Mitsubishi Heavy Industries Technical Review Vol. 60 No. 3 (September 2023)
1Solution Proposal Utilizing the Wind Turbine’s
Maintenance Support Tool- Aiming for Long-term Stable Operation ofWind Power Plant Mitsubishi Heavy Industries, Ltd.
Business Group, Wind Energy
Department, Energy Systems
h t t p s : / / w w w. m h i . c o m / p r o d u c t s / e n e r g
y/wind_turbine_plant_maintenance.html

With a growing renewable energy demand for the achievement of carbon neutrality, anincreasing number of wind power generation facilities (hereafter referred to as wind turbines) are
rapidly being installed in Japan. Wind turbines are required to supply stable power for the longterm. However, various challenges arise in the stage of post-construction operation, because theintricacy of the changing natural environment causes the components of wind turbines to deteriorate
or malfunction, leading to the low availability of wind turbines.
To ensure customers to maintain stable operation of wind turbines, Mitsubishi Heavy
Industries, Ltd. (MHI) has been working on the development of a comprehensive support tool formaintenance. This was brought to fruition as our newly released product “Maintenance Support
Tool for Wind Turbines”. With the introduction of this tool into the wind farms of customers, wehave started providing technical services.

|1. Features of our Maintenance Support Tool
When operating wind turbines for a long time, the importance lies in managing maintenanceand profitability. The former is for public safety and stable operation, and the latter is for keeping thewind farm business successful.
However, the customers are responsible for a wide range of tasks including daily data
monitoring, the conduct of inspection/repair work considering the weather, and recovery fromfailure/shutdown. There are many issues to run a wind farm safely, effectively, and economically.
Therefore, MHI has started providing technical support services that will be a solution tovarious issues. This was enabled by building an advanced system using big data consisting of windturbine operation/maintenance records and others, as well as by means of digital transformation (DX)of a vast amount of analog information such as our extensive experience and expertise acquired afteryears of engagement in the wind power generation business.
Our Maintenance Support Tool visualizes the operation conditions by aggregating/analyzing
daily wind turbine data via an edge device (i.e., Gateway PC) that is installed at the wind farm afteran annual contract is signed between the customer and MHI. The maintenance support informationsuch as facility diagnosis and technical information is shared on a cloud server dedicated to thecustomer.
The employment of this tool can help enhance the facility’s availability and asset value,
because of its wide applicability to, for example, facility maintenance, reduction of the risk of lowavailability, improvement of efficiency in operational maintenance, and wind turbine control
upgrading.
Figure 1 illustrates an overall view of the Maintenance Support Tool and an image of theapplication scene.

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Figure 1

Technical support by Maintenance Support Tool

|2. Availability improvement by Maintenance Support Tool
The key metric for the management of wind turbine operation is the availability. The requisite
for maintaining high availability are the effective execution of facility maintenance, the preventionof wind turbine failure/shutdown, and the minimized downtime.
As shown in Figure 2, the approach to facility maintenance is twofold: “Breakdown
Maintenance (BM)” conducted after some failure or accident occurred, and “PreventiveMaintenance” conducted to prevent failures and accidents.
In addition, preventive maintenance generally refers to “Time Based Maintenance (TBM)”,
which is conducted to replace parts or repair on occasions such as patrol/regular inspections
according to schedule after the lifespan of components is estimated based on the specifications andother documents.
However, since each of the wind turbines is subject to different wind strength and operating
hours depending on their installed environment, the progression of degradation or fatigue ofcomponents also differs. TBM thus fails to prevent failures, resulting in low availability of windturbines for some cases.

Figure 2

Systems of facility maintenanceWe, therefore, recommend adopting another method of preventive maintenance: “Condition
Based Maintenance (CBM)”. In CBM, facility diagnosis is performed by collecting and analyzing
the operational data to detect signs of parts deterioration at an early stage. Thus, timely action can beMitsubishi Heavy Industries Technical Review Vol. 60 No. 3 (September 2023)
3taken. This prevents a serious failure or accident from happening, while the effects such as higher
availability and lower repair costs can be expected.
For developing the function of “facility diagnosis”, which is essential to the realization ofCBM, MHI uses the operational data and failure history for the past 10 years or more. The algorithm,
which the data of both abnormal and normal operation conditions are statistically analyzed toautomatically identify abnormal signs, is being verified.
Figure 3 illustrates the mechanism of facility diagnosis more specifically. The characteristic
data required to identify abnormal conditions are extracted from the daily operational data, and themeasured values are compared with the planned values to automatically determine if there are any
abnormal signs. The results will be automatically sent to the customers.

Figure 3 Conceptual diagram of facility diagnosis by Maintenance Support Tool

The Maintenance Support Tool is equipped as standard with this function of facility diagnosis.
Therefore, CBM can be realized without burdening customers with an extra workload.
Furthermore, facility diagnosis can provide indications of equipment/facility abnormalconditions and their degree of degradation. This enables to determine which repair work should beprioritized and which parts replacement or repair work is unnecessary, thus helping to optimize
maintenance costs.

|3. Line-up of Maintenance Support Tool functions
Based on the voices of the customers who have maintained wind turbines for many years, ourMaintenance Support Tool has repeatedly expanded its functions in the form of a solution proposal
for various issues that are not limited to facility diagnosis. Figure 4 shows the major line-up of thefunctions. These groups of functions for maintenance support can be divided into two groups: one inwhich the standard functions are put together as the basic package, and one in which the optional
functions are lined up for customers to choose one by one depending on their needs and budget.

Figure 4Group of functions for maintenance support

The following is a summary of the functions.

Mitsubishi Heavy Industries Technical Review Vol. 60 No. 3 (September 2023)
4(1)Basic package
This is a start-up package consisting of the basic functions that are expected to be usedfrequently in the process of operational maintenance, including facility diagnosis.
In operational information reporting and facility diagnosis (sign detection), operational
data are automatically collected on a daily basis, which are then outputted in a format useful for
operation management. Other functions include the presentation using a graph (visualization) tomake it easy to compare units or analyze them, and the automatic notification in the case ofabnormal signs being observed in certain types of equipment.
Reference to maintenance drawings and reference to technical data/construction records
are the functions by which drawings or technical data required for on-site maintenance work canbe accessed from tablets and smartphones.
(2) Options for technical support services by MHI engineers
This subgroup of options is related to the technical advice services for customers who
consider it necessary to receive technical support such as dealing with problems in direct dialog
with MHI engineers, and/or for customers who require the facility diagnosis report to besubmitted on a regular basis.
(3) Options for operation management support
This subgroup pertains to the function that can be used to manage the history of each windturbine and spare parts stock. Specifically, customers can easily enter their daily maintenance
operation records (such as maintenance records, construction records, and troubleshootingrecords) via tablets or smartphones to store related information as a database.
(4) Options for upgrading control system
There is also a group of other optional functions to meet a variety of customer needs,
including changing the function of the wind turbine operation control system.
The past examples of the expanded functions include the output control system enabling
the target output of the entire wind farm or each wind turbine to be set at an arbitrary value, thesmart time function to monitor the diagnosis results and the real-time trend data via smartphones
and tablets, and the SCADA (Supervisory Control And Data Acquisition) backup system that canbe used as an alternative monitoring system when the remote monitoring system fails to function.

|4. Expected advantages from using tool
The use of our Maintenance Support Tool is expected to give the following advantages to thecustomers who operate wind turbines.
(1) Improvement of work efficiency- Labor savings in reporting on operation/maintenance records- Improved efficiency of the tasks for regular inspections and periodic service inspections- Improved efficiency in organizing and visualizing data required to make a decision on
construction plan or business management(2) Better maintainability- Understanding of facility conditions to realize appropriate planning of regular inspections
and repair work
- Detection of abnormal signs to avoid the long-term shutdown due to the failure of parts, andprevent a serious failure from happening(3) Higher profitability- Reduction of management costs owing to the improved work efficiency- Reduction of repair costs because of preventive maintenance- Increase in revenues by dealing with abnormal signs at an early stage and reducing thedowntime (i.e., higher availability)|5. Future prospect
Making use of its experience and expertise accumulated through the years of engagement in
the wind power generation business, MHI’s Wind Energy Department has been taking up thechallenge to support customers who are faced with various difficulties in operating wind turbines.

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Specifically, we offer engineering support services for the various wind turbines of othermanufactures including offshore wind turbines.
Likewise, we are currently working to make our Maintenance Support Tool applicable to theother manufacture’s wind turbines. A large-scale introduction of wind power will take place toachieve carbon neutrality. We will further proceed with DX and contribute to realizing a sustainable
society by meeting the needs of customers who want to realize long-term stable operation of windfarms.