27 results about "Static VAR compensator" patented technology

The invention discloses a voltage regulation and control method and system suitable for a distributed energy storage photovoltaic transformer area of a power distribution network. The method comprises the following steps: establishing a transformer area active power distribution network model for carrying out voltage regulation and control by considering distributed photovoltaic, wind power, an energy storage system, a static var compensator and a load node; a voltage regulation problem is modeled as a Markov decision process, a state space comprises multi-source power information and energy storage state information, and an action space is controlled quantities of a static var compensator and an energy storage system; a Markov decision is solved by adopting a depth deterministic strategy gradient algorithm based on Actor-Critic dual networks, a control action is generated through a strategy network Actor, and a current strategy is evaluated through a value network Critic for training; and inputting the trained strategy network based on the current observation state, outputting an optimal energy storage active / reactive power output and SVC reactive power compensation control instruction, realizing online adjustment of node voltage, and realizing stable control of transformer area voltage.

The application discloses a kind of wind farm isolated network heat supply system operation control method and device.Wind farm isolated network heat supply system operation control method includes based on the active stable operation state of wind farm isolated network heat supply system, determine the active output state of diesel generator, fan and network type energy storage unit;Based on the reactive stable operation state of wind farm isolated network heat supply system, determine the reactive output state of diesel generator, fan and network type energy storage unit;Based on the voltage stable operation state of wind farm isolated network heat supply system, determine the voltage output state of diesel generator, fan, network type energy storage unit and static var compensator;According to active output state, reactive output state and voltage output state, to complete the operation control of wind farm isolated network heat supply system.Frequency is adjusted quickly, to ensure that system frequency is stably operated, and the quick grid connection and operation of system are realized.

The invention relates to the technical field of new energy grid-connected system stability analysis, in particular to an SVC new energy short-circuit ratio margin assessment method, system equipment and a medium, and aims to accurately correct a real-time voltage support strength assessment model of a new energy access point by dynamically integrating SVC reactive compensation capacity into a short-circuit ratio calculation process. The defect of system strength misjudgment caused by neglecting reactive compensation in a traditional method is overcome; analyzing a static voltage stability limit based on the maximum transmission power of the new energy, and accurately defining a critical short-circuit ratio as an instability boundary threshold value; a margin index is calculated through a difference value between a short-circuit ratio and a critical short-circuit ratio, the safety redundancy of the system is directly quantified, and a single-station independent access and multi-station strong coupling scene is compatible with the positive and negative characteristics of a unified margin criterion, so that the prevention and control capability on the voltage collapse risk of a high-proportion new energy power grid is remarkably improved; and a grounding stability decision basis is provided for new energy station planning and site selection, SVC reactive compensation configuration and power grid operation scheduling.

The invention provides a medium-voltage power system balancing system based on a balancing unit and an optimization method, and relates to the technical field of power regulation. The medium-voltage power system balance system based on the balance unit is a technical system for realizing dynamic balance of power, voltage and frequency of a medium-voltage power distribution network through an intelligent control strategy, and comprises a power equipment module, a strategy control module, an energy management module, a service application module and a network communication module, the power equipment module comprises a balance adjusting unit, a modular multilevel converter and an energy router. The balance adjusting unit comprises a static var compensator, a static synchronous compensator and a dynamic voltage restorer. Dynamic balance adjustment of the medium-voltage power system is realized by adopting MPC model prediction and an edge AI algorithm, technologies of edge calculation, intelligent optimization, power electronics and the like are fused, limitation of traditional scheduling is broken through, and flexibility and expandability of the system are improved through modular design and a marketization mechanism.

The invention provides a parameter design method considering impedance interaction characteristics of a distributed power supply and an SVC, and the method comprises the steps: constructing a port impedance model of a typical three-phase LCL type grid-connected converter and the SVC, building a node admittance matrix of a converter system, drawing a modal impedance curve of the system before and after the system is connected with the SVC in parallel through a modal analysis method, and determining a resonant mode of the system. The method comprises the following steps: solving a system characteristic root, taking a damping coefficient as a key parameter for representing the stability of the system, analyzing the influence of SVC parameters on the stability of the system, and aiming at a converter multi-machine grid-connected system, considering the reactive capacity configuration requirement of a station, aiming at improving the damping of the system, and combining a particle swarm algorithm to optimize the SVC parameters. According to the method, broadband harmonic oscillation caused by interaction of background harmonic waves and network impedance under complex working conditions can be effectively suppressed, reactive power provided for a power grid can be flexibly set, and the dual targets of electric energy quality optimization and harmonic oscillation treatment are achieved.

The invention relates to a novel power system machine-field-network global stability control system and method, belongs to the technical field of wind power generation systems, and solves the problem of rapid analysis and control of the novel power system machine-field-network global stability in the prior art. The method comprises the following steps: when the novel power system oscillates, establishing a system machine-field-network mathematical model and dividing the mathematical model into a plurality of subsystems, constructing a dynamic energy model of each subsystem by using a first integral method, and revealing an oscillation mechanism of the system from an energy interaction perspective, key interaction energy inducing system machine-field-network oscillation instability is screened out, and further on the basis of the incidence relation between the output power of additional equipment such as a static var compensator and the output dynamic energy of the additional equipment; and the machine-field-network global stability rapid analysis control of the novel power system is realized by adjusting the power instruction value of the additional equipment on line.

The utility model relates to the technical field of low-voltage static var compensation, in particular to a low-voltage static var compensation device, which is provided with an inflating mechanism and a driving mechanism, so that a rubber air bag is replaced by a metal air tank in the low-voltage static var compensation process, the operation stability of equipment is improved, and the service life of the equipment is prolonged. Comprising a heat dissipation mechanism; the device further comprises a filtering mechanism, six air passing mechanisms, six heat conduction mechanisms, three inflation mechanisms and a driving mechanism, the filtering mechanism is installed at the lower end of the heat dissipation mechanism, the six air passing mechanisms are installed in the heat dissipation mechanism, the six heat conduction mechanisms and the air passing mechanisms are connected and installed in the heat dissipation mechanism, and every two air passing mechanisms are connected through one inflation mechanism. The driving mechanism is mounted in the heat dissipation mechanism; the heat dissipation mechanism conducts heat dissipation, the filtering mechanism conducts filtering, the air passing mechanism conducts air, the heat conduction mechanism conducts heat, the air pumping mechanism conducts air pumping, and the driving mechanism drives the air pumping mechanism.

The invention discloses a reactive power resource aggregation method under a multi-time scale voltage support criterion, and belongs to the technical field of power system voltage stability control. The core innovation of the method lies in that a refined voltage support capability criterion system covering three different levels of long time, medium time and short time is constructed, and is used for accurately quantifying the dynamic regulation capability of heterogeneous reactive power resources such as an on-load tap changer (OLTC), a capacitor bank (CBs), a static var compensator (SVC) and a photovoltaic inverter. On the basis, the method introduces a DBSCAN clustering algorithm, combines the time scale criterion with a power grid topological structure, and performs comprehensive clustering analysis on reactive resource access nodes, thereby forming a hierarchical aggregation coordination strategy which realizes optimization in both time dimension and space dimension. According to the invention, the voltage stability, the reactive power resource utilization efficiency and the new energy consumption capability of the power distribution network under the high-proportion new energy access background are remarkably improved.

This application discloses a method, device, equipment, medium, and product for power grid transient voltage support control, relating to the field of power systems. The method includes: in the reactive power control stage, introducing a quasi-steady-state model simulating a synchronous condenser in the module generating voltage amplitude in the static var compensator (SVC), simulating the voltage change at the virtual condenser terminal during transient processes, and determining an improvement strategy for the reactive power control stage; in the phase-locked loop (PLL) stage based on power balance, improving the droop control stage of the SVC based on the swing equation, simulating the electromagnetic torque of the virtual condenser, adjusting phase information, and determining an improvement strategy for the PLL stage; based on the improved strategies for the reactive power control stage and the PLL stage, determining a power grid transient voltage support control strategy based on the virtual condenser to control the grid voltage. This application can solve the overcurrent phenomenon during fault processes and reduce the overvoltage level at the grid connection point after a fault.

The application discloses a kind of integration static reactive compensation device, it is related to reactive power compensation technical field, including heat dissipation mechanism, the outer wall of heat dissipation mechanism is fixedly installed with multiple filtering mechanisms, the outer wall of multiple filtering mechanisms is fixedly installed with two drive mechanisms;Heat dissipation mechanism includes reactive compensation device body;In the application, when the temperature of device internal area is too high, corresponding heat conduction cylinder liquid vaporization pushes piston and baffle to rise, drive heat dissipation fan and suction pump to suck in cold air and discharge hot air, realize rapid cooling, after the temperature of area reduces, gas is condensed with it, spring one is pushed baffle and switch separation, corresponding fan is closed and the suction speed of suction pump is reduced, according to the temperature difference of device internal different areas, the start of corresponding area heat dissipation fan is controlled, accurate heat dissipation can be realized to reduce unnecessary electric energy loss, reduce the failure rate caused by overheating or temperature is too low, improve the reliability and stability of entire reactive compensation device.

The invention discloses a multi-agent voltage cooperative control method for multi-type voltage regulating devices, and relates to the technical field of electrical engineering and the technical field of computer science, and the method comprises the steps: 10), aiming at the operation characteristics of a static var compensator, a photovoltaic inverter, an energy storage device and a line voltage regulator in a power distribution network, carrying out the cooperative control of the voltage of a plurality of types of voltage regulating devices; constructing a voltage control model capable of coordinating different types of voltage regulation equipment; (20) based on the voltage control model, control variables are submitted to different agents for independent learning and decision making, and a voltage control problem is converted into an MDP problem which can be solved by MADRL; (30) an MADRL algorithm based on a multi-agent soft actor-commentator algorithm is adopted to solve the MDP problem, and guide-softmax is introduced for a discrete voltage regulation device to improve the algorithm; and step 40) obtaining a multi-device cooperative voltage control scheme through parallel training and online execution of a plurality of agents. Compared with the prior art, the method has the advantages that a unified voltage control model capable of coordinating different types of voltage regulation equipment is constructed from the perspective of power distribution network voltage optimization regulation and control, strategy optimization is carried out on control decisions of various types of voltage regulation equipment through a multi-agent reinforcement learning algorithm, and coordinated regulation of the power distribution network voltage is achieved.

The invention relates to a fault ride-through capability testing device, method and system for a static var compensator, the testing device is connected with a static var compensator SVG to be tested, the SVG to be tested is connected with a regulation and control system, the regulation and control system is connected with a grid-connected transformer, the grid-connected transformer is respectively connected with a power grid and the SVG to be tested, and the grid-connected transformer is connected with a power grid. The device comprises a first processor, a second processor and a first high-voltage side acquisition end, the first processor is connected with the regulation and control system and the second processor, the first high-voltage side acquisition end is connected between the high-voltage side of the grid-connected transformer and a power grid, and the second processor is connected with the first high-voltage side acquisition end. According to the invention, the safety of SVG and power grid operation during an online test period is practically guaranteed, the synchronization efficiency of the test voltage output by the test device and the SVG grid-connected point voltage is also improved, and the test device can enable the output test voltage to reach a set variation amplitude under any condition of the port voltage of the to-be-tested SVG.

The invention discloses a static var compensator configuration and voltage regulation and control method suitable for a power distribution network, and belongs to the technical field of power system power distribution network optimization operation. The method comprises the steps that according to the position, capacity and operation layer parameters of a static var compensator, operation layer optimization operation calculation is carried out with the economy and voltage quality of the power distribution network as targets, a global optimal solution in each typical scene is obtained, and the annual operation comprehensive cost of the power distribution network is fed back to a configuration layer; performing configuration operation optimization calculation by combining the configuration layer parameters and the annual investment and maintenance cost of the static var compensator to obtain the position and the capacity of the updated static var compensator; judging whether the result converges or not, if not, transmitting the updated static var compensator configuration scheme to the operation layer, and returning to execute the optimization operation calculation of the operation layer; and if yes, outputting an optimization result. According to the method, dual optimization of economy and voltage quality is realized, and the voltage deviation is effectively controlled while the operation economy of the power distribution network is ensured.

The application relates to the field of power system planning, and relates to a static reactive power compensator capacity and location selection method based on electromagnetic transient simulation, which comprises the following steps: randomly generating P simulation scenes and P speed vectors; performing electromagnetic transient simulation on each simulation scene to obtain the result of electromagnetic transient simulation, and calculating the optimization target of each scene based on the result of electromagnetic transient simulation; repeating step S2 until the P simulation scenes are traversed, selecting the historical optimal solution of each simulation scene in the iteration process and all global optimal solutions; updating the speed value vector of each scene, and calculating the static reactive power compensator capacity configuration scheme of each scene based on the updated speed value vector; repeating steps S2-S4 until the iteration converges, so that the final static reactive power compensator configuration scheme is obtained. The application can comprehensively consider economy and power system stability, find the most suitable bus position for a newly-built static reactive power compensator, and provide an optimized strategy scheme for the reactive power voltage support of the system.

This application relates to a method, device, computer equipment, medium, and product for collaborative management of voltage fluctuations in distribution networks. The method includes: obtaining the available reactive power adjustment margin of distributed photovoltaic (PV) nodes under current operating conditions, and then obtaining the reactive power margin deficit to determine candidate configuration nodes and compensation capacity ranges for static var compensators (SVCs); constructing a multi-objective optimization function; selecting reactive power compensation nodes from the candidate configuration nodes; obtaining the reactive power compensation capacity of the reactive power compensation nodes according to the compensation capacity range; using distributed PV nodes, reactive power compensation nodes, PV active power capacity, PV reactive power capacity, and reactive power compensation capacity as initial configuration parameters; solving the multi-objective optimization function in multiple rounds to obtain target configuration parameters; updating the current distribution network configuration according to the target configuration parameters; and collaboratively managing voltage fluctuations in the distribution network based on distributed PV nodes and reactive power compensation nodes. This method can improve the accuracy of management.

The invention belongs to the technical field of optical storage grid connection, and provides an optical storage and load grid connection capacity configuration and energy scheduling method and system, and the method comprises the steps: obtaining power data corresponding to an optical storage and load grid connection system at each time; under the condition that the system investment constraint and the distributed power supply permeability constraint are met at the same time, taking total annual net cost minimization as a target function, and constructing an upper-layer capacity configuration model; under the condition that alternating current and direct current power balance constraint, converter constraint and static reactive power compensator constraint are met at the same time, taking system daily operation cost minimization as a target function, and constructing a lower-layer energy scheduling model; and through cooperative solution of the upper-layer capacity configuration model and the lower-layer energy scheduling model, linkage optimization between upper-layer capacity configuration and lower-layer energy scheduling is realized, and an optical storage load grid-connected system scheduling strategy with optimal economy is determined. Through the method, the operation economy of the optical storage grid-connected system is improved.

The application provides a wind farm reactive power coordination method, device and storage medium, relates to the field of power systems and automatic technology, and first monitors the reactive power output and maximum reactive power output capacity of each wind turbine in real time, synchronously obtains the current voltage drop amount and actual reactive power output power of a static var compensator (SVC); then calculates the reactive power margin of each wind turbine, and determines the total reactive power compensation demand of the system according to the voltage drop amount and equivalent reactance of the power grid, so that the SVC undertakes the initial compensation task; subsequently, the remaining compensation amount is distributed to each wind turbine according to the proportion of the wind turbine reactive power margin, the adjustment instruction is generated by limiting the superposition current output to be not more than the maximum capacity; if the certain wind turbine still exceeds the limit after adjustment, the excess part is redistributed to other wind turbines with margin, until all wind turbines operate within the safe range; finally, the SVC output and power grid state change are tracked in real time, the compensation distribution is dynamically optimized, and the balance of the reactive power coordination is ensured.

The invention discloses a medium-voltage static var compensator. The medium-voltage static var compensator comprises a low-frequency sub-module unit and a high-frequency sub-module unit, the low-frequency sub-module unit is formed by connecting N-1 low-frequency sub-modules with the same structure in series, and each low-frequency sub-module comprises a first direct-current energy storage capacitor (CL) and a plurality of Si-based insulated gate bipolar transistors; the high-frequency sub-module unit is composed of a three-phase bridge type converter unit, and the three-phase bridge type converter unit comprises a second direct-current energy storage capacitor (CH) and a plurality of SiC-based metal oxide semiconductor field effect transistors; and the low-frequency sub-module unit is connected with the high-frequency sub-module unit. According to the medium-voltage SVG, the problem that comprehensive optimization of efficiency, cost and power density of a medium-voltage SVG based on a single device is difficult is solved.

The invention discloses a cascade SVG driving signal fault detection method, and relates to the technical field of power electronics, and the method comprises the steps: collecting the DC voltage data of each cascade module in a static var generator in real time, and carrying out the pulse-free pre-charging of a DC side capacitor in a bypass resistor grid-connected state; when pre-charging of the direct current side capacitor is completed, protection operation is executed on the static var generator; based on the detection target type, averagely grouping a plurality of H-bridge sub-modules in the static var generator to obtain a plurality of sub-module groups; and giving a pulse signal with a preset modulation ratio to the static var generator based on the modulation period with a preset continuous number of times. According to the method, grid-connected operation is prevented from being affected by faults generated during formal grid connection, fault modules of the cascaded SVG are positioned before grid connection, and grid connection failures and unnecessary damage to components caused by misconnection of driving signals of the fault modules are avoided.

The invention relates to the technical field of power system control, in particular to an SVG-based high-voltage direct-current reactive compensation and voltage regulation equipment cooperative control method, which comprises the steps of judging whether adjustment is needed or not according to a scheduling instruction and a real-time active power difference value; calculating a required reactive power difference value; when the reactive power difference value is within the adjustable range of the SVG, adjustment is only carried out through the SVG; if the SVG capacity is exceeded, capacitor group switching and transformer tap voltage regulation operation are started in sequence, the actions of the static var compensator, the capacitor group and the transformer tap are judged and coordinated in sequence according to the priority, the static var compensator preferentially responds to the millisecond-level dynamic requirement, and after switching is confirmed, the static var compensator is switched to the millisecond-level dynamic requirement. The capacitor group and the transformer tap are switched in a time-delay manner to deal with medium continuous change or adjustment so as to process long-term steady-state offset, so that optimization and cooperation of multi-time scale reactive power resources are realized, the system voltage stability is improved, the action frequency of a mechanical switch is reduced, the service life of equipment is prolonged, and dynamic response performance and operation economy are both considered.

The invention relates to the technical field of power grid acceleration, and discloses a power distribution network reactive power distribution acceleration method and system based on an industrial-grade configuration platform. The method comprises the following steps of: constructing a reactive power distribution optimization model: establishing the reactive power distribution optimization model by taking minimization of the total reactive power regulation cost of the transformer area as an objective function and taking meeting of the reactive power demand of the transformer area as a constraint condition; the reactive power demand of the transformer area is modeled into bounded uncertain parameters changing in a determined interval, the two-stage robust optimization decision framework is adopted, the first stage decides the switching state of a discrete equipment capacitor, and the second stage decides the switching state of the discrete equipment capacitor after an uncertain scene is revealed. Reactive power output of the static reactive power compensator is continuously adjusted; solving a model and generating a strategy; operation acceleration is realized based on an industrial-grade configuration platform. The improvement of the method is that operation acceleration of the reactive power distribution model of the power distribution network is realized based on a multi-configuration parallel computing architecture of an industrial-grade configuration platform.

The invention relates to the technical field of power system optimization scheduling, in particular to a water-light-storage complementary and direct current delivery two-stage random optimization scheduling method and system. The method comprises the following steps: establishing a water-light-storage complementary and direct-current delivery system model comprising a thermal power generating unit, a photovoltaic unit, cascade hydropower, a pumped storage unit, a static reactive power compensator and direct-current delivery; the method comprises the following steps: constructing a two-stage stochastic optimization scheduling model by taking operation cost minimization as an objective function and taking node balance constraint, branch power flow constraint, thermal power generating unit constraint, photovoltaic output constraint, pumped storage power station constraint, cascade hydropower constraint, static reactive power compensator constraint and branch operation constraint as constraint conditions; the method comprises the following steps: taking photovoltaic uncertainty into consideration by using a conditional generative adversarial network (CGAN), generating a typical scene, and reducing the generated scene through an Euclidean hierarchical clustering method (EAHCM); and solving the two-stage stochastic optimization scheduling model to obtain an optimization scheduling result, thereby realizing the goal of economic scheduling.

The application provides a method and device for distributed phase modifier third harmonic zero voltage stator grounding protection, the method comprising: collecting the closing position information of the circuit breaker and static var compensator at the generator end and the analog quantity information at the generator end; calculating the third harmonic components of the zero sequence voltage at the generator end and the neutral point zero sequence voltage, the reactive power and the frequency based on the analog quantity information; forming the operating condition with the adjustment criterion, and automatically switching the third harmonic voltage ratio fixed value before and after the grid connection based on the operating condition with the adjustment criterion; forming the power with the adjustment criterion, and determining the third harmonic voltage ratio calculation fixed value based on the power with the adjustment criterion; forming the grounding protection criterion, and judging whether the third harmonic zero voltage stator grounding protection action condition is met based on the grounding protection criterion. The application can quickly identify the operating condition of the unit, and automatically switch the corresponding protection fixed value, thereby improving the flexibility of the protection. The power with the adjustment criterion is braked by the reactive power unit value, thereby further improving the protection reliability under different operating conditions.

The present application relates to the technical field of power system optimization scheduling, and particularly relates to a water-light-storage complementary and DC external sending two-stage random optimization scheduling method and system, which comprises the following steps: establishing a water-light-storage complementary and DC external sending system model containing thermal power units, photovoltaic units, cascade hydropower, pumped storage units, static var compensators and DC external sending; taking the minimization of operation cost as an objective function, and taking node balance constraints, branch power flow constraints, thermal power unit constraints, photovoltaic output constraints, pumped storage power station constraints, cascade hydropower constraints, static var compensator constraints and branch operation constraints as constraint conditions, a two-stage random optimization scheduling model is constructed; considering photovoltaic uncertainty by using a conditional generative adversarial network (CGAN), typical scenarios are generated, and the generated scenarios are reduced by using an Euclidean hierarchical clustering method (EAHCM); the two-stage random optimization scheduling model is solved to obtain an optimization scheduling result, and the goal of economic scheduling is achieved.

The invention discloses an uninterrupted ice melting circuit and equipment for a power distribution network, and relates to the technical field of circuits, and the circuit comprises a static reactive power compensator, a first switch and an interface device. The alternating-current side of the static reactive power compensator is connected with the power supply area, and the direct-current side is connected with the first end of the first switch; the interface device is connected with the second end of the first switch and the first end of the icing line, and the second end of the icing line is grounded. During ice melting, the first switch is closed, and the second end of the iced line is grounded. When the iced line comprises multiple phases of sub-lines, only the target sub-line is grounded, each phase of sub-line is provided with a corresponding grounding switch, and the iced line can be arranged on the upstream and downstream of the power supply area. The interface device comprises a first switch element and a second switch element which are connected in parallel, and when ice melting current is controlled, one switch element is subjected to chopping, the other switch element is disconnected, or the two elements are alternately conducted at a first frequency; when direct current is injected, the single switching element is turned on, and the other switching element is turned off. The circuit can be used for melting ice under the condition that the power distribution network is not powered off.

The invention relates to a power distribution network optimization operation method based on a linearized full-pure embedded power flow model, and belongs to the technical field of power system operation and control. According to the method, first-order linearization processing is carried out on a power series recursive relation of a fully-pure embedded power flow model, and a linearization approximation model between node voltage and power injection increment is constructed by ignoring a high-order attenuation item, so that nonlinear power flow calculation is converted into efficient linear combination operation. And on the basis of the linearization model, constructing a power distribution network multi-period optimization operation model taking system voltage deviation minimization as a target, and coupling operation constraints of the energy storage system and the static reactive power compensation device. According to the method, on the premise that the calculation precision is guaranteed, the efficiency of multi-period continuous power flow calculation and optimal scheduling is remarkably improved, the problems of voltage out-of-limit and power fluctuation of the power distribution network under high-proportion distributed energy access are effectively solved, and the safety and economical efficiency of system operation are improved.

The invention discloses a high-proportion distributed photovoltaic power distribution network reactive power equipment suitability evaluation method, which comprises the following steps of: constructing evaluation indexes for accessing reactive power compensation equipment in three typical scenes of voltage support, fluctuation stabilization and sag relief so as to measure voltage regulation effects in the scenes; the method comprises the following steps: constructing a total voltage regulation cost index according to three voltage regulation devices of an on-load voltage regulation transformer (OLTC), a capacitor bank (CBs) and a static var compensator (SVC) and the voltage regulation cost of a photovoltaic inverter; and calculating the weight of each index by adopting a method of combining a Delphi subjective weighting method and a CRITIC objective weighting method, and finally performing weighted summation to obtain the final adaptability of each reactive power resource scheme, thereby constructing a reactive power equipment adaptability evaluation framework of the high-proportion distributed photovoltaic access power distribution network.