双有源桥（DAB）变换器兼具高效和高功率密度，且其能量可双向流动，从而得到广泛应用。DAB变换器易因电路参数、驱动信号不对称等因素造成磁不平衡，进而影响电路正常稳定工作。因此，设计了一种变压器绕组的直流偏置电流检测控制策略。该策略通过采样电阻和delta-sigma（Δ-Σ）调制将电流转换为1位数据流，采样电阻放置在H桥直流端，可分别获得绕组正半周和负半周中电流平均值，相减可得绕组电流直流分量。同时，设计了一种DAB的直流电流抑制方法，通过设计控制器以实现微调任一桥臂的占空比来调节H桥输出电压的直流分量。最后，通过Matlab仿真验证了直流偏置电流检测与控制策略的有效性。

Dual active bridge (DAB) converters has been widely used because of its high efficiency, high power density and bidirectional energy flow. DAB converters are prone to cause magnetic imbalance due to factors such as circuit parameters and asymmetric driving signals, which would affect the normal and stable operation of the circuit. Therefore, a DC bias detection and control strategy for transformer windings is proposed. This strategy uses the sampling resistance and Δ-Σ modulation, which can convert the current into a 1-bit high-speed data stream, and a sampling resistor is placed at the H-bridge DC end. From this, the average value in the positive and negative half cycles of winding current can be obtained, and the DC component of winding current can be obtained by subtracting it. At the same time, a DC suppression method for DAB is designed, which adjusts the DC component of the H-bridge output voltage by designing a controller to tune the duty cycle of any bridge arm. Finally, the effectiveness of DC bias current detection and control strategies has been verified through Matlab simulation.

TM46

国网江苏省电力有限公司重点科技项目（J2022019）