Advanced Control (EEEE4116)
Coursework 1
Modelling and Advanced Controller Design for a 2-Level Grid-Feeding Inverter
In this assignment you will bring together your skills of state-space equation development and controllerdesign to control a grid-tied 2-Level Converter. The design willmake use of transforming the 3-phase
behaviour of this converter into the dq frame and use the dq equivalent circuit to develop controls. If youhave not yet read the coursework summary, it is highlyrecommended you read this prior to get theunderstanding of what dq transforms are and why we are developing a control system in this way.Figure 1- Notional System Diagram: DC Source interfaced with 3-phase 2-Level Inverter interfaced to the grid. The system under investigation is a very common application when trying tolink renewable energy sourcessuch as solar panels, or energy storage systems to interface them to the national grid, or even microgridapplications where small remotecommunities rely on generatingtheir own power.We are converting DC power into 3-phase AC power to connect to the national grid. The parameters whichwill be used in the design is as follows:= 33uFω
Grid Frequency (rads-1 )= 100π rads-1f
sSwitching Frequency= 20kHzExercise 1 – System Modelling As per the coursework summary, we wish to develop our control strategy using the dq equivalent modelIshown in [ X ] that an equivalent 3-phase inverter can be modelled using the following circuits when
bserving converter dynamics in the dq domain:
gure 2- 3-Phase Inverter dq equivalent average model. Where:md: d-axis modulation index.
q: q-axis modulation index.
ω: frequency of phase voltages (rads-1 )
- Vcd / Vcq: d-axis and q-axis voltage respectively across capacitor
- Iid / Iiq: d-axis and q-axis input current respectively from inverter
- Icd / Icq: d-axis current respectively flowing into capacitor.
- Iad / Iaq: d-axis and q-axis output currents after filter.
- represents a virtual voltage source in the system (due to changing currents in inductor)
- represents a virtual current source in the system (due to changing voltages in capacitor)Hint: Note the directions of the virtual voltage and current sources. Vital to this exercise.Using Kirchhoff’s current and voltage laws on the two circuits shown in Figure 2, develop state-equations for d and qaxis voltage and currents.n our system, we will treatthe modulation indexes as inputs to our system. Using your state equations, go on toshow that the state-space equation defining the model canbe shown to be as: 标签：EEEE4116,controller,system,state,Design,our,Inverter,model,your From： https://www.cnblogs.com/comp9321/p/18539470