Diehl Ako Stiftung & Co. Kg

Stefan Zeh

Martin Weinmann

Nicola-Valeriu Olarescu

Alexander Müller

Rainer Frisch

Valeriu Olarescu

Hartmut Wauer

Radu Liviu Florea

Martin Rieser

Artur Schütz

Simon Bihler

A method controls a three-phase converter with a voltage intermediate circuit by pulse-width modulation for supplying a polyphase system, in particular a three-phase machine. The converter is operated with at least two different modulation methods which are selected from among the group of modulation methods which includes single-phase switching, two-phase switching and three-phase switching, and for changeovers to be made between the at least two different modulation methods depending on the operating state of the polyphase system.

Method for controlling a converter

A method is specified for fault identification when operating a rotating-field motor by means of a pulse-controlled inverter, wherein electromagnetic state variables of the rotating-field motor are determined by means of a mathematical model in space-vector form, and wherein the pulse-controlled inverter is operated electronically using space-vector variables. In this case, the invention provides that, during the operation of the rotating-field motor, the space vector of an uncontrolled state variable of the rotating-field motor is formed, in that the space vector that is formed is analyzed for a spectral component at twice the frequency of the rotating field, and in that, if the spectral component at twice the frequency is present, a partial turns short is deduced in the stator windings.

Method of error detection when controlling a rotating-field motor

A method for operating an electric motor with at least two motor terminals that are driven by a control device contains the steps of short-circuiting of at least two of the motor terminals of the electric motor by the control device; measurement of the motor phase currents at the short-circuited motor terminals; and identification of a standstill of the electric motor if a magnitude and/or a frequency of the motor phase currents measured lies below a predefined limit value. In the case of such a reliable identification of the standstill of the electric motor, an enable signal can then advantageously be generated in order, by way of example, to enable access to an apparatus driven by the electric motor.

Method for operating an electric motor and apparatus for performing the method

Electronic motor regulation for a pump with a multi-phase permanent-magnet synchronous motor (PMSM). The system is enabled to detect and estimate a rotor phase position and rotary speed. Foam or air operation is detected by way of fluctuations in the estimated rotary speed.

Method and device for regulating a pump

A method is specified for controlling a polyphase brushless electric motor, wherein the motor phase currents which are associated with the phases are produced by clocked variation of the respectively applied electrical potential. In this case, the motor phase currents flow back from the electric motor via a common return line with the peak current value in the return line being detected and being included in a controlled variable. Furthermore, a circuit configuration is specified, which is provided in a corresponding manner in order to carry out the control method. The control method and the circuit configuration allow the motor phase currents to be taken into account in the control of the electric motor in a simple and cost-effective manner.

Method and circuit configuration for controlling a polyphase brushless electric motor

A method is specified for controlling a multiphase motor that is commutated by an inverter-side bridge circuit, in the course of which a particularly precise and technically simple detection of a control-relevant variable of a considered motor phase, in particular of a motor phase current and/or a back EMF voltage and/or a variable derived therefrom, takes place. It is provided here to determine the control-relevant variable with the aid of the current state of a freewheeling diode that is disposed in a phase half bridge, assigned to the respective motor phase, of the bridge circuit, the current state being detected during an on time in which a power switch, connected in parallel with the freewheeling diode, of the phase half bridge exhibits a conducting state, and a power switch connected in series with the freewheeling diode exhibits a blocking state.

Method and device for controlling a multiphase electronically commutated motor

Before a washing machine is switched over to a very high spin speed in the spin program of the washing machine, the existing imbalance due to irregular distribution of laundry in the drum should be checked. If the imbalance is too strong, the spin program should be interrupted if there is a threat of excessively high bearing forces to be expected. The fluctuation in rotary speed, which may have a high frequency due to the drum speed, and of the power consumption of the washing machine motor measured downstream of the direct current intermediate circuit prior to the feed thereof into the inverter for producing the rotary field in the motor. There, the vector product of the current and the voltage for imbalance measurement by determining power is blocked off from mains network interference effects by the high capacitance of the direct current intermediate circuit.

Method of determining the imbalance of a laundry drum

In order to accelerate an asynchronous motor with a squirrel-cage rotor even under load extremely quickly, and in particular within the time of an electromagnetic rotor time constant, in order to be able to cause it to start with a so-called kick start, while the rotor is not moving, quasi-stationary magnetic conditions are initially produced, like at the start of a synchronous motor with a permanent-magnetic rotor. For that purpose there is briefly produced a high-frequency rotor induction current which occurs electrically and spatially in a quasi-stationary condition when thereupon still within the rotor time constant, a strong unmoving stator magnetic field is produced, with a stator current vector which is displaced through about 90&deg; for an optimum starting torque in relation to the rotor current vector, whereupon the stator rotary field starts with increasing amplitude and frequency.

Method of rapidly starting an asynchronous motor

An inverter-fed three-phase electrical motor ( ) for a household appliance is grounded through a protective conductor ( ), with the motor being particularly provided for the direct drive of washing machines. The motor includes a pick-up for high-frequency currents originating from an actuation of the inverter ( ) and conducts the currents to one pole of a D.C. voltage supply ( ) for the inverter ( ) through an ohmic or capacitive shunt path ( - ), with the shunt path leading from a stator ( ) of the motor which is installed electrically insulated into the household appliance and is not connected to the protective conductor ( ).

Inverter-fed three-phase motor for household appliance, especially for the direct drive of washing machines

Described is a method of determining the rotary position of the rotor of a synchronous motor, in relation to the rotating magnetic stator field. The instantaneous rotor position is ascertained by measurement of the emf (E.s) induced in at least one stator winding by the rotor in a current gap in the stator current (I.s) flowing through said stator winding, wherein in accordance with the invention when using a sinusoidal or quasi-sinusoidal stator current an artificial current gap in the stator current is produced. In that case the induced emf (E.s) is directly derived from the tapped-off terminal potential (U.s) of the respective stator winding.

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Wangen, Germany

Stefan Zeh