CN113452252B - Serial-connection type multi-path common-ground output communication power supply and overcurrent detection and protection method thereof - Google Patents
Serial-connection type multi-path common-ground output communication power supply and overcurrent detection and protection method thereof Download PDFInfo
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- CN113452252B CN113452252B CN202110719169.2A CN202110719169A CN113452252B CN 113452252 B CN113452252 B CN 113452252B CN 202110719169 A CN202110719169 A CN 202110719169A CN 113452252 B CN113452252 B CN 113452252B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
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- Dc-Dc Converters (AREA)
Abstract
The invention belongs to the technical field of communication power supplies, and particularly relates to a multi-path common-ground output communication power supply and an overcurrent detection and protection method thereof. The method comprises the steps of adopting a multi-stage DC/DC converter serial connection structure to realize multi-path voltage output, wherein the DC/DC converter comprises a first converter and a plurality of second converters; sampling a second current value, and controlling the working condition of the second converter after comparing the second current value with a second voltage reference value; and sampling the first current value, and controlling the working condition of the first converter after comparing the first current value with the first voltage reference value. The invention realizes the independent overcurrent detection and protection of each path of output current of the series-connection type multi-path common-ground output communication power supply.
Description
Technical Field
The invention belongs to the technical field of communication power supplies, and particularly relates to a multi-path common-ground output communication power supply and an overcurrent detection and protection method thereof.
Background
In modern communication equipment, different functional circuits with a common reference ground have different voltage and power requirements, and the power supply timing sequence of the different circuits is also divided in sequence, so that a communication power supply for supplying power needs to have multiple outputs with the common ground, and the output voltage and the output power of each path are different. In order to prevent the failure from expanding continuously when the circuit in the communication equipment fails, each output of the communication power supply is required to have an independent overcurrent protection function, and when the power supply load fails, the power supply can automatically close the output. At present, the following two main overcurrent protection schemes are available for multiplexed output:
scheme 1: each output is composed of independent DC/DC converter circuits, and the overcurrent protection circuits are in one-to-one correspondence and are mutually independent. The output overcurrent protection circuit controls whether the DC/DC converter works or not by comparing the current on the sampling output loop with a set voltage reference. If the output current is larger than the set voltage reference value, the DC/DC output is closed, otherwise, the DC/DC is kept to normally work, and the functional block diagram is shown in figure 1. The scheme adopts independent DC/DC power supply to realize each path of output, and the output current directly detects the current value on the output loop to realize overcurrent protection. In addition, the power density of the power supply is low because the power supply is composed of multiple independent DC/DC modules.
Scheme 2: the input voltage is converted by the multi-winding transformer and then the multi-path output is realized by the multi-path rectifying and filtering circuit. The output overcurrent detection protection circuit is positioned on the primary side of the multi-winding transformer and controls whether the power supply is started or stopped by detecting the input current of the power supply and comparing the input current with a set voltage reference value. If one path of output current is increased, the current converted to the primary side through the multi-winding transformer is also increased, when the current value of the primary side is larger than a set reference value, the power supply is closed to output and stop working, otherwise, the power supply is kept to normally work and output, and the schematic block diagram is shown in fig. 2. The scheme adopts a multi-winding transformer structure to realize multi-path output, the overcurrent detection protection circuit is positioned on the primary side of the transformer, and the output overcurrent protection is realized by detecting the input current, but the detection precision and the response speed of the scheme on the output current overcurrent protection are poor.
Disclosure of Invention
The present invention is directed to the above technical problem, and an object of the present invention is to provide a serial multi-channel common ground output communication power supply and an overcurrent detection and protection method thereof.
An overcurrent detection and protection method for a series-connection type multi-path common-ground output communication power supply comprises the following steps:
the multi-path voltage output is realized by adopting a multi-level DC/DC converter serial connection structure, wherein the DC/DC converter directly connected with an input end is a first converter, the voltage output of the first converter is a first path output end, other DC/DC converters are all second converters, and the voltage output of the second converter is a second path output end;
sampling the current on the positive line of the second output end as a second current value, and controlling the working condition of the second converter after comparing the second current value with a second voltage reference value;
and sampling the current on the power supply common reference ground as a first current value, and controlling the working condition of the first converter after comparing the first current value with a first voltage reference value.
And before controlling the working condition of the first converter, subtracting the second current value from the first current value to obtain a new third current value, and comparing the third current value with the first voltage reference value to control the working condition of the first converter.
A series-connection type multi-path common-ground output communication power supply comprises a DC/DC converter, an input end and a plurality of output ends, wherein the DC/DC converter comprises a first converter and at least one second converter, the input end is connected with the first converter, the first converter is connected with the second converter in series, the output end of the first converter is a first path of output end, and the output end of the second converter is a second path of output end;
the overcurrent detection and protection circuit comprises a first output overcurrent detection protection circuit and a second output overcurrent detection protection circuit, the first output overcurrent detection protection circuit samples a first current on a common reference ground of the first converter and the second converter, and a signal output end of the first output overcurrent detection protection circuit is connected with a control end of the first converter;
the second output overcurrent detection protection circuit samples a second current on the positive line of the second output end, and the signal output end of the second output overcurrent detection protection circuit is connected with the control end of the second converter.
The output voltage of the first converter is greater than the output voltage of the second converter.
The first converter and the second converter are connected with a first current sampling resistor in series on a common reference ground, and the first output overcurrent detection protection circuit samples voltages at two ends of the first current sampling resistor;
and a second current sampling resistor is connected in series with the positive line of the second output end, and the second output overcurrent detection protection circuit samples the voltage at two ends of the second current sampling resistor.
The first output overcurrent detection protection circuit comprises a first differential amplification circuit, a third differential amplification circuit and a fifth comparison circuit, and the second output overcurrent detection protection circuit comprises a second differential amplification circuit and a fourth comparison circuit;
the non-inverting input end and the inverting input end of the first differential amplifying circuit are respectively connected with two ends of the first current sampling resistor, the output end of the first differential amplifying circuit is connected with the non-inverting input end of the third differential amplifying circuit, the output end of the third differential amplifying circuit is connected with the inverting input end of the fifth comparing circuit, the non-inverting input end of the fifth comparing circuit is connected with a first voltage reference, and the output end of the fifth comparing circuit is connected with the control end of the first converter;
the non-inverting input end and the inverting input end of the second differential amplifying circuit are respectively connected with two ends of the second current sampling resistor, the output end of the second differential amplifying circuit is respectively connected with the inverting input end of the third differential amplifying circuit and the inverting input end of the fourth comparing circuit, the non-inverting input end of the fourth comparing circuit is connected with a second voltage reference, and the output end of the fourth comparing circuit is connected with the control end of the second converter;
when the number of the second converters is multiple, each second converter corresponds to one group of the second output overcurrent detection protection circuits, the number of third differential amplifying circuits connected between the first differential amplifying circuit and the fifth comparing circuit is the same as that of the second converters, the non-inverting input terminals of one group of the third differential amplifying circuits are connected with the output of the first differential amplifying circuit, the output terminals of one group of the third differential amplifying circuits are connected with the non-inverting input terminals of the other group of the third differential amplifying circuits, and after the plurality of groups of the third differential amplifying circuits are sequentially connected, the output ends of the last group of the third differential amplifying circuits are connected with the inverting input end of the fifth comparing circuit, and the reverse input end of each group of the third differential amplification circuits is connected with the output end of the corresponding second differential amplification circuit.
The first differential amplification circuit, the second differential amplification circuit and the third differential amplification circuit adopt the same differential amplification circuit structure;
the fourth comparison circuit and the fifth comparison circuit adopt the same comparison circuit structure.
The first differential amplifying circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor and a first operational amplifier, the non-inverting input end of the first operational amplifier is connected with one end of the first current sampling resistor through the first resistor, the inverting input end of the first operational amplifier is connected with the other end of the first current sampling resistor through the second resistor, the non-inverting input end of the first operational amplifier is grounded through the third resistor, the first capacitor is connected with the third resistor in parallel, the inverting input end of the first operational amplifier is grounded through the second capacitor, the third capacitor is connected between the non-inverting input end and the inverting input end of the first operational amplifier, the inverting input end of the first operational amplifier is connected with the output end through the fourth resistor, and the output end of the first operational amplifier is connected with the non-inverting input end of the third differential amplification circuit.
The second differential amplifying circuit comprises a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor and a second operational amplifier, wherein the non-inverting input end of the second operational amplifier is connected with one end of the second current sampling resistor through the fifth resistor, the inverting input end of the second operational amplifier is connected with the other end of the second current sampling resistor through the sixth resistor, the non-inverting input end of the second operational amplifier is grounded through the seventh resistor, the fourth capacitor is connected with the seventh resistor in parallel, the inverting input end of the second operational amplifier is grounded through the fifth capacitor, the sixth capacitor is connected between the non-inverting input end and the inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected with the output end through the eighth resistor, and the output end of the second operational amplifier is respectively connected with the inverting input end of the third differential amplifying circuit, An inverting input of the fourth comparison circuit.
The third differential amplifying circuit comprises a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor and a third operational amplifier, the non-inverting input end of the third operational amplifier is connected with the output end of the first differential amplifying circuit through the ninth resistor, the inverting input terminal of the third operational amplifier is connected with the output terminal of the second differential amplifying circuit through the tenth resistor, the non-inverting input end of the third operational amplifier is grounded through the eleventh resistor, the seventh capacitor is connected with the eleventh resistor in parallel, the inverting input end of the third operational amplifier is grounded through the eighth capacitor, the ninth capacitor is connected between the non-inverting input end and the inverting input end of the third operational amplifier, and the inverting input end of the third operational amplifier is connected with the output end through the twelfth resistor, and the output end of the third operational amplifier is connected with the inverting input end of the fifth comparison circuit.
The fourth comparison circuit comprises a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a tenth capacitor, a fourth comparator and a first diode, the non-inverting input terminal of the fourth comparator is connected to the second voltage reference through the thirteenth resistor, an inverting input terminal of the fourth comparator is connected to an output terminal of the second differential amplifier circuit via the fourteenth resistor, the non-inverting input terminal of the fourth comparator is grounded through the fifteenth resistor, the inverting input terminal of the fourth comparator is grounded through the sixteenth resistor, the inverting input end of the fourth comparator is connected with the output end through the seventeenth resistor and the tenth capacitor in sequence, the output end of the fourth comparator is connected with the cathode of the first diode, and the anode of the first diode is connected with the control end of the second converter.
The fifth comparison circuit comprises an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, an eleventh capacitor, a fifth comparator and a second diode, the non-inverting input end of the fifth comparator is connected with the first voltage reference through the eighteenth resistor, the inverting input terminal of the fifth comparator is connected to the output terminal of the third differential amplifier circuit via the nineteenth resistor, the non-inverting input terminal of the fifth comparator is grounded through the twentieth resistor, the inverting input terminal of the fifth comparator is grounded through the twenty-first resistor, the inverting input end of the fifth comparator is connected with the output end through the twenty-second resistor and the eleventh capacitor in sequence, the output end of the fifth comparator is connected with the cathode of the second diode, and the anode of the second diode is connected with the control end of the first converter.
Has the advantages that: the invention carries out secondary conversion through the power supply serial connection structure, improves the utilization rate of the power supply and the power density of the power supply, reduces the complexity of a circuit, and greatly reduces the cost compared with the prior scheme 1. Each path of output current value of the power supply can be independently and accurately detected and judged, and compared with the existing scheme 2, the accuracy of output current detection and the response time of overcurrent protection are greatly improved. The invention integrates the advantages of the prior scheme 1 and the prior scheme 2, and realizes the independent overcurrent detection and protection of each path of output current of the series-connection type multi-path common-ground output communication power supply.
Drawings
Fig. 1 is a schematic block diagram of a parallel-type multi-output power topology of prior art scheme 1;
fig. 2 is a schematic block diagram of a multi-winding power supply topology according to prior art scheme 2;
FIG. 3 is a schematic block diagram of a serial multi-output communication power supply according to the present invention;
fig. 4 is an over-current detection and protection circuit of the present invention.
FIG. 5 is a schematic block diagram of another serial multiple output communication power supply of the present invention;
fig. 6 is another over-current detection and protection circuit of the present invention.
Detailed Description
In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific drawings.
An overcurrent detection and protection method for a series-connection type multi-path common-ground output communication power supply comprises the following steps:
firstly, building a multilevel series circuit: as shown in fig. 3 and 5, a multi-stage DC/DC converter series connection structure is adopted to realize multi-path voltage output, where a DC/DC converter directly connected to an input terminal is a first converter, a voltage output of the first converter is a first path output terminal, other DC/DC converters are all second converters, and a voltage output of the second converter is a second path output terminal.
And secondly, sampling and controlling: sampling the current on the positive line of the second output end as a second current value, and controlling the working condition of the second converter after comparing the second current value with a second voltage reference value; and sampling the current on the power supply common reference ground as a first current value, and controlling the working condition of the first converter after comparing the first current value with a first voltage reference value.
The first voltage reference value and the second voltage reference value in this step are both preset voltage reference values, and the voltage reference values are determined according to overcurrent protection values of the first converter and the second converter in actual use.
In this step, a first output overcurrent detection protection circuit is used for sampling a first current value and controlling the first converter, and a second output overcurrent detection protection circuit is used for sampling a second current value and controlling the first converter. Because the first output overcurrent detection protection circuit detects the current flowing through the common reference ground, the current of the part has the current output by the first path and the current output by the second path, and the current value output by the second path needs to be subtracted from the current flowing through the common reference ground to accurately detect the current value actually output by the first path. Therefore, in one embodiment of the present invention, before controlling the operation of the first converter, the second current value is subtracted from the first current value to obtain a new third current value, and the operation of the first converter is controlled after comparing the third current value with the first voltage reference value.
When the current is needed to be sampled in a certain path during actual overcurrent detection and protection, a resistor can be connected in series on the path, sampling of the current in the certain path can be realized by detecting the voltage at the two ends of the resistor to obtain a sampling voltage value, and based on the conversion relation among the current, the resistor and the voltage, the comparison between the sampling current value and the voltage reference value is changed into the comparison between the sampling voltage value and the voltage reference value.
A series-connection type multi-path common-ground output communication power supply comprises a DC/DC converter, an input end and a plurality of output ends, wherein the DC/DC converter comprises a first converter 1 and at least one second converter 2, the input end is connected with the first converter 1, the first converter 1 is connected with the second converter 2 in series, the output end of the first converter 1 is a first path of output end, and the output end of the second converter 2 is a second path of output end. The multi-path common-ground output communication power supply adopts a serial topology structure, and a low-voltage output path (a second path) is obtained after secondary conversion through a high-voltage output path (a first path).
The overcurrent detection and protection circuit comprises a first output overcurrent detection protection circuit 3 and a second output overcurrent detection protection circuit 4, the first output overcurrent detection protection circuit 3 samples a first current on a common reference ground of the first converter 1 and the second converter 2, and a signal output end of the first output overcurrent detection protection circuit 3 is connected with a control end of the first converter 1; the second output overcurrent detection protection circuit 4 samples a second current on the positive line of the second output end, and the signal output end of the second output overcurrent detection protection circuit 4 is connected with the control end of the second converter 2.
The output voltage of the first converter 1 is greater than the output voltage of the second converter 2. The first converter 1 and the second converter 2 are connected in series with a first current sampling resistor on a common reference ground, and the first output overcurrent detection protection circuit 3 samples voltages at two ends of the first current sampling resistor; and a second current sampling resistor is connected in series on the positive line of the second output end, and the second output overcurrent detection protection circuit 4 samples the voltage at two ends of the second current sampling resistor. Namely, each second converter 2 connected in series with the first converter 1 corresponds to a second output overcurrent detection protection circuit 4, and a sampling resistor is connected in series on the positive line of the output end of the second converter as a second current sampling resistor, so as to realize the purpose of series-connection type multi-output power supply. The structure enables the current to be converted into voltage through the sampling resistor and then controls the operation of the converter.
In one embodiment, referring to fig. 3, a 2-channel output power supply is taken as an example, that is, the power supply has two output terminals, namely, a1 st output terminal and a2 nd output terminal. The first converter 1 realizes voltage output of 24-48V, the maximum output power is the maximum output power of the whole power supply, and the second converter 2 realizes voltage output of 3.3-5.6V.
Referring to fig. 4, in order to realize the detection and protection of the two output currents, the over-current detection and protection circuit includes a first output over-current detection protection circuit 3 and a second output over-current detection protection circuit 4 as follows:
the first output overcurrent detection protection circuit 3 includes a first differential amplification circuit S1, a third differential amplification circuit S3, and a fifth comparison circuit S5, and the second output overcurrent detection protection circuit 4 includes a second differential amplification circuit S2 and a fourth comparison circuit S4; the non-inverting input end and the inverting input end of the first differential amplifying circuit S1 are respectively connected to the two ends P1 and P2 of the first current sampling resistor, the output end of the first differential amplifying circuit S1 is connected to the non-inverting input end of the third differential amplifying circuit S3, the output end of the third differential amplifying circuit S3 is connected to the inverting input end of the fifth comparing circuit S5, the non-inverting input end of the fifth comparing circuit S5 is connected to the first voltage reference Vref1, and the output end of the fifth comparing circuit S5 is connected to the control end of the first converter 1, so as to control whether the first converter 1 works or not. The non-inverting input end and the inverting input end of the second differential amplifying circuit S2 are respectively connected to two ends P3 and P4 of the second current sampling resistor, the output end of the second differential amplifying circuit S2 is respectively connected to the inverting input end of the third differential amplifying circuit S3 and the inverting input end of the fourth comparing circuit S4, the non-inverting input end of the fourth comparing circuit S4 is connected to the second voltage reference Vref2, and the output end of the fourth comparing circuit S4 is connected to the control end of the second converter 2, so as to control whether the second converter 2 works or not.
By the structure, the output current of the high-voltage output circuit (the first circuit) is sampled on the common reference ground line of the power supply output, and the output current of the low-voltage output circuit (the second circuit) is sampled on the output positive line. Because the current output by the power supply on the common reference ground is the output current of the high-voltage output circuit (the first circuit) and the current superposed with the current of the low-voltage output circuit (the second circuit), the actual output current of the high-voltage output circuit (the first circuit) needs to be subtracted from the current output by the power supply on the common reference ground, and the subtraction is completed by the third differential amplification circuit S3 of the functional circuit. The current is converted into voltage through the sampling resistor, and then the voltage is amplified in multiple stages and compared with a voltage reference standard to control the work of the DC/DC converter.
In the present invention, the first differential amplifying circuit S1, the second differential amplifying circuit S2, and the third differential amplifying circuit S3 adopt the same differential amplifying circuit configuration; the fourth comparing circuit S4 and the fifth comparing circuit S5 have the same comparing circuit structure, and one over-current detecting and protecting circuit structure is as follows:
the first differential amplifying circuit S1 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3 and a first operational amplifier a1, the non-inverting input end of the first operational amplifier a1 is connected to one end P1 of the first current sampling resistor through a first resistor R1, the inverting input end P2 of the first operational amplifier a1 is connected to the other end P2 of the first current sampling resistor through a second resistor R2, the non-inverting input end of the first operational amplifier a1 is grounded through a third resistor R3, the first capacitor C1 is connected in parallel with the third resistor R3, the inverting input end of the first operational amplifier a1 is grounded through a second capacitor C2, a third capacitor C3 is connected between the non-inverting input end and the inverting input end of the first operational amplifier a1, the inverting input end of the first operational amplifier a1 is connected to the output end through a fourth resistor R4, and the output end of the first operational amplifier a1 is connected to the non-inverting input end of the third differential amplifier S3. Specifically, the output terminal of the first operational amplifier a1 is connected to the non-inverting input terminal of the third operational amplifier A3 through the ninth resistor R9 of the third differential amplifier circuit S3. The first differential amplifying circuit S1 samples two ends of a first current sampling resistor on the common reference ground of the power supply output, and the voltage difference of the two ends of the first current sampling resistor is amplified by R4/R1 times through a first operational amplifier A1.
The second differential amplifier circuit S2 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6 and a second operational amplifier a2, wherein the non-inverting input terminal of the second operational amplifier a2 is connected to one end P3 of the second current sampling resistor through the fifth resistor R5, the inverting input terminal of the second operational amplifier a2 is connected to the other end P4 of the second current sampling resistor through the sixth resistor R6, the non-inverting input terminal of the second operational amplifier a2 is grounded through the seventh resistor R7, the fourth capacitor C4 is connected in parallel to the seventh resistor R7, the inverting input terminal of the second operational amplifier a2 is grounded through the fifth capacitor C5, the non-inverting input terminal and the inverting input terminal of the second operational amplifier a2 are connected to the sixth capacitor C6, the inverting input terminal of the second operational amplifier a2 is connected to the inverting input terminal of the second operational amplifier a2 through the eighth resistor R8, and the inverting input terminal of the second operational amplifier a2 is connected to the differential amplifier S3, An inverting input terminal of the fourth comparing circuit S4. Specifically, the output terminal of the second operational amplifier a2 is connected to the inverting input terminal of the third operational amplifier A3 via the tenth resistor R10R10 of the third differential amplifier circuit S3. The output terminal of the second operational amplifier a2 is connected to the inverting input terminal of the fourth operational amplifier a4 via the fourteenth resistor R14 of the fourth comparing circuit S4. The second differential amplifying circuit S2 samples two ends of a second current sampling resistor connected in series on the positive line of the second output end, and the voltage difference between the two ends of the second current sampling resistor is amplified by R8/R6 times through the second operational amplifier A2.
The third differential amplifying circuit S3 includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9 and a third operational amplifier A3, the non-inverting input terminal of the third operational amplifier A3 is connected to the output terminal of the first differential amplifier circuit S1 through a ninth resistor R9, the inverting input terminal of the third operational amplifier A3 is connected to the output terminal of the second differential amplifier circuit S2 through a tenth resistor R10, the non-inverting input terminal of the third operational amplifier A3 is grounded through an eleventh resistor R11, a seventh capacitor C7 is connected in parallel with the eleventh resistor R11, the inverting input terminal of the third operational amplifier A3 is grounded through an eighth capacitor C8, a ninth capacitor C9 is connected between the non-inverting input terminal and the inverting input terminal of the third operational amplifier A3, the inverting input terminal of the third operational amplifier A3 is connected to the output terminal through a twelfth resistor R12, and the output terminal of the third operational amplifier A3 is connected to the inverting input terminal of the fifth comparator circuit S5. Specifically, the output terminal of the third operational amplifier A3 is connected to the inverting input terminal of the fifth comparator a5 via the nineteenth resistor R19 of the fifth comparing circuit S5. The difference between the output voltage of the functional circuit S1 and the output voltage of the functional circuit S2 is amplified by a factor of R12/R10 by the third operational amplifier A3.
The fourth comparison circuit S4 includes a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, a tenth capacitor C10, a fourth comparator a4 and a first diode D1, a non-inverting input terminal of the fourth comparator a4 is connected to the second voltage reference Vref2 through the thirteenth resistor R13, an inverting input terminal of the fourth comparator a4 is connected to the output terminal of the second differential amplification circuit S2 through the fourteenth resistor R14, a non-inverting input terminal of the fourth comparator a4 is grounded through the fifteenth resistor R15, an inverting input terminal of the fourth comparator a4 is grounded through the sixteenth resistor R16, an inverting input terminal of the fourth comparator a4 is sequentially connected to the output terminal through the seventeenth resistor R17 and the tenth capacitor C10, an output terminal of the fourth comparator a4 is connected to the cathode of the first diode D1, and an anode of the first diode D1 is connected to the control terminal of the second inverter. Specifically, Vref2 in the fourth comparison circuit S4 is a voltage reference, and is divided by a voltage division network formed by R13 and R15 and then output to a non-inverting input terminal of the comparator a4, an output of the second operational amplifier a2 is divided by a voltage division network formed by R14 and R16 and then output to an inverting input terminal of the fourth comparator a4, and is compared with a voltage at the non-inverting input terminal of the fourth comparator a4, an output pin of the fourth comparator a4 is connected to a cathode pin of the first diode D1, an anode pin of the first diode D1 is connected to a control pin of the second converter 2 controller, and an RC network formed by R17 and C10 is connected between the inverting input terminal and the output terminal of the fourth comparator a 4. When the reverse input end voltage of the fourth comparator A4 is greater than the non-reverse input end voltage, the fourth comparator A4 outputs low level, the output current of the 2 nd path of the power supply is overcurrent, the second converter 2 stops working, otherwise, the second converter 2 continues to work normally.
The fifth comparison circuit S5 includes an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, an eleventh capacitor C11, a fifth comparator a5, and a second diode D2, the non-inverting input terminal of the fifth comparator a5 is connected to the first voltage reference Vref1 through an eighteenth resistor R18, the inverting input terminal of the fifth comparator a5 is connected to the output terminal of the third differential amplifier circuit S3 through a nineteenth resistor R19, the non-inverting input terminal of the fifth comparator a5 is grounded through a twentieth resistor R20, the inverting input terminal of the fifth comparator a5 is grounded through a twenty-first resistor R21, the inverting input terminal of the fifth comparator a5 is connected to the output terminal through a twenty-second resistor R22 and an eleventh capacitor C11 in sequence, the output terminal of the fifth comparator a5 is connected to the cathode of the second diode D2, and the anode of the second diode D2 is connected to the control terminal of the first converter 1. Specifically, Vref1 is a voltage reference, and is divided by a voltage dividing network formed by R18 and R20 and then output to a non-inverting input terminal of a fifth comparator a5, an output of a third operational amplifier A3 is divided by a voltage dividing network formed by R19 and R21 and then output to an inverting input terminal of a fifth comparator a5, and is compared with a voltage of the non-inverting input terminal of the fifth comparator a5, an output pin of the fifth comparator a5 is connected to a cathode pin of a second diode D2, an anode pin of a second diode D2 is connected to a control pin of the first converter 1 controller, and an RC network formed by R22 and C11 is connected between the inverting input terminal and the output terminal of the fifth comparator a 5. When the reverse input end voltage of the fifth comparator A5 is greater than the non-reverse input end voltage, the fifth comparator A5 outputs low level, the 1 st path output current of the power supply is overcurrent, the first converter 1 stops working, otherwise, the first converter 1 continues to work normally.
In one embodiment, referring to fig. 5, a 3-channel output power supply is taken as an example, i.e. the power supply has 3 output terminals, namely, a1 st output terminal, a2 nd output terminal, and a3 rd output terminal. The first converter 1 realizes 24-48V voltage output, the maximum output power is the maximum output power of the whole power supply, and the second converter 21 and the second converter 22 both realize 3.3-5.6V voltage output. The second converter 21 and the second converter 22 are connected in series with the first converter 1, respectively, and the first converter 1, the second converter 21 and the second converter 22 are connected to a common reference ground, respectively.
Referring to fig. 6, in order to realize the detection and protection of the 3-way output current, the over-current detection and protection circuit includes a first output over-current detection protection circuit 3 and two sets of second output over-current detection protection circuits 4 as follows:
the first output overcurrent detection protection circuit 3 includes a first differential amplification circuit S1, a third differential amplification circuit S6, a third differential amplification circuit S3, and a fifth comparison circuit S5. The set of second output overcurrent detection protection circuits 4 includes a second differential amplification circuit S2 and a fourth comparison circuit S4. The other group of second output overcurrent detection protection circuits 4 includes a second differential amplification circuit S7 and a fourth comparison circuit S8. Compared with the 2-channel output power supply, the 3-channel output power supply has one more group of third differential amplifying circuits S6 and another group of second output overcurrent detection protection circuits 4. The two groups of second output overcurrent detection protection circuits 4 have the same circuit structure and respectively control the second converter 21 and the second converter 22.
The connection relationship of the third differential amplifying circuit S6 may be as shown in fig. 6, in which the output terminal of the first differential amplifying circuit S1 is connected to the non-inverting input terminal of the third differential amplifying circuit S6, the output terminal of the third differential amplifying circuit S6 is connected to the non-inverting input terminal of the third differential amplifying circuit S3, the output terminal of the third differential amplifying circuit S3 is connected to the inverting input terminal of the fifth comparing circuit S5, and the output terminal of the second differential amplifying circuit S7 is connected to the inverting input terminal of the third differential amplifying circuit S6.
The connection relationship of the third differential amplifying circuit S6 may also be set between the third differential amplifying circuit S3 and the fifth comparing circuit S5 in fig. 4, i.e., the output terminal of the third differential amplifying circuit S3 is connected to the non-inverting input terminal of the third differential amplifying circuit S6, the output terminal of the third differential amplifying circuit S6 is connected to the inverting input terminal of the fifth comparing circuit S5, and the output terminal of the second differential amplifying circuit S7 is connected to the inverting input terminal of the third differential amplifying circuit S6.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (8)
1. A serial multi-path common-ground output communication power supply comprises a DC/DC converter, an input end and a plurality of output ends, and is characterized in that the DC/DC converter comprises a first converter and at least one second converter, the input end is connected with the first converter, the first converter and the second converter are connected in series, the output end of the first converter is a first path of output end, and the output end of the second converter is a second path of output end;
the overcurrent detection and protection circuit comprises a first output overcurrent detection protection circuit and a second output overcurrent detection protection circuit, a first current sampling resistor is connected to a common reference ground of the first converter and the second converter in series, the first output overcurrent detection protection circuit samples voltage at two ends of the first current sampling resistor, and a signal output end of the first output overcurrent detection protection circuit is connected with a control end of the first converter;
a second current sampling resistor is connected in series with the positive line of the second output end, the second output overcurrent detection protection circuit samples the voltage at two ends of the second current sampling resistor, and the signal output end of the second output overcurrent detection protection circuit is connected with the control end of the second converter;
the second output overcurrent detection protection circuit controls the working condition of the second converter after comparing the voltage at two ends of the second current sampling resistor with a preset second voltage reference value;
and the first output overcurrent detection protection circuit controls the working condition of the first converter after comparing the third voltage value with a preset first voltage reference value.
2. The series multiple-common-ground-output communication power supply according to claim 1, wherein an output voltage of the first converter is greater than an output voltage of the second converter.
3. The series-connected multi-path common-ground output communication power supply according to claim 2, wherein the first output overcurrent detection protection circuit includes a first differential amplification circuit, a third differential amplification circuit, and a fifth comparison circuit, and the second output overcurrent detection protection circuit includes a second differential amplification circuit and a fourth comparison circuit;
the non-inverting input end and the inverting input end of the first differential amplifying circuit are respectively connected with two ends of the first current sampling resistor, the output end of the first differential amplifying circuit is connected with the non-inverting input end of the third differential amplifying circuit, the output end of the third differential amplifying circuit is connected with the inverting input end of the fifth comparing circuit, the non-inverting input end of the fifth comparing circuit is connected with a first voltage reference, and the output end of the fifth comparing circuit is connected with the control end of the first converter;
the non-inverting input end and the inverting input end of the second differential amplifying circuit are respectively connected with two ends of the second current sampling resistor, the output end of the second differential amplifying circuit is respectively connected with the inverting input end of the third differential amplifying circuit and the inverting input end of the fourth comparing circuit, the non-inverting input end of the fourth comparing circuit is connected with a second voltage reference, and the output end of the fourth comparing circuit is connected with the control end of the second converter;
when the number of the second converters is multiple, each second converter corresponds to one group of the second output overcurrent detection protection circuits, the number of third differential amplifying circuits connected between the first differential amplifying circuit and the fifth comparing circuit is the same as that of the second converters, the non-inverting input terminals of one group of the third differential amplifying circuits are connected with the output of the first differential amplifying circuit, the output terminals of one group of the third differential amplifying circuits are connected with the non-inverting input terminals of the other group of the third differential amplifying circuits, and after the plurality of groups of the third differential amplifying circuits are sequentially connected, the output ends of the last group of the third differential amplifying circuits are connected with the inverting input end of the fifth comparing circuit, and the reverse input end of each group of the third differential amplification circuits is connected with the output end of the corresponding second differential amplification circuit.
4. The series multiple-common-ground-output communication power supply according to claim 3, wherein the first differential amplification circuit, the second differential amplification circuit, and the third differential amplification circuit employ the same differential amplification circuit configuration;
the fourth comparison circuit and the fifth comparison circuit adopt the same comparison circuit structure.
5. The series-type multi-path common ground output communication power supply according to claim 3 or 4, wherein the first differential amplifier circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor and a first operational amplifier, wherein a non-inverting input terminal of the first operational amplifier is connected with one end of the first current sampling resistor through the first resistor, an inverting input terminal of the first operational amplifier is connected with the other end of the first current sampling resistor through the second resistor, a non-inverting input terminal of the first operational amplifier is grounded through the third resistor, the first capacitor is connected with the third resistor in parallel, an inverting input terminal of the first operational amplifier is grounded through the second capacitor, the third capacitor is connected between the non-inverting input terminal and the inverting input terminal of the first operational amplifier, and the inverting input terminal of the first operational amplifier is connected with an output terminal through the fourth resistor, the output end of the first operational amplifier is connected with the non-inverting input end of the third differential amplification circuit;
the third differential amplifying circuit comprises a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a seventh capacitor, an eighth capacitor, a ninth capacitor and a third operational amplifier, the non-inverting input end of the third operational amplifier is connected with the output end of the first differential amplifying circuit through the ninth resistor, the inverting input terminal of the third operational amplifier is connected with the output terminal of the second differential amplifying circuit through the tenth resistor, the non-inverting input end of the third operational amplifier is grounded through the eleventh resistor, the seventh capacitor is connected with the eleventh resistor in parallel, the inverting input end of the third operational amplifier is grounded through the eighth capacitor, the ninth capacitor is connected between the non-inverting input end and the inverting input end of the third operational amplifier, and the inverting input end of the third operational amplifier is connected with the output end through the twelfth resistor, and the output end of the third operational amplifier is connected with the inverting input end of the fifth comparison circuit.
6. The series-connection type multi-path common-ground output communication power supply according to claim 3 or 4, wherein the second differential amplifier circuit comprises a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, a sixth capacitor and a second operational amplifier, a non-inverting input terminal of the second operational amplifier is connected to one end of the second current sampling resistor through the fifth resistor, an inverting input terminal of the second operational amplifier is connected to the other end of the second current sampling resistor through the sixth resistor, a non-inverting input terminal of the second operational amplifier is grounded through the seventh resistor, the fourth capacitor is connected in parallel with the seventh resistor, an inverting input terminal of the second operational amplifier is grounded through the fifth capacitor, the sixth capacitor is connected between the non-inverting input terminal and the inverting input terminal of the second operational amplifier, and the inverting input terminal of the second operational amplifier is connected to the output terminal through the eighth resistor, and the output end of the second operational amplifier is respectively connected with the inverting input end of the third differential amplifying circuit and the inverting input end of the fourth comparing circuit.
7. The serial multi-path common ground output communication power supply according to claim 3 or 4, wherein the fourth comparator circuit comprises a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a tenth capacitor, a fourth comparator and a first diode, a non-inverting input terminal of the fourth comparator is connected to the second voltage reference through the thirteenth resistor, an inverting input terminal of the fourth comparator is connected to the output terminal of the second differential amplifier circuit through the fourteenth resistor, a non-inverting input terminal of the fourth comparator is grounded through the fifteenth resistor, an inverting input terminal of the fourth comparator is grounded through the sixteenth resistor, an inverting input terminal of the fourth comparator is sequentially connected to the output terminal through the seventeenth resistor and the tenth capacitor, an output terminal of the fourth comparator is connected to the cathode of the first diode, and the anode of the first diode is connected with the control end of the second converter.
8. The series-connected multi-path common ground output communication power supply according to claim 3 or 4, wherein the fifth comparator circuit comprises an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, an eleventh capacitor, a fifth comparator and a second diode, a non-inverting input terminal of the fifth comparator is connected to the first voltage reference through the eighteenth resistor, an inverting input terminal of the fifth comparator is connected to the output terminal of the third differential amplifier circuit through the nineteenth resistor, a non-inverting input terminal of the fifth comparator is grounded through the twentieth resistor, an inverting input terminal of the fifth comparator is grounded through the twenty-first resistor, an inverting input terminal of the fifth comparator is connected to the output terminal through the twenty-second resistor and the eleventh capacitor in turn, an output terminal of the fifth comparator is connected to the cathode of the second diode, and the anode of the second diode is connected with the control end of the first converter.
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| US6088205A (en) * | 1997-12-19 | 2000-07-11 | Leviton Manufacturing Co., Inc. | Arc fault detector with circuit interrupter |
| US6356423B1 (en) * | 2000-04-26 | 2002-03-12 | Eaton Corporation | Soild state protection circuit for electrical apparatus |
| CN101127282B (en) * | 2007-06-08 | 2010-05-19 | 西安交通大学 | Intelligent AC contactor control unit based on current-variable control |
| US9696350B2 (en) * | 2013-03-15 | 2017-07-04 | Intel Corporation | Non-linear control for voltage regulator |
| CN103616827B (en) * | 2013-11-18 | 2016-02-24 | 深圳市航嘉驰源电气股份有限公司 | A kind of power output apparatus and power output apparatus control method |
| CN206533293U (en) * | 2016-08-16 | 2017-09-29 | 杨大鸣 | A kind of multiple power source for being controlled by DC electrical appliances |
| CN206850666U (en) * | 2017-06-20 | 2018-01-05 | 中国电子科技集团公司第四十三研究所 | A kind of doubleway output current foldback circuit |
| CN111541386B (en) * | 2020-04-30 | 2022-08-16 | 南京理工大学 | High PF (positive-frequency) fixed switching frequency boost converter of parallel active filter |
| CN112383235B (en) * | 2020-12-29 | 2021-08-20 | 郴州市福瑞康电子有限公司 | Power supply device for parallel connection of LED outdoor advertising screens |
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