  The issues of uncertainty and frequency security could become significantly
serious in power systems with the high penetration of volatile inverter-based
renewables (IBRs). These issues make it necessary to consider the uncertainty
and frequency-related constraints in the economic dispatch (ED) programs.
However, existing ED studies rarely proactively optimize the control parameters
of inverter-based resources related to fast regulation (e.g., virtual inertia
and droop coefficients) in cooperation with other dispatchable resources to
improve the system frequency security and dispatch reliability. This paper
first proposes a joint chance-constrained economic dispatch model that jointly
optimizes the frequency-related inverter control, the system up/down reserves,
and base-point power for the minimal total operational cost. In the proposed
model, multiple dispatchable resources including thermal units, dispatchable
IBRs and energy storage are considered, and the (virtual) inertias, the
regulation reserve allocations and the base-point power are coordinated. To
ensure the system reliability, the joint chance-constraint formulation is also
adopted. Additionally, since the traditional sample average approximation (SAA)
method cost much computational burden, a novel mix-SAA (MSAA) method is
proposed to transform the original intractable model into a linear model that
can be efficiently solved via commercial solvers. The case studies validated
the satisfactory efficacy of the proposed ED model and the efficiency of the
MSAA.
