Reading research papers is must for carrying out updated research that too in right direction. When I was stuck for almost two months on the design issues related to grid-connected PV systems I worked hard to get my issues resolved. While reading and reading and reading I read thesis reports, research papers and a lot of online articles. However, the following papers helped me a lot in expanding the breadth of my knowledge base.
Problem
I encountered a strange problem while co-simulation of a PV grid connected inverter. The problem was that for simulation time less than 2 sec, the simulation results were ok. For time more than 2.5 sec the results were bad. See these figures.
The perturb and observe MPPT can track the power fast if the step increment (Delta V in Fig. 1) in the operating point is increased. Although, it will enhance the dynamic response of the MPPT but it will also increase the power oscillations around the MPP. To solve this issue of power oscillations, the step size in each perturbation can be reduced at the cost of slow tracking speed. Therefore the choice of perturbation size needs proper optimization.
For a flyback inverter one of the design task is to keep the leakage inductance as low as possible. While there are limitations when it comes to the reduction of leakage inductance there exist methods to solve this issue. It must be kept in mind that the low leakage inductance is very much essential for efficient energy transfer to the output. Let us see how experts solve this issue.
Consider Fig. 1 below to understand the topic. When the primary switch Sm is turned on, no current flows to the grid because of the direction of the diodes on secondary side.
A well explained answer is given in the reference below. Quoted as it is from the text.
The Multijunction Solar Cell is indeed not a new technology. Earlier it was mostly used to power up satellites as they provides comparatively high efficiency than other kinds of solar cell. With the current technology advancement and more are in development, Multijunction solar cell are emerging for commercial use.