Independent current control of dual parallel SRM drive using a public current sensor

Switched reluctance motors (SRMs) have been considered a potential candidate for automotive applications due to its rare-earth-free feature and wide speed range. Conventionally, a current sensor is installed in each phase for the current regulation control, which will considerably add the cost and volume to multimotor drives. This paper proposes an independent current control technique for dual parallel SRM drives using only one current sensor. In order to identify the individual motor currents from the public current, a pulse injection scheme is developed accordingly. Two pulses are individually injected into the lower transistors of the dual converter in the excitation regions and the fixed current sampling points triggered by the injected pulse are presented for motor current identification. The independent current control for the dual SRM can be directly implemented by the public current sensing, although the motor parameters are different. The developed system requires only one current sensor without additional hardware or reduced system performance. The simulation and experimental results on parallel 750 W and 150 W three-phase 12/8 SRM drives are presented to confirm the effectiveness of the proposed method. With this scheme, the dual-motor drive can be more compact and cost effective for traction drive applications

New integrated multilevel converter for switched reluctance motor drives in plug-in hybrid electric vehicles with flexible energy conversion

This paper presents an integrated multilevel converter of switched reluctance motors (SRMs) fed by a modular front-end circuit for plug-in hybrid electric vehicle (PHEV) applications. Several operating modes can be achieved by changing the on-off states of the switches in the front-end circuit. In generator driving mode, the battery bank is employed to elevate the phase voltage for fast excitation and demagnetization. In battery driving mode, the converter is reconfigured as a four-level converter, and the capacitor is used as an additional charge capacitor to produce multilevel voltage outputs, which enhances the torque capability. The operating modes of the proposed drive are explained and the phase current and voltage are analyzed in details. The battery charging is naturally achieved by the demagnetization current in motoring mode and by the regenerative current in braking mode. Moreover, the battery can be charged by the external AC source or generator through the proposed converter when the vehicle is in standstill condition. The SRM-based PHEV can operate at different speeds by coordinating the power flow between the generator and battery. Simulation in MATLAB/Simulink and experiments on a three-phase 12/8 SRM confirm the effectiveness of the proposed converter topology

Parameter estimation for VSI-Fed PMSM based on a dynamic PSO with learning strategies

© 1986-2012 IEEE.A dynamic particle swarm optimization with learning strategy (DPSO-LS) is proposed for key parameter estimation for permanent magnet synchronous machines (PMSMs), where the voltage-source inverter (VSI) nonlinearities are taken into account in the parameter estimation model and can be estimated simultaneously with other machine parameters. In the DPSO-LS algorithm, a novel movement modification equation with variable exploration vector is designed to effectively update particles, enabling swarms to cover large areas of search space with large probability and thus the global search ability is enhanced. Moreover, a Gaussian-distribution-based dynamic opposition-based learning strategy is developed to help the pBest jump out local optima. The proposed DPSO-LS can significantly enhance the estimator model accuracy and dynamic performance. Finally, the proposed algorithm is applied to multiple parameter estimation including the VSI nonlinearities of a PMSM. The performance of DPSO-LS is compared with several existing PSO algorithms, and the comparison results show that the proposed parameters estimation method has better performance in tracking the variation of machine parameters effectively and estimating the VSI nonlinearities under different operation conditions

Online sensorless position estimation for switched reluctance motors using one current sensor

This paper proposes an online sensorless rotor position estimation technique for switched reluctance motors (SRMs) using just one current sensor. It is achieved by first decoupling the excitation current from the bus current. Two phase-shifted pulse width modulation signals are injected into the relevant lower transistors in the asymmetrical half-bridge converter for short intervals during each current fundamental cycle. Analog-to-digital converters are triggered in the pause middles of the dual pulse to separate the bus current for excitation current recognition. Next, the rotor position is estimated from the excitation current, by a current-rise-time method in the current-chopping-control mode in a low-speed operation and a current-gradient method in the voltage-pulse-control mode in a high-speed operation. The proposed scheme requires only a bus current sensor and a minor change to the converter circuit, without a need for individual phase current sensors or additional detection devices, achieving a more compact and cost-effective drive. The performance of the sensorless SRM drive is fully investigated. The simulation and experiments on a 750-W three-phase 12/8-pole SRM are carried out to verify the effectiveness of the proposed scheme

Online sensorless position estimation for switched reluctance motors using one current sensor

This paper proposes an online sensorless rotor position estimation technique for switched reluctance motors (SRMs) using just one current sensor. It is achieved by first decoupling the excitation current from the bus current. Two phase-shifted pulse width modulation signals are injected into the relevant lower transistors in the asymmetrical half-bridge converter for short intervals during each current fundamental cycle. Analog-to-digital converters are triggered in the pause middles of the dual pulse to separate the bus current for excitation current recognition. Next, the rotor position is estimated from the excitation current, by a current-rise-time method in the current-chopping-control mode in a low-speed operation and a current-gradient method in the voltage-pulse-control mode in a high-speed operation. The proposed scheme requires only a bus current sensor and a minor change to the converter circuit, without a need for individual phase current sensors or additional detection devices, achieving a more compact and cost-effective drive. The performance of the sensorless SRM drive is fully investigated. The simulation and experiments on a 750-W three-phase 12/8-pole SRM are carried out to verify the effectiveness of the proposed scheme

Flexible Energy Conversion Control Strategy for Brushless Dual-Mechanical-Port Dual-Electrical-Port Machine in Hybrid Vehicles

Due to the advantages of high torque density and compact mechanical structure, brushless dual-mechanical-port dual-electrical-port (BLDD) PM machine has become a promising-alternative in series-parallel HEVs. However, two sets of windings in the same core may also result in flux cross coupling, which deteriorate control performance. Through special design of the magnetic circuit, the two sets of windings in the stator side are decoupled. In this paper, the mathematical model of BLDD-PM machine is analyzed firstly. Then, based on energy management system and the model of machine, the decoupled vector control algorithm for outer and inner rotor is developed. Next, common operation states under city road condition for hybrid vehicles have been summarized. According to operation state of HEV, the power flow analysis in the BLDD-PM machine system has been done. To validate the analysis results, experimental test under different operation condition has been conducted. Test results show good control performance of the BLDD-PM prototype and verify the correctness of analysis. Index Terms-BLDD-PM machine, power flow analysis, HEV