What is distribution network reactive power optimization compensation?

Since the line loss of the power grid is mainly the loss of the line and the loss of the transformer, the loss reduction and energy saving of the distribution network means that all power lines and transformers in the power grid are optimized. The purpose of reactive power optimization is to reduce the active power loss of the network by adjusting the distribution of reactive power flows and maintain good voltage levels. Reactive power optimization compensation generally includes excellent compensation for reactive power load in substations, excellent compensation for distribution lines, and low-voltage side compensation for distribution transformers, while low-voltage side compensation for distribution transformers is one of the focuses of reactive power optimization in distribution networks.

Distribution transformers generally implement follow-up compensation, which is to install low-voltage compensation capacitors directly on the low-voltage side of distribution transformers, and to share the same investment with distribution transformers, to compensate for the distribution transformer's own excitation reactive power loss and inductive power equipment. Reactive power loss. The use of traditional no-load distribution transformers combined with low-voltage parallel-connected capacitor devices, in the actual operation of the distribution transformer can not be automatically shifted, the outlet voltage is generally between 110% to 115%, the parallel capacitor device is affected by the outlet voltage Capacitor operation rate is low, a large number of inductive loads in the distribution network cannot be compensated, and the voltage drop at power peaks is about 30 to 40 V, which directly affects the quality of power supply and economic benefits of the power companies. To solve this problem, automatic voltage regulation and reasonable reactive power compensation can be applied to on-load distribution transformers, which can ensure the quality of the power supply voltage of the distribution network, improve the power factor, achieve the goal of reactive power balancing on the ground, and improve the power supply of the power system. The ability to operate the distribution network system in an economically reasonable, stable and safe state.

Auto-regulation compensation control principle In actual operation, the use of reactive automatic compensation device for on-site compensation can achieve a certain improvement in voltage quality while achieving reduced line losses. However, practice has shown that due to the large changes in the utility distribution load and the large voltage fluctuations, it is often purely relying on reactive power compensation and does not solve voltage quality problems well. Therefore, reactive power and voltage are used as binary control variables. "Nine-zone map" as a basic control algorithm, automatic tracking compensation and automatic pressure adjustment with the measures, can achieve the purpose of further improving the power quality.

In order to make the voltage U and reactive Q reach the required values, the U and Q of the power distribution system are changed by changing the tap position of the on-load distribution transformer and switching the capacitor bank. The change of the tap position of the on-load distribution transformer not only affects U, but also has a certain influence on Q. Similarly, the switching of the capacitor bank affects Q and also has a certain influence on U.