# Sensorless Control for DC-DC Boost Converter via Generalized Parameter Estimation-Based Observer
###### Abstract  
The full-information state feedback controller is usually used for regulating the output voltage of converters. Sufficient sensors should be adopted to measure all of the states. However, the extensive use of current sensors not only increases the cost of the overall system, but also affects the reliability. In this paper, the sensorless control problem of DC-DC boost converters is addressed to avoid the need for the current sensor. First, a PI passivity-based control (PI-PBC) is proposed to stabilize this converter. The main feature of this design is that the exponential convergence of the system is guaranteed. Afterward, a generalized parameter estimation-based observer (GPEBO) is presented to estimate the inductor current with the finite-time convergence (FTC). By adding this estimate in the above PI-PBC, a sensorless controller is developed. Thanks to this FTC, the exponential convergence of an overall closed-loop system is ensured. Finally, the simulation and experimental results are given to assess the performance of the proposed controller. boost converter; PI passivity-based control (PI-PBC); generalized parameter estimation-based observer (GPEBO); stability [EMAIL_ADDRESS]; [EMAIL_ADDRESS] [EMAIL_ADDRESS] [EMAIL_ADDRESS] [EMAIL_ADDRESS] [EMAIL_ADDRESS] [EMAIL_ADDRESS] [EMAIL_ADDRESS] [EMAIL_ADDRESS] [EMAIL_ADDRESS] 20  
The control system of the traditional inner feedback wound induction motor contains a diode rectifier, thyristor current type inverter and a large direct current reactor. This will result in a low power factor and high harmonics. If the boost converter is added to the output port of the rectifier and the turn-off device is use to constitute the inverter, the DC reactor can be eliminated to reduce harmonics and improve the power factor of the inverter power supply [6, 7]. The whole system circuit is simple and the technology is mature, which is shown in Figure 1b. The overall cost is much lower than that of the medium voltage frequency conversion of the stator and the total energy consumption is also less than that of the direct frequency conversion. The boost converter also plays an important role in wind generator systems [8]. In order to better control the three-phase current of the generator, its three-phase windings can be separated to connect the boost converter, which is shown in Figure 1c. The output sides of three boost converters are connected in parallel. In this situation, the control problem of the generator does not need to consider the synchronization problem with the power grid. The output current and the speed of the generator can be regulated by controlling the boost converters. Further, it is easy to achieve the peak power tracking of the power generation system and obtain the maximum output power under a certain wind speed. This scheme is more efficient than others, and causes an increase in total annual power generation. The use of boost in the energy harvest of solar cells is presented in Figure 1d. For this system, each solar cell module connects to a boost converter to increase the voltage, which is conducive to the balanced output of each battery module [9, 10, 11]. Moreover, when adding the maximum power search control, each group of modules can run at the best current operating point. As long as each output voltage is set at the same value, all the outputs can be connected together with the storage pool or inverter. Based on the above statement, it should be pointed out that the boost converter has a great effect on the power system. Therefore, its control performance directly affects the stability and reliability of the overall system. Not surprisingly, many methods have been proposed to stabilize boost converters, such as sliding mode control [12], boundary control [13], robust control [14], passivity-based control [15], H\({}_{\infty}\) control [16] and backstepping control [17]. It is noted that the abovementioned results focus on the full-information feed  
Figure 1: The application cases of a boost converter in a power system.