Voltage waveforms sinusoidal

As standard practice, all motors are designed for a balanced and virtually sinusoidal supply system, but it may not be feasible to obtain the designed supply conditions in practice. Hence, a motor is designed with a certain in-built capacity to sustain small amounts of voltage unbalances and some degree of harmonic quantities, such that the voltage waveform may still be regarded as sinusoidal. 

A supply system would normally contain certain harmonic quantities, as di.scussed in Section 23.5.2. The influence of such quantities on an induction motor is also discussed in Chapter 23. To maintain a near-sinusoidal voltage waveform, it is essential that the harmonic voltage factor (HVF) of the supply voltage be contained within 0.02 for all 1-0 and 3-0 motors, other than design /V motors and within 0.03 for design N motors, where... 

Inverter natural voltage waveform before modulation, improved to a near sinusoidal waveform, with the use ol L and C. 

Power factor correction circuits are intended to increase the conduction angle of the rectifiers and to make the ac input current waveform sinusoidal and in phase with the voltage waveform. The input waveforms can be seen in Figure C-2. This means that all the power drawn from the power line is real power and not reactive. The net result is that the peak and RMS current drawn from the line is much lower than that drawn by the capacitive input Alter circuit traditionally used. 

I will be using a seeond order, eommon-mode filter. The diffieulty in eonsider-ing an input eondueted EMI for this power faetor eorreetion eireuit is its variable frequency of operation. The lowest instantaneous frequency of operation occurs at the crests of the sinusoid voltage waveform. This is where the core requires the longest time to completely discharge the core. The estimated frequency of operation has been 50 kHz, so I will use this as an assumed minimum frequency. 

VSIN, ISIN - Sinusoidal voltage or current source. Typical voltage waveform v(t) = 5 sin(2000t + 30°)... 

The Transient Analysis uses the sinusoidal voltage waveform when it performs the simulation. This circuit would not work if an AC Sweep were used. To set up a Transient Analysis, select PSpice and then New Simulation Profile from the Capture menus ... 

FIGURE 4.2 Nonsinusoidal voltage waveform Fourier series. The Fourier series allows expression of nonsinusoidal periodic waveforms in terms of sinusoidal harmonic frequency components. 

For that purpose, the quartz crystal is simultaneously excited at two frequencies. The response at the lower frequency is processed by a feedback loop dedicated to measure and automatically compensate Cq. The response at the higher frequency is processed by a phase-locked loop that continuously maintains and tracks oscillations at/s. The voltage waveform V hl is the sum of the two sinusoidal signals V h. with frequency/h generated by the voltage controlled oscillator VCO, and Vl, with frequency/, lower than/n, generated by the auxihary oscillator OSC. The frequency/r of the signal Vu is taken as the output frequency/out of the whole circuit. In the frequency domain, the ex-... 

The near-rectangular line currents will produce volt-drops in the series resistance-reactance cables, overhead lines and transformers. These volt-drops will be non-sinusoidal and will distort the waveform at their intermediate points of connection. At snch points there may be a switchboard or distribntion board and the loads connected to them will experience the distorted voltage waveform. 

The transistor collector current and collector-emitter voltage waveforms are sinusoidal, which they... 

Figure 10.15(b) shows the output voltage waveform for a sinusoidal input voltage. If R rp, then Eq. 

The source (and in a few cases the absorber) is mounted on the vibrating axis of an electromagnetic transducer (loudspeaker system) [ 16J which is moved according to a voltage waveform applied to the driving coil of the system. The usual velocity functions are of the triangular, sawtooth, or sinusoidal form. In special cases the source may be moved with a constant velocity,... 

Figure 12.23. Initial voltage waveforms aeross transmission line for a sinusoidal voltage souree.

The voltage must approach a sinusoidal waveform and should be balanced. If at the time of conducting the tests the voltage is almost btit not completely balaticeil. arithmetical average of the phase volttige must be used for calculating the machine s performance. 

The test must be conducted at the rated current, at a frequency with a tolerance of -t-2% and -5% of the rated frequency and the voltage in a sinusoidal waveform, as much as practicable. See also Section 11.3.2. The test is earned out until the temperature reaches almost a stable state, i.e. when the variation does not exceed 1°C per hour. To shorten the test duration, the current may be enhanced during the initial period to reach a fast, stable state. 

In an alternating current system the voltage and current components travel in the shape of a sinusoidal waveform (Figure 17.9) and oscillate through their natural zeros, 100 times a second for a 50 Hz system. 

All such loads generate harmonics and cause variations in the fundamental power frequency of the supply sy.stem which leads to distortion in the sinusoidal waveform of the voltage. This distortion may affect the quality of the supply system (voltage) beyond desirable limits, A non-sinusoidal and distorted supply system may adversely affect the different loads connected on the system, besides leading to outage of the sy.stem itself. 

Quasi-resonant converters are a separate class of switching power supplies that tune the ac power waveforms to reduce or eliminate the switching loss within the supply. This is done by placing resonant tank circuits within the ac current paths to create pseudo-sinusoidal voltage or current waveforms. Because the tank circuits have one resonant frequency, the method of control needs to be modified to a variable frequency control where the resonant period is fixed and the control varies the period of the non-resonant period. The quasi-resonant converters usually operate in the 300 kHz to 2 MHz frequency range. 

The minimum speeified maximum linear limit of the input to the multiplier (pin3) is 2.5 V. This level should be the peak value of the divided reetified input waveform at the highest expeeted ae input voltage at the erest of the sinusoid (370 V). If a sense eurrent of 200jUA is seleeted at this point the resistor divider beeomes... 

Cnrrents and voltages in a power system usually have a sinusoidal waveform of the fundamental power system frequency plus other normal harmon-... 

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