Power converter
AssigneeOMRON Corporation
InventorsTomomi YAMASHITA, Kenji KOBAYASHI, Masao MABUCHI, Satoru IKEMOTO
Life of this patent
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Abstract
A power converter includes a neutral point clamped inverter circuit including a first capacitor and a second capacitor that are connected in series to divide an input direct-current voltage by half. When receiving an instruction to start a single-phase three-wire output control process and finding that a voltage difference between a voltage across the first capacitor and a voltage across the second capacitor exceeds a predetermined threshold, the controller performs a capacitor voltage balancing process for reducing the voltage difference before starting the single-phase three-wire output control process.
Claims9
A power converter, comprising:
- a neutral point clamped inverter circuit including a first capacitor and a second capacitor that are connected in series to divide an input DC voltage by half, a plurality of switching elements, and first to third output terminals;
- and
- a controller configured to perform a single-phase three-wire output control process to cause the inverter circuit to output a first AC voltage from between the first output terminal and the second output terminal and to output a second AC voltage having an inverted polarity from the first AC voltage from between the third output terminal and the second output terminal,
- wherein when receiving an instruction to start the single-phase three-wire output control process and finding that a voltage difference between a voltage across the first capacitor and a voltage across the second capacitor exceeds a predetermined threshold, the controller performs a capacitor voltage balancing process for reducing the voltage difference before starting the single-phase three-wire output control process.
A power converter, comprising:
- a neutral point clamped inverter circuit including a first capacitor and a second capacitor that are connected in series to divide an input DC voltage by half, a plurality of switching elements, and first to third output terminals;
- a DC-DC conversion circuit configured to generate a voltage to be applied across the first capacitor and a voltage to be applied across the second capacitor based on a voltage from a DC power generator, and to independently control the voltage to be applied across the first capacitor and the voltage to be applied across the second capacitor;
- and
- a controller configured to perform a single-phase three-wire output control process to cause the inverter circuit to output a first AC voltage from between the first output terminal and the second output terminal and to output a second AC voltage having an inverted polarity from the first AC voltage from between the third output terminal and the second output terminal, and to control the DC-DC conversion circuit to apply the same voltage across the first capacitor and across the second capacitor.
Dependencies are inferred from the claim text.