再生能源发电中考虑SOC的复合储能控制策略

Control strategy of hybrid energy storage for renewable energy considering SOC

为了维持微网中各发电单元输出功率与负荷功率的瞬时平衡,需要储能单元频繁地充放电,对传统大功率锂离子电池的内部温度等产生较大的负面影响,导致电池容量积累性亏损并在短时间内快速下降,缩短其使用寿命。文中提出了适用于微网的超导磁储能与锂离子电池混合储能结构,将SMES与锂离子电池通过各自DC/DC变换器并联到直流母线,并推导了混合储能的简化模型,利用滑动平均滤波法将波动功率高频部分分配给SMES,低频波动部分分配给锂离子电池。根据不同的SOC工作状态(正常,警告,报警等),动态调节滤波时间常数,从而调节功率分配。该HESS在风力发电中的仿真试验验证了所提出的混合储能拓扑及滑动平均滤波法动态分配策略的有效性。

In order to maintain the instantaneous power balance of each micro-grid power generation unit and load, frequent charging and discharging of the energy storage unit is urgently nee- ded, which has a great negative effect on the internal temperature of traditional high-power lithium-ion battery, leading to the accumulation loss of battery capacity in a rapid way in a short time and shortening its life span. In this paper, a hybrid energy storage system（HESS） topology of superconducting magnetic energy storage （SMES） and lithium-ion battery suitable for micro-grid is proposed , SMES and lithium-ion batteries are connected in parallel to the DC bus by respective DC/DC converters , and simplified model of hybrid energy storage is derived, high frequency part of the fluctuation of the power is allocated to SMES, the low-frequency fluctuation part is assigned to lithium-ion battery by using moving average filtering method. The filter time constant is dynamically adjusted depending on the SOC work status （normal, warning, alarm, etc. ）, thereby adjusting the power distribution. Simulation test of HESS used in wind power generation can validate the effectiveness of the proposed topology and moving average filtering method.