Monitoring the “beat” of power grid
At Regulatory Departments of 21 Power Companies under EVNSPC’s monitoring, controlling and operating the power grid of each area under their management scope, additionally, at Main Control Centers under SCADA EVNSPC Operation Center, 2 engineers were focusing on monitoring a dozen of screens. They are facing a very large screen, displaying all operating parameters of more than 200 110kV substations managed by EVNSPC in 21 provinces and cities.
Mr. Nguyen Van Dung - Head of Maintenance Department - SCADA Operation Center said: “Only with 2 engineers sitting here, through the software of SCADA system and telecommunication, we can monitor, in real time, the “health status” of the power grid system in unmanned substations with basic criteria of voltage, current, capacity, equipment status, warning signal, etc., thereby working out stable, most appropriate operating measures. The status of parameters exceeding the allowable values has no longer occurred as previous periods, contributing to proper implementation of operation management and reduction of power loss”. The engineers monitor not only the operation of the power system, but also the entire telecommunication network to serve the SCADA system such as SDH network, IP network, monitor each telecommunication equipment by the software to direct the units to handle any cases of connection failure from substations to SCADA Operation Center such as optical cable breakage, telecommunications equipment failure, etc.
From Scada Operation Center, engineers are still able to get sufficient information of operating at hundreds of 110kV substations.
In the events of incidents, operating parameters exceeding their allowable values, there will be warning signal (in colour, sound) for each area displayed on the computer. Then, the control operator on duty at the Control Centers in provinces/cities will promptly identify the location of incident or adjust the operating parameters, thereby commanding to promptly and accurately handle the incidents, reducing time for the handling, soon re-supply power to customers, ensuring safe, uninterrupted, reliable and economical operation of the grid.
Previously, in the event of incident, the control operator at substation had to call the Regulatory Departments of affiliated Power Companies and the Southern Region Load Dispatch Center (A2) as per decentralized levels to report to and ask for instruction, or vice versa, the control operators of affiliated Power Companies under the Corporation must call each substation for getting any related information. This takes a lot of time to conduct such exchange. Even when the incident is detected by the customers, the technical staff must manually search for the cause, localize the incident, etc. Currently, the engineers at the Regulatory Department as well as those in duty of the shift at the SCADA Operations Center get accurate information of the incident location, thereby providing a prompt option, reducing time for the handling, early localizing it so as to isolate the incident and re-re-supplying power to customers, ensuring the safe, uninterrupted, reliable and economical operation of the grid.
Particularly, EVNSPC's SCADA system is also connected to the Southern Region Load Dispatch Center (A2) through the Protocol of Inter Control Center (ICCP), sharing operation data of 220kV, 500kV substations and relevant power plants to serve the management of power supply. Automation of the grid also contributes to increasing labour productivity, reducing the number of employees operating stations; improving business efficiency by promptly detecting and handling incidents as well as rapidly switching grids, reducing the power output impossibly to be supplied, increasing commercial power output, increasing electricity sales, etc.
Many challenges still remained
Mr. Nguyen Phuoc Quy Hai - Director of SCADA EVNSPC Operation Center said, put into operation from May, 2017 to May, 2018, the Center has performed remote control for 216 110kV substations, a 220kV substation and a 110kV breaking station. Particularly for the medium voltage grid, the Center is controlling 905 Recloser/LSB units. Thereby, it can be said that this is a big step in the operating mode of grid.
Compared with the previous operating mode, the power grid automation has many advantages along with many challenges as well. First of all, human resources should be considered. When the modern technology applied into the grid, a team of highly qualified staff capable of operating the system is required. Meanwhile, the current salary/bonus regime has not been so attractive to highly qualified human resources. Moreover, the Power sector does not intend to further recruit personnel. Therefore, in order to efficiently operate the SCADA system, the Corporation shall recruit elite members from its affiliated units, organize training courses for the staff domestically and abroad to meet the requirements.
Additionally, the investment to construct new unmanned substations needs a huge capital. At existing 110kV substations, a large quantity of equipment has been operating for many years, which needs improving, replacing to be eligible to operate in unmanned mode. But the capital mobilization of EVNSPC is increasingly difficult. “The problem” in balancing the cost optimization while ensuring the synchronous, modern operation of the system is still very difficult to be solved.
Remote control is a new technology and deployed in a large area scope, so EVNSPC must conduct research itself and simultaneously invite foreign consultants to select the appropriate orientation design. So far, SCADA center under the Corporation and its affiliated units have been stably operated, contributing to improving the reliability of power supply. EVNSPC sets the goal that by the end of 2018, 100% of the Corporation's 110kV substations will be operated under the unmanned regime (except for force of guards and fire prevention and fighting) and by 2020, 100% of substations will be completely operated in unmanned mode. Particularly, EVNSPC also aims to carry out connecting by remote control for more than 90% of switchgear, disconnector and equipment indicating incidents on the medium voltage power grid by 2020; connecting data of the electronic remotely read meters of distribution substations, regular customers and boundaries between units to exploit the functionality on SCADA system, etc.
There are still many difficulties and challenges remained but EVNSPC has been striving to modernize the power grid system, further improving the stability of power supply, bringing satisfaction to power users.
Reliability of power supply in 2017 and quarter I/2018 of EVNSPC:
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2017
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Quarter I/2018
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SAIDI
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791.15/ 1,257 minutes
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130.11/220 minutes
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MAIFI
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0.31/2 times
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0.03/0.5 time
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SAIFI
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3.53/6.73 times
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0.64/1.48 time
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