Aiming at the problem of electromagnetic compatibility caused by the high-voltage electric drive system (HEDS) in electric vehicles, a model of the HEDS based on the vehicle is established to predict conducted electromagnetic interference (EMI) of the HEDS. First, the electromagnetic environment inside electric vehicles is analyzed theoretically. Then, the various parts of the HEDS are accurately modeled, which include the power buses, inverter, and motor. Based on the theory of multiconductor transmission line, a generic model of power buses suitable for two screening designs is presented. In order to accurately simulate the operating characteristics of the inverter, the drive circuit and the parasitic parameters of the dc-link capacitor block and the insulated gate bipolar transistor module are considered. The motor model takes into account the low-impedance antiresonance phenomenon in the measured motor impedance. Finally, the HEDS is simulated with PSPICE 16.6, and the simulation results agree well with the experimental measurements. The proposed model can accurately predict the system-level conducted EMI of the vehicle-mounted HEDS up to 100 MHz, with an error of 4 dB or less at almost all frequencies below 56 MHz and less than 7 dB at most frequencies in the 56–100 MHz.

A new kind of spoof surface plasmon polaritons (SSPPs) structure with periodic loading of T-shape grooves is introduced in this paper. Dispersion property of this proposed structure is investigated in detail, and comparisons of dispersion property of the proposed structure and that of the traditional SSPPs structures, including structure with rectangular grooves and structure with trapezoidal grooves, are also made. The SSPPs field confinement along the orthogonal directions of the proposed structure is studied. Also, some researches on the transmission loss and propagation length of the SSPPs on the proposed structure are made. All the simulation and calculations show that the proposed structure have a great improvement of SSPPs field confinement and the transmission loss is low.

With the growing use of multicarrier technology in wireless communication, wideband receivers are facing increasingly severe nonlinear distortion issues. This paper focuses on the behavioral modeling of direct-conversion receivers (DCRs) for nonlinear distortion mitigation. This model accounts for arbitrary-order RF and baseband nonlinearities as well as the I/Q imbalance and can reproduce nonlinear distortion of the wideband DCR with multiple simultaneous input signals. Meanwhile, a method of model parameters estimation is put forward, which involves the inverse function method, singular value decomposition approach, and least square estimation. The experiment is performed by using a real RX chain and different types of input signals to evaluate the proposed model’s accuracy in reproducing nonlinear distortions. The experimental and simulated results suggest that the proposed model can accurately reproduce signal distortions and intermodulation products (IMDs) of DCRs with several input signals of different modulations and power levels.

Receiver nonlinear distortion severely impacts modern wireless systems. Traditional power series polynomial models suffer from numerical instability in parameter estimation, especially at high orders or with memory. This paper investigates orthogonal memory polynomial models from the perspectives of memory depth, nonlinear order, input signal distribution, and temporal correlation of the input signal, focusing on effective methods for improving the condition number. Comprehensive analysis reveals that the condition number of the Gram matrix grows rapidly with polynomial order and memory depth for the conventional polynomial, while orthogonal polynomials remain well-conditioned due to their inherent orthogonality and normalization. Notably, orthogonal polynomials maintain robust performance even when the input distribution does not perfectly match the basis weight function. Experiments using OFDM and 3-carrier WCDMA signals confirm that orthogonal polynomials achieve condition numbers orders of magnitude lower than those of power series, along with superior fitting accuracy.

In view of the large inertia, large delay, time-varying and nonlinear characteristics of the superheated steam temperature of thermal power plants, the cascade control and internal model control are combined to form an IMC-PID cascade control system. The design steps and parameter calculation formulas are given. The IMC-PID cascade control algorithm is simulated for the superheated steam temperature control of a 300MW unit, and compared with the traditional cascade control algorithm. The results show that the IMC-PID cascade control algorithm is stable, accurate, rapid and robust. The anti-interference performance is better than the traditional cascade control algorithm, and the setting method is simple, which has good engineering practical value.