  Integration of emerging hydrogen-enriched compressed natural gas (HCNG)
distribution network with active distribution net-work (ADN) provides huge
latent flexibility on consuming re-newable energies. However, paucity of energy
trading mechanism risks the stable earnings of the flexibility for both
entities, especially when rising highly-efficient solid oxide fuel cells
(SOFCs) are pioneered to interface gas and electricity. To fill the gap, a
two-stage robust Nash bargaining strategy is pro-posed. In the first stage, a
privacy-preserved Nash Bargaining based on the ADMM is applied to clear energy
trading between the two autonomous entities, i.e., ADN and gas distribution
network (GDN). Via robust dispatch of configured energy storage in ADN, the
next stage de-risks ADN profit collapse from transaction biases, caused by
forecasting errors of distributed energy resources. C&CG is finally utilized to
loop the two stages. The convergence of the entire energy trading strategy is
theoretically proved. As such, sustain-able returns from the integration of ADN
and GDN bridged by SOFC and HCNG are facilitated. Numerical studies indicate
that, the proposed cooperative strategy reaps a stable social welfare of nearly
1.6% to total cost, and benefit-steady situations for both ADN and GDN, even in
the worst case.
