Carrier phase control for polyphase rectifier or inverter

1 . A method for controlling a converter, the method comprising:

obtaining voltage signals indicating phase voltages of three phases at an AC side of the converter;

determining, based on the voltage signals, carrier signals of three-phase switching branches of the converter, wherein carrier signals of two of the three phases have the same phase with each other and have a different phase from a carrier signal of the remaining phase of the three phases, and wherein a magnitude of a phase voltage of the remaining phase is between the phase voltages of the two of the three phases; and

generating, based on the determined carrier signals and modulation wave signals of the three-phase switching branches, control signals of the three-phase switching branches,

wherein determining, based on the voltage signals, the carrier signals of the three-phase switching branches of the converter comprises:

for a switching branch of each phase:

in response to the phase voltage corresponding to the switching branch of this phase among the phase voltages of the three phases declining, determining a first carrier signal as a carrier signal of the switching branch of this phase; or

in response to the phase voltage corresponding to the switching branch of this phase not declining, determining a second carrier signal as the carrier signal of the switching branch of this phase, wherein the second carrier signal and the first carrier signal are in different phases with respect to each other.

2 . The method of claim 1 , wherein a difference between the phase of the carrier signals of the two of the three phases and the phase of the carrier signal of the remaining phase is within a range from 150 degrees to 210 degrees.

3 . The method of claim 2 , wherein the difference between the phase of the carrier signals of the two of the three phases and the phase of the carrier signal of the remaining phase is 180 degrees.

4 . The method of claim 1 , wherein the voltage signals indicating the phase voltages of the three phases include modulation wave signals of the three-phase switching branches.

5 . The method of claim 1 , wherein the voltage signals indicating the phase voltages of the three phases include sensing signals of AC-side supply voltage of the converter.

6 . The method of claim 1 , wherein the converter is a rectifier and wherein the modulation wave signals are determined based on a DC side voltage, an AC side supply voltage, and an AC side inductive current of the rectifier.

7 . The method of claim 1 , wherein generating, based on the determined carrier signals and the modulation wave signals of the three-phase switching branches, the control signals of the three-phase switching branches comprises:

generating, based on a comparison between the determined carrier signals and the modulation wave signals, pulse-width modulated signals as the control signals of the three-phase switching branches.

8 . A converter system comprising:

a converter; and

a control device for controlling the converter, wherein the control device is configured to:

obtain voltage signals indicating phase voltages of three phases at an AC side of the converter;

determine, based on the voltage signals, carrier signals of three-phase switching branches of the converter, wherein carrier signals of two of the three phases have the same phase with each other and have a different phase from a carrier signal of the remaining phase of the three phases, and wherein magnitude of a phase voltage of the rest phase is between the phase voltages of the two of the three phases; and

generate, based on the determined carrier signals and modulation wave signals of the three-phase switching branches, control signals of the three-phase switching branches,

wherein determining, based on the voltage signals, the carrier signals of the three-phase switching branches of the converter comprises:

for a switching branch of each phase:

in response to a phase voltage corresponding to the switching branch of this phase among the phase voltages of the three phases declining, determining a first carrier signal as a carrier signal of the switching branch of this phase; or

in response to the phase voltage corresponding to the switching branch of this phase not declining, determining a second carrier signal as the carrier signal of the switching branch of this phase, wherein the second carrier signal and the first carrier signal are in different phases with respect to each other.

9 . The converter system of claim 8 , wherein a difference between the phase of the carrier signals of the two of the three phases and the phase of the carrier signal of the remaining phase is within a range from 150 degrees to 210 degrees.

10 . The converter system of claim 9 , wherein the difference between the phase of the carrier signals of the two of the three phases and the phase of the carrier signal of the remaining phase is 180 degrees.

11 . The converter system of claim 8 , wherein the voltage signals indicating the phase voltages of the three phases include modulation wave signals of the three-phase switching branches.

12 . The converter system of claim 8 , wherein the voltage signals indicating the phase voltages of the three phases include sensing signals of AC-side supply voltage of the converter.

13 . The converter system of claim 8 , wherein the converter is a rectifier and wherein the modulation wave signals are determined based on a DC side voltage, an AC side supply voltage, and an AC side inductive current of the rectifier.

14 . The converter system of claim 8 , wherein generating, based on the determined carrier signals and the modulation wave signals of the three-phase switching branches, the control signals of the three-phase switching branches comprises:

generating, based on a comparison between the determined carrier signals and the modulation wave signals, pulse-width modulated signals as the control signals of the three-phase switching branches.

15 . A method for controlling a converter, the method comprising:

obtaining voltage signals indicating phase voltages of three phases at an AC side of the converter;

determining, based on the voltage signals, carrier signals of three-phase switching branches of the converter, wherein carrier signals of two of the three phases have the same phase with each other and have a different phase from a carrier signal of the remaining phase of the three phases, and wherein a magnitude of a phase voltage of the remaining phase is between the phase voltages of the two of the three phases; and

generating, based on the determined carrier signals and modulation wave signals of the three-phase switching branches, control signals of the three-phase switching branches,

wherein determining, based on the voltage signals, the carrier signals of the three-phase switching branches of the converter comprises:

comparing, based on the voltage signals, phase voltages of the three phases; and

for a first phase switching branch:

in response to a phase voltage of a second phase being greater than that of a third phase, determining a first carrier signal as a carrier signal of the first phase switching branch; or

in response to the phase voltage of the second phase being no greater than that of the third phase, determining a second carrier signal as the carrier signal of the first phase switching branch, wherein the second carrier signal and the first carrier signal are in different phases with respect to each other;

for a second phase switching branch:

in response to the phase voltage of the third phase being greater than that of a first phase, determining the first carrier signal as a carrier signal of the second phase switching branch; or

in response to the phase voltage of the third phase being no greater than that of the first phase, determining the second carrier signal as the carrier signal of the second phase switching branch;

for a third phase switching branch:

in response to the phase voltage of the first phase being greater than that of the second phase, determining the first carrier signal as a carrier signal of the third phase switching branch; or

in response to the phase voltage of the first phase being no greater than that of the second phase, determining the second carrier signal as the carrier signal of the third phase switching branch.

16 . The method of claim 15 , wherein a difference between the phase of the carrier signals of the two of the three phases and the phase of the carrier signal of the remaining phase is within a range from 150 degrees to 210 degrees.

17 . A converter system comprising:

a converter; and

a control device for controlling the converter, wherein the control device is configured to:

obtain voltage signals indicating phase voltages of three phases at an AC side of the converter;

determine, based on the voltage signals, carrier signals of three-phase switching branches of the converter, wherein carrier signals of two of the three phases have the same phase with each other and have a different phase from a carrier signal of the remaining phase of the three phases, and wherein magnitude of a phase voltage of the rest phase is between the phase voltages of the two of the three phases; and

generate, based on the determined carrier signals and modulation wave signals of the three-phase switching branches, control signals of the three-phase switching branches,

wherein determining, based on the voltage signals, the carrier signals of the three-phase switching branches of the converter comprises:

comparing, based on the voltage signals, phase voltages of the three phases; and

for a first phase switching branch:

in response to a phase voltage of a second phase being greater than that of a third phase, determining a first carrier signal as a carrier signal of the first phase switching branch; or

in response to the phase voltage of the second phase being no greater than that of the third phase, determining a second carrier signal as the carrier signal of the first phase switching branch, wherein the second carrier signal and the first carrier signal are in different phases with respect to each other;

for a second phase switching branch:

in response to the phase voltage of the third phase being greater than that of a first phase, determining the first carrier signal as a carrier signal of the second phase switching branch; or

in response to the phase voltage of the third phase being no greater than that of the first phase, determining the second carrier signal as the carrier signal of the second phase switching branch;

for a third phase switching branch:

in response to the phase voltage of the first phase being greater than that of the second phase, determining the first carrier signal as the carrier signal of the third phase switching branch; or

in response to the phase voltage of the first phase being no greater than that of the second phase, determining the second carrier signal as the carrier signal of the third phase switching branch.

18 . The converter system of claim 17 , wherein a difference between the phase of the carrier signals of the two of the three phases and the phase of the carrier signal of the remaining phase is within a range from 150 degrees to 210 degrees.