Questions tagged [power-factor-correction]
A circuit that compensates the reactive characteristics of a load to make behave as close as possible to a resistive load in order to maximize the power consumption efficiency.
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Boost PFC compensator design
I'm trying to design a type II compensator for my LT1249 boost PFC stage but I'm not sure on how to place the zero and poles frequencies using a typical error amplifier:
I have a working LTspice ...
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LT1249 boost PFC controller CAout pin
Looking at the reference design for the LT1249 PFC controller below:
What is the purpose of the CAout pin? Are there any equations on how to setup the resistor and capacitor network?
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Power factor in AC circuits
A lagging power factor means that it has an inductive load, right?
The final circuit will still be lagging meaning that it will still be inductive?
How is the power factor getting used here? I can get ...
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Bridgeless totem-pole PFC controllers [closed]
I'm considering bridgeless totem-pole PFC for a design and am looking for the quickest integrated solution. Unfortunately, it seems like a lot of implementations currently use MCUs and DSPs for ...
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Selecting PFC topology
I'm considering different PFC topologies for the AC-DC stage of a device around 1 kW with aim of optimizing for efficiency and secondarily component size. This far I have identified following options:
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Buck PFC controller
I'm considering a buck PFC for the design of my SMPS. The input will take 50 VAC rectify it using a full bridge rectifier. The buck PFC stage will then step down the voltage to a 15 V/20 A output.
I'm ...
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Do modern variable frequency drives perform power factor correction?
Do modern variable frequency drives (VFDs) perform power factor correction?
I can't find info to see whether VFDs do power factor correction. If they do, how good are they?
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Does a transformer have different primary and secondary PFs?
I tried connecting two energy meters on primary and secondary and found that they were showing different values when a load was connected to the transformer.
Does a transformer have two different PFs, ...
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Power Quality Measurement & Reporting Standards
I'm analyzing power quality in low and medium voltage facilities (50/60Hz; 0.48 - 69 kV; factories, campuses, etc.) while trying to apply existing standards wherever possible. In addition to demand ...
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PFC (Power Factor Correction) harmonics
I recently succeeded in creating a powerful buck PFC with a value almost equal to 1 (0.999)
As you know there are always problems when dealing with real life circuits. I mean, the PFC value is real, ...
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Half-bridge converter input capacitor setup from boost PFC
I am using a uUC3854 for my boost PFC stage with an output power of 750 W. From my calculations of the output capacitor with a hold-up time of 25 ms and a maximum output voltage of 400 V and a minimum ...
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Inrush current on current sense resistors
The problem is on a circuit which implements PFC circuitry.
There are two parallel 0.36R current sense resistors located in the inrush current path. These resistors measure the PFC current through the ...
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How to choose PFC controller and how to boost voltage
I have found this PFC controller (I am building a rectifier to ~500V). As I understand, because PFC uses a boost converter, it should be able to boost rectified voltage to bigger voltage. How would I ...
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Why the effect of a triphasic capacitor could be as twice as its rated kVar? *(check Update 1)*
Why the effect of a triphasic capacitor could be as twice as its rated kVar?
Please check Update 1, since if its true, then I think my issues are solved.
Intro
This is a real life case of a client of ...
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Why does the variac make a "zing" sound during testing?
I've tested my prototype transition mode 80 W boost PFC with 220 VAC input and 400 VDC output. When I supply the Vcc of the controller and start the switching MOSFET, after a couple of minutes, the ...
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What is the correct arrangement of the EMI filter?
I want to design an EMI filter for the input side of a PFC converter. there are various topologies for EMI filters. in some cases, the CM filter is located on the network side and the DM filter on the ...
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What is an intuitive explanation of using a boost converter for power factor correction?
By theory, a bridge diode and a capacitor bank can convert an AC sine wave into a DC signal, but the source current would appear spikey, having a power factor much smaller than unity.
In order to ...
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One cycle control for PFC
Does anyone know how to build the resettable integrator in SIMPLIS or PSIM simulation?
The figure below is from IRF
I would like to do an OCC control for PFC, but I get into some trouble with how to ...
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Soft start PFC IR1155
I am using the IR1155 PFC controller in a converter. The converter works well in steady state to the maximum of the power, but once the load is stopped, there is a current overload.
Once the load is ...
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Boost CCM PFC inductor current
Does anyone know how to use Mathcad to draw the boost PFC inductor current waveform?
There is no equation to tell me how to do it, so I am confused.
https://www.infineon.com/dgdl/...
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Do DC-DC converters have a power factor smaller than 1?
Say I have a boost converter (picture below) that accepts a constant DC input and outputs a constant DC signal. Does this system have a power factor (PF) that is smaller than 1 (because the circuit ...
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How does the PFC boost circuit work?
I am reading TI's PFC Circuit Basics, and I am having a hard time understanding how the active PFC boost circuit works. I understand that ordinarily the current waveform is not in-phase with the ...
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Is this device claiming to reduce electricity bill a scam? [closed]
I saw something on the net and I have no doubt that it is a scam. This advertises as 90% reduction of electricity bill in a houshold.
I have no idea what it does. From the looks of it it is just a ...
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Purpose of stacked cores
All the PFC that I have seen are equipped with a stacked core inductor. I do not understand what is the purpose of the stacked core.
Why do not just use a bigger core?
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Triangle RMS calculate
About BCM PFC current, why I_L RMS value is
this is from ST document
I try to use rms formula to calculate it, and I also do the research I find the result should be like the below.
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About voltage in power factor correction in three phase systems
So I understand that when you are correcting power factor you are decreasing the system's reactive power. This is usually done by adding capacitors, which also reduce the total current supplied by the ...
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Transformer efficiency with leading and lagging loads
I'm interested in how the efficiency of a transformer changes with the power factor of the load.
I know that in principle you can increase efficiency through power factor correction (i.e. making your ...
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Can large power stations which are not running can be used for power factor improvement of national grid. How? [closed]
My friend told me that the large power stations which are not running can be used for power factor improvement of national grid. I wonder how it can be done? If true, can these stations charge for ...
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Why does the zcd square wave look distorted?
I have connected a capacitor to do some power factor correction on a load. After I connected the capacitor parallel to load, I checked the zero cross detection waveform, which is getting input signal ...
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determining the Bmax for inductor design
at this moment of this youtube video following graph is presented for selecting the proper maximum flux density.
the considered proper amount of core loss is 100mW/cm^3. is this a general amount for ...
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Can VCC be supplied by external power supply?
I've implemented the following 80W PFC boost pre-regulator presented in the following application note. I built the inductor and its auxiliary winding myself with another magnetic core and its ...
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Using fuse during initial tests?
I've implemented the presented 80W PFC boost pre-regulator in the following application note without using the applied fuse at the input. Surely I will add the fuse to the finalized tested circuit. ...
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What the criteria of power factor correction capacitor?
I'm thinking of selecting a load with active power less than 200W and PF<0.5 for my school assignment to show the result of current usage before and after power factor correction. There are ...
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Rectifier circuit behavior - Need an intuitive understanding
Case1: OUT Series res = 10 ohm -> spiky input current reaching upto 15 A -> capacitor charging fast
After a long time:
Case 2: OUT series res = 100 ohm -> almost sinusoidal input current ...
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How critical is the sense resistor?
In the following topology, two 0.68 ohm resistors are paralleled to result in 0.34 ohm for sensing the source current. Can I use three paralleled 1 ohm resistors to result in 0.333 ohm? Does this ...
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implementing dot convention
in the following topology, a boost inductor with secondary winding is operated in which the windings are in opposite directions.
Implementing this structure, in reality, made me confused. Based on my ...
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What is this component in a power supply?
We bought a Cisco 6500 series 6 kW PSU and took it apart. This is a module connected immediately to the inputs of the power supply unit. Does anyone know what it does?
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Can I replace the ceramic capacitor with tantalum?
In the following topology, a 2200nF multilayer ceramic capacitor (SR305E225MAR) is used in the compensation network. Can I replace it with a tantalum capacitor with equivalent voltage and capacitance? ...
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Please verify the proof for percentage of error in power factor measurement
I am constructing an ac wattmeter for my school project, one of the objective is to achieve discrepancy of result(power factor) that is within 5% as compare to the actual measurement result obtained ...
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Power factor problem
I need help solving this problem in my mind, so if anyone had a similar problem it would help me.
In order to make a higher power factor on a receiver, we connect a capacitor of appropriate capacity ...
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CCM Boost PFC avg rms current
I follow the "Fundamentals of Power Electronics-3rd Edition" to derive the below equation.
Now, I would like to derive the Transistor Average,
， and I follow the book formula, but my answer ...
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CCM boost PFC rms current ca;cu;ation
Does anyone know how to calculate the Boost PFC rms current.
I read the "Fundamentals of Power Electronics", there is a formula but I can't total understand.
1.) How to get the red part ...
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Active PFC with discrete components
First of all, I've had no formal training as an electrical engineer, I've taught myself everything I know online, so this may be a stupid question. That said, I've designed an active PFC circuit using ...
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Boost PFC power loss calcaulation
I am studying boost PFC topologies.
I run into a question, how to calculate the CCM / CRM /DCM boost PFC power loss.
I read the On semi document. I would like to derive the Diodes RMS current, but I ...
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DC leakage in single and three-phase rectifier (Electric vehicle chargers)
It seems that the IEC 61851-1 standard ask for a device monitoring DC earth current for any EV charging station, either single or three phases.
What I'm wondering, is, which topology of charger, or ...
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Power factor of a synchronous based DER
I am working on a project including a synchronous based DER (2 Gens).I have a few question, I'll appreciate if you could help me.
1- I want to see what would be the typical control-mode setting of the ...
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Is there any advantage if the PFC inductor is split in between +ve and -ve input line?
While doing the reverse engineering this is what I observed.
The PFC inductor is having 8 set of pins , out of which 4 are shorted to input (+) and 4 are shorted to GND (input return). Obviously , ...
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Bigger NTC = better protection?
A 2.5 ohm NTC is used in the following PFC booster. I've got a 20 ohm one. Can I use it instead of 2.5ohm one? Does it provide better protection or does it disturb the normal operation of the circuit?
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Why did the CS resistor explode in this circuit?
I implemented the following PFC boost converter as shown in the second image and plugged it into 220V with the no-load condition but it exploded at the plug-in. The explosion happened in the sense ...
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Is there any problem to test the following topology without load?
I've implemented the following PFC boost 80W converter. Is there any problem to test the following topology without load?
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