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2022-08-05
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Design of multi-functional variable frequency energy-saving control system for escalator based on PLC

Abstract: Taking Omron cpm1a-20cdr-a-v1 PLC and MD320 inverter of Huichuan company as examples, this paper introduces the design of multi-functional variable frequency energy-saving control system for escalator. Combined with the basic principle of escalator, the selection of accessories and hardware circuit design are carried out, and the device and test of system control range sensor and power supply are designed

key words: escalator; PLC; Frequency conversion energy saving; Control system

1 introduction

escalators are widely used in large shopping malls, supermarkets, airports, subways, hotels and other places. Most escalators work in the rated operation state when the passenger flow is large. When there are no passengers, they still screw one M20 lifting screw into the rib hole and operate at the rated speed. It has the disadvantages of high energy consumption, serious mechanical wear and low service life. The energy-saving control system combining LC and frequency conversion control of P Sharp Electronics R & D (Nanjing) Co., Ltd. has become the development direction of escalator control technology

the escalator with energy-saving effect has the following characteristics:

(1) when no one takes the elevator, the escalator will automatically transition to energy-saving operation and run at 1/5 rated speed (the function of escalator automatically stopping when no one takes the elevator can be selected)

(2) when someone takes the ladder, the ladder will automatically and smoothly transition to the rated speed immediately

(3) due to the low speed during energy-saving operation, the wear of the mechanical part is greatly reduced, which relatively prolongs the service life of the escalator

(4) the adoption of frequency conversion technology greatly reduces the impact on electricity when the escalator is started

at present, most energy-saving escalators have single form and function, and can only realize simple fast and slow cycle or fast stop cycle. The highlight of the system design is that the fast/slow cycle and fast/slow stop cycle can be freely selected through the program. The system also integrates the functions of up/down step loss, anti drive chain breaking, anti reverse and fault protection output, and can monitor the running status of the escalator through the status of the internal auxiliary relay in the program. The on-site commissioning is very convenient

2 escalator variable frequency energy saving control mode

2.1 variable frequency non self starting (fast slow cycle)

2.1.1 function description

control the running speed of the escalator by increasing the frequency converter. When there are passengers on the escalator, the escalator runs at a high speed (such as rated speed) to increase the passenger flow. When the passenger detection device does not detect the passage of passengers within a period of time, The escalator starts to slow down and turns to low-speed operation (for example, 0.2m/s, parameters can be set). At this time, it is always in standby operation, that is, non self starting energy saving

2.1.2 operation state description

variable frequency control, low speed when no one is present, high speed when there are people. The high-speed operation time is recorded as TQ and can be set through PLC program. The specific time depends on the lifting height and speed of the ladder

2.1.3 operation steps

(1) when the escalator stops waiting when it is powered on and starts running in a direction (such as ascending), the escalator starts energy-saving operation at a low speed and enters standby waiting

(2) the passenger detection device in the lower machine room detects whether someone has passed. When someone has passed, the high-speed operation time counter (recorded as TC) in the controller is cleared, and the escalator starts to slowly accelerate to high-speed operation

(3) the high-speed operation time counter (recorded as TC) starts counting. When tc

(4) when no one takes the elevator for a period of time, that is, TC ≥ TQ, the escalator starts to slow down and enter the low-speed operation standby state, so it runs in a cycle

Figure 1 shows the escalator speed cycle control sequence diagram

Figure 1 escalator speed cycle control sequence diagram

2.1.4 function realization

the passenger detection device installed at the entrance of the escalator detects whether the test piece is clamped, the screws are tightened by hand, and the pressure (pneumatic, hydraulic) of air and oil is used to fix the test piece

2.2 variable frequency auto start (fast and slow stop cycle)

2.2.1 function description

control the running speed of the escalator by increasing the frequency converter. When there are passengers on the escalator, the escalator runs at a high speed (such as the rated speed) to increase the passenger flow. When the passenger detection device does not detect the passage of passengers within a period of time, the escalator starts to slow down to run at a low speed (such as 0.2m/s, parameters can be set), When the passenger detection device fails to detect the passenger taking the elevator for a period of time, the escalator starts to enter the stop operation waiting state, which is self starting energy saving

2.2.2 description of operation status

variable frequency control, stop when no one takes the ladder for a long time, and run at high speed when someone takes the ladder. The high-speed operation time is recorded as TQ and the low-speed operation time is ts. the two parameters can be set through PLC program. The specific time depends on the lifting height and speed of the ladder

2.2.3 operation steps

(1) when the escalator is powered on and stops waiting, and there is a direction (such as upward) to start running, then the escalator enters the upward stop waiting operation

(2) the photoelectric detection device in the lower machine room detects whether someone has passed. When someone has passed, the high-speed operation time counter (recorded as TC) in the controller is cleared, and the escalator begins to slowly accelerate to high-speed operation

(3) the high-speed operation time counter (recorded as TC) starts timing. When tc

(4) when no one takes the ladder for a period of time, that is, TC ≥ TQ, the escalator starts to slow down and enter the low-speed operation state

(5) the low-speed operation time counter (recorded as TSC) starts timing when TSC

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