Adaptive control of four-quadrant DC-DC converters in both discontinuous and continuous conduction modes

The inherently different dynamics of a DC-DC converter while operating in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) necessitate an advanced controller to control the inductor current. A conventional PI controller cannot be used across both modes since it does not guarantee a smooth transition between both modes. Furthermore, in time-varying input-output voltage applications of the four-quadrant converter such as in battery charging applications, the location of the boundary between the CCM and the DCM changes dynamically, creating an uncertainty. Therefore, a robust controller is required to accurately track the inductor current in the presence of uncertainties. Thus, an adaptive controller is proposed in this work, which is based on the general inverse model of the four-quadrant converter in both modes. Moreover, gain scheduling is used to switch the parameters of the controller as the converter transits between the DCM and the CCM. The adaptability and effectiveness of the controller in ensuring a smooth transition is validated by numerical simulations conducted on various converter topologies. Experimental results are also presented for a buck converter

Current Sensorless MTPA Operation of Interior PMSM Drives for Vehicular Applications

This paper presents a direct voltage control method for Interior Permanent Magnet Synchronous Motors (IPMSMs) with a single speed regulator. The method achieves Maximum Torque Per Ampere (MTPA) operation by controlling the magnitude and the angle of the voltage vector. For that, the mathematical model for the MTPA trajectory of the IPMSM is derived in the voltage plane. As such, no current sensor is needed, which makes the proposed strategy tolerant to current sensors failure unlike cascaded control loop based methodologies. Although no current sensor is used, the control strategy tracks MTPA trajectory by taking into account both voltage and current limits of the machine. The complete MTPA derivation in the voltage plane is presented in this paper; but, only the final solution is needed for real-time implementation. Henceforth, the simplicity of the control scheme combined with its current sensor dependence free characteristics make it a good candidate for real-time implementation in vehicular applications. The concept is developed and evaluated experimentally on a 10 HP IPMSM

Adaptive Interval Type-2 Fuzzy Logic Control for PMSM Drives with a Modified Reference Frame

In this paper, an adaptive interval type-2 fuzzy logic control scheme is proposed for high-performance permanent magnet synchronous machine drives. This strategy combines the power of type-2 fuzzy logic systems with the adaptive control theory to achieve accurate tracking and robustness to higher uncertainties. Unlike other controllers, the proposed strategy does not require electrical transducers and hence, no explicit currents loop regulation is needed, which yields a simplified control scheme. But, this limits the machine's operation range since it results in a higher energy consumption. Therefore, a modified reference frame is also proposed in this paper to decrease the machine's consumption. To better assess the performance of the new reference frame, comparison against its original counterpart is carried-out under the same conditions. Moreover, the stability of the closed-loop control scheme is guaranteed by a Lyapunov theorem. Simulation and experimental results for numerous situations highlight the effectiveness of the proposed controller in standstill, transient, and steady-state conditions

Adaptive RBF Network Based Direct Voltage Control for Interior PMSM Based Vehicles

This paper presents an adaptive radial basis function (RBF) network based speed control approach for interior permanent magnet synchronous machine (IPMSM) based vehicles. The presented control strategy achieves speed tracking without current measurement or control by acting directly on the machine's voltages. As a result, the current control loop is avoided, greatly simplifying the overall control strategy when compared to most existing speed control schemes. Moreover, no parameter knowledge is required unlike other control strategies. Furthermore, the closed-loop control system's stability is guaranteed by a Lyapunov theorem. Simulation and experimental results for different scenarios along with comparison against the well-established field oriented vector control technique demonstrate the controller's satisfactory behavior in both transient and steady-state. The proposed method yields 99% and 97% tracking accuracy in the presence of parametric uncertainties and friction nonliearities, respectively

Simplified Speed Control of Permanent Magnet Synchronous Motors using Genetic Algorithms

In this paper, a simplified control scheme is introduced for permanent magnet synchronous motors (PMSMs). The control strategy consists of a direct voltage controller that capitalizes on the motor's model to achieve accurate speed tracking. As such, no explicit currents loop regulation is needed which simplifies the control structure and unlike other control strategies, no motor's parameter knowledge, voltage or current transducer is required. But, the absence of current regulation loops yields higher energy consumption which limits the motor's range of operation. Therefore, a genetic algorithm is presented to determine control gains with optimal current consumption ensuring operation at the full range of the machine. Simulation and experimental results for different situations highlight the performance of the proposed controller in transient, steady-state, and standstill conditions. Furthermore, the simplicity of the control scheme makes it a good candidate for a low-cost implementation of real-time PMSM drives