Photovoltaic traffic light system is a significant application of renewable energy source. The development of the system is an alternative effort of local authority to reduce expenditure for paying fees to power supplier which the power comes from conventional energy source. Since photovoltaic (PV) modules still have relatively low conversion efficiency, an alternative control of maximum power point tracking (MPPT) method is applied to the traffic light system. MPPT is intended to catch up the maximum power at daytime in order to charge the battery at the maximum rate in which the power from the battery is intended to be used at night time or cloudy day. MPPT is actually a DC-DC converter that can step up or down voltage in order to achieve the maximum power using Pulse Width Modulation (PWM) control. From experiment, we obtained the voltage of operation using MPPT is at 16.454 V, this value has error of 2.6%, if we compared with maximum power point voltage of PV module that is 16.9 V. Based on this result it can be said that this MPPT control works successfully to deliver the power from PV module to battery maximally.

Multilevel inverters are receiving continuous attention in terms of circuit topology, control methods and applications. This paper presents a modified topology that applies a bidirectional switching module to reduce the number of switches of the 3-level inverter. Common emitter back-toback IGBTs have been used to assemble the bidirectional conducting module. The modified inverter has been controlled using the selected harmonics eliminations technique with 3, 4 and 5 primary switching angles. The control algorithm has been implemented using a basic fixed point, low-cost microcontroller. Results including output voltage and current waveforms, spectrum, harmonic distortion, and converter efficiency data are presented. Simulation and experimental results verified the ability of the inverter to provide a wide range of output voltage and eliminate the targeted harmonics. General TermsAlgorithm development, embedded system, power electronic.

No abstract