SCR Rectifier working principle
All SCR Rectifiers use the same technology to achieve stable output voltage. The output voltage is connected to a reference voltage Vref (Sampled) by a Resistive Divider connected to an Inverting Input of the Error Amplifier, a non-inverting input of the error amplifier The The reference voltage is generated by the bandgap reference inside the IC. The error amplifier always tries to force the input at both ends to be equal. To this end, it provides the load current to ensure that the output voltage is stable:
Principle Analysis of Single - phase AC SCR Rectifier
1. Principle analysis of single phase SVC direct voltage regulator SCR Rectifier
A point for the single-phase SCR Rectifier input side, B point for the single-phase SCR Rectifier output side
In fact, this type of regulator with a direct regulator of the SCR Rectifier is the use of autotransformer principle made of the figure on the AN side is the input side of the autotransformer, BN side is the output side of the autotransformer, if the input When the voltage is higher than the output set point 220V, the autotransformer is operating in a buck state. If the input voltage is below 220V, the autotransformer is operating in a boost state. (The figure shows that it is in a buck state )
This kind of SCR Rectifier is different from the main transformer input point A can be from 0V to 250V any sliding between. So you can always adjust the input voltage input point to meet the output voltage constant. We generally put the input side A point Called the sliding arm, which is driven by the motor through the reduction device, the motor steering control by the regulator control circuit to complete.
SCR Rectifier sampling circuit always monitor the output of the SCR Rectifier between the two points, the output voltage increases, the control motor toward the autotransformer buck direction, (Figure 2) when the output voltage reaches the desired voltage, stop control In addition, the control circuit controls the motor to rotate in the direction of boosting the autotransformer (Figure 3) when the desired voltage is reached.
The size of this type of SCR Rectifier by the output voltage can be transformer transformer autotransformer to bear, but because of its manufacturing process, it can not do much, can only adapt to small power occasions. Power to do more, it is necessary to join the compensation transformer to achieve the SCR Rectifier power expansion ~