電流分流電阻器發(fā)現(xiàn)可再生能源應(yīng)用的新需求

　　來自可再生能源的能源供應(yīng)增長：太陽能、風(fēng)能和潮汐能，也促使人們對更精確的大電流測量解決方案的需求增加。這不僅是為了使公用事業(yè)公司更好地測量電網(wǎng)提供的電力用于計(jì)費(fèi)的目的，或?qū)崿F(xiàn)更精確的發(fā)電廠控制。相反，需要改進(jìn)的精度比傳統(tǒng)的電能計(jì)量裝置，以確保所需的性能的各種元素的分布式電源系統(tǒng)。回歸傳統(tǒng)電表，采用并聯(lián)電阻大電流處理的原則似乎是答案。

　　可再生能源的性質(zhì)

　　而一些形式的可再生能源，如水電，多年來一直是最近開發(fā)的太陽能和風(fēng)力發(fā)電，已經(jīng)成為世界各國政府關(guān)注的焦點(diǎn)，因?yàn)樗麄儗で髮?shí)現(xiàn)其“綠色能源”的政策及承諾。

　　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.