JP2006271018A - Method of driving three-phase synchronous motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of driving a high output of three-phase synchronous motor at an easy rate. <P>SOLUTION: For an independent three-phase winding circuit in the first pair, four coils each of the same phase of a U1-phase coil, a V1-phase coil, and a W1-phase coil are connected in parallel and then are star-connected, and the power wires U1, V1 and W1 are connected to a motor driving unit 1. An independent three-phase winding circuit in the second pair is the same, and four coils each of the same phase of a U2-phase coil, a V2-phase coil, and a W2-phase coil are connected in parallel and then are star-connected, and power wires U2, V2 and W2 are connected to a motor driving unit 2. The stator winding is concentratedly wound individually on a total of twenty four salient poles, and each phase coil in each pair is constituted of a total of twenty four coils. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a driving method for a high-output three-phase synchronous motor.

  Conventionally, in order to cope with an increase in the output of a motor, it is common practice to increase the stator thickness or increase the inner and outer diameters of the stator.

  The stator winding is generally a star connection having a U-phase, V-phase, and W-phase power line and one neutral point that short-circuits the respective phases together (for example, Patent Document 1). ).

On the other hand, the motor drive device requires a large-capacity switching element, and the large-capacity switching element has little demand and has a difficulty in availability. Further, since the other power elements and wirings are increased in size, the motor drive device is also increased in size.
JP 2003-244915 A

  The problem to be solved is that the winding diameter increases with the increase in the output of the three-phase synchronous motor, and the workability of the winding is greatly deteriorated. A large capacity motor driving device must be prepared. Is a point.

  That is, the deterioration of the winding work leads to a decrease in the winding space factor, and there is a problem in increasing the output. In addition, there is little demand for large-capacity switching elements, and there are problems such as a significant increase in manufacturing costs and a prolonged procurement.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a method for driving a high-output three-phase synchronous motor at low cost.

  In order to solve the above-described problems, the present invention includes a motor having a plurality of sets of three-phase winding circuits independently connected to one stator, and a plurality of motor driving devices for driving the motor, the independent This is a driving method in which the motor driving device is connected to each of the three-phase winding circuits and is operated synchronously.

  According to the three-phase synchronous motor of the present invention, a motor having a plurality of independent three-phase winding circuits is connected to a plurality of small-capacity motor driving devices for synchronous operation. However, it can be driven at low cost.

  In addition, the winding diameter is reduced because the winding is concentrated on the salient poles of the stator core and the star phase is connected in parallel with the same phase, making the winding work easier and improving the winding space factor. Can do.

  In addition, a high-capacity motor that is twice to four times the conventional motor can be driven at low cost while using a conventional large-capacity switching element.

  A three-phase synchronous motor according to the present invention includes a motor having a plurality of sets of three-phase winding circuits independently connected to one stator, and a plurality of motor driving devices that drive the motor. The motor drive device is connected to each three-phase winding circuit for synchronous operation. The three-phase winding circuit is concentratedly wound around the salient poles of the stator core, and the same phase is paralleled. The motor capacity is about 60 kW to 120 kW, and the capacity of one motor driving device is about 20 kW to 40 kW.

  In the first embodiment, a three-phase synchronous motor having two sets of three-phase winding circuits independently connected to one stator will be described.

  In FIG. 1, the first set of independent three-phase winding circuits are connected in parallel after four in-phase coils of a U1-phase coil, a V1-phase coil, and a W1-phase coil are connected in parallel, and their power supply lines U1, V1, W1 Is connected to the motor drive device 1. The same applies to the second set of independent three-phase winding circuits, in which four in-phase coils of U2-phase coil, V2-phase coil, and W2-phase coil are connected in parallel and then star-connected, and the power supply lines U2, V2, and W2 are connected. The motor drive device 2 is connected.

  The stator windings are individually concentrated and wound around all 24 salient poles, and each phase coil of each set is composed of a total of 24 coils (2 sets (number of circuits) × 3 phases × 4 Coil = 24 coils).

  For example, in the case of a three-phase synchronous motor (stator having 24 salient poles) with a motor capacity of 60 kW, two salient poles have two Φ2.7 mm coils and are wound 17 times, and the number of rotor magnetic poles is 16 Is the pole.

  A more specific coil arrangement will be described using a U-phase coil. In FIG. 2, the U1 phase coil of the first set of U phase coils is composed of four U1 coils, and U1-2 coil, U1-3 coil, U1 at a mechanical angle interval of 90 ° with reference to U1-1 coil. -4 coils are arranged. The second set of four U2-phase coils is a U2-1 coil disposed at a mechanical angle of 45 ° with respect to the U1-1 coil, and a U1-phase coil with respect to the U2-1 coil. Similarly, the V-phase coil and the W-phase coil are also arranged at intervals of 90 °.

  In this manner, the magnetic attraction force is equalized by arranging the sets of in-phase coils facing each other by 180 °.

  Each of the independent three-phase winding circuits is individually connected to an independent 30 kW capacity motor drive device. The 30 kW capacity motor drive device includes six 640 A switching elements and can drive a three-phase synchronous motor with a motor capacity of 30 kW.

  By driving the respective phase coils of two sets of independent three-phase winding circuits at the same time energized in synchronization, one three-phase synchronous motor (60 kW capacity) can be driven.

  Example 2 describes a three-phase synchronous motor having four sets of three-phase winding circuits independently connected to one stator.

  The difference from the first embodiment is that the number of three-phase winding circuits is 2 to 4, the number of sets of in-phase coils is 4 to 2, and the number of motor drive units is 2 to 4. For convenience, the description will be made on the assumption that the motor has a capacity of 60 kW with the same coil diameter and the same number of turns wound around each salient pole, but only different connections.

  In FIG. 3, the first set of independent three-phase winding circuits are connected in parallel after connecting two in-phase coils of a U1-phase coil, a V1-phase coil, and a W1-phase coil, and their power supply lines U1, V1, W1 Is connected to the motor drive device 11. The same applies to the second set of independent three-phase winding circuits. Two in-phase coils of U2-phase coil V2-phase coil and W2-phase coil are connected in parallel and then star-connected, and the power supply lines U2, V2, W2 are connected to the motor. Similarly, the third set of three-phase winding circuits and the fourth set of three-phase winding circuits are connected to the motor drive device 13 and the motor drive device 14.

  A more specific coil arrangement will be described using a U-phase coil. In FIG. 4, the U1 phase coil of the 1st set of U phase coil has arrange | positioned two U1-1 coils and U1-2 coils facing 180 degrees. The same applies to the U4 phase coil of the 4th set from the U2 phase coil of the second set, with the U2-1 coil at a position 45 ° apart from the U1-1 coil, and at a position 90 ° apart. The U4-1 coil is disposed at a position 135 ° away from the U3-1 coil, and the other one is disposed at a position opposite to the 180 °. A V-phase coil and a W-phase coil are similarly arranged and connected.

  The four motor drive devices may have a half capacity of 15 kW compared with the 30 kW capacity motor drive device of the first embodiment, the switching element capacity may be half, and there is one common control circuit other than the motor drive device. It may be summarized.

  In this embodiment, a three-phase synchronous motor with a capacity of 60 kW and a motor driving device with a capacity of 30 kW or 15 kW have been described, but a motor with higher output can be driven with the same configuration. Further, the description has been given of the stator motor having the number of magnet magnetic poles of 16 and the number of salient poles of 24.

  The driving method of the three-phase synchronous motor of the present invention can be driven at low cost because it can be driven synchronously by connecting a plurality of small-capacity motor driving devices even if it is a high output motor. It is also useful for machine applications.

Connection diagram in Embodiment 1 of the present invention Arrangement of stator windings of a three-phase synchronous motor in Embodiment 1 of the present invention Connection diagram in Embodiment 2 of the present invention Arrangement diagram of stator winding of three-phase synchronous motor in embodiment 2 of the present invention

Explanation of symbols

1, 2, 11, 12, 13, 14 Motor drive unit U1, U2, U3, U4 Power line (U phase)
V1, V2, V3, V4 Power supply line (V phase)
W1, W2, W3, W4 Power line (W phase)

Claims (3)

A motor having a plurality of sets of three-phase winding circuits independently connected to one stator, and a plurality of motor driving devices for driving the motor, each of the independent three-phase winding circuits A method for driving a three-phase synchronous motor, wherein the motor driving devices are connected to perform synchronous operation. The three-phase synchronous motor driving method according to claim 1, wherein the three-phase winding circuit is configured by star connection in which the three-phase winding circuits are concentratedly wound around the salient poles of the stator core and the same phases are connected in parallel. The method for driving a three-phase synchronous motor according to claim 1, wherein the motor capacity is about 60 kW to about 120 kW, and the capacity of one motor driving device is about 20 kW to about 40 kW.

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