阅读说明：本技术 确定电发动机的转子位置的方法、电梯和电转换器单元 (Method for determining the rotor position of an electric motor, elevator and electric converter unit ) 是由 T.考皮嫩 L.斯托尔特 M.帕基嫩 于 2020-03-06 设计创作，主要内容包括：提出了用于确定电发动机(12)的转子位置的方法、电梯(100)和电转换器单元(14)。该方法包括：向电发动机(12)供应(41)第一激励信号(ES1)；确定(42)响应于第一激励信号(ES1)在电发动机(12)中生成的第一响应信号(RS1)；基于第一响应信号(RS1)确定(43)发动机(12)的直轴(D,-D,+D)相对于静止参考系的电角度；向发动机(12)供应(44)第二激励信号(ES2),其中第二激励信号(ES2)基于所确定的电角度；确定(45)响应于第二激励信号(ES2)在发动机(12)中生成的第二响应信号(RS2)；以及基于第二响应信号(RS2)确定(46)转子位置。(A method, an elevator (100) and an electrical converter unit (14) for determining the rotor position of an electrical motor (12) are proposed. The method comprises the following steps: supplying (41) a first excitation signal (ES1) to the electric motor (12); determining (42) a first response signal (RS1) generated in the electric motor (12) in response to the first excitation signal (ES 1); determining (43) an electrical angle of a straight axis (D, -D, + D) of the engine (12) relative to a stationary reference frame based on the first response signal (RS 1); supplying (44) a second energizing signal (ES2) to the engine (12), wherein the second energizing signal (ES2) is based on the determined electrical angle; determining (45) a second response signal (RS2) generated in the engine (12) in response to the second excitation signal (ES 2); and determining (46) the rotor position based on the second response signal (RS 2).)

1. A method for determining a rotor position of an electric motor (12), the method comprising:

-supplying (41) a first excitation signal (ES1) to the electric motor (12),

-determining (42) a first response signal (RS1) generated in the electric motor (12) in response to the first excitation signal (ES1),

characterized in that the method further comprises:

-determining (43), based on the first response signal (RS1), an electrical angle of a straight axis (D, -D, + D) of the electric motor (12) relative to a stationary reference frame, for example with respect to a stator of the electric motor (12),

-supplying (44) a second excitation signal (ES2) to the electric motor (12), wherein the second excitation signal (ES2) is based on the determined electric angle,

-determining (45) a second response signal (RS2) generated in the electric motor (12) in response to the second excitation signal (ES2), and

-determining (46) the rotor position based on the second response signal (RS 2).

2. The method of claim 1, wherein

The first excitation signal (ES1) is, for example, a first alternating voltage signal having a constant amplitude and the first response signal (RS1) is a first response current generated in response to the first alternating voltage signal, or/and

the second excitation signal (ES2) is, for example, a second alternating voltage signal having a constant amplitude, and the second response signal (RS2) is a second response current generated in response to the second alternating voltage signal.

3. The method of claim 1, wherein,

the first excitation signal (ES1) is, for example, a first alternating current signal having a constant amplitude and the first response signal (RS1) is a first response voltage generated in response to the first alternating current signal, or/and

the second excitation signal (ES2) is, for example, a second alternating current signal having a constant amplitude, and the second response signal (RS2) is a second response voltage generated in response to the second alternating current signal.

4. The method according to any of the preceding claims, comprising: -before the supplying of the first excitation signal (ES1), applying a force having a first amount in relation to a direction for counteracting a movement of the rotor (11) in order to keep the rotor (11) of the engine (12) in its position at least during the supplying (41) of the first excitation signal (ES1) and the determining (42) of the first response signal (RS 1).

5. Method according to any of the preceding claims, wherein the first excitation signal (ES1) comprises continuously supplying inside the motor (12) one alternating excitation signal, such as a voltage or a current, generating a rotating field in one direction and another alternating excitation signal, such as a voltage or a current, generating a rotating field in the opposite direction.

6. The method according to any one of the preceding claims, wherein the determining (43) an electrical angle comprises determining an electrical angle of the first excitation signal (ES1) when a maximum amount of the first response signal (RS1) occurs.

7. The method according to any one of the preceding claims, wherein the determining (46) a rotor position comprises comparing values of a maximum amount of the second response signal (RS2) in order to determine positions of a south pole and a north pole of the rotor (11).

8. A method according to any one of the preceding claims, wherein the second excitation signal (ES2) is configured to be supplied by gradually increasing its amplitude so as to avoid a step change in the force generated in the engine (12).

9. Method according to any of claims 4-8, wherein the electric motor (12) is an elevator motor (12) of an elevator (100), wherein the elevator (100) comprises at least one elevator brake (16) for braking the motor (12), the method comprising applying a force by means of the at least one elevator brake (16).

10. Method according to any of claims 4 to 9, wherein the force generated by the first excitation signal (ES1) for moving the rotor (11) is smaller than the first amount such that the rotor maintains its position during the supplying (41) of the first excitation signal (ES 1).

11. Method according to any of the preceding claims, wherein the electric motor (12) is one of the following: the synchronous reluctance motor, the permanent magnet linear motor, the permanent magnet auxiliary synchronous reluctance motor and the linear switch reluctance motor.

12. An elevator (100) comprising:

an elevator car (10),

an elevator motor (12) configured to move the elevator car (10),

an electrical converter unit (14) for operating the elevator motor (12),

at least one elevator brake (16), and

a control unit (1000; 14A) configured to cause at least the elevator (100), preferably its electrical converter unit (14), to:

-supplying (41) a first excitation signal (ES1), such as a first excitation voltage or current signal, to the elevator motor (12),

-determining (42) a first response signal (RS1), such as a first response current or voltage, respectively generated in the elevator motor (12) in response to the first excitation signal (ES 1);

characterized in that the elevator (100) is further configured to:

-determining (43), based on the first response signal (RS1), an electrical angle of a straight axis (D, -D, + D) of the electric motor (12) relative to a stationary reference frame, for example with respect to a stator of the electric motor (12),

-supplying (44) a second excitation signal (ES2), such as a second excitation voltage or current signal, to the electric motor (12), wherein the second excitation signal (ES2) is based on the determined electrical angle,

-determining (45) a second response signal (RS2), such as a second response current or voltage, respectively generated in the electric motor (12) in response to the second excitation signal (ES2), and

-determining (46) a rotor position based on the second response current (RS 2).

13. Elevator (100) according to claim 12, wherein the control unit (1000) is further configured to cause at least the at least one elevator brake (16) to:

-applying, at least during said supplying (41) a first excitation signal (ES1) and said determining (42) a first response signal (RS1), a force having a first amount in a direction for opposing the movement of the rotor (11) in order to hold the rotor (11) of the engine (12) in its position, for example locked in its position.

14. Elevator (100) according to claim 12 or 13, wherein the determining (43) of the electrical angle comprises determining the electrical angle of the first excitation signal (ES1) when the maximum amount of the first response signal (RS1) occurs.

15. Elevator (100) according to any of claims 12-14, wherein the determining (46) of the rotor position comprises comparing the values of the greatest quantities of the second response signal (RS2) in order to determine the position of the south and north poles of the rotor (11).

16. An electrical converter unit (14) configured to:

-supplying (41) a first excitation signal (ES1), such as a first excitation voltage or current signal, to the elevator motor (12),

-determining (42) a first response signal (RS1), such as a first response current or voltage, respectively generated in the elevator motor (12) in response to the first excitation signal (ES 1);

characterized in that the electrical converter unit (14) is further configured to:

-determining (43), based on the first response signal (RS1), an electrical angle of a straight axis (D, -D, + D) of the electric motor (12) relative to a stationary reference frame, for example with respect to a stator of the electric motor (12),

-supplying (44) a second excitation signal (ES2), such as a second excitation voltage or current signal, to the electric motor (12), wherein the second excitation signal (ES2) is based on the determined electrical angle,

-determining (45) a second response signal (RS2), such as a second response current or voltage, respectively generated in the electric motor (12) in response to the second excitation signal (ES2), and

-determining (46) a rotor position based on the second response signal (RS 2).

17. The electrical converter unit (14) as claimed in claim 16, comprising a converter device (14D), such as a frequency converter or an inverter, and a current determining means (14C) and/or a voltage determining means for determining at least the first and second response signals (RS1, RS 2).

Technical Field

The present invention relates generally to electric engines. In particular, but not exclusively, the invention relates to determining the rotor position of an elevator motor.

Background

There are known solutions for determining the rotor position of an electric motor. In some solutions, resolvers have been attached to the rotor in order to measure the absolute position of the rotor. However, this increases the number of components and requires space for the decomposer.

According to another known solution, the rotor position is determined using a frequency converter connected to the engine. In this solution, the load bridge of the converter is installed to supply the electric motor with a first alternating voltage excitation signal. The current of the stator winding of the electric motor, which is generated by the supplied alternating voltage excitation signal, is measured with a current sensor. The measured current forms a first alternating current response signal corresponding to the supplied first alternating voltage excitation signal, and the position of the rotor of the electric motor is determined on the basis of the determined aforementioned first alternating current response signal.

However, problems can arise in the case where the excitation signal moves the rotor. For example, in an elevator, this would mean that the elevator car would also move, which could cause undesirable conditions for passengers inside the car, passengers entering or leaving the car. In these cases, the determination of the rotor position may fail. To avoid failure, the brake used to hold the rotor in place must be oversized, which increases cost. In addition, the excitation signal causes noise and mechanical vibrations in the system. Therefore, there is still a need to develop a solution for determining the rotor position of an electric motor.

Disclosure of Invention

It is an object of the invention to provide a method, an elevator and an electrical converter unit for determining the rotor position of an electrical motor. It is a further object of the invention that the method, elevator and electrical converter unit minimize the forces that cause the rotor to move during the determination of the rotor position and thus minimize the forces that are required to maintain the rotor in its position, such as by means of a brake.

The object of the invention is achieved by a method, an elevator and an electric converter unit as defined in the respective independent claims.

According to a first aspect, a method for determining the rotor position of an electric motor, such as an elevator, is provided. The method comprises the following steps:

-supplying a first excitation signal to the electric motor,

-determining a first response signal generated in the electric motor in response to the first excitation signal,

determining an electrical angle of a straight shaft of the electric motor relative to a stationary reference frame, e.g. with respect to a stator of the electric motor, based on the first response signal,

supplying a second excitation signal to the electric motor, wherein the second excitation signal is based on the determined electrical angle,

-determining a second response signal generated in the electric motor in response to the second excitation signal, and

-determining the rotor position based on the second response signal.

In some embodiments, the first excitation signal may be, for example, a first alternating voltage signal having a constant amplitude and the first response signal may be a first response current generated in response to the first alternating voltage signal, or/and the second excitation signal may be, for example, a second alternating voltage signal having a constant amplitude and the second response signal may be a second response current generated in response to the second alternating voltage signal.

Alternatively, the first excitation signal may be, for example, a first alternating current signal having a constant amplitude and the first response signal may be a first response voltage generated in response to the first alternating current signal, or/and the second excitation signal may be, for example, a second alternating current signal having a constant amplitude and the second response signal may be a second response voltage generated in response to the second alternating current signal.

In an embodiment, the first excitation signal and the second response signal may be a voltage or a current signal, and the second excitation signal and the first response signal may be a current or a voltage signal, respectively.

In various embodiments, the method may comprise: before said supplying a first excitation signal, applying a force having a first amount to hold the rotor of the motor in its position at least during said supplying a first excitation signal and said determining a first response signal, wherein the first amount is related to a direction for opposing the movement of the rotor.

In various embodiments, the first excitation signal may comprise continuously supplying inside the electric motor one alternating excitation signal, such as a voltage or current, generating a rotating field in one direction and another alternating excitation signal, such as a voltage or current, generating a rotating field in the opposite direction.

In various embodiments, the determining the electrical angle may include determining the electrical angle of the first excitation signal when the maximum amount of the first response signal occurs.

In various embodiments, the determining the rotor position may include comparing values of a maximum amount of the second response signal to determine the position of the north and south poles of the rotor.

In various embodiments, the second excitation signal may be configured to be supplied by gradually increasing its amplitude so as to avoid a step change in the force generated in the engine.

In various embodiments, the electric motor is an elevator motor of an elevator, wherein the elevator comprises at least one elevator brake for braking the motor, and wherein the method may comprise applying the force by the at least one elevator brake.

In various embodiments, the force generated by the first excitation signal to move the rotor may be less than a first amount such that the rotor maintains its position during the supply of the first excitation signal.

In various embodiments, the electric motor may be one of the following: the synchronous reluctance motor, the permanent magnet linear motor, the permanent magnet auxiliary synchronous reluctance motor and the linear switch reluctance motor.

According to a second aspect, an elevator is provided. The elevator comprises an elevator car, an elevator motor configured to move the elevator car, an electrical converter unit for operating the elevator motor, at least one elevator brake, and a control unit configured to perform at least the method according to the first aspect or any embodiment thereof.

Thus, the control unit may be configured such that the elevator, preferably such that its electrical converter unit:

supplying a first excitation signal, e.g. a first excitation voltage or current signal, to the elevator motor,

-determining a first response signal, e.g. a first response current or voltage, respectively generated in the elevator motor in response to the first excitation signal;

determining an electrical angle of a straight shaft of the electric motor relative to a stationary reference frame, e.g. with respect to a stator of the electric motor, based on the first response signal,

supplying a second excitation signal, for example a second excitation voltage or current signal, to the electric motor, wherein the second excitation signal is based on the determined electrical angle,

-determining a second response signal, such as a second response current or voltage, respectively generated in the electric motor in response to the second excitation signal, and

-determining the rotor position based on the second response current.

In various embodiments, the control unit may be further configured to cause at least one elevator brake to:

-applying a force having a first amount in a direction for counteracting the movement of the rotor at least during said supplying the first excitation signal and said determining the first response signal in order to hold the rotor of the engine in its position, e.g. locked in its position.

In some embodiments, the determining the electrical angle may include determining the electrical angle of the first excitation signal when the maximum amount of the first response signal occurs.

In some embodiments, the determining the rotor position may include comparing values of a maximum amount of the second response signal to determine the position of the north and south poles of the rotor.

According to a third aspect, an electrical converter unit is provided. The electrical converter unit is configured to perform at least a method according to the first aspect or any embodiment thereof.

Thus, the electrical converter unit may be configured to at least:

supplying a first excitation signal, e.g. a first excitation voltage or current signal, to the elevator motor,

-determining a first response signal, e.g. a first response current or voltage, respectively generated in the elevator motor in response to the first excitation signal;

determining an electrical angle of a straight shaft of the electric motor relative to a stationary reference frame, e.g. with respect to a stator of the electric motor, based on the first response signal,

supplying a second excitation signal, for example a second excitation voltage or current signal, to the electric motor, wherein the second excitation signal is based on the determined electrical angle,

-determining a second response signal, such as a second response current or voltage, respectively generated in the electric motor in response to the second excitation signal, and

-determining the rotor position based on the second response signal.

In various embodiments, the electrical converter unit may comprise a converter device, such as a frequency converter or an inverter, and a current determination means and/or a voltage determination means for determining at least the first response signal and the second response signal.

The invention provides advantages with respect to known solutions. During the supply of the excitation signal in the rotor position determination process, the rotor is easily held or at least can be easily held in its position. Minimizing the forces causing the rotor to move during the determination of the rotor position and thus minimizing the forces required to hold the rotor in its position allows for the use of smaller braking forces and thus smaller brakes or less frequent brakes. This is particularly advantageous e.g. in elevators in which a motor is arranged to move the elevator car. Thus, the elevator car does not move during the determination of the rotor position. The movement may be unpleasant for passengers in the car. Furthermore, the excitation signal(s) cause less noise and vibration in the engine than known solutions that utilize the excitation signal(s) to determine the rotor position.

Various other advantages will become apparent to the skilled person based on the following detailed description.

The expression "a plurality" may here mean any positive integer starting from one (1), i.e. at least one.

The expression "plurality" may refer to any positive integer starting from two (2), i.e. to at least two, respectively.

The terms "first," "second," and "third" are used herein to distinguish one element from another, and do not specifically prioritize or order them, if not explicitly stated otherwise.

The exemplary embodiments of the invention set forth herein should not be construed as limiting the applicability of the appended claims. The verb "to comprise" is used here as an open limitation that does not exclude the presence of also unrecited features. The features recited in the dependent claims may be freely combined with each other, unless explicitly stated otherwise.

The novel features believed characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

Drawings

In the drawings, certain embodiments of the invention are shown by way of example and not limitation.

Fig. 1A to 1C schematically show electrical converter units according to some embodiments of the present invention.

Fig. 2 schematically shows an elevator according to an embodiment of the invention.

Fig. 3 schematically shows an elevator according to an embodiment of the invention.

Fig. 4 shows a flow diagram of a method according to an embodiment of the invention.

Fig. 5A and 5B schematically show examples of first and second response signals according to an embodiment of the present invention.

Fig. 6A and 6B schematically illustrate electrical converter cells according to some embodiments of the invention.

Detailed Description

Fig. 1A schematically shows an electrical converter unit 14 according to an embodiment of the invention. The electrical converter unit 14 may comprise a frequency converter or inverter, or in particular, a power conversion circuit(s) 14B thereof. Furthermore, the electrical converter unit 14 may comprise current determination means 14C and/or voltage determination means (not shown) in order to determine the current(s) flowing into or out of the electrical motor 12, such as three instantaneous phase currents, or the voltage present between the motor phases or between the motor phases and a ground/reference/neutral potential, such as a star point of the motor 12, respectively. The current determining means 14C and/or the voltage determining means may preferably be arranged in connection with the control unit 14A in order to provide the control unit 14A with information about the current (s)/voltage(s). Preferably, the electrical converter unit 14 may be configured to control the current (s)/voltage(s) at least under normal operating conditions in order to control the operation of the engine 12, such as the rotation or movement of the rotor of the engine 12.

Furthermore, the electrical converter unit 14 may comprise a control unit 14A, the control unit 14A being arranged close, e.g. inside the same housing, to a converter device 14D, such as a frequency converter or an inverter, comprising its power conversion circuit(s) 14B. An external connection 15 to the electrical converter unit 14 may also be arranged in order to provide, for example, measurement(s), control signal(s) and/or power from an external system connected to the electrical converter unit 14 or, in particular, to the control unit 14A thereof. The external system may be, for example, a vehicle, an industrial process, or an elevator such as shown in fig. 2 and 3.

Fig. 1B schematically shows an electrical converter unit 14 according to an embodiment of the invention. The electrical converter unit 14 in fig. 1B is otherwise similar to that shown and described with respect to fig. 1A, except that the control unit 14A is arranged separately from the converter device 14D, e.g. the control unit 14A is arranged outside the housing of the converter device 14D. Thus, only the control unit 14A may be arranged in connection with the conversion circuit(s) 14B. The control unit 14A may for example be part of a control unit of an external system comprising the electrical converter unit 14.

Fig. 1C schematically shows an electrical converter unit 14 according to an embodiment of the invention. In fig. 1C, the electrical converter unit 14 may comprise a frequency converter with an energy storage 24, such as a capacitor (bank) or a battery, which energy storage 24 is arranged on its intermediate circuit 23 or, in the case of a battery, is at least connected with the intermediate circuit 23. The frequency converter may be arranged to supply electrical power between the electrical grid 20 and the electrical engine 12. The frequency converter may comprise a load bridge 22, which load bridge 22 is connected to the electric motor 12 for supplying electric power between the electric motor 12 and the load bridge 22. The load bridge 22 may include controllable solid state switches to form, for example, a power conversion circuit of a three-phase two-level or three-phase three-level inverter. The supply voltage of the electric motor 12 may be formed by controlling the solid-state switching of the load bridge 22 with the control unit 14A of the load bridge 22 using, for example, Pulse Width Modulation (PWM) techniques. The frequency converter may comprise a current determining component 14C and/or a voltage determining component, such as a current or voltage sensor, which may be arranged in connection with the supply cable of the stator winding of the motor 12 in order to measure the stator current and/or voltage.

The electrical converter unit 14 as described above with respect to fig. 1A-1C may be configured to control operation of the electrical motor 12, for example, by field-oriented or vector control methods known to those skilled in the art.

In various embodiments of the present invention, the electrical converter unit 14, or specifically the control unit 14A thereof, shown in any one of fig. 1A to 1C and described in connection therewith, may be configured to perform at least one embodiment of the method shown in fig. 4 and/or described in connection with fig. 4, in order to determine the rotor position of the engine 12.

Thus, in various embodiments, the control unit 14A may comprise at least: a processing unit, such as a processor or microcontroller, for example, for performing calculations and/or running computer program code; and a memory for storing the code, measurement data, and the like.

In certain embodiments, the rotor of the electric motor 12 may be arranged to: the force acting against the rotor movement is applied by mechanical or electromechanical braking, and its position is maintained, e.g. locked, to its position at least during a part of the process for determining the rotor position of the engine 12.

In various embodiments, the electric motor 12 may be one of the following: the synchronous reluctance motor, the permanent magnet linear motor, the permanent magnet auxiliary synchronous reluctance motor and the linear switch reluctance motor.

Fig. 2 schematically shows an elevator 100 according to an embodiment of the invention. The elevator 100 may include an elevator car 10 coupled to a counterweight 17 via ropes 19, belts, or the like. A rope 19 or the like may travel around the drive sheave 18, where the electric motor 12 is configured to generate a force to the drive sheave 18 to move the elevator car 10 in response to operation of the electric motor 12. In particular, the elevator car 10 may be arranged to move in response to movement (such as rotation) of the rotor 11 of the motor 12.

At least one elevator brake 16, i.e. one, two or more elevator brakes 16, can be arranged such that when passing the power-off control, the brake 16 is configured to engage the drive sheave 18 and in this way brake the movement of the motor 12, in particular its rotor 11, and thus brake the movement of the elevator car 10 or to keep the elevator car 10 stationary in the shaft. When brake 16 is energized, brake 16 opens, allowing movement of elevator car 10. Alternatively, the elevator 100 may be implemented without the counterweight 17. Alternatively, the motor 12 may be in the form of a linear motor having a stator extending along the elevator shaft and a rotor or "mover" coupled to the elevator car 10, as shown in fig. 3.

The elevator 100 may comprise an elevator control unit 1000 for controlling the operation of the elevator 100. The elevator control unit 1000 can be a separate device or can be comprised in other components of the elevator 100, e.g. in the electric drive 14 or as part of the electric drive 14. The elevator control unit 1000 can also be implemented in a distributed manner, so that e.g. a part of the elevator control unit 1000 can be comprised in the electric drive 14, e.g. in its control unit 14A, and another part in the elevator car 10. It is also possible to arrange the elevator control unit 1000 in a distributed manner at more than two locations or in more than two devices.

The elevator control unit 1000 and/or the control unit 14A may comprise one or more processors, one or more volatile or non-volatile memories for storing parts of the computer program code and any data values, and possibly one or more user interface units. The mentioned elements may be communicatively coupled to each other, for example, using an internal bus.

The processor of the elevator control unit 1000 and/or the control unit 14A may at least be configured to implement at least some of the method steps as described below, such as in fig. 4 and described in connection with fig. 4. Implementation of the method may be accomplished by arranging the processor to run at least some portions of the computer program code stored in the memory to cause the processor, and thus the elevator control unit 1000 and/or the control unit 14A, to implement one or more method steps as described below. Thus, the processor may be arranged to access the memory and retrieve from and store any information to the memory. For the sake of clarity, a processor here refers to any unit that is suitable for processing information and controlling the operation of the elevator control unit 1000 and/or the control unit 14A, among other tasks. The operation can also be implemented with a microcontroller solution with embedded software. Similarly, the memory is not limited to only a certain type of memory, but any type of memory suitable for storing the pieces of information described may be used in the context of the present invention.

Fig. 3 schematically shows an elevator 100 according to an embodiment of the invention. The elevator 100 may comprise at least one or more elevator cars 10 moving in an elevator shaft 13 or elevator car channel 13. The elevator car(s) 10 may comprise an electrical converter unit 14, such as comprising a converter device 14D, e.g. a frequency converter or an inverter, and/or a second energy storage, such as one or more batteries. A mover 11 arranged on the elevator car 10 can be operated with an electrical converter unit 14 in order to move the car 10 along the elevator shaft 13. Other electrically operated devices, such as lighting, doors, user interfaces, emergency rescue equipment, etc., may also be present in the elevator car 10. One or more of the other devices of the elevator car 10 can be operated with the electrical converter unit 14 or another converter such as an inverter or rectifier. Preferably, the second energy storage device may be electrically coupled to the electrical converter unit 14, for example to an intermediate circuit 23 thereof, in order to provide electrical power to the electrical converter unit 14 and/or in order to store electrical energy provided by the electrical converter unit 14 or another converter or other power source. Preferably, the elevator 100 may comprise an elevator control unit 1000 such as described in connection with fig. 2 and/or a control unit 14A or a control unit similar to the one described in connection with fig. 2.

There may be one or more movers 11 coupled to one or each of the elevator cars 10. The number of the movers 11 may vary depending on the structure of the electric linear motor 12, for example, the number of stator beams (beams) 12A.

Preferably, at least two landing floors with landing (landing) floor doors 25 or openings 25 can be included in the elevator 100. Doors may also be included in the elevator car 10. Although two horizontally separated groups or "columns" of vertically aligned landing floors are shown in fig. 3, it is also possible to have only one column, or more than two columns, e.g. three columns, as in a conventional elevator.

With respect to the elevator shaft 13, it may, for example, define a substantially enclosed volume in which the elevator car 10 is adapted and configured to move. The wall may be, for example, concrete, metal, or at least partially glass, or any combination thereof. The elevator shaft 13 here essentially refers to any structure or passage along which the elevator car 10 is arranged to move.

As can be seen in fig. 3, with a multi-car elevator 100, one or more elevator cars 10 can move vertically and/or horizontally along the elevator shaft 13 depending on the direction of the stator beam 12A. According to an embodiment similar in this respect to the one in fig. 3, one or more elevator cars 10 may be configured to move along several vertical and/or horizontal stator beams (e.g., such as two beams in fig. 3). The stator beam 12A is part of an electrical linear motor of the elevator 100 for moving one or more elevator cars 10 in an elevator shaft 13. Preferably, the stator beam 12A may be arranged in a fixed manner, that is to say stationary relative to the elevator shaft 13, for example by means of a fastening part which is stationary relative to the wall of the shaft, which fastening part may be arranged so as to be rotatable in a direction which changes the position of the elevator car 10.

Fig. 4 shows a flow chart of a method according to an embodiment of the invention.

Typically, the method comprises at least two main parts. Furthermore, the rotor 11 of the engine 12 may preferably be arranged to maintain its position, for example by exerting a force opposing the movement of the rotor 11 from its position at least during the first main part and optionally also during the second main part.

In the first main part, at least a first excitation signal, such as a current or a voltage, is supplied to the electric motor 12, and in response to the first excitation signal, a first response signal, such as a voltage or a current, respectively, is generated in the motor. Based on the first response signals, the positions of the direct and orthogonal axes may be determined. An example of this is highly schematically illustrated in fig. 5A, which shows the first response current RS1 as a function of electrical angle, such as one or two complete cycles from zero to 360 degrees or from zero to 720 degrees. The horizontal axis in fig. 5A does not necessarily correspond to zero amplitude but to some finite positive value. In some embodiments, the horizontal axis may refer to zero amplitude.

However, in some embodiments, since the amplitude of the first excitation signal (e.g. its vector quantity) may be arranged low such that the force generated by the first excitation signal for moving the rotor 11 is smaller than the force opposing the movement of the rotor 11, the position of the north and south poles in the rotor 11 may not be determined in the first main part due to the low amplitude of the excitation signal. On the other hand, only a small amount of force is required to hold the rotor 11 in its position. For example, only one brake, such as one elevator brake 16, may be provided for this purpose.

In the second main portion, at least a second excitation signal is supplied to the engine 12. Preferably, the second excitation signal is formed based on the determined position of the direct axis D of the electric motor 12. Therefore, since the characteristic of the second excitation signal corresponds to the position of the straight axis D, in an ideal case, even if the amplitude of the second excitation signal would be significantly higher than the amplitude of the first excitation signal, no force for moving the rotor 11 is generated due to the second excitation signal. In fact, due to the structure of the engine 12, for example, some small amount of force for moving the rotor 11 may be generated by the second excitation signal. Subsequently, a second response current generated in response to the second excitation signal may be determined. Since the amplitude of the second excitation signal is large, or at least higher than the amplitude of the first excitation signal, it can now be arranged in the second main part to determine the position of the north pole in the rotor 11 in relation to + D in fig. 5B and the position of the south pole in relation to-D in fig. 5B.

This example is shown highly schematically in fig. 5B, which shows the second response current RS2 as a function of electrical angle. It can be seen that the higher amplitude can be referred to as north and the lower amplitude can be referred to as south. It should be noted that the electrical angles in fig. 5A and 5B preferably correspond in the following sense: the same straight axes in fig. 5A are at corresponding electrical angles in fig. 5B. The horizontal axis in fig. 5B does not necessarily correspond to zero amplitude but to some finite positive value. In some embodiments, the horizontal axis may refer to zero amplitude.

As can be seen in fig. 5B, said determining 46 the rotor position may comprise comparing the maximum magnitude values of the second response current RS2 in order to determine the position of the north and south poles of the rotor 11. As is apparent from fig. 5, the value of the maximum at the north pole N may be greater than the value of the maximum at the south pole S. At the north pole N, the magnetic core of the motor 12 is magnetized, and therefore, the magnitude of the current increases. At the south pole S, the magnetic core of the motor 12 is demagnetized, and therefore, the magnitude of the current decreases.

Thus, as a result of the first and second main parts, the position of the rotor 11 can be determined without a large amount of force being required to hold the rotor 11 in its position. Moreover, the noise and vibration due to the excitation signal can be made lower than in the known solutions.

Item 40 may refer to a startup phase during which necessary tasks such as components and systems are obtained, and calibration and other configurations may be performed.

Item 41 may direct the electric motor 12 to supply a first excitation signal, such as a first alternating voltage or current signal.

Preferably, the first excitation signal may be configured to rotate about at least one pole pair of the engine 12.

According to various embodiments, the amplitude of the first excitation signal, such as the first alternating voltage signal, may be such that: which generates one or more electrical currents in the motor 12 that magnetically saturate at least a portion of the core material of the rotor 11.

Additionally, the first excitation signal may include continuously supplying one alternating voltage signal that generates a rotating field in one direction and another alternating voltage signal that generates a rotating field in an opposite direction inside the electric motor 12.

Additionally, the method may include: before said supplying 41 of the first excitation signal, at least during said supplying of the first excitation signal and said determining of the first response signal RS1, a force is applied with a first amount in order to keep the rotor 11 of the engine 12 in its position, wherein the first amount is related to the direction for counteracting the movement of the rotor 11, so that the first amount keeps the rotor 11 in its position even if the first excitation signal generates some force that would otherwise cause the rotor 11 to move. Thus, the force generated by the first excitation signal for moving the rotor 11 may be smaller than the first amount, such that the rotor 11 maintains its position at least during the supplying 41 of the first excitation signal. The first amount may e.g. correspond to the braking force of one brake 16, e.g. to the braking force of one of the at least one elevator brake 16.

Item 42 may refer to determining a first response signal RS1, such as a current or voltage, generated in the electric motor 12 in response to the first excitation signal. Preferably, determining the electrical angle may comprise determining the electrical angle of the first excitation signal when the maximum amount of the first response signal RS1, such as current, occurs.

In some embodiments, the amplitude of the first excitation signal is such that it causes a lower force for moving the rotor 11 than a first amount, e.g. a first amount of braking force for opposing the movement of the rotor 11.

Item 43 may refer to determining an electrical angle of the direct axis D of the electric motor 12 relative to a stationary reference frame, e.g., an electrical angle with respect to a stator of the electric motor 12, based on the first response signal RS 1.

Item 44 may direct the electrical motor 12 to supply a second excitation signal, wherein the second excitation signal is based on the determined electrical angle.

In various embodiments, the amplitude of the second excitation signal may be at least twice, preferably at least three times, or even more preferably at least four times the amplitude of the first excitation signal.

In various embodiments, the second excitation signal may be configured to be supplied by gradually increasing its amplitude so as to avoid a step change in the force generated in the engine 13. The gradual increase in excitation signal minimizes noise due to engine bearing clearances (i.e., because the second excitation signal would cause the rotor 11 to move due to the clearances).

Item 45 may refer to determining a second response signal RS2, such as a current or a voltage, generated in the electric motor 12 in response to the second excitation signal.

Item 46 may refer to determining the rotor position based on a second response signal RS2, such as a current or voltage. In various embodiments, determining the rotor position may include comparing the maximum magnitude of the second response signal RS2 to determine the position of the south S and north N poles of the rotor 11.

At item 49, the method operation is ended or stopped. The method may be performed once, continuously, intermittently, on-demand, or periodically.

In various embodiments, the electric motor 12 may be an elevator motor 12 of an elevator 100, wherein the elevator 100 includes at least one elevator brake 16 for braking the motor 12, and the method includes applying the force, e.g., by the at least one elevator brake 16, by a first amount.

It should be kept in mind, for example, with respect to fig. 6A and 6B, that during determining the position of the rotor 11 as described above, such as by means of a brake 16 (such as at least one elevator brake 16), the movement of the rotor 11 or the mover 11 of the electric motor 12 may be prevented.

Fig. 6A schematically shows an electrical converter unit 14 according to an embodiment of the invention. The electrical converter unit 14 may be electrically connected to an electrical motor 12, such as a synchronous reluctance motor, a permanent magnet linear motor, a permanent magnet assisted synchronous reluctance motor, or a linear switched reluctance motor, 12. The motor windings 51, such as comprised in the rotor 11, the stator, or the mover 11 in case of a linear motor, have been schematically shown as inductors. Although the inductors are shown as having a delta configuration, the windings may alternatively be in a wye or star configuration, for example. The converter unit 14 may comprise a converter device 14D such as a solid state semiconductor switch, e.g. a frequency converter or an inverter. The switches may be, for example, insulated gate bipolar transistors or silicon carbide junction field effect transistors. Examples of the converter unit 14 are described above with respect to fig. 1A to 1C.

Fig. 6A shows an example of a first excitation signal ES1 for one winding or across one winding, i.e. for example a first excitation signal ES1 between two phases of the engine 12. It should be noted, however, that in the case of voltage, it may be between the phase and ground potential. In this example, the first excitation signal ES1 is an alternating voltage signal, however, in certain other embodiments, it may be an alternating current signal.

Preferably, the electrical converter unit 14 may be configured to generate the first excitation signal ES 1. As shown in the example shown in fig. 6A, the first excitation signal ES1 is an alternating voltage signal generated by PWM in the converter unit 14. However, similar signals having a phase difference with the signal in question may also be generated through the other two inductors. The converter unit 14 may be controlled by a control unit 14A, in which control unit 14A the reference excitation signal(s) ES _ REF may be formed. In FIG. 6A, the reference drive signal(s) ES _ REF is formed to generate the first drive signal ES1, however, the second drive signal ES2 may be generated in a similar manner. The reference excitation signal(s) ES _ REF may comprise reference signals of all three phases, such as shown in fig. 6A, or may be vectors, such as voltage vectors, which are available in a vector control method operating in the electrical converter unit 14 and are specifically related to the control of its controllable switches.

Thus, in various embodiments, the magnitude of the reference voltage or current vector may be configured to be constant, however, the vector is configured to rotate.

Further, by supplying the first excitation signal ES1 to the engine 12, a first response signal RS1 that may be determined by the current determining component 14C or the voltage determining component is generated in the engine 12. In certain other embodiments, the first response current RS1 may be a voltage signal. The first response current RS1 in fig. 6A is the current of one phase of the motor 12. Since the electric motor 12 is typically an inductive load, the first excitation signal ES1 and the corresponding first response current RS1 have a phase offset.

Fig. 6B schematically shows an electrical converter unit 14 according to an embodiment of the invention. The unit 14 may comprise a conversion unit, preferably in the control unit 14A, for forming a three-phase supply voltage reference ES _ REF, such as a voltage comprising an R-phase, an S-phase and a T-phase, for example, based on the amplitude reference U and the electrical angle reference theta, in which case the three-phase supply voltage reference is formed as a function of the electrical angle reference theta. In this case, for example, the supply voltage reference for the R-phase may be of the form: amplitude x sin (θ), where the amplitude may be equal to U.

In an embodiment, the control block 61 of the load bridge 22 (see fig. 1C) of the electrical converter unit 14 controls the solid-state switches of the load bridge 22, for example in accordance with the aforementioned three-phase supply voltage reference ES _ REF, in order to form the first excitation signal ES1 for supply to the electrical motor 12. In this embodiment, the value of the electrical angle reference θ may be arranged to vary linearly, in which case the rotational or (in a linear motor) speed of movement of the supply voltage reference ES _ REF and the first excitation signal ES1 is arranged to be constant.

The first response signal RS1, i.e. in certain embodiments the three-phase currents, generated in the winding(s) of the electric motor 12 in response to the first excitation signal ES1 may be arranged to be determined, e.g. measured, as a function of the electrical angle reference θ of the electric motor 12.

The instantaneous values, such as amplitude-related instantaneous values, of the determined three-phase currents, i.e. the first response signals RS1, can be determined at the determination unit 62 using methods known in the art.

Furthermore, as is known in the art, based on the phase currents or voltages, current or voltage vectors representing the three-phase currents or voltages of the first response current RS1 may be determined.

According to certain embodiments, a change in inductance in the magnetic circuit of the electric motor 12 may cause a magnitude of the determined first response current RS1, such as a magnitude of a current vector, to change as a function of the electrical angle reference θ. This can be seen in the magnitude of the current vector of the first response current RS1 determined on the basis of the three-phase currents, an example of which is shown highly schematically in fig. 5A. In the ideal case of constant impedance, a sinusoidal excitation voltage will give rise to a sinusoidal response current, the amplitude of which current vector will have a constant amplitude. However, in practice this will never be the case.

In fig. 5A, the variation of amplitude as a function of the electrical angle reference θ is caused by the inductance of the magnetic circuit of the electric machine varying due to local saturation of the magnetic circuit of the engine 12, etc. Here, the local saturation refers to a type of saturation phenomenon of the magnetic circuit, which varies with respect to the electrical angle of the electric motor 12. Such local saturation is caused by the permanent magnets of the rotor or the like, in which case, due to the local saturation, it is possible to determine the position of the permanent magnets in the rotor 11 and thus the positions of the direct axis D and the orthogonal axis Q of the engine 12. On the other hand, a change in the geometry of the magnetic circuit, for example a change in the length of the air gap of the electric motor 12, can also lead to a local change in the inductance of the magnetic circuit of the electric motor 12. Such a change in the length of the air gap occurs, for example, in a salient pole electric motor 12. Local variations in the inductance of the magnetic circuit of the electric motor 12, caused by variations in the geometry of the magnetic circuit of the electric motor 12 of the type described above, can also be used for the determination of the position of the rotor 11. In this case, the impact angle of the rotor 11, i.e., the position of the magnetic pole N, S of the rotor 11, may also be determined in the case where the rotor 11 is locked to its position.

Thus, in various embodiments, the amplitude of the first excitation signal ES1 is arranged at least such that it causes local saturation of the magnetic circuit of the engine 12, such that a change in the amplitude of the response signal occurs as a function of the electrical angle reference θ.

The first excitation signal ES1 may be formed by changing the electrical angle reference theta from zero to 2 pi, i.e. by one complete cycle. Thus, the phase voltages may be UR ═ U × sin (θ), US ═ U × sin (θ +2 × pi/3) and UT ═ U × sin (θ -2 × pi/3). Thus, the voltage vector reference has a constant magnitude, however, it causes a rotating magnetic field in the motor 12. Under ideal conditions, the currents will for example sum to zero. However, due to magnetic saturation, the sum of the currents exhibits a sinusoidal-like variation in their amplitude. The amplitude reveals at which electrical angles the poles are.

The impedance of the magnetic circuit may also result in a phase difference between the supplied first excitation signal ES1 and the determined first response signal RS1, such as a current. To compensate for the phase difference, in certain embodiments, the above described measurements may be repeated by continuously supplying one alternating voltage signal as a function of the electrical angle reference θ and another alternating voltage signal as a function of the electrical angle reference θ, as described above. Thus, the first excitation signal ES1 may actually comprise two or more signals supplied in series. The direction of rotation of the further alternating voltage signal may be chosen to be opposite to the direction of rotation of the one alternating voltage signal of the first excitation signal ES1, in which case the phase difference between the one alternating voltage signal and the corresponding first response current RS1 may be in the opposite direction compared to the phase difference between the further alternating voltage signal of the first excitation signal ES1 and its corresponding current response RS 1. In view of the above, it is clear that the first response current RS1 may actually also comprise two or more consecutively generated signals.

The specific examples provided in the description given above should not be construed as limiting the applicability and/or interpretation of the appended claims. The lists and groups of examples provided in the description given above are not exhaustive unless explicitly stated otherwise.