China Southern Power Grid Official WeChat

中国南方电网有限责任公司（英語：China Southern Power Grid, CSG），简称中国南方电网，成立于2002年12月29日，是原公司经过中国电力体制改革后分离出的两家企业之一（另一家为） ，负责投资、建设和经营、、、、五的包括、以及电力调度等电网业务，此外与、、等周边国家的电网实现了互. [pdf]

Power systems machines

Electric power is the product of two quantities: and . These two quantities can vary with respect to time () or can be kept at constant levels (). Most refrigerators, air conditioners, pumps and industrial machinery use AC power, whereas most computers and digital equipment use DC power (digital devices plugged into the mains typically have an internal or external to convert from AC to DC power). AC power has the a. [pdf]