Optimal control of reactive-power compensators in industrial networks - A virtual compensator concept

In modern industrial processes, the number of nonlinear loads - known to be a major source of current harmonics - is constantly growing. At the same time, the number of reactive-power compensators operating in these networks is growing too. Though the compensators are not the source of harmonic distortions, they may cause high amplifications of harmonics by creating resonance conditions. This can cause malfunctions or even loss of equipment. Due to the increasing number of the reactive-power compensators operating in typical industrial networks, control of these networks is also becoming extremely demanding. An industrial network operator has a difficult task of finding an optimal configuration of compensators, meeting the reactive-power demands and at the same time not causing resonance amplifications of harmonics. The paper thus proposes a concept of a virtual compensator. It combines all the reactive-power devices of a certain network within a single control scheme. This enables the operator to control each compensator independently in real time and to achieve their optimal configuration at any operation point of the network. The effectiveness of the proposed algorithm is demonstrated on a realistic industrial-network model by means of simulations.