逻辑控制无环流可逆调速系统设计外文翻译(编辑修改稿)

逻辑控制无环流可逆调速系统设计外文翻译(编辑修改稿)内容摘要：

, most of the time, ends up being very expensive and time consuming. It is proposed here that this drawback can be alleviated substantially by properly 重庆交通大学二 O一二 届毕业设计（论文） •译文 bining puter simulations and laboratory tests. The conjunct simulation of an electric motor and its speed control has been done before by applying very simple models for the motor and/or for the electronic control modules [1], [8] and [12]. 2. Proposed design for a DC motor speed control Current digital technologies provide several clear advantages over the analog ones for the functions of generating the PWM switching signals and of processing the protection signals of the DC motor speed control. Fig. 1. Pedal signal conditioning circuit. To generate the PWM switching signals, Vcond from Fig. 1 circuit is fed into the microcontroller39。 s first A/D converter input. Vcond is thus discretized into 256 levels, each one of them is taken as an address for the microcontroller39。 s E2PROM. The corresponding memory cell contains the intended duration of the pulse. The pulse width is thus varied in 256 steps according to Vcond. A discrete linear variation is adopted here for the prototype being implemented. This linear characteristic, however, could be easily changed if this is deemed convenient. Before their injection into the power driver gates, the PWM signals are first passed through a gate driver stage consisting in an optoelectronic isolator and a buffer. This is shown in Fig. 2. As for the power electronic stage, a full DC to DC Hbridge converter made with four IGBTs and their corresponding parallel diodes is highly remended [6]. For the work reported here, however, 重庆交通大学二 O一二 届毕业设计（论文） •译文 only one branch of this bridge is implemented in the form shown in Fig. 3. This branch is made to perform as a step down converter [6]. Fig. 2 Gate driver. Fig. 3 Power output stage. In addition to the protection against loss of pedal, the other protection functions listed above are implemented using voltage sensors as well as current and temperature transducers as needed. The analog signals delivered by these devices are then fed into the microcontroller via its additional A/D converter inputs and their monitoring is made by the microcontroller39。 s program. 3. DC series motor modeling using analog behavioral modules 重庆交通大学二 O一二 届毕业设计（论文） •译文 . Motor equations The equations that describe the electromechanical behavior of a DC series motor are given as follows. The electrical equilibrium equation is [2] and [8]: (1) where Vs is the voltage at the two windings connected in series, Ea is the induced electromotive force (emf), Rt is the total series resistance, Is is the current through the windings and Lt is the total series inductance. The relation of Ea with magic flux φ and angular speed ω is [2] and [8] (2) where Ka is a motor constant. The electromagic torque developed by the DC motor depends on Is and on φ in the following manner: (3) The torque balance equation is [2] and [8]: (4) where TL is the load torque, B is the viscous friction constant and J is the motor39。 s rotor and shaft inertia. The magic flux and the windings current are related through the machine39。 s magization curve which is denoted as follows [2] and [5]: (5) Function f(Is) in general includes saturation and hysteresis effects. . Analog behavioral modeling of a DC series motor (1), (2), (3), (4) and (5) provide a mathematical model for a DC series motor suitable for the purposes of thi。