このリファレンス・デザインは、mA レベルの AC/DC グランド障害電流を検出します。自動発振回路は、磁気コアの飽和の入出力を駆動する DRV8220 H ブリッジを使用して実装されます。さらに、障害電流信号とレベルを識別するために、アクティブ・フィルタ回路が実装されています。
TIDA-010237 | デザイン・フォルダ |
DRV8220 | プロダクト・フォルダ |
MSP430F5132、OPA202 | プロダクト・フォルダ |
INA293、SN74LVC2G74 | プロダクト・フォルダ |
TLV7011、TLV172 | プロダクト・フォルダ |
Electric vehicles (EVs) receive energy from the electrical grid through electric vehicle supply equipment (EVSE), more commonly known as EV chargers. To facilitate power delivery to the vehicle, the EVSE sits between the grid and the vehicle.
If a ground fault occurs, the EVSE must respond and trip a relay to disconnect power from the grid. The primary requirement in providing protection during EV charging is the ability to detect AC and DC residual currents and mitigate the risk of electrical shock. This system implements residual current detection (RCD) by monitoring the phase lines and neutral wires through a fluxgate sensor. During normal operation without a fault condition, the sum of currents equals zero. During a ground fault condition, the sum of currents is not equal to zero. This residual current indicates a system short which can be an issue at 6 mA DC and 30 mARMS according to IEC62752, IEC62955.
PARAMETER | NOTES AND CONDITIONS | MIN | NOM | MAX | UNIT | DETAILS |
---|---|---|---|---|---|---|
INPUT CHARACTERISTICS | ||||||
Line Frequency | Line through fluxgate sensor | 60, 50 | Hz | |||
Phase Line Voltages | Universal | V | ||||
Phase Line Current | Universal | A | ||||
TRIP THRESHOLDS | ||||||
Residual DC Current Threshold | 6 | mA | Adjustable via software | |||
Residual AC Current Threshold | 30 | mARMS | Adjustable via software | |||
POINT-OF-LOAD CHARACTERISTICS | ||||||
Board positive supply voltage | +12 | V | Provided by external power supply | |||
Board negative supply voltage | –12 | V | Provided by external power supply | |||
Fluxgate sensor drive voltage | DRV8220 | +12 | V | H-bridge voltage to drive fluxgate sensor into saturation |