计及暂态频率稳定约束的同步惯量经济价值评估

高渗透率新能源接入系统后，保障系统具有充足的在线惯量是维持系统频率安全稳定的关键，同时建立惯性辅助服务市场是解决该问题的有效手段。因此，将同步惯性响应纳入有偿服务，搭建考虑系统最低同步惯量需求约束的定价出清模型，并提出离散变量松弛化的方法，将出清模型转化为凸优化问题。然后，基于边际成本定价法和拉格朗日对偶原理，以最低同步惯量需求约束对应的影子价格来评估其经济价值，为惯性服务定价。最后，以改进的IEEE 39节点系统和IEEE 118节点系统为例，对同步惯量影子价格的存在机理、数值影响因素以及同步机组收益进行分析讨论。结果表明，含高比例新能源系统具有建设惯性辅助服务市场的必要性和迫切性。所提方法和仿真结论为惯性服务市场化提供了参考性意见。

Economic value evaluation of synchronous inertia considering frequency transient stability constraints

Ensuring sufficient online inertia is key to maintaining the security of system frequency when there is a high penetration of renewable energy in the system. The establishment of an inertia auxiliary service market is an effective means of achieving this. Therefore, with integrating synchronous inertia response into paid service, a pricing clearing model considering the minimum synchronous inertia is built, and a discrete variable relaxation method is proposed to transform the clearing model into a convex optimization problem. Then, based on the marginal cost pricing method and the Lagrange duality principle, a shadow price corresponding to the minimum synchronous inertia requirement constraint is extracted to evaluate its economic value and price the inertia service. Finally, taking the improved IEEE 39-bus and IEEE 118-bus systems as examples, the existence mechanism of the synchronous inertia shadow price, the numerical influencing factors and the benefits of the synchronous units are discussed in detail. The results show that it is necessary and urgent to build an inertia auxiliary service market in a power system which has a high proportion of new energy. Consequently the proposed method and simulation are able to provide guidance for the establishment of such an inertia auxiliary services market.