74 results about "Multi machine system" patented technology

The invention provides a grid-connected converter multi-band control device and method for suppressing broadband oscillation. The device comprises a cascade multi-scale controller and a broadband oscillation controller. According to the invention, cooperative damping control is carried out on different controllers of the grid-connected converter by adjusting the software control mode of the grid-connected converter. Oscillation signals of different frequency bands are collected, oscillation frequency bands are divided into a low frequency band, a middle frequency band and a high frequency band, damping controllers are arranged in the different frequency bands, broadband oscillation of the grid-connected converter is restrained, and broadband oscillation caused by interaction between the grid-connected converter and a power grid and interaction between converters under different power grid intensities and different working points can be restrained. And the stability of a grid-connected converter single-machine / multi-machine system is comprehensively improved. Moreover, the method is suitable for equipment and scenes such as a wind power grid-connected converter, a photovoltaic grid-connected converter, a flexible direct current transmission converter, a flexible alternating current system converter and the like.

The invention discloses a new energy station equivalent synchronous machine inertia evaluation method, which comprises the following steps of: constructing a multi-machine system frequency response model containing new energy virtual inertia frequency modulation to obtain a system transfer function; determining the supporting effects of different new energy power system frequency modulation parameters on the frequency; performing simulation to obtain data pairs of new energy frequency modulation control parameters, unit power response time constants and frequency indexes, and a three-dimensional curved surface representing a new energy frequency modulation control effect; removing a new energy virtual inertia frequency modulation module in the frequency response model, and fitting a correlation representation model of power grid inertia frequency modulation capability evaluation parameters and frequency indexes by using a polynomial based on the data set; and a frequency index is used as an intermediate variable, and a three-dimensional curved surface of new energy frequency modulation control parameters and response speed-equivalent synchronous machine inertia is obtained based on a frequency index equivalence principle. According to the method, the influence of the new energy self-response dynamic state and the control parameters can be comprehensively considered, and the virtual inertia frequency supporting capability of the new energy station is correctly evaluated.

The invention discloses a slope type caterpillar track gravity energy storage multi-machine system, and relates to the technical field of gravity energy storage. Comprising a main system unit, a supporting track laid according to a mountain structure, a chain type mass block dragging device arranged on the supporting track, double-motor assemblies arranged at the two ends of the supporting track, and a control system used for controlling the main system unit to operate in a power mode and a phase modulation mode. By designing a dual-mode operation system of a power mode and a phase modulation mode, dual functions of energy storage and discharge and reactive power regulation are realized, and by arranging an auxiliary motor and a kinetic energy recovery device and combining a staggered arrangement scheme of a heavy-load track and a light-load track, efficient recovery and cyclic utilization of energy in the movement process of the mass block are realized, and the energy utilization rate of the mass block is improved. By establishing a mathematical relationship model of track arrangement and adopting a design scheme of performing dynamic optimization according to mountain characteristics, the operation safety is ensured through an automatic mass block carrying and stacking system.

The invention provides a self-adaptive elastic formation control method for a quad-rotor unmanned aerial vehicle under DoS attack, and relates to the technical field of unmanned aerial vehicle safety control, and the method is based on a multi-aerial vehicle formation system in a leader-follower mode under an undirected network topological graph. Establishing a mathematical model for the DoS attack blocking the communication channel, and establishing a changed multi-machine system network topology according to the DoS attack; constructing a distributed elastic observer to obtain unknown leader information under DoS attack, constructing a tracking formation error containing a time-varying offset signal according to the output of the observer, and taking a neighborhood in which the formation error can be converged to zero as a control target; and designing a self-adaptive elastic formation controller by using a backstepping method to realize self-adaptive elastic formation control of the four-rotor unmanned aerial vehicle. According to the control method provided by the invention, the condition that at least one communication channel is subjected to DoS attack is considered, and the constructed adaptive elastic formation controller can ensure that the tracking formation error of the multi-machine formation system is converged to a neighborhood of zero under the DoS attack, so that an expected formation is achieved.

The invention discloses a system energy-saving structure optimization control method based on a dynamic balance strategy, and particularly relates to the technical field of energy management systems, which comprises the steps of dynamic model construction, LASSO regression decoupling, transient compensation, multi-machine system coordination control, power distribution network parameter optimization, multi-target control model construction and improved sparrow algorithm. And source-load-storage coordinated control of the new energy microgrid is realized, and short-term and long-term electric quantity balance is optimized. According to the system energy-saving structure optimization control method based on the dynamic balance strategy, through the optimization control method, the adaptive capacity of the system to rapid changes is enhanced, stable operation of a power grid under various changes is ensured, the stability and economical efficiency of the system are improved, a user is effectively guided to carry out energy adjustment, and the user experience is improved. The energy utilization efficiency is improved, the global optimization capability of the system is enhanced, the efficient and stable operation of the micro-grid is realized, the energy consumption is reduced, and the energy-saving optimization is realized.

The invention discloses a multi-machine system number-real consistency error collaborative prediction method and system based on multi-agent reinforcement learning, and belongs to the technical field of multi-robot systems and artificial intelligence. According to the method, each robot is modeled as an intelligent agent, a centralized training distributed execution framework is adopted, and collaborative prediction of errors is achieved. Each agent collects own, neighbor and environment state information in real time, multi-source information integration is carried out through feature embedding and gating fusion, the influence of different information sources on errors is dynamically evaluated by adopting a layered attention mechanism, and propagation and coupling rules of the errors in a cluster are effectively modeled. In the training stage, the centralized commentator network is utilized to evaluate the global prediction performance, the cooperative optimization of each executor network is guided, and the prediction precision is improved. According to the method, active and collaborative prediction of the multi-machine system number-real consistency error is realized, and a key technical support is provided for error feed-forward compensation and system reliability guarantee.

The invention discloses a power transmission network multi-stage stochastic programming method and a power transmission network multi-stage stochastic programming system considering dynamic frequency security constraints, which are characterized by comprising a model decomposition method based on a piecewise linear fitting method in a maximum affine function form and a step-by-step hedging algorithm. The method comprises the following steps: S1, establishing a multi-machine system frequency response model of dynamic frequency response of a new energy power system, deducing a frequency safety index expression, and proposing a piecewise linear fitting method based on a maximum affine function form; s2, establishing a multi-stage unexpected constraint, and proposing a power transmission network multi-stage stochastic programming model considering a dynamic frequency security constraint; and S3, designing a model decomposition method based on a step-by-step hedging algorithm. The power transmission network multi-stage stochastic programming method and system provided by the invention have more remarkable effectiveness and superiority in the aspects of frequency safety and uncertainty response, and in addition, the multi-stage stochastic programming model can obtain a more economical and more flexible programming scheme.

The invention relates to a transient synchronous stability analysis method for multiple parallel grid-following type converters, which comprises the following steps of: firstly, constructing a grid-following type converter grid-connected system model considering an inner loop current and phase-locked loop coupling effect under a multi-machine system framework; then, through a Newton-Raphson method and an equal area criterion, quantitative evaluation of the existence of the balance point and visual analysis of a transient synchronization behavior are respectively realized; the method comprises the steps that firstly, transient synchronization stability criteria with physical significance are strictly deduced through extended application of a Lyapunov direct method, key factors prone to causing transient synchronization instability and influence rules of the key factors are disclosed, and finally time domain simulation is conducted through MATLAB / SIMULIN so as to verify the accuracy of the method. The transient synchronous instability characteristic description method and the risk quantitative evaluation system have important theoretical guiding significance for parameter optimization design of a power electronic system.

The invention relates to the technical field of dynamic analysis and predictive control of hydraulic machinery, and discloses a method, a device, equipment and a medium for positioning a hydraulic interference source of a pumped storage power station, and the method comprises the steps: constructing a non-uniform density monitoring network of the pumped storage power station; generating a spatial frequency domain matrix of the characteristic frequency band based on the non-uniform density monitoring network, wherein the spatial frequency domain matrix comprises amplitude distribution and phase distribution; based on the phase distribution, a preset inversion algorithm is adopted to solve an interference source space positioning result; and calculating a turbulent energy contribution rate based on the interference source space positioning result and the amplitude distribution, and performing pumped storage power station vortex system energy risk assessment based on the turbulent energy contribution rate. According to the method, the three-dimensional coordinate accurate locking of the hydraulic interference source is realized, the turbulent energy contribution rate is calculated based on the interference source positioning result and the amplitude distribution, the pumped storage power station vortex system energy risk assessment is realized, and the sub-meter positioning and high-risk early warning capabilities are provided for the hydraulic vibration source of the one-pipe multi-machine system of the pumped storage power station.

The invention provides a multi-unmanned aerial vehicle dynamic path planning system and method, and the system comprises a coordinate conversion module which is used for carrying out the bidirectional conversion of latitude and longitude coordinates and three-dimensional grid coordinates, so as to establish a unified space-time coordinate conversion reference; the map module is used for constructing a three-dimensional airspace representation model; the three-dimensional airspace representation model records position information of an obstacle and boundary range information of the temporary no-fly zone so as to provide real-time airspace information; the route module is used for delimiting an exclusive safety area for each unmanned aerial vehicle in the air; the path planning module is used for performing multi-machine path planning based on the real-time airspace information and the space-time occupancy state; the map module, the route module and the path planning module work cooperatively based on a unified space-time coordinate conversion reference. Through unified three-dimensional grid map representation and a space-time occupation management system, integrated coordination optimization of the whole process from flight plan approval to flight execution is realized, and real-time dynamic management of a large-scale multi-machine system is supported.

The invention discloses a double-fed wind power plant grid-connected system subsynchronous oscillation analysis method based on a complex torque coefficient method. Double-fed wind power plant grid connection has the risk of causing subsynchronous oscillation of a system, and meanwhile, the subsynchronous oscillation characteristic of a thermal power generating unit in the system is possibly influenced. The method comprises the following steps: firstly, dividing each generator set in a system into a to-be-researched generator set and a non-researched generator set, and giving a complex frequency domain model general form of the to-be-researched generator set and the non-to-be-researched generator set suitable for a complex torque coefficient method; secondly, a general form complex frequency domain model of a traditional thermal power generating unit suitable for subsynchronous oscillation analysis of the multi-machine system is given, and a general form complex frequency domain model of a double-fed fan is established; and finally, solving a complex torque coefficient by combining the established generator complex frequency domain model with a system complex frequency domain network equation, and further analyzing the subsynchronous oscillation of the double-fed wind power plant grid-connected system.

The invention belongs to the technical field of mechanical transmission, and discloses an intelligent transmission gear dynamic compensation method for multi-machine high-precision cooperation, and the method comprises the steps: collecting the real-time operation data of a multi-machine cooperation system, the real-time operation data including the gear rotation speed, load, temperature and vibration data; constructing a dynamic model of the transmission gear based on the real-time operation data; calculating a dynamic error of the transmission gear according to the dynamic model; predicting the dynamic error by adopting an intelligent algorithm and generating a compensation parameter; the operation parameters of the transmission gear are adjusted according to the compensation parameters, so that multi-machine high-precision cooperation is achieved; and monitoring the operation state of the multi-machine cooperation system in real time, and dynamically adjusting the compensation parameters according to the monitoring data. According to the method, the operation precision and stability of the multi-machine system are remarkably improved, and the method is suitable for high-precision transmission scenes such as robots, numerical control machine tools and aero-engines and has high practical value and popularization prospects.

The invention relates to the technical field of circuit protection, in particular to a hot plug protection circuit of a multi-machine system and electronic equipment. The hot plug protection circuit is applied to a multi-machine system, the system comprises a main battery pack and at least one slave battery pack which are connected in series, and each battery pack is connected with the next slave battery pack through a corresponding wire harness connector in sequence. The wire harness connector is provided with a first signal pin and a second signal pin, and the first signal pin is communicated with the second signal pin of the front wire harness connector when the corresponding wire harness connector is connected to the front wire harness connector. The hot plug protection circuit can control the on-off of the first pin and the second pin based on the connection state of the adjacent wire harness connectors, and outputs a corresponding signal to the controller according to the connection state of the first signal pin and the second signal pin of each wire harness connector. Therefore, the controller correspondingly triggers the protection action of the corresponding battery pack according to the received signal, and the circuit safety and the possible personnel safety are protected.

The invention requests to protect a multi-machine system synchronization method based on a CXL shared cache consistent memory. Relates to the technical field of high-performance computing and memory interconnection, at present, a plurality of synchronization mechanisms are provided in a Linux system, and the synchronization mechanisms are designed to face a multi-core and multi-process environment of a stand-alone system and are used for guaranteeing concurrent access of a plurality of processes to shared data. However, the action range of an existing synchronization mechanism is limited in a single system, and for the situation that multiple processes belonging to multiple independent host systems concurrently access data in a CXL shared memory, the cross-host concurrent access requirement exceeds the application range of the existing Linux synchronization mechanism, data competition and inconsistent access are possibly caused by direct use, and the data access efficiency is improved. Even if the system crashes, the cross-host access security on the CXL shared memory cannot be ensured. The invention aims to construct a safe and efficient synchronization mechanism oriented to multi-system parallel access CXL shared memory data so as to realize cross-host multi-process synchronous access to the data in the CXL shared memory.

The present invention discloses a non-real-time sampling synchronization method for a distributed multi-machine system. After the integer times of the sampling point moments of each slave chassis are put into one-to-one correspondence with the integer times of the sampling point moments of the master chassis, the differences between the sampling point moments of each slave chassis and the fractional times corresponding to the sampling point moments of the master chassis are compared. If the difference is outside the threshold, the fractional time of the sampling point moment of the master chassis is used to replace the fractional time corresponding to the sampling point moment of the slave chassis. If the difference is within the threshold, the fractional time of the sampling point moment of the slave chassis remains unchanged, thus achieving the synchronization of sampling data. The non-real-time sampling synchronization method for a distributed multi-machine system provided by the present invention does not rely on a real-time operating system and a real-time sampling mechanism, has strong versatility, and can ensure the synchronization of sampling data.

The invention discloses an SMES-MMC cooperative frequency supporting method for a new energy sending-out system, discloses a system and a medium with the SMES-MMC cooperative frequency supporting method for the new energy sending-out system, and provides a method for improving the transient stability of a wind power-containing multi-machine system by combining superconducting energy storage. A dynamic power compensation control strategy based on sliding mode control is designed by constructing a mathematical model of a superconducting energy storage and direct-driven wind power generation system, and optimal control of system frequency recovery and voltage stability is realized by combining slope power recovery characteristics of a fan.

The invention discloses a gravity energy storage multi-machine system mass block dynamic distribution method and device and electronic equipment, and the distribution method comprises the steps: calculating a loss function of an energy storage unit, the loss function being a quadratic function about the output power of a mass block; determining a quantity constraint condition of the mass blocks according to the power required to be output by the energy storage system and the rated power of the energy storage unit; and determining an optimal allocation method of the mass blocks according to a Monte Carlo algorithm and the loss function of the energy storage unit under the condition of quantity constraint of the mass blocks. The number of the mass blocks in different energy storage units can be dynamically distributed in real time, the energy efficiency is improved, and the loss of the gravity energy storage multi-machine system is reduced.

The invention discloses a capacity configuration method and system for a reactive power compensation device of a multi-machine system. According to the method, a synchronous machine electromagnetic power phase angle characteristic curve equation and a synchronous machine mechanical power phase angle characteristic equation before a fault of the multi-machine system and after the fault is removed are jointly constructed through parameters of all elements in the multi-machine system configured with the reactive power compensation device, and power angle values before and after the fault of the synchronous machine are calculated according to the equation; the capacity demand value of the reactive power compensation device configured by the collection bus in the multi-machine system is calculated by using an area method according to the constructed equation and the power angle value of the synchronous machine, so that the rationality of the capacity of the reactive power compensation device configured by the multi-machine system is improved, and the probability of transient power angle instability transmission of the synchronous machine of the multi-machine system is further reduced. The problem that in the prior art, due to the fact that the capacity of a configured reactive power compensation device is unreasonable and cannot adapt to faults of a multi-machine system, transient state power angle instability occurs when the multi-machine system breaks down is solved.

The invention relates to the technical field of gravity energy storage multi-machine system power distribution, in particular to a multi-machine system power distribution method, system and device and a medium. Calculating the total efficiency of each stand-alone system based on an efficiency model; constructing a power distribution optimization model based on the total efficiency of each single-machine system; and distributing the power of each unit according to the power distribution optimization model. The method has the beneficial effects that an intelligent power scheduling strategy can be provided for the renewable energy storage system, the energy loss and the equipment overload risk are reduced, and the peak regulation capability and the economic benefit of the power grid are improved.

The application discloses a kind of primary frequency modulation control method and system of hybrid wind farm, including obtaining the data information of target power system and corresponding hybrid wind farm;Multiple-machine system frequency response model of target power system is constructed and is simplified to obtain aggregate response model;Based on the dynamic process of wind turbine output power and fan, the primary frequency modulation dynamic model of hybrid wind farm is constructed;The active output power of network type fan in hybrid wind farm is calculated;Based on the real-time rotor kinetic energy stored in each fan in hybrid wind farm, the droop coefficient of each network type fan and the frequency modulation power required to be provided by follow network type fan cluster are calculated;According to the frequency modulation characteristic parameters of follow network type fan cluster, real-time system frequency and energy state index, the output power of each follow network type fan is calculated;The primary frequency modulation control of hybrid wind farm is completed.The application not only realizes the primary frequency modulation control of hybrid wind farm, but also has higher reliability and better accuracy.

This invention discloses a method for evaluating the inertia of the equivalent synchronous machine in a renewable energy power plant. It constructs a frequency response model of a multi-machine system incorporating renewable energy virtual inertia frequency regulation, obtaining the system transfer function. It determines the frequency support effect of different renewable energy power system frequency regulation parameters. Simulation yields data pairs of renewable energy frequency regulation control parameters, unit power response time constants, and frequency indices, representing a three-dimensional surface characterizing the renewable energy frequency regulation control effect. The renewable energy virtual inertia frequency regulation module is removed from the frequency response model, and a polynomial fit is used to the correlation characterization model of the power grid inertia frequency regulation capability evaluation parameters and frequency indices based on the dataset. Using the frequency indices as intermediate variables, a three-dimensional surface of renewable energy frequency regulation control parameters and response speed versus equivalent synchronous machine inertia is obtained based on the principle of frequency index equivalence. This method comprehensively considers the dynamic response of renewable energy itself and the influence of control parameters, correctly evaluating the frequency support capability of renewable energy power plants using virtual inertia.

The invention discloses a multi-machine system new energy unit phase-locked loop synchronization stability evaluation method and system, and the method comprises the steps: constructing a new energy phase-locked loop output phase angle dynamic equation mathematical model and a synchronization unit steady state power angle; calculating a new energy end phase-locked loop output phase angle before the fault of the multi-machine system, a synchronous machine power angle when the fault is removed, a new energy unit phase-locked loop output phase angle and a new energy unit phase-locked loop stability limit phase angle, and finally calculating an increased area and a reduced area of the new energy phase-locked loop output phase angle when the fault of the multi-machine system is removed. According to the method, the synchronous unit is combined to evaluate the phase-locked synchronous stability of the new energy unit in the multi-machine system, so that the evaluation accuracy of the phase-locked synchronous stability of the new energy unit is improved, and the problem that the influence of a thermal power generating unit on the new energy unit is not considered in the multi-machine system in the prior art is solved; and the accuracy of the phase locking synchronization stability of the new energy power generation unit is not high.

The invention belongs to the related technical field of multi-robot control, and discloses a multi-robot distributed cluster regulation and control method and system, and the method comprises the steps: S1, each robot calculates the state change amplitude of itself, and judges whether to enter an expected cluster stable state or not according to the obtained state change amplitude of itself; s2, the robot exchanges body state judgment marks with neighbors, and judges whether a local group where the robot is located enters an expected cluster stable state or not; s3, the robot exchanges the local state judgment mark with the neighbors again, and judges whether the global multi-machine system enters an expected cluster stable state or not according to the number of the neighbors and the content of the local state judgment mark; and S4, the robots adaptively switch the simplified cluster control model without the space regulation and control items and the complete cluster control model with the space regulation and control items according to the group state judgment marks, and multi-robot distributed cluster regulation and control are realized. Progressive convergence of the multi-robot cluster state is realized.

This invention relates to the field of dynamic analysis and predictive control technology for hydraulic machinery, and discloses a method, device, equipment, and medium for locating hydraulic interference sources in pumped storage power stations. The method includes: constructing a non-uniform density monitoring network for the pumped storage power station; generating a spatial frequency domain matrix of characteristic frequency bands based on the non-uniform density monitoring network, the spatial frequency domain matrix including amplitude distribution and phase distribution; solving for the spatial location result of the interference source using a preset inversion algorithm based on the phase distribution; calculating the turbulent kinetic energy contribution rate based on the spatial location result of the interference source and the amplitude distribution, and conducting an energy risk assessment of the vortex system of the pumped storage power station based on the turbulent kinetic energy contribution rate. This invention achieves precise three-dimensional coordinate locking of hydraulic interference sources, calculates the turbulent kinetic energy contribution rate based on the interference source location result and amplitude distribution, realizes the energy risk assessment of the vortex system of the pumped storage power station, and provides sub-meter-level positioning and high-risk early warning capabilities for hydraulic vibration sources in a multi-machine system of a pumped storage power station.

The present invention discloses a cooperative optimization control method for a doubly-fed wind power multi-machine system under a weak grid symmetrical short-circuit fault. 1) An adaptive damping controller is designed for each DFIG single-machine system. The adaptive damping controller feeds the deviation Δ between the output angular velocity of the phase-locked loop and the system target angular velocity back to the output of the d-axis current loop of the grid-side converter through a PI controller. Once deviates from during the fault, the DFIG will automatically adjust its d-axis current component according to Δ. 2) Combining the actual fault scenario, parameters are configured for the adaptive damping controller in each DFIG. Without adding hardware devices, the present invention redesigns the control strategy of the doubly-fed wind power multi-machine system, enhances the small-signal stability of the system during the weak grid symmetrical short-circuit fault, and improves the success rate of crossing the weak grid symmetrical short-circuit fault. ω pll and the system target angular velocity ω g between the deviation Δ ω pll negative feedback to the q axis current loop output of the grid-side converter. Once ω pll deviates from during the fault ω g , the DFIG will be based on Δ ω pll automatically adjust its q axis current component. 2) Combining the actual fault scenario, configure parameters for the adaptive damping controller in each DFIG. Without adding hardware devices, the present invention redesigns the control strategy of the doubly-fed wind power multi-machine system, enhances the small-signal stability of the system during the weak grid symmetrical short-circuit fault, and improves the success rate of crossing the weak grid symmetrical short-circuit fault.

This invention relates to a transient synchronization stability analysis method for multi-parallel grid-connected converters. First, within a multi-machine system framework, a grid-connected converter system model considering the coupling effect of the inner loop current and the phase-locked loop is constructed. Then, using the Newton-Raphson method and the equal area criterion, quantitative assessments of the existence of equilibrium points and visual analysis of transient synchronization behavior are achieved, respectively. Next, through an extended application of the Lyapunov direct method, a physically meaningful transient synchronization stability criterion is rigorously derived, revealing the key factors that easily lead to transient synchronization instability and their influencing laws. Finally, time-domain simulations using MATLAB / SIMULIN are performed to verify the accuracy of the proposed method. The proposed transient synchronization instability characteristic description method and risk quantification assessment system have significant theoretical guiding significance for the parameter optimization design of power electronic systems.

The invention discloses a multi-direct-drive fan system order reduction method based on a balance truncation theory, which can cover a multi-machine system simplification method of an aggregation model, and realizes ordered truncation of main dynamic energy channels of the system through collaborative analysis of controllability and observability. Firstly, linearization is carried out near a system balance point, and a standard state space model is constructed; secondly, directly performing balance transformation on the full-order small signal model without depending on a physical structure and manual partitioning, so that the controllability and the observability are uniformly distributed in a state space; then, the state variables are sorted according to Hankel singular values, the part with remarkable dynamic contribution in an input and output channel is automatically recognized, and information loss caused by improper structure division is avoided; and finally, by cutting off the redundant state, a reduced-order model of which the dynamic characteristic is highly close to that of an original system is constructed. A simulation result shows that when parameters are consistent, the method is naturally degraded into a traditional aggregation model; and when the parameters are inconsistent, the performance of the reduced-order model is obviously superior to that of an aggregation model, and stronger robustness is shown. The method provides an effective new way for simplifying a multi-direct-drive wind power plant system model in a different-wind-speed scene.

The invention belongs to the field of power grid intensity quantification, and discloses an energy storage heterogeneous multi-machine system intensity quantification method, system and device and a medium, and the method comprises the steps: carrying out the eigenvalue decomposition of an extended admittance matrix, obtaining a generalized short-circuit ratio and a corresponding eigenvector, and calculating a participation factor of the device based on the eigenvector; according to a multivariable feedback control theory, constructing a dynamic model of equipment in an equivalent isomorphic system, identifying a weakest subsystem characteristic equation, and calculating a critical short-circuit ratio of equivalent equipment in a heterogeneous system; and calculating a relative difference value between the generalized short-circuit ratio and the critical short-circuit ratio so as to quantify the small disturbance stability margin of the energy storage heterogeneous system. According to the method, the extended admittance matrix is subjected to eigenvalue decomposition, so that the generalized short-circuit ratio and the eigenvector corresponding to the generalized short-circuit ratio can be extracted, the dynamic characteristics of the energy storage heterogeneous multi-machine system are deeply analyzed, the participation factor of each device is calculated by using the obtained eigenvector, and the specific contribution degree of each device in the dynamic behavior of the system is accurately quantified.

The application discloses a new energy unit phase-locked loop synchronous stability evaluation method and system of a multi-machine system, which constructs a new energy phase-locked loop output phase angle dynamic equation mathematical model and a synchronous unit steady-state power angle, calculates the new energy end phase-locked loop output phase angle of the multi-machine system before a fault, the synchronous machine power angle when the fault is removed, the new energy unit phase-locked loop output phase angle and the new energy unit phase-locked loop stability limit phase angle, and finally calculates the increasing area and the decreasing area of the new energy phase-locked loop output phase angle of the multi-machine system when the fault is removed, and further determines the new energy unit phase-locked loop synchronous stability, that is, the application combines the synchronous unit to evaluate the phase-locked synchronous stability of the new energy unit in the multi-machine system, improves the evaluation accuracy of the new energy unit phase-locked synchronous stability, and solves the problem that the prior art lacks consideration of the influence of the thermal power unit on the new energy unit in the multi-machine system, thereby resulting in low accuracy of the phase-locked synchronous stability of the new energy power generation unit.

The present invention discloses a method, system, terminal device and storage medium for transient stability assessment of a multi-machine system based on a hyper-tangent plane. The method constructs a differential algebraic equation group of the multi-machine system according to the state quantity of the multi-machine system, calculates the equilibrium point and Jacobian matrix of the multi-machine system according to the differential algebraic equation group of the multi-machine system, and then determines a class of unstable equilibrium points and Jacobian matrices thereof. The hyper-tangent plane equation is calculated according to the Jacobian matrix of the class of unstable equilibrium points. The nonlinear characteristics of the multi-machine system are analyzed by the hyper-tangent plane equation and the fault trajectory to calculate the critical fault removal time of the multi-machine system, and the transient stability of the multi-machine system is evaluated according to the critical fault removal time, thereby improving the accuracy of the transient stability assessment of the multi-machine system, ensuring the stable operation of the multi-machine system, and solving the problem that the transient stability assessment result of the multi-machine system is low due to the lack of analysis of the nonlinear characteristics of the multi-machine system in the time domain simulation method.