A verification circuit for an elevator star circuit

Abstract

This utility model discloses a verification circuit for a commonly used star-sealing circuit in elevators, belonging to the field of elevator safety control technology. This solution reuses existing elevator safety circuits by connecting a detection branch after the star-sealing contactor and using the control board's detection points for signal acquisition. The safety circuit applies two detection voltages sequentially between phases A-B and B-C of the motor windings; the detection points capture the capacitor's response signals under the two voltages; only when both detections show a valid high-level signal is the three main contacts of the star-sealing contactor considered reliably connected, and the star-sealing circuit deemed valid. This utility model requires no external detection module, resulting in low cost; the entire process involves static electrical detection, eliminating safety risks; it comprehensively judges contact continuity and contact quality, ensuring high reliability; and it can be automatically executed periodically, fully meeting safety regulations.

Description

Technical Field

[0001] This utility model relates to the field of elevator control circuit technology, and in particular to a verification circuit for a commonly used star-sealing circuit in elevators. Background Technology

[0002] Star-lock braking is a safety protection measure for permanent magnet synchronous motor elevators. When the brake fails, braking force is generated by short-circuiting the three-phase windings of the motor to prevent the elevator car from going out of control. The star-lock function is an important protective measure to ensure the safe operation of elevators driven by permanent magnet synchronous traction machines. In the event of brake failure, it can limit the elevator car from falling or rising too quickly and keep it running at a very low speed, thereby avoiding injury to passengers due to overspeeding or unexpected movement of the car caused by brake failure.

[0003] Given that star-locking braking is currently the mainstream elevator braking method, and existing star-locking braking mainly has the following three implementation forms, including: independent contactor star-locking, etc. Figure 1 As shown, the integrated contactor sealing star is as follows Figure 2 As shown and the software is blocked, as Figure 3 As shown; The independent contactor star-sealing circuit involves adding a specially designed or configured independent contactor KFX to the main circuit. When the elevator detects brake failure or slippage, the control module on the main control board sends a signal to drive the star-sealing contactor KFX to close, simultaneously disconnecting the running contactor KDY, short-circuiting the three-phase windings of the traction machine, thus achieving star-sealing. Similarly, ... Figure 2 The integrated star-sealing circuit shown utilizes the normally closed contact of the existing running contactor in the elevator control cabinet as the star-sealing contact. For example... Figure 3 The software-based star-sealing shown utilizes the existing inverter module of the frequency converter to short-circuit the three-phase windings of the traction machine, thereby achieving star-sealing.

[0004] Since the star-sealing function does not participate in the normal operation of the elevator, maintenance personnel find it difficult to confirm its effectiveness during elevator maintenance. This necessitates that the elevator control system be able to determine the effectiveness of the star-sealing function independently. However, many existing verification methods require complex verification circuits for direct verification. In simplified verification, for example, in patent application number 202210253261.9, entitled "Automatic Detection Method, System, Equipment and Storage Medium for Elevator Star-Sealing Function," the effectiveness of the star-sealing circuit is indirectly determined by calculating the trolley speed or trolley distance. However, this method cannot accurately determine whether the star-sealing contacts of the main contactor are burned out. Therefore, it is evident that practical star-sealing circuit testing still suffers from problems such as poor safety, high cost, or incomplete detection. Utility Model Content

[0005] Therefore, the purpose of this utility model is to provide a verification circuit for a commonly used star-sealing circuit in elevators, which verifies the effectiveness of the commonly used star-sealing circuit in elevators through a simple circuit structure.

[0006] To achieve the above objectives, this utility model provides a verification circuit for a commonly used elevator sealing circuit, comprising: a first safety circuit, a second safety circuit, a detection resistor r, and a detection capacitor c connected to the sealing contactor KFX; Among them, the sealing contactor KFX is connected to the three-phase terminals of the traction motor; the first safety circuit is connected in series between phase A and phase B of the three-phase winding of the traction motor; the second safety circuit is connected in series between phase B and phase C of the three-phase winding of the traction motor; the detection resistor r and the detection capacitor c are connected in parallel; the detection resistor r is connected to the phase B terminal of the three-phase winding of the traction motor, and is also connected to the detection point X29 of the main control board.

[0007] A further preferred embodiment includes a test contactor KCS, wherein the coil of the test contactor KCS is located at the B-phase terminal of the three-phase winding of the traction motor and is connected in series with the detection resistor r. One end of the normally open contact of the test contactor KCS is connected to the detection capacitor c and the other end is connected to the detection resistor r.

[0008] More preferably, the test contactor KCS is a time-delay relay.

[0009] More preferably, the first safety circuit includes a first test power supply and a first resistor; the positive terminal of the first test power supply is connected to phase A of the three-phase winding of the traction motor, the negative terminal is connected to phase B of the three-phase winding of the traction motor, and the first resistor is connected in parallel between the positive and negative terminals of the first test power supply.

[0010] More preferably, the second safety circuit includes a second test power supply and a second resistor; the positive terminal of the second test power supply is connected to phase C of the three-phase winding of the traction motor, the negative terminal is connected to phase B of the three-phase winding of the traction motor, and the second resistor is connected in parallel between the positive and negative terminals of the second test power supply.

[0011] The verification of this utility model includes the following steps: S1: Control the coil of the sealing contactor (KFX) to be energized, so that its main contacts enter a predetermined closed state; S2: Control the first safety circuit to apply the first detection voltage between phase A and phase B of the traction motor winding; S3: Monitor whether a high-level signal is generated across the detection capacitor c during the first voltage application period through the detection point (X29), and perform the first count; S4: Control the second safety circuit to apply a second detection voltage between phase B and phase C of the traction motor winding; S5: Monitor whether a high-level signal is generated across the detection capacitor c during the second voltage application by means of the detection point (X29), and perform a second count; S6: The control motherboard makes a logical judgment based on the two counting results: If both counts result in a high-level signal being detected, it is determined that the three main contacts of the sealing contactor (KFX) are reliably connected and the sealing circuit is effective. If a high-level signal is detected only once in the two count results, it is determined that one of the main contacts of the sealing contactor (KFX) is not reliably connected; If no high-level signal is detected in both counts, it is determined that at least two main contacts of the sealing contactor (KFX) are not reliably connected, or there is an open circuit in the circuit. S7: When the judgment result of step S6 is that the sealing circuit is invalid, the control motherboard outputs a fault signal and controls the elevator to stop running or enter the maintenance state.

[0012] A further preferred embodiment includes controlling the time interval between two applications of the detection voltage by controlling the delay time of the test contactor KCS.

[0013] The verification circuit for a commonly used star-sealed circuit in elevators disclosed in this application has at least the following advantages compared to existing technologies: This application, with a relatively simple circuit structure, realizes the verification of a safe and reliable star-sealing circuit based on the existing elevator circuit. It can directly reflect the contact quality of the main contacts and cleverly solves the contradiction between "safety risk", "cost", "detection depth" and "versatility" that existing solutions cannot balance. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the independent contactor star-sealing circuit mentioned in the background art.

[0015] Figure 2 This is a schematic diagram of the integrated contactor sealing circuit mentioned in the background art.

[0016] Figure 3 This is a schematic diagram of the software-sealed circuit mentioned in the background section.

[0017] Figure 4 A schematic diagram of the circuit structure of the verification circuit for the commonly used sealing star circuit in elevators provided by this utility model.

[0018] Figure 5 A flowchart illustrating the verification method for a commonly used star-sealed circuit in elevators provided by this utility model.

[0019] Figure 6 This is a circuit diagram of a mechanical braking circuit. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 4 As shown, one embodiment of this utility model provides a verification circuit for a commonly used sealing star circuit in elevators, including: a first safety circuit, a second safety circuit, a detection resistor r, and a detection capacitor c connected to the sealing star contactor KFX; Among them, the sealing contactor KFX is connected to the three-phase terminals of the traction motor; the first safety circuit is connected in series between phase A and phase B of the three-phase winding of the traction motor; the second safety circuit is connected in series between phase B and phase C of the three-phase winding of the traction motor; the detection resistor r and the detection capacitor c are connected in parallel; the detection resistor r is connected to the phase B terminal of the three-phase winding of the traction motor, and is also connected to the detection point (X29) of the main control board.

[0022] It also includes a test contactor KCS, whose coil is located at the B-phase terminal of the three-phase winding of the traction motor and connected in series with the detection resistor r. One end of the normally open contact of the test contactor KCS is connected to the detection capacitor c, and the other end is connected to the detection resistor r. The test contactor KCS is a time-delay relay.

[0023] It should be noted that the first safety circuit includes a first test power supply and a first resistor; the positive terminal of the first test power supply is connected to phase A of the three-phase winding of the traction motor, the negative terminal is connected to phase B of the three-phase winding of the traction motor, and the first resistor is connected in parallel between the positive and negative terminals of the first test power supply.

[0024] The second safety circuit includes a second test power supply and a second resistor; the positive terminal of the second test power supply is connected to phase C of the three-phase winding of the traction motor, the negative terminal is connected to phase B of the three-phase winding of the traction motor, and the second resistor is connected in parallel between the positive and negative terminals of the second test power supply.

[0025] like Figure 2 This utility model also provides a verification method for a commonly used star-sealed circuit in elevators, including the following steps: S1: Control the coil of the sealing contactor (KFX) to be energized, so that its main contacts enter a predetermined closed state; S2: Control the first safety circuit to apply the first detection voltage between phase A and phase B of the traction motor winding; S3: Monitor whether a high-level signal is generated across the detection capacitor c during the first voltage application period through the detection point (X29), and perform the first count; S4: Control the second safety circuit to apply a second detection voltage between phase B and phase C of the traction motor winding; S5: Monitor whether a high-level signal is generated across the detection capacitor c during the second voltage application by means of the detection point (X29), and perform a second count; S6: The control motherboard makes a logical judgment based on the two counting results: If both counts result in a high-level signal being detected, it is determined that the three main contacts of the sealing contactor (KFX) are reliably connected and the sealing circuit is effective. If a high-level signal is detected only once in the two count results, it is determined that one of the main contacts of the sealing contactor (KFX) is not reliably connected; If no high-level signal is detected in both counts, it is determined that at least two main contacts of the sealing contactor (KFX) are not reliably connected, or there is an open circuit in the circuit. S7: When the judgment result of step S6 is that the sealing circuit is invalid, the control motherboard outputs a fault signal and controls the elevator to stop running or enter the maintenance state.

[0026] The purpose of this detection circuit is to check whether the three contacts of the sealing contactor KFX are reliably connected when the three-phase windings of the motor are energized. The logic process is as follows: if Figure 4 In the middle, contact point 2 is open. Regardless of whether contact points 1 and 3 are open, no current will flow through resistor R during the two voltage loading processes, and no high level will be generated at the capacitor end. Therefore, the detection point X29 on the control board will not light up in either of the two tests. if Figure 4 In the process, contact point 2 is connected, and only one of contact points 1 or 3 is connected while the other is not connected. As a result, during the two voltage loading processes, current will only flow through the resistor r once, and the capacitor terminal will only generate a high level once. Therefore, the detection point X29 on the control motherboard will only light up once. 3. In Figure 4 In the process, only when all three contact points 1, 2, and 3 are connected will current flow through the resistor r during the two voltage loading processes, and a high level will be generated at the capacitor terminal. Therefore, the detection point X29 on the control motherboard will be lit twice. Based on the above logical analysis, it can be seen that verifying the integrity of all three contact points of the sealing contactor is that a high-level signal can be detected twice at each detection point using two applied voltages. Conversely, if a high-level signal is detected less than twice, it indicates a fault in the contact point of the contactor, and the elevator should be stopped for maintenance based on the detection point's assessment.

[0027] In this application, the focus is on the sealing circuit of the independent contactor commonly used in elevator permanent magnet synchronous drive motors.

[0028] This application connects three small resistors with the same resistance value to the rear side of the sealing contactor. The small resistors serve two purposes: first, the increased resistance can prevent the internal windings of the permanent magnet synchronous motor from burning out due to the transient high current caused by the sudden short circuit when the sealing contactor closes and deceleration is achieved by the sealing action during operation of the permanent magnet synchronous motor; at least it can mitigate the impact. Second, the small resistors can serve as voltage detection points for detecting the continuity of the circuit.

[0029] The detection circuit proposed in this application utilizes existing devices in the elevator control circuit, including safety circuits SCB1 and SCB2 containing electronic components, to generate the applied voltage, including detection point X29. It eliminates the contactor and detection module specifically used for detecting the star-sealing circuit, and completes the reliability detection of the star-sealing circuit using existing hardware, which is more economical.

[0030] The combination method of the detection circuit in this application allows the safety circuits SCB1 and SCB2 to generate voltage every time the elevator stops, thus enabling detection during each elevator stop. The detection time can also be set by the contactor KCS (detection contactor) and the programmable electronic related system, which can fully meet the requirement of detecting the sealing circuit at least once every 24 hours.

[0031] This application presents a circuit that automatically detects the reliable connection of the star-sealing circuit each time it is switched on. Based on a general system, it utilizes a safety circuit containing electronic components and existing elevator circuit board detection points to detect the connection of the star-sealing circuit. This provides a simple and efficient new method for detecting the star-sealing circuit, adding a reliable layer of assurance for the safe operation of other elevator brakes.

[0032] The present application will be compared with the prior art by means of specific embodiments below. Currently, there are three main methods for verifying the effectiveness of the star-sealing system that meet this requirement. The mechanical verification scheme refers to simulating brake failure by manually opening the brake to detect whether the rollover verification is effective. Figure 5 The diagram shows a typical braking circuit, where KDY is the running contactor and KBY is the brake contactor. During verification, the main control board's control module sends a signal to engage the running contactor KDY and the brake contactor KBY, closing the corresponding contacts and releasing the brake. At this point, the traction machine begins to rotate. The control module determines the rotational speed by counting the number of pulses from the encoder installed on the traction machine, thus obtaining the elevator's slip speed during star sealing, thereby verifying the effectiveness of star sealing.

[0033] The advantage of this approach is that it requires no additional hardware, directly verifies the effectiveness of the satellite sealing function, and is highly accurate and low-cost. However, its disadvantages are also obvious: it requires confirmation that no one is in the car before verification, and if the satellite sealing fails during verification, it will cause the car to overshoot the ceiling.

[0034] The second type is the electrical verification scheme, which refers to confirming whether the star-sealing circuit is correctly connected by detecting the continuity of the star-sealing circuit. Figure 6 The diagram shows a typical electrical verification circuit. KDY is the running contactor, and KFX1 and KFX2 are two sealing contactors that perform the sealing operation. To verify the effectiveness of the sealing operation, firstly, the running contactor KDY disconnects, and the elevator enters verification mode. The detection module outputs a voltage signal at point 2. KFX1 and KFX2 disconnect, and no voltage signal is detected at points 1 and 3, indicating that the sealing contactors KFX1 and KFX2 are not short-circuited. Then, KFX2 disconnects, KFX1 closes, and voltage signals are detected at points 1 and 3, indicating that sealing contactor KFX1 is closing normally. Finally, KFX2 closes, KFX1 disconnects, and voltage signals are detected at points 1 and 3, indicating that sealing contactor KFX2 is closing normally. The effectiveness of the sealing operation can be verified using this method.

[0035] The advantage of this approach is that it eliminates the need to open the brake, thus avoiding safety risks. However, it requires an additional detection module, increasing costs, and it cannot determine whether the capacity of each contact in the star-sealing circuit meets the star-sealing requirements. In other words, if the KFX1 or KFX2 star-sealing contactor is replaced due to a fault, this approach cannot detect whether the replaced contactor still meets the required capacity for star-sealing.

[0036] For integrated contactor star-sealing systems, elevator manufacturers have proposed an indirect verification scheme. A pulse generator is installed inside the main contactor, periodically outputting pulse switching signals. The elevator control system's main control board detects these pulse switching signals to determine the on-machine status of the integrated star-sealed contactor. Simultaneously, by setting the period and pulse width of the pulse switching signals, the elevator manufacturer enables the main control board to determine the specifications of the integrated star-sealed contactor, thereby indirectly determining whether the capacity of each contact in the star-sealing circuit meets the requirements.

[0037] The advantages of this approach are low cost and the fact that it eliminates the need to open the brake, thus avoiding safety risks. However, it cannot determine whether the main contactor's star-shaped contacts are burnt out. Furthermore, a unified standard and protocol are required between the main control board and the main contactor, necessitating technical integration between the contactor manufacturer and the main control board manufacturer.

[0038] Therefore, this application has achieved a safe and reliable verification of the star-sealed circuit based on the existing elevator circuit, which can directly reflect the contact quality of the main contacts and cleverly solves the contradiction between "safety risk", "cost", "detection depth" and "universality" that the existing solution cannot balance.

[0039] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A verification circuit for a commonly used star-sealed circuit in elevators, characterized in that, include: Connect the first safety circuit, the second safety circuit, the detection resistor (r), and the detection capacitor (c) of the KFX star-sealing contactor. Among them, the sealing contactor KFX is connected to the three-phase terminals of the traction motor; the first safety circuit is connected in series between phase A and phase B of the three-phase winding of the traction motor; the second safety circuit is connected in series between phase B and phase C of the three-phase winding of the traction motor; the detection resistor r and the detection capacitor c are connected in parallel; the detection resistor r is connected to the phase B terminal of the three-phase winding of the traction motor, and is also connected to the detection point (X29) of the main control board.

2. The verification circuit for the commonly used star-sealing circuit in elevators according to claim 1, characterized in that, It also includes a test contactor KCS, whose coil is set at the B phase terminal of the three-phase winding of the traction motor and connected in series with the detection resistor (r). One end of the normally open contact of the test contactor KCS is connected to the detection capacitor (c) and the other end is connected to the detection resistor r ().

3. The verification circuit for the commonly used star-sealing circuit in elevators according to claim 2, characterized in that, The test contactor KCS is a time-delay relay.

4. The verification circuit for the commonly used star-sealing circuit in elevators according to claim 1, characterized in that, The first safety circuit includes a first test power supply and a first resistor; the positive terminal of the first test power supply is connected to phase A of the three-phase winding of the traction motor, the negative terminal is connected to phase B of the three-phase winding of the traction motor, and the first resistor is connected in parallel between the positive and negative terminals of the first test power supply.

5. The verification circuit for the commonly used star-sealing circuit in elevators according to claim 1, characterized in that, The second safety circuit includes a second test power supply and a second resistor; the positive terminal of the second test power supply is connected to phase C of the three-phase winding of the traction motor, the negative terminal is connected to phase B of the three-phase winding of the traction motor, and the second resistor is connected in parallel between the positive and negative terminals of the second test power supply.

Images