HVDC – The new Emerging Technology
HVDC, regarded as a key technology for future power transmission systems, is continuously impacting the industrial world as well traditional systems since it has been introduced. The predictions and ambitions made in the last couple of decades about huge HVDC networks and grids are gradually converting into reality and large scale projects are running all over the globe. In spite of all the inherent advantages that this technology has and further improvements offered by the modern industry, there is still a lack of clear understanding of certain basic physical phenomena induced by strong electric fields in dielectric materials, which has put constraints on the manufacturing of various devices and equipment. Thus, charge accumulation on solid dielectrics, which is inherent phenomenon in HVDC systems, affect distribution of electrical fields and may even influence flashover performance of insulators. Equally, the increasing penetration of solid insulating polymers in various HVDC applications demands reconsideration of design principles of the electrical equipment. Thus, operating constraints are getting rigid and, therefore, knowledge about physical processes associated with charge dynamics on polymeric surfaces become essential for proper insulation design, testing and co-ordination.
List Of Publications
- M. Akbar, R. Ullah and S. Alam, “Aging of Silicone Rubber-based Composite Insulators under Multi-Stressed Conditions: An overview”, Materials Research Express (MRX), Vol. 6, No. 10, 102003, IOP Publishing, 2019. https://doi.org/10.1088/2053-1591/ab3f0d
- S. Alam, Y. V. Serdyuk and S. M. Gubanski, “Field-dependent electric conductivities of silicone rubbers deduced from measured currents and surface potential decay characteristics”, Published (Vol. 24, No. 1, pp. 54-62, 2019) Open Access in International Journal of Polymer Analysis and Characterization (IJPAC), Taylor and Francis Group, 2019. The library of Chalmers University of Technology approved & provided the Gold Open Access funding for this journal paper. https://doi.org/10.1080/1023666X.2018.1516369
- S. Alam, Y. V. Serdyuk and S. M. Gubanski, “Effect of interfaces on surface potential decay on double layered HTV silicone rubber samples”, IEEE International Conference on Dielectrics (IEEE ICD), July 3-7, 2016, Montpellier, France, paper 85828. https://ieeexplore.ieee.org/document/7547606
- S. Alam, Y. V. Serdyuk and S. M. Gubanski, “Potential decay on silicone rubber surfaces affected by bulk and surface conductivities”, IEEE, Transactions on Dielectrics and Electrical Insulation., Vol. 22, No. 2, pp. 970-978, 2015. https://ieeexplore.ieee.org/document/7076798
- S. Alam, Y. V. Serdyuk and S. M. Gubanski, “Contribution of gas neutralization to the potential decay on silicon rubber surfaces at different ambient pressures”, IEEE International Conference on High Voltage Engineering and Applications (IEEE ICHVE 2014), September 8-11, 2014, Poznan, Poland, paper B-2-4, pp. 1-4, 2014. https://ieeexplore.ieee.org/document/7035427
- S. Alam, Y. V. Serdyuk and S. M. Gubanski, “Surface potential decay on silicon rubber samples at reduced gas pressure”, Proceedings of 23rd Nordic Insulation Symposium, Trondheim, Norway, pp. 19-22, 2013. https://doi.org/10.5324/nordis.v0i23.2448
- S. Kumara, I. R. Hoque, S. Alam, Y. V. Serdyuk and S. M. Gubanski, “Surface charges on cylindrical polymeric insulators”, IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 19, No. 3, pp. 1076-1083, 2012. https://ieeexplore.ieee.org/document/6215115
- S. Kumara, S. Alam, I. R. Hoque, Y. V. Serdyuk and S. M. Gubanski, “DC flashover characteristics of a polymeric insulator in presence of surface charges”, IEEE Transactions on Dielectrics and Electrical Insulation, Vol. 19, No. 3, pp. 1084-1090, 2012. https://ieeexplore.ieee.org/document/6215116
- Project Title: Electrical characterization as a complementary technique for determining aging of composite insulators
- Role: Principal Investigator (PI)
- Funding Body: HEC (under NRPU call 2017-18)
- Duration: Three Years (April 2019 – April 2022)
- Total Approved Budget: Approximately 4.8 MPKR
- Project Summary:
Insulators are one of the most essential components of power systems and their smooth operation is highly essential for reliable transportation of electrical energy, which is the backbone of every economic development. With the emergence of polymers, and later on with the use of advanced technology for forming composites, it has become possible to develop better insulation systems even for ultra-high voltages that provide low energy losses. However, the main problem with polymeric composites is their aging (e.g. when exposed to external environmental stresses and strong electrical fields) and, consequently, the loss of desired insulation properties. Thus, diagnosing the physical processes responsible for degradation of polymeric insulators have become essential for thier proper designing for specific operating environment and thus, maintaining insulation strength.
The proposed research is focused on preparation of different types of polymeric composites, their characterization, ageing in a simulated multi-stressed environment and degradation analysis. For the latter, traditional methods such as FTIR, SEM, etc., and electrical characterization as a complementary technique will be employed. A comparative analysis will be performed to identify the most informative, suitable and economical technique for diagnosing the materials. In addition to that, best performance composite insulating materials will be recommended to energy sectors, particularly in Pakistan.
Expertise in Comsol Multiphysics (Finite Element Based Software)
Comsol MultiPhysics is a finite element based software for numerical analysis of a wide range of real world problems pertinent to the electrical, structural, acoustics, fluid, heat, and chemical disciplines. During my studies (M.Sc. and PhD) at Chalmers, I (together with co-researchers) extensively analyzed the effect of material properties on potential/charge decay characteristics, influence of surface charges on flashover performance of model type cylindrical polymeric insulators and effect of interfacial charges on real permittivity of double layered structures through various models developed in Comsol Multiphysics. Details of the models can be found in my published thesis. In addition, I assisted many M.Sc. level course projects (e.g. overhead transmission lines, HVDC power cables, electromagnets, 3-phase transformers, lightning protections, heat sinks, circuit breakers, string insulators, cable terminations, HV bushings, etc.) implemented in Comsol.
Specialized Courses during PhD at Chalmers
I attended several professional courses during PhD including “English for academic purposes”, “Teaching learning and evaluation”, “Research ethics and sustainable development”, “Information literacy”, “Project management and leadership in professional organizations”.
Teaching Assistant during PhD at Chalmers, Sweden, 2011-2016
Teaching is a compulsory part of the PhD studies at Chalmers and comprises 20% of the total activities (research 60%, collecting 60 credits by attending PhD level courses (20%) and 20% teaching). I had been involved in M.Sc. level courses (MTT040: “High voltage technology”, MTT035: “High voltage engineering” and EEK221: “Applied computational electromagnetics”). I assisted students in their computer based course projects (e.g. overhead transmission lines, HVDC power cables, electromagnets, 3-phase transformers, lightning protections, heat sinks, air core reactors, circuit breakers, string insulators, cable terminations, HV bushings, etc.), which were implemented using Comsol Multiphysics software package. In addition, I took part in HV lab demonstrations, correcting exams and student project reports, etc.
- High voltage technology
- High voltage engineering
- Applied computational electromagnetics
Teaching @ GIK Institute
Undergraduate courses offered:
PE448 – High Voltage Engineering
PE415 – Electrical Machine Drives and Control
EE414 – Power System Analysis
EE315 – Power Distribution and Utilization