Abstract: Embodiments of present disclosure relate to a Safe Torque Off (STO) circuit and a method for the STO circuit. The STO circuit has an input suitable for receiving an input signal, channels coupled to the input in parallel, wherein each of the channels includes a switch, a level conversion circuit, and an isolation circuit connected in series. Each isolation circuit being configured to be turned on when the respective switch is closed and to be turned off when the respective switch is opened. Each of the channels also includes an inverter module, a control unit, a first switch unit, and a second switch unit.

Abstract: Embodiments of present disclosure relate to a Safe Torque Off (STO) circuit and a method for the STO circuit. The STO circuit has an input suitable for receiving an input signal, channels coupled to the input in parallel, wherein each of the channels includes a switch, a level conversion circuit, and an isolation circuit connected in series. Each isolation circuit being configured to be turned on when the respective switch is closed and to be turned off when the respective switch is opened. Each of the channels also includes an inverter module, a control unit, a first switch unit, and a second switch unit.

Abstract: An electrical drive system including an inverter and an electrical machine supplied by the inverter. A method for controlling the electrical drive system includes: receiving a machine current signal and a machine voltage signal of a machine current supplied to the electrical machine; determining a switching signal based on the machine current signal and controlling the inverter with the switching signal; estimating a first speed estimate from the machine current signal; estimating a second speed estimate from the machine voltage signal; and comparing the first speed estimate and the second speed estimate with each other, and, when the first speed estimate and the second speed estimate deviate from each other more than a threshold, activating a fault reaction of the electrical drive system, which sets the electrical drive system to a predefined state.

Abstract: According to an aspect, there is provided a method for evaluating safety of a speed of a motor controlled by a frequency converter. The method includes, first, measuring first, second and third phase currents of three-phase electric power fed from the frequency converter to the motor and forming first, second and third current measurement pairs based thereon. Then, the speed of the motor is estimated separately based on each measurement pair to produce respective first, second and third estimates for the speed of the motor. A voting logic is applied to the first, second and third estimates for the speed of the motor. A voting logic is applied to the first, second and third estimates. An output of the voting logic is fed to a safety logic controlling at least one safety function of the frequency converter. The output of the voting logic includes an estimate for the speed of the motor and an indication whether or not said final estimate is valid according to the voting logic.

Abstract: According to an aspect, there is provided a method for evaluating safety of a speed of a motor controlled by a frequency converter. The method comprises, first, measuring first, second and third phase currents of three-phase electric power fed from the frequency converter to the motor and forming first, second and third current measurement pairs based thereon. Then, the speed of the motor is estimated separately based on each measurement pair to produce respective first, second and third estimates for the speed of the motor. A voting logic is applied to the first, second and third estimates. An output of the voting logic is fed to a safety logic controlling at least one safety function of the frequency converter. The output of the voting logic comprises an estimate for the speed of the motor and an indication whether or not said final estimate is valid according to the voting logic.

Abstract: An electrical drive system including an inverter and an electrical machine supplied by the inverter. A method for controlling the electrical drive system includes: receiving a machine current signal and a machine voltage signal of a machine current supplied to the electrical machine; determining a switching signal based on the machine current signal and controlling the inverter with the switching signal; estimating a first speed estimate from the machine current signal; estimating a second speed estimate from the machine voltage signal; and comparing the first speed estimate and the second speed estimate with each other, and, when the first speed estimate and the second speed estimate deviate from each other more than a threshold, activating a fault reaction of the electrical drive system, which sets the electrical drive system to a predefined state.

Abstract: An actuator assembly is disclosed, which includes a power unit, an actuator powered by the power unit, the power unit being configured to provide a work motion of the actuator, a motion sensor, a timing unit for measuring an immobility time of the actuator, a safety unit for selectively placing the actuator assembly into an operational state and a safety state in which the work motion of the actuator can be prevented, the safety unit being configured to prevent the operational state of the actuator assembly in case the immobility time of the actuator exceeds a predetermined process safety time. The actuator assembly can include an activation unit configured to control the power unit to provide an activation motion of the actuator in case the immobility time exceeds a predetermined activation time.

Abstract: An actuator assembly is disclosed, which includes a power unit, an actuator powered by the power unit, the power unit being configured to provide a work motion of the actuator, a motion sensor, a timing unit for measuring an immobility time of the actuator, a safety unit for selectively placing the actuator assembly into an operational state and a safety state in which the work motion of the actuator can be prevented, the safety unit being configured to prevent the operational state of the actuator assembly in case the immobility time of the actuator exceeds a predetermined process safety time. The actuator assembly can include an activation unit configured to control the power unit to provide an activation motion of the actuator in case the immobility time exceeds a predetermined activation time.

Abstract: A method of manipulating the header field in an ATM cell. In accordance with the method, the ATM cell is transferred via an interface where each byte of the cell appears in a parallel form on a plurality of parallel data conductors and where information on the start of cell (SOC) is also available. In order to be able to carry out header bit manipulation in a simple manner at such an interface, data conductors corresponding to the bits to be manipulated are led to a circuit carrying out the manipulation, and the other data conductors are led past the circuit. The bit to be manipulated is searched for by counting from start of cell up to the byte containing the bit to be manipulated, after which the bit is manipulated. An output conductor corresponding to the manipulated bit is led from the manipulation circuit to its own position among the data conductors that bypassed the circuit.