212 results about "Low voltage ride through" patented technology

The invention discloses an online prediction method for a transient frequency track of a power grid under coexistence of wind power low voltage ride through and off-grid, and belongs to the technical field of operation and control of a power system. A multi-source heterogeneous data fusion monitoring system is constructed, power grid and wind turbine generator data are collected, faults are recognized through an improved algorithm, and feature vectors are output; building an energy flow model based on a fault result, calculating a trajectory divergence index by using technologies such as phase-space reconstruction, estimating power vacancy, and obtaining a power unbalance sequence; designing a prediction algorithm by using the sequence, predicting a frequency trajectory in combination with an improved K-nearest neighbor algorithm and a trajectory feature library, and introducing a confidence coefficient to evaluate a correction error; and finally, establishing a three-level control response system, and implementing multi-time scale cooperative control according to a prediction result. The method can accurately predict the frequency trajectory, effectively deal with the wind power fault, improve the stability of the power grid and the wind power consumption capability, and provide powerful guarantee for the safe and stable operation of the power grid.

The invention discloses a low-voltage ride-through control method of a flywheel energy storage system, which is based on a low-voltage ride-through control strategy of model predictive current control (MPCC) so as to improve the low-voltage ride-through capability of the flywheel energy storage system when a power grid fails. A future current value is predicted through system modeling and a prediction algorithm, so that effective control is realized. The MPCC-based machine side-power grid side coordination control strategy can quickly respond to the voltage sag of the power grid, provide reactive power support, stabilize the voltage of the direct current bus, and ensure the safe and reliable operation of the flywheel energy storage system during the voltage sag period of the power grid. A traditional pulse width modulation (PWM) technology is abandoned, the optimal switching state is directly selected through a limited control set, and hardware implementation of a power grid side converter is simplified. A differential control strategy aiming at a power grid symmetric fault (three-phase voltage sudden drop) and an asymmetric fault (single-phase grounding) is provided, the method is suitable for a complex power grid fault scene, and the system universality is improved.

A low voltage ride through control method for a grid-forming inverter based on dynamic internal potential adjustment comprises the following steps: detecting a voltage per unit value of a grid-connected point in real time, and comparing the voltage per unit value with a threshold value to judge a voltage drop event and trigger low voltage ride through control; dynamically calculating active and reactive power reference values through a reactive compensation equation and an active current limiting equation according to the voltage amplitude and the power reference value before falling during the ride-through period; inputting the active reference value into a virtual rotor motion equation to generate a reference phase, and outputting a phase reference signal in combination with a dual-mode phase compensation controller; superposing the reactive reference value with the reference voltage through a reactive voltage regulating ring to generate a voltage amplitude reference signal; synthesizing an internal potential according to the phase and the amplitude reference signal, and obtaining an inductive current reference value through virtual impedance control and current amplitude limiting; and finally, a driving signal is generated through the current inner loop controller and the modulation module. According to the invention, overcurrent can be effectively inhibited, rapid reactive power support is provided, and synchronous stability and smooth transition in a fault period and a recovery process are ensured.

The invention discloses a tracking-network construction combined low-voltage ride-through control method based on transient support. The method comprises the following steps: S1, analyzing transient voltage characteristics and requirements of a network construction-tracking network converter; s2, analyzing a transient voltage support target of the network construction-network following type hybrid multi-machine system; s3, constructing a network construction-network following type hybrid multi-machine system control strategy; and S4, on the basis of the network construction-network following type hybrid multi-machine system control strategy constructed in the S3, optimizing the low voltage ride-through control of the network following type converter and the transient voltage control of the network construction type converter. According to the control method disclosed by the invention, the advantages of the network-building / network-following converter are complemented, the control between the network-building / network-following converter and the network-building / network-following converter is coordinated, and the transient voltage of the power grid is actively supported by using the multi-machine converter system.

The invention discloses a direct-current voltage self-balancing method in the high-low voltage ride-through process of a high-voltage frequency converter, and the method comprises the steps: obtaining an electric signal of the high-voltage frequency converter, calculating the Lyapunov index of a system in real time based on the electric signal, so as to quantify the chaotic state of the system, and generating a real-time Lyapunov index sequence; according to the real-time Lyapunov index sequence, the gradient of the real-time Lyapunov index sequence relative to a preset system state variable is determined, and a Lyapunov gradient field is constructed; using the Lyapunov gradient field to generate a basic control quantity through nonlinear mapping; and converting the basic control quantity into a pulse width modulation parameter to form a PWM control signal set to be applied to the high-voltage frequency converter. According to the method, the Lyapunov gradient field is constructed to provide prospective direction guidance for control, so that the chaotic oscillation is quickly suppressed, and the dynamic stability of the system under power grid disturbance is remarkably improved.

The invention is suitable for the technical field of power electronics and power transmission, and provides a low voltage ride-through control method and system for a network construction type converter, and the method comprises the steps: carrying out the conventional VSG control according to a VSG control strategy, and continuously monitoring the difference between the voltage of a power grid and a set reference value, so as to judge whether a fault occurs or not; when it is detected that the power grid breaks down, homodyne control is carried out on an active power control ring and a reactive power control ring of the grid-forming type converter so as to fix the phase and the amplitude of the output voltage of the converter; calculating and injecting a positive sequence compensation voltage and a negative sequence compensation voltage according to the drop degree of the power grid voltage; and according to the predicted impact current value, dynamically calculating and inputting adaptive virtual impedance. The power angle and the voltage in the fault period can be ensured to be stable, transient overcurrent is effectively restrained, and large power fluctuation is not caused.

The invention discloses a VSG-based low-voltage ride-through hybrid control method for a network-building converter. The method comprises the following steps: acquiring grid-connected point voltage and output current of a grid-forming converter in real time, and judging whether to enter a low-voltage ride-through state according to a grid voltage drop degree; in the initial stage of a fault, a current reference saturation mode is adopted to quickly limit the output current of the converter so as to prevent a power device from being damaged by overcurrent; in the fault duration stage, a dynamic self-adaptive virtual impedance and reactive power reference coordinated regulation mechanism is introduced, so that the converter gradually recovers the reactive power injection capability while limiting the fault current, thereby realizing effective support for the grid-connected point voltage; when the voltage of the power grid drops seriously, the capacity of the inverter can be reserved for the reactive power support by temporarily reducing the output of the active power. According to the method, the current protection and voltage support requirements during the fault period are considered, and the operation stability and the power grid adaptive capacity of the grid-forming converter in the low voltage ride-through process are improved.

The invention provides a grid-connected converter fault transient process control parameter security domain determination method and device, and relates to the technical field of power systems. The grid-connected converter fault transient process control parameter safety domain determination method comprises the following steps: solving a power system equation of a target phase-locked loop by using structural parameters of a target power grid, and obtaining a first analytical expression of an output phase of the target phase-locked loop in a low-voltage ride-through stage after a short-circuit fault occurs in the target power grid; according to the first analytical expression, determining a low-pass phase-locked stability constraint; wherein the low-voltage ride-through phase-locked stable constraint is used for constraining that the output phase of the target phase-locked loop is not out of step in the low-voltage ride-through stage; determining a first parameter domain of a control parameter of the target grid-connected converter according to the low-pass phase-locked stability constraint; and determining a control parameter security domain of the target grid-connected converter based on the first parameter domain. According to the method, the safety domain of the control parameters of the grid-connected converter can be efficiently and accurately determined, so that the short-circuit fault ride-through capability of the grid-connected converter is effectively improved.

The invention discloses a photovoltaic power grid fault transient control method, device and equipment, and relates to the technical field of photovoltaic auxiliary equipment, and the method comprises the following steps: obtaining the operation data of a photovoltaic grid-connected point, constructing a three-phase coupling characteristic matrix, and generating a disturbance discrimination result according to the dynamic evolution of the three-phase coupling characteristic matrix; based on a disturbance judgment result, collecting three-phase output current of the photovoltaic inverter, calculating disturbance increment of each phase of current, extracting a stable current component during a fault period based on low-voltage ride-through control logic, and calculating equivalent support power of the stable current component at a fault point; the equivalent support power is compared with a preset arc extinguishing threshold value, and the dissociation condition of the fault point is dynamically evaluated; when the fault point is not free, the photovoltaic inverter is controlled to perform state conversion, so that the equivalent support power is lower than an arc extinguishing threshold value; and after detecting that the voltage of the fault point is recovered and the arc light is extinguished, dynamically adjusting the reclosing time sequence based on the voltage recovery rate. The problems that arc light is difficult to extinguish and the reclosing failure rate is high are solved.

The invention provides a distributed photovoltaic grid-connected converter low-voltage ride-through control method based on sum-difference coordinate transformation, and solves the problems of insufficient synchronism, poor stability, insufficient reactive power support potential excavation and the like existing in collaborative response under power grid voltage drop during distributed photovoltaic grid connection. According to the method, impedance modeling and equivalent symmetry transformation are carried out on the distributed photovoltaic inverter, and a coupling multi-dimensional matrix equation is established; an original coupling system is decoupled into a sum current channel and a plurality of difference current channels, the control complexity is simplified, and an open-loop output impedance expression and a closed-loop output impedance expression are deduced; secondly, formulating a refined active / reactive current collaborative distribution strategy for different voltage drop depths, dynamically calculating the minimum reactive current during voltage drop, preferentially meeting the national standard, and maximizing active output or balancing loss under the limit of rated current; and finally, through sum-difference coordinate transformation, the total current demand and distribution are efficiently decoupled and issued to a current loop controller of each inverter, so that rapid, synchronous and stable cooperative operation of multiple inverters is realized.

The invention discloses an improved control method for low voltage ride through of a distributed direct-driven wind turbine generator, and belongs to the technical field of grid-connected control of wind turbine generators. And when the voltage of the power grid drops, the distributed direct-driven fan enters a low-voltage ride-through state. The method comprises the following steps: firstly, establishing a dq-axis grid-connected system model of the distributed direct-driven fan; and then, by taking'reduction of active loss and improvement of terminal voltage 'as double control objectives, under the constraint of a grid-connected guide rule, a machine-side / grid-side current limit and a power limit, an improved multi-objective particle swarm optimization algorithm is adopted to solve optimal set values of active and reactive current online in real time, and the optimal set values directly act on a grid-side converter. Compared with an existing proportional reactive power injection method, on the premise that the grid-connected guide rule requirement is met during the fault period, the method can simultaneously provide reactive power support and raise the terminal voltage; active loss is reduced, and the power grid frequency is supported; according to the method, the low-voltage ride-through capability and the power generation economy of the wind power plant are remarkably improved.

Systems, devices, and methods for controlling grid-tied inverters with instantaneous synchronization and low-voltage-ride-through (LVRT) capabilities under a wide range of grid cable impedance without using a phase-locked loop.

The invention discloses a converter feedforward decoupling control method and system for improving low voltage ride through capability, and the method comprises the steps: firstly carrying out the dynamic lead compensation of a measurement voltage after d-q conversion, so as to actively offset the amplitude attenuation and phase delay introduced by hardware links, such as a low-pass filter, in a measurement link, and restore a real power grid voltage dynamic state; and based on the accurately compensated and corrected voltage signal, positive and negative sequence separation and feed-forward quantity calculation are carried out, and finally a reference voltage instruction is generated. In this way, it can be ensured that the input signal of feedforward control accurately reflects the instantaneous change of the power grid voltage, the dynamic response speed and precision of a control system are greatly improved, current overshoot and oscillation in the voltage drop period are effectively restrained, the low-voltage ride-through capacity of a converter is remarkably enhanced, and the stability of new energy grid connection is guaranteed.

The invention relates to the field of low voltage ride-through control, and particularly discloses a wind power converter low voltage ride-through cooperative control method and system, which starts conventional LVRT response through a fault detection module, provides basic reactive power support and inhibits active power, and evaluates a power grid recovery state through a power grid recovery state evaluation module. Key indexes such as grid-connected point voltage recovery slope, frequency deviation and system short-circuit capacity are comprehensively analyzed, and a power grid recovery health degree index is quantitatively generated. Then, based on the index, a self-adaptive active power recovery slope is decided by combining local states such as a direct current bus voltage of the fan itself and the like. And finally, the active power recovery module smoothly recovers power output according to the adaptive slope. Through the mode, the power recovery behavior of the fan is tightly coupled with the real-time bearing capacity of the power grid, cooperative recovery control of low voltage ride through is realized, the stability of the power grid is ensured, and the efficiency and safety of power recovery are improved.

The invention discloses a network construction type converter low voltage ride through control method and system based on voltage sag depth dynamic adjustment, and a storage medium. The method comprises the following steps: dividing voltage sag depth grades; collecting a grid-connected point voltage signal for preprocessing, calculating the voltage drop depth according to the preprocessed voltage, and judging the level of the voltage drop depth; if the voltage sag depth is in a normal state, traditional VSG control is executed to complete low voltage ride through, otherwise, the reactive-voltage sag coefficient, the output reactive power and the virtual impedance are updated according to the voltage sag depth; when the voltage drop is not recovered to a normal state or is recovered to be normal but does not last for a set time, continuously carrying out the process after dividing the depth grade of the voltage drop, otherwise, adjusting the droop coefficient according to discretization exponential attenuation, and recovering the active power according to a discretization active slope recovery strategy; according to the invention, the power grid support efficiency and safety in the low voltage ride through process can be improved, and secondary oscillation in the recovery period can be avoided.

The invention discloses a self-adaptive control method and system for a wind generating set in a low voltage ride through process, and the method comprises the steps: S1, collecting the operation data of the wind generating set in real time, the operation data comprising the rotating speed of a generator and a low voltage ride through process flag bit; s2, judging whether the flag bit in the low-voltage ride-through process is true or not; if so, switching the unit control system from a conventional power generation control mode to a low voltage ride through control mode; otherwise, maintaining the unit in the conventional power generation control mode; in the low-voltage ride-through control mode, transmission chain resistance-increasing self-adaptive control, variable-pitch response self-adaptive control and advanced variable-pitch self-adaptive control are executed in parallel; and S3, according to the final resistance increasing torque, the superposed variable pitch rate and the self-adaptive advanced variable pitch value, comprehensive control over the unit is executed. On the premise that blade clearance and load safety are ensured, unit power fluctuation in the low-voltage ride-through process can be reduced, and unit operation stability and safety are improved.

The invention discloses a frequency lowest point evaluation method considering a low-voltage ride-through process of a new energy unit, and belongs to the technical field of power systems. The method comprises the following steps: establishing a whole-system quasi-steady-state model, respectively constructing models for a synchronous machine, a new energy unit and a load, and replacing a differential equation of power electronic equipment such as the new energy unit with a nonlinear algebraic equation; based on the model, node voltage and injection current are updated through an alternate iteration method, key quasi-steady-state points when the new energy unit enters a low-voltage ride-through state and is in an off-network state are identified, and overall unbalanced power of the system is output; inputting the unbalanced power of each key quasi-steady-state point into the ASF model, and fitting a system frequency curve to obtain the lowest point of the frequency by considering the power vacancy of the low-voltage ride-through and off-network stages. The method does not need to depend on time domain simulation, can quickly and accurately evaluate the lowest point of the frequency, and is suitable for online stability evaluation of the power system.

The invention discloses a power distribution network voltage sag monitoring point multi-target selection method considering a distributed power supply low voltage ride through characteristic. The method comprises the following steps: providing a distributed power supply low voltage ride through strategy; deriving a voltage sag amplitude analytical expression under various short circuit fault types considering the low voltage ride through characteristic of the distributed power supply; introducing a position variable to construct a function relation between a voltage sag amplitude and a fault position; solving a voltage sag domain critical point by using a differential evolution algorithm; based on the sag domain critical point, establishing a monitoring point multi-target selection model taking economical efficiency, redundancy and construction urgency minimization as a target function; solving the established monitoring point multi-target selection model by adopting a multi-target particle swarm algorithm to obtain a Pareto optimal solution set; and according to the obtained Pareto optimal solution set, adopting an ideal point method to screen out an optimal point distribution scheme. According to the method, the voltage sag domain can be accurately divided, and multi-objective optimization of economical efficiency, low redundancy and low construction urgency of monitoring point layout is realized on the premise of satisfying panoramic observability.

The invention discloses a relay protection short-circuit current calculation method and device of a photovoltaic-energy storage combined system. The method comprises the steps that an inverter equivalent mathematical model of the photovoltaic-energy storage combined power generation system is established, and the inverter equivalent mathematical model enables an inverter in a fault state to be equivalent to a positive sequence current source; based on the inverter equivalent mathematical model, in combination with a low voltage ride-through control strategy, determining a function relationship between the output of the positive sequence current source and the positive sequence voltage of the grid-connected point, and forming a fault current calculation expression; and obtaining positive sequence voltage information of the grid-connected point when the power grid fails, substituting the positive sequence voltage information into the fault current calculation expression, and calculating to obtain the short-circuit current provided by the photovoltaic-energy storage combined system.

The invention discloses a photovoltaic inverter low voltage ride through capability improvement method based on staged control parameter optimization, and belongs to the technical field of photovoltaic power generation control optimization, and the method comprises the following steps: S1, dividing a transient process into three stages, considering different dynamic characteristics of unit operation corresponding to each stage, and constructing evaluation indexes of each stage; s2, performing correlation analysis on each control parameter and the evaluation index of the photovoltaic grid-connected inverter by adopting a Spearman correlation coefficient analysis method, and determining the control parameter having strong correlation with the evaluation index of each stage; and S3, according to a correlation analysis result, performing staged optimization on the control parameters of the inverter by using a particle swarm algorithm. By the adoption of the method, physical characteristics of the whole low-voltage ride-through process are considered, a low-voltage ride-through process multi-target evaluation system is established, and the relation between the control parameters and the performance of all stages of the transient state is revealed through correlation analysis.

The invention provides a cooperative low-voltage ride-through control method and related device based on a network construction type and network following type three-terminal interconnection system, and the method comprises the steps: triggering a cooperative low-voltage ride-through control mechanism in response to a voltage drop fault generated at an AC side connected with a network construction type converter; performing cooperative control on each converter based on the mechanism; wherein the control network construction type converter only undertakes AC side voltage establishment and current safety survival functions, realizes current limiting control through adaptive virtual impedance, and does not participate in DC side energy adjustment of a common DC bus; the DC voltage control type grid-following converter is controlled to suppress DC voltage double-frequency fluctuation of the common DC bus, and actively absorb and compensate double-frequency power disturbance introduced by the grid-forming converter; and controlling the active power control type grid-following converter to avoid active power adjustment during the voltage drop fault period. A collaborative low-voltage ride through control mechanism is provided, the direct-current voltage fluctuation is reduced, and the overall low-voltage ride through capacity of the system is improved.

The utility model relates to a power supply circuit compatible with low voltage ride through, a standby power device and a power conversion device, and the power supply circuit is provided with a voltage transformation module capable of providing main power supply voltage, a rectification module and an auxiliary power supply module capable of providing auxiliary power supply voltage. The voltage transformation module, the rectification module and the auxiliary power supply module can provide power supply voltage for the power supply output end at the same time, and the auxiliary power supply module can provide the power supply voltage for the power supply output end based on the direct current source when a power grid is abnormal such as a low-voltage fault, so that low-voltage ride-through is realized when the power grid is in the low-voltage fault, and the power supply efficiency is improved. And net separation is avoided.

A low voltage ride through detection method and device are provided. The low voltage ride through detection method comprises: determining an adjustment value of a preset parameter of a power grid based on a grid voltage, wherein the preset parameter comprises at least one of current, current frequency and power factor angle; adjusting the preset parameter of the power grid based on the adjustment value; and detecting whether the power grid satisfies a low voltage ride through condition based on the grid voltage after the preset parameter of the power grid is adjusted, thereby enabling a wind power generator to accurately identify a power grid fault under a weak power grid to enter low ride through, while avoiding instability of a power grid fault ride through system under a weak power grid.

The invention discloses a fault component compensation type low-voltage ride-through control method and system of a distributed power generation system and a storage medium, and the method comprises the steps: introducing a difference value between a d-axis voltage instantaneous component of a common coupling point and a system rated voltage into a quadrature-axis voltage compensation branch during the voltage drop period of a power grid, and obtaining a quadrature-axis voltage compensation amount through compensation coefficient calculation, the calculation result is added to the phase-locked loop control link, the q-axis voltage of the common coupling point tracked by the phase-locked loop is adjusted in real time, and the problem that the phase angle of the distributed power generation system is prone to loss stability during the transient state is effectively solved without any additional control information. And the low-voltage ride-through capability of the distributed power generation system under the extreme working condition is obviously enhanced.

The utility model provides a power supply circuit for preventing low voltage ride through and a wind power converter, in the power supply circuit, a first change-over switch comprises a first switch body and a first normally open contact, and a second change-over switch comprises a second switch body, a second normally open contact and a normally closed contact; the first switch body and the normally closed contact are connected in series and then are connected between the first control end and the second control end of the controller; a first power supply input end of the uninterruptible power supply is connected with a first power supply end of the alternating current power supply, one end of the first normally open contact is connected with a second power supply end of the alternating current power supply, the other end of the first normally open contact is connected with a second power supply input end of the uninterruptible power supply, and the second normally open contact is connected with the first normally open contact in parallel; the second switch body is connected between the first power supply output end and the second power supply output end of the uninterruptible power supply. When the high voltage of the primary side of the auxiliary power supply drops too much and the time is too long, the coil of the pre-stage contactor is prevented from being damaged.

The invention discloses a current differential protection adaptability analysis method for an alternating current line of a new energy network flexible direct output system, and belongs to the technical field of power system relay protection. Establishing a system fault equivalent model based on a low-voltage ride-through control strategy of power electronic equipment at two sides of the outgoing line; according to different asymmetric fault types and a fault point boundary condition equation, deriving mathematical models of positive-sequence, negative-sequence and zero-sequence currents on the two sides of a fault phase line; calculating a differential current and a braking current, and establishing a function relationship between the differential current and the braking current and the VSG internal potential reference value, the transition resistance and the current sequence component ratio; and the action sensitivity of protection under different working conditions is judged by comparing the current differential protection ratio braking coefficient setting value with the current differential protection ratio braking coefficient setting value. The association rule of the current differential protection refusal risk and the low-pass control parameters under the high transition resistance fault is disclosed, a basis is provided for protection setting and control strategy optimization of a network construction flexible direct output system, and the problems that a protection adaptability analysis method is weak and the influence rule of the control parameters is not clear yet are solved.

The application discloses a kind of wind turbine group low voltage ride through model construction method and device, comprising: obtaining the operating variable dataset of wind turbine group;According to the operating variable dataset, the initial wind turbine group low voltage ride through model constructed is trained, to obtain wind turbine group low voltage ride through model.The application does not need to construct wind turbine group equivalent model and other mechanism model through the physical principle of wind turbine group, avoids the state of each wind turbine in wind turbine group is different to need to model each wind turbine respectively, and directly realizes the construction of wind turbine group low voltage ride through model through the operating data of wind turbine group, and then does not need to determine the parameter information of each wind turbine in wind turbine group, so that the application has high accuracy and high reliability.

Embodiments of the application disclose a direct-drive wind turbine low-voltage ride-through control method and related equipment. The method comprises: generating a ride-through high-level signal to activate a low-voltage ride-through mode when a low-voltage ride-through trigger module detects that a current voltage value of a target power grid where a target direct-drive wind turbine is located is lower than a preset reference value; calculating a voltage drop depth according to the current voltage value and the preset reference value; a low-voltage period reactive power control module of a grid-side control system controls the target direct-drive wind turbine to output reactive power to the target power grid to support the power grid according to the voltage drop depth; and an active power control module of a machine-side control system controls output power of the target direct-drive wind turbine according to the voltage drop depth. The direct-drive wind turbine low-voltage ride-through control method overcomes the direct-current voltage overvoltage oscillation defect of the prior art and limits the machine-side electromagnetic power during the wind turbine low-voltage ride-through period from the source.

This invention discloses a method and system for evaluating segmented voltage regulation intensity during the low-voltage ride-through process of a new energy power plant, comprising: acquiring key operating parameters of the new energy power plant; calculating voltage constraints at different stages based on the key operating parameters, determining the voltage constraint range corresponding to each stage, thereby dividing the low-voltage ride-through process into three stages; determining the reactive current corresponding to each stage, determining the reactive power based on the reactive current, and establishing a voltage regulation characteristic analysis model corresponding to each stage based on the reactive power; acquiring the grid connection point voltage amplitude at different sampling times during the low-voltage ride-through process of the new energy power plant, determining the target stage corresponding to each grid connection point voltage amplitude based on the grid connection point voltage amplitude and the voltage constraint range, and determining the voltage regulation intensity of the new energy power plant at different sampling times during the low-voltage ride-through process based on the voltage regulation characteristic analysis model corresponding to the target stage.

The embodiment of the invention provides a low-voltage ride-through protection threshold value setting method and device. The method comprises the steps that the power grid strength and equivalent impedance of an alternating current power grid connected with a grid-connected point in a power system are determined; obtaining grid-connected impedance and equivalent transmission power of an energy system connected to a new energy side in the power system; determining the new energy permeability in the power system; constructing a voltage stability analysis model according to the actual power grid parameters of the power system and a preset interface equation; and processing the power grid strength, the equivalent impedance, the grid-connected impedance, the equivalent transmission power and the new energy permeability by using the voltage stability analysis model to obtain a low voltage ride through protection threshold setting value. The method provided by the invention comprehensively considers the power grid strength and the new energy permeability, and is suitable for most new energy grid-connected scenes.