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Discussion Converter Station AC side reactive power compensation and filtering

Hits:Updated:2016-09-23 14:09:16【Print】

  Operation of the power system in our country, the DC converter stand actual transmission process has been consuming a large amount of unwanted power, the AC side filter in the converter station is an important electrical accessories, which will eliminate the commutation at the same time providing useful work resistance generated by the current in order to achieve reduction in weekly communication system affect the results. AC side filtering reliability directly affects the performance of the entire power system operation. From the converter station reactive power compensation and filtering the AC side two discusses its impact on the converter station, as well as its future development trend.
  A reactive power control function
  1. Reactive control priority. As gathered in the converter station control system without control --RPC divided into many levels and have different priorities. In actual operation of the system, we want to perform a specific frequency of the AC side filter according to priority, particular priority as shown in Table 1.
  2. The filter switching selection. In the converter station the actual transmission process, the control system will automatically determine which type of filter selected during the capacitors in parallel, and the AC side filter selection has a certain priority rule. As follows: (1) the different types of filter priority order of HP11 / 13, HP24 / 36, SC. (2) high-priority filter is first connected, will be put into a low-level filter is unavailable. (3) of the same type of filter in order of priority in the program cycle selection, first cast the first retreat.
  3. The filter availability. Found in the converter station signal failure occurs when it is necessary for the filter can be issued if the AC side filter repair test. In the actual power grid control, input filter automatically be overlooked very specific AC side filter general conditions in accordance with Table 2.
  Second, reactive power compensation policy
  1. Reactive control purposes. In the actual converter station transmission process, in order to ensure reliable and stable, requires no power compensation in accordance with the specific needs separate the layers, in order to facilitate specific management in the converter station when the reactive power compensation, the most important is the grid to "voltage converter station connected MRS system" "converter station and the AC system no power" as well as the two main data to compensate. The specific values ​​of the reactive power compensation of reactive power should invest in an array of equipment among the AC system to prevent excessive absorption, impact on the surrounding communication and the entire grid, and in order to take into account the stability of the grid voltage to reduce non-periodic the value of reactive power compensation. These are the means to achieve the requirements of different types of converter stations into several groups and filters.
  2. The demand for reactive power compensation. And reactive power compensation system needs different AC and DC power systems in the value of the DC transmission has a direct relationship, after using different control model calculation, we obtain in the case of bipolar pressure normal operation of the converter station DC power values ​​are not standing in the software interface rectified DC power setting, as a judge, reactive power compensation demand at a fixed condition circumstances will differ from the rectifier to the calculated value, and why it will this happen? Because, in the DC converter station valve Iord and a DC voltage measurements Udio accessories must be in order to obtain the correct value in the combination of the two cases. Converter station reactive power compensation equipment includes not only the inherent reactive power exchange filters and shunt capacitors provided, should also be considered part of the reactive power of the capacitor bank areas of the PLC, the control system also introduces a compensation coefficient K. On this basis, RPC control function compares the converter reactive power loss (Q-Conv) and reactive inputs (Q_Calc_FLT), to determine the type and number of inputs or the removal of the filter group.