What are Electrical Machines?
We use electrical machines to convert mechanical energy into electrical energy as a generator, to transform and distribute electric energy, and to convert electrical energy into mechanical as a motor. Electrical machines support our modern life in a multitude of ways and are indispensable to electrification on our way into a more sustainable future with fewer carbon emissions. Maximizing the energy efficiency of electrical machines is crucial to minimizing resource consumption.
What are the Benefits of Simulating Electrical Machines?
Electromagnetic simulation supports performance and sustainability targets by helping to create machines that use fewer resources, provide higher efficiency, and produce less noise and vibration. Engineers can optimize their designs to produce maximum efficiency in the required operating regime and to find the best trade-offs between competing design factors.
How are Electrical Machines Simulated?
Electrical machines are complex devices that by definition require multiphysics simulation capabilities. Electromagnetic forces translate into torque in a motor, and conversely, the rotation of a generator generates electromagnetic power. Analyzing the conversion between the two requires a motion analysis, capturing the changing behavior of the machine over time. Ripples in the torque curve can give rise to noise and vibration in the machine. The large currents inside electrical machines can also cause significant heating.
The precise evaluation of the coupling of electrical to mechanical forces requires comprehensive material modeling options. Besides the traditional electric losses in realistically modeled conductors. Modeling options also include magnetization and demagnetization effects in service. We are able to consider Iron losses such as eddy current, hysteresis, and excess/rotational losses explicitly during the simulation. The losses can be used in a thermal analysis of the machine.
System Simulation of Electrical Machines
An electrical machine is always part of a larger system, with electrical circuits and controllers on one side and transmission mechanisms and gearboxes on the other. The simulation model can be connected as a functional mock-up unit to a representation of the entire system, including controllers, for a system simulation of the behavior of the machine in real-world scenarios.
Electrical Machine KPIs
Electrical machine KPIs that can be calculated with simulation include:
- Saturation curves
- Short-circuit analysis
- Open-circuit analysis
- Inrush current/load test
- Switch-on transients
- Losses – copper, eddy-current, hysteresis
- Dynamic forces on coils
Electrical Machine Simulation Applications
Energy efficiency is absolutely crucial for reducing operating costs, increasing vehicle range and meeting sustainability goals. Simulation can optimize electrical machines to increase efficiency. Efficiency typically varies according to speed and torque – automated simulation can quickly calculate and map efficiency over the entire operating regime without the time and cost of physical testing.
Switch-on transients and in-rush current
When a machine is switched on, current rushes into the coils. This produces transient effects that are different from the machine’s steady state operation. Time domain simulation models the behavior of the machine in the first critical moments and helps ensure that it can reach optimal performance from a stationary state.
Stray field and shielding analysis
The field strength inside a large motor or generator can be immense, and these fields are capable of interfering with sensitive devices. Shielding prevents field leakage, but adds cost and weight. Simulation allows shielding to be optimized to target the places where it is needed most to meet electromagnetic compatibility (EMC) requirements and weight requirements together.
Noise and vibration
For many applications, especially motors for domestic appliances and electric vehicles, noise and vibration are two of the most important KPIs to target. Noise can be caused by magnetic effects (for example cogging torque), mechanical effects (for example bearings), or windage (airflow through the machine). Multiphysics simulation can model these different sources and help to minimize or mitigate noise and vibration.
Electrical machines are often controlled by electronic systems. The systems match the power supplied to the motor to the speed and load. Understanding performance requires the controllers to be taken into account. System simulation can integrate the electrical machine model into a representation of the whole system to model torque and efficiency under realistic load conditions.
SIMULIA Electromagnetics Technology for Low Frequency Simulation
SIMULIA develops simulation technology that can be used to calculate electromagnetic fields in a wide range of application areas. These technologies are particularly useful for low frequency simulation. Depending on your working environment this technology is available to you in various ways:
Electromagnetics on the 3DEXPERIENCE Platform
EM simulation software is a game changer when it comes to reducing the time and cost of bringing a product to market, not just in the high-tech industries of electronics and communication.
3DEXPERIENCE Works Electromagnetics
Electromagnetics Engineer is a high-performance 3D electromagnetic simulation solution. Powered by the industry proven CST Studio Suite, this cloud-enabled role delivers fast, effective simulation and design guidance of electro-mechanical devices, PCB’s, antennas in a truly multi-physics environment.
Opera Simulation Software is a Finite Element Analysis software suite which, with its strength in low frequency simulation, is extremely useful for the design of magnets, electric motors and other electrical machines.