Agilent 5990-9182EN Troubleshooting VFDs with Low Pass Filter - Application Note c20140818 [7] free download

File name 5990-9182EN Troubleshooting VFDs with Low Pass Filter - Application Note c20140818 [7].pdf

Keysight Technologies Troubleshooting VFDs with Low Pass Filter Application Note Introduction Today, three-phase induction motors are the most important workhorses in industry and commercial facilities. An AC induction motor is commonly used as a constant-speed drive when fed from a voltage source of fixed frequency. Unfortunately, running a motor at maximum speed, regardless of the varying demands of production, means a great deal of electric power is wasted. In many motor applications, energy use can be reduced considerably if the speed of the motor varies in response to the changing process conditions. With the advent of solid state electronics, variable speed drives can regulate the speed of a three-phase AC electric motor by converting three-phase AC line voltage to a quasi-sinusoidal pulse width modulated (PWM) waveform in which the frequency and voltage level can be varied. 03 | Keysight | Troubleshooting VFDs with Low Pass Filter - Application Note Benefits of Variable Variable frequency drives (VFDs) provide many benefits. Energy savings is among them since the VFD allows precise speed control of a standard induction motor and, in many Frequency Drives applications, that ability improves process control. Other benefits include that VFDs can maintain torque at levels to match the needs of the load, reduce mechanical stress on three-phase induction motors by providing a soft start, and improve an electrical system's power factor. This also reduces the voltage sag that can occur when a large motor starts quickly. Voltage sags can dim lights and cause other equipment to shut down or restart. Because of the benefits mentioned above, VFDs are becoming prevalent in a wide range of applications throughout industry: from motion control applications to ventilation systems, from wastewater processing facilities to machining areas, and many others. For example, VFDs are used in ventilation systems for large buildings where air flow requirements change according to the humidity and temperature in the room. Fan speeds in power plants are adjusted according to the varying demands for power at