JPH0628948Y2 - Power converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a power conversion device including a conductor forming a wiring of a DC circuit between a DC intermediate section and an inverter including a switching element.

[Conventional technology]

Generally, in this type of power conversion device, when the switching element forming the inverter is turned off, an overvoltage generated by the inductance of the DC circuit between the DC intermediate portion and each phase of the inverter and the output circuit of the inverter is allowed by the switching element. When the voltage exceeds the voltage, the switching element is damaged and destroyed, and the reliability of the power conversion device itself is impaired. Therefore, suppression of overvoltage is an important issue.

In that case, a freewheeling diode or a feedback diode is provided to release the energy stored in the load circuit, and a snubber circuit is provided to suppress the overvoltage due to the inductance of the power supply circuit or transistor arm to protect the switching elements. It is widely known to do. However, this kind of means for suppressing an overvoltage that appears when the switching element is turned off based on the inductance of each circuit has a drawback that the circuit configuration and wiring of the power conversion device are complicated and the cost is increased.

On the other hand, as described above, as a means for suppressing the overvoltage and protecting the switching element without using a freewheeling diode, a feedback diode, or a snubber circuit, a low-inductance conductor is used to reduce the inductance itself of the circuit wiring. Is being used. Particularly, in the DC circuit from the DC intermediate portion to the inverter, in this case, the transistor inverter, the transistors 7U ₁ and 7V ₁ on the upper arm side of each phase of the DC power source 9 to the inverter 10 as shown in the circuit wiring diagram of FIG. And 7W ₁ and the circuits from the lower arm side transistors 7U ₂ , 7V ₂ and 7W _{2 of} each phase to the DC power supply 9 are formed by a single low-inductance conductor 1 to reduce the wiring inductance of the DC circuit. We are trying to reduce it.

At that time, in the conventional wiring, as shown in FIG. 3, the low-inductance conductor 11 has a copper band 12 through which a positive current flows and a copper band 13 through which a negative current flows in parallel with a thin insulating film 14 in close proximity to each other. It consists of a resin coating 15 fixed all over the periphery, and the copper strips 12 of the conductor 11 are respectively connected to the collectors of the transistors 7U ₁ , 7V ₁ and 7W ₁ on the upper arm side of the inverter 10 via the copper plate terminals 16. Copper strip 13 to copper plate terminal 17
Transistor 7U ₂ on the lower arm side of inverter 10 via
Connected to 7V ₂ and 7W ₂ emitters respectively.

[Problems to be solved by the device]

However, in the wiring of the DC circuit of the conventional power converter, the copper plate terminals 16 extending from the copper strips 12 and 13 of the single conductor 11 to the upper and lower arm transistors of each phase of the inverter are provided.
And 17 are pulled out, the transistors 7U ₁ and 7U ₂ and the transistors 7V ₁ and 7 are used for a test or the like for maintenance and inspection.
The transistors of the positive and negative sides of the same phase so on V ₂ and transistor 7W ₁ and 7W ₂ while a set, could not be separated from the set of transistors in another phase while subjecting the wire . Also, if you dare to separate the conductor
11 to other phase pairs of transistors and their respective copper plate terminals
It has the disadvantage of inconvenience of having to break the connection between 16 and 17.

[Means for Solving the Problems]

In order to solve the above-mentioned drawbacks, the present invention provides a power conversion device including a conductor forming a wiring of a DC circuit between a DC intermediate section and an inverter including a switching element,
In the conductor, a positive flowing copper strip and a negative flowing copper strip are arranged in parallel at a close distance with an insulating film interposed therebetween, and connecting terminals formed at both ends of a conductor unit having the number of phases of the inverter are connected to each other. It is characterized in that the conductor unit is connected to the switching elements of the upper and lower arms of each phase of the inverter via copper plate terminals.

[Action]

According to the present invention, the conductor forming the wiring of the DC circuit between the DC intermediate portion of the power conversion device and the inverter is composed of a conductor unit having the number of phases of the inverter with connection terminals formed at both ends,
Since the integrated direct-current circuit wirings are formed by being connected to each other through the connecting terminals of the conductor unit, it is possible to form mutually separable direct-current circuit wirings for each phase of the inverter.

〔Example〕

Next, the details of the present invention will be explained based on the embodiments shown in the drawings.

As shown in FIG. 2, the wiring of the DC circuit between the DC intermediate portion of the power converter according to the present invention and the inverter composed of a transistor, as shown in FIG.
Wiring 1 of the circuit leading to the upper arm side transistors 7U ₁ , 7V ₁ and 7W ₁ of each phase and the circuit returning from the lower arm side transistors 7U ₂ , 7V ₂ and 7W ₂ of each phase of the inverter 10 to the DC power supply 9 As shown in FIG. 1, a copper strip 2 through which a positive current flows and a copper strip 3 through which a negative current flows are juxtaposed in parallel with each other with a thin insulating film 4 interposed therebetween, and a resin 5 is applied to the entire periphery. Being fixed is similar to the low-inductance conductor used in conventional DC circuits of this type.

However, in the case of the low-inductance conductor 1 of the present invention, as shown in FIG. 1, the conductor 1 is formed as conductor units 1U, 1V and 1W prepared for each phase of the inverter 10. Connection terminal portions 2a, 2b and 3a, 3b capable of connecting the conductor units to each other are formed at both ends of the copper band 2 and the copper band 3 of each conductor unit. In each conductor unit, the connection terminal portions are connected to each other via the connection screw 8 to form an integrated wiring. In each phase of the inverter 10, the conductor unit 1U is similarly connected to the collector of the upper arm side transistor 7U ₁ via the copper plate terminal 6 and to the emitter of the lower arm side transistor 7U ₂ via the copper plate terminal 7. Unit 1V with transistors 7V ₁ and 7V ₂
In addition, the conductor unit 1W is connected to the transistors 7W ₁ and 7W ₂ , respectively, and the conductor units 1U, 1V and 1W are adjacent to each other by the screw 8 via the connection terminals 2a, 2b and 3a, 3b at both ends thereof. By connecting each of them, the wiring of the DC circuit shown in FIG. 2 can be formed.

Therefore, in this case, the screw 8 of the connection terminal between the adjacent conductor units is removed as necessary to connect the upper arm side transistor and the lower arm side transistor of each phase of the inverter 10 in one set. It can be very easily separated from the others. Furthermore, the conductor unit for each phase is formed to be relatively short and lightweight, and the conductor unit is configured by using a wide and thin conductor, and a copper band through which a positive current flows and a copper band through which a negative current flows are formed. It is also advantageous compared to the case of the conventional single conductor in that the inductance can be further reduced by arranging in parallel with each other.

[Effect of device]

As described above, the present invention is directed to a power converter including a conductor forming a wiring of a DC circuit between a DC intermediate portion and an inverter composed of a switching element, wherein the conductor has an insulating film interposed between the conductor and the conductor. A positive flowing copper strip and a negative flowing copper strip are arranged in parallel with each other, and connecting terminals formed at both ends of a conductor unit having the number of phases of the inverter are connected to each other, and the conductor unit is By connecting the switching elements of the upper and lower arms of each phase of the inverter via the copper plate terminals, conductors can be independently provided in each phase of the inverter and connected to each other to form an integrated DC circuit wiring. Therefore, it becomes possible to separate the inverter from each other by making a pair of switching elements for the upper and lower arms for each phase for testing during maintenance and inspection. Convenience on the work at the time of inspection is obtained.

[Brief description of drawings]

FIG. 1 is a schematic connection diagram illustrating wiring of an inverter circuit using a conductor unit according to the present invention, FIG. 2 is a schematic DC circuit wiring diagram between a DC intermediate portion of a power converter and an inverter, and FIG. The figure is a schematic connection diagram illustrating the wiring of an inverter circuit using a conventional conductor. 1: conductor, 1U, 1V, 1W: conductor unit, 2: copper band in which positive current flows, 3: copper band in which negative current flows, 2a, 2b, 3a, 3b:
Connection terminals, 4: Insulation film, 7U ₁ , 7U ₂ , 7V ₁ , 7V ₂ , 7W ₁ ,
7W ₂ : Switching element, 9: DC power supply, 10: Inverter.

Claims (1)

[Scope of utility model registration request] 1. A power conversion device comprising a conductor forming a wiring of a direct current circuit between a direct current intermediate portion and an inverter composed of a switching element, wherein the conductor positively flows at a close distance with an insulating film interposed. The copper band and the negative flowing copper band are arranged in parallel, and the connecting units formed at both ends of the conductor unit having the number of phases of the inverter are connected to each other, and the conductor unit is provided in each of the inverters. A power converter characterized in that it is connected to switching elements of upper and lower arms of a phase via copper plate terminals.