A smart Uninterruptible Power Supply based on frequency linked pricing mechanism

Emerging new technologies like distributed generation, distributed storage, and demand-side load management would change the way we consume and produce energy. In this paper, a smart Uninterruptible Power Supply (UPS) system which helps in efficient utilization of energy storage and non-conventional energy sources (NCES) attached to it has been designed and developed. This system is based on real-time pricing linked to the system frequency. In India, such prices are also known by the name of Availability Based Tariff (ABT). The UPS system has been designed and fabricated by employing intelligent control algorithms which help it to take battery charging and discharging decisions on the basis of real-time prices. The control of UPS has been fabricated in ATmega8 microcontroller of AVR family from ATMEL Corporation. Microcontroller detects the supply frequency & Battery level and accordingly controls the Relays for switching operations among Mains, Load, Rectifier, Inverter, Battery and NCES. The system is checked and verified for multiple system operating conditions depending upon supply frequency, Battery level, and availability of NCES etc. The benefit of this system to the consumer is that the effective cost of supplying the load is reduced and they get more options for the choice of the supply. This system draws power from mains (distribution grid) when price is low, as well as stores power. In contrast when price increases it doesn't take power from mains instead uses the stored power which is stored at cheaper cost. If implemented at large scale, it will also help Distribution Utilities in managing demand, improving reliability, optimizing the procurement cost. Additionally, the Grid Operators will also be benefited in terms of better management of grid frequency and reduction in blackouts. In a country like India, such a system would also be helpful in reducing the gap between peak demand and availability.