US 10,320,310 B2Granted

Power conversion device

AssigneeMitsubishi Electric Corporation

InventorsTakahiro Kato, Kikuo Izumi

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Abstract

A power conversion device includes: a power conversion unit composed of a power conversion circuit having switching elements, an output current measurement unit, an output voltage measurement unit, and reactor; a voltage command generating unit for generating a voltage command; a dead time correction unit for calculating a dead time correction amount for correcting voltage error, between the voltage command and output voltage, caused due to dead time; and a PWM signal generating unit for generating switching signals according to the voltage command and the dead time correction amount, wherein the dead time correction unit calculates the dead time correction amount from the voltage command, the measured output voltage, and the measured output current.

Claims18

Dependent claims

A power conversion device comprising:

power conversion circuitry including:
a power conversion circuit which has a switching element and converts DC power of DC power supply to AC power;
an output current measurement unit for measuring output current of the power conversion circuit;
an output voltage measurement unit for measuring output voltage of the power conversion circuit;
and a reactor which, one of terminals of the reactor being connected to an output side of the power conversion circuit, suppresses a harmonic;
and
control circuitry including:
a voltage command generating unit for generating a voltage command for controlling the switching element;
a dead time correction unit for calculating a dead time correction amount for correcting voltage error, between the voltage command and the output voltage, caused due to dead time for preventing short-circuit of the switching element;
an addition unit for adding the dead time correction amount to the voltage command;
and a PWM signal generating unit for generating a switching signal according to output of the addition unit, wherein
the dead time correction unit estimates reactor voltage from the voltage command, measured output voltage measured by the output voltage measurement unit, and DC output voltage of the DC power supply,
calculates output current value at the time when the switching element changes from ON to OFF from the estimated reactor voltage, a carrier cycle for PWM signal generation of the PWM signal generating unit, and measured output current by the output current measurement unit,
estimates zero current cross time of the output current from the calculated output current value at the time when the switching element changes from ON to OFF and the dead time period, and
calculates the dead time correction amount from the zero current cross time, the calculated output current value at the time when the switching element changes from ON to OFF, the DC output voltage, the carrier cycle, and the dead time period on the assumption that change in the output current is linear with respect to time.

12 more elements

A power conversion device comprising:

power conversion circuitry including:
a power conversion circuit which has a switching element and converts DC power to AC power;
an output current measurement unit for measuring output current of the power conversion circuit;
an output voltage measurement unit for measuring output voltage of the power conversion circuit;
and a reactor which, one of terminals of the reactor being connected to an output side of the power conversion circuit, suppresses a harmonic;
and
control circuitry including:
a voltage command generating unit for generating a voltage command for controlling the switching element;
a dead time correction unit for calculating a dead time correction amount for correcting voltage error, between the voltage command and the output voltage, caused due to dead time for preventing short-circuit of the switching element;
an addition unit for adding the dead time correction amount to the voltage command;
and a PWM signal generating unit for generating a switching signal according to output of the addition unit, wherein
the dead time correction unit estimates reactor voltage from the voltage command, and measured output voltage measured by the output voltage measurement unit, estimates an output current change amount of the output current from the estimated reactor voltage and the measured output current by the output current measurement unit, and
calculates the dead time correction amount on the basis of the estimated output current change amount.

10 more elements

A power conversion device comprising:

power conversion circuitry including:
a power conversion circuit which has a switching element and converts DC power of DC power supply to AC power;
an output current measurement unit for measuring output current of the power conversion circuit;
an output voltage measurement unit for measuring output voltage of the power conversion circuit;
and a reactor which, one of terminals of the reactor being connected to an output side of the power conversion circuit, suppresses a harmonic;
and
control circuitry including:
a voltage command generating unit for generating a voltage command for controlling the switching element;
a dead time correction unit for calculating a dead time correction amount for correcting voltage error, between the voltage command and the output voltage, caused due to dead time for preventing short-circuit of the switching element;
an addition unit for adding the dead time correction amount to the voltage command;
and a PWM signal generating unit for generating a switching signal according to output of the addition unit, wherein
the dead time correction unit estimates reactor voltage from the voltage command, and measured output voltage measured by the output voltage measurement unit, estimates a zero current cross time of the output current and an output current change amount of the output current from the estimated reactor voltage and the measured output current measured by the output current measurement unit, and DC output voltage of the DC power supply, and
calculates the dead time correction amount on the basis of the estimated zero current cross time and the estimated output current change amount.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/316,944Filed 24 Jun 2014
Published: US 2017/0117821 A127 Apr 2017
Granted: 11 Jun 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H02M 7/537
Using devices of a triode or transistor type requiring continuous application of a control signal: using semiconductor devices only, e.g. single…
H02M 1/08
Details of apparatus for conversion: circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in…
H02M 1/12
Details of apparatus for conversion: arrangements for reducing harmonics from AC input or output
H02M 1/38
Details of apparatus for conversion: means for preventing simultaneous conduction of switches

Family

US 2017/0117821 A1Pre-grant publication · published 27 Apr 2017
US 10,320,310 B2This patent

From the US filing history. Foreign family members aren’t listed.

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