Detection of type of configured motor for variable speed drive

Abstract

The invention relates to a method for configuring a variable speed drive, which is responsible for the power supply of an electric motor. The method comprises applying (301) a motor voltage sequence S1 to the electric motor by the variable speed drive, and obtaining (302) a motor current measurement M1 in parallel. The method then determines (303) a characteristic C1 of the electric motor based on the motor current measurement M1, and determines (304) a type of the electric motor at least in dependence on the characteristic C1. The variable speed drive is then set (305) based on the determined type of the electric motor.

Description

TECHNICAL FIELD

[0001] The present invention relates to the configuration of variable speed drives responsible for the power supply of electric motors, in particular to the configuration of variable speed drives according to the type of electric motor, especially for three-phase electric motors. BACKGROUND

[0002] Electric motors can be divided into several categories. They include, on the one hand, direct current electric motors, and on the other hand, alternating current electric motors.

[0003] In industrial applications, most alternating current electric motors are three-phase electric motors. These electric motors can be powered directly connected to the electrical network, or linked to the electrical network through active power converters, electronic starters or variable speed drives.

[0004] Since each type of three-phase alternating current electric motor does not operate in the same way, it is necessary to set the variable speed drive using parameters specific to the type of electric motor to which the variable speed drive is linked.

[0005] Some variable speed drives require the user to manually select the type of electric motor. Such a selection activates functions specific to the type of electric motor, such as alignment, flux identification or functions compatible with other functions.

[0006] The manual selection can include the selection of parameters such as:

[0007] - the vector control law for asynchronous electric motors, which is a control with a speed loop;

[0008] - the control law for permanent magnet synchronous electric motors, which can also be a control with a speed loop according to the vector control principle;

[0009] - the control law for variable reluctance synchronous electric motors, which can also be a control with a speed loop based on the vector control principle;

[0010] - other control laws.

[0011] Such a manual selection can also be erroneous, in which case a bad configuration causes malfunctions of the electric motor (failure to start, degraded performance, etc.), up to the destruction of the electric motor.

[0012] There is therefore a need to simplify the configuration of variable speed drives set to supply several types of electric motors, while preventing errors related to this configuration.

[0013] The present invention solves the aforementioned drawbacks.

[0014] Documents US2014265990A1 and EP1257049A2 disclose a method for configuring and identifying the type of electric motor connected to a variable speed drive. SUMMARY

[0015] A first aspect of the application relates to a method for configuring a variable speed drive in charge of the power supply of an electric motor, for example three-phase, the method comprising the following operations:

[0016] - applying, by the variable speed drive, a sequence of motor voltages S1 to the electric motor;

[0017] - obtaining a measure M1 of the motor current during the application of the sequence of motor voltages S1 ;

[0018] - determining a characteristic C1 of the electric motor based on the measure M1 of the motor current;

[0019] - determining the type of the electric motor at least as a function of the characteristic C1 ;

[0020] - configuring the variable speed drive as a function of the determined type of the electric motor.

[0021] The application thus makes it possible to set the variable speed drive as a function of the determined type of the electric motor without user intervention.

[0022] According to one embodiment, the characteristic C1 can characterize the fact that the electric motor does or does not exhibit anisotropic properties.

[0023] The configuration can thus be applied that is different as a function of whether the electric motor is anisotropic or not.

[0024] Moreover, the sequence of motor voltages S1 can be applied twice in succession in at least two non-collinear voltage directions, according to the following operations:

[0025] - applying the sequence of motor voltages S1 to the electric motor in a direction D1 ;

[0026] - obtaining a measure M11 of the motor current during the application of the sequence of motor voltages S1 in the direction D1 ;

[0027] - in the case where the measure M11 exhibits oscillations, determining that the electric motor exhibits anisotropic properties;

[0028] - otherwise:

[0029] - applying the sequence of motor voltages S1 to the electric motor at least a second time in a direction D2 that is not collinear with the direction D1 ;

[0030] - obtaining a measure M12 of the motor current during the application of the sequence of motor voltages S1 in the direction D2;

[0031] - in the case where the measure M12 exhibits oscillations, determining that the electric motor exhibits anisotropic properties;

[0032] - Otherwise, it is determined that the motor does not exhibit any anisotropic property.

[0033] Such an embodiment makes it possible to improve the detection accuracy of the anisotropic property. Indeed, the injection in two different and non-collinear directions, preferably spaced by 60 degrees, makes it possible to ensure a certain detection or non-detection of the anisotropy. It is also preferable that the two directions D1 and D2 are not orthogonal, which makes it possible to avoid stopping the motor in an unstable equilibrium in the direction D2, in particular when the motor is a variable reluctance synchronous motor.

[0034] Preferably, when the second application sequence S1 is applied, the application of the sequence S1 in different directions is separated by a predetermined delay, for example ranging from 1 to 30 seconds according to the power of the variable speed drive. In the case of an induction motor, such a delay makes it possible to restore the magnetic flux in the motor to zero between the two injections, thus making it possible to avoid a bad detection of the motor type.

[0035] In addition or as a variant, if the motor does not exhibit any anisotropic property, it can be determined that the motor has an induction type.

[0036] It is thus possible to detect an induction motor and to set the variable speed drive linked thereto accordingly.

[0037] According to one embodiment, if the motor exhibits an anisotropic property, the method can further comprise:

[0038] - detecting the main anisotropy axis of the motor after the application of the motor voltage sequence S1 ;

[0039] - applying a motor voltage sequence S2 to drive the motor in rotation according to the anisotropy axis;

[0040] - obtaining a measurement value M2 resulting from the application of the motor voltage sequence S2;

[0041] - determining the type of anisotropy of the motor from the measurement value M2. The type of motor is determined at least according to the characteristic C1 and the characteristic C2.

[0042] In addition, the characteristic C2 can characterize the fact that the motor comprises a rotor with or without permanent magnetic flux.

[0043] It is thus possible to apply a configuration that differs according to whether the motor exhibits a permanent magnetic flux or not.

[0044] The measurement value M2 can be:

[0045] - a measurement of the motor current taken during the application of the sequence S2;

[0046] - a measurement of the motor voltage taken after the application of the sequence S2.

[0047] The measurement M2 of the motor current actually makes it possible to determine whether the rotor comprises or not a permanent magnetic flux. To this end, the sequence S2 can comprise decreasing the motor voltage from a given initial value, observing the percentage of decrease of the motor current and comparing this percentage with a predetermined threshold, as detailed hereafter.

[0048] As a variant, the determination of the feature C2 can be based or not on the measurement M2 of the motor current, but on the measurement of the motor voltage during the freewheeling phase, as detailed hereafter.

[0049] It is thus possible to apply different configurations depending on whether the motor exhibits a permanent magnetic flux or not.

[0050] In addition, if the motor does not comprise any permanent magnet, it is possible to determine that the motor is of the reluctance synchronous type.

[0051] It is thus made possible to detect a motor of the reluctance synchronous type and to set the variable speed drive linked to it accordingly.

[0052] According to one embodiment, the sequence S2 of motor voltages can be applied in a direction orthogonal to the anisotropy direction of the motor, to drive the motor in rotation.

[0053] It is thus applied in a direction favorable to the rotational drive of the motor, which makes it possible to ensure that the injection of the sequence S2 does not damage a motor of an undetermined type.

[0054] According to one embodiment, the method can further comprise determining a steady state gain of the motor based on the measurement Ml and the sequence S l, and the sequence S2 of motor voltages can be determined as a function of the determined steady state gain.

[0055] Such an embodiment makes it possible to inject a sequence S2 of motor voltages that does not harm the motor.

[0056] According to one embodiment, if the motor is anisotropic, the sequence S3 of motor voltages can be applied twice successively in two orthogonal voltage directions, according to the following operations:

[0057] - applying the sequence S3 of motor voltages to the motor in a direction D3;

[0058] - obtaining a measurement M31 of the motor current during the application of the sequence S3 of motor voltages in the direction D3;

[0059] - applying the sequence D3 of motor voltages to the motor in a direction D4 not collinear with the direction D3;

[0060] - obtaining a measurement M32 of the motor current during the application of the sequence S3 of motor voltages in the direction D4;

[0061] - comparing the measurements M31 and M32 in order to determine a characteristic C3 of the motor. The type of motor can be determined at least according to the characteristic Cl and the characteristic C3.

[0062] Thus, by considering several characteristics of the motor, the accuracy related to the configuration of the motor is improved. In the case where the sequence S3 is applied in only two directions D3 and D4, D3 and D4 can be substantially orthogonal. S3 can be applied along three directions D3, D4 and D5 spaced by about 120° from each other.

[0063] In addition, the characteristic C3 can characterize the fact that the motor exhibits or does not exhibit saliency, and, if the motor does not exhibit any saliency of the inductances of the rotor, it can be determined that the motor has a smooth pole motor type with permanent magnets, for example a synchronous motor with magnets on the surface.

[0064] Thus, different configurations can be applied according to whether the motor exhibits saliency or not.

[0065] In addition, if the motor exhibits saliency of the inductances of the rotor, and if the motor comprises a rotor with permanent magnetic flux, it can be determined that the motor has a salient pole motor type with permanent magnets, for example a synchronous motor with magnets inside.

[0066] Thus, a motor of salient type with permanent magnets can be detected and the variable speed drive linked to it can be set accordingly.

[0067] According to one embodiment, the sequence S3 can be a high frequency continuous sequence of motor voltages, or can be a voltage step.

[0068] According to one embodiment, the sequence S1 of motor voltages comprises a gradual increase of the motor voltage as long as the measurement M1 of the motor current remains below a maximum motor current value.

[0069] Such an embodiment makes it possible to ensure that the injection of the sequence S1 does not damage the motor whose type is not yet determined at that time.

[0070] In addition, the method can comprise a preliminary step of manual input of the maximum motor current value.

[0071] Generally, the user has easy access to the maximum motor current value, which can be included in the motor reference.

[0072] According to one embodiment, the sequence S2 of motor voltages can be determined according to the steady state gain and the maximum motor current value.

[0073] Thus, the sequence S2 can be adapted to the electric motor so as not to damage it, which avoids having to monitor the electric motor current in real time at the time of injection of the sequence S2.

[0074] A second aspect of the application relates to a program that can be run by a processor and comprises instructions for implementing the steps of the method according to the first aspect of the application when run by the processor.

[0075] A third aspect of the application relates to a device for configuring a variable speed drive responsible for the power supply of an electric motor (for example, three-phase), the configuration device comprising:

[0076] - a voltage injection unit arranged to apply, via the variable speed drive, a sequence of motor voltages S1 to the electric motor;

[0077] - an acquisition unit arranged to acquire, during the application of the sequence of motor voltages S1, a measure M1 of the electric motor current;

[0078] - a motor type determination unit arranged to determine, on the basis of the measure M1 of the electric motor current, a characteristic C1 of the electric motor, and to determine, at least as a function of the characteristic C1, the type of the electric motor;

[0079] - a configuration unit able to configure the variable speed drive as a function of the determined type of the electric motor. BRIEF DESCRIPTION OF DRAWINGS

[0080] Embodiments of the application will be described, by way of example only, with reference to the drawings in which:

[0081] Figure 1 a system for controlling the power supply of an electric motor according to an embodiment of the application is shown;

[0082] Figure 2 the structure of a control device according to an embodiment of the application is shown;

[0083] Figure 3 is a diagram showing the steps of a method according to a general embodiment of the application;

[0084] Figure 4 is a diagram showing the steps of a method according to a particular embodiment of the application;

[0085] Figure 5 the structure of the units of a configuration device according to an embodiment of the application is shown. DETAILED DESCRIPTION

[0086] Figure 1 a system according to an embodiment of the application is shown.

[0087] The system comprises a variable speed drive 110 according to an embodiment of the application, an electric motor 100 and a configuration device 120. The configuration device can be incorporated in the variable speed drive 110 or can be separate from the variable speed drive 110.

[0088] The variable speed drive 110 can be powered by a transformer 111 linked to a main electrical network 112, such as a network supplying a three-phase electrical supply.

[0089] The configuration device 120 comprises:

[0090] - a unit 121 for obtaining the motor current;

[0091] - a unit 122 for detecting oscillations;

[0092] - a unit 123 for injecting a motor voltage sequence;

[0093] - a unit 124 for determining the motor type;

[0094] - a unit for configuring the variable speed drive 125.

[0095] In the following description, the electric motor 100 is of the three-phase type. However, there is no restriction on the power supply of the electric motor.

[0096] The method can be implemented in a commissioning step before the normal operation of the electric motor in its environment of use.

[0097] The method can be implemented once to identify the type of electric motor.

[0098] The variable speed drive 110 generally comprises, in a non-restrictive manner:

[0099] - a rectifier stage connected to the power supply to receive an alternating voltage; the rectifier stage can be of the passive type (for example a diode bridge) or of the active type based on controlled transistors.

[0100] - a DC power supply bus to which the voltage rectified by the rectifier stage is applied, and which comprises in particular two buses and at least one bus capacitor connected between the two lines to stabilize the bus voltage;

[0101] - an inverter stage connected at the output of the DC bus and for choppering the DC voltage supplied by the bus into a variable voltage for the electric motor 100. The inverter stage comprises several switching arms, each comprising power transistors controlled to apply the variable voltage to the electric motor.

[0102] In Figure 2 the following notations will be used:

[0103] θs: electrical angle;

[0104] ud: motor voltage on axis d;

[0105] uq: motor voltage on axis q;

[0106] id: motor current on axis d;

[0107] iq: motor current on axis q;

[0108] ua, ub and uc: motor voltages;

[0109] ia, ib and ic: motor currents;

[0110] Axes d and q form a reference frame in a plane at right angles to the axis of rotation of the motor 100.

[0111] As shown in Figure 2 The variable speed drive 110 comprises an inverter stage 202 which can be controlled directly by the motor voltages ua, ub and uc or the motor voltages on axes d and q via a transformation block 200. The transformation block 200 is arranged to apply a change of reference frame from the reference frame d, q to the reference frame a, b, c. This block receives as inputs the motor voltage ud on axis d and the motor voltage uq on axis q and determines from the angle θs the voltages ua, ub and uc to be applied to the three phases of the motor 100. Such a block 200 is well known and will not be described in further detail in this specification.

[0112] The variable speed drive 110 further comprises current sensors for measuring the motor currents ia, ib and ic, in particular for measuring the currents ia, ib and ic present in the three phases of the motor M.

[0113] The variable speed drive 110 can further comprise a second transformation block 201 for applying a change of reference frame from the reference frame a, b, c to the reference frame d, q. This block receives as inputs the currents ia, ib and ic measured on the three phases of the motor and determines from the angle θs the current id on axis d and the current iq on axis q.

[0114] The unit 121 for obtaining motor currents of the configuration device 120 can receive the motor currents measured by the variable speed drive 110 or can comprise its own means for measuring the motor currents ia, ib and ic, in particular current sensors for measuring the currents ia, ib and ic present in the three phases of the motor M.

[0115] The variable speed drive can comprise several control laws, which can be set according to these control laws:

[0116] - a control law for asynchronous motors, which is a control with a speed loop;

[0117] - a control law for permanent magnet synchronous motors, which can also be a control with a speed loop according to the vector control principle;

[0118] - a control law for variable reluctance synchronous motors, which can also be a control with a speed loop based on the vector control principle;

[0119] - other control laws.

[0120] Other configuration parameters can be applied to the variable speed drive 110 according to the application, such as alignment, flux, identification or compatibility parameters.

[0121] In particular, the application provides to configure such parameters of the variable speed drive 110 according to the type of motor to which the variable speed drive 110 is linked.

[0122] Reference is made to Figure 3 the description of the configuration device 100.

[0123] Figure 3 is a diagram showing the steps of the method according to an embodiment of the application.

[0124] In an optional step 300, a maximum motor current value is acquired. Such a value can be derived for example from a manual input by a user via a user interface (not shown in Figure 1 ) of the configuration device. This step can be implemented before the other steps of the method according to the application, in particular when or before connecting the variable speed drive 110 to the motor 100. Such a value is easily available to the user, as it is usually explicitly indicated by the reference of the motor.

[0125] In step 301, a first sequence S1 of motor voltages is transmitted to the variable speed drive 110, by the unit 123 for injecting a sequence of motor voltages, to control the power supply of the motor 100. The motor voltages of the first sequence S1 can be the motor voltages ua, ub and uc, or can be the motor voltages ud and uq.

[0126] The motor voltages can in particular be transmitted to the control means of the inverter stage 202.

[0127] The first sequence of motor voltages S1 can comprise a ramp of increasing voltages with a slow time scale. In particular, the motor voltage values can be increased step by step until the motor current reaches the maximum current value obtained in step 300, which makes it possible to protect the motor by guaranteeing that the value of the motor current remains below the maximum value defined in step 300. Indeed, the type of motor is unknown and the variable speed drive 110 is not initially set for the type of motor 100, so it is preferable to act prudently so as not to damage the motor 100.

[0128] In step 302, which is performed in parallel with step 301, a measurement value M1 of the motor current is obtained during the application of the sequence of motor voltages S1. As explained previously, the measurement value M1 can be obtained by the measuring means of the unit for obtaining the motor current 121 or, alternatively, can be received by the unit for obtaining the motor current 121 from the measuring means of the variable speed drive 110.

[0129] In step 303, a characteristic C1 of the motor is determined from the measurement value M1 by the unit for determining the type of motor 124. For example, the characteristic C1 can characterize the fact that the motor 100 does or does not exhibit anisotropic properties. Indeed, this relates to the anisotropy in the rotor of the motor 100. For example, asynchronous motors comprise a rotor in the form of a squirrel cage which is isotropic according to the direction of injection of the motor voltage, whereas synchronous motors exhibit anisotropy and are therefore sensitive to the direction of injection of the motor voltage.

[0130] If it is determined that the motor 100 exhibits anisotropy, step 303 can further comprise detecting the main anisotropy axis. By "main" it is understood to be the axis along which the degree of anisotropy is greatest.

[0131] Step 303 can further comprise determining the steady-state gain of the motor (stator resistance), in particular in the case where the measurement value M1 oscillates, when the motor current value stabilizes after the oscillation.

[0132] The anisotropic characteristic of the motor 110 can be determined from the detection or non-detection of an oscillation in the measurement M1 by the oscillation detection unit 122. In particular, an oscillation can be identified before the motor current measurement value stabilizes. For example, by "oscillation" it is understood to mean a succession of at least two measurement periods above / below the stable value to which the motor current converges, respectively.

[0133] Thus, if the measurement value M1 exhibits an oscillation, it can be deduced that the motor exhibits anisotropy.

[0134] According to one embodiment, the first sequence S1 is applied twice in two non-collinear directions D1 and D2. Non-collinear directions are understood to mean two motor voltage value vectors which are non-collinear with each other. When the motor voltages ud and uq are used to control the variable speed drive 110, the vectors comprise two components; when the motor voltages are used to control the variable speed drive 110, the vectors comprise three components ua, ub and uc. Preferably, the directions D1 and D2 form an angle substantially equal to 60 degrees.

[0135] In particular, the two directions D1 and D2 are preferably not orthogonal.

[0136] For example, when considering a direction D1 corresponding to a zero component along the axis q (and non-zero along the axis d), the direction D2 comprises a non-zero component along the axis q and a non-zero component along the axis d. Such an embodiment makes it possible to avoid blocking the motor in a position of unstable equilibrium along the axis d, in particular when the motor is a synchronous type motor with reluctance.

[0137] In the case of at least two injection sequences S1, a measurement value M11 of the motor current is obtained when the sequence S1 is injected for the first time in a first direction. According to one embodiment, if the measurement value M11 does not comprise oscillations (the motor current value is stable without oscillations), a second injection is carried out in a second direction which is not collinear with the first direction, and a measurement value M12 of the motor current is obtained. If the measurement value M12 again does not comprise oscillations, it can be deduced that the motor 100 does not exhibit anisotropy. Otherwise, the motor 100 exhibits anisotropy.

[0138] The embodiment with two injections in non-collinear directions makes it possible to improve the detection of the characteristic C1 according to which the motor exhibits anisotropy or does not exhibit anisotropy.

[0139] Indeed, if a single injection is carried out, a detection error can occur in the following case: considering a motor which exhibits anisotropy along an anisotropy axis, if the first injection is carried out in the direction of the anisotropy axis, no oscillations will be observed in the measurement value M1, although the motor does indeed exhibit anisotropy. Carrying out a second injection along an orthogonal axis makes it possible to solve such a problem.

[0140] In a step 304, the type of motor can be determined by the unit for determining the type of motor 124, based at least on the characteristic C1 determined in the step 303. Other characteristics can be considered to determine the type of motor 100.

[0141] In a step 305, a configuration unit 125 sets the variable speed drive 110 according to the type of motor 100. As mentioned previously, such a configuration can comprise the definition of a control law or the setting of other configuration parameters.

[0142] According to an embodiment of the application, other characteristics of the electric motor 100 can be determined in order to allow identifying other types of electric motors. In particular, when the characteristic CI characterizes the fact that the electric motor exhibits anisotropic properties, it is possible to determine more precisely what is the anisotropy in order to precisely determine the type of electric motor.

[0143] To this end, the method according to an embodiment of the application can further comprise the optional step of sending a command to the variable speed drive 110 to align the electric motor in the direction of the anisotropy axis determined in step 303. Thus, the axis d is aligned with the anisotropy axis of the electric motor 100.

[0144] According to an embodiment, the method can further comprise steps 307 to 309 which make it possible to determine a second characteristic C2 of the electric motor 100. The characteristic C2 can characterize the fact that the electric motor 100 comprises or not permanent magnets.

[0145] In step 307, a second sequence S2 of electric motor voltages is transmitted to the variable speed drive 110 by the unit 123 for injecting a sequence of electric motor voltages, to control the power supply of the electric motor 100.

[0146] The second sequence S2 can be applied to drive the electric motor to rotate according to the anisotropy axis. Optimal ly, the first sequence S2 comprises applying electric motor voltages along corresponding directions corresponding (or substantially equal) to the normal to the main anisotropy axis determined in step 303. The sequence S2 can be predetermined. As a variant, the sequence S2 can be recalculated according to the maximum electric motor current value of step 300 and according to the steady state gain determined in step 303, to ensure that the electric motor voltages applied in the sequence S2 do not lead to exceeding the maximum electric motor current value.

[0147] In step 308, performed in parallel with step 307, a measure M2 of the electric motor currents is obtained by the unit 121 for obtaining these electric motor currents, during the application of the sequence S1 of electric motor voltages.

[0148] In step 309, based on the measure M2, the unit 124 for determining the electric motor type can determine a characteristic C2 according to which the electric motor 100 comprises or not permanent magnets. Once the main axis (magnet, reluctance) has been identified, the combination of currents (id, iq) makes it possible to detect the presence of a voltage resulting from the back electromotive force (B-EMF) generated by the rotating magnet. This voltage is proportional to the rotation speed multiplied by the magnetic flux of the permanent magnet, so its presence makes it possible to detect the presence of permanent magnets.

[0149] For example, sequence S2 can be applied in a direction orthogonal to the salience axis of motor 100. Sequence S2 can be further determined so as to drive motor 100 at a constant frequency.

[0150] The motor current is then measured along the anisotropic direction d of the motor to obtain a measured value M2. Sequence S2 may then include gradually decreasing the voltage applied to the motor by a predetermined percentage (e.g., substantially equal to 20%) and analyzing the change in the measured value M2. If the percentage change in the measured value M2 (the absolute value of the difference between the initial and final values ​​of the motor current along axis d) is less than a predetermined threshold (e.g., substantially equal to 40%) relative to the absolute value of the initial value of the motor current along axis d, then feature C2 may be that the motor does not contain any permanent magnets. Otherwise, unit 124 may infer that feature C2 is that the motor 100 includes permanent magnets.

[0151] As a variation, in embodiments where the configuration device 120 or the transmission drive 110 includes a device for measuring motor voltage, step 308 may include obtaining a measured value M2 of the motor voltage rather than the motor current. Most transmission drives 110 include such a measuring device, in which case the configuration device may include an acquisition unit ( Figure 1 (Not shown in the diagram) A measuring device (capable of communicating with) is used to link the motor voltage to the transmission drive 110. According to this variant, sequence S2 can be applied, then the transmission drive 110 can be disconnected from the motor (more specifically, the power portion of the transmission drive 110), and a measurement value M2 of the motor voltage can be acquired during this "free-wheeling" phase. If a motor voltage proportional to speed is detected during the free-wheeling phase, unit 124 can determine that the motor includes permanent magnets. To estimate the speed and amplitude of the motor voltage, unit 124 analyzes the measurement value M2. If the ratio of the voltage amplitude to the motor speed does not change or changes very little (the percentage change is below a predetermined threshold), the rotor of the motor exhibits permanent magnetic flux, reflecting the presence of permanent magnets (characteristic C2). Otherwise, the motor 100 does not include any permanent magnets.

[0152] Therefore, in step 304 of determining the type of motor 100, implemented by unit 124 for determining the type of motor, features C2 and C1 can be considered.

[0153] According to one embodiment, the method can further comprise steps 307 to 309, which make it possible to determine a third characteristic C3 of the electric motor 100. The characteristic C3 can characterize the fact that the electric motor 100 does or does not exhibit salience. By "salience" is understood a salient feature of the inductance of the electric motor: the electric flux generated by the current circulates in the stator and in the rotor. Depending on the geometry of the rotor, this electric flux does not always flow through the same paths, which is called geometric salience, due to the geometry of the rotor which depends on the position of the rotor. Thus, in a rotor with salient poles, the inductances along the axes d and q are different due to this salience. On the contrary, in a rotor with smooth poles, the inductances do not vary with the rotor position.

[0154] In step 310, a third sequence S3 of motor voltages is transmitted to the variable speed drive 110, by the unit 123 for injecting a sequence of motor voltages, to control the power supply of the electric motor 100. The sequence S3 is injected at least twice in at least two mutually orthogonal directions D3 and D4. At each injection, corresponding measured values M31 and M32 of motor currents are acquired in step 311 (each of the measured values M31 to M32 is a series of one or more measured values). There is no restriction on the sequence S3 of motor voltages, which can be voltage steps (in the case where the motor is equipped with a brake), or high frequency motor voltages (especially in the case where the motor is not equipped with a brake). As a variant, the sequence S3 can be injected in three directions D3, D4 and D5. D3, D4 and D5 can be separated from each other by 120 degrees.

[0155] The directions D3, D4 and D5 correspond to the three phases (a, b, c) of the motor in a basic three-phase reference frame (at an angle of 120 degrees from each other). In this case, the variable speed drive injects very high frequency voltages directly into the three phases. The three-phase currents ia, ib and ic are directly used to detect the presence of salience.

[0156] In step 312, the measured values M31 and M32 are compared in order to deduce whether the electric motor 100 does or does not exhibit salience. For example, if the measured values M31 and M32 are identical (or similar, i.e. their difference is below a given threshold), it can be deduced by the unit 124 for determining the type of electric motor that the electric motor does not exhibit salience (characteristic C3). On the other hand, if the measured values M31 and M32 are different (for example, their difference is greater than a given threshold), it can be deduced by the unit 124 for determining the type of electric motor that the electric motor exhibits salience (characteristic C3).

[0157] In embodiments with three injections in the three directions D3, D4 and D5, the measurements M31, M32 and M33 are obtained and compared one-to-one in order to infer the third characteristic C3. Again, if the measurements M31, M32 and M33 are identical (or similar) pairwise, the unit for determining the motor type 124 determines that the motor 100 does not exhibit saliency. Otherwise, the unit for determining the motor type 124 determines that the motor 100 exhibits saliency.

[0158] Thus, in step 304, the unit for determining the motor type 124 can determine the type of the motor by considering the characteristic C1 and the characteristic C3, or by considering the characteristics C1, C2 and C3.

[0159] In embodiments where steps 307 to 309 and 310 to 312 (determination of characteristics C2 and C3) are applied simultaneously, steps 310 to 312 can alternatively be performed before steps 307 to 309.

[0160] Figure 4 is a diagram showing the steps of a method according to a particular embodiment of the present application. In particular, it has the determination of characteristics C1 to C3 in order to select the type of the motor 100 from four predetermined motor types, namely an induction motor, a motor with surface permanent magnets (with smooth poles), a motor with interior permanent magnets (with salient poles) and a reluctance synchronous motor.

[0161] Step 400 is similar to step 300 of Figure 3 : defining a maximum motor current value.

[0162] In step 401, a ramp S1 of motor voltage is applied and simultaneously the motor current is measured (measurement M1).

[0163] In parallel, in step 402, the motor current is measured and compared to the maximum motor current value. As long as the measured motor current is below the maximum motor current value, the sequence S1 continues and the applied motor voltage value is increased.

[0164] When the measured current reaches or exceeds the maximum motor current value, the sequence S1 is stopped, the motor 100 is no longer powered for the variable speed drive 110 and the method enters step 403.

[0165] In step 403, the unit for detecting oscillations 122 determines whether the measurement M1 exhibits oscillations. If the unit for detecting oscillations 122 determines in step 404 that the measurement M1 does not exhibit oscillations, the unit for determining the motor type 124 determines in step 405 that the motor has an induction type.

[0166] Otherwise, the unit 122 for detecting oscillations determines in step 406 that the measured values M1 exhibit oscillations, from which it is concluded that the electric motor exhibits anisotropy, and that the main anisotropy axis can be determined by the unit 124 for determining the motor type.

[0167] Then in step 407, the variable speed drive 110 is driven by the unit 123 for injecting motor voltages to align the electric motor with the main anisotropy axis.

[0168] Then in step 408, the unit 123 for injecting motor voltages injects a sequence S3 of motor voltages in at least two mutually orthogonal directions D3 and D4. In parallel, measured values M31 and M32 of the motor current are obtained (at least) for the directions D3 and D4, respectively.

[0169] In step 409, the unit 124 for determining the motor type determines whether the motor 100 exhibits saliency based on a comparison of the measured values M31 and M32.

[0170] If the motor 100 does not exhibit saliency, then in step 410, the unit 124 for determining the motor type determines that the motor 100 is of synchronous type with surface permanent magnets.

[0171] If the motor 100 exhibits saliency, then the unit 123 for injecting motor voltages injects in step 411 a sequence S2 of motor voltages, and in parallel, measured values M2 of the motor current (or motor voltage, depending on the variant considered) are obtained.

[0172] In step 412, the unit 124 for determining the motor type determines in step 412 whether the motor 100 exhibits permanent flux.

[0173] If the motor 100 exhibits permanent flux, then in step 413, the unit 124 for determining the motor type can determine that the motor 100 is of synchronous type with internal permanent magnets.

[0174] If the motor 100 does not exhibit permanent flux, then in step 414, the unit 124 for determining the motor type determines that the motor 100 is of reluctance synchronous type.

[0175] Upon completion of steps 405, 410, 413 or 414, the configuration unit 125 sets the variable speed drive 110 according to the determined motor type.

[0176] Figure 5 The structure of each unit 122 to 125 of the configuration apparatus 120 is illustrated. Figure 1 The structure of each unit 122 to 125 of the configuration apparatus 120 is illustrated.

[0177] The unit comprises a processor 500 associated with a memory 501 such as a random access memory RAM, a read only memory, a flash hard disk and / or any type of memory. The memory 501 stores at least the data necessary for the operation of the unit. It can also store computer program instructions executable by the processor 500 to implement the unit functions. Alternatively, the processor 500 can be replaced by a microcontroller designed and set up to perform the unit functions.

[0178] The unit further comprises two input and output interfaces 502 and 503. Alternatively, the unit comprises a single bidirectional input / output interface. The interfaces 502 and 503 make it possible to communicate with other units of the configuration device and / or with the variable speed drive 110.

[0179] Each of the units 122 to 125 can comprise Figure 5 The structure shown. As a variant, the functions of the units 122 to 125 can be grouped together in one and the same structure by a processor running all these functions.

[0180] Although the application has been described above with reference to particular embodiments, the application is in no way limited to the forms described. The application is only limited by the content defined by the claims, and embodiments other than those described above can fall within the scope of the claims.

[0181] Furthermore, although the embodiments have been described above as a combination of parts and / or functions, it will be clearly understood that alternative embodiments can be obtained by other combinations of parts and / or functions, without in any way departing from the scope of the application.

Claims

1. A method for configuring a variable speed drive (110) for supplying an electric motor (100), the method comprising the operations of: - applying (301) a motor voltage sequence S1 to the electric motor via the variable speed drive; - obtaining (302) motor current measurements M1 during the application of the motor voltage sequence S1; - determining (303) a characteristic C1 of the electric motor based on the motor current measurements M1; - determining (304) a type of the electric motor at least according to the characteristic C1; - configuring (305) the variable speed drive according to the determined type of the electric motor; the method being characterized in that the voltage sequence S1 is applied twice in succession in at least two non-collinear voltage directions according to the operations of: - applying (301) the motor voltage sequence S1 to the electric motor in a direction D1; - obtaining (302) motor current measurements M11 during the application of the voltage sequence in the direction D1; - in case the measurements M11 are determined to exhibit oscillations, determining that the electric motor exhibits anisotropic properties; - otherwise: - applying (301) the motor voltage sequence S1 to the electric motor at least a second time in a direction D2 that is not collinear with the direction D1; - obtaining (302) motor current measurements M12 during the application of the motor voltage sequence S1 in the direction D2; - in case the measurements M12 are detected to exhibit oscillations, determining (303) that the electric motor exhibits anisotropic properties; - otherwise, determining (303) that the electric motor does not exhibit any anisotropic properties.

2. The method of claim 1, wherein, When applying the sequence S1 a second time, the application of the sequence S1 is at least spaced apart by a predetermined delay.

3. The method of claim 1 or 2, wherein, If the electric motor (100) does not exhibit any anisotropic properties, it is determined that the electric motor has an induction type.

4. The method of any one of claims 1 to 3, wherein, If the electric motor (100) exhibits anisotropic properties, the method further comprises: - detecting (306) a main anisotropy axis of the electric motor after the application of the motor voltage sequence S1; - applying (307) a motor voltage sequence S2 to drive the electric motor to rotate according to the anisotropy axis; - obtaining (308) measurements M2 resulting from the application of the motor voltage sequence S2; - determining (309) a type of anisotropy of the electric motor according to the measurements M2; wherein the type of the electric motor is determined at least according to the characteristic C1 and the characteristic C2.

5. The method of claim 4, wherein, The measurements M2 are: - measurements of the motor current taken during the application of the sequence S2; - measurements of the motor voltage taken after the application of the sequence S2.

6. The method of claim 4 or 5, wherein, The characteristic C2 characterizes the fact that the electric motor (100) comprises a rotor with or without permanent magnetic flux.

7. The method of claim 6, wherein, If the electric motor (100) does not comprise any permanent magnet, it is determined that the electric motor has a reluctance synchronous type.

8. The method of any one of claims 5-7, wherein, The motor voltage sequence S2 is applied to drive the electric motor to rotate in a direction orthogonal to the anisotropy direction of the electric motor (100).

9. The method according to any one of claims 5 to 8, further comprising determining a steady state gain of the electric motor based on the measurement value Ml and the sequence SI, and wherein, The motor voltage sequence S2 is determined according to a determined steady state gain.

10. The method of any one of claims 1 to 9, wherein, If the electric motor (100) is anisotropic, the motor voltage sequence S3 is applied twice in succession in two orthogonal voltage directions according to the operations of: - applying (301) the motor voltage sequence S3 to the electric motor in a direction D3; - obtaining (302) motor current measurements M31 during the application of the motor voltage sequence S3 in the direction D3; - in case the measurements M31 are determined to exhibit oscillations, determining that the electric motor exhibits anisotropic properties; - otherwise: - applying (301) the motor voltage sequence S3 to the electric motor in a direction D4 that is orthogonal to the direction D3; - obtaining (302) motor current measurements M32 during the application of the motor voltage sequence S3 in the direction D4; - in case the measurements M32 are detected to exhibit oscillations, determining (303) that the electric motor exhibits anisotropic properties; - otherwise, determining (303) that the electric motor does not exhibit any anisotropic properties. - applying (310) a motor voltage sequence S3 to the motor in a direction D3; - obtaining (311) a motor current measurement M31 during the application of the motor voltage sequence S3 in the direction D3; - applying (310) the motor voltage sequence S3 to the motor in a direction D4 not collinear with the direction D3; - obtaining (311) a motor current measurement M32 during the application of the motor voltage sequence S3 in the direction D4; - comparing (312) the measurements M31 and M32 in order to determine a characteristic C3 of the motor; wherein the type of the motor is determined at least as a function of the characteristic C1 and of the characteristic C3.

11. The method of claim 10, wherein, The characteristic C3 characterizes the fact that the motor (100) exhibits or does not exhibit saliency, and wherein, if the motor does not exhibit any inductance saliency of the rotor, it is determined that the motor has a type with surface permanent magnets.

12. The method of claim 11, wherein, If the motor (100) exhibits inductance saliency of the rotor, and if the motor comprises a rotor with permanent magnetic flux, it is determined that the motor has a type with internal permanent magnets.

13. The method of any one of claims 10-12, wherein, The sequence S3 is a high frequency continuous sequence of voltages or is a voltage step.

14. The method of any of the preceding claims, wherein, The motor voltage sequence S1 comprises a gradual increase of the motor voltage as long as the motor current measurement M1 remains below a maximum motor current value.

15. The method according to claim 14, comprising a preliminary step (300) of manually entering the maximum motor current value.

16. The method according to claim 9 and according to claim 14 or 15, wherein, The voltage sequence S2 is determined as a function of the steady state gain and of the maximum motor current value.

17. A computer program capable of being run by a processor (500), the computer program comprising instructions for implementing the steps of the method according to any one of claims 1 to 16 when run by the processor.

18. A configuration device for configuring a variable speed drive (110) responsible for the power supply of a motor (100), the configuration device comprising: - a voltage injection unit (123) arranged to apply a motor voltage sequence S1 to the motor via the variable speed drive; - an acquisition unit (121) arranged to acquire a motor current measurement M1 during the application of the voltage sequence S1 ; - a motor type determination unit (124) arranged to determine a characteristic C1 of the motor on the basis of the motor current measurement M1 and to determine the type of the motor at least as a function of the characteristic C1 ; - a configuration unit (125) capable of configuring the variable speed drive as a function of the determined type of the motor.

Images