Electric drives and actuation
Converting electrical energy into controlled motion
An electric drive is designed to generate a defined motion. To do so, it must deliver the required torque and the necessary speed or velocity and remain controllable even under changing loads. With an actuator, there is the additional question of how the generated motion or force is transmitted to the mechanical or hydraulic function. What matters, therefore, is not a single component but the coordinated overall system.
Silver Atena develops and integrates electric drive systems and actuation. We consider the motor, power electronics or inverter, sensors, control, mechanics and power supply together. The design is based on the function the system has to perform – from the highly dynamic drive of an auxiliary unit to the electric actuator for a safety-relevant function.
Challenges in electric drives and actuators
The performance of a drive results from the interaction of several components. The motor must suit the load and the operating range. The inverter must provide the required currents and voltages. The control system must produce the desired behaviour while taking into account the electrical, thermal and mechanical limits of the system.
Designing these components separately risks conflicting objectives. The drive may not achieve the required dynamics, losses lead to high heat generation or the power supply limits the available power. Sensors and signal processing also influence how accurately, dynamically and reliably the drive can be controlled.
In safety-relevant applications, aspects such as unintended start-up, unwanted movements, incorrect torques and loss of the drive function must be considered. The monitoring functions and fault responses required depend on the application and the derived safety requirements.
Services for electric drive systems and actuation
Our scope of expertise covers electric, electromechanical and electrohydraulic actuators as well as highly dynamic drives. In addition to functional behaviour, we consider diagnostics, protection functions, thermal load and electromagnetic compatibility (EMC).
System design and component alignment
Development begins with a measurable description of the task. This includes the required motion or power, relevant loads, load spectra and operating states, as well as the limits resulting from supply voltage, available power, installation space, cooling and environmental conditions.
From these boundary conditions, we derive the requirements for the components involved.Motor and inverter alignment
The motor and inverter form the core of the electric drive. Their alignment influences the usable operating range, dynamics, efficiency and thermal load. At the same time, the interfaces to the power supply and the control system must fit into the overall concept.
The development of the power stage builds on our expertise in power electronics and DC/AC inverters. Which parts of the motor design, component selection and integration Silver Atena takes on is defined for each project.Motor and position control
Depending on the application, a drive may need to generate a torque, maintain a speed or move to a position. The control system processes setpoints and measured variables and uses them to calculate the manipulated variables for the inverter and the motor.
Silver Atena develops control systems tailored to the motor, load and required functional behaviour.Sensors and feedback
Controlled motion requires reliable information about the system state. The measured variables and sensors required depend on the function and the control concept. Sensors, signal processing and control are therefore designed together.
The design also addresses the effects of missing or faulty feedback. This results in requirements for plausibility checks, diagnostics and monitoring.Diagnostics, protection and operating strategies
A drive must be able to cope with changing operating conditions and specified fault cases. Diagnostic functions detect relevant states. Protection functions and operating strategies trigger the responses defined for them.
The operating strategy links the desired function with the limits of the system. Among other things, it takes into account the available electrical power and the thermal load, for example through defined power or torque limiting.Integration, test bench testing and qualification
After the design phase, electronics, software, sensors and drive components must work together as a system. Silver Atena integrates the components involved and examines their behaviour in suitable test environments.
Test bench tests and system verification show whether the drive meets the specified requirements. Validation assesses whether the system is suitable for its intended use. Environmental and load tests derived from the requirements complement the functional evidence and, where required, support project-specific qualification.
Development process for electric drives
- Requirements and system concept: Operating states, loads, interfaces, environmental conditions and safety requirements are captured. This results in the system concept, the architecture and the allocation of functions to components. At the same time, it is defined how the requirements will later be verified and validated.
- Design and simulation: Motor, power electronics, sensors, control and mechanics are aligned with one another. Simulation supports the design and enables initial evaluations of operating range, dynamics, losses and thermal load before all components are available as physical prototypes.
- Integration and commissioning: As maturity increases, hardware and software are brought together and tested first at component level and then in the integrated system.
- Verification and qualification: Measurements, test bench tests and project-specific qualification tests provide evidence that the defined requirements are met.
Findings from integration and testing feed back into the requirements, models, design and operating strategy. If, for example, the drive does not achieve the required dynamics or its thermal load rises too much, the cause is investigated in the interaction of components and operating strategy.
Methods and standards for electric drives
System simulations model the interaction of motor, electronics, control and load. They support concept evaluation and control design. Measurements and test bench tests then show how closely the real behaviour matches the model and the requirements.
For safety-relevant automotive applications, ISO 26262 may be decisive. Cyber security requirements may arise from ISO/SAE 21434.
In civil aviation projects, depending on the development scope, DO-178C for software, DO-254 for electronic hardware and ARP4754B for the development of aircraft and systems may be relevant. Safety analyses can be based on ARP4761A. The applicable standards, issues and evidence are defined for each project.
Electric drives in automotive, aerospace and defence
Automotive
In vehicles, electric drives perform tasks in the powertrain, in auxiliary units and in actuators whose function is closely linked to the overall system. Silver Atena develops solutions for active chassis systems, high-voltage traction drives and high-speed drives for turbo compressors. The applications differ in load, power and dynamics.
Aerospace
In aviation, electric systems drive actuators and auxiliary units as well as, in electric or hybrid concepts, the propeller or fan. Mass, installation space, power supply, environmental conditions and safety requirements shape the system design.
Silver Atena develops motor control electronics for electric slat and flap drives. They control the motor and the associated brake and are integrated into the aircraft's high-lift system.
For electric and hybrid aircraft propulsion, we combine drive electronics and control with system design in electric propulsion.Defence
In defence applications, electric drives are designed to meet the respective functional, environmental and safety requirements. Robustness and defined behaviour under the intended operating conditions are key design objectives. Depending on the project, factors such as temperature, vibration, shock, electromagnetic environment and power supply determine the design and the required scope of evidence.
Benefits of a coordinated drive design
Designing the motor, inverter, sensors, control and mechanics together makes interactions visible at an early stage. Dynamics, electrical supply, thermal limits and mechanical load can thus be evaluated in context.
This creates a traceable basis for integration. Operating ranges and limits are defined, interfaces aligned and the necessary diagnostic and protection functions specified. This reduces the risk of late adjustments between components. Specific improvements in efficiency, dynamics or integration effort, however, depend on the application and starting point and must be demonstrated on the respective system.
Electric drives across engineering disciplines
Electric drives and actuation are linked to several development disciplines:
- System architecture and system integration define the technical structure and the interfaces.
- Power supply, on-board power system and charging technology define the electrical boundary conditions.
- Control development and embedded software implement the desired behaviour and the operating strategies.
- Mechanics and enclosure determine the design, installation space and protection of the components. EMC and thermal management influence immunity, emissions and heat dissipation.
- Functional safety and cyber security derive project-specific requirements and measures from the respective analyses.
- Test systems, testing and validation and environmental testing contribute to the required evidence together with analyses, reviews and simulations.
Why Silver Atena for electric drives?
Silver Atena develops electric drives through the interplay of system, power electronics, control engineering, embedded software and testing. This allows interfaces and conflicting objectives to be addressed across disciplines.
Applications range from chassis and high-speed drives to motor control electronics for aviation. This project experience supports the design of interfaces, control, diagnostics and testing.
Discuss the electric drive system for your project
Are you planning an electric drive or actuator? Discuss the function, operating conditions, interfaces and the development scope you need with our team.