Power supply system and control method thereof

The invention relates to a power supply system and a control method thereof. The power supply system (12) includes a diagnostic unit (132) for diagnosing a failure in the power supply system (12). Thediagnostic unit (132), when determining that the first current (Ifc2) in a negative line (92) closer to the side of a power source (50) than a discharge resistor (100) is different from the second current (Ivcu2) in a negative line 172 closer to the side of a load (40) than the discharge resistor (100), turns on a switch (102) to start the discharge by the discharge resistor (100), and esimates afailure part based on a change in the first current (Ifc2) before and after the start of discharge. Thus, the power supply system can be suitable for various current value acquiring mechanisms. 本发明涉及一种电源系统和电源系统的控制方法。电源系统(12)具有对电源系统(12)内的故障进行诊断的诊断部(132)。当判定为比放电电阻器(100)靠电源(50)侧的负极线路(92)中的第1电流(Ifc2)与比放电电阻器(100)靠负载(40)侧的负极线路(172)中的第2电流(Ivcu2)不同时，诊断部(132)使开关(102)接通来开始由放电电阻器(100)进行的放电，且根据开始放电前与开始放电后的第1电流(Ifc2)的变化来推定故障部位。据此，能够适用