Detailed Explanation of Elevator Control System

The Elevator control system is a core technology system used to manage and coordinate the operation of elevators. It mainly realizes the functions of elevator start, speed regulation, parking, safety protection and authority management. It is composed of hardware equipment and software logic to ensure that the elevator responds to passenger needs efficiently and safely. 

The hardware of the elevator control system consists of the car control panel, hall door signal, PLC, inverter, and speed regulation system. The inverter only completes the speed regulation function, and the logic control part is completed by the PLC.

●The PLC is responsible for processing the logical relationship of various signals, thereby sending start and stop signals to the inverter. At the same time, the inverter also transmits its own working status to the PLC to form a two-way communication relationship. The system is also equipped with a rotary encoder and PG card coaxially connected to the motor to complete speed detection and feedback, forming a speed closed loop and a position closed loop. In addition, the system must also be equipped with a braking resistor. When the elevator is decelerating, the motor is in a regenerative power generation state, feeding back electric energy to the inverter to suppress the increase of DC voltage.

●The elevator system is a six-story, six-station system. The hoistway is equipped with a car, safety window, counterweight, safety clamp, sensor, leveling, floor magnetic isolation board, terminal board and various action switches. The bottom of the car is equipped with overload and full load switches. Each floor outside the hoistway is equipped with a floor display, elevator call button and indication, and a base station electric lock on the first floor.

There is a pit, buffer and speed limiter rope pulley at the bottom of the track; the car is equipped with a hall door, car door, door machine mechanism, door knife mechanism, door lock mechanism, door machine power supply circuit, safety touch panel, car top emergency stop, maintenance, slow up and slow down switches and car top lighting, car top connection box, floor display above the car door and hall door, and internal selection button and indication, door opening and closing button, alarm button, overload and full load indication on the right side of the car door.

●DC elevators have the characteristics of fast speed, good comfort and high leveling accuracy. This is because the DC traction system has good speed regulation performance and a wide speed regulation range. The speed regulation methods of DC motors include changing the terminal voltage UA, adjusting the adjustment resistor Rtj, and changing the excitation magnetic field.

●There are two types of traction systems for DC elevators:

(1) A traction system of a generator-motor with thyristor excitation composed of a generator set. Access control elevator control system.

(2) A thyristor-motor traction system directly powered by thyristors.

Both use the method of adjusting the motor terminal voltage Ua for speed regulation. The former is to adjust the speed by adjusting the excitation of the generator to change the output voltage of the generator, so it is called a thyristor excitation system. The latter uses a three-phase thyristor rectifier to convert AC into controllable DC to supply the speed regulation system of the DC motor, eliminating the generator set, thereby reducing the cost and making the structure more compact. DC elevators are often used in high-rise buildings with high speed requirements due to their large number of equipment, complex maintenance and high cost. They have the characteristics of good comfort and high leveling accuracy, and have speeds of 1.5-1.75m/s for fast elevators and 2.5-5m/s for high-speed elevators.