Overview of Model-Free Control for Switching Power Supplies
The model-free control of switching power supply makes switching power supply develop in the direction of digitalization, intelligence and multi-function. This undoubtedly improves the performance and reliability of the switching power supply. However, since the switching power supply itself is a nonlinear object, it is quite difficult to establish an accurate model, and approximate processing is often used, and its power supply system and load changes are uncertain, so it is often difficult to use the above analog or digital PID control method. The parameters of the PID regulator change accordingly, and the control effect is not ideal. Recently developed model-free control is a promising control method. It does not rely on the mathematical model of the controlled object, and integrates modeling and control. This is very suitable for some complex and variable or structurally uncertain systems that are difficult to describe with an accurate mathematical model. It improves the switching power supply. The control system not only meets the high performance and high reliability requirements of the switching power supply.
Overview of Model-Free Control for Switching Power Supplies
With the rapid development of power electronics technology, the relationship between power electronic equipment and people's work and life is becoming increasingly close, and electronic equipment cannot do without a reliable power supply. Switching power supply is a kind of power supply that uses modern power electronics technology to control the time ratio of switching transistor on and off to maintain a stable output voltage. Switching power supply is generally composed of pulse width modulation (pWM) control IC and MOSFET. Most of the switching power supply control parts are designed and worked according to the analog signal, and the disadvantage is that the anti-interference ability is very poor. Due to the rapid development of computer control technology, the processing and control of digital signals has shown obvious advantages: it is convenient for computer processing and control, the flexibility of design is greatly improved, and the software debugging is convenient, etc., and pID control has appeared.
Model-free control mathematical model of switching power supply
In the control law design, it is generally necessary to establish a mathematical model of the dynamic system. Classical methods require that this mathematical model must be established in advance at least its structure must be determined in advance. And the more accurate the model, the better. In the design of the model-free control law, the limitation of the control law on the establishment of the mathematical model as accurately as possible in advance is broken through.
Our modeling procedure is carried out with feedback control. The initial mathematical model can be inaccurate, but it must be ensured that the designed control law has a certain degree of convergence. The model-free control law we designed is to control while modeling. Control. Continuing in this way, the mathematical model obtained each time is gradually accurate, so that the performance of the control law is also improved. We call this procedure the integrated procedure of real-time modeling and feedback control.
