JP4780692B2 - Multiphase motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multiphase motor suitable for use as a redundant motor.
[0002]
[Prior art]
Conventionally, as the above-described multiphase motor, for example, there is a three-phase brushless motor shown in FIG.
[0003]
As shown in FIG. 3, the three-phase brushless motor 50 includes a total of two sets of windings 51 and 52 of the A system and the B system, both of which are connected to the inverters 53 and 54. They are connected to each other, and current control is performed by feeding back currents flowing through the two sets of windings 51 and 52 via the inverters 53 and 54 to the interface circuits 55 and 56, respectively.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional three-phase brushless motor 50, since the two sets of windings 51 and 52 are independent of each other, for example, when a malfunction occurs in the A-system winding 51 or the inverter 53, the remaining windings 51 and 52 remain. However, there is a problem that the output is halved.
[0005]
Further, in the remaining B-system winding 52, even if one of the three phases fails, it becomes inoperable, and when the inverters 53 and 54 in the normal short-circuit mode fail, 1 There is a problem that phase damage induces damage of other phases, and it has been a conventional problem to solve these problems.
[0006]
OBJECT OF THE INVENTION
The present invention has been made paying attention to the above-described conventional problems, and prevents the inverter from becoming inoperable even if the inverter fails or a failure occurs in one of the polyphases of the winding. Of course, it is possible to minimize the decrease in output, and in addition, in the case of an inverter failure in the normal short-circuit mode, there is almost no possibility that damage of one phase will cause damage of other phases. The object is to provide a multiphase motor that can be eliminated.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a multiphase motor including two sets of windings respectively connected to the inverter and performing current control by feeding back currents flowing through the two sets of windings. When a failure occurs in either phase of one of the two windings at both the neutral point of the star connection in the winding and the neutral point of the star connection in the other winding A neutral wire for passing a short-circuit current of the current is connected, and current control is performed via the neutral wire so that approximately twice the current flows in the phase of the other winding corresponding to the phase in which the failure occurs. An interface circuit is provided.
[0008]
According to a second aspect of the present invention, in the configuration described in the first aspect, a sensor that detects a current flowing in each winding and feeds back to the interface circuit is provided, and the interface circuit is fed back from the sensor. A control current is output to the inverter by a current signal flowing through each winding.
[0009]
[Effects of the Invention]
In the multiphase motors according to claims 1 and 2, since the above-described configuration is adopted, for example, in the case of a three-phase motor, if a short-circuit mode failure occurs in the U-phase inverter of one of the windings, the short-circuit current Does not flow to the other elements through the neutral wire, and the remaining other winding is subjected to current control using the neutral wire, resulting in damage to the U phase of one winding. However, in this case, since control for automatically compensating for the current deficit in the U phase can be performed, a significant decrease in output can be suppressed.
Further, for example, when the multiphase motor is a three-phase motor, even if the U-phase inverter in one winding breaks down, approximately twice the current flows in the U ′ phase of the other winding corresponding to this U-phase. If the flow is controlled so that the missing portion in the U phase is automatically compensated for in the U ′ phase, a decrease in output can be suppressed to a small extent.
[0011]
【The invention's effect】
When the multiphase motor according to claim 1 or 2 is, for example, a three-phase motor, even if a short-circuit mode failure occurs in the U-phase inverter of one of the windings, the U-phase of the one winding It is possible to almost eliminate the possibility of damage to the other phase, and in addition, by performing control to automatically compensate for the current loss in the U phase, it is possible to suppress a significant decrease in output.
[0013]
【Example】
Hereinafter, the present invention will be described with reference to the drawings.
[0014]
1 and 2 show an embodiment of a multiphase motor and a control method thereof according to the present invention. In this embodiment, the multiphase motor according to the present invention is a three-phase brushless motor. .
[0015]
As shown in FIG. 1, this three-phase brushless motor 1 includes a total of two sets of windings 2 and 3 of A system and B system, both of which are connected to inverters 4 and 5. A neutral wire 7 is connected to both the neutral point 2 a of the star connection in the A-system winding 2 and the neutral point 3 a of the star connection in the B-system winding 3. It is.
[0016]
In this case, the current flowing in each phase (U phase, V phase, W phase) of the windings 2 and 3 is detected by a sensor (not shown). Is fed back to the interface circuit 6.
[0017]
In the interface circuit 6, as shown in FIG. 2, the fed back current signals IA and IB flowing in the windings 2 and 3 of the A system and the B system are added and summed at a summing point 11, and this summing is performed in a block 12. An average value is calculated, and compared with the current command value at the two addition points 13 and 14 of the comparison unit, respectively, and output to the inverters 4 and 5.
[0018]
In the above-described three-phase brushless motor 1, for example, when a short-circuit mode failure occurs in the UA-phase inverter 4 of the A-system winding 2, the short-circuit current flows through the neutral wire 7 to other elements. However, in the remaining B-system winding 3, current control using the neutral wire 7 is performed, and therefore, damage to the UA phase of the A-system winding 2 may reach other phases. Almost nothing.
[0019]
In the three-phase brushless motor 1 described above, for example, when the UA-phase inverter in the A-system winding 2 fails, the interface circuit 6 feeds back the UA in the A-system and B-system windings 2 and 3. After the current signals IA (IAu) and IB (IBu) flowing in the phase and the UB phase are added and summed at the summing point 11, an average value of the summed value is calculated in the block 12, and this is calculated as 2 in the comparison unit. The summing points 13 and 14 are respectively compared with current command values and output to the inverters 4 and 5.
[0020]
That is, the interface circuit 6 outputs a current signal approximately doubled to the B-system inverter 5 and controls the UA phase so as to automatically compensate for the loss in the UA phase. While the output of the three-phase brushless motor was reduced by half, the above-described three-phase brushless motor 1 would ensure an output of 5/6 or more. The three-phase brushless motor 1 is used as a redundant motor. It is the best one to do.
[0021]
In the above-described embodiments, the case where the multiphase motor according to the present invention is a three-phase brushless motor is shown, but the present invention is not limited to this, and the number of phases and the presence or absence of brushes can be appropriately selected. is there.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a circuit showing an embodiment of a multiphase motor according to the present invention.
FIG. 2 is a detailed explanatory diagram of the interface circuit of FIG. 1;
FIG. 3 is a circuit explanatory diagram showing a conventional multiphase motor.
[Explanation of symbols]
1 Three-phase brushless motor (multi-phase motor)
2, 3 Winding 2a, 3a Neutral point 4, 5 Inverter 6 Interface circuit 7 Neutral wire

Claims (2)

In a multi-phase motor that has two sets of windings connected to each inverter and performs current control by feeding back the currents flowing through these two sets of windings,
Both the neutral point of the star connection in one winding and the neutral point of the star connection in the other winding cause a failure in either phase of one of the two windings. In addition to connecting a neutral wire that carries a short-circuit current when
A multi-phase motor comprising an interface circuit that performs current control through the neutral wire to flow a current that is approximately twice through the phase of the other winding corresponding to the phase in which the failure occurs . A sensor that detects the current flowing in each winding and feeds back to the interface circuit is provided.
The multiphase motor according to claim 1, wherein the interface circuit outputs a control current to the inverter based on a current signal fed through each winding fed back from the sensor .

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