A method for operating a storage-and-retrieval unit (3) is specified, in which a rail line (1)/power-supply rail (6) is set to a hazard-operation voltage when a risk posed by the storage-and-retrieval unit (3) is detected. In the storage-and-retrieval unit (3) the level of the voltage applied to the rail line (1)/power-supply rail (6) is measured and a current path between the rail line (1)/power-supply rail (6) and a drive motor (5, 5a . . . 5c) of the storage-and-retrieval unit (3) disconnected when the voltage measured is below a threshold value associated with a hazardous situation or emergency. Furthermore, a storage-and-retrieval unit (3) as well as an automated rack storage system for performing the proposed method is specified.

A system and method of managing power for an electric motor drive system is provided, where at least two electric motor drives are connected to a common power bus, each of the electric motor drives connected to at least one electric motor. A voltage of the common power bus is monitored, and upon the voltage of the common power bus exceeding a prescribed threshold voltage it is determined which of the at least two electric motor drives is operating in a mode other than a regeneration mode. The electric motor drive operating in a mode other than a regeneration mode is commanded to drive the connected motor into a load to dissipate the regenerated energy.

A method of braking for a vehicle with a multi-phase electric motor, said motor including at least one stator group including a first stator arrangement and a second stator arrangement, each arrangement including three coils, each arrangement connected to respective low side and/or high side circuitry, each low side and/or high side circuitry including respective low side switches and high side switches, said method including: for either of said second or first arrangements, i) setting any two of said switches in said low side circuitry to a closed state and the other switch in an open state, and setting all the switches in the high side to an open state; and/or ii) setting any two of said switches in said high side circuitry to a closed state and setting the other switch to an open state, and setting all the switches on the low side to an open state.

A semitrailer includes a wheel and an electric machine for driving the wheel, wherein the electric machine is configured so as to be operable as an electromotive brake in a braking state.

In order to enable safe deceleration of a transport unit of a long-stator linear motor, wherein in a normal mode a plurality of drive coils of the long-stator linear motor are energized in such a way that a magnetic field coupled to a transport unit is moved along a direction of motion in order to move the transport unit along the direction of motion, according to the invention a switching to a controlled short-circuit mode is performed during the braking operation of the transport unit, in which at least some of the drive coils are short-circuited at least over a first time interval in said mode.

A method for operating a storage and retrieval unit (3) is specified, in which a rail line (1)/power-supply rail (6) is set to a risk-operation voltage when a risk posed by the storage and retrieval unit (3) is detected. In the storage and retrieval unit (3) the level of the voltage applied to the rail line (1)/power-supply rail (6) is measured and a current path between the rail line (1)/power-supply rail (6) and a drive motor (5, 5a . . . 5c) of the storage and retrieval unit (3) disconnected when the voltage measured is below a threshold value associated with a risk situation. Furthermore, a storage and retrieval unit (3) as well as an automated rack storage system for performing the proposed method is specified.

The invention relates to a method and to a device for changing from the idle operating state of an electric motor (5) having three phase terminals (5-1, 5-2, 5-3) to a short-circuit operating state. Thereby significant voltage rises are avoided. For this purpose, after receiving (120) a request for changing of the operating state of the electric motor (5) to the short-circuit operating state, three switching elements (1-1, 1-2, 1-3) are closed. Thereby the switching elements (1-1, 1-2, 1-3) are at least partially closed successively and the times of closing the individual switching elements are predetermined as a function of control parameters of the electric motor.

A drive system establishes a normal state in which a first switch is ON and a gang switch is OFF, in the case where it is determined that there is no abnormality in the state of a first rotating body driven by a first motor. In this normal state, the first motor is driven by a first inverter, while a second motor is driven by a second inverter. It the case where it is determined that there is abnormality in the state of the first rotating body, a first countermeasure state is established in which the first switch is OFF and the gang switch is ON. In this first countermeasure state, the second motor is driven by both the first inverter and the second inverter.

A braking disengagement switch for a drive wheel driven by a two-phase electric motor, the switch comprising a first disengagement channel connected at a first end to a phase of the motor and to a second phase of the motor at a second end, the first channel switching between an open state and a closed state, the switch comprising a device for monitoring the first channel, the monitoring device comprising: a first transmitter connected to the first end of the first disengagement channel, configured to inject a first state signal between the first end of the first disengagement channel and the motor phase of the electric motor; a first receiver connected to the second end of the first disengagement channel, configured to detect the first signal passing through the first channel when the first channel is in the closed state, the first receiver being configured to determine the state of the first channel.

The present invention provides a motor-driven traveling device including: a vehicle body; a motor for travel driving that is capable of braking the vehicle body as a short brake or a dynamic brake; an electromagnetic brake that brakes the vehicle body, separately from the motor; an operation switching circuit that switches between causing the motor to perform travel driving and causing the motor to perform braking; a brake release switch that receives an operation pertaining to brake releasing of the motor and the electromagnetic brake; and a brake control circuit that, while the brake release switch is operated, controls the motor and the electromagnetic brake in response to the operation on the brake release switch.