- Electrical Machines
- Generator converts mechanical energy to electrical energy
- works based on Lorentz Force, wire moves inside magnetic field generating voltage
- Motor converts electrical energy to mechanical energy
- works based on Lorentz Force, current carrying wire inside magnetic field has a force exerted on it
- AC and DC machines cannot operate interchangeably
- DC generator connections must have same voltage
- AC Generator connections must have same frequency, and synchronized
- Fluid Analogy
- Electrical voltage is a measure of the level of electricity
- Current is a measure of the flow of electricity
- Loads consume electricity, slow the flow, and or reduce the level
- Source provides electricity or provides movement/flow
- AC frequency is measured in Hz
- North America power is provided at 60 Hz
- European countries power is provided at 50 Hz
- Voltages of loads and sources must match
- Power capacity of source must be greater than the power of loads
- Frequency of load to source must be the same
- important for attaining required rpm for motors
- (PM) Permanent Magnets are not often used, usually electromagnets
- right hand rule
- DC motor can have any acceptable rpm, AC motor can have speeds at synchronous or close to synchronous speed, dependent on frequency of electricity provided
- generators can be connected together
- Wind Turbines don't generate power when wind speed is below cut-in speed, and does not generate electricity over cut-out speed
- during strong winds wind turbine can be taken out of service, stopped and brakes applied
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