Abstract: A motor control system for a hoist drive having an electric motor operationally connected to a hoisting member for hoisting a load, the motor control system being adapted to generate a final angular frequency reference (?*s) for control of the electric motor, the motor control system comprising a power limiter means adapted to generate a correction term (?s,cor) for angular frequency reference. The power limiter means comprises an integrating controller means, the power limiter means being adapted to generate the correction term (?s,cor) for angular frequency reference using output signal IP of the integrating controller means, initial data of the integrating controller means including information relating to actual value of the power of the electric motor and a power related limit value of the electric motor.

Abstract: A hoist trolley assembly includes first and second hoist trolleys, electric motors to drive the trolleys and a control system. The control system receives a preliminary speed reference for the trolleys and forms a final speed reference for the first hoist trolley by using initial data including the preliminary speed reference. The control system is adapted to use a hoist trolley coefficient Krb that is calculated by k rb = T A_nom T B_nom · v B_nom v A_nom · m TB + m LB m TA + m LA , wherein TA—nom=the rated torque of the electric motor of the first hoist trolley, TB—nom=the rated torque of the electric motor of the second hoist trolley, vA—nom=nominal speed of the first hoist trolley, vB—nom=nominal speed of the second hoist trolley, mTA=dead weight of the first hoist trolley, mTB=dead weight of the second hoist trolley mLA=load of the first hoist trolley, and mLB=load of the second hoist trolley.

Abstract: A hoist trolley assembly includes first and second hoist trolleys, electric motors to drive the trolleys and a control system. The control system receives a preliminary speed reference for the trolleys and forms a final speed reference for the first hoist trolley by using initial data including the preliminary speed reference. The control system is adapted to use a hoist trolley coefficient Krb that is calculated by k rb = T A_nom T B_nom · v B_nom v A_nom · m TB + m LB m TA + m LA , wherein TA—nom=the rated torque of the electric motor of the first hoist trolley, TB—nom=the rated torque of the electric motor of the second hoist trolley, vA—nom=nominal speed of the first hoist trolley, vB—nom=nominal speed of the second hoist trolley, mTA=dead weight of the first hoist trolley, mTB=dead weight of the second hoist trolley mLA=load of the first hoist trolley, and mLB=load of the second hoist trolley.

Abstract: The invention relates to a method for controlling a crane, the method comprising comparing velocity requests (Vref) given by a crane control system with a previous velocity request and, if the velocity request is changed, forming and storing an acceleration sequence for the corresponding velocity change, summing the velocity changes defined by the stored acceleration sequences at a particular time and adding the obtained sum (dV) to the previous velocity request to achieve a new velocity request (Vref2), which is set as a new control and velocity request for the crane drives (11, 12), and performing some of the velocity changes defined by the summed acceleration sequences at the definition time of each selected sequence on each program round, i.e. control step, and performing the rest of them as delayed in such a manner that the stored sequence parts to be performed as delayed are read and summed on a plurality of program rounds.

Abstract: A motor control system for a hoist drive having an electric motor operationally connected to a hoisting member for hoisting a load, the motor control system being adapted to generate a final angular frequency reference (?*s) for control of the electric motor, the motor control system comprising a power limiter means adapted to generate a correction term (?s,cor) for angular frequency reference. The power limiter means comprises an integrating controller means, the power limiter means being adapted to generate the correction term (?s,cor) for angular frequency reference using output signal IP of the integrating controller means, initial data of the integrating controller means including information relating to actual value of the power of the electric motor and a power related limit value of the electric motor.

Abstract: A generator assembly including generator means and a first converter member (11), the generator means being arranged to convert mechanical power to electric power and comprising an AC generator (2), a voltage regulator (4) and an AC coupling, the voltage regulator (4) being arranged to regulate magnetization of the AC generator (2) on the basis of data associated with the voltage of the AC coupling of the generator means, the AC coupling being arranged to supply electric power from the AC generator (2) to the first converter member (11), and the first converter member (11) being arranged to rectify the voltage applied through the AC coupling into DC voltage. The first converter member (11) is arranged to adjust the power of the AC generator (2) by changing the component (I q) associated with the torque of the current passing through the AC coupling so as to provide the power of desired magnitude.

Abstract: A method for controlling a crane includes controlling a rope part connected to a hook of the crane with a friction-operated driving wheel, extra rope being coiled into a plurality of layers onto a storage reel. In the method, two machineries are used, of which the first is intended for the driving wheel and the other for the storage reel, one machinery being controlled with a speed instruction and the other machinery with a torque instruction.

Abstract: A generator assembly including generator means and a first converter member (11), the generator means being arranged to convert mechanical power to electric power and comprising an AC generator (2), a voltage regulator (4) and an AC coupling, the voltage regulator (4) being arranged to regulate magnetization of the AC generator (2) on the basis of data associated with the voltage of the AC coupling of the generator means, the AC coupling being arranged to supply electric power from the AC generator (2) to the first converter member (11), and the first converter member (11) being arranged to rectify the voltage applied through the AC coupling into DC voltage. The first converter member (11) isarranged to adjust the power of the AC generator (2) by changing the component (I q) associated with the torque of the current passing through the AC coupling so as to provide the power of desired magnitude.

Abstract: The invention relates to a method for controlling a crane, the method comprising comparing velocity requests (Vref) given by a crane control system with a previous velocity request and, if the velocity request is changed, forming and storing an acceleration sequence for the corresponding velocity change, summing the velocity changes defined by the stored acceleration sequences at a particular time and adding the obtained sum (dV) to the previous velocity request to achieve a new velocity request (Vref2), which is set as a new control and velocity request for the crane drives (11, 12), and performing some of the velocity changes defined by the summed acceleration sequences at the definition time of each selected sequence on each program round, i.e. control step, and performing the rest of them as delayed in such a manner that the stored sequence parts to be performed as delayed are read and summed on a plurality of program rounds.