10results about How to "Suppression frequency" patented technology

The invention provides a photovoltaic VSG control method based on virtual inertia and damping, and the method comprises the steps: designing a topological structure of a photovoltaic virtual synchronous generator for modeling, and obtaining a power and power angle equation of the virtual synchronous generator; constructing a function expression of the active power of the virtual synchronous generator and combining the function expression with a power and power angle equation of the virtual synchronous generator to obtain a second-order transfer function so as to obtain a step response curve of the output power and the angular frequency of the virtual synchronous generator; secondly, analyzing an influence mechanism of changes of virtual inertia and damping on the dynamic performance of the virtual synchronous generator based on a step response curve, obtaining self-adaptive principles of the virtual inertia and damping in different states based on the influence mechanism to construct a self-adaptive function, and finally setting parameters in the self-adaptive function and designing a starting criterion. Therefore, the photovoltaic virtual synchronous generator can be controlled. Compared with the prior art, the fluctuation of power and frequency can be better suppressed, and the stability of the system is improved.

The invention relates to a preparation method of a'microstructure-liquid-like surface 'underwater drag-reduction, noise-reduction and antifouling multifunctional composite coating, and belongs to the field of underwater equipment. The multifunctional composite coating provided by the invention comprises an anti-drag microstructure arranged on the surface of a substrate and a liquid-like surface arranged on the surface of the anti-drag microstructure, and the liquid-like surface retains the original morphology of the anti-drag microstructure. According to the micro-structure, the distance between the wall face and a turbulent vortex can be increased, the frequency and strength of a flow vortex pair can be restrained, and resistance reduction is achieved; and on the liquid-like surface, resistance reduction can be achieved by enabling fluid to generate wall face slippage and reducing the speed gradient of the fluid on the boundary. The two mechanisms of action are different but do not interfere with each other, and a better drag reduction effect can be achieved through the synergistic effect. Meanwhile, the composite coating can achieve the noise reduction effect by reducing the turbulence intensity of the wall face. In addition, the liquid-like surface can resist adhesion of marine organisms, the integrity of the microstructure is guaranteed, and therefore the long-term drag reduction effect is achieved.

A method for synchronous excitation of multiple exciters relates to the field of dynamic testing and vibration control technology for large civil structures. The method includes the following steps: after constructing a unified time reference based on satellite navigation signals and a rubidium atomic clock, excitation amplitude and phase parameters are obtained based on the target modal requirements, and these parameters are sent to all exciter slave stations; the exciter slave stations generate a reference trajectory based on the excitation amplitude and phase parameters, enabling the exciter motor shaft angle to follow the reference trajectory in real time and output the target excitation; the phase error is obtained based on the measured excitation phase value and the reference trajectory, and then the motor angular velocity of the exciter is corrected based on the phase error. This invention solves the problems of startup phase error and long-term frequency drift in master-slave triggering schemes, ensuring synchronous start-up of all exciters. Combined with dynamic correction of the exciter motor angular velocity, it suppresses phase drift during long-term operation, significantly improving the excitation efficiency of higher-order modes and the clarity of the response signal.

The invention discloses a cooperative control method for a floating type photovoltaic-hybrid energy storage system, and the method employs a flexible connection and semi-tensioning mooring design, and is suitable for a 0-degree head wave long-period working condition. Improving maximum power tracking control, and inhibiting power point oscillation based on a partition variable step size and a prediction power algorithm; hybrid energy storage power is distributed through a low-pass filter, a storage battery and a super capacitor cooperatively process high / low frequency fluctuation, and the service life is prolonged by combining charge partition management; a virtual synchronous generator VSG adaptive control strategy is provided, an improved particle swarm optimization algorithm is adopted to optimize a J / D initial value, and frequency fluctuation is dynamically suppressed; an optical storage grid-connected system is established for verification, and the VSG technology enables the power frequency fluctuation to be quickly stabilized, thereby guaranteeing the stable operation of the system.

The application relates to the technical field of frequency regulation, in particular to a weak-network-construction energy storage frequency self-adaptive regulation method and system, and the following scheme is provided: a node state diagram reflecting device state and coupling relationship is constructed in an island operation stage, main network phase characteristics are extracted based on a common coupling point measurement signal when a grid-connected condition is met, a logical main network node carrying a phase corridor attribute is introduced, and controlled injection of a main network phase reference is realized. Further, a phase convergence diagram is formed according to traction compatibility judgment and diagram reconstruction mechanism, a traction node is subjected to competitive inhibition update through a consistency evaluation index, a grid-connected structure diagram is generated, and thus coordinated regulation of frequency parameters of multiple network-construction energy storage devices under a weak network condition is realized, and stability and controllability of a regrid process are improved.

The invention relates to a charging pile control technology, and provides a dual-mode self-adaptive network construction type electric vehicle charging pile control method. The method comprises the following steps: firstly, constructing a converter frequency control loop, determining whether a charging pile is in an idle mode or a V2G mode according to a change rate of a direct current side capacitor voltage, and calculating a virtual inertia coefficient J in dual modes; then, establishing a small signal model, and calculating the value of a virtual damping coefficient D in the dual mode according to the obtained virtual inertia coefficient value in the dual mode and the relationship between the virtual damping coefficient and the damping ratio; and finally, substituting a calculation numerical result into the constructed converter frequency control loop to calculate the output frequency of the converter in the dual mode. According to the invention, the supporting capability of the energy stored by the direct-current side capacitor on the power grid frequency when the charging pile is idle is fully utilized, the utilization rate of the charging pile is improved, and the grid-side frequency is stabilized.

The invention relates to the technical field of experimental animal model construction methods and anti-environmental factor related epilepsy drug screening, in particular to an epilepsy animal model construction method and a drug obtained through model screening and used for treating epilepsy. The invention discloses a construction method of an epilepsy animal model. The epilepsy animal model is a zebra fish model of epilepsy caused by permethrin exposure. The zebrafish embryo is soaked in permethrin environment for a certain time, and the epilepsy animal model can be obtained. The model can be used for researching the effect of environmental factors in the occurrence and development of epilepsy. The medicine screened by the animal model comprises at least one of topiramate, sodium valproate, carbamazepine, methocarbamol, flecainib acetate, SYM2206, D-AP5, CNQX and baclofen. According to the technical scheme, the technical problem that an epilepsy animal model related to environmental factors is lacked in the prior art can be solved, and the method has ideal application and popularization value.

The invention discloses a motor fault diagnosis method and system fusing order analysis and sparse sensing technologies, and aims at solving the problems that an existing model is poor in generalization ability and lacks interpretability, a vibration signal is resampled into an angular domain stationary signal, and an angle-order spectrum is generated; the method comprises the following steps of: constructing a gate control order Transform diagnosis model consisting of a Transform encoder containing an information bottleneck order gate control module (IB-OG) and a fault classifier, namely embedding the IB-OG module in a self-attention mechanism of the encoder, carrying out sparse screening on input order characteristics by utilizing a built-in microstochastic gate control mechanism, removing redundant noise and reserving key fault characteristics. In addition, class condition domain invariance constraints are introduced into the loss function, and the model is forced to align feature distribution of different working conditions in the same fault class. In conclusion, the diagnosis precision, the generalization ability and the physical interpretability of the model under the complex working condition are remarkably improved.

The invention discloses an energy storage configuration method for improving new energy bearing capacity based on collaborative optimization, which relates to the technical field of new energy power systems, and optimizes a load curve and solves initial energy storage configuration based on a Logistic function by constructing an upper-layer constant volume model; constructing a middle-layer simulation operation model, and calculating a bearing capacity upper limit by taking minimum system operation cost and maximum new energy bearing capacity as double targets; constructing a lower-layer optimization model, optimizing the configuration of the network construction type power supply and the phase modifier, and completing security constraint verification; and iteratively solving the three-layer model by adopting a generalized Benders decomposition algorithm, and outputting a global optimal energy storage configuration and new energy bearing capacity improvement result. According to the method, the load side, power side and system side strategies are optimized in a layered and collaborative manner, economy, reliability and safety are considered, and the new energy bearing and absorption capacity of the power grid is effectively improved.

The invention discloses a network construction type energy storage power control method and system based on feed-forward virtual damping adjustment, and the method comprises the steps: obtaining a power angle compensation amount through an angular frequency difference value and a feed-forward virtual damping coefficient outputted by a corrected adaptive adjustment model; a power angle reference value is obtained through the difference value between the output angular frequency and the power grid frequency, and the sum of the power angle reference value and the power angle compensation amount serves as an output power angle; based on the output voltage amplitude and the output power angle of the virtual synchronous generator, obtaining a reference voltage controlled by an input voltage current inner loop; the problem that dynamic stability and state response characteristics of the system cannot be considered is solved, and steady-state active power deviation cannot be increased.