135 results about "Power oscillation" patented technology

The invention relates to the technical field of energy storage systems, in particular to a symmetric / asymmetric fault ride-through control method for a network-forming type energy storage converter, which comprises the following steps of fault detection and classification, adaptive control target decision and multi-mode unified control. According to the method, adaptive and intelligent fault ride-through is realized, the control accuracy and efficiency are improved, the adaptability and robustness of the energy storage system in different power grid fault scenes are enhanced, the center of gravity is dynamically adjusted and controlled according to the charge state of the energy storage system or the received power grid dispatching instruction, the maximum utilization of system resources is realized, and the power grid fault ride-through efficiency is improved. The voltage and frequency support is provided for the power grid, the response speed is far higher than that of traditional deviation adjustment, the voltage support effect at the moment of a fault is greatly improved, sudden change of power and current is effectively prevented, secondary impact on the recovered power grid caused by off-grid of the converter or power oscillation is avoided, and the friendliness of network forming equipment is embodied.

The invention provides a virtual inertia adaptive control method, device and system, and relates to the technical field of inverter system control. The method comprises the following steps: calculating a reference current value according to a power reference value and an actual output voltage; calculating a current deviation value according to the reference current value and the actual output current value; outputting the current deviation value to an adaptive resonance controller to obtain a compensation control voltage signal; inputting the compensation control signal to an AHO virtual oscillator to obtain a reference value of the output voltage of the inverter; and controlling the output of the three-phase inverter circuit according to the reference value of the inverter output voltage. Wherein the adaptive resonance controller carries out adaptive control through the proportional parameter and the proportional resonance inertial parameter. The virtual inertia output can be dynamically adjusted according to the real-time requirement of the system, the overshoot phenomenon caused by power oscillation is effectively suppressed while the frequency stability is met, and the capacity of the system for resisting sudden load change and frequency disturbance is enhanced.

The invention provides a thermal power generating unit power oscillation on-line monitoring system, and relates to the technical field of monitoring, an output power sequence, a frequency sequence, an operation parameter set and a control instruction set are acquired through a data acquisition module, and a data processing module performs denoising, abnormal value elimination, time alignment and resampling on an original data set to generate a processed data set; the oscillation analysis module calculates an oscillation characteristic index based on the processing data set and generates an oscillation judgment result; the early warning module outputs an early warning signal when determining that power oscillation exists; the linkage control module generates a control instruction after receiving the early warning signal, and cuts off a frequency modulation action loop or adjusts frequency modulation related parameters; and the data storage module is used for carrying out structured storage on the processing data set, the oscillation characteristic indexes, the oscillation judgment result, the early warning signal and the control instruction. Therefore, real-time monitoring, accurate identification and rapid linkage control of power oscillation of the thermal power generating unit can be realized, and the operation stability of the unit and the safety of a power grid are improved.

The invention discloses a power feedback and phase compensation-based oscillation suppression strategy for a multi-configuration-network converter grid-connected system. The multi-configuration-network converter grid-connected system mainly comprises the following modules: a power calculation module, a virtual speed regulator module, a virtual rotor module, a reactive power-voltage droop control module and a voltage and current double-closed-loop module. In the virtual rotor module, the output active power and the output power angle are subjected to a differential link to construct a power feedback loop, the difference value between the output angular frequency of the virtual rotor and the rated power grid frequency is used as the phase compensation amount, and a power feedback and phase compensation strategy is applied; the problem that after grid connection, a multi-grid converter is prone to being disturbed by the power grid frequency to generate violent power oscillation is solved.

The invention discloses a turbine generator set power oscillation emergency valve switching control method, system, equipment and medium based on a thermodynamic model, and belongs to the technical field of electric power system automation control and thermal energy power engineering, and the method comprises the steps: monitoring the operation state of a set in real time, and collecting the current data of the set; calculating a theoretical balance valve position required for maintaining the current target power in real time by using the corrected inverse thermodynamic model; and the power fluctuation condition is monitored in real time, when it is detected that power oscillation happens to a unit and valve cutting logic is triggered, the system intercepts a conventional feedback instruction for tracking the actual valve position, the theoretical balance valve position is directly used as a target instruction, and a control valve is forcibly driven to act to the valve position through a rate limiter. According to the method, it can be ensured that after closed-loop control of the unit is cut off, the valve rapidly returns to the physical balance opening degree matched with the current load, an oscillation source is effectively eliminated, severe fluctuation of main steam pressure and temperature is stabilized, and the safety and stability of the unit under the abnormal working condition are remarkably improved.

The invention relates to an anti-countercurrent device suitable for a miniature grid-connected inverter system, which is characterized in that an anti-countercurrent electric meter and at least one miniature grid-connected inverter form a local area network through a local router to form a system, and the anti-countercurrent electric meter accurately acquires power grid parameters through a power grid voltage sampling terminal and a current measurement signal input terminal of the anti-countercurrent electric meter; and the real-time grid-connected power of each micro grid-connected inverter is inquired regularly as a control center, a power adjustment instruction is calculated and broadcasted, and finally all the micro grid-connected inverters are driven to adjust output synchronously. An anti-countercurrent electric meter is used as a unified control core, and a unified power adjustment instruction is calculated based on real-time countercurrent power and total generated power, so that all micro inverters can adjust power synchronously and proportionally, accurate cooperative control of multiple micro inverters is realized, and power oscillation is avoided; the whole control closed loop operates in a high-speed local area network, is quick in response, meets the grid-connected standard requirement for eliminating countercurrent, and effectively guarantees the safe operation of a power grid.

The application discloses a power oscillation data processing method and device, a storage medium and an electronic device. The method comprises the following steps: determining a plurality of sites, and determining oscillation data corresponding to the plurality of sites respectively; inputting the oscillation data corresponding to the plurality of sites respectively into a target knowledge graph representation learning model to obtain a target knowledge graph representing the relationship between the plurality of sites; and determining an oscillation propagation path of a target oscillation anomaly included in the oscillation anomaly corresponding to the plurality of sites respectively based on the oscillation data corresponding to the plurality of sites respectively. The application solves the technical problem of lacking the ability of monitoring information analysis and display for wideband oscillation in the related art.

The application discloses a kind of based on real-time demand analysis's energy storage power station state evaluation method and system, it is related to power station state evaluation technical field, comprising: obtaining the real-time operation data of energy storage power station;Real-time operation data includes voltage data, current data, temperature data and power data;Based on real-time operation data, establish the real-time evaluation index system of energy storage power station under power grid system demand;Based on the real-time evaluation index system of energy storage power station, establish the performance comprehensive evaluation model of energy storage power station, and the state of energy storage power station is evaluated according to the performance comprehensive evaluation model of energy storage power station.The application obtains operation data from PCS converter, battery body and PCC point multidimension, combined with the systematic evaluation index system of four kinds of demands of power grid frequency modulation, peak regulation, voltage regulation and power oscillation suppression, using dynamic fuzzy comprehensive evaluation and adaptive weight dynamic adjustment combined evaluation method, the overall accurate evaluation of the state of energy storage power station is realized.

The invention discloses an instantaneous power distribution method and device of an isomorphic energy storage converter, terminal equipment and a storage medium, and belongs to the technical field of energy storage converter power distribution.The method comprises the steps that the energy storage output current, the energy storage output voltage, the energy storage input current and the output voltage instruction value of the isomorphic energy storage converter to be distributed are obtained; further calculating to obtain a first output current, a first correction current reference and a second correction current reference; performing gain amplification and difference suppression to obtain a third correction current reference; performing current outer loop control to obtain a phase shift angle of the isomorphic energy storage converter; and finally, performing on-off control on the isomorphic energy storage converter through the phase shift angle to obtain the instantaneous distribution power of the isomorphic energy storage converter. According to the invention, the problem that the continuous power oscillation of the isomorphic energy storage converter is caused because the same instantaneous power distribution cannot be carried out in the prior art can be solved.

The present application relates to photovoltaic and energy storage collaborative control technical field, especially to be applied to 5G integrated power supply photovoltaic control adjustment method and system, the present application proposes the following scheme, the photovoltaic characteristic parameter and corresponding time mark data are collected, three-dimensional curved surface model is constructed to carry out differential geometry curvature analysis, according to the curvature analysis result, the light change event type is determined and the photovoltaic maximum power point is positioned, according to the photovoltaic maximum power point, the photovoltaic output parameter adjustment and energy storage charging and discharging strategy is generated, the present application realizes the quick response to the quick fluctuation of light through the fusion of multidimensional characteristic parameters, adopts the positioning strategy of event-driven, improves the maximum power point tracking accuracy and dynamic stability, reduces power oscillation and energy loss, realizes the collaborative optimization of photovoltaic, energy storage and load.

The application discloses a power fluctuation smoothing control method and system for photovoltaic power station cluster, and particularly relates to the technical field of power system control, and is used for solving the power oscillation and instability problem caused by the existing smoothing control method due to neglecting the internal power grid dynamic characteristics of the cluster; by acquiring historical power flow and historical smoothing control instructions, the information transmission entropy distribution between the instructions and the flow under different frequencies is analyzed to identify the dominant oscillation mode frequency, the nonlinear interaction strength of the smoothing control loop of each substation is evaluated, and the time and space distribution inertia center of the node oscillation energy is calculated, the system dynamic instability criterion is constructed based on the nonlinear interaction strength and the inertia center offset trajectory, the dynamic safety constraint set with the target of inhibiting the oscillation mode is constructed when the criterion is established, and the smoothing control instruction optimization model is solved under the constraint set restriction to generate and execute new control instructions to each substation.

The application discloses a converter control method for improving power transmission stability of a flexible DC interconnection system, relates to the technical field of flexible interconnection system control strategies, and solves the power oscillation problem of the existing flexible DC interconnection device control method.The technical solution points are that the control modes of the converters on the two sides of the flexible interconnection system are adaptively switched according to the energy flow direction of the system.The technology realizes the control by coordinating the DC voltage, the power control outer ring, the limiter, the current control inner ring and other control links, superimposes the power control current feedback instruction after the limiter and the DC voltage control current feedback instruction as the current inner ring control instruction, and controls the operation of the power electronic converter through the current inner ring controller and the PWM modulation instruction.The inner ring current instruction value of the converters on the two sides of the flexible DC interconnection system is adaptively adjusted with the change of the system power flow direction, can be the control of the DC voltage or the control of the system power flow direction, and the control mode of the unilateral converter is not limited to the fixed DC voltage control or the fixed power control.Under the premise of ensuring the reliable and stable switching of the control modes of the two-side converters in the system, the system stability problem caused by the power flow direction under the fixed control mode of the unilateral converter is solved.

The invention discloses a virtual synchronous generator coordination control method and system, and belongs to the technical field of virtual synchronous generator control, and the method comprises the steps: constructing a multi-virtual synchronous generator parallel admittance model, and carrying out the dynamic compensation of a power angle in the multi-virtual synchronous generator parallel admittance model based on an equal area rule, and obtaining an active power reference value; inputting the active power reference value into the multi-virtual synchronous generator parallel admittance model, designing a phase angle decoupling coordination strategy to decouple a phase angle, and eliminating cross coupling in the multi-virtual synchronous generator parallel admittance model and interference of each phase angle control ring; and optimizing multiple virtual synchronous generator parallel admittance model parameters and verifying the system stability of the model to realize virtual synchronous generator coordination control. According to the method, the problems of phase angle coupling, power oscillation and synchronism of the multi-virtual synchronous generator parallel admittance model under asymmetric line parameters are solved, and the transient / steady-state performance and anti-disturbance capability of the model are improved.

The invention discloses a chained energy storage system and network construction hybrid control method based on state switching. The method comprises the following steps: 1) calculating related voltage, current, inductance and resistance; 2) calculating the number of power modules connected in series and parameters of a direct-current accumulator; 3) calculating a grid-following active current given value through a grid-following active regulator, and calculating a grid-following reactive current given value through a grid-following reactive regulator; 4) calculating given values of active current and reactive current of the network; (5) SCR is calculated through a state switching control unit, and state switching is carried out between network construction and network following; 6) obtaining a three-phase modulation wave through an active current and reactive current decoupling controller and an inter-phase voltage-sharing controller; 7, interphase voltage-sharing control is carried out through the interphase voltage-sharing controller, the switching pulse value of each power unit is obtained, corresponding switching tube driving pulses are generated, and state control is achieved.The method belongs to the technical field of chain type energy storage control, and the problems of overcurrent, voltage abrupt change and power oscillation during switching are avoided.

The invention relates to a battery charging and discharging control method for an energy storage system, and the method comprises the steps: collecting the voltage and temperature signals of a single battery in real time, dynamically constructing a safe operation range containing a current boundary and a temperature limit value, and generating a preliminary current distribution scheme based on the load demand of a power grid; and further predicting a risk monomer temperature rise track by using an electrothermal coupling model, dynamically correcting current distribution through negative feedback adjustment, and finally generating a charging and discharging instruction meeting a multi-constraint condition through distributed optimization. According to the method, the limitation of a traditional static threshold strategy is broken through, the power oscillation and thermal runaway risk caused by load sudden change or aging difference in a multi-battery-pack cooperation scene is solved, the system safety, the service life balance and the dynamic response capability are remarkably improved, and a high-robustness control normal form is provided for a large-scale energy storage power station.

The invention belongs to the technical field of stable control of a power system, and particularly discloses a power angle compensation-based method for quickly recovering active power after a fault of a network-forming converter, which comprises the following steps of: monitoring a voltage amplitude and a power difference value at a grid-connected point of the network-forming converter in real time; according to the voltage amplitude and the power difference value, identifying whether the network-forming converter is in an unstable state of active power oscillation after the fault is cleared; if the state is identified as an unstable state, calculating a power angle compensation amount used for counteracting power angle deviation caused by a fault based on detected voltage drop information and system impedance parameters; and superposing the power angle compensation value to a power angle generated by a power control ring of the network-forming type converter, and generating a compensated power angle instruction for controlling pulse modulation of the converter so as to realize active power recovery after the fault is cleared. The method can adapt to different power grid impedance conditions, quickly suppress power oscillation and realize quick recovery of active power, so as to improve the transient stability and reliability of a novel power system.

This application discloses a power control device, a chip, a charging case, and earphones, belonging to the field of power control. The device includes a DC-DC boost circuit, a low-power oscillation circuit, and a logic circuit. The logic circuit is connected to the other two circuits. The DC-DC boost circuit is connected to the output terminal and the power supply, and is used to output electrical energy from the power supply. The low-power oscillation circuit provides a periodic trigger signal to the logic circuit to determine whether the DC-DC boost circuit is activated when the earphones are continuously in the case. The logic circuit controls the DC-DC boost circuit to be activated during a first time period and deactivated during a second time period. The first time period is the period during which electrical energy is output to the output terminal via the power supply. By using the periodic trigger signal from the low-power oscillation circuit and the logic circuit to control the DC-DC boost circuit to be deactivated when it is determined that no electrical energy needs to be output to the output terminal via the power supply, the power consumption of the power control device can be reduced.

An oscillator is proposed that can produce much greater voltage than the input voltage. To accomplish this, the coil and the capacitor in the tank circuit are connected in series. This creates a high voltage point between the capacitor and the coil. However, in order to work it requires a special feedback method. Like the Hartley and Armstrong oscillators, it draws energy from the coil in the tank circuit, except it is accomplished by a separate coil placed a given distance away from the coil in the tank circuit. Ultimately this oscillator has advantages when high power is needed. It has a small component count and is easy to build. Currently if one wants to have high power oscillation, one uses a low voltage signal generator and then goes through several steps to amplify the signal. Here the oscillator already produces the high voltage. Another advantage in the design is that since the feedback has to provide the right amount of energy, this can be adjusted to the optimal feedback by manually adjusting the distance between the coils. Another advantage is that, when aligning the coils correctly, the oscillator produces a virtually perfect sine wave.

This invention provides an active power regulation method and system that considers instantaneous energy distribution efficiency, relating to the field of wind power grid-connected control technology. The invention establishes a synchronized operation system model based on the system parameters of the wind turbine and synchronous machine, determines the total inherent active power regulation coefficient and synchronous torque coefficient of the system to obtain the conservative instantaneous power of the synchronized system; introduces an active power regulation proportional coefficient into the model and constructs an instantaneous energy function during synchronized system oscillation, analyzing the instantaneous energy distribution law between synchronized units; after a disturbance, the instantaneous energy distribution efficiency is determined based on the instantaneous energy of the synchronous machine, a target efficiency is given, and the active power regulation proportional coefficient is solved based on the total instantaneous energy conservation, thereby calculating the design value of the active power regulation coefficient and setting it in the active power controller of the wind turbine unit, so that when the system detects frequency or power disturbances, the wind turbine participates in regulation according to the design value, thereby improving the power oscillation suppression capability.

The application discloses a parameter setting method, device and system for a swing reactance of an excitation regulator, wherein the parameter setting method adds forced oscillation to a speed regulator link in a closed-loop simulation test environment, so as to stimulate equal-amplitude oscillation of mechanical power and unit frequency in a set frequency range; the error between a real signal value output by a real excitation device and a simulation signal value output by a simulation test model is calculated, the initial value of the swing reactance parameter is selected according to the error, the adaptability and effectiveness of the swing reactance are verified based on the initial value, the test result is obtained through a voltage step test under a set working condition, and the swing reactance parameter is modified according to the test result, so that the active power fluctuation when the PSS is put into operation meets the set condition. The parameter setting method provided by the application can reduce the risk of power oscillation accidents caused by large unit speed calculation error due to unreasonable swing reactance parameter setting and weak damping or even negative damping of the PSS.

The invention provides a new energy unit transient stability optimization method and system based on active feed-forward, and belongs to the field of new energy power generation. The system includes a current command generator and a current controller. The method comprises the steps of collecting terminal voltage and current of a unit, calculating active power and detecting a transient fault; when a fault is detected, generating an active current instruction through active feed-forward control based on power grid voltage information obtained by an active power signal, a fault voltage amplitude signal and phase locking; meanwhile, a reactive current instruction is generated; a current reference instruction is synthesized, and a converter is driven through closed-loop control to provide power support. According to the method, an active feed-forward mechanism is introduced, so that the new energy unit can respond to the power shortage of the power grid in advance, active and reactive support is quickly provided, frequency drop and power oscillation in the transient process are effectively inhibited, and the transient stability of the power system under the access of high-proportion new energy is remarkably improved.

The embodiment of the invention discloses a self-adaptive switching control method of a static synchronous compensator and a related device. The method comprises the following steps: acquiring current reactive power output by the static synchronous compensator; obtaining a current reactive oscillation index of the static synchronous compensator by using the current reactive power and a preset feature extraction algorithm; switching the static synchronous compensator to a target control mode according to the current reactive oscillation index and a preset hysteresis switching logic; and controlling a current inner loop of the static synchronous compensator according to the target control mode and the current reactive power to obtain reactive compensation current output by the static synchronous compensator. Through the above mode, the control mode, such as PI control or sliding mode control, of the static synchronous compensator is dynamically selected by taking the current reactive oscillation index as a criterion, so that the reactive power oscillation is effectively suppressed, the dynamic immunity and steady-state precision of the system are ensured, and the stability of the power system is improved.

This invention discloses a flywheel-battery hybrid energy storage method and system for suppressing grid power oscillations, relating to the field of power system stability control technology. It includes: acquiring the real-time rotor speed of the flywheel energy storage unit; generating a first power command based on the deviation from a preset rated speed; determining whether the real-time rotor speed is within a preset speed range; if it exceeds the limit, generating a second power command to control the battery energy storage unit to charge and discharge at a constant power; if it is within the range, generating a third power command based on the DC bus voltage deviation; and controlling the battery to execute the commands based on priority arbitration logic, with the second power command having higher priority than the third power command. This invention addresses the problems of existing centralized control architectures heavily relying on complex communication, experiencing response delays, and batteries suffering from shallow charging and discharging and rapidly declining lifespan due to frequent tracking of power oscillations.

The invention discloses an external power grid-containing line oscillation power calculation method based on amplitude-frequency modulation decomposition. The method comprises the following steps: constructing a simplified wind power parallel impedance line grid-connected system model; establishing a standard form of an amplitude-frequency modulation signal; preliminarily calculating oscillation power response based on a simplified wind power parallel impedance line grid-connected system model; decomposing the oscillation power response into a power response under amplitude modulation and a power response under frequency modulation; and projecting the power response under amplitude and frequency modulation excitation to an XY coordinate system by using a phasor method to obtain a final oscillation power amplitude expression. According to the method, the power oscillation response on the external power grid voltage source circuit of the wind power grid-connected system can be accurately obtained, meanwhile, the calculation method is simple and easy to use, and power flow analysis of subsynchronous oscillation can be researched easily.

The application provides a grid-connected device control method and system, a grid-connected device and a medium. The method comprises the following steps: acquiring a first grid-connected point voltage; when the first grid-connected point voltage enters a preset low penetration buffer interval or a preset high penetration buffer interval, adjusting the active power or the reactive power of the grid-connected device according to the priority mode configuration and the device attribute parameters of the grid-connected device to obtain a second grid-connected point voltage. When the second grid-connected point voltage enters a low penetration interval or a high penetration interval, the priority mode configuration is adjusted to a reactive power priority mode, and reactive power absorption is performed to obtain a third grid-connected point voltage. When the third grid-connected point voltage is greater than a preset low penetration threshold or less than a preset high penetration threshold, the priority mode configuration is adjusted to an active power priority mode. In this way, the problem of power oscillation caused by frequent fluctuations of the grid-connected point voltage at the high and low penetration thresholds is avoided, and the safety of the power grid and the grid-connected device is effectively ensured.

A low power oscillator maintains its oscillation frequency regardless of environmental conditions. The oscillator comprises a reference current source, a voltage source and a ring oscillator. The reference current source outputs a reference current dependent on the first supply voltage, and the voltage source outputs a second supply voltage dependent on the reference current. The oscillation frequency of the ring oscillator depends on the second supply voltage.

The invention discloses a high-low voltage ride-through control method of a static synchronous phase modifier network following working condition. The method comprises the following steps: 1) calculating related voltage, current, inductance and resistance; 2) calculating parameters of an H-bridge power module; 3) according to a network tracking control strategy, considering high and low voltage ride-through working conditions, and calculating active current and reactive current given values; 4) obtaining a three-phase modulation wave initial value of the upper bridge arm of the static synchronous phase modifier through current decoupling control and voltage feedforward control; 5) obtaining a three-phase modulation wave initial value of the lower bridge arm of the static synchronous phase modifier through current decoupling control and voltage feedforward control; the invention belongs to the technical field of high-voltage and low-voltage ride-through control, stable operation can be kept during high-voltage and low-voltage ride-through, and the phenomena of overcurrent, voltage abrupt change and power oscillation are avoided during high-voltage and low-voltage abrupt change.

The invention provides an improved backstepping control method of a three-phase current source type converter under a non-ideal power grid, and relates to the technical field of power electronic converters. Specifically, the power grid current sine degree of the system is ensured, the steady-state performance and the dynamic performance of the control system are improved, the robustness is good, the algorithm design is simple, implementation is easy, active power oscillation suppression is obvious, the total harmonic distortion of the power grid current is lower, and the scheme is economical and reliable.

The invention discloses a dual-mode control method, device and system for a high-inertia energy storage type phase modifier, and belongs to the technical field of power system control. Virtual synchronous machine control is adopted under the normal working condition and the initial stage of the fault, and active inertia support at the moment of the power grid fault is achieved; when the power grid has a deep fault, switching to current source type control after pre-synchronization operation, and eliminating power oscillation; after the fault is cleared, the rotating speed is recovered through current source type control, and then the inertia supporting mode is switched back; according to the method, an active frequency loop of the virtual synchronous machine is improved, when the power grid frequency begins to drop or rise, the phase modifier is controlled to emit or absorb active power, and rotation speed instability caused by continuous supporting is avoided; on the basis, pre-synchronization operation is introduced, so that the output angles of the two control modes are consistent with a current reference value during mode switching, power impact existing in the mode switching process is effectively reduced, smooth switching is achieved, and secondary damage to a power grid is avoided.

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.