Sensorless Vector Control Method Research Articles

Deep Reinforcement Learning Algorithm based PMSM Motor Control for Energy Management of Hybrid Electric Vehicles

Hybrid electric vehicles (HEV) have great potential to reduce emissions and improve fuel economy. The application of artificial intelligence-based control algorithms for controlling the electric motor speed and torque yields excellent fuel economy by reducing the losses drastically. In this paper, a novel strategy to improve the performance of an electric motor-like control system for Permanent Magnet Synchronous Motor (PMSM) with the help of a sensorless vector control method where a trained reinforcement learning agent is used and provides accurate signals which will be added to the control signals. Control Signals referred to here are direct and quadrature voltage signals with reference quadrature current signals. The types of reinforcement learning used are the Deep Deterministic Policy Gradient (DDPG) and Deep Q Network (DQN) agents. Integration and implementation of these control systems are presented, and results are published in this paper. The advantages of the proposed method over the conventional vector control strategy are validated by numerical simulation results.

Three Phase Induction Motor Drive: A Systematic Review on Dynamic Modeling, Parameter Estimation, and Control Schemes

An induction motor is generally used in industrial applications because it is reliable, robust, and low cost. Reliability is one of the essential parameters based on which the motor is selected, and the induction motor primarily comes into force. The well-founded induction motor gives good results under various operating states. To achieve this, the values of the motor are kept in mind. Dynamic simulation plays a significant part in evaluating the model’s design process to eliminate design errors in typical construction types and when testing the motor drive system. The induction motor is modeled in a synchronously revolving rotor flux-oriented frame, which is used as a reference. For sensorless vector control and induction motor control methods, accurate knowledge of a few induction motor parameters is necessary. The presentation of the drive will degrade if the original data in the motor do not match the values utilized in the controller. Various mechanisms have been developed to calculate the online and offline parameters of the induction machine for its application in high-performance drives. The foremost grail of this review paper is to present dynamic modeling and other considerable approaches used for estimating the induction motor parameter. This paper also constitutes some simulation examples related to dynamic modeling and parameter estimation techniques, which may be useful for specialists in the field of electric drive control systems.

An enhanced sensorless control based on active disturbance rejection controller for a PMSM system: design and hardware implementation

PurposeThis paper mainly aims to deal with the problems of uncertainties including modelling errors, unknown dynamics and disturbances caused by load mutation in control of permanent magnet synchronous motor (PMSM).Design/methodology/approachThis paper proposes an enhanced speed sensorless vector control method based on an active disturbance rejection controller (ADRC) for a PMSM. First, a state space model of the PMSM is obtained for the field orientation control strategy. Second, a sliding mode observer (SMO) based on back electromotive force (EMF) is introduced to replace the encode to estimate the rotor flux position angle and speed. Third, an infinite impulse response (IIR) filter is introduced to eliminate high frequency noise mixed in the output of the sliding mode observer. In addition, a speed control method based on an extended state observer (ESO) is proposed to estimate and compensate for the total disturbances. Finally, an experimental set-up is built to verify the effectiveness and superiority of the proposed ADRC-based control method.FindingsThe comparative experimental results show that the proposed speed sensorless control method with the IIR filter can achieve excellent robustness and speed tracking performance for PMSM system.Research limitations/implicationsAn enhanced sensorless control method based on active disturbance rejection controller is designed to realize high precision control of the PMSM; the IIR filter is used to attenuate the chattering problem of traditional SMO; this method simplifies the system and saves the total cost due to the speed sensorless technology.Practical implicationsThe use of sensorless can reduce costs and be more beneficial to actual industrial application.Originality/valueThe proposed enhanced speed sensorless vector control method based on an ADRC with the IIR filter enriches the control method of PMSM. It can ameliorate system robustness and achieve excellent speed tracking performance.

New Sensorless Vector Control System With High Load Capacity Based on Improved SMO and Improved FOO

In the existing sensorless vector control system of permanent magnet synchronous motor (PMSM), direct differential calculation or phase-locked loop (PLL) control is often used to estimate the rotor speed, but this method has some problems of weak load capacity and slow dynamic response. A new sensorless vector control method based on an improved sliding mode observer (SMO) and improved full-order observer (FOO) is proposed in this paper. The cut-off frequency of the low-pass filter is designed as a function of speed, the back EMF is fed back into the stator current estimation mathematical model, and the adaptive rate of feedback gains coefficient is proposed for improving the traditional SMO. The disturbance feedback matrix is introduced for improving the traditional FOO, and the estimated load torque is feedforward compensated to the given end of the quadrature current. An integrated system of corresponding algorithms is established, a test platform is built. The experimental results show that the speed and load torque estimation performance of the improved observer is better than that of the traditional observer in the process of sudden load change. The sensorless vector control system based on the proposed observer has a high dynamic response, load capacity, and reliability.

An Improved Sensorless Vector Control Method for IPMSM Drive with Small DC-Link Capacitors

In this paper, an improved sensorless vector control method for an interior permanent magnet synchronous motor (IPMSM) drive with small DC-link capacitors is proposed. First, a fast sliding-mode observer was applied, to enlarge the observer bandwidth. Then, an improved estimator based on a proportional integral resonant controller was designed for the estimate speed shaping, which means the actual speed can be tracked. This not only reduces the position estimate error, but also enhances the grid power factor and suppresses the input current harmonics. Simulation and experiments were conducted on a sensorless IPMSM drive system with a small film capacitor. The effectiveness of the proposed estimation method was verified by the simulation and experimental results. The estimated error was reduced and the grid current harmonics satisfy the requirements of EN61000-3-2.

Comparison of high‐order and second‐order sliding mode observer based estimators for speed sensorless control of rotor‐tied DFIG systems

In this study, a sensorless vector control for the rotor-tied doubly fed induction generator (RDFIG) is proposed in the grid-connected mode. The proposed sensorless vector control method includes a slip speed/angle estimator which is based on the association of the high-order sliding mode observer (HOSMO) with a phase-locked loop (PLL). In addition, an extensive comparison between the PLL-based HOSMO estimator and the PLL-based second-order sliding mode observer (SMO) estimator is also presented. The Lyapunov stability criterion is used to determine both observer gains to allow their convergence in finite time. Both the proposed HOSMO and the SMO use the three-phase stator current and back-electromotive force (EMF) as state variables which enable the start of the estimation even before the machine is connected to the grid. The proposed HOSMO takes into account the dynamics of the back-EMF space vector. The PLL is used to extract the estimated slip speed/angle from the estimated back-EMF. The performance of the proposed sensorless vector control strategy is validated experimentally with a 5.5-kW custom-designed RDFIG on a test bench based on the National Instrument (NI) PXIe-8115 real-time controller.

Speed Sensorless Vector Control Based on Full-order Adaptive Observer for Induction Motor Drives at Low Speed

This paper presented a speed sensorless vector control method based on adaptive full-order state observer for induction motor. The rotor speed estimated by an adaptive full-order observer is fed back to the vector control system as a feedback signal to form a closed-loop control of speed. In addition, the stator resistance is also recognized and updated in real time, so the effect of change of stator resistance on accuracy of speed estimation can be eliminated. The parameter identification system is achieved according to the Popov’s hyperstability theory, therefore the system is stable enough even at very low speed. The simulation and experimental results illustrated the correctness and effectiveness of the presented control algorithm.

Accurate Modeling of the Nonlinear Characteristic of a Voltage Source Inverter for Better Performance in Near Zero Currents

In a sensorless vector control method, at low speeds and self-commissioning for AC motors, it is necessary to model dead time, rise/fall time, parasitic capacitors, and semiconductors’ voltage drop accurately. In this paper, voltage drop in each phase due to the nonlinear behavior of the inverter from the control system's viewpoint is precisely modeled by using two lookup tables. These lookup tables make the proposed model robust against the dc-link voltage and carrier frequency variations in the entire current range. In conventional methods at standstill, the measured voltage in the dc current test contains the nonlinearity of two phases. Therefore, to obtain the nonlinear voltage of each inverter phase, it is assumed that the values of inverter nonlinearity voltage at both high current and low current are equal. This simplification leads to distortion in measured voltage in the low currents. However, in this paper, the voltage drop equation of each phase is solved by numerical method that is realizable in conventional processors. The results obtained in actual voltage measurement show the superiority of the proposed method over traditional methods in the low currents. The proposed method is verified by using a voltage source inverter feeding a 2.2-kW three-phase induction motor.

A sensorless efficiency test system for a high-speed permanent magnet synchronous motor

We present a sensorless efficiency test system with energy recovery for a high-speed permanent magnet synchronous motor (PMSM). In the system, two identical high-speed PMSMs are used as the motor under test (MUT) and the load machine (LM), respectively. A new sensorless vector control (VC) method based on a hypothetical reference frame is presented to control both the MUT and the LM. Also, a regenerating unit is used to implement energy circulation to save energy. Experiments were carried out on a prototype, with a digital controller based on the TMS320F28335, to verify the adequacy of the sensorless VC method. As a result, the efficiency test system achieves the load test at the speed of 21000 r/min without any reduction equipment. During the test, the energy regenerated by the LM could be fed back to the MUT by the regenerating unit, and 81.31% electrical power was saved. In addition, with the proposed sensorless VC method, both the MUT and the LM can work at id = 0 without a position sensor.

A New Self‐Tuning Power‐Factor‐Based Vector Control Method for Efficient Wide‐Speed Range Sensorless Drive of Permanent‐Magnet Synchronous Motors

SUMMARYAs a simple sensorless vector control method for permanent‐magnet synchronous motor (PMSMs), a power‐factor‐based vector control (PFVC) method has been reported. This method has the attractive characteristics that three functions such as current limit, efficiency and sensorless drive can be performed simultaneously in a simple manner. However, it was developed under the assumption that there is no practical voltage limit, and that it cannot be applied over the rated speed. This paper proposes a new PFVC method that allows PMSMs to be driven even over the rated speed under application of a practical voltage limit, while keeping the desired characteristics. The effectiveness and usefulness of the proposed method are verified through extensive experiments.

Single Inverter Fed Speed Sensorless Vector Control of Parallel Connected Two Motor Drive

This paper describes a speed sensorless vector control method of the torque for cost-effective parallel-connected dual induction motor fed by a single inverter. A natural observer with load torque adaptation is employed to estimate the speeds of the same rating induction motors connected in parallel and fed by a single inverter. The speed difference between the two induction motors for unbalanced load conditions is less in natural observer than the conventional adaptive rotor flux observer. Direct field oriented control is used to calculate the rotor angle from the estimated rotor fluxes and the mean rotor flux is kept constant by rotor flux feedback control. The simulation and experimental results of studies are demonstrated for various running conditions to prove the effectiveness of the proposed method. The closed loop speed control operation with inner current control was performed by TMS320F2812 processor.

Sensorless Vector Control of Induction Motors Using Minimum Dimensional Flux D‐State Observer with Instantaneous Speed Estimation

SUMMARYThis paper proposes a new sensorless vector control method for induction motors using a minimum dimensional flux D‐state observer with instantaneous speed estimation. First, the D‐state observer with a new design rule of constant observer gains is established in a different way. Second, a new speed estimator using flux estimates produced by the observer is established on the basis of the fundamental relationship between the rotor flux and the slip frequency. Speed estimates are reused in the observer as feedback. Characteristic analyses and the usefulness of the proposed vector control method are verified by simulations.

Characteristics of Speed Sensorless Vector Controlled Induction Motor with High Efficiency Taking Core Loss into Account

This paper presents the characteristics of a speed sensorless vector control method of an induction motor operating at high efficiency and high response, in which core loss is taken into account. An improved method of speed estimation that operates on the principle of speed adaptive flux and current observer has been proposed. An observer is basically an estimator that uses a plant model and a feedback loop with measured stator voltage and current. Simulation results show that the proposed direct field oriented control with the proposed observer provides good performance characteristics. The IM is fed by an indirect power electronics converter. This indirect converter is controlled by a pulse width modulation PWM technique that enables minimization of harmonics introduced by the line converter, as well as the control of the power factor and DC-link voltage. We study the robustness of the overall system- using simulation of different modes to operating modes and varied parameters.

センサレス永久磁石同期モータのための離散時間搬送高周波電圧印加法

This paper presents a new sensorless vector control method for permanent-magnet synchronous motors (PMSMs) that employs discrete-time high-frequency voltage injection. The frequency range of the injected voltage is almost the same as that of the pulse width modulation (PWM) carrier of the voltage command. This allows high-speed phase estimation and a high-performance drive, and possibly low acoustic noise caused by the injected voltage. The high-frequency current corresponding to the injected voltage is analyzed in discrete time. Conventional phase estimation methods that employ continuous-time voltage injection are reconstructed by means of the analyses. The reconstructed methods are characterized by high-speed phase estimation, high-performance drive, and high robustness against motor parameter variation. The usefulness of the proposed method is verified through extensive experiments.

Single Inverter Fed Speed Sensorless Vector Control of Parallel Connected Two Motor Drive

This paper describes a speed sensorless vector control method of the torque for cost-effective parallel-connected dual induction motor fed by a single inverter. A natural observer with load torque adaptation is employed to estimate the speeds of the same rating induction motors connected in parallel and fed by a single inverter. The speed difference between the two induction motors for unbalanced load conditions is less in natural observer than the conventional adaptive rotor flux observer. Direct field oriented control is used to calculate the rotor angle from the estimated rotor fluxes and the mean rotor flux is kept constant by rotor flux feedback control. The simulation and experimental results of studies are demonstrated for various running conditions to prove the effectiveness of the proposed method. The closed loop speed control operation with inner current control was performed by TMS320F2812 processor.

Elliptical Trajectory-Oriented Vector Control for Energy-Efficient/Wide-Speed-Range Drives of Sensorless PMSM

This paper proposes a new sensorless vector control method for energy-efficient and wide-speed-range drives of permanent-magnet synchronous motors. The proposed sensorless method has the following features: 1) wide-speed-range drive under voltage limit; 2) current limitation; and 3) high efficiency. These features are realized in a very simple manner and can operate adaptively in all sensorless driving modes, including motoring/regenerating and steady/transient states. The usefulness of the proposed method is verified by extensive experiments.

Speed Sensorless Vector Control of Induction Motor Drive with PI and Fuzzy Controller

<p>This paper directed the speed-sensorless vector control of induction motor drive with PI and fuzzy controllers. Natural observer with fourth order state space model is employed to estimate the speed and rotor fluxes of the induction motor. The formation of the natural observer is similar to and as well as its attribute is identical to the induction motor. Load torque adaptation is provided to estimate the torque and rotor speed is estimated from the load torque, rotor fluxes and stator currents. There is no direct feedback in natural observer and also observer gain matrix is absent. Both the induction motor and the observer are characterized by state space model. Simple fuzzy logic controller and conventional PI controllers are used to control the speed of the induction motor in closed loop. MATLAB simulations are made with PI and fuzzy controllers and the performance of fuzzy controller is better than PI controller in view of torque ripples. The simulation results are obtained for various running conditions to exhibit the suitability of this method for sensorless vector control. Experimental results are provided for natual observer based sensorless vector control with conventional PI controller.</p>

電流推定誤差ベクトルの軌跡に基づいた埋込磁石同期モータの位置センサレス制御

電流推定誤差ベクトルの軌跡に基づいた埋込磁石同期モータの位置センサレス制御

Comparison between the Vector Control Based on Anti-saturation Capability with the Sensorless Vector Control in PMSM

This paper investigates a comparison between the sensorless vector control method based on MRAS (Model Reference Adaptive System) using SVPWM (Space Vector Modulation) and the control method of the PMSM (Permanent Magnet Synchronous Motor) Based on anti-saturation current controller. MRAS algorithm is based on comparison between the estimators. The error between the estimated quantities obtained by the two models is used to evaluate the rotor speed that started in order to create an optimum vector control method. This method is compared with vector control based on anti-saturation current control block. That created in order to reduce the ripple in vector control current. These two control method were simulated in MATLAB and after comparing the current THD(Total Harmonic Distortion) of the two methods, it was observed the vector control based on anti-saturation block with shaft encoder has bigger volume, less current ripple and more cost than sensorless method.

Simplified Model Reference Adaptive Method for Sensorless Vector Control of PMSM

Sensorless control of PMSM is becoming increasingly important among the whole control system. This paper introduced Integral Separation Technology to the PI regulators to decrease overshoot or oscillation of the system. In addition, on the basis of the mathematical model of PMSM, Vector Control System for PMSM is got. Then a simplified model reference adaptive method using the zero excitation current control to modify the adaptive rate is given. At last, the corresponding waveforms are presented and the reasonability and validity has been proved by the simulation.