A beginning was also made in high voltage DC -LRB- HVDC -RRB- transmission , co-generation equipment , etc . The process of upgradation of technology in a variety of manufacturing lines has been initiated . उच्च वोल्टेज के डी . सी . ( एच . वी . डी . सी . ) प्रेषण , सहउत्पादन के उपकरणों आदि के निर्माण की भी शुरुआत की गयी