INVERTER AND INVERTER DEVICE

• US 20170353127A1
• Filed: 05/30/2017
• Published: 12/07/2017
• Est. Priority Date: 06/07/2016
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kouno, Yuusuke, Morishima, Yoichi
• Granted Patent: US 9,998,029 B2
• Time in Patent Office: Days
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 1/0025 Arrangements for modifying reference values, feedback values or error values in the control loop of a converter
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel

Abstract

According to one embodiment, an inverter including a detector which detects a value of an output voltage and a value of an output current; a command value input unit which is capable of receiving a current command value; a current command value compensating unit which, when the value of the output voltage detected by the detector is equal to or lower than a predetermined value, computes a compensation current value for compensating the current command value; an adder which adds the compensation current value to the current command value and outputs the compensated current command value; and a current controller which computes a voltage command value so that a difference between the compensated current command value and the output current detected by the detector becomes zero.

Claims

1. An inverter comprising:

a detector which detects a value corresponding to an output voltage and a value of an output current;

a command value input unit which is capable of receiving a current command value;

a current command value compensating unit which, when the value of the output voltage detected by the detector is equal to or lower than a predetermined value, computes a compensation current value for compensating the current command value;

an adder which adds the compensation current value to the current command value and outputs the compensated current command value; and

a current controller which computes a voltage command value so that a difference between the compensated current command value and the output current detected by the detector becomes zero.

2. The inverter according to claim 1, wherein the compensation current value increases proportional to a difference between a voltage value detected by the detector and the predetermined value.

3. An inverter device comprising:

a first inverter which performs voltage control so that a load voltage becomes a predetermined value and frequency;

at least one of the inverters of claim 1 which is connected in parallel with the first inverter;

a current detector which detects a value corresponding to a load current supplied to a load from the first inverter and the inverter according to claim 1; and

an upper command device which outputs a value that is obtained by dividing a value detected by the current detector by the number of inverters of claim 1 and the first inverter to the inverter according to claim 1 as a current command value.

4. An inverter device comprising:

a first inverter which performs voltage control so that a load voltage becomes a predetermined value and frequency; and

at least one of the inverters of claim 1 connected in parallel with the first inverter, wherein

the first inverter comprises a voltage controller which computes a current command value of the first inverter based on a voltage command value, and a current controller which computes the voltage command value of the first inverter based on the current command value of the first inverter, wherein

the current command value of the inverter of claim 1 is the current command value of the first inverter output from the voltage controller.