Interleaved Converter

Abstract

Embodiments of the present disclosure relate to a voltage converter circuit including a first branch and a second branch. The first branch is coupled between a first DC terminal and a second DC terminal and includes a first winding and a second winding around a magnetic core. The first winding and the second winding are coupled to an AC terminal via a common node. The second branch is coupled in parallel with the first branch between the first DC terminal and the second DC terminal and includes a third winding around the magnetic core. The third winding is coupled to the AC terminal so that the first branch and the second branch are configured to convert a first voltage into a second voltage. The first winding, the second winding, and the third winding are configured to enhance each other: a magnetic flux generated by a differential mode (DM) component of a first current in the first branch, and a magnetic flux generated by a DM component of a second current in the second branch.

Description

Technical Field

[0001] Example embodiments of the present disclosure relate generally to electrical devices, and more particularly to voltage converter circuits and devices including the same. Background Art

[0002] Interleaving is a promising and proven technology for realizing low-cost and high-efficiency power converters. Interleaved converters of various topologies have been applied in electric vehicle (EV) chargers, uninterruptible power systems (UPS), solar or wind energy converters.

[0003] For example, in the power module of an EV charger, the first stage is the power factor correction (PFC), which converts the alternating current (AC) voltage from the AC grid into a stable direct current (DC) bus voltage for feeding the subsequent DC-DC converter. Among various interleaved converters, the interleaved Vienna topology and its variants are widely used.

[0004] US Patent No. 8,395,913 B2 describes this approach in the Vienna topology. However, this type of topology usually requires additional components such as autotransformers to be provided outside the interleaved branches, so its application may be limited. Summary of the invention

[0005] Example embodiments of the present disclosure propose a solution for an interleaved voltage converter.

[0006] In a first aspect, a voltage converter circuit comprising a first branch and a second branch is provided. The first branch is coupled between a first DC terminal and a second DC terminal and comprises a first winding and a second winding around a magnetic core. The first winding and the second winding are coupled to an AC terminal via a common node. The second branch is coupled between the first DC terminal and the second DC terminal in parallel with the first branch and comprises a third winding around the magnetic core. The third winding is coupled to the AC terminal so that the first branch and the second branch are configured to convert a first voltage into a second voltage. The first winding, the second winding, and the third winding are configured to enhance each other: a magnetic flux generated by a differential mode (DM) component of a first current in the first branch, and a magnetic flux generated by a DM component of a second current in the second branch.

[0007] In a second aspect, an electrical system is provided. The electrical system comprises the voltage converter circuit of the first aspect and a control center. The control center is configured to receive a voltage conversion request; and based on the request, control the voltage converter circuit to provide a conversion voltage.

[0008] In a third aspect, a method for manufacturing a voltage converter circuit is provided. The method includes providing a first branch, the first branch is coupled between a DC terminal and a second DC terminal and includes a first winding and a second winding around a magnetic core. The first winding and the second winding are coupled to an AC terminal via a common node. The method also includes a second branch, the second branch is coupled in parallel with the first branch between the first DC terminal and the second DC terminal and includes a third winding around the magnetic core. The third winding is coupled to the AC terminal so that the first branch and the second branch are configured to convert a first voltage into a second voltage. The method also includes configuring the first winding, the second winding, and the third winding so that the following items enhance each other: a magnetic flux generated by a DM component of a first current in the first branch, and a magnetic flux generated by a DM component of a second current in the second branch.

[0009] According to the embodiments of the present disclosure, the converter according to the embodiments of the present disclosure can achieve a desired efficiency based on the proposed topology. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and other purposes, features and advantages of the exemplary embodiments disclosed herein will become more apparent through the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, several exemplary embodiments disclosed herein will be shown in an exemplary and non-limiting manner, in which:

[0011] Figure 1 An AC-DC electrical system according to some example embodiments of the present disclosure is shown;

[0012] Figure 2 shows examples of converters according to some example embodiments of the present disclosure;

[0013] Figure 3 Some example embodiments of the present disclosure are shown. Figure 2 An example of a phase circuit of a converter;

[0014] Figure 4 Some example embodiments of the present disclosure are shown. Figure 3 Example of common mode component of current in a phase circuit;

[0015] Figure 5 An example of a winding around a magnetic core according to some example embodiments of the present disclosure is shown. Figure 4 The flux corresponding to the common-mode component of the current;

[0016] Figure 6 Some example embodiments of the present disclosure are shown. Figure 3 Another example of a common mode component of current in a phase circuit of;

[0017] Figure 7An example of a winding around a magnetic core according to some example embodiments of the present disclosure is shown. Figure 6 The flux corresponding to the common-mode component of the current;

[0018] Figure 8 Some example embodiments of the present disclosure are shown. Figure 3 Example of differential mode component of current in a phase circuit;

[0019] Fig. 9 An example of a winding around a magnetic core according to some example embodiments of the present disclosure is shown. Figure 8 The flux corresponding to the common-mode component of the current;

[0020] Fig.10 Some example embodiments of the present disclosure are shown. Figure 3 Another example of a differential mode component of a current in a phase circuit of;

[0021] Fig.11 An example of a winding around a magnetic core according to some example embodiments of the present disclosure is shown. Fig.10 The flux corresponding to the common-mode component of the current;

[0022] Fig.12 Some example embodiments of the present disclosure are shown. Figure 2 Another example of a phase circuit of a converter;

[0023] Fig.13 Some example embodiments of the present disclosure are shown. Figure 2 Another example of a phase circuit of a converter;

[0024] Fig.14 Some example embodiments of the present disclosure are shown. Figure 2 Another example of a phase circuit of a converter;

[0025] Fig.15 Another example of a converter according to some example embodiments of the present disclosure is shown;

[0026] Fig.16 Some example embodiments of the present disclosure are shown. Fig.15 An example of a phase circuit of a converter;

[0027] Fig.17 Some example embodiments of the present disclosure are shown. Fig.16 Example of common mode component of current in a phase circuit;

[0028] Fig.18 An example of a winding around a magnetic core according to some example embodiments of the present disclosure is shown. Fig.17 The flux corresponding to the common-mode component of the current;

[0029] Fig.19 Some example embodiments of the present disclosure are shown. Fig.16 Another example of a common mode component of current in a phase circuit of;

[0030] Fig. 20 An example of a winding around a magnetic core according to some example embodiments of the present disclosure is shown. Fig.19 The flux corresponding to the common-mode component of the current;

[0031] Fig.21 Some example embodiments of the present disclosure are shown. Fig.16 Example of differential mode component of current in a phase circuit;

[0032] Fig. 22 An example of a winding around a magnetic core according to some example embodiments of the present disclosure is shown. Fig.21 The flux corresponding to the common-mode component of the current;

[0033] Fig.23 Some example embodiments of the present disclosure are shown. Fig.16 Another example of a differential mode component of a current in a phase circuit of;

[0034] Fig.24 Some exemplary embodiments according to the present disclosure are shown. Fig.23 Example of the common mode component of the current corresponding to the flux of the winding around the magnetic core;

[0035] Fig.25 Some example embodiments of the present disclosure are shown. Fig.15 Another example of a phase circuit of a converter;

[0036] Fig.26 Some example embodiments of the present disclosure are shown. Fig.15 Another example of a phase circuit of a converter;

[0037] Fig. 27 Some example embodiments of the present disclosure are shown. Fig.15 Another example of a phase circuit of a converter;

[0038] Fig.28 Another example of a phase circuit of an AC-DC converter according to some example embodiments of the present disclosure is shown;

[0039] Fig.29 shows a DC-AC electrical system according to some example embodiments of the present disclosure;

[0040] Fig.30 shows an example of a phase circuit of a DC-AC converter according to some example embodiments of the present disclosure; and

[0041] Fig.31 An example of a method for manufacturing a converter according to some example embodiments of the present disclosure is shown.

[0042] Throughout the drawings, the same or corresponding reference numerals refer to the same or corresponding parts. DETAILED DESCRIPTION

[0043] The subject matter described herein will now be discussed with reference to several example embodiments. These embodiments are discussed only to enable those skilled in the art to better understand and thus implement the subject matter described herein, without imposing any limitation on the scope of the subject matter.

[0044] The terms "comprises" or "includes" and variations thereof should be understood as open terms meaning "including but not limited to". The term "or" should be understood as "and / or", unless the context clearly indicates otherwise. The term "based on" should be understood as "based at least in part on". The term "operable" refers to a function, action, movement or state that can be achieved through operation induced by a user or an external mechanism. The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment". The term "another embodiment" should be understood as "at least one other embodiment".

[0045] Unless otherwise specified or limited, the terms "mounted," "connected," "supported," and "coupled," and variations thereof, are used broadly and include both direct and indirect mountings, connections, supports, and couplings. Additionally, "connected" and "coupled" are not limited to physical or mechanical connections or couplings. In the following description, like reference numerals and labels are used to describe the same, similar, or corresponding parts of the figures. Additional definitions (explicit and implicit) may be included below.

[0046] Unless otherwise specified or limited, the terms "resistor", "capacitor", "inductor", "switch" and other electrical components may include one or more components that have the same function and operate together to achieve the function. For example, a resistor may refer to two or more resistors connected in series or in parallel to function as one resistor.

[0047] As mentioned above, the conventional topology usually requires additional components such as autotransformers to be arranged outside the interleaved branches, and thus its application may be limited.

[0048] Figure 1An AC-DC electrical system 100 is shown according to some example embodiments of the present disclosure. The electrical system 100 includes an AC power source 11 and a converter 10 for converting AC current to DC current. Although an AC-DC electrical system 100 is shown, this is for illustration only and does not present any limitation on the scope of the subject matter described herein. For example, embodiments of the present disclosure may include a DC-AC electrical system, as described below with reference to Figure 29-30 described.

[0049] Figure 2 1 shows an example of a converter 10 according to some example embodiments of the present disclosure. The converter 10 is a five-level converter and is configured to convert a first DC terminal V A With the second DC terminal V B The AC voltage between 10 and 10 is converted into a DC voltage. Although a five-level converter 10 is shown, this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. For example, embodiments of the present disclosure may include a DC-AC electrical system, as described below with reference to Fig.28 described.

[0050] The converter 10 includes a first phase circuit 12, a second phase circuit 14, and a third phase circuit 16. Each phase circuit is configured to convert an AC current of the phase circuit from the AC power source 11 into a DC current. For example, the first phase circuit 12 is coupled to the AC power source 11 via an inductor L1, and is configured to convert an AC current of the phase circuit from the AC power source 11 into a DC current, thereby providing a DC current across the DC terminal V A and V B The inductor L1 is the AC side boost inductor.

[0051] The first phase circuit 12, the second phase circuit 14 and the third phase circuit 16 are Figure 2 Therefore, for the sake of brevity, only the first phase circuit 12 is described below, and the second phase circuit 14 and the third phase circuit 16 operate similarly. Although the first phase circuit, the second phase circuit, and the third phase circuit adopt the same configuration, this is only for illustration and does not impose any limitation on the scope of the subject matter described herein. For example, in a variation of the present disclosure, the first phase circuit, the second phase circuit, and the third phase circuit adopt different configurations.

[0052] Converter 10 in Figure 2 is a five-level converter, and the common node N C With neutral node N OThe voltage between can present five potential levels. The principle for five potential levels will be described below. Although a five-level converter 10 is shown, this is only for illustration and does not impose any limitation on the scope of the subject matter described herein. For example, within the scope of the subject matter described herein, three or more levels (such as seven or nine levels) may be included.

[0053] The converter 10 includes a control center 18 for controlling the operation of switches in the switching circuits in the first phase circuit, the second phase circuit, and the third phase circuit. The coupling of the control center 18 to the switches in the converter 10 is not shown to avoid obscuring the figure. Although the coupling is not shown, it should be understood that the control center 18 is directly or indirectly coupled to the switches in the converter 10.

[0054] The first phase circuit 12 includes a first branch and a second branch. The first branch is coupled to the first DC terminal V A With the second DC terminal V B The first winding W1 and the second winding W2 are connected via a common node N C coupled to the AC terminal.

[0055] The second branch is coupled in parallel with the first branch between the first DC terminal VA and the second DC terminal VB, and includes a third winding W3 and a fourth winding W4 around the magnetic core L2. The third winding W3 and the fourth winding W4 are connected via a common node N C The first branch is coupled to the AC terminal so that the first branch and the second branch are configured to convert the first voltage to the second voltage. The first winding, the second winding, the third winding, and the fourth winding are configured to enhance each other: a magnetic flux generated by a differential mode (DM) component of the first current in the first branch, and a magnetic flux generated by a DM component of the second current in the second branch.

[0056] Figure 3 Some example embodiments of the present disclosure are shown. Figure 2 The first phase circuit 12 includes a first winding W1 and a second winding W2 located in a first branch and surrounding a magnetic core L2, and a third winding W3 and a fourth winding W4 located in a second branch and surrounding the magnetic core L2.

[0057] The common node between the first winding W1 and the second winding W2, and the common node between the third winding W3 and the fourth winding W4 are coupled together to share the reference numeral N. C Therefore, the first branch and the second branch are staggered.

[0058] The first branch also includes a first winding W1 coupled to the first DC terminal VA The first switch circuit SC1 is coupled between the second winding W2 and the second DC terminal V B The second branch also includes a second switch circuit SC2 coupled between the third winding W3 and the first DC terminal V A The third switch circuit SC3 is coupled between the fourth winding W4 and the second DC terminal V B A fourth switch circuit SC4 is provided between the two.

[0059] The first switch circuit SC1 includes a first diode D1 and a second diode D2 coupled in series, and an intermediate node and a neutral node N coupled to the first diode and the second diode. O The second switch circuit SC2, the third switch circuit SC3 and the fourth switch circuit SC4 are substantially the same as the first switch circuit SC1. Therefore, for the sake of brevity, the description of the second switch circuit SC2, the third switch circuit SC3 and the fourth switch circuit SC4 is omitted here.

[0060] In one embodiment, the second diode D2, the third diode D3, the sixth diode D6 and the seventh diode D7 can be switched at the line frequency (such as 50 Hz or 60 Hz) and the current zero crossing point. Therefore, the switching loss is low, thereby reducing the operating energy loss of the system.

[0061] In summary, the series connection of the first winding W1 and the first switch circuit SC1 and the first DC terminal V A and public node N C The series connection of the third winding W3 and the third switching circuit SC3 is coupled in parallel to the series connection of the first winding W1 and the first switching circuit S1.

[0062] The series connection of the second winding W2 and the second switch circuit SC2 is connected to the second DC terminal V B and public node N C Coupling. Figure 3 In the embodiment, the second branch further comprises a series connection of a fourth winding W4 and a fourth switching circuit SC4. The series connection of the fourth winding W4 and the fourth switching circuit SC4 is coupled in parallel to the series connection of the second winding and the second switching circuit.

[0063] Assume that across the first DC terminal V A and the second DC terminal V B The DC link voltage is V AB , then the voltage across each of capacitors C1 and C2 is V AB / 2. Therefore, the voltage stress on all devices is half of the DC bus voltage, and low voltage rated devices can be used to achieve good switching performance (such as fast speed, low switching loss), and reduce cost.

[0064] Capacitors C1 and C2 represent the DC side capacitors of the DC bus. Assuming the neutral node V O The potential of is "0". In this case, the phase voltage V P (ie, public node N C With neutral node N O The voltage between ) has five voltage levels in this topology.

[0065] The five voltage levels corresponding to the phase voltages and device switching states are shown in Table 1.

[0066] The five voltage levels are represented by '2', '1', '0', '-1' and '-2'. The corresponding five phase voltages are 'V AB / 2'、'V AB / 4'、'0'、'-V AB / 4' and '-V AB / 2'. During modulation, the two branches are controlled in an interleaved manner and five voltage levels are automatically displayed.

[0067] In Table 1, the on state is represented by '1', and the off state is represented by '0'. For example, the symbol '1' of the first switch S1 or the first diode D1 indicates that the first switch S1 or the first diode D1 is on, and the symbol '0' of the first switch S1 or the first diode D1 indicates that the first switch S1 or the first diode D1 is off.

[0068] Table 1. Converter voltage levels and device switching states

[0069]

[0070]

[0071] It should be understood that the switching operation for the switch is controlled by the control center 18, and the state of the diode is based on the current direction. Assume that the currents in the first branch and the second branch are i a1 and i a2 The two currents i a1 and i a2 There will always be a difference. Therefore, the current can be divided into a common mode (CM) component and a differential mode (DM) component. The CM component and the DM component can be expressed as follows,

[0072] i cm =(i a1 +i a2) / twenty one)

[0073] i dm =(i a1 -i a2 ) / twenty two)

[0074] where i cm represents the CM current component, i dm represents the DM current component, i a1 represents the current in the first branch, i a2 represents the current in the second branch. Therefore, the branch current can be expressed as follows,

[0075] i a1 =i cm +i dm (3)

[0076] i a2 =i cm -i dm (4)

[0077] The phase current and circulating current can be expressed as follows.

[0078] i a =i a1 +i a2 =2i cm (5)

[0079] i cir =i dm (6)

[0080] where i a represents the phase current, i cir It can be seen from (5) to (6) that the CM current i cm is the beneficial phase current, while the DM current i dm is an undesirable circulating current. The circulating current is a DM current that does not contribute to power conversion but increases current ripple and loss, so the circulating current should be suppressed to achieve high efficiency.

[0081] Figure 4 Some example embodiments of the present disclosure are shown. Figure 3 Example of the common mode component of the current in the phase circuit of . The common mode component i in the first branch cm The current flows to the first DC terminal V through the inductor L1 and the first winding W1 in the first branch. A To charge capacitor C1. Similarly, the common-mode component i in the second branch cm The current flows to the first DC terminal V through the inductor L1 and the third winding W3 in the second branch. A To charge capacitor C1.

[0082] As mentioned above, the CM component is beneficial to the conversion, and the CM component of the current will not be suppressed, as shown below with reference to Figure 5 described.

[0083] Figure 5 Some exemplary embodiments according to the present disclosure are shown. Figure 4 The common-mode component of the current corresponds to the flux of the winding around the magnetic core. Figure 5 In the drawings, the same-named terminals of the windings are marked with "*". Similar reference numerals "*" may be applied to subsequent drawings to indicate the same-named terminals.

[0084] The terminals of the first winding W1 and the second winding W2 are located away from the common node (N C ) terminals, while the third and fourth winding terminals of the same name are coupled to a common node (N C ) terminals. Figure 5 It also shows the CM component i in the first branch. cm The first flux generated by the CM component i in the second branch cm The second flux generated.

[0085] The first flux and the second flux are generated in the same direction, for example, in the direction from the first winding to the second winding. Therefore, the first magnetic flux and the second magnetic flux cancel each other, so that the inductance of the first winding W1 and the second winding W2 is reduced. This will facilitate voltage conversion.

[0086] Despite Figure 5 The configuration of the first winding, the second winding, the third winding, and the fourth winding around the magnetic core L2 is shown in FIG. 1 , but this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. Other configurations may be applied as long as the CM component i in the first branch cm The first flux generated by the CM component i in the second branch cm The generated second fluxes cancel each other out.

[0087] Although a rectangular shape of the core L2 is shown, this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. The magnetic core L2 can be of any shape such as circular, EI or double E, UU, PQ, etc. The core is not limited to any magnetic material. The layout of the windings can be in any manner as long as the CM component i in the first branch cm The first flux generated by the CM component i in the second branch cm The generated second fluxes cancel each other out.

[0088] Figure 6 Some example embodiments of the present disclosure are shown. Figure 3Another example of the common mode component of the current in the phase circuit of FIG. In this example, the common mode component i in the first branch cm The current flows to the first DC terminal V through the inductor L1 and the first winding W1 in the first branch. A To charge capacitor C1. The common mode component i in the second branch cm The current flows to the second DC terminal V through the inductor L1 and the fourth winding W4 in the second branch. B To charge capacitor C2.

[0089] As mentioned above, the CM component is beneficial to the conversion. Therefore, the CM component of the current is not suppressed, as shown below with reference to Figure 7 described.

[0090] Figure 7 Some exemplary embodiments according to the present disclosure are shown. Figure 6 The common mode component of the current corresponds to the flux of the winding around the magnetic core. Figure 7 configuration, the CM component of the current is not suppressed.

[0091] The same-named terminals of the first winding W1, the second winding W2, the third winding W3 and the fourth winding W4 are Figure 5 Therefore, for the sake of brevity, the description of the terminals with the same name is omitted here. Figure 7 It also shows the CM component i in the first branch. cm The first flux generated by the CM component i in the second branch cm The second flux generated.

[0092] The first flux and the second flux are generated in the same direction, for example, in the direction from the first winding to the second winding. Therefore, the first flux and the second flux cancel each other, so that the inductance of the first winding W1 and the fourth winding W4 is reduced. This will facilitate voltage conversion.

[0093] Figure 8 Some example embodiments of the present disclosure are shown. Figure 3 Example of the differential mode (DM) component of the current in a phase circuit. Figure 8 The electrical configuration and Figure 6 The DM component of the current is Figure 8 shown.

[0094] In this example, the DM component i dm From the third winding in the second branch through the common node N C Flows to the first winding in the first branch, so that the DM component i dm circulates in the first phase circuit 12. Thus, if the DM component i dmIf it is not inhibited, energy will be wasted in the cycle and cannot be converted into beneficial energy, so the DM component i dm Need to be suppressed, such as Fig. 9 shown.

[0095] Fig. 9 Some exemplary embodiments according to the present disclosure are shown. Figure 8 The common mode component of the current corresponds to the flux of the winding around the magnetic core. Fig. 9 The configuration can suppress the DM component of the current.

[0096] The same-named terminals of the first winding W1, the second winding W2, the third winding W3 and the fourth winding W4 are Figure 5 Therefore, for the sake of brevity, the description of the terminals with the same name is omitted here. Fig. 9 It also shows that the i in the first branch dm The first flux generated by the second branch i dm The second flux generated.

[0097] The first flux and the second flux are generated in different directions. Therefore, the first magnetic flux and the second magnetic flux will enhance each other, so that the inductance of the first winding W1 and the fourth winding W3 will increase accordingly. Due to the increase in winding inductance, the DC component of the circulating current is suppressed. Therefore, the undesirable DM component can be suppressed at a lower level, and more energy can be converted into beneficial energy.

[0098] Fig.10 Some example embodiments of the present disclosure are shown. Figure 3 Another example of a differential-mode component of current in a phase circuit. Fig.10 The electrical configuration and Figure 3 The differential mode (DM) component of the current is Fig.10 shown.

[0099] In this example, the DM component i dm From the fourth winding W4 in the second branch through the common node N C Flows to the first winding W1 in the first branch, so that the DM component i dm circulates in the first phase circuit 12. Thus, if the DM component i dm If it is not inhibited, energy will be wasted in the cycle and cannot be converted into beneficial energy, so the DM component i dm Need to be suppressed, such as Fig.11 shown.

[0100] Fig.11 Some exemplary embodiments according to the present disclosure are shown. Fig.10The common mode component of the current corresponds to the flux of the winding around the magnetic core. Fig.11 The configuration can suppress the DM component of the current.

[0101] The same-named terminals of the first winding W1, the second winding W2, the third winding W3 and the fourth winding W4 are Figure 5 Therefore, for the sake of brevity, the description of the terminals with the same name is omitted here. Fig.11 It also shows that the i in the first branch dm The first flux generated by the second branch i dm The second flux generated.

[0102] The first flux and the second flux are generated in different directions. Therefore, the first magnetic flux and the second magnetic flux will enhance each other, so that the inductance of the first winding W1 and the fourth winding W4 will increase. Due to the increase in winding inductance, the DC component of the circulating current is suppressed by the increased inductance. Therefore, the undesirable DM component can be suppressed at a lower level, and more energy can be converted into beneficial energy.

[0103] Through Figure 2-Figure 11 The configuration shown can eliminate harmonics from the interleaved branches, thereby obtaining better harmonic performance and helping to reduce the size of the AC boost inductor. In addition, the configuration of the winding around the magnetic core L2 effectively suppresses the circulating current, thereby achieving lower current ripple and high efficiency. In summary, the configuration of the embodiments of the present disclosure can achieve high efficiency and cost reduction as described above.

[0104] Although Figure 3-Figure 11 The specific configuration of the phase circuits for the CM and DM components and their principles are shown, but this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. For example, other configurations are also possible, as described below.

[0105] Fig.12 Some example embodiments of the present disclosure are shown. Figure 2 Another example of a phase circuit 12 of a converter. Fig.12 The phase circuit 12 is similar to Figure 3 The phase circuit of FIG. 1 is different in that the CM inductor L3 is connected to the common node N between the first winding and the second winding in the first branch. C A first winding of the second branch, and a second winding connected to an intermediate node between the third winding W3 and the fourth winding W4 in the second branch.

[0106] Fig.12 The configuration is similar to Figure 3 In other words, the operation of Table 1 can also be applied to Fig.12Therefore, the DM component of the current can be suppressed because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch enhance each other and the inductance increases accordingly, while the CM component of the current is substantially unaffected because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch cancel each other and the inductance decreases accordingly.

[0107] Fig.13 Some example embodiments of the present disclosure are shown. Figure 2 Another example of the phase circuit 12 of the converter. In addition to the positions of the second diode D2, the third diode D3, the sixth diode D6 and the seventh diode D7, Fig.12 The phase circuit 12 is similar to Figure 3 The second diode D2 is located at the common node N C Between the first winding and the third diode D3, a common node N C Between the second winding, the sixth diode D6 is located at the common node N C Between the third winding, the seventh diode D7 is located at the common node N C Between the fourth winding.

[0108] Fig.12 The configuration is similar to Figure 3 In other words, the operation of Table 1 can also be applied to Fig.13 Therefore, the DM component of the current can be suppressed because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch enhance each other and the inductance increases accordingly, while the CM component of the current is substantially unaffected because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch cancel each other and the inductance decreases accordingly.

[0109] Fig.14 Some example embodiments of the present disclosure are shown. Figure 2 Another example of a phase circuit 12 of a converter. In addition to the switching element, Fig.14 The phase circuit 12 is similar to Figure 3 Phase circuit. Figure 3 The first switch S1 is replaced in Fig.14 In the embodiment, the ninth diode D9 is arranged at an intermediate node between the first diode D1 and the second diode D2 and a neutral node V O and the switch S1 is disposed between the intermediate node between the first diode D1 and the second diode D2 and the intermediate node between the third diode D3 and the fourth diode D4. Figure 3 The second switch S2, the third switch S3, and the fourth switch S4 in the embodiment can be replaced by Fig.14The tenth diode D10, the eleventh diode D11, the twelfth diode D12 and the first switch S1 and the second switch S2.

[0110] Fig.14 The configuration is similar to Figure 3 Therefore, the DM component of the current can be suppressed because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch reinforce each other and the inductance increases accordingly, while the CM component of the current is substantially unaffected because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch reinforce each other and the inductance increases accordingly.

[0111] Fig.15 2 shows another example of a converter 20 according to some example embodiments of the present disclosure. The converter 20 is a five-level converter and is configured to convert a DC terminal V A and V B The AC voltage between 20 and 21 is converted into a DC voltage. Although a five-level converter 20 is shown, this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. For example, embodiments of the present disclosure may include a DC-AC electrical system, as described below with reference to Fig.28 described.

[0112] The converter 20 includes a first phase circuit 22, a second phase circuit 24, and a third phase circuit 26. Each phase circuit is configured to convert an AC current of a phase circuit from an AC power source 11 into a DC current. For example, the first phase circuit 22 is coupled to the AC power source 11 via a boost inductor L1, and is configured to convert an AC current of a phase circuit from an AC power source 11 into a DC current, thereby providing a DC current across a first DC terminal V A and the second DC terminal V B DC voltage.

[0113] The first phase circuit 22, the second phase circuit 24 and the third phase circuit 26 are Fig.15 Therefore, for the sake of brevity, only the first phase circuit 22 is described below, and the second phase circuit 24 and the third phase circuit 26 operate similarly. Although the first phase circuit, the second phase circuit, and the third phase circuit adopt the same configuration, this is only for illustration and does not impose any limitation on the scope of the subject matter described herein. For example, in a variation of the present disclosure, the first phase circuit, the second phase circuit, and the third phase circuit adopt different configurations.

[0114] Converter 20 Fig.15 is a five-level converter, and the common node N C With neutral node N OThe voltage between can present five potential levels. The principle of five potential levels will be described below. Although a five-level converter 20 is shown, this is only for illustration and does not impose any limitation on the scope of the subject matter described herein. For example, within the scope of the subject matter described herein, three or more levels (such as seven or nine levels) may be included.

[0115] The converter 20 includes a control center 28 for controlling the operation of switches in the switching circuits in the first phase circuit 22, the second phase circuit 24, and the third phase circuit 26. The coupling of the control center 28 to the switches in the converter 20 is not shown so as not to obscure the figure. Although the coupling is not shown, it is understood that the control center 28 is coupled to the switches in the converter 20, either directly or indirectly.

[0116] The first phase circuit 22 includes a first branch and a second branch. The first branch is coupled to the first DC terminal V A With the second DC terminal V B The first winding and the second winding are connected via a common node N C coupled to the AC terminal.

[0117] The second branch is coupled in parallel with the first branch between the first DC terminal VA and the second DC terminal VB and includes a third winding W3 around the magnetic core L2. The third winding W3 is connected to the common node N C The first branch and the second branch are coupled to the AC terminal so that the first branch and the second branch are configured to convert the first voltage to the second voltage. The first winding, the second winding, and the third winding are configured to enhance each other: the magnetic flux generated by the DM component of the first current in the first branch, and the magnetic flux generated by the DM component of the second current in the second branch.

[0118] Fig.16 Some example embodiments of the present disclosure are shown. Fig.15 The first phase circuit 22 includes a first winding W1 and a second winding W2 located in a first branch and surrounding a magnetic core L2, and a third winding W3 located in a second branch and surrounding the magnetic core L2.

[0119] The first winding W1, the second winding W2 and the third winding W3 are coupled together to share a common node N C Therefore, the first branch and the second branch are interlaced. The first branch includes a first switch circuit SC1 and a second switch circuit SC2. The first switch circuit SC1 is coupled between the first winding W1 and the first DC terminal V A The second switch circuit SC2 is coupled between the second winding W2 and the second DC terminal V BThe second branch includes a third switch circuit SC3 and a fourth switch circuit SC4. The third switch circuit SC3 is coupled between the third winding W3 and the first DC terminal V A The fourth switch circuit SC4 is coupled between the third winding W3 and the second DC terminal V B between.

[0120] The first switch circuit includes a first diode D1 and a second diode D2 coupled in series, and a first switch S1 coupled to an intermediate node between the first diode and the second diode and a neutral node N O The second switch circuit SC1, the third switch circuit SC2 and the fourth switch circuit SC3 are substantially the same as the first switch circuit SC1. Therefore, for the sake of brevity, the description of the second switch circuit SC1, the third switch circuit SC2 and the fourth switch circuit SC3 is omitted here.

[0121] In summary, the series connection of the first winding W1 and the first switch circuit SC1 and the first DC terminal V A and public node N C The series connection of the third winding W3 and the third switching circuit SC3 is coupled in parallel to the series connection of the first winding W1 and the first switching circuit S1.

[0122] The series connection of the second winding W2 and the second switch circuit SC2 is connected to the second DC terminal V B and public node N C Coupling. Fig.16 The second branch also includes a third winding W3 and a second DC terminal V B The fourth switching circuit SC4 is coupled.

[0123] Assume that across the first DC terminal V A and the second DC terminal V B The DC link voltage is V AB , then the voltage across each of capacitors C1 and C2 is V AB Capacitors C1 and C2 represent the DC side capacitors of the DC bus. Assuming the neutral node V O The potential of is "0". In this case, the phase voltage V P (ie, public node N C With neutral node N O The voltage between ) has five voltage levels in this topology.

[0124] The five voltage levels corresponding to the phase voltage and the device switching state are shown in Table 1. The five voltage levels are represented by '2', '1', '0', '-1' and '-2'. The corresponding five phase voltages are 'V AB / 2'、'VAB / 4'、'0'、'-V AB / 4' and '-V AB / 2'. When modulating, the two branches are controlled in an interleaved manner, and five voltage levels are automatically displayed. In Table 1, the on state is represented by "1", and the off state is represented by "0". For example, the symbol '1' of the first switch S1 or the first diode D1 indicates that the first switch S1 or the first diode D1 is turned on, and the symbol '0' of the first switch S1 or the first diode D1 indicates that the first switch tube S1 or the first diode D1 is turned off.

[0125] Table 2. Converter voltage levels and device switching states

[0126]

[0127]

[0128] It should be understood that the switching operation of the switch is controlled by the control center 18, and the state of the diode is based on the current direction. Assume that the currents in the first branch and the second branch are i a1 and i a2 The two currents i a1 and i a2 There will always be a difference. Therefore, the current can be divided into a common mode (CM) component and a differential mode (DM) component. The CM and DM components can be expressed as follows,

[0129] i cm =(i a1 +i a2 ) / 2 (7)

[0130] i dm =(i a1 -i aa ) / 2 (8)

[0131] where i cm represents the CM current component, i dm represents the DM current component, i a1 represents the current in the first branch, i a2 represents the current in the second branch. Therefore, the branch current can be expressed as follows,

[0132] i a1 =i cm +i dm (9)

[0133] i a2 =i cm -i dm (10)

[0134] The phase current and circulating current can be expressed as follows.

[0135] i a =i a1 +i a2 =2i cm (11)

[0136] i cir =i dm (12)

[0137] Among them, i a represents the phase current, i cir It can be seen from (11) to (12) that the CM current i cm is the beneficial phase current, while the DM current i dm is an undesirable circulating current. The circulating current is a DM current that does not contribute to power conversion but increases current ripple and loss, so the circulating current should be suppressed to achieve high efficiency.

[0138] Fig.17 Some example embodiments of the present disclosure are shown. Fig.16 Example of the common mode component of the current in the phase circuit of . The common mode component i in the first branch cm The current flows to the first DC terminal V through the inductor L1 and the first winding W1 in the first branch. A , to charge capacitor C1. Similarly, the common-mode component i in the second branch cm The current flows to the first DC terminal V through the inductor L1 and the third winding W3 in the second branch. A To charge capacitor C1.

[0139] It can be seen that Fig.17 The configuration is similar to Figure 3 configuration, except that the fourth winding W4 is removed. Fig.17 The configuration can be operated similarly without the fourth winding W4. As mentioned above, the CM component is beneficial to the conversion, and the CM component of the current is not suppressed, as shown below with reference to Fig.18 described.

[0140] Fig.18 Some exemplary embodiments according to the present disclosure are shown. Fig.17 Example of a winding where the common-mode component of the current corresponds to the flux around the magnetic core.

[0141] The terminals of the first winding W1 and the second winding W2 are located away from the common node (N C ) terminal, while the terminal of the third winding of the same name is coupled to the common node (N C ) terminals. Fig.17It also shows the CM component i in the first branch. cm The first flux generated by the CM component i in the second branch cm The second flux generated.

[0142] The first flux and the second flux are generated in the same direction, for example, in the direction from the first winding to the second winding. Therefore, the first magnetic flux and the second magnetic flux cancel each other, so that the inductance of the first winding W1 and the second winding W2 is reduced. This will facilitate voltage conversion.

[0143] Despite Figure 5 The configuration of the first winding, the second winding, and the third winding around the magnetic core L2 is shown in FIG. 1 , but this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. Other configurations may be applied as long as the CM component i in the first branch cm The first flux generated by the CM component i in the second branch cm The generated second fluxes cancel each other out.

[0144] Fig.19 Some example embodiments of the present disclosure are shown. Fig.16 Another example of a common-mode component of current in a phase circuit.

[0145] In this example, in the second branch, the CM component i cm The current flows from the inductor L1 through the third winding W3 to the first DC terminal V A , to charge capacitor C1. In the first branch, the CM component i cm The current flows from the inductor L1 through the second winding W2 to the second DC terminal V B , to charge capacitor C2.

[0146] As mentioned above, the CM component is beneficial to the conversion. Therefore, the CM component of the current is not suppressed, as shown below with reference to Fig. 20 described.

[0147] Fig. 20 Some exemplary embodiments according to the present disclosure are shown. Fig.19 The common mode component of the current corresponds to the flux of the winding around the magnetic core. Fig. 20 configuration, the CM component of the current is not suppressed.

[0148] The same-named terminals of the first winding W1, the second winding W2 and the third winding W3 are Fig.18 Therefore, for the sake of brevity, the description of the terminals with the same name is omitted here. Fig. 20 It also shows the CM component i in the first branch. cm The first flux generated by the CM component i in the second branchcm The second flux generated.

[0149] The first flux and the second flux are generated in the same direction, for example, in the direction from the second winding to the first winding. Therefore, the first magnetic flux and the second magnetic flux cancel each other, so that the inductance of the second winding W2 and the third winding W3 is reduced. This will facilitate voltage conversion.

[0150] Fig.21 Some example embodiments of the present disclosure are shown. Fig.16 Example of the DM component of the current in a phase circuit. Fig.21 The electrical configuration and Fig.16 The DM component of the current is Fig.21 shown.

[0151] In this example, the DM component i dm From the third winding W3 in the second branch through the common node N C Flows to the first winding W1 in the first branch, so that the DM component i dm circulates in the first phase circuit 22. Thus, if the DM component i dm If it is not inhibited, this will cause energy waste in the cycle and cannot be converted into beneficial energy, so the DM component i dm Need to be suppressed, such as Fig. 22 shown.

[0152] Fig. 22 Some exemplary embodiments according to the present disclosure are shown. Fig.21 The common mode component of the current corresponds to the flux of the winding around the magnetic core. Fig. 9 The configuration can suppress the DM component of the current.

[0153] The same-named terminals of the first winding W1, the second winding W2 and the third winding W3 are Fig.18 Therefore, for the sake of brevity, the description of the terminals with the same name is omitted here. Fig. 22 It also shows the DM component i in the first branch. dm The first flux generated by the DM component i in the second branch dm The second flux generated.

[0154] The first flux and the second flux are generated in different directions. Therefore, the first magnetic flux and the second magnetic flux will enhance each other, so that the inductance of the first winding W1 and the fourth winding W3 will increase. Due to the increase in winding inductance, the DC component of the circulating current is suppressed by the increased inductance. Therefore, the undesirable DM component can be suppressed at a lower level, and more energy can be converted into beneficial energy.

[0155] Fig.23 Some example embodiments of the present disclosure are shown. Fig.16 Another example of a DM component of the current in the phase circuit 22. Fig.23 The electrical configuration and Fig.16 The DM component of the current is Fig.23 shown.

[0156] In this example, the DM component i dm From the second winding W2 in the first branch through the common node N C Flows to the third winding W3 in the second branch, so that the DM component i dm circulates in the first phase circuit 22. Thus, if the DM component i dm If it is not inhibited, this will cause energy waste in the cycle and cannot be converted into beneficial energy, so the DM component i dm Need to be suppressed, such as Fig.24 shown.

[0157] Fig.24 Some exemplary embodiments according to the present disclosure are shown. Fig.23 The common mode component of the current corresponds to the flux of the winding around the magnetic core. Fig.24 The configuration can suppress the DM component of the current.

[0158] The same-named terminals of the first winding W1, the second winding W2 and the third winding W3 are Fig.18 Therefore, for the sake of brevity, the description of the terminals with the same name is omitted here. Fig.24 It also shows the DM component i in the first branch. dm The first flux generated by the DM component i in the second branch dm The second flux generated.

[0159] The first flux and the second flux are generated in different directions. Therefore, the first magnetic flux and the second magnetic flux will enhance each other, so that the inductance of the first winding W1 and the third winding W3 will increase. Due to the increase in winding inductance, the DC component of the circulating current is suppressed by the increased inductance. Therefore, the undesirable DM component can be suppressed at a lower level, and more energy can be converted into beneficial energy.

[0160] Through Figure 16-Figure 23 The configuration shown can eliminate harmonics from the interleaved branches, thereby achieving better harmonic performance and helping to reduce the size of the AC boost inductor. In addition, the circulating current is effectively suppressed by the configuration of the winding around the magnetic core L2, thereby achieving lower current ripple and high efficiency. In summary, the configuration of the embodiments of the present disclosure can achieve high efficiency and cost reduction, as described above.

[0161] Although Figure 16-Figure 24 The specific configuration of the phase circuits for the CM and DM components and their principles are shown, but this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. For example, other configurations are also possible, as described below.

[0162] Fig.25 Some example embodiments of the present disclosure are shown. Fig.15 Another example of a phase circuit 22 of a converter. Fig.25 The phase circuit 22 is similar to Fig.16 The phase circuit of FIG. 1 is different in that the CM inductor L3 is provided. The CM inductor L3 includes a common node N connected between the first winding W1 and the second winding W2 in the first branch. C A first winding in the branch, and a second winding connected to an intermediate node between the third winding W3 in the second branch.

[0163] Fig.25 The configuration is similar to Fig.16 In other words, the operation of Table 2 can also be applied to Fig.25 Therefore, the DM component of the current can be suppressed because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch enhance each other and the inductance increases accordingly, while the CM component of the current is substantially unaffected because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch cancel each other and the inductance decreases accordingly.

[0164] Fig.26 Some example embodiments of the present disclosure are shown. Fig.15 Another example of a phase circuit 22 of a converter. In addition to the positions of the second diode D2 and the third diode D3, Fig.26 The phase circuit 22 is similar to Fig.16 The second diode D2 is located at the common node N C Between the first winding W1 and the third diode D3, a common node N C Between the second winding W3.

[0165] Fig.26 The configuration is similar to Fig.16 In other words, the operation of Table 2 can also be applied to Fig.26 Therefore, the DM component of the current can be suppressed because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch enhance each other and the inductance increases accordingly, while the CM component of the current is substantially unaffected because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch cancel each other and the inductance decreases accordingly.

[0166] Fig. 27 Some example embodiments of the present disclosure are shown. Fig.15 Another example of a phase circuit 22 of a converter. Fig. 27 The phase circuit 22 is similar to Figure 3 The difference lies in the switching elements. Fig.16 The first switch S1 is replaced in Fig. 27 In the embodiment, the ninth diode D9 is arranged at an intermediate node between the first diode D1 and the second diode D2 and a neutral node V O and the switch S1 is disposed between the intermediate node between the first diode D1 and the second diode D2 and the intermediate node between the third diode D3 and the fourth diode D4. Fig.16 The second switch S2, the third switch S3, and the fourth switch S4 in the embodiment can be replaced by Fig. 27 The tenth diode D10, the eleventh diode D11, the twelfth diode D12 and the first switch S1 and the second switch S2.

[0167] Fig. 27 The configuration is similar to Fig.16 Therefore, the DM component of the current can be suppressed because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch reinforce each other and the inductance increases accordingly, while the CM component of the current is substantially unaffected because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch reinforce each other and the inductance increases accordingly.

[0168] Fig.28 Another example of a phase circuit 32 of an AC-DC converter according to some example embodiments of the present disclosure is shown. The phase circuit 32 is a nine-level phase circuit and may be a replacement for the phase circuits 12 and 22.

[0169] Assume that across the first DC terminal V A and the second DC terminal V B The DC link voltage is V AB , then the voltage across each of capacitors C1, C2, C3, and C4 is V AB / 4. Assume that the neutral node V O The potential of is "0". In this case, the phase voltage V P (ie, public node N C With neutral node N O The voltage between the two branches has nine voltage levels in this topology. When modulating, the two branches are controlled in an interleaved manner and the nine voltage levels are automatically displayed. The phase voltage V P During operation, a voltage V AB 、V AB *3 / 4, VAB / 2, V AB / 4, 0, -V AB / 4, -V AB / 2, -V AB *3 / 4 and -V AB .

[0170] Fig.29 A DC-AC electrical system 200 according to some example embodiments of the present disclosure is shown. As described above, embodiments of the present application can be applied to a DC-AC electrical system. The electrical system 200 includes an AC system 220 and a converter 210 for converting a DC current into an AC current. The converter 210 may include a three-phase circuit for three phases of the AC system 220.

[0171] Fig.30 2 shows an example of a phase circuit 212 of a DC-AC converter 210 according to some example embodiments of the present disclosure. The converter 210 is a five-level converter and is configured to convert a DC terminal V A and V B Convert the DC voltage between them into AC voltage.

[0172] Public Node N C With neutral node N O The voltage between can present five potential levels of voltage, as described above with reference to the embodiment of AC-DC converter 10. Although a five-level converter 210 is shown, this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. For example, three or more levels (such as seven or nine levels) may be included within the scope of the subject matter described herein.

[0173] The phase circuits in the DC-AC converter 210 can have the same or similar topology, and therefore, for simplicity, only one phase circuit will be described. The converter 210 includes a control center (not shown) for controlling the operation of switches in the switching circuits in the first phase circuit, the second phase circuit, and the third phase circuit. The coupling of the control center to the switches in the converter 210 is not shown to avoid obscuring the figure. Although the coupling is not shown, it should be understood that the control center is directly or indirectly coupled to the switches in the converter 10.

[0174] The first phase circuit 212 includes a first branch and a second branch. The first branch is coupled to the first DC terminal V A With the second DC terminal V B The first winding W1 and the second winding W2 are connected via a common node N C coupled to the AC terminal.

[0175] The second branch is coupled in parallel with the first branch between the first DC terminal VA and the second DC terminal VB, and includes a third winding W3 and a fourth winding W4 around the magnetic core L2. The third winding W3 and the fourth winding W4 are connected via a common node N C The first branch and the second branch are coupled to the AC terminal so that the first branch and the second branch are configured to convert the first voltage into the second voltage. The first winding W1, the second winding W2, the third winding W3 and the fourth winding W4 are configured to enhance each other: the magnetic flux generated by the DM component of the first current in the first branch, and the magnetic flux generated by the DM component of the second current in the second branch.

[0176] The first branch further includes a first switch circuit SC1 and a second switch circuit SC2. The first switch circuit SC1 is coupled between the first winding W1 and the first DC terminal V A The second switch circuit SC2 is coupled between the second winding W2 and the second DC terminal V B The second branch also includes a third switch circuit SC3 and a fourth switch circuit SC4. The third switch circuit SC3 is coupled between the third winding W3 and the first DC terminal V A The fourth switch circuit SC4 is coupled between the fourth winding W4 and the second DC terminal V B between.

[0177] The first switch circuit SC1 includes a first diode D1 and a second diode D2 coupled in series, and a first switch S1 coupled to an intermediate node between the first diode and the second diode and a neutral node N O The second switch circuit SC2, the third switch circuit SC3 and the fourth switch circuit SC4 are substantially the same as the first switch circuit SC1. Therefore, for the sake of brevity, the description of the second switch circuit SC2, the third switch circuit SC3 and the fourth switch circuit SC4 is omitted here.

[0178] In summary, the series connection of the first winding W1 and the first switch circuit SC1 and the first DC terminal V A and public node N C The series connection of the third winding W3 and the third switching circuit SC3 is coupled in parallel to the series connection of the first winding W1 and the first switching circuit S1.

[0179] The series connection of the second winding W2 and the second switch circuit SC2 is connected to the second DC terminal V B and public node N C Coupling. Fig.30 In the embodiment, the second branch further comprises a series connection of a fourth winding W4 and a fourth switching circuit SC4. The series connection of the fourth winding W4 and the fourth switching circuit SC4 is coupled in parallel to the series connection of the second winding and the second switching circuit.

[0180] Assume that across the first DC terminal V A and the second DC terminal V B The DC link voltage is V AB , then the voltage across each of capacitors C1 and C2 is V AB / 2. Assume that the neutral node V O The potential of is "0". In this case, the phase voltage V P (ie, public node N C With neutral node N O The voltage between ) has five voltage levels in this topology.

[0181] The five voltage levels corresponding to the phase voltage and the device switching state are shown in Table 1. The five voltage levels are represented by '2', '1', '0', '-1' and '-2'. The corresponding five phase voltages are 'V AB / 2'、'V AB / 4'、'0'、'-V AB / 4' and '-V AB / 2'. When modulating, the two branches are controlled in an interleaved manner, and five voltage levels are automatically displayed. In Table 1, the on state is represented by '1', and the off state is represented by '0'. For example, the symbol '1' of the first switch S1 or the first diode D1 indicates that the first switch S1 or the first diode D1 is turned on, and the symbol '0' of the first switch S1 or the first diode D1 indicates that the first switch tube S1 or the first diode D1 is turned off.

[0182] Table 3. Converter voltage levels and device switching states

[0183]

[0184] It will be appreciated that the switching operation of the switch is controlled by the control center 18 and the state of the diode is based on the current direction.

[0185] Similar to Figure 5 The configuration of the first winding W1 and the second winding W2 has the same terminals far away from the common node (N C ) terminals, while the terminals of the third and fourth windings of the same name are terminals coupled to a common node (N C ). In one example, for the CM component, the first flux generated by the CM component in the first branch and the second flux generated by the CM component in the second branch can be in the same direction, for example, in the direction from the first winding to the second winding. Therefore, the first magnetic flux and the second magnetic flux cancel each other, so that the inductance of the first winding W1 and the second winding W2 is reduced. This will facilitate voltage conversion.

[0186] In one example, for the DM component, the first flux generated by the DM component in the first branch and the second flux generated by the DM component in the second branch can be in different directions. Therefore, the first flux and the second flux enhance each other, so that the inductance of the first winding W1 and the second winding W2 will increase.

[0187] As described above, the DM component of the current can be suppressed because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch enhance each other and the inductance increases accordingly, while the CM component of the current is substantially unaffected because the magnetic flux generated by the first branch and the magnetic flux generated by the second branch cancel each other and the inductance decreases accordingly.

[0188] Fig.31 An example of a method for manufacturing a converter according to some example embodiments of the present disclosure is shown. The method can be applied to manufacturing converters 10, 20, and 210.

[0189] At 302 , a first branch is provided, the first branch coupled between a first DC terminal and a second DC terminal and comprising a first winding and a second winding around a magnetic core, the first winding and the second winding coupled to an AC terminal via a common node.

[0190] At 304, a second branch is provided, the second branch coupled in parallel with the first branch between the first DC terminal and the second DC terminal and including a third winding around the magnetic core. The third winding is coupled to the AC terminal such that the first branch and the second branch are configured to convert the first voltage to a second voltage.

[0191] At 306 , the first winding, the second winding, and the third winding are configured to reinforce each other: a magnetic flux generated by a DM component of the first current in the first branch and a magnetic flux generated by a DM component of the second current in the second branch.

[0192] Although method 300 Fig.31 , but this is for illustration only and does not impose any limitation on the scope of the subject matter described herein. For example, it should be understood that Figure 2-30 All features of can be applied to method 300 .

[0193] In the following, some example implementations of the subject matter described in this article are listed.

[0194] Item 1: A voltage converter circuit is provided that includes a first branch and a second branch. The first branch is coupled between a first DC terminal and a second DC terminal and includes a first winding and a second winding around a magnetic core. The first winding and the second winding are coupled to an AC terminal via a common node. The second branch is coupled between the first DC terminal and the second DC terminal in parallel with the first branch and includes a third winding around the magnetic core. The third winding is coupled to the AC terminal so that the first branch and the second branch are configured to convert a first voltage into a second voltage. The first winding, the second winding, and the third winding are configured to enhance each other: a magnetic flux generated by a differential mode (DM) component of a first current in the first branch, and a magnetic flux generated by a DM component of a second current in the second branch.

[0195] Item 2: The voltage converter circuit of Item 1, wherein the first winding, the second winding, and the third winding are configured to reduce a magnetic flux caused by a CM current to reduce an inductance of the CM current.

[0196] Item 3: A voltage converter circuit according to Item 1 or 2, wherein the like-named terminals of the first winding and the second winding are terminals away from the common node, and the like-named terminals of the third winding are terminals coupled to the common node.

[0197] Item 4: A voltage converter circuit according to any one of Items 1 to 3, wherein the first branch includes a first switching circuit and a second switching circuit, the first switching circuit being coupled between the first DC terminal and the first winding, and the second switching circuit being coupled between the second DC terminal and the second winding. The second branch includes a third switching circuit coupled between the first DC terminal and the third winding. The first branch and the second branch are configured to operate to provide conversion voltages at different potential levels.

[0198] Item 5: A voltage converter circuit according to any one of Items 1 to 4, wherein the second branch also includes a fourth winding and a fourth switching circuit, the fourth winding surrounds the magnetic core and is coupled to the common node, and the fourth switching circuit is configured to be coupled between the second DC terminal and the fourth winding.

[0199] Item 6: A voltage converter circuit according to any one of items 1 to 5, wherein the first switch circuit includes a first diode and a second diode coupled in series, and a first switch coupled to a neutral node between the first DC terminal and the second DC terminal, and a first intermediate node between the first diode and the second diode. The second switch circuit includes a third diode and a fourth diode coupled in series, and a second switch (S2), the second switch (S2) coupled to the neutral node, and a second intermediate node between the third diode and the fourth diode.

[0200] Item 7: The voltage converter circuit of any one of Items 1 to 6, wherein the third switch circuit includes a fifth diode and a sixth diode coupled in series, and a third switch coupled to the neutral node and an intermediate node between the fifth diode and the sixth diode. The fourth switch circuit includes a seventh diode and an eighth diode coupled in series, and a fourth switch (S4), and the fourth switch (S4) is coupled to the neutral node and an intermediate node between the seventh diode and the eighth diode.

[0201] Item 8: A voltage converter circuit according to any one of Items 1 to 7, wherein the first switch, the second switch, the third switch and the fourth switch are turned off so that the voltage between the common node and the neutral node is at a first level, a third level or a fifth level based on the input voltage at the AC terminal.

[0202] Item 9: A voltage converter circuit according to any one of Items 1 to 8, wherein one of the first switch, the second switch, the third switch and the fourth switch is turned on so that the voltage between the common node and the neutral node is at a second level or a fourth level based on the input voltage at the AC terminal.

[0203] Item 10: A voltage converter circuit according to any one of items 1 to 9, wherein one of the first switch and the second switch and one of the third switch and the fourth switch are turned on so that the voltage between the common node and the neutral node is at the third level.

[0204] Item 11: A voltage converter circuit according to any one of items 1 to 10, wherein the series connection of the first winding and the first switch circuit is coupled to the first DC terminal and the common node. The series connection of the third winding and the third switch circuit is coupled in parallel to the series connection of the first winding and the first switch circuit. The series connection of the second winding and the second switch circuit is coupled to the second DC terminal and the common node.

[0205] Item 12: The voltage converter circuit of any one of items 1 to 11, wherein the second branch further comprises a fourth switching circuit coupled to the third winding and the second DC terminal.

[0206] Item 13: The voltage converter circuit of any one of items 1 to 12, wherein the second branch further comprises a series connection of a fourth winding and a fourth switch circuit. The series connection of the fourth winding and the fourth switch circuit is coupled in parallel to the series connection of the second winding and the second switch circuit.

[0207] Item 14: The voltage converter circuit of any one of items 1 to 13, wherein the first winding and the second winding are coupled to the AC terminal via a first winding of a CM inductor. The third winding is coupled to the AC terminal via a second winding of the CM inductor.

[0208] Item 15: A voltage converter circuit according to any one of Items 1 to 14, wherein the voltage converter circuit includes an AC-DC converter configured to convert the first voltage into the second voltage including a plurality of potential levels. The voltage converter circuit also includes a control center configured to control the operation of a switch of the voltage converter circuit.

[0209] Item 16: A voltage converter circuit according to any one of items 1 to 15, wherein the AC-DC converter includes: a first capacitor coupled to the first DC terminal and a neutral node; and a second capacitor coupled to the second DC terminal and the neutral node.

[0210] Item 17: A voltage converter circuit according to any one of items 1 to 16, wherein the first switch circuit includes a first diode and a second diode coupled in series, and a ninth diode coupled to a neutral node between the first DC terminal and the second DC terminal, and a first intermediate node between the first diode and the second diode. The second switch circuit includes a third diode and a fourth diode coupled in series, and a tenth diode coupled to the neutral node, and a second intermediate node between the third diode and the fourth diode. The first branch also includes a first switch coupled between the first intermediate node and the second intermediate node.

[0211] Item 18: A voltage converter circuit according to any one of items 1 to 17, wherein the third switch circuit includes a fifth diode and a sixth diode coupled in series, and an eleventh diode coupled to a neutral node between the first DC terminal and the second DC terminal, and a third intermediate node between the fifth diode and the sixth diode. The second switch circuit includes a seventh diode and an eighth diode coupled in series, and a twelfth diode coupled to the neutral node, and a fourth intermediate node between the seventh diode and the eighth diode. The second branch also includes a second switch coupled between the third intermediate node and the fourth intermediate node.

[0212] Item 19: An electrical system is provided, comprising: a voltage converter circuit according to any one of items 1 to 18, and a control center. The control center is configured to receive a request for voltage conversion; and control the voltage converter circuit to provide a conversion voltage based on the request.

[0213] Item 20: A method for manufacturing a voltage converter circuit is provided. The method includes providing a first branch, the first branch coupled between a first DC terminal and a second DC terminal, and including a first winding and a second winding around a magnetic core. The first winding and the second winding are coupled to an AC terminal via a common node. The method also includes providing a second branch, the second branch coupled in parallel with the first branch between the first DC terminal and the second DC terminal and including a third winding around the magnetic core. The third winding is coupled to the AC terminal so that the first branch and the second branch are configured to convert a first voltage to a second voltage. The method also includes configuring the first winding, the second winding, and the third winding so that the following items enhance each other: a magnetic flux generated by a DM component of a first current in the first branch, and a magnetic flux generated by a DM component of a second current in the second branch.

[0214] In addition, although the operations are described in a particular order, this should not be understood as requiring the operations to be performed in the particular order shown or in sequence, or to perform all the illustrated operations, to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although the above discussion contains several specific implementation details, these should not be interpreted as limitations on the scope of the present disclosure, but should be interpreted as descriptions that may be specific to the features of a specific embodiment. Certain features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the other hand, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0215] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A voltage converter circuit, comprising: The first branch is coupled to the first DC terminal (V A ) and the second DC terminal (V B ) and includes a first winding (W1) and a second winding (W2) around the magnetic core, the first winding and the second winding being connected via a common node (N C ) coupled to an alternating current (AC) terminal; as well as a second branch coupled between the first DC terminal and the second DC terminal in parallel with the first branch and comprising a third winding (W3) around the magnetic core, the third winding coupled to the AC terminal such that the first branch and the second branch are configured to convert a first voltage to a second voltage; The first winding, the second winding and the third winding are configured to enhance each other: a magnetic flux generated by a differential mode (DM) component of a first current in the first branch and a magnetic flux generated by a DM component of a second current in the second branch.

2. The voltage converter circuit of claim 1, wherein the first winding, the second winding, and the third winding are configured to reduce a magnetic flux caused by a common mode (CM) current to reduce an inductance of the CM current.

3. The voltage converter circuit according to claim 1, wherein the terminals of the first winding and the second winding with the same name are far away from the common node (N C ) terminal, and the same-named terminal of the third winding is coupled to the common node (N C ) terminals.

4. The voltage converter circuit according to claim 1, wherein The first branch includes a first switch circuit (SC1) and a second switch circuit (SC2), wherein the first switch circuit (SC1) is coupled to the first DC terminal (V A ) and the first winding, the second switch circuit (SC2) is coupled to the second DC terminal (V B ) between the first and the second winding; The second branch includes a third switch circuit (SC3) coupled to the first DC terminal (V A ) and the third winding; and The first branch and the second branch are configured to operate to provide switching voltages at different potential levels.

5. The voltage converter circuit of claim 4, wherein the second branch further comprises a fourth winding (W4) and a fourth switch circuit (SC4), the fourth winding (W4) surrounding the magnetic core and coupled to the common node (N C ), the fourth switch circuit (SC4) is configured to be coupled to the second DC terminal (V B ) and the fourth winding.

6. The voltage converter circuit of claim 5, wherein the first switching circuit comprises a first diode (D1) and a second diode (D2) coupled in series, and a first switch (S1), the first switch (S1) being coupled to a neutral node (V O ), and a first intermediate node between the first diode and the second diode; and The second switch circuit includes a third diode (D3) and a fourth diode (D4) coupled in series, and a second switch (S2), the second switch (S2) being coupled to the following items: the neutral node (V O ), and a second intermediate node between the third diode and the fourth diode.

7. The voltage converter circuit of claim 6, wherein the third switching circuit comprises a fifth diode (D5) and a sixth diode (D6) coupled in series, and a third switch (S3), the third switch (S3) being coupled to: the neutral node (V O ), and an intermediate node between the fifth diode and the sixth diode; and The fourth switch circuit includes a seventh diode (D7) and an eighth diode (D8) coupled in series, and a fourth switch (S4), the fourth switch (S4) being coupled to the following items: the neutral node (V O ), and an intermediate node between the seventh diode and the eighth diode.

8. The voltage converter circuit according to claim 7, wherein the first switch, the second switch, the third switch and the fourth switch are turned off so that the common node (N C ) and the neutral node (N O ) is at a first level, a third level, or a fifth level based on the input voltage at the AC terminal.

9. The voltage converter circuit according to claim 8, wherein one of the first switch, the second switch, the third switch and the fourth switch is turned on so that the common node (N C ) and the neutral node (N O ) is at a second level or a fourth level based on the input voltage at the AC terminal.

10. The voltage converter circuit according to claim 9, wherein one of the first switch and the second switch, and one of the third switch and the fourth switch are turned on so that the common node (N C ) and the neutral node (N O ) is at the third level.

11. The voltage converter circuit of claim 4, wherein a series connection of the first winding and the first switching circuit is coupled to the first DC terminal and the common node, a series connection of the third winding and the third switching circuit coupled in parallel to the series connection of the first winding and the first switching circuit; and A series connection of the second winding and the second switching circuit is coupled to the second DC terminal and the common node. 12 . The voltage converter circuit of claim 11 , wherein the second branch further comprises a fourth switching circuit coupled to the third winding and the second DC terminal.

13. The voltage converter circuit of claim 11, wherein the second branch further comprises a series connection of a fourth winding and a fourth switching circuit; and The series connection of the fourth winding and the fourth switching circuit is coupled in parallel to the series connection of the second winding and the second switching circuit.

14. The voltage converter circuit of claim 1, wherein the first winding and the second winding are coupled to the AC terminal via a first winding of a CM inductor; and The third winding is coupled to the AC terminal via the second winding of the CM inductor.

15. The voltage converter circuit of claim 1, wherein the voltage converter circuit comprises an AC-DC converter configured to convert the first voltage into the second voltage comprising a plurality of potential levels; and The voltage converter circuit also includes a control center configured to control operation of switches of the voltage converter circuit.

16. The voltage converter circuit of claim 15, wherein the AC-DC converter comprises: A first capacitor (C1) coupled to the first DC terminal (V A ) and neutral node (N O ); as well as A second capacitor (C2) coupled to the second DC terminal (V B ) and the neutral node (N O ).

17. The voltage converter circuit of claim 4, wherein the first switching circuit comprises a first diode (D1) and a second diode (D2) coupled in series, and a ninth diode (D9), the ninth diode (D9) being coupled to a neutral node (V O ), and a first intermediate node between the first diode and the second diode; The second switch circuit includes a third diode (D3) and a fourth diode (D4) coupled in series, and a tenth diode (D10) coupled to the neutral node (V O ), and a second intermediate node between the third diode and the fourth diode; and The first branch also includes a first switch (S1) coupled between the first intermediate node and the second intermediate node.

18. The voltage converter circuit of claim 17, wherein the third switching circuit comprises a fifth diode (D5) and a sixth diode (D6) coupled in series, and an eleventh diode (D11), the eleventh diode (D11) coupled to a neutral node (V O ), and a third intermediate node between the fifth diode and the sixth diode; The second switch circuit includes a seventh diode (D7) and an eighth diode (D8) coupled in series, and a twelfth diode (D12) coupled to the neutral node (V O ), and a fourth intermediate node between the seventh diode and the eighth diode; and The second branch also includes a second switch (S2) coupled between the third intermediate node and the fourth intermediate node.

19. An electrical system comprising: The voltage converter circuit according to any one of claims 1 to 18, and A control center configured to receive a request for voltage conversion; as well as The voltage converter circuit is controlled to provide a conversion voltage based on the request.

20. A method for manufacturing a voltage converter circuit, comprising: A first branch is provided, wherein the first branch is coupled to a first DC terminal (V A ) and the second DC terminal (V B ) and includes a first winding (W1) and a second winding (W2) around the magnetic core, the first winding and the second winding being connected via a common node (N C ) coupled to an alternating current (AC) terminal; providing a second branch coupled in parallel with the first branch between the first DC terminal and the second DC terminal and comprising a third winding (W3) around the magnetic core, the third winding coupled to the AC terminal such that the first branch and the second branch are configured to convert a first voltage to a second voltage; as well as The first winding, the second winding, and the third winding are configured to reinforce each other: a magnetic flux generated by a differential mode (DM) component of a first current in the first branch and a magnetic flux generated by a DM component of a second current in the second branch.

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