Source inverter also has passive inverter. For example, the DC voltage, through a simple, single-phase thyristor bridge type H, H is the output of the cross on each of the electric meter four H's vertical thyristor, electric energy meter, at 34, 14 and 23 were opened to give a positive negative separated the output voltage and current.
The pulse width modulation inverter technology
Basic square wave inverter circuit is simple, but the output voltage waveform harmonic content is too large, but also both the THD (current harmonic distortion) is too large; the phase shift of multiple superimposed small harmonic content inverter output voltage waveform, That THD is small, but the circuit is more complex. The PWM pulse width modulation inverter, both the computer's circuitry, and the output voltage waveform, which has been widely used.
The so-called PWM technology (Pulse Width Modulation, PWM), is made of a reference wave (usually a sine wave, sometimes with a trapezoidal wave or injected zero sequence harmonic Electric transformer sine wave or square wave, etc.) for the modulation wave (electric energy meter), and to N times the frequency of the modulation wave of the triangular wave (sawtooth wave is also sometimes used) of the carrier (Carrier Wave) waveform comparison, the modulation wave is greater than the carrier portion to generate a set of equal amplitude and a width proportional to the modulated waves equivalent rectangular pulse sequence is used to modulate the wave instead of using analog switch, and through the inverter power switch on / off control, the DC power into AC power, this technique is called pulse control inverter technology. Because triangular carrier wave (or sawtooth) vertical section is a linearly varying degrees, so this technique is called pulse control inverter technology. Since the triangular carrier wave (or sawtooth) is vertical width is linear, so that this modulation is linear, when the modulation wave is a sine wave, a rectangular pulse width of the output pulse train changes sinusoidally, this modulation Air circuit breaker technique typically also known as the sinusoidal pulse width modulation (Sinusoida PWM) technology.
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