Voltage adjustment system and method for parallel-stage power converter

Patent metadata

Field	Value
Publication number	US-9729063-B2
Application number	US-201514848103-A
Country	US
Kind code	B2
Filing date	Sep 8, 2015
Priority date	Sep 8, 2015
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A power system includes a first DC-DC converter circuit and a second DC-DC converter circuit, each including a power input terminal and a sensor. The sensor includes a sensor output terminal and at least one of a current sensor and a voltage sensor. The power system also includes a master Power Factor Correction (PFC) circuit that includes a power output terminal coupled to the power input terminal of the first DC-DC converter circuit; and a slave PFC circuit, which includes a power output terminal coupled to the power input terminal of the second DC-DC converter circuit and a voltage adjustment terminal coupled to the sensor output terminal of the second DC-DC converter circuit and to the sensor output terminal of the first DC-DC converter circuit.

First claim

What is claimed is:

1. A method for power conversion, comprising:
performing, by a plurality of parallel stages, DC-DC conversion on a plurality of input signals to obtain a plurality of output signals each having a respective amplitude;
determining a plurality of measurement signals that each scale in accordance with the respective amplitude of one of the plurality of output signals, wherein determining the plurality of measurement signals comprises measuring a current ripple amplitude of each of the plurality of output signals; and
adjusting, in accordance with the plurality of measurement signals, a respective voltage of at least one of the plurality of input signals.

2. The method of claim 1 , further comprising:
receiving, by a plurality of power factor correction stages, a power signal comprising one of an alternating current signal and a rectified signal; and
performing power factor correction on the power signal to obtain the plurality of input signals.

3. The method of claim 2 , wherein
a first output signal in the plurality of output signals comprises a first current ripple amplitude that scales in accordance with a first input signal in the plurality of input signals,
a second output signal in the plurality of output signals comprises a second current ripple amplitude that scales in accordance with a second input signal in the plurality of input signals, and
the adjusting the respective voltage of at least one of the plurality of input signals comprises:
determining, in accordance with a first measurement signal and a second measurement signal, a control signal that scales in accordance with a difference between the first current ripple amplitude of the first output signal and the second current ripple amplitude of the second output signal; and
adjusting a voltage of the second input signal in accordance with the control signal.

4. The method of claim 3 , wherein the adjusting the voltage of the second input signal comprises one of:
increasing the voltage of the second input signal when the second current ripple amplitude of the second output signal is less than the first current ripple amplitude of the first output signal; and
decreasing the voltage of the second input signal when the second current ripple amplitude of the second output signal is greater than the first current ripple amplitude of the first output signal.

5. The method of claim 4 , wherein:
the plurality of power factor correction stages comprises a master stage configured to output the first input signal, and a slave stage configured to output the second input signal; and
the adjusting the voltage of the second input signal comprises one of:
adjusting a switching frequency of the slave stage; and
adjusting a duty cycle of the slave stage.

6. The method of claim 1 , wherein each of the plurality of output signals further comprises a different signal phase.

7. The method of claim 1 , wherein
the plurality of parallel stages comprises an LLC converter,
the LLC converter comprises a resonant tank, and
the resonant tank comprises a resonance capacitor.

8. The method of claim 7 , wherein
the resonant tank further comprises a shunt resistor, and
the method further comprises determining a measurement signal of the plurality of measurement signals in accordance with a voltage across the shunt resistor.

9. The method of claim 7 , wherein
the LLC converter further comprises a parallel branch circuit coupled in parallel with the resonant tank,
the parallel branch circuit comprises a shunt resistor and a shunt capacitor coupled in series with the shunt resistor, and
the method further comprises determining a measurement signal of the plurality of measurement signals in accordance with a voltage across the shunt resistor.

10. A power circuit, comprising:
a plurality of parallel stages configured to:
perform DC-DC conversion on a plurality of input signals to obtain a plurality of output signals each having a respective amplitude; and
determine a plurality of measurement signals each in accordance with the respective amplitude of one of the plurality of output signals by measuring a current ripple amplitude of each of the plurality of output signals; and

wherein the power circuit is configured to adjust, in accordance with the plurality of measurement signals, a respective input voltage of at least one of the plurality of input signals.

11. The power circuit of claim 10 , further comprising:
a plurality of power factor correction stages configured to:
receive a power signal comprising one of an alternating current signal and a rectified signal; and
perform power factor correction on the power signal to obtain the plurality of input signals.

12. The power circuit of claim 11 , wherein
a first output signal in the plurality of output signals comprises a current ripple amplitude that scales in accordance with a first input signal in the plurality of input signals;
a second output signal in the plurality of output signals comprises a current ripple amplitude that scales in accordance with a second input signal in the plurality of input signals; and
the power circuit is further configured to:
determine, in accordance with a first measurement signal and a second measurement signal, a control signal that scales in accordance with a difference between the current ripple amplitude of the first output signal and the current ripple amplitude of the second output signal; and
adjust a voltage of the second input signal in accordance with the control signal.

13. The power circuit of claim 12 , further configured to:
increase a voltage of the second input signal when the current ripple amplitude of the second output signal is less than the current ripple amplitude of the first output signal; and
decrease a voltage of the second input signal when the current ripple amplitude of the second output signal is greater than the current ripple amplitude of the first output signal.

14. The power circuit of claim 13 , wherein:
the plurality of power factor correction stages comprises a master stage configured to output the first input signal, and a slave stage configured to output the second input signal; and
the power circuit is further configured to adjust the voltage of the second input signal by performing one of:
adjusting a switching frequency of the slave stage; and
adjusting a duty cycle of the slave stage.

15. The power circuit of claim 10 , wherein each of the plurality of output signals further comprises a different signal phase.

16. The power circuit of claim 10 , wherein
the plurality of parallel stages comprises an LLC converter,
the LLC converter comprises a resonant tank, and
the resonant tank comprises a resonance capacitor.

17. A power circuit, comprising:
a plurality of parallel stages configured to:
perform DC-DC conversion on a plurality of input signals to obtain a plurality of output signals each having a respective amplitude; and
determine a plurality of measurement signals each in accordance with the respective amplitude of one of the plurality of output signals, wherein the power circuit is configured to adjust, in accordance with the plurality of measurement signals, a respective input voltage of at least one of the plurality of input signals, wherein
the plurality of parallel stages comprises an LLC converter,
the LLC converter comprises a resonant tank,
the resonant tank comprises a resonance capacitor
the resonant tank further comprises a shunt resistor, and
the power circuit is further configured to determine a meas

Assignees

• Infineon Technologies Austria Ag

Inventors

• Kim Tae Yong

Classifications

• H02M1/42

  Circuits or arrangements for compensating for or adjusting power factor in converters or inverters · CPC title

• H02M3/33507 Primary

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title

• H02M2001/0009

  Electricity · mapped topic

• H02M1/4225

  using a non-isolated boost converter · CPC title

• H02M1/0009

  Devices or circuits for detecting current in a converter · CPC title