PSCAD例子的学习(对部分example的解释).doc

PSCAD例子的学习笔记一、黄金分割法（在optimum_run）二、电能质量（在PowerQuality中）软件的英文说明：This application example is based on a case origionally created at the Manitoba HVDC Research Centre by Dr. M. Reformat, in Manitoba, Canada.This case illustrates the use of a STATCOM to provide active filtering for the ac side of a 6-pulse converter system. The Active filter is connected through a 20 kVA, Y-Y transformer to a 200 V, 50 Hz, 3-Phase bus, with a 6-pulse converter loadREFERENCE: H. Fujita and H. Akagi, A Practical Approach to Harmonic Compensation in Power Systems - Series Connection of Passive and Active Filters, IEEE Trans. on Ind.Applications, vol.27, No.6, Nov/Dec 1991, pp. 1020-1025Revised by J.E. Nordstrom - September 2000软件的英文说明。This application example is based on a case origionally created at Manitoba Hydro, in Manitoba Canada. The problem was that farm animals, during winter months, were experiencing a tingle voltage, due to suspected poor grounding on the local ground grid. Using PSCAD, the engineers were able to simulate the local system and determine that the grounding problem was at least partially related to ground rod resistance. During the winter months, the ground conductivity is poor, resulting in a poor connection between the ground rods and earth.While this case is running, you can adjust the ground rod resistance. Notice the change in voltage across the cow!Revised by J.E. Nordstrom - July 2000三、继电保护Case 1: - Two Thevinen Impedance sources connected via one 100km transmission line.（双电源系统通过100km 长度相连）- System voltage is 230kV settable via source equivalents.（230kV）- Simulates two substations connected via one transmission line.(仿真两个变电所之间的传输线路)- Four fault positions for full fault control ahead and behind station relays.（设计了四个故障点）- Two breakers are independently timed controlled. (Default is closed).（两侧的断路器可以通过时间，默认是合上的）- Independent breaker pole tripping is possible.（可以实现分相操作）CASE2：多个故障点。其它一样CASE3：双回线CASE4：双回线的不同故障点CASE5：双回线的不同故障点再加支出一条线路Case Description: - Two Thevinen Impedance sources connected via transmission lines and a T-tap.- One transmission line terminated with a transformer of configurable size and type.- System voltage is 230kV settable via source equivalents.- Simulates three substations connected via three transmission lines.- Eight (8) fault positions for full fault control ahead and behind station relays.- Five breakers are independently timed controlled. (Default is closed).- Independent breaker pole tripping is possible.CASE6：双回线的不同故障点再加支出一条线路与CASE5类似，细节有所不同。故障点任意设置。Case Description: DOUBLE LINE WITH A T-TAP- Two Thevinen Impedance sources connected via transmission lines and a T-tap.- One transmission line terminated with a transformer of configurable size and type.- System voltage is 230kV settable via source equivalents.- Simulates three substations connected via four transmission lines.- Nine fault positions for full fault control ahead and behind station relays.- Faults can be placed Midline on Line 1, Line2 and Line 3- User must take Care to ensure the sum of the sections, T1 through T6 sum to the length of the lines they are simulating.- Five breakers are independently timed controlled. (Default is closed).- Independent breaker pole tripping is possible.CASE7：联络变压器Case Description: - Two Thevinen Impedance sources connected via a D-Y transformer.- System voltage is 230kV/25kV settable via source equivalents.- Simulates two systems with a feeder load.- Four fault positions for full fault control ahead and behind station relays.- Three breakers are independently timed controlled. (Default is closed).- Independent breaker pole tripping is possible.CASE8：三绕组变压器Case Description: - Two Thevinen Impedance sources connected via a Y-D-Y transformer.- Faults can be applied to the 10 kV Delta tertiary winding - System voltage is 230kV/25kV settable via source equivalents.- Simulates two systems with a feeder load.- Five fault positions for full fault control ahead and behind station relays.- Five breakers are independently timed controlled. (Default is closed).- Independent breaker pole tripping is possible.CASE9：与SEL 321 Relay相关的模型This example system is taken from the SEL 321 Relay Instruction Manual, Chapter 5. The transmission line models are based on inputting R, X, and B data manually.Line data is entered per meter; therefore, the lengths of the different line sections are adjusted simply by changing the line length.四、（次同步机）SubSyncRes文件夹中内容IEEE FIRST BENCHMARK CASE FOR SUB-SYNCHRONOUS RESONANCE STUDIESExample Case Characteristics:- Field Voltage of Synchronous machine held at the same value- Mech. Torque of Synchronous machine held at the initial value- Multimass enabled at time = 1.4 sec. The input Mactiv allows the multimass to be enabled only when the machine is active. The multimass is initialized with smoothed value of electrical torque Testdy from the machine model.Reference: IEEE Transactions on Power Apparatus and System, Vol. 96, No.5, October 1977, pp. 1565-1572.五、（WIND Farm文件夹）风力发电机（异步机）This case shows a induction generator being driven by a wind turbine. The turbine is controled by a wind governor. The wind source is used to model wind speed fluctuations.学习心得（2012-2-21）：这个风机由三个部分组成：一是风机（相当于发电厂是的汽轮机），二是调速器（相当于汽轮机的气门控制装置，三是发电机（实际上是鼠笼电动机）。1、 风机的设置上述参数中，Vw是风速，属于外部输入参数，模型前面的就有风速的调节模块，本例中风速一定。W是电机的机械速度。这个W的单位是（rad/s）因此，在“模拟风机的机械速度”处，w是电动机的输出速度。Output Speed是一个标么值，将其乘以2*PI*f再除以极对数。变所W。还有一个输入就是Beta，就是pitch angle 桨距角（可能叫法不对），我的理解是风机叶片的角度，相当于船的桨的吃水角度。输出Tm给电机，输出P看看的。以上调整风机的叶片长度、空气密度、齿轮箱效率等等参数。2、 调速器的设置Pitch Control就是节距控制。下图中的1.44是风机的要求功率（ref为参照的意思）。Wref为电角速度。对应于50Hz。下图为比例积分调节，属于控制参数。下图为速度阻尼参数，属于控制参数。下图比较重要，是桨距角的调整。3、 鼠笼电机的设置见电动机的控制W，S，T。: 记住：A switch to select speed control mode (1) or torque control mode (0).本例中，在1s时，通过控制设置为“0”变成转矩控制，之前是速度控制。T是风机传过来的。对于模型的初步认识：1）1s时，鼠笼电机转为转矩控制。2）5s时。进入桨距控制。显示出通过控制桨距，满足了功率输出的需求。六、（WIND Farm文件夹）风力发电机（同步机）This case shows a synchronous generator being driven by a wind turbine. The turbine is controled by a wind governor. The wind source is used to model wind speed fluctuations.七、（WIND Farm文件夹）风力发电机并网（软起动）八、Tutorial(教程)1.Chatter波形的抖动的处理Definition of Chatter:-A numerical oscillation（振荡，幅值不定） (every time step) in v or i which is caused by trapezoidal integration.（梯形积分）It is not realistic.Voltage chatter occurs whenever a disturbance is applied at a node to which only inductors are connected.Current chatter occurs whenever a disturbance is applied at a location where capacitors are connected in a loop.Chatter can be initiated by switching actions, or by steps in current injections (or voltage sources).Chatter is not caused by interruption in the current in an inductor at a non-zero point.Chatter Elimination Techniques:-解决方法1) Add damping resistors. This method will cause the oscillation to damp out within a few cycles, but it will add extra damping to the solution.2) CDA - Critical Damping Adjustment. This method eliminates chatter by changing from Trapezoidal Integration to 2 time steps of rectangular integration. This will solve the chatter problem, butthe solution accuracy is degraded (albeit only for a few time steps) due to the less accurate integration approximation. Rectangular integration can also be numerically unstable (whereas trapezoidalis always stable).3) 1/2 Step Interpolation. This method interpolates between 0 and 1 (to 0.5), then steps from 0.5 to 1.5 (using the regular trapezoidal method), and then interpolates back to 1.0 to complete the time step.4) Root Matching. This is a new integration technique which replaces the standard trapezoidal integration algorithm. It does not initiate chatter, so a removal process is not required.- Root matching can only be formulated where branches contain at least 2 or more elements (ie RL, LC.) so is ineffective for pure inductive node problems. - Branches solved with Root Matching can be intermixed in the same solution with branches solved with other integration techniques.- Root Matching is always numerically stable.- Root Matching is as efficient (or more efficient) numerically than trapezoidal integration.2. HARMONIC IMPEDANCE AND FFT（谐波负荷及在线快速傅丽叶FFT）A simple case illustrating application of current injection and the on-line Fast Fourier Transform. Harmonic currents are injected at specified frequencies and of equal magnitude into an RLC network whose resonant frequency is 120 Hz. The voltage drop of the entire RLC network is fed into an online Fast Fourier Transform to determine the magnitudes and phases of the harmonics present.To the right are the harmonic magnitude and phase readings. The harmonic magnitude and phase is displayed in the form of a phasormeter. Each phasor represents a harmonic including the fundamental. Clicking on the proper button in the display selector will display the magnitude and phase for the appropriate harmonic in the status bar.3. INPUT CONTROL COMPONENTS（引入控制模块）A simple case with set of input control components needed for interactive simulation.They are used to make changes in signal and parameter values at the time of simulation.4. SIMPLE GTO DEVICE USING INTERPOLATION（对付自激电动势）nterpolation is an integral part of EMTDC which allows switching devices to switch at any instant of time instead of only on the regular time step grid. This allows the use of a larger time step without missing current zeroes or other switching instants.This circuit shows the simplest form of forced commutation. A dc current will flow into the inductor, slowing reaching its steady state condition. When the gto device turns off, the current from the source will go to 0.0. The current in the inductor cannot change instantaneously however, so a large -ve voltage (due to L.di/dt ) is generated, resulting in the back diode turning on immediately.With fixed time step programs however, the diode will not turn on until the end of the time step. This means that the current in the inductor is reduced to zero. The result is a large voltage spike (of one time step duration), and the inductor current is re-set to 0.0.The EMTDC program uses interpolation, so the diode will turn on at exactly 0.0 voltage, not at the end of the time step. The result is that the inductor current continues to flow in the diode without interruption.5. LEGEND（图例，图注）his example case shows how you can generate a legend that will appear at the bottom of any simulation page.It also shows how you can use pre-defined macros in your text. For example, the use of a macro DateTime (with a %: before it) will generate: %:DateTimeThe legend component below was designed so that both the prompt and the corresponding text are entered as Parameters. Any user can modify the prompt and text for each of the 5 lines in the component. Only macros from the first set can be used here.NOTE:Both components (legend and legend_hardcoded) are stored in this example case (when you point at a component and stop moving the mouse, the fly-by text shows you the casename or library in which this component is located). Some users may want to have a Legend component that is used for all their simulation cases, or maybe common for all users at a company. The best way to accomplish this is to save the legend component toa unique name (such as companyname_legend_portrait). Then move this component into the appropriate library.To move the component definition to different library or case please do the following steps: - first go to the Project Tree, and for the case or library where the original component is located, expand the tree and the Definitions section; - next, point at the component, and with the right button, copy the component definition; - go to the library or case where you want the component to reside (or create a new one), and paste the component into the Definitions section; - finally, cre