CN116316405A - Circuit breaker control circuit with current limiting function and circuit breaker control method - Google Patents
Circuit breaker control circuit with current limiting function and circuit breaker control method Download PDFInfo
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- CN116316405A CN116316405A CN202310486256.7A CN202310486256A CN116316405A CN 116316405 A CN116316405 A CN 116316405A CN 202310486256 A CN202310486256 A CN 202310486256A CN 116316405 A CN116316405 A CN 116316405A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/025—Disconnection after limiting, e.g. when limiting is not sufficient or for facilitating disconnection
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
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Abstract
The application provides a circuit breaker control circuit and a circuit breaker control method with a current limiting function, wherein the circuit breaker control circuit with the current limiting function comprises: sampling resistor, switch unit, current sampling circuit and current-limiting loop circuit, the one end of sampling resistor connects the power of predetermineeing, the other end of sampling resistor is connected with switch unit's input, switch unit's output is connected consumer, current sampling circuit's first input is connected with sampling resistor's one end, current sampling circuit's second input is connected with sampling resistor's the other end, current sampling circuit's output is connected with current-limiting loop circuit's first input, current-limiting loop circuit's second input is used for receiving the benchmark voltage value of input, current-limiting loop circuit's output is connected with switch unit's control end. The driving voltage of the switching unit is reduced by introducing the current loop circuit to limit the current, so that the normal operation of the electric equipment is ensured.
Description
Technical Field
The application relates to the technical field of circuit control, in particular to a circuit breaker control circuit with a current limiting function and a circuit breaker control method.
Background
The electronic solid-state breaker is a new type of distribution and overload protection device, which uses the power electronic device as the main breaking switch. The active current limiting function of the solid-state circuit breaker is that the solid-state circuit breaker can limit the output current of the solid-state circuit breaker for a period of time under the condition of short circuit or overload of a load until the solid-state circuit breaker is recovered to be normally opened after the fault is eliminated or is completely closed after the current is limited.
At present, various emergency situations can not be avoided in the use process of the solid-state circuit breaker, at the moment, whether the reliable work of the circuit breaker can be ensured, the stable power supply of upstream power supply equipment is maintained, and whether the whole power distribution system and other electric equipment can work normally is related.
Disclosure of Invention
In view of this, the embodiment of the application provides a circuit breaker control circuit with current limiting function and a circuit breaker control method, so as to solve the problem that the driving voltage of a switching unit is reduced by introducing a current loop circuit to perform current limiting, thereby ensuring the normal operation of electric equipment.
In a first aspect, an embodiment of the present application provides a circuit breaker control circuit with a current limiting function, including: the current limiting circuit comprises a sampling resistor, a switching unit, a current sampling circuit and a current limiting loop circuit;
one end of the sampling resistor is connected with a preset power supply, the other end of the sampling resistor is connected with the input end of the switch unit, and the output end of the switch unit is connected with electric equipment;
the first input end of the current sampling circuit is connected with one end of the sampling resistor, the second input end of the current sampling circuit is connected with the other end of the sampling resistor, the output end of the current sampling circuit is connected with the first input end of the current limiting loop circuit, the second input end of the current limiting loop circuit is used for receiving an input reference voltage value, and the output end of the current limiting loop circuit is connected with the control end of the switching unit.
In an alternative embodiment, the circuit breaker control circuit with the current limiting function further comprises a driving circuit and a first unidirectional conduction device, wherein the output end of the driving circuit is connected with the output end of the current limiting loop circuit through the first unidirectional conduction device.
In an alternative embodiment, the first unidirectional conduction device is a diode, an anode of the first unidirectional conduction device is connected with an output end of the driving circuit, and a cathode of the first unidirectional conduction device is connected with an output end of the current-limiting loop circuit.
In an alternative embodiment, the circuit breaker control circuit with current limiting function further includes: the voltage dividing circuit and the second unidirectional conduction device are connected with the input end of the switching unit, the other end of the voltage dividing circuit is grounded, a voltage dividing point of the voltage dividing circuit is connected with the control end of the switching unit, and the output end of the current limiting loop circuit is connected with the voltage dividing point of the voltage dividing circuit through the second unidirectional conduction device.
In an alternative embodiment, the second unidirectional conduction device is a diode, an anode of the second unidirectional conduction device is connected with an output end of the current-limiting loop circuit, and a cathode of the second unidirectional conduction device is connected with a voltage division point of the voltage division circuit.
In an alternative embodiment, the circuit breaker control circuit with current limiting function further includes: and the control end of the switch unit is connected with the input end of the switch unit through the third unidirectional conduction device.
In an alternative embodiment, the third unidirectional conduction device is a zener diode, an anode of the third unidirectional conduction device is connected to the control end of the switching unit, and a cathode of the third unidirectional conduction device is connected to the input end of the switching unit.
In a second aspect, an embodiment of the present application further provides a switch control method, which is applied to the circuit breaker control circuit with the current limiting function in any one of the first aspect, where the method includes:
the current sampling circuit collects the current value of a sampling resistor, calculates the voltage values at two ends of the sampling resistor according to the current value and the resistance value of the sampling resistor, and amplifies the voltage values;
the current limiting loop circuit obtains a driving voltage value of the switch unit according to the amplified voltage value and a preset reference voltage value;
the switching unit controls the switching unit according to the driving voltage value to reduce a current value passing through the switching unit.
In an alternative embodiment, the current limiting loop circuit obtains a driving voltage value of the switching unit according to the amplified voltage value and a preset reference voltage value, and the method includes:
and if the amplified voltage value exceeds the reference voltage value, the current limiting loop circuit outputs a first voltage value to enable the first unidirectional conduction device to be conducted so as to pull down the voltage value provided by the driving voltage, wherein the pulled down voltage value is the driving voltage value of the switch unit.
In an alternative embodiment, the current limiting loop circuit obtains a driving voltage value of the switching unit according to the amplified voltage value and a preset reference voltage value, and the method includes:
and if the amplified voltage value exceeds the reference voltage value, outputting a second voltage value by the current-limiting loop circuit, and conducting a second unidirectional conduction device so as to push up the voltage value of a voltage division point of the voltage division circuit, wherein the difference between the voltage value of the voltage division point of the voltage division circuit and the voltage value of the input end of the switching unit is the driving voltage value of the switching unit.
The application provides a circuit breaker control circuit and a circuit breaker control method with a current limiting function, wherein the circuit breaker control circuit with the current limiting function comprises: sampling resistor, switch unit, current sampling circuit and current-limiting loop circuit, the one end of sampling resistor connects the power of predetermineeing, the other end of sampling resistor is connected with switch unit's input, switch unit's output is connected consumer, current sampling circuit's first input is connected with sampling resistor's one end, current sampling circuit's second input is connected with sampling resistor's the other end, current sampling circuit's output is connected with current-limiting loop circuit's first input, current-limiting loop circuit's second input is used for receiving the benchmark voltage value of input, current-limiting loop circuit's output is connected with switch unit's control end. The driving voltage of the switching unit is reduced by introducing the current loop circuit to limit the current, so that the normal operation of the electric equipment is ensured.
In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of solid state circuit breaker current under overload conditions provided by embodiments of the present application;
FIG. 2 is a schematic diagram of a charging current under a large capacitive load condition according to an embodiment of the present disclosure;
fig. 3 is a schematic structural diagram of a circuit breaker control circuit with current limiting function according to an embodiment of the present disclosure;
fig. 4 is a schematic structural diagram II of a circuit breaker control circuit with current limiting function according to an embodiment of the present application;
fig. 5 is a schematic diagram of an output characteristic curve of an N-type power semiconductor device according to an embodiment of the present application;
fig. 6 is a schematic structural diagram III of a circuit breaker control circuit with current limiting function according to an embodiment of the present application;
fig. 7 is a schematic diagram of an output characteristic curve of a P-type power semiconductor device according to an embodiment of the present application;
fig. 8 is a schematic structural diagram of a circuit breaker control circuit with current limiting function according to an embodiment of the present disclosure;
fig. 9 is a flow chart of a switch control method according to an embodiment of the present application.
Reference numerals:
10-sampling resistance; a 20-switch unit; 30-a current sampling circuit; 40-a current limiting loop circuit; a 50-drive circuit; 60-a first unidirectional on device; 70-a voltage dividing circuit; 80-a second unidirectional conducting device; 90-third unidirectional pass device.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, are intended to be within the scope of the present application.
By implementing the active current limiting of the solid-state circuit breaker, the influence on other equipment in the system can be reduced under the unexpected conditions of load short circuit or overload and the like, the active function is played on maintaining the high-reliability stable operation of the system, the reliable operation of components in the solid-state circuit breaker can be ensured, and the impact of excessive current on power electronic devices and the influence on the load life are avoided.
The following are more common conditions that relate to the reliability of a circuit breaker:
solid state circuit breaker current under first, short circuit and overload
In the case of short circuit and overload, if the protection is not in time, the breaker current will surge to a relatively high value, and fig. 1 is a schematic diagram of the solid state breaker current under the overload condition provided in the embodiment of the present application, as shown in fig. 1, the abscissa is the unit of time: ms, ordinate is current value, unit: a, when short circuit and overload occur, the current of the circuit breaker can surge to be higher, and if the protection circuit acts too fast, the impact on each moment can be turned off, so that the fault tolerance of the system is reduced.
The solid-state circuit breaker can limit short-time fault current without being turned off, meanwhile, the voltage of an upstream power supply bus can be kept from being lowered, further other electric equipment on the same bus can not be affected, and the stability of the whole system is improved.
Second, solid state breaker current at start-up under high capacitive load conditions
When the circuit breaker is started under the condition of large capacitive load, if no current limiting is performed, the charging current of the large capacitor flowing in the circuit breaker will be relatively large, and fig. 2 is a schematic diagram of the charging current under the condition of large capacitive load, as shown in fig. 2, and the abscissa is time, with units: ms, ordinate is current value, unit: when the circuit breaker is started under the condition of large capacitance load, an overlarge charging capacitor is generated, along with the establishment of capacitor voltage, current gradually becomes smaller, and the large charging current can cause damage to power electronic devices in the solid-state circuit breaker, so that the capacity of the solid-state circuit breaker for adapting to various loads can be ensured by limiting.
Based on this, this application is in order to realize solid-state circuit breaker and is actively current-limiting function accurately, has put forward implementation simple, reliable operation's solution, through introducing current-limiting negative feedback circuit in order to reduce the drive voltage of power electronic device in the circuit breaker to accurate restriction circuit breaker's electric current, and pass experimental verification scheme circuit simple structure, respond fast, reliable operation.
The circuit breaker control circuit with current limiting function provided in the present application is described below with reference to fig. 3 to 8.
Fig. 3 is a schematic structural diagram of a circuit breaker control circuit with current limiting function according to an embodiment of the present application, as shown in fig. 3, the circuit breaker control circuit with current limiting function includes: sampling resistor 10, switching unit 20, current sampling circuit 30, and current limiting loop circuit 40.
One end of the sampling resistor 10 is connected with a preset power supply, the other end of the sampling resistor 10 is connected with the input end of the switch unit 20, and the output end of the switch unit 20 is connected with electric equipment.
A first input end of the current sampling circuit 30 is connected with one end of the sampling resistor 10, a second input end of the current sampling circuit 30 is connected with the other end of the sampling resistor 10, an output end of the current sampling circuit 30 is connected with a first input end of the current limiting loop circuit 40, a second input end of the current limiting loop circuit 40 is used for receiving an input reference voltage value, and an output end of the current limiting loop circuit 40 is connected with a control end of the switching unit 20.
The preset power source may be an upstream power source, configured to provide a power supply voltage to the electric device, where the sampling resistor 10 and the switching unit 20 are connected in series, the switching unit 20 may be, for example, a circuit breaker, and the switching unit 20 may be a power electronic device in the circuit breaker.
The current sampling circuit 30 is configured to sample a current signal of the sampling resistor 10, convert the current signal into a voltage signal, obtain a voltage value at two ends of the sampling resistor 10, amplify the voltage value, input the amplified voltage value to a first input end of the current limiting loop circuit 40, and a second input end of the current limiting loop circuit 40 is configured to receive the input reference voltage value, that is, a reference voltage value of a set current limiting value, and if the voltage value at two ends of the sampling resistor 10 exceeds the reference voltage value, that is, the current value passing through the switching unit 20 exceeds the set current limiting value, the current limiting loop circuit 40 outputs a voltage value as a driving voltage value of the switching unit 20 to control the switching unit 20 to operate, wherein the voltage value is smaller than a current driving voltage value of the switching unit 20, that is, the voltage value is output by the current limiting loop circuit 40 to reduce the driving voltage value of the switching unit 20.
For the switch unit 20, when the driving voltage value is reduced, the current value through the switch unit 20 is correspondingly reduced, that is, the output current of the switch unit 20 is reduced, thus avoiding the life effect of heavy current on the electric equipment, that is, in the normal working state, the switch unit 20 can be controlled by selecting a higher driving voltage value, ensuring lower conduction voltage drop in the normal state, reducing loss, and when overload and short circuit occur, the driving voltage value can be immediately reduced to a lower voltage, so that the switch unit 20 works in a linear amplifying region, and current limiting is performed by the output characteristic of the switch unit 20.
It should be noted that, in the process of controlling the operation of the switching unit 20 with the reduced driving voltage value, the current sampling circuit 30 may also collect the current signal of the sampling resistor 10 in real time, convert the current signal into a voltage signal, obtain the voltage values of the two ends of the sampling resistor 10, and then compare with the reference voltage value, and repeatedly execute the above process until the voltage values of the two ends of the sampling resistor 10 do not exceed the reference voltage value, that is, the current passing through the switching unit can be accurately controlled at the set value by introducing the current limiting loop circuit 40.
After stabilizing the current-limiting output for a period of time, the current-limiting loop circuit 40 can work normally (i.e. the current-limiting loop circuit 40 does not affect the original driving voltage) or can cut off the driving voltage through other control circuits to implement protection, which can be determined according to practical situations.
In the circuit breaker control circuit with current limiting function of the present embodiment, the circuit breaker control circuit with current limiting function includes: sampling resistor, switch unit, current sampling circuit and current-limiting loop circuit, the one end of sampling resistor connects the power of predetermineeing, the other end of sampling resistor is connected with switch unit's input, switch unit's output is connected consumer, current sampling circuit's first input is connected with sampling resistor's one end, current sampling circuit's second input is connected with sampling resistor's the other end, current sampling circuit's output is connected with current-limiting loop circuit's first input, current-limiting loop circuit's second input is used for receiving the benchmark voltage value of input, current-limiting loop circuit's output is connected with switch unit's control end. The driving voltage of the switching unit is reduced by introducing the current loop circuit to limit the current, so that the normal operation of the electric equipment is ensured.
Fig. 4 is a schematic diagram of a second structure of the circuit breaker control circuit with current limiting function according to the embodiment of the present application, as shown in fig. 4, the circuit breaker control circuit with current limiting function further includes a driving circuit 50 and a first unidirectional conducting device 60, and an output end of the driving circuit 50 is connected to an output end of the current limiting loop circuit 40 through the first unidirectional conducting device 60.
The switching unit 20 may be an N-type power semiconductor device, the driving circuit 50 may be a charge pump circuit, the driving circuit 50 is configured to provide a driving voltage to the switching unit 20, an output end of the driving circuit 50 is connected to an output end of the current limiting ring circuit 40 through a first unidirectional conduction device 60, in a normal working state, the driving circuit 50 may output a higher voltage value to control the switching unit 20 to work, if the voltage value at two ends of the sampling resistor 10 collected by the current sampling circuit 30 exceeds a reference voltage value, the current limiting ring circuit 40 outputs a voltage value smaller than the voltage value provided by the driving circuit 50, and under the action of the voltage value output by the driving circuit 50 and the voltage value output by the current limiting ring circuit 40, the first unidirectional conduction device 60 is turned on, wherein the driving voltage value of the switching unit 20 is the sum of the voltage value output by the current limiting ring circuit 40 and the voltage drop of the first unidirectional conduction device 60, that is, by introducing the voltage value of the current limiting ring circuit 40 to pull down the voltage value of the driving circuit 50, so as to control the switching unit 20 to work under the lower driving voltage value, thereby limiting the output current of the switching unit 20, and avoiding the influence on the service life of the consumer.
For example, in a normal operating state, the driving voltage value of the switching unit 20 is 5V provided by the driving circuit 50, if the voltage value of both ends of the sampling resistor 10 exceeds the reference voltage value, the voltage value output by the current limiting loop circuit 40 is 2V, the voltage drop of the first unidirectional conducting device 60 is 0.7V, and the driving voltage value of the switching unit 20 is adjusted to 2.7V, it can be seen that the voltage value of the driving circuit 50 is pulled down by introducing the current limiting loop circuit 40, so as to achieve the purpose of current limiting.
The first unidirectional conduction device 60 is a diode, the anode of the first unidirectional conduction device 60 is connected with the output end of the driving circuit 50, and the cathode of the first unidirectional conduction device 60 is connected with the output end of the current-limiting loop circuit 40.
It should be noted that, for an N-type power semiconductor device, the input terminal is a drain electrode, the output terminal is a source electrode, the control terminal is a gate electrode (i.e., a gate electrode), the gate electrode is a positive voltage with respect to the source electrode, and when overload or short circuit current limiting occurs, the output voltage of the current limiting loop circuit 40 pulls down the voltage of the charge pump, so as to achieve the purpose of reducing the voltage of the gate electrode, where the source electrode may be connected to the drain electrode through a parasitic diode, the anode of the parasitic diode is connected to the source electrode, and the cathode of the parasitic diode is connected to the drain electrode.
One end of the sampling resistor 10 is input, and an output end of the sampling resistor is used for being connected with a preset power switch unit 20 and an output end of the sampling resistor is used for being connected with electric equipment.
FIG. 5 is a schematic diagram showing an output characteristic curve of an N-type power semiconductor device according to an embodiment of the present application, wherein the abscissa represents a voltage drop V as shown in FIG. 5 DS Units: v, the ordinate is the conducting current through the N-type power semiconductor device, and the unit A shows that different curves correspond to different driving voltages, if the driving voltage of the N-type power semiconductor device reaches a lower value, the maximum conducting current is limited, and if the driving voltage is reduced to 2.8V during current limiting, the maximum conducting current is about 50A.
In the circuit breaker control circuit with the current limiting function of the embodiment, when overload and short circuit occur, the driving voltage value of the switching unit is pulled down by introducing the current limiting loop circuit, so that the N-type power semiconductor device works in the linear amplifying region, and current is limited by the output characteristic of the switching unit.
Fig. 6 is a schematic diagram III of a circuit breaker control circuit with current limiting function according to an embodiment of the present application, and as shown in fig. 6, the circuit breaker control circuit with current limiting function further includes: the voltage dividing circuit 70 and the second unidirectional conduction device 80, one end of the voltage dividing circuit 70 is connected with the input end of the switch unit 20, the other end of the voltage dividing circuit 70 is grounded, the voltage dividing point of the voltage dividing circuit 70 is connected with the control end of the switch unit 20, and the output end of the current limiting loop circuit 40 is connected with the voltage dividing point of the voltage dividing circuit 70 through the second unidirectional conduction device 80.
The voltage dividing circuit 70 may be formed by connecting two voltage dividing resistors in series, a voltage dividing point of the voltage dividing circuit 70 is located between the two voltage dividing resistors, one end of the voltage dividing circuit 70 is connected with an input end of the switch unit 20, and the voltage dividing point of the voltage dividing circuit 70 is connected with a control end of the switch unit 20, that is, a driving voltage value of the switch unit 20 is a voltage value of two ends of a first voltage dividing resistor in the voltage dividing circuit 70.
The switching unit 20 may be a P-type power semiconductor device, the input end is a source electrode, the output end is a drain electrode, the control end is a gate electrode (i.e., a gate electrode), the gate electrode is a negative voltage with respect to the source electrode, when overload or short circuit current limiting occurs, the voltage value of the current limiting loop circuit 40 is greater than the voltage value of the voltage dividing point of the voltage dividing circuit 70, the second unidirectional conducting device 80 is conducted under the action of the output voltage value of the current limiting loop circuit 40 and the voltage value of the voltage dividing point of the voltage dividing circuit 70, and since the voltage dividing point of the voltage dividing circuit 70 is connected with one end of the second voltage dividing resistor, the other end of the second voltage dividing resistor is grounded, the output voltage value of the current limiting loop circuit 40 can push up the gate voltage of the P-type power semiconductor device, i.e., the voltage value of the voltage dividing point of the voltage dividing circuit 70 is pushed up, and the voltage difference between the gate electrode and the source electrode is reduced due to the voltage value of the input end remaining unchanged, i.e., the purpose of reducing the driving voltage is achieved.
For example, in the normal operating state, the driving voltage value of the switching unit 20 is 5V at the two ends of the first voltage dividing resistor, the voltage value of the voltage dividing point of the voltage dividing circuit 70 is 15V, if the voltage value at the two ends of the sampling resistor 10 exceeds the reference voltage value, the voltage value output by the current limiting loop circuit 40 is 18V, so that the second unidirectional conduction device 80 is turned on, the voltage drop of the second unidirectional conduction device 80 is 0.7V, and the voltage value of the voltage dividing point of the voltage dividing circuit 70 is 17.3V, it can be seen that the voltage value of the voltage dividing point is pushed up, so that the driving voltage of the switching unit 20 is reduced, and the purpose of current limiting is achieved.
The second unidirectional conduction device 80 is a diode, the anode of the second unidirectional conduction device 80 is connected with the output end of the current-limiting loop circuit 40, and the cathode of the second unidirectional conduction device 80 is connected with the voltage division point of the voltage division circuit 70.
It should be noted that, for a P-type power semiconductor device, the source may also be connected through a parasitic diode and a drain, the anode of the parasitic diode is connected to the drain, and the cathode of the parasitic diode is connected to the source.
FIG. 7 is a schematic diagram showing an output characteristic curve of a P-type power semiconductor device according to an embodiment of the present application, wherein the abscissa represents a voltage drop V as shown in FIG. 7 DS Units: v, the ordinate is the on-current through the P-type power semiconductor device, and the unit a shows that different curves correspond to different driving voltages, and if the driving voltage of the P-type power semiconductor device is lower, the maximum on-current will be limited, for example, the driving voltage can be reduced to-2.8V during current limiting, and the maximum on-current is about 30A.
Wherein the negative sign indicates that the voltage difference between the gate and the source is negative, i.e., the gate is turned on when the source is negative with respect to the gate for a P-type power semiconductor device.
In the circuit breaker control circuit with current limiting function of the embodiment, when overload and short circuit occur, the gate voltage value of the P-type power semiconductor device is pushed up by introducing the current limiting loop circuit so as to pull down the driving voltage value of the P-type power semiconductor device, thereby enabling the P-type power semiconductor device to work in the linear amplifying region and limiting current by the output characteristic of the switching unit itself.
Fig. 8 is a schematic structural diagram four of a circuit breaker control circuit with current limiting function according to an embodiment of the present application, and as shown in fig. 8, the circuit breaker control circuit with current limiting function further includes: and a third unidirectional conduction device 90, wherein the control end of the switch unit 20 is connected with the input end of the switch unit 20 through the third unidirectional conduction device 90.
Since the gate capacitance of the switching unit 20 easily accumulates charges and is not easily discharged, it is easy to cause a high voltage to be generated at the gate if there is electrostatic induction, breakdown the switching unit 20, and the switching unit 20 may be protected by using the third unidirectional conductive device 90 in order to protect the switching unit 20 to discharge it by reverse breakdown.
The third unidirectional conduction device 90 is a zener diode, the anode of the third unidirectional conduction device 90 is connected with the control end of the switch unit 20, and the cathode of the third unidirectional conduction device 90 is connected with the input end of the switch unit 20.
In the circuit breaker control circuit with the current limiting function of the present embodiment, the switching unit is driven in the form of a voltage dividing circuit and a zener diode to provide a stable voltage for the switching unit.
Based on the same inventive concept, the embodiment of the present application further provides a switch control method corresponding to the circuit breaker control circuit with the current limiting function, and since the principle of solving the problem of the device in the embodiment of the present application is similar to that of the circuit breaker control circuit with the current limiting function in the embodiment of the present application, the implementation of the device may refer to the implementation of the method, and the repetition is omitted.
Fig. 9 is a schematic flow chart of a switch control method according to an embodiment of the present application, where the method is applied to the circuit breaker control circuit with the current limiting function.
As shown in fig. 9, the method may include:
s101, a current sampling circuit collects the current value of a sampling resistor, and calculates and amplifies the voltage values at two ends of the sampling resistor according to the current value and the resistance value of the sampling resistor.
S102, the current-limiting loop circuit obtains a driving voltage value of the switch unit according to the amplified voltage value and a preset reference voltage value.
S103, the switching unit controls the switching unit according to the driving voltage value so as to reduce the current value passing through the switching unit.
The sampling resistor is connected with the switch unit in series, after the current sampling circuit is electrified, the current value of the sampling resistor is collected by the current sampling circuit, the voltage values of the two ends of the sampling resistor are calculated according to the current value and the resistance value of the sampling resistor, the voltage values of the two ends of the sampling resistor are input into the current limiting loop circuit, the current limiting loop circuit obtains the driving voltage value of the switch unit according to the voltage values of the two ends of the sampling resistor and the preset reference voltage value, wherein if the voltage values of the two ends of the sampling resistor exceed the reference voltage value, the current limiting loop circuit outputs a voltage value which is smaller than the current driving voltage value of the switch unit, that is, the current limiting loop circuit outputs the voltage value to reduce the driving voltage value of the switch unit.
The switching unit controls the switching unit according to the driving voltage value so that the switching unit works under the action of the driving voltage value, and therefore the current value passing through the switching unit is reduced.
In the switch control method of the embodiment, the current sampling circuit collects the current value of the sampling resistor, calculates the voltage values at two ends of the sampling resistor according to the current value and the resistance value of the sampling resistor, and the current limiting loop circuit obtains the driving voltage value of the switch unit according to the voltage values at two ends of the sampling resistor and the preset reference voltage value, and the switch unit controls the switch unit according to the driving voltage value so as to reduce the current value passing through the switch unit. The driving voltage of the switching unit is reduced by introducing the current loop circuit to limit the current, so that the normal operation of the electric equipment is ensured.
In an optional embodiment, step S102, the current limiting loop circuit obtains a driving voltage value of the switching unit according to the amplified voltage value and a preset reference voltage value, which may include:
if the amplified voltage value exceeds the reference voltage value, the current-limiting loop circuit outputs a first voltage value to enable the first unidirectional conduction device to be conducted so as to pull down the voltage value provided by the driving voltage, wherein the pulled down voltage value is the driving voltage value of the switching unit.
If the switch unit is an N-type power semiconductor device, when the amplified voltage value exceeds the reference voltage value, the current-limiting loop circuit outputs a first voltage value, and the first unidirectional conduction device is conducted under the action of the first voltage value and the voltage value provided by the drive circuit, so that the voltage value provided by the drive circuit is pulled down, wherein the pulled down voltage value is the drive voltage value of the switch unit, namely, the first voltage value, and the first voltage value is smaller than the voltage value provided by the drive circuit.
In an optional embodiment, step S102, the current limiting loop circuit obtains a driving voltage value of the switching unit according to the amplified voltage value and a preset reference voltage value, which may include:
if the amplified voltage value exceeds the reference voltage value, the current-limiting loop circuit outputs a second voltage value, so that the second unidirectional conduction device is conducted to push up the voltage value of the voltage division point of the voltage division circuit.
If the switch unit is a P-type power semiconductor device, when the amplified voltage value exceeds the reference voltage value, the current-limiting loop circuit outputs a second voltage value, and the second unidirectional conduction device is conducted under the action of the second voltage value and the voltage value provided by the driving circuit, so that the voltage value of the voltage division point of the voltage division circuit is pushed up, wherein the difference between the voltage value of the voltage division point of the voltage division circuit and the input end of the switch unit is the driving voltage value of the switch unit, and therefore, the driving voltage value of the switch unit can be reduced by pushing up the voltage division point of the voltage division circuit under the condition that the voltage value of the input end of the switch unit is unchanged, and the second voltage value is larger than the voltage value of the voltage division point of the voltage division circuit.
In the circuit breaker control circuit with current limiting function of the present embodiment, when overload and short circuit occur, the gate voltage value of the switching unit is pulled down or pushed up by introducing the current limiting loop circuit, so as to pull down the driving voltage value of the switching unit, thereby making the switching unit operate in the linear amplifying region, and current limiting is performed by the output characteristic of the switching unit itself.
It should be noted that: like reference numerals and letters in the following figures denote like items, and thus once an item is defined in one figure, no further definition or explanation of it is required in the following figures, and furthermore, the terms "first," "second," "third," etc. are used merely to distinguish one description from another and are not to be construed as indicating or implying relative importance.
Finally, it should be noted that: the foregoing examples are merely specific embodiments of the present application, and are not intended to limit the scope of the present application, but the present application is not limited thereto, and those skilled in the art will appreciate that while the foregoing examples are described in detail, the present application is not limited thereto. Any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or make equivalent substitutions for some of the technical features within the technical scope of the disclosure of the present application; such modifications, changes or substitutions do not depart from the spirit and scope of the corresponding technical solutions. Are intended to be encompassed within the scope of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (10)
1. A circuit breaker control circuit with current limiting function, comprising: the current limiting circuit comprises a sampling resistor, a switching unit, a current sampling circuit and a current limiting loop circuit;
one end of the sampling resistor is connected with a preset power supply, the other end of the sampling resistor is connected with the input end of the switch unit, and the output end of the switch unit is connected with electric equipment;
the first input end of the current sampling circuit is connected with one end of the sampling resistor, the second input end of the current sampling circuit is connected with the other end of the sampling resistor, the output end of the current sampling circuit is connected with the first input end of the current limiting loop circuit, the second input end of the current limiting loop circuit is used for receiving an input reference voltage value, and the output end of the current limiting loop circuit is connected with the control end of the switching unit.
2. The circuit of claim 1, wherein the circuit breaker control circuit with current limiting function further comprises a drive circuit and a first unidirectional conducting device, an output of the drive circuit being connected to an output of the current limiting loop circuit through the first unidirectional conducting device.
3. The circuit of claim 2, wherein the first unidirectional conduction device is a diode, an anode of the first unidirectional conduction device is connected to an output of the drive circuit, and a cathode of the first unidirectional conduction device is connected to an output of the current-limiting loop circuit.
4. The circuit of claim 1, wherein the circuit breaker control circuit with current limiting function further comprises: the voltage dividing circuit and the second unidirectional conduction device are connected with the input end of the switching unit, the other end of the voltage dividing circuit is grounded, a voltage dividing point of the voltage dividing circuit is connected with the control end of the switching unit, and the output end of the current limiting loop circuit is connected with the voltage dividing point of the voltage dividing circuit through the second unidirectional conduction device.
5. The circuit of claim 4, wherein the second unidirectional current-conducting device is a diode, an anode of the second unidirectional current-conducting device is connected to an output of the current-limiting loop circuit, and a cathode of the second unidirectional current-conducting device is connected to a voltage division point of the voltage division circuit.
6. The circuit of claim 4, wherein the circuit breaker control circuit with current limiting function further comprises: and the control end of the switch unit is connected with the input end of the switch unit through the third unidirectional conduction device.
7. The circuit of claim 6, wherein the third unidirectional current conducting device is a zener diode, an anode of the third unidirectional current conducting device is connected to the control terminal of the switching unit, and a cathode of the third unidirectional current conducting device is connected to the input terminal of the switching unit.
8. A circuit breaker control method applied to the circuit breaker control circuit with current limiting function as claimed in any one of claims 1 to 7, characterized in that the method comprises:
the current sampling circuit collects the current value of a sampling resistor, calculates the voltage values at two ends of the sampling resistor according to the current value and the resistance value of the sampling resistor, and amplifies the voltage values;
the current limiting loop circuit obtains a driving voltage value of the switch unit according to the amplified voltage value and a preset reference voltage value;
the switching unit controls the switching unit according to the driving voltage value to reduce a current value passing through the switching unit.
9. The method of claim 8, wherein the current limiting loop circuit obtains a driving voltage value of the switching unit according to the amplified voltage value and a preset reference voltage value, comprising:
and if the amplified voltage value exceeds the reference voltage value, the current limiting loop circuit outputs a first voltage value to enable the first unidirectional conduction device to be conducted so as to pull down the voltage value provided by the driving voltage, wherein the pulled down voltage value is the driving voltage value of the switch unit.
10. The method of claim 8, wherein the current limiting loop circuit obtains a driving voltage value of the switching unit according to the amplified voltage value and a preset reference voltage value, comprising:
and if the amplified voltage value exceeds the reference voltage value, outputting a second voltage value by the current-limiting loop circuit, and conducting a second unidirectional conduction device so as to push up the voltage value of a voltage division point of the voltage division circuit, wherein the difference between the voltage value of the voltage division point of the voltage division circuit and the voltage value of the input end of the switching unit is the driving voltage value of the switching unit.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310486256.7A CN116316405A (en) | 2023-04-28 | 2023-04-28 | Circuit breaker control circuit with current limiting function and circuit breaker control method |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202310486256.7A CN116316405A (en) | 2023-04-28 | 2023-04-28 | Circuit breaker control circuit with current limiting function and circuit breaker control method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117394698A (en) * | 2023-12-13 | 2024-01-12 | 深圳市芯茂微电子有限公司 | H-bridge power supply circuit control method, device and medium |
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- 2023-04-28 CN CN202310486256.7A patent/CN116316405A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117394698A (en) * | 2023-12-13 | 2024-01-12 | 深圳市芯茂微电子有限公司 | H-bridge power supply circuit control method, device and medium |
| CN117394698B (en) * | 2023-12-13 | 2024-03-26 | 深圳市芯茂微电子有限公司 | H-bridge power supply circuit control method, device and medium |
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