Cascade linear active disturbance rejection voltage control method for DC-DC converter

Abstract

The invention discloses a cascade linear active disturbance rejection voltage control method for a DCDC converter. The method comprises the following steps: step 1, sampling a DCDC converter voltage Vo, a bus voltage Vdc and an inductive current IL; 2, comparing the output voltage Vo of the DCDC converter with a reference voltage value Vdcref of the DCDC converter to obtain a voltage error signalev, and enabling the error signal to pass through an outer loop LADRC controller to obtain a current inner loop instruction current IL<ref>; 3, comparing the inductive current IL detected in the step1 with the current inner loop instruction current IL<ref> obtained in the step 2 to obtain a current error signal ei, and enabling the error signal to pass through an inner loop LADRC controller to obtain an output control quantity u; 4, comparing the output control quantity u in the step 3 with a given carrier signal, generating a switch pulse signal PWM, controlling a power device, and stabilizing the bus voltage or adjusting the output power according to an instruction. The invention provides a DCDC converter cascade linear active disturbance rejection voltage control method for a DCDC converter in a direct-current microgrid, wherein the method can achieve the stable operation of the DCDC converter under the conditions of large-range direct-current bus voltage fluctuation and load disturbance.

Description

technical field [0001] The invention belongs to the field of DC micro-grid control, and in particular relates to a DC-DC converter cascaded linear self-disturbance rejection voltage control method. Background technique [0002] As the basic conversion unit of DC microgrid, the DC-DC converter completes the one-way and two-way transmission of energy in the DC microgrid system, which is an important part of the energy regulation of the DC microgrid. The energy scheduling of each module of the DC microgrid is completed through the control of the DC bus voltage. The output characteristics of the DC-DC converter mainly depend on the control method of the voltage and the distributed power of the conversion device used. The previous control strategy on the DC-DC converter was a voltage or current peak and peak valley control method, and a PI compensation network was used to complete the control. At present, the research on the types of DC-DC converters has been relatively mature....

AI Technical Summary

Problems solved by technology

When the traditional PI controller is used for DC side voltage control, although it can finally meet the DC voltage stability and power distribution, but in the case of large interference or inaccurate models, the control accuracy and performance are limited, and it cannot meet higher requirements.

The sliding mode controller is less dependent on the system, has strong robustness and good dynamic performance, but its inherent system chattering affects the control performance and high energy consumption, so it is rarely used in practice

Compared with the traditional double-loop PI control, the predictive current control reduces the loss and obtains better performance indicators, but its power switch is frequently turned on and off, so that the control frequency cannot be fixed well, and the output filter design is difficult, which reduces the actual possible use

The adaptive control method based on voltage or control parameters is complicated to implement, takes up more resources in the control calculation, and its DC side voltage dynamic performance is not ideal

In addition to the aforementioned methods, there are control methods such as hysteresis control for DC-DC converter current inner loop control methods. The parameters need to be adjusted to meet the different dynamic response requirements of the inner and outer loops. Among them, the traditional PI control algorithm can achieve very good The tracking of the given current, but for the dynamic command signal including the DC bus that changes at all times, it cannot be well tracked without static error; the hysteresis control is a transient feedback control method, which has the advantages of high precision and fast response. , can obtain better control performance, but its switching frequency fluctuates greatly, and the output filter design is quite difficult

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