Abstract: A method for starting and stopping an asynchronous motor by way of a soft starter. The method includes the following steps: determining ignition options of one or more thyristors of the soft starter that are possible at a future calculation time; predicting the motor behavior for the determined ignition options, if an ignition of one or more thyristors of the soft starter is carried out; based on the predicted motor behavior, deciding whether an ignition option is to be selected and which is to be selected; and generating one or more ignition signals for one or more thyristors, if the decision for an ignition option has been made.

Abstract: A battery state estimating apparatus as an embodiment includes a state estimator, a power estimator, and a determiner. The state estimator estimates a state of a battery. The power estimator estimates first power amount charged/discharged by the battery within a charging/discharging period, based on the state. The determiner compares the first power amount with second power amount inputted/outputted to/from the battery within the charging/discharging period and thereby determines validity of the state.

Abstract: A method is for operating a three-phase cage motor on a multiphase electrical grid via a soft starter, with which one or more grid phases of the grid being respectively switchable by firing thyristors. Apart from a grid-related firing criterion, a rotor-flux-related firing criterion is taken into account.

Abstract: A method is for a network synchronization of a permanently excited three-phase machine including a soft starter, including thyristors, and mechanical bypass contacts for bridging the thyristors in the network operation. The method includes generating a first control signal, to initiate switching the mechanical bypass contacts to become conductive, after a criterion is reached while running up the three-phase machine on the soft starter, a time at which the first control signal is generated representing actuation time of the bypass contacts; generating ignition pulses for the thyristors within a time period, running from the actuation time to a contact time of the bypass contacts, using a second control signal; and operating the three-phase machine in the network operation via the bypass contacts. Each ignition pulse for a thyristor is generated when a phase current measurement indicates that the current strength in the assigned phase has fallen below a threshold value.

Abstract: A method is for operating a three-phase cage motor on a multiphase electrical grid via a soft starter, with which one or more grid phases of the grid being respectively switchable by firing thyristors. Apart from a grid-related firing criterion, a rotor-flux-related firing criterion is taken into account.

Abstract: A battery state estimating apparatus as an embodiment includes a state estimator, a power estimator, and a determiner. The state estimator estimates a state of a battery. The power estimator estimates first power amount charged/discharged by the battery within a charging/discharging period, based on the state. The determiner compares the first power amount with second power amount inputted/outputted to/from the battery within the charging/discharging period and thereby determines validity of the state.

Abstract: A method is for a network synchronization of a permanently excited three-phase machine including a soft starter, including thyristors, and mechanical bypass contacts for bridging the thyristors in the network operation. The method includes generating a first control signal, to initiate switching the mechanical bypass contacts to become conductive, after a criterion is reached while running up the three-phase machine on the soft starter, a time at which the first control signal is generated representing actuation time of the bypass contacts; generating ignition pulses for the thyristors within a time period, running from the actuation time to a contact time of the bypass contacts, using a second control signal; and operating the three-phase machine in the network operation via the bypass contacts. Each ignition pulse for a thyristor is generated when a phase current measurement indicates that the current strength in the assigned phase has fallen below a threshold value.

Abstract: An electric motor connected to a switching device is braked from an active operating state by actuating a semiconductor switch arranged in parallel with an electromechanical switch to reduce a current intensity in the electromechanical switch, opening the electromechanical switch, blocking the semiconductor switch for an adjustable period, determining a resulting torque of the electric motor, and determining an actuation time for braking the electric motor based on the resulting torque and actuating the semiconductor switch at the actuation time. The resulting torque is opposite a present direction of rotation of the electric motor at the actuation time. The semiconductor switch is turned on for an adjustable actuation period. Also disclosed are a computer program product and a soft starter configured to implement the described method.

Abstract: An embodiment relates to a method for operating a three-phase machine including a rotor and a stator connected to a three-phase network. The stator is connected to the three-phase network via a first semiconductor circuit arrangement for forming a first rotational field rotating in a first direction of rotation in the stator and via a second semiconductor circuit arrangement for forming a second rotational field rotating in a direction of rotation opposite to the first direction of rotation in the stator. The three-phase machine further includes a controller. The method includes controlling, via the controller, semiconductors of the first and second semiconductor circuit arrangement to accelerate the rotor by current pulses of both the first rotational field and second rotational field in the first direction of rotation.

Abstract: In order to achieve the energy efficiency class IE4 defined in IEC standard 60034, it is necessary to operate permanent-magnet synchronous machines directly from the supply system. Since this is not readily possible, soft-starting devices come into consideration as cost-effective solutions. The problem of transmitter-free running up can be split into two component problems: determining the initial rotor angle and running up the machine. The present invention describes a (rotary) transmitter-free starting method with which the motor can be started using a soft-starting device.

Abstract: In order to achieve the energy efficiency class IE4 defined in the IEC standard 60034, it is necessary to operate permanently excited synchronous machines directly on the mains. Because this is not readily possible, soft start devices may be considered as cost-efficient solutions. A method is described by which the initial rotor angle is defined, which can then be used by an encoderless start process. The fundamental concept is based on energizing in a defined direction. This is achieved in that solely two actuator phases are fired. A current space vector is thereby applied to the machine in a fixed direction and the machine is then aligned thereto. The successful alignment and a blocked motor can thus be recognized based on the profile of the stator current space vector.

Abstract: An electric motor connected to a switching device is braked from an active operating state by actuating a semiconductor switch arranged in parallel with an electromechanical switch to reduce a current intensity in the electromechanical switch, opening the electromechanical switch, blocking the semiconductor switch for an adjustable period, determining a resulting torque of the electric motor, and determining an actuation time for braking the electric motor based on the resulting torque and actuating the semiconductor switch at the actuation time. The resulting torque is opposite a present direction of rotation of the electric motor at the actuation time. The semiconductor switch is turned on for an adjustable actuation period. Also disclosed are a computer program product and a soft starter configured to implement the described method.

Abstract: An embodiment relates to a method for operating a three-phase machine including a rotor and a stator connected to a three-phase network. The stator is connected to the three-phase network via a first semiconductor circuit arrangement for forming a first rotational field rotating in a first direction of rotation in the stator and via a second semiconductor circuit arrangement for forming a second rotational field rotating in a direction of rotation opposite to the first direction of rotation in the stator. The three-phase machine further includes a controller. The method includes controlling, via the controller, semiconductors of the first and second semiconductor circuit arrangement to accelerate the rotor by current pulses of both the first rotational field and second rotational field in the first direction of rotation.

Abstract: In order to achieve the energy efficiency class IE4 defined in the IEC standard 60034, it is necessary to operate permanently excited synchronous machines directly on the mains. Because this is not readily possible, soft start devices may be considered as cost-efficient solutions. A method is described by which the initial rotor angle is defined, which can then be used by an encoderless start process. The fundamental concept is based on energizing in a defined direction. This is achieved in that solely two actuator phases are fired. A current space vector is thereby applied to the machine in a fixed direction and the machine is then aligned thereto. The successful alignment and a blocked motor can thus be recognized based on the profile of the stator current space vector.

Abstract: In order to achieve the energy efficiency class IE4 defined in IEC standard 60034, it is necessary to operate permanent-magnet synchronous machines directly from the supply system. Since this is not readily possible, soft-starting devices come into consideration as cost-effective solutions. The problem of transmitter-free running up can be split into two component problems: determining the initial rotor angle and running up the machine. The present invention describes a (rotary) transmitter-free starting method with which the motor can be started using a soft-starting device.

Abstract: A method for determining an electrical torque of an electrical machine includes determining an electrical torque in a first speed range with a first algorithm, and determining the electrical torque in a second speed range with a second algorithm which differs from the first algorithm. An upper limit of the second speed range is slightly higher than a lower limit of the first speed range. An apparatus is provided to determine the electrical torque of the electrical machine with the aforedescribed method.

Abstract: A method for determining an electrical torque of an electrical machine includes determining an electrical torque in a first speed range with a first algorithm, and determining the electrical torque in a second speed range with a second algorithm which differs from the first algorithm. An upper limit of the second speed range is slightly higher than a lower limit of the first speed range. An apparatus is provided to determine the electrical torque of the electrical machine with the aforedescribed method.

Abstract: A method for the identification without shaft encoder of magnetomechanical characteristic quantities of a three-phase asynchronous comprising: —constant voltage impression U1? in ? axial direction in order to generate a constant magnetic flux; —test signal voltage supply U1? in ? axial direction of the asynchronous motor, whereby the ? axial direction remains supplied with constant current; —measuring signal current measurement I1? in ? stator axial direction of the asynchronous motor; —identification of mechanical characteristic quantities of the asynchronous motor based on the test signal voltage U1? and on the measuring signal current I1?, whereby the rotor can execute deflection movements. Method can also be used for control of electrical drives. An identification apparatus for the determination of mechanical characteristic quantities of an asynchronous motor and for motor control, whereby the identified characteristic quantities can be used to determine, optimize and monitor a motor control.

Abstract: Identification of electrical equivalent circuit parameters (15) of a three-phase asynchronous motor (09) without a shaft encoder. The method comprises—Assumption of a standstill position of the rotor (11);—Equidirectional test signal infeed U1?, U1? in ? and ? in the stator axis direction of the asynchronous motor (09);—Measuring of a measuring signal I1?, I1? of the ? and ? axial direction of the asynchronous motor (09); and—Identification of equivalent circuit parameters of the asynchronous motor (09) on the basis of the test signal voltages U1?, U1? and of the measuring signal currents I1?, I1?; whereby the test signal feed allows the rotor (11) to remain torque-free. Determination of equivalent circuit parameters (15) of an asynchronous motor (09) as well relates to a motor control device (35), whereby the identified equivalent circuit parameters (15) can be used for the determination, optimization and monitoring of a motor control and for control of electrical drives.

Abstract: A method for the identification without a shaft encoder of magnetomechanical characteristic quantities, in particular the mass moment of inertia J and the permanent magnetic flux ?PM between rotor and stator of a three-phase synchronous motor, comprising:—constant voltage supply U1d in the d flux axial direction;—test signal voltage supply U1q in the q transverse flux axial direction;—measuring signal current measuring I1q of the q transverse flux axial direction;—identification of magnetomechanical characteristic quantities of the synchronous motor on the basis of the test signal voltage U1q and of the measuring signal current I1q; whereby the rotor can execute deflection movements with pre-definable maximal amplitudes. Method use also for control of electrical drives.