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This paper compares the machine learning algorithm‐based prediction methods for the traction characteristics in linear traction induction motors operating at common working conditions, i.e. different slip and running velocity, with a symmetric or asymmetric secondary. These models provide a method for obtaining the dynamic characteristics in the motor that considers nonlinear effects. First, some...
In high-power converters based on SiC-MOSFET half-bridge modules, laminated busbar plays a critical role in linking the DC capacitor bank to power modules. The busbar stray capacitance has the same order of magnitude with drain-source capacitance of SiC-MOSFET and has a great impact on the turn-off voltage oscillation of SiC-MOSFET. In this paper, parasitic elements of a three-layer laminated busbar...
Voltage deviations of dc-link capacitors are the main problem of multilevel diode-clamped converters (DCC). In this paper, a novel carrier-based voltage balance method is proposed to balance the dc-link capacitors of five-level DCCs. The proposed method is characterized by injecting proper zero-sequence voltages in the modulation signals of carrier-based modulators. The effects of the injected zero-sequence...
This paper decouples the floating capacitors voltage controlling and the neutral-point potential balancing of Seven-level Active Neutral-point-clamped (ANPC-7L) inverter by using the concept of average state, proposes a neutral-point potential balancing model based on zero-sequence voltage injection and derives the full controllable region of neutral-point potential. Based on this model, a testing-verification...
Voltage Balance of the series-connected dc-link capacitors is the key problem of three-level diode-clamped converters. In this paper, an auxiliary voltage balance circuit (VBC) is presented to maintain the voltage balance of dc-link capacitors. The voltage balance circuit consists of a clamping capacitor and a current-limiting inductor. With the clamping capacitor, the voltage stresses of the auxiliary...
This paper investigates single-sided ironless linear synchronous motor (ILSM) based on permanent magnet Halbach array used for medium-speed maglev. Long primary ironless coil is laid along the track and the Halbach permanent magnet array is attached to the bottom of each bogie as a source of traction, two dimensional analytical model of single-sided ILSM is established used to calculate the characteristics...
This paper presents the development of the single side ironless Halbach permanent magnet linear synchronous motor (PMLSM) for a novel electromagnetic suspension (EMS) maglev vehicle. The basic structure of the propulsion motor and the vehicle are firstly described. Then the thrust and normal force of the ironless PMLSM are analyzed. The configuration of the propulsion system and field oriented control...
Traditional seven-level Active Neutral-point-clamped (ANPC-7L) converters suffer from the problems of dynamic voltage balancing in series switches and multi voltage levels jumping of phase output voltage during switching status transition. This paper presents a novel ANPC-7L topology with auxiliary commutating branches and elaborates on its commutating strategies. The presented topology and its commutating...
This paper introduces seven-level Active Neutral-point-clamped (ANPC-7L) inverter first. Then, the paper decouples the two problems of floating capacitors voltage controlling and neutral-point potential balancing by using the concept of average state, proposes a novel neutral-point potential balancing model based on zero-sequence voltage injection. After that, two neutral-point potential balancing...
The position and speed detection of maglev train is critical to train control system. The common methods of speed measurement include speed sensor measurement and speed sensorless measurement. The use of sensorless method can significantly reduce costs and it's not influenced by various environmental factors. In this paper, a high frequency pulsating voltage injection method is proposed for the PMLSM,...
This paper discusses the dead-time effect of dual bridge series resonant DC/DC converter (DBSRC). The phase-shift modulation is usually adopted in DBSRC. However, the phase-shift angle is usually small, and voltage polarity reversal (VPR) may occur in dead-time, which may deteriorate EMI/EMC and increase loss. This paper analyzes the commutation of DBSRC when VPR occurs and proposes a method to eliminate...
In this paper, a new current control approach applied in linear synchronous motor (LSM) drive system is proposed for traction-system. The proposed method is featured by adjusting the current proportions of paralleled converters in double-end supply. First, the theoretical model of LSM of double-end supply is established and the control strategy consists of an outer PI speed closed-loop, an inner current...
In order to solve the difficulty of measuring the speed and the position of maglev permanent magnet linear synchronous motor (PMLSM), a speed sensorless back electromotive force (EMF)-based sliding mode is proposed. And to overcome the drawback of the sliding mode technique called chattering phenomenon, a series of improvements are provided.
A compact behavioral model for SiC power MOSFET is proposed. By applying more degrees of freedom in the channel current expression, removing the drift resistance and rectifying junction capacitance mathematical model, the proposed model can accurately reproduces those static and dynamic characteristics in datasheet. The convergence problem of original model is solved and less simulation time is needed...
Turn-off delay time is temperature sensitive and can be used to estimate the junction temperature of insulated-gate bipolar transistors (IGBTs). In this paper, a high-resolution measurement circuit is designed to detect the turn-off delay time and estimate the corresponding junction temperature. Details of the circuit are demonstrated. Turn-off delay time at different junction temperature, different...
Improved from the conventional analytical thermal model, a fast compact model based on finite differential method wtih PSPICE is presented in this paper. The paper presents the physical basis and the practical consideration. Based on the model, a cooling system example was introduced and verified for high power density converter systems design.
\n this paper, a novel control strategy applied in permanent magnet linear synchronous motor (PMLSM) drive system is proposed based on Euler-Lagrange (EL) equation and passivity-based control (PBC) theory. The state equation of PMLSM in d-q reference frame is established. Some matrices with special structures are deduced to transform the state equation into EL form. From the energy point of view,...
Five-level neutral point clamped H-bridge (NPCH) converter has been found practical application due to its low EMI and high output capacity. However, the unbalanced loss distribution of semiconductor devices in NPCH converter would limit the lifetime and the output capacity. In this paper, a five-level active neutral point clamped H-bridge (ANPCH) converter topology is studied, which is composed two...
The grating type velocity measuring method shows great promise in getting the velocity of high power and large thrust linear motors. In this paper, the analytical model of velocity measuring sensor is deduced, and verified through experiment. The analytical model of electromagnetic field produced by “8”word rectangular planar spiral coils is obtained from the second order vector potential formulation...
According to the special structure and operation mechanism of the maglev permanent magnet linear synchronous motor (PMLSM), this paper established a theoretical mathematical model of electromagnetic thrust and levitation force of the motor in two-phase rotating reference frame and then realized the stability control of PMLSM with the simulation models under vector control (VC). Considering the large...
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