JP7384053B2 - inverter device - Google Patents

Description

The present invention relates to an inverter device, and relates to a technique for controlling the inverter device based on a load current flowing through a load such as a motor.

2. Description of the Related Art In an inverter device that drives a load such as a motor, there is a configuration that can detect a load current flowing through the load to control the inverter device or monitor the driving status. As a detection configuration for load current, for example, a through-type current detector (hereinafter simply referred to as a through-type detector as appropriate) can be installed in the current path (connection wiring, etc.) between the inverter device and the motor. It has been known.

Here, when a single inverter device drives a plurality of loads having different load capacities by appropriately switching, for example, a load having a relatively large load capacity among the loads (for example, load M1 in the embodiment described below; The inverter capacity of the inverter device and the rated current of the through-type detector may be appropriately selected to suit the load (hereinafter simply referred to as a large capacity load).

However, in the case of a feedthrough type detector selected to be suitable for a large capacity load, the detection accuracy for relatively small load currents may be low. For example, the detection accuracy of the load current in a load having a smaller load capacity than the large capacity load (for example, loads M2 and M3 in the embodiment described below; hereinafter simply referred to as a small capacity load) becomes low, and the inverter device There is a risk that sufficient control accuracy may not be obtained.

Therefore, it is possible to prepare multiple feed-through type detectors with different rated currents, and each time the load changes, install the feed-through type detector that matches the load capacity of the load. This may lead to increased complexity and higher cost of the equipment.

In Patent Documents 1 and 2, an attempt is made to ensure detection accuracy by using an amplifier circuit or the like for the detection current of the feedthrough type detector and operating the full scale of the A/D converter. Furthermore, in Patent Document 3, in a current transformer for detecting load current in which the primary winding is equipped with a tap, the number of primary turns of the current transformer is changed according to the load capacity by switching the tap via a changeover switch. A possible configuration is disclosed.

Japanese Patent Application Publication No. 10-17222 JP2015-24867A Japanese Unexamined Patent Publication No. 61-212778

In configurations such as those disclosed in Patent Documents 1 and 2, the actual detection accuracy of the penetrating detector does not change. For this reason, there is a possibility that a detection error due to, for example, the temperature characteristics of the through-type detector may be increased, and as a result, there is a possibility that desired detection accuracy may not be obtained.

Further, in Patent Document 3, since it is necessary to attach a tap or a changeover switch to the current transformer, there is a risk that the current transformer becomes larger and more complicated.

The present invention has been made in view of the above-mentioned technical problems, and it is an object of the present invention to provide a technology that can contribute to the detection accuracy of load currents of loads having different load capacities.

The inverter device according to the present invention can contribute to solving the above problems, and one aspect of the inverter device is a terminal having a plurality of connection terminal portions, and a load is connected to any one of the connection terminal portions. A power conversion unit that is connected to each connection terminal section via different current paths and drives a load connected to any of the connection terminal sections, and a penetration section through which each current path passes. and a current detector for detecting the load current of the driven load, and is characterized in that the number of turns for each current path with respect to the penetration portion is different.

Furthermore, each current path may be connected by a connection wiring having a different number of turns to each through-hole.

Further, the first connection wiring that passes through the penetration part and connects any one of the connection terminal parts and the power conversion part, and each connection terminal part are electrically connected in series, and the a second connection wiring that passes through the penetration part between two matching connection terminal parts, and each current path is connected by at least the first connection wiring of the first and second connection wirings. It can also be used as a feature.

In addition, the terminal block has a power conversion section side connection section where each connection terminal section is provided, a load side connection section to which the load is connected, and a load side connection section on the power conversion section side connection section. The device may be characterized by comprising a connection switching unit that selectively switches and connects to any one of the following.

Furthermore, the connection switching section may be characterized in that it switches based on the detection result of the current detector.

As described above, according to the present invention, it is possible to contribute to the accuracy of detecting load currents of loads having different load capacities.

1 is a schematic configuration diagram for explaining an inverter device 11 according to a first embodiment. FIG. 3 is a schematic configuration diagram for explaining an inverter device 12 according to a second embodiment. FIG. 3 is a schematic configuration diagram for explaining an inverter device 13 according to a third embodiment. Penetration region current characteristic diagram for A/D resolutions A, B, and C.

The inverter device according to the embodiment of the present invention is completely different from the configurations of Patent Documents 1 to 3, and has a plurality of connection terminal portions, and a load is connected to any one of the connection terminal portions. a terminal block connected to each connection terminal section through different current paths, a power conversion section that drives a load connected to any of the connection terminal sections, and a penetration section through which each current path passes through. and a current detector for detecting the load current of the driven load. Further, the present invention is characterized in that the number of turns for each current path with respect to the penetration portion is different from each other.

The number of turns of each current path is appropriately set depending on the load capacity of the load to be driven. For example, when N loads are to be driven, N current paths having the number of turns from 1 to N (N is a natural number of 2 or more) may be configured.

When driving a large-capacity load among the N loads in a rated operation or the like, the load may be connected to a connection terminal portion related to a current path having a relatively small number of turns. Furthermore, when driving a large capacity load with a relatively low load current, etc., or when driving a small capacity load, it is recommended to connect the respective loads to connection terminals related to current paths with a relatively large number of turns. Can be mentioned.

According to such a configuration, loads having different load capacities can be connected to any one of the connection terminal sections and driven by the current control section. In this case, in the current path to which the load is connected, the current flowing through the area where the penetration part is located (hereinafter simply referred to as the penetration area current) has an amount of current that corresponds to the number of turns for the penetration part. .

Therefore, by appropriately connecting loads with different load capacities to one of the connection terminals, the current in the through-hole region of the connected current path can be adjusted to (or approximate) the rated current of the through-type detector. This makes it possible to easily detect the through-part region current as a load current with good detection accuracy.

By detecting the penetration region current as the load current with good detection accuracy as described above, it is also possible to contribute to the control accuracy of the inverter device.

The connection configuration of each current path in this embodiment includes, for example, applying a configuration in which the through-holes are connected by connection wirings having different numbers of turns (for example, Example 1 described later), but is not limited to this. isn't it. It is also possible to apply other connection configurations (for example, Examples 2 and 3 described below) as appropriate, as long as the number of turns for the penetration portion of each current path is appropriately set according to the load capacity.

That is, in the inverter device of this embodiment, as described above, each current path connecting the power converter and each terminal connection portion passes through the penetration portion of the feedthrough type detector, and the penetration portion of each current path It is sufficient to have a configuration in which the number of turns for the It is possible to modify the design by appropriately referring to technical literature and the like.

Examples 1 to 3 shown below are examples. Note that in Examples 1 to 3, detailed explanations are omitted as appropriate, for example, by applying the same reference numerals to overlapping contents. Furthermore, it is assumed that the load capacities of the loads M1 to M3, which will be described later, decrease in the order of M1 to M3.

≪Example 1≫
FIGS. 1A and 1B show a schematic configuration of an inverter device 11 according to a first embodiment. This inverter device 11 mainly includes a power converter 1, a terminal block 2, a through-type detector 3, and current paths 41 and 42.

The power converter 1 includes switching elements such as IGBTs, and drives loads (such as motors) M1 and M2 having different load capacities. This power converter 1 can be applied in various forms, but it is assumed that the power converter 1 can be adapted to the load M1 having a large load capacity in terms of inverter capacity.

The terminal block 2 is provided with connection terminal portions T1 and T2, and is configured to be able to connect loads M1 and M2 to the connection terminal portions T1 and T2, respectively, as shown in FIGS. 1(A) and (B). .

The penetrating type detector 3 has a penetrating portion 31 having a shape through which the current paths 41 and 42 can pass, and is configured to be able to detect the current in the penetrating portion region of the current paths 41 and 42 as the load current of the loads M1 and M2. It becomes. This penetration type detector 3 can be applied in various forms, but it is assumed that it can be adapted to the load M1 having a large load capacity at the rated current.

The detected current detected by the through-type detector 3 is used, for example, to control the power converter 1 and monitor the driving status of the loads M1 and M2 via a control unit not shown (control unit 7 in FIG. 3 described later). do.

The current paths 41 and 42 are constituted by connection wires 51 and 52 that connect between the output terminal (not shown) of the power conversion section 1 and the connection terminal sections T1 and T2, respectively. The connection wires 51 and 52 penetrate through the penetration portion 31 with different numbers of turns.

The number of turns of the connection wirings 51 and 52 can be appropriately set according to the load capacitance of the loads M1 and M2, and the number of turns can be increased as the load capacitance becomes smaller. In the case of FIG. 1, the number of turns of the connection wiring 51 to which the large capacity load M1 is connected is one, and the number of turns of the connection wiring 52 to which the small capacity load M2 is connected is two.

In the inverter device 11 shown above, when the load M1 is connected to the connection terminal portion T1 as shown in FIG. The load M1 can be driven. In this case, the penetration type detector 3 can detect the penetration region current of the current path 41 as the load current of the load M1.

In addition, when the load M2 is connected to the connection terminal portion T2 as shown in FIG. 1(B), the load M2 is Can be driven. In this case, the penetration type detector 3 can detect the penetration region current of the current path 42 as the load current of the load M2. In addition, since the current path 42 has a larger number of turns than the current path 41, even if the load M2 is a small capacity load, the current in the penetration region of the current path 42 is converted to the rated current of the penetration type detector 3. This makes it possible to fully adapt to the

According to the inverter device 11 described above, the penetration region currents of the current paths 41 and 42 can be detected with good detection accuracy as the load currents of the loads M1 and M2, respectively, contributing to the control accuracy of the inverter device 11. It becomes possible to do so.

Note that the inverter device 11 is not limited to the configuration shown in FIG. 1, and can be modified in design as appropriate depending on the number of driven objects (loads) and load capacity.

For example, as shown in FIGS. 1C and 1D, in the terminal block 2, a connection terminal part T3 is provided in addition to the connection terminal parts T1 and T2, and loads M1 to M3 are provided to the connection terminal parts T1 to T3, respectively. One example is a configuration that allows the connection of

In the case of FIGS. 1(C) and (D), a current path is established by a connecting wiring 53 that connects the output terminal (not shown) of the power converter 1 and the connecting terminal portion T3 and has a number of turns of 3 with respect to the through portion 31. 43 are configured.

By connecting the load M1 to the connection terminal portion T1 as shown in FIG. 1(C), the load M1 can be driven in the same manner as in FIG. It can be detected as the load current.

By connecting the load M2 to the connection terminal T2 in the same way as in FIG. 1(B), the load M2 can be driven in the same manner as in FIG. It can be detected as the load current.

The load M3 can be driven by connecting it to the connection terminal part T3 as shown in FIG. 1(D) and supplying current from the power conversion part 1 via the current path 43. In this case, the penetration type detector 3 can detect the penetration region current of the current path 43 as the load current of the load M3. Furthermore, since the current path 43 has a larger number of turns than the current paths 41 and 42, even if the load M3 is a small capacity load, the current in the through-hole region of the current path 43 is transferred to the through-hole detector 3. It becomes possible to sufficiently match the rated current.

As described above, it can be seen that in the inverter device 11, even if the design is appropriately modified as shown in FIGS.

Note that an example of the application of the loads M1 to M3 is a motor for driving an elevator or the like, but the present invention is not limited to this and can be applied to various embodiments.

≪Example 2≫
FIGS. 2A and 2B show a schematic configuration of an inverter device 12 according to a second embodiment. Like the inverter device 11, this inverter device 12 mainly includes a power converter 1, a terminal block 2, a through-type detector 3, and current paths 41 and 42, and the current paths 41 and 42 are configured as shown below. It has a modified design.

First, the current paths 41 and 42 in FIGS. 2A and 2B are connected by at least the first connection wiring 61 of the first connection wiring 61 and the second connection wiring 62. In the case of FIGS. 2A and 2B, the current path 41 is connected only by the first connection wiring 61, and the current path 42 is connected by the first connection wiring 61 and the second connection wiring 62. ing.

The first connection wiring 61 penetrates through the penetration part 31 and connects to one of the connection terminal parts T1 and T2 (connection terminal part T1 in FIGS. 2A and 2B) and the output terminal of the power conversion section 1. It connects between.

The second connection wiring 62 electrically connects the connection terminal parts T1 and T2 in series, and the central part of the second connection wiring 62 (that is, between the adjacent connection terminal parts T1 and T2 in the series direction) penetrates through the second connection wiring 62. It passes through the section 31.

The number of turns of the first and second connection wirings 61 and 62 can be set appropriately according to the load capacity of the loads M1 and M2, and the number of turns can be increased as the load capacity becomes smaller. Can be mentioned. In the case of FIG. 2, the number of turns of each of the first and second connection wires 61 and 62 is one.

In the inverter device 12 shown above, when the load M1 is connected to the connection terminal portion T1 as shown in FIG. By supplying current to the load M1, the load M1 can be driven. In this case, the penetration type detector 3 can detect the penetration region current of the current path 41 (that is, the first connection wiring 61) as the load current of the load M1.

In addition, when the load M2 is connected to the connection terminal portion T2 as shown in FIG. 2(B), the power conversion unit The load M2 can be driven by supplying current from the load M2 to the load M2. In this case, the penetration type detector 3 can detect the penetration region current of the current path 42 (that is, the first and second connection wires 61 and 62) as the load current of the load M2. In addition, the number of turns of the current path 42 is the sum of the first and second connection wires 61 and 62, and is larger than the current path 41, so even if the load M2 is a small capacity load, the current It becomes possible to sufficiently match the current in the penetration region of the path 42 to the rated current of the penetration type detector 3.

According to the inverter device 12 shown above, in addition to having the same effects as the inverter device 11, the following can be said. That is, since each current path 41, 42 has a configuration in which at least the first connection wiring 61 is shared (that is, a configuration in which a part is shared), when compared with the inverter device 11, each current path 41, 42 is This has the potential to contribute to simplification, cost reduction, and easier wiring work.

Note that the inverter device 12 is not limited to the configuration shown in FIG. 2, and can be modified in design as appropriate depending on the number of driven objects (loads) and load capacity.

For example, as shown in FIGS. 2C and 2D, in the terminal block 2, a connection terminal part T3 is provided in addition to the connection terminal parts T1 and T2, and loads M1 to M3 are provided to the connection terminal parts T1 to T3, respectively. One example is a configuration that allows the connection of

In the case of FIGS. 2C and 2D, the second connection wiring 62 has a configuration in which two connection wirings 62a and 62b are electrically connected in series. Moreover, the connection wiring 62a connects each connection terminal part T1, T2 in electrical series, and the connection wiring 62b connects each connection terminal part T2, T3 in electrical series. Furthermore, the center portions of each of the connection wires 62a and 62b (that is, between the connection terminal portions T1 to T3 adjacent to each other in the series direction) pass through the through portion 31, respectively.

In addition, in the case of the second connection wiring 62 in FIGS. 2(C) and 2(D), the configuration is divided into a plurality of connection wirings (connection wirings 62a, 62b), but the configuration is not limited to this. isn't it. That is, as long as the connection terminal portions T1 to T3 can be electrically connected in series, the plurality of connection wirings may be integrated.

By connecting the load M1 to the connection terminal portion T1 as shown in FIG. 2(C), the load M1 can be driven in the same manner as in FIG. It can be detected as the load current.

By connecting the load M2 to the connection terminal portion T2 in the same manner as in FIG. 2B, the load M2 can be driven in the same manner as in FIG. Then, the current in the through-hole region of the connection wiring 62a) can be detected as the load current of the load M2.

The load M3 can be driven by connecting it to the connection terminal part T3 as shown in FIG. 2(D) and supplying current from the power conversion part 1 via the current path 43. In this case, the penetration type detector 3 can detect the penetration region current of the current path 43 (that is, the first connection wiring 61 and the connection wirings 62a, 62b) as the load current of the load M3. Furthermore, since the current path 43 has a larger number of turns than the current paths 41 and 42, even if the load M3 is a small capacity load, the current in the through-hole region of the current path 43 is transferred to the through-hole detector 3. It becomes possible to sufficiently match the rated current.

Therefore, it can be seen that even if the design of the inverter device 12 is appropriately modified as shown in FIGS. 2(C) and 2(D), for example, the same effects can be achieved.

≪Example 3≫
FIG. 3 shows a schematic configuration of an inverter device 13 according to a third embodiment. The inverter device 13 includes a power converter 1, a terminal block 2, a through-type detector 3, and current paths 41 and 42, as well as a controller 7, which are similar to the inverter device 12. Moreover, the terminal block 2 has a configuration modified in design as shown below.

First, the terminal block 2 in FIG. 3 includes a power conversion side connection section 21 in which each connection terminal section T1 to T3 is provided, and a load side connection section in which a common connection terminal section m to which loads M1 to M3 can be connected is provided. 22, and a connection switching section 23 that selectively connects the load side connection section 22 to any one of the connection terminal sections T1 to T3 of the power conversion side connection section 21.

The connection switching section 23 is provided with connection terminal sections S1 to S3 connected to the connection terminal sections T1 to T3, respectively, and a connection terminal section S4 connected to the common connection terminal section m. The connection terminal portion S4 is configured to be selectively connected to any one of the connection terminal portions S1 to S3.

The control unit 7 A/D converts the penetration region current detected by the penetration type detector 3, and based on the A/D conversion result, connects the connection terminal section S4 of the connection switching section 23 and each connection terminal section S1. - S3 can be switched and controlled (in the figure, switching is controlled by outputting a control signal IO).

Various aspects can be applied to the switching control configuration of the connection switching unit 23 by the control unit 7. An example of this is one in which switching can be controlled as shown below based on the penetration region current characteristics for A/D resolutions A, B, and C as shown in FIG.

The three sine wave current curves in FIG. 4 are related to resolutions A, B, and C, and are current path 43 (number of turns 3), current path 42 (number of turns 2), and current path 41 (number of turns), respectively. 3 shows the through region current when driving the load M1 through the number of turns (1). In addition, A, B, and C displayed on the left side of each curve indicate the detectable range of the penetration region current by the penetration type detector 3, and correspond to the resolutions A, B, and C, respectively. shall be taken as a thing. Similarly, A', B', and C' displayed on the left side of the figure are threshold values related to the peak values of the respective curves, and are set in advance in the control unit 7.

In the switching control shown in FIG. 4, first, the load M1 is driven with a relatively low load current (for example, immediately after starting driving), and the peak value of the penetration region current detected by the penetration type detector 3 is the threshold value A. 'In the following cases, the connection terminal section S4 is connected to the connection terminal section S3 under switching control of the control section 7. In this connected state, the control unit 7 has a resolution of A, and the detectable range of the penetration region current is A or less.

Thereafter, when the peak value of the penetration region current changes to within the range of threshold values A' to B', the connection terminal section S4 is connected by the switching control of the control section 7 at the zero cross point of the penetration region current. Connect to terminal section S2. In this connected state, the control unit 7 has a resolution of B, and the detectable range of the penetration region current is B or less.

Then, when the peak value of the penetration region current changes within the range of threshold values B' to C', the connection terminal section S4 is connected by switching control of the control section 7 at the zero-crossing point of the penetration region current. Connect to terminal section S1. The control unit 7 in this connected state has a resolution of C, and the detectable range of the penetration region current is C or less.

According to the inverter device 13 shown above, in addition to having the same effects as the inverter device 12, the following can be said. That is, for example, even if the load current of the driven object connected to the load-side connection section 22 changes and the penetration region current changes, the connection switching section 23 changes according to the change in the penetration region current. can be appropriately switched and controlled (for example, automatically controlled), and the current in the penetration region can be detected as a load current, which can easily contribute to the control accuracy of the inverter device 13.

Further, in the feedthrough type detector 3 of the inverter device 13, it is possible to appropriately detect the feedthrough region current that changes as described above as a load current without installing a tap or a changeover switch as in Patent Document 3. It is. That is, compared to the case of Patent Document 3, there is a possibility that it can contribute to miniaturization and simplification of the penetrating detector 3.

Note that the inverter device 13 is not limited to the configuration shown in FIGS. 3 and 4, and can be modified in design as appropriate depending on the number of driven objects (loads) and load capacity.

For example, like the inverter device 13, the inverter device 11 also includes a terminal block 2 including a power conversion side connection section 21, a load side connection section 22, and a connection switching section 23, and the connection switching section 23 is switched by the control section 7. It can be controlled, and the same effects as the inverter device 13 can be achieved.

Further, the terminal block 2 may be modified in design as long as it is configured to selectively switch and connect between the load-side connection portion 22 and any of the connection terminal portions T1 to T3. One example is a configuration in which the connection terminal sections S1 to S3 are omitted in the connection switching section 23 so that the connection terminal section S4 can be directly connected to each of the connection terminal sections T1 to T3.

Although only the specific examples described in the present invention have been described in detail above, it is obvious to those skilled in the art that various changes can be made within the scope of the technical idea of the present invention. It is a matter of course that such changes and the like fall within the scope of the claims.

1... Power conversion unit 11, 12, 13... Inverter device 2... Terminal block 3... Penetration type detector 31... Penetration part 41, 42, 43... Current path 51, 52, 53... Connection wiring 61... First connection wiring 62 ...Second connection wiring 7...Control section M1, M2, M3...Load T1, T2, T3...Connection terminal section

Claims (3)

a terminal block having a plurality of connection terminal parts and to which a load is connected to any one of the connection terminal parts;
a power conversion unit that is connected to each connection terminal portion via different current paths and drives a load connected to any one of the connection terminal portions;
a current detector having a penetration portion through which each current path passes, and detecting a load current of the driven load;
The number of turns for the penetration part of each current path is different,
A first connection wiring that passes through the penetration portion only once and connects one of the connection terminal portions to the power conversion portion;
A second connection wiring that connects each connection terminal part in electrical series, and in which two adjacent connection terminal parts in the series direction pass through the penetration part only once ,
An inverter device characterized in that each current path is connected by at least a first connection wiring among the first and second connection wirings. The terminal block is
a power converter side connection section in which each connection terminal section is provided;
a load-side connection to which a load is connected;
a connection switching section that selectively switches and connects the load side connection section to one of the connection terminal sections of the power conversion section side connection section;
The inverter device according to claim 1 , further comprising: 3. The inverter device according to claim 2 , wherein the connection switching section switches based on a detection result of a current detector.

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