Cosine Firing Scheme and Integrator Circuit

Cosine firing scheme is used in power electronic circuits to control the output voltage or current of the circuit. It is a technique used to improve the power factor of an AC circuit. The cosine firing scheme generates a cosine wave and uses it to control the firing angle of the thyristors in the circuit.

To generate a cosine wave, an integrator circuit is used. An integrator circuit is a circuit that performs the mathematical operation of integration. It takes an input signal and produces an output signal that is the integral of the input signal.

Working of Integrator Circuit

The integrator circuit consists of a capacitor and a resistor connected in series. When an input voltage is applied to the circuit, the capacitor charges and discharges through the resistor. The output voltage across the capacitor is the integral of the input voltage.

The output voltage of the integrator circuit is a ramp waveform. To convert this ramp waveform into a cosine waveform, a cosine wave is fed into the integrator circuit as the input voltage. The output voltage of the integrator circuit is then a cosine waveform.

The output of the integrator circuit is then fed into a comparator circuit to generate the firing pulses for the thyristors in the circuit.

Conclusion

In summary, the integrator circuit is used to generate a cosine waveform for the cosine firing scheme in power electronic circuits. The integrator circuit performs the mathematical operation of integration to convert the input waveform into a cosine waveform. The output of the integrator circuit is then used to generate the firing pulses for the thyristors in the circuit.