Energy efficiency of belt conveyor at constant speed operation

Abstract

Belt conveyor drives at the open pit mines consist of motors with large installed power. Each analysis of their energy efficiency presents an important factor for proper control to achieve better financial effects. The paper considers efficiency of each belt conveyor in the V ECS (excavator-belt conveyor-spreader) system at the open pit mine "Drmno" as a function of time, determined based on measured values for the observed period of time. This paper analyses variations of efficiency depending on the load at constant speed. Conversion of electrical energy into mechanical by means of electrical motors and mechanical transmission is performed on belt conveyors. Therefore, the efficiency of drive station driven by electrical motors of multi motor drive is defined as a relation between the output mechanical power of multi motor drive and its input electrical power. Information about the motor torques is obtained from frequency converters, within integrated models which estimate the value of motor torque. Information about the belt speed is achieved by measuring the number of drive drum revolutions in certain period of time. Electrical power for supplying all consumers at the belt conveyor drive station is gained by measuring the power in the supply medium voltage cubicle.