Sliding Mode Control Based Shunt Active Power Filter

Currently the shunt active power filter (APF) is an effective means of reducing inactive components of the power consumed from the network. At the same time, the shunt APF being a nonlinear element is itself a source of higher harmonics, the suppression of which is imposed on the interface filter. When using a passive three-phase L-filter in this capacity, the higher voltage harmonics appear at the connection points to the network and the amplitude of these higher voltage harmonics depends on the ratio of the filter inductance and the network inductance. In this case, it is not always possible to ensure the proper quality of the voltage at the connection points to the network. In order to assess the efficiency of compensation for the inactive power components and the form of voltage at the points of connection to the network, this work considers the shunt APF with an interface three-phase LC-filter of the second order and with a sliding mode control. The synthesis of current loop control of the APF has been shown as well. A system with the shunt APF was simulated under the nonlinear unbalanced load conditions in Matlab software package. The simulation results presented in this work demonstrate the ability of the above-mentioned APF to provide radically high quality of voltage at the points of connection to the network and suppression of all inactive components of the power consumed from the network. In addition, the shunt APF has the property of slow response to disturbances from the load side.