Back to results
US 6,747,884 B2Granted
Power converter device
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsYuji Nishizawa, Akira Hatai, Kei Terada
Life of this patent
Estimating the term…
Abstract
The present invention provides a variable-speed control system which is capable of estimating saturation voltages of respective switching elements in the inverter operation to execute the saturation voltage compensation and thus getting an inverter output voltage indicated by a command value.
Claims14
A power converter device comprising:
- an inverter portion having a switching element and a free wheeling diode element, the inverter portion for converting a DC power into an AC power;
- a control portion for ON/OFF-controlling the switching elements of the inverter portion;
- and
- a current sensor for sensing current flowing through one of the switching element and the free wheeling diode element,
- wherein the control portion comprises:
- a current discriminating circuit for discriminating that sensed currents sensed by the current sensors are either current flowing through the switching elements or current flowing through the free wheeling diode elements;
- a saturation voltage estimation table for showing relationships between temperature of the switching element, current value of the switching element, temperature of the free wheeling element, and current value of the free wheeling element and saturation voltages of the switching elements;
- and
- a saturation voltage compensating unit for receiving the temperature of the switching element and the current discriminated by the current discriminating circuit, estimating a saturation voltage of the switching element by using the saturation voltage estimation table, and forming saturation voltage compensated voltage in which a command voltage to an inverter is compensated with the estimated saturation voltage, and
- wherein the switching elements of the inverter portion are ON/OFF-controlled based on the saturation voltage compensated voltage.
7 more elements
A power converter device comprising:
- an inverter portion having a switching element and a free wheeling diode element, the inverter portion for converting a DC power into an AC power;
- a control portion for ON/OFF-controlling the switching elements of the inverter portion;
- and
- a gate voltage detecting circuit insulating circuit for detecting gate voltage of the switching element,
- wherein the control portion comprises:
- a current discriminating circuit for discriminating that sensed currents sensed by the current sensors are either current flowing through the switching elements or current flowing through the free wheeling diode elements;
- a saturation voltage estimation table for showing relationships between temperature of the switching element, current value of the switching element, temperature of the free wheeling element, and current value of the free wheeling element and saturation voltages of the switching elements;
- and
- a saturation voltage compensating unit for receiving the gate voltage of the switching element and the current discriminated by the current discriminating circuit, estimating a saturation voltage of the switching element by using the saturation voltage estimation table, and forming saturation voltage compensated voltage in which a command voltage to an inverter is compensated with the estimated saturation voltage, and
- wherein the switching elements of the inverter portion are ON/OFF-controlled based on the saturation voltage compensated voltage.
7 more elements
Dependencies are inferred from the claim text.