Siemens Aktiengesellschaft

Siemens Aktiengesell Schaft

Hauke Nannen

Heiko Zatocil

Hubert Schierling

Thomas Beckert

Peter Koellensperger

Dieter Waegele

Wolfgang Feil

Tobias Andersch

A switching device is for coupling a DC voltage branch to a DC voltage bus. The switching device includes a series circuit including a first switching module and a second switching module. A first diode is connected in parallel with the first semiconductor switching element and a second diode is connected in parallel with the second semiconductor switching element. A third semiconductor switching element is connected in parallel with the series circuit. A control device is connected to the first and second semiconductor switching elements, to the bridging semiconductor switching element, to the voltage sensor and to the current sensor. The control device is configured to, upon a first threshold value of the voltage being undershot and current flowing in an exceptional case, switch the bridging semiconductor switching element to the conducting state in order to facilitate a current flow from the DC voltage branch to the DC voltage bus.

Switching device for a DC voltage circuit

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.

Method for starting and stopping an asynchronous motor

A circuit breaker device is for coupling a DC voltage branch to a positive and a negative conductor on a DC voltage bus. In an embodiment, the circuit breaker device includes a series circuit including a safety fuse and a unidirectional switch module. The switch module has a parallel circuit includes a controllable semiconductor switch element that is conductive in a first current direction and a diode that is conductive in the opposite current direction.

Circuit breaker device for DC voltage

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.

Method for controlling the speed of a three-phase permanent magnet machine having a soft starter by means of a controller cascade, and three-phase machine

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.

Method to operate a three-phase cage motor

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.

Method for a network synchronization of a permanently excited three-phase machine comprising a soft starter which comprises thyristors

A drive circuit for a power semiconductor circuit may include input contact means for inputting a control signal, the control signal representing a switching command for the power semiconductor circuit, and also at least one output contact means, to which the power semiconductor circuit is connectable and which serves for outputting a switching signal to the power semiconductor circuit. Furthermore, the drive circuit comprises current path connection means for connecting the drive circuit to a current path to be switched by the power semiconductor circuit, and means for galvanically isolating the input contact means from the output contact means and the current path connection means. Circuit means which output a switching signal that switches on the power semiconductor circuit if a control signal representing the switch-on command for the power semiconductor circuit is input at the input contact means and also voltage is present at the current path connection means.

Drive circuit for a power semiconductor circuit

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.

Braking method for an electric motor

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.

Method for operating a three-phase machine

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.

Method for starting up a permanent-magnet synchronous machine, and permanent-magnet synchronous machine

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.

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Nuremberg, Germany

Hauke Nannen