This paper discusses the “Best practices in the sub-transmission level in Indian scenario” with the latest methodologies and the challenges in implementation. All utilities are aware that the objective of the sub-transmission network is to cover ground i.e. reaching every customer with electrical path of sufficient strength to satisfy the customer demand for electrical power. After the advent of the concept of electrical utility from the year 1892 the hierarchical system structure “reduce voltage and split” to move and distribute power from a few large generating plants to a widely dispersed customer base has proven a most effective way. Beyond the need to deliver power to the customer, the utility's distribution system must also deliver it in ready-to-use form - at the utilization voltage required for electrical appliances and equipment, and free of large voltage fluctuations, high levels of harmonics, or transient electrical disturbances (Engel et al., 1992).Though the average customer has a total demand of only 1/10,000 or 1/100,000 of the output of a large generator, the reliability drops as one moves closer to the customer from generator. A majority of service interruptions are a result of failure (either due to aging or to damage from severe weather) of transformers, connectors, or conductors very close to the customer. As per the latest estimates of ADB (Asian Development Bank) chief economist Shang-Jin Wei said while releasing the bank's annual publication Asian Development Outlook, 2015 stated that the India is all set to overtake China's growth rate by clocking 7.8 per cent GDP in 2015–16 and 8.2 per cent during the following fiscal on the back of structural reforms and government's “pro-investment” attitude.
As the Electrical power is a main parameter for the growth of Indian economy, the GOI (Govt. of India) is focusing on capacity building of Power Generation, transmission and Distribution with an expected capacity addition of current 160 GW to 450 GW by 2020 with an yearly addition of 23 GW introducing advanced technologies and equipment with greater reliability and less maintenance. In continuation of above GOI has launched the IPDS (Indian Power development scheme) with a proposed budget of Rs.32,612 crore's with a budgetary support of 25,354 crore's for all the utilities to improve the Distribution network. Further there is more focus on SMART CITIES in that SMART GRID plays a crucial role. The investments in the Distribution sector alone will be approximately double the investment that is proposed for generation the paper discusses the latest trends and methodologies in Distribution sector for improving the Distribution efficiency. The content of this paper is organized to cover introduction, substation protection features, SCADA Requirement, Interface/interoperability issues and solutions, Communication system within substation and to DCC, pilot implementation details, different topologies for interfacing IEDs with RTU and issues, benefits of the new adopted system in existing substations and conclusion.
