Absolute timeout
An unsuccessful attempt is stopped.
AUTOMATIC INVERTER PRECHARGE CONTROLLER
Controlled power.
Before full power.
PreFlow AIPC manages the precharge of inverter DC-link capacitors before the main power connection is made, reducing uncontrolled inrush current and protecting the system.
PREFLOW AIPC
Automatic Inverter
Precharge Controller
Precharge Controller
READY
PRECHARGING
CONNECT
ONE DEVICE. ONE CLEAR JOB.
Precharge first. Connect full power second.
PreFlow monitors the battery side and the inverter side while a controlled precharge path charges the inverter’s DC-link capacitors.
- White: ready to begin
- Red: precharge in progress
- Green: target reached — main connection can be made
THE PROBLEM HAPPENS IN AN INSTANT
The spark lasts a fraction of a second.
The damage doesn’t have to.
When a battery is connected to an inverter with discharged input capacitors, the first instant can produce a very high inrush current. PreFlow manages a controlled precharge path before the main DC connection is established.
PreFlow does not carry the inverter’s normal power current. It temporarily manages capacitor precharge, monitors the electrical conditions, and indicates when the main connection can be made safely.
ONE BUTTON. THREE CLEAR STATES.
Know when it is safe to make the main connection.
WHITE — READY
System ready. Press the button to start precharge.
→
RED — PRECHARGING
The controlled path is active while voltage rises.
→
GREEN — CONNECT
The precharge target has been reached.
Live electrical supervision
12 V system — Precharge Monitor
Illustrative operating example
Capacitors discharged
Precharge required
Battery12.8 V
→
Inverter DC bus2.1 V
Precharge authorized
PreFlow allows controlled precharge because the inverter DC bus is still well below battery voltage.
Capacitors already charged
Precharge not required
Battery12.8 V
→
Inverter DC bus12.4 V
Precharge bypassed
After a brief inverter disconnection, PreFlow can recognize that the DC bus is already charged and avoid an unnecessary precharge cycle.
PreFlow decides whether precharge is actually needed before starting it. It does not assume that every reconnection begins with discharged capacitors.
NOT JUST A TIMER
PreFlow watches the voltage on both sides.
The controller compares battery-side voltage with inverter-side voltage during precharge. Green is based on the measured result, not simply on waiting a fixed number of seconds.
BATTERY SIDE
INVERTER SIDE
PRECHARGE TARGET
Voltage approaching battery level.
DESIGNED FOR REAL-WORLD MISTAKES
A precharge attempt should never continue blindly.
Voltage progression
Abnormal rise and stagnation detection are being evaluated.
No green on failure
No instruction to connect if the target is not reached.
Clear feedback
Visual and acoustic signalling for clear status.
CURRENT STATUS
Built. Tested. Still being validated.
The prototype has demonstrated the core capacitor-precharge sequence on a real inverter. Higher-power testing, abnormal-condition testing and final hardware design remain part of development.
PROJECT STATUS
IN DEVELOPMENT
IN DEVELOPMENT
Prototype validation in progress
PREFLOW AIPC
Interested in the project?
Development enquiries:
contact@preflowaipc.com