ABSTRACT
The smart grid is the traditional electric grid driven by multiple factors including the deregulation of energy market, evolutions in metering, decentralization, changing regulations, changes on the level of electricity production, the rise of microgeneration and microgrids, renewable energy mandates with more energy sources and where purposes for which electricity is needed according to electricity demand so the grid-connected renewable energy system is gaining much attention. Renewable energy sources such as wind, Photovoltaic (PV), biogas, etc. Among these renewable energy sources, PV energy becomes a promising alternative source to conventional energy sources due to its extensive advantages as being omnipresent, freely available, having lower operational and maintenance costs and being environmentally friendly. More importantly, the usage of conventional sources pollutes the environment and causes global warming. More focus has to be put on environmentally friendly distributed generation technology. The multifunctional solar-based grid-connected system PV inverters have many advantages such as mitigation reactive power burden, current harmonics and power factor improvement in a three-phase supply system. The PV plant generates DC power by the photoelectric effect, which has to be converted to AC by inverters and connected to the grid through proper synchronization. The solar inverters feed the active power to grid during the daytime, and when the PV generation is off at night time, the same inverters work as a filter. The grid-connected solar inverters play a major role in the grid-connected system. This power electronic converter has to be designed in such a way that it not only feeds the active power to the grid but also incorporates it as an active power filter. Continuous increase in the microelectronic technology, chip technology, invention of much smart power electronic equipment creates even order harmonics into the system. These types of harmonics create electromagnetic interference, which leads to the rise of temperature in power electronic devices, and hence the efficiency of the system will degrade. The multifunctional PV inverters work with control techniques to control the active power during daytime and compensate for the aforementioned harmonic currents in the system during the nighttime. Active and harmonic power weight (AHPW)-based control technique is proposed. This AHPW calculates the active power generation by the PV plant and feeds to the grid without any phase delay. Also, it extracts the harmonic weighted components in the supply and is processed for reference current generation. This AHPW uses only three mathematical operators to process; hence, the computational burden will be reduced on the controller, fast, robust, etc. The proposed PV system with AHPW is implemented applying MATLAB Simulink environment to check its performance under various conditions of PV, load and grid power supply. It is also compared with the least mean square and least absolute deviation control technique. The simulation results are confirming that the proposed control algorithm is able to feed the active power to the grid in synchronism without phase delay compensated even order harmonic; hence, there would be no electromagnetic interference problems.
