Timeline for Running Tesla Powerwall 2 Off-Grid - Excess Solar Question
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 26, 2020 at 20:28 | history | migrated | from electronics.stackexchange.com (revisions) | ||
| Jun 23, 2020 at 15:47 | vote | accept | CommunityBot | ||
| Jun 23, 2020 at 10:54 | answer | added | user_1818839 | timeline score: 3 | |
| Jun 23, 2020 at 10:10 | comment | added | ProxyTech | If you want to formulate your above comments into an answer (especially related to the PW artificially raising the frequency as a protection mechanism), I'll mark that as the answer, as I think it's spot on, after watching and reading a bunch online. | |
| Jun 23, 2020 at 10:05 | comment | added | ProxyTech | Apologies, I should have made the diagram clearer. The gateway sits between my meter box outside the house and the consumer unit inside the house. It senses when the grid goes down and throws a mechanical switch to cut the house power completely from the grid. I essentially simulated the power cut by throwing the main breaker in the outside box. You can actually hear the mechanical thonk of the breaker clicking over when it senses the grid loss. The system can't tell the difference between an actual power cut and me just throwing the breaker... It's the same thing to the Powerwall. | |
| Jun 23, 2020 at 9:56 | comment | added | user_1818839 | Not of electricity itself, but of grid generation via rotating machinery, which speeds up a little when lightly loaded (like a car rolling downhill). Powerwall may be programmed to mimic this. My question is : how does your system know if it's been disconnected at the gateway, rather than via a power cut? I'm guessing from your comment the gateway handles this correctly; in my defence, there's no gateway in your schematics! Thanks for the links. | |
| Jun 22, 2020 at 23:25 | comment | added | ProxyTech | @BrianDrummond. Ah ok, so is this just a property of electricity itself? i.e. oversupply and under-demand causes a rise in frequency? | |
| Jun 22, 2020 at 23:22 | comment | added | ProxyTech | @BrianDrummond: Please read the opening lines of the question regarding the gateway device that provides a physical disconnection from the grid in the event of external power loss. It's DNO approved (I had to go through a multi week application process). You can read more here: westernpower.co.uk/connecting-energy-storage | |
| Jun 22, 2020 at 21:46 | comment | added | user_1818839 | This looks like a bug in either Tesla or inverter : I would report it to both suppliers, and check if both components are approved to G83/2. If not, this installation may not be technically legal in the UK. | |
| Jun 22, 2020 at 21:37 | comment | added | user_1818839 | Then it is supposed to shut down when disconnected from the grid. That's a fundamental safety requirement of grid tie inverters called "anti-islanding". The Powerwall fooled it - until the battery was full. Then like any grid with too much capacity and not enough load, its frequency rose until the inverter shut down. This is quite alarming : if you have a Grid Tie Inverter and a Tesla in charging mode, and the grid fails, do you power the local grid segment and electrocute the poor lineman sent out to fix it? | |
| Jun 22, 2020 at 20:21 | comment | added | ProxyTech | @BrianDrummond Done. It is a grid-tie inverter. | |
| Jun 22, 2020 at 18:51 | comment | added | user_1818839 | Is it just a grid tie inverter or is it designed for off-grid applications too? Can you link to its manual in the question? | |
| Jun 22, 2020 at 18:25 | history | asked | ProxyTech | CC BY-SA 4.0 |