 Some slide about high frequency injection, I have to highlight that in version 5 it's not implemented now we are working on that but it's good to know that this is our algorithm and we are working on that because I have already touched this topic we are focused for sensorless and this is a sensorless algorithm and we are going to find additional through the some disadvantage of this this method Why we we are looking for for this kind solution it is due to some limitation of sensorless algorithm Because our reconstruction it's working on the back EMF reconstruction and this is this zero Speed we receive zero Zero back EMF and from that it's not able to recognize nothing and What is the high frequency injection we have for that the patent and how it's work we implement some high frequency to the to the motor and Looking for the for the result our result our feedback from the system. It's a current feedback and Through that it's also the current feedback somehow modulated the modulation which we implement In the voltage it's a somehow modulate through the structure of the motor and through the position of them of the rotor For that it's a first first definition or Request that we have to have some anisotropy that it's a work only with internal permanent magnet structure and We have to use it For the low frequency for the zero speed or Or very low speed we have some possibilities how to How to observe the position? First one, I don't know it. I know only this this name some zero sequence voltage expansion I'm not sure that's some technique which we don't use and Second it's a high frequency injection and another one. It's low frequency injection our team Around three or four years ago Have a look for the solution and recognize that the high frequency. It's a Good solution that's not require additional hardware it's easy to implement to our library and The torque which is inside it's quite avoid that through the high frequency I'm not sure. Yes, I have also additional slide. Maybe there is some comment about the frequency We will implement some some Oscillating injected test signal, which is rotate around cycle and This signal it's name high frequency, but it's not real high frequency, but for motor It's high frequency and motor cannot follow this this speed and Only stay and we measure the result from the high frequency The algorithm is quite quite complex and we have to add additional additional part which is Benefit from nose north-south detection of the of the magnet and these two algorithm work together and We can benefit from this these two Also, there is some simple implementation how to play this is the how to work with these two algorithm because high frequency it's Injection it's only for a low speed We will apply high frequency injection on the background with state observer During low speed or zero speed after some threshold we start up also the standard observer and PLL and After some some additional time for the stabilization we decided that now it's the good time for the switching and Running this only one algorithm and safer CPU for for the another application Similar it's when we slow down again after some threshold we will again activate HFI and After some threshold we switch off switch from the state observer plus PLL to HFI and After again some threshold we stop the PLL and save time because it's not a reliable Worker with PLL at this speed That's a simple some hysteresis Control of this two algorithm and some additional slide. It's came from the Real system we use two duck channels Debug outputs and you see two signals which is a highlight position of the of the rotor one it's coming from PLL and second one from HFI that's This state it's just in the middle when both algorithm running and Reconstruct the position and you see that the result. It's quite similar Then second second slide when we have only PLL because we are running fast and the signal from from HFI it's Only at the at the last value and because the court it's not running That's About signal We have some incremental build this picture from the step seven. It's quite complex and It's not easy to tune it But in this case, it's good to highlight that we have some Some areas first area. It's a start with some injected signal we can which rotate sometimes around the electrical cycle and There is again some debug debug signal, which is named a HR H file H I Debug angle and you see how it's stabilized and this is Controlled by some PID regulator and we have to tune it and you see that after time it's located to some stable stable value which mean some angle Then it's a part with no south Detection which is quite shorter, but with some additional stuff on that and the last one It's a locking to continue spinning. That's the shortest part, but again It contains some PI regulator which have to be tuned somehow and this three part takes some time, but Usually it's shorter than alignment and you will see on the next slide This is Typical approach of the compressor It is very nice to net application because you see that This part it's only two periods and then it's decrease decrease the current. That's mean that after some alignment we apply some rev up face and Through this short time We are able to lock to the to the observation of the angle and decrease Current to the necessary value. That's very perfect Precise to net to net application But you can you can observe what is inside Inside it's first part which is here That's alignment about one more than one seconds with six ampere quite hard high current in this case Then we have Eight ampere some open loop startup very very short start up, but with eight ampere and Then it's switched to the to this closed loop and it's could be could be the same with HFI that's perfect case and we have a slide for the comparison and for the comparison we have some initial part with All three parts what we have described in a slide before and this part need only two ampere the injected signal. It's quite small and only 200 milliseconds, that's shorter and smaller current and Then it's start up, but this start up. It's coming From the start with field oriented control we apply exact angle and if motor don't move Then we increase the current to the necessary value. We will cover all possibility with the load without the load and For that you see that for the start we FOC this closed loop Implement only for ampere, which is because it's necessary Not necessary apply eight ampere like in the case before and Also, you can see in this case that There is modulated injected signal and after some time when we speed up we decided that there is the time that we are running at the reliable speed for the PLL and then we switch only for the one algorithm Yeah, there is without HFI What is the benefit the maximal efficiency because we apply only necessary current and Fast acceleration because we know that rotor is smooth that's the goal of sensor less zero speed algorithm and That's all from this part