A star-sealing contactor electrical control circuit and a star-sealing contactor failure detection method

Abstract

The embodiments of the present invention relate to the field of elevator fault detection, and disclose a star-sealing contactor electrical control circuit and a star-sealing contactor failure detection method. In the present invention, the star-sealing contactor electrical control circuit comprises a frequency converter (16), a permanent magnet synchronous traction machine (11), a star-sealing contactor (10), and a star-sealing failure detection circuit (4). The star-sealing failure detection circuit (4) can be used to detect whether each star-sealing circuit, a current limiting component (3), a power supply (2) and a lower bridge arm (13, 14, 15) in the star-sealing contactor (10) form a normal circuit, and when it is detected that a normal circuit cannot be formed, it is determined that the star-sealing circuit between the star-sealing contactor (10) and the permanent magnet synchronous traction machine (11) in the abnormal circuit is broken, and then it is determined that the star-sealing contactor (10) fails. Based on the star-sealing contactor electrical control circuit provided by the present invention, safe and efficient "star-sealing circuit failure" static detection can be achieved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of elevator fault detection, and in particular to an electric control circuit of a star-sealing contactor and a method for detecting failure of a star-sealing contactor. Background Art

[0002] In the case that the mechanical brake of the permanent magnet synchronous traction machine has insufficient braking force or fails, if the elevator continues to be put into operation or the control system improperly handles the dangerous situation, serious safety accidents will occur. In order to eliminate and reduce this safety hazard, the "Safety Specifications for Elevator Manufacturing and Installation Part 1: Passenger Elevators and Freight Elevators" GB / T 7588.1-2020 requires that "elevators add 'other braking devices' to provide braking protection when the traction machine brake fails." The new "Elevator Type Test Rules" TSG T7007-2022 specifically requires that "the control system should be able to detect whether the 'newly added other braking devices' have failed, and when the 'other braking functions' are cancelled, the elevator cannot be put into normal operation."

[0003] The current mainstream treatment method in the market is to add a star-locking relay to short-circuit the three-phase winding of the synchronous motor for star-locking braking, thereby adding an additional "star-locking braking device" to meet the requirements of GB / T 7588.1-2020. For the failure detection required by the new standard TSG T7007-2022 - failure detection of the newly added "star-locking braking device", a currently known method is the "star-locking and sliding car" detection method: the control system first locks the motor, then opens the gate to slide the car, and determines whether the star-locking braking function has failed based on the sliding speed.

[0004] The defect of the "sealed star sliding car" detection method is that during the test, the elevator will automatically enter a moving state. If there happen to be passengers in the elevator at this time, the "unexpected" movement of the car may cause unnecessary panic among the passengers, or even trigger them to perform dangerous self-rescue behaviors by pulling the door open. Another defect is that the test process requires a series of processes such as "slipping car" - "failure judgment" - "slowing down" - "re-leveling", which takes a relatively long time. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a star-sealing contactor electrical control circuit and a star-sealing contactor failure detection method, so as to achieve efficient and safe star-sealing failure "static detection" and solve the defects in the relevant background technology.

[0006] In order to solve the technical problems in the above-mentioned related background technologies, an embodiment of the present invention provides an electrical control circuit of a star-sealing contactor, comprising: a frequency converter, a permanent magnet synchronous traction machine, a star-sealing contactor and a star-sealing failure detection circuit; the upper and lower bridge arm switches of the IGBT (Insulated Gate Bipolar Transistor) in the frequency converter are respectively connected to the three windings of the permanent magnet synchronous traction machine through the output end of the frequency converter; the three windings of the permanent magnet synchronous traction machine are also connected to the star-sealing contactor; one end of the star-sealing failure detection circuit is connected to the common end of the star-sealing contactor, and the other end is connected to the power supply through the current limiting component in the frequency converter; wherein the star-sealing failure detection circuit is used to detect whether the star-sealing circuit, the current limiting component, the power supply and the lower bridge arm in the star-sealing contactor form a normal circuit, and when it is detected that the normal circuit cannot be formed, it is determined that there is a circuit break in the star-sealing circuit, and then it is determined that the star-sealing contactor fails.

[0007] An embodiment of the present invention further provides a method for detecting failure of a star-sealing contactor, wherein the star-sealing contactor is a star-sealing contactor in an electrical control circuit of the star-sealing contactor disclosed in the present invention, and the method comprises:

[0008] S101: closing all contacts in the loop where the star-failure detection circuit is located;

[0009] S102: outputting at least one PWM wave with a certain duty cycle to all the lower bridge arms in sequence within a preset time period, and executing the following steps S103 to S105;

[0010] S103: monitoring in real time the maximum current value of the inverter output terminal connected to the lower bridge arm;

[0011] S104: Obtaining a peak current coefficient according to the maximum current value;

[0012] S105: If the peak current coefficient is greater than the preset effective coefficient, it is determined that the star-sealing contactor circuit connected to the lower bridge arm is normal; if the peak current coefficient is less than the preset failure coefficient, it is determined that the star-sealing contactor circuit connected to the lower bridge arm is failed.

[0013] An embodiment of the present invention further provides a method for detecting failure of a star-sealing contactor, wherein the star-sealing contactor is a star-sealing contactor in an electrical control circuit of the star-sealing contactor disclosed in the present invention, and the method comprises:

[0014] S201: closing all contacts in the loop where the star-failure detection circuit is located;

[0015] S202: setting a target current value flowing through the inverter output terminal connected to the lower bridge arm; the target current value is a saturation current value of a preset proportion;

[0016] S203: outputting at least one PWM wave to all the lower bridge arms in sequence within a preset time period, monitoring the PWM wave waveform, and performing the following steps on the loop where each lower bridge arm is located respectively;

[0017] S204: at the time of underflow of the PWM wave, sampling the first feedback current value of the inverter output terminal connected to the lower bridge arm, and adjusting the duty cycle of the PWM wave output by the lower bridge arm to control the first feedback current value according to the current target value;

[0018] S205: Determine whether the difference between the first feedback current value after the control and the current target value is less than a preset threshold; if so, execute step S207, otherwise execute step S206;

[0019] S206: If the first feedback current value is less than a preset threshold, execute step S208; if the difference between the first feedback current value and the saturation current value is less than a preset threshold, execute step S209;

[0020] S207: At the overflow moment of the PWM wave, sampling the second feedback current value of the inverter output terminal connected to the lower bridge arm, and determining whether the second feedback current value is less than a preset threshold; if so, executing step S209, otherwise executing step S208;

[0021] S208: determining that the star-blocking contactor circuit connected to the lower bridge arm is failed;

[0022] S209: Determine whether the star-blocking contactor circuit connected to the lower bridge arm is normal.

[0023] In the embodiment of the present invention, the star-sealing contactor electrical control circuit includes a frequency converter, a permanent magnet synchronous traction machine, a star-sealing contactor and a star-sealing failure detection circuit, one end of the star-sealing failure detection circuit is connected to the common end of the star-sealing contactor, and the other end is connected to the power supply through the current limiting component in the frequency converter, so that the star-sealing failure detection circuit can be used to detect whether the star-sealing circuit, the current limiting component, the power supply and the lower bridge arm in the star-sealing contactor form a normal circuit, and when it is detected that the normal circuit cannot be formed, it is determined that the star-sealing circuit has a circuit break, and then the star-sealing contactor is determined to be failed. Using the star-sealing contactor electrical control circuit in the present invention to perform star-sealing failure detection, the elevator car can be in a stationary state during the entire detection period, there is no "slipping", "deceleration", "re-leveling" and other processes, and a detection can be completed quickly. At the same time, since the elevator can always be in a brake-stopped elevator state at the leveling position during the test, and the test time is short, even if there are passengers in the elevator, the passengers will not feel this test process, and will not bring them a bad elevator experience. Therefore, the star-sealing contactor electrical control circuit provided by the present invention can achieve the effect of static detection of "star-sealing failure", and compared with the related art, the present invention has the characteristics of safety, high efficiency and rapidity.

[0024] In addition, in the electrical control circuit of the star-sealing contactor, the current-limiting components in the frequency converter include: a braking resistor or an inductor. The braking resistor can be considered as a series connection of an ordinary resistor and a weak inductance element. After the braking resistor or the inductor is connected to the failure detection circuit of the star-sealing contactor, the saturation current flowing through the IGBT can be controlled to prevent the IGBT from being damaged by excessive current. Therefore, on this basis, the star-sealing contactor failure detection method of the present invention can be used to perform failure detection on the star-sealing contactor circuit.

[0025] In addition, the star-sealing failure detection circuit in the electrical control circuit of the star-sealing contactor is connected to the common end of the star-sealing contactor through at least one switch; the at least one switch is in a closed state when the star-sealing failure detection circuit is working, and is in an open state when the star-sealing failure detection circuit is not working. By setting at least one switch in the star-sealing failure detection circuit, when it is necessary to perform failure detection on the star-sealing contactor, the switch on the star-sealing failure detection circuit can be closed for detection; when it is not necessary to perform failure detection on the star-sealing contactor, the switch on the star-sealing failure detection circuit can be opened to return the electrical control circuit of the star-sealing contactor to the state when the elevator is in normal use. The setting of the switch in the star-sealing failure detection circuit makes the preparation of the star-sealing failure detection circuit convenient and quick; at the same time, it can also ensure that when it is not necessary to perform star-sealing failure detection, the switch on the star-sealing failure detection circuit can be opened so that the elevator can operate normally and safely. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0027] Figure 1 This is a typical schematic diagram of the electrical control circuit of the star-sealing contactor;

[0028] Figure 2 It is a schematic diagram of the electrical control circuit of the star-sealing contactor in the present invention;

[0029] Figure 3 It is a step diagram of a method for detecting failure of a star-sealing contactor in the present invention;

[0030] Figure 4 It is a step diagram of another method for detecting failure of a star-closing contactor in the present invention. DETAILED DESCRIPTION

[0031] like Figure 1 As shown in the figure, it is a schematic diagram of the electrical control circuit of the star-sealing contactor which uses the star-sealing contactor to seal the star of the permanent magnet synchronous traction machine in the current market. The main contact of the star-sealing relay 10 realizes the mechanical star-sealing function to the permanent magnet synchronous traction machine 11 through the common terminal A. The star-sealing contactor is a contactor dedicated to the permanent magnet synchronous traction machine. The principle of the star-sealing contactor applied to the elevator is as follows: when the mechanical brake of the permanent magnet synchronous traction machine is insufficient or fails, or when the elevator is out of power or traps passengers, it is necessary to loosen the elevator brake, the elevator will move in the heavier direction under the action of gravity; when the car moves up or down, it will drive the permanent magnet synchronous traction machine to rotate. When the permanent magnet synchronous traction machine rotates under the action of external force, it is equivalent to a generator. At this time, the star-sealing contactor will short-circuit the three leads of the permanent magnet synchronous traction machine input, and when the generator output is short-circuited, the rotor resistance will be very large, and the speed of the elevator will be very slow and safe.

[0032] and Figure 1The electrical control circuit for sealing the star of the permanent magnet synchronous traction machine using the star-sealing contactor in the market shown cannot directly detect whether there is a circuit break between the main contacts and the wiring between the star-sealing contactor and the U, V, and W phases of the permanent magnet synchronous traction machine. When the star-sealing circuit of the star-sealing contactor is broken and causes the star-sealing to fail, the mechanical brake of the permanent magnet synchronous traction machine is insufficient or fails, or the elevator is out of power and the passengers are trapped, and the elevator brake needs to be loosened, which may cause dangerous elevator casualties. At the same time, a currently known "star-sealing car slipping" detection method - the control system first seals the motor, then opens the brake to slip the car, and judges whether the star-sealing braking function fails according to the size of the slipping speed. There may be defects such as the passenger panic caused by the slipping during the detection process, causing the passenger to choose dangerous self-rescue behavior and taking a long time. Therefore, the present invention proposes a star-sealing contactor electrical control circuit and a star-sealing contactor failure detection method, which realizes the improvement of the relevant technology and can complete the static detection of "star-sealing failure" safely, efficiently and quickly. The following is an embodiment of the present invention.

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in the embodiments of the present invention, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined and referenced with each other without contradiction.

[0034] The first embodiment of the present invention relates to an electrical control circuit for a star-sealing contactor, which can be used in an elevator. In this embodiment, it includes a frequency converter, a permanent magnet synchronous traction machine, a star-sealing contactor, and a star-sealing failure detection circuit; the IGBT upper and lower bridge arm switches in the frequency converter are respectively connected to the three windings of the permanent magnet synchronous traction machine through the output end of the frequency converter; the three windings of the permanent magnet synchronous traction machine are also connected to the star-sealing contactor; one end of the star-sealing failure detection circuit is connected to the common end of the star-sealing contactor, and the other end is connected to the power supply through the current limiting component in the frequency converter; wherein the star-sealing failure detection circuit is used to detect whether the star-sealing circuit, the current limiting component, the power supply and the lower bridge arm in the star-sealing contactor form a normal circuit, and when it is detected that the normal circuit cannot be formed, it is determined that the star-sealing circuit is broken, and then the star-sealing contactor is determined to be failed.

[0035] In the embodiment of the present invention, the star-sealing contactor electrical control circuit includes a frequency converter, a permanent magnet synchronous traction machine, a star-sealing contactor and a star-sealing failure detection circuit, one end of the star-sealing failure detection circuit is connected to the common end of the star-sealing contactor, and the other end is connected to the power supply through the current limiting component in the frequency converter, so that the star-sealing failure detection circuit can be used to detect whether the star-sealing circuit, the current limiting component, the power supply and the lower bridge arm in the star-sealing contactor form a normal circuit, and when it is detected that the normal circuit cannot be formed, it is determined that the star-sealing circuit has a circuit break, and then the star-sealing contactor is determined to be failed. Using the star-sealing contactor electrical control circuit in the present invention to perform star-sealing failure detection, the elevator car can be in a stationary state during the entire detection period, there is no "slipping", "deceleration", "re-leveling" and other processes, and a test can be completed quickly. At the same time, since the elevator can always be in a brake-stopped elevator state at the leveling position during the test, and the test time is short, even if there are passengers in the elevator, the passengers will not feel this test process, and will not bring them a bad elevator experience. Therefore, the star-sealing contactor electrical control circuit provided by the present invention can achieve the effect of static detection of "star-sealing failure", and compared with the related art, the present invention has the characteristics of safety, high efficiency and rapidity.

[0036] The following is a detailed description of the implementation details of the electric control circuit of the star-sealing contactor in this embodiment. The schematic diagram of the circuit can be shown as follows: Figure 2 The following content is only for the convenience of understanding the implementation details, and is not necessary for the implementation of this solution.

[0037] Considering the cost, in the embodiment of the present invention, the current limiting component 3 uses the existing braking resistor Rb in the inverter 16; the power supply 2 uses the DC positive bus.

[0038] like Figure 2 The electrical control circuit of a star-sealing contactor shown includes a frequency converter 16, a permanent magnet synchronous traction machine 11, a star-sealing contactor 10 and a star-sealing failure detection circuit 4;

[0039] The IGBT upper arm switches 17 , 18 , 19 and the IGBT lower arm switches 13 , 14 , 15 in the inverter 16 are respectively connected to the three windings U, V, W of the permanent magnet synchronous traction machine 11 through the output terminals 7 , 8 , 9 of the inverter 16 .

[0040] The three windings U, V, and W of the permanent magnet synchronous traction machine 11 are also connected to the star-sealing contactor 10 .

[0041] The three contacts of the star-sealing contactor 10 are respectively connected to the U, V, and W three-phase winding lead wires of the permanent magnet synchronous traction machine 11. This connection method is simple and convenient, and other equivalent changes in the connection method and number of contacts of the star-sealing contactor do not affect the implementation effect of this embodiment.

[0042] One end of the star-sealing failure detection circuit 4 is connected to the common terminal A of the star-sealing contactor 10 , and the other end is connected to the power source 2 via the current limiting component 3 in the frequency converter 16 .

[0043] The star-sealing failure detection circuit 4 is connected to the common terminal A of the star-sealing contactor 10 through at least one switch; the at least one switch is in a closed state when the star-sealing failure detection circuit 4 is working, and is in an open state when the star-sealing failure detection circuit 4 is not working.

[0044] By setting at least one switch in the star-sealing failure detection circuit 4, when it is necessary to perform failure detection on the star-sealing contactor 10, the switch on the star-sealing failure detection circuit 4 can be closed for detection; when it is not necessary to perform failure detection on the star-sealing contactor, the switch on the star-sealing failure detection circuit 4 can be opened to allow the star-sealing contactor electrical control circuit to return to the state when the elevator is in normal use.

[0045] The setting of the switch in the star-sealing failure detection circuit 4 makes the preparation of the star-sealing failure detection circuit convenient and quick; at the same time, it can also ensure that when there is no need to perform star-sealing failure detection, the switch on the star-sealing failure detection circuit 4 is disconnected, so that the elevator can operate normally and safely.

[0046] The current limiting components in the frequency converter may include: a braking resistor or an inductor.

[0047] The braking resistor can be considered as a series connection of an ordinary resistor and a weak inductance element. After the braking resistor or inductance is connected to the failure detection circuit of the star-sealing contactor, the saturation current flowing through the IGBT can be controlled to prevent the IGBT from being damaged by excessive current. Therefore, the star-sealing contactor failure detection method of the present invention can be used to perform failure detection on the star-sealing contactor circuit.

[0048] The power source 2 may come from a DC positive bus, a DC negative bus or other power sources, as long as it can form a current or voltage detection loop with the “sealed star line where the common terminal A is located”.

[0049] Among them, the star-sealing failure detection circuit 4 is used to detect whether the star-sealing circuits, current-limiting components 3, power supply 2 and the lower bridge arm 13 or lower bridge arm 14 or lower bridge arm 15 respectively connected in the star-sealing contactor 10 form a normal circuit, and when it is detected that a normal circuit cannot be formed, it is determined that the star-sealing circuit is broken, and then the star-sealing contactor is determined to be failed.

[0050] In addition, after making appropriate changes to the connection method of the star-sealing failure detection circuit 4 in the electrical control circuit of the star-sealing contactor, the resulting circuit can also detect whether the star-sealing circuits, current-limiting components 3, and power supply 2 in the star-sealing contactor 10 form a normal circuit with the upper bridge arm 17 or the upper bridge arm 18 or the upper bridge arm 19, respectively, and when it is detected that a normal circuit cannot be formed, it is determined that there is a break in the star-sealing circuit in the abnormal circuit, and then it is determined that the star-sealing contactor has failed.

[0051] In this embodiment, one end of the star-sealing failure detection circuit 4 in the electrical control circuit of the star-sealing contactor is connected to the common terminal A of the star-sealing contactor 10, and the other end is connected to the power supply 2 via the current limiting component 3 in the frequency converter 16, so that the star-sealing failure detection circuit 4 can be used to detect whether the star-sealing circuits, current limiting components 3, and power supply 2 in the star-sealing contactor 10 form a normal circuit with the lower bridge arms 13, 14, and 15 respectively, and when it is detected that a normal circuit cannot be formed, it is determined that there is a circuit break in the star-sealing circuit in the abnormal circuit, and then it is determined that the star-sealing contactor has failed.

[0052] On the basis of the electrical control circuit of the star-sealing contactor in this embodiment, the opening state of the IGBT lower bridge arms 13, 14, 15 in the inverter 16 can be controlled to monitor the current values ​​in the output lines 7, 8, 9 of the inverter 16 respectively connected to the lower bridge arms 13, 14, 15 in real time, and it can be judged whether the star-sealing lines of the star-sealing contactor 10 respectively connected to the output lines 7, 8, 9 of the inverter 16 fail according to the feedback current values, so as to achieve the effect of static detection of "star-sealing failure".

[0053] The use of the star-sealing contactor electrical control circuit in this embodiment to perform star-sealing failure detection can make the elevator car in a stationary state during the entire detection period, and there will be no processes such as "slipping", "deceleration", and "re-leveling". When the test is actually carried out, a test can be completed in a very short time (two to three seconds). At the same time, since the elevator can always be in a brake-held stop state at the leveling position during the test, and the test time is short, even if there are passengers in the elevator, the passengers will not feel the test process and will not have a bad elevator riding experience. Therefore, compared with the related art, the present invention is safe and efficient.

[0054] Another embodiment of the present invention relates to a method for detecting failure of a star-sealing contactor, which can be applied to the electrical control circuit of the star-sealing contactor disclosed in the present invention. The method for detecting failure of a star-sealing contactor provided in this embodiment can actually be understood as a current open-loop detection method. The implementation details of the method for detecting failure of a star-sealing contactor of this embodiment are described in detail below. The following content is only provided for the convenience of understanding the implementation details and is not necessary for implementing this solution.

[0055] like Figure 2As shown, in step S101, all contacts in the loop where the star-off failure detection circuit is located are closed.

[0056] In one example, before detecting any one of the star-sealing lines in the star-sealing contactor 10 in turn, all contacts in the closed loop are closed, that is, the contacts in the star-sealing line in the star-sealing contactor 10 are closed, and all contacts in the star-sealing failure detection circuit 4 are closed. If there is a main contactor 20 in the output circuits 7, 8, and 9 from the frequency converter 16 to the permanent magnet synchronous traction machine 11, the contacts of the main contactor 20 are also closed.

[0057] In step S102, at least one PWM wave with a certain duty cycle is output to all the lower bridge arms in sequence within a preset time period, and the following steps S103 to S105 are performed;

[0058] In one example, the carrier frequency of the PWM wave to be output to the lower bridge arm is determined, such as the carrier frequency is 8K; at least one PWM wave with a certain duty cycle is output to the lower bridge arms 13, 14, and 15 in a preset time period, such as a duty cycle of 10%, indicating that within one PWM wave cycle, the lower bridge arm is turned on for 10% of the time and turned off for 90% of the time.

[0059] In step S103, the maximum current value of the inverter output terminal connected to the lower bridge arm is monitored in real time;

[0060] In an example, when at least one PWM wave with a certain duty cycle is output to the lower bridge arm 13, the maximum current value in the output line 7 of the inverter 16 connected to the lower bridge arm 13 is monitored in real time; when at least one PWM wave with a certain duty cycle is output to the lower bridge arm 14, the maximum current value in the output line 8 of the inverter 16 connected to the lower bridge arm 14 is monitored in real time; when at least one PWM wave with a certain duty cycle is output to the lower bridge arm 15, the maximum current value in the output line 9 of the inverter 16 connected to the lower bridge arm 15 is monitored in real time; and the obtained maximum current value is recorded as Imax (A).

[0061] In step S104, a peak current coefficient is obtained according to the maximum current value;

[0062] In one example, step S104 may include steps S104 - 01 and S104 - 02 .

[0063] Wherein, step S104-01: obtaining a saturation current value according to the real-time voltage of the power supply and the real-time value of the current limiting component;

[0064] In one example, since the power supply 2 in this embodiment selects the DC bus voltage, and the current limiting component 3 selects the existing brake resistor Rb in the inverter 16, the calculation method of the saturation current value is: saturation current (A), I0 = current bus voltage (V) / brake resistor (ohm). When the current limiting component 3 is other components, it is only necessary to change the corresponding saturation current value calculation method according to the properties of the current limiting component and the real-time value in the loop.

[0065] Wherein, step S104-02: obtaining the peak current coefficient according to the saturation current value and the maximum current value;

[0066] In one example, according to the obtained maximum current value Imax and the saturation current value I0, the peak current coefficient a can be obtained according to the calculation formula of the peak current coefficient a=(Imax / I0)*100(%). After obtaining the peak current coefficient, step S105 is executed to determine whether the star-closing contactor 10 is failed.

[0067] In step S105, if the peak current coefficient is greater than the preset effective coefficient, it is determined that the star-sealing contactor circuit connected to the lower bridge arm is normal; if the peak current coefficient is less than the preset failure coefficient, it is determined that the star-sealing contactor circuit connected to the lower bridge arm is failed.

[0068] In one example, when detecting the circuit where the lower bridge arm 13 is located, if the peak current coefficient a obtained is greater than the preset effective coefficient Pmax, such as Pmax=90%, it is determined that the circuit of the star-sealing contactor 10 connected to the lower bridge arm 13 is normal, that is, the U-phase star-sealing of the permanent magnet synchronous traction machine 11 is normal; if the peak current coefficient a obtained is less than the preset failure coefficient Pmin, such as Pmin=30%, it is determined that the circuit of the star-sealing contactor 10 connected to the lower bridge arm 13 is failed, that is, the U-phase star-sealing of the permanent magnet synchronous traction machine 11 is failed. Detecting the circuit where the lower bridge arms 14 and 15 are located is similar to detecting the circuit where the lower bridge arm 13 is located.

[0069] When all the star-sealing circuits in the star-sealing contactors 10 are detected to be normal, the detection can be terminated by default, or "the star-sealing braking function is normal" can be reported; and the switch in the star-sealing failure detection 4 is turned on to restore the circuit operation to the non-star-sealing failure detection state.

[0070] If it is detected that any one of the three phases U, V, and W of the permanent magnet synchronous traction machine 11 fails to lock the star, a "locking brake function fails or is cancelled" fault is reported, and the elevator is prohibited from running.

[0071] The steps of the above method are divided only for the purpose of clear description. When implemented, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent; adding insignificant modifications to the algorithm or process or introducing insignificant designs without changing the core design of the algorithm and process are all within the scope of protection of this patent.

[0072] It is not difficult to find that this embodiment is a method embodiment corresponding to the above circuit embodiment, and this embodiment can be implemented in conjunction with the above circuit embodiment. The relevant technical details mentioned in the above circuit embodiment are still valid in this embodiment, and in order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the above circuit embodiment.

[0073] Another embodiment of the present invention relates to a method for detecting failure of a star-sealing contactor, which can be applied to the electrical control circuit of the star-sealing contactor disclosed in the present invention. The method for detecting failure of a star-sealing contactor provided in this embodiment can actually be understood as a current closed-loop detection method. The implementation details of the method for detecting failure of a star-sealing contactor of this embodiment are described in detail below. The following content is only for the convenience of understanding the implementation details provided, and is not necessary for implementing this solution.

[0074] like Figure 2 As shown, in step S201, all contacts in the loop where the star-failure detection circuit is located are closed.

[0075] In one example, before detecting any one of the star-sealing lines in the star-sealing contactor 10 in turn, all contacts in the closed loop are closed, that is, the contacts in the star-sealing line in the star-sealing contactor 10 are closed, and all contacts in the star-sealing failure detection circuit 4 are closed. If there is a main contactor 20 in the output circuits 7, 8, and 9 from the frequency converter 16 to the permanent magnet synchronous traction machine 11, the contacts of the main contactor 20 are also closed.

[0076] In step S202, a target current value flowing through the inverter output terminal connected to the lower bridge arm is given; the target current value is a saturation current value of a preset proportion;

[0077] In one example, a current target value Iref(%) flowing through output lines 7, 8, 9 of the inverter 16 respectively connected to the lower bridge arms 13, 14, 15, such as 50% of the saturation current I0, is given as a target for adjusting the first feedback current value in step S204.

[0078] In step S203, at least one PWM wave is output to all the lower bridge arms in sequence within a preset time period, the PWM wave waveform is monitored, and the following steps are performed on the loop where each lower bridge arm is located respectively;

[0079] In one example, the carrier frequency of the PWM wave to be output by the lower bridge arms 13, 14, and 15 is determined, such as a carrier frequency of 8K; and at least one PWM wave is output to the lower bridge arms 13, 14, and 15 in turn within a preset time period, thereby performing the remaining steps of failure detection on the star-sealing contactor lines connected to the loops where the lower bridge arms are located.

[0080] In step S204, at the moment of underflow of the PWM wave, the first feedback current value of the inverter output end connected to the lower bridge arm is sampled, and the duty cycle of the PWM wave output by the lower bridge arm is adjusted to control the first feedback current value according to the current target value.

[0081] In one example, when at least one PWM wave is output to the lower bridge arm 13, at the time of PWM wave underflow, the first feedback current value in the output end line 7 of the inverter 16 connected to the lower bridge arm 13 is sampled, and the duty cycle of the PWM wave output by the lower bridge arm 13 is adjusted to control the magnitude of the first feedback current value according to the magnitude of the current target value preset in step S202. When at least one PWM wave is output to the lower bridge arms 14 and 15, the situation is similar to when at least one PWM wave is output to the lower bridge arm 13.

[0082] In step S205, it is determined whether the difference between the first feedback current value after the control and the current target value is less than a preset threshold; if so, step S207 is executed, otherwise, step S206 is executed.

[0083] In one example, when detecting the loop where the lower bridge arm 13 is located, if the difference between the sampled first feedback current value and the current target value is less than a preset threshold value after the duty cycle of the pwm wave output by the lower bridge arm 13 is controlled, that is, the sampled first feedback current value is close to the current target value, then step S207 is executed; otherwise, step S206 is executed. Detecting the loop where the lower bridge arms 14 and 15 are located is similar to detecting the loop where the lower bridge arm 13 is located.

[0084] In step 206 , if the first feedback current value is less than a preset threshold, step S208 is executed; if the difference between the first feedback current value and the saturation current value is less than a preset threshold, step S209 is executed.

[0085] In one example, when detecting the loop where the lower bridge arm 13 is located, if the monitored first feedback current value is less than the preset threshold value, that is, the first feedback current value is close to zero, step S208 is executed; if the difference between the monitored first feedback current value and the saturation current value is less than the preset threshold value, that is, the first feedback current value is close to the saturation current value, step S209 is executed. Detecting the loop where the lower bridge arms 14 and 15 are located is similar to detecting the loop where the lower bridge arm 13 is located.

[0086] In step S207, at the moment when the PWM wave overflows, the second feedback current value of the inverter output end connected to the lower bridge arm is sampled, and it is determined whether the second feedback current value is less than a preset threshold; if so, step S209 is executed, otherwise step S208 is executed.

[0087] In one example, when detecting the loop where the lower bridge arm 13 is located, at the moment of PWM wave overflow, if the sampled second feedback current value in the output end line 7 of the inverter 16 connected to the lower bridge arm 13 is always less than the preset threshold, such as the second feedback current value is always close to zero, then step S209 is executed; otherwise, step S208 is executed. Detecting the loop where the lower bridge arms 14 and 15 are located is similar to detecting the loop where the lower bridge arm 13 is located.

[0088] In order to make the diagram clear, this application is attached Figure 4 Step S206 is divided into step S206 - 1 and step S206 - 2 .

[0089] In step S208, it is determined that the star-blocking contactor circuit connected to the lower bridge arm is failed.

[0090] In one example, when detecting the circuit where the lower bridge arm 13 is located, it is determined that the star-sealing circuit in the star-sealing contactor 10 connected to the lower bridge arm 13 is failed, that is, it is determined that the U-phase star-sealing circuit of the permanent magnet synchronous traction machine 11 is failed, and then it is determined that the star-sealing contactor 10 is failed. Detecting the circuit where the lower bridge arms 14 and 15 are located is similar to detecting the circuit where the lower bridge arm 13 is located.

[0091] In step S209, it is determined that the star-blocking contactor circuit connected to the lower bridge arm is normal.

[0092] In one example, when detecting the circuit where the lower bridge arm 13 is located, after determining that the star-sealing circuit in the star-sealing contactor 10 connected to the lower bridge arm 13 is normal, continue to perform star-sealing circuit failure detection on the circuit where the lower bridge arms 14 and 15 are located. The detection of the circuit where the lower bridge arms 14 and 15 are located is similar to the detection of the circuit where the lower bridge arm 13 is located.

[0093] When all the star-sealing circuits in the star-sealing contactors 10 are detected to be normal, the detection can be terminated by default, or "the star-sealing braking function is normal" can be reported; and the switch in the star-sealing failure detection 4 is turned on to restore the circuit operation to the non-star-sealing failure detection state.

[0094] This implementation can adjust the duty cycle of the PWM wave output by the lower bridge arm to control the feedback current value at the PWM wave underflow moment, and determine whether the star-sealing contactor circuit is failed based on the sampled current value at the inverter output end and the current target value.

[0095] If it is detected that any one of the three phases U, V, and W of the permanent magnet synchronous traction machine 11 fails to lock the star, a "locking brake function fails or is cancelled" fault is reported, and the elevator is prohibited from running.

[0096] The steps of the above method are divided only for the purpose of clear description. When implemented, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent; adding insignificant modifications to the algorithm or process or introducing insignificant designs without changing the core design of the algorithm and process are all within the scope of protection of this patent.

[0097] It is not difficult to find that this embodiment is a method embodiment corresponding to the above circuit embodiment, and this embodiment can be implemented in conjunction with the above circuit embodiment. The relevant technical details mentioned in the above circuit embodiment are still valid in this embodiment, and in order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the above circuit embodiment.

[0098] Those skilled in the art can understand that all or part of the steps in the above-mentioned implementation method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions for a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute all or part of the steps of the method described in each implementation of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0099] Those skilled in the art will appreciate that the above-mentioned embodiments are specific embodiments for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A star-sealing contactor electrical control circuit, It is characterized in that It includes frequency converter, permanent magnet synchronous traction machine, star-sealing contactor and star-sealing failure detection circuit; The IGBT upper and lower bridge arm switches in the frequency converter are respectively connected to the three windings of the permanent magnet synchronous traction machine through the output end of the frequency converter; The three windings of the permanent magnet synchronous traction machine are also connected to the star-sealing contactor; One end of the star-sealing failure detection circuit is connected to the common end of the star-sealing contactor, and the other end is connected to the power supply via the current limiting component in the frequency converter; Among them, the star-sealing failure detection circuit is used to detect whether the star-sealing circuit, the current limiting component, the power supply and the lower bridge arm in the star-sealing contactor form a normal circuit, and when it is detected that a normal circuit cannot be formed, it is determined that there is a circuit break in the star-sealing circuit, and then the star-sealing contactor is determined to be failed.

2. The electric control circuit of the star-sealing contactor according to claim 1, It is characterized in that The current limiting components in the frequency converter include: a braking resistor or an inductor.

3. The electric control circuit of the star-sealing contactor according to claim 1, It is characterized in that The star-sealing failure detection circuit is connected to the common end of the star-sealing contactor through at least one switch; The at least one switch is in a closed state when the star-sealing failure detection circuit is working, and is in an open state when the star-sealing failure detection circuit is not working.

4. The electric control circuit of the star-sealing contactor according to any one of claims 1 to 3, It is characterized in that The three contacts of the star-sealing contactor are respectively connected to the three-phase winding lead wires of the permanent magnet synchronous traction machine.

5. A method for detecting failure of a star-closing contactor, It is characterized in that The star-sealing contactor is a star-sealing contactor in an electrical control circuit of a star-sealing contactor according to any one of claims 1 to 4, and the method comprises: S101: closing all contacts in the loop where the star-failure detection circuit is located; S102: outputting at least one PWM wave with a certain duty cycle to all the lower bridge arms in sequence within a preset time period, and executing the following steps S103 to S105; S103: monitoring in real time the maximum current value of the inverter output terminal connected to the lower bridge arm; S104: Obtaining a peak current coefficient according to the maximum current value; S105: If the peak current coefficient is greater than the preset effective coefficient, it is determined that the star-sealing contactor circuit connected to the lower bridge arm is normal; if the peak current coefficient is less than the preset failure coefficient, it is determined that the star-sealing contactor circuit connected to the lower bridge arm is failed.

6. The method for detecting failure of a star-sealing contactor according to claim 5, It is characterized in that The obtaining of the peak current coefficient according to the maximum current value includes: Acquire a saturation current value according to the real-time voltage of the power supply and the real-time value of the current limiting component; The peak current coefficient is obtained according to the saturation current value and the maximum current value.

7. A method for detecting failure of a star-closing contactor, It is characterized in that The star-sealing contactor is a star-sealing contactor in an electrical control circuit of a star-sealing contactor according to any one of claims 1 to 4, and the method comprises: S201: closing all contacts in the loop where the star-failure detection circuit is located; S202: setting a target current value flowing through the inverter output terminal connected to the lower bridge arm; the target current value is a saturation current value of a preset proportion; S203: outputting at least one PWM wave to all the lower bridge arms in sequence within a preset time period, monitoring the PWM wave waveform, and performing the following steps on the loop where each lower bridge arm is located respectively; S204: at the time of underflow of the PWM wave, sampling the first feedback current value of the inverter output terminal connected to the lower bridge arm, and adjusting the duty cycle of the PWM wave output by the lower bridge arm to control the first feedback current value according to the current target value; S205: Determine whether the difference between the first feedback current value after the control and the current target value is less than a preset threshold; if so, execute step S207, otherwise execute step S206; S206: If the first feedback current value is less than a preset threshold, execute step S208; if the difference between the first feedback current value and the saturation current value is less than a preset threshold, execute step S209; S207: At the overflow moment of the PWM wave, sampling the second feedback current value of the inverter output terminal connected to the lower bridge arm, and determining whether the second feedback current value is less than a preset threshold; if so, executing step S209, otherwise executing step S208; S208: determining that the star-blocking contactor circuit connected to the lower bridge arm is failed; S209: Determine whether the star-blocking contactor circuit connected to the lower bridge arm is normal.

8. A computer-readable storage medium storing a computer program, It is characterized in that When the computer program is executed by a processor, the method for detecting failure of a star-sealing contactor according to any one of claims 5 to 7 is implemented.

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