NTT has proposed a way to charge the whole of one solar cells
March 2, 2009, 4:23 pm
NTT Energy and Environment Systems Laboratories have developed a circuit module, which allows you to charge lead-acid batteries using photovoltaic element of a cell. The module consists of a chain with a boost converter and the DC and the integrated circuit with the function of tracking the point of maximum power (maximum power point tracking, MPPT). The chain of fueling can increase the nominal voltage of 0, 5 and 15 B. The MPPT is designed to maximize the benefits of the galvanic cell in accordance with the parameters of the illumination. Using MPPT increases the amount of electricity generated each day in the 1, 5-fold, say researchers. However, the effectiveness of the chain makeup is quite low, approximately 70-80%, depending on the inductor. If the module is a solar battery for mobile phones, for example, its low efficiency is a little disadvantage in comparison with the possibility of charging a cell - say in NTT. Existing photovoltaic cells are connected sequentially to obtain the required voltage, since the voltage generated by a single cell is too small. The disadvantage of this approach is that the power output system as a whole is declining dramatically in the fall of the power of any of the cells in the chain, with its failure or zaslonenii cells by hand. However, if only one cell, then its partial shading does not lead to a significant drop in output power. NTT Energy and Environment Systems Laboratories developed this type of module some time ago, but then all the elements of the module, including MPPT, are separate parts. In addition, in the previous module MPPT circuit withstand a few volts, limiting the type of batteries. The new module has been used BiCMOS-technology for the deployment of MPPT-chain on the size of IP 4 x 4 mm, maintains the voltage was increased to 15 or higher for charging lead acid batteries. This module will be distributed NTT Electronics Corp. Deliveries have already begun, and the samples are ready to start mass production.