Reactor

Abstract

To provide a reactor which can be reduced in size even when the reactor is operated to step up / down a voltage with a large current.SOLUTION: The reactor 5 includes cores 51 that are separated from each other and arranged in parallel, a bus bar 52 that is arranged so as to penetrate an inner diameter of one of the cores 51, and an excitation coil 53 that is arranged on the other of the cores 51 and around which a coil 532 is wound.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a reactor. [Background technology]

[0002] Patent Document 1 discloses a technique for a reactor structure including a reactor in which a pair of coils are arranged in parallel with an annular core, and a case that houses the reactor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-21448 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned Patent Document 1, when a step-up / step-down reactor is operated at a large current, the coil and annular core must be made large to suppress heat generation in the coil, which poses a problem in that the reactor itself becomes large.

[0005] The present disclosure has been made in view of the above, and has an object to provide a reactor that can be made smaller even when performing step-up / step-down operations with a large current. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the reactor of the present disclosure comprises two cores arranged separately in parallel, a bus bar arranged to penetrate the inner diameter of the other of the two cores, and an excitation coil arranged on the inner diameter of one of the two cores and having a coil wound around it. [Effects of the Invention]

[0007] According to the present disclosure, even when performing buck-boost operation with a large current, an effect of achieving miniaturization can be obtained.

Brief Description of the Drawings

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram of a buck-boost circuit according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view showing a schematic configuration of a reactor according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a front view of a reactor according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a circuit diagram of a conventional chopper-type buck-boost circuit. [Figure 5] FIG. 5 is a diagram showing the relationship between the buck-boost current and time in a conventional chopper-type buck-boost circuit. [Figure 6] FIG. 6 is a diagram showing the relationship between the buck-boost current and time in a buck-boost circuit according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is a cross-sectional view of a reactor in which an excitation coil and a bus bar according to an embodiment of the present disclosure are arranged in series within a space in a core.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, a buck-boost circuit including a reactor according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the components in the following embodiments include those that can be replaced and are easy for those skilled in the art, or those that are substantially the same. Also, each drawing referred to in the following description only schematically shows the shape, size, and positional relationship to an extent that can understand the content of the present disclosure. That is, the present disclosure is not limited only to the shape, size, and positional relationship illustrated in each drawing.

[0010] 〔Configuration of Buck-Boost Circuit〕 Fig. 1 is a schematic configuration diagram of a step-up / step-down circuit according to an embodiment of the present disclosure. The step-up / step-down circuit 1 shown in Fig. 1 is mounted on a vehicle such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an electric vehicle (EV), or a fuel cell electric vehicle (FCEV). The step-up / step-down circuit 1 includes a battery 2, a capacitor 3, an excitation circuit 4, a reactor 5, a rectifier circuit 6, and an inverter 7 (INV).

[0011] The battery 2 is configured as a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The battery 2 may be a battery having a liquid electrolyte between the positive and negative electrodes, or may be an all-solid-state battery having a solid electrolyte. The battery 2 is configured as a battery pack in which a plurality of unit cells (battery cells) such as lithium-ion batteries are electrically connected in series. The battery 2 is electrically connected to an inverter 7 via a reactor 5 and a rectifier circuit 6.

[0012] The capacitor 3 is electrically connected in parallel to the battery 2. When the excitation circuit 4 is in an off state under the control of an ECU (Electronic Control Unit) or the like (not shown), the capacitor 3 stores energy via a diode that constitutes the excitation circuit 4.

[0013] The excitation circuit 4 boosts or lowers the voltage of the power from the battery 2 and outputs it to the rectifier circuit 6. The excitation circuit 4 also boosts or lowers the voltage of the power from the inverter 7 and outputs it to the battery 2. The excitation circuit 4 is configured using four switching elements Q1 to Q4. Diodes D1 to D4 are electrically connected in anti-parallel between the collector and emitter of each of the switching elements Q1 to Q4. Under the control of an ECU (not shown), the excitation circuit 4 alternately switches on and off the switching elements Q2 and Q3 and the switching elements Q1 and Q4 to prevent direct current from flowing through the excitation circuit 4 itself. Specifically, when the excitation circuit 4 is in the on state, it stores voltage in the reactor 5, and when in the off state, it stores voltage in the capacitor 3 via the diodes D1 to D4. This allows the cross-sectional area of ​​the excitation coil of the reactor 5, which will be described later, to be reduced.

[0014] One end of the reactor 5 is electrically connected to the battery 2 or the excitation circuit 4, and the other end is electrically connected to the inverter 7 via the excitation circuit 4 or the rectifier circuit 6. The detailed configuration of the reactor 5 will be described later.

[0015] The rectifier circuit 6 is electrically connected to the battery 2 via the reactor 5, and the other end is electrically connected to the inverter 7. The rectifier circuit 6 converts AC to DC and outputs the DC to the inverter 7. The rectifier circuit 6 is configured using a switching element Q10. A diode D10 is electrically connected in anti-parallel between the collector and emitter of the switching element Q10.

[0016] Under the control of an ECU (not shown), the inverter 7 converts DC power input from the reactor 5 via the rectifier circuit 6 into AC power and outputs it to a motor generator (not shown) or the like to drive it. Also, under the control of an ECU (not shown), the inverter 7 converts AC power generated by a motor generator (not shown) into DC power and outputs it to the battery 2 via the rectifier circuit 6 and the reactor 5.

[0017] [Detailed reactor configuration] Next, a detailed configuration of the above-mentioned reactor 5 will be described. Fig. 2 is a perspective view showing a schematic configuration of the reactor 5. Fig. 3 is a front view of the reactor 5.

[0018] As shown in FIGS. 2 and 3, the reactor 5 includes a core 51, a bus bar 52, and an exciting coil 53.

[0019] The core 51 has an annular shape and includes two separate, parallel-arranged cores: a left core 511 and a right core 512. When viewed from the front, the two left cores 511 and right cores 512 each have a U-shaped side surface (front surface), and are arranged parallel to each other so that they can be connected to each other on a surface perpendicular to the side surface (front surface). While the side surfaces are U-shaped in FIGS. 2 and 3, the shape is not limited thereto, and may be any shape that allows the excitation coil 53 and bus bar 52, which can pass through the inside, to be arranged parallel to each other, such as an I-shape, an H-shape, or a C-shape.

[0020] The bus bar 52 is arranged to penetrate the other space between the two left cores 511 and the right core 512. Specifically, the bus bar 52 is arranged to penetrate the inner diameter of the right core 512. One end of the bus bar 52, point A, is electrically connected to the battery 2, and the other end of the bus bar 52, point B, is electrically connected to the rectifier circuit 6.

[0021] The excitation coil 53 is formed by winding a predetermined number of coils 532 around a bobbin 531. The excitation coil 53 is arranged by winding the coil 532 around the left core 511. Specifically, the excitation coil 53 is arranged with the left core 511 inserted into the hole in the bobbin 531. One end of the excitation coil 53, point C, is electrically connected to the midpoint that electrically connects the switching elements Q1 and Q3 of the excitation circuit 4. Furthermore, the other end of the excitation coil 53, point D, is electrically connected to the midpoint that electrically connects the switching elements Q2 and Q4 of the excitation circuit 4. That is, by sharing the core 51 with the bus bar 52, the excitation coil 53 is electrically connected to the excitation circuit 4, and a ripple that crosses zero in both directions is generated, thereby inducing a voltage between points A and B of the bus bar 52 according to the turn ratio of the coil 532. As a result, the reactor 5 can boost the voltage by supplying a current that flows due to the induced voltage to the rectifier circuit 6 and the inverter 7 by the ripple.

[0022] [Conventional chopper-type step-up / step-down circuit] Here, a conventional chopper-type buck-boost circuit will be described. Fig. 4 is a circuit diagram of a conventional chopper-type buck-boost circuit. Fig. 5 is a diagram showing the relationship between time and the current that is boosted or bucked in a conventional chopper-type buck-boost circuit. Fig. 6 is a diagram showing the relationship between time and the current that is boosted or bucked in a buck-boost circuit 1. In addition, the broken line L1 in Fig. 5 shows the change in the current that is boosted or bucked in the conventional chopper-type buck-boost circuit, the straight line L2 in Fig. 6 shows the current that flows in the reactor 5 (bus bar 52), and the broken line L3 shows the current that flows in the excitation coil 53. Note that the same components as those in the buck-boost circuit 1 are assigned the same reference numerals, and detailed description thereof will be omitted.

[0023] The chopper-type buck-boost circuit 100 shown in Fig. 4 includes a battery 2, a capacitor 3, an inverter 7, a reactor 101, and rectifier circuits 102 and 103 that function as upper and lower arms. The rectifier circuit 103 is electrically connected to the battery 2 via the reactor 101, and the other end is electrically connected to the inverter 7. The rectifier circuit 103 converts AC to DC and outputs the DC to the inverter 7. The rectifier circuit 103 is configured using a switching element Q21. A diode DD21 is electrically connected in anti-parallel between the collector and emitter of the switching element Q21.

[0024] In contrast, as shown in FIGS. 1 and 4, the buck-boost circuit 1 includes an excitation circuit 4 instead of the rectifier circuit 103 in the lower arm of a conventional chopper-type buck-boost circuit 100, and alternately switches on and off switching elements Q2 and Q3 and switching elements Q1 and Q4. This prevents DC current from flowing through the excitation circuit 4, i.e., the DC current can be set to 0 A, allowing the cross-sectional area of ​​the excitation coil 53 to be reduced. Specifically, the buck-boost circuit 1 splits the current flowing through the conventional chopper-type buck-boost circuit 100, as shown by the broken line L1 in FIG. 5, into straight lines L2 and L3 in FIG. 6. This reduces the role of the excitation coil 53, i.e., reduces DC current loss, allowing for a smaller circuit.

[0025] Furthermore, the step-up / step-down circuit 1 can omit the rectifier circuit 103 in the lower arm of the conventional chopper-type step-up / step-down circuit 100, thereby reducing the risk of short-circuiting between the upper and lower arms.

[0026] Furthermore, under the control of an ECU (not shown), the step-up / step-down circuit 1 turns on the switching elements Q3 and Q4 of the excitation circuit 4 during regeneration of the inverter 7, thereby causing a circulating current to flow and consuming the energy equivalent to the induced voltage as heat, thereby preventing the application of an overvoltage.

[0027] [In the case of series arrangement] Next, a description will be given of a reactor in which the excitation coil 53 and the bus bar 52 are arranged in series within the space inside the core 51. Fig. 7 is a cross-sectional view of a reactor in which the excitation coil 53 and the bus bar 52 are arranged in series within the space inside the core 51.

[0028] In the reactor 300 shown in FIG. 7, the excitation coil 53 and the bus bar 52 are arranged in series within the space inside the core 51. In this case, the bus bar 52 shields the magnetic fluxes K1 to K3 generated by the excitation coil 53. Specifically, by shielding the magnetic flux K2, the bus bar 52 pushes the magnetic flux K2 down toward the excitation coil 53 (see arrow U1) and passes through a path K10. As a result, the magnetic flux of the excitation coil 53 increases due to the magnetic flux linking with the coil 532, and heat generation increases. As a result, the reactor 300 is ineffective because the excitation coil 53 and the bus bar 52 are arranged in series within the space inside the core 51.

[0029] In contrast, the reactor 5 described above has the excitation coil 53 and bus bar 52 arranged in parallel within the space within the core 51, so that even when performing voltage increase / decrease operations with a large current, it can be made smaller and heat generation can be prevented.

[0030] According to the embodiment described above, reactor 5 includes core 51 which is separately arranged in parallel, bus bar 52 which is arranged so as to penetrate the other inner diameter of core 51, and excitation coil 53 which is arranged on one inner diameter of core 51 and has coil 532 wound thereon. As a result, reactor 5 can distribute heat generated by excitation coil 53 by separating the excitation current of the AC section (excitation circuit 4) which increases or decreases voltage and the DC current in the current path (bus bar 52), so that it is possible to achieve miniaturization even when performing voltage increase or decrease operation with a large current.

[0031] Furthermore, according to one embodiment, core 51 has two ring-shaped cores, left core 511 and right core 512, which are separated and arranged in parallel, and excitation coil 53 can be arranged with the hole in bobbin 531 inserted into left core 511, so the cross-sectional area of ​​excitation coil 53 can be reduced.

[0032] Further advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0033] Although some of the embodiments of the present application have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be implemented in other forms that have undergone various modifications and improvements based on the knowledge of those skilled in the art, including the aspects described in the disclosure of the present invention. [Explanation of symbols]

[0034] 1. Buck-boost circuit 2 Battery 3. Capacitors 4 Excitation circuit 5 Reactor 6 Rectifier circuit 7 inverters 51 cores 52 Bus Bar 53 Excitation coil 511 Left Core 512 Right Core 531 Bobbin 532 Coil

Claims

1. Two cores arranged in parallel and separated from one another; a bus bar disposed so as to penetrate an inner diameter of one of the two cores; an excitation coil having a coil wound around the other of the two cores; A reactor comprising:

2. The reactor according to claim 1, The two cores are U-shaped, Reactor.

3. The reactor according to claim 1, The bus bar is One end is electrically connected to a battery, and the other end is electrically connected to an inverter via a rectifier circuit; The excitation coil is electrically connected to an excitation circuit; Reactor.

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