**8. Conclusions**

In the South African context, as well as in many other countries, electricity supply capacity could be best increased by promoting the diversity of energy sources in the generation. In this generation mix, renewable energies and particularly PV solar are one of the leading renewable sources of energy despite challenges related to their inability to meet the base load demand of electricity. Therefore, large-scale PV solar projects for reliable electricity supply require both in-depth knowledge pursuit as well as financial investment in energy storage technologies. This work discusses the knowledge gap in the three critical areas concerning the implementation of large-scale electrical energy storage in the South African context.

Based on the proposed case scenario, Li-ion batteries are ascertained to be lucrative in both technical and economic countenances, and thus, they are advisable as a fill-in workable solution in combating the problem of load shedding in South Africa. Some of the technical challenges, i.e., output power smoothing, load shaving, frequency regulation, PV plant dispatchability and energy arbitration can be circumvented using the control algorithms furnished and their corresponding duration thereof.

As a proposal, further investigations should be conducted in order to crack the problem of economic viability under distinctive application set-ups.

**Author Contributions:** B.A.T., conceptualized, carried out the investigation, wrote and prepared the article. P.N.B. was responsible for reviewing, editing, and drafting closing remarks of the article. The published version of the article has been reviewed and approved by all authors. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


**Salah Beni Hamed 1,\*, Mouna Ben Hamed <sup>2</sup> and Lassaad Sbita <sup>2</sup>**


**Abstract:** This paper deals with voltage control in a buck DC-DC converter. In fact, dynamic mathematical equations describing the principle behavior of the above system have been derived. Due to the nonlinearity of the established model, a nonlinear control algorithm is adopted. It is based on the sliding mode control approach. To highlight the performance of the latter, a comparative study with four control algorithms is carried out. The validity of the model and the performance of the conceived algorithms are verified in simulation. Both the system and the algorithm controls are implemented in the Matlab/Simulink environment. Extensive results under different operational conditions are presented and discussed.

**Keywords:** buck DC-DC converter; parameter variation; Matlab/Simulink environment; sliding mode control
