Brake power supply control device and control method

Abstract

The application discloses a kind of brake power supply control device and control method, brake power supply control device includes: first switching element, first switching element drive circuit, second switching element, second switching element drive circuit, freewheeling switch, freewheeling switch control circuit, first switching element drive power supply circuit, second switching element drive power supply circuit and freewheeling component;The power supply of brake is realized by controlling the on-off of first switching element, second switching element in the application, and the contactor is replaced by first switching element, second switching element, which can reduce noise, avoid the problems of high failure rate and low life caused by contactor, and the brake power supply device composed of first switching element and second switching element has simple structure, low cost and low failure rate.

Description

Technical Field

[0001] This invention belongs to the field of brake power supply control technology, specifically relating to a brake power supply control device and control method. Background Technology

[0002] For the power supply control of the brake, the current industry-standard technical solution is to use the normally open contacts of two contactors connected in series in the brake's power supply circuit. Both contactor coils are powered by a safety circuit. When the safety circuit is disconnected, the contactor coils are de-energized, their normally open contacts open, the brake power supply is cut off, and the brake is released to stop the elevator. However, the above contactor solution has a series of shortcomings, such as noise from contactor operation causing disturbance to users, the large size of the contactors making it difficult to further reduce the size of the control cabinet, contactor jamming leading to an increase in passenger entrapment failures, and the short electrical life of the contactors affecting the overall lifespan of the elevator. Against this backdrop, with the popularization of the PESSRAL (Programmable Electronic Safety System) elevator, contactless technical solutions based on PESSRAL have gradually emerged in recent years. These solutions employ a multi-channel redundant structure, incorporating two or more programmable systems to achieve low failure rates. While this technical solution can achieve contactless brake power supply control, the cost is a high failure rate and high cost due to the extremely complex multi-channel system, hindering its widespread adoption. Summary of the Invention

[0003] To overcome the above-mentioned technical defects, the present invention provides a brake power supply control device and control method, which can ensure the safety of brake power supply control.

[0004] To solve the above problems, the present invention is implemented according to the following technical solution:

[0005] A brake power supply control device includes: a first switching element, a first switching element drive circuit, a second switching element, a second switching element drive circuit, a freewheeling switch, a freewheeling switch control circuit, a first switching element drive power supply circuit, a second switching element drive power supply circuit, and a freewheeling component.

[0006] The freewheeling component is connected in parallel with the brake coil;

[0007] The first terminal of the power supply is connected to the second terminal of the power supply through the second switching element, the brake coil, and the first switching element;

[0008] The first terminal of the power supply is connected to the second terminal of the power supply through the freewheeling switch and the first switching element.

[0009] The safety circuit power supply is connected to the first input terminal of the first switching element drive power supply circuit and the first input terminal of the second switching element drive power supply circuit through the safety circuit.

[0010] The control power supply is connected to the second input terminal of the first switching element drive power supply circuit and the second input terminal of the second switching element drive power supply circuit.

[0011] The first switching element drive command 600 is connected to the third input terminal of the first switching element drive power supply circuit;

[0012] The second switching element drive command is connected to the third input terminal of the second switching element drive power supply circuit;

[0013] The output terminal of the first switching element drive power supply circuit is connected to the first switching element through the first switching element drive circuit.

[0014] The output terminal of the second switching element drive power supply circuit is connected to the second switching element through the second switching element drive circuit;

[0015] A safety loop is connected to one end of the freewheeling switch control circuit, and the other end of the freewheeling switch control circuit is connected to the freewheeling switch.

[0016] As a further improvement of the present invention, the first switching element driving power supply circuit includes: a first voltage converter and a first optocoupler;

[0017] The safety circuit power supply is connected to the primary side of the first voltage converter through the safety circuit, and the secondary side of the first voltage converter is connected to the fourth terminal of the first optocoupler.

[0018] The first end of the first optocoupler is connected to the control power supply, the second end of the first optocoupler is connected to the first switching element drive command 600, and the third end of the first optocoupler is connected to the first switching element through the first switching element drive circuit.

[0019] As a further improvement of the present invention, the second switching element drive power supply circuit includes: a second voltage converter and a second optocoupler;

[0020] The safety circuit power supply is connected to the primary side of the second voltage converter through the safety circuit, and the secondary side of the second voltage converter is connected to the fourth terminal of the second optocoupler;

[0021] The first end of the second optocoupler is connected to the control power supply, the second end of the second optocoupler is connected to the second switching element drive command, and the third end of the second optocoupler is connected to the second switching element through the second switching element drive circuit.

[0022] As a further improvement of the present invention, the present invention also includes a fuse connected in series between the brake coil and the first switching element.

[0023] As a further improvement of the present invention, the freewheeling switch is a transistor;

[0024] The first terminal of the power supply is connected to the second terminal of the power supply via the first and second terminals of the transistor;

[0025] The freewheeling switch control circuit includes: a third voltage converter, a third optocoupler, and a transistor drive circuit;

[0026] The safety circuit is connected to the primary side of the third voltage converter, and the secondary side of the third voltage converter is connected to the fourth terminal of the second optocoupler.

[0027] The first end of the third optocoupler is connected to the control power supply, the second end of the third optocoupler is connected to the transistor drive command, and the third end of the third optocoupler is connected to the third end of the transistor through the transistor drive circuit.

[0028] As a further improvement of the present invention, the transistor is a junction field-effect transistor, a metal-oxide-semiconductor field-effect transistor, an insulated-gate bipolar transistor, a bipolar junction transistor, or a junction field-effect transistor.

[0029] As a further improvement of the present invention, the freewheeling switch is a diode;

[0030] The safety circuit power supply is connected to the freewheeling switch control circuit via the safety circuit.

[0031] The first terminal of the power supply is connected to the second terminal of the power supply through the freewheeling switch, the freewheeling switch control circuit, and the first switching element.

[0032] As a further improvement of the present invention, the freewheeling switch control circuit includes: a first relay, a second relay, and a third relay;

[0033] The first terminal of the safety circuit power supply is connected to the second terminal of the safety circuit power supply through the safety circuit, the normally open contact of the first relay, and the coil of the first relay. The normally open contact of the third relay is connected in parallel with the normally open contact of the first relay.

[0034] The first terminal of the safety circuit power supply is connected to the second terminal of the safety circuit power supply through the safety circuit, the normally open contact of the second relay, and the coil of the second relay. The normally open contact of the third relay is connected in parallel with the normally open contact of the second relay.

[0035] The first terminal of the safety circuit power supply is connected to the coil of the third relay and the second terminal of the safety circuit power supply through the safety circuit, the normally closed contact of the first relay, and the normally closed contact of the second relay.

[0036] The first terminal of the power supply is connected to the second terminal of the power supply via the freewheeling switch, the normally open contact of the first relay, the normally open contact of the second relay, and the normally closed contact of the third relay.

[0037] Furthermore, the present invention also provides a control method for a brake power supply control device, applied to the aforementioned brake power supply control device, comprising the following steps:

[0038] When the safety circuit is connected, the control circuit of the freewheeling switch is closed to turn on the freewheeling switch;

[0039] When the elevator is running, the power supply circuit for driving the first switching element is closed to drive the first switching element to chop, and the power supply circuit for driving the second switching element is closed to turn on the second switching element, energize the brake coil, and open the brake.

[0040] When the safety circuit is disconnected, the power supply circuit for the first switching element and the power supply circuit for the second switching element are disconnected, causing the first and second switching elements to turn off, the brake coil to lose power, the brake to release, and the freewheeling switch to stop conducting.

[0041] Compared with the prior art, the present invention has the following advantages: the power supply of the brake is realized by controlling the on and off of the first switching element and the second switching element. The first switching element and the second switching element replace the contactor, which can reduce noise and avoid the problems of high failure rate and low lifespan caused by the contactor. At the same time, the brake power supply device composed of the first switching element and the second switching element has a simple structure, low cost and low failure rate. Attached Figure Description

[0042] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0043] Figure 1 This is a schematic diagram of the main circuit structure of the brake power supply control device described in Example 1;

[0044] Figure 2 This is a schematic diagram of the structure of the first switching element driving circuit, the second switching element driving circuit, and the freewheeling switch control circuit in Embodiment 1.

[0045] Figure 3 This is a schematic diagram of the main circuit structure of the brake power supply control device described in Example 2;

[0046] Figure 4 This is a schematic diagram of the structure of the first switching element driving circuit, the second switching element driving circuit, and the freewheeling switch control circuit in Embodiment 2.

[0047] Labeling Explanation: 1. Fuse; 2. First Switching Element; 3. First Switching Element Drive Circuit; 4. Second Switching Element; 5. Second Switching Element Drive Circuit; 6. Freewheeling Switch; 7. Freewheeling Switch Control Circuit; 701. Third Voltage Converter; 702. Third Optocoupler; 703. Transistor Drive Circuit; 704. First Relay; 705. Second Relay; 706. Third Relay; 8. First Switching Element Drive Power Supply Circuit; 801. First Voltage Converter; 802. First Optocoupler; 9. Second Switching Element Drive Power Supply Circuit; 901. Second Voltage Converter; 902. Second Optocoupler; 10. Freewheeling Assembly; 100. Power Supply; 200. Brake Coil; 300. Safety Circuit Power Supply; 400. Safety Circuit; 500. Control Power Supply; 600. First Switching Element Drive Command; 700. Second Switching Element Drive Command; 800. Transistor Drive Command. Detailed Implementation

[0048] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention. In addition, the step numbers S1, S2, etc. in the text are only for distinguishing different steps and do not mean that these steps need to be strictly performed in the order of the numbers.

[0049] Example 1

[0050] This embodiment provides a brake power supply control device, such as... Figure 1As shown, it includes: a first switching element 2, a first switching element drive circuit 3, a second switching element 4, a second switching element drive circuit 5, a freewheeling switch 6, a freewheeling switch control circuit 7, a first switching element drive power supply circuit 8, a second switching element 4 drive power supply circuit 9, and a freewheeling assembly 10; the freewheeling assembly 10 is connected in parallel with the brake coil 200; the first terminal of the power supply 100 is connected to the second terminal of the power supply 100 through the second switching element 4, the brake coil 200, and the first switching element 2; the first terminal of the power supply 100 is connected to the second terminal of the power supply 100 through the freewheeling switch 6 and the first switching element; the safety circuit power supply 300 is connected to the first input terminal of the first switching element drive power supply circuit 8 and the first input terminal of the second switching element drive power supply circuit 9 through the safety circuit 400. Input terminals: Control power supply 500 is connected to the second input terminal of the first switching element drive power supply circuit 8 and the second input terminal of the second switching element drive power supply circuit 9; First switching element drive command 600 is connected to the third input terminal of the first switching element drive power supply circuit 8; Second switching element drive command 600 is connected to the third input terminal of the second switching element drive power supply circuit 100; Output terminal of the first switching element drive power supply circuit 8 is connected to the first switching element 2 through the first switching element drive circuit 3; Output terminal of the second switching element drive power supply circuit 9 is connected to the second switching element 4 through the second switching element drive circuit 5; Safety circuit 400 is connected to one end of the freewheeling switch control circuit 7, and the other end of the freewheeling switch control circuit 7 is connected to the freewheeling switch 6.

[0051] Power supply 100 can be a DC voltage source, or it can be implemented by using a 220V AC voltage source connected in parallel with a rectifier and a filter capacitor. The first switching element 2 and the second switching element 4 are junction field-effect transistors, metal-oxide-semiconductor field-effect transistors, insulated-gate bipolar transistors, or bipolar junction transistors.

[0052] like Figure 2 As shown, the first switching element drive power supply circuit 8 includes: a first voltage converter 801 and a first optocoupler 802; a safety circuit power supply 300 is connected to the primary side of the first voltage converter 801 through a safety circuit 400, and the secondary side of the first voltage converter 801 is connected to the fourth terminal of the first optocoupler 802; the first terminal of the first optocoupler 802 is connected to the control power supply 500, the second terminal of the first optocoupler 802 is connected to the first switching element drive command 600, and the third terminal of the first optocoupler 802 is connected to the first switching element 2 through the first switching element drive circuit 3. The first voltage converter 801 and the second voltage converter 901 can be implemented using isolation transformers.

[0053] like Figure 2As shown, the second switching element drive power supply circuit 9 includes: a second voltage converter 901 and a second optocoupler 902; a safety circuit power supply 300 is connected to the primary side of the second voltage converter 901 through a safety circuit 400, and the secondary side of the second voltage converter 901 is connected to the fourth terminal of the second optocoupler 902; the first terminal of the second optocoupler 902 is connected to the control power supply 500, the second terminal of the second optocoupler 902 is connected to the second switching element drive command 700, and the third terminal of the second optocoupler 902 is connected to the second switching element 4 through the second switching element drive circuit 5.

[0054] Furthermore, it also includes a fuse 1 connected in series between the brake coil 200 and the first switching element 2.

[0055] In this embodiment, the freewheeling switch 6 is a diode; the safety circuit power supply 300 is connected to the freewheeling switch control circuit 7 through the safety circuit 400; the first end of the power supply 100 is connected to the second end of the power supply 100 through the freewheeling switch 6, the freewheeling switch control circuit 7, and the first switching element 2.

[0056] Specifically, such as Figure 2 As shown, the freewheeling switch control circuit 7 includes: a first relay 704, a second relay 705, and a third relay 706; the first terminal of the safety circuit power supply 300 is connected to the second terminal of the safety circuit power supply 300 through the safety circuit 400, the normally open contact of the first relay 704, and the coil of the first relay 704; the normally open contact of the third relay 706 is connected in parallel with the normally open contact of the first relay 704; the first terminal of the safety circuit power supply 300 is connected to the safety circuit power supply 300 through the safety circuit 400, the normally open contact of the second relay 705, and the coil of the second relay 705. The second terminal of 00, the normally open contact of the third relay 706 is connected in parallel with the normally open contact of the second relay 705; the first terminal of the safety circuit power supply 300 is connected to the coil of the third relay 706 and the second terminal of the safety circuit power supply 300 through the safety circuit 400, the normally closed contact of the first relay 704, and the normally closed contact of the second relay 705; the first terminal of the power supply 100 is connected to the second terminal of the first switching element 2 through the freewheeling switch 6, the normally open contact of the first relay 704, the normally open contact of the second relay 705, and the normally closed contact of the third relay 706.

[0057] The following is a further explanation of this embodiment in conjunction with the specific implementation process:

[0058] 1. When safety circuit 400 is connected:

[0059] On one hand, the coil of the third relay 706 is energized, causing its normally open contacts 1 and 2 to close. This energizes the coils of the first relay 704 and the second relay 705, which in turn closes the normally open contacts 1 of the first relay 704 and the second relay 705. Simultaneously, the normally closed contacts 1 of the first relay 704 and the second relay 705 open, de-energizing the coil of the third relay 706 and closing its normally closed contact 1. Thus, the diode is connected to the circuit.

[0060] On the other hand, the primary sides of the first voltage converter 801 and the second voltage converter 901 are energized. The first voltage converter 801 and the second voltage converter 901 convert the primary side energy to the secondary side, respectively supplying power to the secondary sides of the first optocoupler 802 and the second optocoupler 902. At this time, the first switch element drive command 600 and the second switch element drive command 700 from the elevator control system can control the switching on and off of the first switch element 2 and the second switch element 4, respectively. When the elevator needs to run, the first switch element drive command 600 controls the first switch element 2 to chop, ensuring the maximum duty cycle is below the recommended value of 50%. A current sensor can be added to detect the current in the brake coil 200 to perform closed-loop control of the duty cycle of the first switch element 2. The second switch element drive command 700 controls the second switch element 4 to remain on. Thus, the brake coil 200 receives current, and the brake is activated.

[0061] During the chopping process, when the first switching element 2 is turned on, the current does not flow through the diode; when it is turned off, the brake coil 200 continues to flow through the diode.

[0062] 2. When safety circuit 400 is disconnected:

[0063] On the one hand, the primary side of the first voltage converter 801 and the second voltage converter 901 loses power, thereby the secondary side of the first optocoupler 802 and the second optocoupler 902 loses power. The first switch element drive command 700 and the second switch element drive command 700 from the elevator control system lose their control over the first switch element 2 and the second switch element 4. At this time, the first switch element 2 and the second switch element 4 remain in the off state, the brake coil 200 loses power, and the brake is released.

[0064] On the other hand, the coils of the first relay 704 and the second relay 705 are de-energized, and the normally open contact 1 of the first relay 704 and the normally open contact 1 of the second relay 705 are disconnected, thus cutting off the freewheeling branch where the diode is located.

[0065] 3. The protection principle of this embodiment when a component fails:

[0066] ① First switching element 2

[0067] a. Short circuit fault: This is equivalent to the first switching element 2 having a duty cycle of 100%, causing an overcurrent in the circuit, blowing the fuse 1, and cutting off the power supply circuit of the brake coil 200.

[0068] b. Open circuit fault: The power supply circuit of brake coil 200 is cut off.

[0069] ② Second switching element 4

[0070] a. Short circuit fault: When the safety circuit 400 is connected, the circuit works normally. When the safety circuit 400 is disconnected, the first switching element 2 is disconnected, and the normally open contact 1 of the first relay 704 and the normally open contact 2 of the second relay 705 are disconnected, cutting off the freewheeling branch where the diode is located. This ensures that the brake coil 200 continues to flow through the freewheeling component 10. Since there is a resistor in the freewheeling component 10, the release time of the brake coil 200 current is short enough, so that the release time of the brake is controlled within the specified range.

[0071] b. Open circuit fault: The power supply circuit of brake coil 200 is cut off.

[0072] ③ The normally open contact 1 of the first relay 704 (the normally open contact 1 of the second relay 705 is similar).

[0073] a. Short circuit fault (equivalent to normally closed contact open circuit): After the safety circuit 400 is disconnected and then reconnected, since the normally closed contact 1 of the first relay 704 remains open, the coil of the third relay 706 cannot be energized, and the normally open contact 1 of the second relay 705 cannot be connected. Therefore, the diode cannot be connected to the circuit, so the brake coil 200 can only be driven by the 6 freewheeling component 10, thereby controlling the release time of the brake within the specified range.

[0074] b. Open circuit fault (equivalent to a short circuit of normally closed contacts): The diode cannot be connected to the circuit, so the brake coil 200 can only be connected to the freewheeling component 10, thereby controlling the release time of the brake within the specified range.

[0075] ④ The normally open contact 2 of the third relay 706

[0076] a. Short circuit fault (equivalent to normally closed contact open circuit): The normally closed contact 1 of the third relay 706 is open, the diode cannot be connected to the circuit, so the brake coil 200 can only be connected to the freewheeling component 10, thereby controlling the release time of the brake within the specified range.

[0077] b. Open circuit fault (equivalent to a short circuit of normally closed contacts): The coils of the first relay 704 and the second relay 705 can never be energized. Therefore, the normally open contacts 1 of the first relay 704 and the second relay 705 remain open. The diode cannot be connected to the circuit. Therefore, the brake coil 200 can only be driven by the freewheeling component 10, thereby controlling the release time of the brake within the specified range.

[0078] Example 2

[0079] This embodiment provides another brake power supply control device, which differs from Embodiment 1 in that the freewheeling switch 6 is a transistor, therefore the freewheeling switch control circuit 7 is also different from Embodiment 1, such as... Figure 3 and Figure 4 As shown, the first terminal of power supply 100 is connected to the second terminal of power supply 100 via the first and second terminals of transistor 2; the freewheeling switch control circuit 7 includes: a third voltage converter 701, a third optocoupler 702, and a transistor drive circuit 703; the safety circuit 400 is connected to the primary side of the third voltage converter 701, and the secondary side of the third voltage converter 701 is connected to the fourth terminal of the second optocoupler 902; the first terminal of the third optocoupler 702 is connected to the control power supply 500, the second terminal of the third optocoupler 702 is connected to the transistor drive command 800, and the third terminal of the third optocoupler 702 is connected to the third terminal of the transistor via the transistor drive circuit 703.

[0080] The transistor can be a switching element such as a junction field-effect transistor. When the freewheeling switch 6 is a junction field-effect transistor, its gate is connected to the transistor driving circuit 703, and its drain and source are connected to the fuse 1 and the second switching device, respectively.

[0081] The following explanation uses a junction field-effect transistor (JFET) as an example to further illustrate the working process of this implementation:

[0082] 1. When safety circuit 400 is connected:

[0083] When the secondary sides of the first optocoupler 802, the second optocoupler 902, and the third optocoupler 702 are energized, the control system (host computer) gains control over the first switching element 2, the second switching element 4, and the JFET. At this time, the control system issues a first switching element drive command 600 to make the first switching element 2 chop, and issues a second switching element drive command 700 to keep the second switching element 4 on. Simultaneously, it issues a transistor drive command 800 to make the JFET chop. The first switching element drive command 600 and the transistor drive command 800 are 180° out of phase, meaning that when the first switching element 2 is on, the JFET is off, and when the first switching element 2 is off, the JFET is on.

[0084] 2. When safety circuit 400 is disconnected:

[0085] When the secondary sides of the first optocoupler 802, the second optocoupler 902, and the third optocoupler 702 are de-energized, the control system (host computer) loses control over the first switching element 2, the second switching element 4, and the JFET, and the first switching element 2, the second switching element 4, and the JFET remain disconnected.

[0086] 3. The protection principle of this embodiment when a component fails:

[0087] ① Please refer to Example 1 for the fault protection operation principle of the first switching element 2 and the second switching element 4.

[0088] ② JFET fault protection operation principle:

[0089] a. Short circuit fault: This is equivalent to power supply 100 being short-circuited. The short circuit current causes fuse 1 to blow, brake coil 200 to lose power, and the brake to release.

[0090] b. Open circuit fault: The brake coil 200 cannot form a freewheeling circuit, so the brake coil 200 can only be freewheeled through the freewheeling component 10, thereby controlling the release time of the brake within the specified range.

[0091] Example 3

[0092] This embodiment provides a control method for a brake power supply control device, applied to the brake power supply control device in Embodiment 1 or Embodiment 2, including the following steps:

[0093] When the safety circuit 400 is turned on, the control circuit 7 for the freewheeling switch is closed, so that the freewheeling switch 6 is turned on.

[0094] When the elevator is running, the first switching element drive power circuit 8 is closed to drive the first switching element 2 to chop, and the second switching element drive power circuit 9 is closed to turn on the second switching element 4, energizing the brake coil 200 and opening the brake.

[0095] When the safety circuit is disconnected, the first switching element drive power circuit 8 and the second switching element drive power circuit 9 are disconnected, causing the first switching element 2 and the second switching element 4 to turn off, the brake coil 200 to lose power, the brake to release, and the freewheeling switch 6 to stop conducting.

[0096] For the specific implementation process of this embodiment, please refer to Embodiment 1 or Embodiment 2, which will not be repeated here.

[0097] In summary, the first and second switching elements of the present invention are junction field-effect transistors, metal-oxide-semiconductor field-effect transistors, insulated-gate bipolar transistors, and bipolar junction transistors. Compared with traditional contactors, they have the advantages of being noiseless and small in size, and do not contain programmable devices, which makes the whole circuit simple in structure, low in failure rate and low in cost.

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A brake power supply control device, characterized in that, include: A first switching element, a first switching element driving circuit, a second switching element, a second switching element driving circuit, a freewheeling switch, a freewheeling switch control circuit, a first switching element driving power supply circuit, a second switching element driving power supply circuit, and a freewheeling component; The freewheeling component is connected in parallel with the brake coil; The first terminal of the power supply is connected to the second terminal of the power supply through the second switching element, the brake coil, and the first switching element; The first terminal of the power supply is connected to the second terminal of the power supply through the freewheeling switch and the first switching element. The safety circuit power supply is connected to the first input terminal of the first switching element drive power supply circuit and the first input terminal of the second switching element drive power supply circuit through the safety circuit. The control power supply is connected to the second input terminal of the first switching element drive power supply circuit and the second input terminal of the second switching element drive power supply circuit. The first switching element drive command is connected to the third input terminal of the first switching element drive power supply circuit; The second switching element drive command is connected to the third input terminal of the second switching element drive power supply circuit; The output terminal of the first switching element drive power supply circuit is connected to the first switching element through the first switching element drive circuit. The output terminal of the second switching element drive power supply circuit is connected to the second switching element through the second switching element drive circuit; A safety loop is connected to one end of the freewheeling switch control circuit, and the other end of the freewheeling switch control circuit is connected to the freewheeling switch.

2. The brake power supply control device according to claim 1, characterized in that, The first switching element drive power supply circuit includes: a first voltage converter and a first optocoupler; The safety circuit power supply is connected to the primary side of the first voltage converter through the safety circuit, and the secondary side of the first voltage converter is connected to the fourth terminal of the first optocoupler. The first end of the first optocoupler is connected to the control power supply, the second end of the first optocoupler is connected to the first switching element drive command, and the third end of the first optocoupler is connected to the first switching element through the first switching element drive circuit.

3. The brake power supply control device according to claim 1, characterized in that, The second switching element drive power supply circuit includes: a second voltage converter and a second optocoupler; The safety circuit power supply is connected to the primary side of the second voltage converter through the safety circuit, and the secondary side of the second voltage converter is connected to the fourth terminal of the second optocoupler; The first end of the second optocoupler is connected to the control power supply, the second end of the second optocoupler is connected to the second switching element drive command, and the third end of the second optocoupler is connected to the second switching element through the second switching element drive circuit.

4. The brake power supply control device according to claim 1, characterized in that, It also includes a fuse connected in series between the brake coil and the first switching element.

5. The brake power supply control device according to any one of claims 1-4, characterized in that, The freewheeling switch is a transistor; The first terminal of the power supply is connected to the second terminal of the power supply via the first and second terminals of the transistor; The freewheeling switch control circuit includes: a third voltage converter, a third optocoupler, and a transistor drive circuit; The safety circuit is connected to the primary side of the third voltage converter, and the secondary side of the third voltage converter is connected to the fourth terminal of the second optocoupler. The first end of the third optocoupler is connected to the control power supply, the second end of the third optocoupler is connected to the transistor drive command, and the third end of the third optocoupler is connected to the third end of the transistor through the transistor drive circuit.

6. The brake power supply control device according to claim 1, characterized in that, The first switching element and the second switching element are junction field-effect transistors, metal-oxide-semiconductor field-effect transistors, insulated-gate bipolar transistors, and bipolar junction transistors.

7. The brake power supply control device according to any one of claims 1-4, characterized in that, The freewheeling switch is a diode; The safety circuit power supply is connected to the freewheeling switch control circuit via the safety circuit. The first terminal of the power supply is connected to the second terminal of the power supply through the freewheeling switch, the freewheeling switch control circuit, and the first switching element.

8. The brake power supply control device according to claim 7, characterized in that, The freewheeling switch control circuit includes: a first relay, a second relay, and a third relay; The first terminal of the safety circuit power supply is connected to the second terminal of the safety circuit power supply through the safety circuit, the normally open contact of the first relay, and the coil of the first relay. The normally open contact of the third relay is connected in parallel with the normally open contact of the first relay. The first terminal of the safety circuit power supply is connected to the second terminal of the safety circuit power supply through the safety circuit, the normally open contact of the second relay, and the coil of the second relay. The normally open contact of the third relay is connected in parallel with the normally open contact of the second relay. The first terminal of the safety circuit power supply is connected to the coil of the third relay and the second terminal of the safety circuit power supply through the safety circuit, the normally closed contact of the first relay, and the normally closed contact of the second relay. The first terminal of the power supply is connected to the second terminal of the power supply via the freewheeling switch, the normally open contact of the first relay, the normally open contact of the second relay, and the normally closed contact of the third relay.

9. A control method for a brake power supply control device, characterized in that, The brake power supply control device as described in any one of claims 1-8 includes the following steps: When the safety circuit is connected, the control circuit of the freewheeling switch is closed to turn on the freewheeling switch; When the elevator is running, the power supply circuit for driving the first switching element is closed to drive the first switching element to chop, and the power supply circuit for driving the second switching element is closed to turn on the second switching element, energize the brake coil, and open the brake. When the safety circuit is disconnected, the power supply circuit for the first switching element and the power supply circuit for the second switching element are disconnected, causing the first and second switching elements to turn off, the brake coil to lose power, the brake to release, and the freewheeling switch to stop conducting.

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