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.

The invention discloses a high permeability new energy power grid connection system and stability control method which belongs to the field of a new energy power system. When new energy has high permeability (50% to 100%), a power grid connection system is composed of a prime mover, a motor and a synchronous generator, or is composed of a motor and a synchronous generator. Rotors of the units are coaxially connected. New energy power is transmitted and converted to power the motor. According to the invention, the method is different from a traditional new energy direct grid connection method; a high permeability new energy power system has enough inertia; the frequency stability of the system is improved; the synchronous generator is retained to effectively damp system oscillation; through voltage and reactive power control, the power angle and the voltage stability of the system are improved; the peaking capacity of traditional thermal power and hydropower units and the like is retained; and through coordinated control of the motor, the synchronous generator and the prime mover, the dynamic regulation characteristic of the system is improved.

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.

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.

To provide a tilt angle sensor that is capable of detecting acceleration, a tilt angle, and the like of a device to which the tilt sensor angle is mounted, and also capable of reducing the size and the cost with a simple structure. The tilt angle sensor comprises: a spring member having a fixed end a free end that has a flexibility to be bent at least in one direction; a magnetic field generating device for generating a magnetic field, which is mounted at the free end of the spring member; a magnetic field detecting device provided by facing the magnetic field generating device for detecting a direction of the magnetic field generated by the magnetic field generating device; and a damping device for giving a damping force to a bending action of the spring member.

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.

There is provided a flat panel loudspeaker comprising a resonant panel, an exciter comprising a foot generally cylindrical in shape, coupled to the resonant panel and defining an inner region of the resonant panel. The exciter is drivable to vibrate the resonant panel via the foot, whereby to produce a sound. A stiffness of the resonant panel in the inner region is greater than a stiffness of the resonant panel in a region of the resonant panel outside the inner region. Additionally or alternatively, the flat panel loudspeaker further comprises a damping member in contact with the inner region of the resonant panel and arranged inside the foot to generally brace against the vibration of the resonant panel so as to damp a response of the resonant panel in the inner region to a vibration from the exciter.

The present invention refers to a method for controlling an electronically adjustable steering damper in a two-wheeled vehicle or motor vehicle, and to an apparatus implementing it, in which the steering damper is able to exert a damping torque on a steering assembly (45) of the two-wheeled vehicle (40) that can be adjusted according to a steering speed (s'). The control method comprises the steps of calculating an instantaneous damping coefficient ( cin(t) ) of the electronically adjustable steering damper based on the at least one controlled variable (s, s') and is characterized in that the at least one controlled variable comprises a yaw rate (s) of the two-wheeled vehicle. Correspondingly, the control apparatus comprises processing means connected to at least one measuring means being suitable for calculating an instantaneous damping coefficient value ( cin(t)) of the steering damper and is characterized in that at least one measuring means comprises a means for measuring a yaw rate ( s) of the two-wheeled vehicle (40) and / or a means for measuring a steering angle (sdelta).

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.

To provide a tilt angle sensor that is capable of detecting acceleration, a tilt angle, and the like of a device to which the tilt sensor angle is mounted, and also capable of reducing the size and the cost with a simple structure. The tilt angle sensor comprises: a spring member having a fixed end a free end that has a flexibility to be bent at least in one direction; a magnetic field generating device for generating a magnetic field, which is mounted at the free end of the spring member; a magnetic field detecting device provided by facing the magnetic field generating device for detecting a direction of the magnetic field generated by the magnetic field generating device; and a damping device for giving a damping force to a bending action of the spring member.

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 plasma generator is disclosed. In an embodiment a plasma generator includes a piezoelectric transformer subdivided into an input region and an output region in a longitudinal direction, wherein the piezoelectric transformer comprises an output-side end face facing away from the input region, wherein the plasma generator comprises a passive load arranged permanently in front of the output-side end face, and wherein the plasma generator is configured to generate non-thermal atmospheric-pressure plasma.

An electricity distribution network for a motor vehicle, the network having at least two pieces of equipment connected to a storage battery, at least one of the pieces of equipment operates in a pulse mode likely to create oscillations in the network at a resonant frequency thereof, the network includes at least one resistive element and capacitor that are associated in series and that are of resistance and capacitance determined so that the resistance of the resistive element is equal to a damping resistance for the network.

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 plasma generator is disclosed. In an embodiment a plasma generator includes a piezoelectric transformer subdivided into an input region and an output region in a longitudinal direction, wherein the piezoelectric transformer comprises an output-side end face facing away from the input region, wherein the plasma generator comprises a passive load arranged permanently in front of the output-side end face, and wherein the plasma generator is configured to generate non-thermal atmospheric-pressure plasma.

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.

There is provided a flat panel loudspeaker comprising a resonant panel, an exciter comprising a foot generally cylindrical in shape, coupled to the resonant panel and defining an inner region of the resonant panel. The exciter is drivable to vibrate the resonant panel via the foot, whereby to produce a sound. A stiffness of the resonant panel in the inner region is greater than a stiffness of the resonant panel in a region of the resonant panel outside the inner region. Additionally or alternatively, the flat panel loudspeaker further comprises a damping member in contact with the inner region of the resonant panel and arranged inside the foot to generally brace against the vibration of the resonant panel so as to damp a response of the resonant panel in the inner region to a vibration from the exciter.

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 present invention proposes a capacitor energy control method with short-term frequency support and DC side oscillation suppression functions, which includes: obtaining the reference power command correction value ΔW for capacitor energy control based on AC side frequency deviation control c1 ; Use the virtual capacitor energy control on the DC side to obtain the DC side correction value ΔW c2 ; By correcting the steady-state power of the MMC capacitor energy, the reference power command of the capacitor energy control is obtained so that the MMC capacitor energy responds according to the frequency fluctuation of the AC side and the voltage of the DC bus, and participates in the absorption of oscillation energy. The control method starts from the MMC capacitor It directly absorbs energy and responds quickly to AC side frequency and DC side oscillation. It can have the functions of short-term frequency support and DC side oscillation suppression, and give full play to the advantages of MMC capacitor energy damping control.

The invention discloses a wind turbine simulator rotational inertia compensation improving method based on deviation inhibition. According to the method, the problem that when current wind turbine simulators (WTS) simulate a wind turbine with the large rotational inertia, instability will happen is solved. Through the deviation inhibition link based on a first-order digital low pass filter, divergence deviation components of the WTS rotational inertia compensation link are restrained. According to the method, the problem that when the WTS simulates the wind turbine with the rotational inertia exceeding that of an experimental facility by two times, instability will happen is solved, the stability range of the WTS is expanded, and the WTS can stably simulate the wind turbine with the large rotational inertia.