Please note that we are unable to provide visa sponsorship for this position.Recruiting agencies: Proper Voltage does not accept unsolicited candidate submissions. Please do not contact any employees directly unless you have an existing engagement with the company.Job OverviewProper Voltage designs and builds safety-critical battery energy storage systems. This role leads control design for our bidirectional DC/DC power conversion stage - the current and voltage loops, mode transitions, and protection behavior of multiphase interleaved converters - from plant model through validated hardware.
This role sits where power electronics control meets software. You will model the plant, design and discretize the compensators, and prove them in closed-loop simulation running the actual control code. Then you hand the firmware team a design they can implement without guesswork: coefficients, scaling, sample timing, delay budget, limits, and the margins the implementation must preserve.
You will work as a pair with our Lead Firmware Engineer - Power Conversion Control. You own what the loop should do and why; they own how it runs on the silicon. When measured loop gain disagrees with the model, you find out which one is wrong.
What you'll do- Control design for four-switch buck-boost power stages and successor topologies: current and voltage loops, feedforward, multiphase interleaved operation, and phase current balancing.
- Plant models and closed-loop simulation models for each converter, kept current with the hardware and used as the reference for firmware verification.
- Operating mode and protection behavior: the transition logic, thresholds, and response-time requirements that firmware implements.
- Control design specifications - the documented interface between control design and firmware implementation.
- Control loop verification: model-to-measurement correlation, loop gain and stability margin characterization, transient response, and stability across the full operating envelope.
- Control performance evidence supporting UL 1973, UL 1998, and UL 9540 certification.
Responsibilities- Derive small-signal plant models for buck, boost, four-switch buck-boost, and multiphase interleaved topologies, including coupled-inductor effects, right-half-plane zeros, and operating-point variation across the envelope.
- Design compensators (PID, type II/III, 2p2z/3p3z) and feedforward paths to meet bandwidth, phase margin, and gain margin targets for average current mode inner loops and voltage outer loops.
- Discretize designs for digital implementation, accounting for sampling, zero-order hold, computational delay, and PWM update latency, and specify the sample rates and delay budget the firmware must meet.
- Build closed-loop converter models in PLECS and/or MATLAB/Simulink from scratch, and use SPICE-class tools for switching-cell verification where averaged models fall short.
- Write code for simulation and analysis: scripted parameter sweeps, component-tolerance and worst-case analysis, and automated stability checks across the operating envelope in Python or MATLAB.
- Run the production C control code inside the simulation (PLECS C-Script/DLL blocks or Simulink S-functions) to verify the firmware implementation against the design before it reaches hardware.
- Define operating mode behavior - constant current, constant voltage, constant power, current limit, soft-start, buck-to-boost transition, phase shedding, and charge/discharge direction reversal - including transition conditions and bumpless transfer requirements.
- Define protection thresholds and response-time requirements for cycle-by-cycle current limit, overvoltage, undervoltage, and thermal derating, in coordination with hardware and firmware.
- Translate each design into a specification firmware can implement directly: block diagrams, difference equations, coefficients, fixed-point scaling guidance, saturation and anti-windup limits, and expected margins.
- Work alongside the firmware team through implementation, code review, and bench debug, and review firmware control code for fidelity to the design.
- Measure loop gain by network analyzer injection, step-load transient response, and ripple on hardware, and correlate results against the model.
- Contribute to hardware design reviews covering current and voltage sensing, anti-aliasing filters, magnetics, and gate drive as they affect control.
- Serve as technical lead for converter control design: set design and verification practices and review other engineers' control work.
- Author control specifications and verification evidence to a standard that withstands certification-body review.
Required Qualifications- BS in Electrical Engineering or equivalent demonstrated capability.
- Six or more years designing control systems for switched-mode power converters.
- Direct, hands-on experience designing control loops for switched-mode power converters that reached validated hardware. You can name the topology, control mode, switching and sampling frequencies, compensator structure, and achieved crossover and phase margin for a converter you personally designed.
- Working command of small-signal modeling (state-space averaging or equivalent) and frequency-domain design: Bode and Nyquist analysis, crossover, phase and gain margin, and right-half-plane zeros.
- Working command of discrete-time control: s-to-z mapping (bilinear/Tustin, zero-order hold), the effect of sampling and computational delay on phase margin, aliasing, and quantization.
- Fluency in PLECS or MATLAB/Simulink, with the ability to build a converter model rather than only run an existing one.
- Proficiency in Python or MATLAB scripting for simulation automation and data analysis.
- Working proficiency in C: able to read and write control code, run it in simulation, and judge whether a firmware implementation matches the design.
- Understanding of the digital implementation constraints that shape a design: PWM-triggered ADC sampling, update latency, fixed-point range and resolution, and ISR timing budgets.
- Independent lab capability with oscilloscopes, isolated and differential probes, current probes, electronic loads, bidirectional supplies, and a network or frequency response analyzer for loop gain measurement.
- A track record of written control design specifications that another engineer implemented successfully.
Preferred Qualifications- MS or PhD in Electrical Engineering with a focus in power electronics or control systems.
- Bidirectional and multiphase interleaved converter control, including coupled inductors, current sharing, and phase balancing between paralleled phases.
- Average current mode control specifically, as distinct from voltage mode or peak current mode, and feedforward design for four-switch buck-boost converters.
- Large-signal behavior: buck-to-boost mode transitions, discontinuous conduction boundaries, saturation recovery, and limit cycles.
- Wide-bandgap power stages (GaN, SiC) and their effect on control - sense chain noise, blanking, and dead-time sensitivity.
- Digital power controllers such as dsPIC33C, TI C2000, or STM32G4, at the level of knowing what their PWM and ADC architectures allow.
- Hardware-in-the-loop or real-time simulation platforms such as PLECS RT Box, Typhoon HIL, or OPAL-RT.
- Python numerical tools (NumPy, SciPy, python-control) for control analysis.
- Battery energy storage, EV charging, photovoltaic inverter, or grid-interactive converter experience, including BMS interaction such as current limit negotiation and precharge.
- Functional safety and certification exposure: IEC 61508 concepts, UL 1973, UL 1998, UL 9540, and FMEA.
- Version control and code review applied to models and analysis scripts, not only firmware.
Compensation & Benefits• Salary range: $150,000 - $175,000 depending on experience and qualifications.
• Equity options as part of the compensation package.
• Comprehensive healthcare benefits (medical, dental, vision).
• Generous paid time off and paid holidays (PTO) policy.
Ready to work on power systems that matter? Let's talk.
