基于级联式H--桥多电平变流器的可变速抽水蓄能系统

摘要

本文提出了一种应用于可变速抽水蓄能的级联式多电平换流器。主要研究和分析了基于这种新型换流器的抽水蓄能单元特性。通过H桥级联式逆变器为额定电压为6kV的绕线式感应电机供电，采用多载波移相调制来获得的所需等级的电压。分析了逆变器的输出电压，转子电流及转速等变量的特性。 用于可变速抽水蓄能单元的电力电子换流器主要有:周波变换器，两电平换流器，三电平换流器和H桥级联式换流器。通过对比分析每种换流器对应的双馈异步电机的转子电流总谐波畸变率和速度调节特性，证明了H桥级联式换流器是较好的方案，该方案具有较低的dv/dt、电流THD以及较快的响应速度。作者将两个相同的7电平H桥换流器级联，形成转子侧的6kV电压。H桥级联式换流器的输入电流经过移相变压器后降低了转子电流的总谐波畸变率。 针对可变速抽水蓄能控制，论文作者采用了间接磁场定向的控制策略。双馈异步机的滑差角计算是通过使用间接磁场定向控制的定子磁通获得的。基于电机参数和滑差角的计算，实现变速抽水蓄能单元的控制。 论文针对可变速抽水蓄能对平抑风电出力波动的作用进行了研究。通过检测风能的变化，利用PI控制器生成可变速抽水蓄能发电机组的参考速度。通过对速度的跟踪实现功率的调整，从而实现对风电出力波动的抑制。结合苏丹北部的Dongola风电场的仿真结果证明，在使用抽水蓄能装置后，风电场的功率波动对电网的影响得到了改善。仿真同时也验证了所建模型及控制策略的正确性。研究工作的所有仿真模型都是基于PSIM仿真软件建立的。

目录

声明

摘要

Abstract

Contents

Chapter 1 Introduction

1．1 Background

1．2 Pump storage development

1．2．1 The separate pump and turbine

1．2．2 The single reversible pump turbine machine

1．3 Development of Variable speed pump storage

1．4 Research contents

1．5 Chapters structure

Chapter 2 Multi-Level Inverters

2．1 Introduction

2．2 Cascaded H-bridge Multilevel Inverter

2．3 Diode Clamped Multilevel Inverter

2．4 Flying Capacitor Multilevel Inverter

2．5 Multilevel Inverters PWM Techniques

2．5．1 Phase-shiRed Multicarrier Modulation

2．5．2 Level-Shifted Multicarrier Modulation

2．5．3 Multilevel Space Vector PWM

2．5．4 Selective Harmonic Elimination

Chapter 3 Power Electronics Converters for Variable Speed Pump Storage

3．1 Introduction

3．2 Pumps storage power systems configuration

3．2．1 Fixed speed pump storage

3．2．2 Adjustable speed with synchronous machine

3．2．3 Adjustable speed pump storage with doubly fed induction machine

3．3 Power electronic solutions to obtain variable speed operation of DFASPSU

3．3．1 The cyclo-converter

3．3．2 Back to back two levels voltage source inverter

3．3．3 The three level diode clamped back to back voltage source inverter

3．3．4 Cascaded H-bridge multilevel converter

Chapter 4 Modeling and Simulation of Pump Storage Based on Field Oriented Control

4．1 Introduction

4．2 Induction Machine Model

4．2．1 Space vector machine model

4．2．2 dq Reference Frame Model

4．3 Model of Variable Speed Pump Storage

Chapter 5 Wind Power Compensation Using Variable Speed-Pump Storage

5．1 Introduction

5．2 Wind Hybrid systems

5．2．1 Wind Hydro system

5．2．2 Wind Hydrogen system

5．2．3 Wind-diesel system

5．2．4 Wind-compressed air system

5．2．5 Wind-solar system

5．3 Dongola Wind Power Stations

5．4 Power Fluctuation Compensation Control

5．4．1 The Spectrum Characteristic of Wind Power Fluctuation

5．4．2 The Spectrum Characteristic of Variable Speed Pump Storage System

5．4．3 The Control System of Variable Speed Pump Storage Inhibit Wind Power Fluctuations

5．5 Indirect Field Oriented control and Converter Technology

5．6 Grid Simulation

Chapter 6 Conclusions and Further works

6．1 Conclusions

6．2 The main Contributions of This Thesis

6．3 Recommendation for Further Works

References

Publications

Acknowledgement

About the Author