Design of Dynamic - Static VAr compensation based on microcontroller for improving power factor

The issues related to control of reactive power in order to improve the quality of the electric transmission and distribution nowadays get more interests in readers. There are two most commonly used methods which are dynamic and static VAr compensation (denoted by DVC and SVC respectively) for improving power factor, but both ways still remain some drawbacks such as the over/under or corrupted compensation phenomena due to DVC, or an expensive cost for a large size of inductors of SVC. This paper proposes a new scheme combining both DVC and SVC in order to get the best performance with low installing cost. The proposed scheme, called Dynamic-Static VAr compensation (DSVC), includes two controlled loops. The inner loop, DVC controller, has a function of providing a large amount of the compensating reactive power until a little capacitive leading, then the outer loop, SVC controller, acts on the system to eliminate the over compensation from the inner controlled loop. The feed-back signal in this case is the power factor (cosϕ) that is the same as the reference signal, and the power factor (PF) meter design based on the microcontrollers will be deeply described in this paper. The work is firstly validated via simulating on Matlab/Simulink, and then applied on the experimental setup. The results indicate that the proposed solution gives the good qualities not only in technical requirements, but also in financial statement.