Ramp based constant frequency current control for DSTATCOM Online publication date: Tue, 03-Mar-2009
by S. Srikanthan, Mahesh K. Mishra
International Journal of Power Electronics (IJPELEC), Vol. 1, No. 3, 2009
Abstract: The conventional hysteresis current controller is simple to implement, has inherent peak current-limiting capability, fast dynamic response etc. However, it suffers from the demerit of variable switching frequency, which may be prohibitively high, increasing the stress levels on the switches. Although a ramp controller may be used to achieve a constant switching frequency, the selection of frequency of the triangular carrier waveform plays a crucial role in maintaining the frequency of operation same as that of the carrier. If an appropriate frequency of the carrier is not chosen, the actual current may encounter undesirable effects of over-crossing and under-crossing. This paper proposes an analytical method for proper selection of the carrier so that the above-said effects are eliminated. The method is also extended to a ramp controller with hysteresis to achieve a reduced value of the constant switching frequency. Detailed simulation has been carried out through MATLAB and an experimental prototype is also built to validate the proposed method.
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Power Electronics (IJPELEC):
Login with your Inderscience username and password:
Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.
If you still need assistance, please email subs@inderscience.com
Our Blog 
Follow us on Twitter 
Visit us on Facebook