Additional brake control device for passenger conveyor and passenger conveyor

Abstract

The application discloses an additional brake control device of a passenger conveying equipment, which comprises a relay and a control circuit; the relay has two normally closed contacts, and a coil of the relay is connected in parallel at an incoming power supply of an additional brake control part of the passenger conveying equipment; an input end of the control circuit is connected with a positive end and a negative end of a DC bus, and an output end is connected with an additional brake coil, and the two normally closed contacts are connected in series at two ends of the additional brake coil; when the incoming power supply is powered, the coil of the relay is powered, and the normally closed contacts are disconnected; when the incoming power supply is powered off, the coil of the relay is powered off, and the normally closed contacts are connected. The application has simple structure, reliable performance, and can work by using the energy of a capacitor in a driving system of the passenger conveying equipment.

Description

Technical Field

[0001] This invention relates to the field of passenger transport equipment technology, and more particularly to an additional brake control device for passenger transport equipment and passenger transport equipment. Background Technology

[0002] Escalators and moving walkways are commonly referred to as passenger transport equipment. According to the "Safety Code for the Manufacture and Installation of Escalators and Moving Walkways" GB16899-2011, Clause 5.4.2.2.2 stipulates that when the auxiliary brake is activated, it is not necessary to guarantee the stopping distance required for the working brake (see 5.4.2.1.3). Therefore, when designing auxiliary brakes, manufacturers rarely consider the stopping distance requirements of the auxiliary brake on the escalator or moving walkway in order to ensure effective stopping. However, Clause 5.4.2.2.5 stipulates that if a power failure or safety circuit de-energization occurs, the auxiliary brake and working brake are allowed to operate simultaneously, provided that the stopping conditions meet the specified stopping distance requirements for the escalator or moving walkway. Otherwise, the auxiliary brake and working brake are only allowed to operate synchronously under conditions of 1.4 times the overspeed or reverse direction.

[0003] For safety reasons, most manufacturers design auxiliary brakes as power-off brakes, meaning the brake activates when power is lost. Furthermore, standards stipulate that auxiliary brakes must activate immediately in cases of speed exceeding 1.4 times the rated speed or reversal, without any intentional delay. Therefore, in reality, auxiliary brakes are not designed with stopping distance requirements in mind. When a power failure occurs during escalator operation (e.g., a power outage), the auxiliary brake will inevitably activate and must meet clause 5.4.2.2.5 of the standard: In the event of a power failure or loss of power in the safety circuit, the working brake and auxiliary brake activate simultaneously, and the stopping conditions must comply with the stopping distance requirements.

[0004] To resolve the aforementioned contradiction, if the auxiliary brake is not designed to meet the stopping distance requirements, it is only allowed to activate immediately in cases of speed exceeding 1.4 times or reversing. In other cases such as power failure, the working brake and the auxiliary brake are not allowed to activate simultaneously.

[0005] Existing technologies have disclosed technical solutions for delayed action of auxiliary brakes. For example, CN103253588A discloses an auxiliary brake delayed action device based on a capacitor energy storage circuit, which can effectively solve the above problems. However, its drawbacks are: 1. It cannot monitor the state of the capacitor energy storage, and cannot detect in time when the capacitor performance deteriorates significantly, which may affect the stopping distance of the escalator when the power is cut off, thus failing to meet the standard requirements; 2. For this system, it is also necessary to ensure that the auxiliary brake brakes immediately before 1.4 times the overspeed. In order to achieve this safety function, it is necessary to ensure that the delay circuit is in the open state when the escalator experiences 1.4 times the overspeed. For this purpose, it is necessary to monitor the state of the circuit switching relay in real time. The above patent uses a method of multiple normally open contacts of relays in a straight line, which can achieve the function, but the circuit composition is relatively complex and the cost is high. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an auxiliary brake control device that is simple in structure, reliable in performance, and can operate by utilizing the energy of the capacitor in the passenger transport equipment drive system.

[0007] To solve the above-mentioned technical problems, the present invention provides an auxiliary brake control device for passenger transport equipment, including a relay and a control circuit; the relay has two normally closed contacts, and the coil of the relay is connected in parallel to the power supply of the auxiliary brake control section of the passenger transport equipment; the input terminal of the control circuit is connected to the positive and negative terminals of the DC bus, and the output terminal is connected to the auxiliary brake coil; the two normally closed contacts are respectively connected in series at both ends of the auxiliary brake coil; when the power supply is energized, the coil of the relay is energized and the normally closed contacts are open; when the power supply is de-energized, the coil of the relay is de-energized and the normally closed contacts are closed.

[0008] Preferably, the connection point of the input terminal of the control circuit to the positive terminal of the DC bus is the series connection node between the main capacitors.

[0009] Preferably, the selection of the series connection node matches the voltage level of the additional brake coil.

[0010] Preferably, the additional brake control device further includes a control module; the control module receives the operating status of the passenger transport equipment and monitors the node voltage after the normally closed contact of the relay. When the passenger transport equipment is in operation, if the voltage of the node is detected to be higher than the threshold, the power supply to the machine-side contactor is cut off to stop the escalator, and a shutdown signal is output to the pre-charging device to stop the pre-charging circuit from working.

[0011] Preferably, the control module is also connected to the gate of the braking IGBT in the inverter module. When the DC bus voltage is detected to be higher than the threshold, the control module outputs an on signal to the braking IGBT so that the electrical energy of the bus voltage is consumed through the regenerative resistor.

[0012] Preferably, a current-limiting circuit is also connected in series in the control circuit.

[0013] The present invention also provides a passenger transport device, including an additional brake control device as described in any of the foregoing embodiments. Attached Figure Description

[0014] Figure 1 A schematic diagram of the structure of the motor drive section, the auxiliary brake control section, and the auxiliary brake control device of the present invention for the passenger transport equipment.

[0015] The accompanying drawings are intended to illustrate the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments of the invention, supplementing the description in the specification. However, the drawings are schematic diagrams not drawn to scale and may not accurately reflect the precise structural or performance characteristics of any of the given embodiments. The drawings should not be construed as limiting or restricting the range of numerical values ​​or properties covered by exemplary embodiments of the invention. The invention will now be described in further detail with reference to the accompanying drawings and specific embodiments: Detailed Implementation

[0016] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art.

[0017] Passenger transport equipment is typically an escalator, and the motor drive section of an escalator is exemplary composed of the following parts, such as... Figure 1 As shown:

[0018] The system consists of a machine-side contactor, a DM1 module (rectifier module), multiple main capacitors C (with balancing resistors Rx), a PIM module (inverter module), a pre-charge circuit (including a pre-charge device), and a driver (not shown in the figure); the main capacitors C are exemplarily two or four, or other quantities.

[0019] When the motor drive system is powered on (i.e., after the R, S, T terminals are energized), the pre-charge circuit operates, charging the DCP and DCN terminals of the DC bus. After charging is complete, the machine-side contactor engages, and the driver outputs PWM drive signals to each IGBT in the PIM module to drive the motor. When the motor drive system brakes, the braking IGBT in the PIM module conducts, and the motor is in regenerative mode, rapidly releasing the pumping power to the DC bus through the regenerative resistor RGP. When the system is de-energized (i.e., when the R, S, T terminals are de-energized), the machine-side contactor contacts open, and the pre-charge circuit stops operating. At this time, the voltage on the main capacitor is released through the balancing resistor connected in parallel with the main capacitor, which is a waste of the electrical energy remaining on the main capacitor.

[0020] The auxiliary brake control unit of the escalator consists of a DM2 module, relays AM and AS. Relays AM and AS disconnect their contacts when the escalator experiences 1.4 times overspeed or non-operational reverse.

[0021] The additional brake control device for the passenger transport equipment provided in this specific embodiment, such as Figure 1 The area within the dashed box includes the relay PW and the control circuit.

[0022] The relay PW has two normally closed contacts, and the coil of the relay PW is connected in parallel to the incoming power supply of the auxiliary brake control section of the passenger transport equipment.

[0023] The input terminal of the control circuit is connected to the positive and negative terminals of the DC bus, and the output terminal is connected to the auxiliary brake coil. The two normally closed contacts are connected in series at both ends of the auxiliary brake coil.

[0024] When the incoming power supply is energized, the coil of the relay is energized, the normally closed contact opens, and the power supply from the control circuit to the auxiliary brake coil is cut off.

[0025] When the incoming power supply is cut off, the coil of the relay is de-energized and the normally closed contact is closed; the machine-side contactor is disconnected, the pre-charging device stops working, and the main capacitor begins to discharge slowly through the balancing resistor. At this time, since the coil of the relay PW is de-energized, the normally closed contact of the relay PW returns to the closed state. Therefore, the main capacitor, which has lost its power supply, can discharge to the auxiliary brake coil through the control circuit to maintain it in the energized state for a short time.

[0026] In this way, on the one hand, the electrical energy stored in the main capacitor can be fully utilized, saving energy; on the other hand, it also solves the problem that when the working brake and auxiliary brake coils lose power simultaneously during a system power outage, the stopping distance may not meet the standard requirements. Finally, since the residual DC bus voltage is used for the delay of the auxiliary brake coil, in order to ensure the normal operation of the DC bus, manufacturers generally set up full-process monitoring of the DC bus voltage. That is, once the DC bus voltage value is lower than a certain threshold, that is, when the main capacitor is in poor condition, the machine-side contactor will be immediately disconnected to prevent further failure. Compared with the comparative patent CN103253588A, it can ensure the delay effect of the auxiliary brake coil after power failure, avoiding the risk that the energy storage device added outside the original electrical system will malfunction under uncontrolled conditions, thus causing the intended function to fail.

[0027] However, according to the standard requirements, the auxiliary brake needs to brake immediately when there is an overspeed of 1.4 times and when the escalator reverses without operation. Therefore, it is necessary to monitor the state of the normally closed contacts of the above relay PW when there is no power failure to prevent the safety function from failing when the above dangerous situations occur due to contact adhesion.

[0028] Therefore, preferably, the additional brake control device further includes a control module, which receives the operating status of the passenger transport equipment and monitors the node voltage after the normally closed contact of the relay. When the passenger transport equipment is in operation, if the voltage of the node is detected to be higher than the threshold, the power supply to the machine-side contactor is cut off to stop the escalator, and a shutdown signal is output to the pre-charging device to stop the pre-charging circuit from working.

[0029] Since PW contact sticking is an extremely serious fault, in order to avoid the unsafe situation caused by this risk, since the entire system is energized when entering the above protection state, the DC bus voltage can be quickly consumed by the regenerative resistor RGP to minimize the abnormal delay time of the additional brake coil caused by the additional brake coil delay circuit.

[0030] Therefore, preferably, the control module is also connected to the gate of the braking IGBT in the inverter module. When the DC bus voltage (DCP-DCN) is detected to be higher than the threshold, the control module outputs an on signal to the braking IGBT so that the electrical energy of the bus voltage is consumed through the regenerative resistor RGP.

[0031] Since the electrical parameters of the additional brake coils required for different specifications of escalators vary, it is also necessary to consider the issue of unifying the delay time of the additional brake under different specifications.

[0032] Preferably, to adjust the delay effect of the additional brake coil delay circuit, a current-limiting circuit can be added in series in the additional brake coil control circuit. The current-limiting circuit exemplarily includes a resistor and a diode.

[0033] Preferably, the input terminal of the control circuit is connected to the positive terminal of the DC bus at a connection point between the main capacitors. The selection of the connection point matches the voltage level of the additional brake coil.

[0034] For example, the input voltage of the control circuit is selected from the voltage level of the auxiliary brake coil, which is either the voltage at point 1 / 2 or point 1 / 4 of the main capacitor.

[0035] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. An auxiliary brake control device for a passenger transport equipment, characterized in that: Includes relays and control circuits; The relay has two normally closed contacts, and the coil of the relay is connected in parallel to the incoming power supply of the auxiliary brake control section of the passenger transport equipment. The input terminal of the control circuit is connected to the positive and negative terminals of the DC bus, and the output terminal is connected to the auxiliary brake coil. The two normally closed contacts are connected in series at both ends of the auxiliary brake coil. When the incoming power supply is energized, the coil of the relay is energized and the normally closed contact opens; when the incoming power supply is de-energized, the coil of the relay is de-energized and the normally closed contact closes. The main capacitor, which has lost its power supply, acts as an energy storage element and discharges to the auxiliary brake coil through the control circuit. The additional brake control device also includes a control module; The control module receives the operating status of the passenger transport equipment and monitors the node voltage after the normally closed contact of the relay. When the passenger transport equipment is in operation, if the voltage of the node is detected to be higher than the threshold, the power supply to the machine-side contactor is cut off to stop the escalator from operating, and a shutdown signal is output to the pre-charging device to stop the pre-charging circuit from working.

2. The additional brake control device for the passenger transport equipment as described in claim 1, characterized in that: The input terminal of the control circuit is connected to the positive terminal of the DC bus at the connection point of the series node between the main capacitors.

3. The additional brake control device for the passenger transport equipment as described in claim 2, characterized in that: The selection of the series connection node is matched with the voltage level of the additional brake coil.

4. The additional brake control device for the passenger transport equipment as described in claim 1, characterized in that: The control module is also connected to the gate of the braking IGBT in the inverter module. When the DC bus voltage is detected to be higher than the threshold, the control module outputs an on signal to the braking IGBT so that the electrical energy of the bus voltage is consumed through the regenerative resistor.

5. The additional brake control device for the passenger transport equipment as claimed in claim 1, characterized in that: A current-limiting circuit is also connected in series in the control loop.

6. A passenger transport device, characterized in that: Includes the additional brake control device as described in any of the preceding claims.

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