Power System Protection Evolutions from Traditional to Smart Grid Protection

The power system that we have today has gone through several transformations over the years. These changes are due to either advancement in science and technology or changes in customer demands. Today we have the vision for a future electrical power system known as the `Smart Grid'. This power system has several functional and operational capabilities which are envisioned to solve the reliability, generation deficit and cost issues in the power system. Majority of the power systems in the world are still being operated as the traditional power system with one-way communication and one-way power flow. Transitioning to a Smart Grid (SG) influences the protection schemes and principles of the power system as the smart grid is to incorporate Distributed Generation (DG) units and other Distributed Energy Resources (DERs) hence there is going to be a bi-directional flow of power and information. Therefore, there is also a need for development and advancement in the protection schemes. Over the years there have been a lot of transformational stages in the protection schemes for power system operation. Understanding the protection needs is important for power system operators to know the reason why certain protection schemes cannot work on new and modern power systems as they seek to transform their utilities to the future electrical grid known as the smart grid. This paper presents the transitional stages that power system protection has gone through and the requirements needed for smart grid protection.