Specifications

Dec. 2012

Mitsubishi IPM-series Application Note

9-4 Fault Signal of IPM

IPM (Intelligent Power Modules) have sophisticated built-in protection circuits that prevent the power devices

from being damaged should the system malfunction or be over stressed. Control supply under-voltage(UV)

, over

temperature(OT), and short-circuit(SC) protection are all provided by the IPM's internal gate control circuits. A

fault output signal is provided to alert the system controller if any of the protection circuits are activated. Following

Fig.9.7 is a block diagram showing the IPMs internally integrated functions.

Fig.9.7 Timing chart of Control and protection of IPM

Control Supply Under-Voltage (UV)

The IPM’s internal control circuits operate from an isolated 15V DC supply. If, for any reason, the voltage of

this supply drops below the specified under-voltage trip level (UVt), the power devices will be turned off and a

fault signal will be generated. Small glitches less than the specified tdUV(<10us) in length will not affect the

operation of the control circuitry and will be ignored by the under voltage protection circuit. In order for normal

operation to resume, the supply voltage must exceed the under voltage reset level (UVr). Operation of the

under-voltage protection circuit will also occur during power up and power down of the control supply. This

operation is normal and the system controller's program should take the fault output delay (tfo) into account.

Note)

1. Application of the main bus voltage at a rate greater than 20V/ms before the control power supply is on

and stabilized may cause destruction of the power devices.

2. Voltage ripple on the control power supply with dv/dt in excess of 5V/us may cause a false trip of the UV

lock-out.

Over Temperature (OT)

The IPM has a temperature sensor mounted on surface of IGBT chips. If the temperature of the IGBT chips

exceeds the over temperature trip level (OT) the IPMs internal control circuit will protect the power devices by

disabling the gate drive and ignoring the control input signal until the over temperature condition has subsided.

The fault output will remain as long as the over temperature condition exists. When the temperature falls below

the over temperature reset level (OT

r), and the control input is high (offstate) the power device will be enabled

and normal operation will resume at the next low (on) input signal.

Note)

1. Tripping of the over-temperature protection is an indication of stressful operation. Repetitive tripping

should be avoided.

VGE

Fo outpu

Signal inpu

FoFo

UV protection SC protection

OT protection

Using IPM