Electric power converter device with control means and process and converting power

1. An electric power converter device with control means for controlling semiconductor stages of the electric power converter, said electric power converter comprising:

rectifying means for receiving an input electric voltage or current and for supplying a DC voltage on intermediate DC voltage lines,

DC voltage filtering means connected to the intermediate lines,

conversion means for converting said DC voltage into output AC voltages, said conversion means having at least two stages connected between said DC voltage lines and outputs,

a common neutral or earth conductor connected between the input and at least one of said outputs,

a common stage comprising electronic power components connected between said intermediate DC voltage lines and said common neutral conductor, and

said control means for controlling said at least two stages of the conversion means and said common stage, said control means comprising processing means, said processing means for outputting an over-modulation control signal for over-modulating at least said common stage of said electric power converter,

wherein said processing means are for receiving control signals corresponding to the at least two stages of the conversion means and said common stage, applying a reference voltage to said control signals, modulating said control signals, and outputting modulated control signals to said at least two stages of the conversion means,

said processing means are for outputting a signal for controlling said common stage, said signal for controlling said common stage being based on said reference voltage and said over-modulation control signal, and

the reference voltage has a value between voltage values of the respective intermediate DC voltage lines.

2. A device according to claim 1 wherein:

the control means control the at least two stages of the conversion means, stages of the rectifying means, and the common stage,

the processing means supply modulation signals for each stage according to signals corresponding to said reference voltage, and

said modulation signals modulate carrier signals of similar characteristics for each stage.

3. A device according to claim 2 wherein the signals corresponding to said reference voltage are the same for each modulated stage of the converter and the carrier signals are the same for each stage of the converter.

4. A device according to claim 2 wherein the over-modulation control signal corresponds to modulation signals of the at least two stages of the conversion means and a modulation signal of the common stage.

5. A device according to claim 4 wherein the processing means are for receiving the over-modulation control signal to process modulation signals of the stages of the rectifying means.

6. A device according to claim 5 wherein the processing means comprise correction means for correcting said over-modulation control signal according to signals corresponding to saturation of first modulation signals of the rectifying means.

7. A device according to claim 6 wherein the correction means are for forecasting saturation values and reducing a signal corresponding to the over-modulation control signal according to said saturation values.

8. An electric power converter comprising:

rectifying means for receiving an electric voltage or current on inputs and supplying a DC voltage to intermediate DC voltage lines,

DC voltage filtering means connected to the intermediate lines,

conversion means for converting said DC voltage into output AC voltages and having at least two stages connected between said DC voltage lines and outputs,

a common neutral conductor, ground or earth connection between an input and an output,

a common stage having electronic power components connected between said intermediate DC voltage lines and the common connection,

control means for controlling the at least two stages of said conversion means and said common stage, and comprising processing means for supplying modulated signals to said at least two stages of said conversion means and said common stage, wherein said processing means are for over-modulating at least one of said modulated signals to the at least two stages of said conversion means and to said common stage.

9. A converter according to claim 8 , wherein the modulated signals supplied from the processing means to the at least two stages of the conversion means and to the common stage correspond to voltages different from the respective input voltages of the rectifying means.

10. A converter according to claim 8 , wherein the modulated signals supplied to the at least two stages of the conversion means and to the common stage have a different fundamental frequency from the fundamental frequency of the input voltage signal of the rectifying means.

11. A converter according to claim 8 , wherein the modulated signals supplied to the at least two stages of the conversion means and to the common stage have different phases from the phases of the input voltage of the rectifying means.

12. A converter according to claim 8 , wherein said control means control the at least two stages of said conversion means and the stages of the rectifying means in reversible manner, such that outputs to a load become power inputs, the conversion means become rectifying means, and the inputs become outputs to supply AC electric power.

13. A control process of an electric power convener comprising:

receiving an electric input voltage or current at a rectifying means,

rectifying said electric input voltage or current with said rectifying means,

supplying a DC voltage from said rectifying means to intermediate DC voltage lines,

filtering such DC voltage with a DC voltage filtering means connected to the intermediate lines,

converting such DC voltage into output AC voltages with a conversion means having at least two stages connected between said intermediate DC voltage lines and outputs,

connecting a common neutral conductor, ground, or earth connection between an input and an output,

connecting a common stage between said intermediate DC voltage lines and the common neutral conductor, ground, or earth connection, said common stage comprising electronic power components,

controlling the at least two stages of the conversion means with control means, said control means comprising processing means, and

supplying modulated signals of control signals of the at least two stages of the conversion means and of the common stage,

said process of the processing means comprising:

determining first modulation signals for controlling the at least two stages of the conversion means,

applying a reference voltage to a modulation signal of the common stage and to modulation signals for controlling the at least two stages of the conversion means,

determining an over-modulation control signal value,

generating an over-modulation control signal, and

applying said over-modulation control signal to said common stage modulation signal and to modulation signals for controlling the at least two stages of the conversion means.

14. The process according to claim 13 comprising: applying a reference voltage and the over-modulation control signal to modulation signals for controlling stages of the rectifying means.

15. The process according to claim 14 comprising:

detecting saturation of modulation signals for controlling stages of the rectifying means, and

correcting the over-modulation control signal value according to the detection of saturation of the modulation signals of stages of the rectifying means.