TW201722037A - Reluctance motor and the method of operating the same capable of reducing power required for operating reluctance motor - Google Patents

Abstract

The present invention relates to a method of operating a reluctance motor (1) having a rotor (2) and a stator (3). The reluctance motor has at least two phases (9, 10, 11), in which at least two stator coil pairs (4, 5, 6) of the stator (3) are applied with electric current in order to rotate the rotor (2). The present invention provides an alternative method of operating the reluctance motor (1), which may particularly reduce the power. The present invention proposes that, during the observation period for two rotation cycles (7, 8) of the rotor (2), at least one of the phases (9, 10, 11) will not be supplied with power during at least one rotation cycle (7, 8), or none of the phases (9, 10, 11) will be supplied with power during one of the two rotation cycles (7, 8). Furthermore, the present invention also relates to a reluctance motor (1).

Description

Reluctance motor and method of operating reluctance motor

The present invention is first directed to a method of operating a reluctance motor having a rotor having a stator having at least two phases, wherein a current is applied to at least two pairs of stator coils of the stator for rotating the rotor.

Furthermore, the invention relates to a reluctance motor having at least two phases, the reluctance motor having a rotor, a stator comprising at least two pairs of stator coils, and control means for successively applying current to the pairs of stator coils.

Reluctance motors have long been known in the prior art. The reluctance motors have a metal rotor rotatable about an axis and a stator enclosing the rotor on the outside, the stator having at least two controllable stator coil pairs formed by stator coils arranged opposite each other in the direction of rotation. The two stator coils of the pair of stator coils form a north-south pole pair. If current flows through one of the pair of stator coils, an electromagnetic field is generated between the oppositely disposed stator coils. The rotor attempts to occupy the smallest reluctance position where the rotor is affected by the torque and rotates. The corresponding stator coil pair is continuously energized until the rotor pole is oriented relative to the stator pole. The sequential application of pairs of stator coils arranged in the direction of the circumference of the stator causes the rotor to continue to rotate. Thus, during the rotation cycle of the rotor, current is applied to the pair of stator coils arranged in sequence in the peripheral direction in terms of successive phases. Thus, for example, in two pairs of stator coils, two phases are produced in each revolution cycle, wherein in the case of the first phase, a current is applied to the first stator coil pair, in terms of the second phase, to the second stator Coil Apply current to the pair.

Based on the foregoing prior art, it is an object of the present invention to provide an alternative method of operating a reluctance motor and a reluctance motor wherein the power required to operate the reluctance motor is reduced.

The solution to achieve the above object of the present invention consists in not supplying at least one phase during at least one rotation cycle during the observation period of the two rotation cycles of the rotor, or not in any one of the two rotation cycles powered by.

According to the invention, the power supply interruption is specifically inserted during operation of the reluctance motor, in which no current is applied to the relevant phase. Thereby, the power required to rotate the rotor can be reduced. Once the stator has, for example, two pairs of stator coils, such a power interruption can reduce power by up to 50% in each revolution cycle for one of the two phases. Therefore, only the pair of stator coils to which current is applied during the 360° rotation of the rotor in the current rotation cycle provides assistance for the torque of the rotor. The reluctance motor uses the torque obtained by the pair of stator coils through which the current is applied, as the case may be rotated at a reduced rotational speed due to the period of the power interruption until the reluctance motor passes through the next charged stator The coil pair obtains another angular momentum. The same reluctance motor can be operated at different powers or speeds through different power supply models without structural changes. Therefore, the power can be reduced as needed by inserting a power interruption in the power supply model in a targeted manner.

The application of current to the reluctance motor is observed in the following two or more successive rotation cycles. Each rotation cycle corresponds to a complete 360° rotation of the rotor. Once the reluctance motor has, for example, two pairs of stator coils, two phases are produced in each revolution cycle, ie a total of four phases are produced during one observation period. For example with three stator lines In a reversing reluctance motor, three phases are produced in each rotation cycle, that is, a total of six phases are produced in one observation period. This also applies correspondingly to reluctance motors with a larger number of stator coil pairs.

According to one embodiment, the invention proposes that the first phase is not supplied at all for a plurality of successive observation periods of every two rotation cycles. Therefore, each of the rotation cycles of the reluctance motor does not supply power to at least one phase, thereby reducing the power consumed by the reluctance motor. In a reluctance motor having two pairs of stator coils, for example, the first pair of stator coils can always be powered only during the period in which the second pair of stator coils does not provide assistance for the torque of the rotor. In the three stator coil pairs, for example, only the first stator coil pair or only the first and second stator coil pairs may be powered. Thus, for two phases, only one of the two phases can always be powered during at least one rotation cycle.

Alternatively, a current may be applied to the first pair of stator coils during a first rotation cycle, a current is applied to the second pair of stator coils during a second rotation cycle, and the first is determined in a third rotation cycle The sub-coil pair applies a current, a current is applied to the second stator coil pair in a fourth rotation cycle, and the like. In a three-phase reluctance motor, the powering scheme can always apply current to only two of the three stator coil pairs. As an alternative, for example, a current may not be applied to the first stator coil pair during the first rotation cycle, no current is applied to the second stator coil pair during the second rotation cycle, and the third is not applied during the third rotation cycle A current is applied to the pair of stator coils. There may be other implementations. In general, only a maximum of two of the three stator coil pairs are always applied in each revolution cycle such that the required power is approximately two-thirds of the maximum power possible.

Furthermore, the invention also proposes to supply the second phase once per rotation cycle for a plurality of successive observation periods of every two rotation cycles. According to the technical side The power is supplied to at least one of the plurality of phases of the rotating cycle such that a torque is applied to the rotor in each cycle of rotation. In the case of a combination of the power supply interruptions proposed above, for each phase of each rotation cycle, a power supply model is always generated in a manner independent of the number of phases of the reluctance motor, in the power supply model One of the phases is not powered in each spin cycle, and the other of the phases is powered. In this case, the respective charged and uncharged phases of the rotation cycle can be varied such that, for example, during a first rotation cycle, each of the different phases in the next rotation cycle is powered. Thereby, the charged phases in the rotation cycles are correspondingly changed.

According to another embodiment, the invention proposes to supply two phases in each first rotation cycle for a plurality of successive observation periods of every two rotation cycles, not in any of the second rotation cycles Phase power supply. According to this technical solution, current is always applied to the pair of stator coils only in one rotation cycle of each observation period, so that no angular momentum is applied to the rotor in each second rotation cycle until the next The stator coil pair is re-energized in the spin cycle (for a two-phase reluctance motor). In a three-phase reluctance motor, the solution is accordingly to apply a current to all three pairs of stator coils during the first rotation cycle, and during each second rotation cycle, only one of the three stator coil pairs Provides assistance in rotating the rotor. The power supply model repeats over a plurality of observation periods, particularly throughout the duration of operation of the reluctance motor.

Furthermore, the invention also proposes operating the reluctance motor with a power of less than 70 watts. The power required for the rotation of the rotor is related to the voltage applied to the pair of stator coils and the current flowing through the pair of stator coils. The use of power interruptions can be used to reduce power in a targeted manner in which no current is applied to certain phases during the spin cycle. In one aspect, the number of voltages, currents, or phases that are present in each spin cycle can be designed in such a way that the total consumed power is less than 70 watts.

The invention proposes that the current has a rectangular course. This current progression is particularly suitable for the case where the reluctance motor is, for example, at an extremely low rotational speed of about 100 rpm. At this very low rotational speed, the current is changed by the chopping, wherein a current is applied to the pair of stator coils at a constant amplitude at predetermined time intervals. In this case, with respect to the switches corresponding to the pair of stator coils, the switching circuit that controls the phases of the reluctance motor is controlled in some manner to interrupt the current applied to a certain pair of stator coils and It is turned back on to continuously apply angular momentum to the rotor.

Furthermore, the invention proposes to vary the current based on the current rotational position of the rotor relative to the stator. According to this technical solution, during the power supply to the phase, the current intensity is continuously increased or decreased based on the current position of the rotor. Therefore, no constant current intensity is applied to the direction of the rectangle, but a current pulse with a varying current intensity is applied. This control is particularly suitable for the case of higher rotational speeds, for example greater than 400 rpm. In this rotational speed, based on the higher rotational speed, only a single pulse (Single Puls) can be applied to each of the stator coil pairs in each phase. Therefore, a current of an amplitude of rising or falling is applied to the corresponding pair of stator coils, but a constant current intensity is not applied.

In addition to the method of operating the reluctance motor, the present invention also provides a reluctance motor having at least two phases, having a rotor, a stator including at least two pairs of stator coils, and for sequentially applying current to the pairs of stator coils Control device, wherein the control device facilitates powering only one of every two phases during at least one rotation cycle during an observation period of two rotation cycles of the rotor, or one of the two rotation cycles No power is supplied to any phase. Thus, in accordance with the present invention, the control of the reluctance motor is configured to facilitate implementation of the method of operating the reluctance motor as described above. Therefore, a reluctance motor that can be operated with different powers is proposed. The control device controls the corresponding supply The electrical model is such that, instead of accelerating the phase with each phase, the power supply is intermittently provided, in which no current is applied to any of the pair of stator coils in the pair of stator coils.

Furthermore, the invention proposes that the control device contributes to the fact that the first phase is not supplied at all for a plurality of successive observation periods of every two rotation cycles, in particular the second phase is supplied once per rotation cycle.

As an alternative, the invention also proposes that the control device facilitates powering two phases in each first rotation cycle for each successive observation period of every two rotation cycles, in each second No phase is supplied to the power in the spin cycle.

The different power supply models and their advantages previously described by the control device as described for this method are also applicable to the reluctance motor.

1‧‧‧Reluctance motor

2‧‧‧Rotor

3‧‧‧ Stator

4‧‧‧stator coil pair

5‧‧‧stator coil pair

6‧‧‧stator coil pair

7‧‧‧Rotating cycle

8‧‧‧Rotating cycle

9‧‧‧ phase

10‧‧‧ phase

11‧‧‧ phase

12‧‧‧Power interruption

The invention will now be described in detail in connection with the embodiments. 1 is a cross section of a three-phase reluctance motor, FIG. 2 is a table for different power supply models of the reluctance motor, and FIG. 3 is a current-time diagram for supplying a power supply model I according to the table of FIG. 4 is a current-time diagram for powering model IV according to the table of FIG. 2.

FIG. 1 shows a reluctance motor 1 having a rotor 2 and a stator 3. The stator 3 has a total of three pairs of stator coils 4, 5, 6 each comprising two stator coils, which are arranged equiangularly around the rotor 2. The rotor 2 has four equiangularly arranged rotor segments (shown in dashed lines) with free space left between the rotor segments. To reduce acoustic emissions, the intermediate spaces may be filled with a liner (such as a plastic injection molded part).

The stator coil pairs 4, 5, 6 correspond to a control device, and the control device pair The same electronic switching circuit for the stator coil pairs 4, 5, 6 is controlled. The electronic switching circuit employs an arrangement that provides a rectified current for the stator coil pairs 4, 5, 6. The control device applies a predefined current to the stator coil based on the load of the reluctance motor 1, wherein the magnitude of the induced magnetic field and the torque acting on the rotor 2 are related to the position of the rotor 2 relative to the stator 3.

Other technical solutions of the reluctance motor 1 are not described in detail here since this technical solution is not important to the invention. An example of a reluctance motor 1 suitable for carrying out this method is described in the publication WO 01/76044 A1. The present invention includes the entire contents of the disclosure.

If current flows through one of the stator coil pairs 4, 5, 6, an electromagnetic field is generated between the oppositely arranged stator coils. The rotor 2 attempts to occupy the smallest reluctance position within the field where the rotor is affected by the torque. Each stator coil pair 4, 5, 6 remains energized until the rotor 2 is oriented relative to the respective stator coil pair 4, 5, 6 of the stator 3. Therefore, successive application of the pair of stator coils 4, 5, 6 arranged successively in the circumferential direction of the stator 3 causes the rotor 2 to continuously rotate.

Each complete 360° rotation of the rotor 2 corresponds to a rotation cycle 7, 8 having three phases 9, 10, 11 in the three-phase reluctance motor 1 shown. The first phase 9 corresponds to the supply of power to the first stator coil pair 4. The second phase 10 corresponds to the supply of power to the second stator coil pair 5, and the third phase 11 corresponds to the supply of power to the third stator coil pair 6.

Through the control means of the reluctance motor 1, the supply of the stator coil pairs 4, 5, 6 can be controlled in the rotation cycles 7, 8 by a plurality of different power supply models. Common to these power supply models is that instead of applying current to all of the stator coil pairs 4, 5, 6 in each of the rotation cycles 7, 8 without exception, there is a power supply interruption 12, which is interrupted in two The observation period of successive rotation cycles 7, 8 is associated with at least one phase 9, 10, 11. In the power supply interruption 12, the pair of stator coils 4, 5, A current is applied to any of the stator coil pairs in 6.

2 is a table for three stator coil pairs 4, 5, 6 with twelve different power supply models I through XII. Each of the stator coil pairs 4, 5, and 6 corresponds to one phase 9, 10, and 11. All three phases 9, 10, 11 together form a rotation cycle 7, 8. The power supply model of the present invention is described in a manner comparable to the prior art common power supply model in which all phases 9, 10, 11 are powered for rotating the rotor 2, i.e., in the prior art In the power supply model, a current is applied to each of the three phases 9, 10, 11 of one of the stator coil pairs 4, 5, 6. The first phase 9 corresponds to the letter A, the second phase 10 corresponds to the letter B, and the third phase 11 corresponds to the letter C. Thereby, the power supply models ABC, ABC, ABC, ABC are generated for four successive rotation cycles 7, 8 when fully powered.

The total of twelve power supply models I to XII shown in the table relate to only a number of possible power supply models. Therefore, the form has not been completed. The power supply models I to XII will be described in turn below.

According to the power supply model I, in each of the successive rotation cycles 7, 8, only the second phase 10 and the third phase 11 are applied with current. The first phase 9 corresponds to a power supply interruption 12 in which no current is applied to any of the stator coil pairs 4, 5, 6 in the power supply interruption. Therefore, only the second and third phases 10, 11 provide assistance for the rotating rotor 2. Thereby, the power reduction is achieved by a third of the usual power at full power supply compared to the power supply to all three phases 9, 10, 11. The power supply models -BC, -BC, -BC, -BC are generated by the four rotation cycles 7, 8 shown here.

According to the power supply model II, the second phase 10 is used accordingly as the power supply interruption 12. The power supply models are A-C, A-C, A-C, and A-C.

According to the power supply model III, the third phase 11 is used as the power supply interruption 12, That is, no current is applied to the third stator coil pair 6 in any of the rotation cycles 7, 8. The power supply model is correspondingly regular AB-, AB-, AB-, AB-.

According to the power supply model IV, current is applied to the stator coil pairs 4, 5, 6 only in the first rotation cycle 7 of the two successive rotation cycles 7, 8. With respect to each of the phases 9, 10, 11, a power interruption 12 is provided in each of the second rotation cycles 8, that is, the rotor 2 is in the first of each of the three phases 9, 10, 11. An angular rotation is included in a rotation cycle 7, and in all the second rotation cycles 8, the three phases 9, 10, 11 do not contain any angular momentum at all, but before the rotor re-contains the angular momentum in the next rotation cycle, Rotate the full 360° without additional acceleration. In this embodiment, the required power is reduced by 50% relative to all phases 9, 10, 11 and full power to all of the spin cycles 7, 8. The power supply model is ABC, ---, ABC, ---.

The power supply model V shows a scheme in which power is always supplied only to the first phase 9 of the three phases 9, 10, 11. The second phase 10 and the third phase 11 correspond to a power supply interruption 12 in which a current is applied to the corresponding stator coil pair 5, 6. Therefore, only the first stator coil pair 4 provides assistance for the rotating rotor 2. Therefore, the reluctance motor 1 is operated only with a maximum power of about one third of the reluctance motor. The power supply model is A--, A--, A--, A--.

According to the power supply model VI (corresponding to the power supply model V), only the second stator coil pair 5 of the second phase 10 is powered. The first phase 9 and the third phase 11 are each used as a power supply interrupt 12. The power supply model is -B-, -B-, -B-, -B-.

According to the power supply model VII (corresponding to the power supply model V and the power supply model VI), only the third stator coil pair 6 is powered. The first phase 9 and the second phase 10 are used here as power supply interruptions 12. The power supply model is --C, --C, --C, --C.

According to the power supply model VIII, only one pair of each of the rotation cycles 7, 8 The stator coil pairs 4, 5, 6 are powered, wherein in each of the rotation cycles 7, 8 the other stator coil pair 4, 5, 6 is powered, ie in the first rotation cycle 7 the first stator coil pair 4, The second stator coil pair 5 is supplied to the second stator coil pair 5 in the second rotation cycle 8, and the first stator coil pair 4 is re-powered in the third rotation cycle 8 in the third rotation cycle 8. Therefore, the reluctance motor 1 is also operated here only with a maximum power of one third of the reluctance motor, but wherein in each of the rotation cycles 7, 8, the other phases 9, 10, 11 are provided for the rotary rotor 2 Auxiliary. The power supply model is A--, -B-, --C, A--.

According to the power supply model IX, two currents are applied to each of the three pairs of stator coil pairs 4, 5, 6 in each of the rotation cycles 7, 8 in the first rotation cycle 7 to the first stator coil pair 4 and the second The stator coil pair 5 is powered, i.e., the first phase 9 and the second phase 10 are used to rotate the rotor 2, and in the subsequent second rotation cycle 8, the second phase 10 and the third phase 11 are powered. The first stator coil pair 4 and the third stator coil pair 6 are supplied with power in a subsequent third rotation cycle. Thus, in general, each of the three phases 9, 10, 11 is utilized in each of the rotation cycles 7, 8 to serve as the power supply interruption 12. This reduces power by a factor of one third of the maximum power of the reluctance motor 1. The generated power supply models are AB-, -BC, A-C, AB-.

According to the power supply model X, all phases 9, 10, 11 are supplied in the first rotation cycle 7, in the second rotation cycle 8, only the two phases 9, 10 are supplied, and in the subsequent rotation cycle only the first phase 9 power supply. The power supply modes ABC, AB-, A--, ABC are for example applied during the starting phase of the reluctance motor 1.

The power supply model XI has successive rotation cycles 7, 8, such as according to the power supply model X, in which no power supply interruptions 12 are used first, followed by a power supply interruption 12 in the second rotation cycle 8, followed by a rotation Two power interruptions 12 are used in the loop. Here, the power supply mode is ABC, -BC, --C, ABC.

The power supply model XII shows an embodiment in which all stator coil pairs 4, 5, 6, ie all phases 9, 10, 11 are powered in a first rotation cycle 7. The power supply interruption 12 is inserted at the phase 10 in the second rotation cycle 8. No current is applied to any of the stator coil pairs 4, 5, 6 in the subsequent rotation cycle, i.e., all phases 9, 10, 11 correspond to the power supply interruption 12. The power supply model is ABC, A-C, ---, ABC.

In addition to the above power supply model, of course, there are other power supply models. Furthermore, there are of course also corresponding power supply models for a reluctance motor 1 having two phases 9, 10, with four phases or others. In addition, the power supply model can also be changed during the operation of the reluctance motor 1. For example, a power supply model different from a later point in time can be used for the starting phase of the reluctance motor 1. In particular, the present invention proposes that the power supply model of the present invention can be used only after the start-up phase, when the rotor 2 is reached to eliminate the rotational speed of the power supply interruption 12 in a manner that does not reduce the associated rotational speed.

3 and 4 are current-time diagrams for the two power supply models of the table shown in FIG. 2. Specifically, FIG. 3 is a current-time diagram for power supply model I, and FIG. 4 is a current-time diagram for power supply model IV.

3 is a current-time diagram for power supply model I, where the X axis represents time and the Y axis represents current applied to stator coil pairs 4, 5, 6. As representative of the stator coil pairs 4, 5, 6, each of the three current-time diagrams shown corresponds to phases 9, 10, 11, which correspond to the letters A, B, in the table of Figure 2. C. The power supply models - BC, -BC, - BC shown in the figure are in the range of four rotation cycles 7, 8, wherein each of the two successive rotation cycles 7, 8 is the observation period described in the present invention. The power supply model shown is characterized in that the first phase 9 (A) is not powered in all four rotation cycles 7, 8 , i.e. the current intensity is constantly zero. Therefore, on the rotation cycle 7, For each of 8, power is supplied only to phases 10, 11 (B, C), wherein the power to the phases 10, 11 is successively implemented. Therefore, in the rotation cycle 7, a power supply interruption 12 is generated in the first phase 9 (A), in which the applied current intensity is zero, and then the second phase 10 (B) is supplied with power, wherein The two stator coil pairs 5 apply a current intensity that is not equal to zero. The third phase 11 is then powered, wherein a current that is not equal to zero is applied to the third stator coil pair 6. Thereby, the first rotation cycle 7 is carried out. In view of this, another rotation cycle 8 of the same type, and the other two rotation cycles, are subsequently implemented. During the two observation periods of the total of four rotation cycles 7, 8 shown, the first stator coil pair 4 does not provide assistance in applying torque to the rotor 2, more specifically, in the first stator coil pair 4 A power interruption 12 appears in each of the power supply locations.

4 is a power supply model IV showing a table of current-time diagrams. The power supply models during the two successive observation periods of each of the two rotation cycles 7, 8 correspond to the power supply models ABC, ---, ABC, ---. As shown, all phases 9, 10, 11 (A, B, C) are alternately powered during the first rotation cycle 7, but none of the phases 9, 10, 11 during the subsequent second rotation cycle 8 Phase power supply. This power supply model is repeated during the subsequent observation period. Therefore, the successive power supply to phases 9, 10, 11 is only related to the first of the two successive rotation cycles 7, 8.

1‧‧‧Reluctance motor

2‧‧‧Rotor

3‧‧‧ Stator

4‧‧‧stator coil pair

5‧‧‧stator coil pair

6‧‧‧stator coil pair

Claims (10)

A method of operating a reluctance motor (1) having a rotor (2) and a stator (3), the reluctance motor having at least two phases (9, 10, 11), wherein the rotor (2) is rotated for Current is applied to at least two stator coil pairs (4, 5, 6) of the stator (3), characterized in that during at least one observation period of the two rotation cycles (7, 8) of the rotor (2) No power is supplied to at least one phase (9, 10, 11) during the rotation cycle (7, 8), or no phase (9, 10, 11) is supplied in one of the two rotation cycles (7, 8). The method of claim 1, wherein the first phase (9, 10, 11) is not powered at all for a plurality of successive observation periods of every two rotation cycles (7, 8). The method of claim 1 or 2, wherein, for each of the plurality of successive observation periods of each of the two rotation cycles (7, 8), the second phase (9, 10) of each of the rotation cycles (7, 8) , 11) Power supply once. The method of claim 1, wherein, for each of the plurality of successive observation periods of each of the two rotation cycles (7, 8), two phases are in each of the first rotation cycles (7, 8) (9, 10, 11) Power supply, no power is supplied to any phase (9, 10, 11) in each second rotation cycle. The method of any of the preceding claims, wherein the reluctance motor (1) is operated with a power of less than 70 watts. The method of any one of claims 1 to 5, wherein the current has a rectangular orientation. The method of any one of claims 1 to 5, wherein the current is varied based on a current rotational position of the rotor (2) relative to the stator (3). A reluctance motor (1) having at least two phases (9, 10, 11) having a rotor (2), a stator comprising at least two stator coil pairs (4, 5, 6) (3) And a control device for successively applying current to the pair of stator coils, characterized in that the control device facilitates during the observation period of the two rotation cycles (7, 8) of the rotor (2) Only one of every two phases (9, 10, 11) is supplied during at least one rotation cycle (7, 8), or no phase is present in one of the two rotation cycles (7, 8) (9, 10) , 11) power supply. A reluctance motor (1) according to claim 8, wherein the control device contributes to the first phase (9, 10) in terms of a plurality of successive observation periods of every two rotation cycles (7, 8) , 11) Power supply, especially for the second phase (9, 10, 11) in each rotation cycle (7, 8). A reluctance motor (1) according to claim 8, wherein the control means facilitates each of the first rotation cycles (7) for each of the successive observation periods of each of the two rotation cycles (7, 8) In 8), the two phases (9, 10, 11) are powered, and no phase (9, 10, 11) is supplied in each second rotation cycle.