Abstract: In order to solve the shortage of the measurement for large blower starting characteristic by experience formulas, a novel indirect measurement method based on measuring the electrical parameters and speed of the blower’s drive motor is presented. The revolving transformation of coordinate is used to measure the driving torque resulted from the positive sequence currents and the braking torque resulted from the negative sequence currents. The impacts of the three-phase unbalanced voltages and the three-phase unbalanced winding of the motor are eliminated. The measurement system is designed based on TMS320F2812 digital signal processor (DSP). The principle and hardware structure of the system are analyzed, and the related software algorithm is programmed. The results of simulations and fieldwork show that the method is practical and feasible, and is apt to be realized, the measurement system is precise and stable, and is hardly affected by the machine vibration, pollution and noise on the worksite.

Key words: Digital signal processor, Indirect measurement, Large blower, Starting characteristic