[Objective] Since the introduction of the dual carbon goals

the rapid development of renewable energy has led to an increasing application of inverters in power systems. Hysteresis current control offers advantages such as fast response and simple control

and it has been widely used in inverter control. However

traditional hysteresis current control requires high accuracy of the reference voltage vector sector

and sector switching can easily lead to uncontrollable error currents due to sector misjudgment. To address this

a hysteresis current control strategy based on fixed switch state switching is proposed. [Methods] In the three-level hysteresis current control method

there are various ways to divide the sectors. By combining different sector division methods in the hysteresis control of three-level inverters

the disadvantage of traditional hysteresis control

where both the sector and the control strategy should be updated at sector boundaries

was effectively avoided. This method allowed for errors in sector judgement of the reference voltage vector while ensuring the error current was controlled throughout the entire cycle. With a fixed loop width

the switching frequency was variable

leading to increased switching losses. Therefore

a frequency-fixed control strategy was studied under this approach. By obtaining the error current data from the previous cycle

the hysteresis width for the current cycle was updated to achieve fixed frequency control

and the calculation formula for the next cycle’s hysteresis width was provided. [Results] The method was validated through Matlab/Simulink simulations. The simulation results showed that the proposed method ensured the error current was controlled throughout the entire cycle

even when the reference voltage vector was at the boundaries of sector switching

and the switching frequency remained around 20 kHz. [Conclusion] The proposed frequency-fixed hysteresis current control strategy based on fixed switch state switching aligns well with the theoretical results and demonstrats accuracy.