在Modelica中将逆变器与smpm连接时的错误仿真结果

Question

我使用来自Wolfram的SystemModeler来研究连接到永磁同步电机上的逆变器的系统行为。不幸的是，即使我只使用来自Modelica标准库的组件，我也得到了错误的仿真结果。

到目前为止，我用下面的模型尝试了几种设置。

model InverterSMPM
  import Modelica.Constants.pi;
  parameter Integer m = 3 "Number of phases";
  parameter Modelica.SIunits.Frequency f = 1000 "Switching frequency";
  parameter Modelica.SIunits.Frequency f1 = 50 "Fundamental wave AC frequency";
  parameter Modelica.SIunits.Torque TLoad = 181.4 "Nominal load torque";
  parameter Modelica.SIunits.Inertia JLoad = 0.29 "Load's moment of inertia";
  Modelica.Electrical.Analog.Sources.ConstantVoltage constantVoltage_n(V = 50) annotation(Placement(transformation(extent = {{-10, -10}, {10, 10}}, rotation = 270, origin = {-105, 4}), visible = true));
  Modelica.Electrical.PowerConverters.DCAC.MultiPhase2Level inverter(useHeatPort = false, m = m) annotation(Placement(transformation(extent = {{-50, 20}, {-30, 40}}, origin = {-35, -6}, rotation = 0), visible = true));
  Modelica.Electrical.Analog.Basic.Ground ground annotation(Placement(transformation(extent = {{-10, -10}, {10, 10}}, rotation = 180, origin = {-125, 34}), visible = true));
  Modelica.Electrical.PowerConverters.DCDC.Control.SignalPWM signalPWM[m](each useConstantDutyCycle = false, each f = f) annotation(Placement(transformation(extent = {{-10, -10}, {10, 10}}, origin = {-75, -26}, rotation = 0), visible = true));
  Modelica.Electrical.Analog.Sources.ConstantVoltage constantVoltage_p(V = 50) annotation(Placement(transformation(extent = {{-10, -10}, {10, 10}}, rotation = 270, origin = {-105, 44}), visible = true));
  Modelica.Blocks.Sources.Sine sine[m](phase = -Modelica.Electrical.MultiPhase.Functions.symmetricOrientation(m), startTime = zeros(m), amplitude = fill(0.5, m), offset = fill(0.5, m), freqHz = fill(f1, m)) annotation(Placement(transformation(extent = {{-30, -64}, {-50, -44}}, origin = {-35, -6}, rotation = 0), visible = true));
  Modelica.Electrical.Machines.BasicMachines.SynchronousInductionMachines.SM_PermanentMagnet smpm(Jr = 0.29, p = 8, fsNominal = f1, VsOpenCircuit = 100, TsOperational = 293.15, TrOperational = 293.15, Rs = 4.7, TsRef = 293.15, alpha20s = Modelica.Electrical.Machines.Thermal.Constants.alpha20Aluminium, Lssigma = 0.001, Lmd = 0.0133, Lmq = 0.0133, useDamperCage = false) annotation(Placement(visible = true, transformation(origin = {5, -15}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Machines.Utilities.TerminalBox terminalBox1(terminalConnection = "Y") annotation(Placement(visible = true, transformation(origin = {5, 2.209}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Mechanics.Rotational.Components.Inertia inertia1(J = JLoad) annotation(Placement(visible = true, transformation(origin = {35, -15}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Mechanics.Rotational.Sources.TorqueStep torqueStep1(stepTorque = -TLoad, offsetTorque = 0, startTime = 2, useSupport = false) annotation(Placement(visible = true, transformation(origin = {76.657, -15}, extent = {{10, -10}, {-10, 10}}, rotation = 0)));
  Modelica.Mechanics.Rotational.Sensors.SpeedSensor speedSensor1 annotation(Placement(visible = true, transformation(origin = {35, 20}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
  connect(constantVoltage_p.n, constantVoltage_n.p) annotation(Line(points = {{-70, 40}, {-70, 20}}, color = {10, 90, 224}, visible = true, origin = {-35, -6}));
  connect(constantVoltage_p.p, inverter.dc_p) annotation(Line(points = {{-70, 60}, {-50, 60}, {-50, 40}}, color = {10, 90, 224}, visible = true, origin = {-35, -6}));
  connect(constantVoltage_n.n, inverter.dc_n) annotation(Line(points = {{-70, -0}, {-50, 0}, {-50, 20}}, color = {10, 90, 224}, visible = true, origin = {-35, -6}));
  connect(ground.p, constantVoltage_p.n) annotation(Line(points = {{-90, 30}, {-70, 30}, {-70, 40}}, color = {10, 90, 224}, visible = true, origin = {-35, -6}));
  connect(sine.y, signalPWM.dutyCycle) annotation(Line(points = {{-51, -54}, {-60, -54}, {-60, -20}, {-52, -20}}, color = {1, 37, 163}, visible = true, origin = {-35, -6}));
  connect(signalPWM.fire, inverter.fire_p) annotation(Line(points = {{-46, -9}, {-46, 18}}, color = {190, 52, 178}, visible = true, origin = {-35, -6}));
  connect(signalPWM.notFire, inverter.fire_n) annotation(Line(points = {{-34, -9}, {-34, 18}}, color = {190, 52, 178}, visible = true, origin = {-35, -6}));
  connect(terminalBox1.plug_sn, smpm.plug_sn) annotation(Line(visible = true, origin = {-1, -4.396}, points = {{0, 0.604}, {0, -0.604}}, color = {10, 90, 224}));
  connect(terminalBox1.plug_sp, smpm.plug_sp) annotation(Line(visible = true, origin = {11, -4.396}, points = {{0, 0.604}, {0, -0.604}}, color = {10, 90, 224}));
  connect(smpm.flange, inertia1.flange_a) annotation(Line(visible = true, origin = {20, -15}, points = {{-5, 0}, {5, 0}}, color = {64, 64, 64}));
  connect(inertia1.flange_b, torqueStep1.flange) annotation(Line(visible = true, origin = {55.828, -15}, points = {{-10.828, 0}, {10.828, 0}}, color = {64, 64, 64}));
  connect(speedSensor1.flange, smpm.flange) annotation(Line(visible = true, origin = {20, 2.5}, points = {{5, 17.5}, {0, 17.5}, {0, -17.5}, {-5, -17.5}}, color = {64, 64, 64}));
  connect(inverter.ac, terminalBox1.plugSupply) annotation(Line(visible = true, origin = {-18.333, 15.403}, points = {{-46.667, 8.597}, {23.333, 8.597}, {23.333, -17.194}}, color = {10, 90, 224}));
  annotation(experiment(StartTime = 0.00, StopTime = 5, NumberOfIntervals = 5000, __Wolfram_Algorithm = "dassl", Tolerance = 1e-6, __Wolfram_SynchronizeWithRealTime = false), Diagram(coordinateSystem(extent = {{-150, -90}, {150, 90}}, preserveAspectRatio = true, initialScale = 0.1, grid = {5, 5})));
end InverterSMPM;

• 一个设置是: JLoad=0和TLoad=0 我希望马达能自由地以空闲的速度运转。相反，速度传感器显示的是振幅为-0.46;0.46的正弦波。
• 另一个设置: JLoad=0.29和TLoad=-180 电机有speed=0，当我应用转矩步进时，电机会减少并得到t=2s的负值。

有人可以告诉我，我的模型做错了什么，为什么模拟结果是错误的？

我也尝试了一些图书馆的例子，但他们从来不使用逆变器与电机。但我想研究PWM，不想工作在理想的正弦电压和电流，如在例子中.

谢谢你的帮助！！

Answer 1

在你的模型中，你要做的是，让同步电机从静止状态直接在标称频率上运行。这将使机器“步履蹒跚”，这就是机器不像你所期望的那样运转的原因，而只是以一种看似随机的方式振荡。

试着把sine[*].freqHz降低到fill(0.01*f1, m)，你会看到它--经过一些振荡--开始以其标称频率的百分之一的速度工作。只是机器无法克服向标称频率跳跃的振荡。

解决这一问题有多种可能性：

1. 正确地初始化机器:这可以通过至少将smpm.wMechancial.start和smpm.phiMechancial.start设置为正确的值来完成。另外，正确地初始化相位电流也是很好的。这样做可能会很乏味。但它的优点是你不必加快速度。
2. 复制示例Modelica.Electrical.Machines.Examples.SynchronousInductionMachines.SMPM_Inverter的部分可能更容易，其中使用电压频率控制器启动机器。
3. 许多同步电机实际上是被控制的(例如通过磁场定向或直接转矩控制).为此，可以从Modelica.Electrical.Machines.Examples.SynchronousInductionMachines.SMPM_CurrentSource和Modelica.Electrical.Machines.Examples.SynchronousInductionMachines.SMPM_VoltageSource获得一些线索。

此外，我建议首先尝试让您的例子运行一个连续逆变器，如在Modelica.Electrical.Machines.Examples.SynchronousInductionMachines.SMPM_Inverter。如果这是预期的效果，那就转到切换的那个。

有些事情在我看来很可疑：

• 对于我来说，smpm.Rs看起来很大，有4.7欧姆，特别是考虑到惰性smpm.Jr (有0.29 kg.m2)和inertia1.J (有0.29 kg.m2)。
• 测试时，尽量将开关频率提高到1 1kHz以上。对于50赫兹的基波频率来说，这是有点低的(虽然它应该工作)。