I wasn't aware that Fluke was under their wing, and even since 1998! Other surprises was Marconi, Radiometer, Leica and Tektronix! a.storyblok.com/f/182663/1734x1100/fecb6c684f/danaher-m-a-history.png
If the braking section passive? ie just diode "commutated" and uses a single switching element on the output of that rectification to turn on / off the brake resistors, with no inductive element (ie brake current is just averaged by duty cycle of the single switch)?
With an inductor you couldn’t really break, there needs to be some way for the energy to go: either in the reservoir caps or into heat (by means of resistance).
You recover energy into the filter capacitors using the diodes and the inductor to limit rate of current flow after an initial smaller capacitor. Then the brake resistor is used to dump energy if the capacitor voltage is rising too high, and if there are not other drives sharing the same DC bus to use it. You can have a single large drive being the sole mains connection, fed via a line reactor to limit inrush current on the bridge rectifier, and then the main DC bus is shared with the smaller units, with a single brake resistor bank also on the DC bus, in case the DC bus voltage, due to energy recovery, is rising too high, dissipating this power in the brake resistors, normally with a PWM switch that modulates the power dissipation based on the voltage rise, so it smoothly ramps up according to the excess voltage, so the bus does not sag if there is a sudden draw, while the brake resistor is at full dissipation. typically the brake resistors also have a thermal switch, or thermal sensors, so that they can communicate with the controllers to limit energy recovery if the brake resistor is getting too hot, and the thermal switch forces the controller to shut down (or severely limit operation speed) if the resistor is too hot too long. Finally there is a non resettable thermal fuse to disconnect the brake resistors, and allow the controllers to not have brake resistors, which triggers them all into shutting down with input overvolt warnings, and needing maintenance to reset them and investigate. Easy with a single drive without a brake to do this if you have a very rapid ramp down of the load, and it then trips out on input overvolt, and needs to be power cycled. Had to adjust the ramp down rate from 2 cycles, drive ramping up from 0 to 75Hz in 0.1 seconds, and back down to zero in 3 cycles, to prevent this, with the 1kW motor being perfectly happy with the ramp up and down, even with only the supplied fan cooling, as the motor was sized simply because of torque, and ran for 6 revolutions per cycle. The other motor, a 50 year old Lenze motor, not originally ever designed for VFD use, just needed a 120mm fan bolted to the shroud, and removal of the fan, to make it run cool, because the drive regime was now it running at 30Hz, so needed that external cooling. Removal of a failed variable speed drive that was long obsolete, and where a new drive was not possible, so the old variable side was removed, and replaced with a plain taper lock pulley, machined to reuse the old variable speed belt.
Do you mean the diodes? Check out the pictures on my website, linked in the description. There is Varistors, resistors and 0.33uF MKP capacitors all around the diodes and DC link capacitors.
@@KaizerPowerElectronicsDk When the FETs switch they cause a huge current spike because the C_DS is empty but gets connected to supply. It is much worse than a charge pump where a full C is connected to a almost full C.
@@KaizerPowerElectronicsDk Looked at pictures on the web and there is MAX125 2x4-Channel Simultaneous-Sampling 14-Bit DAS, DAC7624 12-Bit Quad Voltage Output DIGITAL-TO-ANALOG CONVERTER. Wanted to look at that orange part for power supply of the gate but it is too dusty to see the part number.
@@KaizerPowerElectronicsDk I was thinking if it is pulse transformer. Unusual to see pulse transformer next to isolated gate driver chip (I believe it is HCPL-3140). Couldn't find datasheet. To me it is more likely to be DC/DC isolated converter that powers high voltage side of HCPL3140, but without datasheet it is not possible to know.
@@aleksandarsentice3028 Many designers use apulse transformer to provide isolated supplies, as the pulse transformer has very low inter winding capacitance, and the insulation is designed for high voltage and very high dVdt between the windings, while still being able to couple a reasonable amount of energy, often also with multiple isolated secondaries that each are equally isolated from each other. Simple constant frequency drive on the primary, and then each secondary with 4 fast diodes as bridge, and a simple capacitor with zener diode clamp, and you get the 3 isolated supplies that are able to swing with the main output of the drive with no issues. Allows output stages to go to 100% duty cycle without problems, without needing to have very fast low leakage high voltage diodes to provide the floating drivers with power. Those diodes are problematic, easy to blow due to transients, but the pulse transformer will survive typically 5kV for 30s no problems.
Danaher, owner of a lot of test equipment brands as well, like fluke and many other of the top tier.
I wasn't aware that Fluke was under their wing, and even since 1998! Other surprises was Marconi, Radiometer, Leica and Tektronix! a.storyblok.com/f/182663/1734x1100/fecb6c684f/danaher-m-a-history.png
If the braking section passive? ie just diode "commutated" and uses a single switching element on the output of that rectification to turn on / off the brake resistors, with no inductive element (ie brake current is just averaged by duty cycle of the single switch)?
With an inductor you couldn’t really break, there needs to be some way for the energy to go: either in the reservoir caps or into heat (by means of resistance).
Check out the pictures on my website, linked in the description. There is a dual Epcos 1.8mH inductor sitting just beneath the IGBT.
You recover energy into the filter capacitors using the diodes and the inductor to limit rate of current flow after an initial smaller capacitor. Then the brake resistor is used to dump energy if the capacitor voltage is rising too high, and if there are not other drives sharing the same DC bus to use it. You can have a single large drive being the sole mains connection, fed via a line reactor to limit inrush current on the bridge rectifier, and then the main DC bus is shared with the smaller units, with a single brake resistor bank also on the DC bus, in case the DC bus voltage, due to energy recovery, is rising too high, dissipating this power in the brake resistors, normally with a PWM switch that modulates the power dissipation based on the voltage rise, so it smoothly ramps up according to the excess voltage, so the bus does not sag if there is a sudden draw, while the brake resistor is at full dissipation. typically the brake resistors also have a thermal switch, or thermal sensors, so that they can communicate with the controllers to limit energy recovery if the brake resistor is getting too hot, and the thermal switch forces the controller to shut down (or severely limit operation speed) if the resistor is too hot too long. Finally there is a non resettable thermal fuse to disconnect the brake resistors, and allow the controllers to not have brake resistors, which triggers them all into shutting down with input overvolt warnings, and needing maintenance to reset them and investigate.
Easy with a single drive without a brake to do this if you have a very rapid ramp down of the load, and it then trips out on input overvolt, and needs to be power cycled. Had to adjust the ramp down rate from 2 cycles, drive ramping up from 0 to 75Hz in 0.1 seconds, and back down to zero in 3 cycles, to prevent this, with the 1kW motor being perfectly happy with the ramp up and down, even with only the supplied fan cooling, as the motor was sized simply because of torque, and ran for 6 revolutions per cycle.
The other motor, a 50 year old Lenze motor, not originally ever designed for VFD use, just needed a 120mm fan bolted to the shroud, and removal of the fan, to make it run cool, because the drive regime was now it running at 30Hz, so needed that external cooling. Removal of a failed variable speed drive that was long obsolete, and where a new drive was not possible, so the old variable side was removed, and replaced with a plain taper lock pulley, machined to reuse the old variable speed belt.
What about snubbers and filters?
How did they keep the parasitic capacitances of the transistors from generating huge currents?!
Do you mean the diodes? Check out the pictures on my website, linked in the description. There is Varistors, resistors and 0.33uF MKP capacitors all around the diodes and DC link capacitors.
@@KaizerPowerElectronicsDk When the FETs switch they cause a huge current spike because the C_DS is empty but gets connected to supply. It is much worse than a charge pump where a full C is connected to a almost full C.
Intel made some 16bit cpu with floating point unit i960 i think. Does it have separate ADC chip?
I suspect that the Xilinx CPLD would handle the ADC
@@KaizerPowerElectronicsDk Looked at pictures on the web and there is MAX125 2x4-Channel Simultaneous-Sampling 14-Bit DAS, DAC7624 12-Bit Quad Voltage Output
DIGITAL-TO-ANALOG CONVERTER. Wanted to look at that orange part for power supply of the gate but it is too dusty to see the part number.
The SIRIO 132256 pulse transformer?
@@KaizerPowerElectronicsDk I was thinking if it is pulse transformer. Unusual to see pulse transformer next to isolated gate driver chip (I believe it is HCPL-3140). Couldn't find datasheet. To me it is more likely to be DC/DC isolated converter that powers high voltage side of HCPL3140, but without datasheet it is not possible to know.
@@aleksandarsentice3028 Many designers use apulse transformer to provide isolated supplies, as the pulse transformer has very low inter winding capacitance, and the insulation is designed for high voltage and very high dVdt between the windings, while still being able to couple a reasonable amount of energy, often also with multiple isolated secondaries that each are equally isolated from each other. Simple constant frequency drive on the primary, and then each secondary with 4 fast diodes as bridge, and a simple capacitor with zener diode clamp, and you get the 3 isolated supplies that are able to swing with the main output of the drive with no issues. Allows output stages to go to 100% duty cycle without problems, without needing to have very fast low leakage high voltage diodes to provide the floating drivers with power. Those diodes are problematic, easy to blow due to transients, but the pulse transformer will survive typically 5kV for 30s no problems.