Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
  • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
  • B60W40/10—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to vehicle motion
  • B60W40/109—Lateral acceleration
• • 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
  • H02P6/08—Arrangements for controlling the speed or torque of a single motor
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S388/00—Electricity: motor control systems
  • Y10S388/907—Specific control circuit element or device
  • Y10S388/912—Pulse or frequency counter

Definitions

• the invention relates to a method for determining the torque of an electrical, in particular permanently excited, electric machine according to the preamble of claim 1, and to a corresponding device according to the preamble of claim 5.
• Permanently excited synchronous machines used as an electric drive.
• Permanently excited synchronous machines comprise a rotor in which the magnets which generate the magnetic flux are arranged, as well as a stator with the stator windings.
• the electric machine generates a torque, which depends in particular on the phase current and the magnetic flux in the machine.
• the generated torque determines the acceleration or drivability of the vehicle and thus represents an important quantity to be determined.
• the torque of the electric machine is usually calculated by means of a mathematical model. Assuming that no reluctance torque occurs, applies to the torque M:
• An essential aspect of the invention is to measure a phase voltage and the speed of the electric machine and to calculate the torque therefrom.
• the term "rotational speed” should also be understood to mean a proportional variable, such as the angular frequency, which has the significant advantage that the torque M of the electric machine can be calculated more accurately and temperature influences in particular can be taken into account.
• the torque is preferably in accordance with the mathematical model:
• the phase voltage U i nd is preferably measured when the electric machine 1 is idling. In this state, all switches are one with the open circuit connected electrical machine and the phase voltages show a substantially sinusoidal course. The phase voltage can therefore be measured accurately. For the calculation of the moment M, preferably the peak value of the phase voltage Uind is used.
• the control unit preferably generates an output signal for driving a pulse-controlled inverter (PWR), with which, in particular, the power of the electrical machine can be changed.
• PWR pulse-controlled inverter
• FIG. 1 shows a schematic representation of a three-phase electrical machine 1 with a pulse inverter 2 connected thereto.
• the pulse inverter (PWR) 2 comprises circuit breakers 6a-6f which are connected to the individual phases U, V, W of the electrical machine 1 and the phases U , V, W either against a high supply potential
• the pulse inverter 2 further comprises a plurality of free-wheeling diodes 7a-7f, which are each arranged parallel to one of the switches 6a-6f.
• the PWR 2 determines the power and operating mode of the electric machine 1 and is controlled accordingly by a control unit 12.
• the electric machine 1 can thus be operated either in motor or generator mode.
• the pulse inverter 2 also comprises a so-called intermediate circuit capacitor 8, which essentially serves to stabilize a battery voltage.
• the electrical system of the vehicle with a battery 9 is connected in parallel to the DC link capacitor 8.
• the electric machine 1 is here designed in three phases and comprises a stator with three strings 3a-3c and a rotor with a plurality of permanent magnets 11.
• the ohmic resistances of the strings 3a-3c are represented by the elements 10a-10c.
• the electrical machine 1 produces a torque M, which depends in particular on the phase current Iu, Iv, Iw and the cross-current I q (Field Oriented Control) and the prevailing in the electrical machine 1 magnetic flux ⁇ .
• the current torque M of the electric machine is calculated by means of a mathematical model, which is stored in the control unit 12. This model or algorithm calculates the torque M by the following relationship:
• the magnetic flux ⁇ is determined by the law of induction, with
• the angular frequency ⁇ of the electric machine 1 is measured here by means of a speed sensor 5.
• the voltage Uind induced in the stator windings 3a-3c is shown schematically by voltage sources 4a-4c and can be measured by means of a simple voltage sensor.
• the voltage between two of the phases, eg U and V, or the voltage between one of the phases U, V, W and a reference potential can be measured as induced voltage Uind.
• This tension is at the idling of the electric machine 1 sinusoidal and is therefore preferably in this Condition measured. (At idle, all six power switches 6a-6f of the pulse-controlled inverter 2 are open.)
• the speed of the electric machine 1 should be sufficiently large in the measurement, but on the other hand, a maximum speed, from which the
• Free-wheeling diodes 7a - 7f act as rectifier bridge, do not exceed.
• the phase voltages U, V, W would otherwise be distorted and no longer sinusoidal.
• the voltage and speed signals Uind, n are supplied to the controller 12 at its input.
• the peak value is calculated from the voltage signal. This corresponds to the above-mentioned induced voltage Uind- stored in the control unit 12 algorithm processes these variables and determines therefrom the current torque M of the electric machine. 1
• the mathematical model for calculating the torque M may be either analytically or e.g. be deposited as a map in the control unit 12.
• the torque M can be determined in this way particularly accurate and easy.

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• 2006
  • 2006-02-09 DE DE102006005854A patent/DE102006005854A1/de not_active Withdrawn
• 2007
  • 2007-01-30 WO PCT/EP2007/050869 patent/WO2007090760A2/de active Application Filing
  • 2007-01-30 US US12/162,646 patent/US7688012B2/en not_active Expired - Fee Related
  • 2007-01-30 JP JP2008553718A patent/JP2009526512A/ja active Pending
  • 2007-01-30 EP EP07704222A patent/EP1985006A2/de not_active Withdrawn
  • 2007-01-30 CN CNA2007800048494A patent/CN101379690A/zh active Pending
  • 2007-01-30 KR KR1020087019528A patent/KR101056572B1/ko active IP Right Grant

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