Accurate battery state of health (SOH) assessment is one of the keys to the safe and stable operation of battery systems. A novel fast SOH evaluation method for lithium-ion battery modules is proposed based on Lorenz plot (LP). The average Lorenz radius (ALR) of a module in a certain SOC interval is extracted as a health factor for this module SOH. The research results show that the ALR value of the module gradually increases in the low SOC range of the charging curve or the discharge curve as the battery module ages. When the ALR values at 20 % SOC are extracted as health factors, the ALR-SOH evaluation models present a linear negative correlation with a goodness of fit of over 0.99. When the voltage data from any SOC interval containing a voltage of 20 % SOC are extracted to calculate the ALR values of the module, the accuracy of the ALR-SOH evaluation models based on the discharge voltage is generally better than that based on the charging voltage. When the ALR values of the module are calculated using voltage data from any SOC interval starting from 10 % SOC during discharge, the goodness of fit of the ALR-SOH evaluation models based on the discharge voltage data is above 0.97, suggesting the robustness of the SOH evaluation method based on LP. This will provide ample options for the practical application of this method.

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A risk dispatching model for short-term cascaded hydro scheduling during high-water season is proposed in this paper taking into consideration of uncertainty factors and the process of water flow. The uncertainty of natural inflow and market price is simulated by the multi-scenarios method. The conditional value at risk (CVAR) is introduced to quantify the risk caused by these uncertainties. In the objective function, the added CVAR represents the risk preference of the hydropower producer. Based on the degree of risk aversion of the producer, the generation profit and risk are coordinated. In addition, the Muskingum model is used to formulate the process of water flow between upstream and downstream stations. A mixed-integer linear programming model of short-term cascaded hydro system scheduling in the high-water season is developed and solved. Numerical studies demonstrate that the proposed approach can balance the risk and generation profit in the high-water season and the model with the Muskingum constraint is more refined.

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