Control Engineer

sonnen; Atlanta, Northern (GA, KY); Hybrid; USD 120,000 - 150,000; Full time

Job summary

sonnen US is seeking a Controls Engineer (Specialist) to own control design for residential and commercial battery inverters. You will develop, simulate and implement control loops across DC/DC, DC/AC and auxiliary stages using MATLAB/Simulink and TI MCUs, with hands-on HIL and lab validation.

The role requires deep power electronics expertise, model-based design with Embedded Coder, and strong collaboration with firmware and certification teams at the Atlanta site.

Qualifications

• PhD or MSc in Electrical Engineering or related field.
• Minimum of 4 years of proven experience designing digital control for power converters.
• Strong grounding in control theory: small-signal modeling, frequency-domain design, discretization.
• Proven ability to verify controllers through full chain: Simulink, HIL, and real hardware.
• Hands-on experience with grid-connected inverter control: PLLs, current control, and grid synchronization.
• Expert use of MATLAB/Simulink for modeling, loop design and simulation.
• Embedded C on TI C2000 MCUs, including interrupt-driven control loops and PWM/ADC config.
• Comfortable in a high-voltage power lab with test equipment.
• Clear written and spoken English for cross-team communication.

Responsibilities

• DC/DC control: design current/voltage loops for bidirectional converters.
• DC/AC control: design inverter control for single- and three-phase systems.
• Implement grid-support and protection features to meet IEEE 1547 and UL 1741 SA/SB.
• Define supervisory state machine for start-up, transfer, faults and shutdown.
• Model plant in MATLAB/Simulink and PLECS; tune loops with stability margins.
• Implement control on TI C2000 MCUs; use CLA and dual-core partitioning.
• Verify controllers via Simulink, HIL, and real inverter tests.
• Measure Bode plots, step response, THD and efficiency; document results.
• Debug and support certification testing; mentor junior engineers.

Skills

Digital control

MATLAB/Simulink

Embedded C

HIL verification

Grid-connected inverter control

English communication

Education

PhD or MSc in Electrical Engineering

Tools

MATLAB/Simulink

PLECS/Simscape

Code Composer Studio

TI C2000 MCUs

Job description

sonnen US is hiring a Controls Engineer (Specialist) to own the control design of our residential and

commercial battery inverters, from model to firmware. You will design, simulate and implement the

control loops for every power stage in the inverter (DC/DC, DC/AC and auxiliary converters), using

MATLAB/Simulink and Texas Instruments microcontrollers.

This is a hands-on specialist role. You will take control algorithms from analysis through code generation

or hand-written embedded C, then validate them on HIL and real hardware in the lab.

Key responsibilities

• DC/DC control: Design current and voltage loops for bidirectional battery converters (buckboost, dual active bridge, LLC). Cover battery charge/discharge, DC-link regulation and mode transitions.
• DC/AC control: Design inverter control for single- and three-phase systems, both grid-tied (current control, PLL, active/reactive power) and off-grid (voltage control, droop, virtual)
• Grid functions: Implement grid-support and protection features to meet IEEE 1547, UL 1741 SA/SB and utility rules. This includes ride-through, volt-var, frequency-watt and anti-islanding.
• System coordination: Define the supervisory state machine that sequences the power stages through start-up, grid/off-grid transfer, faults and shutdown. Cover parallel operation and backup mode.
• Modeling and design: Build plant models (averaged and switching) in MATLAB/Simulink and PLECS or Simscape. Do the loop design and tuning (PI, PR, state-space/LQR) with stability margins checked across operating points.
• Embedded implementation: Implement control on TI C2000 MCUs, by hand in C or through Embedded Coder with the C2000 support package. Use the CLA and dual-core partitioning to
• Verification: Verify every controller in three stages, each passed before the next: (1) Simulink simulation, model- and software-in-the-loop, across operating points and faults; (2) HIL, running the real C2000 firmware against a real-time plant model; (3) the real inverter in the power lab.
• Measure Bode plots, step response, THD and efficiency at each stage, and document results.
• Debugging and support: Root-cause field and lab issues from captured waveforms and firmware logs. Support certification testing and the transfer to production.
• Documentation and mentoring: Write control design specs and test reports. Review other engineers' designs and code, and mentor junior engineers on controls methods.

Required qualifications

• PhD or MSc in Electrical Engineering or a related field, specialized in control systems.
• Minimum of 4 years of proven experience designing digital control for power converters, with at least one inverter or DC/DC product shipped or brought to certification.
• Strong grounding in control theory: small-signal modeling, frequency-domain design, discretization, and digital control effects such as delay, sampling and quantization.
• Proven ability to verify controllers through the full chain: Simulink simulation first, then a HIL system, then the real power hardware, and to correlate results between the three stages.
• Hands-on experience with grid-connected inverter control: PLLs, current control in dq or stationary frames, and grid synchronization.
• Expert use of MATLAB/Simulink for modeling, loop design and simulation.
• Embedded C on TI C2000 MCUs (F2837x, F2838x, F28004x or similar), including interrupt-driven control loops, PWM/ADC configuration and fixed/floating-point trade-offs.
• Comfortable in a high-voltage power lab: oscilloscopes, differential and current probes, power analyzers, grid simulators and DC sources.
• Clear written and spoken English, and the ability to explain design decisions to firmware, hardware and certification teams.

Preferred qualifications

• Published work in power converter control.
• Model-based design with Embedded Coder and the C2000 Microcontroller Blockset, including code-generation tuning and processor-in-the-loop testing.
• Experience with the C2000 CLA, dual-core (CPU1/CPU2) or Concerto architectures, and interprocessor communication.
• Advanced control methods: LQR or state feedback, repetitive or resonant harmonic compensation, active damping of LCL filters, grid-forming control.
• Off-grid and microgrid operation: seamless transfer, parallel inverters, generator integration.
• Battery energy storage systems (BESS), including BMS interaction and state-of-charge-aware power control.
• HIL platforms (Typhoon HIL, OPAL-RT or dSPACE) and automated test scripting in Python.
• Working knowledge of IEEE 1547, UL 1741 and Rule 21 certification testing.
• CAN or Modbus communication with system controllers.

Tools and technologies

Area Tools

Modeling and simulation MATLAB, Simulink, Simscape Electrical, Control

System Toolbox, PLECS

Code generation Embedded Coder, C2000 Microcontroller

Embedded toolchain Code Composer Studio, C2000Ware, digital

Area Tools

power SDK, Git

Test and validation Typhoon HIL or similar, oscilloscopes, power

analyzers, grid simulators

Communication CAN, Modbus, SCI/UART

Success in the first year

• First 3 months: Learn the existing inverter platform and control architecture, and take ownership of one power stage's control loops.
• First 6 months: Deliver a validated control improvement or new feature (for example a gridsupport function or improved transfer behavior) from Simulink model to tested firmware.
• First 12 months: Act as the technical owner for inverter control across DC/DC and DC/AC stages, and support a product through certification.

The role sits in the US power electronics development team in Atlanta and works closely with firmware,