Brake system and elevator system

Abstract

The embodiment of the utility model relates to the technical field of elevators, and provides a band-type brake system and an elevator system.The band-type brake system comprises an alternating-current power source, a rectifier bridge, a band-type brake circuit and a relay control circuit, and the band-type brake circuit is connected with the alternating-current power source through the rectifier bridge; the relay control circuit comprises a zero point detection module, a trigger, a controller, a delayer, an actuator and a relay, wherein the zero point detection module is connected to two output ends of an alternating current power supply in parallel; the zero point detection module and the trigger are connected in parallel to the input end of the controller; the delayer is connected with the output end of the controller; the actuator is connected with the delayer; a coil of the relay is connected with the actuator, a contact point of the relay is connected between the rectifier bridge and the alternating current power supply, and the actuator controls the sum of preset closing time of closing of the contact point of the relay and preset delay time of the delayer to be equal to the period of the alternating current power supply.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of elevators, and particularly to a brake system and an elevator system. Background Art

[0002] The elevator brake system is an important safety component of the elevator. When the elevator car is stationary and the motor is de-energized, it prevents the elevator from moving again. Its control method is generally that the brake is released when the brake coil is energized, and the brake is tightened when the brake coil is de-energized, thereby preventing the abnormal lifting and lowering of the elevator car. The reliability of the brake device to open and close the brake is a necessary condition for the normal operation of the elevator.

[0003] The brake system controls the energization and de-energization of the brake coil through a relay. At the moment when the relay closes, the two contacts of the relay may be burned due to the flow of a large current, and then the two contacts are welded or adhered together and cannot be normally disconnected, which may lead to the problem of the failure of the brake system. Utility Model Content

[0004] The embodiments of the present application provide a brake system and an elevator system, which at least help to improve the safety of the brake system.

[0005] According to some embodiments of the present application, on the one hand, an embodiment of the present application provides a brake system, including: an AC power supply having two output terminals; a rectifier bridge including two input terminals and two output terminals, and the two input terminals of the rectifier bridge are respectively connected to the two output terminals of the AC power supply; a brake circuit connected to the two output terminals of the rectifier bridge; a relay control circuit including: a zero-crossing detection module connected in parallel to the two output terminals of the AC power supply, and the output terminal of the zero-crossing detection module generates a first level signal based on the zero-crossing voltage of the AC power supply; a trigger that generates a second level signal after being triggered; a controller including two input terminals and one output terminal, one input terminal of the controller is connected to the output terminal of the zero-crossing detection module, and the other input terminal of the controller is connected to the trigger. When the first level signal is the same as the second level signal, the output terminal of the controller outputs a third level signal; a delay unit connected to the output terminal of the controller, and the delay unit receives the third level signal and outputs a fourth level signal after a preset delay time; an actuator connected to the delay unit; a relay, the coil of the relay is connected to the actuator, and the contact of the relay is connected between the rectifier bridge and the AC power supply. The actuator receives the fourth level signal and controls the coil of the relay to be energized so that the contact of the relay closes. The contact of the relay closes after a preset closing time when the actuator receives the fourth level signal, and the sum of the preset closing time and the preset delay time is equal to the period of the AC power supply.

[0006] In some embodiments, the relay includes a first relay and a second relay. The first relay is connected between the positive output terminal of the AC power supply and the positive input terminal of the rectifier bridge, and the second relay is connected between the negative output terminal of the AC power supply and the negative input terminal of the rectifier bridge.

[0007] In some embodiments, the relay includes a first relay and a second relay. The first relay and the second relay are connected in series between the positive output terminal of the AC power supply and the positive input terminal of the rectifier bridge.

[0008] In some embodiments, the delay unit includes a first delay unit and a second delay unit. The first delay unit and the second delay unit are connected in parallel to the output terminal of the controller; the actuator includes a first actuator and a second actuator. The first actuator is connected between the first relay and the first delay unit, and the second actuator is connected between the second relay and the second delay unit.

[0009] In some embodiments, the controller is an AND gate or a NAND gate.

[0010] In some embodiments, the delay unit includes an even number of serially connected inverters.

[0011] In some embodiments, the brake circuit includes a buck circuit and a brake coil. The buck circuit includes: a first switching tube, the first end of the first switching tube is connected to the negative output terminal of the rectifier bridge; a first inductor, the first end of the first inductor is connected to the second end of the first switching tube; a second switching tube, the first end of the second switching tube is connected to the second end of the first inductor, and the first end of the brake coil is connected to the second end of the second switching tube; a first resistor, the first end of the first resistor is connected to the second end of the brake coil, and the second end of the first resistor is connected to the positive output terminal of the rectifier bridge; a first diode, the positive terminal of the first diode is connected to the second end of the first switching tube, and the negative terminal of the first diode is connected to the positive output terminal of the rectifier bridge; a first capacitor, the first end of the first capacitor is connected to the second end of the first switching tube, and the second end of the first capacitor is connected to the positive output terminal of the rectifier bridge.

[0012] In some embodiments, it further includes: a freewheeling circuit, the freewheeling circuit includes a second diode and a transient voltage suppression diode connected in series. The positive terminal of the second diode is connected to the first end of the brake coil, the negative terminal of the second diode is connected to the first end of the transient voltage suppression diode, and the second end of the transient voltage suppression diode is connected to the second end of the brake coil.

[0013] In some embodiments, it further includes: a filter capacitor, the first end of the filter capacitor is connected to the negative output terminal of the rectifier bridge, and the second end of the filter capacitor is connected to the positive output terminal of the rectifier bridge.

[0014] According to some embodiments of the present application, on the other hand, an elevator system is further provided in an embodiment of the present application, including a brake system as in the embodiment.

[0015] The technical solution provided by the embodiment of the present application has at least the following advantages:

[0016] In the brake system provided by the embodiment of the present application, the brake circuit is connected to the AC power supply through a rectifier bridge. The rectifier bridge converts the alternating current of the AC power supply into direct current to be connected to the brake circuit. When the brake coil in the brake circuit is energized, the brake is released, and when the brake coil is de-energized, the brake is tightened. The relay control circuit is used to control the conduction and disconnection of the relay between the AC power supply and the rectifier bridge, so as to control the conduction and disconnection of the brake circuit and the power supply. Among them, the relay control circuit includes a zero-crossing detection module, a trigger, a controller, a delay unit and an actuator. The output end of the zero-crossing detection module generates a first level signal based on the zero-crossing voltage of the AC power supply. After being triggered, the trigger generates a second level signal. When the first level signal is the same as the second level signal, the output end of the controller outputs a third level signal. In this way, the delay unit is triggered at the zero-crossing voltage of the AC power supply. The delay unit receives the third level signal and outputs a fourth level signal after a preset delay time. The actuator receives the fourth level signal and controls the coil of the relay to be energized so that the contact point of the relay is closed. Since the contact point of the relay is closed after the actuator receives the fourth level signal for a preset closing time, and the sum of the preset closing time and the delay time is equal to the period of the AC power supply, in this way, the relay can be closed at the zero-crossing voltage of the AC power supply. At this time, the current flowing through the two contacts of the relay is small, which can reduce the risk of burning of the two contacts of the relay due to the flow of large current, and further reduce the probability of adhesion of the two contacts of the relay, which is beneficial to extending the service life of the relay, avoiding the problem that the brake circuit cannot be controlled, and improving the safety of the brake system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are illustrated by way of example in the accompanying drawings. These illustrative descriptions do not constitute a limitation on the embodiments. Unless otherwise stated, the figures in the accompanying drawings do not constitute a proportional limitation. In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figures 1 to 3 It is a schematic circuit structure diagram of a variety of brake systems provided by the embodiment of the present application;

[0019] Figure 4 It is a timing diagram of each level signal in a relay control circuit provided by the embodiment of the present application;

[0020] Figure 5Schematic diagram of the circuit structure of a specific brake system provided by an embodiment of the present application. Detailed implementation manner

[0021] As can be seen from the background art, the safety of the brake system needs to be improved.

[0022] The brake system is very important during the normal operation of the elevator. Usually, the brake system converts alternating current into direct current through a rectifier bridge to access the brake circuit, and a relay is used to control the power-on of the brake circuit between the rectifier bridge and the AC power supply. If the relay contacts are closed under the relatively high voltage of the AC power supply, the two contacts of the relay may be burned due to the large current flowing through, and then the two contacts are welded or stuck together and cannot be normally disconnected, which may lead to a failure of the brake system; in addition, when the relay contacts are closed under the relatively high voltage of the AC power supply, it will also cause a certain impact on the power grid.

[0023] In the brake system provided by the embodiment of the present application, the brake circuit is connected to the AC power supply through a rectifier bridge. The rectifier bridge converts the alternating current of the AC power supply into direct current to access the brake circuit. When the brake coil in the brake circuit is powered on, the brake is released, and when the brake coil is de-energized, the brake is tightened. The relay control circuit is used to control the conduction and disconnection of the relay between the AC power supply and the rectifier bridge, so as to control the conduction and disconnection of the brake circuit and the power supply. Among them, the relay control circuit includes a zero-crossing detection module, a trigger, a controller, a delay timer, and an actuator. The output end of the zero-crossing detection module generates a first level signal based on the zero-crossing voltage of the AC power supply. After being triggered, the trigger generates a second level signal. When the first level signal is the same as the second level signal, the output end of the controller outputs a third level signal. In this way, the delay timer is triggered at the zero-crossing voltage of the AC power supply. The delay timer receives the third level signal and outputs a fourth level signal after a preset delay time. The actuator receives the fourth level signal and controls the coil of the relay to be powered on so that the contacts of the relay are closed. Since the contacts of the relay are closed after the actuator receives the fourth level signal after a preset closing time, and the sum of the preset closing time and the delay time is equal to the period of the AC power supply, it can be ensured that the relay is closed at the zero-crossing voltage of the AC power supply. At this time, the current flowing through the two contacts of the relay is relatively small, which can reduce the risk of the two contacts of the relay being burned due to the large current flowing through, and then reduce the probability of the two contacts of the relay sticking together, which is beneficial to extending the service life of the relay, avoiding the problem that the brake circuit cannot be controlled, and improving the safety of the brake system.

[0024] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically and clearly defined.

[0025] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and is not necessarily referring to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments of the present application, when a component "comprises" another component, unless otherwise specified, other components are not excluded, and other components may further be included.

[0027] The terms used in the description of the various embodiments herein are for the purpose of describing particular embodiments only and are not intended to be limiting. As used in the description of the various embodiments and the appended claims, "a component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0028] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present application, many technical details are provided for the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented.

[0029] Figures 1 to 3 Schematic diagram of the circuit structure of a multiple brake system provided for the embodiments of the present application.

[0030] Reference Figures 1 to 3, on the one hand, an embodiment of the present application provides a brake system, including: an AC power supply AC, a rectifier bridge 101, a brake circuit 102, and a relay control circuit. The AC power supply AC has two output terminals (a positive output terminal and a negative output terminal); the rectifier bridge 101 includes two input terminals (a positive input terminal and a negative input terminal) and two output terminals (a positive output terminal and a negative output terminal), and the two input terminals of the rectifier bridge 101 are respectively connected to the two output terminals of the AC power supply AC; the brake circuit is connected to the two output terminals of the rectifier bridge 101. Among them, the relay control circuit includes: a zero-crossing detection module 111, a trigger 112, a controller 113, a delay element 114, an actuator 115, and a relay. The zero-crossing detection module 111 is connected in parallel to the two output terminals of the AC power supply AC, and the output terminal of the zero-crossing detection module 111 generates a first level signal A based on the zero voltage of the AC power supply AC; the trigger 112 generates a second level signal B after being triggered; the controller 113 includes two input terminals and one output terminal. One input terminal of the controller 113 is connected to the output terminal of the zero-crossing detection module 111, and the other input terminal of the controller 113 is connected to the trigger 112. When the first level signal A is the same as the second level signal B, the output terminal of the controller 113 outputs a third level signal C; the delay element 114 is connected to the output terminal of the controller 113, and the delay element 114 receives the third level signal C and outputs a fourth level signal D after a preset delay time; the actuator 115 is connected to the delay element 114; the coil of the relay is connected to the actuator 115, and the contact of the relay is connected between the rectifier bridge 101 and the AC power supply AC. The actuator 115 receives the fourth level signal D and controls the coil of the relay to be energized so that the contact of the relay closes. After the actuator 115 receives the fourth level signal D, the contact of the relay closes after a preset closing time. The sum of the preset closing time and the preset delay time is equal to the period of the AC power supply AC.

[0031] In the brake system provided by the embodiment of the present application, the brake circuit 102 is connected to the AC power supply AC through a rectifier bridge 101. The rectifier bridge 101 converts the alternating current of the AC power supply AC into direct current to be connected to the brake circuit 102. When the brake coil in the brake circuit 102 is powered on, the brake is released; when the brake coil is powered off, the brake is tightened. The relay control circuit is used to control the conduction and disconnection of the relay between the AC power supply AC and the rectifier bridge 101, so as to control the conduction and disconnection of the brake circuit 102 and the power supply. Among them, the relay control circuit includes a zero-crossing detection module 111, a trigger 112, a controller 113, a delay unit 114 and an actuator 115. The output terminal of the zero-crossing detection module 111 generates a first level signal A based on the zero-crossing voltage of the AC power supply AC. After being triggered, the trigger 112 generates a second level signal B. When the first level signal A is the same as the second level signal B, the output terminal of the controller 113 outputs a third level signal C. In this way, the delay unit 114 is triggered at the zero-crossing voltage of the AC power supply AC. The delay unit 114 receives the third level signal C and outputs a fourth level signal D after a preset delay time. The actuator 115 receives the fourth level signal D and controls the coil of the relay to be powered on so that the contact of the relay is closed. Since the contact of the relay is closed after the actuator 115 receives the fourth level signal D for a preset closing time, and the sum of the preset closing time and the delay time is equal to the period of the AC power supply AC, in this way, the relay can be closed at the zero-crossing voltage of the AC power supply AC. At this time, the current flowing through the two contacts of the relay is reduced, which can reduce the risk of the two contacts of the relay being burned due to the flow of large current, and further reduce the probability of the two contacts of the relay sticking together, which is beneficial to extending the service life of the relay, avoiding the problem that the brake circuit cannot be controlled, and improving the safety of the brake system.

[0032] Figure 4 It is a timing diagram of each level signal in a relay control circuit provided by an embodiment of the present application.

[0033] With reference to Figure 1 and Figure 4, taking the zero - point detection module 111, trigger 112, controller 113, delay unit 114, and actuator 115 all being triggered by high - level signals as an example. The output terminal of the zero - point detection module 111 generates a first level signal A based on the zero - point voltage of the AC power supply AC, that is, when the voltage of the AC power supply AC is at zero, the first level signal A is briefly triggered to a high - level signal. At time t1, the trigger 112 is triggered, and the second level signal B is a high - level signal; at the first zero - point voltage of the AC power supply AC after time t1, that is, at time t2, the first level signal A and the second level signal B are both high - level signals. At this time, the third level signal C output by the output terminal of the controller 113 is a high - level signal; at time t2, after receiving the third level signal C, the delay unit 114 outputs a fourth level signal D as a high - level signal after a preset delay time S1; at time t3, the fourth level signal D received by the actuator 115 is a high - level signal. At this time, the actuator 115 controls the coil of the relay to be energized so that the contact point of the relay closes. After a preset closing time S2 at time t3, the contact point of the relay closes. Thus, the closing time t4 of the contact point of the relay is the time when the voltage of the AC power supply AC is at zero.

[0034] It can be understood that there may be a deviation between the preset delay time S1 of the delay unit 114 and the actual delay time; or, there may be a deviation between the preset closing time S2 for the actuator 115 to control the coil of the relay to be energized so that the contact point of the relay closes and the actual closing time. As a result, the contact point of the relay may close near the zero - point voltage of the AC power supply AC. However, the current flowing through the two contacts of the relay is still small, which can still reduce the risk of the two contacts of the relay being burned due to the flow of a large current, thereby reducing the probability of the two contacts of the relay sticking together, being beneficial to extending the service life of the relay, avoiding the problem that the brake circuit cannot be controlled, and improving the safety of the brake system.

[0035] Therefore, the sum of the preset delay time S1 and the preset closing time S2 being equal to the period of the AC power supply AC means that the sum of the preset delay time S1 and the preset closing time S2 is approximately equal to the period of the AC power supply AC, and the sum of the preset delay time S1 and the preset closing time S2 and the period of the AC power supply AC can be within an appropriate time - difference range.

[0036] In some embodiments, the duration of the second level signal B generated after the trigger 112 is triggered is less than the period of the AC power supply AC and greater than 1 / 2 of the period of the AC power supply AC. In this way, after the trigger 112 is triggered, at the first zero - point voltage of the AC power supply AC, the first level signal A and the second level signal B can remain the same, so that the controller 113 can output the third level signal C.

[0037] Reference Figures 1 to 3, in some embodiments, the relay may include a first relay KNB1 and a second relay KNB2. The redundant design of setting two contactors in the brake system can help improve the safety of the brake system and avoid dangers caused by the failure of a single relay.

[0038] Reference Figure 1 and Figure 3 , in one example, the first relay KNB1 is connected between the positive output terminal of the AC power supply AC and the positive input terminal of the rectifier bridge 101, and the second relay KNB2 is connected between the negative output terminal of the AC power supply AC and the negative input terminal of the rectifier bridge 101.

[0039] Reference Figure 2 , in another example, the first relay KNB1 and the second relay KNB2 are connected in series between the positive output terminal of the AC power supply AC and the positive input terminal of the rectifier bridge 101.

[0040] Reference Figure 1 and Figure 2 , in one example, when the relay includes the first relay KNB1 and the second relay KNB2, an actuator 115 can be used to control the on and off of the first relay KNB1 and the second relay KNB2.

[0041] Reference Figure 3 , in another example, when the relay includes the first relay KNB1 and the second relay KNB2, the delay unit may include a first delay unit 134 and a second delay unit 144. The first delay unit 134 and the second delay unit 144 are connected in parallel to the output terminal of the controller 113; the actuator includes a first actuator 135 and a second actuator 145. The first actuator 135 is connected between the first relay KNB1 and the first delay unit 134, and the second actuator 145 is connected between the second relay KNB2 and the second delay unit 144. In this way, the first relay KNB1 and the second relay KNB2 can be controlled by different actuators respectively. After the controller 113 generates a third-level signal C, the first delay unit 134 and the second delay unit 144 can generate different fourth-level signals Da and Db after different delay times, so that the first actuator 135 and the second actuator 145 can control the closing of the first relay KNB1 and the second relay KNB2 at different times respectively, and then set the preset delay time more accurately for different relays, so that both the first relay KNB1 and the second relay KNB2 can close at the zero voltage of the AC power supply AC closest to them.

[0042] In some embodiments, the controller 113 can be an AND gate or a NAND gate. When the controller 113 is an AND gate, the flip-flop 112, the zero-crossing detection module 111, and the delay element 114 are all triggered by a high level. When both the first level signal A and the second level signal B are at a high level, the third level signal C generated by the controller 113 is a high level signal. When the controller 113 is a NAND gate, the flip-flop 112, the zero-crossing detection module 111, and the delay element 114 are all triggered by a low level. When both the first level signal A and the second level signal B are at a low level, the third level signal C generated by the controller 113 is a low level signal.

[0043] In some embodiments, the actuator 115 can be triggered by a high level or a low level.

[0044] Both the high level and the low level are the logarithms of the ratio of two powers or voltages in an electrical engineering logic circuit. Here, the high level and the low level are also called relative levels.

[0045] In some embodiments, the delay element 114 includes an even number of inverters connected in series. An inverter can reverse the phase of the input signal by 180 degrees. By repeatedly inverting the third level signal C through an even number of inverters connected in series, the purpose of signal delay can be achieved.

[0046] Figure 5 FIG. is a schematic circuit diagram of a specific brake system provided by an embodiment of the present application. Figure 5 The brake circuit shown in FIG. can be combined with any of the relay control circuits in the above embodiments to obtain a new embodiment.

[0047] Reference Figure 5, the brake circuit includes a buck circuit 120 and a brake coil 140. The buck circuit 120 includes: a first switching transistor Q1, a first inductor L1, a second switching transistor Q2, a first resistor R1, a first diode D1, and a first capacitor C1. The first end of the first switching transistor Q1 is connected to the negative output terminal of the rectifier bridge 101; the first end of the first inductor L1 is connected to the second end of the first switching transistor Q1; the first end of the second switching transistor Q2 is connected to the second end of the first inductor L1, and the first end of the brake coil 140 is connected to the second end of the second switching transistor Q2; the first end of the first resistor R1 is connected to the second end of the brake coil 140, and the second end of the first resistor R1 is connected to the positive output terminal of the rectifier bridge 101; the positive terminal of the first diode D1 is connected to the second end of the first switching transistor Q1, and the negative terminal of the first diode D1 is connected to the positive output terminal of the rectifier bridge 101; the first end of the first capacitor C1 is connected to the second end of the first switching transistor Q1, and the second end of the first capacitor C1 is connected to the positive output terminal of the rectifier bridge 101. In the buck circuit 120, by controlling the on and off states of the first switching transistor Q1 and the second switching transistor Q2 with a PWM (Pulse Width Modulation) wave with a variable input duty cycle, the DC voltage provided by the power supply is converted into an adjustable low-voltage output, so as to meet the power supply requirements of different brake coils. Specifically, in the buck circuit 120, when the first inductor L1 is in the on state, the current is converted into magnetic energy through the magnetic field at the center core of the first inductor L1, and the magnetic energy is stored in the first inductor L1. In the off state, due to the self-inductance of the first inductor L1, a voltage will be generated by the magnetic field, converting the electromagnetic energy into electrical energy and supplying power to the brake coil 140 through the output terminal. Therefore, by controlling the on and off states of the first switching transistor Q1 and the second switching transistor Q2, the periodic conversion and regulation of electrical energy between the first capacitor C1 and the first inductor L1 are realized, and finally a stable DC voltage is output.

[0048] Reference Figure 5 , the brake circuit further includes: a freewheeling circuit 130. The freewheeling circuit 130 includes a second diode D2 and a transient voltage suppression diode Z1 connected in series. The positive terminal of the second diode D2 is connected to the first end of the brake coil 140, the negative terminal of the second diode D2 is connected to the first end of the transient voltage suppression diode Z1, and the second end of the transient voltage suppression diode Z1 is connected to the second end of the brake coil 140. Through a specific circuit design, the freewheeling circuit 130 can prevent the current from passing through the brake resistor during the contactor closing process due to the short circuit of the contact point, thereby reducing the power consumption and heat generation of the resistor. In addition, at the moment when the contact point breaks, by allowing the current to flow through the brake resistor, the voltage at the contact point break can be reduced, thereby extending the service life of the contactor contact point. This design improves the efficiency and reliability of the brake circuit by optimizing the current path and reducing unnecessary resistance losses.

[0049] In some embodiments, the brake circuit further includes a filtering capacitor C2. The first end of the filtering capacitor C2 is connected to the negative output terminal of the rectifier bridge 101, and the second end of the filtering capacitor C2 is connected to the positive output terminal of the rectifier bridge 101. The filtering capacitor C2 can make the output voltage after filtering be a stable DC voltage. Its working principle is that when the output voltage of the rectifier bridge 101 is higher than the voltage of the filtering capacitor C2, the filtering capacitor is charged, and when the output voltage of the rectifier bridge 101 is lower than the voltage of the filtering capacitor C2, the filtering capacitor C2 discharges. During the charging and discharging process, the output voltage is made basically stable.

[0050] Correspondingly, another embodiment of the present application further provides an elevator system, including the brake system as in the embodiment to improve the safety of the elevator system. For the same or corresponding parts as in the previous embodiment, reference may be made to the corresponding description of the previous embodiment, and details will not be elaborated below.

[0051] In the brake system provided by the embodiment of the present application, the brake circuit 102 is connected to the AC power supply AC through the rectifier bridge 101. The rectifier bridge 101 converts the alternating current of the AC power supply AC into direct current to be connected into the brake circuit 102. When the brake coil in the brake circuit 102 is powered on, the brake is released, and when the brake coil is powered off, the brake is tightened. The relay control circuit is used to control the conduction and disconnection of the relay between the AC power supply AC and the rectifier bridge 101, thereby controlling the conduction and disconnection of the brake circuit 102 and the power supply. Among them, the relay control circuit includes a zero-crossing detection module 111, a trigger 112, a controller 113, a delay unit 114, and an actuator 115. The output terminal of the zero-crossing detection module 111 generates a first level signal A based on the zero-crossing voltage of the AC power supply AC. After the trigger 112 is triggered, it generates a second level signal B. When the first level signal A is the same as the second level signal B, the output terminal of the controller 113 outputs a third level signal C. In this way, the delay unit 114 is triggered at the zero-crossing voltage of the AC power supply AC. The delay unit 114 receives the third level signal C and outputs a fourth level signal D after a preset delay time. The actuator 115 receives the fourth level signal D and controls the coil of the relay to be powered on so that the contact points of the relay are closed. Since the contact points of the relay are closed after the actuator 115 receives the fourth level signal D after a preset closing time, and the sum of the preset closing time and the delay time is equal to the period of the AC power supply AC, in this way, the relay can be closed at the zero-crossing voltage of the AC power supply AC. At this time, the current flowing through the two contact points of the relay is reduced, the risk of the two contact points of the relay being burned due to the flow of large current can be reduced, and further the probability of the two contact points of the relay sticking together can be reduced, which is beneficial to extending the service life of the relay, avoiding the problem that the brake circuit cannot be controlled, and improving the safety of the brake system.

[0052] Those of ordinary skill in the art can understand that the above-described embodiments are specific examples for implementing the present application. In actual applications, various changes can be made to its form and details without departing from the spirit and scope of the present application. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A brake system, characterized in that, Comprising: An AC power supply having two output terminals; A rectifier bridge including two input terminals and two output terminals, with the two input terminals of the rectifier bridge respectively connected to the two output terminals of the AC power supply; A brake circuit connected to the two output terminals of the rectifier bridge; A relay control circuit, which includes: A zero-crossing detection module connected in parallel to the two output terminals of the AC power supply, and the output terminal of the zero-crossing detection module generates a first level signal based on the zero voltage of the AC power supply; A trigger that generates a second level signal after being triggered; A controller including two input terminals and one output terminal, with one input terminal of the controller connected to the output terminal of the zero-crossing detection module, and the other input terminal of the controller connected to the trigger. When the first level signal is the same as the second level signal, the output terminal of the controller outputs a third level signal; A delay unit connected to the output terminal of the controller, which receives the third level signal and outputs a fourth level signal after a preset delay time; An actuator connected to the delay unit; A relay, with the coil of the relay connected to the actuator, and the contact of the relay connected between the rectifier bridge and the AC power supply. The actuator receives the fourth level signal and controls the coil of the relay to be energized so that the contact of the relay closes. After the actuator receives the fourth level signal and after a preset closing time, the contact of the relay closes, and the sum of the preset closing time and the preset delay time is equal to the period of the AC power supply.

2. The brake system according to claim 1, characterized in that, The relay includes a first relay and a second relay. The first relay is connected between the positive output terminal of the AC power supply and the positive input terminal of the rectifier bridge, and the second relay is connected between the negative output terminal of the AC power supply and the negative input terminal of the rectifier bridge.

3. The brake system according to claim 1, wherein The relay includes a first relay and a second relay, and the first relay and the second relay are connected in series between the positive output terminal of the AC power supply and the positive input terminal of the rectifier bridge.

4. The brake system according to claim 2 or 3, wherein The delay unit includes a first delay unit and a second delay unit, and the first delay unit and the second delay unit are connected in parallel to the output terminal of the controller; The actuator includes a first actuator and a second actuator. The first actuator is connected between the first relay and the first delay unit, and the second actuator is connected between the second relay and the second delay unit.

5. The brake system according to claim 1, wherein The controller is an AND gate or a NAND gate.

6. The brake system according to claim 5, characterized in that, The delay unit includes an even number of serially connected inverters.

7. The brake system according to claim 1, characterized in that, The brake circuit includes a buck circuit and a brake coil, and the buck circuit includes: A first switching transistor, with the first end of the first switching transistor connected to the negative output terminal of the rectifier bridge; A first inductor, with the first end of the first inductor connected to the second end of the first switching transistor; A second switching transistor, a first end of the second switching transistor is connected to a second end of the first inductor, and a first end of the brake coil is connected to a second end of the second switching transistor; A first resistor, a first end of the first resistor is connected to a second end of the brake coil, and a second end of the first resistor is connected to a positive output terminal of the rectifier bridge; A first diode, a positive terminal of the first diode is connected to a second end of the first switching transistor, and a negative terminal of the first diode is connected to a positive output terminal of the rectifier bridge; A first capacitor, a first end of the first capacitor is connected to a second end of the first switching transistor, and a second end of the first capacitor is connected to a positive output terminal of the rectifier bridge.

8. The brake system according to claim 7, wherein The brake circuit includes a freewheeling loop, the freewheeling loop includes a second diode and a transient voltage suppression diode connected in series, a positive terminal of the second diode is connected to a first end of the brake coil, a negative terminal of the second diode is connected to a first end of the transient voltage suppression diode, and a second end of the transient voltage suppression diode is connected to a second end of the brake coil.

9. The brake system according to claim 1 or 7, characterized in that, The brake circuit includes a filter capacitor, a first end of the filter capacitor is connected to a negative output terminal of the rectifier bridge, and a second end of the filter capacitor is connected to a positive output terminal of the rectifier bridge.

10. An elevator system, characterized in that, Comprising the brake system according to any one of claims 1 to 9.

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