What is a Smart Grid?

The Smart Grid is a combination of 'Smart' and 'Grid', which means electricity and gas supply distribution network and power grid and also called the next generation power grid or intelligent power grid.
The Korea Smart Grid Association explained that 'Smart Grid is a next-generation strategic network that optimizes energy efficiency by combining information and communication technology (ICT) with existing power grid and exchanging power generation and consumption information in both directions and in real time'.

In other words, the Smart Grid is a service that enables more efficient supply management by providing electrical user information to electric suppliers and producers.
Utilizing electricity and information and communication technologies to intelligently and advanced the power grid to provide high-quality power services and maximize energy efficiency.

At the core of smart grid implementations, Energy Storage System(ESS)

In order to build a smart grid, it is necessary to construct various facilities such as energy storage system (ESS), smart meter (AMI), Energy Management System (EMS), electric car and charging station, dispersion (or distributed) power, new and renewable energy, bi-directional information and communication technology, and intelligent transmission and distribution systems.

The core of this is ESS (Energy Storage System). In the past, electricity that was not used after it was produced could be discarded even if electricity supply was controlled by predicting demand, but ESS would help store large amounts of electricity, and if electricity could be stored using ESS, small amounts of electricity from new and renewable energy sources such as solar energy, wind power, tidal power and wave power would be stored for later use. Energy stored in the ESS to adequately control demand and supply, minimizing discard of energy.

What is PCS of Energy Storage System(ESS)?

PCS (Power Conditioning System) - A power conversion system that converts at least one of voltage, current, frequency (including DC) phase and constant between power source and load.

There are many kinds of energy sources in the world, among which electricity is the most useful form of energy for humans. However, electricity frequency, voltage, and current are different in AC/DC form, it is necessary to convert the electricity to a form suitable for the purpose of use.
In this case, it is the power conversion device (PCS), which switches between DC/AC and conversely switches AC/DC while adjusting the current/voltage/frequency to the required value.
Precisely, PCS is an upper concept that includes converters (AC / DC conversion, DC / DC conversion) and inverters (DC / AC conversion), but the bidirectional PCS is also called converter or inverter.