Semiconductor static electric power converter optimized for operation in zero-voltage mode
First Claim
1. A method of controlling a semiconductor static electric power converter, connected to a load and to a DC voltage source E forming a DC voltage input, operating with soft switching in a zero-voltage mode and controlled with pulse width modulation, said converter including converter means having at least one branch of controllable bidirectional current switches that switch in a zero-voltage mode, having an input and having a midpoint connected to the load, said converter further including, in series between said DC voltage input and said converter means, an interface comprising an inductor having a ripple current flowing therethrough, a capacitor connected in parallel with said inductor and having a voltage kE thereacross so that at least one branch has an input terminal voltage window of amplitude (1+k)E, an auxiliary controllable bidirectional current switch that switches in a zero-voltage mode, and control means for said switches providing that:
- when the ripple current through the inductor of said interface is equal to a minimum value relative to a mean value thereof, the input terminal voltage window of amplitude (1+k)E of the at least one branch of the converter is interrupted by switching off the auxiliary controllable switch so as to enable the controllable bidirectional current switches of the at least one converter branch to trigger under zero voltage; and
when the current flowing through the inductor of said interface is equal to a maximum value relative to said mean value, a short circuit stage provided by the at least one branch is interrupted and generating of the voltage window of amplitude (1+k)E is initiated by switching off one of said controllable bidirectional current switches in the at least one branch, thereby enabling the auxiliary controllable switch of the interface to be triggered under zero voltage;
said method further comprising;
immediately before the end of the voltage window of amplitude (1+k)E, a positive current is caused to flow through the auxiliary controllable switch so as to compensate, at least in part, for current flow at said input of the converter means, said current flow being negative when the ripple current in the inductor is equal to said minimum value, so as to reduce in amplitude the ripple current required for switching off said auxiliary controllable switch; and
immediately before said short circuit stage ends, a positive current is caused to flow through the controllable switches of the at least one branch of the converter means when the ripple current in the inductor is equal to said maximum value;
thereby reducing in amplitude the ripple current required in said inductor for enabling the auxiliary controllable switch and the controllable switches of the at least one branch of the converter means to operate in said zero-voltage mode.
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Accused Products
Abstract
The invention relates to static electric power conversion using semiconductors using soft switching in zero-voltage mode and controlled to perform pulse width modulation, having a first interface (L, C, Ta, Da) in series between a DC voltage input (E) and a converter (1), and with a second interface (2) connected to the connection between the first interface and the converter (1) and organized, immediately before the end of a voltage window of amplitude (1+k)E to cause a positive current to flow through the switch (Ta,Dd) to counter the input current of the converter (1) which is negative when the ripple current flowing through the inductor is at its minimum value so as to reduce the current ripple amplitude required for switching off the switch (Ta, Da), thereby reducing the current ripple for controlling interruption of the short circuit provided by the branch(es) of the converter (1).
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Citations
11 Claims
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1. A method of controlling a semiconductor static electric power converter, connected to a load and to a DC voltage source E forming a DC voltage input, operating with soft switching in a zero-voltage mode and controlled with pulse width modulation, said converter including converter means having at least one branch of controllable bidirectional current switches that switch in a zero-voltage mode, having an input and having a midpoint connected to the load, said converter further including, in series between said DC voltage input and said converter means, an interface comprising an inductor having a ripple current flowing therethrough, a capacitor connected in parallel with said inductor and having a voltage kE thereacross so that at least one branch has an input terminal voltage window of amplitude (1+k)E, an auxiliary controllable bidirectional current switch that switches in a zero-voltage mode, and control means for said switches providing that:
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when the ripple current through the inductor of said interface is equal to a minimum value relative to a mean value thereof, the input terminal voltage window of amplitude (1+k)E of the at least one branch of the converter is interrupted by switching off the auxiliary controllable switch so as to enable the controllable bidirectional current switches of the at least one converter branch to trigger under zero voltage; and when the current flowing through the inductor of said interface is equal to a maximum value relative to said mean value, a short circuit stage provided by the at least one branch is interrupted and generating of the voltage window of amplitude (1+k)E is initiated by switching off one of said controllable bidirectional current switches in the at least one branch, thereby enabling the auxiliary controllable switch of the interface to be triggered under zero voltage; said method further comprising; immediately before the end of the voltage window of amplitude (1+k)E, a positive current is caused to flow through the auxiliary controllable switch so as to compensate, at least in part, for current flow at said input of the converter means, said current flow being negative when the ripple current in the inductor is equal to said minimum value, so as to reduce in amplitude the ripple current required for switching off said auxiliary controllable switch; and immediately before said short circuit stage ends, a positive current is caused to flow through the controllable switches of the at least one branch of the converter means when the ripple current in the inductor is equal to said maximum value; thereby reducing in amplitude the ripple current required in said inductor for enabling the auxiliary controllable switch and the controllable switches of the at least one branch of the converter means to operate in said zero-voltage mode. - View Dependent Claims (2, 3, 4)
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5. A semiconductor static electric power converter connected to a load and to a DC voltage source E forming a DC voltage input, and operating with soft switching in zero-voltage mode and controlled by pulse width modulation, said converter including converter means having at least one branch of controllable bidirectional current switches that switch in a zero-voltage mode, said at least one branch having an input and having a midpoint connected to the load, said converter also including, in series between said DC voltage input and said converter means, an interface comprising an inductor having a ripple current flowing therethrough and, a capacitor connected in parallel with said inductor and having a voltage kE thereacross so that the at least one branch has an input terminal voltage window of amplitude (1+k)E and an auxiliary controllable bidirectional current switch that switches in a zero-voltage mode, and control means for said switches providing that:
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when the ripple current through the inductor of said interface is equal to a minimum value relative to a mean value thereof, said input terminal voltage window of amplitude (1+k) E the at least one branch of the converter is interrupted by switching off the auxiliary switch so as to enable the switches of the at least one branch to trigger under zero-voltage; and when the current flowing through the inductor of said interface is equal to a maximum value relative to said mean value, a short circuit stage provided by the at least one branch is interrupted and generation of the voltage window of amplitude (1+k)E is initiated by switching off one of the controllable switches in the at least one branch, thereby enabling the auxiliary controllable switch of the interface to be triggered under zero-voltage; said converter further including a second interface connected to a point where the first interface is connected to the converter means, said second interface including means for, immediately before termination of the voltage window of amplitude (1+k)E, causing a positive current to pass through the auxiliary controllable switch for countering, at least in part, current at the input of the converter means which is negative when the ripple current in the inductor is equal to said minimum value, thereby reducing the current ripple amplitude required for switching off said auxiliary controllable switch, and said second interface reducing the ripple current required for controlling interruption of said short circuit stage provided by the at least one converter branch. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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Specification