Power Quality Assessment for a 150 MW Hybrid Renewable Energy Plant
As renewable energy projects continue to grow in scale and complexity, maintaining power quality at the Point of Interconnection (POI) is an important part of successful grid integration.
Power Projects was engaged by a leading renewable energy developer to perform a comprehensive Power Quality Study for a 150 MW hybrid renewable energy plant in Rajasthan, India, prior to grid synchronisation.
The project combines solar PV, wind generation, Battery Energy Storage Systems (BESS), and Static VAR Generators (SVGs) within a common 33 kV collection network. Power is evacuated to the grid through a 150 MVA, 220/33 kV transformer and an 11.8 km transmission line connected to the 220 kV network.
The study was performed using detailed electromagnetic transient (EMT) simulations in PSCAD™/EMTDC® Version 5.0.2, with the assessment focused on power quality performance at the 220 kV POI.
The Project
The 150 MW hybrid renewable energy plant brings together multiple generation and power-electronic technologies within a single grid-connected system.
The electrical configuration included:
- Solar PV
- Wind turbine generators
- Battery Energy Storage System (BESS)
- Static VAR Generators (SVGs)
- 33 kV collection network
- 150 MVA, 220/33 kV power transformer
- 11.8 km transmission line
- 220 kV Point of Interconnection
The Engineering Challenge
Hybrid renewable energy plants can involve several converter-based technologies operating together. Solar inverters, wind turbine generators, BESS converters and SVGs can each have their own harmonic emission characteristics.
For this project, it was therefore important to assess the combined power quality performance of the plant at the grid interface, rather than considering the individual technologies separately.
The assessment focused on four key areas:
- Harmonic distortion
- Voltage quality
- DC current injection
- Voltage flicker
The objective was to verify the plant's performance against the applicable power quality requirements before grid synchronisation and commissioning.
Detailed PSCAD EMT Modelling
Power Projects developed a detailed PSCAD electromagnetic transient model representing the hybrid renewable energy plant and its connection to the 220 kV transmission network.
The model represented the major electrical components, including:
- Utility grid equivalent
- 220 kV transmission network
- 150 MVA grid transformer
- Solar inverter systems
- Wind turbine generators
- BESS power conversion systems
- Static VAR Generators
- Collection transformers
- 33 kV collection network
- Point of Interconnection
Manufacturer-provided harmonic emission data for the relevant wind turbines, solar inverters, BESS converters and SVGs were incorporated into the PSCAD model.
The assessment considered plant loading from 10% to 100% of rated capacity, allowing the power quality performance to be evaluated across the specified operating range.
Power Quality Assessments Performed
Harmonic Assessment
A comprehensive harmonic assessment was performed at the 220 kV Point of Interconnection.
The study evaluated:
- Individual voltage harmonics
- Individual current harmonics
- Voltage THD
- Current THD
- Total Demand Distortion (TDD)
- Higher-order harmonic components
- Combined harmonic contribution from the converter-based equipment
The results were assessed against the applicable limits specified in IEEE 519:2022.
The assessment provided an overall view of the harmonic performance resulting from the combined operation of the solar PV, wind, BESS and SVG systems across the evaluated plant loading range.
IEEE 519:2022DC Current Injection Assessment
The study also evaluated DC current injection from the converter-based generation into the AC transmission network.
DC current injection was assessed under rated operating conditions, with the results evaluated with reference to IEEE 1547-2018.
The assessment confirmed that the DC current injection remained within the applicable requirements.
IEEE 1547-2018Flicker Assessment
Voltage fluctuations associated with plant operation were evaluated through a dedicated flicker assessment.
Both short-term flicker (Pst) and long-term flicker (Plt) were assessed with reference to applicable IEC 61000 requirements.
The assessment verified the voltage flicker performance at the grid interface under the evaluated operating conditions.
IEC 61000Study Outcomes
The power quality assessment demonstrated satisfactory performance under all evaluated operating scenarios.
The key outcomes included:
- Voltage THD remained within the applicable IEEE 519:2022 limits.
- Current harmonic distortion complied with the applicable limits across the assessed 10%–100% plant loading range.
- Individual harmonic components remained within permissible values at the Point of Interconnection.
- DC current injection satisfied the applicable IEEE 1547-2018 requirements.
- Short-term and long-term flicker indices complied with applicable IEC 61000 requirements.
- The combined operation of solar PV, wind turbines, BESS and SVGs did not introduce unacceptable power quality issues at the transmission interface.
As an engineering best practice, post-commissioning power quality measurements at the 220 kV POI were recommended to validate actual field performance under combined operating conditions.
Supporting Grid Connection and Project Delivery
The study provided the project developer with a technically validated basis for demonstrating power quality performance before plant commissioning.
The assessment supported the project team by:
- Providing technical evidence for the grid connectivity process
- Evaluating power quality performance during the design stage
- Reducing potential commissioning risks associated with power quality compliance
- Assessing the combined operation of multiple OEM technologies
- Supporting confidence in grid-compatible plant operation
For large renewable and hybrid renewable projects, carrying out these assessments during the design stage can provide valuable insight into the expected performance of the plant at the grid interface.
Power Projects' Expertise in Renewable Energy Grid Studies
This project demonstrates Power Projects' capability in performing power quality and grid integration studies for utility-scale renewable energy projects.
Our experience includes projects involving solar PV, wind generation, BESS and reactive power compensation, with detailed assessment of their interaction with the connected transmission network.
Using PSCAD electromagnetic transient simulations, Power Projects can assess the power quality performance of complex renewable and hybrid renewable plants at the Point of Interconnection.
Our engineering studies can support project teams through the grid connection, compliance and commissioning stages.
Planning a Renewable or Hybrid Renewable Energy Project?
Power Projects can support your project with:
Contact Power Projects to discuss your project requirements.
Software and Standards
Software
Standards and Requirements
- IEEE 519:2022 – Harmonic Control in Electric Power Systems
- IEEE 1547-2018 – Interconnection and Interoperability of Distributed Energy Resources
- IEC 61000 – Electromagnetic Compatibility
- CEA Technical Standards for Connectivity to the Grid, November 2025
Need a Power Quality Study for Your Renewable Project?
Power Projects delivers PSCAD EMT-based power quality, harmonic, flicker, and DC injection studies for solar, wind, BESS and hybrid renewable plants worldwide.
