19results about "Power oscillations reduction/prevention" patented technology

The invention provides a flywheel energy storage system with an electromagnetic coupler, which comprises a motor, a flywheel rotor, the electromagnetic coupler, a frequency converter and a generator, and is characterized in that the motor is connected with the flywheel rotor to drive the flywheel rotor to rotate, the electromagnetic coupler comprises an outer rotor and an inner rotor, and the outer rotor sleeves the inner rotor and is spaced from the inner rotor; the flywheel rotor is in transmission connection with the inner rotor, the inner rotor generates a rotating magnetic field to drive the outer rotor to rotate, and the frequency converter is connected with the outer rotor to change the current frequency of the outer rotor so as to change the magnetic field rotating speed matched with the current, so that the mechanical rotating speed of the outer rotor is kept constant. The generator generates power, accesses the power grid and inputs electric energy with stable frequency into the power grid, the requirement of power transmission to the power grid is met, power electronic devices are not needed, rotational inertia in the power grid can be improved, necessary voltage and frequency support is provided for the power grid, and the capacity of the power grid for efficiently accepting new energy is improved.

A system for frequency regulation in a AC power supply system is disclosed, wherein the system comprises an uninterruptible power supply being electrically connected to the AC power supply system and comprising a phase-locked loop and / or a frequency-locked loop for monitoring the frequency of an AC input voltage received from the AC power supply system, wherein the phase-locked loop and / or the frequency-locked loop is / are designed to be operated with an operation frequency being higher than a nominal grid frequency and being selected to detect a deviation of the monitored frequency from the nominal grid frequency within a predefined time span after a frequency drop-off of the monitored frequency occurred, wherein a control signal (19) is generated based on the detected deviation of the monitored frequency from the nominal grid frequency, and wherein the generated control signal is used to regulate the power flow between the uninterruptible power supply.

According to one embodiment, a control device for an electric power system capable of supplying power to load devices in a plurality of demand areas based on first to N-th power devices in first to N-th placement areas and configured to be able to perform at least one of discharge or charge of power, comprising: a controller configured to detect, based on information of power consumption in each of the demand areas, a demand area in which the power consumption fluctuates more significantly than usual, and determine, according to distances between a detected demand area and the first to N-th placement areas, a control parameter related to input and output of power in the first to N-th power devices.

Disclosed in the present application are an oscillation suppression system and oscillation suppression method for an electric power system. The oscillation suppression system comprises a hydrogen production and hydrogen storage apparatus mounted at a sending-end power generation unit in an electric power system and a power generation apparatus mounted at a receiving-end power generation unit in the electric power system, wherein power generation fuel of the power generation apparatus is from the hydrogen production and hydrogen storage apparatus; and when active power oscillation occurs in the electric power system, the hydrogen production and hydrogen storage apparatus and the power generation apparatus are put into operation, such that a decrease in active power, which is transmitted by the sending-end power generation unit, is kept equal to an increase in active power, which is transmitted by the receiving-end power generation unit. Therefore, there is no need to cut off grid-connected power generation units in turns when active power oscillation occurs in an electric power system, and oscillation suppression can be directly performed by means of a hydrogen production and hydrogen storage apparatus and a power generation apparatus, thereby maintaining high-permeability wind / light consumption.

To provide a power supply device, an energy management system, and a power system that can improve the stability of power supply.SOLUTION: The power supply device to be connected to the power system includes an inverter, control means for controlling the operation of an inverter using a first parameter value so as to simulate the characteristics of a synchronous generator, and acquisition means for acquiring a second parameter value different from the first parameter value. The control means controls the operation of the inverter by changing the first parameter value to the acquired second parameter value.SELECTED DRAWING: Figure 1

The present specification relates to a method for selecting an optimal wind power generation prediction model, and an apparatus for performing same, the apparatus selecting an optimal wind power generation prediction model. The method for selecting an optimal wind power generation prediction model comprises the steps of: detecting weather prediction data having a most similar pattern by comparing weather prediction data for a future time duration with weather prediction data for past time durations; calculating, for the weather prediction data having the most similar pattern, predicted power generation amounts based on respective power generation amount prediction models; and comparing the predicted power generation amounts based on the respective power generation amount prediction models with the actual power generation amount in a time duration of the weather prediction data having the most similar pattern, and selecting, as an optimal wind power generation prediction model from among the plurality of power generation amount prediction models, the prediction model that has calculated a predicted power generation amount closest to the actual power generation amount.

The present invention relates to an operating system of a power system transient state compensated renewable power plant. The operating system comprises: a renewable power plant; a smart converter coupled to the renewable power plant; a point common coupling (PCC) power monitoring sensor installed at a PCC to collect state information about a power system; and a compensation command generation device for adjusting an output of the smart converter by transmitting a control command to the smart converter, determining a transient state of the power system by receiving the state information about the PCC power monitoring sensor, and adding a compensation command to the smart converter in real time when the transient state of the power system occurs and resolving the transient state, wherein when the transient state of the power system occurs, an output of the smart converter is automatically controlled and compensated. According to the present invention, it is advantageous to provide an operating system of a power system transient state compensated renewable power plant, the power system rapidly adjusting an output to stabilize a system frequency when a transient state of the power system occurs, contributing to maintaining a voltage, supplying reactive power to maintain a system voltage, improving power quality, providing inertia like a rotary generator to improve stability of the system, and integrally managing a plurality of distributed energy resources to improve system stability.

The present invention relates to a feasible-region solving and reconstruction method and system for a hybrid grid-following and grid-forming converter grid-tied system. The method comprises: acquiring hybrid converter grid-tied system parameters and alternating-current power grid parameters; by means of grouping and equivalent aggregation, simplifying a hybrid converter grid-tied system into a plurality of equivalent grid-following or grid-forming converters; theoretically determining a capacity feasible region satisfying overload capacity constraints and a static voltage stability feasible region satisfying static voltage stability constraints; discretizing an intersection of the capacity feasible region and the static voltage stability feasible region; determining, point by point, whether an operating condition satisfies wideband oscillation constraints, and if so, determining that the operating condition belongs to an operational feasible region of the hybrid converter grid-tied system, so as to finally obtain an operational feasible region of a hybrid grid-following and grid-forming converter grid-tied system; and expanding and reconstructing the operational feasible region by configuring grid-forming converters. The present invention considers the differences between different converters and all operating conditions that the converters may face, and can ensure the safe and stable operation of the converter grid-tied system.

A method of controlling the operation of a power converter of a power generation system is provided. The power generation system (100) may be electrically coupled to a power grid (150) to provide electrical power generated by the power generation system (100) to the power grid and the power converter (105) may control an output power of the power generation system (100). The method (500) may operate the power converter (105) in an impedance compensating mode. The impedance compensating mode may comprise monitoring (S710) a parameter indicative of a grid voltage of the power grid (150), applying (S720) a compensating transfer function (215, 235) to the monitored parameter (ug) to generate a modification parameter (uv) and modifying (S730) a control (210, 230) of the power converter (105) by applying the modification parameter (uv) to a control parameter of the control of the power converter (105). The compensating transfer function (215, 235) may be configured to reduce a reactance of an output impedance of the power generation system (100) to provide a compensated output impedance of the power generation system.

Disclosed in the present application are a power system and a frequency modulation control method therefor. The method comprises: first, determining whether the current power grid frequency of a power system falls within a preset allowable frequency deviation range; if not, performing calculation according to the current power grid frequency and a power grid rated frequency to obtain an input current change value of a hydrogen production power generation unit in the power system; on the basis of the size relationship between the input current change value and limit values thereof and the size relationship between the changed input current value and limit values thereof, determining a target input current of the hydrogen production power generation unit; and finally, adjusting an input current of the hydrogen production power generation unit according to the target input current, so as to allow the power grid frequency of the power system to fall within the preset allowable frequency deviation range. Therefore, by means of the relationship between system power consumption and frequency fluctuation, the present application can guide input current setting for the hydrogen production power generation unit on the basis of a measured system frequency to achieve frequency modulation control of the power system, thus solving the problem of frequency fluctuation of power grid systems caused by randomness and fluctuation of renewable energy power generation.

The present application relates to the technical field of power system automatic control, and discloses a primary frequency regulation method and apparatus for a controllable load resource participating in a power system, a computer device, a computer-readable storage medium, and a computer program product. The method comprises: acquiring load status data of a power system, and performing multidimensional load clustering on the load status data to obtain a load characteristic time series data set; on the basis of the load characteristic time series data set, using an extended dynamic mode decomposition algorithm to establish a Koopman operator high-dimensional linear model of the power system; using the Koopman operator high-dimensional linear model of the power system to optimize and calculate the load status of the power system to obtain an optimal load control sequence; and using the optimal load control sequence to perform frequency regulation on a controllable load resource participating in the power system. The present application achieves stable prediction of the load status of the power system, and accurate frequency regulation for the controllable load resource participating in the power system, thereby improving the operating efficiency and stability of the power system.

The present invention relates to a system and a method for controlling steady-state power decoupling of a grid-forming inverter and, more specifically, to a system and a method for controlling steady-state power decoupling of a grid-forming inverter, which estimate an optimal virtual impedance value and a transient virtual resistance value at which steady-state power decoupling control can be achieved during operation of the grid-forming inverter, and control so that output reactive power fluctuations due to active power command fluctuations of the grid-forming inverter do not occur.

Provided are multi-terminal flexible direct-current adaptive grid-forming control system and method, a device, and a medium. Power set values of a first adaptive grid-forming converter and a second adaptive grid-forming converter are set according to loss of a high-voltage direct-current line. An adaptive grid-forming control model is constructed, and an alternating-current voltage instruction is determined based on the adaptive grid-forming control model. A current inner loop constraint control strategy is established based on virtual admittance and current clamping. A current inner loop control instruction is determined according to the current inner loop constraint control strategy. An operation of the multi-terminal flexible direct-current adaptive grid-forming control system is controlled based on the power set values, the alternating-current voltage instruction, and the current inner loop control instruction.

The present invention discloses a frequency regulation method and device for a power grid using a wind turbine, wherein the method comprises steps of: real-time achieving a frequency information of the power grid at a connection point of the wind turbine and a wind speed information of the wind turbine, wherein the frequency information comprises a frequency deviation and a rate of change of frequency; in response to the frequency deviation being greater than a deviation threshold, determining an adaptive deloading coefficient according to the rate of change of frequency, wherein the adaptive deloading coefficient is set based on the rate of change of frequency and the wind speed information of the wind turbine; determining a deloading information of frequency regulation for the power grid using a wind turbine according to the determined adaptive deloading coefficient, the frequency deviation and the wind speed information of the wind turbine; performing frequency regulation on the power grid using the wind turbine according to the deloading information and the wind speed information of the wind turbine. By the present invention, the deloading of frequency regulation at different times for the power grid using a wind turbine can be effectively controlled, and the accuracy of the frequency regulation for the power grid using a wind turbine can be improved.

To provide a power system stabilization device and method that efficiently perform power supply limitation of a renewable energy power supply and a synchronous power generator while ensuring synchronization power in a power system including both the synchronous power generator and the renewable energy power supply.SOLUTION: A power system stabilization device 1 includes: a stability calculation unit that calculates the stability when a power system 9a including synchronous power generators 2-1 to 2-3 and a renewable energy power supply 3 break down; a contraction system model creation unit that creates a contraction system model by using one or more nodes as contraction starting point nodes to make a topology of a power system including unstable power generators in a radial shape and contracting the power system including a stable power generator at an upper level from the contraction starting point node; a P-δ curve calculation unit that extracts the synchronous power generator that steps out based on the contraction system model and calculates a P-δ curve showing a relation between a phase angle and output effective power for each synchronous power generator; and a power control device selection unit that selects a target to limit the power supply from the synchronous power generator and the renewable energy power supply based on power supply limitation effect calculated based on the P-δ curve.SELECTED DRAWING: Figure 1

Disclosed in the present application are a reinforcement learning-based inertia flywheel control method and system. The method comprises: storing into an experience replay buffer transition experience tuples obtained by interaction with a simulated environment and a neural network, and randomly sampling a set number of experience tuples from the experience replay buffer at the current moment, so as to update the neural network; on the basis of rewards in the current experience replay buffer, determining whether a neural network update ending condition is satisfied, and if yes, using the updated neural network as a trained neural network, and otherwise continuing to update the neural network until the ending condition is satisfied; and inputting to the trained neural network a state variable of an output end of an inertia flywheel requiring control quantity calculation, so as to obtain an action, and on the basis of the action and a torque set value, acquiring a control quantity to be input to the inertia flywheel. By means of the solution of the present application, the neural network can adjust the policy thereof on the basis of actual performance, so as to more accurately predict and calculate the action corresponding to the state variable of the inertia flywheel output end.

The present invention relates to an energy-function-based transient synchronization stability evaluation method for a grid-connected system including multiple virtual synchronous generators, the method comprising the following steps: constructing a system non-linear reduced-order mathematical model suitable for transient synchronization stability analysis; taking into consideration dynamic strong coupling of active power control and reactive power control and dynamic interaction of multiple virtual synchronous generators, analyzing and constructing an energy function of the system; by means of the closest unstable equilibrium point method and an optimization method, respectively calculating a maximum energy value for ensuring system stability and a maximum energy value for ensuring that the system does not trigger current amplitude limiting under the condition that the system does not trigger current amplitude limiting after fault removal; taking the smaller value of the two to obtain a critical energy value for ensuring transient stability of the system; calculating a trajectory of the system during the fault by means of numerical integration to obtain the state of the system at the moment of fault removal; substituting the state of the system at the moment of fault removal into the energy function to calculate an energy function value of the system at the moment of fault removal; and evaluating transient synchronization stability of the system.

In a water electrolysis system that changes a power consumption by detecting a grid frequency in order to rapidly change the power consumption, deterioration and breakdown of the electrolyzer are suppressed by calculating an appropriate adjustment margin that allows an electrolyzer to instantaneously respond. The water electrolysis system includes: a rectifier that converts an AC power from a power grid to a DC power; an electrolyzer that performs a water electrolysis with the DC power from the rectifier; a gas-liquid separator that separates the oxygen and the hydrogen from a mixed fluid of oxygen and water from the electrolyzer; and a cooling system that supplies water to the electrolyzer. The rectifier is controlled so as to adjust power consumption according to a frequency of the power grid, and the power consumption is adjusted so as to fall within a limit range of the power consumption in the electrolyzer, and the limit range of the power consumption is determined on the basis of a temperature of the electrolyzer, a deterioration rate thereof, a water pressure in an electrolyzer outlet, and a flow rate of supply water.

An invention offers a broadband oscillation suppression method and apparatus for wind-storage combinations. The method involves several steps: first, acquiring the operational state of a wind-storage station system at an initial moment. Next, different control variables and this operational state are input into a prediction model to identify two wind turbine frequencies and their corresponding operational states for a subsequent moment. Then, these control variables and the new operational states are used in the prediction model to derive wind turbine frequencies for a third moment. Finally, a control variable from the initial moment, linked to the wind turbine frequency with the lowest value function among the two frequencies at the third moment, is selected as the final control variable for managing the wind turbine and energy storage system. The method effectively reduces regulation costs during broadband oscillation suppression, enhancing the operational safety and stability of the wind-storage station.