[Objective] To address the problems that photovoltaic inverter models provided by manufacturers are mostly delivered as black-box dynamic libraries with inaccessible internal control structures

and that detailed electromagnetic transient (EMT) models for large-scale photovoltaic power stations suffer from large model size and low simulation efficiency

this paper proposes an EMT modeling method for photovoltaic units based on test data of manufacturer-supplied black-box models

as well as an equivalent modeling method for photovoltaic power stations following the principle of consistent collection-line losses. It provides a model foundation for the transient characteristic analysis of grid-connected photovoltaic power stations and large-grid simulation calculations. [Methods] First

the manufacturer black-box model was connected to the simulation test system

and fault ride-through tests were carried out under different active power output levels and voltage disturbance amplitudes. The response data including terminal voltage

current

active power

reactive power

d- and q-axis currents

were collected to analyze the dynamic variation laws during fault occurrence

fault duration and fault recovery. Then

the parameter set to be identified for the PSModel inverter model was constructed

including main circuit parameters

normal-operation control parameters

fault ride-through thresholds

current limiting parameters

reactive current support coefficients and time criteria. A parameter tuning process of “feature extraction—staged identification—simulation iterative correction” was adopted

and the normalized error and comprehensive error objective function were introduced to evaluate the deviation between the PSModel model and the manufacturer black-box model. After the unit-level model verification was completed

a detailed EMT model of a 100 MW photovoltaic power station in Anhui province was established based on the PSModel platform independently developed by China Electric Power Research Institute. Furthermore

according to the actual collector network topology

the collector-line structures

including branch-trunk

trunk and radial structures

were equivalently transformed under the principle of active power loss consistency

and the photovoltaic power station equivalent model was formed. Finally

considering the many combinations of load rates

fault types and voltage disturbance amplitudes

representative operating conditions were selected for comparative verification between the detailed model and the equivalent model. Meanwhile

to avoid the limitation of evaluating the equivalent effect only by active power curves

the voltage

current

active power

reactive power and reactive current at the 35 kV bus were further selected as evaluation variables. The sectional average deviation

maximum deviation and weighted average total deviation were used for quantitative analysis. [Results] The established photovoltaic unit model effectively reproduced the active and reactive power dynamic response characteristics of different manufacturer models during fault ride-through. The detailed model and equivalent model of the photovoltaic power station showed basically consistent active power variation trends at the 35 kV bus during fault occurrence

fault duration and fault recovery. The multi-condition error statistics showed that

under the selected symmetrical and asymmetrical disturbance scenarios

the sectional errors and weighted average total deviations of voltage

current

active power

reactive power and reactive current were all lower than the allowable limits specified in GB/T32892—2026. [Conclusion] The proposed method can construct a photovoltaic unit EMT model suitable for engineering simulation when manufacturer control details cannot be fully disclosed. It can also reduce the scale of the photovoltaic power station model and improve simulation efficiency while maintaining the dynamic port characteristics at the 35 kV bus

providing an effective modeling approach for subsequent analysis of the grid-connection security and stability influence of photovoltaic power stations.