Power lines and the cosmic vortex?
- Thread starter A.O.
- Start date
It would seem that DJI disagrees with you... Here is a quote from their email when I inquired about the warning:
”It is just safety warning, if you flying your aircraft near radar/cellular tower, it will affect signal. And for your safety, please choose flight environment...”
How many amps do you suppose they carry?
Ok so I looked it up. The largest transmission lines are rated 4000A, but typically carry 700A. The article referenced a 400kv line but two separate paragraphs.
It did note though that the return current, or other phases also being transmitted would lower the overall field.
Current
www.emfs.info
dronerdave
Well-Known Member
Really depends on the conductor size and voltage coupled to what the station is rated for. A couple of video opening a station switch:
That really demonstrates voltage and not so much current. At least the distance of the arc doesn't. The brilliance suggests lots of current.
dronerdave
Well-Known Member
Yes and no. Under low or no load, the arc generally breaks a bit differently. Opening any high voltage switch (even a lower voltage 12kV switch) under a large load can be quite an eye opener. I ended up in a cross phase once when I grounded a 13,800 amp 12kV station bus (not my fault) and it's not a good way to get a tan. But yes, higher voltages do arc further under no load. It's why insulators are longer on higher voltage circuits. Many switches have ways to help control the arc so some have less visual effect.
More on topic I've always said unless you know how to build, maintain, and repair electrical equipment, it's best to just stay clear of it. That includes flying drones around lines and substations. Basically just kind of a bad idea.
It would be most interesting to see the actual warning message.
It's not one that I've seen or heard of.
Could you post your flight data?
Same here. I've never had issues with power lines affecting the frequency but I've heard it can happen. I know that pipes under ground or those rods in concrete can interfere with the compass.
My house is next to a power plant substation so there are several large powerlines coming into this station. They can be seen Handheld-to-Flying video camera brainstorm/contest When I posted this thread a few members made comments about the power lines.
The powerlines have not created an issue for me, but occasionally when flying from my backyard, which is closest to the power station, the drone does strange behaviors - particularly drifting a little while descending to land in my backyard in the final 20' AGL.
I don't fly from this location often and typically fly the drone straight up to take some sunset pictures if I do.
The powerlines have not created an issue for me, but occasionally when flying from my backyard, which is closest to the power station, the drone does strange behaviors - particularly drifting a little while descending to land in my backyard in the final 20' AGL.
I don't fly from this location often and typically fly the drone straight up to take some sunset pictures if I do.
If you try and fly into the power line, more than likely you will miss! And vice versa.
Evil, evil, evil..........If you try and fly into the power line, more than likely you will miss! And vice versa.
dronerdave
Well-Known Member
Ha...exactly what happened to me in sports mode with a heavy tail wind. Thought I was well under a 70kV line but was heading right at it. The OA saw the wire thankfully but when it pulled up, the wire popped off the rear landing gear and both the gear and drone dropped into a canyon out of my sight. A couple seconds later I found my Mavic hovering down in the canyon. I then had to learn how to hand catch it for obvious reasons, something I had never done. I was so pumped up surprised I didn't have a stroke.If you try and fly into the power line, more than likely you will miss! And vice versa.
I have lost all control of my mavic mini under heavy power lines multiple times steer clear of them or your drone will find the closest bush/tree to smash into. So don’t fly near power lines it’s a potential disaster
TS_Thomas02
Well-Known Member
I think the 60HZ on the lines is definitely WAY far from the gigahertz range of your drone but that does not mean 60HZ induction won’t occur and the amperage is anyone’s guess depending on how close you get. Hence: Stay Away. Personally, I have a water reservoir with power lines at one end where the public access is. If I do fly it with the drone, I plan to set my home point on a peninsula that juts put away from those lines and have my RTH set way lower than the power lines. Just be careful to give them plenty of space.
I think you'll find transmission lines 120kv and above run at a frequency of around 2ghz so yes they can affect your signal performance
"I think you'll find transmission lines 120kv and above run at a frequency of around 2ghz so yes they can affect your signal performance"
That is incorrect. Voltages are raised and lowered using transformers, the frequency remains fixed at 60 Hz (US) or 50 Hz (Europe, Australia etc.)
That is incorrect. Voltages are raised and lowered using transformers, the frequency remains fixed at 60 Hz (US) or 50 Hz (Europe, Australia etc.)
dronerdave
Well-Known Member
Actually some transmission lines in the US do transmit data over the conductors while also supplying power.
"Utility companies use special coupling capacitors to connect radio transmitters to the AC power carrying conductors. Frequencies used are in the range of 24 to 500 kHz, with transmitter power levels up to hundreds of watts. These signals may be impressed on one conductor, on two conductors or on all three conductors of a high-voltage AC transmission line. Several PLC channels may be coupled onto one HV line. Filtering devices are applied at substations to prevent the carrier frequency current from being bypassed through the station apparatus and to ensure that distant faults do not affect the isolated segments of the PLC system. These circuits are used for control of switchgear, and for protection of transmission lines. For example, a protective relay can use a PLC channel to trip a line if a fault is detected between its two terminals, but to leave the line in operation if the fault is elsewhere on the system".
"Utility companies use special coupling capacitors to connect radio transmitters to the AC power carrying conductors. Frequencies used are in the range of 24 to 500 kHz, with transmitter power levels up to hundreds of watts. These signals may be impressed on one conductor, on two conductors or on all three conductors of a high-voltage AC transmission line. Several PLC channels may be coupled onto one HV line. Filtering devices are applied at substations to prevent the carrier frequency current from being bypassed through the station apparatus and to ensure that distant faults do not affect the isolated segments of the PLC system. These circuits are used for control of switchgear, and for protection of transmission lines. For example, a protective relay can use a PLC channel to trip a line if a fault is detected between its two terminals, but to leave the line in operation if the fault is elsewhere on the system".
Power is transmitted at supply frequency, 50 or 60 Hz, data at much higher frequencies (if I remember correctly, power on the outside of the cable, whereas data is transmitted on the inside of the cable).
I flew my mavic air down a river at about 3m high above water and I noticed in the distance about 200m away what looked like power lines crossing the river above the drone,I quickly panicked went to stop the drone and reverse back out, but I had no control what so ever over the drone, it automatically went into RTH mode going up between the wires and I was unable to control or cancel it . So I absolutely Avoid wires.
At 2 metres maybe, but at 200 metres, the cables had no effect on your drone.
The incident you describe sounds like a simple case of failsafe RTH.
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