Electric power conversion device
First Claim
1. An electric power conversion device connected between a direct current power system and an alternating current power system for transferring electric power between the direct current power system and the alternating current power system, said device comprising:
- an alternating current section connected to said alternating current power system;
a direct current section connected to said direct current power system;
a switching section which is connected between said direct current section and said alternating current section and performs power conversion by switching operation; and
a control section for controlling said switching section;
wherein said direct current section is provided with a ripple detection means for detecting a ripple component emerging in a direct current side and for generating a ripple detection signal; and
said control section receives said ripple detection signal from said ripple detection means, generates a direct current component compensation signal for controlling a direct current component included in a current of said alternating current section based on said ripple detection signal, and controls said switching section by a control signal including said direct current component compensation signal to compensate the direct current component included in said alternating current section.
1 Assignment
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Accused Products
Abstract
The electric power conversion device includes an AC section, a DC section, a switching section connected between the AC section and the DC section for making power conversion by switching operation, and a control section for control the switching section. In the DC section is installed a ripple detection device for detecting a ripple component emerging into the DC side and for generating a ripple detection signal. When the DC component is included in the output current of the AC section, a ripple component having the same frequency with the AC frequency of the AC section output current is superimposed in the DC section. The ripple detection device is installed in the DC section, and thereby the ripple component emerging into the DC section is detected by the ripple detection device as a reflection of the DC offset included in the output current. The control section receives the ripple detection signal from the ripple detection device, generates the DC component compensation signal for controlling the DC component included in the AC side current based on the ripple detection signal, and controls the switching section by the control signal including the DC component compensation signal to compensate the DC offset.
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Citations
16 Claims
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1. An electric power conversion device connected between a direct current power system and an alternating current power system for transferring electric power between the direct current power system and the alternating current power system, said device comprising:
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an alternating current section connected to said alternating current power system; a direct current section connected to said direct current power system; a switching section which is connected between said direct current section and said alternating current section and performs power conversion by switching operation; and a control section for controlling said switching section; wherein said direct current section is provided with a ripple detection means for detecting a ripple component emerging in a direct current side and for generating a ripple detection signal; and said control section receives said ripple detection signal from said ripple detection means, generates a direct current component compensation signal for controlling a direct current component included in a current of said alternating current section based on said ripple detection signal, and controls said switching section by a control signal including said direct current component compensation signal to compensate the direct current component included in said alternating current section. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An electric power conversion device connected to an alternating current power source to use it, said device comprising:
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an electronic power conversion means provided with a direct current connecting section connected to a direct current power source and an alternating current connecting section connected to an alternating current power source; an output power control means for controlling an output power of said electric power conversion means; a modulator means for operating an alternating current command value based on an output power command signal given by said output power control means and for generating an alternating current command signal; and a current control means for controlling said electric power conversion means based on the current command signal given by said modulator means; said device characterized by further comprising; a current detection means for detecting a current of direct current side of said electric power conversion means; and a direct current component outflow blocking means for detecting a direct current component included in an alternating current output emerging into said alternating current connecting section from a detected current value by said current detection means and for generating a signal for removing or reducing said direct current component. - View Dependent Claims (13, 14, 15, 16)
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Specification