Papers by Keyword: Charge Control

Abstract: For the maximum output power varies with changes in load characteristics match the characteristics of solar cells in photovoltaic power generation system, the system runs through dynamic MPPT maximum power of self-optimizing process to achieve power from the PV charge control match. First, the output characteristic simulation analysis of the solar load resistive, capacitive load showed that solar power batteries for load matching efficiency is higher than in a purely resistive load. Then, using the improved algorithm for variable step size perturbation and observation of the received output power of solar power and load matching control, experiments showed that the optimum operating point of the circuit can control the real-time monitoring of solar cells and load. The output power from the battery load matching circuit to match the time working in the best working condition, if the energy is surplus or shortage, the system can control dynamic self-optimizing adjustment to charge, which leads to batteries absorbed power increasing and the efficiency of solar energy collection improving.

Abstract: The high-capacity lithium batteries are optimization in coal mine backup power supply. Their electricity properties directly affect their related equipment performance. So it is crucial importance for controlling lithium battery charge and discharge and understanding their characteristics. It puts forward design scheme of lithium-ion battery charging and discharging controller with STM32F103 chip. It includes DC/DC adopting full bridge phase shift high power switch, the sampling and processing circuit of voltage, current and temperature, charge and discharge control circuit, and software design flow of the real-time monitoring of lithium-ion batteries. The test shows that the charging and discharging control meet the design requirements.

Abstract: In this paper, charge control mechanism and carrier features have been precisely investigated in InxGa1-xN/InN/InxGa1-xN based quantum-well double heterostructure high electron mobility transistors (QW-DHEMTs). A study of charge control in the InxGa1-xN/InN/InxGa1-xN structure is performed by self-consistently solving Schrödinger equation in conjunction with Poisson’s equation taking into account the spontaneous and piezoelectric polarization effects. The potential profile and the distribution of electron density in the channel as a function of gate voltage are investigated here. A large conduction band offset of about 2.2eV is obtained for the proposed device for In content x=0.05, which ensure better carrier confinement and higher sheet charge density. The influence of In composition(x) and doping concentration of InxGa1-xN upper barrier on sheet charge density and carrier distributions in channel is also presented. This analysis provides a platform to investigate the InN based QW-DHEMTs and to optimized their design.