Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
  • H02P6/14—Electronic commutators
  • H02P6/16—Circuit arrangements for detecting position
  • H02P6/18—Circuit arrangements for detecting position without separate position detecting elements
  • H02P6/185—Circuit arrangements for detecting position without separate position detecting elements using inductance sensing, e.g. pulse excitation
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
  • G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
  • H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
  • H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
  • H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
  • H02P6/14—Electronic commutators
  • H02P6/16—Circuit arrangements for detecting position
  • H02P6/18—Circuit arrangements for detecting position without separate position detecting elements
  • H02P6/187—Circuit arrangements for detecting position without separate position detecting elements using the star point voltage

Definitions

• the invention relates to a method for determining the rotational angular position of the rotor of a polyphase electrical machine with pole windings, the inductances in the currentless state, at least within rotational angle periods in clear relation to the rotational angular position of the rotor, wherein for determining the rotational angular position at a measuring point between
• Hall probes The measurement of voltage signals and their evaluation takes place within periods in which changes in the rotational position of the rotor are negligible.
• a new method of the type mentioned is provided, which is characterized in that for determining the rotational position each measurement signals are tapped at several, each one and the same phase strand measuring points. According to the invention, these measuring points allow the determination of a measuring signal which depends only on inductances of this one phase strand. Advantageously, it is thus possible to select a particularly suitable phase strand for determining the position of the rotor.
• the rotational angular position of the rotor For the determination of the rotational angular position of the rotor, it is expedient to respectively select that phase strand in which the lowest instantaneous operating current flows.
• this can reduce falsifying influences of operating currents on the inductances of the pole windings and more accurately determine the rotational angular position on the basis of a predetermined relationship between the inductances of the pole windings influenced by the rotor field and the rotational angular position.
• the measuring signal used is preferably a voltage signal divided according to the inductances of the pole windings of the electric machine and generated by dividing the voltage jump, and in particular a potential jump corresponding to the voltage jump at the respective measuring point.
• Voltages at the measuring points e.g. Induced voltages or over ohmic resistors falling voltages, advantageously eliminate.
• a signal which is independent of the inductances of the other phase strands is preferably formed.
• a quotient of measuring signals determined at different measuring points is formed to form the independent signal.
• the several measuring points suitably include the star point as a measuring point.
• the voltage jump is preferably a potential edge of an operating voltage pulse applied to the electric machine, in particular a PWM pulse, or a separate measuring voltage pulse, which only negligibly influences the operation of the electrical machine.
• the electric machine may be a multi-pole machine comprising, for example, twelve pole windings and magnet pairs for the formation of five magnetic periods.
• the measuring points which concern one and the same phase strand can be those which are tapped by a measuring winding, wherein a corresponding measuring signal jump is induced in the measuring winding by the voltage jump.
• FIG. 1 is a schematic representation of an electrical machine whose rotor position can be determined by the method according to the invention
• FIG. 2 is a schematic representation of the star-connected phase strands of the electric machine of Fig. 1,
• Fig. 3 is an explanatory diagram of the process according to the invention.
• Fig. 4 is a further schematic representation of an electrical machine with a
• FIG. 1 shows an electric machine with a stator 1 and a rotor 2, in the present case an external rotor.
• the stator 2 has six stator poles 3 in the example shown. Connected in series pole windings 4 adjacent stator poles 3 each form one of three current phase strands R, S, T, which are brought together at a neutral point 5.
• the pole windings each have an iron core 6.
• Fig. 2 shows separately the phase strands R, S, T with the pole windings 4 of the electric machine.
• a tapping point 7, 7 'or 7 "for a measuring voltage signal is provided in each case between the two pole windings of each phase strand
• a further tapping point 8 for a measuring voltage signal is located at the star point ⁇ 5.
• the iron cores 6 of the pole windings 4 of the electric machine are magnetized differently by the magnetic field of the rotor 2, wherein different degrees of saturation of the core material to different inductances of the
• each pole winding depends on the rotational angular position of the rotor 2. Within two rotation angle ranges of each 180 ° between the rotational position of the rotor and the inductance of the pole windings 4 each have a clear functional relationship.
• Fig. 1 could be a larger number of magnetic periods forming magnetic pairs and a larger number of stator poles 3 or
• Decisive for the jump height is the respective voltage divider ratio at the tapping points.
• the voltage divider ratio for the resulting potential jump at the points of application depends only on the instantaneous inductivities of the pole windings 4.
• the inductances are in turn dependent on the rotational position of the rotor 2.
• the magnetic field of the rotor changes the degree of saturation of the magnetization of the iron cores 6 and thus the inductance of the pole windings 4.
• FIG. 3 shows a circuit state in which a battery voltage UB is applied to the current phase line R.
• the other two current phase strands S, T are grounded (potential zero point).
• the difference UB - ai behaves to the battery voltage UB as the instantaneous inductance Li of the pole winding 4 'of the phase strand R to the sum of the current Inductance LR of the Phasenstra R and R of the instantaneous inductance LS, T of the parallel connection of the Phasensträ lengths S and T:
• the quotient signal a hangs within each half magnetic period of the rotor field, i. in the case described within two rotational angle ranges of 180 °, clearly from the angle of rotation of the rotor and can therefore be a measure of the rotor rotation angle.
• the determination of the quotient signal a permits a determination of the position of the rotor largely undisturbed by operating currents of the electrical machine on the basis of a predetermined functional combination between the rotor position and the quotient signal a by selecting that phase phase R, S, T in each case in which the lowest instantaneous operating current flows.
• phase phase R, S, T essentially only the magnetic field (6) of the rotor is essentially transmitting, and the degree of saturation of the iron cores which determines the inductances is only slightly influenced by the operating currents.
• a voltage jump across a pole winding 4 the magnitude of which depends on the respective inductance of the pole winding, as a result of a jump in the voltage across a phase winding, could also be tapped off by a measuring winding 9 shown in FIG.
• the voltage jump at the pole winding 4 transmits tra nsformatorisch on the measuring winding 9.
• Such a measuring windings 9 could at least one pole winding of each phase strand
• a measuring point for tapping a spawning signal could, unlike the embodiments described above, also be provided on a phase winding with a single winding, the measuring point subdividing the single winding into partial windings. Due to the spatially different arrangement of the partial windings, the ratio of the inductances of the partial windings depends on the rotational position of the rotor.
• measuring points including measuring windings could be interconnected via resistor networks.
• the signal conditioning described above could, if necessary, be carried out digitally within the electrical machine, the processed signals being fed to a power output stage arranged externally of the electric machine.
• a highly integrated circuit / evaluation unit is considered, which picks up signals at the measuring points, possibly via a measuring winding, directly inside the motor.
• the evaluation unit could be designed to co-operate with power stages a, as they are conventionally used for the reception of signals from external position encoders, eg resolvers, a.
• the detection and evaluation of the signals can be optimized by appropriate wiring of the windings.
• windings belonging to the same rotor position can be connected in series in order to increase the signal level.
• Signal conditioning can, for example, be an orthogonalization of the signals, in that sums and differences are formed. For scaling required for this, number of turns can be suitably selected.
• the preferable selection of the strand with the lowest operating current may be less advantageous depending on the design of the electric machine, e.g. on machines with strong magnets because of the high saturation the measuring sensitivity decreases.
• a different selection option can be used here, wherein possibly the approximately simultaneous evaluation of several phase strands is considered.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=61226351

Family Applications (1)

Country Status (5)

Families Citing this family (1)

Family Cites Families (13)

• 2017
  • 2017-01-12 DE DE102017100515.3A patent/DE102017100515A1/de not_active Withdrawn
• 2018
  • 2018-01-09 EP EP18705311.1A patent/EP3568910A1/de not_active Withdrawn
  • 2018-01-09 US US16/477,442 patent/US20190386591A1/en not_active Abandoned
  • 2018-01-09 WO PCT/DE2018/100009 patent/WO2018130244A1/de unknown
  • 2018-01-09 CN CN201880006396.7A patent/CN110402537A/zh active Pending

Also Published As

Similar Documents

Legal Events