05/06/2026
For many years, the grid was mainly built around conventional generation: thermal power plants, synchronous machines, predictable dispatch, and traditional protection philosophy. In that type of system, many dynamic behaviors were familiar to grid operators. Fault current was high. Generator inertia was naturally available. Voltage and frequency response were mainly controlled by rotating machines.
Now the system is changing.
Uzbekistan is adding large-scale solar PV, wind power, battery energy storage systems, and modern digital grid infrastructure. This is the right direction. It supports energy security, reduces fuel dependency, and helps modernize the national power system.
But there is one technical step that must not be ignored:
Power system model validation.
Model validation is not just a study requirement. It is a reliability requirement.
1. What Is Model Validation?
In simple terms, model validation means checking whether the simulation model behaves like the real equipment in the field.
A developer may submit a model for a solar plant, wind farm, BESS, or power plant controller. That model may run correctly in software such as PSS/E, DIgSILENT PowerFactory, PSCAD, or another approved platform.
But that alone is not enough.
A model can run without errors and still be wrong.
The real question is:
If the grid voltage dips, frequency changes, or a fault occurs, does the model respond the same way as the actual plant?
That is the purpose of model validation.
2. Why Uzbekistan Needs It Now?
Uzbekistan is moving quickly toward renewable integration. Recent projects already include utility-scale solar, wind, and battery storage.
This means Uzbekistan is no longer connecting only conventional generation. It is connecting inverter-based resources.
That changes the engineering problem.
Solar PV, wind turbines, and BESS plants do not naturally behave like synchronous generators. Their response depends on inverter controls, plant power controllers, protection settings, phase-locked loops, current limits, reactive power logic, and ride-through functions.
During normal operation, the difference may not be visible. But during a disturbance, the real behavior can be very different from the study model.
That is where risk appears.
A study may show that the grid is stable.
A real event may show that the plant reduces output, blocks current, enters momentary cessation, or recovers voltage too slowly.
If the model is wrong, the planning conclusion is also wrong.
а) The Hidden Risk of Unvalidated Models
The most dangerous model is not the one that obviously fails.
The most dangerous model is the one that looks professional, passes a software check, and gives a false sense of confidence.
Unvalidated models can create several problems:
For a growing system like Uzbekistan, this matters because renewable plants may be located far from strong grid nodes. Some areas may have weaker short-circuit strength, longer transmission corridors, and more sensitivity to voltage and reactive power behavior.
In such systems, accurate models are not optional.
b) Verification vs Validation
These two terms are often confused.
Model verification asks:
Is the model built correctly? Are the parameters complete? Does it run in the required software?
Model validation asks:
Does the model match real field performance?
Both are needed.
A verified model is like a passport. It confirms the model is formally acceptable.
A validated model is like a field test. It proves the model represents the actual plant.
Uzbekistan should require both.
c) RMS and EMT Models
For most transmission planning studies, RMS dynamic models are still useful. They are suitable for large-system stability studies, frequency response, voltage recovery, and many interconnection cases.
But for inverter-based resources, RMS models are not always enough.
EMT models may be required when the project is connected to a weak grid, uses complex inverter controls, includes grid-forming functions, connects through HVDC, or shows fast control interactions.
A practical approach for Uzbekistan could be:
RMS models for system-wide planning.
EMT models for detailed inverter, weak-grid, protection, and control interaction studies.
This is especially important for BESS, large solar PV plants, wind farms, and hybrid projects.
3. How Model Validation Should Be Done?
A proper validation process does not need to be complicated at the beginning. It can be introduced step by step.
First, every major generation or storage project should submit approved steady-state, short-circuit, RMS dynamic, and where necessary EMT models.
Second, commissioning tests should collect real field data from the point of interconnection. The minimum signals should include voltage, current, active power, reactive power, frequency, breaker status, plant controller signals, inverter status, and protection events.
Third, the plant should be tested for key functions:
Fourth, the same event should be replayed in simulation. The simulated voltage, active power, reactive power, and frequency response should be compared with actual measured data.
If the response does not match, the model must be tuned.
This is model validation.
4. Who Should Be Responsible?
Model validation cannot be left only to one party.
The developer must provide accurate models.
The OEM must provide correct inverter, turbine, BESS, and controller parameters.
The consultant must perform the validation study.
The grid operator must define the requirements and approve the final model.
The regulator must make the process enforceable.
Without clear responsibility, model quality becomes inconsistent.
For Uzbekistan, this is an opportunity. The country can build a modern grid-code practice early, before renewable penetration becomes more difficult to manage.
A National Model Database
One practical recommendation is to create a national validated model database.
The grid operator should maintain the approved models for all major power plants, solar PV projects, wind farms, BESS plants, and large industrial loads.
This database should not be static. It should be updated whenever there is:
A model should represent the real plant today, not the plant as it was during the original connection study.
5. Why This Matters for Grid Security?
Power system studies are only as good as the models behind them.
If Uzbekistan wants to integrate more renewables safely, reduce curtailment, improve voltage stability, and operate BESS effectively, validated models must become part of the technical foundation.
This is not paperwork.
It is how the grid operator knows whether a plant will ride through a fault, support voltage, respond to frequency, and recover after a disturbance.
The future Uzbek grid will be more digital, more inverter-based, and more dynamic. That future requires better visibility, better data, and better models.
Model validation is the bridge between simulation confidence and real grid reliability.
6. Conclusion
Uzbekistan is building the next generation of its power system. Solar, wind, BESS, and digital grid technologies will play an important role. But these assets must be represented correctly in planning and operation.
A renewable plant should not only be connected to the grid physically.
It should also be connected accurately in the grid model.
That is why model validation should become a standard requirement in Uzbekistan’s power sector.