基于PLC的电梯控制系统的设计英文文献

Design and Practice of an Elevator Control System Based on PLC Xiaoling Yang1, 2, Qunxiong Zhu1, Hong Xu1

1College of Information Science &Technology,

Beijing University of Chemical Technology, Beijing 100029, China

2 Automation College of Beijing Union University,Beijing,100101, China

yxl_lmy@ , zhuqx@,

Abstract

This paper describes the development of 2 nine-storey elevators control system for a residential building. The control system adopts PLC as controller, and uses a parallel connection dispatching rule based on "minimum waiting time" to run 2 elevators in parallel mode. The paper gives the basic structure, control principle and realization method of the PLC control system in detail. It also presents the ladder diagram of the key aspects of the system. The system has simple peripheral circuit and the operation result showed that it enhanced the reliability and performance of the elevators.

1. Introduction

With the development of architecture technology, the building is taller and taller and elevators become important vertical transportation vehicles in high-rise buildings. They are responsible to transport passengers, living, working or visiting in the building, comfortable and efficiently to their destinations. So the elevator control system is essential in the smooth and safe operation of each elevator. It tells the elevator in what order to stop at floors, when to open or close the door and if there is a safety-critical issue.

The traditional electrical control system of elevators is a relay-controlled system. It has the disadvantages such as complicated circuits, high fault ratio and poor dependability; and greatly affects the elevator’s running quality. Therefore, entrusted by an enterprise, we have improved electrical control system of a relay-controlled elevator in a residential building by using PLC. The result showed that the reformed system is reliable in operation and easy for maintenance.

This paper introduces the basic structure, control principle and realization method of the elevator PLC control system in detail.

2. System structure

The purpose of the elevator control system is to manage movement of an elevator in response to user’s requests. It is mainly composed of 2 parts:

2.1. Electric power driving system

The electric power driving system includes: the elevator car, the traction motor, door motor, brake mechanism and relevant switch circuits.

Here we adopted a new type of LC series AC contactors to replace the old ones, and used PLC’s contacts to substitute the plenty of intermediate relays. The circuits of traction motor are reserved. Thus the original control cabinet’s disadvantages, such as big volume and high noise are overcome efficiently.

2.2. Signal control system

The elevator’s control signals are mostly realized by PLC. The input signals are: operation modes, operation control signals, car-calls, hall-calls, safety/protect signals, door open/close signal and leveling signal, etc. All control functions of the elevator system are realized by PLC program, such as registration, display and elimination of hall-calls or car-calls, position judgment of elevator car, choose layer and direction selection of the elevator, etc. The PLC signal control system diagram of elevator is showed in Figure 1.

Figure 1 PLC signal control system diagram

2.3. Requirements

The goal of the development of the control system is to control 2 elevators in a 9-storey residential building.

For each elevator, there is a sensor located at every floor. We can use these sensors to locate the current

2008 Workshop on Power Electronics and Intelligent Transportation System