# Tag: Single Phase Circuits

• ## 10.8 Harmonic Phase Sequences

In the last section, we saw how the 3rd harmonic and all of its integer multiples (collectively called triplen harmonics) generated by 120° phase-shifted fundamental waveforms are actually in phase with each other. In a 60 Hz three-phase power system, where phases A, B, and C are 120° apart, the third-harmonic multiples of those frequencies…

• ## 10.7 Harmonics in Polyphase Power Systems

In the chapter on mixed-frequency signals, we explored the concept of harmonics in AC systems: frequencies that are integer multiples of the fundamental source frequency. With AC power systems where the source voltage waveform coming from an AC generator (alternator) is supposed to be a single-frequency sine wave, undistorted, there should be no harmonic content…

• ## 10.6 Three-phase Transformer Circuits

Since three-phase is used so often for power distribution systems, it makes sense that we would need three-phase transformers to be able to step voltages up or down. This is only partially true, as regular single-phase transformers can be ganged together to transform power between two three-phase systems in a variety of configurations, eliminating the…

• ## 10.5 Three-phase Y and Delta Configurations

Three-phase Wye(Y) Connection Initially, we explored the idea of three-phase power systems by connecting three voltage sources together in what is commonly known as the “Y” (or “star”) configuration. This configuration of voltage sources is characterized by a common connection point joining one side of each source. (Figure below) Three-phase “Y” connection has three voltage…

• ## 10.4 Polyphase Motor Design

AC Motors Perhaps the most important benefit of polyphase AC power over single-phase is the design and operation of AC motors. As we studied in the first chapter of this book, some types of AC motors are virtually identical in construction to their alternator (generator) counterparts, consisting of stationary wire windings and a rotating magnet…

• ## 10.3 Phase Rotation

Three-Phase Alternator Let’s take the three-phase alternator design laid out earlier and watch what happens as the magnet rotates. Three-phase alternator The phase angle shift of 120° is a function of the actual rotational angle shift of the three pairs of windings. If the magnet is rotating clockwise, winding 3 will generate its peak instantaneous…

• ## 10.2 Three-phase Power Systems

What is Split-Phase Power Systems? Split-phase power systems achieve their high conductor efficiency and low safety risk by splitting up the total voltage into lesser parts and powering multiple loads at those lesser voltages while drawing currents at levels typical of a full-voltage system. This technique, by the way, works just as well for DC…

• ## 10.1 Single-phase Power Systems

Single phase power system schematic diagram shows little about the wiring of a practical power circuit. Depicted above, is a very simple AC circuit. If the load resistor’s power dissipation were substantial, we might call this a “power circuit” or “power system” instead of regarding it as just a regular circuit. The distinction between a…