High-frequency direct-current switching power supply monitoring system

Abstract

The utility model relates to the technical field of power supplies, and provides a high-frequency direct-current switching power supply monitoring system, which comprises a power module consisting of a plurality of power tubes, each power tube is correspondingly provided with a power tube short-circuit monitoring circuit, and the power tube short-circuit monitoring circuit comprises a first voltage comparison circuit, a second voltage comparison circuit and a third voltage comparison circuit, the first power tube is used for outputting a first level signal when voltage of a control end of the first power tube is larger than first reference voltage. The second voltage detection circuit is used for outputting a second level signal when the voltage of the first end of the first power tube is greater than a second reference voltage; the output end of the first voltage comparison circuit and the output end of the second voltage comparison circuit are connected to the two input ends of the AND gate circuit respectively, the latch is used for latching output signals of the AND gate circuit, and the output end of the latch is used for being connected to the control end of the first power tube. According to the technical scheme, the problem that in the prior art, a high-frequency direct-current switching power supply monitoring system is low in load short-circuit fault detection speed is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply, in particular to a high-frequency direct current switching power supply monitoring system. Background Art

[0002] The high-frequency DC switching power supply converts the input AC power supply into energy and controls the voltage / current through the fast switching action of the switching device, and finally outputs a stable DC voltage or current for use in various electrical equipment. Due to its efficient energy conversion capability and good power factor, the high-frequency DC switching power supply is widely used in many application fields such as industrial automation, communication equipment, transportation and renewable energy systems. The high-frequency DC switching power supply monitoring system can monitor and manage the working status of the high-frequency DC switching power supply in real time to ensure the stable operation of the high-frequency DC switching power supply. As the core component of the high-frequency DC switching power supply, the power tube is also a device that is prone to failure. For example, when the load is short-circuited, if the monitoring system cannot act in time, it will cause damage to the high-frequency DC switching power supply. Utility Model Content

[0003] The utility model provides a high-frequency DC switching power supply monitoring system, which solves the problem of slow detection speed of load short-circuit fault in the high-frequency DC switching power supply monitoring system in the related art.

[0004] The technical solution of the utility model is as follows:

[0005] A high-frequency DC switching power supply monitoring system, the high-frequency DC switching power supply includes a power module composed of a plurality of power tubes, each power tube is provided with a power tube short-circuit monitoring circuit, the power tube short-circuit monitoring circuit includes:

[0006] A first voltage comparison circuit, used for outputting a first level signal when the voltage at the control end of the first power tube is greater than a first reference voltage;

[0007] A second voltage detection circuit, used for outputting a second level signal when the voltage at the first end of the first power tube is greater than a second reference voltage;

[0008] an AND gate circuit, wherein a first input terminal of the AND gate circuit is connected to an output terminal of the first voltage comparison circuit, and a second input terminal of the AND gate circuit is connected to an output terminal of the second voltage comparison circuit,

[0009] A latch is used to latch the output signal of the AND gate circuit, and the output end of the latch is used to access the control end of the first power tube.

[0010] In an exemplary embodiment of the present utility model, a driving module is provided between the output end of the latch and the control end of the first power tube.

[0011] The anode of the input diode of the driving module is connected to the first power supply through a pull-up resistor, the cathode of the input diode of the driving module is connected to the output end of the latch, the collector of the output transistor of the driving module is connected to the control end of the first power tube, and the emitter of the output transistor of the driving module is connected to the second end of the first power tube.

[0012] In an exemplary embodiment of the present utility model, the first voltage comparison circuit includes a first voltage acquisition circuit and a first comparison circuit connected in sequence.

[0013] The input end of the first voltage acquisition circuit is the input end of the first voltage comparison circuit, the output end of the first voltage acquisition circuit is connected to the first end of the first comparison circuit, the second end of the first comparison circuit is connected to the first reference voltage, and the output end of the first comparison circuit is the output end of the first voltage comparison circuit.

[0014] In an exemplary embodiment of the present utility model, the second voltage comparison circuit includes a second voltage acquisition circuit and a second comparison circuit connected in sequence.

[0015] The input end of the second voltage acquisition circuit is the input end of the second voltage comparison circuit, the output end of the second voltage acquisition circuit is connected to the first end of the second comparison circuit, the second end of the second comparison circuit is connected to the second reference voltage, and the output end of the second comparison circuit is the output end of the second voltage comparison circuit.

[0016] In an exemplary embodiment of the present invention, an overvoltage protection circuit is also included. The overvoltage protection circuit includes a switch tube Q1, a switch tube Q2, a resistor R10 and a resistor R9.

[0017] The control end of the switch tube Q1 is connected to the third reference voltage, the first end of the switch tube Q1 is connected to the output end of the high-frequency DC switching power supply, and the second end of the switch tube Q1 is grounded through a resistor R9.

[0018] The second end of the switch tube Q1 is connected to the control end of the switch tube Q2, the first end of the switch tube Q2 is connected to the output end of the high-frequency DC switching power supply, the second end of the switch tube Q2 is connected to the load circuit, the first end of the resistor R10 is connected to the first end of the switch tube Q1, and the second end of the resistor R10 is connected to the second end of the switch tube Q2.

[0019] The working principle and beneficial effects of the utility model are:

[0020] The utility model takes into account that when a power tube is short-circuited, its gate voltage (i.e., the control terminal voltage) will rise rapidly, and the collector voltage (i.e., the first terminal voltage) will rise rapidly to near the bus voltage. Accordingly, the utility model sets a first voltage comparison circuit and a second voltage comparison circuit. When the power tube is short-circuited, the first voltage comparison circuit and the second voltage comparison circuit both output high-level signals to the AND gate circuit, and the AND gate circuit outputs a high-level signal. The high-level signal output by the AND gate circuit is latched by the latch, and the latched signal can control the power tube to shut down in time, thereby realizing rapid short-circuit protection and avoiding damage to the equipment caused by a long short-circuit fault time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] Figure 1 This is the schematic diagram of the power tube short circuit monitoring circuit in the utility model;

[0023] Figure 2 This is the schematic diagram of the overvoltage protection circuit in the utility model. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] This embodiment provides a high-frequency DC switching power supply monitoring system. The high-frequency DC switching power supply includes a power module composed of a plurality of power tubes. Each power tube is provided with a power tube short-circuit monitoring circuit. Figure 1 As shown, the power tube short circuit monitoring circuit includes:

[0026] A first voltage comparison circuit, used for outputting a first level signal when the voltage at the control end of the first power tube is greater than a first reference voltage;

[0027] A second voltage detection circuit, used for outputting a second level signal when the voltage at the first end of the first power tube is greater than a second reference voltage;

[0028] An AND gate circuit U3, wherein a first input terminal of the AND gate circuit U3 is connected to an output terminal of the first voltage comparison circuit, and a second input terminal of the AND gate circuit U3 is connected to an output terminal of the second voltage comparison circuit.

[0029] The latch U4 is used to latch the output signal of the AND gate circuit U3, and the output end of the latch U4 is used to connect to the control end of the first power tube.

[0030] In this embodiment, the first power tube is any power tube in the power module. Considering that when the power tube is short-circuited, its gate voltage (i.e., the control terminal voltage) will rise rapidly, and the collector voltage (i.e., the first terminal voltage) will rise rapidly to near the bus voltage. Accordingly, the utility model is provided with a first voltage comparison circuit and a second voltage comparison circuit. When the power tube is short-circuited, the first voltage comparison circuit and the second voltage comparison circuit both output high-level signals to the AND gate circuit U3, and the AND gate circuit U3 outputs a high-level signal. The high-level signal output by the AND gate circuit U3 is latched by the latch U4. The latched signal can control the power tube to shut down in time, thereby realizing rapid short-circuit protection and avoiding damage to the equipment caused by a long short-circuit fault time.

[0031] In an exemplary embodiment of the present invention, Figure 1 As shown, a driving module U5 is provided between the output end of the latch U4 and the control end of the first power tube.

[0032] The anode Anode of the input diode of the driving module U5 is connected to the first power supply 5V through the pull-up resistor R6, the cathode Cathode of the input diode of the driving module U5 is connected to the output end of the latch U5, the collector Collector of the output transistor of the driving module U5 is connected to the control end G-1 of the first power tube, and the emitter Emitter of the output transistor of the driving module U5 is connected to the second end E-1 of the first power tube.

[0033] In this embodiment, the driving module U5 can amplify the voltage signal output by the latch U4 to achieve reliable driving of the first power tube. At the same time, the driving module U5 has an optical coupling isolation module inside to play the role of electrical isolation to avoid mutual interference between the front and rear circuits.

[0034] In an exemplary embodiment of the present invention, Figure 1 As shown, the first voltage comparison circuit includes a first voltage acquisition circuit and a first comparison circuit connected in sequence,

[0035] The input end of the first voltage acquisition circuit is the input end of the first voltage comparison circuit, the output end of the first voltage acquisition circuit is connected to the first end of the first comparison circuit, the second end of the first comparison circuit is connected to the first reference voltage, and the output end of the first comparison circuit is the output end of the first voltage comparison circuit.

[0036] In this embodiment, the operational amplifier U1A constitutes a first voltage acquisition circuit, which is used to collect and further amplify the voltage UG at the control end of the first power tube; the operational amplifier U2A constitutes a first comparison circuit. When the first power tube is short-circuited, the output voltage of the first voltage acquisition circuit is greater than the first reference voltage ref1, and the first comparison circuit outputs a high-level signal.

[0037] In an exemplary embodiment of the present invention, Figure 1 As shown, the second voltage comparison circuit includes a second voltage acquisition circuit and a second comparison circuit connected in sequence,

[0038] The input end of the second voltage acquisition circuit is the input end of the second voltage comparison circuit, the output end of the second voltage acquisition circuit is connected to the first end of the second comparison circuit, the second end of the second comparison circuit is connected to the second reference voltage, and the output end of the second comparison circuit is the output end of the second voltage comparison circuit.

[0039] In this embodiment, the operational amplifier U1B constitutes a first voltage acquisition circuit, which is used to collect and further amplify the voltage of the first end (collector) of the first power tube; the operational amplifier U2B constitutes a second comparison circuit. When the first power tube is short-circuited, the output voltage of the second voltage acquisition circuit is greater than the second reference voltage ref2, and the second comparison circuit outputs a high-level signal.

[0040] In an exemplary embodiment of the present utility model, the high-frequency DC switching power supply monitoring system further includes an overvoltage protection circuit, such as Figure 2 As shown, the overvoltage protection circuit includes a switch tube Q1, a switch tube Q2, a resistor R10 and a resistor R9.

[0041] The control end of the switch tube Q1 is connected to the third reference voltage, the first end of the switch tube Q1 is connected to the output end of the high-frequency DC switching power supply, and the second end of the switch tube Q1 is grounded through the resistor R9.

[0042] The second end of the switch tube Q1 is connected to the control end of the switch tube Q2, the first end of the switch tube Q2 is connected to the output end of the high-frequency DC switching power supply, the second end of the switch tube Q2 is connected to the load circuit, the first end of the resistor R10 is connected to the first end of the switch tube Q1, and the second end of the resistor R10 is connected to the second end of the switch tube Q2.

[0043] In this embodiment, the output end of the high-frequency DC switching power supply is used to supply power to the load or charge the battery. If the voltage at the output end of the high-frequency DC switching power supply is too high, the load or the battery will be damaged. To this end, this embodiment is provided with an overvoltage protection circuit. When the voltage at the output end of the high-frequency DC switching power supply is less than or equal to the third reference voltage ref3, the switch tube Q1 is turned off. Due to the voltage dividing effect of the resistor R10, the voltage between the source and the gate of the switch tube Q2 is greater than the conduction voltage, the switch tube Q2 is turned on, and the high-frequency DC switching power supply supplies power to the load or charges the battery; when the voltage at the output end of the high-frequency DC switching power supply is greater than the third reference voltage ref3, the switch tube Q1 is turned on, the resistor R10 is short-circuited, and the switch tube Q2 is turned off, thereby disconnecting the high-frequency DC switching power supply from the load or the battery.

[0044] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-frequency DC switching power supply monitoring system, wherein the high-frequency DC switching power supply comprises a power module composed of a plurality of power tubes, characterized in that: A power tube short circuit monitoring circuit is included, and the power tube short circuit monitoring circuit includes: A first voltage comparison circuit, configured to output a first level signal when the voltage at the control end of the first power tube is greater than a first reference voltage; A second voltage comparison circuit, used for outputting a second level signal when the voltage at the first end of the first power tube is greater than a second reference voltage; an AND gate circuit, wherein a first input terminal of the AND gate circuit is connected to an output terminal of the first voltage comparison circuit, and a second input terminal of the AND gate circuit is connected to an output terminal of the second voltage comparison circuit, A latch is used to latch the output signal of the AND gate circuit, and the output end of the latch is used to connect to the control end of the first power tube.

2. A high-frequency DC switching power supply monitoring system according to claim 1, characterized in that: A driving module is provided between the output end of the latch and the control end of the first power tube. The anode of the input diode of the driving module is connected to the first power supply through a pull-up resistor, the cathode of the input diode of the driving module is connected to the output end of the latch, the collector of the output transistor of the driving module is connected to the control end of the first power tube, and the emitter of the output transistor of the driving module is connected to the second end of the first power tube.

3. A high-frequency DC switching power supply monitoring system according to claim 1, characterized in that: The first voltage comparison circuit includes a first voltage acquisition circuit and a first comparison circuit connected in sequence, The input end of the first voltage acquisition circuit is the input end of the first voltage comparison circuit, the output end of the first voltage acquisition circuit is connected to the first end of the first comparison circuit, the second end of the first comparison circuit is connected to the first reference voltage, and the output end of the first comparison circuit is the output end of the first voltage comparison circuit.

4. A high-frequency DC switching power supply monitoring system according to claim 1, characterized in that: The second voltage comparison circuit includes a second voltage acquisition circuit and a second comparison circuit connected in sequence. The input end of the second voltage acquisition circuit is the input end of the second voltage comparison circuit, the output end of the second voltage acquisition circuit is connected to the first end of the second comparison circuit, the second end of the second comparison circuit is connected to the second reference voltage, and the output end of the second comparison circuit is the output end of the second voltage comparison circuit.

5. A high-frequency DC switching power supply monitoring system according to claim 1, characterized in that: The overvoltage protection circuit includes a switch tube Q1, a switch tube Q2, a resistor R10 and a resistor R9. The control end of the switch tube Q1 is connected to the third reference voltage, the first end of the switch tube Q1 is connected to the output end of the high-frequency DC switching power supply, and the second end of the switch tube Q1 is grounded through a resistor R9. The second end of the switch tube Q1 is connected to the control end of the switch tube Q2, the first end of the switch tube Q2 is connected to the output end of the high-frequency DC switching power supply, the second end of the switch tube Q2 is connected to the load circuit, the first end of the resistor R10 is connected to the first end of the switch tube Q1, and the second end of the resistor R10 is connected to the second end of the switch tube Q2.

Images