Converter
The multi-channel interleaved DC-DC converter constructed using SEPIC circuits solves the problems of complex control and numerous components in traditional power factor correction circuits, achieving simple and low-cost battery charging conversion while reducing current ripple and the number of capacitors.
Patent Information
- Application Number
- CN202423022372.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-09
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2034-12-09
AI Technical Summary
Traditional power factor correction circuits are complex to control, difficult to achieve input-output electrical isolation, have large input current ripple, and complex EMI filter design. In addition, existing DC-DC converter circuits have complex topologies, many components, and high costs.
The DC-DC converter using SEPIC circuitry includes a multi-channel interleaved rectifier section and a conversion circuit. Electrical isolation is achieved using a bridge rectifier and a transformer. The multi-channel interleaved output reduces current ripple and the number of output capacitors.
It achieves a DC-DC converter with simple topology, few components, and low cost, reduces output voltage and current ripple, is suitable for battery charging, and lowers costs.
Smart Images
Figure CN223567539U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to inverter technical field especially relates to a kind of inverters. BACKGROUND
[0002] Traditional power factor correction circuit is constituted by BOOST circuit, and this kind of circuit control is complex, output voltage is higher than input, and it is difficult to realize the electrical isolation of input and output.The power factor correction circuit constituted by flyback circuit must work in the state of inductance current discontinuity, input current pulsation is big, and it often needs more complex EMI filter design.
[0003] In recent years, SEPIC circuit is receiving more and more attention.SEPIC circuit has its natural advantages for power factor correction circuit, since its front stage is similar to BOOST, so that very small input current switching ripple can be guaranteed, and input EMI design is reduced, and its output is similar to flyback, easy to realize electrical isolation, and Buck / Boost conversion can also be carried out.
[0004] Therefore, it is necessary to provide an inverter, which has simple topology, few devices and small current ripple, and can complete DC-DC conversion for battery charging. INVENTION CONTENTS
[0005] The utility model discloses a kind of inverters, including a kind of structure simple output multiway staggered, low-cost DC-DC converter circuit, it is related to power electronics technology and automatic control principle, it can be widely applied in V2G field, it can effectively solve the technical problems involved in background technology.
[0006] To achieve the above object, the technical scheme of the utility model is as follows:
[0007] An inverter includes port A, port B and port C, the output end of the port A is connected to the input end of the first rectifying part and the input end of the third rectifying part, the output end of the port B is connected to the input end of the first rectifying part and the input end of the second rectifying part, the output end of the port C is connected to the input end of the second rectifying part and the input end of the third rectifying part, the output end of the first rectifying part is connected to both ends of the capacitor C1, the output end of the second rectifying part is connected to both ends of the capacitor C2, and the output end of the third rectifying part is connected to both ends of the capacitor C3.
[0008] The transformer further comprises a first conversion circuit, the capacitor C1 is connected between two ends of the capacitor C10 and two ends of the capacitor C11 through the first conversion circuit, the first conversion circuit comprises an inductor L1, one end of the inductor L1 is connected to one end of the capacitor C1, the other end of the inductor L1 is connected to a drain of a MOS tube Q1 and one end of a capacitor C4, the other end of the capacitor C4 is connected to a pin 1 of a transformer T1, a pin 2 of the transformer T1 is connected to a source of the MOS tube Q1, the other end of the capacitor C1 and a port GNDAB, a pin 3 of the transformer T1 is connected to one end of the capacitor C11 and a port GNDV2, a pin 4 of the transformer T1 is connected to a positive end of a diode D2, a negative end of the diode D2 is connected to the other end of the capacitor C11 and a port V2, a pin 5 of the transformer T1 is connected to one end of the capacitor C10 and a port GNDV1, and a pin 6 of the transformer T1 is connected to a positive end of a diode D1, a negative end of the diode D1 is connected to the other end of the capacitor C10 and a port V1;
[0009] The transformer further comprises a second conversion circuit, the capacitor C2 is connected between two ends of the capacitor C10 and two ends of the capacitor C11 through the second conversion circuit, the second conversion circuit comprises an inductor L3, one end of the inductor L3 is connected to one end of the capacitor C2, the other end of the inductor L3 is connected to a drain of a MOS tube Q3 and one end of a capacitor C6, the other end of the capacitor C6 is connected to a pin 1 of a transformer T3, a pin 2 of the transformer T3 is connected to a source of the MOS tube Q3, the other end of the capacitor C2 and a port GNDBC, a pin 3 of the transformer T3 is connected to one end of the capacitor C11 and a port GNDV2, a pin 4 of the transformer T3 is connected to a positive end of a diode D6, a negative end of the diode D6 is connected to the other end of the capacitor C11 and a port V2, a pin 5 of the transformer T3 is connected to one end of the capacitor C10 and a port GNDV1, a pin 6 of the transformer T3 is connected to a positive end of a diode D5, and a negative end of the diode D5 is connected to the other end of the capacitor C10 and a port V1;
[0010] The transformer further comprises a third conversion circuit, the capacitor C3 is connected between two ends of the capacitor C10 and two ends of the capacitor C11 through the third conversion circuit, the third conversion circuit comprises an inductor L5, one end of the inductor L5 is connected to one end of the capacitor C3, the other end of the inductor L5 is connected to a drain of a MOS tube Q5 and one end of a capacitor C8, the other end of the capacitor C8 is connected to a pin 1 of a transformer T5, a pin 2 of the transformer T5 is connected to a source of the MOS tube Q5, the other end of the capacitor C3 and a port GNDCA, a pin 3 of the transformer T5 is connected to one end of the capacitor C11 and a port GNDV2, a pin 4 of the transformer T5 is connected to a positive end of a diode D10, a negative end of the diode D10 is connected to the other end of the capacitor C11 and a port V2, a pin 5 of the transformer T5 is connected to one end of the capacitor C10 and a port GNDV1, and a pin 6 of the transformer T5 is connected to a positive end of a diode D9, a negative end of the diode D9 is connected to the other end of the capacitor C10 and a port V1.
[0011] As a preferred improvement of the utility model: the first rectification part, the second rectification part and the third rectification part all include bridge rectifiers.
[0012] As a preferred improvement of the utility model: the input end of the port A, the input end of the port B and the input end of the port C are connected to three-phase electricity.
[0013] As a preferred improvement of the utility model: the port V1 and the port V2 are connected to the same battery in parallel through relays, or the port V1 and the port V2 are connected to the same battery in series through relays.
[0014] As a preferred improvement of the utility model: the number of the first conversion circuits is multiple, one end of the inductor L1 of the multiple first conversion circuits is connected, the port GNDAB is connected, the negative end of the diode D1 is connected, the pin 5 of the transformer T1 is connected, the negative end of the diode D2 is connected, and the pin 3 of the transformer T1 is connected.
[0015] As a preferred improvement of the utility model: the number of the second conversion circuits is multiple, one end of the inductor L3 of the multiple second conversion circuits is connected, the port GNDBC is connected, the negative end of the diode D5 is connected, the pin 5 of the transformer T3 is connected, the negative end of the diode D6 is connected, and the pin 3 of the transformer T3 is connected.
[0016] As a preferred improvement of the utility model: the number of the third conversion circuits is multiple, one end of the inductor L5 of the multiple third conversion circuits is connected, the port GNDCA is connected, the negative end of the diode D9 is connected, the pin 5 of the transformer T5 is connected, the negative end of the diode D10 is connected, and the pin 3 of the transformer T5 is connected.
[0017] The utility model discloses the beneficial effect is as follows:
[0018] Topological simple, device few, cost is also low, multi -way staggered output voltage, current ripple is small, can complete the DC-DC conversion of battery charging, through nine -way staggered reduction output voltage, current ripple, reduce the number of output capacitor, reduce cost. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the technical scheme in the utility model embodiment, the following will be needed to use the drawing in the embodiment description briefly introduced, obviously, the drawing in the following description only some embodiments of the utility model, for ordinary skilled person in the art, under the premise of not paying creative labor, can also obtain other drawings according to these drawings, wherein:
[0020] Figure 1 It is the circuit schematic diagram of a transformer of the utility model;
[0021] Figure 2 It is Figure 1 Circuit diagram decomposition Figure 1 ;
[0022] Figure 3 It is Figure 1 Circuit diagram decomposition Figure 2 ;
[0023] Figure 4 It is Figure 1 Circuit diagram decomposition Figure 3 ;
[0024] Figure 5 It is the circuit principle schematic diagram of the utility model. DETAILED DESCRIPTION
[0025] The technical scheme in the utility model embodiment will be described clearly and completely below in conjunction with the embodiment of the utility model, obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiment.Based on the embodiment in the utility model, all other embodiments obtained by ordinary skilled person in the art without making creative labor belong to the scope of protection of the utility model.
[0026] It should be noted that all directionality instructions (such as up, down, left, right, front, back...) in the embodiment of the utility model are only used to explain the relative position relationship, movement condition etc. between components in a certain specific posture (as shown in the drawings), if the specific posture changes, then the directionality instruction also changes accordingly.
[0027] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description and cannot be understood as indicating or implying the relative importance of the technical features or implying the number of the technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.
[0028] In the present application, unless otherwise specifically defined and limited, the terms "connection", "fixing" and the like should be understood broadly, for example, "fixing" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0029] In addition, the technical solutions of various embodiments of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection required by the present application.
[0030] Please refer to Figure 1 The utility model provides a converter, including port A, port B and port C, the output of port A connects the input of first rectification part and the input of third rectification part, the output of port B connects the input of first rectification part and the input of second rectification part, the output of port C connects the input of second rectification part and the input of third rectification part, the output of first rectification part connects the both ends of electric capacity C1 respectively, the output of second rectification part connects the both ends of electric capacity C2 respectively, the output of third rectification part connects the both ends of electric capacity C3 respectively. First rectification part, second rectification part and third rectification part all include bridge rectifier, also can be other rectification circuit, can realize rectification effect just can, can select full -bridge or half -bridge structure. The input of port A, the input of port B and the input of port C connect three -phase electricity, or other input power supply, port V1 and port V2 are connected with same battery in parallel through relay, or port V1 and port V2 are connected with same battery in series through relay.
[0031] Please refer to Figure 2As shown, the converter further comprises a first conversion circuit, the capacitor C1 is connected between two ends of the capacitor C10 and two ends of the capacitor C11 through the first conversion circuit, the first conversion circuit comprises an inductor L1, one end of the inductor L1 is connected to one end of the capacitor C1, the other end of the inductor L1 is connected to the drain of a MOS tube Q1 and one end of a capacitor C4, the other end of the capacitor C4 is connected to pin 1 of a transformer T1, pin 2 of the transformer T1 is connected to the source of the MOS tube Q1, the other end of the capacitor C1 and a port GNDAB, pin 3 of the transformer T1 is connected to one end of the capacitor C11 and a port GNDV2, pin 4 of the transformer T1 is connected to the positive end of a diode D2, the negative end of the diode D2 is connected to the other end of the capacitor C11 and a port V2, pin 5 of the transformer T1 is connected to one end of the capacitor C10 and a port GNDV1, pin 6 of the transformer T1 is connected to the positive end of a diode D1, the negative end of the diode D1 is connected to the other end of the capacitor C10 and a port V1. Preferably, the number of the first conversion circuits is multiple, one end of the inductor L1 of multiple first conversion circuits is connected, the port GNDAB is connected, the negative end of the diode D1 is connected, pin 5 of the transformer T1 is connected, the negative end of the diode D2 is connected, and pin 3 of the transformer T1 is connected. In this embodiment, the number of the first conversion circuits is 3, and the circuit structures are all the same and are connected in parallel. In the first path, the inductor L1, the MOS tube Q1, the capacitor C4, the transformer T1, the diode D1 and the diode D2 are used. In the second path, the inductor L2, the MOS tube Q2, the capacitor C5, the transformer T2, the diode D3 and the diode D4 are used. In the third path, the inductor L7, the MOS tube Q7, the capacitor C12, the transformer T7, the diode D13 and the diode D14 are used. The inductor L2 and the inductor L7 are equivalent to the inductor L1, the MOS tube Q2 and the MOS tube Q7 are equivalent to the MOS tube Q1, and so on.
[0032] Please refer to Figure 3As shown, the transformer further comprises a second conversion circuit, the capacitor C2 is connected between both ends of the capacitor C10 and both ends of the capacitor C11 through the second conversion circuit, the second conversion circuit comprises an inductor L3, one end of the inductor L3 is connected to one end of the capacitor C2, the other end of the inductor L3 is connected to the drain of a MOS tube Q3 and one end of a capacitor C6, the other end of the capacitor C6 is connected to pin 1 of a transformer T3, pin 2 of the transformer T3 is connected to the source of the MOS tube Q3, the other end of the capacitor C2 and a port GNDBC, pin 3 of the transformer T3 is connected to one end of the capacitor C11 and a port GNDV2, pin 4 of the transformer T3 is connected to the positive end of a diode D6, the negative end of the diode D6 is connected to the other end of the capacitor C11 and a port V2, pin 5 of the transformer T3 is connected to one end of the capacitor C10 and a port GNDV1, pin 6 of the transformer T3 is connected to the positive end of a diode D5, the negative end of the diode D5 is connected to the other end of the capacitor C10 and a port V1. Preferably, the number of the second conversion circuits is multiple, one end of the inductor L3 of multiple second conversion circuits is connected, the port GNDBC is connected, the negative end of the diode D5 is connected, pin 5 of the transformer T3 is connected, the negative end of the diode D6 is connected, and pin 3 of the transformer T3 is connected. In this embodiment, the number of the second conversion circuits is three, and the circuit structures are all the same and are connected in parallel. In the first path, the inductor L3, the MOS tube Q3, the capacitor C6, the transformer T3, the diode D5 and the diode D6 are used. In the second path, the inductor L4, the MOS tube Q4, the capacitor C7, the transformer T4, the diode D7 and the diode D8 are used. In the third path, the inductor L8, the MOS tube Q8, the capacitor C13, the transformer T8, the diode D15 and the diode D16 are used. The inductor L4 and the inductor L8 are equivalent to the inductor L3, the MOS tube Q4 and the MOS tube Q8 are equivalent to the MOS tube Q3, and so on.
[0033] Please refer to Figure 4As shown, the converter further comprises a third conversion circuit, the capacitor C3 is connected across the capacitor C10 and the capacitor C11 through the third conversion circuit, the third conversion circuit comprises an inductor L5, one end of the inductor L5 is connected to one end of the capacitor C3, the other end of the inductor L5 is connected to the drain of a MOS tube Q5 and one end of a capacitor C8, the other end of the capacitor C8 is connected to pin 1 of a transformer T5, pin 2 of the transformer T5 is connected to the source of the MOS tube Q5, the other end of the capacitor C3 and a port GNDCA, pin 3 of the transformer T5 is connected to one end of the capacitor C11 and a port GNDV2, pin 4 of the transformer T5 is connected to the positive end of a diode D10, the negative end of the diode D10 is connected to the other end of the capacitor C11 and a port V2, pin 5 of the transformer T5 is connected to one end of the capacitor C10 and a port GNDV1, and pin 6 of the transformer T5 is connected to the positive end of a diode D9, the negative end of the diode D9 is connected to the other end of the capacitor C10 and a port V1. Preferably, the number of the third conversion circuits is multiple, one end of the inductor L5 of multiple third conversion circuits is connected, the port GNDCA is connected, the negative end of the diode D9 is connected, pin 5 of the transformer T5 is connected, the negative end of the diode D10 is connected, and pin 3 of the transformer T5 is connected. In this embodiment, the number of the third conversion circuits is three, and the circuit structures are all the same and are connected in parallel. In the first path, the inductor L5, the MOS tube Q5, the capacitor C8, the transformer T5, the diode D9 and the diode D10 are used. In the second path, the inductor L6, the MOS tube Q6, the capacitor C9, the transformer T6, the diode D11 and the diode D12 are used. In the third path, the inductor L9, the MOS tube Q9, the capacitor C14, the transformer T9, the diode D17 and the diode D18 are used. The inductor L6 and the inductor L9 are equivalent to the inductor L5, the MOS tube Q6 and the MOS tube Q9 are equivalent to the MOS tube Q5, and so on.
[0034] A DC-DC converter circuit with simple structure, multiple output interlaced and low cost, mainly applied in the field of V2G. After rectification, the three-phase sine AB, BC and CA line voltages form steamed buns waves, completing AC-DC conversion. The steamed buns waves on the filter capacitors C1, C2 and C3 are not common ground, and after common ground, the steamed buns waves are interlaced with each other. Finally, the steamed buns waves are filtered flat, the input current cannot follow the voltage well, resulting in low input power factor and high THD value.
[0035] After AB phase rectification, 3-way SEPIC conversion circuit is connected, 120-degree interlacing is formed between 3-way SIC-MOSFET Q1, Q2, Q7 PWM waves, and independent 2-way is output through SIC-diode. After BC phase rectification, 3-way SEPIC conversion circuit is connected, 120-degree interlacing is formed between 3-way SIC-MOSFET Q3, Q4, Q8 PWM waves, and independent 2-way is output through SIC-diode. After CA phase rectification, 3-way SEPIC conversion circuit is connected, 120-degree interlacing is formed between 3-way SIC-MOSFET Q5, Q6, Q9 PWM waves, and independent 2-way is output through SIC-diode. 40-degree interlacing is formed between Q1, Q2, Q7 / Q3, Q4, Q8 / Q5, Q6, Q9 three ways, and nine-way interlacing parallel of SIC-diod D1, D3, D13, D5, D7, D15, D9, D11, D17 is formed, V1 is output; nine-way interlacing parallel of SIC-diod D2, D4, D14, D6, D8, D16, D10, D12, D18 is formed, V2 is output, the output voltage and current ripple is reduced after nine-way interlacing, the output capacitor quantity is reduced, and the cost is reduced.
[0036] V1 and V2 pass through the relay in parallel when low voltage and large current are output, and V1 and V2 pass through the relay in series when high voltage and small current are output.
[0037] Working principle:
[0038] Please refer to Figure 5 As shown in the figure, the sine voltage passes through the BD1 rectifier bridge to form a steamed bun wave, and C1 is a filter capacitor.
[0039] When Q1 is turned on: the converter has three loops, the first one is C1→L1→Q1→C1, L1 charges through Q1; the second one is C4→Q1→T1→C4, C4 discharges through Q1 and T1, and T1 stores energy; the third one is C10, C11 to provide energy to the load circuit.
[0040] When Q1 is turned off: the converter has two loops, the first one is C1→L1→C4→T1→C1, L1 discharges, C4 charges, and T1 transmits energy to the secondary side; the second one is converted to the secondary side through the T1 transformer→D1(D2)→C10(C11) to charge the output electrolytic capacitor.
[0041] The topology is simple, the device is few, the cost is low, the multi-way interlaced output voltage and current ripple is small, the DC-DC conversion for charging the battery can be completed, the output voltage and current ripple is reduced after nine-way interlacing, the output capacitor quantity is reduced, and the cost is reduced.
[0042] While the embodiments of the present application have been disclosed as above, it is not limited to the use listed in the specification and the embodiments, and can be applied to various fields suitable for the present application. Those skilled in the art can easily implement other modifications, and thus the present application is not limited to specific details and the figures shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.
Claims
1. A converter, characterized in that: It includes ports A, B, and C. The output of port A is connected to the input of the first rectifier section and the input of the third rectifier section. The output of port B is connected to the input of the first rectifier section and the input of the second rectifier section. The output of port C is connected to the input of the second rectifier section and the input of the third rectifier section. The output of the first rectifier section is connected to the two ends of capacitor C1. The output of the second rectifier section is connected to the two ends of capacitor C2. The output of the third rectifier section is connected to the two ends of capacitor C3. The converter further includes a first conversion circuit. The capacitor C1 is connected to the two ends of capacitor C10 and the two ends of capacitor C11 through the first conversion circuit. The first conversion circuit includes an inductor L1. One end of the inductor L1 is connected to one end of capacitor C1. The other end of the inductor L1 is connected to the drain of MOSFET Q1 and one end of capacitor C4. The other end of capacitor C4 is connected to pin 1 of transformer T1. Pin 2 of transformer T1 is connected to the source of MOSFET Q1, the other end of capacitor C1, and port GNDAB. Pin 3 of transformer T1 is connected to one end of capacitor C11 and port GNDV2. Pin 4 of transformer T1 is connected to the positive terminal of diode D2. The negative terminal of diode D2 is connected to the other end of capacitor C11 and port V2. Pin 5 of transformer T1 is connected to one end of capacitor C10 and port GNDV1. Pin 6 of transformer T1 is connected to the positive terminal of diode D1. The negative terminal of diode D1 is connected to the other end of capacitor C10 and port V1. The converter further includes a second conversion circuit. The capacitor C2 is connected to the two ends of the capacitor C10 and the two ends of the capacitor C11 through the second conversion circuit. The second conversion circuit includes an inductor L3. One end of the inductor L3 is connected to one end of the capacitor C2. The other end of the inductor L3 is connected to the drain of the MOSFET Q3 and one end of the capacitor C6. The other end of the capacitor C6 is connected to pin 1 of the transformer T3. Pin 2 of the transformer T3 is connected to the source of the MOSFET Q3, the other end of the capacitor C2, and port GNDBC. Pin 3 of the transformer T3 is connected to one end of the capacitor C11 and port GNDV2. Pin 4 of the transformer T3 is connected to the positive terminal of the diode D6. The negative terminal of the diode D6 is connected to the other end of the capacitor C11 and port V2. Pin 5 of the transformer T3 is connected to one end of the capacitor C10 and port GNDV1. Pin 6 of the transformer T3 is connected to the positive terminal of the diode D5. The negative terminal of the diode D5 is connected to the other end of the capacitor C10 and port V1. The converter also includes a third conversion circuit. Capacitor C3 is connected to the two ends of capacitor C10 and capacitor C11 through the third conversion circuit. The third conversion circuit includes an inductor L5. One end of inductor L5 is connected to one end of capacitor C3. The other end of inductor L5 is connected to the drain of MOSFET Q5 and one end of capacitor C8. The other end of capacitor C8 is connected to pin 1 of transformer T5. Pin 2 of transformer T5 is connected to the source of MOSFET Q5, the other end of capacitor C3, and port GNDCA. Pin 3 of transformer T5 is connected to one end of capacitor C11 and port GNDV2. Pin 4 of transformer T5 is connected to the positive terminal of diode D10. The negative terminal of diode D10 is connected to the other end of capacitor C11 and port V2. Pin 5 of transformer T5 is connected to one end of capacitor C10 and port GNDV1. Pin 6 of transformer T5 is connected to the positive terminal of diode D9. The negative terminal of diode D9 is connected to the other end of capacitor C10 and port V1.
2. The converter according to claim 1, characterized in that: The first rectification section, the second rectification section, and the third rectification section all include bridge rectifiers.
3. A converter according to claim 1, characterized in that: The input terminals of port A, port B, and port C are connected to three-phase power.
4. A converter according to claim 1, characterized in that: Port V1 and port V2 are connected in parallel to the same battery via a relay, or port V1 and port V2 are connected in series to the same battery via a relay.
5. A converter according to claim 1, characterized in that: There are multiple first conversion circuits. One end of the inductor L1 of the multiple first conversion circuits is connected, the port GNDAB is connected, the negative end of the diode D1 is connected, the pin 5 of the transformer T1 is connected, the negative end of the diode D2 is connected, and the pin 3 of the transformer T1 is connected.
6. A converter according to claim 1, characterized in that: There are multiple second conversion circuits. One end of the inductor L3 of the multiple second conversion circuits is connected, the port GNDBC is connected, the negative end of the diode D5 is connected, the pin 5 of the transformer T3 is connected, the negative end of the diode D6 is connected, and the pin 3 of the transformer T3 is connected.
7. A converter according to claim 1, characterized in that: The number of the third conversion circuits is multiple. One end of the inductor L5 of the multiple third conversion circuits is connected, the port GNDCA is connected, the negative end of the diode D9 is connected, the pin 5 of the transformer T5 is connected, the negative end of the diode D10 is connected, and the pin 3 of the transformer T5 is connected.