Star sealing protection circuit, frequency converter and elevator

Abstract

The utility model discloses a star sealing protection circuit, a frequency converter and an elevator, and relates to the technical field of elevator control, and the star sealing protection circuit comprises a rectification module, a blocking module and an inversion module; the rectification module is connected with the inversion module through positive and negative DC buses, the inversion module is connected with the motor through a wiring terminal, and at least one of the positive and negative DC buses is connected with a blocking module; when the positive direct current bus and the negative direct current bus are in short circuit with the motor through the inversion module to form a star-sealing loop, the blocking module is used for disconnecting current between a power grid and the star-sealing loop, so that the wiring terminal is not electrified. According to the invention, electric shock accidents caused by live-line mistaken touch can be avoided, and the operation safety of maintenance personnel is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of elevator control, and in particular to a star-sealing protection circuit, a frequency converter and an elevator. Background Art

[0002] In the field of elevators, commonly used star-locking braking solutions include star-locking contactor braking and electronic star-locking braking. In the star-locking contactor braking solution, the terminal block between the inverter and the traction machine is usually not energized, so maintenance personnel often operate directly without powering off the system; in the electronic star-locking braking solution, the star-locking short circuit of the three-phase winding of the traction machine is achieved by controlling the inverter bridge in the inverter, and the terminal block between the inverter and the traction machine will always be energized. In this case, if the maintenance personnel forget to turn off the power and work directly, it is easy to accidentally touch the energized terminal block, causing an electric shock accident. Utility Model Content

[0003] The main purpose of this application is to propose a star-sealing protection circuit, a frequency converter and an elevator, aiming to solve the technical problem in the related art that there is a risk of electric shock in maintenance operations under the star-sealing condition of the elevator.

[0004] To achieve the above-mentioned purpose, the present application proposes a star-blocking protection circuit, which is connected to the power grid and the motor respectively, and the circuit includes a rectifier module, a blocking module and an inverter module;

[0005] The rectifier module is connected to the power grid and is connected to the inverter module through the positive and negative DC bus bars. The inverter module is connected to the motor through the wiring terminals. At least one of the positive and negative DC bus bars is connected to a blocking module.

[0006] When the positive and negative DC busbars are short-circuited with the motor through the inverter module to form a star-sealing circuit, the blocking module is used to disconnect the current between the grid and the star-sealing circuit to make the wiring terminals non-energized.

[0007] In one embodiment, one of the positive and negative DC bus bars is connected to a blocking module, a first output terminal of the rectifier module is connected to a first input terminal of the inverter module through the blocking module, and a second output terminal of the rectifier module is connected to a second input terminal of the inverter module through the other of the positive and negative DC bus bars.

[0008] In one embodiment, the inverter module includes an upper bridge arm switch tube and a lower bridge arm switch tube, and a common connection point of the upper bridge arm switch tube and the lower bridge arm switch tube is connected to the motor;

[0009] One of the upper bridge arm switch tube or the lower bridge arm switch tube is closed, so that the positive DC bus connected to the blocking module is short-circuited with the motor through the closed upper bridge arm switch tube, or the negative DC bus connected to the blocking module is short-circuited with the motor through the closed lower bridge arm switch tube, forming a star-sealing circuit; and when the blocking module disconnects the current between the grid and the star-sealing circuit, the motor star-sealing braking is performed.

[0010] In one embodiment, the circuit further comprises a control module;

[0011] The control module is respectively connected to the blocking module, the upper bridge arm switch tube and the lower bridge arm switch tube;

[0012] The control module is used to generate a driving signal, control the blocking module to disconnect according to the driving signal to disconnect the current between the power grid and the star-sealing circuit, and control the upper bridge arm switch tube or the lower bridge arm switch tube in the inverter module to close according to the driving signal to short-circuit the motor for star-sealing braking.

[0013] In one embodiment, the control module is further used to control the blocking module to be turned on according to the driving signal, and control the inverter module to normally invert and control the wave so that the motor can work normally.

[0014] In one embodiment, the circuit further comprises a bus capacitor;

[0015] One end of the bus capacitor is connected to the positive DC bus, and the other end of the bus capacitor is connected to the negative DC bus;

[0016] The bus capacitor is used to provide the starting voltage required for the motor to work.

[0017] In one embodiment, the inverter module adopts a full-bridge topology, and the motor adopts a three-phase winding motor;

[0018] The full-bridge topology includes three upper-arm switching tubes and three lower-arm switching tubes.

[0019] In one embodiment, the blocking module uses a controllable switch device, and the controllable switch device includes an electronic switch or a mechanical switch.

[0020] In addition, to achieve the above purpose, the present application also proposes a frequency converter, comprising:

[0021] Such as the star-sealing protection circuit mentioned above.

[0022] In addition, to achieve the above-mentioned purpose, the present application also proposes an elevator, comprising:

[0023] Such as the inverter mentioned above;

[0024] Motor, inverter drives the motor to control the operation of the car.

[0025] One or more technical solutions proposed in this application have at least the following technical effects:

[0026] A proposed star-sealing protection circuit is provided with a blocking module connected to the positive DC bus and / or the negative DC bus between the rectifier module and the inverter module. When the positive and negative DC buses are short-circuited with the motor through the inverter module to form a star-sealing circuit, the blocking module is used to disconnect the current between the power grid and the star-sealing circuit, thereby indirectly making the star-sealing circuit uncharged, thereby making the connection terminals between the inverter module and the motor uncharged, avoiding electric shock accidents caused by accidental contact with power on, and ensuring the working safety of maintenance personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a connection block diagram of the first embodiment of the star-sealing protection circuit of the present application;

[0030] Figure 2 Another connection block diagram of the first embodiment of the star-sealing protection circuit of the present application;

[0031] Figure 3 This is a connection block diagram of the second embodiment of the star-sealing protection circuit of the present application;

[0032] Figure 4 This is a topological diagram of the second embodiment of the star-sealing protection circuit of the present application;

[0033] Figure 5 This is a star-sealing schematic diagram of the second embodiment of the star-sealing protection circuit of the present application.

[0034] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0036] It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0037] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0038] In the field of elevators, the electrical braking of elevators can be achieved through the holding brake. When the holding brake fails, the elevator sliding speed can be limited by closing the star of the traction machine as an additional electrical braking solution. Closing the star means short-circuiting the three-phase winding of the traction machine to provide braking torque for the rotating traction machine to achieve braking.

[0039] At present, the commonly used star-sealing braking schemes include star-sealing contactor braking and electronic star-sealing braking. In the star-sealing contactor braking scheme, the star-sealing contactor set between the frequency converter and the traction machine is used to short-circuit the three-phase winding of the traction machine to achieve star-sealing. At this time, the frequency converter has no external output, and the wiring terminals between the frequency converter and the traction machine are not energized; in the electronic star-sealing braking scheme, the star-sealing short-circuiting of the three-phase winding of the traction machine is achieved by controlling the inverter bridge in the frequency converter. The three-phase winding of the traction machine is short-circuited to the positive and negative busbars of the frequency converter. Since the positive and negative busbars of the frequency converter are directly connected to the power grid, they belong to the primary power supply. At this time, the three-phase windings of the traction machine are all energized.

[0040] Under the star-sealing contactor braking scheme, because the wiring terminals between the inverter and the traction machine are usually not energized, maintenance personnel often operate directly without powering on the system, which can easily lead to bad habits. Based on this, when the star-sealing brake of the elevator is changed to the electronic star-sealing brake scheme for the sake of silence and life, maintenance personnel may still operate without powering on out of old habits, but because the wiring terminals between the inverter and the traction machine will always be energized under the electronic star-sealing brake scheme, if the maintenance personnel accidentally touch the wiring terminals during operation, it will cause accidents such as electric shock. At present, in order to avoid accidents, maintenance personnel are mainly required to turn off the power before operation through marking in product manuals or posting signs, but it is inevitable that they forget to turn off the power. In this case, if the maintenance personnel forget to turn off the power and work directly, it is still easy to accidentally touch the energized wiring terminals, thereby causing electric shock accidents.

[0041] Therefore, in the related art, there is a risk of electric shock in the maintenance work under the elevator star-locking condition. Figure 1 and Figure 2 , Figure 1 This is a connection block diagram of the first embodiment of the star-sealing protection circuit of the present application. Figure 2 This is another connection block diagram of the first embodiment of the star-sealing protection circuit of the present application.

[0042] In this embodiment, the star-blocking protection circuit is connected to the power grid and the motor respectively, and the circuit includes:

[0043] Rectification module, blocking module and inverter module;

[0044] The rectifier module is connected to the power grid and is connected to the inverter module through the positive and negative DC bus bars. The inverter module is connected to the motor through the wiring terminals. At least one of the positive and negative DC bus bars is connected to a blocking module.

[0045] When the positive and negative DC busbars are short-circuited with the motor through the inverter module to form a star-sealing circuit, the blocking module is used to disconnect the current between the grid and the star-sealing circuit to make the wiring terminals non-energized.

[0046] It should be noted that the star-sealing brake is a technology that makes the elevator's traction machine and the star-sealing circuit form a star-shaped loop, which is a rapid braking technology. It can prevent the elevator from slipping or flying due to the elevator's failure to brake in time when the elevator brake fails. Generally, the star-sealing circuit can be a frequency converter or a part of a frequency converter, and the star-shaped loop formed with the motor is the star-sealing circuit, wherein the star-sealing circuit can specifically be an inverter module in the frequency converter that converts the input voltage to drive the motor to start or stop running. In practical applications, the inverter module can be controlled by an elevator controller or a motor driver.

[0047] In this embodiment, the power grid is a three-phase power grid, and the rectifier module is connected to the three-phase power grid, and is used to rectify and filter the power grid input, such as the three-phase input of R, S, and T. The rectifier module is also connected to the inverter module through the positive DC bus DC+ and the negative DC bus DC-. The inverter module is connected to the motor M through the wiring terminal, and the inverter module is used to output three-phase electricity to drive the motor M to rotate. Among them, the wiring terminal specifically refers to the terminal row used for wiring between the inverter and the motor M. For example, in this embodiment, the motor M adopts a three-phase motor with three-phase windings of U, V, and W. The wiring terminal includes three corresponding wiring terminals A1, A2, and A3.

[0048] In the electronic star-sealing braking scheme of the related art, under the application condition without a star-sealing contactor, the inverter module is controlled to short-circuit the U, V, and W three-phase windings of the motor, and the U, V, and W three-phase windings are also short-circuited with the positive DC bus or the negative DC bus. At this time, the terminal will be energized. If the maintenance personnel forget to turn off the power and directly operate manually, such as manually operating the terminal wiring, it is easy to have the risk of electric shock, causing an electric shock accident. Therefore, it is necessary to add a protection function to the star-sealing circuit to obtain the star-sealing protection circuit of this embodiment, that is, the star-sealing protection circuit in this embodiment at least includes the rectifier module and the inverter module of the frequency converter.

[0049] In this embodiment, Figure 1 and Figure 2 As shown, at least one of the positive and negative DC busbars located between the rectifier module and the inverter module is connected to the blocking module. It can be understood that the blocking module can be connected to the positive DC busbar, or to the negative DC busbar, and can also include two parts, which are respectively connected to the positive and negative DC busbars. Optionally, for the setting mode of being respectively connected to the positive and negative DC busbars, only a part of them can be controlled to work when the inverter and the motor are short-circuited to perform star-sealing braking, for example, only the blocking module on the positive DC busbar is controlled to work to disconnect the current between the power grid and the star-sealing loop, or only the blocking module on the negative DC busbar is controlled to work to disconnect the current between the power grid and the star-sealing loop. In actual application, it can be selected according to actual needs.

[0050] It is understandable that, due to the provision of a blocking module, when the positive and negative DC busbars are short-circuited with the motor through the inverter module to form a star-sealing circuit, the blocking module can promptly disconnect the current between the power grid and the star-sealing circuit, thereby indirectly making the star-sealing circuit de-energized, thereby making the wiring terminals de-energized. At this time, maintenance personnel can work on the wiring terminals without the risk of electric shock, thus avoiding safety accidents. As a result, there is no need for maintenance personnel to take the initiative to cut off the power, which not only reduces the workload, but also avoids electric shock accidents caused by maintenance personnel forgetting to cut off the power, thereby ensuring the maintenance personnel's work safety and improving operational safety.

[0051] In a specific embodiment, one of the positive and negative DC busses is connected to a blocking module, a first output terminal of the rectifier module is connected to a first input terminal of the inverter module through the blocking module, and a second output terminal of the rectifier module is connected to a second input terminal of the inverter module through the other of the positive and negative DC busses.

[0052] In a specific implementation manner, Figure 1 As shown, a blocking module may be connected to the negative DC bus. In this case, the first output terminal of the rectifier module, i.e., the negative output terminal, is connected to the blocking module using the negative DC bus, and then connected to the first input terminal, i.e., the negative input terminal, of the inverter module; and the second output terminal, i.e., the positive output terminal, of the rectifier module is directly connected to the second input terminal, i.e., the positive input terminal, of the inverter module through the positive DC bus.

[0053] In another specific embodiment, Figure 2 As shown, a blocking module may be connected to the positive DC bus. In this case, the first output terminal of the rectifier module, i.e., the positive output terminal, is connected to the blocking module using the positive DC bus, and then connected to the first input terminal, i.e., the positive input terminal, of the inverter module; and the second output terminal, i.e., the negative output terminal, of the rectifier module is directly connected to the second input terminal, i.e., the negative input terminal, of the inverter module through the negative DC bus.

[0054] It should be noted that, based on different types of motors, such as two-phase motors or three-phase motors, the topology in the inverter module can be a half-bridge topology or a full-bridge topology, which can be set according to actual needs. However, regardless of the circuit topology, the inverter module includes at least one bridge arm, which can further include an upper bridge arm switch tube and a lower bridge arm switch tube.

[0055] In a feasible implementation manner, the inverter module includes an upper bridge arm switch tube and a lower bridge arm switch tube, and a common connection point of the upper bridge arm switch tube and the lower bridge arm switch tube is connected to the motor;

[0056] One of the upper bridge arm switch tube or the lower bridge arm switch tube is closed, so that the positive DC bus connected to the blocking module is short-circuited with the motor through the closed upper bridge arm switch tube, or the negative DC bus connected to the blocking module is short-circuited with the motor through the closed lower bridge arm switch tube, forming a star-sealing circuit; and when the blocking module disconnects the current between the grid and the star-sealing circuit, the motor star-sealing braking is performed.

[0057] In this embodiment, when the blocking module is set on the negative DC bus, the star-blocking control can specifically control the lower bridge arm switch tube in the inverter module to be turned on and short-circuited with the motor to form a star-blocking loop; when the blocking module is set on the positive DC bus, the star-blocking control can specifically control the upper bridge arm switch tube in the inverter module to be turned on and short-circuited with the motor to form a star-blocking loop. The two specific setting methods can be selected according to actual needs to meet more actual needs.

[0058] In a specific implementation, the blocking module uses a controllable switch device, and the controllable switch device includes an electronic switch or a mechanical switch.

[0059] Specifically, the electronic switch includes a triode, a controllable switch tube or a power semiconductor switch (such as gallium nitride power semiconductor, silicon carbide power device, etc.), among which the controllable switch tube can be a MOS tube (MOSFET, Metal-Oxide-Semiconductor Field-Effect Transistor, Metal Oxide Semiconductor Field-Effect Transistor), a JFET tube (Junction Field-Effect Transistor, Junction Field-Effect Transistor) and other field effect tubes or an IGBT tube (Insulated Gate Bipolar Transistor, Insulated Gate Bipolar Transistor); the mechanical switch includes a relay, a contactor, etc. This embodiment blocks the current flow between the power grid and the star sealing circuit by disconnecting the controllable switch device, and provides anti-electric shock protection for the electronic star sealing application condition.

[0060] The present embodiment provides a star-sealing protection circuit, which adds a blocking module and is connected to the positive DC bus and / or the negative DC bus between the rectifier module and the inverter module. When the positive and negative DC buses are short-circuited with the motor through the inverter module to form a star-sealing circuit, the blocking module is used to disconnect the current between the power grid and the star-sealing circuit, thereby indirectly making the star-sealing circuit unpowered, thereby making the connection terminals between the inverter module and the motor unpowered, avoiding electric shock accidents caused by accidental touching with power on, and ensuring the working safety of maintenance personnel.

[0061] Based on the first embodiment of the star-sealing protection circuit of the present application, in the second embodiment of the star-sealing protection circuit of the present application, the same or similar contents as those in the above embodiment can be referred to the above introduction, and will not be described in detail later. Figure 3 , Figure 3 This is a connection block diagram of the second embodiment of the star sealing protection circuit of the present application, and the star sealing protection circuit also includes a control module;

[0062] The control module is respectively connected to the blocking module, the upper bridge arm switch tube and the lower bridge arm switch tube;

[0063] The control module is used to generate a driving signal, control the blocking module to disconnect according to the driving signal to disconnect the current between the power grid and the star-sealing circuit, and control the upper bridge arm switch tube or the lower bridge arm switch tube in the inverter module to close according to the driving signal to short-circuit the motor for star-sealing braking.

[0064] In a feasible implementation manner, the control module is further used to control the blocking module to be turned on according to the driving signal, and control the inverter module to normally invert and control the wave so that the motor can work normally.

[0065] It should be noted that when the system is powered on, in order to make the motor work normally, the control module can generate a drive signal to control the upper bridge arm switch tube and the lower bridge arm switch tube in the inverter module to close or disconnect as needed to meet actual needs and make the motor work normally; afterwards, when the control module receives the shutdown command of the system and needs to perform elevator star-locking braking, the control module can generate a drive signal to first control the inverter module to stop the inverter wave, and then control the blocking module to disconnect according to the drive signal, and control the upper bridge arm switch tube or the lower bridge arm switch tube in the inverter module to close, so that the motor is short-circuited for star-locking braking. After that, if it is necessary to restore the normal operation of the motor, the control module can control the blocking module to turn on according to the drive signal, and control the inverter module to normally invert and control the wave, that is, the inverter module performs normal inverter work to provide the motor drive signal to the motor, so that the motor works normally. Among them, if the blocking module is located on the positive DC bus, the upper bridge arm switch tube is directly controlled to be closed, and if the blocking module is located on the negative DC bus, the lower bridge arm switch tube is directly controlled to be closed.

[0066] In this embodiment, Figure 3 As shown, the blocking module is located on the negative DC bus DC-. When the control module controls the blocking module to be disconnected, the lower bridge arm switch tube of the inverter module can be directly controlled to be closed, so that the inverter module and the U, V, and W three-phase windings of the motor M are short-circuited to form a star-sealing circuit. At this time, the disconnected blocking module prevents current from flowing between the power grid and the star-sealing circuit, that is, the star-sealing circuit is not energized, so that A1, A2, and A3 on the wiring terminals are not energized.

[0067] In a feasible implementation manner, the star-sealing protection circuit further includes a bus capacitor;

[0068] One end of the bus capacitor is connected to the positive DC bus, and the other end of the bus capacitor is connected to the negative DC bus;

[0069] The bus capacitor is used to provide the starting voltage required for the motor to work.

[0070] like Figure 3 As shown, one end of the bus capacitor C1 is connected to the positive DC bus DC+, and the other end is connected to the negative DC bus DC-; the bus capacitor C1 is used to provide the starting voltage required for the motor to work, and can also be used to absorb surge signals. In practical applications, the rectifier module can convert the AC power provided by the three-phase input R, S, and T into DC power, and then charge the bus capacitor C1. The inverter module can generate a motor drive signal according to the drive signal sent by the control module and the starting voltage provided by the bus capacitor C1 to drive the motor to work.

[0071] In a feasible implementation manner, the inverter module in the star-sealing protection circuit adopts a full-bridge topology, and the motor adopts a three-phase winding motor;

[0072] The full-bridge topology includes three upper-arm switching tubes and three lower-arm switching tubes.

[0073] It should be noted that the switch tube in the full-bridge topology can be a power semiconductor switch (such as gallium nitride power semiconductors, silicon carbide power devices, etc.), or a controllable switch tube such as a MOS tube, an IGBT tube or a JFET tube. The switch tube in the full-bridge topology can be controlled by the control module to be turned on or off according to actual needs, and the specific selection of the switch tube is not limited here.

[0074] For example, in order to help understand the star-blocking protection circuit obtained by combining this embodiment with the above-mentioned first embodiment, refer to Figure 4 , Figure 4 A topological diagram of a star-sealing protection circuit is provided, specifically:

[0075] A bus capacitor C1 is connected between the positive DC bus DC+ and the negative DC bus DC- of the rectifier module, one end of the bus capacitor C1 is connected to the positive DC bus DC+, and the other end is connected to the negative DC bus DC-; a ​​controllable switch K1 is connected to the negative DC bus DC-, the control end of the controllable switch K1 is connected to the control module, the input end of the controllable switch K1 is connected to the negative output end of the rectifier module, the output end of the controllable switch K1 is connected to the negative input end of the inverter module, and the positive DC bus DC+ is directly connected to the positive input end of the inverter module, that is, the positive output end of the rectifier module is directly connected to the positive input end of the inverter module;

[0076] In the inverter module, the full-bridge topology adopted includes switch tubes Q1, Q2, Q3, Q4, Q5 and Q6, and the three-phase winding motor includes U-phase winding, V-phase winding and W-phase winding; among them, switch tubes Q1 to Q6 are all normally open switch tubes; the collector of Q1, the collector of Q2 and the collector of Q3 are all connected to the positive DC bus DC+, the emitter of Q1 is respectively connected to the W-phase winding and the collector of Q4, the emitter of Q2 is respectively connected to the V-phase winding and the collector of Q5, the emitter of Q3 is respectively connected to the U-phase winding and the collector of Q6, the emitter of Q4, the emitter of Q5 and the emitter of Q6 are all connected to the negative DC bus DC-, and at the same time, the gates of Q1-Q6 can be connected to the control module.

[0077] It should be noted that the drive signal output by the control module reaches each switch tube of the inverter module, which can make the corresponding switch tube produce corresponding actions to realize the normal operation of the motor; it can also make the corresponding switch tube produce corresponding actions to realize the elevator star-sealing braking. For example, the control module can output a low-level signal to the upper bridge arm switch tube, i.e., Q1-Q3, and output a high-level signal to the lower bridge arm switch tube, i.e., Q4-Q6, so that the three upper bridge arm switch tubes are disconnected at the same time, the three lower bridge arm switch tubes are closed at the same time, and the lower three bridges of the inverter module are turned on, thereby forming a star-sealing loop to realize the elevator star-sealing braking; it can also output a high-level signal to the upper bridge arm switch tube, i.e., Q1-Q3, and output a low-level signal to the lower bridge arm switch tube, i.e., Q4-Q6, so that the three lower bridge arm switch tubes are disconnected at the same time, the three upper bridge arm switch tubes are closed at the same time, and the upper three bridges of the inverter module are turned on, thereby forming a star-sealing loop to realize the elevator star-sealing braking.

[0078] based on Figure 4 In the circuit topology shown in the figure, since the controllable switch K1 is connected to the negative DC bus DC-, correspondingly, if the elevator star-locking braking is to be realized, the lower three bridges of the inverter module need to be turned on. At this time, the control module controls the three upper bridge arm switch tubes Q1-Q3 to be disconnected at the same time, and the three lower bridge arm switch tubes Q4-Q6 to be closed at the same time. The control module also controls the controllable switch K1 to be disconnected, forming the following Figure 5 The star sealing diagram shown in the figure is Figure 5 In the process, the three closed lower bridge arm switch tubes Q4-Q6 are short-circuited with the motor M to form a star-sealing circuit. However, since the controllable switch K1 is in the off state, the rectifier module is isolated from the inverter module, that is, the three-phase input R, S, T is isolated from the output of the inverter, so that the current cannot reach the star-sealing circuit, that is, no current flows in the star-sealing circuit, and the three connection terminals A1, A2 and A3 are not energized, that is, the connection terminals are not energized. At this time, direct operation on them will not cause electric shock accidents.

[0079] This embodiment provides a star-sealing protection circuit, which provides a safe and reliable anti-electric shock protection solution for the electronic star-sealing application conditions of the inverter, fully considers the unsafe factors of elevator shutdown maintenance, avoids output liveness from the perspective of system solutions, ensures operational safety, improves the product's usability and anti-fool index, and can effectively avoid the risk of electric shock for maintenance personnel.

[0080] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the star-sealing protection circuit of the present application. More simple transformations based on this technical concept are all within the protection scope of the present application.

[0081] The present application also provides a frequency converter, the frequency converter comprising:

[0082] A star-sealing protection circuit as in any of the above embodiments.

[0083] It is understandable that the frequency converter may also include common circuit topologies such as a voltage transformation module and a voltage conversion module, which are not limited here.

[0084] Among them, the specific structure of the star-sealing protection circuit can refer to the above embodiments. The inverter provided in this application adopts all the technical solutions of all the above embodiments of the star-sealing protection circuit, and therefore has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0085] The present application also provides an elevator, the elevator comprising:

[0086] Frequency converter and motor, the frequency converter can drive the motor to control the operation of the car.

[0087] Among them, the frequency converter is used to drive the motor to realize the operation of the elevator. The motor can be an elevator traction machine. Through the cooperation of the star-locking protection circuit in the frequency converter and the motor, the elevator star-locking braking is realized, and anti-electric shock protection is provided at the same time as the elevator star-locking braking.

[0088] It is understandable that the elevator may also include common equipment such as a main power supply, a backup power supply, a controller, etc., which are not limited here.

[0089] Among them, the specific structure of the frequency converter can refer to the above embodiments. The elevator provided in this application adopts all the technical solutions of the above frequency converter embodiments, and therefore has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0090] The above are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A star-sealing protection circuit, characterized in that: The star-blocking protection circuit is connected to the power grid and the motor respectively, and the circuit includes a rectifier module, a blocking module and an inverter module; The rectifier module is connected to the power grid and connected to the inverter module through positive and negative DC bus bars. The inverter module is connected to the motor through a wiring terminal. At least one of the positive and negative DC bus bars is connected to the blocking module. When the positive and negative DC busbars are short-circuited with the motor through the inverter module to form a star-sealing circuit, the blocking module is used to disconnect the current between the grid and the star-sealing circuit to make the connection terminals non-energized.

2. The star-sealing protection circuit according to claim 1, characterized in that: One of the positive and negative DC busbars is connected to the blocking module, the first output end of the rectifier module is connected to the first input end of the inverter module through the blocking module, and the second output end of the rectifier module is connected to the second input end of the inverter module through the other of the positive and negative DC busbars.

3. The star-sealing protection circuit according to claim 2, characterized in that: The inverter module comprises an upper bridge arm switch tube and a lower bridge arm switch tube, and a common contact point of the upper bridge arm switch tube and the lower bridge arm switch tube is connected to the motor; One of the upper bridge arm switch tube or the lower bridge arm switch tube is closed, so that the positive DC bus connected to the blocking module is short-circuited with the motor through the closed upper bridge arm switch tube, or the negative DC bus connected to the blocking module is short-circuited with the motor through the closed lower bridge arm switch tube, so as to form the star-sealing circuit; and when the blocking module disconnects the current between the power grid and the star-sealing circuit, the motor star-sealing braking is performed.

4. The star-sealing protection circuit according to claim 3, characterized in that: The circuit also includes a control module; The control module is respectively connected to the blocking module, the upper bridge arm switch tube and the lower bridge arm switch tube; The control module is used to generate a driving signal, control the blocking module to be disconnected according to the driving signal to disconnect the current between the power grid and the star-sealing circuit, and control the upper bridge arm switch tube or the lower bridge arm switch tube in the inverter module to be closed according to the driving signal to short-circuit the motor for star-sealing braking.

5. The star-sealing protection circuit according to claim 4, characterized in that: The control module is also used to control the blocking module to be turned on according to the driving signal, and control the inverter module to normally invert and control the wave so that the motor can work normally.

6. The star-sealing protection circuit according to any one of claims 1 to 5, characterized in that: The circuit also includes a bus capacitor; One end of the bus capacitor is connected to the positive DC bus, and the other end of the bus capacitor is connected to the negative DC bus; The bus capacitor is used to provide the starting voltage required for the motor to work.

7. The star-sealing protection circuit according to any one of claims 1 to 5, characterized in that: The inverter module adopts a full-bridge topology, and the motor adopts a three-phase winding motor; The full-bridge topology includes three upper-bridge arm switch tubes and three lower-bridge arm switch tubes.

8. The star-sealing protection circuit according to any one of claims 1 to 5, characterized in that: The blocking module adopts a controllable switch device, and the controllable switch device includes an electronic switch or a mechanical switch.

9. A frequency converter, characterized in that: Connected with the motor, the frequency converter comprises: The star-sealing protection circuit according to any one of claims 1 to 8.

10. An elevator, characterized in that: include: The frequency converter according to claim 9; The inverter drives the motor to control the operation of the car.

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