WO2017199304A1

WO2017199304A1 - Motor drive device and air conditioner

Info

Publication number: WO2017199304A1
Application number: PCT/JP2016/064513
Authority: WO
Inventors: 崇山川; 成雄梅原; 篠本　洋介
Original assignee: 三菱電機株式会社
Priority date: 2016-05-16
Filing date: 2016-05-16
Publication date: 2017-11-23
Also published as: JPWO2017199304A1; JP6892856B2

Abstract

Provided is a motor drive device that comprises: an inverter unit which outputs AC power to a motor and which has a plurality of inverter modules 25-1 to 25-3, each of the plurality of inverter modules 25-1 to 25-3 having a plurality of switching elements, and each of the plurality of switching elements being a wide bandgap semiconductor element; a control unit for controlling each of the plurality of inverter modules 25-1 to 25-3; a first substrate 30 on which the control unit is disposed and which has a first main surface 30a and a second main surface 30b; and a second substrate 31 which has a third main surface 31a facing the second main surface 30b and a fourth main surface 31b on which the plurality of inverter modules 25-1 to 25-3 are disposed.

Description

Motor drive device and air conditioner

The present invention relates to a motor driving device and an air conditioner for driving a motor.

The inverter constituting the motor drive device has an inverter module, and a plurality of switching elements are arranged in the inverter module. When mounting a plurality of switching elements as chips, reducing the chip area improves the yield when removing from the wafer. In addition, using a wide band gap (WBG) semiconductor with a high chip cost as a switching element and using a plurality of low-capacity inverter modules connected in parallel can reduce the cost of the inverter. There are cases where it is possible.

Patent Document 1 discloses a technique of dividing an inverter unit and using a plurality of small capacity units to drive in parallel.

JP 2010-161846 A

However, when a plurality of low-capacity inverter modules are arranged in parallel on the same substrate, not only the arrangement area of the inverter modules is increased, but also the pattern routing on the substrate is complicated. As the pattern routing on the substrate becomes complicated, the pattern wiring length becomes relatively long, and the impedance of the pattern wiring increases. Further, the switching element malfunctions due to the influence of noise caused by the increase in the impedance of the pattern wiring, and there is a possibility that the reliability of the inverter is lowered. In addition, a switching element using a WBG semiconductor has a high voltage fluctuation rate dV / dt and can be switched at high speed, so that noise is more likely to occur.

The present invention has been made in view of the above, and an object of the present invention is to obtain a motor drive device capable of suppressing the occurrence of malfunctions while reducing costs.

In order to solve the above-described problems and achieve the object, a motor drive device according to the present invention is a motor drive device that drives a motor, and includes an inverter module that outputs AC power to the motor. A part. The motor drive device according to the present invention includes a control unit that controls each of the plurality of inverter modules, a first substrate having the first main surface and the second main surface, the control unit being disposed, And a second substrate having a third main surface facing the second main surface and a fourth main surface on which the plurality of inverter modules are arranged.

The motor driving device according to the present invention has an effect that it is possible to suppress the occurrence of malfunction while reducing costs.

The figure which shows the structural example of the motor drive device which concerns on embodiment of this invention. The figure which shows typically the internal structure of the inverter module which comprises a general inverter The figure which shows typically the some inverter module which comprises the inverter shown in FIG. The figure which shows typically the board | substrate which has arrange | positioned the inverter module shown in FIG. The figure which shows typically the board | substrate which has arrange | positioned the several inverter module shown in FIG. The figure which shows the pattern layout on the board | substrate shown in FIG. 5 typically The figure which shows the 1st board | substrate and 2nd board | substrate which comprise the motor drive device which concerns on embodiment of this invention. The figure which shows the pattern layout on the board | substrate shown in FIG. 7 typically The figure which shows the 1st modification of the pattern layout shown in FIG. The figure which shows the 2nd modification of the pattern layout shown in FIG. The figure which shows the state which has arrange | positioned the several inverter module shown in FIGS. 7-10 to the 2nd board | substrate. The figure which shows the pattern layout on the 2nd board | substrate shown in FIG. The figure which shows the state which combined the 1st board | substrate and 2nd board | substrate which comprise the motor drive device which concerns on embodiment of this invention. The figure which shows the example which changed the arrangement position of the snubber capacitor shown in FIG. FIG. 13 is a side view of the first substrate, the second substrate, and the three inverter modules shown in FIG. The block diagram of the air conditioner carrying the motor drive device which concerns on embodiment of this invention

Hereinafter, a motor drive device and an air conditioner according to an embodiment of the present invention will be described in detail based on the drawings. Note that the present invention is not limited to the embodiments.

Embodiment.
FIG. 1 is a diagram showing a configuration example of a motor drive device according to an embodiment of the present invention.

The motor drive device 100 includes a rectifier circuit 3 that converts AC power output from the AC power source 1 into DC power, a reactor 2, and a smoothing capacitor 4 that smoothes the DC voltage output from the rectifier circuit 3.

Further, the motor drive device 100 includes a voltage detection unit 8 that detects the voltage across the smoothing capacitor 4 and an inverter unit 5 that drives the motor 6 that is a three-phase motor by converting DC power into three-phase AC power.

In addition, the motor driving device 100 detects a motor current that is an alternating current flowing through the motor 6 and outputs detection information, a short-circuit unit 7 that short-circuits the AC power supply 1, and a control power supply to the control unit 11. Power supply circuit 10 and control unit 11.

The positive power supply line 12 is a DC power supply bus that is output from the rectifier circuit 3 and to which a positive voltage is applied.

The negative power supply line 13 is a DC power supply bus that is output from the rectifier circuit 3 and to which a negative voltage is applied.

The positive power line 12 and the negative power line 13 are wired between the rectifier circuit 3 and the inverter unit 5.

The smoothing capacitor 4 has one end connected to the positive power line 12 and the other end connected to the negative power line 13.

The control unit 11 generates a pulse width modulation (PWM) signal for controlling the inverter unit 5 on the basis of the detection information output from the current detection unit 9 and performs on / off operation of the short-circuit unit 7. Control.

The motor drive device 100 is a device such as an air conditioner, a refrigerator, a washing dryer, a refrigerator, a dehumidifier, a heat pump water heater, a showcase, a vacuum cleaner, a fan motor, a ventilator, a hand dryer, and an induction heating electromagnetic cooker. Can be used as a device for driving a motor built in the device.

FIG. 2 is a diagram schematically showing an internal configuration of an inverter module constituting a general inverter.

The inverter unit 5A shown in FIG. 2 includes a single inverter module 5A1.

The positive terminal 14 of the inverter module 5A1 is connected to the positive power line 12. The negative terminal 15 of the inverter module 5A1 is connected to the negative power line 13.

In FIG. 2, a shunt resistor 16 is connected between the negative terminal 15 and the negative power line 13 of the inverter module 5A1. However, the position of the shunt resistor 16 is not limited to the illustrated example.

The inverter module 5A1 includes six

switching elements

50a, 50b, 50c, 50d, 50e, and 50f.

Specifically, the inverter module 5A1 includes

switching elements

50a and 50b connected in series,

switching elements

50c and 50d connected in series, and

switching elements

50e and 50f connected in series.

Switching elements

50a and 50b correspond to the U phase,

switching elements

50c and 50d correspond to the V phase, and

switching elements

50e and 50f correspond to the W phase.

The

switching elements

50a, 50c, and 50e constitute an upper arm, and the

switching elements

50b, 50d, and 50f constitute a lower arm.

The connection point between the switching element 50a and the switching element 50b, the connection point between the switching element 50c and the switching element 50d, and the connection point between the switching element 50e and the switching element 50f are connected to the motor 6, respectively.

The DC power supplied from the positive power line 12 and the negative power line 13 is converted into AC power by the switching operation of the

switching elements

50a, 50b, 50c, 50d, 50e, and 50f. It is supplied to the motor 6.

FIG. 3 is a diagram schematically showing a plurality of inverter modules constituting the inverter shown in FIG.

The inverter unit 5 includes an inverter module 51 corresponding to the U phase, an inverter module 52 corresponding to the V phase, and an inverter module 53 corresponding to the W phase.

The positive terminals 14 of the

inverter modules

51, 52, and 53 are connected to the positive power line 12.

The negative terminals 15 of the inverter modules 51 to 53 are connected to the negative power line 13.

In FIG. 3, shunt resistors 16-1, 16-2 and 16-3 are connected between the negative terminal 15 and the negative power line 13 of each of the inverter modules 51 to 53. However, the positions of the shunt resistors 16-1 to 16-3 are not limited to the illustrated example.

The inverter module 51 includes six

switching elements

51a, 51b, 51c, 51d, 51e, and 51f.

Specifically, the inverter module 51 includes switching

elements

51a and 51b connected in series, switching

elements

51c and 51d connected in series, and switching

elements

51e and 51f connected in series.

The

switching elements

51a, 51c, 51e constitute an upper arm, and the switching

elements

51b, 51d, 51f constitute a lower arm.

The connection point between the switching element 51a and the switching element 51b, the connection point between the switching element 51c and the switching element 51d, and the connection point between the switching element 51e and the switching element 51f are each connected to the motor 6 via the output terminal 17. Is done.

Similarly to the inverter module 51, the inverter module 52 includes six

switching elements

52a, 52b, 52c, 52d, 52e, and 52f. Similarly to the inverter module 51, the inverter module 53 includes six

switching elements

53a, 53b, 53c, 53d, 53e, and 53f. The connection configuration of the switching elements of the

inverter modules

52 and 53 is the same as the connection configuration of the switching elements of the inverter module 51.

Hereinafter, although description of the switching elements 52a to 52f and the switching elements 53a to 52f is omitted, the switching elements 52a to 52f and the switching elements 53a to 52f are configured in the same manner as the switching elements 51a to 51f.

As the switching elements 51a to 51f, silicon carbide (SiC) called a wide band gap semiconductor is used as an example.

The use of a wide bandgap semiconductor provides a high voltage resistance and a high allowable current density, thereby enabling a reduction in the size of the module. Since the wide band gap semiconductor has high heat resistance, it is possible to reduce the size of the radiating fin 47 described later.

Each of the inverter modules 51 to 53 having 6 switching elements constitutes one leg. Therefore, the inverter unit 5 is configured by a total of 18 switching elements.

On the other hand, the inverter unit 5A in FIG. 2 described above is composed of a total of six switching elements. Therefore, the value of the current flowing through each of the switching elements 51a to 51f shown in FIG. 3 is one third of the value of the current flowing through each of the

switching elements

50a, 50b, 50c, 50d, 50e, and 50f shown in FIG. .

As a result, the current capacities of the switching elements 51a to 51f can be reduced, and the chip areas of the inverter modules 51 to 53 can be reduced. Therefore, the yield when taking out from the wafer is improved, and the manufacturing cost of the inverter modules 51 to 53 can be reduced.

FIG. 4 is a diagram schematically showing a substrate on which the inverter module shown in FIG. 2 is arranged. FIG. 5 is a diagram schematically showing a substrate on which a plurality of inverter modules shown in FIG. 3 are arranged.

4 and 5 are provided with devices used in a general motor drive device.

4 includes a power input unit 21, a noise filter 22, a converter circuit 23, a smoothing capacitor 24, an inverter module 25, a detection circuit 26, and a microcomputer peripheral unit 27.

1 is connected to the power input unit 21. The converter circuit 23 includes the rectifier circuit 3 and the short-circuit portion 7 of FIG.

The smoothing capacitor 24 corresponds to the smoothing capacitor 4 in FIG. The inverter module 25 corresponds to the inverter module 5A1 in FIG.

The detection circuit 26 corresponds to the shunt resistor 16 in FIG. The microcomputer peripheral section 27 corresponds to the control section 11 in FIG.

1 is connected between the noise filter 22 and the converter circuit 23. However, in FIG. 4, the illustration of the reactor 2 is omitted.

AC power input from the power input unit 21 is converted into DC power by the noise filter 22, the reactor 2, the converter circuit 23 and the smoothing capacitor 24, and this DC power is input to the inverter module 25.

The board 20-1 in FIG. 5 has three inverter modules 25-1, 25-2, 25-3 and three detection circuits 26-1, 26- instead of the inverter module 25 and the detection circuit 26 in FIG. 2, 26-3 are arranged. Since the other components are the same as those of the substrate 20, the description thereof is omitted.

The detection circuits 26-1 to 26-3 correspond to the shunt resistors 16-1 to 16-3 in FIG.

The inverter modules 25-1 to 25-3 correspond to the inverter modules 51 to 53 in FIG. The inverter modules 25-1 to 25-3 are arranged linearly along the longitudinal direction of the substrate 20-1 in the order of the inverter module 25-1, the inverter module 25-2, and the inverter module 25-3.

FIG. 6 is a diagram schematically showing a pattern layout on the substrate shown in FIG.

The positive power pattern P1 corresponds to the positive power line 12 in FIG. 1, and is electrically connected to the converter circuit 23, the smoothing capacitor 24, and the inverter modules 25-1 to 25-3.

The power pattern N1 on the negative electrode side corresponds to the negative power supply line 13 in FIG. 1, and is electrically connected to the converter circuit 23, the smoothing capacitor 24, and the detection circuits 26-1 to 26-3.

In the power patterns P1 and N1, the amount of heat generation increases as the value of the current flowing through the power patterns P1 and N1 increases. Therefore, it is necessary to increase the pattern width or the pattern thickness according to the current value. On the other hand, when lead wires are used to connect the pattern wirings, the length of the pattern wiring including the lead wires becomes long, so that they are easily affected by noise. By using the lead wire, it is possible to design so as to suppress the influence of impedance while suppressing the increase in the substrate size.

In the substrate 20-1 shown in FIG. 6, since the three inverter modules 25-1 to 25-3 are arranged, it is necessary to secure an area for arranging the inverter modules 25-1 to 25-3. It is also necessary to secure an area for routing the power patterns P1, N1 connected to each of the inverter modules 25-1 to 25-3.

Also, as the number of modules arranged on the substrate 20-1 increases, the distance between the microcomputer peripheral portion 27 and the inverter modules 25-1 to 25-3 is increased. In particular, when three inverter modules 25-1 to 25-3 are arranged in a straight line in this order near the microcomputer peripheral portion 27 as shown in FIG. 6, from the inverter module 25-3 to the microcomputer peripheral portion 27. The distance is longer than the distance from the inverter module 25-1 to the microcomputer peripheral portion 27.

Thus, as the distance from the inverter module 25-3 to the microcomputer peripheral portion 27 becomes longer, the control wirings 71-1 to 71-3 wired between the microcomputer peripheral portion 27 and the inverter modules 25-1 to 25-3 are increased. The length of the film becomes long, and it is likely to be affected by noise, and the detectability may be lowered.

Specifically, when noise is added to the motor current detection signal transmitted to the control wiring, the motor controllability is lowered, and there is a concern that the protection circuit malfunctions. The malfunction of the protection circuit means that the protection works at a low value with respect to the overcurrent design value, for example.

Also, noise is added to the gate drive signal, which is a PWM signal transmitted to the control wiring, and the ON / OFF timing of each switching element constituting the upper and lower arms is shifted, which may cause a short circuit between the upper and lower arms.

Further, since SiC switching elements are used in the inverter modules 25-1 to 25-3, dV / dt due to switching is large, and noise generated with respect to the same wiring impedance is large.

Also, since the threshold Vth of the gate drive voltage is as low as about 1V, there is a high risk of malfunction due to noise.

The motor drive device according to the embodiment of the present invention has a configuration for solving these problems. Hereinafter, this configuration example will be specifically described.

FIG. 7 is a diagram showing a first substrate and a second substrate constituting the motor drive device according to the embodiment of the present invention. FIG. 8 schematically shows a pattern layout on the substrate shown in FIG.

Differences from the substrate 20-1 in FIG. 6 are as follows.
(1) The control terminal 28, the GND terminal 40, and the power terminal 41 are disposed on the first substrate 30.
(2) The inverter modules 25-1 to 25-3 are arranged on the second substrate 31.
(3) The detection circuits 26-1 to 26-3 are arranged on the second substrate 31.

On the first substrate 30, a power input unit 21 for converting AC power supplied from the AC power source 1 into DC power, a noise filter, and a converter circuit 23 are arranged.

Further, a smoothing capacitor 24 for smoothing DC power and supplying it to the inverter modules 25-1 to 25-3 is disposed on the first substrate 30.

Further, on the first substrate 30, a microcomputer peripheral part 27, a control terminal 28, a GND terminal 40 and a power terminal 41 are arranged.

The control terminal 28 is connected to the microcomputer peripheral part 27. The power terminal 41 is connected to the power pattern P1. The GND terminal 40 is connected to the power pattern N1.

On the second substrate 31, inverter modules 25-1 to 25-3 and detection circuits 26-1 to 26-3 are arranged.

The inverter modules 25-1 to 25-3 are arranged linearly along the longitudinal direction of the second substrate 31 in the order of the inverter module 25-1, the inverter module 25-2, and the inverter module 25-3.

The positive-side power pattern P2 on the second substrate 31 corresponds to a part of the positive-side power line 12 in FIG. 1, and electrically connects the inverter modules 25-1 to 25-3.

The negative-side power pattern N2 on the second substrate 31 corresponds to a part of the negative-side power line 13 in FIG. 1, and is electrically connected to the detection circuits 26-1 to 26-3. The power pattern N3 on the negative electrode side 31 is electrically connected to the inverter modules 25-1 to 25-3 and the detection circuits 26-1 to 26-3, respectively.

The detection circuits 26-1 to 26-3 have one end connected to the power pattern N2 and the other end connected to the power pattern N3.

The three inverter modules 25-1 to 25-3 are connected in parallel between the power pattern P2 and the power pattern N2.

The positive terminals 14 of the inverter modules 25-1 to 25-3 are connected to the power pattern P2. The power pattern P2 is connected to a power terminal 41 on the first substrate 30 through a power wiring 42 that supplies DC power to the inverter modules 25-1 to 25-3.

Thereby, a current flows between the positive terminal 14 of each of the inverter modules 25-1 to 25-3 and the power pattern P1 on the first substrate 30.

The negative terminals 15 of the inverter modules 25-1 to 25-3 are connected to the power pattern N3. The power pattern N3 is connected to the power pattern N2 via the detection circuits 26-1 to 26-3. The power pattern N2 is connected to the GND terminal 40 and the power pattern N1 on the first substrate 30 through the power wiring 43.

Thereby, a current flows between the negative terminal 15 of each of the inverter modules 25-1 to 25-3 and the power pattern N1 on the first substrate 30.

In addition, the power pattern P2 and the power wiring 42 are configured by metal plate leads on the positive electrode side. Further, the power pattern N2, the power pattern N3, and the power wiring 43 are configured by metal plate leads on the negative electrode side. Details of the metal plate lead will be described later.

The inverter modules 25-1 to 25-3 are electrically connected to the microcomputer peripheral portion 27 via the control terminal 28 and the control terminal 44. The control terminal 44 is provided in each of the inverter modules 25-1 to 25-3 and is arranged on one side of the pair of sides of the second substrate 31. In the illustrated example, each control terminal 44 is located outside the side portion of the second substrate 31. The control terminal 44 is connected to the control wiring 45, and the control wiring 45 is connected to the control terminal 28 on the first substrate 30. By moving the control wiring 45 away from the power wiring 43, the influence of noise can be suppressed. In this way, the inverter modules 25-1 to 25-3 have terminal arrangements as shown in FIG. 11, and the control terminal group 44 located outside the side of the second substrate 31 is a low voltage terminal for control. It is. On the second substrate 31, it is desirable that the power wiring 43 and the control wiring 45 be as far away as possible, so the control terminal 28 is disposed on the first substrate 30. However, since the length of the control terminal 44 of the inverter modules 25-1 to 25-3 may be insufficient, in that case, a control terminal (not shown) is provided on the second substrate 31, and the control terminal is connected to the inverter module 25. -1 to 25-3 are connected to a group of control terminals 44, one end of the control wiring 45 is connected to the control terminal, and the other end of the control wiring 45 is connected to the control terminal 28 on the first substrate 30. .

Thereby, a current flows between the negative terminal 15 of each of the inverter modules 25-1 to 25-3 and the microcomputer peripheral portion 27 on the first substrate 30.

8 is compared with the substrate 20-1 in FIG. 6, the arrangement positions of the converter circuit 23 and the smoothing capacitor 24 are the same. Therefore, the layout of the power patterns P1 and N1 around the converter circuit 23 and the smoothing capacitor 24 is the same between the first substrate 30 and the substrate 20-1.

On the other hand, in the first substrate 30 of FIG. 8, the power pattern connected in parallel to each of the inverter modules 25-1 to 25-3 of FIG. 6 is omitted. Then, instead of omitting the power pattern from the first substrate 30, power patterns P2, N2, and N3 are provided on the second substrate 31.

As described above, since the power patterns P2, N2, and N3 on the second substrate 31 are configured by metal plate leads, the metal plate leads can be easily reduced in thickness and width unlike pattern wiring on the substrate. Can be adjusted. That is, when the pattern width is changed in the power patterns P2, N2, and N3, a process such as a mask change occurs, but the pattern width can be easily adjusted in the metal plate lead.

Therefore, the thickness of the power patterns P2, N2, and N3 can be made larger than the thickness of the pattern on the first substrate 30. The pattern thickness is typically 18 um, 35 um, or 70 um. Further, the widths of the power patterns P2 and N2 can be made narrower than the width of the pattern on the first substrate 30.

The inverter modules 25-1 to 25-3 are designed so that the difference in internal impedance between them is small. However, in general, when a plurality of modules are mounted on a board in parallel, the value of the wiring impedance of the power pattern connected to each module is different. For this reason, a difference in output of each module occurs.

In the second substrate 31 according to the embodiment of the present invention, the value of the wiring impedance can be adjusted by changing the thickness and width of the metal plate lead with respect to the wiring length.

More specifically, assuming that the connection point between the power wiring 43 and the power pattern N2 is near the detection circuit 26-3 shown in FIG. 8, the wiring impedance from the connection point to the detection circuit 26-1 The pattern length or pattern width of the power pattern N2 is adjusted so that the wiring impedance from the connection point to the detection circuit 26-2 is equal to the wiring impedance from the connection point to the detection circuit 26-3. .

Thereby, it is possible to suppress the difference between the outputs of the inverter modules 25-1 to 25-3. As a result, a decrease in motor controllability is suppressed, and local heat generation of the inverter modules 25-1 to 25-3 due to current imbalance can be suppressed.

In the first substrate 30, the power patterns P 1 and N 1 can be arranged on the outer peripheral side of the first substrate 30. Therefore, it becomes easy to route the pattern wiring for the control signal with respect to the power patterns P1, N1, P2, and N2, and the distance between the patterns can be increased.

In the second substrate 31, the ground of the power pattern N2 and the grounds of the control signal patterns 72-1 to 72-3 are provided separately. The ground of the power pattern N2 is grounded at a single point to the grounding portion of the first substrate 30.

As a result, the noise due to the current input to the inverter modules 25-1 to 25-3 and the noise due to the current output from the inverter modules 25-1 to 25-3 are controlled signal patterns 72-1 to 72-. 3 is difficult to propagate to the ground.

The grounds of the detection circuits 26-1 to 26-3 may be connected to the ground of the power pattern N2. However, grounding separately from the ground of the power pattern N2 can suppress the influence of noise. it can.

FIG. 9 is a diagram showing a first modification of the pattern layout shown in FIG. Differences from FIG. 8 are as follows.
(1) One detection circuit 26 is arranged on the first substrate 30-1 instead of the plurality of detection circuits 26-1 to 26-3 shown in FIG.
(2) A power pattern N3 for connecting the detection circuit 26 and the GND terminal 40 is provided on the first substrate 30-1.
(3) The detection circuit 26 has one end connected to the power pattern N3 and the other end connected to the power pattern N1.
(4) The power wiring 43 is connected to the detection circuit 26 on the first substrate 30-1.
(5) The power pattern N2 on the second substrate 31-1 is directly connected to the negative terminal 15 of each of the inverter modules 25-1 to 25-3.

FIG. 10 is a diagram showing a second modification of the pattern layout shown in FIG. Differences from FIG. 8 are as follows.
(1) One detection circuit 26 is arranged on the second substrate 31-2 instead of the plurality of detection circuits 26-1 to 26-3.
(2) The power pattern N3 is provided on the second substrate 31-2, and the power pattern N3 connects the negative terminal 15 and the detection circuit 26 of each of the plurality of inverter modules 25-1 to 25-3. thing.
(3) The detection circuit 26 has one end connected to the power pattern N3 and the other end connected to the power wiring 43.

9 and 10, current flows between the positive terminal 14 of each of the inverter modules 25-1 to 25-3 and the power pattern P1 on the first substrate 30. In addition, a current flows between the negative terminal 15 of each of the inverter modules 25-1 to 25-3 and the power pattern N1 on the first substrate 30. Thereby, the same effect as the structure shown in FIG. 8 can be acquired.

FIG. 11 is a diagram showing a state in which the plurality of inverter modules shown in FIGS. 7 to 10 are arranged on the second substrate. FIG. 12 is a diagram showing a pattern layout on the second substrate shown in FIG.

In FIG. 11, the positive terminal 14, the negative terminal 15 and the output terminal 17 of each of the inverter modules 25-1 to 25-3 are arranged in the center portion of the second substrate 31 in the short direction.

The control terminals 44 of the inverter modules 25-1 to 25-3 are arranged at positions that do not face the second substrate 31.

In FIG. 12, the power patterns P2 and N2 are arranged on the outer peripheral side of the second substrate 31. A power pattern N3 is disposed between the power pattern N2 and the negative terminals 15 of the inverter modules 25-1 to 25-3.

The shunt resistors 16-1 to 16-3 are arranged between the power pattern N2 and the power pattern N3.

Each of the shunt resistors 16-1 to 16-3 has one end connected to the power pattern N2 and the other end connected to the power pattern N3.

Further, snubber capacitors 46-1, 46-2, 46-3 are arranged between the power pattern N3 and the power pattern P2. Snubber capacitors 46-1 to 46-3 each have one end connected to power pattern N3 and the other end connected to power pattern P2.

FIG. 13 is a view showing a state in which the first substrate and the second substrate constituting the motor driving apparatus according to the embodiment of the present invention are combined.

The first substrate 30 has a first main surface 30a and a second main surface 30b opposite to the first main surface 30a. The second substrate 31 has a third main surface 31a that faces the second main surface 30b, and a fourth main surface 31b opposite to the third main surface 31a.

A pedestal 60 is provided between the second substrate 31 and the first substrate 30. The pedestal 60 is for adjusting the distance from the first substrate 30 to the second substrate 31.

FIG. 13 shows an example in which the second substrate 31 according to the embodiment of the present invention is configured as a lead frame mold substrate. The lead frame mold substrate is a substrate in which metal plate leads 37 are integrally molded with an insulating resin 49. By applying the insulating resin 49 to the metal plate lead 37, the insulating property of the metal plate lead 37 can be ensured, and the motor drive device 100 with higher quality can be provided.

In FIG. 13, one metal plate lead 37 is shown, but the metal plate lead 37 is provided with a positive electrode side and a negative electrode side, respectively. For the metal plate lead 37, generally plated copper or brass is used. The metal plate lead 37 is provided by a method such as punching, bending, wire cutting, laser processing, or etching.

For the resin 49 enclosing the metal plate lead 37, nylon, unsaturated polyester, or epoxy resin mixed with a filler is used for the purpose of insulation.

In the example of FIG. 13, the microcomputer peripheral portion 27 is arranged on the first main surface 30a side, and the smoothing capacitor 24 is arranged on the second main surface 30b. However, the arrangement positions of the microcomputer peripheral portion 27 and the smoothing capacitor 24 are not limited to the illustrated example.

The inverter modules 25-1 to 25-3, the shunt resistor 16, and the snubber capacitors 46-1 to 46-3 are arranged on the fourth main surface 31b side.

Radiator fins 47 are attached to the inverter modules 25-1 to 25-3.

The smoothing capacitor 24 is disposed at a location where the second substrate 31 is not installed in the second main surface 30b.

On the second main surface 30b side of the first substrate 30, a pedestal 60, a second substrate 31, a second substrate 31, inverter modules 25-1 to 25-3, and heat radiation fins 46 are laminated. Compared with the first main surface 30a side of the first substrate 30, the thickness constituted by the entire component is larger. Therefore, when the smoothing capacitor 24 is arranged on the second main surface 30b side as in the illustrated example, the first substrate 30 and the second substrate 30 are compared to the case where the smoothing capacitor 24 is arranged on the first main surface 30a side. Therefore, the size of the entire component composed of the substrate 31 can be reduced. As a result, an electrical component box (not shown) for housing the first substrate 30 and the second substrate 31 can be reduced in size.

The inverter plates 25-1 to 25-3, the shunt resistor 16, and the snubber capacitors 46-1 to 46-3 are connected to the metal plate lead 37.

One end portion of the metal plate lead 37, that is, a portion where the resin 49 is not applied is bent toward the first substrate 30, passes through a through hole on the first substrate 30, and is soldered to the first substrate 30. Connected.

The control wiring 45 connected to the inverter modules 25-1 to 25-3 extends to the first substrate 30 side, penetrates through holes on the first substrate 30, and is connected to the first substrate 30 by solder. The

FIG. 14 is a diagram showing an example in which the arrangement position of the snubber capacitor shown in FIG. 13 is changed. Differences from FIG. 13 are as follows.
(1) The height of the pedestal 60 is different, and the distance from the first substrate 30 to the second substrate 31 in FIG. 14 is wider than the distance from the first substrate 30 to the second substrate 31 in FIG. thing.
(2) The snubber capacitors 46-1 to 46-3 are arranged on the third main surface 31a side.

When the snubber capacitors 46-1 to 46-3 are arranged at the positions shown in FIG. 13, there are many parts arranged on the fourth main surface 31b of the second substrate 31, and the power pattern is avoided while avoiding these parts. Since it is necessary to route P2 and N2, the routing amount of the power patterns P2 and N2 becomes long, and the impedance of the power patterns P2 and N2 increases. As this impedance increases, the influence of noise upon occurrence of a surge increases.

According to the configuration shown in FIG. 14, parts are avoided by arranging the snubber capacitors 46-1 to 46-3 using the third main surface 31a having a small part arrangement among the end faces of the second substrate 31. Therefore, the amount of power patterns P2 and N2 is reduced, and the occurrence of surge is further suppressed.

FIG. 15 is a view of the first substrate, the second substrate, and the three inverter modules shown in FIG. 13 as viewed from the side, and is a view as viewed from the direction of arrow B in FIG. Note that the radiation fins attached to the inverter module are not shown.

In the example of FIG. 15, among the three inverter modules 25-1 to 25-3 arranged in series on the second substrate 31, the inverter module 25 located at the center of the inverter modules 25-1 and 25-3 on both sides. -2 is arranged at a position overlapping the area A corresponding to the projection surface of the microcomputer peripheral portion 27. That is, the three inverter modules 25-1 to 25-3 are arranged so that the distance between the three inverter modules 25-1 to 25-3 and the microcomputer peripheral portion 27 is the shortest. The area A is an area formed by projecting the microcomputer peripheral portion 27 toward the first substrate 30 and the second substrate 31.

Note that each inverter module is preferably arranged so that the position in the depth direction of the drawing also overlaps the region A. The depth direction is a direction along a plane parallel to the fourth main surface 31b, and is a direction orthogonal to the arrangement direction of the inverter modules 25-1 to 25-3.

According to the configuration example of FIG. 15, since the distance between each of the inverter modules 25-1 to 25-3 and the microcomputer peripheral section 27 is short, the inverter modules 25-1 to 25-3 are connected to the microcomputer peripheral section 27. The lengths of the extending metal plate lead 37 and the control wiring 45 can be further shortened. Therefore, the impedance of each of the power pattern P2, the power pattern N2, and the control wiring 45 is reduced, and the influence of noise can be further reduced.

In the embodiment, SiC is used for the switching elements 51a to 51f. However, a gallium nitride material or diamond may be used instead of SiC.

As described above, the motor drive device according to the embodiment of the present invention includes an inverter unit that has a plurality of inverter modules and outputs AC power to the motor, a control unit that controls each of the plurality of inverter modules, A first substrate having a first main surface and a second main surface, a third main surface opposite to the second main surface, and the plurality of inverter modules. And a second substrate having a fourth main surface.

According to the motor drive device of the embodiment of the present invention, since the low-capacity WBG semiconductor having a small chip size is used as the switching element, it is possible to suppress the difference in the output of each of the plurality of inverter modules. As a result, a decrease in motor controllability is suppressed, and local heat generation of the inverter module due to current imbalance can be suppressed.

Further, according to the motor drive device of the embodiment of the present invention, the wiring impedance can be suppressed by adjusting the pattern area, pattern length, or pattern width of the power pattern. Even if the distance is given, the impedance can be suppressed, and the degree of freedom of pattern wiring can be increased.

Further, according to the motor drive device of the embodiment of the present invention, the impedance difference for each power module is suppressed by adjusting the value of the wiring impedance by changing the thickness and width of the metal plate lead with respect to the wiring length. Therefore, the snubber capacitors have the same capacity, and the snubber capacitors can be shared. “Identical” does not indicate complete coincidence, and may include some deviation due to an error or the like.

Further, according to the motor drive device of the embodiment of the present invention, the length of the metal plate leads and control wiring extending from each inverter module to the peripheral portion of the microcomputer can be further reduced by using the second substrate. Wiring impedance can be suppressed, and depending on the current level, one snubber capacitor can be used for a plurality of power modules, the circuit configuration can be simplified, cost can be reduced, and reliability can be improved. .

In addition, the motor driving device according to the embodiment of the present invention suppresses the impedance as described above, and the ground of the power pattern is grounded at a single point to the grounding portion of the first substrate so that it is difficult to propagate to the ground. Therefore, it is suitable for driving a switching element using a WBG semiconductor having a high dV / dt and capable of high-speed switching, and can prevent malfunction of the switching element due to the influence of noise, thereby improving quality. Can do.

In addition, since the inverter module of the motor drive device according to the embodiment of the present invention is configured by a switching element using a WBG semiconductor, switching loss is reduced and efficiency can be improved.

Further, in the motor drive device according to the embodiment of the present invention, the plurality of inverter modules are arranged at positions overlapping the areas formed by projecting the microcomputer peripheral portion including the control unit toward the first substrate and the second substrate. . For this reason, the distance between the control signal of each inverter module and the peripheral portion of the microcomputer is reduced, so that it is possible to suppress deterioration in controllability and erroneous detection.

Further, in the motor drive device according to the embodiment of the present invention, since a plurality of inverter modules are arranged on the second board, an increase in the board area of the first board can be suppressed, and the outer case accompanying the increase in the board size can be suppressed. An increase in size can be suppressed, an increase in the manufacturing cost of the outer case can be suppressed, and an increase in size of the motor drive device can be suppressed.

FIG. 16 is a configuration diagram of an air conditioner equipped with a motor drive device according to an embodiment of the present invention. The air conditioner 300 includes an indoor unit 304 and an outdoor unit 301 connected to the indoor unit 304. The indoor unit 304 and the outdoor unit 301 are provided with a motor 6. For example, in the outdoor unit 301, the motor 6 is used as a driving source for each of the blower fan 303 and the compressor 302.

Further, the motor drive device 100 is used for the indoor unit 304 and the outdoor unit 301 in order to control the drive source. By using the motor drive device 100, the air conditioner 300 with good quality can be obtained at low cost.

The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

1 AC power supply, 2 reactor, 3 rectifier circuit, 4,24 smoothing capacitor, 5,5A inverter section, 5A1,25,25-1,25-2,25-3,51,52,53 inverter module, 6 motor, 7 short circuit part, 8 voltage detection part, 9 current detection part, 10 power supply circuit, 11 control part, 12 positive power supply line, 13 negative power supply line, 14 positive terminal, 15 negative terminal, 16, 16-1, 16-2, 16-3 shunt resistor, 17 output terminal, 20, 20-1 board, 21 power input unit, 22 noise filter, 23 converter circuit, 26, 26-1, 26-2, 26-3 detection circuit, 27 Microcomputer peripheral part, 28, 44 control terminal, 30, 30-1 first substrate, 30a first main surface, 30b second main surface, 31, 31-1, 3 -2nd substrate, 31a 3rd main surface, 31b 4th main surface, 37 metal plate lead, 40 GND terminal, 41 power terminal, 42, 43 power wiring, 45 control wiring, 46-1, 46- 2,46-3 snubber capacitor, 47 heat radiation fin, 50a, 50b, 50c, 50d, 50e, 50f, 51a, 51b, 51c, 51d, 51e, 51f switching element, 60 pedestal, 71-1, 71-2, 71 -3 Control wiring, 72-1, 72-2, 72-3 Control signal pattern, 100 motor drive device, 300 air conditioner, 301 outdoor unit, 302 compressor, 303 blower fan, 304 indoor unit.

Claims

A motor driving device for driving a motor,
An inverter unit having a plurality of inverter modules and outputting AC power to the motor;
A control unit for controlling each of the plurality of inverter modules;
A first substrate on which the control unit is disposed and having a first main surface and a second main surface;
A second substrate having a third main surface facing the second main surface and a fourth main surface on which the plurality of inverter modules are disposed;
A motor drive device comprising:
The motor drive device according to claim 1, wherein the second substrate has a metal plate lead connected to each of a positive terminal and a negative terminal of the plurality of inverter modules.
3. The motor drive device according to claim 1, wherein the plurality of inverter modules are arranged at positions overlapping with regions formed by projecting the control unit toward the first substrate and the second substrate. .
The motor driving device according to claim 2 or 3, wherein the metal plate lead connected to each of the plurality of inverter modules has a width and a thickness in which each wiring impedance value is the same.
Each of the plurality of inverter modules includes a plurality of control terminals connected to the first substrate,
5. The motor drive device according to claim 1, wherein the plurality of control terminals are arranged on one side of a pair of sides of the second substrate.
Each of the plurality of inverter modules has a plurality of switching elements,
Each of the plurality of switching elements is a wide bandgap semiconductor element,
The motor driving apparatus according to any one of claims 1 to 5, wherein the wide band gap semiconductor element is formed of silicon carbide, a gallium nitride-based material, or diamond.
The motor drive device according to any one of claims 1 to 6, further comprising a snubber capacitor disposed on the third main surface.
4. The motor driving device according to claim 2, wherein the metal plate lead is molded with an insulating resin.
An air conditioner equipped with the motor drive device according to any one of claims 1 to 8.