PWM power supplies using controlled feedback timing and methods of operating same
AssigneeEaton Power Quality Corporation
InventorsJohn G. Tracy, Frederick Tassitino, Jr., Hans Pfitzer, Rennie Bobb, Julius Rice
Life of this patent
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Abstract
A closed loop power converter circuit of a UPS or other power supply includes a pulse width modulator circuit in a forward path of the closed loop power circuit. A compensation circuit provides pulse width commands to the pulse width modulator at a first rate. A feedback circuit digitally filters samples of an output of the closed loop power converter at a second rate greater the first rate and that provides the filtered samples to the compensation circuit. In some embodiments, the compensation circuit may be operative to compensate for the phase lag associated with a low pass output filter.
Claims34
A UPS, comprising:
- a DC power generation circuit;
- and
- a closed loop power converter circuit operative to produce an AC output from the DC power generation circuit, the closed loop power converter circuit including:
- a pulse width modulator circuit in a forward path of the closed loop power converter circuit, coupled to the DC power generation circuit;
- a compensation circuit that provides pulse width commands to the pulse width modulator at a first rate;
- a sampling circuit configured to generate samples of the AC output;
- and
- a feedback circuit that digitally filters the samples of the AC output at a second rate greater than the first rate and that provides the filtered samples to the compensation circuit.
A closed loop power converter circuit for producing an output voltage from a DC power source, the closed loop power converter circuit including:
- a pulse width modulator circuit in a forward path of the closed loop power converter circuit, configured to be coupled to the DC power source;
- a compensation circuit that provides pulse width commands to the pulse width modulator circuit at a first rate;
- a sampling circuit configured to generate samples of the AC output;
- and
- a feedback circuit that digitally filters samples of the output voltage at a second rate greater than the first rate and that provides the filtered samples to the compensation circuit.
A closed loop power converter circuit for producing an output voltage from a DC power source, the closed loop power converter circuit including:
- a pulse width modulator circuit in a forward path of the closed loop power converter circuit, configured to be coupled to the DC power source;
- a compensation circuit that provides pulse width commands to the pulse width modulator circuit at first times that occur at a predetermined rate;
- and
- a time-offset feedback circuit that samples the output voltage at second times that occur at the predetermined rate and that are offset with respect to the first times, and that provides the filtered samples to the compensation circuit.
A method of operating a UPS, comprising:
- generating an AC output responsive to pulse width commands provided at a first rate to a pulse width modulated power converter circuit of the UPS;
- generating samples of the AC output;
- digitally filtering the samples of the AC output at a second rate greater than the first rate;
- and
- generating the pulse width commands at the first rate from the digitally filtered samples of the AC output.
A method of operating a closed loop power converter circuit of a power supply, the closed loop power converter circuit including a pulse width modulator in its forward path, the method comprising:
- digitally compensating the closed loop power converter circuit at a first rate responsive to samples of an output of the closed loop output circuit that are digitally filtered at a second rate that is greater than the first rate.
Dependencies are inferred from the claim text.