Hai Duong Power's automatic voltage maintenance solution brings practical efficiency

The solution "Automatically maintaining medium voltage busbar voltage of 110kV transformers using TTĐK software (Spectrum Power 5 - Siemens)" by the group of authors Ngo Minh Nhat, Pham Trung Nghia, Pham Hoang Phuong, Ngo Van Vong and colleagues at Hai Duong Electricity One Member Co., Ltd. has just won first prize at the 13th Provincial Technical Innovation Contest (2022-2023).

In grid operation, voltage is an important parameter that determines the quality of electricity. Operating the grid at too low or too high voltage is not good, it will cause power loss, the output product will not achieve the best quality... Therefore, maintaining stable voltage plays an important role in grid operation.

Each shift at the company's Remote Control Center must monitor the busbar voltage of 34 110kV transformers throughout the province, with the number of adjustments having to be repeated about 96 - 192 times. Sometimes the person on duty has to handle many tasks, leading to untimely voltage adjustment, which is prone to errors...

To overcome this limitation, the group of authors has researched the solution "Automatically maintaining medium voltage busbar voltage of 110kV transformers using TTĐK software (Spectrum Power 5 - Siemens)" to build automatic voltage maintenance software instead of humans.

Based on the current voltage maintenance regulations, the authors built an algorithm, determined the input variables, output variables and wrote the code to run the program. After running the simulation on the software, it was evaluated as effective and stable. In June 2021, the solution was put into actual operation at transformer T2 of the 110kV Pha Lai transformer station. Through monitoring and evaluation, the solution operated reliably and stably, bringing practical results, so in September 2021, the solution was applied to the entire Hai Duong power grid.

The solution is to maintain the 22kV busbar voltage between 21.5 - 23kV and the 35kV busbar voltage between 36 - 38kV. When the 22kV busbar voltage is less than 21.5kV or the 35kV busbar voltage is less than 36kV, the program automatically increases the 110kV transformer by 1 step. When the 22kV busbar voltage is greater than 23kV or the 35kV busbar voltage is greater than 38kV, the program automatically decreases the 110kV transformer by 1 step.

Applying this solution, the result is to free up work for the on-duty team when they do not have to perform any operations. The quality of power transmission, the reduction of power loss, and power saving are improved. The durability of equipment on the grid is improved, thereby reducing repair and maintenance costs. The risk of incidents due to overvoltage or undervoltage is reduced, thereby improving the reliability of power supply. Customers' machines and production lines operating at optimal voltage will create maximum productivity and produce the best quality products. The risk of incidents causing danger to people and equipment... is reduced.

Mr. Ngo Minh Nhat, a member of the research team, said that during the implementation process, the team also encountered certain difficulties. This is a new solution, no other unit has implemented it, so we have to explore and adjust it accordingly. Because there are only instructions in a foreign language, the team has to translate it themselves as they learn. “The company does not have its own testing system, but has to test it on an operating electrical system, so we have to study it carefully and evaluate all possible situations to have a suitable solution. However, during the testing process, some situations also appeared such as not being able to send signals, the program has not yet detected voltage errors, etc., so the team has adjusted the software to be more suitable,” said Mr. Nhat.

As the unit applying this solution, Mr. Nguyen Tuan Cuong, Head of Mobile Operation Team No. 6, belonging to the company's High Voltage Grid Operation Management Team, commented: "Previously, the operators had to manually adjust and continuously monitor the voltage on the machine, so they could not do other work and sometimes could not adjust in time due to many fluctuations occurring at the same time. After applying the solution, the operator is more relaxed because the software automatically adjusts the voltage. The voltage is maintained within the operating range, so the quality of equipment and machinery is stable, without damage as before."

With practical effectiveness, this solution is applied on the power grid of 26 northern provinces and cities and is highly appreciated by all units.