Split rail PFC and AC inverted architecture
View Patent ↗A power conversion system including power factor correction circuitry and power inversion circuitry. The power factor correction circuitry has a split-rail configuration and includes a bidirectional switch used to produce intermediate direct current power. The power inversion circuitry selectively operates switches to produce sinusoidal alternating current output power. The output power and the intermediate power are regulated together.
1. A power conversion system, comprising: an AC power source;
a power factor correction (PFC) stage including:
a first inductor directly connected to the power source via a first electrical path and directly connected to a first node via a second electrical path,
a first diode directly connected the first node via a third electrical path and directly connected to a second node via a fourth electrical path,
a second diode directly connected to the first node via a fifth electrical path and directly connected to a third node via a six electrical path,
a bidirectional switch directly connected to the first node via a seventh electrical path and directly connected to a fourth node via an eighth electrical path, a filter stage including:
a first capacitor directly connected to the second node via a ninth electrical path and directly connected to a fifth node via a tenth electrical path,
a second capacitor directly connected to the third node via an eleventh electrical path and directly connected to the fifth node via a twelfth electrical path,
the fourth node directly connected to the fifth node via a thirteenth electrical path and directly connected to a common AC return line via a fourteenth electrical path, a power inversion phase including:
a first switch directly connected to the second node via a fifteenth electrical path and directly connected to a sixth node via a sixteenth electrical path,
a second switch directly connected to the third node via a seventeenth electrical path and directly connected to the sixth node via an eighteenth electrical path,
the sixth node directly connected to a second inductor via a nineteenth electrical path,
the second inductor directly connected to a seventh node via a twentieth electrical path,
a third capacitor directly connected to the seventh node via a twenty first electrical path and directly connected to the common AC return line via a twenty second electrical path;
wherein the forth electrical path and fifteenth electrical path together constitute a positive distribution rail and the sixth electrical path and seventeenth electrical path constitute a negative distribution rail;
wherein the power factor correction stage is configured to receive input AC power from the AC power source and produce intermediate DC power by alternately producing a positive intermediate DC output voltage along the positive distribution rail and a negative intermediate DC output voltage along the negative distribution rail through operation of the bidirectional switch;
wherein the power inversion phase is configured to create output AC power through alternating operation of the first switch and the second switch; and
wherein the common AC return is connected to the AC power source such that the input AC power, the intermediate DC power and the output AC power are connected to the common AC return line so as to prevent common mode fluctuations and harmonics.
2. The power conversion system of claim 1 wherein the AC power source is a generator on an aircraft.
3. The power conversion system of claim 1 wherein the AC input power is 360-800 Hz 115 VAC and the output AC power is 50/60 Hz 115 VAC.
4. The power conversion system of claim 1 wherein the PFC stage draws current directly proportional to a waveform of an applied voltage of the AC input power.