A Multi-step Model Predictive Control Approach for VSC-HVDC

Abstract

The invention discloses a multi-step model predictive control method suitable for VSC-HVDC, comprising: step 10) for the VSC-HVDC system at kT s The relevant electrical parameters of the time are measured and sampled; step 20) establishes a multi-step model prediction function and a correction prediction function, and calculates ((k+p)T s Output voltage u at any time 2 The predicted value of the predicted value; step 30) Construct the adaptive multi-objective optimization performance index function of the inverter station, and calculate the output predicted value and the corresponding performance index function value of the inverter side under all possible switch combinations in the prediction time domain; step 40) Compare the performance index function values ​​corresponding to each switch state separately, and select the switch state g that makes it the smallest min The switching signal is generated and applied to the inverter after being driven and amplified. This control method has a strong ability to resist load disturbance and unbalance, and at the same time, compared with the existing method, when there is a large error in the line parameters, it can significantly improve the stability and robustness of the control.

Description

technical field [0001] The invention belongs to the field of flexible direct current transmission control, and in particular relates to a multi-step model predictive control method suitable for a VSC-HVDC system inverter station supplying power to a distribution network. Background technique [0002] In recent years, with the increasing maturity of long-distance DC transmission technology, the advantages of HVDC transmission in terms of economy and safety have been proven worldwide, and my country has become one of the countries with the most promising application prospects for DC transmission. [0003] The development of High Voltage Direct Current (HVDC) technology mainly goes through two stages: the traditional thyristor-based grid commutation high-voltage direct current transmission (LCC-HVDC) has large harmonic content and cannot control active and reactive power independently. ; Voltage source converter-based flexible direct current transmission (VSC-HVDC) can effectiv...

AI Technical Summary

Problems solved by technology

The traditional inverter station control is mainly based on the double closed-loop control strategy of the current inner loop and the voltage outer loop. Since the response speed of the voltage outer loop is significantly lower than that of the current inner loop, the voltage quality is poor when supplying power to nonlinear loads. , the response time of voltage recovery is longer when the load fluctuates

At the same time, the overall control structure is relatively complex, including multiple PI regulators, which are easily affected by model structural parameters, and PI parameter tuning is difficult

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