AC regulated power supply with wide range adaptability

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AC regulated power supply with wide range adaptability [Copy link]

Based on extensive investigations and long-term accumulated experience, it is necessary to configure military electronic equipment with high reliability, high performance, and high stability AC stabilized power supplies. The wide range adaptability includes: effective value voltage stabilization function, which is very necessary when the voltage waveform distortion rate increases. There are also special environmental conditions, high reliability, high voltage stabilization accuracy, good dynamic characteristics, etc. We have successfully developed a new generation of compensated effective value AC stabilized power supplies based on adaptability.

　　The usual compensation method has three disadvantages: low voltage stabilization accuracy, poor reliability, and slow response speed (not suitable for impact loads). Therefore, a solution to replace it with a contactless method was proposed. In the early stage of development, it was found that the minimum adjustment amount of the contactless compensation structure was difficult to reduce, which limited the improvement of voltage stabilization accuracy. From this point of view, the mechanical voltage regulation solution was still adopted. While retaining the mechanical voltage regulation mechanism, several special research projects were carried out. After practice, the main defects of the compensation method were overcome, and the three performances of the small batch of products were: voltage stabilization accuracy is better than ±0.5%; the maximum overshoot is 2.4% during full load impact, and the dynamic recovery time is 0.3s; MTBF is 50,000h.

　　The new product also has the following features:

　　(1) In addition to meeting general environmental conditions, the allowable ambient temperature is -40 to +50°C and can be used at an altitude of 4000m.

　　(2) Measured results of the effective value voltage regulation function: When the waveform distortion rate is 20%, the output voltage effective value deviation is 0.2%.

　　(3) Three-phase voltage regulation allows the load imbalance of each phase to reach 100%, and the voltage asymmetry increment is not higher than 0.3%. The short-term overload capacity is 160% for 5 minutes.

　　(4) It can withstand frequent impact loads and its response to various step disturbances must meet the overshoot requirement of ≤0.5%.

　　After extensive use and testing, military electronic equipment equipped with this voltage-stabilized power supply has avoided many faults and operates well.

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Discussion (1) Consider the power supply equipment as a product. When users select products, they should consider the principle of adaptability, that is, the various parameters and performance of the power supply are considered as the adaptability of the power supply. This makes it easier to achieve the most reasonable selection. From this point of view, power supply products can also be classified according to adaptability. This understanding still regards the power supply and the load as two independent devices, and there is an adaptability relationship between them. (2) In a narrow sense, adaptability is defined as "the power supply equipment and the load form a system". Under certain conditions, the voltage regulation and transient power supply indicators of the power supply can meet the expected requirements. This characteristic of the system composed of the power supply and the load is called adaptability. Here, a new point of view is proposed, that is, "the power supply and the load form a system". Under certain conditions, this point of view is beneficial to promote the development of power supply products. (3) Give an example to illustrate this point of view. When the voltage and frequency regulated power supply is subjected to step load disturbance, the output voltage and frequency have a transition process. In order to obtain a smaller overshoot and stabilization time, the method of a big horse pulling a small cart was adopted in the early days. This not only increases the initial investment, but also increases the operating and maintenance costs accordingly. The power supply and the load form a system. The control quantity of the regulator is not only taken from the output of the power supply, but also the parameter changes of the disturbance are introduced into the regulator. As a result, the overshoot and stabilization time are greatly reduced. It is worth noting that after "forming a system", a number of technical measures can be applied to this "one system". Therefore, the power supply and the load form a system. The power supply equipment is developed according to the requirements of the system, which will help to obtain a power supply with higher technical performance to meet the needs of specific loads. (4) The power supply and the load form a system. Adding new content to the performance assessment of the power supply, that is, summarizing the test conditions and test methods of specific items according to the operating characteristics. The content of this type of test may be varied, collectively referred to as adaptability test. The adaptability assessment of the voltage stabilized power supply for radar equipment is an example. The operation of the radar is a strong and frequent impact load for the power supply equipment. If the dynamic characteristics of the power supply are poor, it is easy to cause failures or even system instability. This is difficult to identify, judge and repair under field conditions. In view of this situation, a corresponding adaptability test project is set up to use the test method to pre-assess the adaptability of the power supply for radar. The newly developed effective value voltage stabilized power supply was first subjected to adaptability test and then used with various types of radars to achieve good results. The project setting, test conditions, and test methods of the adaptability test must effectively reproduce the operating conditions of the original system, so that the adaptability test results can be directly used to judge the actual operating conditions. (5) The adaptability research of future power supplies is one of the development directions of power supply products. For example, the application of nanotechnology has attracted full attention from all parties, and the corresponding power supply research is an important development branch. (6) Adaptability also involves the production management of the power supply industry. For example, in the original relationship between the supply and demand parties, one party produces the product and the other party selects it. Now it seems that this is only one aspect of the relationship between the two. In addition, users can also make requirements, and the manufacturer must meet this specific demand in the entire process from design to manufacturing.