H. D. Stryczewska, K. Nalewaj, T. Janowski, Lublin University of Technology Faculty of Electrical Engineering and Computer Science, Institute of Electrical Engineering and Electrotechnologies

1. Introduction

Swimming pools water treatment in Poland is mainly carried out through chlorination. The better solution from the point of view of environment protection is the application of ozone, well-known sterilization and disinfection agent, commonly used nowadays for water and wastes treatment. Lublin Province has been regarded as the second in respect of the insolation conditions in Poland. In this upland region there are few rivers and natural lakes and therefore the need for open-air swimming pools in the summer season arises. The ozone generation power supply system requires AC high voltage in the range of 10 to 20 kV and frequency of 50-1000 Hz. Photovoltaic panels produce energy at the DC voltage of several tens volts and this energy should be converted to be applied as the power for the ozone generation system. The main components of the ozone water treatment system energized from photovoltaic panels are DC/AC converter and high voltage transformer. The value and the frequency of the supply voltage are important factors influencing the ozone productivity. The greater frequency and voltage means the greater ozone productivity but also the greater power losses in the HV transformer. Since the ozone generator represents a non-linear active — capacitive load while the DC/AC converter with HV transformer is of active — inductive nature, they may cooperate in resonance conditions that assures the best efficiency and productivity of the ozone installation. To ensure the optimal operation of the solar energy energized ozone installation the frequency of the supply voltage should be carefully estimated. The paper presents the results of investigations of the ozone generator laboratory model that consists of the 1100 mm long discharge tube of 50 W energized from photovoltaic system that comprises six batteries of 450 W total power. The application of photovoltaic panels to supply swimming pool water treatment ozonizers is the solution which is consistent with environment protection regulations. Since the most favorable conditions for using solar energy in Poland are during spring and summer season (80% of total annual insolation is noticed during six months, from early June until end of September) at periodic operation of the ozonizer, photovoltaic panel may completely fulfill the demand for energy. The usage of renewable energy in Poland in relation to its potential is still low. In neighboring countries of comparable solar conditions the usage of solar energy is much higher.