Mathematical Model of Model Free Control for Switching Power Supply
The modelless control of switching power supplies has led to the development of digital, intelligent, and multifunctional switching power supplies. This undoubtedly improves the performance and reliability of switching power supplies. However, due to the fact that the switching power supply itself is a nonlinear object, the establishment of its precise model is quite difficult, often using approximate processing, and the uncertainty of its power supply system and load changes, so using the above analog or digital PID control methods is often difficult to make the parameters of the PID regulator change accordingly, and the control effect is not ideal. The 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, which is very suitable for some complex and variable systems or systems with uncertain structures that are difficult to describe accurately using mathematical models. It improves the control system of the switching power supply and not only meets the requirements of high performance and high reliability 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 devices and people's work and life is becoming increasingly close, and electronic devices cannot do without reliable power sources. Switching power supply is a type of power supply that utilizes modern power electronics technology to control the time ratio of switching transistors on and off, maintaining a stable output voltage. Switching power supply is generally composed of pulse width modulation (pWM) control IC and MOSFET. The majority of the control parts of the switching power supply are designed and operated based on analog signals, with the disadvantage of poor anti-interference ability. Due to the rapid development of computer control technology, the processing and control of digital signals have shown obvious advantages: ease of computer processing and control, greatly improved design flexibility, and convenient software debugging, resulting in the emergence of pID control.
Mathematical Model of Model Free Control for Switching Power Supply
In control law design, it is generally necessary to establish a mathematical model of the dynamic system. The classical method requires 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 model free control laws, the limitation of establishing mathematical models as accurately as possible in advance is overcome.
Our modeling process is accompanied by feedback control. The initial mathematical model can be imprecise, but it is necessary to ensure that the designed control law has a certain degree of convergence. The model free control law we designed is to model while controlling, and then model and control after obtaining new observation data. This continues to make the obtained mathematical model gradually accurate, thereby improving the performance of the control law. We refer to this process as the integration of real-time modeling and feedback control.
