Harmonic and reactive power compensation as ancillary services in inverter-based distributed generation

Abstract

Decomposition of observed voltages and currents into harmonic terms that are phasesynchronised to the grid voltage is a challenge in real-time systems. Kalman observers are used to achieve this with the additional advantage of avoiding explicit phase-locking while producing quadrature components useful in instantaneous calculation of reactive power and in providing feed-forward compensation terms.

A Distributed Feedback Control Approach to the Optimal Reactive Power Flow Problem

“…We will show in Section 5 how the algorithm is inspired by a dual decomposition approach [17] to (2). While problem (2) might not be convex in general, we rely on the results presented in [18] which show that zero duality gap holds for the ORPF problems, under some conditions that are commonly verified in practice and in particular in radial networks like the ones that we are considering.…”

“…The availability of a large number of these generators in the distribution grid can yield relevant benefits for the network operation, which go beyond the availability of clean, inexpensive electrical power. They can be used to provide a number of ancillary services that are of great interest for the management of the grid [1,2].…”

“…Different strategies have been recently proposed in order to address these issues, ranging from purely local algorithms, in which each generator is operated according to its own measurements [2], to distributed approaches that do not require any central controller, but still require measurement at all the buses of the distribution grid [5]. Only recently, algorithms that are truly scalable in the number of generators and do not require the monitoring of all the buses of the grid, have been proposed for the problem of power loss minimization (with no voltage constraints) [6,7].…”

A distributed control strategy for optimal reactive power flow with power and voltage constraints

“…The availability of a large number of these generators in the distribution grid can yield relevant benefits to the network operation. Indeed, they can be used to provide a number of ancillary services that are of great interest for the management of the grid [1], [2]. In particular, many inverters have the capability, when they are running below their rated output current, to inject (or to absorb) reactive power together with active power [3].…”

A distributed control strategy for optimal reactive power flow with power constraints

“…The availability of a large number of these generators in the distribution grid can yield relevant benefits to the network operation. Indeed, they can be used to provide a number of ancillary services that are of great interest for the management of the grid [1], [2]. In particular, many inverters have the capability, when they are running below their rated output current, to inject (or to absorb) reactive power together with active power [3].…”