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A completely different approach to function generation is to use software instructions to generate a waveform, with provision for output. For example, a general-purpose digital computer can be used to generate the waveform; if frequency range and amplitude are acceptable, the sound card fitted to most computers can be used to output the generated wave.
As the generator speed changes, the lights will flicker at the beat frequency proportional to the difference between generator frequency and system frequency. When the voltage at the generator is opposite to the system voltage (either ahead or behind in phase), the lamps will be bright. When the voltage at the generator matches the system ...
The cumulative frequency is the total of the absolute frequencies of all events at or below a certain point in an ordered list of events. [1]: 17–19 The relative frequency (or empirical probability) of an event is the absolute frequency normalized by the total number of events:
A permanent magnet synchronous generator is a generator where the excitation field is provided by a permanent magnet instead of a coil. The term synchronous refers here to the fact that the rotor and magnetic field rotate with the same speed, because the magnetic field is generated through a shaft-mounted permanent magnet mechanism, and current is induced into the stationary armature.
Using this frequency, the Bode phase plot finds the phase of βA OL. If the phase of βA OL (f 0 dB) > −180°, the instability condition cannot be met at any frequency (because its magnitude is going to be < 1 when f = f 180), and the distance of the phase at f 0 dB in degrees above −180° is called the phase margin.
Simple example of a Pareto chart using hypothetical data showing the relative frequency of reasons for arriving late at work. A Pareto chart is a type of chart that contains both bars and a line graph, where individual values are represented in descending order by bars, and the cumulative total is represented by the line.
The slightly faster frequency is intended to prevent the generator paralleling onto the grid as a motor load, potentially damaging the prime mover (steam turbine or reciprocating internal combustion engine). The machine may be protected from this occurrence by a "reverse power" trip.
The rotating magnetic field is the key principle in the operation of induction machines.The induction motor consists of a stator and rotor.In the stator a group of fixed windings are so arranged that a two phase current, for example, produces a magnetic field which rotates at an angular velocity determined by the frequency of the alternating current.