Speed Regulation Performance Research Articles

A novel squirrel cage eddy current coupling with adjustable radial air gap and its performance analysis

A novel squirrel cage eddy current coupling with adjustable radial air gap was presented, which can change the output speed by changing the air gap thickness in radial direction between the copper strips and the permanent magnet. It has the advantages of no axial force in speed regulation and less eccentric force in axisymmetric structure. The 2-D electromagnetic torque model of the rotor was established, and the influence of the air gap thickness on the electromagnetic torque was also studied by finite element method. Further, a novel method to solve the dynamic equation of the eddy current coupling was proposed based on the effect of air gap thickness and relative speed on torque characteristics, and was applied to the speed regulation performance analysis. In addition, the influence of the relative magnetic permeability of the permanent magnet back yoke and the internal rotor on the speed regulation performance was studied.

Dynamic Performance Enhancement of an Armature Controlled Separately Excited D.C. Motor

In this paper the dynamic performance (speed regulation performance versus reference and load torque changes) of a separately excited D.C. motor is enhanced, the D.C. motor is fed by a D.C. source through a chopper which consists of GTO thyristor and free-wheeling diode. The motor drives a mechanical load characterized by inertia J, friction coefficient B, and load torque TL. The performance enhancement is achieved by using a speed control loop uses a proportional-integral (PI) controller which produces the reference signal for the current control loop and this is a (PI) current controller compares the sensed current with the reference and generates the trigger signal for the GTO thyristor to force the motor current to follow the reference. The simulation of the D.C. drive is performed using MATLAB/Simulink program version 7.10 (R2010a).

Analysis and optimization of speed regulation ability with field weakening of the stator hybrid laminated remanufactured motor

To improve the efficiency, a 13 kW used vehicle permanent magnet synchronous motor was remanufactured, whose stator core was replaced by a combination of amorphous alloy laminations and silicon steel laminations. But the speed regulation ability with field weakening of the remanufactured motor limits its development towards high speed direction. Taking the remanufactured motor as the object, based on the theory of speed regulation with field weakening, the maximum speed range was improved by increasing direct-axis inductance, and the structural optimization parameters affecting the direct-axis inductance were analysed. The two-dimensional inductance superposition method was proposed to calculate the direct-axis and quadrature-axis inductance of the remanufactured motor, and its accuracy and feasibility were verified by finite element simulation. The segmented structure of the V-type permanent magnet was used, and the motor structure was optimised from three aspects: the width and position of magnetic bridge and the magnetic pole implantation depth. The orthogonal experiments were designed to determine the best parameter combination. The results show that the direct-axis inductance of the optimised remanufactured motor is increased by 16.33%, and the performance of speed regulation with field weakening is improved significantly.

Specified time consensus control of ESSs for frequency support with DFIG wind turbines

Small scale energy storage systems (ESSs) can assist grid integration of doubly fed induction generators (DFIG), potentially in power system frequency regulation. However, the extensive communication between ESSs may cause frequency response delays and may deteriorate the performance. Thus, this paper aims to propose a frequency response scheme with ESS assisted DFIGs wind turbines (WTs) via a specified time consensus (STC) approach. The load frequency control model with high penetration of WT is firstly constructed. A delay margin estimation (DME) procedure is conducted afterwards to estimate the allowable time delays for the system to provide frequency response. Meanwhile, the coordination strategy of the WTs and the ESSs is proposed for load sharing among the WT-ESS. Subsequently, the STC control for the ESSs is proposed to achieve consensus among the ESSs within a specified time requirement induced by the delay margin. Simulations are conducted to validate the effectiveness of the proposed method. The simulation results show that the DME is meaningful for shaping the allowable system time delay; the STC control can effectively smooth the power output of WTs and enhance the frequency regulation capability; comparing with conventional methods, the novel method shows faster convergence speed and better frequency regulation performance.

Comparison Method of PI, PID and Fuzzy Logic Controller to Maintain Speed Stability in Single Phase Induction Motors

Induction motor speed control is one of the operating conditions that is often used so that feedback with a low error rate is required. To fulfill this, PI and PID controls have been implemented for single phase induction motors. This control has parameters, namely Kp, Ki and Kd. PI and PID controls can cover a variety of desired response conditions, but these controls still have weaknesses in the tuning process. The tuning process used still has a fairly large error value. So in this case we need an intelligent control to meet the desired motor speed response specifications. The performance of motor speed regulation was evaluated using a comparison between PI and PID control with Fuzzy in a closed loop. With a setting point of 1500 rpm, for PI control, with Kp = 7.32 and Ki = 0.005 can produce motor speeds up to 1499. While PID control with Kp = 0.95, Ki = 0.005 and Kd = 0.04 can produce similar speeds. 1492. Fuzzy control can produce an output of 1490 rpm. Fuzzy control is able to produce a settling time of 0.25 seconds and a steady error of 0.67%.

Maximum torque per ampere and maximum power per ampere sliding mode control for interior permanent magnet synchronous motors

This paper presents novel maximum torque per ampere (MTPA) and maximum power per ampere (MPPA) sliding mode control (SMC) approaches for interior permanent-magnet synchronous motors (IPMs). We first derive the first-order SMC methods to improve the field-oriented control's resiliency against the external perturbations, extraneous noise and modelling uncertainties. After that, we propose the higher-order SMC to significantly reduce the chattering phenomenon, which is inherent in the first-order sliding mode method. Based on the comparison studies, the conventional proportional-integral-derivative based field oriented control shows sluggish response and is more sensitive to parameter perturbations and external torque disturbances. By introducing the novel SMC methods, both the speed and torque regulation performance of interior permanent magnet synchronous motor can be greatly improved. Computer simulation studies have demonstrated the superior performance of the first-order and higher-order sliding mode controllers for interior permanent magnet synchronous motor speed and torque regulation applications.

Novel Asynchronous Activation of the Bio-Inspired Adaptive Tuning in the Speed Controller: Study Case in DC Motors

The fusion of bio-inspired algorithms into online controller tuning (adaptive controller tuning) is one of the main topics in Intelligent Control. One crucial issue is to reduce the times that the tuning process performs over time. In this work, a novel Asynchronous Adaptive Controller Tuning (AACT) approach is proposed to reduce the number of tuning process activations, and hence, this promotes resource savings in the overall computational cost for the tuning process. In this approach, an event function is designed to determine the control parameter update where the use of identification and predictive stages set the current control parameters. Furthermore, an elitist initialization in the differential evolution algorithm is also incorporated for solving the optimization problems at each stage. The speed regulation of the DC motor under disturbances is the study case in the ACCT approach. Comparative results with state-of-the-art bio-inspired algorithms in control tuning reveal in the AACT approach that the elitist initialization in differential evolution notably benefits the controller performance. Moreover, the comparative results with the Synchronous Adaptive Controller Tuning (SACT) approach show that the proposal reduces 61% the tuning process computation frequency with a similar speed regulation performance when disturbances appear.

Optimization of the speed regulation performance of a rubber belt CVT for a vehicle

The structure of a CVT in a vehicle is explained, and its characteristics is analyzed. The optimal scheme is selected, according to the influence of various parameters on the speed regulation characteristics of the transmission. The results show that the speed regulation performance can be optimized by changing the structure of the transmission, and the state of working near the maximum power point can be maintained for the engine. Compared with the general transmission, CVT (continuously variable transmission) has the advantages of simple operation, smooth transmission, less noise and small size. The speed regulation characteristics of the rubber belt CVT refers to the CVT’s own structure is changed with the changing driving conditions of the vehicle, so that it can achieve the purpose of a better speed regulation. CVT’s speed regulation characteristics affect the degree of matching between CVT and the vehicle’s power transmission system, and the power transmission performance of the whole vehicle.

DESIGN OF ELECTRONIC CONTROL GOVERNOR FOR A SINGLE CYLINDER GASOLINE ENGINE BASED ON AN INTELLIGENT SENSING ALGORITHM

At present, most large machinery and vehicle engines are electronically controlled but their electronic control systems are too expensive to be popularised and applied in small gasoline engines with relatively low prices. Therefore, small gasoline engines still use mechanical speed regulators. Mechanical speed regulators not only have the defects of inertia lag, friction resistance, inherent speed regulation and the like, but also have the disadvantage that dynamic performance and steady performance cannot be combined, which is not suitable for the increasingly improved speed regulation performance of gasoline engines. This paper describes the design of an electronically controlled intelligent governor for small gasoline engines. Starting from a low cost, it adopts the idea of “replacing part of the hardware with an intelligent sensing algorithm” and proposes an intelligent sensing algorithm scheme. It combines the “coarse tuning” of MAP and the “fine tuning” of adaptive expert PID. The system is proved experimentally and it not only overcomes the inherent defects of a mechanical governor and realises programmable speed regulation, but it also obtains good dynamic and steady performance, improves the power output of the engine, relieves the trouble of engine travelling and improves the freedom of carburetor matching.

A Multimodulation Times SVPWM for Dead-Time Effect Elimination in Three-Level Neutral Point Clamped Converters

In order to improve the speed regulation performance of induction motors, a multimodulation times space vector pulsewidth modulation (MMT-SVPWM) is proposed for the three-level neutral point clamped (NPC) converter. This method can eliminate the dead-time effect (DTE), which is caused by the addition of the dead time (DT) in the SVPWM. This article first analyzes the deviation of the output voltage that is caused by the DTE in the SVPWM, and then proposed the MMT-SVPWM. The generation of driving signals in this method is different from the ideal SVPWM. According to the directions of three-phase currents, the driving signals of a pair of complementary power switches are obtained by comparing a pair of multiple modulation times with the triangular carrier. Thus, this method directly eliminate the DTE, which is different from the SVPWM with DT. The output voltage vector is the same as that of the ideal SVPWM, and there is no zero-current clamping effect. Finally, the simulation and experimental results show that the proposed method effectively eliminates the DTE and improves the output currents of the three-level NPC converter.

Research on adaptive control strategy of hydraulic mechanical continuously variable transmission of a cotton picker

Hydraulic mechanical continuously variable transmission has the advantages of good hydraulic stepless speed regulation performance and high efficiency of mechanical transmission, which can achieve the optimal matching of transmission system load and power source. In this article, an adaptive control strategy based on radial basis function neural network and proportional–integral–derivative control was proposed. The speed compound control method was used to solve the problems that the output speed of the hydraulic mechanical continuously variable transmission system was poor at the variable speed input and was difficult to control. The throttle opening and the engine speed were used as controller inputs. The pump–motor's displacement ratio and the output speed were used as controller outputs. Finally, the output speed of the cotton picker was stably controlled. Simulation and experimental results show that the transmission can quickly respond to the target speed and had little fluctuation based on different initial input speeds. The control strategy had good control precision and robustness. Compared with the traditional proportional–integral–derivative algorithm, the average steady-state error of the system output speed was controlled between ±0.0125%. The proposed algorithm based on radial basis function neural network proportional–integral–derivative adaptive control strategy had obvious control effect, and the stability of the speed output of the system was improved under the nonlinear input complex conditions. It provided research for the speed ratio adjustment and control of the hydraulic mechanical continuously variable transmission of the cotton picker.

A new continuously variable transmission system parameters matching and optimization based on wheel loader

On the basis of improving efficiency and automatic adaptability, a novel hydraulic mechanical power reflux transmission (HMPRT) is a considerable framing and suitable for a wheel loader. However, in the design of HMPRT parameter matching, the improvement of transmission efficiency, speed regulation, and power performance are mutually affected and restricted. To obtain good comprehensive transmission performance, a parameter matching design method for HMPRT is proposed. First, the basic transmission characteristics of the HMPRT system are analyzed, and the maximum and minimum system speed ratios are determined. Then, the influence rules of transmission parameters on the transmission performance of the HMPRT are analyzed. Based on the determined evaluation indexes, a multi-objective optimization model is established and its weight coefficients of the sub-objectives are determined by an analytic hierarchy process. The transmission parameters are optimized using a particle swarm optimization algorithm of simulated annealing. Finally, the structural parameters of the relevant parts are determined. The simulation results reveal that when compared with the prototype loader, the HMPRT loader with optimized matching parameters can effectively improve the system efficiency and reduce fuel consumption while ensuring the power performance.

Optimisation of the power-cycle hydro-mechanical parameters in a continuously variable transmission designed for agricultural tractors

Power transmission is a critical component of agricultural tractor designs and more demanding requirements have been placed on transmissions due to the complexities of their operational environments. However, economic performance is usually sacrificed in favour of using high-powered engines to satisfy the dynamic performance requirements related to power. In this study, a new power-cycle hydro-mechanical continuously variable transmission (PCHMCVT) device is proposed for use in agricultural tractors. The effects of various structural parameters on the system performance is analysed, and an evaluation index for the performance of the PCHMCVT performance is proposed. A comprehensive examination of speed regulation performance, economic performance, and dynamic performance are performed. A multi-objective optimisation design numerical model is established, which utilises the NSGA-ΙΙ multi-objective genetic algorithm to optimise the transmission. Finally, the feasibility of the optimisation results is verified by comparing and analysing the speed ratios, torque ratios and efficiency characteristics of the transmission before and after optimisation. This study provides an optimised design method for the selection of the structural parameters of the PCHMCVT to ensure competent overall performance.

Research on brushless DC hub motor control system

The brushless DC hub motor is an important part of the wheeled electric vehicle. It has the advantages of simple structure, reliable operation, high efficiency and good speed regulation performance. Based on the mathematical model of brushless DC motor (BLDCM), the ontology model of BLDCM is established based on Matlab2016/Simulink environment combined with S-function. Then the model of speed-current double closed-loop PID, fuzzy adaptive PID and sliding mode control system of brushless DC hub motor is established, and the control system of BLDCM is simulated according to the demand of the electric vehicle. The results show that the sliding mode control system has a good control effect and lays a solid foundation for the design of the actual control system.

ADynamic AI Controllerfor aField-Oriented ControlledBLDC Motorto Achieve the Desired AngularVelocity and Torque

Compared to traditional motor controlling techniques, the modern Artificial Intelligent (AI) controllers have many advantages. During the past decades, stochastic search and heuristic optimization algorithms such as Genetic Algorithm (GA) and Simulated Annealing (SA) have effectively enhanced the performance of motor control applications. This paper presents a metaheuristic adaptive fuzzy logic-particle swarm optimization control mechanism to optimize the speed regulation of the electric current space vector-controlled BLDC motor while modelling in MATLAB Simulink environment. This is a part of the designed and developed AI controller, for stability and traction control of a four-wheel drive electric rover. To identify the behaviour of the parameters and the algorithm of the proposed controller, this developed simulation model was utilized by taking into account only the behaviour of a one BLDC motor. In the proposed TSK-PSO-FL controller, the PSO technique is utilized to define the heuristic fuzzy associative matrix and another separately dedicated zero-order fuzzy logic controller (TSK-FLC) utilized to optimize the PSO parameters online such as the swarm hyperspace (population size), inertia weights and the acceleration. Simulated test results are presented, analyzed and compared with the developed hardware test model in addition to the newly published research work. Moreover, in addition to the simulation model, the proposed TSK-PSO-FLC was tested on a 3-ph / 250W power BLDC motor in real-time operation. The analyzed test results are clearly showing that the proposed control mechanism has been optimized and enhanced the speed regulation performance of the BLDC motor significantly while increasing the frequency of the desired input trajectory.

Improvements of the Starting Performance of A Novel Brushless Doubly-fed Motor Based on the Composite Coils

Brushless doubly-fed motor (BDFM) has well applicable potentials in the speed control driving field due to its excellent speed regulation performance. However, the poor starting performance becomes a shortage that still limits the development and application of wound BDFM. To solve the problem, this paper presents a novel BDFM adopted rotor winding based on the principle of the composite coil. Both the principle of the composite coil and the designed example of the rotor winding are analyzed in detail in this content, and the stator winding designed by the change-pole method is described. The performance of the prototype was tested by simulation and experiments, both results reveal that this method can effectively improve the starting performance of BDFM, the system is simplified, and the stability of it is prompted.

Application of fuzzy PID controller for valveless hydraulic system driven by PMSM

For the disadvantages of low efficiency, slow speed response and unsteady speed regulation performance in the application of traditional motor drive in valve less hydraulic system, A vector controlled permanent magnet synchronous motor (PMSM) is proposed to replace the conventional motor to drive the quantitative pump in the valveless system, and a mathematical model of the valveless hydraulic system is established. In view of the non-linear and time-varying problems in the control process of the valve free hydraulic system designed, the traditional PID is difficult to solve. So the fuzzy PID position controller based on the system designed is designed. The joint simulation of the hydraulic system is carried out by using AMESim and Matlab software, and the simulation results are compared with the simulation results with traditional PID. The joint simulation results show that the fuzzy PID control method has a good effect on response speed, anti-interference and position tracking accuracy.

Analytical Analysis of a Novel Brushless Hybrid Excited Adjustable Speed Eddy Current Coupling

A novel brushless hybrid excited adjustable speed eddy current coupling is proposed for saving energy in the drive systems of pumps and fans. The topology and operation principle of the coupling are presented. Based on the real flux paths, the fluxes excited by permanent magnet (PM) and field current are analyzed separately. A magnetic circuit equivalent (MEC) model is established to efficiently compute the no-load magnetic field of the coupling. The eddy current and torque are calculated based on the proposed MEC model, Faraday’s law, and Ampere’s law. The resultant magnetic fields, eddy currents, and torques versus slip speeds under different field currents are studied by the MEC-based analytical method and verified by finite element analysis (FEA). The copper loss, core loss, and efficiency were investigated by FEA. The analytically predicted results agree well with the FEA, and the analysis results illustrate that a good speed regulation performance can be achieved by the proposed hybrid excited control.

Design of model predictive controllers for PMSM drive system based on the extended Kalman filter observer

Considering some technical and economic reasons, it is not easy to directly measure the time-varying states which have a great impact on speed regulation performance in permanent magnet synchronous motor (PMSM) drive system. This paper proposes a method to estimate rotor speed, rotor position and load torque disturbance by utilising real-time estimations, based on the extended Kalman filter (EKF). In order to guarantee the accuracy and stability of PMSM drive system while running under load torque disturbance, this paper proposes a cascade closed-loop control strategy as a solution. The entire system is designed to track reference speed trajectory based on the estimated rotor speed, rotor position and load torque, using the model predictive control (MPC) algorithm based on linear PMSM model. Simulation results demonstrate the effectiveness of the states observer, and the cascade MPC structure shows the good performance in speed tracking of PMSM drive system.

Optimization Design of Bearingless Synchronous Reluctance Motor

In order to overcome common drawbacks of the low torque density and power factor for conventional bearingless synchronous reluctance motors (BSynRMs), a novel BSynRM rotor structure with ferrite magnets is designed in this paper. First, the basic structure and operation principle of the BSynRM are introduced, and the mathematical models of torque and suspension forces are deduced. Second, based on the finite element analysis method, the parameters of flux barriers layer, rotor rib width, and permanent magnets are optimized to increase the salient pole ratio and the difference between d and q axes inductance. Third, the performance of torque, suspension forces, and power factor for the optimized motor is compared with that of the traditional BSynRM. The research results show that the torque density and power factor increase about 54.4% and 56.3% respectively at optimal angle, whereas the average suspension force decreases about 15.7% owing to magnetic saturation. The optimized motor is validated to have good suspension and speed regulation performance.