Voltage-source inverter apparatus utilizing ripple voltage
View Patent ↗An inverter apparatus that can lengthen a lift span provides only a noise absorption film capacitor in a DC intermediate circuit between rectifying and inverter circuits, instead of a conventional electrolytic capacitor. In a voltage command generating unit, when a frequency set by a frequency setting unit is within a predetermined range including the frequency of an AC input power supply, PLL control is performed to make the frequency set by an output voltage command signal equal to the frequency of the AC input power supply voltage, and to substantially synchronize the peak value of the inverter circuit output voltage with the peak value of a voltage formed between both ends of the film capacitor. Accordingly, output voltage amplitude is generated when the frequency set by the output voltage command signal equals the frequency of the voltage of the AC input power supply.
1. A voltage-source inverter apparatus comprising:
a rectifying circuit that rectifies a three-phase AC voltage of an AC input power supply;
a voltage command generating unit that generates a voltage command signal having a frequency set by a frequency setting unit; and
an inverter circuit that converts a DC voltage rectified by the rectifying circuit into a three-phase AC output voltage having predetermined frequency and amplitude, which is subjected to pulse width modulation (PWM) control, on the basis of the output voltage command signal generated by the voltage command generating unit,
wherein the inverter apparatus is a voltage-source inverter, and
wherein the voltage command generating unit is provided with a voltage synchronizing unit that synchronizes the output voltage command signal generated by the voltage command generating unit with a ripple voltage generated by a DC intermediate circuit provided between the rectifying circuit and the inverter circuit to synchronize the three-phase AC output voltage of the inverter with the ripple voltage generated by the DC intermediate circuit.
2. The inverter apparatus according to claim 1 ,
wherein, when the frequency of the output voltage command signal is within a predetermined range including the frequency of the voltage of the AC input power supply, the voltage synchronizing unit fixes the frequency of the output voltage command signal to a frequency that is equal to the frequency of the voltage of the AC input power supply, and synchronizes the output voltage command signal with the ripple voltage of the DC intermediate circuit.
3. The inverter apparatus according to claim 1 ,
wherein, when the frequency of the output voltage command signal is within a predetermined range including the frequency of the voltage of the AC input power supply and only when a current output from the inverter circuit is larger than a predetermined upper limit, the voltage synchronizing unit fixes the frequency of the output voltage command signal to a frequency that is equal to the frequency of the voltage of the AC input power supply, and synchronizes the output voltage command signal with the ripple voltage of the DC intermediate circuit.
4. The inverter apparatus according to claim 1 ,
wherein the voltage synchronizing unit detects the phase of the voltage of the AC input power supply and synchronizes the output voltage command signal with the ripple voltage of the DC intermediate circuit on the basis of the detected phase.
5. The inverter apparatus according to claim 1 ,
wherein the voltage synchronizing unit detects the phase of the ripple voltage and synchronizes the output voltage command signal with the ripple voltage of the DC intermediate circuit on the basis of the detected phase.
6. The inverter apparatus according to claim 1 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
7. The inverter apparatus according to claim 2 ,
wherein the voltage synchronizing unit detects the phase of the ripple voltage and synchronizes the output voltage command signal with the ripple voltage of the DC intermediate circuit on the basis of the detected phase.
8. The inverter apparatus according to claim 3 ,
wherein the voltage synchronizing unit detects the phase of the ripple voltage and synchronizes the output voltage command signal with the ripple voltage of the DC intermediate circuit on the basis of the detected phase.
9. The inverter apparatus according to claim 2 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
10. The inverter apparatus according to claim 3 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
11. The inverter apparatus according to claim 4 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
12. The inverter apparatus according to claim 5 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
13. The inverter apparatus according to claim 7 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
14. The inverter apparatus according to claim 8 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
15. The inverter apparatus according to claim 2 ,
wherein the voltage synchronizing unit detects the phase of the voltage of the AC input power supply and synchronizes the output voltage command signal with the ripple voltage of the DC intermediate circuit on the basis of the detected phase.
16. The inverter apparatus according to claim 3 ,
wherein the voltage synchronizing unit detects the phase of the voltage of the AC input power supply and synchronizes the output voltage command signal with the ripple voltage of the DC intermediate circuit on the basis of the detected phase.
17. The inverter apparatus according to claim 15 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
18. The inverter apparatus according to claim 16 ,
wherein the voltage command generating unit includes a voltage correcting unit that corrects the voltage of the output voltage command signal on the basis of the ripple voltage of the DC intermediate circuit.
19. A voltage-source inverter apparatus comprising:
a voltage rectifying circuit that voltage rectifies a three-phase AC voltage of an AC input power supply into a DC voltage;
a film capacitor connected across an output of the voltage rectifying circuit;
a DC voltage detector that detects a voltage formed between both ends of the film capacitor;
an AC voltage detector that detects a voltage of the AC input power supply and provides a detection value of the voltage of the AC input power supply;
an AC input power supply voltage phase detector that detects the phase of the voltage of the AC input power supply based on the detection value of the AC voltage detector;
a voltage command generating unit that generates a voltage command signal having a frequency set by a frequency setting unit, the voltage command generating unit having an input from the AC input power supply voltage phase detector to receive the detected phase of the voltage of the AC input power supply; and
an inverter circuit that converts a DC voltage rectified by the rectifying circuit into a three-phase AC output voltage having predetermined frequency and amplitude, which is subjected to pulse width modulation (PWM) control, on the basis of the output voltage command signal generated by the voltage command generating unit, the inverter circuit being connected across both ends of the film capacitor so that the film capacitor is provided between the rectifying circuit and the inverter circuit,
wherein the voltage command generating unit comprises a voltage synchronizing unit that synchronizes the output voltage command signal generated by the voltage command generating unit with a ripple voltage generated by the film capacitor provided between the rectifying circuit and the inverter circuit to synchronize the three-phase AC output voltage from the inverter with a ripple voltage of the film capacitor.
20. A voltage-source inverter apparatus comprising:
a voltage rectifying circuit that voltage rectifies a three-phase AC voltage of an AC input power supply into a DC voltage;
a DC voltage intermediate circuit connected across an output of the voltage rectifying circuit;
a DC voltage detector that detects a voltage formed by the DC voltage intermediate circuit;
an AC voltage detector that detects a voltage of the AC input power supply and provides a detection value of the voltage of the AC input power supply;
an AC input power supply voltage phase detector that detects the phase of the voltage of the AC input power supply based on the detection value of the AC voltage detector;
a voltage command generating unit that generates a voltage command signal having a frequency set by a frequency setting unit, the voltage command generating unit having an input from the AC input power supply voltage phase detector to receive the detected phase of the voltage of the AC input power supply; and
an inverter circuit that converts a DC voltage rectified by the rectifying circuit into a three-phase AC output voltage having predetermined frequency and amplitude, which is subjected to pulse width modulation (PWM) control, on the basis of the output voltage command signal generated by the voltage command generating unit, the inverter circuit being connected across the DC voltage intermediate circuit so that the DC voltage intermediate circuit is provided between the rectifying circuit and the inverter circuit,
wherein the voltage command generating unit comprises a voltage synchronizing unit that synchronizes the output voltage command signal generated by the voltage command generating unit with a ripple voltage generated by the DC intermediate circuit provided between the rectifying circuit and the inverter circuit to synchronize the three-phase AC output voltage from the inverter with a ripple voltage of the DC voltage intermediate circuit.