• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Process for obtaining a switched reluctance machine with improved torque ripple, with a rotor (10) comprising several sections (7) of magnetic sheets in the axial direction of lengths (l1, l <sub > 2 ..., ln) different and with different angular displacements (α1, α2 .. ., αn) in the axial direction. The procedure includes: - define a search space for the number (n) of rotor sections, the lengths (l2 ..., ln) and the angular displacement (α2 ..., αn) of each section; - define an objective function that considers the average torque (2) and the torque ripple (3) of the switched reluctance machine. - obtain, using a mathematical method of optimization of the objective function, a number of sections (7) of the rotor (10), with their different lengths (l1, l2 ..., ln) and angular displacements (α1, α2 ..., αn). - assemble a rotor (10) stacking along the axis sections (7) of magnetic sheets according to the number of sections, lengths and angular displacements previously obtained.
    公开号:ES2589155A1
    申请号:ES201630881
    申请日:2016-06-29
    公开日:2016-11-10
    发明作者:Pablo MORENO-TORRES CONCHA；Marcos LAFOZ PATOR；Gustavo NAVARRO SORIANO；Marcos BLANCO AGUADO；Luis GARCÍA-TABARÉS RODRÍGUEZ；Jorge TORRES MIRANDA
    申请人:Centro de Investigaciones Energeticas Medioambientales y Tecnologicas CIEMAT；
    IPC主号:
    专利说明:

    image 1
    PROCEDURE FOR OBTAINING A SWITCHED RELUCTANCE MACHINE WITH IMPROVED TORQUE DESCRIPTION
    5 Field of the Invention
    The present invention falls within the field of rotary electric machines. Background of the invention
    10 Torque curling is a characteristic effect of rotary electric machines. It consists of periodic variations of the torque produced by the machine as it rotates (as the position of the moving part or rotor with respect to the fixed part or stator changes). Torque curling is measured as the difference between the maximum and minimum torque over a full revolution or revolution, and is usually expressed as a percentage with respect to the average torque produced
    15 during that revolution. Torque curling is always an unwanted phenomenon, since it entails other detrimental effects for the whole system, including mechanical vibrations (which in turn generate acoustic noise) and the increase in the radial component of the electromagnetic force (and consequently of the load on the bearings or bearings).
    20 Therefore, reducing torque curling can be synonymous with reducing vibrations, acoustic noise, or radial forces, and vice versa. Patent document CN104810946-A collects the design of a permanent magnet electric machine with low levels of vibration and noise, which is achieved through a decrease in torque curling. Other
    An example is that described in patent EP1628381-B1, which describes the design of a permanent magnet electric motor with suppression of radial forces in the rotor, for which they employ a method that in practice also reduces the curling of pair. Similarly, the TWI497872-B patent presents the design of an electric reluctance motor characterized by a low level of vibration and, therefore, torque curling.
    30 Switched reluctance machines are a type of rotary electric machine that can act as a motor, transforming electrical energy into mechanics, or as a generator, transforming mechanical energy into electrical. The state of the art states that the main qualities of this type of machines are its wide speed range, its
    35 robustness, its constructive simplicity and its tolerance to high temperatures, since they lack permanent magnets, rotary windings and brushes, potentially more fragile, complex and temperature sensitive elements. Switching reluctance machines are a very interesting alternative to other more conventional types, especially for certain applications (aircraft generators,
    image2
    5 electric vehicles or kinetic energy storage, among others). However, the state of the art also states that one of the main drawbacks of switched reluctance machines is their torque curling, a parameter that is commonly high compared to other electric machines.
    10 Within the state of the art, two groups of technical solutions are described to reduce the torque curling of an electric machine. The first are to design the electromagnetic circuit of the machine (stator, rotor, windings, permanent magnets, etc.) to reduce torque curling. Normally these modifications have negative repercussions, either an increase in the size of the machine (and consequently the cost), or
    15 well a reduction of the average torque (and consequently of the power). The latter consist of optimizing the control of the electric machine to minimize torque oscillations. This optimization, which is very specific for each type of machine, is complementary to the solutions of the first group.
    20 One of the solutions belonging to the first group is based on manufacturing what is called an inclined rotor (“skewed rotor”, Figure 2) instead of what is called a straight rotor (“straight rotor” or “non-skewed rotor ", Figure 1). The inclined rotor consists in manufacturing a rotor in which the magnetic plates that compose it (both the stator and the rotor are formed by stacked plates, of typical thickness between 0.1 mm and 1 mm) have a
    25 some angular displacement with respect to each other. This ensures that each section of the rotor is in a different angular position from the rest, so that the torque oscillations produced by each section are no longer in phase and compensate each other, partially or totally. In other words, it is achieved that not all sections produce torque oscillations at the same time, counteracting the effect of some
    30 sections with that of others, which reduces the overall torque of the machine.
    There are two well established methods in the state of the art for tilting the rotor of an electric machine (both methods are frequent in the scientific literature specific to the discipline of electric machines). The first one, which we could call “continuous tilt 35” (“continuosly skewed rotor” or simply “skewed rotor”, Figure 2), consists of
    image3
    rotate each magnetic plate a small angle with respect to the previous one, so that no sheet has exactly the same turn as the rest. This is the method used in induction machines, which are the type of electric motor most used today. This technique is used in patent documents JP5078867-B2, WO9307671-A1,
    5 GB2497667-A.
    The second method belonging to the state of the art is the so-called “step skewed rotor” or “discretely skewed rotor”, and consists of rotating the plates by packages, instead of doing sheet metal to sheet (Figure 3) . Normally the number of 10 steps (number of packages of sheets) is reduced, from 2 to 5, depending on the length of the machine. For most machines, this second method is less effective in reducing torque curling, but it has important constructive advantages - grouping the sheets by packages reduces the number of tools and simplifies assembly - and may even be the only option viable for certain types of machines. For example, him
    15 US2009224621-A1 patent document employs packet tilt in a permanent magnet machine to avoid the complexity associated with making inclined magnets.
    There are two types of rotors with step inclination. The first and clearly 20 majority is the one that presents a symmetrical configuration of the sheet packages
    (Figure 3), symmetrically understanding the following: 1) That all sheet packages have the same length. 2) That the packages of sheets can be rearranged so that the angle of rotation
    between two packages of consecutive plates always have the same value (although not necessarily the same sense).
    Examples of this type of rotor are those proposed in patent documents EP1628381-B1 and KR101092046-B1.
    30 A somewhat particular variant of this first type is the so-called "v-shaped" configuration ("v-shape", Figure 4), very common in scientific literature and especially for permanent magnet machines. Despite its asymmetrical appearance, these types of rotors actually belong to the first type, since it is possible to reorder the sheet packages so that the resulting configuration is completely symmetrical and equal to that of
    35 Figure 3 (note that a reordering of the plate packages does not have
    image4
    significant consequences on the average torque or on the torque curling of a rotating electric machine). The symmetry of this example is of the electromagnetic type (therefore it is not a purely geometric symmetry): from the electromagnetic point of view, the order of the packages does not matter, which implies that the packages can be rearranged and configurations obtained. 100% equivalent. In the case shown in Figure 4, packages 1 and 6 can be stacked first, then packages 2 and 5, and finally packages 3 and 4, obtaining the same configuration as in Figure 3. Therefore, from the electromagnetic point of view they are equal configurations, although geometrically and mechanically they are not. Examples of this setting in “v” are those shown in the
    10 Figure 7 of patent document JP2001359266-A and in Figure 14 of patent document US6777847-B1.
    The second type of rotor, of very residual use (you can hardly find examples of application in the current state of the art), is characterized by having packages of sheets of 15 different lengths and / or different angles of rotation (Figure 5). It is therefore a generalization of the first type.
    For the purposes of the present invention, and with the aim of differentiating between both types of rotors, hereafter referred to as "rotor with symmetric packet tilt 20" and "rotor with asymmetric packet tilt", respectively.
    Two of these methods of inclination, "continuous inclination" and "inclination by symmetrical steps", have been widely studied and published in the scientific literature for different types of machines, including those of switched reluctance. An example of continuous inclination 25 in this type of machines can be found in patent document GB2497667-A, while up to four examples of symmetric step inclination (including a "v-shape") are those described in patent document TW201421861 -TO. However, none of these methods (continuous inclination and symmetric step inclination) is completely suitable for switched reluctance machines,
    30 since they do not have the capacity to optimize the torque curling (which is the really important variable that can be improved in this type of machines).
    The proposed invention applies the "asymmetric step inclination" method to optimize torque curling for the specific case of this type of switched reluctance machines. The invention relates to the design process of said inclination, which
    image5
    It is completely different from the other two conventional methods. Description of the invention
    The present invention relates to a method of obtaining a switched reluctance machine with improved torque curling, in particular a switched reluctance machine of the type comprising a stator with a certain number of poles and coils housed in slots and a rotor with a plurality of sections of magnetic plates in axial direction, with equal number of poles, with different lengths and with angular displacement in axial direction with respect to a different reference angle in all of them.
    The process object of the present invention comprises the following steps:
    -Determine a total rotor length and the number of rotor poles.
    -Define a search space for the variables to be optimized, where the variables to be optimized comprise the number of rotor sections, the different lengths of each section and the angular displacement of each section with respect to a reference angle.
    -Define an objective function that considers the average torque and torque curling of the switched reluctance machine.
    -To obtain, using a mathematical method of optimization of the objective function, a number of rotor sections, with their different lengths and angular displacements.
    - Assemble a rotor by stacking sections of magnetic plates along the axis according to the number of sections, lengths and angular displacements previously obtained.
    In a preferred embodiment, the optimization step of the objective function comprises calculating the average torque and the torque ripple for the different values within the search space of the number of rotor sections, the lengths and angular displacements of each section; and select the number of rotor sections, the lengths and angular displacements of each section that optimize the objective function. In another possible embodiment, the optimization of the objective function is carried out by means of evolutionary algorithms.
    image6
    The step of defining a search space of the variables to be optimized may comprise determining a minimum and maximum range of the number of rotor sections stacked along the axis, a minimum and maximum range of the angular displacement allowed between two consecutive sections, and / or a minimum and maximum range of section lengths.
    The proposed invention therefore consists of a new method for optimizing the rotor design of a switched reluctance machine in the case of a rotor with asymmetric step inclination.
    10 The "inclination by asymmetric steps" consists in using a number N of sheet steps, but of different lengths and angles of rotation with respect to an initial reference position (that is, with respect to the 0 ° which are defined by the system of control, and that are the ones that are taken as reference to feed the coils of the machine). This generalization of the step tilt method makes no sense to
    15 Most types of electric machines, since the optimal solution is to use steps of the same length (of the same number of plates) and with the same angular offset between steps (“inclination by symmetric steps”), or any equivalent configuration (such as the "v" shaped configuration described in the state of the art). However, the torque curling of switched reluctance machines has some
    20 different characteristics to the rest of conventional machines. Because the torque curve as a function of the angular position is asymmetric in this type of machines, the inclination of the rotor that minimizes the torque curling should also be.
    To define both the lengths and the angles of rotation of each package, the
    The use of an optimization procedure comprising the following steps: 1) The starting point is a rotor design of length L with N packets of arbitrary lengths L1, L2 ... LN-1 (the length of the package N, LN , is defined by the total length of the rotor L minus the lengths of the rest of the packages L1, L2 ... LN-1), all of them with the same angular position. This solution is equivalent to a straight rotor. Be
    30 calculates the torque and torque curling for this solution by any method commonly used in electric machines (although it is recommended to use a high precision method, specifically an analysis using the finite element method and preferably with a three-dimensional model) . 2) A search space is defined for the variables to be optimized (the number of
    35 packages N, the length of each package L1, L2 ... LN-1 (LN is considered known from the rest of the lengths and the total length of the rotor), and the turning angles of each package α1, α2 ... αN (the The control system uses the angle of 0º as a reference to feed the machine coils) according to the characteristics of the specific machine.
    image7
    3) One or several objective functions are defined for the optimization process, which will usually take into account at least two variables: the average torque and the torque curling.
    4) The optimization problem defined in points 2) and 3) is solved by any mathematical method that is appropriate. For problems and simple calculations (analytical calculation of the average torque and the torque curl) the brute force method can be used, since the search space is usually not very wide. For complex problems or for advanced calculations (finite elements) evolutionary algorithms are recommended, since these methods allow addressing the optimization problem by evaluating many fewer solutions, thus reducing the calculation time, and being able to solve very complex problems for which the Brute force method is not applicable. To evaluate the torque and torque curling in each design, the same method as in point 1), or a simplified (analytical) method that allows evaluations to be carried out more quickly, is preferably used. Brief description of the drawings
    A series of drawings that help to better understand the invention and that expressly relate to an embodiment of said invention which is presented as a non-limiting example thereof is described very briefly below.
    Figure 1 shows an example of a 4-pole straight rotor according to the state of the art.
    Figure 2 shows an example of a 4-pole rotor with continuous inclination according to the state of the art.
    Figure 3 shows an example, according to the state of the art, of a 4-pole rotor with inclination by 3 steps, the resulting configuration being symmetrical.
    image8
    Figure 4 shows an example, according to the state of the art, of a 4-pole rotor with inclination by 6 steps, the resulting configuration being symmetrical in the form of "v". Although only 5 steps are visible to the naked eye, it should be noted that the middle step is actually made up of two steps of the same length as
    5 the rest. Configurations of this type that employ an odd number of steps do not have this particularity.
    Figure 5 shows an example according to the state of the art of 4-pole rotor with inclination by 3 steps, the resulting configuration being asymmetric.
    10 Figure 6 shows an example of a torque-position curve for a reluctance machine switched along half an electric turn.
    Figure 7 shows an example of torque in permanent mode for a switched reluctance machine.
    Figure 8 shows three examples of permanent torque for three switched reluctance machines: a straight rotor machine, a machine with symmetric step inclination, and a machine with optimized asymmetric step inclination
    20 according to the proposed invention. Detailed description of the invention
    The present invention discloses a rotor design procedure of a switched reluctance machine. One way of implementing this procedure would be the following: 1) It is based on a design of a switched reluctance machine whose rotor is straight (like the one in Figure 1). 2) The torque curve is calculated based on the rotor angle or torque-position curve 1 of said reluctance machine switched over half an electric turn (from
    30 a position of minimum reluctance to the next position of minimum reluctance), as shown in Figure 6. Next, the 1 ’permanent torque curve of said switched reluctance machine is calculated (Figure 7). This pair is characterized by an average value and by a curl (the curling is defined by the angles of activation and deactivation of the phases of the machine). TO
    From this curve, the average torque 2 and the curling of torque 3 are calculated, the latter preferably expressed as a percentage with respect to the first. In order to obtain these two values, simplifications may be made that facilitate the calculation, such as assuming that the machine is powered by ideal currents (pulses of curly current and with infinite up / down slopes). The methodology and the
    image9
    The solution obtained is valid in all cases, but the results are closer to reality if real current waveforms are used, considering the evolution times and their curling.
    3) An optimization problem arises with N = 2 packages of plates stacked in rotor 10, and therefore with 2N-1 = 3 design variables to optimize: L1, α1, α2 (being
    10 L2 defined by the difference between the total length of the rotor L and the length of the first package L1, with α1 and α2 being the respective angles of the packages 1 and 2 with respect to the virtual angle of 0 ° defined by the control system). 4) A parametric analysis is performed by simulation for all possible values of these 3 parameters, discretizing them according to the particular case. By
    For example, LX = [5% 10% ... 95%] and αX = [- 20 ° -19 °… 0 °… 20 °] for a 4-pole machine. For each design, the average torque 2 and the curling of torque 3 are calculated analogously to step 2. The result of this step will be a set of designs, of which those that have a lower torque curl than the machine are of interest original from step 1.
    20 5) Additionally, an optimization problem arises with N = 3 packages of sheets or steps 7 (as shown in Figure 5), and therefore with 2N-1 = 5 design variables: L1, L2, α1 , α2, α3 (where L3 is defined by the difference between the total length of the rotor L and the lengths of the rest of packages L1 and L2). 6) A parametric analysis is performed by simulation for all values
    25 possible of those 5 parameters, discretizing them according to the particular case. For example, LX = [5% 10% ... 95%] and αX = [- 20 ° -19 °… 0 °… 20 °] for a 4-pole machine. For each design, the average torque 2 and the curling of torque 3 are calculated analogously to step 2. The result of this step will be a set of designs, of which those that have a curly torque less than that of the
    30 original machine from step 1. 7) Alternatively, steps 5 and 6 are repeated for values of N = 4, 5… All designs obtained that have a curl of par 3 less than that of the original machine of step 1 are added to the designs resulting from steps 4 and 6.
    Finally, a design of those obtained in steps 4, 6 and 7 is selected. This selection 35 can be made manually (for example, by choosing the design that presents the least curly torque of all those that provide a sufficient average torque for the application) or by an automatic calculation procedure (for example, defining an objective function that weighs both the average torque and the torque curl).
    image10
    5 Figure 8 shows three examples of permanent torque for three switched reluctance machines: a straight rotor machine 1 ', a machine with symmetrical step inclination 4, and a machine with optimized asymmetric step inclination according to the proposed invention 5 As can be seen, the optimization method object of the present invention improves both the average torque and the torque curling with respect to the
    10 method of inclination by symmetrical steps.
    What is defined in this detailed description is provided to help a thorough understanding of the invention. Consequently, persons skilled in the art will recognize that variations, changes and modifications of the embodiments are possible.
    15 described herein without departing from the scope of the invention. In addition, the description of functions and elements well known in the state of the art is omitted for clarity and conciseness.
    The embodiments of the invention can be implemented in a wide variety of
    20 architectural platforms, protocols, devices and systems, so the specific designs and implementations presented are provided solely for purposes of illustration and understanding, and never to limit aspects of the invention.
    权利要求:
    Claims (6)
    [1]
    image 1
    1. Procedure for obtaining a switched reluctance machine with torque curling
    5 improved, the switching reluctance machine of the type comprising: - a stator with a certain number of poles and coils housed in slots; - a rotor (10) comprising a plurality of sections (7) of plates
    magnetic in axial direction, with equal number of poles, with different lengths (L1, L2 ..., LN) and with angular displacement (α1, α2 ..., αN) in axial direction 10 with respect to a different reference angle in all of them ;
    characterized in that the method comprises: - determining a total rotor length (L) and the number of rotor poles (10); -define a search space of the variables to optimize, where the variables to
    optimize comprises the number (N) of rotor sections, the different lengths (L2 ..., LN) of each section and the angular displacement (α2 ..., αN) of each section with respect to a reference angle; -define an objective function that considers the average torque (2) and the torque curl (3) of the switched reluctance machine; -to obtain, using a mathematical method of optimization of the objective function, 20 a number of sections (7) of the rotor (10), with their different lengths (L1, L2 ..., LN) and angular displacements (α1, α2 ..., αN );
    - Assemble a rotor (10) by stacking sections (7) of magnetic plates along the axis according to the number of sections, lengths and angular displacements previously obtained.
    25
    [2]
    2. Method according to claim 1, characterized in that the step of optimizing the objective function comprises: - calculating the average torque (2) and the torque curling (3) for the different values within the search space of the number of rotor sections , the lengths and the 30 angular displacements of each section;
    -select the number of sections of the rotor, the lengths and angular displacements of each section that optimize the objective function.
    [3]
    3. Method according to any of the preceding claims, characterized in that the step of defining a search space of the variables to be optimized comprises
    12
    image2
    determine a minimum and maximum range of the number of rotor sections (7) stacked along the axis.
    [4]
    4. Method according to any of the preceding claims, characterized in that
    5 The step of defining a search space of the variables to be optimized comprises determining a minimum and maximum range of the angular displacement allowed between two consecutive sections (7).
    [5]
    5. Method according to any of the preceding claims, characterized in that
    The step of defining a search space of the variables to be optimized comprises determining a minimum and maximum range of the lengths (L1, L2 ..., LN) of section.
    [6]
    6. Method according to any of the preceding claims, characterized in that
    The optimization stage of the objective function comprises an optimization using 15 evolutionary algorithms.
    13
    类似技术:
    公开号 | 公开日 | 专利标题
    ES2314986T3|2009-03-16|POLYPHASIC MACHINE WITHOUT BRUSHES, ESPECIALLY FOR AUTOMOTIVE VEHICLE ALTERNATOR.
    US7315102B2|2008-01-01|Axial gap motor
    EP3261220B1|2020-08-12|Electric machine
    JP5714189B2|2015-05-07|Rotor and rotating electric machine equipped with the rotor
    ES2322450T3|2009-06-22|PERMANENT ROTARY MAGNET ELECTRIC MOTOR THAT HAS POLAR EXPANSIONS OF VARIABLE DIMENSIONS STATOR.
    US5374865A|1994-12-20|Multi-phase hybrid stepper motor
    ES2310423T3|2009-01-01|DOUBLE EXCITATION ELECTRICAL MACHINE, AND IN PARTICULAR AN AUTOMOTIVE VEHICLE ALTERNATOR.
    JP3638944B1|2005-04-13|Method for determining pole arc ratio of rotary motor with built-in permanent magnet and rotary motor with built-in permanent magnet
    JP2005051982A|2005-02-24|Buried-type magnetic motor
    ES2444770T3|2014-02-26|Electric motor
    US20020047432A1|2002-04-25|Interior permanent magnet synchronous motor
    JP2010098929A|2010-04-30|Double gap motor
    US9716411B2|2017-07-25|Permanent-magnet-type rotating electric mechanism
    US9276443B2|2016-03-01|Rotating element with embedded permanent magnet and rotating electrical machine
    BR112012024767B1|2020-06-16|ROTOR OF AN ELECTRICAL MACHINE WITH EMBEDDED PERMANENT MAGNETS AND ELECTRICAL MACHINE
    JP2006129616A|2006-05-18|Rotor
    EP1261103A1|2002-11-27|Brushless dc motor
    ES2368348T3|2011-11-16|ELECTRICAL MACHINES WITH REDUCED RELUCTANCE.
    JP6304478B2|2018-04-04|Reluctance motor
    ES2200580T3|2004-03-01|ROTATING ELECTRIC MACHINE WITH PERMANENT MAGNETS AND MAGNETIC RESISTANCE WITH IMPROVED FLOW ATTENTION PROPERTIES.
    ES2589155B1|2017-08-17|PROCEDURE FOR OBTAINING A SWITCHED RELUCTANCE MACHINE WITH IMPROVED TORQUE
    ES2704179T3|2019-03-14|Breathing electric motor
    JP5594304B2|2014-09-24|Rotating electric machine
    ES2815926T3|2021-03-31|High frequency motor or generator
    JP6227377B2|2017-11-08|motor
    同族专利:
    公开号 | 公开日
    ES2589155B1|2017-08-17|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20070205689A1|2003-05-29|2007-09-06|Hitachi, Ltd.|Electric Motor|
    US20040245880A1|2003-06-04|2004-12-09|Feng Liang|Rotor skew methods for permanent magnet motors|
    EP1684400A1|2005-01-21|2006-07-26|Hitachi, Ltd.|Rotating electric machine|
    WO2008062701A1|2006-11-22|2008-05-29|Daikin Industries, Ltd.|Rotor and rotary device|
    US20150015107A1|2012-03-30|2015-01-15|Bayerische Motoren Werke Aktiengesellschaft|Vibration Prevention in Synchronous Machines|
    法律状态:
    2017-08-17| FG2A| Definitive protection|Ref document number: 2589155 Country of ref document: ES Kind code of ref document: B1 Effective date: 20170817 |
    优先权:
    申请号 | 申请日 | 专利标题
    ES201630881A|ES2589155B1|2016-06-29|2016-06-29|PROCEDURE FOR OBTAINING A SWITCHED RELUCTANCE MACHINE WITH IMPROVED TORQUE|ES201630881A| ES2589155B1|2016-06-29|2016-06-29|PROCEDURE FOR OBTAINING A SWITCHED RELUCTANCE MACHINE WITH IMPROVED TORQUE|
    [返回顶部]