110V DC output  battery  surge voltage protection  - Page 1
Forum section: electronics / projects

author: electronx
author_rank: Regular Contributor
timestamp: November 26, 2024, 06:38:21 am
content: I have a battery system with 72V-110V DC output. The surge voltage will be around 120 Volts and I want to clamp it to 110V. There are ready-made clamp surge protector ICs, but the clamp voltages are around 60V-80. Maybe I can create my own active clamp surge protector with mosfets .Does anyone have a solution for this? It would be great if it also had overcurrent protection.

author: Zero999
author_rank: Super Contributor
timestamp: November 26, 2024, 05:06:09 pm
content: How long does the surge last for?And why is it a problem? It's less than 10% over the maximum nominal voltage.

author: ajb
author_rank: Super Contributor
timestamp: November 26, 2024, 08:08:31 pm
content: The impedance/available energy also matters, in terms of how much energy the clamping device will need to absorb. Are you trying to clamp the battery voltage, or the output from the battery system to some load?

author: electronx
author_rank: Regular Contributor
timestamp: November 29, 2024, 02:17:14 pm
content: Thanks for your feedbacks.Surge voltage is between 180-200 volts. I want to correct this information.Actually each arm draws around 15-20 amps of current.(depending on torque)Here is a graph of what I want to prevent.I think I should first estimate the voltage time graph of the surge.Then I need an active clamp circuit.It could be an active clamp circuit like LTC4363.However, the problem is that the clamp voltage is lower than I want, they usually have a clamp voltage of 40-80Volt.In this case, I will need to design a discrete active surge stopper.

author: mtwieg
author_rank: Frequent Contributor
timestamp: November 29, 2024, 04:20:12 pm
content: For such high power levels, you will have to be very careful in your selection of the devices (MOSFET, probably) that will drop the excess voltage during surges. If you're not already familiar with safe operating area (SOA) curves, youhave some reading to do.

author: Zero999
author_rank: Super Contributor
timestamp: November 29, 2024, 05:36:42 pm
content: Where does the surge come from?Is it from the motor driver when it's braking?

author: electronx
author_rank: Regular Contributor
timestamp: November 29, 2024, 08:22:15 pm
content: The motor performs position control with FOC, there are high current draws with sudden acceleration.

author: Zero999
author_rank: Super Contributor
timestamp: November 29, 2024, 10:27:50 pm
content: Quote from: electronx on November 29, 2024, 08:22:15 pmI'm asking about the voltage, not current surge.

author: NiHaoMike
author_rank: Super Contributor
timestamp: November 29, 2024, 10:42:16 pm
content: Add in wiring inductance and the current surges turn into voltage surges. The solution is to add capacitors, but then you have to consider precharge so that the inrush doesn't become excessive.

author: moffy
author_rank: Super Contributor
timestamp: November 29, 2024, 11:14:07 pm
content: If it is a high energy surge you might want to consider switching in a load/breaking resistor across the voltage bus for high voltages to absorb the energy.