Fuente: WIPO "tomato" Distance protection for electric power delivery systems using distance elements with characteristics that prevent distance element overreach. The distance protection systems and methods herein may be used in systems that experience incoming power flow with enhanced security. Improved mho and quadrilateral elements are described that may have observation windows longer or shorter than half a cycle of transmission line signals. Such mho and quadrilateral elements may determine fault conditions, such as resistive faults, with improved reliability and efficiency.