Controlador con medición de bajo costo aplicado a correctores de factor de potencia

Power factor correctors with dual-boost topology (PFC-DBs) are very efficient. They have less conduction losses than those using a conventional boost (PFC-BC) topology. In order to control PFC-DBs input voltage and current measurements are usually needed, but measuring these signals is difficult and relatively expensive when the controller is implemented with commercial integrated circuits. This is because the ground is not shared by the input and output circuits. On the contrary, in the PFC-BC topology the ground is shared by the input and output circuits. Then, the voltage and current signals required to perform the control can be measured through resistors connected to the same ground. In PFC-DBs controllers, the measurement circuits are complex and increase the cost of the system. This is an important disadvantage. In order to overcome this drawback, in this paper, a controller with a cheaper and rugged measurement hardware is proposed. The proposed circuit can be used in both topologies (i.e. PFC-DB and PFC-BC). This controller does not require the measurement of the input voltage, and uses the dc bus current instead of the input current. This current can be measured with a simple resistor connected to the ground shared by the input and output circuits. The proposal is promising for its low cost, simplicity and performance. Experimental results obtained in a laboratory prototype are included.