考虑动态损失厌恶的V2G市场交易激励机制设计

Transaction incentive mechanism design in V2G market considering dynamic loss aversion

为推进V2G服务设想的实现,本文将电动汽车用户的动态损失厌恶特性考虑在内,分析了一般“保底收购,随行就市”市场制度下,电动汽车用户与电网公司间关于V2G服务交易的博弈行为,并提出了相应的激励机制。研究发现:在一般“保底收购,随行就市”市场制度下,电动汽车用户关于V2G服务的行为选择无法满足电网公司关于V2G服务电量的期望;电动汽车用户对V2G服务电量的决策受其对未来交易价格预期的影响,且存在违约风险。鉴于此,文章引入“激励保证金+违约金”的激励机制,并给出了对应的保底价格策略、激励保证金与违约金等策略,以使电动汽车用户的V2G服务选择与电网公司的期望相统一。算例分析结果验证了本文提出的模型与理论分析的可行性。

With the enhancement of social awareness of energy conservation and environmental protection as well as the development of key core technologies such as on-board batteries,electric vehicles(EVs)are regarded by lots of experts as the main component in future transportation system.Based on this outlook,how to promote the better and faster development of EVs has become one of the hot topics in current academic circle,in which the research on the impact of EVs on the power system is one of the focuses.In this regard,most studies argue that the widespread diffusion of EVs not only would increase the electricity sales of the power grid but also would challenge the stable,safe and economic operation of the power grid.To solve this problem,professor Kemption W put forward the concept of V2G(vehicle-to-grid)creatively.In his V2G vision,EVs were treated as the potential partners of power grid companies.According to the vision,at some moments,through flexible control means and with charging facilities as the intermediary,the electric energy inside EVs could be inversely transferred into the power grid and participate in auxiliary services trade such as frequency regulation and voltage regulation.Via this innovative trade form,it might well achieve a win-win situation between the EV users and the power grid company.However,after reviewing the currently relevant studies,it is found that there are limited studies on the V2G service trading mechanism between power grid companies and EV users so far.Most of the studies were based on the hypothesis that both power grid companies and EV users were complete rational when engaging in the V2G service trading process,without taking into account the irrational behaviors of both parties(especially to EV users).Hence,the future suitability of existing V2G service trading schemes is in doubt.In fact,the trade decision-making of people vary in different circumstances,who are not completely rational,and often show more sensitivity to losses than to profits.These irrational decision-making behaviors of people in trade are conceptualized as loss aversion.Therefore,this paper considers the loss aversion of EV users,analyzes their dynamic decision-making behavior in the process of V2G service trading when profit and loss are uncertain,and finally introduces the V2G service trading incentive mechanism of“incentive deposit+penalty”.The main research conclusions are as follows:When the expected transaction price of EV users in the following trading period is no lower than that of the previous transaction price,the utility of EV users increases with the increase of the trading electricity of EV users in V2G service transaction.On the other aspect,if the expected transaction price of EV users is lower than the previous transaction price,the utility of EV users would be affected not only by the previous transaction price but also by their initial loss aversion coefficient.Because of the dominant position of power grid company in V2G service transaction,the V2G service transaction process between the power grid companies and EV users is subjective to a Stackelberg game relationship.During this process,the power grid company first releases the price strategy,i.e.the lowest guaranteed purchase price and the maximum transaction price of V2G service in next transaction period.Then EV users set their trading strategies based on the price signal.However,according to this transaction paradigm,the optimal trading electricity of EV users cannot meet the expectation of the power grid company.This is mainly because EV users are still unsure whether they will be able to earn at least as much as they did in the previous round of V2G transaction influenced by the loss aversion.For the purpose that making the V2G trading electricity of EV users meet the demand of the power grid company,meanwhile considering the trading behavioral characteristics of EV users,this paper introduces the incentive mechanism:“incentive deposit+penalty”,and puts forward the corresponding guaranteed price strategy,i.e.incentive margin and liquidated damages strategies,so as to make the V2G service quantity choice of EV users consistent with the expectation of power grid company.Under this incentive mechanism,the optimal incentive deposit is positively correlated with the power network performance probability.When the expectation of EV users for the next V2G service transaction price is higher than that of the previous period,the optimal incentive deposit for EV users has little influence to the loss aversion coefficient.On the contrary,if the EV users expectation of the V2G service trading price in the next period is lower than that in the previous period,the optimal incentive deposit is positively correlated with the loss aversion coefficient.The results of numerical examples verify the feasibility of the proposed results and strategies of this article.