CN114498549B - Control circuit and method for circuit breaker and electronic equipment - Google Patents

Abstract

The application provides a control circuit, a method and electronic equipment for a circuit breaker, wherein in the control circuit, a current change rate comparison module outputs a first comparison signal according to the magnitude relation between the current change rate of a bus at the current moment and a first preset threshold value; the locking module outputs a second comparison signal; the safety current comparison module outputs a third comparison signal according to the magnitude relation between the current of the bus at the current moment and the safety current; the control module controls the circuit breaker to be turned off under the conditions that the current change rate of the first comparison signal representing the bus at the current moment is larger than a first preset threshold value, the current change rate of the second comparison signal representing the bus at the first moment is larger than the first preset threshold value and the current of the third comparison signal representing the bus at the current moment is larger than the safety current. By implementing the application, the circuit breaker can be controlled to make corresponding actions aiming at different fault types, and the requirements of the current standard on the circuit breaker are met.

Description

A control circuit, method and electronic device for circuit breaker

Technical Field

The present application relates to the field of power supply technology, and in particular to a control circuit, method and electronic equipment for a circuit breaker.

Background Art

In the power supply system, a circuit breaker is required to realize the function of system fault protection. The control method of system fault protection adopted by the prior art is that when the current of the power supply system where the circuit breaker is located is too large, the circuit breaker is immediately controlled to be shut down. This control method regards a short circuit as occurring as long as the current of the power supply system exceeds a certain threshold value, regardless of the fault state of the power supply system, and immediately controls the circuit breaker to be shut down. However, according to the requirements for circuit breakers in the standard GB/T14048.1-2012, if the power supply system is struck by lightning, or the current caused by the overload of the power supply system exceeds a certain threshold value, it is not desirable for the circuit breaker to be shut down or shut down immediately. That is, the control method in the prior art cannot meet the action requirements of the current standard for circuit breakers when a fault occurs, which can easily cause the circuit breaker to malfunction.

Summary of the invention

The present application provides a control circuit, method and electronic device for a circuit breaker, which can distinguish the fault types of the power supply system, so as to control the circuit breaker to take corresponding actions for different fault types, meet the requirements of the current standards for circuit breakers, and have high accuracy and good safety.

In a first aspect, an embodiment of the present application provides a control circuit of a circuit breaker, which is connected in series to a busbar of a power supply system, and the control circuit includes a current change rate comparison module, a locking module, a control module and a safety current comparison module; wherein the output end of the current change rate comparison module is coupled to the input end of the locking module and the first input end of the control module; the output end of the locking module is coupled to the second input end of the control module; and the output end of the safety current comparison module is coupled to the third input end of the control module.

In the specific implementation, the current change rate comparison module outputs a first comparison signal according to the magnitude relationship between the current change rate of the bus at the current moment and the first preset threshold; the locking module outputs a second comparison signal; the second comparison signal is determined according to the magnitude relationship between the current change rate of the bus at the first moment and the first preset threshold; wherein the first moment is before the current moment and is separated from the current moment by a first preset time length; the control module determines that the power supply system is in the first state when the first comparison signal indicates that the current change rate of the bus at the current moment is greater than the first preset threshold, and the second comparison signal indicates that the current change rate of the bus at the first moment is greater than the first preset threshold; the safety current comparison module outputs a third comparison signal according to the magnitude relationship between the current of the bus at the current moment and the safety current; the control module is in the first state, at which time the first state of the power supply system can be considered to have a short circuit or normal load shedding, and when the third comparison signal indicates that the current of the bus at the current moment is greater than the safety current, the power supply system is considered to be short-circuited, and the circuit breaker is controlled to be turned off to protect the power supply system.

In combination with the first aspect, in a first possible implementation method, the control module determines that the power supply system is in the second state when the first comparison signal indicates that the current change rate of the bus at the current moment is less than the first preset threshold, and the second comparison signal indicates that the current change rate of the bus at the first moment is greater than the first preset threshold; at this time, the second state of the power supply system can be considered to be a lightning strike, and the control module controls the circuit breaker not to operate.

In combination with the first aspect or the first possible implementation method of the first aspect, in a second possible implementation method, when the power supply system is in the first state and the third comparison signal indicates that the current of the bus at the current moment is less than the safety current, the control module 1112 considers that the power supply system is normally shedding the load and no fault has occurred, and there is no need to control the circuit breaker to shut down, that is, the circuit breaker is controlled not to operate.

In combination with the first aspect or any one of the above possible implementations of the first aspect, in a third possible implementation, the above control circuit further includes an overload current comparison module, and an output end of the overload current comparison module is coupled to a fourth input end of the control module.

In a specific implementation, the overload current comparison module outputs a fourth comparison signal according to the magnitude relationship between the current of the bus at the current moment and the overload current; wherein the overload current is greater than the safety current; the control module determines that the power supply system is in the third state when the first comparison signal indicates that the current change rate of the bus at the current moment is less than the first preset threshold, and the second comparison signal indicates that the current change rate of the bus at the first moment is less than the first preset threshold; at this time, the third state of the power supply system can be considered to be overloaded or working normally. When the power supply system is in the third state, and the fourth comparison signal indicates that the current of the bus at the current moment is greater than the overload current, the control module considers that the power supply system is overloaded and controls the circuit breaker to shut down.

In combination with the third possible implementation method of the first aspect, in a fourth possible implementation method, when the power supply system is in the third state and the fourth comparison signal indicates that the current of the bus at the current moment is less than the overload current, the control module considers that the power supply system is operating normally and controls the circuit breaker not to operate.

In combination with the first aspect or any one of the above possible implementation methods of the first aspect, in a fifth possible implementation method, the above-mentioned circuit breaker includes a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; the solid-state switch is closed first during the closing process of the circuit breaker; during the closing process of the circuit breaker, if the current change rate of the bus at a current moment is greater than the first preset threshold value, and the current of the bus at a current moment is greater than the overload current, the control module controls the solid-state switch to turn off.

In combination with the fifth possible implementation method of the first aspect, in a sixth possible implementation method, during the process of closing the circuit breaker, the control module continues to control the mechanical switch to close if the current change rate of the bus at the current moment is less than the first preset threshold, or the current of the bus at the current moment is less than the overload current.

In combination with the first aspect or any one of the above possible implementations of the first aspect, in a seventh possible implementation, the above-mentioned circuit breaker includes a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; the control module also includes a mechanical control submodule and a delay submodule; wherein the mechanical control submodule controls the mechanical switch to be turned off, and the delay submodule delays the solid-state switch to be turned off for a second preset time after the mechanical switch is turned off.

In combination with the seventh possible implementation method of the first aspect, in an eighth possible implementation method, the above-mentioned delay submodule delays the second preset time length to control the solid-state switch to turn off after the mechanical switch is turned off. The specific implementation is: when the current passing through the mechanical switch during the mechanical switch shutdown process is less than the preset reference current, the delay submodule delays the second preset time length to control the solid-state switch to turn off.

In combination with the seventh to eighth possible implementations of the first aspect, in a ninth possible implementation, when the solid-state switch is in an off state, the mechanical switch does not operate.

In the second aspect, an embodiment of the present application provides a control method for a circuit breaker, wherein the circuit breaker is connected in series to a bus of a power supply system, and the control method is specifically implemented as follows: the current change rate of the bus at a current moment is greater than a first preset threshold, and the current change rate of the bus at a first moment is greater than the first preset threshold, and the power supply system is determined to be in a first state; wherein the first moment is before the current moment, and is separated from the current moment by a first preset time length; when the power supply system is in the first state, and the current of the bus at the current moment is greater than the safety current, the circuit breaker is controlled to be shut down.

In combination with the second aspect, in a first possible implementation method, the current change rate of the bus at the current moment is less than the first preset threshold, and the current change rate of the bus at the first moment is greater than the first preset threshold, and it is determined that the power supply system is in the second state; when the power supply system is in the second state, the circuit breaker is controlled not to operate.

In combination with the second aspect or in combination with the first possible implementation of the second aspect, in the second possible implementation, when the power supply system is in the first state, if the current current of the bus at a current moment is less than the safety current, the circuit breaker is controlled not to operate.

In combination with the second aspect or any one of the above possible implementation methods of the second aspect, in a third possible implementation method, when the current change rate of the bus at a current moment is less than a first preset threshold, and the current change rate of the bus at a first moment is less than the first preset threshold, it is determined that the power supply system is in a third state; when the power supply system is in the third state and the current of the bus at a current moment is greater than the overload current, the circuit breaker is controlled to be turned off; wherein the overload current is greater than the safety current.

In combination with the third possible implementation of the second aspect, in a fourth possible implementation, when the power supply system is in the third state and the current of the bus at the current moment is less than the overload current, the circuit breaker is controlled not to operate.

In combination with the second aspect or any one of the above possible implementation methods of the second aspect, in a fifth possible implementation method, the circuit breaker includes a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; the solid-state switch is closed first during the closing process of the circuit breaker; during the closing process of the circuit breaker, if the current change rate of the bus at a current moment is greater than the first preset threshold value, and the current of the bus at a current moment is greater than the overload current, the solid-state switch is controlled to be turned off.

In combination with the fifth possible implementation method of the second aspect, in a sixth possible implementation method, during the process of closing the circuit breaker, if the current change rate of the bus at the current moment is less than the first preset threshold, or the current of the bus at the current moment is less than the overload current, the mechanical switch continues to be controlled to close.

In combination with the second aspect or any one of the above possible implementation methods of the second aspect, in a seventh possible implementation method, the circuit breaker includes a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; controlling the circuit breaker to turn off can be specifically implemented as follows: controlling the mechanical switch to turn off, and delaying the solid-state switch to turn off for a second preset time after controlling the mechanical switch to turn off.

In combination with the seventh possible implementation method of the second aspect, in an eighth possible implementation method, after controlling the mechanical switch to turn off, delaying the solid-state switch to turn off for a second preset time period is performed, and specifically implemented as follows: in the process of controlling the mechanical switch to turn off, obtaining the current passing through the mechanical switch; when the current passing through the mechanical switch is less than the preset reference current, delaying the solid-state switch to turn off for a second preset time period.

In combination with the seventh to eighth possible implementations of the second aspect, in a ninth possible implementation, when the solid-state switch is in an off state, the mechanical switch does not operate.

In a third aspect, an embodiment of the present application provides an electronic device, which includes a circuit breaker and a control circuit for the circuit breaker in combination with the first aspect or in combination with any possible implementation of the first aspect.

It should be understood that the implementation and beneficial effects of the above-mentioned aspects of the present application can be referenced to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a structural block diagram of an electronic device provided in an embodiment of the present application;

FIG2 is a structural block diagram of a control circuit for a circuit breaker provided in an embodiment of the present application;

FIG3 is another structural block diagram of a control circuit for a circuit breaker provided in an embodiment of the present application;

FIG4 is a circuit schematic diagram of a control circuit for a circuit breaker provided in an embodiment of the present application;

5A to 5B are partial circuit schematic diagrams of a control module provided in an embodiment of the present application;

FIG. 6 is another circuit schematic diagram of a control circuit for a circuit breaker provided in an embodiment of the present application.

DETAILED DESCRIPTION

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

The implementation of the technical solution of the present application is further described in detail below in conjunction with the accompanying drawings.

Referring to FIG. 1 , FIG. 1 is a block diagram of a structure of an electronic device provided in an embodiment of the present application. As shown in FIG. 1 , an electronic device 11 is arranged between a power supply 12 and a load 13, and the electronic device 11 includes a circuit breaker 110 and a control circuit 111. In a specific implementation, the circuit breaker 110 can be connected in series to the positive bus BUS+ between the power supply 12 and the load 13, or the circuit breaker 110 can also be connected in series to the negative bus BUS- between the power supply 12 and the load 13 (not shown in the figure), or the positive bus BUS+ and the negative bus BUS- are respectively connected in series with circuit breakers (not shown in the figure). In general, the present application does not limit the number of circuit breakers and the bus positions where the circuit breakers are set.

The control circuit 111 may establish at least one of an electrical connection or a mechanical connection with the circuit breaker 110. Exemplarily, the circuit breaker 110 is a solid state breaker, and the control circuit 111 is electrically connected to the control end of the solid state switch, and the closing or shutting down of the solid state switch is controlled by controlling the level of the control end of the solid state switch; or, the circuit breaker 110 is a mechanical breaker, and the mechanical switch includes a static contact and a moving contact, the static contact is connected in series to the positive bus BUS+, and there is a mechanical linkage connection relationship between the moving contact and the control circuit 111, and the control circuit 111 may control the closing or shutting down of the mechanical switch by controlling the moving contact of the mechanical switch to contact or separate from the static contact; or, the circuit breaker 110 is a hybrid solid state breaker, which includes both a solid state switch and a mechanical switch, and the control circuit 111 is electrically connected to the control end of the solid state switch and is mechanically linked to the moving contact of the mechanical switch.

The power source 12 may be, for example, a power battery (such as a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-ion battery, a lithium polymer battery, etc.), a storage battery, a photovoltaic panel, or a power grid, etc. Optionally, the power source 12 may also be used to couple an upper level circuit such as an AC/DC converter (Alternating Current/Direct-Current converter) or other DC/DC converters (such as a BUCK converter, a BOOST converter, a BUCK-BOOST converter, etc.). In other words, the power source 12 may be a direct power source or an indirect power source transmitted through a circuit.

The load 13 may be, for example, a photovoltaic inverter, an electric vehicle, other DC/DC converters or a DC/AC converter (Direct-Current/Altemating Current converter), etc.

In some feasible implementations, the control circuit 111 may include various components, which are specifically implemented as various packaged components soldered on a printed circuit board (PCB).

Optionally, in some feasible implementations, the control circuit 111 may be disposed inside the chip, that is, the components included in the control circuit 111 may be made of silicon by doping, exposing, and other processes on silicon. That is, the control circuit 111 may be specifically implemented as a central processing unit (CPU), other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc.

In some feasible implementations, a Rogowski coil may be further provided on the bus (eg, the positive bus BUS+), and the Rogowski coil may detect the current change rate of the positive bus BUS+ and transmit the detected current change rate to the control circuit 111 .

In the embodiment of the present application, the control circuit 111 adopts a different circuit structure to obtain the current change rate of the bus and the current of the bus, and distinguish the fault type of the power supply system according to at least one or more of the relationship between the current change rate of the bus and the first preset threshold, the relationship between the current of the bus and the safety current, and the relationship between the current of the bus and the overload current, so as to control the circuit breaker to take corresponding actions for different fault types, meet the requirements of the current standards for circuit breakers, and have high accuracy and good safety.

The specific structure of the control circuit for the circuit breaker is introduced below in conjunction with the accompanying drawings.

Refer to Figure 2, which is a structural block diagram of a control circuit for a circuit breaker provided in an embodiment of the present application. As shown in Figure 2, the control circuit includes a current change rate comparison module 1110, a locking module 1111, a control module 1112 and a safety current comparison module 1113. Among them, the output end of the current change rate comparison module 1110 is coupled to the input end of the locking module 1111 and the first input end ① of the control module 1112; the output end of the locking module 1111 is coupled to the second input end ② of the control module 1112; the output end of the safety current comparison module 1113 is coupled to the third input end ③ of the control module 1112.

It should be noted that the "coupling" described in this application refers to direct or indirect connection. For example, the coupling between A and B can be either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components, for example, A can be directly connected to C, and C can be directly connected to B, so that A and B are connected through C.

The current change rate comparison module 1110 can output a first comparison signal according to the magnitude relationship between the current change rate of the bus at the current moment and the first preset threshold. Exemplarily, the current change rate of the bus can be expressed as di/dt, and the first preset threshold can be expressed as shortcircuit_min. If at the current moment, di/dt is greater than shortcircuit_min, the first comparison signal is a high level (i.e., 1); if at the current moment, di/dt is less than shortcircuit_min, the first comparison signal is a low level (i.e., 0).

The locking module 1111 outputs a second comparison signal, which is determined according to the magnitude relationship between the current change rate of the bus at the first moment and the first preset threshold. Among them, the first moment is before the current moment and is separated from the current moment by a first preset time length. The locking module 1111 can be specifically implemented as a delay device triggered by a rising edge, and the output of the current change rate comparison module 1110 at the first moment can be locked. That is, at the first moment, di/dt is greater than shortcircuit_min, the output of the current change rate comparison module 1110 at the first moment is a high level (i.e., 1), and the output of the current change rate comparison module 1110 before the first moment is a low level (i.e., 0), then the locking module 1111 monitors the rising edge of the output of the current change rate comparison module 1110 at the first moment, triggering the locking module 1111 to lock the high level within the first preset time length. Optionally, the locking module 1111 may also be provided with an inverter, so that the locking module 1111 outputs a low level (ie, 0) within a first preset time period, and resumes outputting a high level (ie, 1) after the first preset time period.

The first preset time is related to the parameter value selected by the RC in the locking module, for example, the first preset time may be 30 microseconds. In practical applications, the first preset time may be determined according to the standard requirements for lightning strike testing, and different RC parameters may be selected based on different first preset time.

The control module 1112 determines that the power supply system is in the first state when the first comparison signal indicates that the current change rate of the bus at the current moment is greater than the first preset threshold value (i.e., the first comparison signal is 1), and the second comparison signal indicates that the current change rate of the bus at the first moment is greater than the first preset threshold value (i.e., the second comparison signal is 1). In other words, the control module 1112 determines that the power supply system is in the first state when the current change rate of the bus is greater than the first preset threshold value for a period of time of a first preset duration. At this time, the first state of the power supply system can be considered to have occurred a short circuit or normal load shedding.

The safety current comparison module 1113 can output a third comparison signal according to the magnitude relationship between the current of the bus at the current moment and the safety current. Exemplarily, the current of the bus can be expressed as I _BUS , and the safety current can be expressed as I _nom . If I _BUS is greater than I _nom at the current moment, the third comparison signal is a high level (i.e., 1); if I _BUS is less than I _nom at the current moment, the third comparison signal is a low level (i.e., 0). The safety current is related to each device used in the power supply system, that is, the safety current is a device attribute, for example, it can be 500A.

When the power supply system is in the first state and the third comparison signal indicates that the current of the busbar at the current moment is greater than the safety current (i.e., the third comparison signal is 1), the control module 1112 considers that a short circuit occurs in the power supply system and controls the circuit breaker to shut down. Since the circuit breaker is connected in series to the busbar of the power supply system, the control module 1112 controls the circuit breaker to shut down, thereby cutting off the path for the power supply to the load, thereby protecting the power supply system.

In some feasible embodiments, when the power supply system is in the first state and the third comparison signal indicates that the current of the bus at the current moment is less than the safety current (i.e., the third comparison signal is 0), the control module 1112 considers that the power supply system is shedding load normally and no fault has occurred, and there is no need to control the circuit breaker to shut down, i.e., the control module 1112 controls the circuit breaker not to operate.

It should be noted that the present application is based on the control of the power supply system when it is operating normally, that is, the circuit breaker is closed in the default state, and the control module controlling the circuit breaker not to operate can be understood as the control module controlling the circuit breaker to be in a closed state.

In some feasible implementations, the control module 1112 determines that the power supply system is in the second state when the first comparison signal indicates that the current change rate of the bus at the current moment is less than the first preset threshold value (i.e., the first comparison signal is 0), and the second comparison signal indicates that the current change rate of the bus at the first moment is greater than the first preset threshold value (i.e., the second comparison signal is 1). In other words, the control module 1112 determines that the power supply system is in the second state when the current change rate of the bus is greater than the first preset threshold value, but the current change rate of the bus decreases to less than the first preset threshold value after the first preset time. At this time, the second state of the power supply system can be considered to be a lightning strike.

When the power supply system is in the second state, the control module 1112 considers that a lightning strike occurs in the power supply system and controls the circuit breaker not to operate, thereby avoiding an erroneous shutdown of the circuit breaker when a lightning strike occurs.

In the embodiment of the present application, a locking module is added to the control circuit, which can output the current change rate of the bus at the first moment, so that the control circuit can distinguish between lightning strikes and short circuits and normal load shedding in the power supply system according to the magnitude relationship between the current change rate of the bus at the current moment and the first preset threshold, and the magnitude relationship between the current change rate of the bus at the first moment and the first preset threshold; and further distinguish between short circuits and normal load shedding according to the magnitude relationship between the current of the bus and the safety current. That is, the control circuit provided by the embodiment of the present application can distinguish between short circuits, normal load shedding and lightning strikes, so that different operations can be performed for different types of faults, improving the accuracy of the operation and meeting the requirements for circuit breakers in current standards.

Referring to Fig. 3, Fig. 3 is another structural block diagram of a control circuit for a circuit breaker provided in an embodiment of the present application. As shown in Fig. 3, the control circuit further includes an overload current comparison module 1114, the output end of which is coupled to the fourth input end ④ of the control module 1112.

In a specific implementation, the overload current comparison module 1114 can output a fourth comparison signal according to the magnitude relationship between the current of the bus at the current moment and the overload current. Exemplarily, the current of the bus can be expressed as I _BUS , and the overload current can be expressed as I _{overload_max} . If at the current moment, I _BUS is greater than I _{overload_max} , the fourth comparison signal is a high level (i.e., 1); if at the current moment, I _BUS is less than I _{overload_max} , the fourth comparison signal is a low level (i.e., 0). Among them, the overload current is also related to the various components used in the power supply system, but the overload current is greater than the above-mentioned safety current, for example, it can be 1000A. In some feasible implementations, the control module 1112 determines that the power supply system is in the third state when the first comparison signal indicates that the current change rate of the bus at the current moment is less than the first preset threshold value (i.e., the first comparison signal is 0), and the second comparison signal indicates that the current change rate of the bus at the first moment is less than the first preset threshold value (i.e., the second comparison signal is 0). At this time, the third state of the power supply system can be considered to be overloaded or working normally.

For example, when the power supply system is in the third state and the fourth comparison signal indicates that the current current of the bus is greater than the overload current (ie, the fourth comparison signal is 1), the control module 1112 considers that the power supply system is overloaded and controls the circuit breaker to shut down.

For another example, when the power supply system is in the third state and the fourth comparison signal indicates that the current current of the bus is less than the overload current (ie, the fourth comparison signal is 0), the control module 1112 considers that the power supply system is operating normally and controls the circuit breaker not to operate.

To sum up, the power supply circuit provided in the embodiment of the present application can distinguish between short circuit, lightning strike, overload, normal load shedding and normal operation, and can control the circuit breaker to perform different actions for different fault types, meeting the requirements of current standards for circuit breakers, with high accuracy and good safety.

The specific circuit diagram of the control circuit provided in the embodiment of the present application is exemplarily described below in conjunction with Figures 4 to 6.

In some feasible implementations, see Fig. 4, which is a circuit schematic diagram of a control circuit for a circuit breaker provided in an embodiment of the present application. As shown in Fig. 4, the locking module 1111 includes a monostable trigger 1 and a NAND gate _Q41 ; the control module 1112 includes an AND gate _Q42 , an AND gate _Q43 , an AND gate _Q44 , an OR gate _Q45 and a latch _U41 .

In a specific implementation, the output end of the current change rate comparison module 1110 is coupled to the input end of the monostable trigger 1, one input end of the AND gate Q ₄₂ , and the input end of the latch U ₄₁ ; and the output end of the monostable trigger 1 is coupled to the two input ends of the NAND gate Q ₄₁ , and the output end of the NAND gate Q ₄₁ is coupled to the other input end of the AND gate Q ₄₂ ; the output end of the AND gate Q ₄₂ is coupled to one input end of the AND gate Q ₄₃ , and the other input end of the AND gate Q ₄₃ is coupled to the safety current comparison module 1113, and the output end of the AND gate Q ₄₃ is coupled to one input end of the OR gate Q ₄₅ ; one output end of the latch U ₄₁ is coupled to one input end of the AND gate Q ₄₄ , the output end of the overload current comparison module 1114 is coupled to the other input end of the AND gate Q ₄₄ , and the output end of the AND gate Q ₄₄ is coupled to the other input end of the OR gate Q ₄₅ .

Exemplarily, when the control module 1112 believes that a short circuit occurs in the power supply system, the current change rate of the bus at the current moment is greater than the first preset threshold, that is, di/dt＞shortcircuit_min, the first comparison signal output by the current change rate comparison module 1110 at the current moment is a high level (that is, 1), and one input end of the AND gate _Q42 is 1. Moreover, the current change rate of the bus at the first moment is also greater than the first preset threshold, and the output of the current change rate comparison module 1110 at the first moment is also 1, then the trigger monostable trigger 1 maintains the first preset time length from the first moment to the current moment to output a high level (that is, 1) and then returns to a low level (that is, 0). In other words, the NAND gate _Q41 outputs 1 at the current moment, and the other input end of the AND gate _Q42 is also 1. At this time, both input ends of the AND gate _Q42 are 1, and the AND gate _Q42 outputs 1 (that is, one input end of the AND gate _Q43 is 1). In addition, the current of the bus at the current moment is greater than the safety current, that is, I _BUS >I _nom , and the safety current comparison module 1113 outputs a high level (that is, 1), and the other input terminal of the AND gate Q ₄₃ is also 1. In general, both input terminals of the AND gate Q ₄₃ are 1, and the AND gate Q ₄₃ outputs 1 (that is, one input terminal of the OR gate Q ₄₅ is 1), then no matter whether the other input terminal of the OR gate Q ₄₅ is 0 or 1, the output terminal of the OR gate Q ₄₅ (that is, point A) is a high level, and the high level of point A can control the circuit breaker to be turned off.

When the control module 1112 believes that the power supply system is shedding normally, although the first comparison signal output by the current change rate comparison module 1110 is 1 at the current moment, and the second comparison signal output by the locking module 1111 is also 1 at the current moment (i.e., the NAND gate _Q41 also outputs 1), at this time, both input terminals of the AND gate _Q42 are 1, the AND gate _Q42 outputs 1, and one input terminal of the AND gate _Q43 is 1. However, the current of the bus at the current moment is less than the safety current, i.e., I _BUS ＜I _nom , the safety current comparison module 1113 outputs a low level (i.e., 0), and the other input terminal of the AND gate _Q43 is 0. In general, one input terminal of the AND gate Q ₄₃ is 0, and the AND gate Q ₄₃ outputs 0 (that is, one input terminal of the OR gate Q ₄₅ is 0), and the overload current is greater than the safety current, that is, I _nom <I _{overload_max} , then I _BUS <I _{overload_max} , the overload current comparison module 1114 outputs a low level (that is, 0), so that one input terminal of the AND gate Q ₄₄ is 0, and the AND gate Q ₄₄ outputs 0 (that is, the other input terminal of the OR gate Q ₄₅ is also 0), therefore, the output terminal of the OR gate Q ₄₅ (that is, point A) is a low level, and point A is a low level.

It should be noted that the present application is based on the control when the power supply system is operating normally, that is, the circuit breaker is closed in the default state. At this time, the low level at point A can also be understood as the control circuit breaker not operating.

The control module 1112 believes that when a lightning strike occurs in the power supply system, the current change rate of the busbar at the current moment is less than the first preset threshold value, that is, di/dt＜shortcircuit_min, and the first comparison signal output by the current change rate comparison module 1110 at the current moment is a low level (that is, 0). At this time, one input terminal of the AND gate _Q42 is 0, and the AND gate _Q42 outputs 0 (that is, one input terminal of the AND gate _Q43 is 0), and the AND gate _Q43 outputs 0 (that is, one input terminal of the OR gate _Q45 is 0). In addition, the current change rate of the bus at the first moment is greater than the first preset threshold value, and the current change rate comparison module 1110 outputs 1 at the first moment. The latch U ₄₁ is triggered by the rising edge, so the latch U ₄₁ outputs 0 to the AND gate Q ₄₄ from the first moment, so that one input end of the AND gate Q ₄₄ is 0, and the AND gate Q ₄₄ outputs 0 (that is, the other input end of the OR gate Q ₄₅ is also 0). Therefore, the output end of the OR gate Q ₄₅ (that is, point A) is a low level, and point A is a low level, so the control circuit breaker does not operate and the circuit breaker is maintained closed.

When the control module 1112 considers that the power supply system is overloaded, the current change rate of the bus at the first moment is less than the first preset threshold value, and the current change rate of the bus at the current moment is also less than the first preset threshold value, that is, di/dt＜shortcircuit_min, the current change rate comparison module 1110 outputs a low level (that is, 0) at both the current moment and the first moment, and the latch U ₄₁ is triggered by the rising edge, so the latch U ₄₁ outputs 1 to the AND gate Q ₄₄ from the first moment to the current moment, so that one input end of the AND gate Q ₄₄ is 1. In addition, the current of the bus at the current moment is greater than the overload current, that is, I _BUS ＞I _{overload_max} , the overload current comparison module 1114 outputs 1, and the other input end of the AND gate Q ₄₄ is also 1. In general, both input terminals of AND gate Q ₄₄ are 1, and AND gate Q ₄₄ outputs 1 (i.e., one input terminal of OR gate Q ₄₅ is 1). Then, regardless of whether the other input terminal of OR gate Q ₄₅ is 0 or 1, the output terminal of OR gate Q ₄₅ (i.e., point A) is at a high level. Point A being at a high level can control the circuit breaker to be turned off.

When the control module 1112 believes that the power supply system is working normally, the current change rate of the bus at the first moment is less than the first preset threshold value, and the current change rate of the bus at the current moment is also less than the first preset threshold value, that is, di/dt＜shortcircuit_min, and the current change rate comparison module 1110 outputs a low level (that is, 0) at both the current moment and the first moment. At this time, if one input terminal of the AND gate _Q42 is 0, the AND gate _Q42 outputs 0 (that is, one input terminal of the AND gate _Q43 is 0), and the AND gate _Q43 outputs 0 (that is, one input terminal of the OR gate _Q45 is 0). Moreover, the current of the bus at the current moment is less than the overload current, that is, I _BUS <I _{overload_max} , and the overload current comparison module 1114 outputs 0, then the other input terminal of the AND gate Q ₄₄ is also 0, and the AND gate Q ₄₄ outputs 0 (that is, one input terminal of the OR gate Q ₄₅ is 0), and both input terminals of the OR gate Q ₄₅ are 0, then the output terminal of the OR gate Q ₄₅ (that is, point A) is a low level, and point A is a low level, the control circuit breaker does not operate, and the circuit breaker is maintained closed.

In some feasible implementations, the circuit breaker provided in the embodiments of the present application may be a hybrid circuit breaker, including a mechanical switch and a solid-state switch connected in parallel with the mechanical switch. It can be seen that the use of a hybrid circuit breaker can combine the advantages of low conduction loss of the mechanical switch and high speed of the solid-state switch.

The control module provided in the embodiment of the present application further includes a mechanical control submodule and a delay submodule. The mechanical control submodule can control the mechanical switch to turn off, and the delay submodule can delay the solid-state switch to turn off after the mechanical switch is turned off for a second preset time. For specific circuit implementation, see Figures 5A to 5B.

For example, see Fig. 5A, which is a schematic diagram of a portion of a circuit of a control module provided in an embodiment of the present application. As shown in Fig. 5A, the mechanical control submodule 11121 includes a latch _U51 and the control module 1112 shown in Fig. 4 above, and the delay submodule 11122A may include a monostable trigger 2, a NAND gate _Q51 , an AND gate _Q52 , and a latch _U52 .

Among them, point A described in FIG4 is coupled to the input end of latch _U51 , and the level of one output end (i.e., point B) of latch _U51 controls the closing or closing of the mechanical switch. Point B is coupled to the input end of monostable trigger 2 and one input end of AND gate _Q52 , the output end of monostable trigger 2 is coupled to the two input ends of NAND gate _Q51 , the output end of NAND gate _Q51 is coupled to the other input end of AND gate _Q52 , the output end of AND gate _Q52 is coupled to the input end of latch _U52 , and the level of one output end (i.e., point C) of latch _U52 controls the closing or closing of the solid-state switch. In the circuit schematic diagram shown in FIG5A , when the level output at point B of the mechanical control submodule 11121 is high, the mechanical switch is controlled to be turned off, triggering the monostable trigger 2 to maintain the output of a high level for a second preset time and then recover to a low level, then the NAND gate _Q51 correspondingly maintains the output of a low level for a second preset time and then recovers to a high level, and when the NAND gate _Q51 recovers to output a high level, the AND gate _Q52 outputs a high level, triggering an output terminal (i.e., point C) of the latch _U52 to output a low level, thereby controlling the solid-state switch to be turned off.

Further, referring to FIG. 5B , the difference between the circuit schematic diagram shown in FIG. 5B and the circuit schematic diagram shown in FIG. 5A is that the delay submodule 11122B in FIG. 5B further includes a commutation state judgment submodule, one input end of the AND gate Q ₅₂ is coupled to the output end of the NAND gate Q ₅₁ , and the other input end of the AND gate Q ₅₂ is coupled to the output end of the commutation state judgment submodule. The commutation state judgment submodule is specifically used to judge the magnitude relationship between the current passing through the mechanical switch during the mechanical switch off process and the preset reference current. For example, when the current passing through the mechanical switch during the mechanical switch off process is less than the preset reference current, the commutation state judgment submodule outputs a high level (i.e., 1), and the AND gate Q ₅₂ can output a high level after the second preset of the high level output at point B, triggering an output end (i.e., point C) of the latch U ₅₂ to output a low level, and controlling the solid-state switch to turn off. The magnitude of the preset reference current is preset according to the specific use of the power supply system, for example, it can be 50A.

Exemplarily, an interlocking device (not shown in the figure) may be provided at point B and point C so that the mechanical switch does not operate when the solid-state switch is in the off state.

In some feasible implementations, see FIG. 6 , which is another circuit schematic diagram of a control circuit for a circuit breaker provided in an embodiment of the present application. As shown in FIG. 6 , in the embodiments described in conjunction with FIG. 4 to FIG. 5B , the control module provided in an embodiment of the present application further includes an AND gate Q ₆₁ , an AND gate Q ₆₂ and an OR gate Q ₆₃ . Among them, one input end of the AND gate Q ₆₁ is coupled to the current change rate comparison module 1110, another input end of the AND gate Q ₆₁ is coupled to the overload current comparison module 1114, the output end of the AND gate Q ₆₁ is coupled to one input end of the AND gate Q ₆₂ , the other input end of the AND gate Q ₆₂ is used to receive a closing instruction for the circuit breaker, the output end of the AND gate Q ₆₂ is coupled to one input end of the OR gate Q ₆₃ , the other input end of the OR gate Q ₆₃ is coupled to the output end of the AND gate Q ₅₂ , and the output end of the OR gate Q ₆₃ is coupled to the latch U ₅₂ .

The embodiment of the present application adds a method of controlling the solid-state switch to turn off by setting an OR gate Q ₆₃ between the AND gate Q ₅₂ and the latch U _52. In a specific implementation, the other input end of the AND gate Q ₆₂ receives a closing command for the circuit breaker (i.e., the other input end of the AND gate Q ₆₂ is 1), and the solid-state switch is closed first. However, if a fault occurs in the power supply system, i.e., the current change rate of the bus at the current moment is greater than the first preset threshold value (i.e., the current change rate comparison module 1110 outputs 1), and the current of the bus at the current moment is greater than the overload current (i.e., the overload current comparison module 1114 outputs 1), both input ends of the AND gate Q ₆₁ are 1, and the AND gate Q ₆₁ outputs 1, so that one input end of the AND gate Q ₆₂ is 1. In addition, the other input end of the AND gate Q ₆₂ receives the closing command for the circuit breaker (i.e., the other input end of the AND gate Q ₆₂ is also 1), the AND gate Q ₆₂ outputs 1, the OR gate Q ₆₃ outputs 1, and one output end of the latch U ₅₂ (i.e., point D) outputs a low level, controlling the solid-state switch to turn off.

Optionally, if there is no fault in the power supply system, that is, the current change rate of the bus at the current moment is less than the first preset threshold value (that is, the current change rate comparison module 1110 outputs 0), or the current of the bus at the current moment is less than the overload current (that is, the overload current comparison module ₁₁₁₄ outputs 0), any input end of the AND gate _Q61 is 0, and the AND gate Q61 outputs 0, so that one input end of the AND gate _Q62 is 0, and the AND gate _Q62 outputs 0, and the AND gate _Q61 and the AND gate _Q62 branch are invalidated, and the control circuit can continue to control the mechanical switch to close.

Since the hybrid circuit breaker closes the solid-state switch first and then the mechanical switch when closing, in the event of a short circuit during the closing process, the solid-state switch is turned off instead of continuing to close the mechanical switch in the embodiment of the present application.

It is understandable that the circuits shown in FIG. 4 to FIG. 6 are only exemplary illustrations, and other circuit expressions may be possible, for example, a NAND gate may be specifically composed of a connection between an AND gate and a NOT gate, a monostable trigger may be a time delay device, etc. The safety current comparison module, the current change rate comparison module, and the overload current comparison module may refer to the application of comparators in the prior art, and will not be described in detail here.

In some feasible implementations, the circuits shown in Figures 4 to 6 may be made of silicon by performing doping, exposure, and other processes on silicon. That is, the control of the circuit breaker in the embodiment of the present application may be specifically implemented by a controller.

The controller can determine that the power supply system is in a first state when the current change rate of the bus at the current moment is greater than a first preset threshold, and the current change rate of the bus at the first moment is greater than the first preset threshold; wherein the first moment is before the current moment and is separated from the current moment by a first preset time length.

For example, when the power supply system is in the first state and the current of the busbar at the current moment is greater than the safety current, the controller controls the circuit breaker to turn off.

For another example, when the power supply system is in the first state, if the current of the busbar at the current moment is less than the safety current, the controller controls the circuit breaker not to operate.

In some feasible embodiments, the controller determines that the power supply system is in the second state when the current change rate of the bus at the current moment is less than the first preset threshold and the current change rate of the bus at the first moment is greater than the first preset threshold; and when the power supply system is in the second state, the control circuit breaker does not operate.

Optionally, the controller determines that the power supply system is in the third state when the current change rate of the bus at the current moment is less than a first preset threshold, and the current change rate of the bus at the first moment is less than the first preset threshold; and when the power supply system is in the third state and the current of the bus at the current moment is greater than the overload current, the controller controls the circuit breaker to shut down, wherein the overload current is greater than the safety current.

Alternatively, when the power supply system is in the third state and the current of the bus at the current moment is less than the overload current, the controller controls the circuit breaker not to operate.

In some feasible implementations, the circuit breaker includes a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; the solid-state switch is closed first during the closing process of the circuit breaker. Before determining that the power supply system is in the first state, the controller controls the solid-state switch to be turned off during the process of controlling the closing of the circuit breaker if the current change rate of the bus at the current moment is greater than the first preset threshold value and the current of the bus at the current moment is greater than the overload current.

Optionally, when the controller is controlling the circuit breaker to close, if the current change rate of the busbar at the current moment is less than the first preset threshold, or the current of the busbar at the current moment is less than the overload current, the controller continues to control the mechanical switch to close.

In some feasible implementations, the controller controls the mechanical switch to turn off, and controls the solid-state switch to turn off after delaying a second preset time period after controlling the mechanical switch to turn off.

Furthermore, the controller obtains the current passing through the mechanical switch during the process of controlling the mechanical switch to turn off; and when the current passing through the mechanical switch is less than a preset reference current, the controller delays for a second preset time to control the solid-state switch to turn off.

Optionally, the controller may control the mechanical switch to not operate when the solid-state switch is in an off state.

In the embodiment of the present application, the control of the circuit breaker is specifically implemented by a controller. The signal data flow inside the controller can refer to the embodiment described in the previous text in combination with Figures 2 to 6, and the technical effects of the embodiment described in the previous text in combination with Figures 2 to 6 can be achieved, which will not be repeated here.

It should be noted that the above terms “first” and “second” are only used for descriptive purposes and should not be understood as indicating or implying relative importance.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (19)

1. A control circuit for a circuit breaker, characterized in that the circuit breaker is connected in series to a busbar of a power supply system, and the control circuit comprises a current change rate comparison module, a locking module, a control module, an overload current comparison module and a safety current comparison module; wherein the output end of the current change rate comparison module is coupled to the input end of the locking module and the first input end of the control module; the output end of the locking module is coupled to the second input end of the control module; the output end of the safety current comparison module is coupled to the third input end of the control module, and the output end of the overload current comparison module is coupled to the fourth input end of the control module; The current change rate comparison module is used to output a first comparison signal according to the magnitude relationship between the current change rate of the bus at the current moment and a first preset threshold; The locking module is used to output a second comparison signal; the second comparison signal is output after determining and locking a first preset time length according to the magnitude relationship between the current change rate of the bus at the first moment and the first preset threshold; wherein the first moment is before the current moment and is separated from the current moment by the first preset time length; The control module is configured to determine that the power supply system is in the first state when the first comparison signal indicates that the current change rate of the bus at the current moment is greater than the first preset threshold, and the second comparison signal indicates that the current change rate of the bus at the first moment is greater than the first preset threshold; The safety current comparison module is used to output a third comparison signal according to the magnitude relationship between the current of the bus at a current moment and the safety current; The control module is further configured to control the circuit breaker to be turned off when the power supply system is in the first state and the third comparison signal indicates that the current of the bus at a current moment is greater than the safety current; The overload current comparison module is used to output a fourth comparison signal according to the magnitude relationship between the current of the bus at the current moment and the overload current; wherein the overload current is greater than the safety current; The control module is further configured to determine that the power supply system is in the third state when the first comparison signal indicates that the current change rate of the bus at the current moment is less than the first preset threshold, and the second comparison signal indicates that the current change rate of the bus at the first moment is less than the first preset threshold; The control module is further configured to control the circuit breaker to be turned off when the power supply system is in the third state and the fourth comparison signal indicates that the current of the bus at the current moment is greater than the overload current; Wherein, the locking module includes a monostable trigger 1 and a NAND gate , the control module includes an AND gate , AND gate , AND gate , OR gate and latch The output end of the current change rate comparison module is coupled to the input end of the monostable trigger 1, the AND gate An input terminal of the latch The input end of the monostable trigger 1 is coupled to the NAND gate The two input terminals of the NAND gate The output terminal of the AND gate is coupled The other input terminal of the AND gate The output terminal of the AND gate is coupled One input terminal of the AND gate The other input terminal is coupled to the safety current comparison module, and the AND gate The output terminal of the OR gate is coupled One input terminal of the latch One output terminal of the AND gate is coupled to An input terminal of the overload current comparison module is coupled to the AND gate The other input terminal of the AND gate The output terminal of the OR gate is coupled The other input terminal of the OR gate as the output end of the control module. 2. The control circuit according to claim 1, characterized in that: The control module is further configured to determine that the power supply system is in the second state when the first comparison signal indicates that the current change rate of the bus at the current moment is less than the first preset threshold, and the second comparison signal indicates that the current change rate of the bus at the first moment is greater than the first preset threshold; The control module is further configured to control the circuit breaker not to operate when the power supply system is in the second state. 3. The control circuit according to claim 1, characterized in that: The control module is further configured to control the circuit breaker not to operate when the power supply system is in the first state and the third comparison signal indicates that the current of the bus at a current moment is less than the safety current. 4. The control circuit according to claim 1, characterized in that: The control module is further used to control the circuit breaker not to operate when the power supply system is in the third state and the fourth comparison signal indicates that the current of the bus at a current moment is less than the overload current. 5. The control circuit according to any one of claims 1 to 4, characterized in that the circuit breaker comprises a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; the solid-state switch is closed first during the closing process of the circuit breaker; The control module is also used to control the solid-state switch to shut down if the current change rate of the bus at a current moment is greater than the first preset threshold, or the current of the bus at a current moment is greater than the overload current during the closing process of the circuit breaker. 6. The control circuit according to claim 5, characterized in that: The control module is also used to continue controlling the mechanical switch to close if the current change rate of the busbar at a current moment is less than the first preset threshold and the current of the busbar at a current moment is less than the overload current during the closing process of the circuit breaker. 7. The control circuit according to any one of claims 1 to 4, characterized in that the circuit breaker comprises a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; The control module also includes a mechanical control submodule and a delay submodule; wherein, The mechanical control submodule is used to control the mechanical switch to turn off, and the delay submodule is used to delay the second preset time length after the mechanical switch is turned off to control the solid-state switch to turn off. 8. The control circuit according to claim 7, characterized in that the delay submodule is used to delay the solid-state switch to turn off for a second preset time after the mechanical switch is turned off, specifically comprising: The delay submodule is used to delay the second preset time length to control the solid-state switch to turn off when the current passing through the mechanical switch during the mechanical switch turning off process is less than the preset reference current. 9 . The control circuit according to claim 5 , wherein when the solid-state switch is in an off state, the mechanical switch does not operate. 10. A control method for a circuit breaker, characterized in that the method is applicable to the control circuit according to any one of claims 1 to 9, the circuit breaker is connected in series to a busbar of a power supply system, and the control method comprises: When the current change rate of the bus at the current moment is greater than the first preset threshold, and the current change rate of the bus at the first moment is greater than the first preset threshold and locked for a first preset time, it is determined that the power supply system is in the first state; wherein the first moment is before the current moment and is separated from the current moment by a first preset time; When the power supply system is in the first state and the current of the busbar at the current moment is greater than the safety current, the circuit breaker is controlled to be turned off; When the current change rate of the bus at the current moment is less than the first preset threshold, and the current change rate of the bus at the first moment is less than the first preset threshold, it is determined that the power supply system is in the third state; When the power supply system is in the third state and the current of the busbar at a current moment is greater than the overload current, the circuit breaker is controlled to be turned off; wherein the overload current is greater than the safety current. 11. The control method according to claim 10, characterized in that the control method further comprises: The current change rate of the bus at the current moment is less than the first preset threshold, and the current change rate of the bus at the first moment is greater than the first preset threshold, determining that the power supply system is in the second state; When the power supply system is in the second state, the circuit breaker is controlled not to operate. 12. The control method according to claim 10, characterized in that the control method further comprises: When the power supply system is in the first state, if the current of the busbar at a current moment is less than the safety current, the circuit breaker is controlled not to operate. 13. The control method according to claim 10, characterized in that the control method further comprises: When the power supply system is in the third state and the current of the busbar at a current moment is less than the overload current, the circuit breaker is controlled not to operate. 14. The control method according to any one of claims 10 to 13, characterized in that the circuit breaker comprises a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; the solid-state switch is closed first during the closing process of the circuit breaker; Before determining that the power supply system is in the first state, the control method further includes: During the closing process of the circuit breaker, if the current change rate of the busbar at the current moment is greater than the first preset threshold, or the current of the busbar at the current moment is greater than the overload current, the solid-state switch is controlled to be turned off. 15. The control method according to claim 14, characterized in that the control method further comprises: During the process of closing the circuit breaker, if the current change rate of the busbar at the current moment is less than the first preset threshold value, and the current of the busbar at the current moment is less than the overload current, the mechanical switch continues to be controlled to close. 16. The control method according to any one of claims 10 to 13, characterized in that the circuit breaker comprises a mechanical switch and a solid-state switch connected in parallel with the mechanical switch; The controlling the circuit breaker to shut down specifically includes: The mechanical switch is controlled to be turned off, and after the mechanical switch is controlled to be turned off, a second preset time period is delayed to control the solid-state switch to be turned off. 17. The control method according to claim 16, characterized in that the delaying a second preset time length after controlling the mechanical switch to turn off to control the solid-state switch to turn off specifically comprises: In the process of controlling the mechanical switch to be turned off, obtaining the current passing through the mechanical switch; When the current passing through the mechanical switch is less than a preset reference current, the second preset time period is delayed to control the solid-state switch to turn off. 18. The control method according to claim 14, wherein when the solid-state switch is in an off state, the mechanical switch does not operate. 19. An electronic device, characterized in that the electronic device comprises a circuit breaker and a control circuit for the circuit breaker according to any one of claims 1 to 9.