To provide operational safety, the DC-Link capacitor must be discharged in two distinct operational scenarios: normal operation, such as after turning off the vehicle, and emergency situations, like post-vehicle collision or dangerous fault scenarios during maintenance.
This paper first analyzes the necessity of active discharge in automotive inverters and then introduces the commonly used discharge methods. After reviewing the pros and cons of the current methods, a new discharge solution using IGBT (Insulated Gate Bipolar Transistor) modules WSC (Weak Short Circuit) is proposed.
How a battery inverter works?
An Inverter not only converts the DC Voltage of battery to 220-V/120-V AC Signals but also charge the Battery when the AC mains is present. The block diagram shown above is a simple depiction of the way an Inverter Works. The method, in which the low voltage DC power is inverted, is completed in two steps.
In EVs, there are different types of discharge requirements. For safety-critical events, such as a crash, the capacitor must be discharged in under a few seconds, the exact time varying between manufacturers. For non-emergency cases, the discharge can be on the order of minutes.
What is a power inverter?
All trademarks are the property of their respective owners. Power inverter is a device that converts electrical power from DC form to AC form using electronic circuits. It is typical application is to convert battery voltage into conventional household AC voltage allowing you to use electronic devices when an AC power is not available.
The simulation and experimental results show that this method can not only discharge the DC link capacitor fast, but also has no risk of IGBT damaging since the IGBT electric and thermal stresses are in the safe operation range during the discharge time.
To provide operational safety, the DC-Link capacitor must be discharged in two distinct operational scenarios: normal operation, such as after turning off the vehicle, and emergency situations, like post-vehicle collision or dangerous fault scenarios during maintenance.