Due to its low harmonic, high efficiency and high power factor (PF), the multi-pulse autotransformer has been frequently used in the aviation sector. Many studies have been carried out on the theoretical calculation and simulation analysis of the autotransformer. However, the practical application of the multi-pulse rectifier in practical engineering field is inevitable. This work investigates an 18-pulse rectifier power supply of 11 kW being constructed using a multi-pulse autotransformer to suppress the harmonics of a radar power system, in which the parameters of the various parts are designed in detail, and test results are simulated using MATLAB/Simulink software. The actual test suggests that, at the rated condition, the PF of the rectifier is 0.99, the total harmonic distortion (THD) of the input current is below 6.7%, and the efficiency is more than 96%. The power supply is successfully applied to the radar power supply system of a large transport aircraft, and meets the requirements of an environmental test. Furthermore, the results also provide powerful application support for the power supplies and distribution systems in other fields.

The low-harmonic and high-power density multi-pulse autotransformer has many advantages, such as simple structure, high reliability, high efficiency, strong overload ability, and so on. Therefore, it has a broad application prospect in aviation field. The multi-pulse rectifier power system is more and more widely used in aerospace. However, there are many practical engineering problems of the aircraft power supply characteristics that are difficult to predict. In this paper, the aircraft power supply characteristics of the rectified power system with 18-pulse autotransformer rectifier are simulated and investigated. According to the handbook MIL-HDBK-704-3, the performance of the power supply in the normal, abnormal, and fault state is verified and tested in detail. The research and discussion are carried out from six aspects: the load measurement, the steady-state limits, the voltage phase difference, the voltage transient, the frequency transient, and the power failure. The system can meet the requirements of the U.S. military standard MIL-STD-704A for the aircraft power supply characteristics. It has been applied to the radar power supply system of a large transporter, and the conformance verification test of the aircraft power supply characteristics has been completed, which provides the practical application basis for the engineering realization of the multi-pulse rectifier power supply in the radar power supply system. It also provides a reference for the development of the power supply system for other aircraft.

The extensive application of nonlinear components and power electronic devices in power systems has led to increasingly deteriorating harmonic pollution. The rapid and high-precision harmonic detection and analysis technology will set the prerequisite for mitigating the harmonic crisis. This article presents a robust, stable, and real-time approach based on broad learning system (BLS) for detecting and analyzing the amplitudes of fundamental and harmonic components, which only requires half or even quarter cycle input. Additionally, a fast-converging adaptive parameter learning strategy using rectified adaptive moment estimation (RAdam) for BLS is proposed. To obtain the actual distorted signals, the signal acquisition system is built on the basis of the designed multi-pulse rectifier power supply (6/18 pulse). With the fundamental frequency deviation, interharmonics and noise, etc., the simulated signals synthesized by MATLAB tool and the actual signals acquired from the built system are attained to verify the performance of methods. The proposed approach differentiates from other existing methods not only due to its superior precision and robustness in the presence of multitudinous interference factors but also its real-time performance because of low average computing time.

Due to its advantages of small size and light weight, multi-pulse rectifier has a broad application prospect in the field of aviation. The 18-pulse rectifier is more popular in practical engineering application because of its better rectifier characteristics than 12-pulse, its simpler structure process and easier to realize than 24-pulse. The theoretical research and engineering application of the 18-pulse rectifier have achieved some success. However, whether the reliability of the system can be satisfied has always been one of the key problems to be solved in practical engineering. The aim of this work is to study the reliability modeling and prediction of the 18-pulse rectifier power supply. Its reliability block diagram and mathematical model are established. According to US Military handbook MIL-HDBK-217F, the most authoritative and widely used in the world, the two most commonly used methods for reliability prediction are parts count method and part stress analysis method. The reliability data are estimated by these two methods. It is concluded that the value of mean time between failures in airborne environment is 23326 h, which meets the requirement of 1.5 times of 15000 h. According to the reliability data, the failure mode and effect analysis of its weak links are carried out, and the improvement measures are proposed. This will promote and guide the reliability growth and engineering popularization of the 18-pulse rectifier power supply. At the same time, the reliability of the actual project can be extended to other related engineering applications to ensure the reliable operation of the system.

When the power transformer is connected to power grids, due to the existing remanent magnetism (RM) and the voltage transient component, the transformer will generate a large magnetizing inrush current (MIC). The MIC not only seriously threatens the safe operation of the transformer, but also causes the misoperation in the differential protections. To solve the aforementioned problems, a novel MIC elimination strategy of the hybrid transformer (HT) based on an asynchronous closing technology is proposed in this article. First, through the rational design of the HT topology, the parallel auxiliary winding (PAW) of the HT is established and the magnetic coupling mechanism is realized, which lay the magnetic circuit foundation for the MIC management. Second, a step-type synchronous magnetic field is established through PAW without considering RM. After the action of step-type magnetic field, the core flux increases sinusoidal linearly and enters into the rated steady stable. Finally, by controlling the stabilization time of the oblique wave and the primary voltage signal of the power grid, when the core flux is stabilized, the nonsynchronous closing of the HT can effectively alleviate the generation of the MIC. The validity and feasibility of the proposed scheme are verified by building an HT prototype platform, which provides some reference for the difficulty of measuring RM and avoiding MIC in the power system.

With the development of radar power supply system, the power density of DC/DC power supply is becoming larger and larger, but the volume is becoming smaller and smaller, which makes the power density of the power supply increase, and the combination of power modules needs to be optimised to realise the power supply of the whole system. Here, a modular design scheme is introduced, which adopts a three‐layer combined structure, and finally realises the DC/DC combined power supply with a total power of 15.6 kW in the total height of 105 mm. The heat design of the power supply is reasonable, the rectangular liquid cooling channel is arranged inside the cooling plate of the chassis, the rectangular heat exchanger fin is added inside the liquid cooling channel with concentrated heat source, and the series‐parallel technology is used in the liquid cooling channel inside the plate. The series reliability prediction model can meet the requirements of radar overall design. The project is difficult to implement, and more precise process is needed in practical engineering to strictly control it. The successful implementation of this scheme provides a reference for the realisation of similar radar products.