电流分流电阻器发现可再生能源应用的新需求

　　电流分流电阻器发现可再生能源应用的新需求

　　来自可再生能源的能源供应增长：太阳能、风能和潮汐能，也促使人们对更精确的大电流测量解决方案的需求增加。这不仅是为了使公用事业公司更好地测量电网提供的电力用于计费的目的，或实现更精确的发电厂控制。相反，需要改进的精度比传统的电能计量装置，以确保所需的性能的各种元素的分布式电源系统。回归传统电表，采用并联电阻大电流处理的原则似乎是答案。

　　可再生能源的性质

　　而一些形式的可再生能源，如水电，多年来一直是最近开发的太阳能和风力发电，已经成为世界各国政府关注的焦点，因为他们寻求实现其“绿色能源”的政策及承诺。

　　Unlike established coal， gas and nuclear generating plants which use turbines to directly generate AC （alternating current） power that can be fed into the grid via sub-station transformers， the nature of solar and wind power either generates DC （direct current） power or involves some conversion to and from DC. Solar power from photovoltaic panels is inherently DC generation and needs some form of inverter device to convert it to AC for connection to the grid. Many wind turbines， especially smaller units deployed in generating electricity for domestic， agricultural and industrial premises， also generate DC.

　　Even the larger wind turbines found on commercial wind farms， using generators that produce AC， can’t necessarily be directly connected to the grid. This is because not only does the voltage need to be compatible， but also so does the frequency， which is determined by the rotational speed of the turbine that in turn is dependent on wind speed. Gearboxes have been used to increase the rotational speed to overcome this problem， but they are heavy and expensive. So the trend is towards “direct drive” generators， even though this requires AC outputs to first be converted to DC and then back to AC via an inverter that ensures the correct frequency and voltage for the grid.