DC voltage compensation method of parallel hybrid multi-level inverter
A multi-level converter, DC voltage technology, applied in the field of DC voltage compensation, can solve problems such as abnormal operation, DC voltage drop, DC voltage fluctuation, etc., to achieve system AC fault ride-through and solve the problem of DC voltage fluctuation. Effect
Active Publication Date: 2016-03-02
STATE GRID CORP OF CHINA +2
View PDF6 Cites 3 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0007] However, the AC-DC side voltage of the new topology is seriously coupled, which causes the DC voltage of the flexible DC system to change with different working conditions, especially when the AC system fails, the DC voltage of the converter drops sharply , can not operate normally, which is contrary to the operation requirements of the flexible DC system, that is, the stable DC voltage and the AC fault ride-through capability
[0008] US2012 / 0069610A1 discloses this topology, but does not give the corresponding DC voltage compensation mechanism. In the article "ALowLossModularMultilevelVoltageSourceConverterforHVDCPowerTransmissionandReactivePowerCompensation", a voltage compensation method based on third harmonic voltage injection is proposed, but this method cannot address system failures , especially for voltage dips under asymmetrical faults
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0027] The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.
[0028] The invention provides a DC voltage compensation method for a parallel hybrid multi-level converter. The converter has a three-phase power transmission structure, and the three-phase power transmission structure is composed of a parallel-connected single-phase structure in series; a parallel-connected type The single-phase structure is composed of a parallel H-bridge fully-controlled device structure and a sub-module cascaded structure. The H-bridge fully-controlled device structure is composed of four fully-controlled devices. The sub-modules are connected in series. The specific implementation of the method is as follows:
[0029] Such as image 3 As shown, in the normal operation mode, when S1 and S4 are turned on, the output voltage of module 1 is led to the AC side, forming an AC positive half wave; when S2...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The present invention provides a DC voltage compensation method of a parallel hybrid multi-level inverter. The inverter is a three-phase power transmission structure which is formed by the series connection of parallel single-phase structures. Each of the parallel single-phase structures is formed by an H-bridge full control device structure and a sub-module cascade structure in parallel connection. The H-bridge full control device structure is formed by the cascade structures of four full control devices. The sub-module cascade structure is formed by the series connection of half-bridge sub modules. The compensation method comprises the steps of adding an isolation time in an inverter normal operation mode process and freely controlling the sub-module cascade structure in the isolation time to output needed compensation voltage, the compensation of DC voltage vacancy is realized, and the three-phase distribution proportion is adjusted according to needs by the compensation proportion in the three-phase power transmission structure. Through the method provided by the invention, the DC voltage fluctuation compensation of a parallel hybrid new topology can be effectively realized, and the method is especially suitable for the voltage compensation under an AC system failure.
Description
technical field [0001] The invention relates to a direct current voltage compensation method, in particular to a direct current voltage compensation method for a parallel hybrid multilevel converter. Background technique [0002] The flexible direct current transmission system is a direct current transmission system based on a voltage source converter with a fully controlled device (IGBT) as the core. It has broad applications in many fields such as wind power access, grid interconnection, urban power supply, and island power supply. Foreground, since the development of flexible DC technology, it has experienced two main technical routes, namely two-level technology and modular multi-level technology, the latter has low switching frequency and low loss, and has become the main development of flexible DC transmission technology trend. [0003] The converter of the flexible DC transmission system is the core component of the whole system, used to realize the conversion of AC ...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More IPC IPC(8): H02M7/17H02J3/36
CPCH02M7/17Y02E60/60
Inventor 杨杰贺之渊李强马巍巍周扬
Owner STATE GRID CORP OF CHINA