14 results about "Power system stability control" patented technology

The present application relates to the technical field of power system stability control, and is a steady-state voltage control method and system for reducing transient voltage instability risk of a new energy collection station, the method comprising: establishing a new energy collection station bus transient voltage model of a new energy sending end power grid after a DC bipolar blocking fault; setting a new energy collection station transient voltage instability limit of the new energy sending end power grid after the DC bipolar blocking fault; and setting a steady-state voltage control threshold for reducing the transient voltage instability risk of the new energy collection station bus based on the new energy collection station bus transient voltage model. The present application can achieve the purpose of reducing transient voltage instability risk by controlling the steady-state operating voltage of a high-proportion new energy sending end power grid without increasing dynamic reactive power compensation equipment. The present application is used to solve the problem of transient voltage instability caused by new energy off-grid of a new energy collection station of a DC sending end power grid after a DC fault due to excessively high transient voltage caused by excessively high steady-state operating voltage of the power grid.

The present application relates to the technical field of power system stability control simulation analysis, and provides a transient simulation analysis and decision method, device and equipment for power grid harmonic oscillation, which comprises the following steps: combining the model and model parameters of electromagnetic transient offline simulation with the topology of the power grid to be analyzed to obtain an electromagnetic transient example, and then describing the calculation process of electromagnetic transient with a hierarchical directed acyclic graph, and taking each calculation model with redistributed resources as the electromagnetic transient algorithm; performing risk analysis on the harmonic oscillation condition according to the simulation result, and making an optimized decision on the harmonic oscillation suppression measures; through example design and electromagnetic transient algorithm design, an electromagnetic online simulation model is constructed to meet the simulation requirements of large power grids and realize the analysis and suppression decision of harmonic oscillation.

This application relates to the field of power system stability control technology, specifically to a method and system for online stability assessment and control of hybrid systems based on an improved short-circuit ratio. The method includes: constructing an equivalent model of the integrated / grid-connected hybrid system; calculating the improved short-circuit ratio of multiple renewable energy power plants based on the voltage source characteristics of grid-connected equipment to quantify the grid strength at each grid connection point; constructing a characteristic polynomial based on the impedance matrix; and using the circular loop theorem to quickly search for the dominant eigenvalues, avoiding high-dimensional calculations, to obtain the critical short-circuit ratio. If the real-time short-circuit ratio is lower than the critical value, an instability risk is determined, triggering a control strategy that increases the capacity of grid-connected equipment or adjusts the grid connection point. This method, through the combination of the improved short-circuit ratio and the circular loop theorem, achieves online quantitative assessment and closed-loop control of the small-disturbance stability of integrated / grid-connected hybrid systems.

This invention relates to the field of power system stability control technology, and is a wind power converter control method and system for reducing the risk of transient voltage instability at wind power collection stations. The method includes: establishing a transient voltage model of the wind power collection station in the renewable energy sending-end grid after a DC bipolar blocking fault; establishing a reactive power control model of the wind power converter under the transient voltage control mode based on active power output; and setting transient voltage instability limits for the wind power collection station in the renewable energy sending-end grid after a DC bipolar blocking fault. This invention can fully leverage the rapid reactive power control advantages of the wind power converter when the transient voltage instability risk of the wind power collection station is caused by the UHVDC bipolar blocking in the renewable energy sending-end grid, thereby reducing the peak transient voltage of the wind power collection station, preventing the wind farm units connected to the wind power collection station from tripping and disconnecting from the grid due to high voltage ride-through failure, thus reducing the risk of transient voltage instability at the wind power collection station and improving the transient voltage stability of the system.

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

The application provides a coupling power system stability control strategy collaborative control method, device, equipment and readable storage medium, which can be used for a stability control master station of a power system, especially a wide-area collaborative stability control master station. When multiple coupling stability control strategies exist in the power system, such as a stability control strategy triggered locally by the power system and a strategy for processing a remote control command simultaneously or sequentially exporting an action command in a short time and acting on the same group of controlled objects, the collaborative control of the multiple stability control strategies can be realized through a coordination mechanism independent of the stability control strategies, without changing the related strategies or changing other strategies after the partial strategies are updated, so as to reduce the under-tripping and over-tripping risks of the stability control master station of the power system when the coupling strategies exist, reduce the design difficulty of the stability control strategy collaborative control, reduce the mutual influence of the strategy and device updating, effectively realize that the total control amount result is controlled reasonably, and neither cause over-control nor cause loss of control, which harms the stability of the power system.

This invention belongs to the field of power system stability control technology and discloses a method for assessing the frequency support strength of a power grid based on inertial response and primary frequency regulation coordination. It constructs typical operating modes and a set of anticipated faults based on power grid planning data, obtains the frequency response trajectory through time-domain simulation, and extracts frequency change rate, minimum frequency, and steady-state frequency deviation characteristics. Based on power grid safety and stability guidelines, it establishes safety boundary values ​​for the frequency change rate and minimum frequency adapted to the current scenario. It constructs a comprehensive evaluation function including inertia, frequency regulation speed, and capacity strength, and introduces configurable dynamic weighting coefficients to calculate the comprehensive frequency strength evaluation index S. Based on the dual criteria of boundary non-exceeding limits and the comprehensive frequency strength index S≥1, it determines system safety and identifies weak links in scenarios that do not meet the requirements. This invention can effectively quantify the frequency support capability of the power grid under different planning schemes, providing a basis for grid optimization and resource allocation in high-proportion renewable energy power grids.

This invention discloses a control method for improving the transient stability of doubly-fed induction generator (DFIG) wind turbine systems connected to the grid, belonging to the fields of wind power grid connection technology and power system stability control technology. First, a reduced-order model of the system is established to accurately reflect the dynamic behavior during low-voltage ride-through. Based on this model, the attraction domain boundary and maximum power angle constraint are obtained, and then adaptive current reference control is proposed: the rotor d-axis current limit is calculated based on the maximum power angle constraint and the grid voltage, and compared with the original reference generated by maximum power point tracking. The smaller value is taken as the command to achieve adaptive limiting of the rotor current. Simultaneously, transient pitch collaborative control is proposed: the rotor speed is monitored in real time, and when the speed exceeds the safe upper limit, a transient load reduction power command is calculated and the pitch angle is rapidly increased to reduce mechanical torque. This invention can significantly enhance the fault ride-through capability and grid-connected operation reliability of DFIG wind turbines during transient processes such as voltage dips.

This invention provides a method for calculating energy storage reserve capacity based on the coordination of wind power and energy storage in the sending-end power grid, relating to the field of power system stability control technology. This invention connects large-scale wind power and energy storage equipment to the renewable energy sending-end power grid and constructs a sending-end system by equivalently representing multiple generators. Then, it constructs a transient power fluctuation curve after adding energy storage. For multiple fault scenarios in the sending-end system, it sets a dynamic safety domain boundary for each fault scenario and determines the hyperplane normal vector. Then, based on the power at the injection point, it determines whether the injection point of the sending-end system is outside the safety domain. When the injection point is outside the safety domain, the energy storage reserve capacity is calculated. Thus, this invention connects large-scale wind power and energy storage equipment to the renewable energy sending-end power grid, realizing the analysis of the transient stability of the sending-end system and thereby calculating the energy storage reserve capacity.

This invention relates to the field of power system stability control technology, and discloses a low-frequency load shedding control system and method. In this invention, the system includes a master station, power supply equipment connected to the master station, and controlled objects. The controlled objects are connected to the master station via communication, or via a substation. Controlled objects connected to the master station collect their real-time load information and upload it to the master station. Substations collect the real-time load information of their connected controlled objects and upload it to the master station. Power supply equipment sends its real-time status parameters to the master station. The master station measures the current system frequency, receives real-time status parameters and real-time load information. In response to the system frequency meeting a preset frequency triggering condition and the real-time status parameters meeting a preset overload enable criterion, the target load shedding amount is determined, and a disconnection action is triggered for at least one controlled object. This addresses the problems of load shedding malfunction and strategy mismatch under low inertia conditions.

The application discloses a kind of model prediction transient stability control methods of multi-organization network system under saturation constraint, belong to power system stability control technical field, including the following steps: considering the influence of current saturation limit, construct the transient analysis mathematical model of grid-forming two-machine parallel system before and after power grid fault;Saturation current phase control strategy is constructed based on transient analysis mathematical model;When saturation current phase control strategy cannot maintain the transient stability of grid-forming two-machine parallel system, the control strategy of active power reference value compensation amount is constructed;A kind of model predictive control strategy of combined saturation current phase control strategy and active power reference value compensation amount control strategy is proposed.The application adopts the model prediction transient stability control method of multi-organization network system under saturation constraint described above, it is favorable to meet the demand of the transient stability of grid-forming multi-machine parallel system.

The application discloses a network-constructed energy storage power station wide-frequency oscillation active damping adaptive suppression method, and belongs to the technical field of power system stability control. The method comprises the following steps: a data acquisition control system acquires real-time grid-connected point electrical quantity data and energy storage unit operation state data; a plurality of oscillation mode components of the wide-frequency oscillation are identified according to the electrical quantity data, and each component corresponds to an oscillation frequency interval; an active damping control subtask containing a target damping coefficient and a phase compensation angle is dynamically constructed for each oscillation mode component; all control subtasks are distributed to power control loops of each energy storage unit according to the energy storage unit operation state data; real-time monitoring of actual damping response data of each energy storage unit is performed, and an iterative update of a distribution strategy of the control subtask is performed according to a dynamic deviation between the actual damping response and the target damping coefficient. The method realizes multi-mode adaptive suppression of wide-frequency oscillation of the network-constructed energy storage power station and collaborative damping control among the energy storage units.