1 Introduction
The rapid development of China's real estate industry has led to the widespread installation of elevators in various buildings, including ordinary residential buildings, which has spurred the rapid growth of China's elevator industry in recent years. As people's living standards and quality of life improve, they have higher demands for elevator safety and comfort. Traditional elevators relied on a main controller to collect status signals from peripheral components, which then controlled the drive unit to move the traction machine. This resulted in complex wiring, difficulties in troubleshooting, and a high demand for after-sales technical support. While focusing on improving their quality of life, people also crave more convenient and safer vertical transportation services, making elevators with integrated control systems increasingly popular.
2. Basic characteristics of integrated control systems
The integrated control system has the following characteristics: The integrated control and drive technology not only fundamentally improves the elevator's operational performance and reliability, but also brings unparalleled benefits to customers in terms of floor space, peripheral configuration, installation, commissioning, and manufacturing costs. The application of a full suite of the latest technologies, including N-curve operation, direct docking, building intelligence, remote monitoring, SMS repair reporting, PDA debugging, and battery operation, provides a new direction for elevator control development.
3 Control System Planning
3.1 Concept of Integrated Control System
Traditional elevator control systems mostly employ a combination of microcomputer boards (or PLCs) and frequency converters; while integrated elevator control systems organically combine and highly integrate elevator logic control with frequency converter drive control. The functions of the elevator's proprietary microcomputer control board are integrated into the frequency converter's control functions, and on this basis, the frequency converter's elevator drive function is fully optimized.
Figure 1 Block diagram of the integrated IED control system
The integrated elevator control system mainly consists of a main controller, floor call system, and floor display system. The main controller highly integrates the elevator's logic control and drive control functions, receiving and processing hoistway information such as leveling and deceleration, as well as other external signals, and outputting control to the running contactor and brake contactor. The block diagram of the system components is shown in Figure 1.
3.2 Integrated Planning of IED Series Elevators
Delta's IED series elevator integrated machines achieve true integration of the main controller and drive controller through a single, highly integrated MCU, unlike many previous integrated machines that used two MCUs for logic control and drive control respectively. Using a single MCU for logic and drive control offers many advantages: direct stopping is possible with a single MCU; all digital signals are processed together for high speed; independent operation by a single MCU results in a low failure rate; and the absence of communication issues between MCUs eliminates processing delays; there is no interference due to the lack of data transfer between MCUs; and the single chip saves space, resulting in a compact size. Furthermore, the IED series elevator integrated machines feature technologies such as direct commissioning without load removal and perfect start-stop without weighing compensation.
3.3 Main Control Board Input/Output Port Planning
The main control board's input ports employ optocoupler isolation, while the output ports utilize relay outputs to accommodate different functions. The corresponding communication signals utilize CANbus and Modus communication methods. The appendix shows the definitions of the main control board's input and output ports.
Appendix: Definitions of Main Control Board Input and Output Ports
3.4 Display Panel Planning
The communication signal adopts the Modus communication method. The display panel uses a 4-bit XH-4 interface for input of up call, down call, elevator lock, and fire alarm buttons, as shown in Figure 2.
Figure 2 Display panel layout
3.5 Instruction Board Planning
The communication signal adopts the CAN bus communication method. A single command board uses a 4-bit XH-4 interface for inputting the buttons for floors 1-16 inside the car. Through cascading of command boards, it can be expanded to 64 floors. It also integrates inputs for the car's open and close door buttons, as well as interfaces for firefighter, driver, reversing, and express switches, as shown in Figure 3.
Figure 3 Command Board Planning
3.6 Car roof panel design
The car top panel integrates the system's door opening and closing signal outputs to the door operator controller, and the door operator controller outputs door opening and closing position signals back to the system. It also integrates analog weighing signals, car arrival bell signals, car communication signals, and car fan and lighting energy-saving control signals, as shown in Figure 4. Furthermore, its terminals are designed with multi-functional input capabilities, allowing for flexible parameter definition and adjustment of the functions of each terminal.
Figure 4 Car roof panel planning
4 Control System Design
4.1 Main Circuit
Figure 5 Main circuit
The main circuit in Figure 5 consists of an integrated controller, a safety contactor KAD, a running contactor KMY, and a traction motor MO.
4.2 Input Port Design
The low-voltage input port circuit (as shown in Figure 6) is completely based on the optocoupler input circuit of a general PLC, effectively controlling signal interference.
Figure 6 Low-voltage input circuit
4.3 No automatic weighing compensation design at startup
Traditional variable frequency drives (VFDs) often require a start-up compensation function to improve start-up comfort. The purpose is to apply appropriate torque to the motor based on the elevator's intended direction of travel, even when the elevator load is unknown, ensuring a smooth start and minimizing slippage during startup, thus increasing start-up comfort. The IED series integrated unit pre-generates a basic compensation control quantity in its programming. After the VFD outputs this quantity, it quickly determines the motor's actual operating condition by continuously monitoring changes in the encoder output at startup. Based on this pre-generated basic compensation control quantity, it continuously and dynamically adjusts the VFD output, resulting in a smoother start-up process.
5 applications
The IED series integrated elevator control system underwent a complete test in an office building of a company in Changshu, Jiangsu Province. The test involved a three-story, three-stop glass-car, machine-room-less elevator using a Tongrun GTW2-81P0 main unit. The elevator had a load capacity of 800kg, a rated speed of 1.0m/s, a traction machine with a rated power of 5.5kW, a rated voltage of 380V, a rated current of 12.8A, a rated frequency of 16Hz, and a rated speed of 96r/min. The traction machine was equipped with a Heidenhain 1387 (sin/cos type) encoder as standard. During the test, the IED series integrated elevator control system successfully achieved control of the permanent magnet synchronous machine-room-less elevator, as shown in Figure 7.
Figure 7. On-site test photos
6. Conclusion
Practice has proven that elevator control systems using the IED series are reliable and operate stably. Furthermore, their ease of use has made them a mainstream choice for many elevator manufacturers.
About the Author
Lu Xiaochun (1982-) is a male engineer who currently works at Suzhou Yuanzhi Technology Co., Ltd., and is mainly engaged in the design of elevator control systems.
References
[1] National Elevator Standardization Technical Committee. GB7588-2003 Safety Specifications for Elevator Manufacturing and Installation [M]. Beijing: China Standards Press, 2004.
[2] Delta Electronics Co., Ltd. Basic concepts of elevator applications and IED debugging steps [Z]. 2010(12).
[3] Delta Electronics Industrial Co., Ltd. Delta Elevator Integrated Machine (IED) User Manual [Z]. 2012.
