What is HIL Testing for Power Electronics?
Hardware-in-the-Loop (HIL) testing is a cutting-edge validation technique that integrates real-time simulation with physical control hardware. This allows engineers to test embedded controllers—such as those used in EV inverters, motor drives, and power converters—under realistic, dynamically simulated conditions before full system prototypes are built.
With Impedyme’s HIL solutions, you can simulate electrical grids, dynamic loads, and fault events to validate algorithms and optimize behavior early in the design cycle—saving time, reducing cost, and improving product reliability.
HIL and PHIL Testing for Power Electronics
As electrification expands across automotive, aerospace, and renewable energy sectors, testing complexity grows exponentially. Impedyme addresses this challenge with real-time HIL and Power Hardware-in-the-Loop (PHIL) platforms that accelerate validation across the entire development lifecycle.
Our HIL systems allow:
- Rapid prototyping of embedded control logic
- Safe simulation of extreme operating conditions
- High-fidelity testing of protection and fault mechanisms
- Iterative improvement of control algorithms with confidence
Our PHIL systems extend HIL testing into the power domain, introducing actual voltage and current for complete system emulation—including motor drives, converters, and grid-tied inverters
Common HIL Testing Challenges in Power Electronics
Modern electric drive ECUs require significantly faster control input and output speeds compared to traditional internal combustion engine powertrain ECUs. The high-speed digital switching signals used to control electric motor systems often exceed the capabilities of conventional HIL testing platforms.
One key challenge lies in accurately simulating high-frequency PWM (pulse-width modulation) signals. As the simulation time step increases, the fidelity of PWM signal emulation declines. For example, using a 25 µs simulation loop to replicate an 8 kHz PWM signal can introduce a relative error of up to 20%. By reducing the simulation step to sub-µs time steps, this error can be minimized to under 1%, dramatically improving accuracy.
Real-world electric motors exhibit nonlinear behavior like:
- Magnetic saturation
- Cogging torque
- Hysteresis
Impedyme’s Electric Motor Simulation Toolkit utilizes FEA-based lookup tables and real-time computation on FPGA to replicate these phenomena with ultra-high fidelity.
From Signal to Power: A Complete Testing Workflow
Power electronics validation typically progresses through three key stages:
- Signal-Level Testing – Simulating the entire system to validate control electronics in a closed-loop environment.
- Power-Level Testing – Incorporating a motor emulator to evaluate both control logic and power-stage hardware.
- Mechanical/Dynamometer Testing – Final system validation under actual mechanical loads.
Traditionally, limited simulation speeds necessitated costly and time-consuming dynamometer and field testing late in the development cycle. Impedyme’s high-fidelity, real-time simulation technology enables accurate testing much earlier in the process. This shift reduces development costs, accelerates timelines, and increases confidence in overall system performance.
FPGA-Based Real-Time HIL: Faster. Smarter. More Accurate.
Unlike processor-based HIL platforms limited to 20–50 kHz due to I/O bottlenecks, Impedyme's FPGA-based HIL runs simulation steps as fast as 1 µs by co-locating processing and I/O functions. This enables:
- True real-time simulation of switching devices
- Fine-grained control and signal generation
- Seamless integration with power-level systems
Our FPGA approach is optimized for Si, SiC, and GaN devices, making it ideal for next-generation power systems.
Enabling Ultra-Fast, High-Fidelity HIL with FPGA Technology
Achieving simulation time steps in the 1 µs range requires a fundamental departure from traditional HIL architectures. At Impedyme, we address this challenge by leveraging high-performance FPGA-based simulators in place of conventional processor-driven systems.
While processor-based HIL platforms are typically limited to simulation rates around 50 kHz—due to communication delays between the CPU and I/O nodes—Impedyme’s architecture eliminates this bottleneck. By co-locating processing and I/O functions on a single FPGA device, we drastically reduce latency and unlock industry-leading simulation speeds.
Maintaining high fidelity without compromising speed is another major hurdle in motor drive simulation. Basic linear models may suffice for initial functional testing, but advanced development requires detailed representation of nonlinear effects such as magnetic saturation and cogging torque. To meet this need, Impedyme utilizes parameterized lookup tables generated from finite-element analysis (FEA) data or empirical measurements. These tables are updated in every simulation cycle, providing accurate, cycle-level replication of complex physical behaviors—without adding unnecessary computational load.
Unified Platform: Impedyme RT + Simulation Toolkit
Impedyme delivers a state-of-the-art platform that seamlessly integrates advanced hardware and software to redefine real-time testing for power electronics and electric motor systems. At the core of this ecosystem is the Impedyme Electric Motor Simulation Toolkit, designed to help control engineers rapidly configure high-performance test environments.
Fully compatible with Impedyme’s broader real-time testing infrastructure, this toolkit streamlines setup and ensures robust, scalable integration—empowering teams to accelerate development, improve test coverage, and enhance overall system reliability.
Impedyme-RT
Impedyme-RT is a configuration-driven, real-time testing environment designed to streamline the creation of powerful and flexible test applications. It enables efficient real-time communication between target and host, robust data logging, dynamic stimulus generation, and intelligent alarm detection and handling — all in a unified platform.
With Impedyme-RT, you can seamlessly transition from pure simulation-based testing to full hardware-in-the-loop (HIL) validation. It allows you to reuse essential test assets, including profiles, alarms, procedures, and analysis routines, saving significant time during regression testing. By easily remapping model parameters to real-world hardware channels, Impedyme-RT simplifies the integration of simulation models with physical I/O systems. Furthermore, it supports automation through test executive tools availble in MATLAB Simulink for comprehensive, scalable test execution.
Built with an open architecture, Impedyme-RT empowers users to extend its capabilities with real-time plug-ins, delivering maximum adaptability for application-specific needs. Combined with the Power HIL, engineers can achieve advanced motor modeling capabilities, whether on a standard real-time hardware setup or leveraging high-speed FPGA-based platforms for ultra-precise simulation and testing.
Combined HIL and Power (CHP): A Unified Platform for Real-Time and Power-Level Testing
Impedyme’s Power HIL solutions extend traditional Hardware-in-the-Loop testing by introducing actual power flow into the test environment—enabling engineers to validate not only control logic but also the behavior of power-stage hardware under dynamic, real-world conditions.
Our Combined HIL and Power (CHP) platform unifies signal-level simulation with power-level emulation in a single, integrated solution. This allows users to seamlessly transition from controller development to full system testing—without switching tools or architectures. CHP supports the direct connection of real power devices such as inverters, converters, and motor drives, providing a safe and controlled environment to test protection schemes, switching behavior, and thermal performance.
By combining the precision of FPGA-based HIL with the realism of power-level interaction, Impedyme empowers engineering teams to:
- Test and tune systems under real voltage and current conditions
- Identify issues earlier and reduce reliance on physical prototypes
- Shorten development cycles while increasing system confidence and safety
With CHP, you get the speed of simulation and the truth of power—all in one powerful platform.
Applications We Power
- Electric Vehicle (EV) Inverter and Motor Drive Testing
- Onboard and Offboard Charger Validation
- Renewable Energy System Emulation (Solar Inverters, Wind Turbines)
- Microgrid and Smart Grid Controller Testing
- Aerospace Power Systems Validation
Why Choose Impedyme for Power Electronics HIL and PHIL Testing?
- High Fidelity, Real-Time Simulation
Our powerful real-time systems ensure fast, accurate modeling of power converters, electric machines, and dynamic loads—supporting precise control testing and validation.
- Scalable Architecture
From small subsystem testing to full-system emulation, Impedyme’s HIL platforms scale with your project’s complexity. Easily adapt your test environment as your needs grow.
- Seamless Integration
Integrate with your existing control hardware, sensors, and test equipment. Our flexible interfaces and customizable setups help you maximize your investment in validation tools.
- Accelerated Development Cycles
By finding and fixing issues earlier, Impedyme’s HIL systems help cut months from the development schedule, enabling faster innovation, lower costs, and more reliable launches.
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