Circuit for improving safety of bridge circuit for magnetic bearing suspension current

Abstract

The utility model discloses a circuit for improving the safety of a bridge circuit for magnetic bearing suspension current. The circuit comprises an intercommunication detection module and a driving control module, the intercommunication detection module comprises a first logic circuit, a second logic circuit and a hybrid decision circuit; the first logic circuit comprises a first OR gate and two first NOT gates, in two paths of enable signals of the double-path magnetic suspension bearing, the negative current of the first enable signal and the positive current of the second enable signal are respectively input into the input ends of the two first NOT gates, and the output ends of the two first NOT gates are correspondingly connected with the two input ends of the first OR gate; the second logic circuit comprises a second OR gate and two second NOT gates, the positive current of the first enable signal and the negative current of the second enable signal are respectively input into the input ends of the two second NOT gates, and the output ends of the two second NOT gates are correspondingly connected with the two input ends of the second OR gate; according to the utility model, intercommunication of two MOS transistors on the same bridge arm can be avoided, the structure is simple and reliable, the cost is low, and the circuit is suitable for large-scale mass production.

Description

TECHNICAL FIELD

[0001] The utility model relates to magnetic bearing suspension control circuit technical field, specifically is a kind of circuit for improving the safety of magnetic bearing suspension current bridge circuit. BACKGROUND

[0002] With the integration of magnetic bearing suspension current bridge circuit more and more mature, based on three-bridge-arm bridge circuit can realize the output frequency same, same direction, amplitude controllable two-way magnetic bearing suspension current, this technology can greatly reduce the volume of magnetic bearing suspension current controller and reduce cost, at the same time, improve the stability and reliability of magnetic bearing suspension, when output two-way magnetic bearing suspension current, need to use the same MOS tube, when artificial factor leads to the direction of the two-way magnetic bearing suspension current opposite, then the mutual communication of two MOS tubes on the same bridge arm occurs, leading to output power circuit breaker, it can cause magnetic bearing suspension current controller damage. SUMMARY

[0003] To solve the problem that two MOS tubes on the same bridge arm are mutually communicated due to the opposite direction of two-way magnetic bearing suspension current in the prior art, the utility model provides a circuit for improving the safety of magnetic bearing suspension current bridge circuit, which can avoid the mutual communication of two MOS tubes on the same bridge arm, has simple and reliable structure, low cost and is suitable for large-scale production and use.

[0004] To achieve the above purpose, the utility model adopts the specific scheme as follows: a circuit for improving the safety of magnetic bearing suspension current bridge circuit, comprising a mutual communication detection module and a drive control module.

[0005] The mutual communication detection module comprises a first logic circuit, a second logic circuit and a hybrid decision circuit.

[0006] The first logic circuit comprises a first OR gate and two first NOT gates. The negative current of the first enable signal and the positive current of the second enable signal in the two-way enable signal of the two-way magnetic suspension bearing are input to the input terminals of the two first NOT gates, and the output terminals of the two first NOT gates are connected to the two input terminals of the first OR gate.

[0007] The second logic circuit comprises a second OR gate and two second NOT gates. The positive current of the first enable signal and the negative current of the second enable signal are input to the input terminals of the two second NOT gates, and the output terminals of the two second NOT gates are connected to the two input terminals of the second OR gate.

[0008] The hybrid decision circuit comprises a first AND gate, and the two input terminals of the first AND gate are connected to the output terminals of the first OR gate and the second OR gate.

[0009] The drive control module comprises a second AND gate and a third AND gate, one input end of the second AND gate and one input end of the third AND gate are connected with the output end of the first AND gate, a first drive signal is input to the other input end of the second AND gate, and a second drive signal is input to the other input end of the third AND gate.

[0010] As an optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the two input ends of the first NAND gate are respectively connected with a resistor R92 and a resistor R96.

[0011] As another optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the output ends of the two first NAND gates are respectively connected with a resistor R93 and a resistor R105.

[0012] As another optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the two input ends of the first OR gate are respectively connected with a resistor R94 and a resistor R106.

[0013] As another optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the output end of the first OR gate is connected with a resistor R95.

[0014] As another optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the two input ends of the second NAND gate are respectively connected with a resistor R114 and a resistor R118.

[0015] As another optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the output ends of the two second NAND gates are respectively connected with a resistor R115 and a resistor R119.

[0016] As another optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the two input ends of the second OR gate are respectively connected with a resistor R116 and a resistor R120, and the output end of the second OR gate is connected with a resistor R117.

[0017] As another optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the two input ends of the first AND gate are respectively connected with a resistor R109 and a resistor R113, and the output end of the first AND gate is connected with a resistor R110.

[0018] As another optimization scheme of the above-mentioned circuit for improving the safety of the bridge circuit for the suspension current of the magnetic bearing, the two input ends of the second AND gate are respectively connected with a resistor R126 and a resistor R132, and the output end of the second AND gate is connected with a resistor R130.

[0019] Compared with the prior art, the utility model have following beneficial effect: the utility model discloses a kind of circuit for improving the safety of bridge circuit of magnetic bearing suspension current, according to enable signal and with door, non-door, first or door, second or door and third or door output drive signal, whether two MOS tubes on the same bridge arm will be connected according to drive signal determination, if will be connected, then drive signal will affect the drive of two MOS tubes and make it close;If will not be connected, then drive signal will not affect the drive of two MOS tubes and make it normal work;The utility model structure is simple and reliable, and cost is lower, and it is suitable for large-scale mass production use. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is intercommunication detection module circuit schematic diagram;

[0021] Figure 2 It is drive control module circuit schematic diagram;

[0022] Figure 3 It is same bridge arm MOS tube intercommunication protection circuit partial PCB layout diagram;

[0023] Figure 4 It is same bridge arm MOS tube intercommunication protection circuit partial actual object diagram;

[0024] Figure 5 It is control signal waveform diagram when first road output positive current, second road output negative current;

[0025] Figure 6 It is control signal waveform diagram when first road output positive current, second road output positive current. DETAILED DESCRIPTION

[0026] The technical scheme of the utility model will be further described in detail in combination with specific embodiment, and the part not detailedly recorded and disclosed in each embodiment of the utility model should be understood as the prior art known or should be known by those skilled in the art.

[0027] Embodiment 1

[0028] The application discloses a circuit for improving the safety of a bridge circuit for a magnetic bearing suspension current, comprising an intercommunication detection module and a drive control module; the intercommunication detection module comprises a first logic circuit, a second logic circuit and a mixed decision circuit; the first logic circuit comprises a first OR gate and two first NOT gates, the negative current of a first enable signal and the positive current of a second enable signal in two paths of a double-path magnetic suspension bearing are input to the input ends of the two first NOT gates, and the output ends of the two first NOT gates are connected to the two input ends of the first OR gate in correspondence; the second logic circuit comprises a second OR gate and two second NOT gates, the positive current of the first enable signal and the negative current of the second enable signal are input to the input ends of the two second NOT gates, and the output ends of the two second NOT gates are connected to the two input ends of the second OR gate in correspondence; the mixed decision circuit comprises a first AND gate, and the two input ends of the first AND gate are connected to the output ends of the first OR gate and the second OR gate in correspondence; the drive control module comprises a second AND gate and a third AND gate, one input end of the second AND gate and one input end of the third AND gate are connected to the output end of the first AND gate, a first drive signal is input to the other input end of the second AND gate, and a second drive signal is input to the other input end of the third AND gate.

[0029] The input ends of the two first NOT gates are connected with resistors R92 and R96 respectively, and the output ends of the two first NOT gates are connected with resistors R93 and R105 respectively. The two input ends of the first OR gate are connected with resistors R94 and R106 respectively, and the output end of the first OR gate is connected with a resistor R95. The input ends of the two second NOT gates are connected with resistors R114 and R118 respectively, and the output ends of the two second NOT gates are connected with resistors R115 and R119 respectively. The two input ends of the second OR gate are connected with resistors R116 and R120 respectively, the output end of the second OR gate is connected with a resistor R117, the two input ends of the first AND gate are connected with resistors R109 and R113 respectively, and the output end of the first AND gate is connected with a resistor R110. The two input ends of the second AND gate are connected with resistors R126 and R132 respectively, and the output end of the second AND gate is connected with a resistor R130.

[0030] As Figure 1As shown, the first NAND gate and the second NAND gate are located on the U15 chip, the first OR gate and the second OR gate are located on the U7 chip, the first AND gate, the second AND gate and the third AND gate are located on the U9 chip, specifically, the first NAND gate corresponds to U15A, the input ends of the two first NAND gates correspond to the 1st pin and the 3rd pin of U15, and the output ends of the two first NAND gates correspond to the 2nd pin and the 4th pin of U15. The second NAND gate corresponds to U15C, the input ends of the two second NAND gates correspond to the 11th pin and the 13th pin of U15, and the output ends of the two second NAND gates correspond to the 10th pin and the 12th pin of U15. The first OR gate corresponds to U7C, the two input ends of the first OR gate correspond to the 8th pin and the 9th pin of U7, and the output end of the first OR gate corresponds to the 10th pin of U7. The second OR gate corresponds to U7D, the two input ends of the second OR gate correspond to the 12th pin and the 13th pin of U7, and the output end of the second OR gate corresponds to the 11th pin of U7. The first AND gate corresponds to U9C, the two input ends of the first AND gate correspond to the 8th pin and the 9th pin of U9, and the output end of the first AND gate corresponds to the 10th pin of U9. The second AND gate corresponds to U9A, the two input ends of the second AND gate correspond to the 1st pin and the 2nd pin of U9, and the output end of the second AND gate corresponds to the 3rd pin of U9. The third AND gate corresponds to U9B, the two input ends of the third AND gate correspond to the 5th pin and the 6th pin of U9, and the output end of the third AND gate corresponds to the 4th pin of U9.

[0031] The first end of the resistor R92 is connected to the signal IG_N1 (negative current of the first enable signal), the second end of the resistor R92 is connected to the 1st pin of U15, the first end of the resistor R93 is connected to the 2nd pin of U15, the second end of the resistor R93 is connected to the first end of the resistor R94, the second end of the resistor R94 is connected to the 8th pin of U7, the first end of the resistor R95 is connected to the 10th pin of U7, and the second end of the resistor R95 is connected to the first end of the resistor R109; the first end of the resistor R96 is connected to the signal IG_P2 (positive current of the second enable signal), the second end of the resistor R96 is connected to the 3rd pin of U15, the first end of the resistor R105 is connected to the 4th pin of U15, the second end of the resistor R105 is connected to the first end of the resistor R106, the second end of the resistor R106 is connected to the 9th pin of U7, the first end of the resistor R110 is connected to the 10th pin of U9, and the second end of the resistor R110 is connected to the signal IG_NP.

[0032] The first end of the resistor R113 is connected to the second end of the resistor R117, the second end of the resistor R113 is connected to the 9th pin of U9, the first end of the resistor R114 is connected to the signal IG_P1 (positive current of the first enable signal), the second end of the resistor R114 is connected to the 11th pin of U15, the first end of the resistor R115 is connected to the 10th pin of U15, the second end of the resistor R115 is connected to the first end of the resistor R116, the second end of the resistor R116 is connected to the 12th pin of U7, and the first pin of the resistor R117 is connected to the 11th pin of U7.

[0033] The first pin of resistor R118 is connected to signal IG_N2 (the negative current of the second enable signal), the second pin of resistor R118 is connected to pin 13 of U15, the first pin of resistor R119 is connected to pin 12 of U15, the second pin of resistor R119 is connected to the first end of R120, and the second end of the twenty-first resistor R120 is connected to pin 13 of U7.

[0034] like Figure 2 As shown, the first terminal of resistor R126 is connected to signal DRV_2 (first drive signal), and the second terminal of resistor R126 is connected to pin 1 of U9. The first terminal of resistor R130 is connected to pin 3 of U9, and the second terminal of resistor R130 is connected to signal G2. Signal G2 is used to drive the upper MOSFET on the same bridge arm. The first terminal of resistor R132 is connected to signal IG_NP, and the second terminal of resistor R132 is connected to pin 2 of U9. The first terminal of resistor R138 is connected to signal IG_NP, and the second terminal of resistor R138 is connected to pin 5 of U9. The first terminal of resistor R150 is connected to pin 4 of U9, and the second terminal of resistor R150 is connected to signal G5. Signal G5 is used to drive the lower MOSFET on the same bridge arm. The first terminal of resistor R189 is connected to signal DRV_5 (second drive signal), and the second terminal of resistor R189 is connected to pin 6 of U9.

[0035] like Figure 1 As shown, the first terminal of resistor R107 is connected to GND, and the second terminal of resistor R107 is connected to pin 5 of U15. The first terminal of resistor R108 is connected to pin 6 of U15, and the second terminal of resistor R108 is connected to GND. The second terminal of resistor R109 is connected to pin 8 of U9. The first terminal of resistor R111 is connected to GND, and the second terminal of resistor R111 is connected to pin 9 of U15. The first terminal of resistor R112 is connected to pin 8 of U15, and the second terminal of resistor R112 is connected to GND. The first terminal of resistor R86 is connected to GND, and the second terminal of resistor R86 is connected to pin 1 of U7. The first terminal of resistor R87 is connected to pin 3 of U7, and the second terminal of resistor R87 is connected to GND. The first terminal of resistor R88 is connected to GND, and the second terminal of resistor R88 is connected to pin 2 of U7. The first terminal of resistor R89 ​​is connected to GND. The second terminal of resistor R89 ​​is connected to pin 5 of U7. The first terminal of resistor R90 is connected to pin 4 of U7, and the second terminal of resistor R90 is connected to GND. The first terminal of resistor R91 is connected to GND, and the second terminal of resistor R91 is connected to pin 6 of U7. The first terminal of resistor R287 is connected to GND, and the second terminal of resistor R287 is connected to pin 12 of U9. The first terminal of resistor R291 is connected to pin 11 of U9, and the second terminal of resistor R291 is connected to GND. The first terminal of resistor R293 is connected to GND, and the second terminal of resistor R293 is connected to pin 13 of U9. The first terminal of capacitor C24 is connected to +12V, and the second terminal of capacitor C24 is connected to GND. The first terminal of capacitor C62 is connected to +12V, and the second terminal of capacitor C62 is connected to GND. The first terminal of capacitor C89 is connected to +12V, and the second terminal of capacitor C89 is connected to GND.

[0036] In this embodiment, U7 is selected from CD4071BM model, U9 is selected from CD4081BM model, and U15 is selected from CD40106BM96 model.

[0037] The control logic network composed of U7, U9 and U15 is used to determine whether the two MOS transistors of the same bridge arm can communicate with each other according to the high or low level signal of the magnetic bearing suspension current enable signal, and then the driving signal of the MOS transistor is processed accordingly. The topology circuit has the advantages of simple and reliable structure, low cost and fast response speed, and is suitable for long-term large-scale use.

[0038] The working principle of this invention is as follows: When IG_N1 is high, IG_P2 is high, IG_N2 is low, and IG_P1 is low, it indicates that the first magnetic levitation bearing outputs negative current, and the second magnetic levitation bearing outputs positive current. At this time, pins 2 and 4 of U15 output low level, pins 10 and 12 of U15 output high level, pin 10 of U7 outputs low level, pin 11 of U7 outputs high level, and pin 10 of U9 outputs low level. When IG_NP is low, this signal will turn off the upper and lower MOSFETs on the same bridge arm, preventing the two MOSFETs from short-circuiting due to mutual communication. When IG_N1 is low, IG_P2 is low, IG_N2 is high, and IG_P1 is high, it indicates that the first magnetic levitation bearing outputs positive current and the second magnetic levitation bearing outputs negative current. At this time, pins 2 and 4 of U15 output high level, pins 10 and 12 of U15 output low level, pin 10 of U7 outputs high level, pin 11 of U7 outputs low level, and pin 10 of U9 outputs low level. When IG_NP is low, this signal will turn off the upper and lower MOSFETs on the same bridge arm to prevent the two MOSFETs from short-circuiting due to mutual communication. When IG_N1 is low, IG_P2 is high, IG_N2 is low, and IG_P1 is high, it indicates that the first magnetic levitation bearing is outputting positive current and the second magnetic levitation bearing is outputting positive current. At this time, pin 2 of U15 outputs high level and pin 4 outputs low level, pin 10 of U15 outputs low level and pin 12 outputs high level, pin 10 of U7 outputs high level, pin 11 of U7 outputs high level, and pin 10 of U9 outputs high level. When IG_NP is high, this signal will not affect the driving of the upper and lower MOSFETs on the same bridge arm, which means that the driving of the MOSFETs is working normally. When IG_N1 is high, IG_P2 is low, IG_N2 is high, and IG_P1 is low, it indicates that the first magnetic levitation bearing outputs negative current and the second magnetic levitation bearing outputs negative current. At this time, pin 2 of U15 outputs low level, pin 4 outputs high level, pin 10 of U15 outputs high level, pin 12 outputs low level, pin 10 of U7 outputs high level, pin 11 of U7 outputs high level, and pin 10 of U9 outputs high level. When IG_NP is high, this signal will not affect the driving of the upper and lower MOSFETs on the same bridge arm, which means that the driving of the MOSFETs is normal.

[0039] like Figure 2As shown, when IG_NP is high, it indicates that the upper and lower MOS transistors on the same bridge arm do not appear to be intercommunicated, and the DRV_2 driving waveform can be normally output to the 3 pin of U9, that is, the G2 driving waveform is the same as the DRV_2 driving waveform. Similarly, the DRV_5 driving waveform can be normally output to the 4 pin of U9, that is, the G5 driving waveform is the same as the DRV_5. When IG_NP is low, it indicates that the upper and lower MOS transistors on the same bridge arm appear to be intercommunicated, at this time, the DRV_2 and DRV_5 driving waveforms cannot be output to the 3 pin and 4 pin of U9 respectively, that is, G2 and G5 are low, and the driving of the MOS transistor is closed. The 12 pin, 13 pin and 11 pin of U9 are connected to the ground through R287, R293 and R291 respectively, which is to prevent the 11 pin of U9 from outputting an abnormal level.

[0040] In summary, only when the two-way magnetic bearing suspension currents are positive currents or negative currents, the driving of the MOS transistor is normal, when the directions of the two-way magnetic bearing suspension currents are inconsistent, the driving of the upper and lower MOS transistors on the same bridge arm will be turned off, avoiding the short circuit phenomenon caused by the intercommunication of the two MOS transistors.

[0041] Embodiment 2

[0042] The utility model is applied to a 100V electromagnetic bearing controller control circuit, and the PCB layout of the control circuit is as shown in Figure 3 , a PCB is printed and tested by welding components, and the physical control circuit is as shown in Figure 4 , which is tested, and the test results show that when the first given magnetic bearing suspension current is positive and the second given magnetic bearing suspension current is negative, the 10 pin of U9 outputs low; when the first given magnetic bearing suspension current is positive and the second given magnetic bearing suspension current is positive, the 10 pin of U9 outputs high; when the first given magnetic bearing suspension current is negative and the second given magnetic bearing suspension current is positive, the 10 pin of U9 outputs low; and when the first given magnetic bearing suspension current is negative and the second given magnetic bearing suspension current is negative, the 10 pin of U9 outputs high. The circuit measurement results are as shown in Figure 5 , 6 respectively.

[0043] The above description of the disclosed embodiments enables those skilled in the art to implement or use the utility model. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the utility model. Therefore, the utility model will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A circuit for improving the safety of a bridge circuit used for levitation current in magnetic bearings, characterized in that: Includes an interoperability detection module and a drive control module; The interoperability detection module includes a first logic circuit, a second logic circuit, and a hybrid decision circuit; The first logic circuit includes a first OR gate and two first NOT gates. In the two enable signals of the dual-channel magnetic levitation bearing, the negative current of the first enable signal and the positive current of the second enable signal are respectively input to the input terminals of the two first NOT gates, and the output terminals of the two first NOT gates are connected to the two input terminals of the first OR gate. The second logic circuit includes a second OR gate and two second NOT gates. The positive current of the first enable signal and the negative current of the second enable signal are respectively input to the input terminals of the two second NOT gates, and the output terminals of the two second NOT gates are connected to the two input terminals of the second OR gate. The hybrid decision circuit includes a first AND gate, whose two inputs are connected to the outputs of a first OR gate and a second OR gate, respectively. The drive control module includes a second AND gate and a third AND gate. One input terminal of the second AND gate and one input terminal of the third AND gate are both connected to the output terminal of the first AND gate. The first drive signal is input to the other input terminal of the second AND gate, and the second drive signal is input to the other input terminal of the third AND gate.

2. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 1, characterized in that: The input terminals of the two first NOT gates are respectively connected to resistors R92 and R96.

3. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 1, characterized in that: The outputs of the two first NOT gates are respectively connected to resistors R93 and R105.

4. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 1, characterized in that: The two input terminals of the first OR gate are connected to resistors R94 and R106, respectively.

5. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 1, characterized in that: The output of the first OR gate is connected to a resistor R95.

6. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 1, characterized in that: The inputs of the two second NOT gates are connected to resistor R114 and resistor R118, respectively.

7. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 1, characterized in that: The outputs of the two second NOT gates are respectively connected to resistors R115 and R119.

8. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 7, characterized in that: The two input terminals of the second OR gate are connected to resistor R116 and resistor R120 respectively, and the output terminal of the second OR gate is connected to resistor R117.

9. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 1, characterized in that: The two input terminals of the first AND gate are connected to resistors R109 and R113 respectively, and the output terminal of the first AND gate is connected to resistor R110.

10. The circuit for improving the safety of a bridge circuit for levitation current in magnetic bearings as described in claim 1, characterized in that: The two input terminals of the second AND gate are connected to resistors R126 and R132 respectively, and the output terminal of the second AND gate is connected to resistor R130.

Images