1. WECC REMTF Workshop Spencer Tacke Spencert@mid.org
WECC Renewable Energy System Models Workshop
March 9, 2016

2. REMTF Workshop
Accurate, validated models are required for reliable and economic power system operations
NERC Reliability Standards require that power flow and dynamics models be provided

3. REMTF Workshop
Under WECC modeling guidelines (i.e., Generating Unit Model Validation Policy), all wind and PV power plants with aggregated capacity 20 MVA or larger must be modeled explicitly in WECC power flow and dynamics base cases, using models in the WCC Approved Dynamic Model Library
Manufacturer-specific dynamic models commonly provided for interconnection studies are not adequate for regional planning. WECC requires the use of approved models.

4. Recent Data Gathered by PPMVDTF
WECC base cases have close to 29 GW of total wind generation
74 plants with 5 GW of generating capacity are connected at 24 to 35-V level, and therefore have no collector system representation
94 plants with 5.2 GW of generating capacity have no dynamic models
54 plants with 2.8 GW of generating capacity are modeled with inappropriate dynamic models

5. REMTF Workshop
There is a significant opportunity for model improvement
The REMTF (under the MVWG) has led a multi-year effort developing dynamic models for wind and PV generators
The effort has been a broad industry effort
The collaborative community has worked under the auspices of the WECC and the REMTF, and the developed models have been WECC approved and are in major commercial software platforms

6. Wind Generation Dynamic Models
Development was done in phases
Initial implementation of type 3 and 4 types represented a limited set of manufacturers
Recently developed second generation models have the capabilities to capture a wider group of wind generation turbine makes and models

7. Grid-Connected PV Systems
Most are residential and commercial scale connected to distribution networks
But many are large generation facilities connected to the transmission system

8. Second Generation Models
They were developed deliberately in a modular format to facilitate the ability to add new features and functions to the library of models without significant effort
1st generation models were developed without the flexibility to represent various vendor equipment
2nd generation models were developed with more flexibility and were validated against several vendor data

9. Goals of Second Generation Generic Models
Allow for easy implementation of new modules to build on existing components and allow for the ever-growing and changing technology, and
Allow for emulation of a wider range of control philosophies and thus the ability to be parameterized for representing a wide range of equipment

10. Wind Turbine Diagrams

11. The 2nd Generation Renewable Energy System (RES) Models
Function
1st or 2nd Generation
regc_a
RES Generator/Converter Model
2nd
reec_a
RES Electrical Controls Model A
reec_b
RES Electrical Controls Model B
reec_c
RES Electrical Controls Model C
repc_a
RES Plant Controls Model A
repc_b
RES Plant Controls Model B
2nd (not yet finalized)
wtgt_a
WTG Turbine Shaft Model A
wtgar_a
WTC Aero-dynamic Model A
wtgpt_a
WTG Pitch Controller Model A
wtgtrq_a
WTG Torque Controller Model A
wt1p_b
Pitch Controller for type 1 WTG Model B
wt1g
Type 1 WTG generator model
1st
wt1t
Type 1 WTG turbine shaft model
wt2g
Type 2 WTG generator model
wt2e
Type 2 WTG variable external rotor resistance controller
wt2t
Type 2 WTG turbine shaft model
lhvrt
low/high voltage ride-through relay model
lhfrt
low/high frequency ride-through relay model

12. The 2nd Generation RES Models
Model Combination
Type 1 WTG
wt1g, wt1t, wt1p_b
Type 2 WTG
wt2g, wt2e, wt2t, wt1p_b
Type 3 WTG
regc_a, reec_a, repc_a, wtgt_a, wtgar_a, wtgpt_a, wtgtrq_a
Type 4 WTG
regc_a, reec_a, repc_a (optional: wtgt_a)
PV plant
regc_a, reec_b (or reec_a), repc_a
BESS
regc_a, reec_c (optional: repc_a)

13. The 2nd Generation RES Models

14. The 2nd Generation RES Model: WTG Type 1 and Type 2

15. The 2nd Generation RES Model: WTG Type 3

16. The 2nd Generation RES Model: WTG Type 4

17. The 2nd Generation RES Model: PV

18. References
WECC 2nd Generation WTG Model Specifications:
WECC PV Model Specifications:
WECC PV Modeling Guide:
WECC WTG Modeling Guide:
Model User Guide for Generic Renewable Energy System Models: