I am working on an engine driven, hybrid generator for a drone. The primary power source is my BLDC in regen braking mode. I have an 8HP engine driving a Flipsky 80100 7KW BLDC. I have a 12S2P LiON battery in parallel with the BLDC regen output and the load. The battery is intended to soak up voltage surges, act as an emergency power source in case the engine dies, and in general be a very large capacitor. I am intending on starting with the battery nearly at nearly 100% SOC, and have made a circuit to limit the max output voltage from the BLDC to about 48 volts. I am using a large MOSFET with a very low Rds of less than 2 milliohms, in the linear range as the voltage regulator, since I expect a max of 100 amps to pass through the MOSFET
This is the circuit I have made, it seems to do a good job of regulating the output voltage, both in simulation and in a simplified hardware test with a variable voltage power supply
Will this circuit somehow fry my VESC? If the VESC max regen current is set to 100 amps, and the MOSFET limits the voltage to 48 volts, will the VESC keep trying to raise the voltage in order to try to pass the full 100 Amps? Will the circuit protect the battery at the expense of the VESC, or will somehow everything work?
Hi, I am very interested in the regen part, so if someone knows where it is discussed, please show me a link. I plan to use it in my electric sailboat to generate power when sailing. My concern is that the propeller will turn the electric motor at a very low rpm 300 till 800 rpm. The correct numbers is unknown to me at this time, but I hope I will be able to find out this summer. Then maybe a need to put in a DC to DC boost converter to get the voltage I need to charge the batteries?
Sounds like a very interesting project, with similar challenges to my generator. I do know that so much more power can be generated by water than wind due to the density. I am not an electrical engineer, but would think if you had the proper KV rating on your generator to match your propeller speeds, that the VESC would be able to act as a buck/boost converter for your battery. I am also thinking for my project of a circuit that limits the Regen voltage to be within a volt or so of the battery, acting as a hardware current control to the battery, but still allows very high current to the load. Most BMS systems I see can't handle 100 amps, and they don't assume a battery is in parallel with the load while the generator is providing most of the power to the load at the same time