Solar PV Powered Shunt Active Filter
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Solar PV Powered Shunt Active Filter
𝐈𝐧𝐭𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧
Nonlinear loads such as three-phase diode rectifiers draw distorted current from the electrical grid. Although the grid and load voltages remain nearly sinusoidal, the source current contains significant harmonics that reduce overall power quality.
A Solar PV Powered Shunt Active Filter provides an effective solution by injecting
compensating current into the power system.
The MATLAB/Simulink model demonstrates how the filter reduces source-current distortion and converts the grid current into a near-sinusoidal waveform.
The system reduces the source-current Total Harmonic Distortion (THD) from approximately 24.21% to 0.59%.
𝐒𝐲𝐬𝐭𝐞𝐦 𝐎𝐯𝐞𝐫𝐯𝐢𝐞𝐰
The complete simulation is developed in MATLAB/Simulink and includes:
Three-phase utility grid
Grid-side resistance and inductance
Three-phase diode rectifier
Nonlinear RL load
Solar PV array
DC–DC boost converter
DC-link capacitor
Voltage source inverter
Coupling inductor
Shunt active power filter
PI-based DC-link voltage controller
Harmonic current compensation controller
FFT and THD analysis
The three-phase rectifier with an RL load acts as the nonlinear load and produces distorted load current.
𝐌𝐚𝐢𝐧 𝐒𝐲𝐬𝐭𝐞𝐦 𝐏𝐚𝐫𝐚𝐦𝐞𝐭𝐞𝐫𝐬
Parameter | Value |
Grid voltage | 415 V |
Grid frequency | 50 Hz |
Grid-side resistance | 0.1 Ω |
Grid-side inductance | 0.15 mH |
Additional line resistance | 0.4 Ω |
Additional line inductance | 3.55 mH |
Nonlinear load resistance | 60 Ω |
Nonlinear load inductance | 20 mH |
DC-link voltage range | 500–800 V |
Filter activation time | Approximately 0.04–0.05 s |
THD without compensation | Approximately 24.21% |
THD with compensation | Approximately 0.59% |
𝐒𝐲𝐬𝐭𝐞𝐦 𝐎𝐩𝐞𝐫𝐚𝐭𝐢𝐨𝐧 𝐖𝐢𝐭𝐡𝐨𝐮𝐭 𝐭𝐡𝐞 𝐀𝐜𝐭𝐢𝐯𝐞 𝐅𝐢𝐥𝐭𝐞𝐫
Before connecting the shunt active filter:
The three-phase grid supplies the nonlinear rectifier load.
The rectifier draws a highly distorted current.
Grid voltage remains nearly sinusoidal.
Load voltage also remains nearly sinusoidal.
Source current becomes non-sinusoidal.
FFT analysis indicates a high current THD.
The measured THD is approximately 24.21%.
This harmonic level is considerably higher than the commonly preferred power-quality limit of 5%.
𝐖𝐨𝐫𝐤𝐢𝐧𝐠 𝐏𝐫𝐨𝐜𝐞𝐬𝐬
1. Harmonic Generation
The diode rectifier and RL load draw current only during particular intervals of the voltage waveform. This results in a distorted load-current waveform containing harmonic components.
2. Current Measurement
The simulation measures:
Three-phase grid voltage
Three-phase grid current
Nonlinear load current
Shunt active filter current
Grid-side and load-side voltages
DC-link voltage
3. Reference Current Generation
The controller analyses the measured grid voltage and nonlinear load current. It then determines the compensating current required to cancel the harmonic component.
4. Compensating Current Injection
The voltage source inverter generates the required compensating current and injects it into the grid through the coupling inductor.
5. Source-Current Improvement
The filter supplies the harmonic portion of the load current. As a result, the utility grid supplies mainly the fundamental current component, making the source current nearly sinusoidal.
𝐒𝐨𝐥𝐚𝐫 𝐏𝐕 𝐚𝐧𝐝 𝐁𝐨𝐨𝐬𝐭 𝐂𝐨𝐧𝐯𝐞𝐫𝐭𝐞𝐫
The shunt active filter is powered using a solar photovoltaic system.
The PV section performs the following functions:
Generates renewable DC power
Supplies the active filter through a boost converter
Supports the inverter DC link
Reduces dependence on an external DC source
Improves the sustainability of harmonic compensation
The boost converter increases and regulates the PV output voltage before supplying it to the inverter DC link.
𝐂𝐨𝐧𝐭𝐫𝐨𝐥 𝐒𝐭𝐫𝐚𝐭𝐞𝐠𝐲
DC-Link Voltage Control
A PI controller regulates the DC-link voltage within the required operating range.
Its main functions are:
Maintaining a stable DC-link voltage
Compensating converter losses
Supporting continuous inverter operation
Improving filter response during load variations
Harmonic Compensation Control
The compensation controller determines the reference current required by the inverter.
The controller ensures that:
Harmonic current is supplied by the active filter
Source current becomes nearly sinusoidal
Grid voltage and load voltage remain stable
Current distortion at the grid side is significantly reduced
Inverter Switching Control
The reference compensating current is compared with the measured filter current. The switching controller generates gate pulses for the inverter switches, allowing the inverter to track the required current waveform.
𝐅𝐢𝐥𝐭𝐞𝐫 𝐀𝐜𝐭𝐢𝐯𝐚𝐭𝐢𝐨𝐧
The shunt active filter is connected at approximately 0.04–0.05 seconds.
Before Activation
Source current is distorted.
Load current contains strong harmonic components.
Current THD is high.
The grid supplies both fundamental and harmonic currents.
After Activation
The inverter injects compensating current.
Source-current distortion decreases rapidly.
Grid current changes to a near-sinusoidal waveform.
The nonlinear load current remains distorted.
Grid and load voltages remain almost unchanged.
Source-current THD falls to approximately 0.59%.
𝐒𝐢𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐑𝐞𝐬𝐮𝐥𝐭𝐬
Current-Waveform Performance
Waveform | Observation |
Grid current before compensation | Highly distorted |
Grid current after compensation | Near sinusoidal |
Nonlinear load current | Remains distorted |
Active filter current | Contains the required harmonic compensation |
Grid voltage | Remains sinusoidal |
Load voltage | Remains sinusoidal |
THD Comparison
Operating Condition | Source-Current THD |
Without shunt active filter | Approximately 24.21% |
With shunt active filter | Approximately 0.59% |
Overall improvement | Approximately 97.6% reduction |
The FFT result confirms that the proposed filter provides substantial harmonic reduction.
𝐖𝐡𝐲 𝐭𝐡𝐞 𝐋𝐨𝐚𝐝 𝐂𝐮𝐫𝐫𝐞𝐧𝐭 𝐑𝐞𝐦𝐚𝐢𝐧𝐬 𝐃𝐢𝐬𝐭𝐨𝐫𝐭𝐞𝐝
The purpose of the shunt active filter is not to change the nonlinear load itself.
Instead:
The nonlinear load continues drawing distorted current.
The active filter supplies an equal compensating harmonic current.
The grid supplies mainly sinusoidal fundamental current.
Harmonics are prevented from flowing into the utility source.
Therefore, a distorted load current with a clean source current indicates proper active-filter operation.
𝐊𝐞𝐲 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐬
Complete MATLAB/Simulink implementation
Solar PV-powered harmonic compensation
Three-phase nonlinear rectifier load
Boost-converter-based PV voltage regulation
PI-controlled DC-link voltage
Inverter-based compensating current injection
Grid, load and filter-current measurement
FFT-based harmonic analysis
Source-current THD reduction to approximately 0.59%
Near-sinusoidal grid-current operation
Improved power quality without changing the load
𝐁𝐞𝐧𝐞𝐟𝐢𝐭𝐬
Reduces current harmonics
Improves utility-side power quality
Minimizes waveform distortion
Supports renewable energy integration
Maintains stable grid and load voltages
Reduces stress on electrical equipment
Improves system efficiency and reliability
Demonstrates active power-filter control clearly
Helps users understand FFT and THD analysis
𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬
The Solar PV Powered Shunt Active Filter can be studied for:
Industrial power-distribution systems
Renewable-energy-based microgrids
Commercial electrical networks
Three-phase rectifier loads
Variable-speed motor-drive systems
Battery-charging systems
Data centres and power-electronic loads
Grid-connected solar installations
Harmonic mitigation studies
Power-quality improvement research
𝐖𝐡𝐨 𝐂𝐚𝐧 𝐔𝐬𝐞 𝐓𝐡𝐢𝐬 𝐌𝐨𝐝𝐞𝐥?
This simulation is useful for:
Electrical engineering students
Power-electronics learners
MATLAB/Simulink users
Power-quality researchers
Renewable-energy engineers
Control-system developers
Academic trainers
Grid-integration specialists
𝐋𝐞𝐚𝐫𝐧𝐢𝐧𝐠 𝐎𝐮𝐭𝐜𝐨𝐦𝐞𝐬
By studying this model, users can understand:
How nonlinear loads generate current harmonics
How to measure source-current THD
How a shunt active filter compensates harmonic current
How solar PV power can support an active filter
How a boost converter regulates the DC-link voltage
How inverter current injection improves power quality
How to compare compensated and uncompensated operation
How to perform FFT analysis in MATLAB/Simulink
𝐂𝐨𝐧𝐜𝐥𝐮𝐬𝐢𝐨𝐧
The Solar PV Powered Shunt Active Filter offers an effective renewable-energy-based solution for current harmonic compensation. Without filtering, the nonlinear rectifier load produces a highly distorted source current with a THD of approximately 24.21%.
After activating the shunt active filter, the inverter injects the required compensating current into the system. The source current becomes nearly sinusoidal, while the grid and load voltages remain stable. FFT analysis shows that the source-current THD is reduced to approximately 0.59%.
The MATLAB/Simulink model clearly demonstrates the operation of solar PV generation, boost conversion, DC-link voltage regulation, inverter control and harmonic compensation in a single integrated system.
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