Just wanted to share our project and thank the LVGL devs for a great library.
The product is a managed Power Distribution Unit (PDU) with switched outlets and various power/energy measurement sensors. The LVGL library was used on the control module with 1.8" TFTLCD screen that’s built-in to each of these PDUs. The PDUs come in many configurations (outlet count, measurement capabilities, 1-phase/3-phase distribution) and the LCD screen info adapts depending on the type of PDU connected.
The screen is used to view the status of sensor measurements, view outlet states, control/switch outlets, configure network settings, and more.
You can see demos of the screen and read about the front panel functionality in our recent blog post:
Some more product photos showing the screen in the vertical and horizontal orientations.
I wonder how fast the switching can be. For example in case of an overload, is it possible to disconnect the load in 1 cycle or faster? With what type of circuit the switching is done?
Depends on the overload condition. For overload events that require fast detection to shut down for safety reasons, a circuit breaker or fuse is better suited. Our PDUs that are rated above 20A have built-in branch circuit breakers. The circuit breaker delay curve determines the response time based on the overload condition.
Our PDUs continuously sample power metrics at a high rate and can be configured by the user to send alerts or toggle outlets when thresholds are exceeded. Detection and switching speeds depend on the power metric that’s being monitored.
We use a variety of power relays depending on the application for switching and either CTs or shunts for the current/power/energy measurements.
Do you also monitor power outages? It may be necessary to disconnect some high power loads from the grid “as fast as possible” to prevent overloading of UPSs. In this case, fast detection of the power outage becomes important.
If the PDU is downstream from the UPS then it is only possible for the PDU to detect an outage with some additional input. Otherwise, the changeover from the failed power source to the UPS battery would be too fast for the PDU to detect and attribute to an outage.
There are some methods for the PDUs to detect outages but again it depends on the setup. Feel free to message me directly if you would like to further discuss this in detail.
