EFFECTIVE EFFICIENT OPERATION OF INDUCTIVE MOTORS

POWER MANAGEMENT SYSTEM

LIMITER TEAM

LIMITER was created by a professional network of members active in the electrical and mechanical engineering field. Comprising a wealth of knowledge, the LIMITER Power Management System partners have 120 years of combined experience in electrical machine design, analysis, control and maintenance. The partners are all largely active in the renewable energy space. This, coupled with the current and ongoing South African energy crisis, resulted in a breakthrough energy saving solution presenting itself to the LIMITER team.

LOSSES & EFFICIENCY

motor-losses-efficiency-chart

With a given motor, these losses and the proportions of the losses are determined by the designer of the motor.

Essentially the core losses are dependent on the laminated core steel properties and the flux in the core. Flux is dependent on operating voltage, the number of turns in the winding and the frequency.

power

In essence this means that for any given motor (design), when operating at rated voltage, the core losses are fixed irrespective of load, as the iron losses are dependent on
voltage and frequency and not on the operating load.

Stray, windage and friction loss are basically fixed and are determined by the design of the motor. I2R losses in the motor for any fixed design are solely dependent on the square of the current drawn by the motor. Note the stator and rotor resistances are fixed by the design of the winding. Resistance does, however, change with temperature. Both stator and rotor currents increase or decrease with load.

POWER FACTOR

power-factor-2

power-factor-curves-2