JP4957762B2 - AC motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an AC motor driving a main motor and an auxiliary motor by switching them by a plurality of standard design inverters irrespective of a motor type. <P>SOLUTION: When p is a pole pair count, coils 11 and 12 stored in a plurality of slots 10 each constituting one pole for one phase are constituted of coils of 2p sets or 2p&times;1.5 sets. Arrangement positions to the slots and coil connections of the coils of 2p sets or 2p&times;1.5 sets are decided so that one synthetic magnetic pole is formed with a voltage vector caused by each coil set. Thus, the motor can be driven by inverters whose number is twice as much as 2p sets of the coils or is the same as the number of 2p&times;1.5 sets of the coils. The inverters are also driven by a rotation speed which is 60/p times as much as an inverter output frequency in the AC motor. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an AC motor including a multi-winding stator coil and driven by a plurality of inverters.

  As an example of an AC motor having a multi-winding configuration, there is one used in a marine propulsion motor (see Patent Document 1). This electric motor is constituted by a plurality of multi-windings having a special structure so that it can be driven by a plurality of inverters. For example, even if one of the inverters fails, the remaining inverters can navigate. In this example, each inverter can be switched and connected to a multi-winding motor, or an auxiliary motor such as a thruster or cargo pump, via a switch, and the inverter is used as an inverter for the motor during navigation. When the vehicle is not sailing, it is switched as an auxiliary motor inverter.

  A conventional configuration of this system will be described with reference to FIG. FIG. 14 shows inverters 2 </ b> A, 2 </ b> B, 2 </ b> A, 2 </ b> B, and 5 </ b> 2C and 2D are connected via reactors 3A, 3B, 3C and 3D and changeover switches 4A, 4B, 4C and 4D. Further, when the load of the main motor 5 is reduced or stopped, any or all of the inverters 2A, 2B, 2C, and 2D are connected to an auxiliary motor 8 that drives the compressor 9, for example, via the changeover switches 4A, 4B, 4C, and 4D. Try to supply power. In this case, the auxiliary motor 8 is also composed of the same multi-winding as the main motor. FIG. 15 shows the stator coils of the main motor 5 and the auxiliary motor 8 of FIG. 14, and these motors are provided with windings consisting of four sets of windings, for example, 10A, 10B, 10C and 10D. And each is independent. In FIG. 15, each set of coils is a star connection, but may be a delta connection.

This type of multi-winding motor has a complicated winding method unlike a stator coil of a normal motor, and an example thereof will be described with reference to FIG. That is, the connection diagram of FIG. 16 is a three-phase four-pole slot number 48.
Number of slots per pole / phase 4
2-layer lap winding (upper coil, lower coil)
Coil pitch 1-11
Number of parallel circuits 4
The case of star connection is shown as an example. However, for simplicity, it is a coil connection diagram of only the U layer. In FIG. 15, U1, U2, U3 and U4 are U-phase coils, V1, V2, V3 and V4 are V-phase coils, W1, W2, W3 and W4 are W-phase coils, and N1, N2, N3 and N4 are neutral points of each coil.

  In FIG. 16, a plurality of slots 10 are indicated by numerals [1], [2], [3],... [47], [48]. The solid line of the hexagonal coil in FIG. 16 indicates the upper coil 11, the broken line indicates the lower coil 12, and the upper and lower coils are accommodated in the slot. All the hexagonal coils have the same shape, and are configured such that related coils are connected in series at the end portions of the respective coils by connecting wires 13 to exhibit characteristics as a stator coil. The upper coil of U1 is accommodated in slots [1], [2], [3], [4] and connected to the neutral point N1, and the upper coil of U2 is connected to slots [16], [15], [14], [13] is connected to the neutral point N2 and the upper coil of U3 is connected to the neutral point N3 in the slots [25], [26], [27], [28], and the upper coil of U4 Are accommodated in slots [40], [39], [38], [37] and connected to the neutral point N4. This connection method is a well-known coil connection method.

  By winding a plurality of sets of stator coils in this way, the inverters 2A, 2B, 2C, and 2D all supply power to the main motor 5 when the main motor 5 in FIG. 14 is at the rated maximum load. If it is necessary to stop the inverter 2A or operate the auxiliary motor 8 at this time, the changeover switch 4A of the inverter 2A can be switched to the auxiliary machine side. For this reason, there is no need to provide separate dedicated inverters for the main motor 5 and the auxiliary motor 8, so that there is an advantage that the facility cost is reduced and the space can be used effectively.

By the way, when driving different motors by switching the inverters in this way, it is necessary to change the drive frequency if the rotational speeds of the maximum efficiency points of the respective motors are different. For example, if the rotational speed at which the 4-pole main motor 5 exhibits the highest efficiency is 1,200 rpm ⁻¹ ,
f = Pn / 120 = 4 × 1200/120 = 40 [Hz]
That is, the output of the inverter may be 40 Hz. However, if the rotational speed at which the same 4-pole auxiliary motor 8 shows the highest efficiency is 7,200 rpm- ¹ ,
f = Pn / 120 = 4 × 7200/120 = 240 [Hz]
Therefore, the output of the inverter needs to be 240 Hz. If the inverter is shared by the main motor 5 and the auxiliary motor 8, an inverter capable of frequency control up to 240 Hz is employed in this case.

  However, inverters with a standard design currently used in Japan have an upper limit of 120 Hz, and an inverter capable of outputting up to a high frequency of 240 Hz is a non-standard design and very expensive for each manufacturer. Therefore, when frequency control is required up to a high frequency of 240 Hz, an expensive non-standard inverter is used, and the cost reduction effect cannot be obtained sufficiently.

  Furthermore, when the auxiliary motor 8 is operated with a 240 Hz power source, the iron loss and stray load loss increase compared to when operated with a 120 Hz power source, and an impulse appears in the inverter output voltage waveform as the frequency increases. Since it becomes easy to superimpose, dielectric breakdown may occur in the auxiliary motor 8.

  In order to solve this problem, it is considered that if the number of poles of the auxiliary motor 8 is two, it can be solved by using a 120 Hz inverter, but as is well known, the number of parallel circuits of the motor stator coil is Since this is a divisor of the number of poles, the number of parallel circuits other than 1 or 2 cannot be selected in the case of a two-pole motor. Accordingly, in this case, if the number of poles of the auxiliary motor is two, the number of parallel circuits is one or two, and the maximum number of inverters used is two.

  In this embodiment, four inverters are required in capacity to drive the auxiliary motor 8, but since only two parallel circuits can be selected, only two inverters can be connected and the power capacity is insufficient. there's a possibility that. That is, even if the auxiliary motor 8 is a two-pole machine, an economical inverter with a standard design with an upper limit frequency of 120 Hz cannot be used with a rated capacity due to the limitation on the number of parallel circuits.

  As described above, in the conventional system shown in FIG. 14, when there is a difference in the capacity, characteristics, required rotational speed, and rotational speed of the maximum efficiency point between the main motor 5 and the auxiliary motor 8, a standard design inexpensive inverter cannot be used. However, there is a drawback that it may not be possible to obtain the same operating characteristics while suppressing the cost and installation space of the inverter.

JP-A-8-72796

  The present invention has been made in view of the above-mentioned drawbacks, and is driven by inverters having twice the number of poles and 1.5 times the number of poles in consideration of the winding method of the stator coil of the auxiliary motor. It is an object of the present invention to provide an AC motor that enables an economical drive system that does not require the use of an expensive non-standard design inverter that can be used and has a wide output frequency range.

For the present invention to achieve the above object, when the pole pairs of the p, constitute the coil Ru housed in a plurality of slots constituting one pole 1 phase 2p sets of coils or 2p × 1.5 sets of coils The stator coil is composed of 2p × 1.5 sets of coils by connecting 4p sets of coils or pole-pair coils via wiring, and each of the 2p sets of coils or 2p × voltage vector synthesis decided slot position location and the coil connection of the respective 2p sets of coils or 2p × 1.5 set of coils so as to be substantially in phase the same potential with respect to the magnetic pole center resulting from the 1.5 sets of coils, An inverter is connected to each of the 4p set coil or 2p × 1.5 set coil, and it is driven by the same number of inverters as the number of 4p set coil or 2p × 1.5 set coil . Is.

  In the present invention, when adopting a system in which the inverters of the main motor and the auxiliary motor are switched and used, the winding method of the stator coil of the auxiliary motor is configured as described above, so that the number of motor poles is 2 The inverter can be driven at double and 1.5 times the number of inverters and at a rotational speed 60 / p times the inverter output frequency. For this reason, for example, it is not necessary to employ an expensive non-standard inverter with a wide output frequency range, such as 0 to 240 Hz, and a relatively inexpensive inverter with a standard design can be employed, which is economically efficient. There is an effect that space can be secured. Furthermore, since it becomes possible to operate at a low frequency, iron loss and stray load loss do not increase, and impulses are not superimposed on the inverter output voltage waveform, thereby preventing the breakdown of the auxiliary motor 8 from occurring. effective.

It is the connection diagram of the U phase made into star connection among the alternating current motor stator coils which shows Embodiment 1 of this invention. It is a figure of the voltage vector produced | generated by the alternating current motor stator coil by Embodiment 1 of this invention. It is the figure which synthesize | combined the voltage vector produced | generated by the alternating current motor stator coil by Embodiment 1 of this invention. It is the connection diagram of the U phase made into the delta connection among the alternating current motor stator coils which shows Embodiment 1 of this invention. It is an example of the other connection diagram of the U phase made into star connection among the alternating current motor stator coils of Embodiment 1 of the present invention. It is a figure of the voltage vector produced | generated by the alternating current motor stator coil by the other example of connection of Embodiment 1 of this invention. It is the figure which synthesize | combined the voltage vector produced | generated by the alternating current motor stator coil by the other example of connection of Embodiment 1 of this invention. It is the connection diagram of the U phase made into star connection among the alternating current motor stator coils which shows Embodiment 2 of this invention. It is a figure of the voltage vector produced | generated by the alternating current motor stator coil by Embodiment 2 of this invention. It is the figure which synthesize | combined the voltage vector produced | generated by the alternating current motor stator coil by this Embodiment 2. FIG. It is an example of the other connection diagram of the U phase made into star connection among the alternating current motor stator coils of Embodiment 2 of the present invention. It is a figure of the voltage vector produced | generated by the alternating current motor stator coil by the other example of connection of Embodiment 2 of this invention. It is the figure which synthesize | combined the voltage vector produced | generated by the alternating current motor stator coil by the other connection example of this invention Embodiment 2. FIG. It is a figure which shows an example of the system for ships which switches and supplies electric power to a propulsion motor and an auxiliary motor using several conventional inverters. It is a figure which shows the structure of the stator coil of 4 parallel circuits. It is a coil connection diagram which shows only U phase among the stator coils of the conventional 4 winding 3 phase alternating current motor.

(Embodiment 1)
FIG. 1 is a diagram showing Embodiment 1 of the present invention in which the same parts as those in FIG. 16 are denoted by the same reference numerals, and is a connection diagram showing only the U phase among the stator coils of the auxiliary motor. The coil is formed by winding the upper coil 11 and the lower coil 12 in two layers on [1], [2], [3],... [47], [48] of the slot 10 in a hexagonal shape. All of the coils have the same shape. The point that each coil end is connected in series with the related coil by the crossover wiring 13 to exhibit the performance as the stator coil is the same as that of FIG. 16 which is the conventional example. However, in the embodiment of the present invention, the number of slots per one pole and one phase is 8
Coil pitch 1-21
FIG. 16 is different from FIG. 16 in that two sets of coils are provided in one pole / one phase slot and the number of poles is two.

  That is, if only the U phase is taken as an example, the U1 set of coils are placed in the slots [1], [4], [6], [7] and then connected to the neutral point N1, and the U2 set of coils are connected to the slots. [2], [3], [5], [8] and then connected to the neutral point N2. Similarly, U3 sets of coils are placed in slots [31], [30], [28], and [25], and the U4 sets of coils are placed in slots [32], [29], and [27]. [26] and then connected to the neutral point N4. In this embodiment, the pitch of the stator coil is set to 1 to 21 as an example, but can be arbitrarily selected.

Thus, by storing two sets of coils U1 and U2 in the 1-pole 1-phase slots 1 to 8 and storing two sets of coils U3 and U4 in the slots 25 to 32, voltages generated by the coils of each set The vector is as shown in FIG. The voltage vector due to the coils in the slots [1] to [8] and the voltage vector due to the coils in the slots [25] to [32] in FIG. 1 are like straight lines with arrows in FIG. That is, [1], [4], [6], [7] are U1 sets of voltage vectors, [2], [3], [5], [8] are U2 sets of voltage vectors, [25], [ 28], [30] and [31] are U3 sets of voltage vectors, and [26], [27], [29] and [32] are U4 sets of vectors. Among these, the electrical angle between each coil of U1 set and U2 set is
360 ° ÷ 48 slots = 7.5 °
It is. In FIG. 2, the horizontal axis is the x axis, the vertical axis is the y axis, and the y axis is the magnetic pole center. Here, the U1 set of voltage vectors is a composition of voltage vectors by the stator coils stored in the slots [1], [4], [6], and [7]. The angle between is slot [1] 3 x 7.5 + 3.75 = 26.25 °
Slot [4] 3.75 °
Slot [6] 7.5 + 3.75 = 11.25 °
Slot [7] 2 × 7.5 + 3.75 = 18.75 °
It is. Similarly, slot [2] 2 × 7.5 + 3.75 = 18.75 °
Slot [3] 7.5 + 3.75 = 11.25 °
Slot [5] 3.75 °
Slot [8] 3 × 7.5 + 3.75 = 26.25 °
It is.

  Therefore, when the values of these vectors are set to 1, the angle is subjected to the Radian transformation, and divided into the x-axis component and the y-axis component, the result is as follows.

X1 component of U1 -sin26.25 ° -sin3.75 ° + sin11.25 ° + sin18.75 ° = 0.008838
U1 y-axis component cos26.25 ° + cos3.75 ° + cos11.25 ° + sin18.75 ° = 3.82245
X2 component of U2 -sin18.75 ° -sin11.25 ° + sin3.75 ° + sin26.25 ° = -0.008838
U2 y-axis component cos18.75 ° + cos11.25 ° + cos3.75 ° + sin26.25 ° = 3.82245
FIG. 3 shows voltage vectors of U1 group and U2 group obtained from the calculation result. As can be seen from FIG. 3, the combined vectors U1 and U2 have the same magnitude, and the phase difference is θ = 2 × tan ⁻¹ (0.008838 / 3.82245) = 0.265 °.
It is. The U3 and U4 sets are obtained in the same way.

After all, in the embodiment shown in FIG. 1, the voltage vector generated by the stator coil of the auxiliary motor 8 is composed of one pole by the coils U1 and U2 in FIG. 1, and one pole is also composed by the coils U3 and U4. Is done. As a result, it becomes equivalent to a two-pole configuration, and therefore, a two-pole machine can be driven by four inverters by a four parallel circuit that could not be realized by the conventional method. For this reason, even a 4-parallel multi-phase motor that needs to be operated at a rotational speed of 7,200 min ⁻¹ can be made equivalent to a 2-pole machine, and the 2-pole machine is related to the number of conventional poles and the number of parallel circuits. Even if the motor could not be manufactured, if the winding method of the motor according to the first embodiment of the present invention is used, a 240 Hz high frequency inverter is not necessary, and an inverter with a standard design maximum output frequency of 120 Hz can be operated for 7,200 min ^−1. It is economical. Furthermore, compared with the case of operating a quadrupole machine at 240 Hz, there is an advantage that the loss is reduced because the maximum frequency is 120 Hz.

Although the above-mentioned form is the case of 2 poles, the same effect as the case of 2 poles can be obtained when the number of poles is increased to 4, 6,. That is, S: number of slots p: number of pole pairs P: number of poles = 2p
m: Number of phases q: Number of slots per phase per pole f: Output frequency of inverter [Hz]
N: Number of rotations of the motor [rpm ^-1 ]
n: When the number of parallel circuits is used, the following equation is established in the electric motor of the above embodiment.

Number of slots S = 2pmq = 2p × 3 × 8 = 48p -------- (1)
Number of parallel circuits n = 4p = 2P -------------------- (2)
Rotational speed N = 120f / P = 120f / 2p = 60f / p --------- (3)
That is, from equation (3), the rotational speed of the AC motor is 60 / p of the inverter output frequency f. Here, when the number of pole pairs p 1 is changed to 1 to 5, the rotational speed of the electric motor is as shown in Table 1.

  In the above embodiment, the motor coil is in the star connection, but in the case of the delta connection, the connection of the stator coil is as shown in FIG. The connection method of FIG. 4 and FIG. 1 is different from the neutral points N1, N2, N3, and N4 in that they are connected to the V-phase coils V1, V2, V3, and V4, which are the next phases. In the case of the delta connection, the voltage vector relationship does not change, so that the same effect as the star connection can be obtained.

  The above is summarized as follows.

  AC motor with three phases, number of poles 2 x p (p: positive integer (number of pole pairs)), eight slots per pole, two layers winding, and lap winding, constituting one pole and one phase In the star connection, coils 1, 4, 6, 7, and neutral points are connected in order when the coils that are placed in the slots to be called are sequentially called coils 1, 2, 3, 4, 5, 6, 7, and 8. At the same time, the coils 2, 3, 5, 8 and the neutral point are connected in order.

  In the delta connection, the coils 1, 4, 6, 7 and the coil 1 of the next phase V1 are connected in order, and the coils 2, 3, 5, 8 and the coil 2 of the next phase V2 are connected in order to reduce the number of parallel circuits. The driving speed is 4 × p and 4 × p inverters are driven at a rotational speed 60 / p times the output frequency of the inverter.

  Next, another example of the first embodiment will be described with reference to FIG. FIG. 5 shows a modification of FIG. 1, in which each coil of the U1 set is placed in the slots [1], [4], [5], [8] and connected to the neutral point N1, and each coil of the U2 set is connected. Is placed in slots [2], [3], [6], [7] and then connected to the neutral point N2. Similarly, each coil of the U3 set is placed in the slots [32], [29], [28], and [25] and then connected to the neutral point N3, and each coil of the U4 set is connected to the slots [31] and [30]. , [27], and [26] and then connect to the neutral point N4. When connected in this way, the voltage vector generated by the stator coil of FIG. 5 is as shown in FIG. 6, and when they are combined, it is as shown in FIG. As can be seen from FIG. 7, the X-axis direction is bilaterally symmetrical and has the same phase, and only a slight voltage difference occurs in the Y-axis direction, but the same effect can be obtained by such a winding configuration.

(Embodiment 2)
Embodiment 1 above shows the case where the number of parallel circuits is 4, but in order to reduce the number of inverters, an example where the number of parallel circuits is 3 is assigned the same reference numerals in FIG. This will be described with reference to FIG.

In the second embodiment, the number of three-phase slots is 72.
12 slots per pole per phase
Coil pitch 1-31
The coil of U1 is placed in slots [1], [4], [7], [10], [48], [45], [42], [39] and connected to the neutral point N1. , U2 coils are placed in slots [2], [5], [8], [11], [47], [44], [41], [38] and connected to the neutral point N2, A star connection in which the coil is housed in slots [3], [6], [9], [12], [46], [43], [40], [37] and connected to the neutral point N3. .

In this way, the coils are accommodated in the respective slots and connected by the crossover wiring 13 to constitute a plurality of coils U1, U2, and U3. The voltage vector generated by this stator coil is as shown in FIG. In FIG. 9, the straight line of each arrow has shown the voltage vector by the coil accommodated in [1]-[12] and [37]-[48]. The electrical angle between the coils is 360 ÷ 72 slots = 5 °.

As in FIG. 2 of the first embodiment, the horizontal axis is the x axis and the vertical axis is the y axis. In FIG. The voltage vector is a radial line in FIG. Of these, the voltage vector of the slots [1], [4], [7], [10] is a voltage vector of the U1 phase. Is a U2-phase voltage vector, and a voltage vector of slots [3], [6], [9], [12] is a U3-phase voltage vector. The electrical angle between the voltage vector of each slot [1], [4], [7], [10] and the magnetic pole center is slot [1] 5 × 5.0 + 2.5 = 27.5 °
Slot [4] 2 × 5.0 + 2.5 = 12.5 °
Slot [6] 2.5 °
Slot [7] 3 × 5.0 + 2.5 = 17.5 °
It is. Similarly, the electrical angle between the voltage vector of the slots [2], [5], [8] and [11] and the magnetic pole center is slot [2] 4 × 5.0 + 2.5 = 22.5 °
Slot [5] 5.0 + 2.5 = 7.5 °
Slot [8] 5.0 + 2.5 = 7.5 °
Slot [11] 4 × 5.0 + 2.5 = 22.5 °
It is. In the voltage vectors of slots [3], [6], [9], and [12], the electrical angle to the magnetic pole center is slot [3] 3 × 5.0 + 2.5 = 17.5 °
Slot [6] 2.5 °
Slot [9] 2 × 5.0 + 2.5 = 12.5 °
Slot [12] 5 × 5.0 + 2.5 = 27.5 °
It is.

Therefore, when the values of these vectors are set to 1, the x-axis component and the y-axis component are combined,
U1 x-axis component -sin27.5 ° -sin12.5 ° + sin2.5 ° + sin17.5 ° = -0.33386
U1 y-axis component cos27.25 ° + cos12.5 ° + cos2.5 ° + cos17.5 ° = 3.8161
X2 component of U2 -sin22.5 ° -sin7.5 ° + sin7.5 ° + sin22.5 ° = 0
U2 y-axis component cos22.5 ° + cos7.5 ° + cos7.5 ° + cos22.5 ° = 3.83065
X3 component of U3 -sin17.5 ° -sin2.5 ° + sin17.5 ° + sin27.5 ° = -0.33386
U3 y-axis component cos17.5 ° + cos2.5 ° + cos12.5 ° + cos27.5 ° = 3.8131
Since the phase difference between U1 and U3 is symmetric with respect to the magnetic pole center, the phases of U1, U2 and U3 can be completely matched by changing the position by connection with the next pole. The voltage vector according to this embodiment is as shown in FIG. However, A is a voltage vector generated by slots [1] and [4], B is [7] and [10], C is [9] and [12], and D is [3] and [6]. From FIG. 10, the magnitude of the voltage is slightly different at U1 = U3 = 3.8161 × 2 and U2 = 3.88305 × 2, but this voltage difference is (1−3.881010 / 3.830665) × 100 = 0. .38%
Degree. Therefore, it is possible to constitute two poles of the electric motor by the stator coils of U1, U2 and U3.

In this embodiment, a two-pole motor with three parallel circuits has been described as an example. However, even when the number of poles increases to 4, 6,..., The number of slots S = 2pmq = 2p × 3 × 12 = 72p ------- (4)
Number of parallel circuits n = 3p = 1.5P ------------------ (5)
Rotational speed N = 120f / P = 120f / 2p = 60f / P --------- (6)
When the number of pole pairs p is a parameter, the number of rotations of the motor is as shown in Table 2.

  The above is summarized as follows.

  The coils placed in the slots constituting one pole and one phase are referred to as coils 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 in order from the end, and the next one pole and one phase Are called coils 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, and 48 in this order from the end. 7, 7, 10, 46, 43, 40, 37, the neutral points are connected in order and the coils 2, 5, 8, 11, 47, 44, 41, 38, the neutral points are connected in order, and the coil 3, 6, 9, 12, 48, 45, 42, 39, and neutral points are connected in order, and in the delta connection, coils 1, 4, 7, 10, 46, 43, 40, 37, and coil 1 of the next phase are connected. Connect in order, coils 2, 5, 8, 11, 47, 44, 41, 38, Are connected in order, and the coils 3, 6, 9, 12, 48, 45, 42, 39, and the next phase coil 3 are connected in order, so that the number of parallel circuits is 3 × p, and 3 × p units. The inverter is driven at a rotational speed 60 / p times the output frequency of the inverter.

  Next, an example in which the number of parallel circuits is four in another example of the second embodiment will be described with reference to FIG. FIG. 11 is a modification of the winding configuration of FIG. 1, and the U1-phase coils are placed in slots [1], [4], [6], [7], [9], and [12]. Connect to the neutral point N1, and connect each coil of the U2 phase in the slots [2], [3], [5], [8], [10], [11] and then connect to the neutral point N2. . Similarly, each U3-phase coil is placed in slots [48], [45], [43], [42], [40], [37] and connected to the neutral point N3, and the U4-phase coil is inserted into the slot. [47], [46], [44], [41], [39], [38] and then connected to the neutral point N4. When connected in this way, the voltage vector generated by the stator coil of FIG. 11 is as shown in FIG. 12, and when they are combined, it is as shown in FIG. As can be seen from FIG. 13, the X-axis direction is bilaterally symmetrical and has the same phase, and only a slight voltage difference occurs in the Y-axis direction. However, the same effect can be obtained by such a winding configuration.

  In the above embodiment, the motor coil is a star connection, but in the case of a delta connection, the stator coil is connected to the V-phase coil V1 which is the next phase instead of the neutral points N1, N2, N3 and N4. , V2, V3, and V4. In the case of the delta connection, the voltage vector relationship does not change, so that the same effect as the star connection can be obtained.

  As described above, when p is the number of pole pairs, the coils stored in a plurality of slots constituting one pole and one phase are constituted by 2p sets or 2p × 1.5 sets of coils, By determining the arrangement position and coil connection of the 2p set or 2p × 1.5 set coils in the slot so as to form one composite magnetic pole with the generated voltage vector, the number of parallel circuits is reduced to the number of sets of 2p set coils. Since it is twice or 2p × 1.5 sets of coils, it can be driven by the same number of inverters as the number of coils, and can be driven at a rotational speed 60 / p times the inverter output frequency. Therefore, it is possible to use a standard design economical inverter.

1 Power Bus 2A, 2B, 2C, 2D Inverter 3A, 3B, 3C, 3D Reactor 4A, 4B, 4C, 4D Changeover Switch 5 Main Motor (Motor Electric Propulsion Motor)
6 Load machines (propellers for ship propulsion)
7A, 7B, 7C, 7D Multi-winding coil 8 Auxiliary motor 9 Load machine (compressor)
10 Slot 11 Upper coil 12 Lower coil 13 Crossover

Claims (2)

when the pole pairs of the p, as well as constituting the stator coil constituting the coils Ru housed in a plurality of slots constituting one pole 1 phase 2p sets of coils 4p sets of coils, constituting one pole 1 phase each voltage vector synthesis caused by 2p sets of coils determines the slot position location and the coil connection of the respective 2p sets of coils to be substantially in phase the same potential relative to the magnetic pole center, respectively inverters this 4p sets of coils And an AC motor that is driven by the same number of inverters as the number of 4p coil sets . When p is the number of pole pairs, the coils that fit in a plurality of slots constituting one pole and one phase are composed of 2p × 1.5 sets of coils, and the pole pair coils are connected by wiring and the stator coil is 2p ×. The slot position and coil connection of the 2p × 1.5 coils are configured so that the voltage vector composition generated by the 2p × 1.5 coils is approximately the same isotropic potential with respect to the magnetic pole center. The AC motor is characterized in that an inverter is connected to each of 2p × 1.5 coils and driven by the same number of inverters as the number of 2p × 1.5 coil sets.

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