29 results about "Damped oscillations" patented technology

The invention relates to the technical field of power system fault detection, in particular to a 35kV power distribution network fault distance measurement method based on natural oscillation frequency. After the fault is isolated, the set time is delayed to extinguish the arc; the pre-charging standby capacitor is connected to the fault section through the two-way controllable switch to form an under-damped oscillation circuit; synchronously acquiring damped oscillation voltage waveforms at two ends of the capacitor; establishing an exponential decay sine fitting model by adopting a Prony algorithm to extract a characteristic angular frequency; and based on the function relationship between the cable unit length parameter and the fault distance, calculating the fault distance through a reverse mapping function. According to the method, the active excitation strategy and the Prony algorithm are combined, so that the fault positioning precision and the response speed are improved, and the anti-interference capability is enhanced.

The purpose of the present invention is to evaluate a battery with high accuracy using a simple method. A control unit (12) executes each of operation in a first mode in which the operation of a first switch (SW1) corresponding to a first resonance circuit (Rs1) and the operation of a second switch (SW2) corresponding to a second resonance circuit (Rs2) are different, and operation in a second mode. The control unit (12) determines the internal impedance of a battery (10) on the basis of the damped oscillation waveform of the first resonance circuit (Rs1) when operating in the first mode, the damped oscillation waveform of the first resonance circuit (Rs1) when operating in the second mode, and the damped oscillation waveform of the second resonance circuit (Rs2) when operating in the second mode.

The invention relates to the technical field of frequency stability control, in particular to a power system inertia damping reverse optimization configuration method, system and device based on a reverse distribution principle and a storage medium. A multi-equipment mathematical model containing a synchronous machine and a converter interface power generation device is constructed, equipment phase angle response under active disturbance is simulated, a weak damping oscillation mode is identified, the incidence relation between inertia distribution and oscillation amplitude is analyzed, and the mechanism of inertia dominant oscillation amplitude is clearly displayed; the influence of inertia and damping on the damping ratio is analyzed based on characteristic value disturbance, and a reverse distribution principle of transferring damping from a high-inertia area to a low-inertia area is proposed; three configuration types of reverse distribution, uniform distribution and extreme distribution are defined, and the advantages of reverse distribution are verified through dual-equipment system damping ratio distribution comparison; differentiated configuration strategies are designed for symmetric region, asymmetric region and multi-region scenes, and the performance of a reverse distribution principle is verified through simulation comparison of a frequency response track and a damping ratio numerical value.

The invention relates to the technical field of unmanned aerial vehicle calibration, in particular to an unmanned aerial vehicle holder calibration method and device and electronic equipment, and the method comprises the steps: controlling a frame shaft of a holder to enter a free state; initial angular displacement is applied to the frame shaft in the free state, so that the frame shaft is subjected to free damped oscillation; acquiring a time-varying attenuation response data sequence of the angular displacement of the frame shaft in free attenuation oscillation; fitting the attenuation response data sequence with a preset system model, wherein the system model comprises kinetic parameters used for representing the rotational inertia and the damping ratio of the frame shaft, and constant offset parameters used for representing the zero deviation of the angle sensor; and according to a fitting result, calculating a numerical value of the constant offset parameter as a zero calibration value, and driving a motor of the holder according to the zero calibration value, so that the frame shaft rotates and is locked in a calibrated zero posture. According to the method, the calibration process is simplified, and errors caused by manual observation or dependence on unstable reference are avoided.

The present invention discloses a damping oscillating magnetic field test device with adjustable intensity, which relates to the technical field of magnetic force test detection. It includes a test frame and also includes a protection device. Among them, a damping oscillating magnetic field interference generator is arranged on the front side of the test frame, a magnetic field sensor is arranged on the left side of the test frame, and a temperature control device is arranged on the right side of the damping oscillating magnetic field interference generator. Among them, the protection device includes a test hole, a shielding rod, an L-shaped plate, a separation plate, a hollow frame, a T-shaped rod and a protection plate. The protection plate moves backward to contact the top of the L-shaped plate and limit the L-shaped plate. The test hole is opened on the right side of the test frame, and the shielding rod is fixedly installed on the top of the test frame. By limiting the L-shaped plate with the protection plate, the test frame during the test can be prevented from being opened, the test conditions can be kept stable, and thus the reliability and accuracy of the test detection data can be ensured.

The invention discloses a characteristic frequency interaction device based on a self-rising structure, an array and a preparation method thereof. The device comprises a conductive coil and a magnetic self-lifting structure, the self-lifting structure comprises a fixed end, a three-dimensional main body and an interaction end; wherein the fixed end is arranged on the conductive coil; the interaction end is physically connected with the fixed end through the three-dimensional main body; through mutual restriction of magnetic field force, mechanical force and gravity of the self-lifting structure, the self-lifting structure is in a stable three-dimensional form; when the interaction end generates relative displacement under the action of external force and is separated from the balance position, the interaction end performs damped oscillation around the balance position at a characteristic frequency, and magnetic field change generated by oscillation can be sensed by the conductive coil and converted into an electric signal. The electromagnetic induction principle is combined with damped oscillation of a three-dimensional structure, the oscillation process can be captured by a conductive coil below in the form of an electric signal, and further personalized application is realized through acquisition, analysis and transmission of the electric signal.

The invention provides an automatic calibration method and device for a detector tester, electronic equipment and a medium, and relates to the field of calibration measurement test.The initial moment T0 of a detector for obtaining a damped oscillation signal is obtained through the detector tester, and the method comprises the steps that i-M, i-M + 1 and i-M + 2 are obtained, and sample point signals x [i-M], x [i-M + 1], x [i-M + 2]... x [i] corresponding to the moment i are obtained, and calculating a filtered signal y [i-1] through a formula, when x [i] is greater than G * y [i-1] and G is a multiple of a threshold coefficient, determining a starting moment T0 of a damped oscillation signal, obtaining a damping coefficient, a natural frequency and sensitivity based on T0, and automatically calibrating a detector tester based on the damping coefficient, the natural frequency and the sensitivity. According to the method, the detector tester is automatically calibrated, complicated operation of calibration personnel is avoided, and the calibration precision and the calibration efficiency are improved.

The present invention discloses a method for suppressing additional damped oscillations in an AC-DC hybrid power system including a grid-type HVDC, comprising the steps of obtaining data information of a target AC-DC hybrid power system including a grid-type HVDC; establishing a model of a VSC-HVDC system; establishing a mathematical model of a grid-type inverter station; establishing a mathematical model of a two-region AC system; and establishing a model predictive controller to control the established model to complete the suppression of additional damped oscillations in the target AC-DC hybrid power system including a grid-type HVDC. The present invention also discloses a system for implementing the method for suppressing additional damped oscillations in an AC-DC hybrid power system including a grid-type HVDC. The present invention models the target system and uses fuzzy predictive control to control the model. Therefore, the present invention can not only suppress additional damped oscillations in an AC-DC hybrid power system including a grid-type HVDC, but also has higher reliability and better accuracy.

The invention discloses a low-power-consumption wireless charging foreign matter detection method. The method comprises the following steps: measuring a damped oscillation waveform; performing envelope detection on the damped oscillation waveform, and sampling to obtain an envelope average voltage VCOIL; analyzing whether the difference value between the average envelope voltage VCOIL and the reference voltage Va is smaller than a preset threshold value or not; if yes, wireless communication transmission is started for the to-be-detected object, and whether the to-be-detected object returns a communication packet is detected; and if yes, determining that the to-be-detected object is a charging device with a wireless charging function. Therefore, in a low-power-consumption standby dormant state, envelope detection is periodically carried out on the damped oscillation signal, the envelope average voltage is measured, whether the to-be-detected object is placed on the wireless charging area is judged, then wireless communication with the to-be-detected object is carried out to judge whether the to-be-detected object is the foreign matter or the charging equipment, the foreign matter can be accurately recognized only based on a simple operation circuit, the operation power consumption is low, and the reliability is high. The method effectively avoids the phenomenon of false triggering of wireless charging, and is suitable for equipment scenes with limited electric energy, such as mobile power supplies.

The invention discloses a power system oscillation mechanism identification method and a model construction method, and relates to the field of power system low-frequency oscillation, and the method comprises the steps: collecting the active power data of a generator and the active power data of a tie line; performing linear normalization and principal component analysis dimension reduction processing on the data, and constructing a multi-dimensional time sequence to-be-tested sample; a sample is input into a pre-trained deep belief network (DBN) model, the model is formed by stacking a plurality of restricted Boltzmann machines (RBM), data deep features are extracted through unsupervised layer-by-layer greedy pre-training, and parameter optimization is performed in combination with supervised fine tuning. According to the method, negative damping oscillation and forced power oscillation can be automatically identified, the uncertainty of manual feature selection is avoided, the influence of noise and amplitude difference on the identification precision is effectively suppressed, and the adaptability of the model to an actual power grid complex disturbance condition is improved.

The invention belongs to the technical field of electric power measurement, and discloses a damped oscillation wave working condition identification method of an intelligent electric energy meter, which comprises the following steps: acquiring sampling signals of voltage and current; preprocessing the sampling signals of the voltage and the current to obtain characteristic data; calculating a score corresponding to the voltage sampling signal by combining the dynamic threshold with the feature data; and judging whether the score is greater than a threshold value, if so, marking as an oscillation working condition, if not, judging whether the current sampling signal meets an amplitude change condition and whether the current and voltage sampling signals meet a phase mutation condition, and if so, marking as the oscillation working condition. According to the invention, the recognition accuracy can be improved, and misjudgment is reduced.

The invention discloses a multi-mode damping compensation control method for suppressing multi-source subsynchronous oscillation. The multi-mode damping compensation control method is applied to a system for bundling new energy and a conventional power supply and transmitting the new energy and the conventional power supply through high-voltage direct current. The method comprises the following steps: identifying each subsynchronous weak damped oscillation mode dominated and excited by different oscillation sources in the delivery system and strongly correlated dominant equipment thereof; screening a high-participation control loop of the subsynchronous weak damping oscillation mode, and decomposing damping path contributions of different control loops to each oscillation mode; an index used for evaluating the damping lifting capacity of a control loop is constructed, and a damping compensation control loop of the subsynchronous weak damping oscillation mode is determined; designing parameters of a damping compensation control channel of the subsynchronous weak damping oscillation mode; and the overall damping improvement effect of the multi-mode damping compensation control channel is verified, and potential influences on other oscillation modes of the system are evaluated.

The present application relates to a VSG-based energy storage coordinated controller end damping control method and device, in the energy storage coordinated controller, the phase relationship of the damping control quantity and the power grid oscillation frequency is analyzed, the quantitative relationship model of the virtual rotational inertia and the damping coefficient is constructed when the phase delay is combined to make the damping power produce reverse damping effect on the oscillation component of the oscillation frequency to be suppressed; the amplitude-frequency characteristic of the small signal increment of the damping control quantity is analyzed, the calculation model of the virtual rotational inertia and the damping coefficient is obtained combined with the target damping strength and the quantitative relationship model; the energy storage coordinated controller detects the damping oscillation frequency in real time, obtains the current damping control quantity as the damping power instruction combined with the calculation model, and issues it to the grid-connected energy storage converter. The present application realizes the fast and accurate damping suppression of the power grid frequency oscillation at the coordinated controller level, and improves the transient stability of the power system containing a high proportion of new energy.

The objective of this invention is to perform highly accurate evaluation of batteries using a simple method. [Solution] The control unit 12 performs first mode and second mode operations, respectively, in which the operation of the first switch SW1 corresponding to the first resonant circuit Rs1 and the operation of the second switch SW2 corresponding to the second resonant circuit Rs2 are different. Based on the damped oscillation waveform of the first resonant circuit Rs1 when operating in first mode, the damped oscillation waveform of the first resonant circuit Rs1 when operating in second mode, and the damped oscillation waveform of the second resonant circuit Rs2 when operating in second mode, the control unit 12 determines the internal impedance of the battery 10.

The invention discloses an energy storage low-frequency oscillation suppression method based on a damping controller and a resonance controller, particularly relates to the field of low-frequency oscillation suppression, and comprises the following steps: judging the type of low-frequency oscillation, then adaptively selecting and online setting the corresponding damping or resonance controller, and generating compensation power. According to the energy storage low-frequency oscillation suppression method based on the damping controller and the resonance controller, a negative damping oscillation and forced oscillation dual-discrimination access is constructed, so that the type of low-frequency oscillation is effectively identified, and the defect that the effective identification capability of the oscillation type is lacked is overcome; the controller is adaptively selected according to the oscillation type, targeted suppression is applied to different types of oscillation, invalid adjustment of a single control strategy is avoided, resource waste of the energy storage system is reduced, suppression efficiency is improved, service life attenuation of the energy storage device is slowed down, and forced oscillation energy propagation is suppressed.

The invention provides a main power supply type new energy station cluster control and damped oscillation system and a control method thereof, and the method comprises the steps: S1, recognizing the grid frequency and voltage change amplitude of a grid-forming inverter, based on the identified grid frequency and voltage change amplitude of the grid-forming inverter, primary frequency modulation is actively carried out and grid-connected point voltage is actively supported through a grid-forming power generation unit; s2, dynamically selecting an adjustment stride according to the difference between target power and actual power on the basis of active primary frequency modulation of a grid-forming power generation unit; and S3, on the basis that the grid construction power generation unit actively supports the grid-connected point voltage, dynamically selecting a voltage adjustment stride according to the difference between the target reactive power and the actual reactive power.

This invention discloses a novel wideband pMUT unit and array. The novel wideband pMUT unit and array, from bottom to top, comprises a base layer, a driving layer, and a multi-gradient vibration layer. The base layer includes a support, a back cavity, a back load, and a silicon dioxide insulating layer. The driving layer includes a bottom electrode, a top electrode, and an adhesion layer. The gradient of the multi-gradient vibration layer is guided by its thickness dimension, and the multi-gradient vibration layer is a multi-gradient piezoelectric thin film. The pMUT unit with the multi-gradient vibration layer has multiple resonant modes, giving it multi-frequency performance. The back load is formed by etching to amplify the damped oscillation of the pMUT unit, while adjusting the equivalent vibrating mass, stiffness, and effective vibrating area distribution of the pMUT unit, and coupling the multi-frequency bands into a wideband. This invention is applicable to the acoustic field and, compared with conventional pMUT structures, can effectively broaden the operating frequency band of the pMUT unit.

The present application relates to a high-resolution variable-frequency damped oscillation signal generator, characterized in that it includes an FPGA, a 14-bit D / A converter, and a MOSFET switch. The FPGA receives damped oscillation waveform data transmitted from an external source, converts the data into an analog waveform through the 14-bit D / A converter at a conversion rate of 100MHz, and then processes the data through filtering and op amp processing, and outputs the waveform through the MOSFET switch. The present invention achieves a waveform rising edge of 3.49ns under the premise of using a low-bandwidth device (data conversion rate 100MHz). The use of a 14-bit D / A converter effectively ensures the accuracy of the output waveform at low voltage and low frequency, resulting in better consistency in test results. In addition, since the operating frequency of the device used in the present invention is relatively low, the device cost is also relatively low. Moreover, this operating frequency can use a double-sided board, unlike high-speed devices that require a multi-layer board, which greatly reduces the development difficulty and makes the processing technology simple and easy to implement.

The invention provides a dielectric electrical characteristic testing method based on damped oscillation voltage. The dielectric electrical characteristic testing method comprises the following steps: firstly, measuring electrical parameters of a sample at different frequencies and temperatures by adopting a two-electrode testing system; substituting the measured dielectric constant and conductivity into the simulation model, and analyzing the influence of different frequency voltages on the electric field of the cable; secondly, a DAC cable oscillation wave partial discharge detection system is used for generating damped oscillation voltages with different frequencies, and partial discharge signals are collected; and finally, the electrical characteristic test of the dielectric is completed by comparing simulation and experiment results. The method has the advantages that the interference of large capacitance of the cable can be eliminated, the electrical characteristics of the cable in practical application can be accurately reflected, and the method is easy to implement and suitable for different testing environments. The method is free of field interference, has high test precision and wide application prospect, and is particularly suitable for electrical performance evaluation and fault detection of the high-voltage cable.

The invention discloses a control method of a six-degree-of-freedom platform, which comprises the following steps: step 1, six control systems are constructed, and the control systems are in one-to-one correspondence with six driving joints of the six-degree-of-freedom platform; wherein the control system comprises a CMAC model and a PID (Proportion Integration Differentiation) controller; step 2, acquiring overshoot, damping ratio and damped oscillation period of the control system at the current moment, inputting the overshoot, damping ratio and damped oscillation period into a CMAC model, and outputting PID controller parameter variation by the CMAC model; wherein the parameter variable quantity comprises a proportion variable quantity, an integral variable quantity and an integral gain variable quantity; and thirdly, the parameter variation is input into the PID controller, and the PID controller outputs a drive joint control signal at the next moment according to the adjusted parameters.

The application provides a novel photovoltaic grid-connected reactive power compensation decentralized control device, which is applied to the technical field of smart grid, and through an electrical acquisition module, the device acquires grid-connected node voltage, current and power characteristic quantities in real time to form complete time series data; an oscillation suppression module identifies local oscillation modes based on the time series data, and generates synchronous damping current through mode consensus and damping compensation to realize active suppression of low-frequency or weak-damping oscillation; a compensation module combines the damping current and the reactive power regulation current to perform coordinate transformation, decomposition and superposition, generates a reactive power compensation current reference, and injects the grid-connected node through a power electronic execution module. Through the above technical means, the application can realize parallel fusion of reactive power regulation and oscillation suppression in the photovoltaic grid-connected system, effectively suppress the cascading outage risk caused by oscillation, and thus enhance the stability of the photovoltaic grid-connected system.

This invention discloses a method for suppressing low-frequency oscillations in energy storage based on a damped controller and a resonant controller, specifically relating to the field of low-frequency oscillation suppression. The method involves identifying the type of low-frequency oscillation and then adaptively selecting and online tuning the corresponding damped or resonant controller to generate compensation power. This method constructs a dual-discrimination path for negatively damped oscillations and forced oscillations, effectively identifying the type of low-frequency oscillation and overcoming the deficiency of lacking effective oscillation type identification capability. By adaptively selecting the controller according to the oscillation type, targeted suppression is applied to different types of oscillations, avoiding ineffective adjustment of a single control strategy, reducing resource waste in the energy storage system, improving suppression efficiency, slowing down the lifespan decay of the energy storage device, and curbing the propagation of forced oscillation energy.

The present invention discloses a damping optimization method and system for grid-connected converters to correct the dynamics of active / reactive current commands, belonging to the field of power system stability control. The present invention adds a command correction signal to the dq-axis current command values of the grid-connected converter. By correcting the active current command and reactive current command of the converter that are in the same direction and orthogonal to the terminal voltage position and making them subject to proportional regulation of the terminal voltage frequency dynamics during the dynamic process, positive damping can be provided for the grid-connected system of the converter equipment without adding electrical measurement links and without reducing the power transmission efficiency of the converter. It can improve the weak damping dynamic regulation process or suppress the divergence phenomenon of underdamped oscillation, and improve the system stability. Different from various additional damping control methods, the present invention corrects the dynamics of the active / reactive current commands and makes them subject to proportional regulation of the terminal voltage frequency dynamics. The damping effect will not be affected by the oscillation frequency, expanding the effective damping frequency band, and realizing damping optimization in the full frequency band.

This application proposes a method and system for suppressing wind turbine oscillations in heterogeneous wind farms. The method includes: designing a robust damped oscillation suppression controller based on the control logic of grid-connected and grid-following wind turbines; adding the controller to the open-loop system for wind turbine oscillation suppression to construct a closed-loop system; and solving for the closed-loop system using a linear matrix inequality solver in simulation software. H ∞ A robust damped oscillation suppression controller is proposed. The phase angle and voltage deviations of the wind turbines, measured under different grid strengths, are input into the controller, which generates active power compensation values ​​for grid-connected and grid-adapted wind turbines. This method ensures robust stability of the wind turbines under grid-connected or grid-connected control, effectively suppressing low-frequency oscillations in different wind turbines.

The application discloses an AC sampling system resisting damping oscillation wave interference, and belongs to the technical field of data sampling of a relay protection device.The system comprises sequentially connected collecting modules, a hardware filtering module, an analog-digital conversion module and an embedded processing module; wherein the collecting modules input collected AC signals containing damping oscillation wave interference to the hardware filtering module; the hardware filtering module filters high-frequency components of the AC signals, obtains filtered signals and inputs the filtered signals to the analog-digital conversion module; the analog-digital conversion module converts the filtered signals into digital filtered signals and inputs the digital filtered signals to the embedded processing module; and the embedded processing module extracts, classifies and conditions damping oscillation wave interference of the digital filtered signals, so that the damping oscillation wave interference in the AC signals is removed, and the problem that the AC sampling system is weak in resisting oscillation wave and the oscillation wave is not completely suppressed is solved.

The invention provides an electric power system negative damping oscillation source identification method and device and electronic equipment, and relates to the technical field of electric power systems. The power system negative damped oscillation source identification method comprises the following steps: acquiring monitoring data when a target power system generates negative damped oscillation; determining a quantitative index of negative damped oscillation of the target power system according to the monitoring data; according to the quantitative index, constructing a target function, and representing the intensity of the negative damped oscillation of the target power system based on the target function; utilizing a preset sensitivity analysis algorithm to determine sensitivity indexes of various correlation parameters of the quantitative indexes for the target function; and determining the negative damped oscillation source of the target power system according to the sensitivity indexes of the various correlation parameters for the target function. According to the invention, the negative damped oscillation source of the novel power system can be identified efficiently and accurately.

The application provides a main power supply type new energy station cluster control and damping oscillation system and a control method thereof, and comprises the following steps: S1, identifying grid-connected inverter grid frequency and voltage variation amplitude, and based on the identified grid-connected inverter grid frequency and voltage variation amplitude, actively performing primary frequency regulation and actively supporting grid-connected point voltage by a grid-connected power generation unit; S2, on the basis of active primary frequency regulation of the grid-connected power generation unit, dynamically selecting an adjustment step size according to a difference between target power and actual power; and S3, on the basis of active support of the grid-connected power generation unit on the grid-connected point voltage, dynamically selecting a voltage adjustment step size according to a difference between target reactive power and actual reactive power.

The invention discloses an on-line full-detection pressure management system for the overall sealing performance of a pressure cooker. The method comprises the following steps: carrying out constant-current inflation to enable pressure overshoot to generate damped oscillation, and solving an equivalent volume by utilizing a simultaneous equation of an overshoot peak value and an oscillation period; calculating the second-order curvature fidelity Cf and Cflt of the pressure-time curve in a passive attenuation section when the gas source is closed; and 1.15, determining that the product is qualified. The system only comprises a constant flow valve, a single pressure sensor, an electromagnetic valve and an MCU, the detection period is 2.3 seconds, the misjudgment rate is 0.8%, and the hardware cost is 50 yuan / station. According to the invention, through mining pressure signal self-contained information, extremely simple online full detection of zero newly added sensors and zero black box algorithm is realized, technical stacking defects in the prior art are avoided, and detection performance and economical efficiency are both improved in order of magnitude.

The utility model provides a high-speed damped oscillation generating circuit, which comprises a damping generating module 4 for generating high-speed pulses, the damping generating module 4 comprises a high-voltage end HV + and a low-voltage end HV-which are connected with a high-voltage power supply module 3, and a pulse output port BNC1 for outputting the pulses, a resistor R1, a relay switch K1, an inductor L2 and a resistor R2 are sequentially connected in series between the high-voltage end HV + and the pulse output port BNC1, a capacitor C1 is connected in series between the first end of the relay switch K1 and the low-voltage end HV-, and an inductor L1 is connected in series between the second end of the relay switch K1 and the low-voltage end HV-; a relay corresponding to the relay switch K1 is connected with the main control module 2, the relay is a novel tungsten contact vacuum relay, and the relay switch K1 is a semiconductor switch. According to the high-speed pulse generator, a simple circuit can be used, and high-speed pulses meeting the national military standard GJB 151B 2013CS116 can be generated.