MOSFETs are widely used in residential energy storage systems, mainly in the following aspects:
During the charging and discharging processes of residential energy storage, DC-DC conversion circuits are used to regulate voltage to meet the needs of different devices. They can be applied in MPPT (Maximum Power Point Tracking) solar charging modules. The fast switching time (td(on) = 12ns, tr = 9ns) of MOSFETs reduces switching losses at high frequencies and improves the dynamic response of MPPT modules. Meanwhile, the low on-resistance of 7mΩ also effectively reduces conduction losses.
Inverters convert the DC power stored in batteries into AC power for household electrical equipment. MOSFETs in inverters are mainly used in two parts: front-stage boost and rear-stage inversion. The common topology for rear-stage inversion is full-bridge inversion, which generally uses high-voltage MOSFETs with a voltage range of 650V-1200V, such as 650V/800V SJMOSFETs and 750V/1200V SiCMOSFETs.
MOSFETs are used in BMS for active balancing circuits and charge-discharge control. Through the MOSFET switching network, energy transfer between individual battery cells can be achieved, reducing SOC (State of Charge) differences. For example, a 48V/100Ah energy storage module uses N-channel MOSFETs to build an active balancing network, which can achieve a balancing current of 500mA and shorten the balancing time by 50%.
PFC circuits are used to improve the efficiency of electrical energy utilization and reduce harmonic pollution to the power grid. Through the composite buffer layer + carrier lifetime control technology, the Qrr (reverse recovery charge) is reduced to 55nC, and the peak value of reverse recovery current Irr is cut by 42%. This effectively solves the problems of high switching losses and body diode reverse recovery failure of traditional MOS devices in PFC circuits.
In the battery connection link of residential energy storage systems, MOSFETs can be used in reverse polarity protection circuits. They are applicable to battery reverse polarity protection scenarios: when the positive and negative poles of the battery are connected in reverse, the MOSFET turns off to prevent circuit damage and protect the safety of energy storage equipment and other connected devices.
