In power electronic converters, how do the power loss and heat dissipation of formed resistors affect the efficiency and stability of the entire system?
Publish Time: 2024-11-27
In power electronic converters, formed resistors play a pivotal role. Their power loss and heat dissipation are like the key links in a domino chain. One move affects the whole system and profoundly affects the efficiency and stability of the system.Power loss is the "energy loss" that formed resistors cannot avoid when the current "travels" through them. According to Joule's law, current generates heat through resistance, and electrical energy is irreversibly converted into heat energy and dissipated. This part of the power loss is proportional to the square of the current and the resistance value. In power electronic converters, high-frequency and high-current working conditions are common. Formed resistors continue to "swallow" electrical energy, reducing the proportion of output useful power and lowering the overall efficiency of the system, just like multiple leaks in water supply pipes, resulting in a decrease in terminal water volume.Heat dissipation problems follow power loss, and the two are closely "entangled". Under poor heat dissipation, the accumulated heat causes the resistor temperature to soar, and the resistance value of the resistor is not constant with temperature. The resistance value of most formed resistors with positive temperature coefficient increases, further increasing their own power loss, and falling into a vicious cycle. Excessive temperature also impacts the physical structure of the resistor, causing it to age and become brittle, and reliability plummets.From the perspective of system stability, unstable resistor performance is like a circuit "time bomb". Power loss causes overheating, causing resistance fluctuations, and destroying the precise voltage and current control loop of the converter. Taking the inverter as an example, the "abnormal change" of the resistor distorts the feedback signal, triggers the wrong power device switching action, deteriorates the output power quality, and surges harmonics, threatening the normal operation of the load, and even affecting the entire power network, causing the system to vibrate and lose control, and the stability is at risk.It can be seen that controlling the power loss and heat dissipation of formed resistors is a necessary measure to lay a solid foundation for the efficiency and stability of power electronic converters. Only by optimizing the selection of resistors, designing heat dissipation paths and other multi-dimensional efforts can the system be guaranteed to have a stable "power pulse" and efficient "blood delivery".
