# Grid Nodes Selection Strategies for Power Quality Monitoring
## 4 Problems and Future Prospects
### PQ--Part of Smart Grid and Its Communication Network  
Earlier, PQ was not seriously regarded in traditional power systems planning: the attention should have been given to more fundamental problems such as generation planning, energy demand forecasting, and evaluation of stability and reliability. Nowadays, technological progress opens new opportunities: PQ monitoring enables better situation observability which will consequently update comprehension and give rise to new ideas. Deeper experience in the understanding of the nature of PQ will not only update PQ assessment methodology but also will tighten the requirements for power systems planning. Currently, power systems are facing big changes in a broader context, and renewable energy generators together with new types of loads based on power electronics become not only emission sources but also vulnerable elements to PQ phenomena. Therefore, PQ evaluation is becoming crucially important at the beginning stages of electrical grid planning through a prism of sustainable development. However, currently, PQ monitoring application is also not highlighted or at least mentioned in many papers oriented to Smart Grid research, for example, in [27; 29]. Moreover, as previously referred to, PQ application is not involved in IEEE Std 2030 [5]--the most sophisticated Smart Grid guideline. On the other hand, energy policy attempts to attract attention to PQ. For example, the CEER 6 th Benchmarking Report [30] highlights the importance of voltage monitoring and regulation in the chapter \"Voltage Quality\", and affirms that PQ is becoming \"an increasingly important issue due to, among other things, the increasing susceptibility of end-user equipment and industrial installations to voltage disturbances.\" In addition to earlier given examples of new grid polluters types, rapid load switching (for energy-saving purposes) is mentioned in the document. The future concept of electric power system planning is presented in Figure 9: PQ evaluation is incorporated into the beginning stages along with traditional stages (such as energy balance, stability, and reliability estimation) required for a new investment project. Deep knowledge in the field of PQ will lead to grid-designing methodic updates, and enable efficient allocation of PQ mitigation devices in order to maximize their individual and mutual effect. Efficient PQ monitors' allocation will allow not only the tracking of all PQ events propagation path (which is important for development of a mitigation strategy) but also to inspire more complex research for the distributed-element model of electrical grid, for example, transient wave reflection from surge arrester. Similar to the case of PQ monitors, there are many types of PQ mitigating devices with their own characteristics. For example, synchronous condenser, static synchronous compensator (STATCOM), or static VAR compensator (SVC) can be used for voltage sags' mitigation; however, each type has its own unique features such as energy, latency, and voltage level, thus the mitigation will be selective (i.e., will depend on voltage sag characteristics--voltage, duration, depth, energy, rise time, etc.). Obviously, additional CAPEX is required for PQ mitigation planning but it highly correlates with risk reduction, OPEX minimization, losses minimization, and profit maximalization. In addition, grid development and relevant decisions will remain being highly influenced by many external factors--for example, policy, macroeconomics, environment protection, participants' skills. Information and communication technologies (ICT) is a relatively new and important layer converting traditional electric power system to a smart system. On the one hand, ICT will solve many problems and add new functionality, on the other hand it will bring new challenges. A new layer in PQ monitors' allocation strategy must be considered with the advance in ICT.