VSC-MTDC (Voltage source converter-multi-terminal high voltage direct current) voltage control method for offshore wind farm integration
A DC voltage and control method technology, applied in the direction of power transmission AC network, etc., can solve the problems of DC voltage deviation, complexity of switching instructions, and difficult to adjust the proportion of active power distribution accurately, and achieve good control effect
Inactive Publication Date: 2015-12-02
SHANGHAI JIAO TONG UNIV +1
View PDF2 Cites 13 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
But this will inevitably introduce DC voltage deviation, and the active power distribution ratio based on line impedance is difficult to adjust accurately, especially when the topology of the multi-terminal DC transmission system becomes more complex
There are also literatures that propose some methods that combine the above several control strategies to achieve the required control effect through the switching of control modes, but the complexity of switching instructions is unavoidable.
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 1
[0040] Embodiment 1: based on the electromagnetic transient simulation software PSCAD / EMTDC established such as figure 1 The simulation model of the five-terminal DC transmission system shown, the main parameters are shown in Table 1. The simulation verifies the control effect of the control method proposed by the invention on the system when the wind speed changes step by step, the grid has a three-phase short-circuit fault and the converter station is out of operation.
[0041] Table 1 Main parameters of the simulation system
[0042]
[0043]
[0044] see figure 1 , in this example, based on figure 1A five-terminal direct current transmission system shown in the figure verifies the control method proposed by the present invention. The five-terminal direct current transmission system includes: two wind farm side converter stations, a wind farm, a direct current transmission line, and three grid side converter stations. substation, the three AC grids and their AC lin...
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 invention provides a VSC-MTDC (Voltage source converter-multi-terminal high voltage direct current) voltage control method for offshore wind farm integration. The method comprises steps: voltage outer-loop control in a control system for a grid-side converter station is put to an integrated control center; an active power distribution ratio Ki is set according to power requirements, the power distribution ratio Ki is overlapped to a current given value for ith converter station inner-loop control, the Ki is sent to a corresponding converter station in a communication mode, and thus through adjusting a power distribution coefficient of the integrated control center, adjustment on active power distribution ratios of different converter stations can be realized, and stability and accuracy of DC voltage are barely influenced. When the strategy is compared with the traditional voltage droop control strategy in three conditions in which a wind speed varies, three-phase short circuit fault happens to the power grid and the converter station quits operation, better control effects are realized in aspects of DC voltage control precision and flexible active power distribution.
Description
technical field [0001] The invention relates to the field of high-voltage direct current transmission, in particular to a VSC-MTDC (voltage source converter multi-terminal high voltage direct current) direct current voltage control method for grid-connected offshore wind farms. Background technique [0002] More and more offshore wind farms will be put into construction in Europe, Asia and North America. In order to realize the grid connection of these large-scale and long-distance fluctuating wind power, the VSC-MTDC system has many technical advantages, such as reducing transmission Loss, increase control flexibility and improve power quality, etc. For the control of multi-terminal flexible DC transmission system, it is very important to stabilize the DC voltage and allocate active power flexibly. At the same time, in order to ensure the safe operation of the multi-terminal DC transmission system, it is also necessary to satisfy the N-1 rule, that is, when one of the conv...
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): H02J3/36
CPCY02E60/60
Inventor 蔡旭李汶婷施刚吕敬迟永宁张占奎
Owner SHANGHAI JIAO TONG UNIV