Detection and diagnosis of faults in electrical machines in steady state and transient conditions.
The detection and diagnosis system reports the presence of rotor faults and the existence of eccentricity in electrical machines and serves to prevent these faults from leading to a catastrophic failure of the machine, and consequently to unscheduled shutdowns, thus eliminating their negative impact on the company’s activities. In this way, the condition of the induction motors is known and maintenance, repair or replacement measures for the machines evaluated can be programmed in advance.
This system is based on the non-invasive measurement of the motor stator current and, in some cases, also of its supply voltage and also adapts to any type of power supply, whether direct from the mains or via inverter. In addition, the motor can work in steady state or in transient, such as starts and stops or speed variations.
The members of this GIR have extensive experience in continuous or punctual monitoring of induction motors of any power and any voltage level, as evidenced by the studies carried out for companies such as FACSA, Fertiberia, Volconsa, Redalsa, Sanidad de Castilla y León, Renfe, Hidromedia, etc.
Thanks to this experience we can offer to any interested company a diagnostic service for their induction motors to prevent failures such as rotor bar breakage or eccentricity from leading to a catastrophic failure of the machine that would mean an unscheduled stop of the company’s activity, common failures in submerged pumps and in other uses characterized by work cycles with frequent starts and stops. Bearing diagnosis is also possible if additional bearing information is provided.
Measurement, calculation and analysis of electric power quality
The concept of Electric Power Quality is becoming more and more relevant due to the awareness that the competitiveness of companies depends on it as it is directly related to their efficiency and productivity, mainly in the industrial sector, and there is an increasing interest in its study with the purpose of optimizing electrical systems or productive facilities.
According to the international standard IEC 61000-4-30 in standard terms, “Power Quality” is defined as the characteristics of electricity at a given point in the electrical network, evaluated in relation to a set of technical reference parameters.
Approximately 20% of power quality disturbances or losses originate in the electrical production and distribution systems, while the remaining 80% take place in the user’s own installations, mainly due to the increasingly sophisticated current production processes, the use of power electronics, the use of inductive motors, the implementation of in-house generation systems and the strong increase in the demand for electrical energy, together with the poor condition or deficient dimensioning of the installations.
It is these disturbances in the user’s own installations on which action can be taken, since they are located downstream of the supply and within the installations themselves, and they are the ones on which the members of this GIR have been working and researching for years, as supported by the projects and publications developed in this regard.
Specifically, disturbances can be generated by overloads in circuits and transformers, poorly dimensioned and incorrectly connected neutrals, unbalanced loads, poorly tightened connections, harmonics caused by electronic loads and reactive energy due to the use of inductive elements, among others. All of them significantly affect the quality of the electrical energy that circulates through the installation, causing serious inconveniences and operating complications in the devices connected to the network, reduction of the life cycle of equipment, as well as very important cost overruns due to maintenance and unwanted consumption leaks.
The main objective of this line of work is to develop protocols for measuring the quality of the power supply in all types of electrical installations, implement algorithms to detect quality events and develop procedures for quality analysis, possible repercussions and corrective measures.
To help achieve this goal, “smart” instruments are being developed to measure electrical (and other signals, if necessary) and have computational capabilities to perform energy calculation and monitoring of events, disturbances and quality problems.
Reliability and Maintenance of Electrical Installations
The reliability of electric power supply could be defined as the property of a power system to satisfy, continuously, the energy demand required by the consumer and to maintain its operating rates within the pre-established limits for given regimes and working conditions, during a given time. The importance of the study of reliability derives from the effects of the losses that arise when the energy supply fails, which sometimes go beyond what is no longer produced.
The members of this GIR have extensive experience in the analysis of the reliability of electrical systems, as evidenced by their participation in projects and publications focused, in particular, on the following installations:
Analysis of the railroad’s Overhead Contact Line, where, in addition to a study of its reliability, reliability-based maintenance techniques, RCM techniques, were proposed.
- Reliability analysis of electrical distribution networks.
Analysis of hospital electrical installations. Proper maintenance is essential for the proper functioning of any industrial company, as it has a direct impact on its production process. It is a very important aspect to take into account in the development of any productive field, having as final objective to guarantee the production in any industrial process, its quality and to maintain a correct operation of the equipment extending its useful life.
In this sense, the members of this GIR have been working for years in this field from two points of view:
Directly related to the previous lines, by means of the application of techniques and procedures previously mentioned, particularized for an adequate maintenance of machines and electrical installations.
In particular, and more recently, we have focused part of our work on improving the maintenance of photovoltaic solar modules, which is a milestone of great interest because their loss of efficiency directly affects the productivity of photovoltaic plants, which has recently been widely implemented.
The early detection of possible faults in these panels would be an important achievement as they contribute about 60% to the cost of the plant and, therefore, their correct operation is needed to ensure their profitability and efficiency, and since there are many common causes of their incorrect operation, we are working on different techniques for inspection of defects in solar photovoltaic cells and modules, such as:
Measurement of the module’s solar photovoltaic parameters and their comparison with the module specifications (e.g. I-V curve measurements).
Use of cameras that access different regions of the electromagnetic spectrum (Short Wave InfraRed (SWIR) for electroluminescence (EL) measurements and Long Wave InfraRed (LWIR) for infrared thermography measurements.)
Consumption Prediction and Energy Efficiency
An efficient use of energy must be a necessity to be achieved in any field, both in the search for a reduction in electricity costs that will result in financial savings for the consumer, and in the reduction of greenhouse gas emissions that will provide a social benefit.
In order to ensure that energy consumption is sustainable and responsible, it will be necessary to have a high level of knowledge that will allow us to determine the existence of unnecessary consumption, optimize daily demand, balance loads, optimize electric energy generation and storage systems, if they are available, etc. If, in addition, the liberalization of the energy market is taken into account, the knowledge extracted can be used to improve negotiations with the supply company, thus reducing costs.
In this line, the members of this GIR have extensive experience in conducting electrical energy audits, and in the development of procedures that have allowed characterizing and modeling electrical energy consumption in buildings, as evidenced by the publications and projects developed for the Regional Health Management of Castilla y León (SACYL).
This work is being continued with the research work that is currently being undertaken aimed at the prediction of consumption in buildings, with the aim of defining a tool to anticipate consumption and serve as an instrument for proactive energy management system that allows not only to optimize consumption but also to have immediate information of any anomaly that might occur in such consumption.
Renewable energies and integration with Distributed Generation (DG) in Smart Grids and Microgrids
Study of the effect of the penetration of renewables in the form of DG in Smart Grids and Microgrids. It is also intended to investigate the effect of electrical/electronic elements on data transport in low/medium voltage through PLC (specifically in low voltage by means of PLC PRIME) and to address the design and implementation of efficient Microgrids.
The effect of DG and electrical storage elements on PLC-based communications systems is critical. The loss of communications in PLC-based systems influences the power quality associated with electrical and electronic devices distributed at low voltage.