Miscellaneous active electrical nonlinear devices – circuits – and – Signal converting – shaping – or generating – Current driver
Patent
1999-03-17
2000-11-14
Tran, Toan
Miscellaneous active electrical nonlinear devices, circuits, and
Signal converting, shaping, or generating
Current driver
327427, H03B 100, H03K 17687
Patent
active
061475246
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a method for driving an inverter device.
FIG. 1 is a diagram showing a prior known drive circuit of an inverter circuit, wherein this circuit is configured including a first direct current (DC) power supply 1, a upper semiconductor switching element 2 connected to a positive polarity side of the first DC power supply 1, a second drive circuit 4 for turn-on/off drive of the upper switching element 2, and a capacitor 7 for supplying a drive voltage to the drive circuit 4 when this capacitor 7 is charged. This circuit configuration is generally known as the "bootstrap" circuit. During the turn-on period of a lower semiconductor switching element 3 connected to a negative polarity side of the first DC power supply 1, a voltage at an output terminal of FIG. 1 becomes substantially equal to a voltage on the negative side of the first DC power supply 1 so that a circuit for charging and supplying electrical charge to the capacitor 7 from a second DC power supply 6, which is a drive power supply of a first drive circuit 5 for on/off-driving the lower semiconductor switching element 3 connected to the negative polarity side, is provided via a route indicated by dotted line portions in FIG. 1.
The final charge-up voltage being charged by this circuit at the capacitor 7 becomes nearly equal to the voltage of the second DC power supply 6 thereby enabling this capacitor 7 to be directly used as a drive power supply of the second drive circuit 4 which causes the upper semiconductor switching element 2 coupled to the positive polarity side to turn on and off.
Next, one exemplary prior art in the aforementioned configuration is shown in FIG. 2.
The circuit shown in FIG. 2 is designed such that a voltage monitoring circuit 9 is provided for monitoring a voltage between both terminals of the capacitor 7 while also providing an operation function of protecting the upper semiconductor switching element 2 by preventing turn-on of the upper semiconductor switching element 2 connected to the positive polarity side in cases where the capacitor 7 is low in voltage potential, thus eliminating thermal destruction or breakdown otherwise occurring due to turn-on of the upper semiconductor switching element 2 which operates in the state that the drive voltage is kept low in potential (Published Unexamined Japanese Patent Application or "PUJPA" No. 3-150075).
Incidentally, in most cases, it will hardly occur during normal operations that the charged voltage of the capacitor 7 in FIG. 2 becomes lower then a voltage value as set at the voltage monitoring circuit 9, except that this occurs exclusively at a specific time when the capacitor 7 undergoes an initial charge-up at the beginning of start-up of an inverter operation in the inverter device.
Under the features stated above, further in the inverter device, with regard to a means for transferring turn-on/off drive signals to an on/off drive circuit of an upper arm-side semiconductor switching element, another problem occurs in the case where the device employs an on/off signal edge transfer/latch scheme using a drive signal transfer section 12 for use with the upper arm-side semiconductor switching element which section contains therein a high breakdown voltage IC 11 as shown in FIG. 3, rather than continuous signal transfer schemes based on the turn-on/off of a photo-coupler that has been traditionally employed as electrical insulation means, as will be discussed below.
Upon startup of the inverter operation of the inverter device, a lower arm-side semiconductor switching element is typically held in the turn-on state continuously for along time period in order to increase the charge up speed of the capacitor 7. On the other hand, in view of the fact that the turn-on/off signal transmission of the upper arm-side semiconductor switching element follows the edge transfer/latch scheme, where the turn-on signal is accidentally latched during this initial charge up period due to malfunction of the upper arm-side semiconductor sw
REFERENCES:
patent: 5543740 (1996-08-01), Wong
patent: 5963066 (1999-10-01), Fukunaga
Kudo Masaichi
Ueda Hidefumi
Kabushiki Kaisha Yaskawa Denki
Tran Toan
LandOfFree
Inverter device driving method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Inverter device driving method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Inverter device driving method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2068574