With the acceleration of urbanization construction in China, the number of high-rise and small high-rise buildings is gradually increasing, and elevators, as vertical transportation vehicles in cities, are also constantly increasing. According to relevant data, as of May 2005, there were 15000 elevators in use in Tianjin. About 30% of these elevators are controlled by relays that have been in use for over ten years. These types of elevators have high energy consumption, high failure rates, poor safety performance, and some have significant safety hazards, directly affecting the safety of passengers.

The Ministry of Construction has issued a document titled "Several Regulations on Improving the Quality of Elevators" based on elevators with more such problems, requiring technical transformation of old elevators in use. From a national perspective, relevant departments in Shanghai have performed well in implementing the above documents and have basically completed the renovation of old style elevators. Major cities such as Beijing, Guangzhou, and Tianjin are entering a peak period of renovation of old style elevators.

Due to the significant difference in funding between replacing a new elevator and renovating an old elevator, but with similar operational results, we predict that renovating an old elevator has broad market prospects and development space. Early elevator renovations were limited to transforming old-fashioned relay elevators into imported programmable controllers, which involved developing software programs with the same characteristics and functions as the original elevators based on their logical relationships. The content of the transformation is also very simple, changing the original AC dual speed to AC dual speed, but such transformation will not take many years. Today's users not only demand that elevators be renovated, but also that passengers have a sense of comfort and safety. Elevators pursue zero malfunctions and have network computer control. In this way, the entire renovation process of the elevator will require a lot of technical support to complete.

The company conducted a detailed survey and testing of three old-fashioned elevators, recorded relevant data, and conducted in-depth research on the control and driving systems, mechanical parts, as well as the host and door machine systems of the original elevators. It was found that the original elevators had the following common problems:

1. The control system of elevators was from the early days of Xunda, not the widely used microcomputer serial communication today;

2. The elevator drive system is a VF governor drive system, not a VVVF variable frequency drive specifically designed for elevators;

3. The door machine control is controlled by parallel resistors, not the widely used VVVF variable frequency control door machine today;

4. Excessive service life of elevators may lead to serious wear and tear;

5. The elevator does not have a direct stopping function, crawls for a long time, and consumes a lot of electricity;

6. Elevators often experience safety malfunctions such as closing people, slipping, and disorderly floors, which directly affect the safety of passengers.

The company has developed detailed configuration plans and construction renovation plans for the three renovated elevators, ensuring that the project renovation is completed without affecting normal work. A consensus has been reached and a renovation agreement has been signed, which includes the world's advanced network elevator serial communication technology. The system is equipped with the following functions:

1. The network type adopts CAN BUS serial communication technology, connecting the main control CPU and the elevator car CPU to form the elevator network system through CAN BUS connection;

2. The system adopts the principle of distance deceleration, allowing the elevator to stop directly, greatly saving patients time spent on medical treatment;

3. The automatic fault recording function greatly reduces maintenance time;

4. The full serial communication of elevators greatly reduces the wiring and wiring of renovated elevators, reduces construction time, and also saves users a lot of costs;

5. The system is equipped with a LCD display operator, providing a rich human-computer interaction interface. Debugging and maintenance personnel can not only directly observe the floor position, running direction, running speed, automatic/driver/maintenance status, instructions for each floor, call registration status, and the status of each CPU board input port through the LCD display, but also visually see the speed command curve and speed feedback curve during elevator operation.

At the same time, the operator can also directly set the basic parameters of the elevator, such as the number of floors, rated speed, encoder pulse number, base station position, single elevator/parallel/group control, etc., which brings great convenience to debugging and maintenance. The driving system adopts the iAStar-S3 series elevator specific frequency converter produced by Shanghai Xinshida Company, which is a new type of frequency converter developed based on the characteristics of elevator transportation. It adopts a 32-bit motor specific digital signal microprocessor DSP, programmable ultra large scale logic device CPLD, and intelligent power module IPM. It uses motor full vector speed regulation technology and combines the characteristics of the potential energy load model to ensure stable, comfortable, and efficient elevator operation.

Innovative load free sensor startup compensation technology enables elevators to have excellent startup comfort without the need for weighing devices. Integrated elevator operation control signals, automatically generated the optimal operating curve based on dynamic stop destination layer instructions, achieved direct stop, and improved elevator operation efficiency. New PWM dead zone compensation technology effectively reduces motor noise and reduces motor losses. After elevator installation, there is no need for on-site elevator self-tuning or complex on-site debugging. The elevator frequency converter can achieve excellent comfort and meet the operational requirements of the elevator, and can be directly put into use. Ensuring the excellence, stability, and consistency of elevator operation quality. The door machine system adopts our new Shida company type VVVF variable frequency door machine with no dead angle full speed measurement.

So far, the elevator operation has been smoother, more comfortable, and safer than before the renovation, thus receiving unanimous praise from hotel leaders and passengers. In recent years, the elevator control system produced by the company has been used in various brands of elevators in multiple units for elevator renovation and new elevators, and has received praise from users. We believe that only by being constructed by excellent engineering companies and adopting excellent elevator control systems and elevator drive systems, can the modernization of elevators achieve satisfactory results, have a very stable market, and have a bright future.