Source:JASE-W Japanese Smart Energy Products & Technologies

https://www.jase-w.eccj.or.jp/technologies/index.html

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Keywords

Y4

system or software

Z4PowerF33

Electric Utility
TEPCO Power Grid, Inc.

Engineering Service: Power System PlanningFeatures
When developing a power supply network in accordance with demand increases and power generation plantdevelopments, an optimum development plan is formulated with consideration for the following aspects, tomaximize the effect of investment.
◆ Power supply reliability (N-1 criteria, etc.)◆ Tidal current and voltage◆ Fault current◆ Stability◆ Voltage stability◆ Overvoltage analysis
A highly reliable, as well as economical and efficient power system, can be formed through optimum powersystem planning, which will produce the following benefits:◆ Reduce frequency and time power outages◆ Improve power quality (supply voltage, etc.)◆ Reduce transmission losses◆ Optimize the loading ratio of power transmission facilities◆ Reduce power transmission equipment failures
Overview or Principles
TEPCO Power Grid, Inc. offers technical assistance for power system planning, in order to achieve a highly
reliable power system that can provide high quality power in a stable manner.
Deterioration in the quality of the power system is a matter of concern, as the scale of the power system
expands. There are, for instance, such issues as the overloading of facilities, increased fault current, as well
as declines in system stability and voltage stability. It is essential that such matters are thoroughly
considered during the planning stage, in order to ensure that the whole power system functions in awell-balanced manner.
TEPCO Power Grid, Inc. identifies issues with the power systems of customers before consideringcountermeasures for such issues. Such countermeasures may include enhancing the transmission facility,changing the configuration of the system, installing protective and control facilities and the like. Overvoltage
analysis can also be conducted as needed, to identify problems and propose countermeasures.

Example 1: Reduced fault current
The fault current flows from each generator to a fault point, when a power system fault occurs. The fault
current increases throughout the system when the system is upgraded and expanded with additional powergeneration and transmission facilities.
◆ Problems with fault current increases- Facility damage occurs as the fault current on transmission lines exceeds the allowable current andbreaking capacity.
- Faults occur on communication lines, due to electromagnetic induction.
◆ Countermeasures- Unloop the power system (network partition)- Enhance the transmission facilities

Example 2: System interconnection
Independently operated systems are linked with system interconnection facilities to facilitate power
pooling, achieving economical, efficient power system planning and system operations.
◆ Purpose of system interconnection- Reduce supply reserve capacity- Pool power for emergencies- Power pooling for economical operations◆ Consideration details- Consider system interconnection measures for various situations- Change system constants, due to system interconnection- Economic assessments◆ Problems of interconnection- Decline in stability of whole system (network partition)- Unexpected loop tidal current
Example 3: Power system master plan
An economical and efficient power system master plan is formulated, with consideration for suchrequirements as the supply reliability of the target nation.
◆ Power supply reliability- Required power supply reliability is established, with consideration for the conditions of the targetedarea◆ Preparation and evaluation of power system master plan according to power supply reliability- A power system master plan is formulated, with consideration for the supply reliability, such as the
N-1 standard and the like
- Current power system and existing power system plans are also assessed- An economical and efficient power system plan is proposed
Energy saving effects & special notes
TEPCO Power Grid, Inc. provides technology transfers through consultation services, based onexperience gained in Japan. The principal indices of power supply reliability and efficiency, at TEPCOPower Grid, Inc., are described below:◆ Annual total number of accidental power outages per user - 0.09 times (2017)◆ Annual total duration of accidental power outages per user - 6 minutes (2017)◆ Transmission and distribution loss rate: 3.8% (2017)ractice or Schedule
Past or planned implementations
Domestic

Power system planning by TEPCO Power Grid, Inc. (system capacity scale of 55 GW)

Overseas◆◆◆◆◆◆◆◆

Contact:Overseas Business Office, Tokyo Electric Power Company Holdings, Inc.
URL：https://www.tepco.co.jp/en/hd/ourbusiness/consulting/index-e.html

Power System Master Plan for the Kingdom of Bhutan (2021)
Power Network System Master Plan in Lao People’s Democratic RepublicPower System Master Plan for the Democratic Socialist Republic of Sri Lanka
Project feasibility survey for reactive power management in India (2018)
Survey for power system stabilization countermeasures in India (2017)
Power System Master Plan for Bangladesh (2016)
Formulation of the Black Start Plan for Abu Dhabi (2016)
Consideration of Grounding Current for the Design of a Wiring Trough in the Underground
Power Transmission Lines of Singapore (2015)

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