Multi-power Sources Research Articles

Study on the Complementary Characteristics of Multi-Power Supply and the Local Absorption Capacity and Outward Demand of New Energy in West China

This paper studies the multi-power complementary characteristics of the western power supply and the local energy consumption and delivery requirements of new energy sources. Based on a comprehensive analysis of the characteristics of western energy power, the paper studies the spatial and temporal differences and adjustment performance of the main power base output characteristics. Based on the complementary characteristics of the western multi-power source, the western power supply capacity and delivery demand of the western power are reasonably evaluated, and the theoretical basis for solving the large-scale new energy consumption in the west is provided, and corresponding suggestions are put forward.

New method for power allocation of multi-power sources considering speed-up transient vibration of planetary power-split HEVs driveline system

Abstract One of the major issues for hybrid electric vehicles (HEVs) powertrain is the torsional vibration in the process of speed-up condition, which is unavoidable. The broader goal of this article is to re-examine the classical gear transmission machinery transient vibration problem in the context of a 4 + N degree of freedom nonlinear torsional system that essentially describes a planetary coupling transmission system (PCTS) of HEVs example, and further provide a new method for power allocation of multi-power sources considering speed-up transient vibration of planetary power-split HEVs driveline system. In particular, resonant amplifications during acceleration, as excited by angular displacement-based meshing stiffness of gear teeth, are investigated using a nonlinear torsional model, and the transient vibration predictions are successfully compared with test bench results. Then a quasi-linear model during acceleration process is proposed and numerically solved to obtain the transient vibration acceleration as well as its envelope curve. Dynamic response results of PCTS are also successfully compared and analyzed under different speed-allocation rules. Finally, an improved genetic algorithm method is applied to construct optimal relationship between the motor speeds and vehicle speeds, and the influences of vibration character and energy consumption are successfully considered in multi-optimized function. Experimental results under the speed-up condition show that transient vibration acceleration of the optimized powertrain is decreased within the safe range, thus new power-allocation solutions provide more insight to the enhancement of planetary power-split HEVs quality.

The Lz-Transform Method for the Reliability and Fault Tolerance Assessment of Norilsk-Type Ship’s Diesel-Geared Traction Drives

Abstract This paper focuses on a comparative analysis of the most important parameters of an icebreaker ship’s sustainable operations: the operational availability, power performance and power performance deficiency of the multi-state Multi-Power Source Traction Drives of Norilsk-type Arctic icebreaker ships. These parameters have a significant impact on the correct choice of the propulsive system of icebreaking vessels. The parameters’ evaluation was based on statistical operational data on Arctic icebreaker ships with diesel-geared traction drive. The Lz-transform approach was used to arrive at a solution of that problem. This approach drastically simplifies the solution compared with the straightforward Markov method.

Model predictive control strategy for energy optimization of series-parallel hybrid electric vehicle

Series-parallel hybrid electric vehicle (SPHEV) is a compact and effective configuration of HEV, which has great potential to save fuel consumption. Because of multi power sources (one engine and two electric motors) and various driving conditions, it is difficult to design an optimal energy management strategy (EMS). To obtain better fuel economy, a novel particle swarm optimization based (PSO-based) nonlinear model predictive control (NMPC) strategy is proposed for EMS of SPHEV. First, a nonlinear model predictive control framework is designed. Then, a modified particle swarm optimization is used for receding horizon optimization. Next, in order to realize fast computing, a two-steps optimization method is adopted. Finally, the proposed strategy are verified by simulations based on the data of a real bus and a driving cycle. The results show that the fuel consumption of SPHEV is greatly decreased by more than 10% compared to that with CD-CS strategies.

Jerk Analysis of a Power-Split Hybrid Electric Vehicle Based on a Data-Driven Vehicle Dynamics Model

Given its highly coupled multi-power sources with diverse dynamic response characteristics, the mode transition process of a power-split Hybrid Electric Vehicle (HEV) can easily lead to unanticipated passenger-felt jerks. Moreover, difficulties in parameter estimation, especially power-source dynamic torque estimation, result in new challenges for jerk reduction. These two aspects entangle with each other and constitute a complicated coupling problem which obstructs the realization of a valid anti-jerk method. In this study, a vehicle dynamics model with reference to a data-driven modeling method is first established, integrating a full-time artificial neural network engine dynamic model that can accurately predict engine dynamic torque. Then the essential reason for the occurrence of vehicle jerks in real driving conditions is analyzed. Finally, to smooth the mode transition process, a more practical anti-jerk strategy based on power-source torque changing rate limitation (TCRL) is proposed. Verification studies indicate that the data-driven vehicle dynamics model has enough accuracy to reflect the vehicle dynamic characteristics, and the proposed TCRL strategy could reduce the vehicle jerk by up to 85.8%, without any sacrifice of vehicle performance. This research provides a feasible method for precise modeling of vehicle dynamics and a reference for improving the riding comfort of hybrid electric vehicles.

Ant Lion Optimizer for Optimal Coordination of DOC Relays in Distribution Systems Containing DGs

Traditionally, the distribution system is typically radial and the protection system has been designed for this purpose. After increasing the distributed generations (DG) in distribution systems, the direction of the electrical power flow and the short-circuit currents in the system should be changed. Moreover, at least a part of the system is converted from radial to loop due to the system contains multi power sources (main source and DGs). Thus, the protection relays are severely affected by the presence of DGs in the distribution networks and lost their coordination. Three fertile and robust meta-heuristic optimization techniques are competing in this paper for finding the optimal value of the pickup currents, Ip, and time multipliers setting of the directional over current relays (DOC) with different DG penetration levels, sites, and fault types and locations. These are an ant lion optimizer (ALO), artificial immune system, and particle swarm optimization. The objective function is minimizing the total operating time of the DOC relays. The transient stability of the distribution system is used as a new constraint for getting the optimal coordination of the DOC relays. Two study systems are considered to test the functionality of the proposed algorithms; they are IEEE-30 bus (distribution section) and practical 11-bus distribution system from Egyptian West Delta Distribution Utility. The comparative results verify the robustness and reliability of the ALO in minimizing the total operating time of the DOC relays while confines with the constraints. Moreover, they show that ALO has the highest accuracy and convergence efficiency while enjoying the reduced execution time.

Performance Availability Assessment of Combined Multi Power Source Traction Drive Considering Real Operational Conditions

Abststract The present paper deals with the vehicle’s traction electric drive, consisting of several various electric power sources. One of the main requirements for such systems are the safety and sustainable operations, achieved largely the implementation of an uninterrupted supply of the vehicle’s propulsion system with an electric power. One way of realization of the required level of operational sustainability is usage of Multi Power Source Traction Drive. This type of vehicle’s propulsion systems is widely applied on the ships, trains, planes, heavy trucks. The most important impact on the sustainability of functioning of the ship’s propulsion system have operational conditions, especially for the cargo ship, operating in Arctic region. This paper presents the application of the LZ-transform method to assessing the important parameter of the vehicle’s operational sustainability - availability of the multi-state (MSS) Multi Power Source Traction Drive, which includes Diesel-Generators and Gas-Turbine-Generators considering the impact of the real operating conditions. Straightforward Markov method applied to solve this problem will require building of a system’s model with numerous numbers of states and solve a corresponding system of multiple differential equations. LZ-transform method, drastically simplified the solution.

Predictive-model-based dynamic coordination control strategy for power-split hybrid electric bus

Parameter-matching methods and optimal control strategies of the top-selling hybrid electric vehicle (HEV), namely, power-split HEV, are widely studied. In particular, extant research on control strategy focuses on the steady-state energy management strategy to obtain better fuel economy. However, given that multi-power sources are highly coupled in power-split HEVs and influence one another during mode shifting, conducting research on dynamic coordination control strategy (DCCS) to achieve riding comfort is also important. This paper proposes a predictive-model-based DCCS. First, the dynamic model of the objective power-split HEV is built and the mode shifting process is analyzed based on the developed model to determine the reason for the system shock generated. Engine torque estimation algorithm is then designed according to the principle of the nonlinear observer, and the prediction model of the degree of shock is established based on the theory of model predictive control. Finally, the DCCS with adaptation for a complex driving cycle is realized by combining the feedback control and the predictive model. The presented DCCS is validated on the co-simulation platform of AMESim and Simulink. Results show that the shock during mode shifting is well controlled, thereby improving riding comfort.

Torsional vibration active control of hybrid construction machinery complex shafting

Due to the coaxial connection of engine, motor and pump, the dynamic characteristics of hybrid construction machinery are changed, which generates a new torsional vibration problem of multi-power sources. To reduce the torsional vibration of the hybrid construction machinery complex shafting, torsional vibration active control was proposed. The three-mass model of coaxial shafting of hybrid construction machinery was established. The PID control and the fuzzy sliding mode control were chosen to weaken torsional vibration by controlling the motor speed and torque. The simulation results show that the fuzzy sliding mode control has 12% overshoot of the PID control when the engine torque changes. The active control is effective and can realize smooth power switch.

Engine-Generator's Optimized Control Strategy for Electric Drive Armored Vehicle

By analyzing the enginegenerator units (EGU) work characteristics of electric drive armored vehicles, engine is controlled running along the optimum fuel curve. Voltage regulation of DC side and generator working condition are optimized through designing voltage space vector PWM (SVPWM) rectifier control system. Adopting rule-based method to solve the nonlinear problem during multi-power source coordination output, developed the multi-power source coordination output control strategy, satisfied the load power needs and the working state of the EGU is optimized.