This work focuses on expressing the TSP with Time Windows (TSPTW for short) as a quadratic unconstrained binary optimization (QUBO) problem. The time windows impose time constraints that a feasible solution must satisfy. These take the form of inequality constraints, which are known to be particularly difficult to articulate within the QUBO framework. This is, we believe, the first time this major obstacle is overcome and the TSPTW is cast in the QUBO formulation. We have every reason to anticipate that this development will lead to the actual execution of small scale TSPTW instances on the D-Wave platform.

https://www.mdpi.com/1999-4893/12/11/224/pdf

A QUBO Model for the Traveling Salesman Problem with Time Windows

외란 관측기법을 이용한 영구자석형 동기 전동기의 비선형 속도 제어 = A nonlinear speed control for a PM synchronous motor using a simple disturbance estimation technique

High-resistance connection (HRC) is a common electrical fault for the electric machine drive system. This fault can lead to the increased power loss and heat, thus possibly causing the damage of the electric machine drive system due to the excessive temperature. Hence, this paper first proposes a vector control strategy of the surface-mounted permanent magnet synchronous machine (PMSM) drive system with the HRC fault to minimize the copper loss. The mathematical model of the PMSM with the HRC is presented in abc stationary frame. The function relationship between the copper loss and the direct axis current, quadrature axis current, stator resistance, and the additional resistance due to the HRC is established and analyzed. The expression of the direct axis current, which minimizes the copper loss, is deduced under the condition of the HRC in one phase and two phases. Consequently, the proposed vector control strategy for the surface-mounted PMSM driving system is achieved. Both the simulation and experimental results show that the proposed method not only preserves the performance of the conventional vector control method, but also can effectively reduce the copper loss, thus protecting the PMSM from the damage due to the increased temperature possibly caused by the HRC fault.

Research on Vector Control Strategy of Surface-Mounted Permanent Magnet Synchronous Machine Drive System With High-Resistance Connection

This article proposes an equivalent conversion-based improved loss minimization control method for interior permanent magnet synchronous motor (IPMSM). In the proposed control method, both the copper loss and iron loss are studied and the efficiency optimization problem due to the unequal inductance parameters of IPMSM is considered and solved, thus achieving the optimal efficiency. First, according to the mathematical model of the IPMSM considering iron loss resistance, the equivalent conversion method is presented to derive the relationship between electromagnetic torque, d -axis and q -axis currents. Then, by the polynomial fitting method, the d -axis and q -axis currents which minimize the electrical loss (copper loss and iron loss) are calculated. Additionally, to further show the performance of the proposed control method, the maximum torque per ampere control method and the approximate processing control method are studied for the comparative analysis. Both the simulation and experimental results show that the proposed control method can comprehensively reduce the electrical loss of the IPMSM, showing the effectiveness of the proposed control method.

Improved Loss Minimization Control for IPMSM Using Equivalent Conversion Method

A Discrete Hybrid Invasive Weed Optimization Algorithm for the Capacitated Vehicle Routing Problem

Aim at the demands for high efficiency and fast dynamic response of electric vehicle drives, an efficiency optimization control strategy of the direct torque controlled induction motors is proposed. Firstly, the mathematical model of induction motors is established in stator-field-oriented reference frame considering core losses. Secondly, the function relationship between the power losses and the developed torque, rotor speed and stator flux is analyzed, and the computational formula of the stator flux amplitude which makes the power losses minimization is derived at different operating conditions. Consequently, the efficiency optimization of the driving system is achieved. The experimental results show that the proposed control strategy not only preserves fast torque dynamic response, but also improves operating efficiency of the driving system and lengthens the travel distance of electric vehicles.

Efficiency optimization of direct torque controlled induction motor drives for electric vehicles

An efficiency optimization control strategy of the direct torque controlled interior permanent magnet synchronous motors is proposed. Firstly, the mathematical model of the IPMSM is established in the rotor frame considering iron losses. Secondly, the function relationship between the power losses and the output torque, speed and stator flux is analyzed, and the computational formula of the stator flux amplitude which makes the power losses minimization is derived under different operating conditions. Consequently, the efficiency optimization control for direct torque controlled IPMSM driving systems is achieved. The experimental results show that the proposed control method not only preserves the fast torque dynamic response of the conventional direct torque control, but also improves operating efficiency of the driving system.

Efficiency optimization of direct torque controlled interior permanent magnet synchronous motor considering iron losses

An adaptive fuzzy sliding mode control for angle tracking of human musculoskeletal arm model

Considering the existence of disturbance in the induction machine (IM) drive system, this paper develops a composite control scheme based on linear extended state observer (LESO) and continuous finite time control (FTC) to improve the disturbance rejection property of system. First, a LESO is introduced to estimate the disturbances of system. The estimated value is used in the feed-forward compensation design. Second, a continuous finite-time feedback control technique is applied in the feedback design. Then the stability of the controller is analyzed. Simulation and experimental comparisons with two other control methods, traditional Proportional Integral (PI) and Proportional feedback plus feedforward compensation based on LESO(P+LESO), are provided to verify the effectiveness of the proposed method.

Direct torque control of induction machine using finite-time control and disturbance compensation

The vehicle routing problem is a kind of NP problem.In order to solve this problem,this paper employs a Hybrid Quantum Genetic Algorithm(HQGA ) which not only has the global searching capacity of Conventional Quantum Genetic Algorithm(QGA),but also uses immune operator as a local searching scheme to optimize subroutes. The implementation method and procedure of this algorithm are introduced in detail in the paper.The experimental results of a VRP instance show that HQGA is superior to the conventional quantum genetic algorithm and other reported algorithms.HQGA can avoid the problem of premature convergence,so it is an efficient method for solving the vehicle routing problem.

Zhang Xing-hua

Papers

Efficiency optimization of direct torque controlled induction motor drives for electric vehicles

Efficiency optimization of direct torque controlled interior permanent magnet synchronous motor considering iron losses

An adaptive fuzzy sliding mode control for angle tracking of human musculoskeletal arm model

Direct torque control of induction machine using finite-time control and disturbance compensation

Hybrid Quantum Genetic Algorithm and Its Application in VRP