Rotational Inertia Ancillary Services Based on System Inertia Pricing Scheme for Consumers

With the gradual development of new power systems, there is a large-scale integration of new energy units into the system, resulting in a significant decrease in the rotational inertia level of the power system. There is an urgent need to introduce new forms of rotational inertia into the current power system. Virtual synchronous inertia technology (VSG) has emerged. However, the implementation difficulty lies in the lack of inertia trading schemes. The current inertia trading lacks economic payment schemes for rotational inertia consumers and clear benefits for VSG units. In fact, new energy units have a capacity-occupying characteristic when providing inertia. The lack of this trading scheme leads to uncertainty in the profits of asynchronous power sources in supporting inertia. Therefore, it is urgently needed to clarify the pricing scheme of the rotational inertia service market to attract more asynchronous power sources to participate in the rotational inertia market transactions. This paper establishes a minimum inertia purchasing cost model and an inertia consumer pricing model, analyzes the capacity shared by each consumer, and conducts experimental simulation of this model using genetic algorithms in Matlab. The experimental results show that the cost allocation situation obtained by the consumer pricing scheme proposed in this paper can ensure the economic balance of inertia market transactions and reflect the differences in characteristics among consumers, such as differences in power demand and inertia supply between loads, as well as differences in the distribution of generating capacity allocated to inertia among asynchronous power sources. The larger the capacity allocated to inertia by asynchronous power sources, the smaller the inertia cost they bear.