Modeling and Simulation of a UV Water Treatment System Fed by a GPV Source Using the Bond Graph Approach

Abstract

This work presents a simulation model for a UV water treatment system, powered by a photovoltaic generator, which relates the current consumed by the lamp to the UV flux and water quality. The overall system also includes electronic converters, electronic ballast (RLC resonant circuit), a UV lamp (UV irradiation source), and a centrifugal pump. To optimize the power transfer from the PV generator to the ballast and the UV lamp, a Maximum Power Point Tracking (MPPT) device is used. The overall water treatment system presents a complex model due to its hybrid components. The bond graph tool with a multidisciplinary vocation allows precisely, by its graphic nature, using a unified language, to explicitly display the nature of the power exchanges in the system and facilitate its control. This tool is a solution for non-linear systems that guarantees and facilitates their modeling without difficulties.

A Real-time Comparative Study of Sliding Mode and State Feedback Control for the Centrifugal Motor Pump in an Ultraviolet Water Treatment System Using the Bond Graph Approach

“…The bond-graph model of a photovoltaic source coupled to a RL load is given in Figure 2. The capacitor Ca is often used in the PV system for start-up assistance during low sunlight [7,18]. To simulate the characteristic of the photovoltaic panel I=f(V), we use the BG model represented by Figure 3.…”

“…The UV water treatment system is powered by a photovoltaic panel through a storage battery, so it has a continuous power supply of 24V. The resonant circuit requires a square voltage ±E, which is obtained with an inverter [7,20].…”

“…Taking into account the high impedance presented by the lamp before the ignition, the current chooses the shortest path and crosses Cr2. The overvoltage created by the resonant circuit, ignites the lamp, which by its low impedance value, short-circuits Cr2 [7,20]. After the application of an overvoltage to the lamp terminals (400V ignition voltage), it takes at least 2 to 3 ms (overvoltage duration) for the lamp to ignite.…”

“…The water treatment process consists of circulating the water through a UV reactor to kill viruses and bacteria. Turning on the centrifugal pump causes the impeller to rotate produces a pressure and a speed that determines the flow of the fluid in the hydraulic system [7,23].…”

“…The water treatment system also incorporates a motor pump that draws contaminated water from the input reservoir, a flow control valve to generate different flow rates, and a filter designed to enhance the quality of contaminated water [5,6,24]. The circulation of water between the input reservoir (contaminated water) and the output reservoir (disinfected water) occurs through the UV lamp, facilitated by a centrifugal motor pump [7][8][9].…”