| Work Detail |
Turkish scientists have developed a new algorithm to optimize the efficiency of photovoltaic water pumps. The novel technique is based on the extended Kalman-Bucy filter, a predictor-corrector algorithm widely used in control systems engineering to estimate unmeasured states of a process.
A Turkish research group has created a novel control algorithm for photovoltaic-powered water pumps that operate with variable irradiation intensity.
Photovoltaic powered water pumps are mainly used in agricultural irrigation, in places where energy transportation is expensive or unavailable. They usually use induction motors due to their small size, robustness and high performance. However, according to the researchers, controlling induction motors to produce constant torque is challenging as they involve non-linear dynamics and unknown load inputs, as well as time-varying mechanical and electrical parameters.
The scientists explained that their new adaptive power control (APC) technique has a structure that allows the water pump to work with high performance and efficiency at each operating point, since the algorithm is able to precisely determine the point maximum power of the photovoltaic system and the rotor speed of an induction motor under variable atmospheric conditions.
“By using a single irradiance sensor and eliminating the need for a velocity sensor, the method is more cost-effective and practical,” they say. “The proposed sensorless maximum power point tracking (MPPT) method successfully tracks the maximum power points of the PV system and efficiently transfers the variable power produced by the PV system to the pump.”
To calculate the actual motor speed without the speed sensor, the new method also uses the Extended Kalman-Bucy filter, which is often used to estimate state vectors of tracking objects. “The Extended Kalman-Bucy filter was selected for its reputation as the most efficient and systematic estimator of states and parameters in the literature,” the academics note. “The ability of the filter to be easily applied to the state space model of a known system, its ability for parameter estimation, and most importantly, its ability to filter out noise are the reasons for choosing this algorithm.”
Through a simulation, the group verified the effectiveness of the algorithm in a water pumping system based on a 1.2 kW photovoltaic array and a 1.1 kW induction motor. It was verified that the motor correctly follows the reference speed generated by the APC.
“The adaptive method developed not only improves the overall efficiency of the photovoltaic water pumping system, but also contributes to the sustainability and viability of renewable energy applications,” the scientists conclude. “By reducing the dependence on additional sensors and control hardware, the proposed method provides a cost-effective solution for harnessing solar energy in water pumping applications.”
They presented the algorithm in the article “ Speed ??sensorless Adaptive Power Control for photovoltaic-fed water pump using Extended Kalman-Bucy filter.” , published in energy reports . The researchers come from Batman University and Firat University in Türkiye.
Looking ahead, they suggested further testing the novel controller in a larger scale photovoltaic-powered water pumping system, along with its combination with different energy storage techniques. |
