Finite control set model prediction control method of llcl battery energy storage converter

A finite control set model predictive control method of an LLCL battery energy storage converter, comprising:

• collecting electrical physical quantities by using sensors, wherein the electrical physical quantities comprise a current at a grid side, a current at a converter side, a grid voltage and a capacitor voltage at a current time;
• building a state space mathematical model of an LLCL filter based on the electrical physical quantities;
• setting a sampling period and discretizing the state space mathematical model of the LLCL filter to obtain a discrete model;
• deriving reference values of the current at the converter side and reference values of the capacitor voltage in a k-th sampling period by using a given value of the current at the grid side in the k-th sampling period;
• based on the reference values of the current at the converter side and the reference values of the capacitor voltage in the k-th sampling period, predicting reference values at time k+1 according to the discrete model;
• defining a cost function to quantitatively evaluate control performance of each voltage vector in a finite set;
• calculating the cost function corresponding to each voltage vector based on the reference values at time k+1, and selecting an optimal output voltage vector which minimizes a result of the cost function;
• based on a corresponding relationship between each voltage vector and a circuit switch, sending the optimal output voltage vector to control an appropriate circuit switch state for operating.