配电变压器无触点有载自动调容技术的研究

发布时间：2018-05-15 06:14

本文选题：无触点 + 有载自动调容　；参考：《东北农业大学》2015年硕士论文

【摘要】：农村电网负荷波动大,因此造成变压器时而满负荷甚至过负荷,时而轻载甚至空载。变压器的损耗是由铁损和铜损两部分构成。若变压器容量不变而负荷变化,必将造成铁损和铜损的比例也不同,使变压器的损耗发生变化,所以,为使变压器的损耗较小,必须当负荷变化超过一定范围时,改变变压器的容量,即变压器的容量应该根据负荷的大小而变化。变压器容量的改变是通过触发调容开关的通断来完成的,在调容开关进行触发动作后,改变配电变压器高压侧与低压侧绕组的连接关系,从而改变配电变压器上匝数的数量关系,达到调容的目的。为了达到降低这种调容变压器损耗带来的经济损失的目的,本文以无触点有载自动调容分接开关及其触发方式作为研究对象,该调容分接开关由两个晶闸管反并联构成,智能控制器根据检测部分收集到的实时负荷数据,控制调容分接开关的导通与关断,进行高压侧D、Y转换和低压侧串并联变换,实现有载自动调容,使得变压器容量符合用户端负荷大小,降低变压器空载损耗。本文从现有的配电变压器调容技术中所采用的分接开关,分析其在调容过程中产生的诸多不安因素,如结构复杂、调节速度缓慢等。通过对晶闸管过零触发和移相触发方式的分析比较,设计了基于反并联晶闸管光纤触发方式的配电变压器无触点有载自动调容分接开关,对于一次侧触发电路中光接收器的供电问题,设计了自取能直流供电电路。光纤触发因其能有效处理高低压电气隔离问题且更加安全稳定得到了广泛的应用,它也是提高有载自动调容技术安全性与稳定性的关键所在。结合本文对无触点有载自动调容技术的研究,选取适合的电力电子元件在仿真软件Matlab/Simulink中搭建了无触点有载自动调容技术的仿真模型,对调容开关的触发切换过程进行了模拟仿真分析研究。根据示波器得到的波形可以看出,调容开关动作时会产生较大的冲击电流,由于晶闸管具有过零触发的特性,对触发时间进行延时处理可以合理的解决晶闸管因冲击电流导致的过热烧毁。理论分析与仿真结果表明,调容开关光纤触发方式的提出,提高了调容过程中的安全性与可靠性,并且调容过程较稳定。利用有载自动调容技术可以减少变压器总损耗,达到节能降损的效果,同时也减少了人员的投入,更加经济高效。
[Abstract]:Rural power grid load fluctuates greatly, resulting in transformer sometimes full load or even overload, sometimes light load or no load. Transformer loss is composed of iron loss and copper loss. If the transformer capacity is constant and the load changes, the ratio of iron loss and copper loss will be different, and the transformer loss will change. Therefore, in order to make the transformer loss less, it is necessary to change the load beyond a certain range. Changing the capacity of a transformer, that is, the capacity of a transformer should vary according to the size of the load. The change of transformer capacity is accomplished by triggering the on-off of the capacitive switch. After the capacitive switch is triggered, the connection between the high-voltage side of the distribution transformer and the low-voltage side winding is changed, and the connection between the high-voltage side of the distribution transformer and the low-voltage side winding is changed. In order to change the number of turns on the distribution transformer to achieve the purpose of capacity adjustment. In order to reduce the economic loss caused by the loss of this kind of adjusting transformer, this paper takes the contactless on-load automatic adjusting and capacitive switch and its triggering mode as the research object, which is composed of two thyristors in reverse parallel connection. According to the real time load data collected from the detection part, the intelligent controller controls the on-off and turn-off of the adjustable and capacitive switch, carries out the DY conversion of the high-voltage side and the series-parallel conversion of the low-voltage side, and realizes the on-load automatic capacity adjustment. Make the transformer capacity in line with the user load size, reduce the transformer no-load loss. In this paper, based on the tap switch used in the current capacitive adjustment technology of distribution transformer, many uneasiness factors, such as complex structure and slow adjusting speed, are analyzed. Based on the analysis and comparison of thyristor zero-crossing trigger and phase-shift trigger mode, an unloaded automatic capacitive switch for distribution transformer based on anti-parallel thyristor fiber trigger is designed. For the power supply of optical receiver in primary side trigger circuit, a DC power supply circuit is designed. Fiber trigger has been widely used because it can effectively deal with the problem of high and low voltage electrical isolation, and it is also the key to improve the security and stability of load automatic capacity adjustment technology. Combined with the research of contactless load automatic capacity adjustment technology in this paper, the simulation model of contactless load automatic capacity adjustment technology is built in the simulation software Matlab/Simulink, which is suitable for power electronic components. The trigger switching process of the capacitive switch is simulated and analyzed. According to the waveform obtained from the oscilloscope, it can be seen that the surge current will be produced when the capacitive switch is in action, because the thyristor has the property of zero crossing trigger. The delay treatment of trigger time can reasonably solve the overheating and burnout of thyristor caused by impact current. The theoretical analysis and simulation results show that the security and reliability of the capacitive adjusting process are improved by the proposed trigger mode of the capacitive switch fiber, and the capacitive adjusting process is more stable. Using the technology of automatic capacity adjustment on load can reduce the total loss of transformer, achieve the effect of saving energy and reducing the loss, at the same time, it also reduces the investment of personnel, and is more economical and efficient.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM421

【参考文献】