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Three-level power conversion device

A power conversion device, three-level technology, applied in the direction of output power conversion device, motor generator control, electrical components, etc., to achieve the effect of suppressing fluctuations

Active Publication Date: 2016-08-24
TOSHIBA MITSUBISHI-ELECTRIC IND SYST CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this three-level power conversion device, it is configured to have three levels of DC voltages: positive potential, negative potential, and neutral point. If the potential of the neutral point fluctuates, the voltage of the AC power source and the motor as a load fluctuates. , resulting in unwanted higher harmonics

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0022] figure 1 It is a circuit configuration diagram of the three-level power conversion device according to Embodiment 1 of the present invention. Three-level converters 2A, 2B are supplied with AC voltages from an AC power supply system via transformers 1A, 1B, respectively. The respective three-level DC outputs of the three-level converters 2A and 2B are connected in parallel with each other, a DC capacitor 3P is connected between the positive potential terminal and the neutral potential terminal for smoothing, and between the negative potential terminal and the neutral potential terminal A DC capacitor 3N is connected between them for smoothing. Then, the three-level DC output is supplied to the three-level inverter 4 , and the three-level inverter 4 outputs a three-level AC voltage to drive the AC motor 5 .

[0023] A speed detector 6 is attached to the AC motor 5, and a current detector 7 is attached to the input side of the AC motor 5, and their output signals are su...

Embodiment 2

[0031] figure 2 It is a circuit configuration diagram of a three-level power conversion device according to Embodiment 2 of the present invention. For each part of this embodiment 2, the same symbols are used to represent and figure 1 The description of the parts that are the same as those of the three-level power conversion device according to Embodiment 1 of the present invention will be omitted. This second embodiment differs from the first embodiment in that the circulating current correction circuit 13 is moved from the output side of the voltage controller 12 to the output side of the current controllers 15A, 15B in the converter control unit 10a.

[0032] As described in Embodiment 1, the respective outputs of the current controllers 15A and 15B are the q-axis voltage reference and the d-axis voltage reference. In this Embodiment 2, the circulating current correction circuit 13 corrects the q-axis voltage reference as the active energy. Therefore, the meaning of the...

Embodiment 3

[0035] image 3 It is a circuit configuration diagram of a three-level power conversion device according to Embodiment 3 of the present invention. For each part of this embodiment 3, the same symbols are used to represent and figure 1 The description of the parts that are the same as those of the three-level power conversion device according to Embodiment 1 of the present invention will be omitted. The difference between Embodiment 3 and Embodiment 1 is that the three-level inverter is set as a parallel structure of three-level inverters 4A, 4B, and the AC motor 5 is driven through the coupling reactor 9; 10b is a structure in which the circulating current correction circuit 13 is omitted; clearly shows the inverter control unit 30 .

[0036] The three-level inverter 4A is supplied with a three-level DC voltage from the three-level converter 2A via the DC capacitors 3AP and 3AN, and the three-level inverter 4B is supplied with a three-level DC voltage from the three-level conv...

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PUM

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Abstract

Provided is a three-level power converter capable of suppressing fluctuations in neutral point potential even when operating as a reactive power regulator. It is composed of the following parts: first and second three-level converters (2A, 2B) connected to the AC power system; DC capacitors (3P, 3N) on the positive and negative sides; a flat inverter (4); and a converter control unit (10) controlling the three-level converters (2A, 2B). The converter control unit (10) has first and second reactive current control units (15A) that control the reactive amounts of the input currents of the three-level converters (2A, 2B) to become predetermined reactive current references, respectively. , 15B); control the PWM control unit (17A, 17B) so that the difference in the voltage applied to the DC capacitor (3P, 3N) is zero, the first and second neutral point potential fluctuation suppression unit; and from the three-level converter (2A) An active current control unit for passing a predetermined circulating active current to the three-level converter (2B).

Description

[0001] Citations for Associated Applications [0002] This application is based on and claims the benefit of priority based on Japanese Patent Application No. 2012-002911 filed on January 11, 2012, the entire contents of which are hereby incorporated by reference. technical field [0003] The present invention relates to a three-level power conversion device including a three-level converter for obtaining a three-level direct current from an alternating current power supply, and a three-level inverter for converting the direct current into an alternating current. Background technique [0004] Conventionally, a three-level power conversion device including a three-level converter and a three-level inverter for converting the output direct current to alternating current has been used as a power conversion device for driving a relatively large-capacity motor or the like. In this three-level power conversion device, it is configured to have three levels of DC voltages: positive ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02M5/458H02M7/487
CPCH02M7/487H02M5/4585H02P27/14H02P2201/01
Inventor 织田健志福间胜彦
Owner TOSHIBA MITSUBISHI-ELECTRIC IND SYST CORP