arm; S6, sixth bridge arm; S7, seventh bridge arm; S8, eighth bridge arm; S9, ninth bridge arm; S10, tenth bridge arm; S11, eleventh bridge arm; S12, twelfth bridge arm; S13, thirteenth bridge arm;

[0065] C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; C5, fifth capacitor; C6, sixth capacitor; C7, seventh capacitor; C8, eighth capacitor; C9, ninth capacitor;

[0066] L1, first inductor; L2, second inductor; L3, third inductor; L4, fourth inductor; L5, fifth inductor; L6, sixth inductor; L7, seventh inductor; L8, eighth inductor;

[0067] R, resistance;

[0068] V1, first switching element; V2, second switching element; V3, third switching element; V4, fourth switching element; V5, fifth switching element; V6, sixth switching element; V7, seventh switching element; V8, eighth switching element; V9, ninth switching element; V10, tenth switching element. DETAILED DESCRIPTION

[0069] In the embodiments of the present application, the terms "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature specified as "first," "second," "third," "fourth," "fifth," and "sixth" may explicitly or implicitly include one or more of the features.

[0070] In the embodiments of the present application, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0071] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0072] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0073] As mentioned in the background, OBCs are key components of electric vehicles, converting AC power to DC power to charge the battery. OBCs can use a two-stage converter or a single-stage AC / DC converter to achieve this conversion.

[0074] A two-stage converter consists of a cascaded power factor correction (PLC) converter (i.e., AC / DC converter) and a resonant converter (LLC) converter (i.e., DC / DC converter). The intermediate bus uses a large electrolytic capacitor for power decoupling. The AC / DC converter improves the converter's power factor and reduces input current THD. However, a two-stage converter is not conducive to achieving higher power density.

[0075] A single-stage AC / DC converter implements a two-stage converter with a single-stage AC / DC converter, eliminating the intermediate bus electrolytic capacitor and some electronic components, thereby increasing the power density of the on-board charger.

[0076] To achieve power factor correction in a single-stage AC / DC converter, a sinusoidal control strategy is required. However, in addition to achieving power factor correction, a single-stage AC / DC converter must also achieve output voltage matching.

[0077] In a single-stage AC / DC converter, the output voltage is related to the input voltage and the duty cycle. Specifically, the output voltage satisfies the following formula:

[0078] Vout=Vin / (1-D);

[0079] Among them, Vout is used to represent the output voltage, Vin is used to represent the input voltage, and D is used to represent the duty cycle.

[0080] If a single-stage AC / DC converter needs to meet the output voltage of 400V, when the input voltage is 100V, the duty cycle is 0.75. When the input voltage is 1V, the duty cycle is 0.9975.

[0081] When the AC input voltage is near zero, the duty cycle of the switch must be close to 1. However, the duty cycle of this converter is difficult to control at the time when the input voltage crosses zero. This can cause current distortion on the AC side and increase the AC current distortion rate.

[0082] For example, the waveform of the AC signal on the AC side of the prior art is as follows: Figure 1 shown.

[0083] Figure 1 In FIG, the dotted line represents the AC voltage of the AC signal on the AC side, and the solid line represents the AC current of the AC signal on the AC side.

[0084] Depend on Figure 1 It can be seen that the AC current is distorted, so the single-stage AC / DC converter has the problem of poor input current THD.

[0085] To address the above problems, an embodiment of the present application provides an AC / DC converter that can be applied to an energy conversion system.

[0086] like Figure 2 As shown, the energy conversion system 1 includes a controller 10 and an AC / DC converter 20 .

[0087] The controller 10 is connected to the AC / DC converter 20 .

[0088] The AC / DC converter 20 is used to convert an externally connected AC signal into a DC signal.

[0089] The controller 10 can control the AC / DC converter 20 to operate.

[0090] Specifically, the controller 10 can sample the voltage of the AC signal input to the AC / DC converter 20 to control the operation of the main power converter and / or the auxiliary power converter in the AC / DC converter 20. The AC / DC converter 20 can obtain an AC signal from an AC power source and output the converted DC signal to the battery.

[0091] The structural diagram of the AC / DC converter 20 is shown in FIG. Figure 3As shown, the AC / DC converter 20 includes an input port 201 , a main power converter 202 , an auxiliary power converter 203 and an output port 204 .

[0092] The input port 201 is used to connect to an AC power source, and the output port 204 is used to connect to a battery.

[0093] The main power converter 202 and the auxiliary power converter 203 are connected between the input port 201 and the output port 204 , and the main power converter 202 and the auxiliary power converter 203 are connected in parallel.

[0094] In some embodiments, when the voltage of the AC signal received by the input port 201 is within a preset voltage range, the auxiliary power converter 203 operates and can convert the AC signal into a DC signal and output it to the battery.

[0095] When the voltage of the AC signal received by the input port 201 is outside the preset voltage range, the main power converter 202 operates. The main power converter 202 can convert the AC signal into a DC signal and output it to the battery.

[0096] The two endpoint values of the preset voltage interval are respectively a first voltage value and a second voltage value, the first voltage value is less than 0, and the second voltage value is greater than 0.

[0097] In other embodiments, when the voltage of the AC signal received by the input port is outside a preset voltage range, the auxiliary power converter 203 operates. The auxiliary power converter 203 can convert the AC signal into a DC signal and output it to the battery. The sum of the output power of the auxiliary power converter and the output power of the main power converter is equal to the rated output power.

[0098] The two endpoint values of the preset voltage interval are respectively a first voltage value and a second voltage value, the first voltage value is less than 0, and the second voltage value is greater than 0.

[0099] It's understandable that the duty cycle is related to the input voltage and output voltage. Therefore, the preset voltage range can be selected based on the output voltage and duty cycle. For ease of control, the duty cycle can be set to 0.99, 0.9, or 0.999. The more digits after the decimal point in the duty cycle, the more difficult it is to control.

[0100] In the embodiment of the present application, if the output voltage is 400 V, the preset voltage interval may be [-4 V, 4 V], that is, the first voltage value is -4 V and the second voltage value is 4 V. If the output voltage is 400 V, the preset voltage interval may also be [-0.4 V, 0.4 V], that is, the first voltage value is -0.4 V and the second voltage value is 0.4 V.

[0101] In the embodiments of the present application, both the main power converter and the auxiliary power converter are AC / DC converters. Because the main and auxiliary power converters have different operating power levels, the main power converter has a higher power level and the auxiliary power converter has a lower power level. Therefore, the main power converter typically has a higher input voltage (e.g., 100V, 50V), while the auxiliary power converter typically has a lower input voltage (e.g., 10V, 5V).

[0102] Before introducing the main power converter and the auxiliary power converter provided in the embodiment of the application, the two bridge arms involved in the application are first introduced.

[0103] The structural diagram of the first bridge arm is as follows Figure 4 As shown in (a), the first bridge arm includes: a seventh switch tube Q7, an eighth switch tube Q8, a seventh diode D7 and an eighth diode D8.

[0104] The seventh switch tube Q7 is connected in parallel with the seventh diode D7, the eighth switch tube Q8 is connected in parallel with the eighth diode D8, and the seventh switch tube Q7 and the eighth switch tube Q8 are connected in series.

[0105] That is, the first end of the seventh switch tube Q7 is connected to the first end of the seventh diode D7, serving as the first end of the bridge arm, and the second end of the seventh switch tube Q7 is connected to the second end of the seventh diode D7. That is, the first end of the eighth switch tube Q8 is connected to the first end of the eighth diode D8, and the second end of the eighth switch tube Q8 is connected to the second end of the eighth diode D8, serving as the second end of the bridge arm. The second end of the seventh switch tube Q7 is connected to the first end of the eighth switch tube Q8, serving as the midpoint of the bridge arm.

[0106] By controlling the on / off of the seventh switch tube Q7, the eighth switch tube Q8, the seventh diode D7 and the eighth diode D8, the on / off of the upper half bridge and the lower half bridge in the first bridge arm can be controlled.

[0107] When the switch tube is turned on, the first end to the second end of the switch tube is conductive. In other cases, the switch tube is regarded as an open circuit, and the second end to the first end of the diode conducts forward current.

[0108] Exemplarily, when the seventh switch Q7 is turned on and the seventh diode D7 is turned off, the first end of the bridge arm is connected to the midpoint of the bridge arm. When the seventh switch Q7 is turned off and the seventh diode D7 is turned on, the midpoint of the bridge arm is connected to the first end of the bridge arm.

[0109] Accordingly, when the eighth switch Q8 is turned on and the eighth diode D8 is turned off, the middle point of the bridge arm is connected to the second end of the bridge arm. When the eighth switch Q8 is turned off and the eighth diode D8 is turned on, the second end of the bridge arm is connected to the middle point of the bridge arm.

[0110] The structural diagram of the second bridge arm is as follows Figure 4 As shown in (b), the second bridge arm includes: a ninth switching tube Q9, a tenth switching tube Q10, a ninth diode D9 and a tenth diode D10.

[0111] The ninth switch tube Q9 is connected in parallel with the ninth diode D9 , the tenth switch tube Q10 is connected in parallel with the tenth diode D10 , and the ninth switch tube Q9 and the tenth switch tube Q10 are connected in anti-series.

[0112] That is, the first end of the ninth switching tube Q9 is connected to the first end of the ninth diode D9, and the second end of the ninth switching tube Q9 is connected to the second end of the ninth diode D9, serving as the first end of the bridge arm. That is, the first end of the tenth switching tube Q10 is connected to the first end of the tenth diode D10, and the second end of the tenth switching tube Q10 is connected to the second end of the tenth diode D10, serving as the first end of the bridge arm. The first end of the ninth switching tube Q9 is connected to the first end of the tenth switching tube Q10.

[0113] By controlling the on-off of the ninth switch tube Q9, the tenth switch tube Q10, the ninth diode D9 and the tenth diode D10, the on-off of the second bridge arm can be controlled.

[0114] When the switch tube is turned on, the first end to the second end of the switch tube is connected. In other cases, the switch tube is regarded as an open circuit, the second end to the first end of the diode is connected, and the first end to the second end of the diode is cut off.

[0115] Illustratively, when a forward current is input to the first end of the bridge arm, the ninth diode D9 and the tenth switch tube Q10 are turned on, and the forward current is conducted from the first end of the bridge arm to the second end. When a reverse current is input to the first end of the bridge arm, the ninth switch tube Q9 and the tenth diode D10 are turned on, and the reverse current is conducted from the first end of the bridge arm to the second end.

[0116] The main power converter and the auxiliary power converter provided in the embodiments of the present application are introduced below respectively.

[0117] The main power converter includes a first rectifier circuit, a first transformer M1, an inverter circuit, a first filter circuit, and a second filter circuit. The first rectifier circuit is connected to the input port. The first rectifier circuit, the first transformer M1, and the inverter circuit are connected in sequence. The inverter circuit is connected to the output port. The first filter circuit is connected between the input port and the first rectifier circuit, or between the first rectifier circuit and the first transformer M1. The second filter circuit is connected between the inverter circuit and the output port.

[0118] In an embodiment of the present application, the first rectifier circuit can receive an AC signal through an input port, convert the AC signal into a first AC signal, and output the first AC signal to the first transformer M1. The first transformer M1 can receive a first AC signal, convert the first AC signal into a second AC signal, and output the second AC signal to the inverter circuit. The inverter circuit can receive a second AC signal, convert the second AC signal into a DC signal, and output the DC signal to the battery. The first filter circuit can filter the AC signal from the input port, or the first AC signal output by the first rectifier circuit. The second filter circuit can filter the DC signal output by the inverter circuit.

[0119] In some embodiments, the structure of the main power converter is as follows Figure 5 As shown, the main power converter 202 includes: a first rectifier circuit, a first transformer M1, a first filter circuit, an inverter circuit and a second filter circuit.

[0120] The first rectifier circuit includes a first bridge arm S1, a second bridge arm S2, and a third bridge arm S3. The first filter circuit includes a first inductor L1, a second inductor L2, and a first capacitor C1. The inverter circuit includes a twelfth bridge arm S12 and a thirteenth bridge arm S13. The second filter circuit includes a fifth capacitor C5 and an eighth inductor L8.

[0121] The first ends of the first bridge arm S1 , the second bridge arm S2 and the third bridge arm S3 are connected, and the second ends of the first bridge arm S1 , the second bridge arm S2 and the third bridge arm S3 are connected.

[0122] The midpoint of the first bridge arm S1 is connected to the positive terminal of the input port 201 through the first inductor L1 , the midpoint of the second bridge arm S2 is connected to the positive terminal of the input port 201 through the second inductor L2 , and the midpoint of the third bridge arm S3 is connected to the negative terminal of the input port 201 .

[0123] The midpoint of the first bridge arm S1 is also connected to the first end of the first transformer M1 , and the midpoint of the second bridge arm S2 is also connected to the second end of the first transformer M1 .

[0124] A first end of the first inductor L1 is connected to the positive terminal of the input port 201 , and a second end of the first inductor L1 is connected to the midpoint of the first bridge arm S1 and to the first end of the first transformer M1 .

[0125] A first end of the second inductor L2 is connected to the positive terminal of the input port 201 , and a second end of the second inductor L2 is connected to the midpoint of the second bridge arm S2 and to the second end of the first transformer M1 .

[0126] A first end of the first capacitor C1 is connected to the first ends of the first bridge arm S1, the second bridge arm S2, and the third bridge arm S3. A second end of the first capacitor C1 is connected to the second ends of the first bridge arm S1, the second bridge arm S2, and the third bridge arm S3.

[0127] The first ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 are connected and connected to the positive terminal of the output port 204 . The second ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 are connected and connected to the negative terminal of the output port 204 .

[0128] The midpoint of the twelfth bridge arm S12 is connected to the fourth terminal of the first transformer M1. The midpoint of the thirteenth bridge arm S13 is connected to the third terminal of the first transformer M1 via the eighth inductor L8.

[0129] A first end of the fifth capacitor C5 is connected to the first end of the twelfth bridge arm S12 and the first end of the thirteenth bridge arm S13, and the fifth capacitor C5 is also connected to the positive terminal of the output port 204. A second end of the fifth capacitor C5 is connected to the second end of the twelfth bridge arm S12 and the second end of the thirteenth bridge arm S13, and the fifth capacitor C5 is also connected to the negative terminal of the output port 204.

[0130] A first end of the eighth inductor L8 is connected to the first end of the first transformer M1 , and a second end of the eighth inductor L8 is connected to the midpoint of the thirteenth bridge arm.

[0131] In the embodiment of the present application, the first bridge arm S1, the second bridge arm S2, the third bridge arm S3, the twelfth bridge arm S12 and the thirteenth bridge arm S13 are all first-type bridge arms, and the first bridge arm S1 is a low-speed bridge arm, and the second bridge arm S2, the third bridge arm S3, the twelfth bridge arm S12 and the thirteenth bridge arm S13 are all high-speed bridge arms.

[0132] In the embodiment of the present application, the duty cycle is further controlled by controlling the conduction frequency of the switch tube in the bridge arm to control the signal voltage of the AC signal output to the battery.

[0133] It can be understood that the switching frequency of the switching device in the high-speed bridge arm is high frequency, and the switching frequency of the switching device in the low-speed bridge arm is low frequency.

[0134] In some embodiments, the structure of the main power converter is as follows Figure 6 As shown, the main power converter 202 includes: a first rectifier circuit, a first transformer M1, a first filter circuit, an inverter circuit and a second filter circuit.

[0135] The first rectifier circuit includes a fourth bridge arm S4, a fifth bridge arm S5, a sixth bridge arm S6, and a seventh bridge arm S7. The first filter circuit includes a third inductor L3. The inverter circuit includes a twelfth bridge arm S12 and a thirteenth bridge arm S13. The second filter circuit includes a fifth capacitor C5.

[0136] The first ends of the fourth bridge arm S4 and the fifth bridge arm S5 are connected to the positive terminal of the input port 201. The second end of the fourth bridge arm S4 is connected to the first end of the sixth bridge arm S6 and is connected to the first end of the first transformer M1 through the third inductor L3. The second end of the fifth bridge arm S5 is connected to the first end of the seventh bridge arm S7 and is connected to the second end of the first transformer M1. The second ends of the sixth bridge arm S6 and the seventh bridge arm S7 are connected to the negative terminal of the input port 201.

[0137] A first end of the third inductor L3 is connected to the second end of the fourth bridge arm S4 and the first end of the sixth bridge arm S6 , and a second end of the third inductor L3 is connected to the first end of the first transformer M1 .

[0138] The first ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 are connected and connected to the positive terminal of the output port 204 . The second ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 are connected and connected to the negative terminal of the output port 204 .

[0139] The midpoint of the twelfth bridge arm S12 is connected to the fourth terminal of the first transformer M1. The midpoint of the thirteenth bridge arm S13 is connected to the third terminal of the first transformer M1.

[0140] A first end of the fifth capacitor C5 is connected to the first end of the twelfth bridge arm S12 and the first end of the thirteenth bridge arm S13, and the fifth capacitor C5 is also connected to the positive terminal of the output port 204. A second end of the fifth capacitor C5 is connected to the second end of the twelfth bridge arm S12 and the second end of the thirteenth bridge arm S13, and the fifth capacitor C5 is also connected to the negative terminal of the output port 204.

[0141] In the embodiment of the present application, the fourth bridge arm S4, the fifth bridge arm S5, the sixth bridge arm S6, and the seventh bridge arm S7 are all second-type bridge arms, and the twelfth bridge arm S12 and the thirteenth bridge arm S13 are all first-type bridge arms. Furthermore, the fourth bridge arm S4, the fifth bridge arm S5, the sixth bridge arm S6, the seventh bridge arm S7, the twelfth bridge arm S12, and the thirteenth bridge arm S13 are all high-speed bridge arms.

[0142] In the embodiment of the present application, the duty cycle is further controlled by controlling the conduction frequency of the switch tube in the bridge arm to control the signal voltage of the AC signal output to the battery.

[0143] It can be understood that the switching frequency of the switching devices in the high-speed bridge arm is high frequency.

[0144] In some embodiments, the structure of the main power converter is as follows Figure 7 As shown, the main power converter 202 includes: a first rectifier circuit, a first transformer M1, a first filter circuit, an inverter circuit and a second filter circuit.

[0145] The first rectifier circuit includes an eighth bridge arm S8 and a ninth bridge arm S9. The first filter circuit includes a fourth inductor L4, a fifth inductor L5, a second capacitor C2, and a third capacitor C3. The inverter circuit includes a twelfth bridge arm S12 and a thirteenth bridge arm S13. The second filter circuit includes a fifth capacitor C5.

[0146] The first ends of the eighth bridge arm S8 and the ninth bridge arm S9 are connected. The second ends of the eighth bridge arm S8 and the ninth bridge arm S9 are connected.

[0147] The midpoint of the eighth bridge arm S8 is connected to the positive terminal of the input port 201 and the midpoint of the eighth bridge arm S8 is also connected to the first terminal of the first transformer M1 . The midpoint of the ninth bridge arm S9 is connected to the positive terminal of the input port 201 .

[0148] A first end of the fourth inductor L4 is connected to the positive terminal of the input port 201. A second end of the fourth inductor L4 is connected to the midpoint of the eighth bridge arm S8.

[0149] The first end of the fifth inductor L5 is connected to the midpoint of the eighth bridge arm S8, and the first end of the fifth inductor L5 is also connected to the second end of the fourth inductor L4. The second end of the fifth inductor L5 is connected to the first end of the first transformer M1.

[0150] The first end of the second capacitor C2 is connected to the first end of the eighth bridge arm S8 and the first end of the ninth bridge arm S9. The second end of the second capacitor C2 is connected to the first end of the third capacitor C3, and the second end of the second capacitor C2 is also connected to the second end of the first transformer M1.

[0151] The second end of the third capacitor C3 is connected to the second ends of the eighth bridge arm S8 and the ninth bridge arm S9.

[0152] The first ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 are connected to each other and are also connected to the positive terminal of the output port 204 .

[0153] The second ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 are connected to each other and are also connected to the negative terminal of the output port 204 .

[0154] A midpoint of the twelfth bridge arm S12 is connected to the fourth end of the first transformer M1 .

[0155] A midpoint of the thirteenth bridge arm S13 is connected to the third end of the first transformer M1 .

[0156] A first end of the fifth capacitor C5 is connected to the first end of the twelfth bridge arm S12 and the first end of the thirteenth bridge arm S13 . The fifth capacitor C5 is also connected to the positive terminal of the output port 204 .

[0157] The second end of the fifth capacitor C5 is connected to the second ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 . The fifth capacitor C5 is also connected to the negative terminal of the output port 204 .

[0158] In the embodiment of the present application, the eighth bridge arm S8, the ninth bridge arm S9, the twelfth bridge arm S12 and the thirteenth bridge arm S13 are all first-type bridge arms, and the eighth bridge arm S8, the ninth bridge arm S9, the twelfth bridge arm S12 and the thirteenth bridge arm S13 are all high-speed bridge arms.

[0159] In the embodiment of the present application, the duty cycle is further controlled by controlling the conduction frequency of the switch tube in the bridge arm to control the signal voltage of the AC signal output to the battery.

[0160] It can be understood that the switching frequency of the switching devices in the high-speed bridge arm is high frequency.

[0161] In some embodiments, the structure of the main power converter is as follows Figure 8 As shown, main power converter 202 includes a first rectifier circuit, a first transformer M1, a first filter circuit, and a second filter circuit. The first rectifier circuit includes a tenth bridge arm S10, an eleventh bridge arm S11, a first switch transistor Q1, a second switch transistor Q2, a third switch transistor Q3, and a fourth switch transistor Q4. The first filter circuit includes a fourth capacitor C4 and a sixth inductor L6. The inverter circuit includes a twelfth bridge arm S12 and a thirteenth bridge arm S13. The second filter circuit includes a fifth capacitor C5.

[0162] The first end of the first switching transistor Q1, the third switching transistor Q3, the tenth bridge arm S10, and the first end of the eleventh bridge arm S11 are connected. The second end of the second switching transistor Q2, the fourth switching transistor Q4, the tenth bridge arm S10, and the second end of the eleventh bridge arm S11 are connected. The second end of the first switching transistor Q1 is connected to the first end of the second switching transistor Q2 and to the positive terminal of the input port 201. The second end of the third switching transistor Q3 is connected to the first end of the fourth switching transistor Q4 and to the negative terminal of the input port 201.

[0163] The midpoint of the tenth bridge arm S10 is connected to the first end of the first transformer M1. The midpoint of the eleventh bridge arm S11 is connected to the second end of the first transformer M1.

[0164] A first end of the fourth capacitor C4 is connected to the first end of the first switch tube Q1, the third switch tube Q3, the tenth bridge arm S10, and the first end of the eleventh bridge arm S11. A second end of the fourth capacitor C4 is connected to the second end of the second switch tube Q2, the fourth switch tube Q4, the tenth bridge arm S10, and the second end of the eleventh bridge arm S11.

[0165] A first end of the sixth inductor L6 is connected to the midpoint of the tenth bridge arm S10 , and a second end of the sixth inductor L6 is connected to the first end of the first transformer M1 .

[0166] The first ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 are connected and connected to the positive terminal of the output port 204 . The second ends of the twelfth bridge arm S12 and the thirteenth bridge arm S13 are connected and connected to the negative terminal of the output port 204 .

[0167] The midpoint of the twelfth bridge arm S12 is connected to the fourth terminal of the first transformer M1. The midpoint of the thirteenth bridge arm S13 is connected to the third terminal of the first transformer M1.

[0168] A first end of the fifth capacitor C5 is connected to the first end of the twelfth bridge arm S12 and the first end of the thirteenth bridge arm S13, and the fifth capacitor C5 is also connected to the positive terminal of the output port 204. A second end of the fifth capacitor C5 is connected to the second end of the twelfth bridge arm S12 and the second end of the thirteenth bridge arm S13, and the fifth capacitor C5 is also connected to the negative terminal of the output port 204.

[0169] In the embodiment of the present application, the tenth bridge arm S10, the eleventh bridge arm S11, the twelfth bridge arm S12 and the thirteenth bridge arm S13 are all first-type bridge arms, and the tenth bridge arm S10 and the eleventh bridge arm S11 are low-speed bridge arms, and the twelfth bridge arm S12 and the thirteenth bridge arm S13 are both high-speed bridge arms.

[0170] In the embodiment of the present application, the duty cycle is further controlled by controlling the conduction frequency of the switch tube in the bridge arm to control the signal voltage of the AC signal output to the battery.

[0171] It can be understood that the switching frequency of the switching device in the high-speed bridge arm is high frequency, and the switching frequency of the switching device in the low-speed bridge arm is low frequency.

[0172] The auxiliary power converter includes: a second rectifier circuit, a second transformer M2 and a rectifier filter circuit. Figure 3 The second rectifier circuit is connected to the input port 201 , the second rectifier circuit, the second transformer M2 and the rectifier filter circuit are connected in sequence, and the rectifier filter circuit is connected to the output port 204 .

[0173] In the embodiment of the present application, the second rectifier circuit can receive an AC signal through the input port 201, convert the AC signal into a first AC signal, and output the first AC signal to the second transformer M2. The second transformer M2 can receive the first AC signal, convert the first AC signal into a second AC signal, and output the second AC signal to the output rectifier and filter circuit. The output rectifier and filter circuit can receive the second AC signal, convert the second AC signal into a DC signal, and output the DC signal to the battery.

[0174] In some embodiments, the auxiliary power converter is structured as follows: Figure 9 As shown, the auxiliary power converter 203 includes: a second rectifier circuit, a second transformer M2, a rectifier filter circuit, an absorption circuit, a fifth switch tube Q5 and an eighth capacitor C8.

[0175] The absorption circuit can absorb the voltage spike in the first AC signal to protect the fifth switch tube Q5.

[0176] The second rectifier circuit includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The rectifier and filter circuit includes a fifth diode D5 and a sixth capacitor C6. The absorption circuit includes a seventh capacitor C7, a sixth diode D6, and a resistor R.

[0177] The first ends of the first diode D1 and the third diode D3 are connected to the first end of the second transformer M2. The second end of the first diode D1 is connected to the first end of the second diode D2 and to the positive terminal of the input port 201. The second end of the third diode D3 is connected to the first end of the fourth diode D4 and to the negative terminal of the input port 201. The second ends of the second diode D2 and the fourth diode D4 are connected to the second end of the second transformer M2.

[0178] The seventh capacitor C7 is connected to the first end of the resistor R, to the second ends of the second diode D2 and the fourth diode D4, and to the first end of the second transformer M2.

[0179] The seventh capacitor C7 is connected to the second end of the resistor R and to the first end of the sixth diode D6.

[0180] The second end of the sixth diode D6 is connected to the first end of the fifth switch tube Q5.

[0181] A first end of the fifth switch tube Q5 is connected to the second end of the second transformer M2 , and a second end of the fifth switch tube Q5 is connected to the second ends of the second diode D2 and the fourth diode D4 .

[0182] A first end of the eighth capacitor C8 is connected to the first end of the first diode D1 and the first end of the third diode D3. The first end of the eighth capacitor C8 is also connected to the first end of the second transformer M2. A second end of the eighth capacitor C8 is connected to the second end of the second diode D2 and the second end of the fourth diode D4. The eighth capacitor C8 is also connected to the second end of the fifth switch tube Q5.

[0183] A first end of the fifth diode D5 is connected to the third end of the second transformer M2 , a second end of the fifth diode D5 is connected to the first end of the sixth capacitor C6 , and a second end of the fifth diode D5 is also connected to the positive terminal of the output port 204 .

[0184] A second end of the sixth capacitor C6 is connected to the fourth end of the second transformer M2 . The second end of the sixth capacitor C6 is also connected to the negative terminal of the output port 204 .

[0185] In some embodiments, the auxiliary power converter is structured as follows: Figure 10 As shown, the auxiliary power converter 203 includes: a second rectifier circuit, a second transformer M2, a rectifier and filter circuit, a sixth switch tube Q6, a seventh inductor L7 and a ninth capacitor C9.

[0186] The second rectifier circuit includes a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4. The rectifier and filter circuit includes a fifth diode D5 and a sixth capacitor C6.

[0187] The first ends of the first diode D1 and the third diode D3 are connected, and are connected to the first end of the second transformer M2 through the seventh inductor L7. The second end of the first diode D1 is connected to the first end of the second diode D2 and to the positive terminal of the input port 201. The second end of the third diode D3 is connected to the first end of the fourth diode D4 and to the negative terminal of the input port 201. The second ends of the second diode D2 and the fourth diode D4 are connected, and are connected to the second end of the second transformer M2.

[0188] A first end of the sixth switch tube Q6 is connected to a first end of the second transformer M2 via an eighth capacitor C8 , and a second end of the sixth switch tube Q6 is connected to a second end of the second transformer M2 .

[0189] A first end of the seventh inductor L7 is connected to the first end of the first diode D1 and the first end of the third diode D3 , and a second end of the seventh inductor L7 is connected to the first end of the sixth switch tube Q6 .

[0190] The first end of the ninth capacitor C9 is connected to the first end of the sixth switch Q6, and the second end of the ninth capacitor C9 is connected to the second end of the seventh inductor L7. The second end of the ninth capacitor C9 is connected to the first end of the second transformer M2.

[0191] A first end of the fifth diode D5 is connected to the third end of the second transformer M2 , a second end of the fifth diode D5 is connected to the first end of the sixth capacitor C6 , and a second end of the fifth diode D5 is also connected to the positive terminal of the output port 204 .

[0192] A second end of the sixth capacitor C6 is connected to the fourth end of the second transformer M2 . The second end of the sixth capacitor C6 is also connected to the negative terminal of the output port 204 .

[0193] In the embodiment of the present application, the main power converter can be arbitrarily combined with the auxiliary power converter.

[0194] The following is the main power converter Figure 10 The main power converter is shown, and the auxiliary power converter is Figure 8 Taking the auxiliary power converter shown as an example, an AC / DC converter provided by the present application is described.

[0195] like Figure 11 As shown, the AC / DC converter includes: Figure 5 The main power converter shown and Figure 9 Auxiliary power converter shown.

[0196] In the embodiment of the present application, the operation of the main power converter 202 and / or the auxiliary power converter 203 is controlled by controlling the switching elements in the AC / DC converter 20. Specifically, in the main power converter 202, the first bridge arm includes a first switching element V1 and a second switching element V2, the second bridge arm includes a third switching element V3 and a fourth switching element V4, the third bridge arm includes a fifth switching element V5 and a sixth switching element V6, the twelfth bridge arm includes a seventh switching element V7 and an eighth switching element V8, and the thirteenth bridge arm includes a ninth switching element V9 and a tenth switching element V10.

[0197] The auxiliary power converter 203 includes a fifth switch tube Q5 .

[0198] It can be understood that the first switching element V1, the second switching element V2, the third switching element V3, the fourth switching element V4, the fifth switching element V5, the sixth switching element V6, the seventh switching element V7, the eighth switching element V8, the ninth switching element V9 and the tenth switching element V10 are all the same as the fifth switching tube Q5.

[0199] The first switching element V1, the second switching element V2, the third switching element V3, the fourth switching element V4, the sixth switching element V6, the seventh switching element V7, the eighth switching element V8, the ninth switching element V9, the tenth switching element V10, and the fifth switching transistor Q5 are high-frequency switching devices. The fifth switching element V5 and the sixth switching element V6 are low-frequency switching devices.

[0200] The so-called high frequency and low frequency refer to the frequencies used in this application to control conduction.

[0201] Combine Figure 2 In order to facilitate the control of the duty cycle of the AC / DC converter and avoid the difficulty in controlling the input voltage at the zero-crossing point, which in turn causes AC side current distortion, the controller can control the operation of the main power converter and / or auxiliary power converter in the AC / DC converter according to the voltage of the AC signal received by the AC power supply at the input port.

[0202] That is, when the voltage of the AC signal received at the input port (which can be represented by Vg) is within the preset voltage range (such as [U1, U2]), the controller controls the auxiliary power converter to operate; when the voltage of the AC signal received at the input port is outside the preset voltage range, the controller controls the main power converter to operate.

[0203] For example, the preset voltage range is as follows: Figure 12 As shown in the figure, [U1, U2] is the preset voltage range. Figure 12 In FIG, the ordinate represents the voltage Vg of the AC signal received at the input port, and the abscissa represents the time t.

[0204] Specifically, in one AC cycle, the controller can Figure 13 The control signal timing diagram shown in the figure is Figure 11 The switching elements shown (i.e., the first switching element V1, the second switching element V2, the third switching element V3, the fourth switching element V4, the fifth switching element V5, the sixth switching element V6, the seventh switching element V7, the eighth switching element V8, the ninth switching element V9, the tenth switching element V10 and the fifth switching tube Q5) operate to control the main power converter and / or the auxiliary power converter.

[0205] exist Figure 13 In the figure, the abscissa represents time t, and the ordinate represents the voltage Vg of the AC signal received at the input port, or the control signals of each switching element. The control signals include: the control signal of the first switching element V1 / fourth switching element V4, the control signal of the second switching element V2 / third switching element V3, the control signal of the fifth switching element V5, the control signal of the sixth switching element V6, the control signal of the seventh switching element V7, the control signal of the eighth switching element V8, the control signal of the ninth switching element V9, the control signal of the tenth switching element V10, and the control signal of the fifth switching transistor Q5.

[0206] As the voltage Vg of the AC signal received at the input port changes, the control signals of the various switch elements (first switch element V1, second switch element V2, third switch element V3, fourth switch element V4, fifth switch element V5, sixth switch element V6, seventh switch element V7, eighth switch element V8, ninth switch element V9, tenth switch element V10 and fifth switch tube Q5) are at a high level or a low level. When the control signal is at a high level, the switch element is turned on. When the control signal is at a low level, the switch element is turned off. Figure 13 It can be seen that outside the preset voltage range, the controller controls the control signal to turn on the main power converter (i.e., the control signals of the first switching element V1, the second switching element V2, the third switching element V3, the fourth switching element V4, the fifth switching element V5, the sixth switching element V6, the seventh switching element V7, the eighth switching element V8, the ninth switching element V9, and the tenth switching element V10) and turns off the control signal of the auxiliary power converter (i.e., the control signal of the fifth switch Q5), thereby controlling the main power converter to convert the AC signal into a DC signal outside the preset voltage range. Within the preset voltage range, the controller controls the control signal to turn off the main power converter and turns on the control signal of the auxiliary power converter, thereby controlling the auxiliary power converter to convert the AC signal into a DC signal within the preset voltage range.

[0207] Optionally, when the voltage of the AC signal received by the input port is outside the preset voltage range, the controller can control the auxiliary power converter to operate so that the sum of the output power of the auxiliary power converter and the output power of the main power converter is the same as the rated output power.

[0208] In combination with the above embodiments, the present application also provides a THD optimization method, which is applied to Figure 2 The controller 10 shown, as Figure 14 As shown, the THD optimization method includes:

[0209] S1401 : Sample the voltage of the AC signal input to the AC / DC converter.

[0210] Combine Figure 3 , the controller can sample the voltage of the AC signal input to the AC / DC converter from the input port.

[0211] S1402: When the voltage of the AC signal is within a preset voltage range, control the auxiliary power converter to operate.

[0212] S1403 : When the voltage of the AC signal is outside the preset voltage range, control the main power converter to operate.

[0213] The two endpoint values of the preset voltage interval are respectively a first voltage value and a second voltage value, the first voltage value is less than 0, and the second voltage value is greater than 0.

[0214] For details, please refer to Figure 11 、 Figure 13 The above-mentioned implementation method will not be described in detail here.

[0215] In some embodiments, combined Figure 14 ,like Figure 15 As shown, the THD optimization method also includes:

[0216] S1501. When the voltage of the AC signal is outside a preset voltage range, control the auxiliary power converter to operate, and make the sum of the output power of the auxiliary power converter and the output power of the main power converter equal to the rated output power.

[0217] For details, please refer to Figure 11 、 Figure 13 The above-mentioned implementation method will not be described in detail here.

[0218] An embodiment of the present application also provides a vehicle, which includes any one of the AC / DC converters and / or energy conversion systems in the above embodiments.

[0219] An embodiment of the present application further provides a computer-readable storage medium, which includes computer-executable instructions. When the computer-executable instructions are executed on a computer, the computer executes the THD optimization method provided in the above embodiment.

[0220] The embodiment of the present application also provides a computer program, which can be directly loaded into a memory and contains software code. After being loaded and executed by a computer, the computer program can implement the THD optimization method provided in the above embodiment.

[0221] In the description of the embodiments of the present application, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0222] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An AC / DC converter, characterized in that: include: an input port, an output port, a main power converter, and an auxiliary power converter; The input port is used to connect to an AC power source, and the output port is used to connect to a battery; The main power converter and the auxiliary power converter are connected between the input port and the output port, and the main power converter and the auxiliary power converter are connected in parallel; The auxiliary power converter is configured to operate when the voltage of the AC signal received by the input port is within a preset voltage range, so as to convert the AC signal into a DC signal and output the DC signal to the battery; The two endpoint values of the preset voltage interval are a first voltage value and a second voltage value, respectively, the first voltage value is less than 0, and the second voltage value is greater than 0; the preset voltage interval is a voltage interval where the voltage of the AC signal is near a zero crossing point; The main power converter is configured to operate when the voltage of the AC signal received by the input port is outside the preset voltage range, so as to convert the AC signal into a DC signal and output the DC signal to the battery; The number of power devices of the auxiliary power converter is smaller than the number of power devices of the main power converter.

2. The AC / DC converter according to claim 1, wherein: The main power converter includes: a first rectifier circuit, a first transformer and an inverter circuit; The first rectifier circuit is connected to the input port, the first rectifier circuit, the first transformer and the inverter circuit are connected in sequence, and the inverter circuit is connected to the output port; The first rectifier circuit is configured to receive an AC signal through the input port, convert the AC signal into a first AC signal, and output the first AC signal to the first transformer; The first transformer is configured to receive the first AC signal, convert the first AC signal into a second AC signal, and output the second AC signal to the inverter circuit; The inverter circuit is configured to receive the second AC signal, convert the second AC signal into the DC signal, and output the DC signal to the battery.

3. The AC / DC converter according to claim 2, wherein: The main power converter further includes: a first filtering circuit; The first filter circuit is connected between the input port and the first rectifier circuit, or between the first rectifier circuit and the first transformer; The first filtering circuit is configured to filter the AC signal from the input port or the first AC signal output by the first rectifier circuit.

4. The AC / DC converter according to claim 3, wherein: The first rectifier circuit includes: a first bridge arm, a second bridge arm and a third bridge arm; The first ends of the first bridge arm, the second bridge arm and the third bridge arm are connected, and the second ends of the first bridge arm, the second bridge arm and the third bridge arm are connected; The midpoint of the first bridge arm and the midpoint of the second bridge arm are both connected to the positive terminal of the input port, and the midpoint of the third bridge arm is connected to the negative terminal of the input port; The midpoint of the first bridge arm is further connected to the first end of the first transformer, and the midpoint of the second bridge arm is further connected to the second end of the first transformer; The midpoint of the bridge arm is the connecting end of the upper half bridge and the lower half bridge of the bridge arm.

5. The AC / DC converter according to claim 4, characterized in that: The first filtering circuit includes: a first inductor, a second inductor and a first capacitor; A first end of the first inductor is connected to the positive terminal of the input port, and a second end of the first inductor is connected to the midpoint of the first bridge arm and to the first end of the first transformer; A first end of the second inductor is connected to the positive terminal of the input port, a second end of the second inductor is connected to the midpoint of the second bridge arm, and is connected to the second end of the first transformer; The first end of the first capacitor is connected to the first ends of the first bridge arm, the second bridge arm and the third bridge arm, and the second end of the first capacitor is connected to the second ends of the first bridge arm, the second bridge arm and the third bridge arm.

6. The AC / DC converter according to claim 3, wherein: The first rectifier circuit includes: a fourth bridge arm, a fifth bridge arm, a sixth bridge arm and a seventh bridge arm; The fourth bridge arm and the first end of the fifth bridge arm are connected to each other, and are also connected to the positive terminal of the input port; The second end of the fourth bridge arm is connected to the first end of the sixth bridge arm, and is also connected to the first end of the first transformer; The second end of the fifth bridge arm is connected to the first end of the seventh bridge arm, and is also connected to the second end of the first transformer; The second ends of the sixth bridge arm and the seventh bridge arm are connected to each other and are also connected to the negative terminal of the input port.

7. The AC / DC converter according to claim 6, characterized in that: The first filtering circuit includes: a third inductor; The first end of the third inductor is connected to the second end of the fourth bridge arm and the first end of the sixth bridge arm, and the second end of the third inductor is connected to the first end of the first transformer.

8. The AC / DC converter according to claim 3, wherein: The first rectifier circuit includes: an eighth bridge arm and a ninth bridge arm; The eighth bridge arm and the first end of the ninth bridge arm are connected; The second ends of the eighth bridge arm and the ninth bridge arm are connected; The midpoint of the eighth bridge arm is connected to the positive terminal of the input port, and the midpoint of the eighth bridge arm is also connected to the first end of the first transformer; The midpoint of the ninth bridge arm is connected to the positive terminal of the input port.

9. The AC / DC converter according to claim 8, characterized in that: The first filtering circuit includes: a fourth inductor, a fifth inductor, a second capacitor, and a third capacitor; A first end of the fourth inductor is connected to the positive terminal of the input port; The second end of the fourth inductor is connected to the midpoint of the eighth bridge arm; The first end of the fifth inductor is connected to the midpoint of the eighth bridge arm, and the first end of the fifth inductor is also connected to the second end of the fourth inductor; The second end of the fifth inductor is connected to the first end of the first transformer; The first end of the second capacitor is connected to the first end of the eighth bridge arm and the first end of the ninth bridge arm; The second end of the second capacitor is connected to the first end of the third capacitor, and the second end of the second capacitor is also connected to the second end of the first transformer; The second end of the third capacitor is connected to the second ends of the eighth bridge arm and the ninth bridge arm.

10. The AC / DC converter according to claim 3, wherein: The first rectifier circuit includes: a tenth bridge arm, an eleventh bridge arm, and a first switch tube, a second switch tube, a third switch tube and a fourth switch tube; The first end of the first switch tube, the third switch tube, the tenth bridge arm, and the first end of the eleventh bridge arm are connected; The second ends of the second switch tube, the fourth switch tube, the tenth bridge arm, and the eleventh bridge arm are connected; The second end of the first switch tube is connected to the first end of the second switch tube, and is also connected to the positive terminal of the input port; The second end of the third switch tube is connected to the first end of the fourth switch tube and is also connected to the negative end of the input port; The midpoint of the tenth bridge arm is connected to the first end of the first transformer; The midpoint of the eleventh bridge arm is connected to the second end of the first transformer; The midpoint of the bridge arm is the connecting end of the upper half bridge and the lower half bridge of the bridge arm.

11. The AC / DC converter according to claim 10, wherein: The first filtering circuit includes: a fourth capacitor and a sixth inductor; The first end of the fourth capacitor is connected to the first end of the first switch tube, the third switch tube, the tenth bridge arm, and the first end of the eleventh bridge arm; The second end of the fourth capacitor is connected to the second ends of the second switch tube, the fourth switch tube, the tenth bridge arm, and the eleventh bridge arm; The first end of the sixth inductor is connected to the midpoint of the tenth bridge arm; The second end of the sixth inductor is connected to the first end of the first transformer.

12. The AC / DC converter according to claim 3, wherein: The inverter circuit includes: a twelfth bridge arm and a thirteenth bridge arm; The first end of the twelfth bridge arm is connected to the first end of the thirteenth bridge arm, and is also connected to the positive terminal of the output port; The second ends of the twelfth bridge arm and the thirteenth bridge arm are connected, and are also connected to the negative terminal of the output port; The midpoint of the twelfth bridge arm is connected to the fourth end of the first transformer; The midpoint of the thirteenth bridge arm is connected to the third end of the first transformer; The midpoint of the bridge arm is the connecting end of the upper half bridge and the lower half bridge of the bridge arm.

13. The AC / DC converter according to claim 12, wherein: The main power converter further includes: a second filtering circuit; The second filter circuit is connected between the inverter circuit and the output port; The second filter circuit is configured to filter the DC signal output by the inverter circuit; The second filtering circuit includes: a fifth capacitor; The first end of the fifth capacitor is connected to the first end of the twelfth bridge arm and the first end of the thirteenth bridge arm, and the fifth capacitor is also connected to the positive terminal of the output port; The second end of the fifth capacitor is connected to the second ends of the twelfth bridge arm and the thirteenth bridge arm, and the fifth capacitor is also connected to the negative terminal of the output port.

14. The AC / DC converter according to claim 1, wherein: The auxiliary power converter includes: a second rectifier circuit, a second transformer and a rectifier filter circuit; The second rectifier circuit is connected to the input port, the second rectifier circuit, the second transformer and the rectifier and filter circuit are connected in sequence, and the rectifier and filter circuit is connected to the output port; The second rectifier circuit is configured to receive an AC signal through the input port, convert the AC signal into a first AC signal, and output the first AC signal to the second transformer; The second transformer is configured to receive the first AC signal, convert the first AC signal into a second AC signal, and output the second AC signal to the output rectifier and filter circuit; The output rectification and filtering circuit is configured to receive the second AC signal, convert the second AC signal into the DC signal, and output the DC signal to the battery.

15. The AC / DC converter according to claim 14, wherein: The second rectifier circuit includes: a first diode, a second diode, a third diode and a fourth diode; The first ends of the first diode and the third diode are connected to the first end of the second transformer; The second end of the first diode is connected to the first end of the second diode and is connected to the positive terminal of the input port; The second end of the third diode is connected to the first end of the fourth diode and is also connected to the negative terminal of the input port; The second ends of the second diode and the fourth diode are connected to the second end of the second transformer.

16. The AC / DC converter according to claim 14, wherein: The rectification and filtering circuit includes: a fifth diode and a sixth capacitor; The first end of the fifth diode is connected to the third end of the second transformer; The second end of the fifth diode is connected to the first end of the sixth capacitor, and the second end of the fifth diode is also connected to the positive terminal of the output port; The second end of the sixth capacitor is connected to the fourth end of the second transformer, and the second end of the sixth capacitor is also connected to the negative terminal of the output port.

17. The AC / DC converter according to any one of claims 14 to 16, characterized in that: The auxiliary power converter further includes: a fifth switching tube; The first end of the fifth switching tube is connected to the second end of the second transformer; The second end of the fifth switch tube is connected to the second ends of the second diode and the fourth diode.

18. The AC / DC converter according to claim 17, wherein: The auxiliary power converter further includes: an absorption circuit, the absorption circuit including: a seventh capacitor, a sixth diode and a resistor; The seventh capacitor is connected to the first end of the resistor, and is connected to the second ends of the second diode and the fourth diode, and is also connected to the first end of the second transformer; The seventh capacitor is connected to the second end of the resistor and is also connected to the first end of the sixth diode; The second end of the sixth diode is connected to the first end of the fifth switch tube; The absorption circuit is configured to absorb voltage spikes in the first AC signal to protect the fifth switching tube.

19. The AC / DC converter according to claim 18, wherein: The auxiliary power converter further includes: an eighth capacitor; The first end of the eighth capacitor is connected to the first end of the first diode and the first end of the third diode, and the first end of the eighth capacitor is also connected to the first end of the second transformer; The second end of the eighth capacitor is connected to the second ends of the second diode and the fourth diode, and the eighth capacitor is also connected to the second end of the fifth switch tube.

20. The AC / DC converter according to any one of claims 14 to 16, characterized in that: The auxiliary power converter further includes: a sixth switch tube; The first end of the sixth switching tube is connected to the first end of the second transformer; The second end of the sixth switching tube is connected to the second end of the second transformer.

21. The AC / DC converter according to claim 20, characterized in that The auxiliary power converter further includes: a seventh inductor and a ninth capacitor; The first end of the seventh inductor is connected to the first end of the first diode and the first end of the third diode; The second end of the seventh inductor is connected to the first end of the sixth switch tube; The first end of the ninth capacitor is connected to the first end of the sixth switch tube, and the first end of the ninth capacitor is also connected to the second end of the seventh inductor; The second end of the ninth capacitor is connected to the first end of the second transformer.

22. The AC / DC converter according to claim 1, wherein: The auxiliary power converter is also configured to operate when the voltage of the AC signal received at the input port is outside the preset voltage range, so as to convert the AC signal into a DC signal and output it to the battery; the sum of the output power of the auxiliary power converter and the output power of the main power converter is the same as the rated output power.

23. An energy conversion system, characterized in that: The energy conversion system comprises: a controller, and an AC / DC converter according to any one of claims 1 to 22; The controller is configured to sample the voltage of the AC signal input to the AC / DC converter, and control the operation of the main power converter and / or the auxiliary power converter in the AC / DC converter according to the voltage of the AC signal.

24. A vehicle, characterized in that: Comprising the AC / DC converter according to any one of claims 1 to 22, and / or the energy conversion system according to claim 23.

25. A THD optimization method, characterized in that: The AC / DC converter according to any one of claims 1 to 22 comprises: sampling the voltage of the AC signal input to the AC / DC converter; When the voltage of the AC signal is within the preset voltage range, controlling the auxiliary power converter to operate; When the voltage of the AC signal is outside the preset voltage range, controlling the main power converter to operate; the two endpoint values of the preset voltage range are the first voltage value and the second voltage value, respectively, the first voltage value is less than 0, and the second voltage value is greater than 0; The main power converter is connected in parallel with the auxiliary power converter.

26. The THD optimization method according to claim 25, characterized in that: Also includes: When the voltage of the AC signal is outside the preset voltage range, the auxiliary power converter is controlled to operate, and the sum of the output power of the auxiliary power converter and the output power of the main power converter is made equal to the rated output power.

27. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores computer program instructions suitable for execution by the processor, and the computer program instructions are executed by the processor to perform the method according to any one of claims 25 to 26.

28. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the method according to any one of claims 25 to 26 is executed.

29. A computer program product, characterized in that The computer program product comprises: a computer program or instructions, and when the computer program or instructions are run on an electronic device, the electronic device is caused to perform the method according to any one of claims 25-26.

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