Development status and trend of marine power drive in China

Review on the Present Situation and Future of Marine Electric Propulsion System

6? 1 Introduction

6? 1 History —— Review of the development of marine electric propulsion

6? The present situation of 1-the main form of ship electric propulsion

6? 1 future-proposal and development of all-electric ships

6? 1 new energy ship and our research work

6? 1 conclusion

1. Introduction

6? Development background of 1

6? 1 problems and challenges

Research background

Since the world's first ship powered by a steam engine came out, the mechanical propulsion system that directly drives the propeller by heat engines (such as diesel engines, steam turbines and gas turbines) has become the main way of ship propulsion and occupies a dominant position in the ship power plant.

Problems and challenges

(1) There are still some problems in the mechanical propulsion system of marine internal combustion engine, such as large noise, small speed range and poor flexibility.

Compared with the mechanical propulsion system, the marine electric propulsion system directly driven by the motor has the advantages of wide speed range, large driving torque, easy forward and reverse rotation, small size, flexible layout, convenient installation, easy maintenance, low vibration and noise.

(2) Especially in recent years, with the rapid development of power electronic devices, converter technology, transmission control system, new energy and new materials, the marine electric propulsion system is undergoing tremendous changes.

As one of the important application fields of high-power electric drive control system, marine electric propulsion system has not received due attention and attention due to its professional particularity, which makes the gap between domestic research in this field and foreign advanced level more obvious.

(3) With the exhaustion of global oil resources, the internal combustion engine will gradually withdraw from the historical stage, and people must find new energy sources and their power devices within about 60 years before the exhaustion of oil.

This is one of the major problems and challenges facing mankind in the 2 1 century. Therefore, people have been trying to find new and renewable energy sources with high energy utilization efficiency and no pollution to the environment and their utilization methods.

This paper attempts to summarize the history, present situation and development of marine electric propulsion system from the aspects of system structure, converter mode, control method and application of power electronic devices. On this basis, according to the author's many experiences in international cooperation and exchange, some problems worthy of attention in the future development of marine electric propulsion system are put forward for reference by peers, and it is hoped that more scholars will pay attention to and devote themselves to the new research field of power electronics and transmission control.

2. History-Review the development of ship electric propulsion.

6? 1 The history of ship electric propulsion can be traced back to 1860. The first ship in the world was powered by batteries, and its motor was straight.

The connected electric propulsion submarine is put into use.

6? 1 In the 20th century, most submarines used electric propulsion. When a conventional submarine sails on the water, the diesel engine-generator set charges the battery and supplies power to the motor to drive the ship. When sailing underwater, the battery is powered and the motor drives the ship. Nuclear submarines use atomic energy to generate electricity and motor to drive propulsion.

In the 1920s, six Mexican-class warships (40,000 HP) and two aircraft carriers (180,000 HP) built by the United States adopted the electric propulsion system driven by steam turbine-generator-motor.

During World War II, the United States alone built more than 300 warships and transport ships driven by diesel engines-generators-motors.

Since then, icebreakers, scientific research vessels and other special-purpose vessels have also been equipped with electric propulsion systems. During this period, Ward -DC speed control system, namely G-M system, is widely used in the electric propulsion system of ships.

6? In 65438+70s, thyristor converter replaced Ward-Leonard converter as the main speed regulation mode of marine electric propulsion system.

Since 1980s, with the continuous progress of power electronic devices, the AC speed control system with semiconductor switch turned off has gradually replaced the thyristor DC speed control system and become the main speed control mode of marine electric propulsion system.

6? 1 During this period, AC -DC- AC frequency converter was adopted in the electric propulsion system in 1980s, and the AC speed regulation mode was driven by induction motor or synchronous motor. In 1990s, AC-AC frequency converter was used to supply power, and synchronous motor was used to drive AC speed regulation.

Enlightenment from history

From the historical track of the development of marine electric propulsion system, it can be seen that every progress and breakthrough is basically synchronous and closely related to the development of power electronics technology and transmission control system.

However, because marine electric propulsion system is mostly used in military or special occasions (although it is currently used on large ferries and luxury passenger ships), this important application field is unfamiliar to scholars engaged in power electronics and transmission control research.

3. Present situation-main forms of ship electric propulsion

6? 1 system structure

6? 1 drive mode

6? 1 speed regulation method

6? 1 control strategy

6? 1 system example

3. 1 system structure

Basic structure of ship electric propulsion;

The motor drives the propeller.

6? 1 High-speed irreversible heat engine is adopted, which reduces the weight and volume of marine power plant;

6? 1 The required large-capacity power supply can be easily obtained through generator connection, which improves the reliability of the system;

6? 1 allows the selection of the optimal speed and diameter of the ship propeller, which shortens the length of the connecting shaft;

6? 1 has high economic performance when sailing at medium and low speeds and ships often stop;

The mechanical characteristics required by the propulsion motor can be obtained to meet the requirements of different navigation conditions;

6? 1 Simple control and good maneuverability;

6? 1 can eliminate the vibration and impact of the propeller on the heat engine.

3.2 driving mode

6? 1 classification of marine electric propulsion system

6? 1 Multi-motor combined drive mode

Classification of marine electric propulsion system

(1) Driving mode (FPP) in which the variable speed motor drives the fixed-pitch propeller,

(2) a constant-speed motor drives a variable-pitch propeller,

According to the power required by the ship, one motor can be dragged alone or several motors can be dragged together.

Multi-motor combined drive mode can be divided into series drive mode or parallel drive mode.

(a) Single-propeller double-machine series drive mode;

(b) Single-propeller dual-machine parallel drive mode;

(c) Double-propeller and double-machine series drive mode;

(d) Dual-propeller dual-machine parallel drive mode.

Several marine electric propulsion modes are a new decentralized drive mode, and their advantages are as follows:

6? 1 propeller rotates 360 degrees, which can generate thrust in any required direction without rudder and side thruster, greatly improving the maneuverability and maneuverability of the ship;

6? 1 reduces the stand-alone capacity of the drive system (motor and frequency converter);

6? 1 the stern shaft, reducer and steering gear are removed, which simplifies the installation and saves the cabin space, making the hull design and spatial layout flexible;

6? 1 Reduce ship vibration and noise;

6? 1 Reduce hull resistance by 5- 10% and improve transportation efficiency 15% (including increasing speed, reducing fuel consumption and reducing cost).

For more information about ............., please visit/2009/1228/16945.html.