  We develop a system-level design for the provision of Ancillary Service (AS)
for control of electric power grids by in-vehicle batteries, suitably applied
to Electric Vehicles (EVs) operated in a sharing service. The provision is
called in this paper the multi-objective AS: primary frequency control in a
transmission grid and voltage amplitude regulation in a distribution grid
connected to EVs. The design is based on the ordinary differential equation
model of distribution voltage, which has been recently introduced as a new
physics-based model, and is utilized in this paper for assessing and regulating
the impact of spatiotemporal charging/charging of a large population of EVs to
a distribution grid. Effectiveness of the autonomous V2G design is evaluated
with numerical simulations of realistic models for transmission and
distribution grids with synthetic operation data on EVs in a sharing service.
In addition, we present a hardware-in-the-loop test for evaluating its
feasibility in a situation where inevitable latency is involved due to power,
control, and communication equipments.
