Comparative Study of PI Controller and PID Controller for Power Quality Improvement

Abstract

Power factor correction (PFC) is a mandatory functionality of electronic products in the industrial and commercial market in order to mitigate grid harmonics to improve power quality. Since the load characteristics of most PFC applications such as home appliances, battery chargers, switched mode power supplies and other digital products support unidirectional power flow, the general ac - dc boost converter is considered a popular topology. It is one of the low cost, simple methodologies and their performance is well - proven. Maintaining dc - link voltage constantly inside the system in order to feed loads at different power ratings is the main task. Active power filters (APF) is another approach capable of improving grid power quality to control input current with a pure sinusoidal waveform in phase with input voltage. Unlike PFC circuits, the APF is a system in itself which provides compensation of harmonics and reactive power in order to reduce undesirable effects from non-linear loads and uncontrolled passive loads in power systems. The paper introduces a versatile method for mitigating grid power quality using unidirectional ac ? dc boost converter. The additional focus of this paper is to measure the quantity of input current distortions by the unidirectional ac ? dc boost converter used for supplying active power to the load and reactive power. By using this method, the amount of reactive power injected due to input current distortion from an individual converter to the grid should be restricted. This paper presents, control strategy by using dual boost PFC converter. An improved simulation software using MATLAB was developed to study the proposed method to mitigate harmonics in order to improve power quality. Comparative results for power quality improvement by using PI controller and PID controller are observed.