Thanks for the shout out. I work as an EE for a living, so I have some experience and knowledge about inverters. Typically grid tied inverters use a form of closed loop control as opposed to open loop so that the user can set the power level and PF without having to manually control it. Typically, grid following control is done in terms of the instantaneous voltage and current as opposed to magnitude and phase angle. The current controller can be employed in the Synchronously Rotating Reference Frame (SRF) using DQ PI controllers or Natural Reference Frame (NRF) using PR controllers. Only some grid forming inverters and generators use the magnitude and phase angle which is known as single loop droop control. Other grid forming inverters use a combination of both, which is known as multi loop droop control. All these full bridge rectifiers in our appliances are causing havoc on the grid in terms of harmonics. It has gotten to the point that the EU has introduced a new standard "IEC 61000-3-2" that sets limits on the amount of current harmonics appliances are allowed to produce. The newer active rectifiers which are basically inverters that import power from the grid as opposed to export eliminate this problem. You could try setting the power angle negative which turns your inverter into an active rectifier. There is another standard "IEEE 519" that defines the harmonic limits for inverters. You could investigate improving the filter design to help the inverter meet these limits.
Grid Tie Inverters use a digital PLL to sync up to the grid, and monitor phase change. However too may grid tie inverters can cause severe distortions in the grid frequency & phase. This is why some utilities limit or prevent grid tie inverters. Its very difficult to track a signal (ie sinewave) when your outputting a signal on the input (ie like audio feedback noise when the mic picks up sound from the output speakers).
@@guytech7310 The PLL is fundamentally the same as the synchroscope on a generator. Both are prone to tracking issues on weak grids and high harmonics. The harmonics are caused by low quality inverters with high THDi. The best mitigation strategy it too only allow higher quality inverters to connect that generate harmonics within acceptable levels. Active power filters can also help which are inverters that inject a current in opposite phase to eliminate the harmonics like noise cancelling headphones.
Wow... having finished my electrical engineering degree and an honours degree in power electronics, you just taught me something I have been wondering about for YEARS! Thank you
You're making good progress. Implement a phase locked loop that initially sycronizes at a zero degree phase shift. Then monitor the current and adjust the phase angle of the PLL to deliver the correct current. A potentiometer could be used to set the amount of current you want to deliver. Look at your inverter as being a current source feeding the grid. Add a low frequency inductor from the output of the LC filter to the input of the transformer. Consider the grid to be a negative resistance. Next you can use voltage feedback to help correct your power factor. Can't wait to see your next version. Good luck.
The transformer has its own leakage inductance so additional inductance may not be needed. In the literature they consider the grid as a voltage source with series positive impedance. Since the inverter is considered as a current source you would want to use current feedback to control Q/P. The grid voltage is only needed to determine the reference angle of the grid.
Quite an interesting look into grid tie inverters! I broke out my 'scope and showed a sparky how the mains waveform looked at my location a while ago and he was quite surprised, so much so that he called over his apprentice to take a look too. He was expecting what he'd been taught, a nice pretty sine wave, but instead saw the tips chomped into the typical high crest load slope you've shown here.
Not sure why yours is distorted. Mine is a very smooth sine wave output. Maybe you have a load on the circuit your running your test on, has higher resistance in your wiring (Alumium wiring, long run, insufficent wire thickness). distortions can cause AC motors to run efficient (run hot).
@@guytech7310 It's pretty common these days and can be seen in many countries. I'm surprised that you don't see it, your electricity supply must be quite low impedance. I can see it here regardless of load at my house so it's present on at least the local LV network but may even be visible on the HV side of the transformer. I'm on a 200kVA transformer with about 100 other houses but people on 315kVA transformers with 30 houses see it too.
@@retrozmachine1189 I don't have a shared transformer. Ground mount transformed about 40 feet from my breaker panel. Are you using a small transform between your osc. probe & mains, or directly connecting the Osc. to the mains (using high resistance resistor in series)?
@@guytech7310 I've heard from people in the USA that see the issue for what it's worth. It is visible using a high voltage probe, or for that matter a transformer that is not in saturation.
yeah, they get taught its a sine wave, that waving a magnet through a conductor makes a sine wave... they dont get taught about peaking transformers, or pole shaping in the generator, pole arcs, pole pitches, the challenges in making an alternator actually produce a sinewave whilst having an efficient magnetic circuit...
I like this Frankenstein buzzing sound when you start the controller, presumably when the BTS7960 is current limiting and the inductor / transformer makes you hear the huge currents. The option without current limiting may be even more exiting, though.
@@raymundhofmann7661 I'm not entirely sure it goes into current limiting, but there's definitely a lot of current when it has this synchronisation error. Fortunately it doesn't happen if you start the device with a more appropriate combination of phase and voltage.
Modern Switch mode inverters do not rely on LCR filters. They use a PWM on the H-bridge to create the sine wave output. The simpliest is a BTL Bridge Tied Load Inverter. Use a 170VDC (120VAC) or 325DC (230 VAC Euro) source & BTL circuit to convert the DC into sinewave AC. A high frequency (>20Khz) PWM driver is used to drive two half bridges, into an inductor & a small AC Cap between for filtering. The higher the frequency the smaller the Inductors needed for the output power, as well as better power regulation.
I didn't mention it in this video, but the inverter uses 20khz pwm on the h-bridge to produce a sine wave output. The LC filter is still needed to remove the high frequency harmonics.
@@AKIOTV You have an RCL filter with resistance. at least in the simple schematic shown. Modern inverters do not use resistors for filtering as it would increase losses.
@@guytech7310 The resistances in the schematic are not an intentional part of the filter design. The 10m was basically to model the internal resistance of the wires, the inductor, the H bridge mosfets themselves etc. This resistance isn't a choice really, it's just the unavoidable resistance of the components. I suspect 10m is actually on the low side for this, but close enough for that little simulation. The 50m (or in the new version 25m) is just a measurement shunt for the scope. Remove the shunt and it still works fine, might need to alter the phase a bit but it doesn't change much. In the old version, the shunt resistor did play a more important role because you couldn't alter the phase, but that wasn't by design. I put that resisor there to measure the current, not to tune the filter.
FWIW I managed a few years ago to build a trivial inverter based on a ZVS oscillator connected to a transformer. It would naturally be synchronized with the grid since the output of the inverter drivers the MOSFETs gates. I was impressed by how simple and effective it was. I was a bit sad to think about the fact that the gates are poorly driven during about 1/3 of the period but I failed to make it work via a pair of MOSFET drivers, so I gave up.
Can you try use IR2110 mos driver instead in H Bridge you definitely gonna get higher efficiency than that driver cause it use P channel mos highside internally in chip. I think your inverter might even exceed some other inverter out there in terms of efficiency you can try taking h bridge in the egs002 datasheet as reference. Also can you pls try using the esp32 dev board or stm32 bluepill, ads1115 or ads1015 I love your video btw it's very informative attempt this is the kind of video you rarely see on the internet, pls keeps going ❤❤
Back in the day they used to have ways to use mechanical means like a spinning wheel maybe that would make and break or flip the connections at the right rate to create AC. Basically if the current was always on, and there was a mechanism akin to a DPDT switch that could break the circuit and then make the connection with reverse polarity. Not entirely sure how it worked but if you think of it it's a easy way to create AC currents when all you have is a battery or generator etc. We have forgotten about these solutions and sometime they might be useful to investigate. The average person can't build an inverter, well they could but they would get overwhelmed at first and would really want to or have to build it. Even then it could take years to self teach and learn how to build one. If u can just follow directions its easy but most of us will end up learning so much stuff just to feel like comfortable in trying to build such a thing. The mechanical solution could be figured out with very little electrical knowledge or education as long as one knows safety rules. Just saying this, not to detract from the video. But just because I find it interesting. That some times the only solution there was becomes lost or forgotten and sounds silly. But that is why the transistor was so highly prized and sought after.
@@Sim-q9t Electromechanical inverters exist, they usually use a mechanism similar to an old doorbell, basically a relay that flips back and forth rapidly. The output however is a nasty square wave, and the contacts wear out quickly. It also can't be used properly for grid-tied operation. If you're going mechanical, a better option is to just drive an AC generator using a brushed DC motor. That'll give you a reliable, pure sine wave "inverter", which could also be tied to a grid.
Rotary phase converters: used to convert single phase AC into 3 phase AC. They are common for commerical sites that need 3 phase power, but only single phase is available at their location.
@tripplefives1402 Not really. inverters do voltage conversion such as step up voltage to AC voltage, as well operate with inductive loads (ie AC motors, power transformers). While its possible to use a audio amp as a very small inverter, its horrible inefficient & usually very limited in power. The worst efficiency are the Linear Audio amps that use impediance to control the output signal. More efficiencient are Class D with a BTL output. These usually for Audio amps over 100 watts. In the case of Grid Tied inverters that also have a digital PLL PID control to keep the output in sync (frequency & phase) with the grid.
@tripplefives1402 Everything that has wheels is a car. Truck Its just larger car, A train, even larger car. Using your logic since an amplifer can be made with a transistor, we can simplify all amplifers as just transistors. It does matter how the amp works, Its just a simple transistor, right? Amplifiers do not increase (step up the voltage. The max output voltage is limited to at best twice the source voltage. inverters can also use transformers to step up the source voltage.
I'm thinking: Why fix the distortion at all? If all the devices want the current at that point of time, why not just give it to them? That should actually help stabilize the grid. The only worry I have is if the transformer is happy about that. I am very curious: Have you measured the efficiency of the inverter with the various configurations? Another thought: Phase shift selection should be easy to automate, no potentiometer needed: Measure the phase difference between the voltage and current and if they don't match, slowly adjust.
Hello, I am trying to do a similar type of project. But before implementing this in hardware, I would like to run a software version of this said "Grid Tie Inverter". Is there any way I can simulate this in proteus? Because I checked, the H_Bridge motor driver (IBT_2 / BTS7960) library isn't available. Please do tell which software would be best to use in this scenario.
@@mohammadfaieqhaider9174 The IBT2 uses a pretty simple circuit with 2 BTS7960 (or BTN7960) half bridge chips. You can probably find libraries of this device, then recreate your own "IBT2" in the simulator.
Hello, very interesting video. Question: how could use an UPS as a grid- tie inverter? I would like to take advantage of existing electronics in the UPS. Any ideas ??
I don't think that's practical. From what I know about UPS's, converting one to a GTI seems harder than starting from scratch. You'd have to deal with far more modifications than you expect.
Only the newer big data center UPS can do this through fast frequnecy response. Older and smaller UPS would require siginificant modifcation of the control electronics to do this. You could still re-use the power electronics and filter though.
@@CSGATI The current and voltage are in phase (as seen from the grid) when a load consumes power. When power is supplied, current flows the other way, so 180deg apart. I wired up the scope to view it in this perspective. But then, if you wired up one of the probes the other way round that would flip that signal on the display. Then they would look in phase. Also I can assure you there was no short, the H bridge wouldn't last seconds. This isn't an electroboom video ;)
Hello, how are you, I am very satisfied with your project, it is a very practical set, I would like to know if there is a way to send the modification lines to apply in 60hz because here in my region the network is 60hz, thank you!
5:54 isn't it exactly opposite? If current and voltage are out of phase, you get reactive power, if voltage and current are in phase, you get clean ohmic power. The more difference between the phases, the lower your cosinus phi. Just draw a resistive load in your simulation. Because that's the opposite of what you want to achieve. I think we mean the same as I'm further in the video. If you try to lower your voltage, you get positive or in phase current, and if you try to rise your voltage, you get current exactly 180 degrees out of phase
@@Robbedoes2 phi is the phase difference between voltage and current. No phase shift: cos(0) = 1 (a resistive load), 90 degree phase shift: cos(90) or cos(-90) = 0 so, no real power at all (inductor or capacitor), 180 degree shift: cos(180) = -1, so negative (but entirely real) power, so the "load" supplies power now. Of course, this is as seen from the grid. If you hook up the current probe the other way round it flips the current waveform on the scope.
In the video he is talking about the phase angle between the sending and recieving voltage (power angle δ) not the voltage and current (phase angle Φ).
great video ,we are exciting to see another progress.It seems quite tricky project . i think LC filter not quite calculated for L material u need sedust Toroid,it is cheap and wind it by self because has much saturation no noise and buz again . for filters th-cam.com/video/ViYSB59iYLY/w-d-xo.htmlsi=h0CKK6apPJv9is9a .......for injucting power ..... th-cam.com/video/b8WZn6YYoxw/w-d-xo.htmlsi=_-4elkLT5obGHdix
Thanks for the shout out. I work as an EE for a living, so I have some experience and knowledge about inverters.
Typically grid tied inverters use a form of closed loop control as opposed to open loop so that the user can set the power level and PF without having to manually control it. Typically, grid following control is done in terms of the instantaneous voltage and current as opposed to magnitude and phase angle. The current controller can be employed in the Synchronously Rotating Reference Frame (SRF) using DQ PI controllers or Natural Reference Frame (NRF) using PR controllers. Only some grid forming inverters and generators use the magnitude and phase angle which is known as single loop droop control. Other grid forming inverters use a combination of both, which is known as multi loop droop control.
All these full bridge rectifiers in our appliances are causing havoc on the grid in terms of harmonics. It has gotten to the point that the EU has introduced a new standard "IEC 61000-3-2" that sets limits on the amount of current harmonics appliances are allowed to produce. The newer active rectifiers which are basically inverters that import power from the grid as opposed to export eliminate this problem. You could try setting the power angle negative which turns your inverter into an active rectifier.
There is another standard "IEEE 519" that defines the harmonic limits for inverters. You could investigate improving the filter design to help the inverter meet these limits.
Grid Tie Inverters use a digital PLL to sync up to the grid, and monitor phase change. However too may grid tie inverters can cause severe distortions in the grid frequency & phase. This is why some utilities limit or prevent grid tie inverters. Its very difficult to track a signal (ie sinewave) when your outputting a signal on the input (ie like audio feedback noise when the mic picks up sound from the output speakers).
Also think about anti islanding. Without it it's illegal to feed in. It works by creating a less than ideal cosinus phi to look if the grid is rigid
@@guytech7310 The PLL is fundamentally the same as the synchroscope on a generator. Both are prone to tracking issues on weak grids and high harmonics. The harmonics are caused by low quality inverters with high THDi. The best mitigation strategy it too only allow higher quality inverters to connect that generate harmonics within acceptable levels. Active power filters can also help which are inverters that inject a current in opposite phase to eliminate the harmonics like noise cancelling headphones.
Wow... having finished my electrical engineering degree and an honours degree in power electronics, you just taught me something I have been wondering about for YEARS! Thank you
This often overlooked device is very important to learn. And very oftentimes unknown.
This is a fascinating deep dive into improving your grid tie inverter. I appreciate the work you've put into this project so far, keep them coming!
You're making good progress. Implement a phase locked loop that initially sycronizes at a zero degree phase shift. Then monitor the current and adjust the phase angle of the PLL to deliver the correct current. A potentiometer could be used to set the amount of current you want to deliver. Look at your inverter as being a current source feeding the grid. Add a low frequency inductor from the output of the LC filter to the input of the transformer. Consider the grid to be a negative resistance. Next you can use voltage feedback to help correct your power factor. Can't wait to see your next version. Good luck.
The transformer has its own leakage inductance so additional inductance may not be needed. In the literature they consider the grid as a voltage source with series positive impedance. Since the inverter is considered as a current source you would want to use current feedback to control Q/P. The grid voltage is only needed to determine the reference angle of the grid.
Quite an interesting look into grid tie inverters! I broke out my 'scope and showed a sparky how the mains waveform looked at my location a while ago and he was quite surprised, so much so that he called over his apprentice to take a look too. He was expecting what he'd been taught, a nice pretty sine wave, but instead saw the tips chomped into the typical high crest load slope you've shown here.
Not sure why yours is distorted. Mine is a very smooth sine wave output. Maybe you have a load on the circuit your running your test on, has higher resistance in your wiring (Alumium wiring, long run, insufficent wire thickness). distortions can cause AC motors to run efficient (run hot).
@@guytech7310 It's pretty common these days and can be seen in many countries. I'm surprised that you don't see it, your electricity supply must be quite low impedance. I can see it here regardless of load at my house so it's present on at least the local LV network but may even be visible on the HV side of the transformer. I'm on a 200kVA transformer with about 100 other houses but people on 315kVA transformers with 30 houses see it too.
@@retrozmachine1189 I don't have a shared transformer. Ground mount transformed about 40 feet from my breaker panel.
Are you using a small transform between your osc. probe & mains, or directly connecting the Osc. to the mains (using high resistance resistor in series)?
@@guytech7310 I've heard from people in the USA that see the issue for what it's worth. It is visible using a high voltage probe, or for that matter a transformer that is not in saturation.
yeah, they get taught its a sine wave, that waving a magnet through a conductor makes a sine wave... they dont get taught about peaking transformers, or pole shaping in the generator, pole arcs, pole pitches, the challenges in making an alternator actually produce a sinewave whilst having an efficient magnetic circuit...
I like this Frankenstein buzzing sound when you start the controller, presumably when the BTS7960 is current limiting and the inductor / transformer makes you hear the huge currents. The option without current limiting may be even more exiting, though.
@@raymundhofmann7661 I'm not entirely sure it goes into current limiting, but there's definitely a lot of current when it has this synchronisation error. Fortunately it doesn't happen if you start the device with a more appropriate combination of phase and voltage.
Modern Switch mode inverters do not rely on LCR filters. They use a PWM on the H-bridge to create the sine wave output. The simpliest is a BTL Bridge Tied Load Inverter. Use a 170VDC (120VAC) or 325DC (230 VAC Euro) source & BTL circuit to convert the DC into sinewave AC. A high frequency (>20Khz) PWM driver is used to drive two half bridges, into an inductor & a small AC Cap between for filtering. The higher the frequency the smaller the Inductors needed for the output power, as well as better power regulation.
I didn't mention it in this video, but the inverter uses 20khz pwm on the h-bridge to produce a sine wave output. The LC filter is still needed to remove the high frequency harmonics.
@@AKIOTV You have an RCL filter with resistance. at least in the simple schematic shown. Modern inverters do not use resistors for filtering as it would increase losses.
@@guytech7310 The resistances in the schematic are not an intentional part of the filter design.
The 10m was basically to model the internal resistance of the wires, the inductor, the H bridge mosfets themselves etc. This resistance isn't a choice really, it's just the unavoidable resistance of the components. I suspect 10m is actually on the low side for this, but close enough for that little simulation.
The 50m (or in the new version 25m) is just a measurement shunt for the scope.
Remove the shunt and it still works fine, might need to alter the phase a bit but it doesn't change much.
In the old version, the shunt resistor did play a more important role because you couldn't alter the phase, but that wasn't by design. I put that resisor there to measure the current, not to tune the filter.
@@AKIOTV OK. Thanks for the clarification.
How about using high frequency transformer to convert pwm to 220 and then do the LC filtering?
FWIW I managed a few years ago to build a trivial inverter based on a ZVS oscillator connected to a transformer. It would naturally be synchronized with the grid since the output of the inverter drivers the MOSFETs gates. I was impressed by how simple and effective it was. I was a bit sad to think about the fact that the gates are poorly driven during about 1/3 of the period but I failed to make it work via a pair of MOSFET drivers, so I gave up.
@@levieux1137 I want to make a zvs device some time. IMO it's one of the coolest types of electronic circuit.
I think the same. I hope you will post a third episode
Can you try use IR2110 mos driver instead in H Bridge you definitely gonna get higher efficiency than that driver cause it use P channel mos highside internally in chip. I think your inverter might even exceed some other inverter out there in terms of efficiency
you can try taking h bridge in the egs002 datasheet as reference.
Also can you pls try using the esp32 dev board or stm32 bluepill, ads1115 or ads1015
I love your video btw it's very informative attempt this is the kind of video you rarely see on the internet, pls keeps going ❤❤
Back in the day they used to have ways to use mechanical means like a spinning wheel maybe that would make and break or flip the connections at the right rate to create AC. Basically if the current was always on, and there was a mechanism akin to a DPDT switch that could break the circuit and then make the connection with reverse polarity. Not entirely sure how it worked but if you think of it it's a easy way to create AC currents when all you have is a battery or generator etc. We have forgotten about these solutions and sometime they might be useful to investigate. The average person can't build an inverter, well they could but they would get overwhelmed at first and would really want to or have to build it. Even then it could take years to self teach and learn how to build one. If u can just follow directions its easy but most of us will end up learning so much stuff just to feel like comfortable in trying to build such a thing. The mechanical solution could be figured out with very little electrical knowledge or education as long as one knows safety rules. Just saying this, not to detract from the video. But just because I find it interesting. That some times the only solution there was becomes lost or forgotten and sounds silly. But that is why the transistor was so highly prized and sought after.
@@Sim-q9t Electromechanical inverters exist, they usually use a mechanism similar to an old doorbell, basically a relay that flips back and forth rapidly. The output however is a nasty square wave, and the contacts wear out quickly. It also can't be used properly for grid-tied operation.
If you're going mechanical, a better option is to just drive an AC generator using a brushed DC motor. That'll give you a reliable, pure sine wave "inverter", which could also be tied to a grid.
Rotary phase converters: used to convert single phase AC into 3 phase AC. They are common for commerical sites that need 3 phase power, but only single phase is available at their location.
@tripplefives1402 Yes! HF inverters are very very similar layout to high power switching audio amps.
@tripplefives1402 Not really. inverters do voltage conversion such as step up voltage to AC voltage, as well operate with inductive loads (ie AC motors, power transformers). While its possible to use a audio amp as a very small inverter, its horrible inefficient & usually very limited in power. The worst efficiency are the Linear Audio amps that use impediance to control the output signal. More efficiencient are Class D with a BTL output. These usually for Audio amps over 100 watts.
In the case of Grid Tied inverters that also have a digital PLL PID control to keep the output in sync (frequency & phase) with the grid.
@tripplefives1402 Everything that has wheels is a car. Truck Its just larger car, A train, even larger car.
Using your logic since an amplifer can be made with a transistor, we can simplify all amplifers as just transistors. It does matter how the amp works, Its just a simple transistor, right?
Amplifiers do not increase (step up the voltage. The max output voltage is limited to at best twice the source voltage. inverters can also use transformers to step up the source voltage.
I'm thinking: Why fix the distortion at all? If all the devices want the current at that point of time, why not just give it to them? That should actually help stabilize the grid. The only worry I have is if the transformer is happy about that. I am very curious: Have you measured the efficiency of the inverter with the various configurations?
Another thought: Phase shift selection should be easy to automate, no potentiometer needed: Measure the phase difference between the voltage and current and if they don't match, slowly adjust.
Thanks for sharing
Hello, I am trying to do a similar type of project. But before implementing this in hardware, I would like to run a software version of this said "Grid Tie Inverter". Is there any way I can simulate this in proteus? Because I checked, the H_Bridge motor driver (IBT_2 / BTS7960) library isn't available. Please do tell which software would be best to use in this scenario.
@@mohammadfaieqhaider9174 The IBT2 uses a pretty simple circuit with 2 BTS7960 (or BTN7960) half bridge chips. You can probably find libraries of this device, then recreate your own "IBT2" in the simulator.
what software are you using to show the simulations; seems quite nice.
falstad.com/circuit
See falstad - circuit simulator.
Interesting, thx for sharing!
Hello, very interesting video.
Question: how could use an UPS as a grid- tie inverter? I would like to take advantage of existing electronics in the UPS.
Any ideas ??
I don't think that's practical. From what I know about UPS's, converting one to a GTI seems harder than starting from scratch. You'd have to deal with far more modifications than you expect.
Only the newer big data center UPS can do this through fast frequnecy response. Older and smaller UPS would require siginificant modifcation of the control electronics to do this. You could still re-use the power electronics and filter though.
If it is 180 deg out of phase isn't it just shorting out? It should be in phase with a higher voltage or amplitude?
@@CSGATI The current and voltage are in phase (as seen from the grid) when a load consumes power. When power is supplied, current flows the other way, so 180deg apart.
I wired up the scope to view it in this perspective. But then, if you wired up one of the probes the other way round that would flip that signal on the display. Then they would look in phase.
Also I can assure you there was no short, the H bridge wouldn't last seconds. This isn't an electroboom video ;)
Hello, how are you, I am very satisfied with your project, it is a very practical set, I would like to know if there is a way to send the modification lines to apply in 60hz because here in my region the network is 60hz, thank you!
@@aurismarsolar Sure, you can run it at 60Hz by changing a couple of values in the code.
5:54 isn't it exactly opposite? If current and voltage are out of phase, you get reactive power, if voltage and current are in phase, you get clean ohmic power. The more difference between the phases, the lower your cosinus phi.
Just draw a resistive load in your simulation. Because that's the opposite of what you want to achieve.
I think we mean the same as I'm further in the video. If you try to lower your voltage, you get positive or in phase current, and if you try to rise your voltage, you get current exactly 180 degrees out of phase
@@Robbedoes2 phi is the phase difference between voltage and current. No phase shift: cos(0) = 1 (a resistive load), 90 degree phase shift: cos(90) or cos(-90) = 0 so, no real power at all (inductor or capacitor), 180 degree shift: cos(180) = -1, so negative (but entirely real) power, so the "load" supplies power now.
Of course, this is as seen from the grid. If you hook up the current probe the other way round it flips the current waveform on the scope.
In the video he is talking about the phase angle between the sending and recieving voltage (power angle δ) not the voltage and current (phase angle Φ).
Where are you based? Your accent says British, your sockets say European?
I'm from Holland actually
@@AKIOTV :-), verrassend
@@erichertsens haha
great video ,we are exciting to see another progress.It seems quite tricky project .
i think LC filter not quite calculated for L material u need sedust Toroid,it is cheap and wind it by self because has much saturation no noise and buz again .
for filters
th-cam.com/video/ViYSB59iYLY/w-d-xo.htmlsi=h0CKK6apPJv9is9a
.......for injucting power .....
th-cam.com/video/b8WZn6YYoxw/w-d-xo.htmlsi=_-4elkLT5obGHdix
for much more efficincy H bridge not effective more power losses
for injucting power ....
th-cam.com/video/b8WZn6YYoxw/w-d-xo.htmlsi=_-4elkLT5obGHdix