Generator Loads And Power Factor
Posted 04 December 2007 - 02:48 AM
Situation: Have generator that runs multiple conveyors as well as other asphalt machinery.
Question: If we use custom made capacitors to correct the Power Factor in circuit with each motor running off the generator. Then at a later time add additional conveyors (motors), will this effect the Power Factor of the motors we previously optimized.
Posted 04 December 2007 - 04:48 AM
Welcome to the forum.
There are two types of power factor, displacement power factor and distortion power factor. Typically, most people considering power factor, are concerned with displacement power factor only.
Every motor has a component of the current drawn which is called the magnetizing current. This is a characteristic of that particular motor and varies between motors. The magnetizing current is constant and independent of load.
The magnetizing current is an inductive current and would generally be between 20% and 50% of the motor rated current.
When the motor operates open shaft, it is essentially the magnetizing current that is drawn.
Power factor correction capacitors are applied to the circuit to cancel out the inductive magnetizing current of the motor. If you add the correct amount of correction, then the power factor would typically be greater than 0.95. If you then add additional motors, the total magnetizing current will be increased and so the capacitor current needs to be increased also to give good correction.
Mark Empson | administrator
Skype Contact = markempson | phone +64 274 363 067
LMPForum | Power Factor | L M Photonics Ltd | Empson family | Advanced Motor Control Ltd | Pressure Transducers | Smart Relay | GSM Control | Mark Empson Website | AuCom | Soft Starters
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users