IET Power Electronics最新文献

This article presents an adaptive model predictive control (AMPC) algorithm for real-time management of a six-phase permanent magnet synchronous motor. The system optimizes both speed control and power dissipation, featuring an automated power derating mechanism for overload conditions. AMPC demonstrated advantages over traditional field-oriented control, including reduced losses and lower energy consumption, while maintaining robust performance and high speed control precision. Validation through hardware-in-the-loop testing on the dSPACE platform confirmed its effectiveness. The contribution focuses on enhanced stability, robustness, and integrating predictive features to further improve efficiency and adaptability in electric drive systems.

The cascaded H-bridge (CHB) converter is a promising topology for medium-voltage and high-power offshore wind turbines. Recently, the quad-active-bridge (QAB) converter has been used to reduce the required DC-link capacitors by transferring and mitigating the low-frequency pulsation power. However, the existing power control schemes transfer all the low-frequency pulsation power to the QAB side, increasing current stress on the QAB converter. This article proposes a flexible power decoupling control for the QAB converter using a proposed coordinate transformation method. This scheme can easily decouple the instantaneous power into two parts: the constant DC power delivered to the grid-side inverter and the low-frequency pulsation power canceled inside the QAB converter, both of which can be independently controlled. By flexibly adjusting the DC-link reference voltages and designing appropriate regulators for the decoupling voltage loops, the low-frequency pulsation power flowing into the QAB converter can be precisely regulated, meaning the ripple voltage of the DC-link can be flexibly controlled as required. This method is also beneficial for reducing the current stress (peak and RMS) of the QAB converter. Simulation and experimental results are presented to validate the feasibility of the proposed flexible power decoupling control scheme.

Rapid variations in motor speed can cause significant angular errors in traditional synchronous modulation voltage sampling methods, leading to increased current harmonics and exacerbated torque fluctuations. To address this challenge, this paper introduces a real-time reference voltage angle error compensation technique employing quasi-continuous sampling angles. In each control cycle, the angular discrepancy between the voltage sampling angle and the desired quasi-continuous output angle is computed and transformed into a frequency error to determine the compensation frequency. This compensation frequency is then integrated, using the quasi-continuous angle from the previous control cycle as the initial value to ascertain the current cycle's quasi-continuous angle. Subsequently, this angle undergoes 2N (carrier ratio) frequency multiplication to produce a sawtooth waveform. To minimise angular errors during transitions between different carrier ratios, switching occurs at the intersection points of the sawtooth waves, ensuring both are ascending, which ultimately generates a triangular carrier wave. This approach obviates the need for a phase-locked loop, facilitating angle error compensation in each control cycle, reducing voltage sampling angle errors, and enabling smoother transitions. The method demonstrates robust real-time performance and resilience, as validated by experimental results confirming its effectiveness and feasibility.

The hybrid clamped converter (HCC) is a novel high-performance four-level multilevel converter for medium-voltage motor drives. However, the high common mode voltage (CMV) in motor drives will cause harmful shaft voltages and bearing currents, which threaten the system's safety. The CMV performance of the HCC is unknown compared with traditional two-/three-level converters, as well as its reduction method. This paper studies the HCC's CMV modeling and clarifies the relationship between CMV amplitude and reference voltage. Then, an algorithm is proposed to determine the CMV envelope accurately, and an optimal injected zero-sequence voltage (ZSV) is obtained to suppress the CMV amplitude based on the proposed algorithm. Finally, a silicon carbide (SiC)-based HCC prototype is established to verify the proposed method. Results show that the proposed method for HCCs can reduce the CMV from ± 5V_dc/18 to ± V_dc/18 at a high modulation index, which is much smaller than existing two- or three-level converters. Compared with the traditional control method of HCCs, the peak-to-peak value of CMV can be reduced by more than 70%. In addition, the loss can be reduced at a high modulation index with the proposed method.

This paper introduces a novel control strategy aimed at reducing power losses in switched reluctance motors (SRMs) with a ring winding structure by implementing a speed-scheduling mechanism for circuit switching. Unlike traditional methods that utilize a three-phase inverter with an additional voltage source, this new approach switches the driving circuit from a DC-DC converter to a single diode circuit in the high-speed region, enhancing efficiency. The minimum speed for operating mode switching is determined by analyzing the amplitude and direction of the winding currents. The paper presents comparative evaluations of power losses before and after implementing the new operating mode switching strategy, including a comparison with the pulse current method used in an asymmetric half-bridge (AHB) driven system. Simulation and experimental results demonstrate that the proposed method significantly reduces power losses in ring structure circuits and improves operational efficiency. Compared to the conventional AHB circuit, it lowers torque ripple and reduces manufacturing costs of the hardware circuit. This strategy provides a practical solution for boosting the energy efficiency of SRMs, especially in high-speed applications.

A DC–DC interleaved converter with a coupled inductor is proposed in this study. This converter is capable of generating high voltage through the use of switched capacitors and additional components. It is designed to serve as an interface device in renewable energy applications. The proposed interleaved design features minimal ripple in the input current, enhancing the longevity of solar panels. This configuration can function as a single or dual-input design for boosting input power. In addition to the mentioned benefits, the proposed converter also reduces voltage stress on the components. This decrease in voltage stress results in smaller component sizes and lower conductive losses in the MOSFETs. The theoretical examination of the proposed structure includes steady-state analysis and evaluation of voltage stress on components, as well as the design of the converter. An in-depth comparison is conducted to highlight the strengths and weaknesses of the proposed structure. Following the calculations and theoretical analysis, a laboratory prototype with a 400 W power capacity is implemented to test the performance of the proposed structure.

For applications featuring a wide input voltage range (90–265 V), the buck-boost power factor correction (PFC) converter frequently adopts the constant on-time (COT) control strategy, which facilitates achieving low total harmonic distortion (THD) and high power factor (PF). However, due to phase differences and harmonic distortions between the average input current and voltage waveforms, PF theoretically cannot attain unity. To theoretically eliminate the impact of harmonics in buck-boost PFC converters, this paper introduces a variable on-time (VOT) control strategy. In this strategy, the on-time and off-time intervals within the current switching cycle are detected to correct the modulation wave of the traditional COT control strategy. During the subsequent switching cycle, the modified modulation wave and the peak inductor current are sent to the comparator to generate pulse-width modulation (PWM) pulses. Additionally, the switching frequency is calculated based on the on-time and off-time. When the switching frequency reaches a sufficiently high level, the converter automatically transitions to discontinuous conduction mode (DCM) to minimize switching losses. Experimental results, obtained using a 100 W buck-boost PFC converter platform, reveal that this strategy reduces THD by an average of 3.07% and enhances PF by 0.34% compared to the traditional COT control strategy.

To address the issue of synchronisation control for multi-motor intelligent gaming systems under saturation constraints and parameter uncertainty, an anti-saturation sliding mode control algorithm is proposed. First, considering that output saturation makes it difficult for the virtual navigator motor to achieve target tracking, an anti-output saturation sliding mode control strategy based on the combination of the obstacle Lyapunov function and sliding mode control is proposed to solve the problem of control performance degradation of sliding mode control under output saturation constraints. Second, based on the model of multiple follower motors, we propose an improved disturbance-resistant saturation compensator, allowing multiple motors to compensate for input saturation deviations stably and swiftly even in the presence of unknown disturbances. Subsequently, the designed anti-disturbance saturation compensator is fed back into the multi-motor control system, structuring an anti-input saturation adaptive terminal sliding mode control algorithm that addresses the impact of input saturation and parameter uncertainty on the synchronisation accuracy of multiple motors, and the stability of the control system is verified using Lyapunov stability theory. Finally, simulation and experimental results demonstrate that the algorithm exhibits superiority in terms of anti-saturation and adaptation parameter uncertainty, achieving synchronisation of follower motors with the leader motor effectively.

In existing single-wire simultaneous power and data transmission (SSPDT) system, either the power level or data rate is often restricted. In this paper, an SSPDT system based on Tesla coils is proposed, which can transmit data at a high rate while transmitting energy at high power. The data carrier modulated by frequency shift keying is coupled to the Tesla coil and then transmitted in a single-wire through frequency division multiplexing with the power carrier. The transmission principle of the power channel is analysed based on the lumped parameter circuit model. During data transmission, the Tesla coil is considered to be composed of a large number of electric dipoles and magnetic dipoles connected in series alternately. Helical antenna theory is applied to analyse the data transmission mechanism. By designing circuit parameters, the crosstalk between the power channel and the data channel is reduced. In the experiment at 70 m, a power of 144 W is transmitted with an efficiency of 88.1% while achieving a communication rate of 600 kb/s.

Environments with high humidity and corrosive gases have been shown to cause dendritic corrosion growth in isolation trenches of power semiconductor modules. In their previous study, Rautio et al. showed that applying local heating to unpotted test vehicles with bare copper–alumina isolation trenches inhibits dendritic corrosion growth by reducing effective relative humidity and thereby the thickness of the adsorbed water layer on the test vehicle surface. In this paper, the applicability of the results to a silicone gel potted insulated gate bipolar transistor modules is studied. Although the gel is capable of holding more water vapour than air, heating the surface to a similar temperature as in the previous study with bare test vehicles was found effective in slowing down dendritic corrosion growth in the isolation trenches. Increasing the surface temperature further stopped all migrating corrosion in the isolation trenches within the duration of the corrosive gas test.