Mobile monitoring of small hydropower plants.
Production equipment is needed to perform a production process. The installed equipment is a complex high tech machinery used in discrete manufacturing, process industry or energy production. Not only design, development and manufacturing but also operating and the maintenance of such equipment require high level specialized knowledge and skills, which are, especially at the beginning of exploitation, usually not gained adequately by its user. The operational performance, such as the output, costs, quality, equipment utilization, availability is far from optimal, as a consequence. The root of the problem lies in the existing relation between the customers and suppliers of production equipment, which are predominantly based on a traditional buy-sell relationship. This relationship is concentrated on acquisition and delivery of equipment and as such does not offer acceptable support to end users.
The customer and supplier relationship has to be transformed into a new one, with the focus on equipment utilization by providing products and related services for the entire equipment life cycle. The idea of a product service system has been introduced. It is defined as a marketable set of products and services capable of jointly fulfilling user's needs (Goedkoop et al., 1999). An industrial product service system is an integrated product and service offering that delivers values in industrial applications (Meier, 2009). The way of thinking leads to new business models including new financing concepts from buying or leasing to "pay-on-production" (Meier, 2004).
In the project a new customer/supplier business model is being researched. It is based on a lasting partnership and collaboration among a customer, an original equipment manufacturer, suppliers and service providers. It is focused on the equipment utilization by providing products and related services. It is expected that due to the synergetic effects, better equipment utilization could be achieved and thus additional value could be generated and fairly shared among partners.
The business model incorporates the adequate on-line information service system, which provides information services related to equipment operations. The system has to make the equipment's behavior visible to all stakeholders in real time. Therefore, needs for services can be detected and provided adequately at the right time.
Implementation of services into complex industrial equipment is possible only with the use of new communication and information technologies (Selak & Sluga, 2009). They enable cost effective and reliable monitoring and control of production equipment.
In the research, small hydropower plants (SHP) are being considered as a prototype implementation of the information service system. There are approximately 500 SHP-s which operate in Slovenia, most of them ranging from 25 to 100 kW of output power. They provide about 12 % of electricity produced from renewable sources (Slovenian small hydro power association, 2009). The majority of them were built in the 90-ties by private landowners. Building renewable energy plants was encouraged by government's policy with subventions and bounties. Many of them are rather simple designed and controlled only manually.
The manual control is performed like this. An operator occasionally goes to a plant, typically located in remote, hardly accessible areas, and visually inspects various parameters, such as dam water level, output electric power, bearings temperature, vibrations. Based on the identified state, he sets a reference value for control manually. He manipulates guide vanes opening according to head, energy production and assurance of ecologically acceptable water flow in a river bed. Then, the plant runs according to this setting until he inspects it again. During this interval the situation on the plant may change. For example, it can happen that the power-plant is cut out from the electricity grid and the plant is out of operation for hours. In such a case the operator has to activate the system manually. It is evident that such control is not adequate.
Because of all problems mentioned above the decision about developing a system for remote monitoring and control of a SHP was made to enable more efficient and effective operations. It has been realized as a modular service system for mobile monitoring and control.
2. REMOTE INFORMATION SERVICE SYSTEM
The basic objective of the information service system is to provide the following remote services to operators and other stakeholders concerned in safe and efficient SHP operations: (1) operation monitoring, (2) activation and deactivation of the plant, (3) guide vanes manipulation, and (4) alarming about abnormal and critical situations.
The developed system is implemented as a functional prototype of a remote service system in SHP "Volaka", which uses a Francis type turbine with nominal output power of 70 kW. The remote service system consists of the following units:
* data acquisition system with sensors and signal processing for collecting data about key operational parameters;
* control loops for plant activation/deactivation and manipulation of the guide vane opening;
* on-site control and monitoring system based on a PC with control software, database and internet server;
* web application for remote users;
* short message service (SMS) module for alarms; and
* mobile communication network.
The mobile communication is selected because a broadband connection is usually not available on SHP sites and because it suits better mobile users and enables around-the-clock availability which is needed during 24/7 plant operations.
[FIGURE 1 OMITTED]
Fig. 1 shows the semi-operational scheme of the remote service system integrated in a small hydro power plant.
Several plant operational parameters, e.g. output power, dam water level, guide vanes angular position, temperatures of critical elements and generator frequency, are constantly measured and monitored. The acquired data are logged into the database and enable visualization of an actual situation and elaboration of periodical reports, invoices for customers, etc.
Measurement of output power and produced electric energy is the basic information on power-plant operation. The output power depends on the flow and dam water level. Power readings are acquired from a digital power meter periodically. Any deviation in operations (e.g. generator speed increase, power loss, water level fall) is reflected in this measurement and results in a corresponding control action and/or triggering of an alarm message to the operator.
Three functionalities are enabled for remote users: plant monitoring, remote control and access to the database. A remotely located operator connects with a laptop computer to the mobile network and logs onto a mobile private network within the public one. The mobile private network interconnects the SHP control and monitoring system with remote users. The crucial advantage of the mobile network lies in its ubiquitous signal. Business users are entitled to communicate business data with a safe private mobile IP network. Inside such a private network communication between any particular SIM card is possible anytime anywhere. An APN (access point number) and a password are assigned to the user, and each SIM card obtains its own IP address.
[FIGURE 2 OMITTED]
Once connected, the operator can access to the SHP via a web application. This application enables him to view the monitoring data and to trigger the appropriate actions when necessary. Fig. 2 shows a typical screenshot of the application.
The described remote service system has been in operation for several months. During this time the following advantages have been identified:
* energy production is increased for about 5 % in average;
* sensing of selected operations parameters and graphic user interface improves the insight in the SHP, which makes its operation easier;
* remote monitoring and control facilitates operator's work;
* flexible system design enables easy adoption of the system;
* alarm messaging is automatic and prompt;
* database offers numerous reporting possibilities and automation of various functions;
* better control of water flow due to prompt water level observation and remote control of guide vanes;
* moderate communication costs and adequate security.
The implemented remote service system shows economical, technical, social and ecological benefits of integrating product and services. This knowledge will used further on in the EUREKA project E! 5343 "Collaborative platform for operations support of work systems--case of hydro power plants" with the cooperation of two OEM providers with competence in diagnostics, one software provider for supporting collaboration, and one operations and maintenance provider. The major aims of the project are to research the issue of relationship between customers and suppliers of production equipment and to develop a new business model of this customer/supplier partnership and adequate services related to support of equipment operations and maintenance. That would significantly improve the equipment utilization and contribute to competitiveness of customers, OEMs and service providers.
This work was partially supported by Slovene Ministry of Higher Education, Science and Technology, Grant No. P2 0270 and Grant No. 1000-09-310150.
Goedkoop, M.; van Halen C.; te Riele, H. & Rommens, P. (1999). Product Service Systems, Ecological & Economical Basics, Pre Consultants, the Netherlands, 1999
Meier, H. & Massberg W. (2004). Life Cycle-Based Service Design for Innovative Business Models, CIRP Annals Manufacturing Technology Vol. 53, No. 1, 393-396
Meier, H. (2009). Industrial Product-Service Systems IPS2, IPS2 Spring School, Cranfield, February 2009
Selak, L. & Sluga A. (2009). Mobile control of a small hydropower plant (in Slovene), Ventil, Vol.15, No. 3, 240245, ISSN 1318-7279
Slovenian small hydro power association, Available from: http://www.zdmhe.si/, Accessed: 2009-09-24
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|Author:||Selak, Luka; Sluga, Alojzij; Butala, Peter|
|Publication:||Annals of DAAAM & Proceedings|
|Date:||Jan 1, 2009|
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