A low-cost microcomputer based direct load control scheme for small electric utilities

A low-cost microprocessor based direct load control scheme is described. The scheme is particularly suitable for small- to medium-sized public utilities which do not possess large financial resources to implement a large-scale SCADA based load management system. The system is designed around the 8-bit 68HC11 microcontroller manufactured by Motorola. The hardware consists of two basic systems: the transmitter and the receiver. The transmitter consists of a PC, and HC11 Evaluation Board and a radio transmitter. The receiver consists of the radio receiver and an HC11 running in single-chip mode. The system uses an addressing scheme to control up to four loads at each of 4095 different receiver sites. It uses redundant data transmission to ensure error-free operation.