  Distribution network operation is becoming more challenging because of the
growing integration of intermittent and volatile distributed energy resources
(DERs). This motivates the development of new distribution system state
estimation (DSSE) paradigms that can operate at fast timescale based on
real-time data stream of asynchronous measurements enabled by modern
information and communications technology. To solve the real-time DSSE with
asynchronous measurements effectively and accurately, this paper formulates a
weighted least squares DSSE problem and proposes an online stochastic gradient
algorithm to solve it. The performance of the proposed scheme is analytically
guaranteed and is numerically corroborated with realistic data on IEEE-123 bus
feeder.
