A multi-level-objective-oriented method for coordination and control of voltage/reactive power in distribution network is proposed. By referring to the demand for integrated voltage and reactive power control between county and district power network, three-level objective include regional voltage control of the gate area, gate power factor control and reactive control within the power station of the gate area. The control strategy of the adjusting unit based on the nine-zone theory is analyzed, and then the correspondence between the global AVQC and local VQC is discovered, based on which the optimal and suboptimal control strategy of the adjusting unit are proposed. Finally, three steps including urgently cutting off the capacitors, combinatorial control of the capacitors and combinational control of the transformer stalls are taken one after another to realize the coordination and control over the voltage and reactive power between the superior and inferior power network. This method is implemented in the AVQC system of TianJin Chengxi grid, which operates stably and has gained good effect.
Alleviation of overloads in transmission network: A multi-level framework using the capability from active distribution network