Bidirectional magnet power supply

Abstract

The utility model provides a bidirectional magnet power supply comprising an AC / DC module used for converting commercial power voltage into DC voltage; the inverting and filtering module is used for inverting and filtering the direct-current voltage so as to output bidirectional positive and negative voltages; and the linear voltage stabilization module is electrically connected between the AC / DC module and the inversion and filtering module, and the linear voltage stabilization module is used for reducing low-frequency ripples of a power grid. According to the utility model, commercial power is converted into 24V voltage through the AC / DC module, but the voltage output by the AC / DC module still has power grid ripples with the amplitude of 50mV, so that the linear voltage stabilization module is introduced to reduce the low-frequency ripples of the power grid, and then inversion and filtering are carried out through the inversion and filtering module to output bidirectional positive and negative voltage.

Description

Technical Field

[0001] The utility model relates to the technical field of power supplies, in particular to a bidirectional magnet power supply. Background Art

[0002] A bidirectional electromagnet is a device that generates electromagnetic force when energized. A conductive winding, matched to its power, is wound around the outside of an iron core. This current-carrying coil has magnetic properties similar to a magnet and is also called a bidirectional electromagnet. Furthermore, to ensure rapid demagnetization after a power outage, bidirectional electromagnets are often made of soft iron or silicon steel, which have a rapid demagnetization rate. This type of bidirectional electromagnet exhibits magnetic properties when energized and loses them when the power is removed. Bidirectional electromagnets are widely used in daily life. Their invention has significantly increased the power of generators.

[0003] Because the load magnet inductance of a bidirectional magnet power supply is very small, approximately 300-600uH, if the low-frequency ripple voltage is too large, the corresponding low-frequency ripple current will also be large, making it difficult for the power supply to achieve the 50ppm current stability indicator. Current technologies typically use AC / DC to eliminate 50Hz multiplied-frequency grid ripple through filter capacitors and voltage loops, but the amplitude is still 50mV, which cannot meet the current stability indicator requirements. Utility Model Content

[0004] In view of this, the problem to be solved by the present invention is to provide a bidirectional magnet power supply.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A bidirectional magnet power supply, comprising:

[0007] AC / DC module, used to convert mains voltage into DC voltage;

[0008] An inversion and filtering module, configured to invert and filter the DC voltage to output bidirectional positive and negative voltages;

[0009] A linear voltage regulator module is electrically connected between the AC / DC module and the inverter and filter module. The linear voltage regulator module includes a voltage regulator input terminal and a voltage regulator output terminal. A voltage regulator MOS transistor is provided between the voltage regulator input terminal and the voltage regulator output terminal. The voltage regulator MOS transistor is used to reduce low-frequency ripple of the power grid.

[0010] In the present utility model, further, the inverter and filtering module includes an H-bridge inverter module and a filtering module, the H-bridge inverter module is electrically connected to the filtering module, the H-bridge inverter module is used to obtain bidirectional positive and negative output voltages, and the filtering module is used to filter the bidirectional positive and negative output voltages.

[0011] In the present invention, further, a control module is included, which is electrically connected to the AC / DC module and the H-bridge inverter module. The control module is used to control the on and off of the AC / DC module and to drive the H-bridge inverter module.

[0012] In the present utility model, further, the H-bridge inverter module includes an H-bridge circuit, and the H-bridge circuit is composed of a first MOS tube, a second MOS tube, a third MOS tube, and a fourth MOS tube, wherein the first MOS tube and the third MOS tube are driven by a reverse signal, and the second MOS tube and the fourth MOS tube are driven by a reverse signal.

[0013] In the present invention, further, the H-bridge inverter module includes a voltage stabilizing circuit, the voltage stabilizing circuit includes a fifth MOS tube, the source of the fifth MOS tube is connected to the first filter capacitor, and the source of the fifth MOS tube is connected to the fourth capacitor.

[0014] In the present invention, further, the linear voltage regulator module includes an operational amplifier, the non-inverting input end of the operational amplifier is connected to the voltage regulator output end after RC filtering, the reverse input end of the operational amplifier is connected to the voltage regulator ground end after passing through an eighth voltage regulator diode, and the reverse output end of the operational amplifier is connected to the gate of the voltage regulator MOS tube.

[0015] In the present invention, preferably, the filtering module adopts a fourth-order filtering circuit.

[0016] In the present utility model, further, the fourth-order filter circuit includes a first inductor, a second inductor, a third inductor, a fourth inductor and a second capacitor and a third capacitor. The first inductor and the third inductor are connected and a first node is provided between the two. The second inductor and the fourth inductor are connected and a second node is provided between the two. The second capacitor is connected between the first node and the second node. The output end of the third inductor is provided with a third node. The output end of the fourth inductor is provided with a fourth node. The third capacitor is arranged between the third node and the fourth node.

[0017] In the present invention, further, the first MOS transistor and the second MOS transistor are driven by reverse signals with a phase shift of 180 degrees.

[0018] In the present invention, further, the output end of the fourth-order filter circuit is connected to the current sampling port of the control module, and the current sampling port of the control module is used to sample the current output by the fourth-order filter circuit.

[0019] The advantages and positive effects of the utility model are:

[0020] The utility model adds a linear voltage regulator module between the AC / DC module, the inverter and the filter module, and eliminates the low-frequency ripple at the voltage regulator input end through the variable resistance area of the voltage regulator MOS tube. Since the bandwidth of the linear power supply is very high, it has a good suppression effect on the 50Hz multiplied frequency grid ripple. Finally, the voltage regulator circuit in the H-bridge inverter module reduces the low-frequency ripple of the grid to 1mV, meeting the requirements of the current stability index. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 This is the overall structural diagram of a bidirectional magnet power supply of the utility model;

[0023] Figure 2 This is a circuit diagram of a linear voltage regulator module in a bidirectional magnet power supply of the utility model;

[0024] Figure 3 This is a circuit diagram of an inverter and filter module in a bidirectional magnet power supply of the utility model;

[0025] In the figure: 1-AC / DC module; 2-linear voltage regulator module; 3-H-bridge inverter module; 31-H-bridge circuit 31; 4-filter module; 5-control module; 51-soft start port; 52-H-bridge drive port; 53-current sampling port. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a central component. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of this invention are intended only to describe specific embodiments and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] like Figure 1-Figure 3 As shown, the utility model provides a bidirectional magnet power supply, comprising:

[0030] AC / DC module 1, used to convert mains voltage into DC voltage;

[0031] An inversion and filtering module, configured to invert and filter the DC voltage to output bidirectional positive and negative voltages;

[0032] The linear voltage stabilization module 2 is electrically connected between the AC / DC module 1 and the inverter and filter module. The linear voltage stabilization module 2 is used to reduce low-frequency ripple of the power grid.

[0033] Specifically, the utility model converts the mains power into 24V voltage through the AC / DC module 1, but the voltage output by the AC / DC module 1 still has a grid ripple with an amplitude of 50mV. Therefore, this solution introduces a linear voltage regulator module 2 to reduce the low-frequency ripple of the grid, and then inverts and filters through the inverter and filter module to output bidirectional positive and negative voltages.

[0034] In the present invention, further, as Figure 2 As shown, the linear voltage regulator module 2 includes a voltage regulator input terminal VIN, a voltage regulator output terminal VOUT, and a voltage regulator ground terminal GND. A voltage regulator MOSFET Q7 is disposed between the voltage regulator input terminal VIN and the voltage regulator output terminal VOUT. This MOSFET Q7 is used to suppress low-frequency grid ripple at the input terminal VIN. This solution eliminates low-frequency ripple at the voltage regulator input terminal Vin by utilizing the variable resistance region of MOSFET Q7. Due to the high bandwidth of the linear power supply, it effectively suppresses 50mV grid ripple.

[0035] In one embodiment provided by this solution, the gate of the voltage-stabilizing MOS transistor Q7 is also connected to the third voltage-stabilizing transistor Z3 and one end of the twenty-eighth resistor R28, and the other ends of the third voltage-stabilizing transistor Z3 and the twenty-eighth resistor R28 are connected to the connection line between the voltage-stabilizing input terminal VIN and the voltage-stabilizing ground terminal GND. The linear voltage-stabilizing module includes an operational amplifier U7, and the non-inverting input terminal of the operational amplifier U7 is connected to the voltage-stabilizing output terminal VOUT after RC filtering, wherein the RC filtering is composed of a 30th resistor R30 and a 93rd capacitor C93, and the reverse input terminal of the operational amplifier U7 is grounded through the 29th resistor R29 and the eighth voltage-stabilizing diode U8, and the reverse output terminal of the operational amplifier U7 is connected to the gate of the voltage-stabilizing MOS transistor through the 19th resistor R19.

[0036] In the present invention, further, as Figure 3 As shown, the inverter and filtering module includes an H-bridge inverter module 3 and a filtering module 4. The H-bridge inverter module 3 is electrically connected to the filtering module 4. The H-bridge inverter module 3 is used to obtain bidirectional positive and negative output voltages, and the filtering module 4 is used to filter the bidirectional positive and negative output voltages.

[0037] In an embodiment provided by this solution, the H-bridge inverter module 3 includes a voltage stabilizing circuit and an H-bridge circuit 31. The voltage stabilizing circuit includes a fifth MOS transistor U5. The source of the fifth MOS transistor U5 is connected to the first filter capacitor C1. The source of the fifth MOS transistor U5 is connected to the fourth capacitor C4.

[0038] The first filter capacitor C1 is a DC source filter capacitor, which carries a 50Hz frequency-multiplied grid ripple with an amplitude of about 50mV. The fifth MOS tube U5 performs linear voltage regulation to reduce the grid ripple on the fourth capacitor C4 to 1mV, thereby meeting the requirements of the current stability index.

[0039] The H-bridge circuit 31 is composed of a first MOS transistor U1, a second MOS transistor U2, a third MOS transistor U3, and a fourth MOS transistor U4. The first MOS transistor U1 and the third MOS transistor U3 are driven by reverse signals, the second MOS transistor U2 and the fourth MOS transistor U4 are driven by reverse signals, and the first MOS transistor U1 and the second MOS transistor U2 are driven by reverse signals with a phase shift of 180 degrees. In this way, the inverter frequency reaches 50 kHz through the H-bridge circuit 31.

[0040] In the present invention, preferably, the filter module 4 uses a fourth-order filter circuit. Since the inverter frequency is 50 kHz, the filter frequency is 100 kHz. To achieve better filtering effects, a fourth-order filter circuit is now used, which makes the LC value relatively small, which is conducive to increasing the current closed-loop bandwidth and the filter decreases faster after reaching the corner frequency.

[0041] In one embodiment provided by the present solution, the fourth-order filter circuit includes a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, a second capacitor C2, and a third capacitor C3. The first inductor L1 and the third inductor L3 are connected with a first node provided therebetween, the second inductor L2 and the fourth inductor L4 are connected with a second node provided therebetween, the second capacitor C2 is connected between the first node and the second node, the output end of the third inductor L3 is provided with a third node, the output end of the fourth inductor L4 is provided with a fourth node, and the third capacitor C3 is arranged between the third node and the fourth node.

[0042] The present invention further includes a control module 5, which is electrically connected to the AC / DC module 1 and the H-bridge inverter module 3. The control module is used to control the on / off state of the AC / DC module 1 and drive the H-bridge inverter module 3 to perform inversion. Specifically, the control module 5 includes at least a soft start port 51, an H-bridge drive port 52, and a current sampling port 53. The soft start port 51 is connected to the AC / DC module 1 and is used to control the on / off state of the AC / DC module 1. The H-bridge drive port 52 is connected to the H-bridge inverter module 3 to drive the four MOS transistors in the H-bridge circuit 31 to perform inversion. The current sampling port 52 of the control module is connected to the output of the fourth-order filter circuit and is used to sample the current output by the fourth-order filter circuit. The control module can generate an alarm based on the comparison of the sampled current with a preset value, or control the AC / DC module 1 and the fifth MOS transistor U5 to be turned off to protect the MOS transistors in the H-bridge circuit 31 from damage.

[0043] The above embodiments of the present invention are described in detail. However, the above contents are only preferred embodiments of the present invention and should not be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of this patent.

Claims

1. A bidirectional magnet power supply, characterized in that: include: AC / DC module, used to convert mains voltage into DC voltage; An inversion and filtering module, configured to invert and filter the DC voltage to output bidirectional positive and negative voltages; A linear voltage regulator module is electrically connected between the AC / DC module and the inverter and filter module. The linear voltage regulator module includes a voltage regulator input terminal and a voltage regulator output terminal. A voltage regulator MOS transistor is provided between the voltage regulator input terminal and the voltage regulator output terminal. The voltage regulator MOS transistor is used to reduce low-frequency ripple of the power grid.

2. A bidirectional magnet power supply according to claim 1, characterized in that: The inverter and filter module includes an H-bridge inverter module and a filter module. The H-bridge inverter module is electrically connected to the filter module. The H-bridge inverter module is used to obtain bidirectional positive and negative output voltages. The filter module is used to filter the bidirectional positive and negative output voltages.

3. A bidirectional magnet power supply according to claim 2, characterized in that: The system further includes a control module, which is electrically connected to the AC / DC module and the H-bridge inverter module. The control module is used to control the on and off of the AC / DC module and to drive the H-bridge inverter module.

4. A bidirectional magnet power supply according to claim 2, characterized in that: The H-bridge inverter module includes an H-bridge circuit, which is composed of a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor. The first MOS transistor and the third MOS transistor are driven by a reverse signal, and the second MOS transistor and the fourth MOS transistor are driven by a reverse signal.

5. A bidirectional magnet power supply according to claim 2, characterized in that: The H-bridge inverter module includes a voltage stabilizing circuit, which includes a fifth MOS transistor. The source of the fifth MOS transistor is connected to a first filter capacitor, and the source of the fifth MOS transistor is connected to a fourth capacitor.

6. A bidirectional magnet power supply according to claim 1, characterized in that: The linear voltage regulator module includes an operational amplifier, the non-inverting input end of the operational amplifier is connected to the voltage regulator output end after RC filtering, the reverse input end of the operational amplifier is connected to the voltage regulator ground end after passing through an eighth voltage regulator diode, and the reverse output end of the operational amplifier is connected to the gate of the voltage regulator MOS tube.

7. A bidirectional magnet power supply according to claim 3, characterized in that: The filtering module adopts a fourth-order filtering circuit.

8. A bidirectional magnet power supply according to claim 7, characterized in that: The fourth-order filter circuit includes a first inductor, a second inductor, a third inductor, a fourth inductor, a second capacitor, and a third capacitor. The first inductor and the third inductor are connected with a first node provided therebetween. The second inductor and the fourth inductor are connected with a second node provided therebetween. The second capacitor is connected between the first node and the second node. A third node is provided at the output end of the third inductor. A fourth node is provided at the output end of the fourth inductor. The third capacitor is arranged between the third node and the fourth node.

9. The bidirectional magnet power supply according to claim 4, characterized in that: The first MOS transistor and the second MOS transistor are driven by reverse signals with a phase shift of 180 degrees.

10. The bidirectional magnet power supply according to claim 7, characterized in that: The output end of the fourth-order filter circuit is connected to the current sampling port of the control module, and the current sampling port of the control module is used to sample the current output by the fourth-order filter circuit.

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