Grid power quality control system and method based on unified power quality regulator
A technology of power quality and control method, which is applied in the direction of AC network voltage adjustment, multi-phase network asymmetry reduction, multi-phase network elimination/reduction of asymmetry, etc., and can solve problems such as complex modulation strategies, unbalance, and equipment failure protection , to achieve the effect of solving the power quality problem, the number of output levels is large, and the content of voltage harmonics is small
Active Publication Date: 2019-01-18
LIAONING TECHNICAL UNIVERSITY
View PDF2 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
The document "Multilevel voltage-source-converter topologies for industrial medium-voltage drives" proposes that the application of this topology will have great limitations in medium and high voltage applications, such as the need for a large number of capacitors, and the acquisition of capacitor signals is complicated. To maintain capacitor voltage balance, it is necessary Complex modulation strategies, etc., so UPQC implemented with diode-clamped type is limited to three or four levels
[0004] Literature "Based on Modular Multilevel Converter MMC (Modular Multilevel Converter ) topology of a new medium-voltage unified power quality controller" and the literature "Research on the control strategy of a unified power quality controller based on MMC" have studied the compensation function of MMC-UPQC, but they all focus on the distortion of the grid voltage and the harmonic of the load current. Involving reactive power and other aspects, there is no discussion on the situation of unbalanced power supply voltage and unbalanced load
In the actual operation of the power grid, various imbalances may occur, which will affect the normal operation of some important loads, and even cause some equipment to fail to protect, resulting in large economic losses.
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
[0038] The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.
[0039] A grid power quality control system based on a unified power quality regulator, such as figure 1 shown, including:
[0040] The modular multilevel converter connected in series between the grid and the load is the series MMC;
[0041] The modular multilevel converter connected in parallel with the load is the parallel MMC;
[0042] Control circuit: According to the voltage and current signals of the grid side and the load side voltage and current signals, the voltage quality problems caused by the grid side and the current quality problems caused by the load side are compensated and controlled through series MMC and parallel MMC respectively;
[0043]Series MMCs ...
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
A grid power quality control system and method based on a unified power quality regulator, the system includes a series MMC, a parallel MMC, and a control circuit; the series MMC and the parallel MMC form an MMC-based unified power quality regulator UPQC topology, respectively through the transformer Connect to grid side and load side. The method includes transforming the MMC model in the abc static coordinate system to obtain the differential equation matrix model in the dq rotating coordinate system; obtaining the small signal model of the series MMC and the parallel MMC of the MMC in the dq rotating coordinate system; using the parallel MMC to output compensation current and Stabilize the DC side voltage; use the series MMC to output the compensation voltage. The present invention adopts PI regulator for the fundamental positive sequence voltage component and fundamental positive sequence current component, and adopts quasi-PR regulator for other components to realize no static error control, not only compensates for distortion, harmonic and reactive power, but also Compensate for unbalanced power supply voltage and unbalanced load, so that the load can be reliably powered.
Description
technical field [0001] The invention relates to the technical fields of flexible AC power transmission and distribution and power electronics, in particular to a power quality control system and method for a grid based on a unified power quality regulator. Background technique [0002] In the modern industrial power grid, various disturbances such as the start of the motor, the start and stop of the heavy load, and the nonlinearity of the load lead to voltage distortion, unbalanced voltage rise and fall, voltage flicker, load current imbalance, etc., causing industrial power grid The power quality is obviously degraded. With the widespread application of a large number of new technologies, the proportion of sensitive loads such as various detection and control equipment is increasing, and accordingly the requirements for power quality of the power grid are getting higher and higher. Then, in order to provide users with pure power, the research on the power quality comprehen...
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 Patent Type & AuthorityPatents(China)
IPC IPC(8): H02J3/12H02J3/26
CPCY02E40/50
Inventor姜艳华张连勇孙方红
OwnerLIAONING TECHNICAL UNIVERSITY