• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.4
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• pp.231-237
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• 2006

This paper proposes an effective drive of high intensity discharge (HID) lamp ballast for cars. All control functions of the proposed ballast are implemented using a low-cost single chip microcontroller, PIC16C73 to optimize the total system size and to minimize cost through minimization of total component number. The proposed ballast generates high open-circuit voltage to ignite the lamp and is controlled to supply effectively the power required to shorten warm-up period after the breakdown. The DC-DC converter of the DC-AC converter part of the ballast utilizes the flyback converter topology that can minimize component number. Also, because to more minimize the ballast size, the transformer size must be minimized, for this, PWM (Pulse Width Modulation) pulses are generated with high frequency using the PWM module of the microcontroller. An analysis for this is explained, briefly. As if the operation of the lamp and ballast arrives at steady-state, then the ballast must AC-control the lamp, for this, the microcontroller utilizes the other PWM module. And the part related to the igniter is explained, briefly. It is shown through experimental results that the controller of the proposed ballast has good performance for the HID lamp for cars.

• Journal of Power Electronics
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• v.17 no.4
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• pp.1037-1047
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• 2017

The Differential Power Processing (DPP) converter is a promising multi-module photovoltaic inverter architecture recently proposed for photovoltaic systems. In this paper, a DPP converter architecture, in which each PV-panel has its own DPP converter in shunt, performs distributed maximum power point tracking (DMPPT) control. It maintains a high energy conversion efficiency, even under partial shading conditions. The system architecture only deals with the power differences among the PV panels, which reduces the power capacity of the converters. Therefore, the DPP systems can easily overcome the conventional disadvantages of PCS such as centralized, string, and module integrated converter (MIC) topologies. Among the various types of the DPP systems, the feed-forward method has been selected for both its voltage balancing and power transfer to a modified H-bridge inverter that needs charge balancing of the input capacitors. The modified H-bridge multi-level inverter had some advantages such as a low part count and cost competitiveness when compared to conventional multi-level inverters. Therefore, it is frequently used in photovoltaic (PV) power conditioning system (PCS). However, its simplified switching network draws input current asymmetrically. Therefore, input capacitors in series suffer from a problem due to a charge imbalance. This paper validates the operating principle and feasibility of the proposed topology through the simulation and experimental results. They show that the input-capacitor voltages maintain the voltage balance with the PV MPPT control operating with a 140-W hardware prototype.