time：2015-01-27 03:01:12 reading：1534次
1.Positive average current IF(AV) (rectifier)/ Average on state current IT(AV) (SCR) is the maximum half sine wave current average value at heat sink temperature(THS ) or package temperature( TC). At this time, the junction temperature of device will be allowed to maximum.
2. Positive RMS current IF（RMS）(rectifier)/On state RMS current IT（RMS）(thyristor) is the maximum effective current value at heat sink temperature(THS ) or package temperature( TC). Users in the use, shall ensure that in any condition, the effective value of current flowing through the device does not exceed the root mean square current corresponding package temperature value.
3． Surge current IFSM(rectifier)/ ITSM(thyristor)
In exceptional circumstances, device can be bear the maximum instantaneous overload current value. Surge current value is 80% VRRM of device in the maximum allowable junction temperature.
4． Non repetitive peak off state voltage VDSM/Non repetitive peak reverse voltage VRSM
Means Thyristor or rectifier can be withstand in maximum turning off state voltage, generally use single pulse to test and prevent device damage.
5． Repetitive peak off state voltage VDSM/Repetitive peak reverse voltage VRRM
In the condition off state, off state and reverse can bear max repetitive peak voltage, generally equal to 90% non-repeat voltage of the devices
6． Repetitive peak off state (leakage) current IDRM/Repetitive peak reverse (leakage) current IRRM
In the condition of off state, the current will pass through thyristor which applied with VDSM / VRRM.
7． VTM=VTO+rT*ITM VFM=VFO+rF*IFM
On State peak voltage V (thyristor)/Peak forward voltage VFM(rectifier)
Means peak voltage of device which through the peak forward current IFM (rectifier) or on State peak current of I TM (thyristor). This parameter reflects directly the conduction loss characteristics of the device, influences on state current rating. The threshold voltage and the slope resistance:
VTM=VTO+rT*ITM VFM=VFO+rF*IFM
8． Circuit commutated turn off time tq（thyristor）
Under specified conditions, thyristor forward main current drop zero, tq is minimum time interval from zero to the components can withstand the repetitive voltage to block. The thyristor turn off time is determined in the test conditions, the following is measured tq values of fast switching thyristor or high frequency thyristor each device:
On State peak current ITM=ITAV;
On state current rate of decline di/dt=-20A/μs
Repetition rate of voltage rise dv/dt=30A/μs；
Reverse voltage VR=50V
Junction temperature Tj=125°C
9． On state current critical rate of rise di/dt（thyristor）
Thyristor can withstand the maximum on state current rate of rise from blocking state to conducting state. Because gate trigger will effect di/dt, so we suggest that the user may try to apply with strong triggering mode, that is:
the trigger pulse current amplitude: IG≥10IGT；
Pulse rise time tr≤1μs.
10． Critical rate of rise of off state voltage dv/dt
This refers to the lowest voltage rate of rise of thyristor from off state to on state, under the junction temperature and gate short-circuit conditions at rated.
11． Gate trigger voltage VGT/ Gate trigger current IGT
Under specified conditions, it is a minimum gate voltage and gate current of thyristor which from off state too state. The trigger signal strength effect of turn-on time and turn-on loss. So we suggest that the user may try to apply with strong triggering mode, that is: the trigger pulse current amplitude: IG≥10IGT；
Pulse rise time tr≤1μs. In order to ensure the devices reliability
IG ＞IGT.
Under the conditions high altitude and low temperature environment of thyristor, diode and other power electronic devices should be used with reasonable ensures that the device can reliably work. The parameters which we marked such as blocking voltage, leak current, di/dt or dv/dt can ensure its reliable performance even at low temperature; The parameters such as the value of IGT or VGT is the value at 25℃ It will decreases due to environmental temperature increases, and increases with the decrease of temperature. So, for use in high altitude, low temperature conditions, please pay attention to: 1. At -40 C, the thyristor gate trigger current value will increase one times than 25 C., gate trigger voltage increased by about 30%. So, in order to ensure the equipment reliable starting, need for sufficient strength of the thyristor gate trigger current. 2. In the high altitude conditions, the heatsink dissipation capability of the air cooling radiator will decrease, but in the lower temperature of the environment, it has better cool, the current of device should be slightly larger than the actual current. 3. If the equipment is very frequent startup or stop, device will be used frequently between -35℃ -125℃, the service life and reliability of devices will be lower, should pay attention to the use of. |
