Matrix converter

Patent metadata

Field	Value
Publication number	US-9543851-B2
Application number	US-201414514390-A
Country	US
Kind code	B2
Filing date	Oct 15, 2014
Priority date	Oct 24, 2013
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A matrix converter includes: a power converter configured to couple an AC power supply and a load together; and a controller configured to selectively execute: a first control mode in which the controller is configured to perform power conversion between the AC power supply and the load; and a second control mode in which the controller is configured to directly combine the AC power supply with the load. The controller is configured to: increase the output voltage and cause a phase of the output voltage follow up a voltage phase of the AC power supply in a case where a difference between a frequency of an output voltage from the power converter to the load and a frequency of the AC power supply becomes within a predetermined range.

First claim

What is claimed is:

1. A matrix converter, comprising:
a power converter that includes a plurality of bidirectional switches configured to couple respective phases of an AC power supply and respective phases of a load together; and
a controller configured to selectively execute:
a first control mode in which the controller is configured to perform power conversion between the AC power supply and the load by performing a PWM control on the plurality of bidirectional switches; and
a second control mode in which the controller is configured to directly combine the AC power supply with the load by controlling the plurality of bidirectional switches, wherein

the controller is configured to:
perform a voltage increase control and a follow-up control in response to a determination that a difference between a frequency of an output voltage from the power converter to the load and a frequency of the AC power supply is within a predetermined range, the voltage increase control increasing the output voltage, the follow-up control causing a phase of the output voltage to follow a voltage phase of the AC power supply; and
make a transition of a mode for driving the plurality of bidirectional switches from the first control mode to the second control mode in a case where the voltage increase control and the follow-up control terminate.

2. A matrix converter comprising:
a power converter that includes a plurality of bidirectional switches configured to couple respective phases of an AC power supply and respective phases of a load together; and
a controller configured to selectively execute:
a first control mode in which the controller is configured to perform power conversion between the AC power supply and the load by performing a PWM control on the plurality of bidirectional switches; and
a second control mode in which the controller is configured to directly combine the AC power supply with the load by controlling the plurality of bidirectional switches, wherein

the controller is configured to:
perform a voltage increase control and a follow-up control in a case where a difference between a frequency of an output voltage from the power converter to the load and a frequency of the AC power supply becomes within a predetermined range, the voltage increase control increasing the output voltage, the follow-up control causing a phase of the output voltage to follow a voltage phase of the AC power supply; and

make a transition of a mode for driving the plurality of bidirectional switches from the first control mode to the second control mode in a case where the voltage increase control and the follow-up control terminate, wherein
the controller further includes:
a frequency determiner configured to output a frequency coincidence signal in a case where the difference between the frequency of the output voltage and the frequency of the AC power supply is within the predetermined range;
a voltage-limitation controller configured to perform the voltage increase control in a case where the frequency coincidence signal is output from the frequency determiner;
a voltage determiner configured to output a voltage coincidence signal in a case where a difference between an amplitude of the output voltage and a voltage amplitude of the AC power supply is within a predetermined range;
a phase operator configured to perform the follow-up control in a case where the frequency coincidence signal is output from the frequency determiner;
a phase determiner configured to output a phase coincidence signal in a case where a difference between the phase of the output voltage and the voltage phase of the AC power supply is within a predetermined range; and
a switch driver configured to make a transition of the mode for driving the plurality of bidirectional switches from the first control mode to the second control mode in a case where the matrix converter outputs the voltage coincidence signal and outputs the phase coincidence signal.

3. The matrix converter according to claim 2 , wherein
the controller further includes a mode-switching determination device configured to output a mode switching signal in a case where a difference between the phase of the output voltage and nπ/6 (n is one or more integers from 1 to 12) is within a predetermined range in a state where the matrix converter outputs the frequency coincidence signal, the voltage coincidence signal, and the phase coincidence signal, and
the switch driver is configured to make a transition of the mode for driving the plurality of bidirectional switches from the first control mode to the second control mode at a time when the mode switching signal is output from the mode-switching determination device.

4. The matrix converter according to claim 2 , wherein
the phase operator is configured to terminate the follow-up control after termination of the voltage increase control by the voltage-limitation controller.

5. The matrix converter according to claim 2 , wherein
the controller further includes:
a frequency-command generation device configured to generate a frequency command such that the frequency of the output voltage approaches a set frequency as time passes; and
a voltage-command generator configured to generate a voltage command for controlling the output voltage based on the frequency command, and

the switch driver is configured to perform the PWM control based on the voltage command.

6. The matrix converter according to claim 5 , wherein
the voltage-limitation controller includes:
a limiter configured to limit a magnitude of the voltage command; and
a voltage-limitation remover configured to remove limitation on the voltage command by the limiter in phases in a case where the frequency coincidence signal is output from the frequency determiner.

7. The matrix converter according to claim 5 , wherein
the frequency determiner is configured to output the frequency coincidence signal in a case where the difference between the frequency of the AC power supply and the frequency of the output voltage is within the predetermined range and a difference between the frequency command and the frequency of the AC power supply is within a predetermined range.

8. The matrix converter according to claim 5 , wherein
the phase operator includes:
a virtual phase operator configured to configured to compute a virtual phase of the output voltage so as to reduce the difference between the voltage phase of the AC power supply and the phase of the output voltage;
a compensation-value operator configured to compute a phase compensation value by adding the frequency of the AC power supply and the frequency command while changing ratios of the frequency of the AC power supply and the frequency command such that the ratio of the frequency of the AC power supply increases as time passes; and
a phase compensator configured to calculate the phase of the output voltage by adding the phase compensation value to the virtual phase, and

the switch driver is configured to perform the PWM control based on the voltage command output from the voltage-command generator and the phase of the output voltage calculated by the phase operator.

9. The matrix converter according to claim 8 , wherein
the controller further includes a phase detector configured to detect the voltage phase of the AC power supply, wherein
the phase operator includes:
a phase replacer configured to replace a rotation direction of the voltage phase of the AC power supply by a predetermined direction and output a result of the replacement to the virtual phase operator in a case where the rotation direction of the voltage phase of the AC power supply output from the phase detector is not the predetermined direction; and
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Assignees

• Yaskawa Electric Corp

Inventors

• Ebisu Joji
• Yamazaki Akira

Classifications

• H02M5/293 Primary

  using semiconductor devices only · CPC title

• Y02B70/1491

  Cross-Sectional Technologies · mapped topic

• H02M2001/0054

  Electricity · mapped topic

• H02M1/00 Primary

  Details of apparatus for conversion · CPC title

• H02M2005/2932

  Electricity · mapped topic