这是我们在2017年为美国University of Michigan学生做的一篇electronic engineering代写范文。 Introduction介绍文章的背景信息，介绍一种流行的控制方法，也就是可编程逻辑控制器（PLC）。在一个单位功率因数下，在启动状态和控制电机时会导致电压下降。同时，由于能够降低制造成本，提高生产质量和可靠性，PLC也被许多工厂广泛接受。以下是electronic engineering代写节选范文。
One of the popular control methods is programmable logic controller (PLC). It is conductive to under a unity power factor to induce voltage drop at starting status and control motor . Meanwhile, due to the ability to decrease manufacture cost and improve production quality and reliability, PLC is also widely accepted by many factories  . The published papers relative with PLC can be divided into some aspects. Firstly, it researches on the implementation of speed control via altering the armature voltage of induction motors and the incorporation of the adaptive control above ‘self-tuning regulator technology’ . Secondly, it concentrates on the control capability of drive systems, such as passenger elevators, and its data acquirement .
As far as high performance requirement, the field oriented control has been applied on induction motor. In order to reach decoupling control, it bases on synchronous angular velocity  . Unfortunately, there are sensitive parameters, rotor time constant particularly that would variant due to temperature fluctuation and the magnetizing inductance in saturation . The one of the most proposed method to come over this weakness is to adapt a rotor resistance or rotor time constant identification control loop. For an instance, there is novel observation technique that bases on ‘model reference adaptive system (MRAS)’, which makes a magnetizing current model to an indirect rotor flux oriented induction . Although it still cannot meet current high accuracy industry production requirement because of imperfect speed control.
In this design, it is going to design a series control loops based on VVVF control method to achieve induction motor speed control. Meanwhile, it would point out the effect of each control loops and make a analysis on different core parameters. Last the outcome goes to make compensators to fix up the gaps between theory design and reality conditions.