Job Overview

Proper 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.