Frequency converter control method and device based on safe torque off and storage medium

Abstract

The application relates to the technical field of frequency converter control, and particularly discloses a frequency converter control method and device based on safety torque cancellation and a storage medium, the method comprising the following steps: judging whether the current elevator triggers a stop; if yes, outputting a brake band control instruction to execute a brake band operation, and acquiring an elevator running speed; executing a safety torque cancellation verification operation based on the elevator running speed; if the verification result represents normal function, executing safety torque cancellation; determining a safety parameter of a driving component, and controlling the elevator host to execute corresponding safety star sealing control operation based on the safety parameter. The safety torque cancellation function of the elevator is quickly verified, so that the electronic star sealing operation is safely and reliably executed, the elevator fault response speed and the safety of fault emergency treatment are improved, and the actual requirements of enterprises are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of frequency converter control, and in particular to a frequency converter control method and device based on safe torque off and a storage medium. BACKGROUND

[0002] As a necessary transportation tool in modern buildings, elevators are widely used in modern society. Due to their vertical operation characteristics, the control reliability is closely related to the personal safety of passengers.

[0003] Modern elevators are often comprehensively controlled by frequency converters. In order to improve the safety of elevator operation control, technicians have adopted a large number of safety designs, including setting a safe torque off module in the frequency converter, and applying safe torque off (STO) technology as a key technology to ensure that the elevator main machine cannot output any torque, which is widely used in many elevators.

[0004] In the actual application process of STO, STO is activated according to the trigger signal of a specific device in the safety circuit, such as the activation of a maintenance switch, the activation of an emergency stop switch, and the activation of a shaft safety switch. At this time, STO cuts off the upper and lower levels of the elevator main machine power supply (such as the upper and lower bridge arms IGBT of the inverter), thereby cutting off the driving capability of the elevator main machine from the source to ensure the safety of elevator maintenance and operation. In the actual application process, technicians have found that this technology at least has the following technical problems:

[0005] Since STO directly cuts off the upper and lower levels of the elevator main machine power supply, the action timing of STO and the safety functions such as mechanical brake and star braking must be accurate, otherwise it may cause equipment damage or safety risks. For example, when the elevator is running at high speed, if the star braking is cut in too early, it will generate a large current, damaging the motor and the driver, and causing great loss to the enterprise. SUMMARY

[0006] In order to overcome the above technical problems in the prior art, the present application provides a frequency converter control method and device based on safe torque off and a storage medium, which quickly verifies the safe torque off function of the elevator, thereby safely and reliably performing electronic star braking, improves the elevator fault response speed and the safety of fault emergency handling, and meets the actual needs of enterprises.

[0007] In order to achieve the above object, the embodiment of the present application provides a frequency converter control method based on safe torque cancel, which is applied to a master control unit of a frequency converter connected with an elevator host, and the method comprises the following steps: judging whether the elevator currently triggers a stop; if yes, outputting a brake holding control instruction to execute a brake holding operation, obtaining an elevator running speed; executing a safe torque cancel verification operation based on the elevator running speed; if the verification result represents a normal function, executing a safe torque cancel; determining a safety parameter of a driving component, and controlling the elevator host to execute a corresponding safety star seal control operation based on the safety parameter.

[0008] Preferably, the safe torque cancel verification operation based on the elevator running speed comprises: if the elevator running speed is zero, determining an elevator jitter current; controlling the elevator host to execute a corresponding elevator jitter operation based on the elevator jitter current; obtaining jitter information of a car for the elevator jitter operation; generating a corresponding verification result based on the jitter information; if the elevator running speed is not zero, obtaining an elevator load, determining an expected deceleration based on the elevator load; determining an actual deceleration based on the elevator running speed; and generating a corresponding verification result based on the expected deceleration and the actual deceleration.

[0009] Preferably, the determination of the elevator jitter current comprises: obtaining jitter data of an elevator car; judging whether there is a frightened passenger based on the jitter data; if yes, determining a corresponding passive jitter operation based on the jitter data, and determining a corresponding elevator jitter current based on the passive jitter operation; otherwise, determining that the passenger can accept jitter, determining an active jitter operation based on the jitter data and the passenger can accept jitter, and determining a corresponding elevator jitter current based on the active jitter operation.

[0010] Preferably, the corresponding elevator jitter operation based on the elevator jitter current comprises: determining an output timing of the elevator jitter current; synchronously generating an opening timing for a brake holding based on the output timing; and controlling the brake holding and the elevator host to execute corresponding brake holding opening operation and host driving operation respectively based on the opening timing and the output timing.

[0011] Preferably, the determining the safety parameter of the drive component comprises: determining all drive components of the elevator; determining a limit parameter of each drive component, the limit parameter comprising a maximum operating current, a maximum operating power, a maximum temperature resistance of each drive component, and a maximum reverse torque of the elevator host; determining an operating current threshold based on the maximum operating current of each drive component, determining an operating power threshold based on the maximum operating power of each drive component, and determining an operating temperature threshold based on the maximum temperature resistance of each drive component; determining a correlation between the operating current, the operating power, and the operating temperature, and adjusting the operating current threshold, the operating power threshold, and the operating temperature threshold in linkage based on the correlation to generate an adjusted current threshold, an adjusted power threshold, and an adjusted temperature threshold; and generating a corresponding safety parameter based on the adjusted current threshold, the adjusted power threshold, the adjusted temperature threshold, and the maximum reverse torque.

[0012] Preferably, the controlling the elevator host to perform a corresponding safety star-enclosure control operation based on the safety parameter comprises: determining a star-enclosure safety speed based on the safety parameter; controlling the elevator host to perform a corresponding star-enclosure control operation based on the star-enclosure safety speed; and determining a corresponding induced current based on the star-enclosure control operation, and performing a corresponding current-limiting control operation based on the induced current.

[0013] Preferably, the determining the star-enclosure safety speed based on the safety parameter comprises: determining a first current threshold based on the maximum reverse torque; determining a first star-enclosure safety speed based on the first current threshold; determining a current temperature of each drive component; determining a temperature that can be raised based on the current temperature and the adjusted temperature threshold; determining a second current threshold based on the adjusted current threshold, the adjusted power threshold, and the temperature that can be raised; determining a second star-enclosure safety speed based on the second current threshold; and determining a star-enclosure safety speed based on the first star-enclosure safety speed and the second star-enclosure safety speed.

[0014] Preferably, the drive component comprises a power switch, and the performing the corresponding current-limiting control operation based on the induced current comprises: determining a maximum power switch current of the power switch according to the limit parameter; determining whether the induced current is greater than the maximum power switch current; if yes, controlling a preset current controller to process the induced current to generate a limiting value current, and controlling the limiting value current to flow through the power switch; and if not, controlling the induced current to flow through the power switch.

[0015] Correspondingly, the application further provides a frequency converter control device based on safe torque cancel, applied to a master control unit of a frequency converter, wherein the frequency converter is connected with an elevator host, and the device comprises: a judging unit, configured to judge whether the elevator currently triggers a stop; a brake holding unit, configured to output a brake holding control instruction to perform a brake holding operation and acquire an elevator running speed in the case of triggering the stop; a verifying unit, configured to perform a safe torque cancel verifying operation based on the elevator running speed; a function executing unit, configured to perform the safe torque cancel if a verifying result represents a normal function; and a star sealing control unit, configured to determine a safety parameter of a driving component, and control the elevator host to perform a corresponding safety star sealing control operation based on the safety parameter.

[0016] In another aspect, the application further provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the method provided by the embodiments of the application.

[0017] Through the technical solutions provided by the application, the application has at least the following technical effects:

[0018] By improving the existing elevator control method, when the elevator triggers a stop, the frequency converter first verifies the safe torque cancel function of the elevator according to the actual running condition of the elevator and the state of the passengers, and then controls the elevator host to perform the corresponding electronic star sealing brake according to the actual electrical parameters of each driving component, thereby effectively protecting the running safety of the electrical components of the elevator, effectively ensuring the fault response speed and response reliability of the elevator, meeting the actual needs of enterprises, and improving the user experience.

[0019] Other features and advantages of the embodiments of the application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are included to provide a further understanding of the embodiments of the application, and constitute a part of the specification, and are used together with the following specific implementation part to explain the embodiments of the application, but do not constitute a limitation on the embodiments of the application. In the drawings:

[0021] Figure 1 is a specific implementation flowchart of the frequency converter control method based on safe torque cancel provided by the embodiments of the application;

[0022] Figure 2 is a structural schematic diagram of the frequency converter control device based on safe torque cancel provided by the embodiments of the application. DETAILED DESCRIPTION

[0023] The specific implementation of the embodiments of the present application is described in detail below with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiments of the present application, and is not used to limit the embodiments of the present application.

[0024] The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "Multiple" means two or more, and in view of this, "multiple" can also be understood as "at least two" in the embodiments of the present application. "And / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / ", if not specially stated, generally represents that the associated objects before and after are in an "or" relationship. In addition, it should be understood that in the description of the embodiments of the present application, "first", "second", etc. are only used for the purpose of distinguishing the description, and cannot be understood as indicating or implying relative importance, nor can it be understood as indicating or implying order.

[0025] Please refer to Figure 1 The embodiments of the present application provide a frequency converter control method based on safety torque cancellation, which is applied to a master control unit of a frequency converter, the frequency converter is connected with an elevator host, and the method comprises:

[0026] S10, judging whether the current elevator triggers a stop;

[0027] S20, if yes, outputting a brake holding control instruction to execute a brake holding operation and obtaining an elevator running speed;

[0028] S30, performing a safety torque cancellation verification operation based on the elevator running speed;

[0029] S40, if the verification result represents normal function, performing safety torque cancellation;

[0030] S50, determining a safety parameter of a driving component, and controlling the elevator host to perform a corresponding safety star seal control operation based on the safety parameter.

[0031] In a possible implementation, the running state of the elevator is monitored in real time, and once the elevator is found to trigger a stop, such as an abnormal power supply, a communication interruption, an elevator coasting, a steel wire rope breakage, and other abnormal trigger elevator unexpected stops, a brake holding operation is immediately performed to mechanically brake the elevator car, so as to first perform an elevator safety control operation, and in order to facilitate subsequent further safety processing, a safety torque cancellation operation must be immediately performed to cut off the power source of the elevator main machine from the source, while the fast start-up capability when the elevator abnormally recovers is retained. However, if the safety torque cancellation is directly performed, equipment damage may be caused, such as a main control that considers that the STO has been performed but actually has not been performed, and at this time, if the electronic star braking is immediately performed, the power device or the elevator main machine may be damaged.

[0032] Therefore, in order to solve the above technical problems, after the brake holding operation is performed, a safety torque cancellation verification operation is further immediately performed according to the elevator running speed. For the verification of the safety torque cancellation, generally, static and dynamic verification are divided. For the static verification, driving force is applied to the elevator main machine in the STO state (the main control considers that it is actually not in the STO state), and whether the STO is activated is determined by judging whether the elevator main machine is in action; and for the dynamic verification, whether the elevator car is uniformly decelerated is observed in the STO state. However, in the actual application process, the elevator stop is often caused by a fault, such as a passenger trapping fault, an elevator overspeed fault, and the like, at this time, direct verification may cause panic of passengers in the car and further cause an accident to occur.

[0033] In the embodiment of the present application, the safety torque cancellation verification operation based on the elevator running speed comprises: if the elevator running speed is zero, determining an elevator jitter current; controlling the elevator main machine to perform a corresponding elevator jitter operation based on the elevator jitter current; obtaining jitter information of the car for the elevator jitter operation; generating a corresponding verification result based on the jitter information; and if the elevator running speed is not zero, obtaining an elevator load, determining an expected deceleration based on the elevator load, determining an actual deceleration based on the elevator running speed, and generating a corresponding verification result based on the expected deceleration and the actual deceleration.

[0034] In a possible implementation, the current state of the elevator is first determined according to the elevator running speed, and if the current elevator is in a static state (that is, the elevator running speed is zero), a small amplitude jitter operation is performed on the elevator, so as to avoid causing panic of passengers caused by directly driving the elevator. In the actual application process, for passengers in a trapped state, they often walk back and forth in the car, so that the car has a certain jitter, which may interfere with the verification operation on the one hand, and may increase the jitter amplitude of the jitter operation, and further increase the panic of the passengers on the other hand.

[0035] To solve the above technical problems, in the embodiment of the present application, the elevator jitter current is determined, comprising: obtaining jitter data of the elevator car; determining whether there is a panic passenger based on the jitter data; if yes, determining a corresponding passive jitter operation based on the jitter data, determining a corresponding elevator jitter current based on the passive jitter operation; otherwise, determining that the passengers can accept jitter, determining an active jitter operation based on the jitter data and the passengers can accept jitter, and determining a corresponding elevator jitter current based on the active jitter operation.

[0036] In a possible implementation, before performing the jitter operation, first, the jitter data of the elevator car is obtained, and whether there is a panic passenger is analyzed, for example, the jitter data of the elevator car is obtained by a vibration sensor (or in combination with a sound sensor, a camera, etc.) in the car. The frequency and amplitude of the data are analyzed: if continuous, irregular high-amplitude vibration (indicating that a passenger is in panic movement or is continuously hitting the car door) is detected, it is determined that there is a panic passenger; if the vibration data is weak and regular (such as slight shaking like heartbeat), it is determined that the passenger is relatively calm.

[0037] Specifically, if the passenger is relatively panicked at this time, such as walking back and forth in the car or continuously hitting the car door, etc., at this time, whether there is a panic passenger can be determined according to the car jitter data; if the passenger is relatively calm at this time, the jitter data of the elevator car can be weak or even without jitter. At this time, if there is a panic passenger (i.e., the car jitter is severe), a corresponding passive jitter operation is determined according to the jitter data, such as generating a reverse elevator jitter current according to the fluctuation of the jitter data. In the subsequent elevator jitter operation, on the one hand, a verification operation can be performed, and on the other hand, the elevator jitter amplitude can be reduced to reduce the panic psychology of other passengers, thereby achieving the purpose of pacifying the passengers.

[0038] If the passengers in the elevator car are relatively calm, it is determined that the passengers can accept jitter (such as acceleration less than 0.1 m / s²), which can be determined in advance according to big data or test. Then, the action amplitude of the jitter action that can be performed is determined according to the jitter data of the elevator car and the passengers can accept jitter, and a corresponding elevator jitter current is determined according to the action amplitude, so that in the subsequent verification process, the elevator performs a small-amplitude jitter operation that does not affect the passengers' emotions, ensuring that the verification process is almost imperceptible to the passengers.

[0039] In the embodiment of the present application, by utilizing the actual situation of the elevator during operation, different jitter verification operations are taken according to the panic reaction of the elevator passengers, so that the jitter verification action can be accurately performed while pacifying the panic emotions of the passengers, thereby realizing fast, safe and reliable function verification, providing accurate decision for the subsequent safety operation to be immediately performed, and improving user experience.

[0040] After the elevator jitter current is determined, corresponding elevator jitter operation is performed. In the specific implementation process, since the brake is controlled to be in the combined state in advance, and the brake needs to be released at this time in order to verify the STO, in order to ensure the reliability and safety of the function verification, the consistency of the jitter action and the brake opening action needs to be strictly maintained, otherwise it may cause stronger jitter effect and intensify the panic effect of the passengers.

[0041] In the embodiment of the application, the corresponding elevator jitter operation is performed based on the elevator jitter current, comprising: determining the output timing of the elevator jitter current; synchronously generating an opening timing for the brake based on the output timing; and controlling the brake and the elevator main machine to perform corresponding brake opening operation and main machine driving operation respectively based on the opening timing and the output timing.

[0042] In a possible implementation, the output timing of the elevator jitter current (such as a pulse current lasting for 100 milliseconds) is first determined, and then the opening timing of the brake (the brake is released for about 100 milliseconds at the same time instant) is synchronously generated, that is, the synchronous actions of the elevator main machine and the brake need to be maintained, and at this time, the elevator main machine and the brake are controlled to synchronously perform corresponding main machine driving (jitter) operation and brake opening operation respectively, so as to ensure that the brake can be closed in time at the moment when the jitter action is completed, thereby ensuring the safety of the elevator car in the case of rapid collection of verification data. At this time, the jitter information of the car corresponding to the elevator jitter is obtained, if the elevator car does not generate jitter data corresponding to the elevator jitter operation, it can be determined that the STO function is normal, and the STO can be executed; otherwise, for example, the motor drives the car to generate a small displacement or vibration, it can be determined that the STO function is abnormal, and the instruction for activating the STO can be output, but the electronic star sealing operation cannot be further executed.

[0043] In the embodiment of the application, by accurately controlling the timing of the brake opening and the elevator main machine jitter, the safety of the passengers in the car is strictly guaranteed on the basis of reliable verification operation, the occurrence of unexpected situations is avoided, the safety of the passengers can be ensured before the technicians arrive at the scene, and the actual demand is met.

[0044] If the elevator is in a dynamic state (that is, the current running speed of the elevator is not zero), the load of the elevator is directly obtained at this time, and the inertia force corresponding to the whole elevator car is determined according to the load of the elevator, the counter electromotive force of the elevator main machine can be determined according to the current running speed of the elevator, and the expected deceleration is further determined, at this time, the actual deceleration of the elevator can be determined according to the running speed of the elevator, and whether the STO verification result can be determined according to whether the two decelerations match, specifically, if the two decelerations match, it can be determined that the STO can be normally activated, otherwise, it can be determined that the STO is not normally activated.

[0045] In the embodiment of the present application, by adopting different function verification strategies according to the actual situation of the elevator operation, the passenger-unaware rapid function verification can be realized under the condition of ensuring the minimum disturbance to the passengers and the safety guarantee, the fault response speed is improved, and the user experience is improved.

[0046] After determining that the STO function can be normally activated, the control elevator immediately executes the safety torque cancellation function and performs the corresponding electronic star braking operation. However, in actual application, if the electronic star braking operation is immediately performed after the execution of the STO, the induced current generated due to the too fast running speed of the elevator can be too large to cause damage to the elevator device.

[0047] In the embodiment of the present application, the determination of the safety parameters of the driving components includes: determining all driving components of the elevator; determining limit parameters of each driving component, the limit parameters including maximum running current, maximum running power, maximum tolerance temperature of each driving component, and maximum reverse torque of the elevator host; determining a running current threshold based on the maximum running current of each driving component, determining a running power threshold based on the maximum running power of each driving component, and determining a running temperature threshold based on the maximum tolerance temperature of each driving component; determining a correlation relationship of the running current, the running power and the running temperature, and performing linkage adjustment on the running current threshold, the running power threshold and the running temperature threshold based on the correlation relationship to generate an adjusted current threshold, an adjusted power threshold and an adjusted temperature threshold; and generating corresponding safety parameters based on the adjusted current threshold, the adjusted power threshold, the adjusted temperature threshold and the maximum reverse torque.

[0048] In a possible implementation, all driving components are first determined, for example, all driving components of the current elevator are determined by a technician in advance, and the driving components include but are not limited to the elevator host, the power switch, the braking resistor and the like, then the safety parameters of each driving component are determined, and different driving components correspond to different safety parameters. Since each driving component in the elevator system is cooperated to realize the complete function of the entire elevator, and all electrical components are operated under the same electrical parameter in the process of cooperation, the corresponding control operation cannot be performed according to the safety parameters of each driving component, and the electrical component with the lowest normal operation parameter value should be taken as the parameter constraint of the whole.

[0049] Specifically, first, limit parameters of each drive component are determined, including but not limited to maximum operating current, maximum operating power, maximum temperature tolerance of each drive component, and maximum reverse torque of the elevator main machine. For example, for a power device (such as an IGBT), its maximum operating current should be determined, and once the current is exceeded, for example, the electronic star braking is performed in advance in the event of a successful STO activation under high-speed elevator operation, a huge induced current will cause the IGBT to burn out and further cause damage to the entire component. Therefore, in the specific implementation process, the operating current threshold is determined according to the maximum operating current of each drive component, the operating current threshold is the operating current value determined according to the maximum operating current of all drive components to meet the normal operation of all drive components and the maximum current value; the operating power threshold is determined according to the maximum operating power of each drive component, different drive components have different temperature rise rates at different powers, and excessive operating power can cause rapid burning of the drive component; and the operating temperature threshold is determined according to the maximum temperature tolerance of each drive component.

[0050] At this time, further, since the operating current has a related influence on the operating power, and the operating power has a related influence on the operating temperature, the operating current- operating power- operating temperature relationship is established, and the operating current threshold, the operating power threshold and the operating temperature threshold are further adjusted in linkage to determine the adjusted current threshold, the adjusted power threshold and the adjusted temperature threshold that meet the actual operation requirements, and finally, the safety parameters are generated according to the above adjusted parameters and the maximum reverse torque of the elevator main machine.

[0051] In the embodiment of the application, by analyzing the actual highest operating parameters of each drive component of the elevator in combination with the linkage constraint relationship between different drive components, the maximum safety parameter that the entire elevator system can withstand is determined, and in the subsequent safety control process, electronic star braking is only performed when the elevator operating parameters meet the safety parameter, thereby protecting each drive component of the elevator system to the greatest extent, avoiding enterprise loss, and meeting the actual needs of enterprises.

[0052] After the safety parameters are determined, the corresponding safety star braking control operation is performed. However, in actual application, due to various reasons such as deviation of sensing data, change of elevator operating conditions, deviation of data estimation, etc., the elevator operating parameters may have a certain deviation, which may still cause damage to the power device.

[0053] In the embodiment of the present application, the control of the elevator main machine to perform the corresponding safe star sealing control operation based on the safety parameter comprises: determining a star sealing safety speed based on the safety parameter; controlling the elevator main machine to perform the corresponding star sealing control operation based on the star sealing safety speed; and performing the corresponding current limiting control operation based on the induced current determined based on the star sealing control operation.

[0054] In a possible implementation, the star sealing safety speed is first determined based on the safety parameter. In the embodiment of the present application, the determination of the star sealing safety speed based on the safety parameter comprises: determining a first current threshold based on the maximum reverse torque; determining a first safe star sealing speed based on the first current threshold; determining a current temperature of each drive component; determining a temperature that can be raised based on the current temperature and the adjusted temperature threshold; determining a second current threshold based on the adjusted current threshold, the adjusted power threshold and the temperature that can be raised; determining a second safe star sealing speed based on the second current threshold; and determining the star sealing safety speed based on the first safe star sealing speed and the second safe star sealing speed.

[0055] Specifically, the first current threshold is first determined based on the maximum reverse torque. When the induced current is too large (possibly up to 10-20 times of the rated current), the reverse torque generated during the star sealing operation can be greater than the bearing range of the mechanical structure of the elevator main machine, thereby causing damage to the whole elevator main machine. Therefore, the maximum current that can be borne by the elevator main machine during the star sealing is first determined, and the first safe star sealing speed is further determined. At this time, further, for a power device (such as an IGBT), the temperature of the power device will rise when a large current passes through, and the excessively high temperature will also cause damage to the power device; for a motor, when the passing power is too large, the motor will also quickly rise in temperature and cause permanent damage (such as demagnetization, etc.). Therefore, the current temperature of each drive component is further determined, the temperature that can be raised is determined based on the current temperature and the adjusted temperature threshold, the second current threshold is determined based on the temperature generated by the current passing through each drive component, and the corresponding second safe star sealing speed is further determined. Finally, the star sealing safety speed is determined based on the two safe star sealing speeds, such as taking the smaller one as the star sealing safety speed (for example, 0.3 m / s). That is, the system will continuously monitor the actual running speed of the elevator, and only when the speed is reduced to below 0.3 m / s, the star sealing will be allowed to be performed.

[0056] In the embodiment of the present application, the maximum electrical operating parameters that can be borne by each drive component during the operation of the elevator are overall constrained, the star sealing speed is constrained from multiple dimensions, and therefore the operation safety of the elevator components can be guaranteed, and the reliability of the star sealing operation can be ensured.

[0057] After the safe star-enclosure speed is determined, the corresponding star-enclosure control operation is performed immediately, at this time, the induced current will be generated, since the induced current estimated in advance can be deviated from the actual induced current, the induced current corresponding to the star-enclosure control operation needs to be further obtained, and the corresponding current-limiting control operation is performed.

[0058] In the embodiment of the application, the driving component includes a power switch, and the performing of the corresponding current-limiting control operation based on the induced current includes: determining a maximum power switch current of the power switch according to the limit parameter; judging whether the induced current is greater than the maximum power switch current; if yes, controlling a preset current controller to process the induced current to generate a limiting value current, and controlling the limiting value current to flow through the power switch; and if not, controlling the induced current to flow through the power switch.

[0059] In a possible implementation, in order to further protect the power switch and other power devices in the elevator system, firstly, the maximum current of the power device is determined, for example, the maximum power switch current of the power switch, at this time, it is further judged whether the current induced current is greater than the maximum current, if yes, the current-limiting operation must be performed, and the induced current cannot directly flow through the power switch, otherwise, the power switch will be burned out, for example, in the embodiment of the application, the current controller with the current limiting value is configured in the system, and the current flowing through the IGBT is accurately adjusted through hysteresis control or peak current control, so that the current is limited to the corresponding current value I o slightly higher than the maximum torque generated by the star-enclosure braking, which can be pre-set through experiments or formulas (such as I o ≈ ψ r / L, wherein ψ r is the rotor flux, and L is the motor inductance), so as to ensure the safety of the power switch. If the current induced current is less than or equal to the maximum current, the current is directly allowed to flow through the power switch to generate the braking torque.

[0060] In the embodiment of the application, by improving the existing elevator control system, for the elevator with the safe torque cancellation function, the running state of the elevator under the influence of various environments for a long time is analyzed, various actual defects faced by the safe torque cancellation function in the actual application process are determined, and before the electronic star-enclosure braking is performed, the fast safe torque cancellation function verification is performed first, so that the damage of the elevator components caused by the time sequence inconsistency or unreasonable use of the safe torque cancellation function and the electronic star-enclosure braking is effectively avoided, the enterprise loss is greatly reduced, the impact on passengers is avoided, the actual needs of enterprises are met, and the user experience is improved.

[0061] Please refer to Figure 2Based on the same inventive concept, the embodiment of the present application provides a frequency converter control device based on safe torque cancellation, which is applied to a master control unit of a frequency converter connected with an elevator host, and comprises: a judging unit for judging whether the elevator currently triggers a stop; a brake holding unit for outputting a brake holding control instruction to perform a brake holding operation and obtaining an elevator running speed in the case of triggering the stop; a verifying unit for performing a safe torque cancellation verification operation based on the elevator running speed; a function executing unit for performing the safe torque cancellation if a verification result represents a normal function; and a star sealing control unit for determining a safety parameter of a driving component and controlling the elevator host to perform a corresponding safety star sealing control operation based on the safety parameter.

[0062] Further, the embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to realize the method of the embodiment of the present application.

[0063] The optional embodiments of the embodiment of the present application are described in detail above in combination with the drawings, however, the embodiment of the present application is not limited to the specific details in the above embodiments, and various simple modifications can be made to the technical solutions of the embodiment of the present application within the technical concept of the embodiment of the present application, and these simple modifications all belong to the protection scope of the embodiment of the present application.

[0064] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again in the embodiment of the present application.

[0065] Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiment methods can be completed by programs instructing related hardware, the programs are stored in a storage medium, and the storage medium includes a plurality of instructions for making a single-chip microcomputer, a chip or a processor execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk and various program code storage media.

[0066] In addition, various different embodiments of the embodiment of the present application can also be combined in any appropriate manner, as long as they do not contradict the technical concept of the embodiment of the present application, and they should also be considered as disclosed by the embodiment of the present application.

Claims

1. A variable frequency drive control method based on safe torque off, applied to a master control unit of a variable frequency drive connected with an elevator main machine, characterized in that, The method comprises: determining whether the elevator currently triggers a stop; if yes, outputting a brake control instruction to perform a brake operation, obtaining an elevator running speed; based on the elevator running speed, performing a safety torque cancellation verification operation; if the verification result represents normal function, performing safety torque cancellation; determining a safety parameter of a drive component, and based on the safety parameter, controlling the elevator main machine to perform a corresponding safety star seal control operation; the safety torque cancellation verification operation based on the elevator running speed comprises: if the elevator running speed is zero: determining an elevator jitter current; based on the elevator jitter current, controlling the elevator main machine to perform a corresponding elevator jitter operation; obtaining jitter information of the car for the elevator jitter operation; based on the jitter information, generating a corresponding verification result; if the elevator running speed is not zero: obtaining the elevator load, and based on the elevator load, determining an expected deceleration; based on the elevator running speed, determining an actual deceleration; based on the expected deceleration and the actual deceleration, generating a corresponding verification result.

2. The method of claim 1, wherein, The determination of the elevator jitter current comprises: obtaining jitter data of the elevator car; based on the jitter data, determining whether there is a panic passenger; if yes, based on the jitter data, determining a corresponding passive jitter operation, and based on the passive jitter operation, determining a corresponding elevator jitter current; otherwise, determining that the passenger can accept jitter, based on the jitter data and the passenger's acceptable jitter, determining an active jitter operation, and based on the active jitter operation, determining a corresponding elevator jitter current.

3. The method of claim 1, wherein, The control of the elevator main machine to perform a corresponding elevator jitter operation based on the elevator jitter current comprises: determining an output timing of the elevator jitter current; based on the output timing, synchronously generating an opening timing for the brake; based on the opening timing and the output timing, controlling the brake and the elevator main machine to perform corresponding brake opening operations and main machine driving operations, respectively.

4. The method of claim 1, wherein, The determination of the safety parameter of the drive component comprises: determining all drive components of the elevator; determining the limit parameters of each drive component, including the maximum running current, the maximum running power, the maximum temperature tolerance of each drive component, and the maximum reverse torque of the elevator main machine; based on the maximum running current of each drive component, determining a running current threshold, based on the maximum running power of each drive component, determining a running power threshold, and based on the maximum temperature tolerance of each drive component, determining a running temperature threshold; determining the correlation of running current-running power-running temperature, and based on the correlation, adjusting the running current threshold, the running power threshold and the running temperature threshold in linkage to generate an adjusted current threshold, an adjusted power threshold and an adjusted temperature threshold; based on the adjusted current threshold, the adjusted power threshold, the adjusted temperature threshold and the maximum reverse torque, generating a corresponding safety parameter.

5. The method of claim 4, wherein, The control of the elevator main machine to perform a corresponding safety star seal control operation based on the safety parameter comprises: determining a star seal safety speed based on the safety parameter; based on the star seal safety speed, controlling the elevator main machine to perform a corresponding star seal control operation; Determine a corresponding induced current based on the starve control operation, and perform a corresponding current limiting control operation based on the induced current.

6. The method of claim 5, wherein, The determining the starve safety speed based on the safety parameter comprises: Determining a first current threshold based on the maximum reverse torque; Determining a first starve safety speed based on the first current threshold; Determining a current temperature of each drive component; Determining a temperature that can be raised based on the current temperature and the adjusted temperature threshold; Determining a second current threshold based on the adjusted current threshold, the adjusted power threshold, and the temperature that can be raised; Determining a second starve safety speed based on the second current threshold; Determining a starve safety speed based on the first starve safety speed and the second starve safety speed.

7. The method of claim 6, wherein, The drive component comprises a power switch, and the performing the corresponding current limiting control operation based on the induced current comprises: Determining a maximum power switch current of the power switch according to the limit parameter; Determining whether the induced current is greater than the maximum power switch current; If yes, controlling a preset current controller to process the induced current to generate a limiting value current, and controlling the limiting value current to flow through the power switch; Otherwise, controlling the induced current to flow through the power switch.

8. A safety torque off based frequency inverter control device applied to a master control unit of a frequency inverter connected to an elevator main machine, characterized by, The device comprises: A judging unit configured to determine whether the elevator currently triggers a stop; A brake unit configured to output a brake control instruction to perform a brake operation in the case of triggering the stop, and acquire an elevator running speed; A verifying unit configured to perform a safety torque cancellation verification operation based on the elevator running speed; A function execution unit configured to perform the safety torque cancellation if a verification result represents a normal function; A starve control unit configured to determine a safety parameter of a drive component, and control the elevator main machine to perform a corresponding safety starve control operation based on the safety parameter; The verifying unit is specifically configured to: If the elevator running speed is zero: Determine an elevator jitter current; Control the elevator main machine to perform a corresponding elevator jitter operation based on the elevator jitter current; Acquire jitter information of a car for the elevator jitter operation; Generate a corresponding verification result based on the jitter information; If the elevator running speed is not zero: Acquire an elevator load, and determine an expected deceleration based on the elevator load; Determine an actual deceleration based on the elevator running speed; Generate a corresponding verification result based on the expected deceleration and the actual deceleration.

9. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the method in any one of claims 1-7.

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