IEEE ISGT 2019 

Washington, D.C.

February 17–20, 2019

NREL/PO-5D00-73289

Equivalent Test Bed in PSCAD and PSLF for Studying 

Advanced Power Systems Controller Performance

Reetam Sen Biswas1,2, Jin Tan1, Himanshu Jain1, Vahan Gevorgian1, and Yingchen Zhang1

1. National Renewable Energy Laboratory, Golden, CO 80401

2. Arizona State University, Tempe, AZ 85287

This work was authored by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided 

by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Solar Energy Technologies Office. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. 

The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the 

published form of this work, or allow others to do so, for U.S. Government purposes.

I. BACKGROUND

• An increased interest for developing an advanced controller 

for inverter-based renewable energy resources to provide 

reliability support to the grid.

• Urgent need to ensure the integrity of newly developed 

models for renewables in positive-sequence simulators for 

large power system studies.

• Validation of the dynamic performance of the proposed 

model with detailed electromagnetic models.

Electromagnetic simulation Electromechanical simulation

• Facilitates accurate study of 

inverters and their control 

strategies

• Problem of excessive solution time: 

cannot be used for interconnectionlevel studies

• For example, PSCAD.

• Detailed analysis of controls 

associated with power electronics’ 

dynamic is not possible 

• Reasonable solution time: can be 

used for interconnection-level 

studies 

• For example, PSLF.

• Key challenge

 It is difficult to find a reference system with identical machine models 

in PSLF and PSCAD.

 The initialization technique of the system dynamic states with base 

case power flow is different between PSCAD and PSLF.

• Therefore, a systematic approach is taken to develop an equivalent test 

bed in PSCAD and PSLF.

PSCAD Equivalent test bed PSLF

• Creation of the test bed would enable the following:

 Easy validation of any user-defined model in PSCAD and PSLF

 PSCAD version of the test bed would be useful to study unbalanced fault 

scenarios that could not be studied in positive-sequence tools.

II. PROPOSED METHODOLOGY

• The IEEE 9-bus system was used to create two equivalent standard 

test cases in PSCAD and PSLF. 

• Five steps were taken in the process.

1. Validate the power flow in PSCAD and PSLF.

2. Select the equivalent machine models.

3. Obtain the same predisturbance steady state in PSCAD and PSLF.

4. Fine-tune the machine parameters.

5. Integrate the inverter-based model with controller in the network.

PSLF PSCAD Error

Volt. 

Mag.

(p.u.)

Volt. 

Ang.

(deg.)

Volt. 

Mag.

(p.u.)

Volt. 

Ang.

(deg.)

Volt. 

Mag.

(p.u.)

Volt. 

Ang.

(deg.)

Bus 1 1.04 0 1.039 0.021 0.001 0.021

Bus 2 1.025 9.35 1.025 9.33 0 0.020

Bus 3 1.025 5.14 1.024 5.12 0.001 0.020

Bus 4 1.025 -2.22 1.025 -2.19 0 -0.030

Bus 5 0.999 -3.68 0.9996 -3.64 -0.0006 -0.04

Bus 6 1.012 -3.57 1.012 -3.53 0 -0.04

Bus 7 1.027 3.80 1.026 3.77 0.001 0.030

Bus 8 1.017 1.34 1.017 1.32 0 0.02

Bus 9 1.033 2.44 1.032 2.42 0.001 0.02

Table I. Power Flow Results in PSCAD and PSLF

Table II. Machine Models Used in PSCAD and PSLF

Type Equipment PSCAD PSLF

Hydropower 

plant at 

Bus 2

Generator Sync1 Genrou

Exciter AC1A Exac1

Turbine/

Governor

Hydro Tur1/

Hydro Gov 1 Hygov4

Steam 

power 

plant at 

buses 1, 3 

Generator Sync1 Genrou

Exciter AC1A Exac1

Turbine/

Governor

Steam Tur1/ 

Steam Gov4 Ieeeg1

Fig. 1. Terminal voltage of different generators in the IEEE 9-

bus system for a bolted three-cycle fault at Bus 8

Fig. 2. Active power response of the generator at Bus 3 when 

30-MW load is increased at Bus 6

III. APPLICATION OF THE TEST BED

• The test bed created was used to validate the 

modeling of the synthetic inertia controller in 

PSLF from the detailed modeling in PSCAD. 

• A renewable machine with synthetic inertia 

controller (wind, solar photovoltaics, or battery 

storage) is integrated into the system.

Fig. 3. Integration of the synthetic inertia controller for a 

renewable machine in the IEEE 9-bus system

Fig. 4. Frequency response

Fig. 5: Active power response of BESS

V. CONCLUSION

• A systematic approach is proposed to develop an

equivalent test bed in PSCAD and PSLF.

• An equivalent 9-bus system with photovoltaics, wind or

battery has been developed in PSCAD and PSLF. The

same dynamic response and frequency response of the

system is achieved in PSCAD and PSLF.

• Further, a user-defined model of synthetic inertia was

developed for renewables in PSLF and validated with the

detailed model presented in PSCAD.

• The proposed equivalent test bed will help validate the

performance of advanced frequency controllers from the

detailed modeling to positive-sequence simulation tools.

Event

• 30 MW of load at Bus 6 

is increased at 1 s.

Observation

• In response to the 

frequency dip, the 

renewable machine 

increases its active 

power output because 

of synthetic inertia 

controller action.

• The active power 

response of the 

renewable source in 

PSLF is similar to the 

one in PSCAD.

• The user-defined model 

of the battery with 

synthetic inertia 

developed in PSLF can 

reflect an accurate 

frequency dynamic 

response, like the 

detailed model in 

PSCAD.