GENEVA, May 4 -- YUNNAN POWER GRID CO., LTD. TRANSMISSION BRANCH (Yangxianpo No.1 Transmission Branch, Wuhua DistrictKunming, Yunnan 650102), 云南电网有限责任公司输电分公司 (中国云南省昆明市五华区羊仙坡一号输电分公司), YUNNAN ELECTRIC POWER TEST AND RESEARCH INSTITUTE (GROUP) CO., LTD (Yundian Technology Park, No. 105 Yunda West Road, Economic and Technological Development ZoneKunming, Yunnan 650214), 云南电力试验研究院(集团)有限公&...