Electromechanical Systems

Electromechanical systems are a general term for devices that integrate electrical energy with mechanical motion, enabling energy and information conversion between these two physical domains. These systems not only convert electrical energy into mechanical work (actuators/motors) or mechanical motion into electrical signals (generators/transducers), but also manage the reciprocal conversion processes between energy and information. As seen in hard disk drive (HDD) technologies, the encoding of energy into digital information via magnetic flux variations and the transfer of processed information into mechanical positioning signals characterize the information-based energy management capability of these systems.

Operation of an Electromechanical System

The operational mechanism of electromechanical systems is based on physical interactions that occur during the transfer of energy from one form to another. This process is carried out according to the following fundamental stages and principles.

Principles of Energy Conversion

The functioning of electromechanical systems is grounded in classical laws of electromagnetism and theories of electromechanical energy conversion. Energy conversion in these systems typically occurs through the following fundamental physical approaches:

• Electromagnetic Force and Induction (Commonly Used Foundations): The Lorentz Force and Faraday’s Law of Induction are the most frequently referenced principles in the conversion of electrical energy into mechanical motion (motor effect) or mechanical motion into electrical energy (generator effect).
• Energy and Co-energy Principles: This approach, based on the conservation of total system energy, is used to analyze how energy stored in a magnetic field is converted into mechanical force, particularly in nonlinear magnetic circuits such as reluctance motors or electromagnets.
• Field Equations and Circuit Characteristics: Maxwell’s equations and Ampère’s Law determine the magnetic flux density and field distribution within the system, defining the efficiency and limits of the conversion process.
• Special Conversion Mechanisms: In certain specific applications, material-based conversion principles such as piezoelectric or magnetostrictive effects also enable electromechanical interaction.

Operational Stages of the System

The operational process of an electromechanical system begins with the interface between low-power data signals from a control unit and high-current energy supplied by a power source. In modern systems, this stage is not merely an energy input but also a decision-making mechanism that interprets incoming commands from a driver circuit and regulates energy delivery. Upon triggering, electrical energy is transmitted to the system’s active components, where a physical field transformation occurs. The magnetic flux generated in coils or the electric field in piezoelectric materials converts energy from a static form into a field form capable of producing potential work.

This generated electromagnetic field interacts with moving components of the system—such as rotors or pistons—to produce mechanical force. This interaction, shaped by the Lorentz force or reluctance principle, generates torque or linear motion, enabling the system to transition from a static state to a dynamic one. The resulting kinetic energy is transmitted to the point of final application via shafts, gears, or precision actuators, and the process is not limited to unidirectional transfer.

In the final stage of operation, position and velocity data obtained through sensors complete the system’s information loop. These feedback signals, derived from mechanical motion, are converted back into electrical signals and transmitted to the control unit. Thus, a continuous cycle is established between energy, mechanical action, and information, ensuring high-precision operation and stable fulfillment of the intended function.

Feedback and Control Loop

Modern electromechanical systems do not merely convert energy; they also regulate this conversion. Sensors integrated into the system—such as encoders and tachometers—measure the speed, position, and torque of mechanical motion and transmit this data to the control unit. Based on this information, the electrical input is adjusted in real time to ensure stable and precise system operation.

Energy Losses and Efficiency

During operation, not all energy in electromechanical systems is converted into useful output. Various losses occur during energy conversion or transfer. These primarily include copper losses due to electrical resistance in conductors, iron losses caused by hysteresis and eddy currents from time-varying magnetic fields, and mechanical losses arising from friction and air resistance. These losses are fundamental factors directly affecting overall system efficiency. The goal in electromechanical system design is to minimize these losses as much as possible to enhance the effectiveness of energy transfer or conversion.

Components of Electromechanical Systems

Electromechanical systems require the coordinated operation of specific key components to convert electrical input into physical output (or vice versa). These parts are examined in three main functional groups:

Energy Conversion Units (Actuators)

These components form the “muscle” structure of the system and play a role in energy conversion or the creation of physical interactions. However, not all of these components directly convert energy; some merely facilitate switching or interaction between electrical and mechanical domains.

Electric motors are among the most commonly used components in electromechanical systems. These structures generate rotational motion through magnetic field interactions between the stator (stationary part) and the rotor (moving part). Motors are classified as alternating current (AC) or direct current (DC) motors based on their operating principles and power supply types and are considered primary examples of devices converting electrical energy into mechanical energy.

Solenoids are electromagnetic devices that produce linear motion when an electric current passes through them. They are commonly used in applications such as valve control, actuation of locking mechanisms, or any scenario requiring short-stroke linear motion. Such components exemplify specialized electromechanical structures where an electrical input is converted into a mechanical response.

Relays, however, are not energy conversion components. They function as electromagnetic switches that physically open or close a higher-power electrical circuit using a small electrical control signal. In this capacity, relays serve as components that enable architectural separation between signal and power paths in electromechanical systems.

Sensing and Feedback Units (Sensors)

These components function as the “sensory organs” of electromechanical systems. They detect changes in mechanical conditions within the system and convert this information into electrical signals, transmitting it to the control unit. This enables monitoring of system status and the establishment of feedback-based control mechanisms.

Encoders detect the angular position, rotation amount, and rotational speed of a shaft and generate this information as digital signals. They are critical in applications requiring precise positioning and motion control.

Tachometers are sensors designed to measure the rotational speed of moving parts. The acquired speed data is used to monitor system performance and regulate speed.

Limit switches detect whether a mechanical component has reached a predefined boundary point through physical contact. These switches are widely used in control circuits to ensure safe system operation and prevent mechanical overtravel.

Transmission and Support Components (Mechanical Elements)

These components serve as passive mechanical elements that modify and regulate the direction, speed, or transmitted force of mechanical motion generated within electromechanical systems. They do not directly produce or convert energy but play a decisive role in system functionality by ensuring motion is transmitted in the desired manner.

Gearboxes and shafts transmit mechanical energy to the point of application by altering the torque and rotational speed produced by a motor or similar driving element according to application requirements. These structures enable controlled and efficient power transmission.

Bearings and bearings are used to reduce friction between moving parts and to support loads appropriately. This minimizes mechanical wear, extends system lifespan, and ensures smoother motion.

Couplings connect two separate shafts to transmit mechanical power. They also accommodate installation tolerances and compensate for minor shaft misalignments, contributing to the safe operation of the system.

Control and Power Interfaces

These components serve as elements that regulate and direct the flow of energy in electromechanical systems. The manner in which electrical power is delivered to motors or other components depends on the proper design and use of these structures.

Drivers (driver/inverter) are power electronics-based units that adjust the frequency, amplitude, or voltage of electric current to control the speed, direction of rotation, and torque of a motor. By acting as an intermediary layer between control signals and the power path, they enable the control system to influence motor behavior.

Brushes and commutators are conductive mechanical parts in direct current (DC) machines that transfer electric current from the stationary part to the rotating part (rotor). These components enable the reversal of current direction based on rotor position, forming the fundamental basis of DC machine operation.

Fault Diagnosis and Condition Monitoring

In electromechanical systems, fault diagnosis and condition monitoring are technical processes applied to ensure operational continuity and prevent unexpected shutdowns. These processes rely on continuous monitoring of physical parameters and analytical interpretation of collected data.

Condition Monitoring Methods

The operational health of electromechanical systems is monitored by comparing measurement data from components against predefined reference values. This monitoring process forms the foundation of predictive maintenance approaches aimed at detecting failures before they occur.

Vibration analysis is widely used to identify mechanical problems such as bearing wear, shaft misalignment, and imbalance. Changes in the system’s characteristic vibration frequencies are monitored to detect mechanical degradation at early stages.

Thermal monitoring involves examining abnormal temperature increases in system components. Overheating in windings, loose electrical connections, or heat from friction are monitored using infrared (thermal) cameras and temperature sensors. This method is used to identify both electrical and mechanical issues.

Current signature analysis (Motor Current Signature Analysis – MCSA) analyzes harmonic components and irregularities in the current drawn by the motor. This analysis enables prediction of electrical faults such as broken rotor bars, winding short circuits, or magnetic imbalances before the system is shut down.

Acoustic monitoring uses ultrasonic sensors to analyze sounds generated by friction, leaks, or arcing at frequencies beyond human hearing. This approach is considered a complementary diagnostic method, particularly effective in detecting early-stage faults.

Fault Diagnosis Processes

When an anomaly is detected in the system, various analytical approaches are employed to accurately determine the root cause of the fault. These methods aim not only to identify the symptom but also to uncover the underlying factors causing the failure.

• Root cause analysis evaluates whether a fault originated from a manufacturing defect, electrical fluctuation, or physical factors such as mechanical fatigue, based on technical data. This method plays a critical role in preventing recurring failures.
• Fault tree analysis (FTA) provides a logical framework to evaluate all potential component failures that could lead to a system-level fault. Possible failure combinations are analyzed through diagrams based on cause-effect relationships to trace pathways to the fault.
• Digital model comparison uses the system’s digital twin. Theoretical data from the digital model is compared with real-world operational data collected from the field to determine the magnitude and nature of deviations in system behavior. This method serves as a complementary analytical tool, especially for evaluating complex systems requiring high precision.

Maintenance Strategies

Data obtained from diagnosis and monitoring processes directly shape maintenance planning in electromechanical systems. This data enables determination of when and to what extent maintenance activities should be performed.

Predictive maintenance analyzes time-dependent trends in monitoring data to predict potential failures before they occur. Intervention timing is determined based on deviations in measured parameters. This method is applied to reduce unplanned downtime and improve the efficiency of maintenance operations.

Preventive maintenance is based on scheduled maintenance regardless of monitoring data, relying on operating hours, number of cycles, or time intervals. Periodic activities include part replacements, cleaning, and general inspections. This approach aims to maintain system reliability.