3 phase load current imbalance
In three phase systems, current unbalance is defined as the maximum deviation of any phase current from average divided by average current. Current unbalance can occur due to reasons within the control of the end user or outside the control of end user. Some of the reasons for current unbalance (or imbalance) are:
Current unbalance leads to heating of the stator windings, as a higher current is required to provide the same overall torque. Typically 1% voltage unbalance causes 5% current unbalance, which leads to a 10ÅãC temperature rise, which in turn halves the life of the motor windings.
Current unbalance leads to oscillating torque output from the motor – which places additional loads on shafts, couplings and shear-pins.
Poor Power Factor
Harmonics Current
Harmonic currents increase losses on the power system conductorsand transformers, adding heat to the power chain that drives up power and cooling costs.
The heat created by harmonics can increase downtime by causing premature equipment failure or malfunctions, overheated wiring, and other hardware issues, including generator transfer switch and control malfunctions.
Harmonics can reduce the lifespan of electrical equipment, forcingcompanies to purchase replacement devices sooner than would otherwise be necessary. They canalso compel data center managers to compensate for increased heating and distortion by investing in oversized generators, neutral conductors, and transformers.
Electrical utilities must compensate for harmonic-related waste by deploying additional generating capacity. For that reason, and to discourage harmonic pollution, many utilities penalize customers that exceed distortion limits defined by the IEEE-519 standard. In addition,many utilities penalize customers with a power factor below 0.9.
Phase imbalances and high harmonic voltages and currents cancause electrical meters to report figures that are inaccurate by as much as 20 percent.
YTPQC-APF Active Power Filter: Best Power Quality Control Device
YTPQC-APF Active Power Filters are power electronic devices dedicated to improving the quality of the electrical energy and the efficiency of its use.
YTPQC-APF compensate current harmonics by injecting equal but opposite harmonic compensating current. In this case, the shunt Active Power Filter operates as a current source injecting the harmonic components generated by the load but phase shifted by 180 degrees. As a result, components of harmonic currents contained in the load current are canceled by the effect of the active filter, and the source current remains sinusoidal and in phase with the respective phase-to-neutral voltage. This principle is applicable to any type of load considered as a harmonic source. Moreover, YTPQC-APF can also compensate the load power factor and 3 phase unbalance.
Any inquiry,please contact sales@yt-electric.com
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