Search

This paper studies the mechanism of spinning reserve on transient voltage stability in ultra-high voltage (UHV) DC/AC hybrid power grids. Taking an actual received power grid with an UHVDC system as an example, the transient voltage stability is introduced and a certain scale of spinning reserve has to be retained to keep the transient voltage stability of the system. And then, the steady state of synchronous generators with different spinning reserve is studied using the method of phasor diagram analysis. At last, the relation of spinning reserve, excitation voltage, and dynamic reactive power is analyzed and the mechanism of spinning reserve on transient voltage stability is revealed. The actual received power grid is used to demonstrate the validity of the mechanism.

The purpose of voltage stability prevention and control strategy is to minimize the impact of expected accidents on the whole power grid while ensuring safe power supply. In this paper, it is expected that the accident has a large impact on the system voltage and makes the voltage margin of each node low. in order to not only adjust the node voltage, but also reduce the disturbance impact, a voltage stability prevention and control strategy is proposed based on the characteristic analysis.

In order to select the optimal quasi-bidding project for an investment enterprise, a bidding decision-making model for international PPP projects was established in this paper. Firstly, the literature frequency statistics method was adopted to screen out the bidding decision-making indexes, and accordingly the bidding decision-making index system for international PPP projects was constructed. Then, the group decision-making characteristic root method, the entropy weight method, and the optimization model based on least square method were used to set the decision-making index weights. The optimal quasi-bidding project was thus determined by calculating the consistent effect measure of each decision-making index value and the comprehensive effect measure of each quasi-bidding project. Finally, the bidding decision-making model for international PPP projects was further illustrated by a hypothetical case. This model can effectively serve as a theoretical foundation and technical support for the bidding decision-making of international PPP projects.