JP2002051403A - Electrical system for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constitution which is ideal for an electrical system for automobile which supplies electric power from a DC power source to electrical equipment via a semiconductor power converter. SOLUTION: Radio disturbances to a car radio, etc., are suppressed, in such a way that an electric wire formed by successively concentrically forming a conductor 231, first insulating material 232, electrostatic shielding material 233 which covers the entire surface of the conductor 231, second insulating material 234; and electromagnetic shielding material 233 which covers the entire surface of the shielding material 233, in this order is used as a feeder line 23au, which supplies electric power from an inverter 2 constituting the semiconductor power converter to an AC motor 3, constituting the electric equipment and one ends of the electrostatic and electromagnetic shielding materials 233 and 235 are respectively connected to the grounding potential and frame of the AC motor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric system of a motor vehicle for supplying electric power from a DC power supply to a power supply through a semiconductor power converter.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing the configuration of an electric system of an electric vehicle as an example of an electric system of an automobile of this type, wherein 1 is a DC power supply such as a storage battery, 2 is an inverter as a semiconductor power converter, and 3 is an inverter. Is an AC motor for driving a vehicle as electric equipment.

In FIG. 4, an inverter 2 includes semiconductor switching elements 21u and 22 constituting a u-phase arm 20u.
u, the semiconductor switching elements 21v and 22v forming the v-phase arm 20v, and the semiconductor switching elements 21w and 22w forming the w-phase arm 20w are turned on and off based on a predetermined sequence, so that the output terminals 2u, 2v and 2w, a three-phase AC voltage having a desired frequency and amplitude is generated.
1 and the electric vehicle runs.

In FIG. 4, reference numeral 23u denotes an inverter 2
, A u-phase power supply line from the inverter 2 to the AC motor 3, 23 w a w-phase power supply line from the inverter 2 to the AC motor 3, 24 an input capacitor of the inverter 2, 12 p , 12n indicate a power supply line between the DC power supply 1 and the inverter 2, and 1p is a positive terminal of the DC power supply 1, 1n is a negative terminal of the DC power supply 1, 2p is a positive terminal of the inverter 2, and 2n is a negative terminal of the inverter 2. The terminals 3u, 3v, and 3w are the terminals u of the winding 31 of the AC motor 3.
The input terminals of the phase, v-phase, and w-phase are shown.

FIG. 5 shows an example of a line voltage waveform output from the inverter 2. The line voltage is the voltage E of the DC power supply 1.
The tooth voltage of the comb of d is shown, and the broken line shows the waveform of the fundamental wave voltage of the tooth voltage of the comb (solid line). In other words, the comb tooth voltage shown by the solid line includes many harmonic voltages in addition to the fundamental wave voltage shown by the broken line, and this harmonic voltage causes a reception failure in a car radio or the like.

Hereinafter, the causes of the above-described reception failure of the car radio and the like will be described with reference to the drawings (FIGS. 6 to 8).

FIG. 6 shows the potential of the output terminal 2u of the inverter 2 with respect to the vehicle body 4, and shows the potential between times T1 and T2.
Is the semiconductor switching element 21u of the inverter 2.
Is on, the semiconductor switching element 22u is off, and
During the period from time T2 to T3, the semiconductor switching element 22u
Is on and the semiconductor switching element 21u is off.

That is, since the DC power supply 1 is substantially uniformly insulated from the vehicle body 4, the potential of the positive terminal 2p with respect to the vehicle body 4 is + Ed / 2, and the potential of the negative terminal 2n is
Is -Ed / 2. Therefore, when the semiconductor switching elements 21u and 22u are turned on and off alternately, the potential of the output terminal 2u with respect to the vehicle body 4 is + Ed / 2,
Or it becomes -Ed / 2.

FIG. 7 is a schematic diagram for explaining the details of the potential fluctuation between the inverter 2 and the AC motor 3, and the same components as those shown in FIG. 4 are denoted by the same reference numerals. .

That is, in FIG. 7, 25 is a cooling plate of the semiconductor switching element, 26 is an insulating material between the semiconductor switching element 21u (or 22u) and the cooling plate 25, and a housing 27 of the inverter 2 is The cooling plate 25 is fixed to the vehicle body 4. further,
32 is an insulating material of the winding 31 of the AC motor 3, 33 is an iron core of the AC motor 3, 34 is a frame of the AC motor 3, and a frame 34 of the AC motor 3 is fixed to the vehicle body 4.

Therefore, as shown in FIG. 6, the voltage at which the potential changes sharply with respect to the vehicle body 4 is applied to the winding 31 of the AC motor 3.
, The insulators 26, 32 act as components of the capacitor, through which high frequency current flows.

FIG. 8 is a schematic configuration diagram for explaining the details of the potential fluctuation between the DC power supply 1 and the inverter 2, and FIG.
The same components as those shown in FIG.

That is, in FIG.
The conductive material 11 is a conductive part 10 of the DC power source 1 and the DC power source 1
Of the DC power supply 1 is shown.
Is fixed to the vehicle body 4 by the housing 12.

Therefore, as shown in FIG. 6, the voltage at which the potential changes sharply with respect to the vehicle body 4 is applied to the switching element 21.
When applied to u, 22u, the insulators 11, 26 act as components of the capacitor, through which high frequency current flows.

Electromagnetic radiation due to a harmonic voltage accompanied by a steep potential fluctuation as described above, and electromagnetic radiation due to high-frequency current flowing through the insulators 11, 26, 32 and the vehicle body 4 acting as components of the capacitor due to the harmonic voltage. This causes reception problems in car radios and the like.

[0016]

FIG. 9 is a schematic configuration diagram showing an example of a conventional countermeasure against the above-mentioned reception failure to a car radio or the like, in which power supply lines 23au, 23av, 23av, 23av, and 23b from the inverter 2 to the AC motor 3 are shown. A shield wire is used for 23aw, and a zero-phase reactor 5 is inserted therein. Although not shown, a shield line is also used as a power supply line from the DC power supply 1 to the inverter 2, and a zero-phase reactor is inserted.

The zero-phase reactor 5 and the shield wire shown in FIG. 9 will be described below.

That is, since the sum of the instantaneous current values of the fundamental frequency of the three-phase alternating current to the AC motor 3 is zero, the driving characteristics of the AC motor 3 are not affected. As is well known, the instantaneous value of is not zero, so the high-frequency current is suppressed by the zero-phase reactor 5, and as a result, the high-frequency current is reduced.

As shown in FIG. 10, the shield wire is generally formed by forming a conductive material 23u1, an insulating material 23u2, a net-shaped shielding material 23u3, and an insulating material 23u4 in concentric circles in order from the center. The conductive material 23
A current flows through the shield member 23u3 so as to cancel the electromagnetic wave generated from the main current flowing through u1, thereby reducing electromagnetic radiation to the outside. When the shield wire shown in FIG. 10 is applied to the configuration of FIG.
When one end of the au shield material (reference numeral 23u3 in FIG. 10) is connected to the ground point of the inverter 2, the effect of suppressing the high-frequency current by the zero-phase reactor 5 is not obtained, and the current flowing through the shield material (23u3) itself is not obtained. There is a problem that electromagnetic radiation is generated.

Further, the switching frequency of semiconductor power converters has been increasing with the increase in the frequency of power devices in recent years, and a shielded wire having a high shielding effect up to a higher frequency region has been desired. . However,
Since the shield of the current shielded wire is mesh-shaped, there is a problem that the effect of the electromagnetic reaction due to the shield wire current is weakened in the middle portion of the mesh.

An object of the present invention is to provide an electric system for a motor vehicle which solves the above problems.

[0022]

According to a first aspect of the present invention, there is provided an electric system of an automobile for supplying electric equipment from a DC power supply via a semiconductor power converter, wherein a wiring from the DC power supply to the semiconductor power converter is provided. Uses an electric wire formed by forming a conductive material, a first insulating material, a thin plate-shaped electrostatic shielding material, a second insulating material, and a thin plate-shaped magnetic shielding material in concentric circles in order from the center; The main current is passed through the material, one end of the electrostatic shield material is connected to the ground potential of the semiconductor power converter, and one end of the magnetic shield material is connected to the housing of the semiconductor power converter. Features.

According to a second aspect of the present invention, in the electric system of the vehicle, a wiring from the semiconductor power converter to the electric device includes a conductive material, a first insulating material, a thin plate-shaped electrostatic shielding material, and a second insulating material. And a thin plate-shaped magnetic shield material and an electric wire formed concentrically in order from the center, a main current is allowed to flow through the conductive material, and one end of the electrostatic shield material is connected to the electrical device. The magnetic shield member is connected to a ground potential, and one end of the magnetic shield member is connected to a housing of the electric device.

According to a third aspect of the present invention, in the electric system of the automobile, wiring from the DC power supply to the semiconductor power converter includes a conductive material, a first insulating material, and a thin plate-shaped electrostatic shielding material in order from the center. An electric wire is formed by bundling a plurality of electric wire bodies formed in concentric circles, and forming the bundled electric wire body, the second insulating material, and the thin plate-shaped magnetic shield material in concentric circle order from the center. Use, let the main current flow through the conductive material,
One end of the electrostatic shield material is connected to a ground potential of the semiconductor power converter, and one end of the magnetic shield material is connected to a housing of the semiconductor power converter.

According to a fourth aspect of the present invention, in the electric system of the automobile, wiring from the semiconductor power converter to the electric equipment includes a conductive material, a first insulating material, and a thin plate-shaped electrostatic shielding material in order from the center. A plurality of concentrically formed electric wire bodies are bundled, and the bundled electric wire body, the second insulating material, and the thin plate-shaped magnetic shield material are used in order from the center to form a concentrically formed electric wire. A main current is passed through the conductive material, one end of the electrostatic shield material is connected to a ground potential of the electric device,
One end of the magnetic shield material is connected to a housing of the electric device.

According to a fifth aspect of the present invention, in the electric system for an automobile according to the first to fourth aspects, a zero-phase reactor is inserted in the middle of the concentrically formed electric wire. .

According to the present invention, since a reception failure to a car radio or the like is caused by electromagnetic radiation due to a high-frequency current accompanying switching of a semiconductor power converter and electromagnetic radiation due to fluctuations in electric potential with respect to a vehicle body accompanying the switching, electric equipment can be used. In order to prevent electromagnetic radiation due to high-frequency current from the feeder line, and to prevent electromagnetic radiation due to current flowing through the shield of the shield wire,
Wiring for supplying power from the DC power supply to the semiconductor power converter and from the semiconductor power converter to the electric equipment is an electrostatic shield material that is coated on one surface with a conductive material via an insulating material, and one end of the shield material is supplied with power. The side is grounded to the vehicle body, is further covered on one side with an electromagnetic shielding material via an insulating material, and a zero-phase reactor is inserted in the middle of the wiring.

[0028]

FIG. 1 is a schematic structural view of an electric system of an automobile showing a first embodiment of the present invention. The same components as those shown in FIG. 4 are denoted by the same reference numerals. ing.

That is, in FIG. 1, 23au, 23a
v and 23aw are power supply lines, and 23u and 2aw shown in FIG.
3v, 23w, and 231 in the feeder line 23au.
Denotes a conductive material, 232 denotes a first insulating material, 233 denotes an electrostatic shielding material, 234 denotes a second insulating material, and 235 denotes an electromagnetic shielding material. As shown in FIG. I have. In addition, one end of the electrostatic shield member 233 is connected to the ground portion 30 on the AC motor 3 side via a ground line 236u. Similarly, the power supply lines 23av and 23aw are connected to the ground portion 30 via the ground lines 236v and 236w. It is connected. Further, the electromagnetic shield member 235 is connected to the frame of the AC motor 3.

As is apparent from the configuration diagram shown in FIG. 1, the electrostatic shielding material 233 covers the conductive material 231 over the entire surface without any gap, and the electromagnetic shielding material 235 covers the electrostatic shielding material 233 over the entire surface without any gap. It is coated.

FIG. 2 shows an equivalent circuit diagram of the configuration shown in FIG. 1. As is apparent from FIG. 2, the equivalent capacitor of the first insulating material 232 is changed by the change of the potential of the conductive material 231 with respect to the vehicle body on the feeder line 23au. The leakage current is2 flowing through the AC motor 232c and the AC motor 3
The current flows through the vehicle body through the frame a, but this current is suppressed by the zero-phase reactor 5a. Further, a radiation flux is generated by a current flowing through the shield member 233, but the radiation flux is confined by the electromagnetic shield member 235 and is not radiated outside the electromagnetic shield 235.

FIG. 3 is a schematic structural view of an electric system of a vehicle showing a second embodiment of the present invention, and the same components as those shown in FIG. 1 are denoted by the same reference numerals.

That is, in the configuration shown in FIG.
On the other hand, in the configuration shown in FIG. 3, the power supply lines are not provided with the electromagnetic shielding material, but are bundled together in three phases, and the electromagnetic shielding material is provided outside the electromagnetic shielding material. The difference is that a member 237 is provided, but the operation is the same as that of the configuration shown in FIG.

Although FIGS. 1 to 3 have described the configuration and connection of the power supply line from the inverter 2 to the AC motor 3, the power supply line from the DC power supply 1 to the inverter 2 is also shown in FIG. 1 or FIG. It can be configured. Further, although an example of an inverter has been described as a semiconductor power converter, the configuration of the embodiment of the present invention can be applied to a DC-DC converter and the like.

Furthermore, although the description has been given of the case of the electric system of an electric vehicle equipped with a DC power supply, the present invention is also applied to a conventional electric system of an automobile using an internal combustion engine, an electric system of a hybrid electric vehicle, and an electric system of a fuel cell vehicle. Applicable.

[0036]

According to the present invention, in order to suppress the problem of reception failure of a car radio by a conventional feed line in which a net-like electrostatic shield wire and a zero-phase reactor are combined, a static feed line is entirely covered. By forming an electric shield material and a shield wire in which the outside of the electrostatic shield material is entirely covered with an electromagnetic shield material, and further inserting a zero-phase reactor in the middle of the power supply line, the following (1) and (2) Bring the effect. (1) Electromagnetic radiation to the outside due to displacement of the power supply line with respect to the vehicle body and high-frequency current can be suppressed. (2) It is possible to reduce a communication failure of a communication device, which is an essential problem of an electric vehicle, which can greatly contribute to the spread and development of electric vehicles and hybrid electric vehicles.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electric system of an automobile showing a first embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram for explaining the operation of FIG. 1;

FIG. 3 is a schematic configuration diagram of an electric system of an automobile showing a second embodiment of the present invention.

FIG. 4 is a configuration diagram of an electric system of the electric vehicle.

FIG. 5 is an example of a waveform of an output voltage of the inverter shown in FIG. 4;

FIG. 6 is a diagram showing a potential of an output terminal of the inverter shown in FIG. 4 with respect to a vehicle body;

FIG. 7 is a schematic configuration diagram between the inverter and the AC motor shown in FIG. 4;

8 is a schematic configuration diagram between the DC power supply and the inverter shown in FIG.

FIG. 9 is a schematic configuration diagram of an electric system of a conventional electric vehicle.

FIG. 10 is a schematic configuration diagram of a conventional shielded wire.

[Description of Signs] 1 ... DC power supply, 1p ... Positive electrode terminal, 1n ... Negative electrode terminal, 2,
2a: inverter, 2u, 2v, 2w: output terminal, 2p
... Positive electrode terminal, 2n ... Negative electrode terminal, 3,3a ... AC motor,
3u ... u phase terminal, 3v ... v phase terminal, 3w ... w phase terminal, 4
... Vehicle, 5, 5a ... Zero-phase reactor, 10 ... Conductive material, 1
DESCRIPTION OF SYMBOLS 1 ... Insulation material, 12 ... Housing, 20u ... u-phase arm, 20v
... v-phase arm, 20w ... w-phase arm, 21u, 21v,
21w, 22u, 22v, 22w ... switching elements,
23u, 23au, 23bu ... u-phase feeder, 23v, 2
3av, 23bv... V-phase feeder, 23w, 23aw, 2
3bw: w-phase power supply line, 23u1: conductive material, 23u2: insulating material, 23u3: electrostatic shielding material, 23u4: insulating material,
24 input capacitor, 25 cooling plate, 26 insulating material,
27: housing, 30: ground terminal, 31, 31a: winding, 3
2 ... winding insulation material, 33 ... iron core, 34 ... frame, 231
... conductive material, 232 ... first insulating material, 233 ... electrostatic shielding material, 234 ... second insulating material, 235,237 ... electromagnetic shielding material, 236u, 236v, 235w ... connecting wires.

Claims (5)

[Claims] 1. An electric system for a motor vehicle which supplies electric equipment from a DC power supply via a semiconductor power converter, wherein a wiring from the DC power supply to the semiconductor power converter includes a conductive material, a first insulating material, and a thin plate. Using an electric wire formed by forming concentric circles in order from the center of an electrostatic shield material, a second insulating material, and a thin magnetic shield material in a shape of a circle, and passing a main current through the conductive material, An electric system for an automobile, wherein one end of an electrostatic shield material is connected to a ground potential of the semiconductor power converter, and one end of the magnetic shield material is connected to a housing of the semiconductor power converter. 2. An electric system of an automobile for supplying electric equipment from a DC power supply via a semiconductor power converter, wherein wiring from the semiconductor power converter to the electric equipment includes a conductive material, a first insulating material, and a thin plate. Using an electric wire formed by forming concentric circles in order from the center of an electrostatic shield material, a second insulating material, and a thin magnetic shield material in a shape of a circle, and passing a main current through the conductive material, An electric system for an automobile, wherein one end of an electrostatic shield material is connected to a ground potential of the electric device, and one end of the magnetic shield material is connected to a housing of the electric device. 3. An electric system of an automobile for supplying electric equipment from a DC power supply via a semiconductor power converter, wherein wiring from the DC power supply to the semiconductor power converter includes a conductive material, a first insulating material, and a thin plate. A plurality of electric wire bodies formed concentrically in order from the center with the shape of the electrostatic shield material are bundled, and the bundled electric wire body, the second insulating material, and the thin plate-shaped magnetic shield material are sequentially arranged from the center. Using an electric wire formed concentrically, allowing a main current to flow through the conductive material, connecting one end of the electrostatic shield material to a ground potential of the semiconductor power converter, An electric system for an automobile, wherein one end of the electric power converter is connected to a housing of the semiconductor power converter. 4. An electric system for a motor vehicle for supplying electric equipment from a DC power supply via a semiconductor power converter, wherein wiring from the semiconductor power converter to the electric equipment includes a conductive material, a first insulating material, and a thin plate. A plurality of electric wire bodies formed concentrically in order from the center with the shape of the electrostatic shield material are bundled, and the bundled electric wire body, the second insulating material, and the thin plate-shaped magnetic shield material are sequentially arranged from the center. A concentric wire is used, a main current is passed through the conductive material, one end of the electrostatic shield material is connected to a ground potential of the electric device, and one end of the magnetic shield material is used. A vehicle electrical system connected to a housing of the electrical device. 5. The vehicle electric system according to claim 1, wherein a zero-phase reactor is inserted in the middle of the concentrically formed electric wire. Electrical system.