DE102017121766A1 - Electric machine and method for operating an electrical machine - Google Patents

Abstract

Electric machine (100), comprising at least one stator with at least one excitation winding and at least one rotor with at least one armature winding, wherein the electrical machine (100) has at least one magnetoresistive sensor (104, 108) and the at least one magnetoresistive sensor (104, 108 ) is arranged on the at least one field winding to detect a magnetic field of the at least one field winding, and method for operating such an electrical machine (100), wherein by means of the at least one magnetoresistive sensor (104, 108), a magnetic field and / or a magnetic field course the at least one field winding is detected and, taking into account the detected magnetic field and / or magnetic field profile, a state of the electrical machine (100) is checked.

Description

The invention relates to an electrical machine comprising at least one stator having at least one field winding and at least one rotor having at least one armature winding. Moreover, the invention relates to a method for operating such an electric machine.

From the document EP 3 068 039 A1 a method is known for protecting electric motors against critical operating conditions, wherein a motor current value and / or a motor voltage value is measured and compared with an allowable operating range during operation of the electric motor, wherein an output signal is generated when leaving the permissible operating range, wherein the permissible operating range is determined during operation of the electric motor from the measured motor current value and / or the measured motor voltage value and adjusted continuously.

From the document DE 10 2014 218 381 A1 a method is known for measuring the temperature of a arranged on a rotor of an electric machine permanent magnet, wherein a dependent of the temperature of the permanent magnet magnetic property of the permanent magnet detected and from the temperature of the permanent magnet is determined.

The invention has for its object to improve an electrical machine mentioned above structurally and / or functionally. In addition, the invention has for its object to improve a method mentioned above.

The object underlying the invention is achieved with an electric machine having the features of claim 1. In addition, the object underlying the invention is achieved with a method having the features of claim 4. Advantageous embodiments and further developments are the subject of the dependent claims.

The electric machine may be a rotary machine. The electric machine may be a linear machine. The electric machine can be operated as a motor. The electric machine may be for use in a traction drive. The electric machine can be operated as a generator. The electric machine may be for use in an actuator. The electric machine can be a DC machine. The electric machine may be an electrically excited DC machine. The electric machine can be a series machine. The electric machine may be a shunt machine. The electric machine may be a compound machine. The electric machine can be a foreign-excited machine. The electric machine can be a three-phase machine. The electric machine may be a three-phase three-phase machine. The electric machine can be used for space travel.

The electric machine may have a housing. The at least one stator may be arranged housing solid. The stator may have a stator core. The electric machine may have a shaft. The at least one rotor can be arranged wave-firm. The rotor may have an armature core.

The at least one magnetoresistive sensor can serve to detect a change in the magnetic field of the at least one field winding. The at least one magnetoresistive sensor may have an electrical resistance which correlates with the magnetic field of the at least one field winding. The at least one magnetoresistive sensor may have an electrical resistance that is proportional to the magnetic field of the at least one field winding. The at least one magnetoresistive sensor can output an electrical voltage that correlates with the magnetic field of the at least one field winding. The at least one magnetoresistive sensor can output an electrical voltage that is proportional to the magnetic field of the at least one field winding. The at least one magnetoresistive sensor can use a magnetoresistive effect. The at least one magnetoresistive sensor can use a GMR effect (giant magnetoresistance). The at least one magnetoresistive sensor can use an anisotropic magnetoresistive effect, in short AMR effect. The at least one magnetoresistive sensor may use a tunneling magnetoresistance (TMR) or TMR effect.

The at least one magnetoresistive sensor may be a miniature sensor. The at least one magnetoresistive sensor can be arranged directly on the at least one field winding. The at least one magnetoresistive sensor can be arranged within the at least one field winding. The at least one magnetoresistive sensor may be arranged between the at least one field winding and the stator core. The at least one magnetoresistive sensor may be arranged in the stator core.

The electric machine may have a housing. The electric machine may have a shaft. The shaft and the housing may be rotatably mounted to each other. The electric machine may be an internal rotor machine. The at least one stator can be fixed to the housing and the at least one rotor can be arranged in a wave-proof manner. The electric machine may be an external rotor machine. The at least one stator can be shaft-mounted and the at least one rotor can be arranged fixed to the housing. The electric machine may have at least one inverter. The electric machine may include an electronic control device. The electronic control device may include an analog-to-digital converter, a processor, a field programmable gate array (FPGA), a system supervisor, a passive electronics, a metal-oxide-semiconductor field-effect transistor, MOSFET) and / or freewheeling diodes.

The electric machine may include a first part machine and a second part machine. The first sub-machine may have a first stator with at least one first excitation winding and at least one first rotor with at least one first armature winding. The first sub-machine may have at least one first magnetoresistive sensor arranged on the at least one first field winding for detecting a magnetic field of the at least one first field winding. The second sub-machine may have a second stator with at least one second exciter winding and at least one second rotor with at least one second armature winding. The second sub-machine may have at least one second magnetoresistive sensor arranged on the at least one second field winding for detecting a magnetic field of the at least one second field winding.

The first stator may include a first stator core and the second stator may include a second stator core. The first stator core and the second stator core may be structurally separate from each other. The first stator core and the second stator core can be structurally combined.

A first magnetoresistive sensor and a second magnetoresistive sensor for detecting a magnetic field of the at least one field winding may be arranged on the at least one field winding. A first magnetoresistive sensor and a second magnetoresistive sensor for detecting a magnetic field of the at least one first exciter winding and / or the at least one second exciter winding may each be arranged on the at least one first exciter winding and / or the at least one second exciter winding.

An electrical resistance and / or resistance characteristic of the at least one magnetoresistive sensor can be proportional to a magnetic field applied to the at least one field winding and / or a magnetic field profile.

The condition check of the electric machine may aim to detect anomalies. The detected magnetic field and / or the detected magnetic field profile can be compared with a desired magnetic field and / or a desired magnetic field profile. If a predefined maximum permissible deviation is exceeded, an electrical signal can be output. The maximum permissible deviation can be adjustable. When the signal is present, the electric machine can be switched off and / or a warning signal can be output.

The first part machine can be operated regularly. The second sub-machine can be operated redundantly. A regular operation of the electric machine can be done using only the first part machine while the second part machine is not operated. If the first submachine can not be operated, then irregular operation of the electric machine can be performed by the second submachine.

During operation of the first part machine, the second part machine can be decoupled. The at least one second armature winding can be decoupled. The at least one second excitation winding can be decoupled. The second sub-machine, in particular the at least one second armature winding and / or the at least one second field winding, can be decoupled from the electronic control device. The second sub-machine, in particular the at least one second armature winding and / or the at least one second field winding, can be electrically decoupled.

During operation of the first sub-machine, a magnetic field and / or magnetic field profile of the at least one first field winding can be detected by means of the at least one first magnetoresistive sensor. During operation of the first sub-machine, a magnetic field and / or magnetic field profile of the at least one second exciter winding can be detected by means of the at least one second magnetoresistive sensor.

At the at least one field winding, a magnetic field and / or magnetic field profile of the at least one field winding can be detected by means of a first magnetoresistive sensor and / or a second magnetoresistive sensor. At the at least one first exciter winding and / or the at least one second exciter winding, a magnetic field and / or magnetic field profile of the at least one first exciter winding and / or the at least one second exciter winding can each be detected by means of a first magnetoresistive sensor and / or a second magnetoresistive sensor.

The first magnetoresistive sensor can be operated regularly. The second magnetoresistive sensor can be operated redundantly. In a regular operation, a magnetic field and / or magnetic field profile can be detected using only the first magnetoresistive sensor, while the second magnetoresistive sensor is not used for detecting a magnetic field and / or magnetic field profile. If a magnetic field and / or magnetic field profile can not be detected with the aid of the first magnetoresistive sensor, in an irregular operation a magnetic field and / or magnetic field profile can be detected with the aid of the second magnetoresistive sensor. A magnetic field and / or magnetic field profile can be detected with the aid of both the first magnetoresistive sensor and the second magnetoresistive sensor. The second magnetoresistive sensor can be used to improve or to plausibilize a signal and / or a signal course of the first magnetoresistive sensor.

In summary and in other words, the invention thus provides inter alia a magnetoresistive motor protection. A magnetic field sensor can be used which measures a magnetic field in all excitation windings of an engine directly on site and can immediately point out anomalies. Suitable magnetic field sensors operate, for example, on the basis of the so-called xMR effects. These include in particular the AMR (anisotropic magnetoresistive) effect, the GMR (giant magnetoresistive) effect and the TMR (tunnel magnetoresistive) effect. An analog voltage output from the sensors is proportional to an applied magnetic field and to the magnetic field direction, and may be supplied to a system, FPGA, system supervisor via analog-to-digital converters present in a system. By installing the sensors in the motor excitation winding and error cases can be covered, which are not covered by a motor current monitoring.

The engine can be redundant. The redundant motor can be particularly suitable for use in space travel. The motor protection can be used with a redundant motor. The redundant motor may be implemented as a "cold redundant" system in which the primary side is active and the second - redundant - side is not active to conserve the components. The redundant motor comprises two independent motors mounted side by side on one axle. The active motor must therefore drive the passive-redundant - motor with. In order for this second motor does not become an eddy current brake, the leads (phase A, phase B and phase C) are separated by a passive electronics, otherwise flows through the internally in the MOSFET freewheeling diodes, a current flowing through the magnetic field Conductor (= motor 2 ) is induced. This induction would generate a braking torque in the redundant motor that counteracts the desired rotation of the active motor and this may even be overloaded. Using a simple magnetic field analysis, it can be shown that the passive redundant side is still intact without having to be powered. Due to their small size, the magnetic field sensors can also be installed redundantly, although they can also be connected crosswise by the principle-based galvanic insulation: Sensor A nominal winding at evaluation nominal and sensor B nominal winding at evaluation redundant. Of course, also in reverse order for the redundant winding. Another application of inductive motor protection is the load analysis of the powered motor. The generated magnetic field is proportional to the current in the field winding. Thus it can be analyzed by means of a simple summation of the measured values in which load state the motor is currently located.

With the invention, a protection of the electrical machine is simplified. An expense, such as construction costs, costs and / or operating costs overhead time, especially in a real-time analysis, is reduced. A current measurement can be omitted. A temperature monitoring can be omitted. A protection of the electrical machine can also be done with decoupled winding. Reliability is increased.

By "may" in particular optional features of the invention are referred to. Accordingly, there is an embodiment of the invention each having the respective feature or features.

The description may provide further features and advantages. Concrete features of these embodiments may represent general features of the invention. Features associated with other features of these embodiments may also constitute individual features of the invention.

Hereinafter, embodiments of the invention will be described with reference to a figure.

1 shows schematically and by way of example an electrical machine with two magnetoresistive sensors for detecting a magnetic field of a field winding.

According to a first embodiment has an operable as a motor electric machine 100 a housing 102 , one in the case 102 swiveling mounted shaft, a stator fixed to the stator with a stator core and a field winding, a shaft-fixed rotor with an armature core and armature windings, arranged on the field winding magnetoresistive sensor 104 to detect a magnetic field of the at least one field winding, and an electronic control device 106 on.

The magnetoresistive sensor 104 uses a magnetoresistive effect, such as GMR effect, AMR effect or TMR effect and serves to detect a magnetic field and / or a magnetic field change of the exciter winding. The magnetoresistive sensor 104 has an electrical resistance and / or resistance characteristic which is proportional to a magnetic field applied to the excitation winding and / or a magnetic field profile.

Using the magnetoresistive sensor 104 a magnetic field and / or magnetic field profile of the exciter winding is detected and, taking into account the detected magnetic field and / or magnetic field profile, a state of the electrical machine is checked. The condition check of the electric machine 100 aims to detect anomalies.

For this purpose, a voltage and / or a voltage curve of the magnetoresistive sensor 104 supplied via an analog-to-digital converter, for example, a processor, an FPGA or a system supervisor.

The detected magnetic field and / or the detected magnetic field profile is compared with a desired magnetic field and / or a desired magnetic field profile. When a predetermined maximum permissible deviation is exceeded, an electrical signal will be output, in the presence of which the electric machine 100 is switched off to the electric machine 100 to protect.

The electric machine 100 can also be arranged on the exciter winding magnetoresistive sensors 104 . 108 exhibit. A magnetic field and / or magnetic field course magnetic field and / or magnetic field course of the exciter winding can optionally by means of one of the magnetoresistive sensors 104 . 108 be recorded. The magnetoresistive sensors 104 . 108 can be used redundantly. The magnetoresistive sensors 104 . 108 can be used cold redundant or hot redundant.

According to a further embodiment, the electric machine 100 a first sub-machine on a second sub-machine. The electric machine 100 has a common housing for the first part machine and the second part machine 102 and a common wave.

The first sub-machine has a stator with a stator core and a field winding, a rotor with an armature core and armature windings, a magnetoresistive sensor arranged on the field winding 104 on.

The second sub-machine in turn has a stator with a stator core and a field winding, a rotor with an armature core and armature windings, a magnetoresistive sensor arranged on the field winding 108 on.

The stator of the first sub-machine and the stator of the second sub-machine are fixed to the common housing 102 the electric machine 100 arranged. The rotor of the first part machine and the rotor of the second part machine are fixed to the common shaft of the electric machine 100 arranged.

The submachines are used cold redundantly. In a regular operation of the electric machine 100 If only the first part machine is used, the second part machine is then decoupled from a passive electronics, in order to avoid that the second part machine acts as a brake. If the first part machine is not available, may cause irregular operation of the electric machine 100 done using the second sub-machine.

Using the magnetoresistive sensors 104 . 108 a state of the sub-machines can be checked regardless of whether the sub-machine for operation of the electric machine 100 is used or decoupled, as for an electrical application of an excitation coil is not required.

The electric machine 100 it is also possible to use two magnetoresistive sensors arranged on the excitation winding of the first sub-machine and / or two on the exciter winding of the second sub-machine 104 . 108 exhibit. A magnetic field and / or magnetic field course Magnetic field and / or magnetic field course of the exciter windings can be selected by means of one of the magnetoresistive sensors 104 . 108 be recorded. The magnetoresistive sensors 104 . 108 can be used redundantly. The magnetoresistive sensors 104 . 108 can be used cold redundant or hot redundant.

Incidentally, reference is additionally made in particular to the description of the first embodiment.

LIST OF REFERENCE NUMBERS

100

electric machine

102

casing

104

magnetoresistive sensor

106

electronic control device

108

magnetoresistive sensor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 3068039 A1 [0002]
• DE 102014218381 A1 [0003]

Claims (11)

Electric machine (100), comprising at least one stator with at least one excitation winding and at least one rotor with at least one armature winding, characterized in that the electrical machine (100) has at least one magnetoresistive sensor (104, 108) and the at least one magnetoresistive sensor (100). 104, 108) is arranged on the at least one field winding in order to detect a magnetic field of the at least one field winding. Electric machine (100) after Claim 1 , characterized in that the electrical machine (100) comprises a first sub-machine having a first stator with at least one first field winding, at least one first rotor with at least one first armature winding and at least one arranged on the at least one first field winding first magnetoresistive sensor (104) Detecting a magnetic field of the at least one first excitation winding and a second sub-machine having a second stator with at least one second excitation winding, at least one second rotor with at least one second armature winding and at least one arranged on the at least one second excitation winding second magnetoresistive sensor (108) for detecting a Having magnetic field of at least one second excitation winding. Electric machine (100) according to at least one of the preceding claims, characterized in that on the at least one field winding, a first magnetoresistive sensor (104) and a second magnetoresistive sensor (108) for detecting a magnetic field of the at least one field winding or at least a first A first magnetoresistive sensor (104) and a second magnetoresistive sensor (108) are arranged for detecting a magnetic field of the at least one first exciter winding and / or the at least one second exciter winding. Method for operating an electrical machine (100) according to at least one of the preceding claims, characterized in that by means of the at least one magnetoresistive sensor (104, 108) a magnetic field and / or a magnetic field profile of the at least one field winding detected and taking into account the detected magnetic field and / or magnetic field course, a state of the electrical machine (100) is checked. Method according to Claim 4 , characterized in that the detected magnetic field and / or the detected magnetic field profile compared with a desired magnetic field and / or a desired magnetic field profile and when a predetermined maximum allowable deviation is exceeded, an electrical signal is output. Method according to Claim 5 , characterized in that in the presence of the signal, the electrical machine is switched off and / or a warning signal is output. Method for operating an electrical machine according to Claim 2 , characterized in that the first part machine is operated in a regular manner and the second part machine is operated redundantly. Method according to Claim 7 , characterized in that when operating the first part of the machine, the at least one second part machine is decoupled. Method according to at least one of Claims 7 to 8th , characterized in that during operation of the first part of the machine using the at least one first magnetoresistive sensor (104), a magnetic field and / or magnetic field course of the at least one first excitation winding and / or by means of at least one second magnetoresistive sensor (108), a magnetic field and / or Magnetic field profile of the at least one second excitation winding is detected. Method for operating an electrical machine (100) according to Claim 3 , characterized in that on the at least one field winding, a magnetic field and / or magnetic field of the at least one field winding using a first magnetoresistive sensor (104) and / or a second magnetoresistive sensor (108) or at least a first field winding and / or at least a second excitation winding, a magnetic field and / or magnetic field profile of the at least one first exciter winding and / or the at least one second exciter winding is respectively detected by means of a first magnetoresistive sensor (104) and / or a second magnetoresistive sensor (108). Method according to Claim 10 , characterized in that the first magnetoresistive sensor (104) is operated regularly and the second magnetoresistive sensor (108) is operated redundantly.

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