Improvements according to requirements and user wishes
VEO has invested in system features and usability in the development work made to fulfil the new requirements.
“Today, all hydropower automation projects where we renew the turbine regulation and control system will include a system with a frequency support ability, in accordance with the new grid code regulations,” says Kelloniemi.
When a plant participates in the frequency reserve market, the reserve supplier must ensure that the plant’s supply and control equipment also meet the agreed regulation features between the control tests performed for the transmission system operator. Therefore, the checking of regulation features must be made easy.
“To ensure that things run smoothly, VEO has now made several improvements that take into account the wishes of the users. One target for development in our system has been the user interface, which now includes parameters to control the operation of the turbine governor and the operating points of the turbine. The user interface makes it easy to check and adjust the operation of the system.”
In the hydropower market, energy and frequency reserves are traded separately. In addition, regarding the turbine governor, the frequency reserve is further divided into containment reserve, disturbance reserve and so-called automatic Frequency Restoration Reserve (aFRR). Therefore, the owner of the machinery must also be able to switch off the product and direction of control that is not traded and to limit the amount and direction of control allowed for aFRR.
“The control speed of aFRR is the speed set by the transmission system operator and the grid code defines the power regulation speed at which the hydropower plant must be able to function. However, the speed at which the normal power setpoint is executed is a matter for the users to decide, so it’s useful for them to be able to adjust it due to seasonal variation, for example. During the formation of the ice cap, the flow through the machine is allowed to change slightly more steadily than at other times. In addition, in a situation where a spare part has to be replaced, the user interface can be used to calibrate the sensors controlling the system. This increases the usability of the system and speeds up the recovery from the disturbance situation considerably. These numerous features have been taken into account in the design of VEO’s turbine regulation and control system,” says Kelloniemi.
User-friendliness at the heart of VEO’s design
The guiding idea of VEO’s design is that when the system is made as easy to use as possible, the required testing and maintenance measures are also performed regularly and in accordance with the requirements.
“This increases the safety and service life of the system and reduces overall costs during the system’s lifecycle. VEO’s strengths are found in the company’s long experience in this area, knowledgeable professionals and in-house product development, which allows the system to be modified according to the specific needs of a project and to be updated whenever needed. For example, the renewal of hydraulics or components should not mean that the entire system has to be renewed,” Kelloniemi points out.
Although many improvements have already been made, further development of the system is ongoing at VEO. Further improvements are being planned, among other things, regarding information availability and how to solve both the mechanical wear on the hydropower plant caused by the frequency control and the resultant increasing maintenance costs.
“We have launched a development project at VEO to find a solution to reduce mechanical wear without having to compromise on the amount of reserve produced. If successful, the improvement will bring customers direct savings in maintenance costs and increase the operational reliability of the plant.”