Energy storage system high voltage box pre-charge resistance

A precharge resistor is your system's first line of defence against potentially destructive inrush currents. But what exactly is it? Simply put, it's a specialised power resistor that acts like a traffic controller when you power up a circuit. When you flip that switch, capacitors in your system are eager to charge—too eager, in fact.

PEC precharge resistors are built with decades of problem-solving experience and technical knowledge. They provide the reliability and performance necessary for modern high-voltage applications while protecting valuable system components. Required fields are marked *

Figure 1. Pre-charge Initial State In a high voltage system, a typical block diagram may consist of two high current contactors with a separate pre-charge contactor, and a DC link capacitor in parallel with a load (for example, traction inverter).

Electric Vehicles (EVs): Every time you start your electric car, precharge resistors are protecting the sensitive battery management systems and power electronics from potentially damaging current surges. They're the silent guardians that help ensure your EV's reliability mile after mile.

High voltage (HV) positive and negative contactors are used in this system to act as an emergency disconnect when the motor regulator fails. Without a pre-charge circuit, welding can occur within the contactor as it closes and there could be a brief arc resulting in pitting. Figure 1. Pre-charge Initial State

Solar inverters and wind power converters incorporate precharge resistors to protect expensive power electronics from the stresses of grid connection and disconnection.