23 results about "Low-frequency oscillation" patented technology

The application discloses a kind of power system low-frequency oscillation characteristic signal extraction methods, comprising: the electrical variation data of acquisition each generator outlet is preprocessed;Through complementary ensemble empirical mode decomposition, variation data is decomposed, and noise component is filtered out;SPA smoothing algorithm is used to process the electrical variation signal after denoising;Prony method is used to decompose the signal after smoothing, and the amplitude and phase of each frequency component are extracted;The application has more excellent noise suppression capability and signal fidelity, can effectively solve the problem of modal aliasing, can adaptively identify and filter out various noise components, and shows good adaptability to noise interference under different operating conditions of power system;SPA smoothing algorithm reduces the error introduced by complementary ensemble empirical mode decomposition while effectively retaining the key features of low-frequency oscillation;Combined with Prony method, the characteristic parameters of the oscillation signal can be accurately extracted in a strong noise environment, providing a reliable data basis for low-frequency oscillation source identification.

The application discloses a kind of grey-box isomeric doubly-fed wind farm low-frequency oscillation suppression method based on virtual damping modulation, comprising: 1 grey-box isomeric doubly-fed wind farm is divided into white box and black box unit, and the state space model of all white box units of traditional doubly-fed induction generator, virtual synchronous machine control and installation additional damping controller is established;2 improve subspace identification method to obtain black box unit model;3. white box and black box model are coupled by feedback interconnection, and the overall state space model of wind farm is constructed;4 determine target low-frequency oscillation mode based on coefficient matrix;5 real-time extraction and target mode strong correlation common bus power signal, combined with adaptive time-varying gain generates virtual synchronous machine damping coefficient adjustment amount;6 according to complex mode controllability factor and unit distribution coefficient, allocate the virtual damping modulation instruction of each white box unit.The application realizes the identification and suppression of grey-box isomeric doubly-fed wind farm low-frequency oscillation, and improves the ability of wind farm damping low-frequency oscillation.

This disclosure relates to the field of water supply testing and provides a test water supply system, including: a water supply pipeline, the water supply pipeline including a first water supply pipeline and a second water supply pipeline connected to the first water supply pipeline, the first water supply pipeline and the second water supply pipeline being connected by a connecting pipeline; a constant pressure and constant flow component, including a pressure transmitter and a bipolar booster pump installed on the connecting pipeline. This invention has the following advantages: by setting a pressure transmitter and a bipolar booster pump on the connecting pipeline, real-time monitoring and rapid compensation of the pressure within the water supply pipeline are achieved. When the test scenario requires instantaneous pressure stabilization or rapid switching, the pressure transmitter can instantly feed back the pressure signal. Combined with the rapid action characteristics of the bipolar booster pump, the pressure regulation response time is significantly shortened, effectively avoiding pressure overshoot and low-frequency oscillation caused by actuator lag, thereby ensuring the repeatability and data comparability of the impact test waveform.

This invention belongs to the technical field of engineering vibration control and discloses a real-time suppression method for low-frequency oscillations based on a fully closed-loop servo drive system. The invention utilizes dual encoder feedback on the motor and load sides to extract the position deviation signal, which is then input to a PD compensator with a first-order low-pass filter. The output of this compensator is superimposed on the torque command side to suppress low-frequency self-excited oscillations caused by nonlinear factors. Based on this, the fully closed-loop system is equivalent to a second-order model, and its natural frequencies are identified. ω Based on the damping ratio and the tolerable oscillation level, the input shaper pulse sequence is designed to convolve and shape the original position command, suppressing low-frequency residual oscillations. Simultaneously, the differential and second-order differential signals of the command are shaped and used in conjunction with the feedforward gain to generate the speed and acceleration feedforward amount, compensating for the time delay introduced by the shaper. This invention achieves real-time suppression of low-frequency oscillations under all operating conditions through the synergistic effect of feedforward shaping and feedback compensation, making it easy to deploy and apply in industrial servo drives.

The present application relates to the technical field of power system stability control, and particularly relates to a power system stability control method based on input and output data optimization control parameters. The method first collects power system input data, output data and oscillation response data; then constructs a parameterized stability controller with several undetermined coefficients, and sets the initial value of the to-be-optimized coefficients; then superimposes the controller output to the additional control channel of the controlled object, constructs an optimization function with the minimum system oscillation as the target, and sets the constraint condition that the average value of the parameters is 0, so as to ensure that the controller output is 0 after the oscillation disappears; then iteratively updates the to-be-optimized coefficients under the constraint condition by using an optimization algorithm, and obtains the target control coefficients; finally, writes the optimized target control coefficients into the parameterized controller, and forms the final stability controller. The simulation results show that the present application can effectively suppress the subsynchronous oscillation and low-frequency oscillation of the synchronous generator, reduce the oscillation amplitude, and speed up the oscillation decay process.

The application relates to the technical field of smart grids, in particular to a power grid flexible load collaborative optimization scheduling system for high-proportion new energy access. The system comprises a data acquisition module, which acquires voltage data of a new energy access port; a low-frequency oscillation analysis module, which obtains a voltage fluctuation sequence of a current monitoring period according to the fundamental frequency characteristics of the voltage data of the current monitoring period; and obtains low-frequency oscillation energy degrees of different time periods according to the difference between noise energy characteristics and total energy characteristics of the different time periods in the voltage fluctuation sequence; and a low-frequency oscillation suppression module, which obtains an adaptive Kpss gain parameter of a next monitoring period according to the change trend and size of the low-frequency oscillation energy degree in the current monitoring period, and suppresses low-frequency oscillation in the voltage of the new energy access port in the next monitoring period. The application adaptively obtains the Kpss gain parameter, improves the stability of the voltage of the new energy access port, and further improves the accuracy of the power grid flexible load collaborative scheduling.

This invention relates to the field of permanent magnet synchronous motor (SPMSM) control technology, and discloses a downhole SPMSM temperature rise suppression I-F control strategy based on optimal power angle self-tuning. It aims to solve the problems of low-frequency oscillations and severe stator winding temperature rise caused by conservative current setting in traditional low-speed I-F control of downhole motors. The method first derives the optimal target power angle that balances high disturbance rejection and low heat generation by constructing a stiffness-heat dissipation comprehensive evaluation model. Then, with torque overload margin as a constraint, the optimal power angle is closed-loop tuned through adaptive stator current adjustment. This invention significantly suppresses redundant heat loss while maintaining high system disturbance rejection stiffness, effectively reducing the risk of downhole thermal failure; simultaneously, it optimizes system damping, suppresses low-frequency oscillations, and ensures reliable equipment operation.

This invention discloses a method and apparatus for analyzing low-frequency oscillations in a converter-synchronous machine hybrid power supply system, belonging to the field of power system transmission and distribution technology. The method includes: establishing a linearized model of the entire hybrid power supply system under small disturbances; establishing a port impedance model of the converter and an impedance model of the power network, as well as an external port impedance model of the synchronous machine considering the embedded internal impedance of the converter and a damping torque model of the synchronous machine; constructing a damping torque stability criterion based on the external port impedance matrix of the synchronous machine; analyzing the influence of the converter's dynamic characteristics on the phase shift of the main and auxiliary diagonal elements of the external port impedance model of the synchronous machine, and deriving the key factors inducing low-frequency oscillations in the converter-synchronous machine hybrid power supply system. This invention achieves a unified analysis framework independent of specific converter control strategies, effectively protecting the information privacy of both the power grid dispatching department and the converter operator, and providing guidance for suppressing low-frequency oscillations in converter-synchronous machine hybrid power supply systems.

The application discloses a kind of network type converter adaptive control method based on bus voltage synchronization, including based on bus voltage synchronization link, band pass filter adaptive parameter adjustment link and initial phase generation link.First, based on system closed-loop transfer function calculation closed-loop pole determines low-frequency oscillation frequency, and accordingly designs band pass filter;DC bus voltage deviation is handled in parallel by proportion controller and adaptive band pass filter, constitutes based on bus voltage synchronization link.Second, in the process of operation, real-time monitoring grid impedance variation and bus voltage low-frequency oscillation frequency deviation, by online parameter identification and spectrum analysis dynamically updates band pass filter parameter, realizes the adaptive adjustment of additional damping.In addition, introduce initial phase generation link to give converter initial phase, to realize the active output of system initial time, ensure fast grid connection.The method of the application can inhibit new energy grid-connected system low-frequency oscillation, improve system stability.

The utility model relates to the technical field of drilling equipment, concretely relates to integrated drilling fluid pulse oscillator, it includes drilling outer tube, the upper end of drilling outer tube connects hydraulic propeller, the axial sliding sleeve of drilling outer tube is equipped with drilling rod, is connected through elastic assembly between drilling outer tube and drilling rod, and the drill bit end of drilling rod contacts with formation, is provided with oscillation subassembly in the cylinder of drilling outer tube, and oscillation subassembly includes high frequency oscillation subassembly and low frequency oscillation subassembly, is used for providing different oscillation effects for drilling rod, is applicable to the drilling work of different geological formation. The utility model solves the technical problem of different frequency oscillation effect for different geological formation in the drilling process.

The present application relates to a kind of Hall thruster in-orbit operating state monitoring method and system, utilize non-invasive means to collect the discharge current of Hall thruster anode side, filter discharge current, obtain low-frequency oscillation signal, then determine the reference inflection point of scatter diagram according to low-frequency oscillation signal, and then determine the deviation rate threshold value using reference inflection point, when steady-state deviation rate is greater than deviation rate threshold value, it is judged that Hall thruster exists perturbation.The present application uses the low-frequency oscillation of discharge current that is easy to measure in the process of Hall thruster operation in orbit as state operation indicator, realizes the in-orbit monitoring of thruster operating state.

This invention addresses the problems of inconsistent switching frequency and unbalanced midpoint potential in traditional model predictive control (MMC) and three-level T-type inverters. It proposes a midpoint potential balancing method for three-level T-type inverters based on MPCC-DSVM. By generating virtual vectors through linear combination of real vectors, the output current ripple is effectively reduced, achieving a fixed switching frequency. The introduced specific virtual vectors eliminate low-frequency oscillations in the midpoint potential, avoiding the need for weight factor selection. The feasibility and effectiveness of this control strategy are verified using Matlab / Simulink. Simulation results show that this invention achieves a fixed switching frequency, effectively improves output current quality, enables midpoint potential balancing, and ensures the system's dynamic response performance.

The present application relates to the technical field of power system stability analysis, and is a low-frequency oscillation severity evaluation method and system for a new energy direct current sending system, which comprises the following steps: calculating correlation factors affecting the low-frequency oscillation severity of the new energy direct current sending system; determining the weights between the correlation factors based on stability simulation analysis; calculating a comprehensive evaluation index reflecting the low-frequency oscillation severity of the new energy direct current sending system based on the correlation factors and the weights between the correlation factors; and obtaining the threshold value of the comprehensive evaluation index based on data simulation driving. The present application can directly evaluate the possibility and severity of low-frequency oscillation of the system by using system steady-state operation state data such as new energy power generation output, direct current sending power and operating voltage, and compared with the traditional low-frequency oscillation evaluation method, the present application does not need to perform transient simulation or stability analysis each time, has small calculation amount and strong operability, and has guiding significance for evaluating the stability of the new energy direct current sending system.

This invention provides a system and method for analyzing and suppressing low-frequency oscillations in thermal power units. It eliminates timing discrepancies between electrical and non-electrical signals through a time alignment module, and achieves dynamic matching of frequency domain and statistical characteristics through an eigenvalue splicing module, significantly improving data fusion accuracy. Based on a real-time simulation-based unified electrothermal model, it quantifies the impact of unit thermal changes on electrical damping, supporting precise oscillation mode tracing. Simultaneously, a collaborative suppression mechanism is designed, synchronously triggering multi-module linkage of CCS, DEH, AVR, and PSS based on classification and grading results, avoiding control conflicts and improving suppression efficiency. By introducing multi-criteria fusion and dynamic threshold adjustment, it enhances the online identification capability of complex oscillation types, ultimately achieving high-precision analysis and rapid suppression of low-frequency oscillations, providing reliable assurance for the safe operation of thermal power units.

This invention discloses a method for locating generator units based on low-frequency oscillation mode correlation in a power system. It constructs a generator unit location model guided by modal information and combines it with a phased training strategy to achieve coordinated optimization of low-frequency oscillation mode identification and related generator unit location. Specifically, in the first phase, the first branch of the model is trained using generator operation measurement data and power system topology information. In the second phase, the second branch is trained based on the low-frequency oscillation mode parameters output from the first phase and the generator power angle time series. During generator unit location, the two types of features are fused through feature mapping and weight allocation mechanisms, allowing oscillation mode information to participate in the weight calculation of generator time series features, thereby obtaining the correlation prediction results of each generator under different oscillation modes.

The present application belongs to the technical field of stability control of power system after new energy access, and particularly relates to a low-frequency oscillation suppression method considering energy storage SOC. The method comprises the following steps: a virtual synchronous generator control strategy is adopted for the energy storage inverter to simulate a synchronous generator to provide inertia and damping support for the system; on the basis of the energy storage inverter control strategy, an oscillation cycle is divided into four stages; according to the swing limit of the synchronous generator, the maximum change of the electromagnetic power output by the synchronous generator is calculated, and an energy storage inverter control strategy for suppressing low-frequency oscillation of the system is established; the capacity of the energy storage battery is calculated; and the power value that can be output by the energy storage battery under a certain state of charge is calculated. The present application verifies the suppression effect of a certain capacity of energy storage battery on the same small disturbance of the system under different SOC, improves the reliability and dynamic response effect of the energy storage for suppressing low-frequency oscillation of the system, and prolongs the service life of the battery.

This invention provides a low-frequency oscillation control method, apparatus, electronic device, and storage medium. The method relates to the field of power system detection technology and includes: inputting data to be processed into at least one controller to obtain a first identification result output by each controller; the data to be processed is generated by a low-frequency oscillation mode of the power system; based on the first identification results output by each controller, determining the distance between each first identification result and a preset identification result of each controller; based on the distances corresponding to each controller, determining a target controller from among the controllers; the target controller is used to control the data to be processed within a target range. The method provided by this invention achieves the control of the data to be processed within a target range, improving the control effect of the data and thus enhancing the control performance of the power system.

This invention discloses a virtual PSS control method and system for suppressing low-frequency oscillations in grid-connected converters. The method includes: sampling the PCC voltage of the grid-connected converter system and performing Park transformation to obtain the voltage at low frequency. dq The PCC voltage component under the axis. (The PCC voltage...) dq The axial component is differentiated and then filtered by a second-order low-pass filter to remove high-frequency components; the filtered PCC voltage is calculated in each sampling period. dq The 2-norm of the differential value of the axis component is used to set the sign of the calculated result to be the same as the PCC voltage obtained above. q The axis differential values ​​are the same, and the signed value of the output is counted as... m ;Will m The signal is fed forward to the reactive power loop (RFL) via a phase compensator to suppress low-frequency oscillations in the system. This invention solves the problem of insufficient low-frequency oscillation suppression capability of traditional virtual PSS under weak power grid conditions, and improves the robustness and adaptability of virtual PSS.

This invention provides an adaptive music-controlled upper limb movement method and system based on a brain-computer interface, relating to the field of computer vision technology. The method includes: acquiring acoustic envelope sequences of multi-channel physiological electrical signals and digital audio streams; sequentially calculating the temporal synchronization features of the physiological electrical signals and acoustic envelope sequences, the spatial asymmetric features constrained by the temporal synchronization feature frequency band, and the event response delay features constrained by the channel weights of the spatial asymmetric features; calculating the consistency deviation index, iteratively correcting the features that failed verification using a dynamic confidence smoothing factor, and outputting the corrected target feature set; mapping and calculating spatial azimuth parameters, reverberation wet / dry ratio, and low-frequency oscillation modulation parameters, generating and outputting a dynamic dual-channel output data sequence to perform acoustic reconstruction; collecting the posterior target feature set after acoustic reconstruction to calculate the temporal physiological state gradient, and updating the feature extraction parameters and consistency decision threshold based on the temporal physiological state gradient.

This application provides a method, system, and equipment for suppressing low-frequency oscillations in generator sets, relating to the field of generator technology. The methods include: real-time monitoring of the generator set to obtain a monitoring sequence; low-frequency oscillation detection of the generator set to obtain an oscillation heatmap; adjustment of the generator set control decisions based on the oscillation heatmap; multiple mutation optimizations of the generator set control group based on generator set regulation adaptability evaluation conditions to obtain the optimal regulation result; and low-frequency oscillation suppression management of the generator set based on the optimal regulation result. This application solves the technical problem in existing technologies where oscillation suppression is difficult to balance with power supply tracking and equipment failure risk, leading to insufficient power system stability, power supply quality, and equipment safety. It achieves optimal low-frequency oscillation suppression management that balances oscillation suppression effectiveness, power supply adaptability, and generator set operational safety, ensuring the long-term stable operation of the target generator set.

This invention discloses a method for suppressing low-frequency oscillations of VSG composite damping based on equivalent circuit mapping, belonging to the field of power electronics technology. A sampling module acquires the electrical signal of the VSG and performs coordinate transformation. A power calculation module calculates active and reactive power based on the acquired electrical signal. An equivalent circuit-power control mapping module maps the VSG active power control loop to an equivalent circuit model. A composite damping control module introduces a composite damping network into the equivalent circuit model. An equivalent circuit-power control inverse mapping module inversely maps the equivalent circuit model after introducing composite damping back to an active power control loop. A voltage control module performs inverse coordinate transformation, generates a PWM signal, and drives the inverter bridge. Using this method, the problem of low-frequency power oscillations of the VSG under multiple disturbance conditions such as power command step and grid frequency disturbances is effectively solved, improving the transient damping characteristics and dynamic operating stability of the system.

This invention relates to the field of power system condition monitoring technology, and is a method and system for identifying source-load parameter combinations for suppressing low-frequency oscillations based on damping ratio sensitivity. The system includes a simulation model establishment unit, a new energy unit selection unit, a motor load selection unit, and a source-load parameter combination identification unit. It establishes a power system simulation model containing multiple new energy units and multiple motor loads and calculates the initial system damping ratio. By calculating the damping ratio sensitivity, this invention identifies the new energy units, motor loads, and source-load parameter combinations that are most sensitive to power system oscillations, providing a reference for improving the damping ratio and suppressing oscillations. This method can simultaneously identify parameter combinations of new energy units and motor loads, reflecting the synergistic effect of both the source and load sides on the system damping ratio and oscillations. Compared with the identification of single power source or load parameters, this method has guiding significance for locating and suppressing low-frequency system oscillations.