FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
DRIVE UNIT
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION
ORGANISED AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE
ADDRESS IS 7-3, MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO
1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED
2
DESCRIPTION
Field
[0001] The present disclosure relates to a drive unit
including a converter and an inverter.5
Background
[0002] On a main circuit substrate including a converter
and an inverter thereon, wiring pattern routing on the
negative side of a power module has an important role in10
noise reduction and in prevention of malfunction. On the
other hand, some pin assignment of the power module leads
to a long length in wiring pattern routing, posing a
question of performance improvement. For example, Patent
Literature 1 discloses a technology for providing an15
antinoise measure in a configuration in which the positive
terminal of the converter and the positive terminal of the
inverter are connected to each other by a conductor bar,
and the negative terminal of the converter and the negative
terminal of the inverter are connected to each other by20
another conductor bar, and these conductor bars pass
through the core.
Citation List
Patent Literature25
[0003] Patent Literature 1: WO 2015/056286 A
Summary of Invention
Problem to be solved by the Invention
[0004] The conventional technology does not have a30
structure in which the conductor bars are disposed on the
substrate. A drive unit is demanded that can reduce noise
superimposed on wiring and can prevent malfunction of the
3
circuit in a case where a converter and an inverter are
installed on a substrate to form a power module.
[0005] The present disclosure has been made in view of
the foregoing, and it is an object of the present
disclosure to provide a drive unit capable of reducing5
noise superimposed on wiring and of preventing malfunction
of the circuit in a case where a converter and an inverter
are installed on a substrate to form a power module.
Means to Solve the Problem10
[0006] To solve the problem and achieve the object
described above, a drive unit according to the present
disclosure includes a substrate, a converter installed on
the substrate, an inverter installed on the substrate, a
positive-side busbar that connects a positive terminal of15
the converter and a positive terminal of the inverter, and
a negative-side busbar that connects a negative terminal of
the converter and a negative terminal of the inverter.
Each of the positive-side busbar and the negative-side
busbar is covered with an electrically insulating material.20
The positive-side busbar and the negative-side busbar are
disposed in parallel with each other above the substrate.
Effects of the Invention
[0007] A drive unit according to the present disclosure25
provides an advantageous effect in capability of reducing
noise superimposed on wiring and of preventing malfunction
of the circuit in a case where a converter and an inverter
are installed on a substrate to form a power module.
30
Brief Description of Drawings
[0008] FIG. 1 is a diagram schematically illustrating a
configuration of a drive unit according to a first
4
embodiment.
FIG. 2 is a schematic diagram illustrating
installation positions of a power module, a P-side busbar,
and an N-side busbar included in the drive unit according
to the first embodiment.5
FIG. 3 is a diagram schematically illustrating a
configuration of a drive unit according to a second
embodiment.
FIG. 4 is a schematic diagram illustrating
installation positions of the power module, the P-side10
busbar, the N-side busbar, and an alternating-current
reactor included in the drive unit according to the second
embodiment.
Description of Embodiments15
[0009] A drive unit according to embodiments will be
described in detail below with reference to the drawings.
[0010] First Embodiment.
FIG. 1 is a diagram schematically illustrating a
configuration of a drive unit 101 according to a first20
embodiment. The drive unit 101 includes a substrate 1, a
capacitor 4 installed on the substrate 1, and a power
module 5 installed on the substrate 1. The power module 5
includes a converter 6 and an inverter 7. A P-side output
terminal 8, which is an output terminal on the positive25
side of the converter 6, is connected to a P-side input
terminal 10, which is an input terminal on the positive
side of the inverter 7. An N-side output terminal 9, which
is an output terminal on the negative side of the converter
6, is connected to an N-side input terminal 11, which is an30
input terminal on the negative side of the inverter 7. The
term P side means the plus (+) side, and the term N side
means the minus (–) side. The plus (+) side is the
5
positive side, and the minus (–) side is the negative side.
[0011] FIG. 1 also illustrates a three-phase
alternating-current (AC) power supply 2. The converter 6
has a first input terminal 14, a second input terminal 15,
and a third input terminal 16, each of which is connected5
to the three-phase AC power supply 2. A three-phase AC
voltage input from the three-phase AC power supply 2 to the
converter 6 is converted into a direct-current (DC) voltage
by the converter 6, and the DC voltage generated by the
converter 6 is smoothed by the capacitor 4.10
[0012] The inverter 7 converts the DC voltage generated
by the converter 6 into an AC voltage having a desired
frequency. FIG. 1 also illustrates an electric motor 3.
The AC voltage generated by the inverter 7 is supplied to
the electric motor 3 via a first output terminal 17, a15
second output terminal 18, and a third output terminal 19.
[0013] As illustrated in FIG. 1, the P-side output
terminal 8 of the converter 6 and the P-side input terminal
10 of the inverter 7, and the N-side output terminal 9 of
the converter 6 and the N-side input terminal 11 of the20
inverter 7, included in the power module 5, are positioned
apart from each other due to the pin assignment. The P-
side output terminal 8 of the converter 6 and the P-side
input terminal 10 of the inverter 7 are connected to each
other by a P-side busbar 12. The N-side output terminal 925
of the converter 6 and the N-side input terminal 11 of the
inverter 7 are connected to each other by an N-side busbar
13. That is, the drive unit 101 further includes the P-
side busbar 12 and the N-side busbar 13, where the P-side
busbar 12 is a positive-side busbar that connects the P-30
side output terminal 8, which is the positive terminal of
the converter 6, and the P-side input terminal 10, which is
the positive terminal of the inverter 7; and the N-side
6
busbar 13 is a negative-side busbar that connects the N-
side output terminal 9, which is the negative terminal of
the converter 6, and the N-side input terminal 11, which is
the negative terminal of the inverter 7.
[0014] Each of the P-side busbar 12 and the N-side5
busbar 13 is covered with an electrically insulating
material. The P-side busbar 12 and the N-side busbar 13
are disposed in parallel with each other above the
substrate 1. The drive unit 101 further includes a core 21.
Each of the P-side busbar 12 and the N-side busbar 13 has a10
portion that passes through a penetration opening provided
in a center portion of the core 21. The P-side busbar 12,
the N-side busbar 13, and the core 21 form a common-mode
choke coil.
[0015] FIG. 2 is a schematic diagram illustrating15
installation positions of the power module 5, the P-side
busbar 12, and the N-side busbar 13 included in the drive
unit 101 according to the first embodiment. To provide
more appropriate description of the installation positions
of the P-side busbar 12 and the N-side busbar 13 relative20
to the power module 5, FIG. 2 provides a plan view and a
front view in combination. The P-side busbar 12 and the N-
side busbar 13 are disposed above the power module 5. More
specifically, each of the P-side busbar 12 and the N-side
busbar 13 has a portion that is positioned above the power25
module 5 without contact with the power module 5.
[0016] The use of the P-side busbar 12 and the N-side
busbar 13 can minimize both the length of wiring that
connects the P-side output terminal 8 and the P-side input
terminal 10 and the length of wiring that connects the N-30
side output terminal 9 and the N-side input terminal 11.
In addition, disposition of the P-side busbar 12 and the N-
side busbar 13 above the power module 5, more specifically,
7
disposition of each of the P-side busbar 12 and the N-side
busbar 13 to have a portion that is positioned above the
power module 5 without contact with the power module 5,
eliminates the need for wiring to route the copper foil
pattern around the power module 5, thereby enabling a5
reduction in the patterning area of the substrate 1. This
enables the drive unit 101 to achieve a reduction in the
size of the substrate 1, and also a reduction in impedance
caused by wiring, thereby enabling noise immunity to be
improved, and malfunction of the circuit to be prevented.10
In addition, since each of the P-side busbar 12 and the N-
side busbar 13 has a portion that passes through a
penetration opening provided in a center portion of the
core 21, the drive unit 101 can achieve further improvement
in noise immunity. That is, the drive unit 101 can reduce15
noise superimposed on wiring and can prevent malfunction of
the circuit in a case where the converter 6 and the
inverter 7 are installed on the substrate 1 to form a
single component of the power module 5.
[0017] Second Embodiment.20
FIG. 3 is a diagram schematically illustrating a
configuration of a drive unit 102 according to a second
embodiment. The drive unit 102 is configured similarly to
the drive unit 101 according to the first embodiment.
Accordingly, the description of the second embodiment will25
primarily describe differences from the first embodiment.
Similarly to the drive unit 101, the drive unit 102
converts the three-phase AC voltage input from the three-
phase AC power supply 2 to the converter 6 into a DC
voltage by the converter 6, and converts the DC voltage30
generated by the converter 6 into an AC voltage having a
desired frequency by the inverter 7 to thereby drive the
electric motor 3.
8
[0018] The drive unit 101 according to the first
embodiment is configured such that the P-side busbar 12 and
the N-side busbar 13 are disposed in parallel with each
other, and each of the P-side busbar 12 and the N-side
busbar 13 has a portion that passes through a penetration5
opening provided in a center portion of the core 21, which
configuration improves noise immunity. In the second
embodiment, in contrast, the drive unit 102 includes an AC
reactor 23 disposed in a portion of the P-side busbar 12,
and the P-side output terminal 8 of the converter 6 and the10
P-side input terminal 10 of the inverter 7 are connected to
each other via the AC reactor 23. The N-side busbar 13 is
disposed above the substrate 1 similarly to the first
embodiment. The drive unit 102 includes a core 22 in place
of the core 21 of the first embodiment. No portion of the15
P-side busbar 12 passes through a penetration opening of
the core 22. On the contrary, the N-side busbar 13 has a
portion that passes through the penetration opening
provided in a center portion of the core 22, thereby
enabling the drive unit 102 to improve noise immunity.20
[0019] FIG. 4 is a schematic diagram illustrating
installation positions of the power module 5, the P-side
busbar 12, the N-side busbar 13, and the AC reactor 23
included in the drive unit 102 according to the second
embodiment. To provide more appropriate description of the25
installation positions of the P-side busbar 12, the N-side
busbar 13, and the AC reactor 23 relative to the power
module 5, FIG. 4 provides a plan view and a front view in
combination. The AC reactor 23 is disposed outside the
substrate 1.30
[0020] The above configuration can minimize the length
of wiring that connects the N-side output terminal 9 and
the N-side input terminal 11. In addition, disposition of
9
the N-side busbar 13 above the power module 5 eliminates
the need for wiring to route the pattern around the power
module 5 on the substrate 1, thereby enabling a reduction
in the patterning area of the substrate 1. This enables
the drive unit 102 to achieve a reduction in the size of5
the substrate 1, and also a reduction in impedance of
wiring, thereby enabling noise immunity to be improved, and
malfunction of the circuit to be prevented.
[0021] The configurations described in the foregoing
embodiments are merely examples. These configurations may10
be combined with another known technology, and
configurations of different embodiments may be combined
together. Moreover, such configurations may be partly
omitted or modified without departing from the gist.
15
Reference Signs List
[0022] 1 substrate; 2 three-phase AC power supply; 3
electric motor; 4 capacitor; 5 power module; 6
converter; 7 inverter; 8 P-side output terminal; 9 N-
side output terminal; 10 P-side input terminal; 11 N-side20
input terminal; 12 P-side busbar; 13 N-side busbar; 14
first input terminal; 15 second input terminal; 16 third
input terminal; 17 first output terminal; 18 second
output terminal; 19 third output terminal; 21, 22 core;
23 AC reactor; 101, 102 drive unit.25
10
We Claim:
[Claim 1] A drive unit comprising:
a substrate;
a converter installed on the substrate;
an inverter installed on the substrate;5
a positive-side busbar to connect a positive terminal
of the converter and a positive terminal of the inverter;
and
a negative-side busbar to connect a negative terminal
of the converter and a negative terminal of the inverter,10
wherein
each of the positive-side busbar and the negative-side
busbar is covered with an electrically insulating material,
and
the positive-side busbar and the negative-side busbar15
are disposed in parallel with each other above the
substrate.
[Claim 2] The drive unit according to claim 1, further
comprising20
a core, wherein
each of the positive-side busbar and the negative-side
busbar has a portion that passes through a penetration
opening in a center portion of the core, and
the positive-side busbar, the negative-side busbar,25
and the core form a common-mode choke coil.