Voltage conversion circuit, inversion device and energy storage device

Abstract

The utility model discloses a voltage conversion circuit, an inversion device and an energy storage device. The voltage conversion circuit comprises an auxiliary switch circuit of a Heric topology circuit; the auxiliary switch circuit comprises a first switch unit, a second switch unit, a transformer, a first inductor and a first diode, the first end of the first switch unit is connected with the positive electrode of the direct current side of the Heric topology circuit, the second end of the first switch unit is connected with the first end of the transformer, and the first end of the second switch unit is connected with the second end of the transformer; the anode of the first diode is connected with the third end of the transformer, and the fourth end of the transformer is connected with the cathode of the direct current side; the first end of the first inductor is connected with the fifth end of the transformer, and the second end of the first inductor is connected with the midpoint of a follow current bridge arm in the Heric topology circuit. By arranging the auxiliary switch circuit of the Helic topology circuit, soft switching of the semiconductor device of the Helic topology circuit is realized, so that the loss is reduced, and the cost is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of conversion circuits, in particular to a voltage conversion circuit, an inverter device and an energy storage device. BACKGROUND

[0002] A bidirectional DC-AC converter can be used for bidirectional conversion of a direct-current voltage and an alternating-current voltage, and can realize bidirectional flow of power between an AC side and a DC side. With the development of technology, the bidirectional DC-AC converter technology has attracted extensive attention.

[0003] In a traditional DC-AC converter, the switching tube in the DC-AC converter has a hard conduction or hard disconnection, so that the switching tube has a loss in the conduction or disconnection state. CONTENT OF THE UTILITY MODEL

[0004] The application mainly solves the technical problem of providing a voltage conversion circuit, an inverter device and an energy storage device to solve the problem of switching tube loss.

[0005] The application provides a voltage conversion circuit, which comprises an auxiliary switching circuit of a Heric topology circuit; the auxiliary switching circuit comprises a first switching unit, a second switching unit, a transformer, a first inductor and a first diode, a first end of the first switching unit is connected to a positive pole of a DC side of the Heric topology circuit, a second end of the first switching unit is connected to a first end of the transformer, a first end of the second switching unit is connected to a second end of the transformer, a second end of the second switching unit is used for connecting a negative pole of the DC side, a positive pole of the first diode is connected to a third end of the transformer, and a fourth end of the transformer is connected to the negative pole of the DC side; a first end of the first inductor is connected to a fifth end of the transformer, and a second end of the first inductor is connected to a midpoint of a freewheeling bridge arm in the Heric topology circuit.

[0006] The first switching unit comprises a first switching tube and a second diode, a first end of the first switching tube is connected to the positive pole of the DC side, a second end of the first switching tube is connected to the first end of the transformer, a positive pole of the second diode is connected to the second end of the first switching tube, and a negative pole of the second diode is connected to the first end of the first switching tube.

[0007] The second switching unit comprises a second switching tube and a third diode, a first end of the second switching tube is connected to the second end of the transformer, a second end of the second switching tube is connected to the negative pole of the DC side, a positive pole of the third diode is connected to the second end of the second switching tube, and a negative pole of the third diode is connected to the first end of the second switching tube.

[0008] The Heric topology circuit comprises a third switch unit, a fourth switch unit, a fifth switch unit, a sixth switch unit, a seventh switch unit, an eighth switch unit, a second inductor and a third inductor, the first end of the third switch unit and the first end of the fifth switch unit are connected to the positive pole of the DC side, the second end of the third switch unit is connected to the first end of the fourth switch unit, the second end of the fourth switch unit is connected to the negative pole of the DC side, the second end of the fifth switch unit is connected to the first end of the sixth switch unit, the second end of the sixth switch unit is connected to the negative pole of the DC side, the first end of the seventh switch unit is connected to the second end of the third switch unit and the first end of the second inductor, the second end of the seventh switch unit is connected to the first end of the eighth switch unit and the second end of the first inductor, the second end of the eighth switch unit is connected to the second end of the fifth switch unit and the first end of the third inductor, the second end of the second inductor is connected to the first end of the AC side of the Heric topology circuit, and the second end of the third inductor is connected to the second end of the AC side.

[0009] The third switch unit comprises a third switch tube and a fourth diode, the first end of the third switch tube is connected to the positive pole of the DC side, the positive pole of the fourth diode is connected to the second end of the third switch tube, and the negative pole of the fourth diode is connected to the first end of the third switch tube.

[0010] The fourth switch unit comprises a fourth switch tube and a fifth diode, the first end of the fourth switch tube is connected to the second end of the third switch tube, the second end of the fourth switch tube is connected to the negative pole of the DC side, the positive pole of the fifth diode is connected to the second end of the fourth switch tube, and the negative pole of the fifth diode is connected to the first end of the fourth switch tube.

[0011] The fifth switch unit comprises a fifth switch tube and a sixth diode, the first end of the fifth switch tube is connected to the positive pole of the DC side, the positive pole of the sixth diode is connected to the second end of the fifth switch tube, and the negative pole of the sixth diode is connected to the first end of the fifth switch tube.

[0012] The sixth switch unit comprises a sixth switch tube and a seventh diode, the first end of the sixth switch tube is connected to the second end of the fifth switch tube, the second end of the sixth switch tube is connected to the negative pole of the DC side, the positive pole of the seventh diode is connected to the second end of the sixth switch tube, and the negative pole of the seventh diode is connected to the first end of the sixth switch tube.

[0013] The seventh switch unit comprises a seventh switch tube and an eighth diode, a first end of the seventh switch tube is connected to a second end of the third switch tube, a positive electrode of the eighth diode is connected to a second end of the seventh switch tube, and a negative electrode of the eighth diode is connected to a first end of the seventh switch tube.

[0014] The eighth switch unit comprises an eighth switch tube and a ninth diode, a first end of the eighth switch tube is connected to a second end of the seventh switch tube, a second end of the eighth switch tube is connected to a second end of the fifth switch tube, a positive electrode of the ninth diode is connected to a second end of the eighth switch tube, and a negative electrode of the ninth diode is connected to a first end of the eighth switch tube.

[0015] The auxiliary switch circuit further comprises a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor and a sixth capacitor, the first capacitor is connected between the first end and the second end of the third switch tube, the second capacitor is connected between the first end and the second end of the fourth switch tube, the third capacitor is connected between the first end and the second end of the fifth switch tube, the fourth capacitor is connected between the first end and the second end of the sixth switch tube, the fifth capacitor is connected between the first end and the second end of the seventh switch tube, and the sixth capacitor is connected between the first end and the second end of the eighth switch tube.

[0016] The third switch tube comprises a first capacitor, the fourth switch tube comprises a second capacitor, the fifth switch tube comprises a third capacitor, the sixth switch tube comprises a fourth capacitor, the seventh switch tube comprises a fifth capacitor, and the eighth switch tube comprises a sixth capacitor, the first capacitor is connected between the first end and the second end of the third switch tube, the second capacitor is connected between the first end and the second end of the fourth switch tube, the third capacitor is connected between the first end and the second end of the fifth switch tube, the fourth capacitor is connected between the first end and the second end of the sixth switch tube, the fifth capacitor is connected between the first end and the second end of the seventh switch tube, and the sixth capacitor is connected between the first end and the second end of the eighth switch tube.

[0017] The Heric topology circuit further comprises a seventh capacitor and an eighth capacitor, one end of the seventh capacitor is connected to a positive electrode of the direct current side, the other end of the seventh capacitor is connected to a negative electrode of the direct current side, one end of the eighth capacitor is connected to the first end of the alternating current side, and the other end of the eighth capacitor is connected to the second end of the alternating current side.

[0018] The voltage conversion circuit further comprises a controller, and the controller is connected with the third end of the first switch tube, the third end of the second switch tube, the third end of the third switch tube, the third end of the fourth switch tube, the third end of the fifth switch tube, the third end of the sixth switch tube, the third end of the seventh switch tube and the third end of the eighth switch tube respectively.

[0019] The application further provides an inverter device comprising the voltage conversion circuit and a shell, and the voltage conversion circuit is accommodated in the shell, and the voltage conversion circuit is used for converting AC voltage / direct current voltage into direct current voltage / AC voltage.

[0020] The application further provides an energy storage device comprising the voltage conversion circuit and a battery, and the voltage conversion circuit is electrically connected with the battery, and the voltage conversion circuit is used for converting direct current on the battery into AC voltage or converting external input AC voltage into direct current into the battery.

[0021] The auxiliary switch circuit of the application comprises a first switch unit, a second switch unit, a transformer, a first inductor and a first diode, the first end of the first switch unit is connected with the positive pole of the direct current side of the Heric topology circuit, the second end of the first switch unit is connected with the first end of the transformer, the first end of the second switch unit is connected with the second end of the transformer, the second end of the second switch unit is used for connecting the negative pole of the direct current side, the positive pole of the first diode is connected with the third end of the transformer, and the fourth end of the transformer is connected with the negative pole of the direct current side; the first end of the first inductor is connected with the fifth end of the transformer, and the second end of the first inductor is connected with the midpoint of the freewheeling bridge arm in the Heric topology circuit. The semiconductor devices in the Heric topology circuit in the prior art all have body diodes, and part of the semiconductor devices realize hard switching, and switching loss occurs. The auxiliary switch circuit of the Heric topology circuit is arranged in the application, the first switch unit or the second switch unit can assist the semiconductor of the Heric topology circuit to realize zero-voltage conduction or zero-current disconnection, so that the semiconductor devices of the Heric topology circuit realize soft switching, and then the loss is reduced and the cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0023] Figure 1 is a circuit schematic diagram of an embodiment of the voltage conversion circuit provided by the application;

[0024] Figure 2 is Figure 1 a timing diagram of an embodiment of the voltage conversion circuit in

[0025] Figure 3 is a frame diagram of an embodiment of the inverter device provided in the present application;

[0026] Figure 4 is a frame diagram of an embodiment of the energy storage device provided in the present application. DETAILED DESCRIPTION

[0027] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0029] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0030] In this document, the term "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean that it refers to the same embodiment, nor is it independent or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0032] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0033] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be connected between them, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0034] Please refer to Figure 1 and Figure 2 , Figure 1 is a circuit schematic diagram of an embodiment of the voltage conversion circuit provided by the present application; Figure 2 is Figure 1 a timing diagram of an embodiment of the voltage conversion circuit in. The voltage conversion circuit 1 of the embodiment is used to realize bidirectional conversion of direct current voltage and alternating current voltage, and the voltage conversion circuit 1 can also be called a bidirectional DC-AC converter, which has a rectification mode and an inversion mode.

[0035] The voltage conversion circuit 1 includes a Heric topology circuit 11 and an auxiliary switch circuit 12 of the Heric topology circuit 11, and the auxiliary switch circuit 12 includes a first switch unit 121, a second switch unit 122, a transformer T, a first inductor L1 and a first diode D1.

[0036] In some embodiments, the direct current side of the Heric topology circuit 11 can be connected with a direct current power supply, and the alternating current side of the Heric topology circuit 11 can be connected with an alternating current power supply. Among them, the direct current side of the Heric topology circuit 11 serves as the direct current side of the voltage conversion circuit 1, and the alternating current side of the Heric topology circuit 11 serves as the alternating current side of the voltage conversion circuit 1.

[0037] The first end of the first switch unit 121 is connected to the positive pole DC+ of the direct current side of the Heric topology circuit 11, the second end of the first switch unit 121 is connected to the first end of the transformer T, the first end of the second switch unit 122 is connected to the second end of the transformer T, and the second end of the second switch unit 122 is connected to the negative pole DC- of the direct current side.

[0038] The positive pole of the first diode D1 is connected to the third end of the transformer T, the fourth end of the transformer T is connected to the negative pole DC- of the direct current side; the first end of the first inductor L1 is connected to the fifth end of the transformer T, and the second end of the first inductor L1 is connected to the midpoint of the freewheeling bridge arm in the Heric topology circuit 11.

[0039] The first end, the second end and the fifth end of the transformer T are three ends of the secondary winding of the transformer T, and the fifth end of the transformer T is located between the first end and the second end of the transformer T; the third end and the fourth end of the transformer T are two ends of the primary winding of the transformer T.

[0040] The first end of the first switch unit 121 is connected to the positive pole DC+ of the direct current side of the Heric topology circuit 11, the second end of the first switch unit 121 is connected to the first end of the transformer T, the first end of the second switch unit 122 is connected to the second end of the transformer T, and the second end of the second switch unit 122 is connected to the negative pole DC- of the direct current side; the positive pole of the first diode D1 is connected to the third end of the transformer T, the fourth end of the transformer T is connected to the negative pole DC- of the direct current side; the first end of the first inductor L1 is connected to the fifth end of the transformer T, and the second end of the first inductor L1 is connected to the midpoint of the freewheeling bridge arm in the Heric topology circuit 11. The semiconductor devices in the Heric topology circuit in the prior art all have body diodes, and part of the semiconductor devices realize hard switching, and switching loss occurs. According to the application, the auxiliary switch circuit 12 of the Heric topology circuit 11 is arranged, and the first switch unit 121 or the second switch unit 122 can assist the semiconductor of the Heric topology circuit to realize zero-voltage conduction or zero-current disconnection, so that the semiconductor devices of the Heric topology circuit 11 realize soft switching, thereby reducing loss and cost.

[0041] According to some embodiments of the application, the first switch unit 121 of the embodiment includes a first switch tube Q1 and a second diode D2, the first end of the first switch tube Q1 is connected to the positive pole DC+ of the direct current side, the second end of the first switch tube Q1 is connected to the first end of the transformer T, the positive pole of the second diode D2 is connected to the second end of the first switch tube Q1, and the negative pole of the second diode D2 is connected to the first end of the first switch tube Q1.

[0042] The second switch unit 122 comprises a second switch tube Q2 and a third diode D3, a first end of the second switch tube Q2 is connected to a second end of the transformer T, a second end of the second switch tube Q2 is connected to a negative pole DC- of the DC side, a positive pole of the third diode D3 is connected to the second end of the second switch tube Q2, and a negative pole of the third diode D3 is connected to the first end of the second switch tube Q2.

[0043] In some embodiments, the second diode D2 is a body diode of the first switch tube Q1, and the third diode D3 is a body diode of the second switch tube Q2. For example, the first switch tube Q1 and the second switch tube Q2 can both be MOS transistors with body diodes.

[0044] In some embodiments, the first switch tube Q1 and the second switch tube Q2 can both be IGBTs with anti-parallel diodes, or other controllable switch tubes with anti-parallel diodes. It can be understood that the implementation forms of the various switch tubes of the present application can not necessarily be the same, and can form various mixed combinations.

[0045] According to some embodiments of the present application, the Heric topology circuit 11 of the present embodiment comprises a third switch unit 111, a fourth switch unit 112, a fifth switch unit 113, a sixth switch unit 114, a seventh switch unit 115, an eighth switch unit 116, a second inductor L2, and a third inductor L3.

[0046] The first end of the third switch unit 111 and the first end of the fifth switch unit 113 are respectively connected to a positive pole DC+ of the DC side, the second end of the third switch unit 111 and the first end of the fourth switch unit 112 are connected, the second end of the fourth switch unit 112 is connected to a negative pole DC- of the DC side; the second end of the fifth switch unit 113 is connected to the first end of the sixth switch unit 114, and the second end of the sixth switch unit 114 is connected to the negative pole DC- of the DC side.

[0047] The first end of the seventh switch unit 115 is connected to the second end of the third switch unit 111 and the first end of the second inductor L2, the second end of the seventh switch unit 115 is connected to the first end of the eighth switch unit 113 and the second end of the first inductor L1, the second end of the eighth switch unit 116 is connected to the second end of the fifth switch unit 113 and the first end of the third inductor L3, the second end of the second inductor L2 is connected to a first end L of the AC side of the Heric topology circuit 11, and the second end of the third inductor L3 is connected to a second end N of the AC side.

[0048] The third switch unit 111 and the fourth switch unit 112 are the first inverter bridge arm of the Heric topology circuit 11, the fifth switch unit 113 and the sixth switch unit 114 are the second inverter bridge arm of the Heric topology circuit 11, the seventh switch unit 115 and the eighth switch unit 116 are the middle freewheeling bridge arm of the Heric topology circuit 11, and the connection point of the second end of the seventh switch unit 115 and the first end of the eighth switch unit 116 is the middle point of the middle freewheeling bridge arm.

[0049] In some embodiments, the third switch unit 111 includes a third switch tube Q3 and a fourth diode D4, the first end of the third switch tube Q3 is connected to the positive pole DC+ of the direct current side, the positive pole of the fourth diode D4 is connected to the second end of the third switch tube Q3, and the negative pole of the fourth diode D4 is connected to the first end of the third switch tube Q3.

[0050] The fourth switch unit 112 includes a fourth switch tube Q4 and a fifth diode D5, the first end of the fourth switch tube Q4 is connected to the second end of the third switch tube Q3, the second end of the fourth switch tube Q4 is connected to the negative pole DC- of the direct current side, the positive pole of the fifth diode D5 is connected to the second end of the fourth switch tube Q4, and the negative pole of the fifth diode D5 is connected to the first end of the fourth switch tube Q4.

[0051] The fifth switch unit 113 includes a fifth switch tube Q5 and a sixth diode D6, the first end of the fifth switch tube Q5 is connected to the positive pole DC+ of the direct current side, the positive pole of the sixth diode D6 is connected to the second end of the fifth switch tube Q5, and the negative pole of the sixth diode D6 is connected to the first end of the fifth switch tube Q5.

[0052] The sixth switch unit 114 includes a sixth switch tube Q6 and a seventh diode D7, the first end of the sixth switch tube Q6 is connected to the second end of the fifth switch tube Q5, the second end of the sixth switch tube Q6 is connected to the negative pole DC- of the direct current side, the positive pole of the seventh diode D7 is connected to the second end of the sixth switch tube Q6, and the negative pole of the seventh diode D7 is connected to the first end of the sixth switch tube Q6.

[0053] The seventh switch unit 115 includes a seventh switch tube Q7 and an eighth diode D8, the first end of the seventh switch tube Q7 is connected to the second end of the third switch tube Q3, the positive pole of the eighth diode D8 is connected to the second end of the seventh switch tube Q7, and the negative pole of the eighth diode D8 is connected to the first end of the seventh switch tube Q7.

[0054] The eighth switch unit 116 includes an eighth switch tube Q8 and a ninth diode D9, the first end of the eighth switch tube Q8 is connected to the second end of the seventh switch tube Q7, the second end of the eighth switch tube Q8 is connected to the second end of the fifth switch tube Q5, the positive pole of the ninth diode D9 is connected to the second end of the eighth switch tube Q8, and the negative pole of the ninth diode D9 is connected to the first end of the eighth switch tube Q8.

[0055] In some embodiments, the auxiliary switching circuit 12 further comprises a first capacitor C1 connected between the first terminal and the second terminal of the third switch Q3, a second capacitor C2 connected between the first terminal and the second terminal of the fourth switch Q4, a third capacitor C3 connected between the first terminal and the second terminal of the fifth switch Q5, a fourth capacitor C4 connected between the first terminal and the second terminal of the sixth switch Q6, a fifth capacitor C5 connected between the first terminal and the second terminal of the seventh switch Q7, and a sixth capacitor C6 connected between the first terminal and the second terminal of the eighth switch Q8.

[0056] According to some embodiments of the present application, the third switch Q3 comprises the first capacitor C1, the fourth switch Q4 comprises the second capacitor C2, the fifth switch Q5 comprises the third capacitor C3, the sixth switch Q6 comprises the fourth capacitor C4, the seventh switch Q7 comprises the fifth capacitor C5, and the eighth switch Q8 comprises the sixth capacitor C6.

[0057] The first capacitor C1 is connected between the first terminal and the second terminal of the third switch Q3, the second capacitor C2 is connected between the first terminal and the second terminal of the fourth switch Q4, the third capacitor C3 is connected between the first terminal and the second terminal of the fifth switch Q5, the fourth capacitor C4 is connected between the first terminal and the second terminal of the sixth switch Q6, the fifth capacitor C5 is connected between the first terminal and the second terminal of the seventh switch Q7, and the sixth capacitor C6 is connected between the first terminal and the second terminal of the eighth switch Q8.

[0058] In some embodiments, the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, and the sixth capacitor C6 can all be the parasitic capacitances of the corresponding controllable switches.

[0059] In some embodiments, the fourth diode D4 is the body diode of the third switch Q3, the fifth diode D5 is the body diode of the fourth switch Q4, the sixth diode D6 is the body diode of the fifth switch Q5, the seventh diode D7 is the body diode of the sixth switch Q6, the eighth diode D8 is the body diode of the seventh switch Q7, and the ninth diode D9 is the body diode of the eighth switch Q8. For example, the third switch Q3, the fourth switch Q4, the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, and the eighth switch Q8 can all be MOS transistors with body diodes.

[0060] In some embodiments, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, the sixth switch tube Q6, the seventh switch tube Q7 and the eighth switch tube Q8 can all be IGBTs with anti-parallel diodes, or other controllable switch tubes with anti-parallel diodes.

[0061] The third switch tube Q3 of the present embodiment includes a first capacitor C1, the fourth switch tube Q4 includes a second capacitor C2, the fifth switch tube Q5 includes a third capacitor C3, the sixth switch tube Q6 includes a fourth capacitor C4, the seventh switch tube Q7 includes a fifth capacitor C5, and the eighth switch tube Q8 includes a sixth capacitor C6, i.e., the first capacitor C1, the second capacitor C2, the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5 and the sixth capacitor C6 can all be parasitic capacitors of the corresponding controllable switch tubes, without the need for additional first capacitor C1, second capacitor C2, third capacitor C3, fourth capacitor C4, fifth capacitor C5 and sixth capacitor C6, thereby reducing costs, simplifying the circuit and facilitating implementation. In addition, the fourth diode D4 is the body diode of the third switch tube Q3, the fifth diode D5 is the body diode of the fourth switch tube Q4, the sixth diode D6 is the body diode of the fifth switch tube Q5, the seventh diode D7 is the body diode of the sixth switch tube Q6, the eighth diode D8 is the body diode of the seventh switch tube Q7, and the ninth diode D9 is the body diode of the eighth switch tube Q8, without the need for additional fourth diode D4, fifth diode D5, sixth diode D6, seventh diode D7, eighth diode D8 and ninth diode D9, thereby further reducing costs.

[0062] According to some embodiments of the present application, the Heric topology circuit 11 of the present embodiment further includes a seventh capacitor C7 and an eighth capacitor C8, one end of the seventh capacitor C7 being connected to the positive pole DC+ of the DC side, the other end of the seventh capacitor C7 being connected to the negative pole DC- of the DC side, one end of the eighth capacitor C8 being connected to the first end L of the AC side, and the other end of the eighth capacitor C8 being connected to the second end N of the AC side.

[0063] In some embodiments, the voltage conversion circuit 1 further includes a controller 13, the controller 13 being connected to the third end of the first switch tube Q1, the third end of the second switch tube Q2, the third end of the third switch tube Q3, the third end of the fourth switch tube Q4, the third end of the fifth switch tube Q5, the third end of the sixth switch tube Q6, the third end of the seventh switch tube Q7 and the third end of the eighth switch tube Q8, respectively, and the controller 13 being configured to control the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, the sixth switch tube Q6, the seventh switch tube Q7 and the eighth switch tube Q8.

[0064] The working principle of the voltage conversion circuit 1 is described as follows:

[0065] The controller 100 is used to control the third switch Q3 and the sixth switch Q6 to be turned on, control the fourth switch Q4 and the fifth switch Q5 to be turned off, and control the seventh switch Q7 to be turned on and the eighth switch Q8 to be turned off. In other embodiments, the controller 100 is used to control the third switch Q3 and the sixth switch Q6 to be turned off, control the fourth switch Q4 and the fifth switch Q5 to be turned on, control the eighth switch Q7 to be turned on, and control the eighth switch Q8 to be turned off.

[0066] When the controller 100 controls the seventh switch Q7 to turn on, the voltage at the first and second terminals of the eighth switch Q8 drops, so that the ninth diode D9 turns on, achieving zero-voltage conduction, thereby reducing losses and lowering costs.

[0067] In some embodiments, the voltage conversion circuit 1 of this embodiment is in inverter mode, which includes a positive half-cycle and a negative half-cycle. In this embodiment, the voltage conversion circuit 1 is in the positive half-cycle of inverter mode, that is, the positive terminal DC+ and the negative terminal DC- on the DC side of the voltage conversion circuit 1 flow to the first terminal L and the second terminal N on the AC side. The control process of the controller 13 in the negative half-cycle of inverter mode is the same as that in the positive half-cycle of inverter mode, and will not be described again here.

[0068] The controller 13 is used to control the third switch Q3 and the sixth switch Q6 to be turned on, control the fourth switch Q4 and the fifth switch Q5 to be kept off, and control the seventh switch Q7 to be turned on, so that the voltage conversion circuit 1 is in the positive half-cycle of the inverter mode.

[0069] like Figures 1-2 As shown, at time t0, controller 13 controls the drive signal of the third switch Q3 to switch from a first level to a second level. The first level is high, and the second level is low; that is, the drive signal of the third switch Q3 switches from high to low, so that the drive of the third switch Q3 is set low. Since the first capacitor C1 is connected in parallel between the first and second terminals of the third switch Q3, the voltage across the first capacitor C1 will not instantaneously become zero. During the process of controller 13 controlling the third switch Q3 to turn off, the current flowing through the third switch Q3 gradually commutates to the first capacitor C1 (the direction of the current flowing through the third switch Q3 is from the first terminal to the second terminal), and thus the current in the first capacitor C1 gradually increases, so that the third switch Q3 achieves zero-voltage disconnection.

[0070] After the third switch Q3 is turned off, the current in the first capacitor C1 gradually decreases, and the voltage between the first and second terminals of the third switch Q3 gradually increases. At this time, the voltage between the first and second terminals of the eighth switch Q8 decreases, and the ninth diode D9 turns on.

[0071] The third switch tube Q3 of the embodiment can realize zero-voltage turn-off, thereby reducing the loss of the third switch tube Q3, reducing the cost, and improving the working frequency of the third switch tube Q3.

[0072] In some embodiments, the controller 13 is configured to switch the driving signal of the sixth switch tube Q6 from the first level to the second level, and switch the driving signal of the eighth switch tube Q8 from the second level to the first level, and the ninth diode D9 is turned on, so that the eighth switch tube Q8 realizes zero-voltage turn-on, and the sixth switch tube Q6 realizes zero-current turn-off.

[0073] In the time interval from time t1 to time t2, at time t1, the controller 13 is configured to switch the driving signal of the sixth switch tube Q6 from the first level to the second level, i.e., the driving of the sixth switch tube Q6 is low. At the same time, the controller 13 is configured to switch the driving signal of the eighth switch tube Q8 from the second level to the first level, i.e., the driving of the eighth switch tube Q8 is high.

[0074] Since the ninth diode D9 is turned on in the time interval from time t0 to time t1, the eighth switch tube Q8 realizes zero-voltage turn-on, and the sixth switch tube Q6 realizes zero-current turn-off. After the eighth switch tube Q8 is turned on, the voltage of the first end L and the second end N of the alternating current side is applied to the second inductor L2 and the third inductor L3, at which time the current of the second inductor L2 and the current of the third inductor L3 gradually decrease, the current of the second inductor L2 and the current of the third inductor L3 realize current continuation through the eighth switch tube Q8, and provide current to the first end L and the second end N of the alternating current side through the eighth capacitor C8.

[0075] The eighth switch tube Q8 of the embodiment realizes zero-voltage turn-on, and the sixth switch tube Q6 realizes zero-current turn-off, thereby reducing the loss of the eighth switch tube Q8 and the sixth switch tube Q6, reducing the cost, and improving the working frequency of the eighth switch tube Q8 and the sixth switch tube Q6.

[0076] In some embodiments, the controller 13 is configured to switch the driving signal of the eighth switch tube Q8 from the first level to the second level, and switch the driving signal of the sixth switch tube Q6 from the second level to the first level, so that the sixth switch tube Q6 realizes zero-current turn-on, and the eighth switch tube Q8 realizes zero-voltage turn-off.

[0077] In the time interval from time t2 to time t3, the controller 13 is configured to switch the driving signal of the eighth switch tube Q8 from the first level to the second level, i.e., the driving of the eighth switch tube Q8 is low, and the current of the eighth switch tube Q8 is switched to the ninth diode D9, so that the eighth switch tube Q8 realizes zero-voltage switching off. The controller 13 is configured to switch the driving signal of the sixth switch tube Q6 from the second level to the first level, i.e., the driving of the sixth switch tube Q6 is high, and at this time, the sixth switch tube Q6 has no current flowing through, so that the sixth switch tube Q6 realizes zero-current switching on.

[0078] In some embodiments, the controller 13 is configured to switch the driving signal of the first switch tube Q1 from the second level to the first level, so that the first switch tube Q1 realizes zero-current switching on.

[0079] The controller 13 is configured to switch the driving signal of the first switch tube Q1 from the second level to the first level, i.e., the driving of the first switch tube Q1 is high, and because the current of the first inductor L1 cannot be abrupt, the current of the first switch tube Q1 remains zero during the conduction of the first switch tube Q1, so that the first switch tube Q1 realizes zero-current switching on.

[0080] The controller 13 of the present embodiment is configured to increase the current of the first inductor L1 after the first switch tube Q1 is turned on, and under the coupling action of the transformer T, the first diode D1 is turned on, and the voltage of the third and fourth terminals of the transformer T is equal to the direct current voltage between the positive DC+ and the negative DC- of the direct current side.

[0081] After the first switch tube Q1 is turned on, the voltage of the first switch tube Q1 is superimposed with the voltage of the first inductor L1, and then the current of the first inductor L1 is increased. Under the coupling action of the transformer T, the first diode D1 is turned on, and the voltage of the third and fourth terminals of the transformer T is clamped to the voltage of the positive DC+ of the direct current side, i.e., the voltage of the third and fourth terminals of the transformer T is equal to the direct current voltage between the positive DC+ and the negative DC- of the direct current side. For example, the transformation ratio of the transformer T is n:n:1, and the voltage between the first and second terminals of the secondary winding of the transformer T is n*VDC, and at this time, the voltage across the first inductor L1 is (1-n)*VDC, so that the current of the first inductor L1 is rapidly increased.

[0082] The first switch tube Q1 realizes zero-current switching on, the sixth switch tube Q6 realizes zero-current switching on, and the eighth switch tube Q8 realizes zero-voltage switching off, thereby reducing the loss of the eighth switch tube Q8, the first switch tube Q1 and the sixth switch tube Q6, reducing the cost, and improving the working frequency of the eighth switch tube Q8, the sixth switch tube Q6 and the first switch tube Q1.

[0083] In some embodiments, the controller 13 is configured to control the current of the ninth diode D9 of the eighth switch Q8 to be zero when the current of the first inductor L1 is equal to the sum of the current of the second inductor L2 and the current of the third inductor L3, so that the eighth switch Q8 achieves zero-current turn-off.

[0084] In the time interval from time t3 to time t4, the current flowing through the first inductor L1 increases until the current of the first inductor L1 is equal to the sum of the current of the second inductor L2 and the current of the third inductor L3, and the current of the ninth diode D9 of the eighth switch Q8 is zero, so that the eighth switch Q8 achieves zero-current turn-off.

[0085] The controller 13 of the present embodiment is configured to discharge the first capacitor C1 through the first inductor L1 and charge the second capacitor C2 when the current of the first inductor L1 is greater than the sum of the current of the second inductor L2 and the current of the third inductor L3.

[0086] The current flowing through the first inductor L1 increases, and since the inductance of the second inductor L2 and the inductance of the third inductor L2 are greater than the inductance of the first inductor L1, it can be considered that the current of the second inductor L2 and the current of the third inductor L3 remain unchanged. The current of the first inductor L1 is supplied to the second inductor L2 and the third inductor L3, the first inductor L1 discharges the first capacitor C1 and charges the second capacitor C2, so that the voltage at the first end and the second end of the fourth switch Q4 gradually increases, and the voltage at the first end and the second end of the third switch Q3 gradually decreases until the diode of the third switch Q3 is turned on.

[0087] In some embodiments, the controller 13 is configured to control the fourth diode D4 to be turned on and switch the drive signal of the third switch Q3 from the second level to the first level, so that the third switch Q3 achieves zero-voltage turn-on.

[0088] In the time interval from time t4 to time t5, since the fourth diode D4 is turned on in the time interval from time t3 to time t4, at time t4, the controller 13 is configured to control the drive signal of the third switch Q3 to switch from the second level to the first level, i.e. the drive of the third switch Q3 is high, so that the third switch Q3 achieves zero-voltage turn-on.

[0089] The controller 13 of the present embodiment is configured to control the current of the first inductor L1 to decrease to zero and the current of the first diode D1 to decrease to zero, so that the first diode D1 achieves zero-current turn-off.

[0090] The node potential between the third switch tube Q3 and the fourth switch tube Q4 is clamped to the voltage of the positive pole DC+ of the direct current side, the voltage across the first inductor L1 is n*VDC, the direction of the voltage across the first inductor L1 is opposite to the direction of the current increase of the first inductor L1, so that the current of the first inductor L1 rapidly decreases to zero, and the current of the first diode D1 decreases to zero, so that the first diode D1 realizes zero-current turn-off. At this time, the voltage of the primary winding of the transformer T is no longer clamped, the voltage of the secondary winding of the transformer T is zero, and the current of the first inductor L1 decreases to zero. Since the voltage across the first inductor L1 continues to be zero, the current of the first inductor L1 continues to be zero.

[0091] The third switch tube Q3 of the embodiment realizes zero-voltage turn-on, and the first diode D1 realizes zero-current turn-off, thereby reducing the loss of the third switch tube Q3 and the first diode D1, reducing the cost, and improving the working frequency of the third switch tube Q3 and the first diode D1.

[0092] In some embodiments, the controller 13 is configured to switch the driving signal of the first switch tube Q1 from the first level to the second level when the current of the first switch tube Q1 is zero, so that the first switch tube Q1 realizes zero-current turn-off.

[0093] In the interval from time t5 to time t6, the current of the first switch tube Q1 is zero, and the controller 13 is configured to switch the driving signal of the first switch tube Q1 from the first level to the second level at time t5, so that the driving of the first switch tube Q1 is low, and the first switch tube Q1 realizes zero-current turn-off.

[0094] The controller 13 of the embodiment is configured to control the eighth capacitor C8 to filter the current of the second inductor L2 and the current of the third inductor L3 when the current of the second inductor L2 and the current of the third inductor L3 increase.

[0095] In the interval from time t5 to time t6, the current of the second inductor L2 and the current of the third inductor L3 continue to increase, and the current of the second inductor L2 and the current of the third inductor L3 flow through the eighth capacitor C8 to output to the first end L and the second end N of the alternating current side.

[0096] The first switch tube Q1 of the embodiment realizes zero-current turn-off, thereby reducing the loss of the first switch tube Q1, reducing the cost, and improving the working frequency of the first switch tube Q1.

[0097] The application also provides an inverter device, such as Figure 3As shown, the power supply device 2 includes the voltage conversion circuit 1 disclosed in the above embodiments and a housing 21, the voltage conversion circuit 1 is accommodated in the housing 21, and the voltage conversion circuit 1 is used to convert an alternating voltage or a direct voltage into a direct voltage or an alternating voltage. For example, the voltage conversion circuit 1 is used to convert an alternating voltage into a direct voltage, or the voltage conversion circuit 1 is used to convert a direct voltage into an alternating voltage.

[0098] The application also provides an energy storage device, such as Figure 4 As shown, the energy storage device 3 includes the voltage conversion circuit 1 disclosed in the above embodiments and a battery 31, the voltage conversion circuit 1 is electrically connected with the battery 31, and the voltage conversion circuit 1 is used to convert a direct current on the battery 31 into an alternating current, or the voltage conversion circuit 1 is used to convert an external input alternating current into a direct current and place it in the battery 31.

[0099] The above is only the embodiment of the application, and does not limit the patent scope of the application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A voltage conversion circuit, characterized in that, The voltage conversion circuit includes an auxiliary switching circuit for the Heric topology circuit. The auxiliary switching circuit includes a first switching unit, a second switching unit, a transformer, a first inductor, and a first diode. The first terminal of the first switching unit is connected to the positive terminal of the DC side of the Heric topology circuit. The second terminal of the first switching unit is connected to the first terminal of the transformer. The first terminal of the second switching unit is connected to the second terminal of the transformer. The second terminal of the second switching unit is used to connect to the negative terminal of the DC side. The positive terminal of the first diode is connected to the third terminal of the transformer. The fourth terminal of the transformer is connected to the negative terminal of the DC side. The first terminal of the first inductor is connected to the fifth terminal of the transformer. The second terminal of the first inductor is connected to the midpoint of the freewheeling arm in the Heric topology circuit.

2. The voltage conversion circuit according to claim 1, characterized in that, The first switching unit includes a first switching transistor and a second diode. The first end of the first switching transistor is connected to the positive terminal of the DC side, and the second end of the first switching transistor is connected to the first terminal of the transformer. The positive terminal of the second diode is connected to the second terminal of the first switching transistor, and the negative terminal of the second diode is connected to the first terminal of the first switching transistor. The second switching unit includes a second switching transistor and a third diode. The first end of the second switching transistor is connected to the second end of the transformer, and the second end of the second switching transistor is connected to the negative terminal of the DC side. The positive terminal of the third diode is connected to the second end of the second switching transistor, and the negative terminal of the third diode is connected to the first end of the second switching transistor.

3. The voltage conversion circuit according to claim 2, characterized in that, The Heric topology circuit includes a third switch unit, a fourth switch unit, a fifth switch unit, a sixth switch unit, a seventh switch unit, an eighth switch unit, a second inductor, and a third inductor. The first terminals of the third switch unit and the fifth switch unit are respectively connected to the positive terminal of the DC side. The second terminal of the third switch unit is connected to the first terminal of the fourth switch unit, and the second terminal of the fourth switch unit is connected to the negative terminal of the DC side. The second terminal of the fifth switch unit is connected to the first terminal of the sixth switch unit, and the second terminal of the sixth switch unit is connected to the negative terminal of the DC side. The first terminal of the seventh switch unit is connected to the second terminal of the third switch unit and the first terminal of the second inductor. The second terminal of the seventh switch unit is connected to the first terminal of the eighth switch unit and the second terminal of the first inductor. The second terminal of the eighth switch unit is connected to the second terminal of the fifth switch unit and the first terminal of the third inductor. The second terminal of the second inductor is connected to the first terminal of the AC side of the Heric topology circuit, and the second terminal of the third inductor is connected to the second terminal of the AC side.

4. The voltage conversion circuit according to claim 3, characterized in that, The third switching unit includes a third switching transistor and a fourth diode. The first terminal of the third switching transistor is connected to the positive terminal of the DC side, the positive terminal of the fourth diode is connected to the second terminal of the third switching transistor, and the negative terminal of the fourth diode is connected to the first terminal of the third switching transistor. The fourth switching unit includes a fourth switching transistor and a fifth diode. The first end of the fourth switching transistor is connected to the second end of the third switching transistor, and the second end of the fourth switching transistor is connected to the negative terminal of the DC side. The positive terminal of the fifth diode is connected to the second end of the fourth switching transistor, and the negative terminal of the fifth diode is connected to the first end of the fourth switching transistor. The fifth switching unit includes a fifth switching transistor and a sixth diode. The first terminal of the fifth switching transistor is connected to the positive terminal of the DC side, the positive terminal of the sixth diode is connected to the second terminal of the fifth switching transistor, and the negative terminal of the sixth diode is connected to the first terminal of the fifth switching transistor. The sixth switching unit includes a sixth switching transistor and a seventh diode. The first end of the sixth switching transistor is connected to the second end of the fifth switching transistor, and the second end of the sixth switching transistor is connected to the negative terminal of the DC side. The positive terminal of the seventh diode is connected to the second end of the sixth switching transistor, and the negative terminal of the seventh diode is connected to the first end of the sixth switching transistor. The seventh switching unit includes a seventh switching transistor and an eighth diode. The first terminal of the seventh switching transistor is connected to the second terminal of the third switching transistor. The anode of the eighth diode is connected to the second terminal of the seventh switching transistor, and the cathode of the eighth diode is connected to the first terminal of the seventh switching transistor. The eighth switching unit includes an eighth switching transistor and a ninth diode. The first end of the eighth switching transistor is connected to the second end of the seventh switching transistor, the second end of the eighth switching transistor is connected to the second end of the fifth switching transistor, the anode of the ninth diode is connected to the second end of the eighth switching transistor, and the cathode of the ninth diode is connected to the first end of the eighth switching transistor.

5. The voltage conversion circuit according to claim 4, characterized in that, The auxiliary switching circuit further includes a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, and a sixth capacitor. The first capacitor is connected between the first and second terminals of the third switching transistor, the second capacitor is connected between the first and second terminals of the fourth switching transistor, the third capacitor is connected between the first and second terminals of the fifth switching transistor, the fourth capacitor is connected between the first and second terminals of the sixth switching transistor, the fifth capacitor is connected between the first and second terminals of the seventh switching transistor, and the sixth capacitor is connected between the first and second terminals of the eighth switching transistor.

6. The voltage conversion circuit according to claim 4, characterized in that, The third switch includes a first capacitor, the fourth switch includes a second capacitor, the fifth switch includes a third capacitor, the sixth switch includes a fourth capacitor, the seventh switch includes a fifth capacitor, and the eighth switch includes a sixth capacitor. The first capacitor is connected between the first and second terminals of the third switch, the second capacitor is connected between the first and second terminals of the fourth switch, the third capacitor is connected between the first and second terminals of the fifth switch, the fourth capacitor is connected between the first and second terminals of the sixth switch, the fifth capacitor is connected between the first and second terminals of the seventh switch, and the sixth capacitor is connected between the first and second terminals of the eighth switch.

7. The voltage conversion circuit according to claim 3, characterized in that, The Heric topology circuit also includes a seventh capacitor and an eighth capacitor. One end of the seventh capacitor is connected to the positive terminal of the DC side, and the other end of the seventh capacitor is connected to the negative terminal of the DC side. One end of the eighth capacitor is connected to the first terminal of the AC side, and the other end of the eighth capacitor is connected to the second terminal of the AC side.

8. The voltage conversion circuit according to any one of claims 1-7, characterized in that, The voltage conversion circuit also includes a controller, which is connected to the third terminal of the first switch, the third terminal of the second switch, the third terminal of the third switch, the third terminal of the fourth switch, the third terminal of the fifth switch, the third terminal of the sixth switch, the third terminal of the seventh switch, and the third terminal of the eighth switch.

9. An inverter device, characterized in that, Includes a voltage conversion circuit as described in any one of claims 1-8 and a housing; the voltage conversion circuit is housed within the housing, and the voltage conversion circuit is used to convert AC voltage or DC voltage into DC voltage or AC voltage.

10. An energy storage device, characterized in that, The device includes a voltage conversion circuit as described in any one of claims 1-8 and a battery, wherein the voltage conversion circuit is electrically connected to the battery, and the voltage conversion circuit is used to convert the direct current on the battery into alternating current, or to convert externally input alternating current into direct current and supply it to the battery.

Images