The Principle of Construction of Capacitive Reactive Power Compensators with Three-Stage Regulation

Abstract

Abstract It is proposed to reduce the number of electrical and electronic devices by 1.5 times in three-stage capacitor installations by changing the connections in the power circuit and using a special control method. The new principle of construction of reactive power compensators will allow, with minimal changes and additions to existing installations, to reduce the costs of their production and the cost of finished products. The existing installations contain three blocks of the same type of capacitors, each of which is equipped with an electrical and electronic device and resistors for their discharge. It is proposed to connect two of these three blocks in parallel without changing the design of the products, using a common electronic device for connecting and disconnecting the resulting block of capacitors with double capacity and a common electrical device in the capacitor discharge circuit of this block. A model is presented in the Matlab environment for the study of dynamic and stationary processes of three-stage reactive power regulation in a new scheme of a capacitor plant. Numerical experiments have shown that when the installation is switched on and off, as well as when switching from one stage of reactive power regulation to another, the proposed device does not create bursts of starting currents. After starting, it almost immediately enters the steady-state operation mode and when switching stages, it also immediately passes from one level of the steady-state values of such to another level of their steady-state values. The installation is switched off without switching losses and without arcing on the mechanical contacts, since thyristor switches with natural switching are switched off first, and then the de-energized mains switch.