Battery charging controllers in autonomous photovoltaic systems

In the work, the authors explain the concept of operation of an autonomous photovoltaic system with particular focus on the role of battery charging controllers. Didactic experiments that complement the theoretical knowledge on the construction and the principles of operation of photovoltaic systems of the “off-grid” type were conducted. The laboratory set described provides the capabilities to analyze the operation of small autonomous photovoltaic systems which are analogous to complex systems that are used in real settings. The systems are especially popular in Poland and that is why it is important to deepen the knowledge on them. Particular attention is put in the article on the cooperation of photovoltaic elements with energy storage devices (condensers and batteries) and with the load points with the use of battery charging controllers (serial and shunt) and of a module protecting the energy storage devices against discharging. The review of different solutions is complemented with sample measurement tests and with the test results for the tested system of the “off-grid” type.