Multi-period Coordination Research Articles

Critical load restoration in coupled power distribution and traffic networks considering spatio-temporal scheduling of electric vehicles

In order to recover the power supply of critical loads after an accidental blackout, a critical load restoration strategy in coupled power distribution and traffic networks considering spatio-temporal scheduling of electric vehicles (EVs) is proposed in this paper. First, an EV route planning model is established based on the traffic network. And a multi-period coordination load restoration model is constructed containing distributed generators and EV charging stations. Next, simultaneously considered as constraints, the traffic network and power distribution network are coupled and the route planning model is integrated into the load restoration model to realize the spatio-temporal scheduling of EVs. The load recovery, the power distribution network economy, and EV driving cost are taken into consideration at the same time. Then, piecewise linearization, second-order conic relaxation (SOCR), and deterministic transformation of chance constraints are leveraged to reformulate the model. Finally, comparative analysis of the scheduling results in specific faulty scenarios is conducted on different strategies, confidence levels of chance constraints, and penalty factors. Numerical studies have proven the effectiveness and superiority of the proposed strategy, and the accuracy is verified as well.

Two-Stage Multi-Period Coordinated Load Restoration Strategy for Distribution Network Based on Intelligent Route Recommendation of Electric Vehicles

To cope with the frequent blackouts in recent years and improve the resilience of the distribution network, a two-stage multi-period coordinated load restoration strategy for the distribution network based on intelligent route recommendation of electric vehicles (EVs) is proposed. The first stage of the model aims at maximizing the weighted power supply time of load, minimizing the total network loss, optimizing the output of each power supply source at each time period, and determining the optimal charging station assignment scheme for schedulable EVs. The second stage is based on the optimal charging station assignment scheme for EV determined in the first stage, with the shortest total time for all EVs to reach the designated charging stations as the objective and determining the optimal travel route of each EV. The model dispatches the idle EVs during blackout as a flexible power supply resource, realizing the multi-period coordination output of multiple sources and recommending the routes for EVs to reach the designated charging stations to optimize the restoration effect of critical loads. The methods of piecewise linearization, second-order conic relaxation (SOCR) and the Dijkstra algorithm are applied to ensure the feasibility and accuracy of the model. Finally, by comparing the proposed strategy with two different single-stage strategies, the effect of these three strategies on the critical load’s restoration and the operation status of the distribution network is further analyzed, which verifies the effectiveness and superiority of the proposed strategy.

Multi-Period Coordination Mechanism Based on Revenue Sharing Contract in VMI Model

Multi-Period Coordination Mechanism Based on Revenue Sharing Contract in VMI Model

Multiperiod Coordination of Local Voltage Controllers and Energy Storage for Voltage Regulation in Distribution Feeder-Connected Renewable Energy Sources

Connection of renewables to the distribution system is growing very rapidly. The inherent uncertainty of renewable energy sources, however, can potentially introduce operational conflicts, disrupting the typical operation pattern of local voltage regulation devices and causing system voltage rise beyond the acceptable limits. This paper describes a joint platform to maintain voltage regulation in a distribution network incorporating a large share of PV energy sources. With an objective to improve the voltage profile and minimize feeder losses, the operation of local voltage controllers and energy storage is coordinated. An optimization approach, based on the genetic algorithm, is developed to find out the optimal settings of the load tap-changing transformers and switched shunt capacitors, as well as the optimal dispatch of energy storage. The proposed method is applied to the IEEE 123 test feeder, using time series analysis over a daily, 24 h, simulation period. Test results clearly exhibit that the close coordination between the voltage control devices and energy storage scales back system energy losses, minimizes the interaction among local voltage controllers and prevents reverse power flow. It consequently upholds the voltage at the customer terminals within the statutory limits, under high penetration levels of solar-fueled generation.

Multiperiod Coordination Models of Coal-Electricity Supply Chain with Double Price Regulations

Using game models, we study multiperiod coordination contract and model of coal-electricity supply chain under the condition of double price regulations to alleviate the price conflicts of coal and electricity enterprises. The study reveals that, in boom seasons of coal demand, the multiperiod coordination mechanism may not only reduce the price of thermal coal but also increase the fulfillment rate of thermal coal. Meanwhile, the ordering quantity of thermal coal is increased and the shortage probability of electricity supply is decreased. Thereby, the conflicts between coal and electricity are also alleviated effectively.