Irwan Purnama

Analysis and Design of a Photovoltaic System DC Connected to the Utility With a Power Factor Corrector

This paper presents a photovoltaic (PV) system parallel connected to an electric power grid with a power factor corrector (PFC) for supplying the DC loads. The operation principles and design considerations for the presented PV system are analyzed and discussed. The balanced distribution of the power flows between the utility and the PV panels is achieved automatically by regulating the output DC voltage of the PFC. Experimental results are shown to verify the feasibility of the proposed topology, which can effectively transfer the tracked maximum power from the PV system to the DC load, while the unity power factor is obtained at the utility side.

A fuzzy control maximum power point tracking photovoltaic system

Conventional maximum power point tracking (MPPT) method, e.g. perturbation and observation (P&O) and incremental conductance (INC), have the drawbacks such as oscillation at the MPP during power fast tracking and power divergence under rapidly changing atmospheric condition. Thus, a fuzzy logic controller (FLC) is implemented in the PV system to avoid the conventional problem. FLC method has not only fast response under rapidly changing atmospheric conditions but also small oscillation at the maximum power point (MPP). However, FLC presents tuning difficulty of membership function, scaling factor and control rules. The FLC disadvantages can be reduced using single-fuzzy logic controller (S-FLC) without degrading its performance. The experiment results are shown to verify the studied S-FLC MPPT method.

A DSP-based differential boost inverter with maximum power point tracking

This paper presents a DSP-based differential boost inverter (DBI) with maximum power point tracking (MPPT) for photovoltaic (PV) applications. In a conventional DC/AC MPPT system, power of photovoltaic is delivered into two stages, they are DC/DC boost converter and buck type DC/AC inverter. A DC link capacitor appears between these two stages. Furthermore the system has higher complexity and costly than that of DC/AC MPPT system with a single stage boost inverter. Here, a single stage differential boost inverter is implemented. Since it can produce a sinusoidal output voltage higher than its DC voltage input, it is not only able to reduce the stage number of DC/AC MPPT system but also able to eliminate the DC link capacitor. The MPPT method employed in this study is P&O method. This technique is widely used due to its easy implementation, and unimportant extreme weather change consideration. To implement this technique, a digital signal processor (DSP) was used. In this paper, a review of DBI and MPPT implementation are presented. Finally a 400 W laboratory prototype has been built. The result shows that the P&O MPPT method has been successfully implemented for various PV power and it can reach 95% maximum MPPT accuracy. In addition, the DBI is able to produce a sinusoidal output voltage at the various PV power conditions.

Isolated dual boost bridgeless power factor correction AC-DC converter

Isolated power factor correction converters expose several shortcomings such as: the presence of slow-recovery diodes on conduction path leading to conduction losses and complexity in sensing circuit. This paper presents a new topology named isolated dual boost bridgeless PFC converter not only to improve efficiency by discarding of the low-recovery diodes but also to simplify the sensing circuit methodology. Additionally, a laboratory prototype with 100-140 V input, 400 V/750 W output was built and verified to demonstrate the circuit feasibility in this study. The experimental results shown that the efficiency improved by using bridgeless converter concept.

Improved one-cycle controlled buck converter using Type-III compensator

One-cycle control (OCC) is widely used in many power converter topologies because of its advantages. However, in the control process, OCC uses integration of chopped diode voltage to control the output voltage of the converter where, in the case of the dc-dc buck converter, the chopped diode voltage represents only the input voltage. Thus, it will lead to the nonzero steady state error of the output voltage. Moreover, the output disturbance will have more effect to the converter performance. In this paper, a type-III compensator is designed for improving the performance of one-cycle controlled buck converter. Furthermore, the controller can eliminate both input and output disturbance with zero steady-state error. The simulation results verify the performance of the designed controller.