JP-7855976-B2 - Capacitor

JP7855976B2JP 7855976 B2JP7855976 B2JP 7855976B2JP-7855976-B2

Inventors

秋山浩慶
徳永翔平
山本裕加
小林透典
遠藤優
沢木勇人
友田侑希

Assignees

株式会社明電舎

Dates

Publication Date: 20260511
Application Date: 20220914

Claims (3)

A capacitor installed in a power conversion device, Capacitor element and A capacitor case with a roughly rectangular parallelepiped shape for housing the aforementioned capacitor element, A main body portion housed together with the capacitor element in the capacitor case, a terminal portion exposed from the capacitor case, and a cooling plate, A resin that is filled inside the capacitor case and fixes the capacitor element and the cooling plate in an insulated state, Equipped with, One of the rectangular parallelepiped capacitor cases, which is the bonding surface, is bonded to the housing of the power converter either directly or via a heat transfer member. The main body of the cooling plate is positioned near the surface of the capacitor case opposite to the bonding surface. The terminal portion of the cooling plate and the housing of the power converter are connected , A capacitor characterized in that the cooling plate is provided with studs for mounting to a circuit board .
A capacitor installed in a power conversion device, Capacitor element and A capacitor case with a roughly rectangular parallelepiped shape for housing the aforementioned capacitor element, A main body portion housed together with the capacitor element in the capacitor case, a terminal portion exposed from the capacitor case, and a cooling plate, A resin that is filled inside the capacitor case and fixes the capacitor element and the cooling plate in an insulated state, Equipped with, One of the rectangular parallelepiped capacitor cases, which is the bonding surface, is bonded to the housing of the power converter either directly or via a heat transfer member. The main body of the cooling plate is positioned near the surface of the capacitor case opposite to the bonding surface. The terminal portion of the cooling plate and the housing of the power converter are connected , A capacitor characterized in that a discharge resistor connected in parallel to the capacitor element is placed on the cooling plate .
A capacitor installed in a power conversion device, Capacitor element and A capacitor case with a roughly rectangular parallelepiped shape for housing the aforementioned capacitor element, A main body portion housed together with the capacitor element in the capacitor case, a terminal portion exposed from the capacitor case, and a cooling plate, A resin that is filled inside the capacitor case and fixes the capacitor element and the cooling plate in an insulated state, Equipped with, One of the rectangular parallelepiped capacitor cases, which is the bonding surface, is bonded to the housing of the power converter either directly or via a heat transfer member. The main body of the cooling plate is positioned near the surface of the capacitor case opposite to the bonding surface. The terminal portion of the cooling plate and the housing of the power converter are connected , The terminal portion of the cooling plate is exposed toward the outside of the capacitor case from the vicinity of two opposing sides of the four sides of the side of the capacitor case opposite to the joining surface. The electrode terminals of the capacitor element are exposed toward the outside of the capacitor case from the vicinity of two opposing sides of the four sides of the side of the capacitor case opposite to the bonding surface. A capacitor characterized in that the side of the cooling plate that exposes the terminal portion and the side of the capacitor element that exposes the electrode terminal are different.

Description

This invention relates to a cooling technology for capacitors installed in power conversion devices (such as inverter units). Figure 7 shows the electrical circuit diagram of a typical inverter unit. As shown in Figure 7, a capacitor (e.g., a film capacitor) C is connected between the P terminal and the N terminal. Furthermore, switching elements Su, Sx, Sv, Sy, and Sw, Sz are connected in series between the P terminal and the N terminal. The switching elements are, for example, IGBTs, and the switching elements Su to Sz constitute an inverse converter (IGBT package) 1. A motor M is connected to the AC side of the inverter 1 (the connection points of switching elements Su and Sx, Sv and Sy, and Sw and Sz). A current sensor 2 is also provided between the inverter 1 and the motor M. Capacitor C smooths the DC link voltage. A discharge resistor R is connected in parallel to capacitor C. The discharge resistor R is provided to discharge the charge from capacitor C when the inverter unit's input power is turned off. This prevents electric shock accidents. Figure 8 shows the configuration of a conventional capacitor C. As shown in Figure 8, capacitor C is housed in a rectangular capacitor case 3. Japanese Patent Publication No. 2013-169070Japanese Patent Publication No. 2021-197838 A perspective view showing the configuration of a conventional capacitor and the capacitor of Embodiment 1.A diagram showing how to set the cooling plate in the capacitor of Embodiment 1.This figure shows the capacitor of Embodiment 1 installed in the casing of the inverter unit.A diagram showing the cooling path of the capacitor in Embodiment 1.A perspective view showing the configuration of the capacitor in Embodiment 2.A perspective view showing the configuration of the capacitor in Embodiment 3.Electrical circuit diagram of a typical inverter unit.A diagram showing the configuration of a conventional capacitor. The following describes in detail embodiments 1 to 3 of the capacitor according to the present invention, based on Figures 1 to 6. [Embodiment 1] This first embodiment describes a capacitor provided in a power conversion device. Figure 1(a) shows an existing capacitor, and Figure 1(b) shows the capacitor of this first embodiment. As shown in Figures 1(a) and 1(b), the capacitor element C is housed within a rectangular capacitor case 3. The electrode terminals 6 of the capacitor element are exposed from the capacitor case 3. As shown in Figure 1(b), the capacitor of this embodiment 1 is integrally molded with the capacitor element C and cooling plate 7 arranged inside the capacitor case 3. The cooling plate 7 is substantially flat and has a main body portion 7a housed within the capacitor case 3 together with the capacitor element C, and a terminal portion 7b exposed from the capacitor case 3. As shown in Figures 1(b) and 2, the capacitor element C and cooling plate 7 are placed inside the capacitor case 3, and resin is filled in, fixing the electrode terminals (P terminal, N terminal) 6 of the capacitor element C and the cooling plate 7 in an electrically insulated state. As shown in Figure 3, the capacitor case 3 is placed on the inverter unit housing 5. A heat transfer member (e.g., a thermal conductive sheet, hereinafter referred to as the thermal conductive sheet) 4 is provided between the capacitor case 3 and the inverter unit housing 5. The thermal conductive sheet 4 may be omitted. That is, one face of the rectangular capacitor case 3, which is the joining surface, is joined to the inverter unit housing 5 either directly or via the thermal conductive sheet 4, and the main body 7a of the cooling plate 7 is placed near the face opposite the joining surface. In this specification, "near the face opposite the joining surface" refers to the upper half of the capacitor case 3. The inverter unit's housing 5 has four cylindrical sections 8 erected on it. Screw holes are formed in these cylindrical sections 8. The terminal section 7b of the cooling plate 7 and the cylindrical sections 8 of the housing 5 are fixed together with screws 9 or the like. Furthermore, the side of the capacitor case 3 opposite the joint surface (the opening surface) consists of four sides forming a rectangle. Of the four sides of the opening surface of the capacitor case 3, the terminal portion 7b of the cooling plate 7 is exposed from two sides different from the sides (two sides) where the electrode terminals 6 of the capacitor C are exposed. The following describes the capacitor cooling method based on Figure 4. By placing the cooling plate 7, the heat generated inside the capacitor C (capacitor elements and internal conductors) is dissipated via the resin mold (short distance) → cooling plate 7 → inverter unit housing 5, as shown in Figure 4. In the conventional configuration, heat generated inside the capacitor is dissipated via the resin mold (at a distance) → capacitor case 3 → thermal conductive sheet 4 → inverter unit housing 5. Therefore, th