JWG C1/C4.36 Review of Large City & Metropolitan Area power system development trends taking into account new generation, grid and information technologies


We are experiencing a prolonged period of population growth globally and an increase in urbanization. The number of Large Cities & Metropolitan Areas is increasing as is their size both in terms of population and surface area. Accordingly, electricity consumption and power system load are growing and are concentrated in densely populated areas. In addition, Large Cities & Metropolitan Areas are important political and economic centers, and loss of load, or even load curtailment, can have a significant financial impact on companies and consumers. The safety and reliability of power systems must endure when facing today’s challenges such as capacity and power balancing adequacy, restoration and modernization of the networks, and the installation of new generating and power system equipment.
New technologies have been developed since the turn of the century and this coincides with the need to replace ageing, key assets in the power systems which grew rapidly in the middle of the 20th Century. Rather than replace assets on a like-for-like basis, however, it is important to recognise that economic drivers have changed and these will influence the power system of the future. Cross industry coordination and cooperation is required to successfully manage power system operations for Large City & Metropolitan Areas while new technologies are being deployed. Criteria and principles for large cities power system operation and development will be proposed.
The following items will also be taken into account: power flows to and from the distribution network; application of innovative measurement devices; development of electric vehicles; active and reactive power flow control technologies and their increasing automation; economic drivers for Large City & Metropolitan Area development; large scale HV and UHV cable route penetration; and, rooftop PV penetration etc. The Large City & Metropolitan Area power system development trends and operational features will be assessed both for transmission and distribution networks due to their growing interaction.
In order to address the issues highlighted above, this JWG will:
1. Review the current state of Large City & Metropolitan Area power system supplies with a view to:

  • Defining the terms «Large City» and «Metropolitan Area» in relation to the power system; Identifying power system development trends over the past 10 years in relation to the expansion of Large City & Metropolitan Areas, and analysing how these trends are shaped by the planning process for transmission, distribution and security of supply;
  • Defining the characteristics, features, challenges, and common requirements in relation to the planning for Large City & Metropolitan Area power systems. Particular attention will be paid to: high generating capacity and load concentration; electricity consumption structures; power balancing using local electricity generation capacity and external power flows; rated voltage level increase; reliability and stability problems; fault (short circuit current) levels; power factor and power quality issues; effects of reverse power flows; and, anti-islanding issues etc.;
  • Documenting current special requirements for Large City & Metropolitan Area development planning (if any);
  • Determining the existing and prospective economic drivers related to the development of Large City & Metropolitan Area power systems.

2. Define the existing and potential prospective technologies at transmission and distribution level to be applied in Large City & Metropolitan Area power systems for improved sustainability and controllability, including the following:

  • Exploitation of the control capabilities of Renewable Energy Sources (RES) and dispersed generation;
  • Battery storage systems, FACTS and HVDC, and other generator technologies for voltage and power flow control, reactive power compensation and power system stability improvement;
  • Use of modern HV and UHV cable lines, gas-insulated substations, high capacity substation installation near load centers, underground electric equipment installations (underground substation);
  • Use of smart metering, demand response approach and other smart grid concepts.

3. Identify Large City & Metropolitan Area power system development trends, highlight common issues, and highlight drivers for the further development of power system security criteria and planning principles.

Convener: Valdson Simoes (BR) & Stanislav Utts (RU)