  Voltage regulation in distribution networks is challenged by increasing
penetration of distributed energy resources (DERs). Thanks to advancement in
power electronics, these DERs can be leveraged to regulate the grid voltage by
quickly changing the reactive power outputs. This paper develops a hybrid
voltage control (HVC) strategy that can seamlessly integrate both local and
distributed designs to coordinate the network-wide reactive power resources
from DERs. \ws{By minimizing a special voltage mismatch objective, we achieve
the proposed HVC architecture using partial primal-dual (PPD) gradient updates
that allow for a distributed and online implementation}. The proposed HVC
design improves over existing distributed approaches by integrating with local
voltage feedback. As a result, it can dynamically adapt to varying system
operating conditions while being fully cognizant to the instantaneous
availability of communication links. Under the worst-case scenario of a total
link outage, the proposed design naturally boils down to a surrogate local
control implementation. Numerical tests on realistic feeder cases have been to
corroborate our analytical results and demonstrate the algorithmic performance.
