JP2014072926A - Electrical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a cable connected between a power conversion unit and a control circuit board, and to prevent functional degradation of a circuit-board mounting chassis.SOLUTION: An electrical apparatus includes: a power conversion unit 1 including a plurality of switch elements 24 that convert DC power into AC power; a control circuit 14 controlling the operation of the plurality of switch elements 24; a metal plate member 16 interposed between the power conversion unit 1 and the control circuit 14, and including a portion configured so that an end portion protrudes toward the power conversion unit side; and a cable connecting the plurality of switch elements 24 and the control circuit 14 through the portion of the plate member. The plurality of switch elements 24 and the plate member 16 are commonly connected to a ground potential, thereby preventing damage of the cable. Moreover, the purposely notching of a mounting surface 16b to route the cable is not required, thereby preventing functional degradation of the circuit-board mounting chassis 16.

Description

  The present invention relates to an apparatus that converts input power into AC power.

There is an electric device called a power converter that inputs DC power output from a solar cell, a fuel cell, a storage battery, etc., converts this power into AC power (for example, AC power synchronized with a commercial power system), and supplies it. Is provided. In addition, this DC power is converted into AC power of a desired frequency and used for driving an induction motor, or the brushless motor is driven by switching the energization timing to the stator winding according to the rotational position of the rotor. Is also provided.

As such a power conversion device, for example, the one described in Patent Document 1 is known. This patent document 1 discloses a main board on which heat-generating electronic components such as an inverter device and an electrolytic capacitor are mounted, a sub board for generating a control signal for controlling a switching element of the inverter apparatus, the main board and the sub board. The power converter provided with the mounting bracket of the sub-board | substrate located in between is described.

JP 2003-1993360 A

The sub-board mounting bracket (circuit board mounting chassis) serves to protect the control circuit board from the heat and noise of the main board as well as the sub board (control circuit board).

By the way, in order for the circuit board mounting chassis to perform such a function, the control circuit board needs to be separated from the main board as much as possible. Therefore, if the distance between the main board and the control circuit board is increased, the front side of the control circuit board (the side opposite to the main board side) in the limited housing
The space becomes narrower.

In such a situation, the cable connecting the control circuit board and the main board may be sandwiched between the control circuit board and a member on the front side of the control circuit board, for example, the front panel, and may be damaged or disconnected. is there.

Further, as shown in FIG. 7 of Patent Document 1, when the cable is routed through the notch in the planar base surface that constitutes the sub-board mounting bracket, the notch
The shield function and heat shield function of the circuit board mounting chassis described above may deteriorate.

Therefore, an object of the present invention is to suppress the deterioration of the function of the circuit board mounting chassis and to suppress the breakage of the cable connecting the power conversion unit including the main board and the control circuit.

In order to achieve the above object, an electrical apparatus of the present invention includes a power conversion unit including a plurality of switch elements that convert DC power into AC power, a control circuit that controls operations of the plurality of switch elements,
A metallic plate member including a portion interposed between the power conversion unit and the control circuit and having an end portion projecting toward the power conversion unit side, and via the portion of the plate member And a cable for connecting the plurality of switch elements to the control circuit, and the plurality of switch elements and the plate member are connected to a common ground potential.

ADVANTAGE OF THE INVENTION According to this invention, damage to the cable used for a connection between a power converter and a control circuit board can be suppressed.

It is an appearance perspective view of the power converter of an embodiment. It is an exploded perspective view of the power converter of an embodiment. It is a circuit diagram of the power converter of an embodiment. It is a circuit block diagram of the power converter device of embodiment. It is the external appearance perspective view which removed the surface panel from the power converter device of FIG. FIG. 6 is an external perspective view of the power conversion device of FIG. 5 with a front shield cover removed. It is a top view of the power converter device of FIG.

Embodiments of the present invention will be described below with reference to the drawings. However, each embodiment shown below exemplifies an electric device for understanding the technical idea of the present invention, and is not intended to specify the present invention as the electric device. The electric device can be applied to various devices using the technical idea shown in the claims.

A configuration of a power conversion device that converts DC power to AC power will be described with reference to FIGS. 1 and 2 as an embodiment of an electric device. The power conversion device 1 has a substantially rectangular parallelepiped housing including a front panel 2, a back panel 3, a top panel 4, a bottom main panel 5, a bottom auxiliary panel 6, a right side panel 7 and a left side panel 8. . In addition, as for this power converter device 1, the back panel 3 is attached to the wall surface (illustration omitted) so that the surface panel 2 side may become a front surface. Moreover, each panel can be appropriately selected and integrated according to the design.

The front panel 2 can be made of metal or plastic, and an opening 10 is provided so that the display unit 9 is exposed from the entire surface. Upper surface panel 4, lower surface main panel 5, lower surface auxiliary panel 6
The right side panel 7 and the left side panel 8 constitute a frame, and the surface panel 2 is attached to the frame so that it can be attached and detached. The frame is made of metal and is attached to the metal back panel 3 by screwing, welding or the like so as to be electrically at the same potential.

The lower surface main panel 5 is provided with a ventilation hole 5a and a ventilation slit 5b, and a flow of cooling air is created corresponding to the ventilation hole 4a and the ventilation slit (not shown) of the upper surface panel 4, respectively. A heat sink 21 is disposed between the two ventilation slits, and air entering from the ventilation slit 5 b flows between the fins 21 a of the heat sink 21 toward the ventilation slit of the upper panel 4. The heat sink 21 is made of aluminum and is screwed to the back panel 3 so that it has the same potential as the back panel 3, that is, the same ground potential.
The right side panel 7 can be appropriately provided with a power switch 7b, an AC outlet 7c, and the like.

A plurality of boards such as the main board 20, the sub board 26, the first control circuit board 14, and the second control circuit board 15 are accommodated in the housing.

The main board | substrate 20 is a board | substrate for performing operation | movement which converts direct-current power into alternating current power, and contains a power conversion part. The main board 20 is connected to a DC reactor DCL, an AC reactor ACL, a switch element module 24, and the like, and is connected to a DC / DC converter circuit 3.
6 and a DC / AC inverter circuit 37 (power converter). The DC / DC converter circuit 36 and the DC / AC inverter circuit 37 will be described later.

As shown in FIG. 2, the main board 20 is mounted on a heat sink 21 via a plurality of metal supports 23 (spacers). Therefore, the ground potential of the main board 20 is the same as that of the back panel 3 via the support 23 and the heat sink 21.

The switch element module 24 is constructed by incorporating a plurality of switch elements in a switch element fixing holder 25. By fixing the switch element fixing holder 25 on the heat sink 21 through the hole 20c of the main board 20, heat dissipation of the switch element to the heat sink 21 is enabled. Further, the ground point C (described later) of the switch element module 24 is connected to the ground potential of the main board 20 and is the same potential as the back panel 3.

A DC reactor DCL and an AC reactor ACL are arranged side by side on the left side panel 8 side of the main board 20. Further, a sub-board 26 is disposed on the right side panel 7 side of the main board 20, and the sub-board 26 is connected to the AC output from the main board 20 and the electrical connection and disconnection between the systems. Four relays RLY are provided. The sub board 26 is also attached to the back panel 3 by a support (not shown).

Further, a DC switch 60 is attached to the inner side of the right side panel 7 above (on the front panel 2 side) the sub-board 26 on which the four interconnection relays RLY are mounted. A box-shaped communication module 70 containing a communication board is placed above the DC switch 60 (on the front panel 2 side).
Is fixed between the support portion 7 c and the upper panel 4. The communication module 70 is a module for performing communication with another power conversion device.

The second control circuit board 15 is appropriately connected with a current sensor or a voltage sensor such as a current and voltage input to or output from the DC / DC converter 36 or the DC / AC inverter, and a current and voltage at a predetermined location in the main board 20. The detected current and voltage are inputted, converted into signals, and sent to the first control circuit board (board on which the control circuit is mounted) 14. The first control circuit board 14 is connected to the second control circuit board 15 by sharing at least a ground potential via a signal line, and the main board 20 is based on the current and voltage values detected by the second control circuit board 15. And the sub-board 26 is controlled. The first control circuit board 14 includes a first control circuit board 14 and a second control circuit board 15.
A plurality of setting switches 11 for setting the operation and a display unit for displaying a state based on each setting of the various setting switches 11 is provided. The first control circuit board 14 and the second control circuit board 15 include a control circuit for controlling the power conversion unit.

The first control circuit board 14 and the second control circuit board 15 have a ground potential on a circuit board mounting chassis 16 (plate member) formed in a step shape via a metal support (not shown). It is attached so as to have the same potential as the attachment chassis 16. The circuit board mounting chassis 16 is disposed above the main board 20 (on the front panel 2 side), and the upper panel 4 side and the lower main panel 5 side are screwed to the upper panel 4 and the lower main panel 5, respectively. It has the same potential (ground potential) as that of the rear panel 3 through the panel. The step of the circuit board mounting chassis 16 is bent in accordance with the height difference between the capacitor portion of the main board 20 and other members.

The first control circuit board 14 and the plurality of setting switches 11 and the display unit 9 are exposed.
A front shield cover 12 (cover) that covers the second control circuit board and the power conversion unit and is covered by the front panel 2 is provided. The front shield cover 12 is a conductive metal such as an iron plate and is appropriately screwed to the frame. This front shield cover 12
Are attached with a predetermined distance between the first control circuit board 14 and the second control circuit board 15 and have a shield function that makes them less susceptible to electromagnetic noise.

An insulating sheet 13 is disposed between the first control circuit board 14 and the second control circuit board 15 and the front shield cover 12. The insulating sheet 13 is formed so that the display unit 9 and various setting switches 11 of the first control circuit board 14 are exposed, and the first control circuit board 14 and the second control circuit board 14 are exposed.
It arrange | positions so that the surface of the control circuit board 15 may be covered. Moreover, the upper surface panel 4 side of the insulating sheet 13 is fixed to the upper surface panel 4, and the lower surface main panel 5 side is in a free state. The insulating sheet 13 is provided to prevent the front panel 2 and the first control circuit board 14 or the second control circuit board 15 from being short-circuited.

In addition, a terminal block 17 having a DC input terminal and an AC output terminal is disposed on the lower surface auxiliary panel 6. The terminal block 17 is fixed between the terminal block holding plate 18 attached to the back panel 3 and the right side panel 7. The terminal block 17 is connected to a DC input wiring or an AC output wiring (both not shown) introduced into the power converter 1 through a notch 3a formed in the back panel 3. . The DC input wiring and AC output wiring may be provided with an opening in the bottom auxiliary panel 6 and connected to the terminal block 17 through this opening.

Next, main circuit configurations of the power conversion unit will be described with reference to FIGS. 3 and 4. The power conversion device 1 includes a first noise filter circuit CMF1 and a second noise filter circuit CMF2 that attenuate noise. The power converter 1 also includes a DC / DC converter circuit 36 that boosts the DC input power supplied from the solar cell module 30, and a DC that converts the DC power boosted by the control DC / DC converter circuit 36 into AC power. An AC inverter circuit 37 is provided. These first noise filter circuit CMF1 and second noise filter circuit CMF2
The DC / DC converter circuit 36 and the DC / AC inverter circuit 37 can be mainly included on the main board 20.

Here, the switch element module 24 is formed by connecting three first to third arm circuits, each of which is a series connection of a parallel circuit of a transistor and a freewheeling diode, and is connected to the arm circuit on the noise filter circuit CMF1 side. The DC / DC converter 36 is configured by using the positive-side reflux diode, the negative-side transistor, the DC reactor DCL, and the smoothing capacitor CON, and the remaining two arm circuits are used for the inverter circuit 37. .

The input side of the DC reactor DCL is connected to the positive electrode of the solar cell module 30 via the first noise filter circuit CMF1, and the output side is the input side A point (2 of the arm circuit) of the arm circuit.
Connection point of two switch elements). Further, both ends B and C of the arm circuit are connected in parallel to the smoothing capacitor CON, and this B and C are connected to the input side (DC side) of the DC / AC inverter circuit 37. Further, the output point D and E point (AC side) of the DC / AC inverter circuit 37 are respectively connected to the AC reactor ACL.

The DC reactor DCL and the AC reactor ACL have a frequency of 50 Hz to 60 H.
A large reactance with respect to the frequency of z is required, and the size is large and heavy.
Even in the case of the home power converter 1 (output is about 4 Kw to 6 Kw) as in this embodiment,
Each has a weight of about 2-3 kg. Similarly, the smoothing capacitor CON needs to have a large capacity.

By doing in this way, the direct-current power from the solar cell module 30 becomes two D which are not shown in figure.
The signal is input to the DC input terminals 17a and 17b of the terminal block 17 through the C input wiring. The DC power input to the DC input terminals 17a and 17b is supplied from the DC switch 60 and the lead wire 19a,
The signal is input to the input terminals 20a and 20b of the main board 20 through 19b.

The DC power input to the main board 20 is supplied to the DC / DC via the noise filter circuit CMF1.
The voltage is input to the DC converter circuit 36 and boosted. The boosted DC power is DC / A
The C inverter circuit 37 converts the DC power into AC power synchronized with the commercial power system 80 and outputs the AC power to the sub-board 26 through the noise filter circuit CMF2. The sub-board 26 is
The AC power output from the main board 20 is supplied to the terminal block 17 via the relays RLY1 to RLY4.
Output to the AC output terminals 17c to 17e. The AC power output to the AC output terminals 17c to 17e is superimposed on the commercial power system 80 through the AC output wiring and supplied to the load connected to the commercial power system 80.

The DC / DC converter circuit 36, the DC / AC inverter circuit 37, and the interconnection relay RLY that constitute the power conversion unit include the first control circuit board 14 including a part of the control circuit, the second
It is controlled by a signal from the control circuit board 15. Since specific control by the control circuit 35 can use a known method, detailed description thereof is omitted.

The power conversion device 1 includes a control circuit including a first control circuit board 14 and a second control circuit board 15;
A cable 80 is provided for connecting to the power converter including the main board 20 and the sub board 26. Then, control signals from the first control circuit board 14 and the second control circuit board 15 are transmitted to the cable 8.
0 is transmitted to the main board 20 or the like via 0, and the switching element of the power conversion device 1 is controlled to convert the DC power into the AC power. At this time, input / output voltages and currents are detected from the main board 20 and the like, and this information is sent to the first control circuit board 14 and the like via the cable 80 and used for controlling the power converter.

Next, the first control circuit board and the like and the main board 2 in the power conversion device 1 of the present embodiment.
The routing of the cable 80 connected between 0 and the like will be described with reference to the drawings. FIG. 5 is an external perspective view of the power converter 1 shown in FIG. 1 with the front panel 2 removed. FIG. 6 is an external perspective view of the power converter 1 shown in FIG. 5 with the front shield cover further removed. FIG. 7 is a plan view of the power conversion device 1 shown in FIG.

As described above, the first control circuit board 14 and the second control circuit board 15 are disposed on the circuit board mounting chassis 16. The circuit board mounting chassis 16 is made of a single sheet metal, and is provided with a step 116 by bending or the like, whereby the first mounting surface 16a.
(First plate member) and a second mounting surface 16b (second plate member) that forms a step with the first mounting surface 16a so as to be lower on the power conversion unit side than the first mounting surface 16a. Have

The first mounting surface 16a is a region that is close (high) to the front cover 2 side, and the first control circuit board 14 is disposed thereon. Side walls 16c and 16d are formed on the left and right ends of the mounting surface 16a (the ends on the right side panel 7 and the left side panel 8 side), respectively, and the front shield cover 12 is provided on the side walls 16c and 16d. It can be attached by screwing or the like.

Further, the second mounting surface 16b is a region that protrudes toward and is close (lower) to the back panel 3 side (power conversion unit side) to which many of the components constituting the power conversion unit are fixed. Two control circuit boards are arranged. The left and right ends of the second mounting surface 16b (the ends on the right side panel 7 and the left side panel 8 side) are open. That is, the circuit board mounting chassis 16 is provided with the opening region A and the opening region B formed by the step portions 116 (steps between the first plate member portion and the second plate member portion).

A plurality of cables 80 extending from the first control circuit board 14 and a plurality of cables 80 extending from the second control circuit board 15 are portions of the second mounting surface protruding from the first mounting surface 16a toward the power conversion unit. And it is routed through the opening area A and the opening area B and connected to the main board 20 and the like.

At this time, since the cable 80 passes through the opening area A and the opening area B, a sufficient space is secured between the cable 80 and the front shield cover 12 positioned above (front surface). Therefore, in the power conversion device 1 according to the first embodiment, damage due to the cable being sandwiched between the front shield cover 12 occurs as in the case where the cable is routed from the mounting surface 16a via the side walls 16c and 16d. It becomes difficult. The circuit board mounting chassis 16 and the front shield cover 12
In the region formed by the circuit board mounting chassis 16, there is no cutout or the like, and the effect of blocking the heat from the power conversion unit of the main board 20 is not reduced. In addition, the circuit board mounting chassis 16 and the switch element module 24 are connected to a common ground potential, and the area of the circuit board mounting chassis 16 is not reduced by a notch or the like, thereby reducing noise from the power conversion unit. Will not decrease.

In other words, the opening area A and the opening area B are the step portions 116 provided in the circuit board mounting chassis 16.
Therefore, it is not necessary to cut out the flat portion of the second mounting surface 16b in order to route the cable 80.

Further, when the stepped circuit board mounting chassis 16 as in the present embodiment is used, the space between the first mounting surface 16a and the front shield cover 12 disposed on the upper side (front side) becomes narrower, and the second mounting surface 16a becomes smaller. The mounting surface 16b has a large space with the front shield cover 12. In the present embodiment, in order to make effective use of this space, mounting is performed mainly on large electronic components such as large transformers, coils, and capacitors on the side of the second control circuit board 15 having a wide upper space. Yes. In addition, mounting is performed mainly on small electronic components such as ICs on the first control circuit board 14 side where the upper space is narrow.

In the present embodiment, the plurality of connectors 8 mounted on the first control circuit board 14 is also used.
1 is provided at the end of the step 116 side (second mounting surface 16b side). The connector 81 is a component to which the cable 80 is actually connected. As described above, the connector 81 is mounted on the end portion on the stepped portion 116 side, whereby the cable 80 using the opening areas A and B can be easily routed. That is, without routing the cable 80 between the first control circuit board 14 and the side wall 16c or the side wall 16d, the opening area A or the opening area B is passed through the space above the second mounting surface 16b from the connector 81. The cable 80 can be routed. Accordingly, when the cable 80 is routed between the first control circuit board 14 and the side wall 16c or the side wall 16d, the front shield cover 12 and the circuit board mounting chassis 16 are provided.
It is possible to prevent a situation in which the cable 80 is sandwiched between the side wall and breakage or disconnection. This also makes it possible to narrow the space between the first control circuit board 14 and the side walls 16c and 16d.

Further, since the connector 81 on the first control circuit board 14 is mounted on the end portion on the stepped portion 116 side (second attachment surface 16b side), the second attachment surface 16b is immediately attached from the first control circuit board 14. The cable 80 can be routed to the upper space. As a result, the cable 80 is not positioned on the first control circuit board 14, so that the electronic parts are not damaged by the contact between the cable 80 and the first control circuit board 14.

7 and the like, not all connectors 81 are shown, and some connectors 8
In the case where the connector 81 cannot be mounted at all the end portion on the stepped portion 116 side of the first control circuit board 14, a part of the connector 81 is placed on the first control circuit board 14. You may provide in another area | region.

For example, the communication module 70 is not always provided in the power conversion device 1 and is often attached depending on whether or not the display unit is used. That is, the communication module 7
0 may be an optional part.

In the present embodiment, the control circuit board includes two boards including the first control circuit board 14 and the second control circuit board 15. However, all electronic components can be mounted on the first control circuit board 14 side. Therefore, it is not always necessary to use two control circuit boards, and one control circuit board may be used.
In another embodiment, the DC power can be a power obtained by rectifying the AC power of the power system. In this case, the output of the power conversion unit can drive the induction motor by controlling the frequency of the output. If it is an AC output that switches the output according to the rotational position (electrical angle) of the rotor with this output, it is suitable to use for driving a brushless motor (synchronous motor). Thus, the present invention can be widely applied to electric devices that convert DC power into AC power.

DESCRIPTION OF SYMBOLS 1 ... Power converter 2 ... Front panel 3 ... Back panel 3a ... Notch 4 ... Top panel 4a ... Vent hole 5 ... Lower surface main panel 5a ... Vent hole 5b ... Vent slit 6 ... Lower side auxiliary panel 7 ... Right side panel 7a ... Power switch 7b ... AC outlet 8 ... Left side panel 9 ... Display unit 10 ... Opening 11 ... Various setting switches 12 ... Front shield cover
DESCRIPTION OF SYMBOLS 13 ... Insulation sheet 14 ... 1st control circuit board 15 ... 2nd control circuit board 16 ... Chassis for board mounting (plate member) 16a, 16b ... Mounting surface 16c, 16d ... Side wall 116 ...
Step 17 ... Terminal block 17a, 17b ... DC input terminal 17c, 17d ... AC output terminal
18 ... Terminal block holding plate 19a, 19b ... Lead wire 20 ... Main board 20a, 20b ...
Terminal 20c ... Opening 21 ... Heat sink 21a ... Fin 23, 23a ... Conductive support 24 ... Switch element module 25 ... Switch element fixing holder 26 ... Sub-board 30 ... Solar cell module 31, 32 ... DC power line 36 ... DC / DC Converter circuit 37 ... DC / AC inverter circuit 42a, 42b ... Lead wires 43, 44
… AC power line DCL… DC reactor ACL… AC reactor CON…
Smoothing capacitors RLY1 to RLY4 ... interconnection relay 60 ... DC switch 70 ... communication module 73, 80 ... cable 81 ... connector

Claims (5)

A power converter including a plurality of switch elements for converting DC power into AC power;
A control circuit for controlling operations of the plurality of switch elements;
A metallic plate member including a portion interposed between the power conversion unit and the control circuit and configured such that an end portion protrudes toward the power conversion unit side;
A cable connecting the plurality of switch elements and the control circuit via the portion of the plate member;
An electrical apparatus, wherein the plurality of switch elements and the plate member are connected to a common ground potential. The plate member includes a first plate material portion on the control circuit side and a second plate material portion on the power conversion portion side including the portion configured to protrude toward the power conversion portion side. Part and second
The electric device according to claim 1, wherein the plate member has a step shape. The electric device according to claim 3, wherein one end of the cable is connected to the control circuit via a connector in the vicinity of the second plate member. The electric device according to claim 3, wherein the DC power is power supplied from a solar battery, a storage battery, or the like, and AC power output from the power conversion unit is superimposed on a power system. The DC power is power rectified from AC power of a power system or power supplied from a storage battery, and the output of the power converter is used to drive a brushless motor or an induction motor. The electrical equipment described.

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