power lines

[Aussie Oldtimer]

I was following some wild horse at high speed and the drone suddenly stopped. I had come upon a set of very high tension power lines. It must have been directly in the line of the sensor because I didn’t see them from my POV

Lucky for me, it didn’t make contact and I just had to RTH

 

[Aussie Oldtimer]

Electricity can jump 2/3 Mtr under the right conditions from power lines generally best to give them as much room as possible.

The regs for construction work (NSW) is/was remain 6m clear of 330 plus kva lines.

Years ago, we did a controlled experiment to replicate a fatal accident where the crane operator stated he was 4m away and the power jumped to the crane rope.

We cranked it up to 330kva and couldn’t get it to jump any more than 450mm, even in simulated rainstorm.

So from that point on, I realised that its just a built-in safety margin

I cant see any voltage jumping to an unearthed drone

 

[The Editor]

The capacitance of the aircraft is negligibly small, so I don't understand what you are envisaging here.

I'm not envisaging anything - You said 'it won't jump to an airborne object'.
I simply pointed out that that statement is factually wrong due to not taking into account capacitive loading.
Whilst the toys talked about here maybe small and thus the phenomenon unlikely (but still possible), larger UAV's increase the risk of an incidence.
I was simply pointing out the error in your statement so that people should not emphatically rely on close proximity flying to HT lines is being safe.

 

[sar104]

I'm not envisaging anything - You said 'it won't jump to an airborne object'.
I simply pointed out that that statement is factually wrong due to not taking into account capacitive loading.
Whilst the toys talked about here maybe small and thus the phenomenon unlikely (but still possible), larger UAV's increase the risk of an incidence.
I was simply pointing out the error in your statement so that people should not emphatically rely on close proximity flying to HT lines is being safe.

I was looking for a mechanistic description of what you are hypothesizing. Capacitative loading of what circuit?

 

[skiptv]

No effect. Unless you hit them. PG&E the power company in CA uses Inspire 2s to get within 5 feet of high voltage transmission lines with no errors. Sometimes we get a live video feed break up but no issues with drone interference

 

[Dave Maine]

Any object has some capacitance, so when close to a power source it will charge up to the source’s voltage. When it moves away, the charge will bleed off quickly. Also note that this charge recharge happens 60 times per second since the high tension wires are all ac.

 

[sar104]

Any object has some capacitance, so when close to a power source it will charge up to the source’s voltage. When it moves away, the charge will bleed off quickly. Also note that this charge recharge happens 60 times per second since the high tension wires are all ac.

I think that you are confusing charge with potential, where capacitance is the ratio between those. For an isolated object surrounded by a non-conducting gas there is no net movement of charge in an electric field, only some charge separation in conducting parts of the object.

 

[dronerdave]

I've worked in the power industry for most of my life. John Q public can only get so many feet from a high voltage line by law, so flying too close might not cause a flight issue but you may be in violation. I'd never recommend flying between phases under any condition. Just because one day you were able to get really close to a particular line doesn't mean you can do it the next day. It all depends on the line voltage and the weather...mainly wind or areas during thunderstorms. On breezy or windy days when one circuit of the line is de-energized for maintenance, wind can make it difficult to handle the induced voltage from the neighboring energized line. It might also make trouble for a drone.

Small drones would be more likely to do damage to a strand of transmission wire or insulator compared to causing a cross phase. Most of the lines rated from 110kv or higher have fairly large air clearances. A lower voltage distribution line however doesn't have as much clearance so getting between those lines might be more of a risk.
Each drone is different as well. We used a Phantom to run lines out the lower voltage transmission lines. At one tower the operator got too close to a 110Kv line and the Phantom did a flip and crashed. According to one company we researched, the Phantom got high rates for being more forgiving around high transmission voltages. I was surprised the inspire was rated poorly. Our company purchased a M-210 as the workhorse multi rotor.

The main thing is to keep a reasonable distance, and fly safe.

 

[Sixgun89]

The RF noise level alone could interfere with any number of circuits or signals! I would steer clear!
Just my 2 cents
I am an electrical engineer involved in military avionics

 

[able2ru]

But it will only jump if there is a ground or neutral phase close enough.

There are other factors involved, including static electricity. The attached video shows power line maintenance using a helicopter. Before they can touch the wires, they have to neutralize their static charges and essentially become charged like the line. Even though the helicopter is not "grounded", you can see the energy discharges on approach and depart. Now, whether that will affect your drone as you get close, or actually touch the wire, to me, it's not worth the risk finding out and you're supposed to avoid power lines also.

 

[johnmeyer]

Absolutely unbelievable video! That chopper pilot's skill is absolutely amazing, and the guts of the guy clamping the spacers on the lines is off the charts.

 

[sar104]

There are other factors involved, including static electricity. The attached video shows power line maintenance using a helicopter. Before they can touch the wires, they have to neutralize their static charges and essentially become charged like the line. Even though the helicopter is not "grounded", you can see the energy discharges on approach and depart. Now, whether that will affect your drone as you get close, or actually touch the wire, to me, it's not worth the risk finding out and you're supposed to avoid power lines also.

Right - but that's an issue because a helicopter is a conducting structure with a much larger self-capacitance than a largely non-conducting small UAV and will build up a large static charge (and potential) even without any power lines involved, as anyone who has inadvertently grabbed a hoist line before it grounded will tell you.