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This paper presents a modular self-controlled photovoltaic (PV) charger with maximum power point tracking (MPPT) and pulse-charging schemes. The studied PV modules can be flexibly parallel connected through interleaved operation using an interintegrated circuit (I2C) interface. The MPPT control of PV panel is implemented by using a current-sensing technique with the on-state resistance of the power switch. Both an expensive hall-effect sensor and additional current-sensing resistor are not needed. A pulse-charging scheme without extra battery-current sensor is also designed to prolong the lifetime of the acid-lead battery. The operation principles and design considerations of the proposed PV charger are analyzed and discussed. A laboratory prototype is implemented and tested to verify its feasibility.

This paper presents the design and implementation of a DSP-based single-stage photovoltaic (PV) inverter system which can extract maximum power from solar panel. A perturbation and observation (P&O) method is realized and cooperated with a digital unipolar voltage switching sinusoidal pulse width modulation. The studied single-stage topology provides the benefits of low cost, simple configuration and good overall efficiency compared with the conventional two-stage structure. Moreover, this paper also presents a new current sensing technique for maximum power point tracking (MPPT) to enhance the system flexibility and MPPT accuracy. A prototype system is implemented and tested. The experimental results are shown to verify the feasibility of the proposed scheme.

This paper presents a modular self-controlled photovoltaic (PV) charger with maximum power point (MPP) tracking and pulse-charging schemes. The studied PV modules can be flexibly parallel-connected through interleaved operation using an Inter-Integrated Circuit (I2C) interface. The MPP tracking (MPPT) control of a PV panel is implemented by using a current-sensing technique with the on-state resistance, R ds(on) , of the power switch. An expensive hall-effect sensor and additional current-sensing resistor are both not needed. A pulse-charging scheme is also designed to prolong the lifetime of the acid-lead battery. The operation principles and design considerations of the proposed PV charger are analyzed and discussed. A laboratory prototype is implemented and tested to verify its feasibility.

A battery charger with MPPT function for low-power PV system applications is presented in this study. For effective miniaturization, the battery charger is designed with high frequency operation. Some current-sensing techniques are studied, and their MPPT implementation is compared. A pulse charging method is also designed to prolong battery lifetime. The operation principles and design considerations of the proposed PV charger are analyzed and discussed in detail. A laboratory prototype is implemented and tested to verify the feasibility of the proposed scheme. Experimental results show that high MPPT accuracy and conversion efficiency can be simultaneously achieved under high frequency operation.

Energy-retaining snubbers of a current-regulated power supply for an AC arc welding machine are proposed in this paper. Although a second output inductor is added, a current- steering diode connected across the output choke keeps the inductor current continuous and retains the energy during the commutation period. Thus no lossy RC snubber is required and no voltage spike is produced. The stored energy can be released in the next energy transfer cycle to reduce the commutation time. Satisfactory experimental results on a 100-A AC arc welding machine are recorded to validate the effectiveness of the presented scheme.