Solar PV Fed BLDC Motor for Water Pump Under Partial Shading Condition
- lms editor
- 17 hours ago
- 4 min read
Introduction
Solar photovoltaic (PV) powered water pumping systems have gained significant attention due to their suitability for remote and agricultural applications. Among various motor options, Brushless DC (BLDC) motors are widely preferred because of their high efficiency, low maintenance, and excellent speed control characteristics. However, the performance of solar PV systems is highly affected by partial shading conditions, which create multiple local maximum power points and reduce overall energy extraction.
To address this challenge, this work presents a Solar PV fed BLDC motor driven water pumping system employing a hybrid P&O–PSO Maximum Power Point Tracking (MPPT) algorithm. The performance of the proposed hybrid MPPT is analyzed and compared with conventional Perturb and Observe (P&O) and Particle Swarm Optimization (PSO) MPPT techniques under both uniform irradiance and partial shading conditions.
System Description
The developed MATLAB/Simulink model consists of two series-connected solar PV panels, each operating at a constant temperature of 25 °C. Under standard test conditions, the combined PV system delivers approximately 3.4 kW of power. Partial shading is intentionally created by applying different irradiance levels to the two panels.
A Zeta DC–DC converter is used as the power conditioning stage between the PV array and the BLDC motor drive. The Zeta converter is selected due to its ability to operate in both buck and boost modes, ensuring stable DC voltage regulation over a wide operating range.
The electrical energy from the converter feeds a Voltage Source Inverter (VSI), which drives the BLDC motor using hall sensor-based commutation. To emulate a water pumping load, the motor torque is modeled using the centrifugal pump equation:
T=Kω2T = K \omega^2T=Kω2
where torque is proportional to the square of the motor speed. This approach accurately represents real-world water pump characteristics.
Hybrid P&O–PSO MPPT Control Strategy
The MPPT algorithm is the key component of this system. A hybrid P&O–PSO MPPT strategy is implemented to overcome the individual limitations of conventional MPPT methods.
P&O MPPT is simple but suffers from slow convergence and steady-state oscillations.
PSO MPPT provides global optimization capability but may take longer to converge and can be sensitive to sudden irradiance changes.
The hybrid approach combines the fast tracking ability of P&O with the global searching capability of PSO. A mode selection switch allows the system to operate in:
Hybrid P&O–PSO mode
Pure PSO mode
Pure P&O mode
The MPPT algorithm generates the optimal duty cycle, which is processed through a PWM generator to control the MOSFET in the Zeta converter.
Performance Under Uniform Irradiance Condition
Initially, the system is tested under uniform irradiance, where both PV panels receive 1000 W/m². Under this condition, the hybrid P&O–PSO MPPT rapidly tracks the global maximum power point with minimal oscillations.
Simulation results show:
Fast convergence to maximum PV power
Stable converter output voltage and current
Smooth BLDC motor speed, torque, and electromagnetic force (EMF) response
When the system is operated using PSO MPPT alone, the initial duty cycle is randomly generated, causing temporary power fluctuations. Although PSO eventually converges to the optimal operating point, it requires more iterations and exhibits slower dynamic response.
With P&O MPPT, the system experiences noticeable oscillations around the maximum power point and takes a longer time to stabilize, confirming the known drawbacks of the conventional method.
Performance Under Partial Shading Condition
To evaluate partial shading performance, the irradiance of the first PV panel is reduced from 1000 W/m² to 500 W/m² after one second, while the second panel remains at 1000 W/m². This creates a non-uniform irradiance condition with multiple local maxima in the PV characteristic curve.
Under this scenario:
The hybrid P&O–PSO MPPT successfully identifies the global maximum power point.
The extracted PV power reaches approximately 1800 W, which is significantly higher than the power obtained using PSO or P&O alone.
The BLDC motor continues to operate smoothly, maintaining stable speed and torque despite irradiance disturbance.
In contrast, the PSO MPPT extracts only about 1200 W under the same partial shading condition, indicating convergence to a local maximum. The P&O MPPT also struggles due to oscillations and slow tracking.
Comparative Analysis
The comparative study clearly demonstrates that:
Hybrid P&O–PSO MPPT provides faster convergence
It avoids local maximum trapping
It ensures higher power extraction under partial shading
It improves overall system efficiency and motor performance
These advantages make the hybrid MPPT particularly suitable for solar-powered water pumping systems, where shading is common due to clouds, trees, or panel orientation mismatch.
Conclusion
This study successfully demonstrates a Solar PV fed BLDC motor water pumping system operating under both uniform and partial shading conditions. The use of a hybrid P&O–PSO MPPT algorithm significantly enhances maximum power extraction compared to conventional P&O and PSO techniques.
Simulation results confirm that the proposed approach:
Effectively handles partial shading conditions
Ensures stable BLDC motor operation
Maximizes energy utilization for water pumping applications
The developed system is highly suitable for agricultural irrigation, remote water supply, and off-grid solar pumping applications.
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