Abstract:

Local compensation for reactive power of asynchronous motors is an economical and efficient power factor compensation method. It introduces the principle of compensation for motors and current calculation method of compensation capacity. Taking a YKK7104 high voltage primary air fan of a power station as the prototype, the Matlab simulation is carried out under the condition different load factor. If highvoltage motors are in light load, the compensation of motor that is calculated according to rated capacity performs poor. It puts forward a compensation capacity fitting method based on the optimum compensation data. Based on the Matlab toolkit which provides nonlinear fitting data, the optimum experimental data are processed .The error rates of fitting curve of compensation capacity and load rate are less than 1%. The fitting curves of compensation capacity at 30%, 50%, 70% and 90% working load are verified. The fitting curves at 35% and 75% load rates are also verified. The compensation results obtained in the experiment reach 94%~95% of the requirements, which proves that this method can give a more accurate compensation to a specific motor under different load rates in the practice.

Key words:

reactive power compensation, nonlinear fitting, highvoltage motor, load rate, fitting curve