Need of Power Quality in High-tech facilities

Power Quality (PQ) phenomenon has made a common occurrence in today’s electrical power system leading to inefficiencies, safety hazard and higher operating costs. It requires attention by high-tech facilities in order to operate with ease as they use highly sensitive devices.

pManifold, National Support Network (NSN) partner of APQI recently interviewed Mr. Naveen Basva, an industry expert from L&T Mitsubishi Hitachi Power System (MHPS) Turbine & Generators Pvt. Ltd. to understand his viewpoints on ‘Need of Power Quality in High-tech facilities’. (The views here are personal, and not to be associated with any company in any forms.)

Q 1. Please let us know about your role in your company.

A. I am responsible for Plant Engineering & Maintenance of Power systems & utility section at L&T MHPS Turbine Generators Pvt. Ltd. I am Deputy MR for Integrated Management Systems (ISO 50001, ISO 9001, ISO 140001, OHSAS 18001) – responsible for implementation, Internal and External audits. I make sure that we provide reliable power supply to all manufacturing facilities which includes high precision CNC machines that are very sensitive. My team and I maintain the power system network with 100% Uptime and maintain Transmission & Distribution losses within the limit.

Q 2. Please help us understand in brief about your manufacturing facility.

A. We manufacture Supercritical Turbine & Generators in the range of 500MW, 660MW, 800MW and 1000MW. This testing facility not only tests turbines manufactured by L&T – MHPS Turbine Generator but also turbines manufactured by other manufacturers. Thus, this testing facility is also a revenue generator for the plant. The machinery used are high Precision CNC machines with an accuracy of 10 microns. We also have State of the Art testing facility for Generators and Rotor balancing. (First in India of 1000 MW Range).

Q 3. How power quality is important for your facility?

A. In our facility, the CNC machines that we use are highly precise, they are very sensitive to Power Quality. CNC machines sense the voltage dip, sag swell, fluctuations, noise and stops the machine with an appropriate alarm. For instance, the Turbine & Generators Rotor are very large in size and its raw materials (Forged Rotor) are imported in our facility. Machine stoppage during these Rotor machining is not tolerable, which may lead to rejection of job and delay the project schedule. Hence, maintaining good power quality is prime objective to produce finest products and deliver on time.

Q 4. What are the key PQ challenges/gaps you were facing in your facility?

A. We faced the following PQ challenges:

  • We experienced Voltage Fluctuations/Dip due to fault on other 220 KV Transmission Lines- which lead to stoppage of our sensitive machines.
  • We observed transients in the Power System Network.
  • Current & voltage Harmonics were generated through AFE drive when connected to our power system network.
  • Apart from increase in level of harmonics, it was observed that crest factor of voltage and current increased significantly and could create operational issues.

Q 5. What was the approach and steps undertaken by you to mitigate PQ issues?

A. In order to find correct mitigation solution to the problem, a detailed study was carried out by the plant team. Various countermeasures that we undertook were:

  • We installed a UPS 560 KVA with 15 minutes back up, supported by 1250 KVA DG set on critical machines. UPS had Zero Transition time to changeover between grid to battery and vice versa.
  • To eliminate transients, Ultra Isolation Transformers were provided before CNC Machines.
  • To limit the harmonics as per IEEE 519 – we have installed Passive Tuned Harmonic filter for 7th and 11th component connected in Shunt to our power system network.

Q 6. What are the key benefits achieved focusing on below points? Return on investment, Payback, Savings in O&M, reliability etc.

A. Overall, there was power quality improvement for the plant electrical system. Specific benefits that were achieved are:

  • Return on Investment (ROI) – Quality of the manufacturing product has improved a lot. (There is no failure of Critical Machine Power since last 2 years)
  • Payback period was reduced to less than 6 months.
  • Operation & Maintenance expenses were reduced to great extent. (We could avoid the Cost of Poor power quality to INR 20,443 per hour)
  • Carbon foot print reduced by avoiding usage of Diesel for DG sets.
  • With PQ under control, we could maintain 99.98% reliability of power.
  • Reliable power availability improved productivity which saved INR 8 Million per year for the plant.

Q 7. What message would you to like to give to fellow industry professionals to improve PQ environment?

A. In an era of IoT, all loads shall be non-linear and PQ issues are bound to increase further. Nothing to panic, with a systematic approach we can resolve power quality challenges. In case of Green Field Project, I recommend PQ detailed study to be done along with Short circuit and load flow studies.

REFERENCES

Mitigating Harmonics in MV (6.6 kV) System (This blog is based on a APQI case study titled “Mitigating Harmonics in MV (6.6 kV) System”. It depicts the case of a unit/plant facing power quality issues due to internal and external factors and highlights various mitigation techniques adopted & benefits realized by the unit to mitigate these issues.)

ABOUT THE EXPERT

Naveen Kumar Basva is an engineering graduate in Electrical and Electronics from Prathyusha Engineering College Affiliated to ANNA UNIVERSITY, and post graduate diploma in project management from IIM-Indore – L&T IPM. He is also a certified energy auditor and life member of Society of Power Engineers. With 10 years total Experience diversified in ,Design, Installation ,testing & Commissioning of Electrical Systems, Distribution of Power ,Energy Efficiency & Conservation, EPC Power Plant Erection commissioning and now in Manufacturing facilities Maintenance.