直流微网中母线电压对直流负载影响

The Impact of Bus Voltage on the DC Load for DC Micro Grid

在直流微网中,由于没有无功功率的流动,电压成为反映系统功率平衡的唯一指标,当设备投入和从母线上切除时,直流母线电压会有波动和小范围的突变,母线电压的变化会对直流负载有很大的影响,为了使此时挂接在直流微网上的直流设备仍能正常工作,必须尽量消除直流母线电压的扰动对直流负载输出端的影响。采用能量守恒法建立DC/DC的小信号模型,用前馈加反馈的控制策略来消除直流母线电压波动对输出负载的影响。通过仿真对控制策略进行了模拟,并通过实验近似对理论进行了验证。实验结果表明控制方法可以近似消除母线电压对直流负载的影响。

In DC micro grid, Because reactive power flow is not considered, only the quality of voltage can reflect the power banlance of the system, when devices input and removal from the bus, the DC bus voltage is subject to fluctuations and small-scale mutations. In order to make devices attached to the DC bus work normally, We must try to eliminate the DC bus voltage disturbances on the DC load of output. In this paper, the energy conservation principle is used to establish a DC/DC small-signal model, feedforward and feedback of control strategy is used to eliminate the effect of DC bus voltage fluctuations on DC load. Through the simulation, effect of the DC bus voltage can be approximately eliminated. It is also tested the feasibility of the theory by experiment. The experimental results show that the control method of this article can be approximated to eliminate the impact of bus vohage on DC load.