JP5017997B2 - Inverter device - Google Patents

Description

The present invention relates to an inverter device .

  The inverter device is a power conversion device that generates AC power from DC power. The inverter device includes a switching module including a plurality of switching elements, a switching control circuit that controls the switching elements, and a smoothing capacitor that smoothes a direct current supplied by the switching elements.

  The switching element is an element having a function of connecting or disconnecting an electric circuit. As the switching element, an IGBT (Insulated Gate Bipolar Transistor), a power MOS-FET (Metal Oxide Semiconductor-Field Effect Transistor), or the like is used. By controlling the on / off operation of the switching element by PWM (Pulse Width Modulation), the inverter device is operated under optimum conditions.

  Among inverter devices, for example, an inverter device used for an electric vehicle, a hybrid vehicle, a train, an elevator, or the like needs to generate electric power having a large rated voltage or rated current. These devices include a motor as a driving source, and require a large amount of power to move a heavy object.

  In the inverter device corresponding to such a large power, a smoothing capacitor having a very large capacity is used. For example, as a smoothing capacitor used in a hybrid vehicle, a capacitor having a capacity of several hundred μF to several thousand μF is used. Since the large-capacity smoothing capacitor has a large size, it is usually arranged outside the inverter body including the switching module. The smoothing capacitor and the inverter main body are electrically connected by, for example, a bus bar that is a connection conductor.

  FIG. 13 is a schematic exploded perspective view of an inverter device according to a conventional technique. The inverter device includes an inverter body 20. A switching module including a plurality of switching elements is disposed inside the inverter body 20.

  The inverter device includes a capacitor housing portion 28. A smoothing capacitor is disposed inside the capacitor housing portion 29. The positive electrode side bus bar 5 and the negative electrode side bus bar 6 are connected to the capacitor housing portion 28. Each bus bar is formed in a flat plate shape.

  The positive side bus bar 5 is connected to a positive side electric circuit disposed inside the inverter body 20. The negative side bus bar 6 is connected to a negative side electric circuit arranged inside the inverter body 20. The positive electrode side bus bar 5 has a connecting portion 5a. The negative electrode side bus bar 6 has a connecting portion 6a. The connection parts 5a and 6a have openings.

  The inverter main body 20 has terminal portions 15 and 16. The terminal portion 15 is connected to an electric circuit on the positive electrode side arranged inside the inverter body 20. The terminal portion 16 is connected to a negative-side electric circuit arranged inside the inverter body 20.

  Capacitor accommodating portion 28 is fixed to inverter body 20 as indicated by arrow 61. Positive bus bar 5 is fixed to terminal portion 15 by a fixing member such as a bolt, for example. The negative electrode side bus bar 6 is fixed to the terminal portion 16. By fixing each bus bar and terminal, the smoothing capacitor is electrically connected to the electric circuit of the inverter body. Thus, the capacitor | condenser accommodating part is electrically connected with the inverter main body by two bus bars.

  FIG. 14 is a schematic plan view when the capacitor housing portion is viewed from the side where the bus bar is disposed. The positive electrode side bus bar 5 and the negative electrode side bus bar 6 are arranged side by side. The positive electrode side bus bar 5 and the negative electrode side bus bar 6 are arranged so that the maximum area surfaces having the maximum area are in the same plane.

In Japanese Patent Laid-Open No. 10-146064, both side surfaces of the external line connection terminal attached to the power supply side main circuit terminal of the magnetic contactor are bent substantially vertically, and a fastening hole for the electromagnetic contactor is provided at one end, and the other end is provided at the other end. There is disclosed a cubicle for a power converter in which a fastening hole for a main circuit electric wire is provided so that a bent portion is in contact with a side surface of a crimp terminal.
JP-A-10-146064

  Each electrical component arranged in the electrical device is electrically connected by a connection conductor. The connection conductor has conductivity. There exists an apparatus with which the voltage of a connection conductor changes continuously or intermittently in an electric equipment. In the above-described inverter device, the switching element performs a switching operation at a frequency of 10 kHz, for example, thereby connecting and disconnecting the electric circuit.

  In such an electric circuit, since the voltage fluctuates, the wiring inductance in the connection conductor inside the switching module and the bus bar connecting the inverter main body and the capacitor housing portion cannot be ignored. Due to the stray inductance in these connection conductors, a large surge voltage appears in the electric circuit when the switching operation is performed.

  FIG. 15 shows a graph for explaining the surge voltage. The horizontal axis represents time, and the vertical axis represents voltage and current. A solid line graph indicates a voltage, and a one-dot chain line graph indicates a current. The voltage indicates the voltage across the switching element.

  When the switching element changes from the disconnected state to the connected state, the voltage decreases and the current increases. When the switching element is switched from the connected state to the disconnected state (when turned off), the voltage increases and the current decreases. At this turn-off, a large voltage is developed. By switching the switching element from the connected state to the disconnected state, an overshoot portion is generated in the voltage curve. That is, the voltage increment ΔV shown in FIG. 15 occurs, and the voltage becomes larger than the voltage in the steady connection state. The voltage at this time is a surge voltage.

  Due to the occurrence of the surge voltage, for example, there is a problem that the voltage applied to the switching element is increased and the withstand voltage of the switching element must be increased.

  In order to suppress the surge voltage, it is conceivable to reduce the wiring inductance. The wiring inductance depends on the length of the connecting conductor. It is conceivable to reduce the wiring inductance by shortening the length of the connection conductor. However, there is a problem that there is a limit to shortening the wiring.

An object of this invention is to provide the inverter apparatus which suppresses a surge voltage.

An inverter device according to the present invention includes an inverter body including a circuit having a switching element, a first capacitor and a second capacitor connected in parallel to the circuit having the switching element, the inverter body, and the first capacitor. And a connection conductor for electrical connection. The connection conductor includes a first conductor to be connected to one pole and a second conductor to be connected to the other pole. Each of the first conductor and the second conductor is formed in a plate shape. Each of the first conductor and the second conductor includes a U-shaped portion having a U-shaped cross section . The first capacitor and the second capacitor are connected to the inverter body via a connecting conductor, and the U-shaped portion has two flat plate portions facing each other and a curved portion interposed between the flat plate portions, Of the conductors and the second conductor, the other U-shaped part is arranged inside one U-shaped part, so that four flat plate parts are arranged side by side, and the first conductor and the second conductor are arranged. The two conductors are arranged such that the two flat plate portions of the first conductor and the two flat plate portions of the second conductor are substantially parallel to each other, and the four flat plate portions are arranged in a direction in which current flows. When cut along a vertical plane, along one direction, to one pole of the first capacitor, the other pole of the first capacitor, the other pole of the second capacitor, and the one pole of the second capacitor, They are connected in this order.

ADVANTAGE OF THE INVENTION According to this invention, the inverter apparatus which suppresses a surge voltage can be provided.

(Embodiment 1)
With reference to FIG. 1 to FIG. 5, the connection conductor and the inverter device in the first embodiment based on the present invention will be described. The connection conductor in this Embodiment is arrange | positioned at the inverter apparatus.

  The inverter device in the present embodiment is an inverter device mounted on a hybrid vehicle. A hybrid vehicle is a vehicle powered by a motor in addition to an engine. A hybrid vehicle is a vehicle that obtains power by driving an engine, and also obtains power by converting electric power from a DC power source including a secondary battery into AC power and driving a motor.

  FIG. 1 is an electric circuit diagram of the inverter device according to the present embodiment. The inverter device 18 includes an inverter main body 20 and a capacitor housing portion 21. The inverter device 18 includes a control device 30, a power supply line PL, a ground line SL, and output lines UL, VL, WL. Inverter body 20 is connected to battery B through power supply line PL and ground line SL. The inverter body 20 is connected to a motor generator MG that is an electric load via output lines UL, VL, WL.

  The inverter body 20 includes a switching module. The switching module includes npn transistors Q1 to Q6 as switching elements. Each of the npn transistors Q1 to Q6 is made of, for example, an IGBT. The switching module is connected to the power supply line PL at the connection point 52a. The switching module is connected to the ground line SL at the connection point 52b.

  The switching module includes a U-phase arm 22, a V-phase arm 24 and a W-phase arm 26. U-phase arm 22, V-phase arm 24, and W-phase arm 26 are connected in parallel with battery B between power supply line PL and ground line SL.

  U-phase arm 22 includes npn-type transistors Q1 and Q2 connected in series, V-phase arm 24 includes npn-type transistors Q3 and Q4 connected in series, and W-phase arm 26 is connected in series. Npn transistors Q5 and Q6. Further, diodes D1 to D6 for flowing current from the emitter side to the collector side are connected between the collector and emitter of npn transistors Q1 to Q6, respectively.

  The connection point of the npn transistor in each phase arm is connected to the anti-neutral point side of each U, V, W phase coil of motor generator MG via output lines UL, VL, WL. The output lines UL, VL, and WL output three-phase AC U-phase, V-phase, and W-phase electricity, respectively.

  Motor generator MG driven by inverter device 18 is, for example, a three-phase AC synchronous motor. Motor generator MG generates driving force by AC power received from inverter body 20 via output lines UL, VL, WL. During regenerative braking, motor generator MG generates AC power and outputs the generated AC power to inverter body 20 via output lines UL, VL, WL.

  The battery B is a direct current power source. Battery B includes, for example, a secondary battery such as nickel metal hydride or lithium ion. Battery B supplies the generated DC power to inverter body 20 through power supply line PL. Alternatively, battery B is charged with a DC voltage from inverter body 20 via power supply line PL during regenerative braking.

  Capacitor C1 in the present embodiment is a smoothing capacitor. The smoothing capacitor is a capacitor for removing unnecessary vibration components of the voltage waveform and smoothing the waveform. As the smoothing capacitor, a large capacity electrolytic capacitor or the like is used. The capacitor C <b> 1 in the present embodiment is disposed in the capacitor housing portion 21.

  Capacitor C1 is connected between power supply line PL and ground line SL. Capacitor C1 reduces the influence on battery B and inverter body 20 due to voltage fluctuation. The capacitor C1 is connected in parallel to the circuit of the switching module including the switching element. Capacitor C1 is connected to power supply line PL at connection point 51a. Capacitor C1 is connected to ground line SL at connection point 51b.

  Control device 30 generates a control signal for driving motor generator MG based on signals such as the input voltage of inverter main body 20, the motor current of motor generator MG and the torque command value, and the control signal is used as the inverter main body 20. Output to. The input voltage of inverter main body 20 and the motor current of motor generator MG are detected by a sensor (not shown).

  As described above, the inverter device 18 receives DC power from the battery B through the power supply line PL and the ground line SL, converts the DC power into AC power by the switching module, and transmits AC power through the output lines UL, VL, WL. Is output to the motor generator MG. Further, inverter device 18 receives AC power generated by motor generator MG through output lines UL, VL, WL, converts AC power into DC power, and supplies battery B via power supply line PL and ground line SL. To charge.

  FIG. 2 is a schematic exploded perspective view of the inverter device according to the present embodiment. The inverter device in the present embodiment includes a capacitor housing portion 21 in which a smoothing capacitor is disposed. The capacitor housing part 21 in the present embodiment is formed in a rectangular parallelepiped shape.

  The inverter device 18 includes an inverter main body 20 in which a switching module is disposed. Inverter body 20 in the present embodiment is formed in a rectangular parallelepiped shape. Inverter body 20 has terminal portions 11 and 12 for electrical connection with capacitor housing portion 21. The terminal portions 11 and 12 are electrically connected to the switching module. The terminal part 11 is a terminal on the positive electrode side. The terminal part 12 is a terminal on the negative electrode side. The terminal portions 11 and 12 protrude from the side surface of the inverter body 20 so as to correspond to the connection portions 1c and 2c formed on the bus bar.

  Inverter device 18 in the present embodiment includes a connection conductor for electrically connecting capacitor housing portion 21 and inverter body 20. The connecting conductor includes a positive-side bus bar 1 as a first conductor to be connected to one pole. The connection conductor includes a negative electrode side bus bar 2 as a second conductor to be connected to another pole.

  In the connection conductor in the present embodiment, the positive electrode side bus bar 1 and the negative electrode side bus bar 2 are formed of copper. Each conductor is not limited to copper but can be formed of any conductive material. For example, each conductor may be made of aluminum.

  The positive electrode side bus bar 1 has a connecting portion 1c. The negative electrode side bus bar 2 has a connecting portion 2c. As indicated by an arrow 61, the capacitor housing portion 21 is brought close to the inverter body 20. The connection portions 1c and 2c of the respective bus bars are fixed to the terminal portions 11 and 12 with, for example, bolts as fixing members. The connection part 1c is fixed to the terminal part 11, and the connection part 2c is fixed to the terminal part 12, whereby each bus bar and the terminal part are electrically connected.

  FIG. 3 shows a schematic perspective view of the connection conductor in the present embodiment. Each of the positive electrode side bus bar 1 and the negative electrode side bus bar 2 is formed in a plate shape. Each of the positive electrode side bus bar 1 and the negative electrode side bus bar 2 in the present embodiment is formed by bending a plate-like conductive material.

  The positive electrode side bus bar 1 has a U-shaped portion 1e. The U-shaped portion 1e has a U-shaped cross section. The positive electrode side bus bar 1 has a connecting portion 1c at the tip. The connecting portion 1c is formed so as to be fixable to the terminal portion 11 of the inverter body 20. In the connection portion 1c in the present embodiment, an opening for passing a screw is formed.

  The negative electrode side bus bar 2 in the present embodiment has a cross-sectional shape substantially the same as that of the positive electrode side bus bar 1. The negative electrode side bus bar 2 has a U-shaped portion 2e. The U-shaped portion 2e has a U-shaped cross section. The negative electrode side bus bar 2 has a connecting portion 2c at the tip. The connection portion 2c is formed so as to be fixable to the terminal portion 12 of the inverter body 20. In the connecting portion 2c in the present embodiment, an opening for passing a screw is formed.

  FIG. 4 is a schematic plan view of the capacitor housing portion in the present embodiment as viewed from the side where the connection conductor is disposed. A capacitor C <b> 1 as a first capacitor is disposed inside the capacitor housing portion 21.

  The positive electrode side bus bar 1 has an extending portion 1d. The extending portion 1d is formed to extend from the U-shaped portion 1e toward one end face of the capacitor C1. The extending portion 1d is electrically connected to one pole of the capacitor C1. The negative electrode side bus bar 2 has an extending portion 2d. The extending part 2d is formed so as to extend from the U-shaped part 2e toward the other end face of the capacitor C1. The extending part 2d is electrically connected to the other pole of the capacitor C1.

  Referring to FIGS. 3 and 4, each flat plate portion 1 a, 2 a is formed so as to stand from the surface of the capacitor housing portion 21. Each of the flat plate portions 1 a and 2 a is disposed so as to extend in a direction substantially perpendicular to the surface of the capacitor housing portion 21. The positive electrode side bus bar 1 and the negative electrode side bus bar 2 in the present embodiment are arranged side by side.

  The positive electrode side bus bar 1 has two flat plate portions 1a and a curved portion 1b interposed between the flat plate portions 1a. Each of the flat plate portions 1a is formed in a flat plate shape. The flat plate portions 1a are arranged so that the area-maximum surfaces having the largest areas are substantially parallel to each other. The two flat plate portions 1a are arranged so that the extending directions are substantially parallel to each other. The curved portion 1b is formed in an arc shape in cross section.

  The negative electrode side bus bar 2 has two flat plate portions 2a and a curved portion 2b interposed between the flat plate portions 2a. Each of the flat plate portions 2a is formed in a flat plate shape. The flat plate portions 2a are arranged so that the area-maximum surfaces having the largest areas are substantially parallel to each other. The two flat plate portions 2a are arranged so that the extending directions are substantially the same. The curved portion 2b is formed in an arc shape in cross section.

  The connection conductor in the present embodiment is arranged so that the surface of the flat plate portion 1a of the positive electrode side bus bar 1 and the surface of the flat plate portion 2a of the negative electrode side bus bar 2 are substantially parallel to each other. The flat plate portion 1a and the flat plate portion 2a are formed to extend in the same direction.

  In the present embodiment, the U-shaped portion 1e and the U-shaped portion 2e are arranged so that the directions thereof are opposite to each other. In other words, the U-shaped portions 1e and 2e are arranged so that the opening directions are opposite to each other.

  The transistor as a switching element in this embodiment connects and disconnects an electric circuit in a short time. The transistor in this embodiment performs a switching operation on the order of megahertz, for example.

  With reference to FIG. 15, the voltage of the switching element in the present embodiment changes intermittently. That is, when the switching element is connected, the voltage increases and the predetermined time becomes constant. Thereafter, the switching element disconnects the circuit, so that the voltage drops and becomes constant at a value of almost 0 for a predetermined time. Thereafter, it is repeated that the switching element connects the electric circuit again.

  A surge voltage is generated when the switching element operates to shift from the state where the electrical circuit is connected to the state where it is disconnected. The voltage increment ΔV from the steady voltage of the surge voltage is expressed by the following equation, where L is the wiring inductance, i is the current, and t is the time.

ΔV = L · (di / dt) (1)
For example, in an electrical circuit that connects and disconnects switching elements at high frequencies on the order of megahertz, dt in equation (1) is small. For this reason, the surge voltage which arises becomes large. In order to reduce the surge voltage, it is preferable to reduce the inductance L due to the wiring inductance.

  The connection conductor in the present embodiment includes a positive electrode side bus bar 1 and a negative electrode side bus bar 2, and a U-shaped portion is formed on each bus bar. For this reason, the surface area of the conductor of each pole can be increased. The inductance L in the connection conductor can be reduced, and the surge voltage can be reduced. For example, compared with the connection conductor in the prior art shown in FIG. 13, the surface area of the conductor of each pole can be enlarged. The connection conductor in the present embodiment can almost double the surface area compared to the connection conductor in the prior art.

  In particular, when the driving frequency is increased like a high frequency, the current flows near the surface due to the skin effect. Current does not flow to the center of the conductor. In an electric circuit in which a switching element is driven at a high frequency, the surface area can be increased by forming the conductor in a plate shape, and the inductance when such a high-frequency current is passed can be reduced. Further, since each conductor has a U-shaped portion, the surface area can be further increased, and the inductance L can be further reduced.

  In the connection conductor in the present embodiment, the first conductor and the second conductor both include a U-shaped portion. However, the present invention is not limited to this, and the first conductor and the second conductor One of them may include a U-shaped part.

  FIG. 5 is a schematic perspective view of the connection conductor for explaining the operation of the parallel plate. The connection conductor shown in FIG. 5 has a bus bar 41 and a bus bar 42. Each of the bus bars 41 and 42 is formed in a flat plate shape. The bus bars 41 and 42 are arranged so that the area-maximum surfaces having the largest areas are substantially parallel to each other. That is, the bus bars 41 and 42 are arranged so as to extend in one direction. The bus bar 41 is a bus bar having one pole of the positive electrode and the negative electrode, and the bus bar 42 is a bus bar having another pole.

  Here, it is assumed that a current flows in the direction indicated by the arrow 62 in the bus bar 41 and a current flows in the direction indicated by the arrow 64 in the bus bar 42. The direction of the current flowing through the bus bar 41 and the direction of the current flowing through the bus bar 42 are opposite to each other.

  For example, when a current flows through the bus bar 41 in the direction indicated by the arrow 62, a magnetic field having the direction indicated by the arrow 63 is generated around the bus bar 41. Further, when a current flows through the bus bar 42 in the direction indicated by the arrow 64, a magnetic field in the opposite direction is generated around it. The respective magnetic fields generated by the bus bar 41 and the bus bar 42 are canceled each other, and the inductance of the connection conductor including the bus bars 41 and 42 is reduced. Thus, the connection conductor having the parallel plate configuration can obtain the mutual canceling effect of the inductance, and can reduce the inductance L.

  3 and 4, positive electrode side bus bar 1 and negative electrode side bus bar 2 in the present embodiment are arranged such that flat plate portion 1a and flat plate portion 2a are substantially parallel to each other. For this reason, the mutual cancellation effect of an inductance can be acquired and the inductance in a connection conductor can be made small. As a result, the surge voltage can be suppressed.

  Further, the connection conductor in the present embodiment can reduce the distance between the flat plate portions of the respective bus bars. That is, the flat plate portions can be easily brought close to each other, and mutual cancellation with a large inductance can be obtained.

  Alternatively, in the inverter device according to the present embodiment, since inductance L can be reduced, for example, the value of (di / dt) in equation (1) can be increased. That is, the time Δt during which the voltage is changed in FIG. 15 can be shortened. Electric power is lost at time Δt. By reducing the time Δt, power loss can be reduced. For example, when the inverter device is mounted on an automobile, fuel efficiency can be improved.

  The connection conductor in the present embodiment is used in an electric circuit that connects the capacitor housing portion including the smoothing capacitor and the inverter main body. However, the connection conductor is not limited to this form, and by using it in the electric circuit in which the voltage varies, The voltage can be reduced.

  For example, referring to FIG. 1, in the present embodiment, a connection conductor including a U-shaped portion is used in the circuit from capacitor C1 to connection points 51a and 51b. By using the connection conductor in the present embodiment in the circuit from the capacitor C1 to the connection points 52a and 52b shown in FIG.

  For example, referring to FIG. 2, by using the connection conductor in the present embodiment in the circuit from the respective terminal portions 11 and 12 of the inverter body 20 to the switching module including the internal switching element, the surge voltage can be reduced. Reduction can be achieved.

  The connection conductor in this embodiment is used as a connection conductor of an electric circuit whose voltage changes intermittently, but is not limited to this form, and the present invention is applied to an electric circuit whose voltage changes continuously. Can do. In this embodiment, the inverter device is taken as an example. However, the present invention is not limited to this embodiment, and the present invention can be applied to any electric appliance.

(Embodiment 2)
With reference to FIGS. 6 to 12, a connection conductor and an inverter device according to the second embodiment of the present invention will be described. The inverter device in the present embodiment is an inverter device mounted on an automobile.

  FIG. 6 is an electric circuit diagram of the inverter device according to the present embodiment. Inverter device 19 in the present embodiment includes capacitor C2 as a snubber capacitor in addition to capacitor C1 as a smoothing capacitor. The capacitor C2 has a function of reducing the surge voltage. Capacitor C2 is connected between power supply line PL and ground line SL. The capacitor C2 is connected in parallel with the switching module. The capacitor C2 is connected in parallel with the battery B.

  FIG. 7 is a schematic exploded perspective view of the inverter device according to the present embodiment. The inverter device 19 includes an inverter main body 20 in which a switching module is disposed. The inverter body 20 has terminal portions 13 and 14 that are electrically connected to the switching module. The terminal portions 13 and 14 protrude from the side surface of the inverter main body 20 so as to correspond to respective connecting portions formed on a bus bar described later.

  The inverter device 19 has a capacitor housing portion 29. The capacitor housing part 29 in the present embodiment is formed in a rectangular parallelepiped shape. Inside the capacitor housing 29, a capacitor C1 as a first capacitor and a capacitor C2 as a second capacitor are arranged. Thus, in this Embodiment, the 1st capacitor | condenser and the 2nd capacitor | condenser are arrange | positioned inside the one housing | casing.

  Inverter device 19 in the present embodiment includes a connection conductor. The connection conductor includes a positive electrode side bus bar 3 as a first conductor and a negative electrode side bus bar 4 as a second conductor. The positive electrode side bus bar 3 and the negative electrode side bus bar 4 are arranged so as to stand in a direction perpendicular to the surface of the capacitor housing portion 29.

  FIG. 8 shows a schematic perspective view of the connection conductor in the present embodiment. The positive electrode side bus bar 3 has a U-shaped portion 3h. The U-shaped portion 3h includes flat plate portions 3a and 3b that face each other, and a curved portion 3c that connects the flat plate portions 3a and 3b. The curved portion 3 c in the present embodiment is formed at the distal end portion of the positive electrode side bus bar 3.

  The negative electrode side bus bar 4 has a U-shaped portion 4h. The U-shaped portion 4h includes flat plate portions 4a and 4b that face each other and a curved portion 4c that connects the flat plate portions 4a and 4b. The curved portion 4 c in the present embodiment is formed at the tip portion of the negative electrode side bus bar 4.

  The positive electrode side bus bar 3 has a connection part 3 d for connecting to the terminal part 13 on the positive electrode side of the inverter body 20. The negative electrode side bus bar 4 has a connection portion 4 d for connecting to the negative electrode side terminal portion 14 of the inverter body 20. The connecting portions 3d and 4d are formed so as to protrude from the end portions of the flat plate portions 3a and 4a. Each of the connection portions 3d and 4d has an opening, and is formed so that a fixing member for performing connection fixation can be inserted.

  The positive electrode bus bar 3 in the present embodiment has a notch 3e formed in the curved portion 3c. The notch 3e is formed to extend along the direction in which the flat plate portions 3a and 3b extend. The notch 3e is formed so as to extend along the direction in which the current of the flat plate portions 3a and 3b flows. By forming the notch 3e, a part of the flat plate part 3a and a part of the flat plate part 3b are separated.

  The negative electrode side bus bar 4 in the present embodiment has a cutout portion 4e formed in the curved portion 4c. The notch 4e is formed to extend along the direction in which the flat plate portions 4a and 4b extend. The notch 4e is formed so as to extend along the direction in which the current of the flat plate portions 4a and 4b flows. By forming the notch 4e, a part of the flat plate part 4a and a part of the flat plate part 4b are separated.

  FIG. 9 shows a schematic plan view of the capacitor housing portion in the present embodiment as viewed from the side where the bus bar is disposed. A capacitor C1 and a capacitor C2 are disposed inside the capacitor housing portion 29. For example, the snubber capacitor has a capacitance of several μF. The capacitor C2 as a snubber capacitor has a smaller capacity than the capacitor C1 as a smoothing capacitor. The capacitor C2 is smaller than the capacitor C1.

  The capacitor C2 is disposed on one side of the connection conductor when viewed in plan. The capacitor C1 is disposed on the other side of the connection conductor when viewed in plan. Each capacitor C1, C2 is arranged so as to be close to the connection conductor.

  The U-shaped part 4 h of the negative electrode side bus bar 4 is arranged inside the U-shaped part 3 h of the positive electrode side bus bar 3. The U-shaped portion 4h and the U-shaped portion 3h are arranged so that the surfaces are substantially parallel to each other. In the present embodiment, the curved portion 3c of the U-shaped portion 3h and the curved portion 4c of the U-shaped portion 4h are arranged on the same side.

  FIG. 10 shows a schematic plan view of the connection conductor and the capacitor in the present embodiment. The positive electrode side bus bar 3 has an extending portion 3f formed so as to extend from the flat plate portion 3a. The extending part 3f is electrically connected to one pole of the capacitor C1. The negative electrode side bus bar 4 has an extending portion 4f formed so as to extend from the flat plate portion 4a. The extending portion 4f is electrically connected to the other pole of the capacitor C1.

  FIG. 11 is a schematic perspective view of the smoothing capacitor and the connection conductor when viewed from the side where the smoothing capacitor is disposed. Referring to FIGS. 10 and 11, extension portion 3 f of positive electrode side bus bar 3 and extension portion 4 f of negative electrode side bus bar 4 are arranged so as to intersect each other. Each of the extending portions 3f and 4f is formed in a plate shape.

  FIG. 12 shows a schematic perspective view of the capacitor and the connection conductor when viewed from the side where the snubber capacitor is disposed. Referring to FIGS. 10 and 12, positive electrode side bus bar 3 has an extending portion 3g formed so as to extend from flat plate portion 3b. The extending part 3g is formed in a plate shape. The extending portion 3g is electrically connected to one pole of the capacitor C2. The negative electrode side bus bar 4 has an extending portion 4g formed so as to extend from the flat plate portion 4b. The extending part 4g is formed in a plate shape. The extending portion 4g is electrically connected to the other pole of the capacitor C2.

  With reference to FIGS. 8 to 10, the connection conductor in the present embodiment is arranged such that flat plate portion 3 a, flat plate portion 4 a, flat plate portion 4 b and flat plate portion 3 b are arranged in this order. The flat plate portions 3a, 3b, 4a, 4b are arranged so as to extend substantially parallel to each other. Each of the flat plate portions 3a, 3b, 4a, 4b is arranged so that the maximum area surfaces are substantially parallel to each other.

  Also in the connection conductor in the present embodiment, the surface area of the conductor can be increased, and the inductance can be reduced. As a result, the surge voltage can be suppressed.

  Referring to FIGS. 9 to 12, four flat plate portions 3a, 3b, 4a, and 4b have one pole of capacitor C1 along one direction when cut by a plane perpendicular to the direction of current flow. , The other pole of the capacitor C1, the other pole of the capacitor C2, and the one pole of the capacitor C2. In addition, notches 3e and 4e are formed so as to electrically isolate a part of each flat plate portion.

  The flat plate portion 3a and the flat plate portion 4a are formed so as to extend in the same direction and are connected to the capacitor C1. The flat plate portion 3a and the flat plate portion 4a have a parallel plate configuration. For this reason, in the flat plate portions 3a and 4a, an effect of canceling out the inductances can be obtained.

  Similarly, the flat plate portion 3b and the flat plate portion 4b are formed so as to extend in the same direction and are connected to the capacitor C2. That is, the flat plate portion 3b and the flat plate portion 4b have a parallel plate configuration. For this reason, in the flat plate portions 3b and 4b, it is possible to obtain an effect of canceling the inductances.

  Referring to FIG. 6, in the present embodiment, the connection conductor in the present embodiment is arranged at a portion connecting capacitors C1, C2, power supply line PL, and ground line SL. That is, the connection conductor in the present embodiment is arranged in a circuit between the capacitors C1 and C2 and the connection point 51a. The section of the circuit in which the connection conductor in the present embodiment is useful is not limited to this form. For example, by using the connection conductor in the section connecting the capacitors C1 and C2 indicated by arrows 66 and 67 and the switching module. Similar actions and effects can be obtained.

  In the present embodiment, each conductor is provided with a notch. However, the present invention is not limited to this, and the notch may not be formed. In the present embodiment, two capacitors are arranged. However, the present invention is not limited to this configuration, and the present invention can be applied to connection conductors for connecting any number and any electric element. .

  In the present embodiment, the U-shaped portion of the negative electrode-side conductor is disposed inside the U-shaped portion of the positive-electrode-side conductor. However, the present invention is not limited to this configuration. The U-shaped part of the conductor on the positive electrode side may be arranged inside. Further, the conductors are arranged so that the curved portions of the U-shaped portion are in the same direction as each other. However, the present invention is not limited to this configuration, and the curved portions of the U-shaped portion may be arranged in opposite directions. I do not care.

  Since other configurations, operations, and effects are the same as those in the first embodiment, description thereof will not be repeated here.

  In the respective drawings described above, the same or corresponding parts are denoted by the same reference numerals.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

FIG. 3 is an electric circuit diagram of the inverter device in the first embodiment. 1 is a schematic exploded perspective view of an inverter device in a first embodiment. 3 is a schematic perspective view of a connection conductor in the first embodiment. FIG. 4 is a schematic plan view of a connection conductor and a capacitor housing portion in the first embodiment. FIG. It is a schematic perspective view of the connection conductor which has the structure of a parallel plate. FIG. 5 is an electric circuit diagram of an inverter device in a second embodiment. FIG. 6 is a schematic exploded perspective view of an inverter device according to a second embodiment. 6 is a schematic perspective view of a connection conductor in Embodiment 2. FIG. FIG. 9 is a schematic plan view of a capacitor housing portion and a connection conductor in the second embodiment. FIG. 6 is a schematic plan view of a connection conductor and a capacitor in the second embodiment. FIG. 10 is a first schematic perspective view illustrating connection between a connection conductor and a capacitor in the second embodiment. FIG. 10 is a second schematic perspective view illustrating connection between a connection conductor and a capacitor in the second embodiment. It is a general | schematic disassembled perspective view of the inverter apparatus in a prior art. It is a schematic plan view of the capacitor | condenser accommodating part and connection conductor in a prior art. It is a graph explaining a surge voltage.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Positive side bus bar, 1a Flat plate part, 1b Curved part, 1c Connection part, 1d Extension part, 1e U-shaped part, 2 Negative electrode side bus bar, 2a Flat plate part, 2b Curved part, 2c Connection part, 2d Extension part, 2e U-shaped part, 3 positive side bus bar, 3a, 3b flat plate part, 3c curved part, 3d connecting part, 3e notch part, 3f, 3g extension part, 3h U-shaped part, 4 negative side bus bar, 4a, 4b flat plate part 4c curved portion, 4d connecting portion, 4e notch portion, 4f, 4g extending portion, 4h U-shaped portion, 5 positive side bus bar, 5a connecting portion, 6 negative side bus bar, 6a connecting portion, 11-16 terminal portion, 18, 19 Inverter device, 20 Inverter body, 21, 28, 29 Capacitor housing, 22 U-phase arm, 24 V-phase arm, 26 W-phase arm, 30 control device, 41, 42 Busbar, 51a, 5 b, 52a, 52b Connection point, 61-64, 66, 67 arrow, C1, C2 capacitor, D1-D6 diode, MG motor generator, Q1-Q6 npn transistor, B battery, PL power supply line, SL ground line, UL , VL, WL Output line.

Claims (1)

An inverter body including a circuit having a switching element;
A first capacitor and a second capacitor connected in parallel to the circuit having the switching element;
A connection conductor for electrically connecting the inverter body and the first capacitor;
The connection conductor includes a first conductor to be connected to one pole;
A second conductor to be connected to the other pole,
Each of the first conductor and the second conductor is formed in a plate shape,
Each of the first conductor and the second conductor includes a U-shaped portion having a U-shaped cross-section ,
The first capacitor and the second capacitor are connected to the inverter body via the connection conductor,
The U-shaped portion has two flat plate portions facing each other and a curved portion interposed between the flat plate portions,
Of the first conductor and the second conductor, the other U-shaped part is arranged inside one U-shaped part, so that the four flat plate parts are arranged side by side,
The first conductor and the second conductor are arranged so that the two flat plate portions of the first conductor and the two flat plate portions of the second conductor are substantially parallel to each other. And
When the four flat plate portions are cut along a plane perpendicular to the direction in which the current flows, one pole of the first capacitor, the other pole of the first capacitor, and the second, along one direction. An inverter device connected to the other pole of the capacitor and one pole of the second capacitor in this order .

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