A brake control device and method for output voltage ramp starting

Abstract

A brake control device and method with output voltage ramp start, which relates to the field of elevator control, includes a first rectifier filter circuit, a switch power supply, a brake power supply control relay, a brake voltage control circuit, a second rectifier filter circuit, a chopper output circuit, an output filter circuit, an output voltage acquisition circuit and an output current acquisition circuit. The brake power supply control relay adopts two safety relays to control the neutral line and the live line of the mains input respectively. The feedback contact signal of the safety relay is output to the input end of the elevator main control board to ensure that when the relay contact is fused, the elevator main control board can report the elevator fault and stop running to ensure the safety of the elevator operation; the chopper output circuit and the output filter circuit effectively ensure the output power of the brake power supply, which can increase the rated output power of the original component and improve the power of the entire brake voltage output. The output voltage acquisition circuit adopts a resistor voltage divider, and the output current acquisition circuit adopts a milliohm resistor for sampling.

Description

Technical Field

[0001] The present invention relates to the field of elevator control, and in particular to a brake control device and method for output voltage ramp starting. Background Art

[0002] With the leap of electronic science and technology, elevator technology has developed rapidly. After several generations of upgrades, the drive technology and control technology have achieved permanent magnet synchronous speed regulation and microcomputer full intelligent control, which has improved the reliability and stability of the whole machine. As one of the most important parts of the elevator, the "brake circuit" can achieve braking and stopping by disconnecting the brake circuit of the motor when the elevator stops normally or in an emergency, avoiding abnormal displacement of the car when it is stationary or the power motor loses power, thereby ensuring the safety of life and property of elevator passengers.

[0003] At present, the mainstream brake circuit uses the elevator brake control device to control the electromagnetic traction brake to perform parking brake. The elevator brake control device is usually implemented by an uncontrollable full-wave or half-wave rectification scheme. The output waveform is as shown in the attached figure. Fig.15 . The implementation principle is to use an industrial frequency transformer to convert the industrial power supply 380VAC or the mains 220VAC into 110VAC, and then perform full-wave or half-wave rectification through a rectifier bridge or a thyristor circuit, thereby changing the output voltage to control the traction brake coil (i.e., the brake coil) to achieve elevator braking. The disadvantages of the above technical solution: First, since it is impossible to achieve linear adjustment of the output voltage amplitude, it is impossible to match a single brake control device with brake coils of different models. It has the disadvantages of high supporting cost, poor power adaptability and matching, large size, large weight, and high installation and maintenance costs. Secondly, the elevator brake control device is generally required to have a strong excitation output for rapid opening of the gate with a large power, and a weak excitation output characteristic for maintaining the current state with a small power to meet the environmental protection requirements of energy saving and consumption reduction, while the above device cannot meet the requirements of energy saving and consumption reduction. Thirdly, at the moment of opening the gate, the voltage applied to both ends of the brake coil is a full-wave rectified voltage of 110VAC (i.e. 130VDC), which makes a lot of noise when the gate is opened. Sometimes, due to the gate opening too quickly, it will also affect the comfort of the elevator when starting, thus affecting the user's elevator riding experience. Summary of the invention

[0004] In view of the deficiencies in the prior art, an object of the present invention is to provide a brake control device and method for output voltage ramp starting.

[0005] The technical solution adopted by the invention is: A brake control device with output voltage ramp start, the technical key points of which are:

[0006] A first rectifier and filter circuit, whose input end is connected to the mains and whose output end is connected to the switching power supply, is used to rectify the mains, convert the connected mains into a DC bus voltage, and provide it to the switching power supply after filtering;

[0007] The switching power supply, the output end of which is respectively connected to the brake power control relay and the brake voltage control circuit, is used to output two isolated DC regulated power supplies, one for the coil of the brake power control relay, and the other for the brake voltage control circuit and the output current acquisition circuit;

[0008] The brake power supply control relay has an input end connected to the mains and the brake voltage control circuit, and an output end connected to the rectifier filter circuit and the output current acquisition circuit respectively, and is used to connect or disconnect the mains and the second rectifier filter circuit according to the control signal of the brake voltage control circuit;

[0009] The brake voltage control circuit has an input end connected to the elevator main control board, an output current acquisition circuit and an output voltage acquisition circuit respectively, and an output end connected to the chopper output circuit, and is used to receive a control signal from the elevator main control board. When the control signal is valid, the brake voltage output control timing is started to be executed, and the feedback signals of each input are monitored;

[0010] The second rectifier filter circuit has an output end connected to the chopper output circuit, and is used to rectify the mains power, convert the 220VAC output of the brake power control relay into a DC bus voltage of about 310VDC, and provide it to the chopper circuit after filtering;

[0011] The chopper output circuit, whose output end is connected to the output filter circuit, is used to control the duty cycle of the main chopper tube control signal, thereby controlling the output voltage of the brake output power supply and controlling the opening and closing of the brake;

[0012] The output filter circuit, whose output end is connected to the output voltage acquisition circuit, is used to continue to provide current to the load brake coil when the output MOS tube of the chopper output circuit is turned off, so as to make the brake work stably;

[0013] The output voltage acquisition circuit is used to collect the output brake voltage and output a feedback signal to the brake voltage control circuit to accurately control the output voltage;

[0014] And the output current acquisition circuit, the output end is connected to the traction machine brake coil to detect whether the output is over-current. When over-current occurs, over-current protection will be performed.

[0015] In the above scheme, the brake voltage controller includes a four-channel voltage comparator circuit, a constant current source control rising slope circuit, a pulse width modulation control chip and a timer chip. The input end of the four-channel voltage comparator circuit is connected to the brake control signal, and the output end of the four-channel voltage comparator circuit is connected to the pulse width modulation control chip via the constant current source control rising slope circuit, and the pulse width modulation control chip is connected to the timer chip.

[0016] In the above scheme, the constant current source control rising slope circuit includes a parallel regulator, a first operational amplifier, a second operational amplifier and a PNP transistor, the negative electrode of the parallel regulator is connected to a DC power supply, the positive electrode of the parallel regulator is connected to one end of the twenty-first resistor and the positive input end of the first operational amplifier, the reverse input end of the first operational amplifier is connected to one end of the seventeenth resistor and the emitter of the PNP transistor, the output end of the first operational amplifier is connected to one end of the eighteenth resistor, the other end of the eighteenth resistor is connected to the base of the PNP transistor, the collector of the PNP transistor is connected to one end of the nineteenth resistor, one end of the twenty-sixth resistor, and one end of the eleventh capacitor, the other end of the twenty-sixth resistor is connected to the positive input end of the second operational amplifier, the reverse input end of the second operational amplifier is connected to the output end of the second operational amplifier and the pulse width modulation control chip; the other end of the nineteenth resistor R19 is connected to the positive electrode of the eleventh diode, the negative electrode of the eleventh diode is connected to the constant current source current reset signal, and the other end of the eleventh capacitor is grounded.

[0017] The beneficial effects of the present invention are as follows: the brake control device with output voltage ramp start includes a first rectifier filter circuit, a switch power supply, a brake power supply control relay, a brake voltage control circuit, a second rectifier filter circuit, a chopper output circuit, an output filter circuit, an output voltage acquisition circuit and an output current acquisition circuit, and the brake power supply control relay adopts two safety relays to control the neutral line and the live line of the main power input respectively. The feedback contact signal of the safety relay is output to the input end of the elevator main control board to ensure that when the relay contact is fused, the elevator main control board can report the elevator fault and stop running to ensure the safety of the elevator operation; the chopper output circuit and the output filter circuit effectively ensure the output power of the brake power supply, which can increase the rated output power of the original component and improve the power of the entire brake voltage output. The output voltage acquisition circuit adopts a resistor voltage divider, and the output current acquisition circuit adopts a milliohm resistor for sampling. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the structure of a brake control device with output voltage ramp starting in an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of the structure of a rectifier and filter circuit in an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the structure of a switching power supply circuit in an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the structure of a power control relay circuit in an embodiment of the present invention;

[0023] Figure 5 This is a circuit structure block diagram of a brake voltage controller in an embodiment of the present invention;

[0024] Figure 6 Schematic diagram of the circuit structure of a four-channel voltage comparator in an embodiment of the present invention;

[0025] Figure 7 Schematic diagram of the structure of a constant current source controlling a rising slope circuit in an embodiment of the present invention;

[0026] Figure 8 This is a schematic diagram of the circuit structure of a pulse width modulation control chip in an embodiment of the present invention;

[0027] Fig. 9 A schematic diagram of the circuit structure of a timer chip in an embodiment of the present invention;

[0028] Fig.10 A schematic diagram of the structure of a rectifier and filter circuit in an embodiment of the present invention;

[0029] Fig.11 A schematic diagram of the structure of a chopper output circuit in an embodiment of the present invention;

[0030] Fig.12 It is a schematic diagram of the structure of an output filter circuit in an embodiment of the present invention;

[0031] Fig.13 Schematic diagram of the circuit structure of the output voltage acquisition circuit in an embodiment of the present invention;

[0032] Fig.14 Schematic diagram of the circuit structure of the output current acquisition circuit in an embodiment of the present invention;

[0033] Fig.15 This is a schematic diagram of an output waveform of a common brake voltage control board in an embodiment of the present invention;

[0034] Fig.16 Schematic diagram of output voltage waveform in an embodiment of the present invention;

[0035] The serial numbers in the figure are explained as follows: 1 AC power, 2 rectification and filtering circuit, 3 switching power supply, 4 brake power supply control relay, 5 brake voltage control circuit, 51 four-channel voltage comparator, 52 constant current source control rising slope circuit, 53 timer chip, 54 pulse width modulation control chip, 6 rectification and filtering circuit, 7 chopping output circuit, 8 output filtering circuit, 9 output voltage acquisition circuit, 10 output current acquisition circuit. DETAILED DESCRIPTION

[0036] To make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the following is a brief description of the present invention in conjunction with the attached Figures 1 to 16 The present invention is further described in detail with specific implementation modes.

[0037] The brake control device with output voltage ramp start adopted in this embodiment includes:

[0038] Mains 1: provides 220VAC to the rectifier filter circuit 2 and the brake power control relay;

[0039] The rectifier filter circuit 2 has an input end connected to the mains 1 and an output end connected to the switch power supply 3, and is used to rectify the mains 1, convert the connected mains 1 into a DC bus voltage, and provide it to the switch power supply 3 after filtering;

[0040] The switching power supply 3, the output ends of which are respectively connected to the brake power control relay 4 and the brake voltage control circuit 5, is used to output two isolated DC regulated power supplies, one of which provides power for the coil of the brake power control relay 4, and the other provides power for the brake voltage control circuit 5 and the output current acquisition circuit 10;

[0041] The brake power supply control relay 4 has an input end connected to the mains 1 and the brake voltage control circuit 5, and an output end connected to the rectifier filter circuit 6 and the output current acquisition circuit respectively, and is used to connect or disconnect the mains and the second rectifier filter circuit according to the control signal of the brake voltage control circuit;

[0042] The brake voltage control circuit 5 has an input end connected to the elevator main control board, an output current acquisition circuit and an output voltage acquisition circuit respectively, and an output end connected to the chopper output circuit, and is used to receive a control signal from the elevator main control board. When the control signal is valid, the brake voltage output control timing is started to be executed, and the feedback signals of each input are monitored;

[0043] The rectifier filter circuit 6, whose output end is connected to the chopper output circuit, is used to rectify the mains power, convert the 220VAC output of the brake power control relay into a DC bus voltage of about 310VDC, and provide it to the chopper circuit after filtering;

[0044] The chopper output circuit 7, whose output end is connected to the output filter circuit, is used to control the duty cycle of the main chopper tube control signal, thereby controlling the output voltage of the brake output power supply and controlling the opening and closing of the brake;

[0045] The output filter circuit 8, whose output end is connected to the output voltage acquisition circuit, is used to continue to provide current to the load brake coil when the output MOS tube of the chopper output circuit is turned off, so as to make the brake work stably;

[0046] The output voltage acquisition circuit 9 is used to collect the output brake voltage and output a feedback signal to the brake voltage control circuit to accurately control the output voltage;

[0047] And the output current acquisition circuit 10, the output end of which is connected to the traction machine brake coil, is used to detect whether the output is over-current. When over-current occurs, over-current protection will be performed.

[0048] The rectifier and filter circuit 2 in this embodiment is as follows: Figure 2 As shown, it includes a bridge rectifier module D1 and a filter capacitor C1, wherein the model of the bridge rectifier module D1 is GBJ2510, which rectifies the mains power, converts the mains power 220VAC connected to the terminal CN4 into a DC bus voltage of about 310VDC, and provides it to the switching power supply 3 after filtering by the filter capacitor C1. The specific connection relationship is as follows: the neutral line N1 of the mains input 1 is connected to the pin 2 of the terminal CN4, and the live line L1 is connected to the pin 1 of the terminal CN4. The pin 2 of the terminal CN4 is connected to the AC input terminal 1 of the bridge rectifier module D1, and the pin 1 of the terminal CN4 is connected to the AC input terminal 3 of the bridge rectifier module D1. The output terminal 2 of the bridge rectifier module D1 is connected to the positive electrode of the filter capacitor C1 and the DC1+ terminal of the switching power supply 3, and the output terminal 4 of the bridge rectifier module D1 is connected to the negative electrode of the filter capacitor C1 and the DC1- terminal of the switching power supply 3.

[0049] The switching power supply 3 in this embodiment is as follows: Figure 3 As shown. A flyback switching power supply architecture is adopted, including a switching power supply control chip FA13844, a MOS tube QK1, a pulse transformer TK1, and a rectifier filter diode DK1, a rectifier filter diode DK2, a capacitor CK1 and a capacitor CK2 for outputting isolated power. The switching power supply 3 outputs two isolated DC regulated power supplies, U1 and U2 respectively. Among them, one isolated power supply U1 provides power for the coil of the brake power control relay 4; the other isolated power supply U2 provides power for the brake voltage control circuit 5 and the output current acquisition circuit 10. The PWM signal output by the 6th pin of the switching power supply control chip FA13844 in the switching power supply 3 controls the conduction and shutdown of the main switch tube QK1, replenishes energy for the pulse transformer TK1, and enables it to output two completely isolated and stable low-voltage DC power supplies U1 and U2. Its circuit structure is:

[0050] The DC1+ terminal is connected to one end of the main coil of the pulse transformer TK1, and the DC1- terminal is grounded. The pin 6 of the switch power control chip is connected to the gate of the MOS tube QK1, the source of the MOS tube QK1 is connected to the other end of the main coil of the pulse transformer TK1, and the source and drain of the MOS tube QK1 are connected to the DC1- terminal and grounded. One end of the first secondary coil of the pulse transformer TK1 is connected to the positive electrode of the rectifier filter diode DK1, the negative electrode of the rectifier filter diode DK1 is connected to one end of the capacitor CK1 and the U1+ terminal of the brake power control relay 4, and the other end of the first secondary coil of the pulse transformer TK1 is connected to the other end of the capacitor CK1 and the U1- terminal of the brake power control relay 4. One end of the first second secondary coil of the pulse transformer TK1 is connected to the positive electrode of the rectifier filter diode DK2, the negative electrode of the rectifier filter diode DK2 is connected to one end of the capacitor CK2 and the U2+ end of the brake power supply control circuit 5, and the other end of the second secondary coil of the pulse transformer TK1 is connected to the other end of the capacitor CK2 and the U2- end of the output current acquisition circuit 10.

[0051] The brake power supply control relay 4 in this embodiment is as follows: Figure 4As shown, it includes two safety relays JR1 and JR2 with normally closed feedback contacts, and a diode DJ1, wherein the models of the safety relays JR1 and JR2 are both HFA2-24-HD1ST. Terminal 2 of the safety relay JR1 and terminal 2 of the coil of the safety relay JR2 are both connected to the U1+ terminal of the switching power supply 3, and the coil 1 terminal of the safety relay JR1 is connected to the JRC# signal terminal of the brake voltage control circuit 5. The normally open contact 9 of the safety relay JR1 is connected to the L2 terminal of the rectifier filter circuit 6, the normally open contact 9 of the safety relay JR2 is connected to the N2 terminal of the rectifier filter circuit 6, the normally open contact 11 of the safety relay JR1 is connected to the L1 terminal of the mains wiring terminal CN4, and the normally open contact 11 of the safety relay JR2 is connected to the N1 terminal of the mains wiring terminal CN4. The normally closed contact 10 of the safety relay JR1 and the normally closed contact 10 of the safety relay JR2 are both connected to the feedback point BY_COM of the elevator main control board 12. The normally closed contact 8 of the safety relay JR1 is connected to the feedback point BY1 of the elevator main control board 12, and the normally closed contact 8 of the safety relay JR2 is connected to the feedback point BY2 of the elevator main control board 12. The cathode of the diode DJ1 is connected to the 2 ends of the safety relay RJ2, and the anode of the diode DJ1 is connected to the 1 end of the safety relay RJ2. The anode of the diode is also connected to the DC-GND ground terminal. Its working process is: the brake power control relay 4 controls the N2 and L2 power supplies of the rectifier filter circuit 6 according to the JRC# signal end of the brake voltage control circuit 5 to ensure that the input of the brake power supply is completely disconnected when the control signal is invalid. Since the safety relays JR1 and JR2 have a forced guide contact structure, in the event that one of the contact points is fused, the feedback contact signal is fed back to the elevator main control board 12, causing it to stop the elevator from opening the gate to ensure safety. When the brake voltage control circuit 5 outputs a valid control signal, the normally open contacts 11 of the two safety relays JR1 and JR2 will close, so that the mains output 220VAC is connected to the rectifier filter circuit 6, and at the same time, the feedback signal of the two normally closed contacts 8 and 10 disconnected is transmitted to the elevator main control board 12. The elevator main control board 12 monitors the feedback signal in real time. When the feedback signal is abnormal, the elevator main control board 12 will immediately control the brake voltage control circuit 5 to stop outputting the brake voltage, and immediately stop the elevator and display the fault code to ensure the safety and stability of the elevator operation. The brake power supply control relay 4 will connect and disconnect the mains 220VAC and the rectifier filter circuit 6 according to the control signal of the brake voltage control circuit 5.

[0052] When the brake voltage output power is large, circuits such as surge relays and surge resistors can be added at both ends of the safety relay's contacts to ensure that the current is less than its rated current when the safety relay is energized.

[0053] The brake voltage control circuit 5 in this embodiment is the control center of the brake power output. Figure 5 As shown. It includes a four-channel voltage comparator 51 (model LM2901-N), a constant current source control rising slope circuit 52, a pulse width modulation control chip 54 (model TL494) and a timer chip 53 (model SA555). Among them, the main components of the constant current source control rising slope circuit 52 include: a parallel regulator (model TL431A), an operational amplifier (model TLV2372) and a PNP transistor (model LBC807-25). The specific circuit connection relationship is:

[0054] One end of the resistor R20 is connected to DC+14V, the other end of the resistor R20 is connected to Ref10V, one end of the resistor R29, and the cathode of the Zener diode D6, and the anode of the Zener diode D6 is connected to DC-GND. The other end of the resistor R29 is connected to one end of the resistor R28 and the positive input terminal 5 of the comparator U3A, the other end of the resistor R28 is connected to the output end of the comparator U3A and one end of the resistor R39 of the pulse width modulation control chip TL494, the reverse input terminal 4 of the comparator U3A is connected to one end of the resistor R32, the other end of the resistor R32 is connected to one end of the capacitor C16 and one end of the resistor R33, the other end of the capacitor C16 is connected to the DC-GND terminal, the other end of the resistor R33 is connected to one end of the resistor RF1, one end of the resistor R52 and the elevator control board 12, the other end of the resistor RF1 is connected to one end of the capacitor CF1 and one end of the resistor RF4, the other end of the resistor RF4 is connected to the positive input terminal 11 of the comparator U3D and one end of the resistor RF6, the other end of the resistor RF6 is connected to the output end of the comparator U3D and the input end of the brake power control relay 4, and the reverse input terminal 10 of the comparator U3D is connected to Ref10V. The other end of resistor R52 is connected to one end of resistor R53 and one end of capacitor C22. The other end of resistor R53 is connected to the positive input terminal 7 of comparator U3B and one end of resistor R49. The other end of resistor R49 is connected to the output terminal of comparator U3B and the negative electrode of diode D11 in the constant current source control rising slope circuit. The other end of capacitor C22 is grounded. The reverse input terminal 6 of comparator U3B is connected to the Ref10V terminal.

[0055] The positive electrode of diode D11 is connected to one end of resistor R19, the other end of resistor R19 is connected to the collector of transistor Q1, one end of resistor R26, and one end of capacitor C11, and the other end of resistor C11 is connected to the DC-GND end. The other end of resistor R26 is connected to the positive input terminal 3 of operational amplifier U2A, and the negative input terminal 2 of operational amplifier U2A is connected to the output terminal 1 of comparator U2A and one end of resistor R9 of pulse width modulation control chip TL494. The emitter of transistor Q1 is connected to one end of resistor R17 and the negative input terminal 6 of operational amplifier U2B, the other end of resistor R17 is connected to the DC+14V end, the positive input terminal 5 of operational amplifier U2B is connected to one end of resistor R21 and the positive electrode of parallel regulator D3, the negative electrode of parallel regulator D3 is connected to DC+14V, and the other end of resistor R21 is connected to the DC-GND end.

[0056] The other end of the resistor R39 of the pulse width modulation control chip TL494 is connected to one end of the resistor R5 and pin 2 of the pulse width modulation control chip TL494, the other end of the resistor R5 is connected to one end of the resistor R38, pin 3 of the pulse width modulation control chip TL494 and one end of the resistor R11 of the timing chip, the other end of the resistor R38 is connected to pin 15 of the pulse width modulation control chip TL494 and the other end of the resistor R39, pins 1, 3 and 16 of the pulse width modulation control chip TL494 are connected to each other and can be connected to one end of the resistor R3, and the other end of the resistor R3 is connected to the output voltage acquisition circuit 9. Pin 11, pin 8 and chopping output circuit 7 of the pulse width modulation control chip TL494 are connected.

[0057] The other end of the resistor R11 is connected to the pin 3 of the timer chip U4, the pin 2 of the timer chip U4 is connected to the output end 14 of the comparator U3C and one end of the resistor R12, the reverse input end 8 of the comparator U3C is connected to one end of the resistor R16, and the other end of the resistor R16 is connected to the output current collection circuit 10. The positive input end 9 of the comparator U3C is connected to the other end of the resistor R12, one end of the resistor R14, and one end of the resistor R13, the other end of the resistor R14 is connected to V5, and the other end of the resistor R13 is connected to DC-GND.

[0058] The pulse width modulation control chip TL494 is a fixed frequency pulse width modulation circuit, which includes all the functions required for switching power supply control. The switching power supply 3 provides the working power supply for the circuit. The brake control signal of the elevator main control board 12 is the external control signal source. The output voltage acquisition circuit 9 and the output current acquisition circuit 10 provide the circuit with the feedback signal of the output voltage. At the same time, the circuit outputs the control signal for the brake power supply control relay 4 and the PWM signal of the output chopper output circuit 7.

[0059] The working process of the brake voltage control circuit 5 is: accepting the control signal from the elevator main control board 12. When the control signal is valid, the brake voltage control circuit 5 starts to execute the brake voltage output control timing and monitors the feedback signals of each input. First, the control signal is output to the brake power control relay 4 to make it energized; second, it is detected whether the bus voltage output by the rectifier filter circuit 6 reaches the voltage value required by the design; third, the output chopping signal controls the chopping output circuit 7 to start chopping the output brake voltage. At the same time, it is necessary to monitor whether the feedback value of the output voltage and current acquisition circuit is normal, and dynamically adjust the output brake voltage value through the feedback value, so as to realize the output brake voltage ramp start and have the output full voltage start and half voltage maintenance function.

[0060] The rectifier and filter circuit 6 of this embodiment is as follows: Figure 6 As shown, it includes a bridge rectifier module D2 and a filter capacitor C2, wherein the model of the bridge rectifier module D2 is GBJ2510. It rectifies the mains electricity, converts the 220VAC output by the brake power control relay 4 into a DC bus voltage of about 310VDC, and provides it to the chopper circuit 7 after filtering by the C2 capacitor. Its circuit structure is: the zero line N2 of the power control relay 4 is connected to the pin 1 of the AC input end of the bridge rectifier module D2, and the live line L2 of the power control relay 4 is connected to the pin 3 of the AC input end of the bridge rectifier module D2. The output pin 2 of the rectifier bridge module D2 is connected to the positive pole of the filter capacitor C2 and the DC2+ end of the chopper output circuit 7, and the output pin 4 of the rectifier bridge module D2 is connected to the negative pole of the filter capacitor C2 and the DC2- end of the chopper output circuit 7.

[0061] The chopping output circuit 7 in this embodiment is as follows: Figure 7As shown, it is mainly composed of a main chopper MOS tube QZ1, a freewheeling diode DZ1, an output energy storage inductor LZ1 and a capacitor CZ1. Its circuit structure is: the emitter of the main chopper MOS tube QZ1 is connected to the DC2+ end of the rectifier filter circuit 6, the gate of the main chopper MOS tube QZ1 is connected to the PWM output end of the brake voltage control circuit 5, the drain of the main chopper MOS tube QZ1 is connected to the negative electrode of the freewheeling diode DZ1 and one end of the output energy storage inductor LZ1, the other end of the output energy storage inductor LZ1 is connected to one end of the capacitor CZ1 and the DCOUT end of the output filter circuit 8, and the positive electrode of the freewheeling diode DZ1 is connected to the DC2- end of the rectifier filter circuit 6, the other end of the capacitor CZ1 and the DC2- end of the output filter circuit 8. Its working process is as follows: the chopper MOS tube QZ1 is controlled to be turned on or off by the brake voltage control circuit 5. When the main chopper MOS tube QZ1 is turned on, the bus current output from the DC2+ terminal and DC2- terminal of the rectifier filter circuit 6 flows to the output inductor LZ1 through the chopper tube QZ1, and the output energy storage inductor LZ1 begins to store energy. At this time, the freewheeling diode DZ1 is turned off. The current flows out from the rectifier filter circuit 6, passes through the main chopper MOS tube QZ1, the output energy storage inductor LZ1, and the brake load, and finally flows back to the negative electrode of the bus power supply to form a closed loop. When the main chopper MOS tube QZ1 is turned off, since the output inductor LZ1 has the characteristic that the current cannot change suddenly, the current direction remains unchanged and begins to release the stored energy. After the current flows out from the output energy storage inductor LZ1, it passes through the brake load and then returns to the inductor through the freewheeling diode to form a closed loop. By controlling the duty cycle of the main chopper tube control signal, the output voltage of the brake output power supply can be accurately controlled. This allows the opening and closing of the brake to be accurately and stably controlled.

[0062] The output filter circuit 8 in this embodiment is as follows: Figure 8 As shown, it includes an energy storage inductor L1 and an energy storage capacitor CL1. Its circuit structure is as follows: one end of the energy storage inductor L1 is connected to the DCOUT end of the chopper output circuit 7, the other end of the energy storage inductor L1 is connected to one end of the energy storage capacitor CL1 and the DCOUT+ end of the output voltage acquisition circuit 9, and the other end of the energy storage capacitor CL1 is connected to the DC-end of the chopper output circuit 7 and the DC end of the output current acquisition circuit 10. Its working process is: using the principle that the current flowing through the energy storage inductor L1 will not suddenly change and the principle that the voltage across the two ends of the energy storage capacitor CL1 will not suddenly change, during the period when the output MOS tube of the above-mentioned chopper output circuit 7 is turned off, the energy storage inductor L1 and the energy storage capacitor CL1 continue to provide current to the load brake coil to ensure the stable operation of the brake.

[0063] The output voltage acquisition circuit 9 in this embodiment is as follows: Fig. 9As shown, it is mainly composed of a voltage-dividing resistor RC1, a voltage-dividing resistor RC2, a voltage-dividing resistor RC3, a voltage-dividing resistor RC4, a capacitor CC1 and a capacitor CC2, and its specific circuit structure is: one end of the voltage-dividing resistor RC1 is connected to the DCOUT+ end of the output filter circuit 8, the other end of the voltage-dividing resistor RC1 is connected to one end of the voltage-dividing resistor RC2, the other end of the voltage-dividing resistor RC2 is connected to one end of the capacitor CC1, one end of the voltage-dividing resistor RC3 and one end of the voltage-dividing resistor RC4, the other end of the voltage-dividing resistor RC4 is connected to one end of the capacitor CC2 and the V_FB end of the brake voltage control circuit 5, and the other end of the capacitor CC1, the other end of the voltage-dividing resistor RC3 and the other end of the capacitor CC2 are respectively connected to the DC- end of the output filter circuit 8 and the DC- end of the brake voltage control circuit. Its working process is: responsible for collecting the output brake voltage DCOUT+, and outputting the feedback signal V_FB to the brake voltage control circuit 5, so that it can accurately control the output voltage. The voltage divider resistors RC1, RC2 and RC3 are responsible for voltage division of DCOUT+, and the voltage divider resistors CC1 and CC2 are responsible for filtering the output feedback signal to prevent malfunction caused by interference signals. The maximum output power supply DCOUT+ is 110V. The feedback voltage V_FB output to the voltage control circuit 5 is:

[0064]

[0065] The brake voltage control circuit 5 controls the output PWM duty ratio according to the voltage value, thereby outputting a stable 110V voltage.

[0066] The output current acquisition circuit 10 in this embodiment is as follows: Fig.10As shown, it includes resistor RB1, resistor RB2, resistor RB3, resistor RB4, resistor RB5 and op amp UB1A, wherein the model of op amp UB1A is TLV2372. Its circuit structure is as follows: one end of resistor RB1 is connected to the DC- (overlined) end of the output filter circuit 8 and one end of resistor R3, the other end of resistor RB1 is connected to one end of resistor RB2 and the BK- end of the traction machine brake coil 13, the other end of resistor RB2 is connected to one end of resistor RB4 and the positive input end 3 of op amp UB1A, and the other end of resistor RB4 is connected to the DC- end. The other end of resistor RB3 is connected to the reverse input end 2 of op amp UB1A and one end of resistor R5, the output end of op amp UB1A is connected to the 1_FB end of the brake voltage control circuit 5 and the other end of resistor RB5, and the 4 end of op amp UB1A is connected to the DC- (overlined) end of the brake voltage control circuit 5. Its working process is: collect the output brake current and feed it back to the brake voltage control circuit 5 so that it can control the output current. When the brake power supply starts working, the current output by the output filter circuit 8 flows through the brake coil via DCOUT+, returns to the BK- terminal, then enters this circuit, passes through the milliohm sampling resistor RB1, and finally flows back to the DC- terminal. According to Ohm's law, when the current passes through RB1, a corresponding voltage will be generated on RB1, and the voltage will be adjusted by the op amp UB1A and output to the brake voltage control circuit 5. The brake voltage control circuit 5 controls the output PWM duty cycle according to the current value, thereby outputting a stable 110V voltage, and can detect whether the output is overcurrent, and will perform overcurrent protection when overcurrent occurs.

[0067] Attached Fig.15 This is the voltage waveform output by the elevator brake control device implemented with an uncontrollable full-wave / half-wave rectification scheme. When the brake control signal changes from invalid to valid, the mains is connected, the output brake voltage instantly reaches the target voltage, and maintains this voltage until the brake control signal becomes invalid and the mains input is disconnected.

[0068] Attached Fig.16 The voltage waveform output by the elevator brake control device using the specific implementation of the present invention. When the brake control signal changes from invalid to valid, the mains is connected, and the output brake voltage rises slowly until it reaches the target voltage. When the output voltage reaches the target voltage and is maintained for 2 to 3 seconds, the output brake voltage drops to the maintenance voltage value and maintains the maintenance voltage until the brake control signal becomes invalid and the mains input is disconnected.

[0069] Embodiment 2:

[0070] The output voltage ramp-start brake control method adopted in this embodiment controls the output voltage ramp-start brake control device in Embodiment 1, and specifically includes the following steps:

[0071] Step 1: Device power-on procedure.

[0072] After the mains is connected to the rectifier filter circuit 2 and the brake power control relay 4 of the brake control device, the rectifier filter circuit 2 rectifies the 220VAC voltage input from the mains into a 310V DC bus voltage through the rectifier bridge module D1 and the filter capacitor C1. The DC bus voltage is provided to the switching power supply 3, and the switching power supply 3 is converted by the high frequency of the flyback switching power supply to output two isolated DC power supplies. One of them is provided to the brake power control relay coil; the other is provided to the brake voltage control circuit 5 and the output current acquisition circuit 10.

[0073] Step 2: Brake voltage output step.

[0074] The control signal of the elevator main control board 12 is connected to the brake power control circuit 5. When the control signal is at a valid high level, the four-channel voltage comparator 51 in the brake voltage control circuit 5 starts to process the signal. First, capacitors C16, CF1, and C22 are charged through charging resistors R33, RF1, and R52 respectively.

[0075] The charging formula of the capacitor is as follows:

[0076]

[0077] In the formula, is the voltage value on the capacitor; Q is the amount of charge charged into the capacitor; C is the capacitance of the capacitor; I is the charging current, t is the charging time; Ui is the input voltage value; R is the charging resistance.

[0078] From the above, we can see that the charging speed is determined by the capacitance and the charging resistance.

[0079] In this design, the capacitors C16, CF1, and C22 have the same value of 4.7uF, and the time t for the voltage on the capacitors C16, CF1, and C22 to reach 10V is adjusted by configuring the resistance values ​​of the charging resistors R33, RF1, and R52, respectively. This realizes the output control timing of the three-way comparator.

[0080] When the elevator main control board 12 signal is valid, the working process of this device is as follows in chronological order:

[0081] (1) The period from 0ms to 30ms is to prevent jitter. In order to prevent the input signal jitter from causing malfunction of the subsequent circuit, the subsequent circuit will not operate even if the input signal is valid during this period.

[0082] (2) From 30ms to 180ms is the bus capacitor charging time period, the brake relay control signal JRC# output by the four-channel voltage comparator 51 becomes valid, so that the brake power control relay 4 is energized. The city power enters the rectifier filter circuit 6 through the relay, and then rectifies and filters to output a DC310V voltage. At the same time, the feedback signal of the safety relay is output to the elevator main control board.

[0083] (3) From 180ms to 1000ms is the output voltage ramp start time period, the output constant current source current reset signal RST becomes invalid, the constant current source control rising slope circuit 52 starts to work, and its output ramp voltage signal starts to increase gradually from 0. The brake voltage control circuit 5 controlled by this signal starts to output PWM chopping signal, driving the chopping output circuit 7 to output a ramp-up brake voltage, and finally the brake voltage will rise to DC110V. The brake voltage passes through the output filter circuit 8 and the output current acquisition circuit 10 to reach the traction machine brake coil 13. This process is the output voltage ramp start process.

[0084] (4) From 1000ms to 3000ms is the full voltage excitation opening time period. After the ramp start is completed, the output brake voltage will be maintained for 2 seconds. The brake coil excitation process is completed and the brake is fully opened. Currently, the common brake coils are DC110V, so the output DC110V in this process is full voltage excitation to open the brake.

[0085] (5) The half-voltage maintenance period is from 3000ms until the signal of the elevator main control board 12 is invalid. When the full-voltage excitation gate is opened, the half-voltage maintenance control signal becomes valid. This signal controls the pulse width modulation control chip 54 to enter the half-voltage maintenance stage. The pulse width modulation control chip 54 will automatically adjust the output PWM signal duty cycle according to the output voltage acquisition circuit, so that the output voltage of the chopper output circuit 7 is adjusted to DC77V. This process is the half-voltage maintenance process.

[0086] In the entire process of (1) to (5) above, the output voltage acquisition circuit 9 and the output current acquisition circuit 10 will collect the actual output point voltage and current values ​​in real time, and feed them back to the brake voltage control circuit 5 so that it can accurately control the output voltage and current values.

[0087] When the rated voltage value of the brake coil used on site is other, the output voltage can be adjusted by adjusting the resistance value in the brake power supply control circuit according to the actual situation, thus achieving the purpose of applying different brakes.

[0088] Step 3: Braking voltage stop step.

[0089] When the control signal output by the elevator main control board 12 becomes invalid, the constant current source current reset signal output by the four-channel voltage comparator 51 immediately becomes valid, so that the constant current source control rising slope circuit 52 enters the reset state, and the output voltage becomes 0V. Then the brake voltage control circuit 5 stops outputting the PWM control signal, so that the chopper output circuit 7 stops outputting, the brake voltage will stop outputting, the brake coil loses power, and the brake is closed. At the same time, the half-voltage maintenance control signal and the brake power control relay control signal become invalid, the brake power control relay 4 is disconnected, and the rectifier filter circuit 6 loses power, so that the chopper output circuit 7 has no power supply, ensuring the safe stop of the elevator.

[0090] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A brake control device with output voltage ramp start, characterized in that: include: A first rectifier and filter circuit, whose input end is connected to the mains and whose output end is connected to the switching power supply, is used to rectify the mains, convert the connected mains into a DC bus voltage, and provide it to the switching power supply after filtering; The switching power supply, the output end of which is respectively connected to the brake power control relay and the brake voltage control circuit, is used to output two isolated DC regulated power supplies, one for the coil of the brake power control relay, and the other for the brake voltage control circuit and the output current acquisition circuit; A brake power supply control relay, whose input end is connected to the mains and the brake voltage control circuit, and whose output end is respectively connected to the second rectifier filter circuit and the output current acquisition circuit, and is used to connect or disconnect the mains and the second rectifier filter circuit according to the control signal of the brake voltage control circuit; The brake voltage control circuit has an input end connected to the elevator main control board, an output current acquisition circuit and an output voltage acquisition circuit respectively, and an output end connected to the chopper output circuit, and is used to receive a control signal from the elevator main control board. When the control signal is valid, the brake voltage output control timing is started to be executed, and the feedback signals of each input are monitored; The second rectifier filter circuit has an output end connected to the chopper output circuit, and is used to rectify the mains power, convert the 220VAC output of the brake power control relay into a DC bus voltage of about 310VDC, and provide it to the chopper circuit after filtering; The chopper output circuit, whose output end is connected to the output filter circuit, is used to control the duty cycle of the main chopper tube control signal, thereby controlling the output voltage of the brake output power supply and controlling the opening and closing of the brake; The output filter circuit, whose output end is connected to the output voltage acquisition circuit, is used to continue to provide current to the load brake coil when the output MOS tube of the chopper output circuit is turned off, so as to make the brake work stably; The output voltage acquisition circuit is used to collect the output brake voltage and output a feedback signal to the brake voltage control circuit to accurately control the output voltage; Output current acquisition circuit, the output end is connected to the traction machine brake coil to detect whether the output is overcurrent. When overcurrent occurs, overcurrent protection will be performed; The brake voltage control circuit includes a four-channel voltage comparator circuit, a constant current source control rising slope circuit, a pulse width modulation control chip and a timer chip. The input end of the four-channel voltage comparator circuit is connected to the brake control signal, and the output end of the four-channel voltage comparator circuit is connected to the pulse width modulation control chip via the constant current source control rising slope circuit, and the pulse width modulation control chip is connected to the timer chip. The constant current source control rising slope circuit includes a parallel regulator, a first operational amplifier, a second operational amplifier and a PNP transistor, the negative electrode of the parallel regulator is connected to a DC power supply, the positive electrode of the parallel regulator is connected to one end of the twenty-first resistor and the positive input end of the first operational amplifier, the reverse input end of the first operational amplifier is connected to one end of the seventeenth resistor and the emitter of the PNP transistor, the output end of the first operational amplifier is connected to one end of the eighteenth resistor, the other end of the eighteenth resistor is connected to the base of the PNP transistor, the collector of the PNP transistor is connected to one end of the nineteenth resistor, one end of the twenty-sixth resistor, and one end of the eleventh capacitor, the other end of the twenty-sixth resistor is connected to the positive input end of the second operational amplifier, the reverse input end of the second operational amplifier is connected to the output end of the second operational amplifier and the pulse width modulation control chip; the other end of the nineteenth resistor is connected to the positive electrode of the eleventh diode, the negative electrode of the eleventh diode is connected to the constant current source current reset signal, and the other end of the eleventh capacitor is grounded.

2. A brake control method for output voltage ramp start, which controls the brake control device for output voltage ramp start according to claim 1, characterized in that: The following steps are involved: Step 1, the step of powering on the device; The first rectifier filter circuit and the brake power control relay rectify the AC input voltage into a DC bus voltage and provide it to the switching power supply. After high-frequency conversion by the flyback switching power supply, two isolated DC power supplies are output, one of which is provided to the brake power control relay coil; the other is provided to the brake voltage control circuit and the output current acquisition circuit. Step 2, the step of outputting the brake voltage; The elevator main control board sends a control signal to the brake power control circuit. When the control signal is at a valid high level, the four-channel voltage comparator in the brake voltage control circuit starts to process the signal and obtains the three-way comparator output control timing: (1) During the anti-jitter period, in order to prevent the input signal jitter from causing malfunction of the subsequent circuit, the subsequent circuit will not operate even if the input signal is valid during this period; (2) During the bus capacitor charging period, the brake relay control signal output by the four-channel voltage comparator becomes valid, causing the brake power control relay to be energized. The AC power enters the second rectifier and filter circuit through the brake power control relay for rectification and filtering, and then outputs the DC bus voltage. The feedback signal of the safety relay is output to the elevator main control board. (3) The output voltage ramp starting process is as follows: during the output voltage ramp starting time period, the constant current source current reset signal output by the four-channel voltage comparator becomes invalid, and the constant current source control rising slope circuit starts to work, and its output ramp voltage signal gradually increases from 0. The brake voltage control circuit controlled by this signal starts to output a PWM chopping signal, driving the chopping output circuit to output a ramp-up brake voltage until the brake voltage rises to the full-voltage excitation start voltage. The brake voltage passes through the second output filter circuit and the output current acquisition circuit to reach the traction machine brake coil; (4) During the full voltage excitation start time period, after the ramp start is completed, the output brake voltage will be maintained for a certain period of time until the brake coil excitation process is completed and the brake is fully opened; (5) From the beginning of half-voltage maintenance until the elevator main control board signal is invalid, when the full-voltage excitation gate is opened, the half-voltage maintenance control signal becomes valid, and this signal controls the pulse width modulation control chip to enter the half-voltage maintenance stage; the pulse width modulation control chip automatically adjusts the output PWM signal duty cycle according to the output voltage acquisition circuit, so that the output voltage of the chopper output circuit is adjusted to the half-voltage maintenance voltage; Step 3, brake voltage stopping step; When the control signal output by the elevator main control board becomes invalid, the constant current source current reset signal output by the four-channel voltage comparator immediately becomes valid, causing the constant current source control rising slope circuit to enter the reset state, and the output voltage becomes 0V. Then the brake voltage control circuit stops outputting the PWM control signal, causing the chopper output circuit to stop outputting, the brake voltage will stop outputting, the brake coil will lose power, and the brake will close; at the same time, the half-voltage maintenance control signal and the brake power control relay control signal become invalid, the brake power control relay is disconnected, and the second rectifier and filter circuit loses power, so that the chopper output circuit has no power, ensuring the safe stop of the elevator.

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