36results about How to "Damped oscillation" patented technology

A means for improving the dynamic and voltage stability of utility transmission systems is provided by the coordinated control of windfarms. Electrical measurements of the system, which may include synchronized phasors, are supplied to one or more windfarm controllers, which in turn perform a regulation function improving the damping of electromechanical oscillations or voltage performance in the utility system. The control structure is of a decentralized nature, which maintains operation in case of communication failures. The benefits are improved damping to electromechanical oscillations and better voltage performance and ultimately increased utilization of assets, reducing the install additional network assets.

An apparatus for the production of pocketed coil springs is disclosed. The apparatus includes a coiling section in which a coil is formed from wire fed to the coiling section, the coiling section including coiling elements, whose position and/or orientation determines the form of the coil, and an encapsulation section in which the coil is inserted between juxtaposed sheets of material and in which the sheets of material are joined together to form a pocket enclosing the coil. The apparatus further includes programmable control means operably linked to the coiling elements in such a way as to control the position and/or orientation of the coiling elements.

The present invention refers to a method for operating a wind turbine, the wind turbine particularly comprising a tower and a rotor with rotor blades. The pitch angles of the rotor blades are adjusted to generate a force on the rotor and the tower. The force is adjusted to counteract and damp an oscillation. The adjustment is enabled by an activation decision unit, if the activation decision unit decides that certain parameters characterising the oscillation or loads of the tower indicate a requirement and/or if the activation decision unit determines that the generated force is sufficient to counteract an oscillation of the tower. In various embodiments the parameters characterising the oscillation or loads of the tower comprise current oscillations and their amplitude, an estimate of loads incurred in the turbine structure, an estimate whether damping in the near future might become necessary, an indication whether a different oscillation damping algorithm than individual blade pitch control is currently performing, and an indication whether a wind speed is above a certain portion of a rated wind speed.

A piping system for visco elastic damping, which system oscillates with high frequency, small amplitude oscillations. The system includes one or more autonomous visco elastic dampers that includes one or more layers of visco elastic damping material fixedly bonded between stiff members. The visco elastic dampers may be provided with a temperature controlling element.

A method and apparatus for controlling a voltage source converter to energise a DC link. A voltage order generating module generates a voltage order for controlling the voltage source converter to generate a DC voltage on the DC link. An oscillation damping module monitors the DC current flow to determine an indication of current oscillation and the voltage order is based on a voltage reference signal which is modulated by the indication of current oscillation to provide oscillation damping.

A disc unit includes a head that records information onto and/or reproduces information from a disc, a suspension that includes a top surface and a side surface, and supports the head on the top surface, a flexible printed circuit board attached to the side surface of the suspension through an air gap, the flexible printed circuit board transmitting a signal indicative of the information to and from the head, and a damper that damps oscillation of the flexible printed circuit board.

An electronic ballast for a lamp having a bridge circuit, includes at least one first switch and a second switch, a center point of the bridge circuit between the first and second switch, the center point coupled on one side to a reference potential via the series circuit including a first capacitor and a diode and on the other side to a first connection for the lamp via an inductance; a control unit for driving the first and second switches. The control unit has a supply connection coupled to the connection point between the first capacitor and the diode, the voltage across the supply connection being limited in terms of its amplitude, and having a measurement signal input for feeding a measurement signal to the control unit; the measurement signal input being coupled to the connection point between the first capacitor and the diode.

The invention relates to an attenuation circuit for an energy storage device having one or more energy storage modules which are connected in series in one or more energy supply lines and have at least one energy storage cell and a coupling device which has a multiplicity of coupling elements and is designed to selectively switch or bridge the energy storage cell in the respective energy supply line. The attenuation circuit comprises a current detection device which is designed to detect an output current of the energy supply lines or of the energy storage device and to generate an output current signal dependent on the output current, a control circuit which is coupled to the current detection device and is designed to control the output current signal to a desired current signal and to output a corresponding current control signal, and a pulse width modulation device which is coupled to the control circuit and is designed to control the coupling device of at least one of the energy storage modules in a clocked manner on the basis of the current control signal.

Brassieres are provided which provide enhanced levels of comfort and support to the wearer. In one aspect, the invention provides a brassiere comprising an elastic material and clamping means, wherein the clamping means is arranged so as to clamp movements of a strap or cup caused by movement of a breast. In another aspect there is provided a brassiere having a strap and cup arrangement which is configured to distribute the breast load. Also provided is a brassiere for constraining movement of a wearer's breasts during wear, wherein said brassiere is configured such that movement of one breast caused by movement of the wearer is restrained by a remaining breast.

The invention discloses a parallel converter system controller and a control method. The controller comprises a common direct current instruction generation unit and independent control units of all converters. The direct current instruction generation unit generates a direct current reference value and sends the direct current reference value to the control unit of each converter in the constantactive power control mode through communication to serve as a converter control signal; and the converters are controlled to correct the bridge arm control reference voltage value of the modular multilevel converter in real time according to the received control signal and the acquired direct current flowing through the converters, thereby realizing common control of the direct current power by the parallel converter system. The method and the system are high in reliability, have the capability of distributing power among the parallel converters, can effectively ensure the synchronization of the plurality of converters, avoid direct current oscillation among the converters, and improve the stability of the system.

Various embodiments provide a material handling vehicle (MHV) and associated method provide for damping of mast oscillations of a mast of the MHV. In one approach, mast oscillations can be detected and/or anticipated and a countering force can be generated by an elevated reach actuator of the MHV to damp the oscillations.

A magnetic-pole detecting system for synchronous AC motors and a magnetic-pole detecting method therefor are provided. The magnetic-pole detecting system for synchronous AC motors includes a position detector 10 for detecting the relative position between the moving element 3 and the stator of an AC motor 5; a phase-update command unit 52 for making a plurality of currents with different phases flow in coils 3a and 3b so that the moving element 3 moves to a plurality of stable points; a reversal command unit 56 for making currents flow in the coils 3a and 3b so that the moving element 3 reverses from the previous direction in which the moving element 3 has been moved by the phase-update command unit 52; a current cut-off command unit 54 for cutting off the currents flowing in the coils 3a and 3b when the position-detector 10 detects a movement of the moving element 3; a reversal-determining unit 64 for determining, based on a position-detecting signal from the position-detector 10, a direction in which the moving element has moved based on the phase-update command unit 52, and for determining that the determined direction has reversed between the previous and the present instances; and a stable-point-simulator for simulating a stable point by means of the phase of the currents flowing in the moving element 3 when the reversal-determining unit 64 has detected the reversal.

The invention provides a capacitor energy control method with short-term frequency support and direct-current side oscillation suppression functions. The capacitor energy control method comprises the following steps: obtaining a reference power instruction correction delta(Wc1) of capacitor energy control based on alternating-current side frequency deviation control; obtaining the direct-current side correction delta(Wc2) through direct-current side virtual capacitor energy control; correcting the steady-state power of the MMC capacitor energy to obtain a reference power instruction for capacitor energy control, so that the MMC capacitor energy responds according to the frequency fluctuation of an alternating current side and the voltage of a direct current bus and participates in absorption of oscillation energy. The control method directly absorbs energy from an MMC capacitor, the response to the frequency of the alternating current side and the oscillation of the direct current side is rapid, and the control accuracy is high. The method can have the functions of short-term frequency support and direct current side oscillation suppression, and gives full play to the advantages of MMC capacitor energy damping control.

A damping circuit for an energy storage device. The damping circuit comprises a current detection device designed to detect an output current of energy supply strings or the energy storage device and to generate an output current signal dependent on the output current. The damping circuit also includes a closed-loop control circuit coupled to the current detection device. The closed-loop control circuit designed to adjust the output current signal to a setpoint current signal and to output a corresponding current control signal. A first winding of a transformer is coupled to an output connection of the energy storage device. A second winding is galvanically isolated from the first winding. A compensation current generation device is coupled to the closed-loop control circuit, and is designed to feed a compensation current into the second winding of the transformer depending on the current control signal.