Efficiency Optimization Control Strategy Research Articles

High Step-Up IPOS DC/DC Converter Based Efficiency Optimization Control Strategy

This article introduces a symmetrical, high step-up, input-parallel output-serial (IPOS), dc–dc converter based on voltage multiplier (VM) cells and active clamp circuits to obtain a very high voltage conversion ratio. The VM using a switched capacitor and the coupled inductor makes high voltage gain achievable, which results in reduced voltage stress on power switches. Meanwhile, the IPOS structure also makes great improvements in the above aspects. Importantly, by incorporating active clamp circuits, not only voltage spikes caused by leakage inductance are restrained but also the clamped circuit plays a role in energy transfer to boost the gain. Especially, zero voltage switching for all switches can be obtained. Furthermore, the optimization control strategy is proposed to further improve the overall efficiency. A detailed mathematical analysis of the proposed converter is conducted for systematizing its design. Finally, a prototype of 768 W output power and the 480 V output voltage is implemented to verify the excellent performance of the proposed converter.

Improved Efficiency Optimization Control for Brushless Doubly Fed Induction Generator–DC System by Regulating Stator Frequency

Taking into account the relatively low efficiency of brushless doubly fed induction generator (BDFIG) at present, the efficiency optimization is important to promote the industrial application of BDFIGs. The power winding (PW) frequency of the BDFIG–dc system is with the additional freedom of control, which provides an important condition for efficiency optimization. In this article, based on the loss analysis of the power converter and the improved steady-state equivalent circuit of BDFIG considering iron loss, the loss model of BDFIG–dc system is derived. Furthermore, the system loss model is established with the PW frequency of BDFIG as the main state variable. From the proposed loss model, the maximum efficiency of BDFIG–dc system can be achieved by optimizing the PW frequency. The comprehensive simulation and experimental results demonstrate that proposed efficiency optimization control strategy can increase the efficiency of both the standalone and grid-connected BDFIG–dc systems by 0.2–7.8% under different operation conditions.

Research on efficiency optimization control strategy of WPT system based on optimal load matching

Aiming at the problem that the transmission efficiency of SS-compensated MCR-WPT (Magnetic resonance wireless power transmission) is affected by load changes, this paper uses mutual inductance theory to analyze the equivalent circuit model, obtains the relationship between load and transmission efficiency, and proposes a controllable rectifier bridge for load matching, the front-end cascaded buck converter makes the output voltage regulation control scheme. Finally, modeling and simulation are used to verify the correctness of the load matching theory and control strategy.

A Novel Energy Optimization Control Strategy for Electric Drive System Based on Current Angle

The combination of permanent magnet synchronous motor (PMSM) and inverter is the key electric drive system (EDS) of electric vehicles (EVs), and its overall efficiency seriously affects the energy consumption of EVs. In order to further improve the efficiency of PMSM-inverter, the influence of a special control object current angle β on EDS was studied and the general rule between β and EDS efficiency was obtained in this paper. Then, the golden section search (GSS) method was used to obtain optimal β and its corresponding stator current is, which can realize EDS working in optimal efficiency in the whole EDS working area. On this basis, an overall efficiency optimization control strategy for EDS based on the current angle β look-up table was proposed in this paper. To verify the effectiveness of the proposed control strategy, simulation considering iron loss and copper loss of motor and inverter loss was completed, which showed that compared with traditional control, the control strategy proposed in this paper can effectively improve the working efficiency of EDS under steady state and transient state.

Efficiency Optimization Control of Direct Drive Permanent Magnet Synchronous Motor

High-performance permanent magnet synchronous motor(PMSM) systems used in electric vehicle(EV) are required to deliver high efficiency over the wide speed and torque ranges. This paper proposes a novel efficiency optimization control strategy of PMSM system EV which can maximize the system efficiency in both steady and dynamic state. As the PMSM is directly connected with the load, caused the output torque of motor is a function of the rotate speed, this study is focused on the dynamic system model with the driving cycle which considers about motor copper loss, motor iron loss and inverter loss. Based on the dynamic system model, the proposed control strategy can optimize motor loss and inverter loss together, by which the system efficiency is increased over the whole operation duty. Compared with traditional control strategy, the proposed control strategy can decrease the energy consumption over the whole driving cycle. Both theoretical analysis and experimental results verifies the validity of proposed efficiency optimization control strategy.

Research on Efficiency Optimization Control Strategy of Permanent Magnet Synchronous Motor System

Research on Efficiency Optimization Control Strategy of Permanent Magnet Synchronous Motor System

A hierarchical energy efficiency optimization control strategy for distributed drive electric vehicles

Distributed drive electric vehicle with four in-wheel motors is widespread with various characteristics, such as performance potentials for independent wheel drive control and energy efficiency. However, in future, one of the biggest obstacles for its success in the automotive industry would be its limited energy storage. This paper proposes a hierarchical control method that involves a high-level motion controller that uses sliding mode control to calculate the total desired force and yaw moment and a low-level allocation controller in which an optimal energy-efficient control allocation scheme is presented to provide optimally distributed torques of four in-wheel motors in all the normal cases. A practicable motor energy efficiency model as a motor actuator is proposed by incorporating the electric motor efficiency map based on measured data into the motor efficiency experiment and a current closed-loop motor model. Moreover, both tracking performance and energy-saving are carried out in this research and evaluated via a co-simulation approach using MATLAB/Simulink and CarSim. A ramp maneuver at a constant speed and New European Driving Cycle and Urban Dynamometer Driving Schedule maneuvers have been conducted. To conclude, it is demonstrated that distributed drive electric vehicle with four in-wheel motors can reduce total power consumption and enhance tracking performance compared with a simple control allocation in which the torques are the fixed ratio distribution.

Efficiency Enhancement of Traction System Based on Loss Models and Golden Section Search in Electric Vehicle

Abstract Due to the main traction force of electric vehicles (EVs), the overall efficiency of inverter-motor in traction system can seriously affect the energy consumption of EVs. In this paper, a novel hybrid methodology based on loss model and golden section search is proposed. Firstly, the iron loss, copper loss and stray loss of motor, combined with conduction loss and switching loss of inverter, are modeling. And the models of losses are validated by an experiment. Secondly, two efficiency improvement methodologies are investigated, namely loss model strategy and gold section search strategy. Then, a hybrid efficiency optimization control strategy is proposed based on losses model of the inverter-motor system and the two conventional methods, which yields a high efficiency operation point of inverter-motor system during different loads. Additionally, such novel methodology manifests faster search speed and more search accuracy than the conventional methods. Finally, an experiment results validates the effectiveness of the proposed hybrid control strategy.

Efficiency Optimization in Speed-Sensorless Control of Induction Motors

An efficiency optimization model for induction motors with speed-sensorless control is presented in this paper. An mathematical loss model with stator iron loss in DTC(Direct Torque Control) system is used to calculate the motors loss, the loss efficiency and the optimal flux. Additionally, the efficiency optimization control strategy combined with the speed-sensorless model is used to rebuild the simulation modeling. The simulation results with the proposed control strategy show superior effects compared to the traditional control methods. The optimal control strategy can be achieved to improve the motor efficiency.

A Novel Efficiency Optimization Strategy of IPMSM for Pump Applications

According to the operating characteristics of pump applications, they should exhibit high efficiency and energy saving capabilities throughout the whole operating process. A novel efficiency optimization control strategy is presented here to meet the high efficiency demand of a variable speed Permanent Magnet Synchronous Motor (PMSM). The core of this strategy is the excellent integration of mended maximum torque to the current control algorithm, based on the losses model during the dynamic and the grade search method with changed step by fuzzy logic during the steady. The performance experiments for the control system of a variable speed high efficiency PMSM have been completed. The test results verified that the system can reliably operate with a different control strategy during dynamic and steady operation, and the system exhibits better performance when using the efficiency-optimization control.