Elevator control loop based on safe torque turn-off technology

Abstract

The utility model belongs to the technical field of elevators, and particularly discloses an elevator control loop based on the safety torque turn-off technology, which comprises an elevator main control board, a frequency converter with an STO function, an interface board and a control contactor, the output end of the frequency converter is connected with a traction machine, and the input end of the frequency converter is connected with the output end of the control contactor. The input end of the control contactor is connected with a power source, and the elevator main control board is connected with the interface board through an interface circuit. According to the utility model, through the control loop consisting of the elevator main control board, the frequency converter with the STO function, the interface board, the control contactor, the safety loop and the traction machine, the existing frequency converter is utilized to send a safety suppression pulse to cut off torque output, so that an elevator operation contactor is canceled; the influence of the action noise of the contactor on residents when the elevator is started each time is effectively solved, and the elevator taking comfort is improved.

Description

Technical Field

[0001] This utility model relates to the field of elevator technology, specifically to an elevator control circuit based on safe torque shut-off technology. Background Technology

[0002] The elevator drive circuit is an important component of the elevator system. It is responsible for controlling the operation of the elevator traction machine, thereby driving the elevator car to rise and fall.

[0003] Currently, the existing elevator drive circuit method is as follows: Figure 5 As shown, the input terminal of the frequency converter is connected to the power supply R, S, and T through the three sets of main contacts of the power contactor, and the output terminal of the frequency converter is connected to the three-phase coils U, V, and W of the traction machine through the three sets of main contacts of the running contactor. When the elevator is powered on and the software detects that everything is normal, the power contactor coil is turned on, its main contacts are energized, and the input side of the frequency converter's main circuit is connected to the power supply. When the elevator needs to run, the frequency converter outputs torque, the main contacts of the running contactor are energized, the output side of the frequency converter's main circuit is connected to the three-phase coils of the traction machine, the traction machine brake is opened, and the frequency converter drives the elevator to run. When a fault occurs during elevator operation, the frequency converter stops outputting torque, the main contacts of the running contactor are released, disconnecting the connection between the frequency converter's output side and the traction machine, the traction machine brake is closed, and the elevator stops running.

[0004] However, since the frequency converter is connected to the power supply via a power contactor and to the traction machine via a running contactor, the running contactor actuates every time the elevator runs. This frequent elevator starts and stops generate noise during operation, especially the noise from the contactor actuation inside the control cabinet, which can affect residents, reduce their elevator experience, and impact their living comfort and quality of life. Therefore, we need to propose an elevator control circuit based on safe torque shut-off technology to solve the above-mentioned problems, effectively reduce the noise from the contactor actuation during elevator operation, improve passenger comfort, and reduce the impact on residents. Utility Model Content

[0005] The purpose of this invention is to provide an elevator control circuit based on safe torque shut-off technology, which can effectively solve the contactor operation noise during elevator operation, improve passenger comfort, and reduce the impact on residents, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: an elevator control circuit based on safe torque shutdown technology, comprising an elevator main control board, a frequency converter with STO function, an interface board, and a control contactor. The output terminal of the frequency converter is connected to a traction machine, and the input terminal of the frequency converter is connected to the output terminal of the control contactor. The input terminal of the control contactor is connected to a power supply. The elevator main control board is connected to the interface board through an interface circuit. The elevator main control board is provided with a feedback interface for monitoring contactor operation and a safety circuit monitoring input interface. The interface board is provided with a safety circuit monitoring point for connection to the safety circuit. The elevator main control board is also provided with a relay control output interface and an STO command output interface. The interface board is also provided with a control auxiliary relay #6Z and a brake auxiliary relay #B4Z. The relays on the interface board and the contactor in the safety circuit are connected to the traction machine main circuit and the brake circuit.

[0007] Preferably, a safety circuit is formed by the coil of the control contactor (2), the coil of the brake contactor #B4, the contact of the control auxiliary relay #6Z, and the contact of the brake auxiliary relay #B4Z. One end of the normally open contact of the control auxiliary relay #6Z is provided with a safety circuit monitoring point for connection to the interface board. The other end of the normally open contact of the control auxiliary relay #6Z is connected to the A1 end of the control contactor coil and one end of the normally open contact of the brake auxiliary relay #B4Z, respectively. The other end of the normally open contact of the brake auxiliary relay #B4Z is connected to the A1 end of the brake contactor #B4 coil. The A2 end of the control contactor coil is connected in parallel with the A2 end of the brake contactor #B4 coil.

[0008] Preferably, one end 14 of the first set of normally open contacts of the brake contactor #B4 is connected to one end 54 of the normally open contact of the control contactor, the other end 13 of the first set of normally open contacts of the brake contactor #B4 is connected to one end of the traction machine brake coil, one end 34 of the second set of normally open contacts of the brake contactor #B4 is connected to the other end of the traction machine brake coil, and the other end 33 of the second set of normally open contacts of the brake contactor #B4 and the other end 53 of the normally open contact of the controller contactor are both connected to the brake power supply in the brake circuit.

[0009] Preferably, one end of the three main contacts of the control contactor is connected to the R, S and T terminals of the frequency converter, respectively, and the other end of the three main contacts of the control contactor is connected to the R, S and T three-phase terminals of the power supply, respectively. The U phase, V phase and W phase of the traction machine coil are connected to the U terminal, V terminal and W terminal of the frequency converter, respectively.

[0010] Preferably, the interface board is provided with a transistor XI connected to the safety circuit monitoring point, one end of the optocoupler *I at the safety circuit monitoring point is connected to the base of the transistor XI, and the other end of the optocoupler *I at the safety circuit monitoring point is connected to VCC. The interface board is also provided with a control auxiliary relay #6Z and a brake auxiliary relay #B4Z.

[0011] Preferably, the interface circuit includes a 6Z interface for connecting to the control auxiliary relay #6Z, a B4Z interface for connecting to the brake auxiliary relay #B4Z, and an XI interface for connecting to the optocoupler *I at the safety circuit monitoring point, and the interface circuit on the interface board is configured in correspondence with the interface circuit on the elevator main control board.

[0012] Preferably, the feedback interface is configured as a CH6 interface, and the safety circuit monitoring input interface includes a CHB4 interface and a CA2- interface. The CH6 interface is connected to one end 61 of the normally closed contact of the control contactor, the CHB4 interface is connected to one end 21 of the normally closed contact of the brake contactor #B4, and the CA2- interfaces are connected to the other end 22 of the normally closed contact of the brake contactor #B4 and the other end 62 of the normally closed contact of the control contactor.

[0013] Preferably, the control output interface of the relay includes an output interface 6Z, an output interface B4Z, and an output interface X0. The output interface 6Z is connected to the coil of the control auxiliary relay #6Z through a corresponding interface on the interface board. The output interface B4Z is connected to the coil of the brake auxiliary relay #B4Z through a corresponding interface on the interface board. The output interface X0 is connected to the IPM drive interface of the frequency converter and is used to output STO commands.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This utility model uses a control circuit consisting of an elevator main control board, a frequency converter with STO function, an interface board, a control contactor, a safety circuit, and a traction machine. It utilizes the existing frequency converter to send a safety suppression pulse to cut off the torque output, thereby eliminating the elevator running contactor. This effectively solves the problem of contactor operation noise affecting residents every time the elevator starts, and improves the comfort of riding the elevator.

[0016] 2. This utility model sets a control contactor at the input end of the frequency converter. When a sudden fault occurs during elevator operation, especially when the safety circuit is disconnected, the coil power supply of the control contactor is cut off, thereby cutting off the electrical connection between the input end of the frequency converter and the power supply. At the same time, it also cuts off the electrical connection between the traction machine brake and the braking power supply, ensuring that the drive circuit of the traction machine and the brake is cut off in time, ensuring that the elevator stops immediately. This allows for safer and more reliable elevator operation control with the help of existing contactors without increasing the elevator material cost. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structural connection of the elevator drive circuit of this utility model;

[0018] Figure 2 This is a schematic diagram of the structural connection of the safety circuit of this utility model;

[0019] Figure 3 This is a schematic diagram of the structural connection of the elevator control circuit of this utility model;

[0020] Figure 4 This is a schematic diagram of the control circuit of the traction machine brake of this utility model;

[0021] Figure 5 This is a schematic diagram of an elevator drive circuit in the prior art.

[0022] In the diagram: 1. Frequency converter; 2. Control contactor; 3. Elevator main control board; 4. Interface board; 5. Traction machine. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Please see Figure 1-4This utility model provides a technical solution: an elevator control circuit based on safe torque shutdown technology, including an elevator main control board 3, a frequency converter 1 with STO function, an interface board 4, and a control contactor 2. The output end of the frequency converter 1 is connected to a traction machine 5, and the input end of the frequency converter 1 is connected to the output end of the control contactor 2. The input end of the control contactor 2 is connected to a power supply. The elevator main control board 3 is connected to the interface board 4 through an interface circuit. The elevator main control board 3 is provided with a feedback interface for monitoring contactor operation and a safety circuit monitoring input interface. The interface board 4 is provided with a safety circuit monitoring point for connection to the safety circuit. The elevator main control board 3 is also provided with a relay control output interface and an STO command output interface. The interface board 4 is also provided with a control auxiliary relay #6Z and a brake auxiliary relay #B4Z. The relays on the interface board 4 and the contactors in the safety circuit are connected to the traction machine main circuit and the brake circuit.

[0025] The STO (Safe Torque Off) function of inverter 1 is a well-known technology. STO is a safety feature of inverter 1 that ensures inverter 1 does not output torque when stopped, thus preventing accidental elevator start-up. When the STO function is activated, inverter 1 cuts off the electrical energy supply to traction machine 5 to generate torque, thereby avoiding injury or damage caused by accidental elevator start-up. The STO function cuts off torque output by sending a safety suppression pulse to prevent accidental start-up of traction machine 5. Although the electrical connection between inverter 1 and traction machine 5 remains, and the DC bus remains energized, the power output is shut off. This design ensures rapid start-up when needed, and the dual-channel design with internal detection and verification improves safety and reliability.

[0026] A safety circuit is formed by the coil of the control contactor (2), the coil of the brake contactor #B4, the contact of the control auxiliary relay #6Z, and the contact of the brake auxiliary relay #B4Z. One end of the normally open contact of the control auxiliary relay #6Z is provided with a safety circuit monitoring point for connection to the interface board 4. The other end of the normally open contact of the control auxiliary relay #6Z is connected to the A1 end of the coil of the control contactor 2 and one end of the normally open contact of the brake auxiliary relay #B4Z. The other end of the normally open contact of the brake auxiliary relay #B4Z is connected to the A1 end of the coil of the brake contactor #B4. The A2 end of the coil of the control contactor 2 is connected in parallel with the A2 end of the coil of the brake contactor #B4.

[0027] One end 14 of the first set of normally open contacts of the brake contactor #B4 is connected to one end 54 of the normally open contact of the control contactor 2. The other end 13 of the first set of normally open contacts of the brake contactor #B4 is connected to one end of the traction machine brake coil. One end 34 of the second set of normally open contacts of the brake contactor #B4 is connected to the other end of the traction machine brake coil. The other end 33 of the second set of normally open contacts of the brake contactor #B4 and the other end 53 of the normally open contact of the controller contactor 2 are both connected to the brake power supply in the brake circuit.

[0028] One end of the three sets of main contacts of the control contactor 2 (i.e. Figure 1 Terminals 1, 3, and 5 of the control contactor 2 are respectively connected to the R, S, and T terminals of the frequency converter 1. The other end of the three sets of main contacts of the control contactor 2 (i.e., Figure 1 Terminals 2, 4, and 6 are respectively connected to the R, S, and T three-phase terminals of the power supply, and the U, V, and W phases of the traction machine 5 coil are respectively connected to the U, V, and W terminals of the frequency converter 1.

[0029] The interface board 4 is equipped with a transistor XI connected to the safety circuit monitoring point. One end of the optocoupler *I at the safety circuit monitoring point is connected to the base of the transistor XI, and the other end of the optocoupler *I at the safety circuit monitoring point is connected to VCC. The interface board 4 is also equipped with a control auxiliary relay #6Z and a brake auxiliary relay #B4Z, which facilitates the control contactor 2 to be operated through the elevator main control board 3.

[0030] The interface circuit includes a 6Z interface for connecting to the control auxiliary relay #6Z, a B4Z interface for connecting to the brake auxiliary relay #B4Z, and an XI interface for connecting to the optocoupler *I at the safety circuit monitoring point. The interface circuit on the interface board 4 is configured in a corresponding manner to the interface circuit on the elevator main control board 3, which facilitates the connection between the interface board 4 and the elevator main control board 3.

[0031] The feedback interface is set as CH6 interface, and the safety circuit monitoring input interface includes CHB4 interface and CA2- interface. CH6 interface is connected to one end 61 of the normally closed contact of control contactor 2, CHB4 interface is connected to one end 21 of the normally closed contact of brake contactor #B4, and CA2- interface is connected to the other end 22 of the normally closed contact of brake contactor #B4 and the other end 62 of the normally closed contact of control contactor 2.

[0032] The control output interface of the relay includes output interface 6Z, output interface B4Z, and output interface X0. The output interface 6Z is connected to the coil of the control auxiliary relay #6Z through the corresponding interface on the interface board 4. The output interface B4Z is connected to the coil of the brake auxiliary relay #B4Z through the corresponding interface on the interface board 4. The output interface X0 is connected to the IPM drive interface of the frequency converter 1 and is used to output STO command.

[0033] By installing a control contactor 2 at the input terminal of inverter 1, when a sudden malfunction occurs during elevator operation, especially when the safety circuit is disconnected, the coil power supply of the control contactor 2 is cut off. This disconnects the electrical connection between the input terminal of inverter 1 and the power supply, and simultaneously cuts off the electrical connection between the traction machine brake and the braking power supply. This ensures that the drive circuit of the traction machine 5 and the brake is promptly cut off, guaranteeing an immediate stop for the elevator. Although inverter 1 will also stop torque output at this time, the electronic components are susceptible to electromagnetic interference, and there is still a risk of malfunction in terms of reliability. The control contactor 2 compensates for the shortcomings of inverter 1's electronic components being susceptible to electromagnetic interference and reduced reliability. Combined with Safe Torque Turn-Off (STO) technology, it realizes a dual control circuit of software and hardware, eliminating noise while ensuring the safety and reliability of the elevator.

[0034] When the elevator is powered on, the safety circuit is activated, and the software detection is normal, the elevator main control board 3 outputs the 6Z control command. The coil of the control auxiliary relay #6Z on the interface board 4 is energized, and its normally open contact closes. The coil of the control contactor 2 in the safety circuit is energized, and its three sets of main contacts (1-2, 3-4, 5-6) close, connecting the input terminal of the frequency converter 1 to the power supply. Its normally open contact (53-54) closes, allowing the traction machine brake circuit to conduct. Its normally closed contact (61-62) opens, feeding back the completed action to the elevator main control board 3, forming a closed loop. At this time, the STO function cuts off the torque output by sending a safety suppression pulse to prevent the traction machine 5 from starting unexpectedly.

[0035] When the elevator needs to run, inverter 1 releases the safety torque shutdown command, the main control board outputs a torque command, inverter 1 outputs torque, the three-phase coils of traction machine 5 are energized, and pre-torque is generated on the main shaft of traction machine 5. The elevator main control board 3 outputs the B4Z control command, the coil of brake auxiliary relay #B4Z on interface board 4 is energized, and its normally open contact closes; the coil of brake contactor #B4 in the safety circuit is energized, its first set of normally open contacts (13-14) and second set of normally open contacts (33-34) close, brake coils BRAKE1 and BRAKE2 are energized, the traction machine brake opens, and the elevator runs. The normally closed contact (21-22) of brake contactor #B4 opens, feeding back the completion of the action to the elevator main control board 3, forming a closed loop.

[0036] When the elevator reaches the landing floor, the main control board B4Z control command is OFF. The coil of the brake auxiliary relay #B4Z on interface board 4 is de-energized, and its normally open contact opens. In the safety circuit, the coil of the brake contactor #B4 is de-energized, and its first set of normally open contacts (13-14) and second set of normally open contacts (33-34) open. Brake coils BRAKE1 and BRAKE2 are de-energized, the traction machine brake closes, and the elevator stops. The normally closed contact (21-22) of brake contactor #B4 closes, feeding back the completed action to the elevator main control board 3. The torque command is then OFF, and the STO function cuts off the torque output by sending a safety suppression pulse to prevent accidental start-up of the traction machine 5.

[0037] If a sudden malfunction occurs during elevator operation, especially if the safety circuit is disconnected, the monitoring point *I in the safety circuit will detect the circuit abnormality and transmit this status to the elevator main control board 3 through the XI interface of the interface board 4. The elevator main control board 3 will immediately stop the torque output and cut off the coil power supply of the control contactor 2 and the brake contactor #B4. This will open the three main contacts (1-2, 3-4, 5-6) and normally open contacts (53-54) of the control contactor 2, cutting off the power supply to the traction machine 5 coil and the brake coil, causing the elevator to stop immediately.

[0038] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An elevator control circuit based on safe torque shutdown technology, characterized in that: The system includes an elevator main control board (3), a frequency converter (1) with STO function, an interface board (4), and a control contactor (2). The output end of the frequency converter (1) is connected to a traction machine (5), and the input end of the frequency converter (1) is connected to the output end of the control contactor (2). The input end of the control contactor (2) is connected to a power supply. The elevator main control board (3) is connected to the interface board (4) through an interface circuit. The elevator main control board (3) is provided with a feedback interface for monitoring the action of the contactor and a safety circuit monitoring input interface. The interface board (4) is provided with a safety circuit monitoring point for connection to the safety circuit. The elevator main control board (3) is also provided with a relay control output interface and an STO command output interface. The interface board (4) is also provided with a control auxiliary relay #6Z and a brake auxiliary relay #B4Z. The relays on the interface board (4) and the contactors in the safety circuit are connected to the traction machine main circuit and the brake circuit.

2. The elevator control circuit based on safe torque shutdown technology according to claim 1, characterized in that: A safety circuit is formed by the coil of the control contactor (2), the coil of the brake contactor #B4, the contact of the control auxiliary relay #6Z, and the contact of the brake auxiliary relay #B4Z. One end of the normally open contact of the control auxiliary relay #6Z is provided with a safety circuit monitoring point for connection to the interface board (4). The other end of the normally open contact of the control auxiliary relay #6Z is connected to the A1 end of the coil of the control contactor (2) and one end of the normally open contact of the brake auxiliary relay #B4Z. The other end of the normally open contact of the brake auxiliary relay #B4Z is connected to the A1 end of the coil of the brake contactor #B4. The A2 end of the coil of the control contactor (2) is connected in parallel with the A2 end of the coil of the brake contactor #B4.

3. The elevator control circuit based on safe torque shutdown technology according to claim 2, characterized in that: One end 14 of the first set of normally open contacts of the brake contactor #B4 is connected to one end 54 of the normally open contact of the control contactor (2). The other end 13 of the first set of normally open contacts of the brake contactor #B4 is connected to one end of the traction machine brake coil. One end 34 of the second set of normally open contacts of the brake contactor #B4 is connected to the other end of the traction machine brake coil. The other end 33 of the second set of normally open contacts of the brake contactor #B4 and the other end 53 of the normally open contact of the controller contactor (2) are both connected to the brake power supply in the brake circuit.

4. The elevator control circuit based on safe torque shutdown technology according to claim 3, characterized in that: One end of the three main contacts of the control contactor (2) is connected to the R, S and T terminals of the frequency converter (1) respectively, and the other end of the three main contacts of the control contactor (2) is connected to the R, S and T three-phase terminals of the power supply respectively. The U phase, V phase and W phase of the traction machine (5) coil are connected to the U terminal, V terminal and W terminal of the frequency converter (1) respectively.

5. An elevator control circuit based on safe torque shutdown technology according to claim 4, characterized in that: The interface board (4) is provided with a transistor XI connected to the safety circuit monitoring point. One end of the optocoupler *I on the safety circuit monitoring point is connected to the base of the transistor XI, and the other end of the optocoupler *I on the safety circuit monitoring point is connected to VCC.

6. An elevator control circuit based on safe torque shutdown technology according to claim 5, characterized in that: The interface circuit includes a 6Z interface for connecting to the control auxiliary relay #6Z, a B4Z interface for connecting to the brake auxiliary relay #B4Z, and an XI interface for connecting to the optocoupler *I at the safety circuit monitoring point. The interface circuit on the interface board (4) is configured in correspondence with the interface circuit on the elevator main control board (3).

7. An elevator control circuit based on safe torque shutdown technology according to claim 6, characterized in that: The feedback interface is set as CH6 interface, and the safety circuit monitoring input interface includes CHB4 interface and CA2- interface. CH6 interface is connected to one end 61 of the normally closed contact of control contactor (2), CHB4 interface is connected to one end 21 of the normally closed contact of brake contactor #B4, and CA2- interface is connected to the other end 22 of the normally closed contact of brake contactor #B4 and the other end 62 of the normally closed contact of control contactor (2).

8. An elevator control circuit based on safe torque shutdown technology according to claim 7, characterized in that: The control output interface of the relay includes a 6Z output interface, a B4Z output interface, and an X0 output interface. The 6Z output interface is connected to the coil of the control auxiliary relay #6Z through the corresponding interface on the interface board (4). The B4Z output interface is connected to the coil of the brake auxiliary relay #B4Z through the corresponding interface on the interface board (4). The X0 output interface is connected to the IPM drive interface of the frequency converter (1).

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