CN114509708A

CN114509708A - Power system, magnetic induction module, magnetic induction intensity detection device, and transformer

Info

Publication number: CN114509708A
Application number: CN202210007668.3A
Authority: CN
Inventors: 樊孝斌; 刘建斌
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2022-01-06
Filing date: 2022-01-06
Publication date: 2022-05-17

Abstract

The application provides a power system, a magnetic induction component, a magnetic induction intensity detection device and a transformer, which can inhibit the generation of excitation surge current. The power system comprises a first switch, a transformer, a magnetic induction assembly and a control circuit; a first end of the first switch is coupled to the first power supply, and a second end of the first switch is coupled to the electric load through the transformer; the magnetic induction component generates a voltage parameter under the induction of the residual magnetic induction intensity of the transformer and sends the voltage parameter to the control circuit; the voltage parameter is used for determining the residual magnetic induction intensity of the transformer by the control circuit; the control circuit determines at least one target input voltage based on the relationship between the set voltage of the input transformer and the magnetic induction intensity generated by the transformer; the first magnetic induction intensity corresponding to the target input voltage is the same as the residual magnetic induction intensity in size and opposite in direction; and controlling the first switch to enable the initial voltage of the alternating current input into the transformer to be any one of the at least one target input voltage.

Description

Power system, magnetic induction module, magnetic induction intensity detection device, and transformer

Technical Field

The application relates to the technical field of electronics, especially, relate to electric power system, magnetic induction subassembly, magnetic induction intensity detection device and transformer.

Background

Typically, the power system includes a transformer. Because of the residual magnetic induction intensity of the magnetic core of the transformer, when the transformer is put into operation, the magnetic induction intensity of the magnetic core of the transformer is saturated, so that impact current is caused, namely, magnetizing inrush current is generated. The magnetizing inrush current not only increases the heat productivity of the magnetic core of the transformer, but also affects the service life of the transformer. In addition, the magnetizing inrush current contains a large number of higher harmonics, which affects the power quality of the power system.

The existing scheme is generally to change the internal structure of the transformer to weaken the magnetizing inrush current generated when the transformer is put into operation. Or the resistor is connected in series outside the transformer to weaken the magnetizing inrush current generated when the transformer is put into operation. The existing scheme can only reduce the influence of the magnetizing inrush current and cannot eliminate the phenomenon of generating the magnetizing inrush current no matter the internal structure or the external structure of the transformer is changed.

Disclosure of Invention

The application provides a power system, a magnetic induction module, a magnetic induction intensity detection device and a transformer, which can restrain the generation of excitation surge current.

In a first aspect, an embodiment of the present application provides an electric power system, which may include a first switch, a transformer, a magnetic induction component, and a control circuit. The first switch has a first terminal coupled to a first power source and a second terminal coupled to an electrical load through the transformer. The first power source is capable of providing alternating current to the power system. The magnetic induction component may be configured to generate a voltage parameter under the induction of the remaining magnetic induction of the transformer, and send the voltage parameter to the control circuit, where the voltage parameter is used for the control circuit to determine the remaining magnetic induction of the transformer. The control circuit may be configured to determine at least one target input voltage based on a set relationship between a voltage input to the transformer and a magnetic induction generated by the transformer, where a first magnetic induction corresponding to the target input voltage is the same as and opposite to the residual magnetic induction. And controlling the first switch to enable the initial voltage of the alternating current input into the transformer to be any one of the at least one target input voltage.

In the embodiment of the application, the voltage parameter provided by the magnetic induction component in the power system can be used for the control circuit to determine the residual magnetic induction intensity of the transformer. The control circuit can control the first switch, and the initial voltage of the alternating current input into the transformer can be the target input voltage after the first switch is conducted. The magnetic induction intensity generated by the transformer under the action of the target input voltage is the first magnetic induction intensity corresponding to the target input voltage, the first magnetic induction intensity is the same as the residual magnetic induction intensity in size, and the first magnetic induction intensity and the residual magnetic induction intensity are opposite in direction, so that the total magnetic induction intensity of the transformer is zero when the transformer is put into use and is smaller than the saturated magnetic induction intensity of the transformer, and the transformer cannot generate excitation inrush current.

In one possible design, when the magnetic induction assembly includes a hall element, the voltage parameter represents a voltage formed by an operating current in the hall element under the action of a residual magnetic induction of the transformer; or when the magnetic induction component comprises a magnetic resistance circuit, the equivalent resistance of the magnetic resistance circuit is changed under the action of the residual magnetic induction intensity of the transformer, wherein the ratio of the working voltage of the magnetic resistance circuit to the voltage parameter represents the variation of the equivalent resistance of the magnetic resistance circuit.

In the embodiment of the present application, the magnetic induction component may include a hall element or a magnetoresistive circuit. The voltage parameter provided by the magnetic induction component can represent the Hall voltage formed by the Hall element under the action of the residual magnetic induction intensity of the transformer. Or may characterize the amount of equivalent resistance change of the magnetoresistive circuit. In a visible power system, the control circuit and the magnetic induction assembly can realize detection of the residual magnetic induction intensity of the transformer together.

In one possible design, the magnetic induction assembly includes a hall element. The control circuit can also determine the magnetic induction intensity corresponding to the voltage parameter as the residual magnetic induction intensity of the transformer based on the set relation among the voltage of the Hall element, the working current and the magnetic induction intensity. The control circuit and the magnetic induction component in the power system provided by the embodiment of the application can realize detection of the residual magnetic induction intensity of the transformer together.

In one possible design, the magnetic induction component includes a magnetoresistive circuit. The control circuit may further determine, based on a set relationship between a variation of an equivalent resistance of the magnetoresistive circuit and magnetic induction, magnetic induction corresponding to a target variation as remaining magnetic induction of the transformer, where the target variation is a ratio of the voltage parameter to a working voltage of the magnetoresistive circuit. In the power system provided by the embodiment of the application, the control circuit and the magnetic induction component can be used for detecting the residual magnetic induction intensity of the transformer together.

In one possible approach, the control circuit is further configured to: after the at least one target input voltage is determined and before a first switch is controlled, determining the closing time of the first switch, wherein the initial voltage of the alternating current at the closing time is the same as any target input voltage; when the control circuit controls the first switch, the control circuit is specifically configured to: and controlling the first switch to be in a conducting state at the closing moment.

In a second aspect, an embodiment of the present application further provides an electric power system, which may include a transformer, an inverter circuit, a magnetic induction component, and a control circuit. One end of the transformer is coupled with the inverter circuit, and the other end of the transformer is coupled with an electric load. The inverter circuit may output an alternating current under the control of the control circuit. The transformer may convert power of the ac power supplied from the inverter circuit and supply the converted ac power to the power load. The magnetic induction component can generate a voltage parameter under the induction of the residual magnetic induction of the transformer, and send the voltage parameter to the control circuit, wherein the voltage parameter is used for the control circuit to determine the residual magnetic induction of the transformer. The control circuit may determine a target output voltage based on a set relationship between a voltage of the transformer and a magnetic induction generated by the transformer, wherein a first magnetic induction corresponding to the target output voltage is a difference between a maximum magnetic induction of the transformer and a residual magnetic induction, and the maximum magnetic induction of the transformer is smaller than a saturation magnetic induction of the transformer. And controlling the inverter circuit to enable the initial voltage of the alternating current output by the inverter circuit to be the target output voltage.

In the embodiment of the application, the voltage parameter provided by the magnetic induction component in the power system can be used for the control circuit to determine the residual magnetic induction intensity of the transformer. The control circuit can control the inverter circuit to enable the output voltage of the inverter circuit to be the target output voltage. The magnetic induction intensity generated by the transformer under the action of the target output voltage is the first magnetic induction intensity. The sum of the first magnetic induction and the residual magnetic induction of the transformer is the maximum magnetic induction of the transformer and is less than the saturation magnetic induction of the transformer. The magnetic induction intensity of the transformer when the transformer is put into operation is smaller than the saturation magnetic induction intensity, so that the transformer cannot generate excitation inrush current.

In one possible design, the magnetic induction assembly includes a hall element. The control circuit is further configured to: and determining the magnetic induction intensity corresponding to the voltage parameter as the residual magnetic induction intensity of the transformer based on the set relation among the voltage of the Hall element, the working current and the magnetic induction intensity. The control circuit and the magnetic induction component in the power system provided by the embodiment of the application can realize detection of the residual magnetic induction intensity of the transformer together.

In one possible design, the magnetic induction component includes a magnetoresistive circuit. The control circuit is further configured to determine, based on the set relationship between the variation of the equivalent resistance of the magnetoresistive circuit and the magnetic induction intensity, the magnetic induction intensity corresponding to the target variation as the residual magnetic induction intensity of the transformer, where the target variation is a ratio of the voltage parameter to the operating voltage of the magnetoresistive circuit. The control circuit and the magnetic induction component in the power system provided by the embodiment of the application can realize detection of the residual magnetic induction intensity of the transformer together.

In a third aspect, an embodiment of the present application further provides an electric power system, including: the power supply device comprises a first power supply branch circuit, a second power supply branch circuit, a first switch, a second switch, a transformer, a magnetic induction assembly and a control circuit. The first power supply branch is coupled with a first power supply, and the first power supply branch is coupled with a user load through the first switch; the first power supply is capable of providing a first alternating current to the first power supply branch; the first power supply branch is used for transmitting the first alternating current to the first switch. The second power supply branch is coupled with a second power supply; the second power supply branch is coupled with one end of the transformer through the second switch; the other end of the transformer is coupled with the user load; the second power supply is capable of providing a first direct current to the second supply direct current; the second power supply branch is used for converting the first direct current into second alternating current and then transmitting the second alternating current to the second switch. The magnetic induction assembly is used for generating a voltage parameter under the induction of the residual magnetic induction of the transformer and sending the voltage parameter to the control circuit, and the voltage parameter is used for the control circuit to determine the residual magnetic induction of the transformer. The control circuit can be used for determining at least one target input voltage based on a set relation between the voltage input into the transformer and the magnetic induction intensity generated by the transformer, wherein the first magnetic induction intensity corresponding to the target input voltage is the same as the residual magnetic induction intensity in magnitude and opposite in direction; controlling the first switch to enable the initial voltage of the first alternating current input into the transformer to be any one target input voltage in the at least one target input voltage; or, the control circuit may determine a target output voltage of the second power supply branch based on the set relationship between the voltage input to the transformer and the magnetic induction generated by the transformer, where a second magnetic induction corresponding to the target output voltage is a difference between a maximum magnetic induction of the transformer and the residual magnetic induction, and the maximum magnetic induction of the transformer is smaller than a saturated magnetic induction of the transformer; and controlling the second power supply branch to enable the initial voltage of the second alternating current output by the second power supply branch to be the target output voltage.

In the embodiment of the application, the voltage parameter provided by the magnetic induction component in the power system can be used for the control circuit to determine the residual magnetic induction intensity of the transformer. When the first power supply supplies power to the electric load, the control circuit can control the first switch, and the initial voltage of the alternating current input into the transformer can be the target input voltage after the first switch is conducted. The magnetic induction intensity generated by the transformer under the action of the target input voltage is the first magnetic induction intensity corresponding to the target input voltage, the first magnetic induction intensity is the same as the residual magnetic induction intensity in size, and the first magnetic induction intensity and the residual magnetic induction intensity are opposite in direction, so that the total magnetic induction intensity of the transformer is zero when the transformer is put into use and is smaller than the saturated magnetic induction intensity of the transformer, and the transformer cannot generate excitation inrush current. When the second power supply supplies power to the power load, the control circuit can control the inverter circuit to enable the output voltage of the inverter circuit to be the target output voltage. The magnetic induction intensity generated by the transformer under the action of the target output voltage is the first magnetic induction intensity. The sum of the first magnetic induction and the residual magnetic induction of the transformer is the maximum magnetic induction of the transformer and is less than the saturation magnetic induction of the transformer. The magnetic induction intensity of the transformer when the transformer is put into operation is smaller than the saturation magnetic induction intensity, so that the transformer cannot generate excitation inrush current.

In one possible design, the first power source includes one or more of an ac power grid or a first energy conversion device; the first energy conversion device is used for converting non-electric energy into alternating current electric energy.

In one possible design, when the first power source includes the ac power grid and the first energy conversion device, the first power supply branch further includes a switching module; the switching module is coupled to the ac power grid and the first energy conversion device, and coupled to the first switch, respectively, and is configured to output the first ac power provided by the ac power grid or the first ac power provided by the first energy conversion device to the first switch.

In one possible design, the second power supply branch comprises an inverter circuit; the inverter circuit is used for converting the direct current provided by the second power supply into the second alternating current.

In one possible design, the second power source includes one or more of a second energy conversion device and an energy storage device; the second energy conversion device is used for converting non-electric energy into direct current and supplying the direct current to the inverter circuit; and the energy storage device is used for providing direct current to the inverter circuit.

In a fourth aspect, an embodiment of the present application further provides a magnetic induction assembly, which may include a hall element and a processing circuit; the Hall element is arranged on a magnetic core of the transformer or in an air gap of the magnetic core; the processing circuit may be configured to provide a set operating current to the hall element; the current direction of the working current is vertical to the magnetic induction intensity direction of the transformer during working, and the working current forms a first voltage at the Hall element under the action of the residual magnetic induction intensity of the transformer; the first ratio of the first voltage to the working current has a linear relation with the residual magnetic induction. Sending the first voltage to a controller communicatively coupled to the processing circuit, wherein the first voltage is used by the controller to determine a residual magnetic induction of the transformer.

In one possible design, a ratio of the first ratio to the residual magnetic induction strength is the same as a second ratio of a hall coefficient of the hall element to a thickness of the hall element.

In a fifth aspect, embodiments of the present application provide a magnetic induction assembly that may include a magnetoresistive circuit and a processing circuit, the magnetoresistive circuit being disposed on a core of a transformer or within an air gap of the core; the magnetic resistance circuit comprises a first series branch formed by connecting a first magnetic resistance and a second magnetic resistance in series and a second series branch formed by connecting a third magnetic resistance and a fourth magnetic resistance in series; the first end of the first series branch is connected with the first end of the second series branch, and the second end of the first series branch and the second end of the second series branch are respectively grounded; the first end of the first series branch is configured to receive an operating voltage provided by the processing circuit; the processing circuitry may provide a set operating voltage to the magnetoresistive circuitry; collecting a voltage difference, wherein the voltage difference is a difference value between a first voltage at one end connected with the first magnetic resistance and the second magnetic resistance and a second voltage at one end connected with the third magnetic resistance and the fourth magnetic resistance; the equivalent resistance of the reluctance circuit is changed under the action of the residual magnetic induction intensity of the transformer, and the variation of the equivalent resistance of the reluctance circuit is the same as the ratio of the voltage difference to the working voltage; the variation and the residual magnetic induction intensity have a linear relation; sending the voltage difference to a controller communicatively coupled to the processing circuit, the voltage difference being used by the controller to determine a residual magnetic induction of the transformer.

In one possible design, the magnetoresistive circuit includes one or more of a tunnel magnetoresistive sensor (TMR), an Anisotropic Magnetoresistive (AMR), and a Giant Magnetoresistive (GMR).

In a sixth aspect, an embodiment of the present application provides a magnetic induction intensity detection apparatus, including a magnetic induction assembly and a controller; the Hall element of the magnetic induction assembly is arranged on a magnetic core of the transformer or in an air gap of the magnetic core; the magnetic induction component is used for sending a first voltage, and the first voltage represents a voltage formed by working current in the Hall element under the action of residual magnetic induction of the transformer; the controller may receive the first voltage; and determining the magnetic induction intensity corresponding to the first voltage as the residual magnetic induction intensity of the transformer based on the set relation among the voltage of the Hall element, the working current and the magnetic induction intensity.

In a possible design, the magnetic induction assembly is the magnetic induction assembly according to the fourth aspect and any of its designs.

In a seventh aspect, an embodiment of the present application provides a magnetic induction intensity detection apparatus, including a magnetic induction component and a controller; the magnetic resistance circuit of the magnetic induction assembly is arranged on a magnetic core of the transformer or in an air gap of the magnetic core; the magnetic induction component is used for sending voltage parameters; the equivalent resistance of the reluctance circuit is changed under the action of the residual magnetic induction intensity of the transformer, wherein the variation of the equivalent resistance of the reluctance circuit is the same as the ratio of the voltage parameter to the working voltage of the reluctance circuit; the controller may receive the voltage parameter; and determining the magnetic induction intensity corresponding to the variable quantity as the residual magnetic induction intensity of the transformer based on the set linear relation between the variable quantity of the equivalent resistance of the magnetic resistance circuit and the magnetic induction intensity.

In one possible design, the magnetic induction assembly is the magnetic induction assembly according to the fifth aspect and any design thereof.

In an eighth aspect, embodiments of the present application provide a transformer, which includes a magnetic core, a primary winding, a secondary winding, and the magnetic induction intensity detection apparatus according to the sixth aspect and any design thereof or the seventh aspect and any design thereof. The primary winding and the secondary winding are respectively wound on the magnetic core to realize power conversion; and part or all of the magnetic induction intensity detection device is arranged on the magnetic core, or is arranged in an air gap of the magnetic core and is used for detecting the magnetic induction intensity of the magnetic core.

Drawings

Fig. 1 shows a schematic diagram of a transformer;

FIG. 2 illustrates a schematic structural view of a magnetic induction assembly;

FIG. 3 is a schematic diagram illustrating the position of a Hall element in a magnetic induction assembly;

FIG. 4 is a schematic diagram of a magnetic induction detection assembly;

FIG. 5 shows a schematic structural view of another magnetic induction assembly;

FIG. 6 is a schematic diagram illustrating the placement of magnetoresistive circuitry in a magnetic induction assembly;

FIG. 7 is a schematic view of another magnetic induction detection assembly;

FIG. 8 shows a schematic of a power system configuration;

FIG. 9 is a graph showing the relationship between the voltage input to the transformer and the magnetic induction produced by the transformer;

FIG. 10 shows a schematic of another power system configuration;

fig. 11 shows a schematic configuration of yet another power system;

fig. 12 shows a schematic flow diagram of the operation of a control circuit in an electric power system.

Detailed Description

The terminology used in the following examples is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of this application and the appended claims, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, such as "one or more", unless the context clearly indicates otherwise.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless otherwise specifically stated.

In the description of the present application, "at least one" means one or more, wherein a plurality means two or more. In view of this, the "plurality" may also be understood as "at least two" in the embodiments of the present invention. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" generally indicates that the preceding and succeeding related objects are in an "or" relationship, unless otherwise specified. In addition, it is to be understood that the terms first, second, etc. in the description of the present application are used for distinguishing between the descriptions and not necessarily for describing a sequential or chronological order.

It is to be noted that "coupled" in the embodiments of the present application may be understood as an electrical connection, and the coupling of two electrical components may be a direct or indirect coupling between the two electrical components. For example, a and B may be directly coupled, or indirectly coupled through one or more other electrical elements, for example, a and B, or directly coupled, or C and C, where C and B are directly coupled, and a and B are coupled through C. In some scenarios, "coupled" may also be understood as coupled, such as an electromagnetic coupling between two inductors. In summary, the coupling between a and B can enable the transmission of electrical energy between a and B.

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be described in further detail with reference to the accompanying drawings.

Power systems typically include a transformer. The transformer can perform power conversion on the electric energy, and the electric energy after the power conversion is provided for the electric load. As shown in fig. 1, a transformer generally includes a magnetic core, a primary winding, and a secondary winding. The primary winding and the secondary winding are respectively wound on the magnetic core. The primary winding can receive the electric energy provided by the power supply, and the secondary winding outputs the electric energy after power conversionTo the electrical load. As the current in the primary winding increases, the magnetic induction (also referred to as flux density) of the generated magnetic field also increases. Magnetic induction intensity in the embodiment of the present application

Is a vector, having a magnitude and a direction.

In an electrical power system, transformer input may refer to a transformer with electrical energy input. Before the transformer is put into operation, no electric energy can be input into the transformer. Residual magnetic induction in the magnetic core of a magnetized transformer

(also referred to as residual magnetic induction of the transformer, which is understood to mean the magnetic induction in the core of the transformer after the coil of the transformer has no excitation voltage). If the transformer is put into operation, the voltage input into the transformer causes the magnetic induction intensity generated by the transformer

Residual magnetic induction strength with transformer

Total magnetic flux induction intensity of

Exceeding the saturation induction of the core. Saturation of the core causes the transformer to produce a field current, i.e., a field inrush current. The magnetizing inrush current flows into the power supply side where electric power is input to the primary winding. The magnetizing inrush current may cause a power supply side trip protection operation. Harmonic waves may also be included in the normal magnetizing inrush current, and the harmonic waves entering the power supply side pollute the power quality of the power supply side.

The existing scheme is generally used for weakening the magnetizing inrush current generated when the transformer is put into operation by changing the internal structure of the transformer. Or the resistor is connected in series outside the transformer to weaken the magnetizing inrush current generated when the transformer is put into operation. The existing scheme can only reduce the influence of the magnetizing inrush current and cannot eliminate the phenomenon of generating the magnetizing inrush current no matter the internal structure or the external structure of the transformer is changed.

The excitation inrush current is generated because when the transformer is put into a power system, the working voltage input into the transformer is not appropriate, so that the sum of the magnetic induction intensity generated by the transformer under the action of the working voltage and the residual magnetic induction intensity of the transformer is greater than the saturation magnetic induction intensity.

The residual magnetic induction intensity of the transformer is accurately determined, the adjustment of the working voltage input into the transformer is facilitated, the phenomenon that the magnetic induction intensity of the transformer is larger than or equal to the saturation magnetic induction intensity is avoided, and therefore magnetizing inrush current cannot be generated. The application firstly provides a magnetic induction assembly for detecting the residual magnetic induction intensity of a transformer. Referring to fig. 2, the magnetic induction assembly may include a hall element and a first processing circuit. The hall element is coupled to the first processing circuit.

The hall element may include, but is not limited to, a hall device, a hall chip, and the like. In the embodiment of the present application, the hall element may be an element based on the hall effect. For example, when the current direction in the hall element is perpendicular to the external magnetic field direction, the positive negative carriers in the current are accumulated at both ends of the hall element along the direction of the external magnetic field by the lorentz force, and finally reach a dynamic balance, and a voltage is formed at both ends of the hall element, and this voltage may be a hall voltage.

In the magnetic induction assembly, the first processing circuit can provide working current for the Hall element

The first processing circuit provides working current to the Hall element

The direction of the magnetic flux is vertical to the magnetic induction intensity direction when the transformer works. The transformer can receive voltage by the primary winding when working. The magnetic induction direction of the transformer during operation can be the magnetic induction generated by the source winding of the transformer under the action of voltage after the voltage is received by the source winding of the transformer.

Operating current in Hall element

Positive negative current carriers in an external magnetic field, e.g. residual magnetic induction strength of a transformer

Under the action of the voltage, a Hall voltage is formed at two ends of the Hall element

And hall voltage

Residual magnetic induction strength with transformer

The relationship between is

Wherein Rh is the Hall coefficient of the Hall element, d is the thickness of the Hall element,

is the operating current of the hall element,

in order to be the voltage of the hall,

the residual magnetic induction strength of the transformer.

The first processing circuit can detect (or collect) the hall voltage across the hall element

Using detected Hall voltage

Hall coefficient Rh of Hall element, thickness d of Hall element, and operating current of Hall element

The residual magnetic induction strength of the transformer can be determined

In some application scenarios, the first processing circuit provides the operating current to the hall element

Is a predetermined current

The Hall coefficient and the thickness of a Hall element in the magnetic induction assembly are fixed values. Hall voltage

And operating current

Ratio of

Residual magnetic induction strength with transformer

Have a linear relationship therebetween, i.e.

Therefore, in the magnetic induction assembly provided by the embodiment of the application, the hall voltage collected by the first processing circuit

Can be used for determining residual magnetic induction of transformer

In order to improve the detection accuracy or detection effect, the hall element in the magnetic induction assembly can be arranged in the transformerOn the core of the device (as shown in fig. 3 (a)), or the hall element may be disposed within the air gap of the core (as shown in fig. 3 (b)). In some scenarios, the magnetic induction component may be disposed on a magnetic core of a transformer, or within an air gap of the magnetic core.

In one possible implementation, the first processing circuit may be communicatively coupled to a controller (or processor). In the embodiment of the present application, the communication connection may include, but is not limited to, a wireless communication connection and a wired communication connection. The wireless communication may be a communication method implemented based on any wireless communication technology. Wired communications include, but are not limited to, bus communications.

The controller may be a controller of an electric power system to which the magnetic induction component belongs, or may be a controller of a magnetic induction intensity detection apparatus to which the magnetic induction component belongs. The controller may pre-acquire parameters of the hall element in the magnetic induction assembly, and the parameters of the hall element may include, but are not limited to, a hall coefficient Rh, a thickness d, and an operating current of the hall element

And so on. The controller can acquire the parameters of the Hall element by interacting with the magnetic induction assembly. Alternatively, the controller may store the parameters of the hall element in advance. The embodiment of the application does not limit the way for the controller to acquire the parameters of the hall element.

In some examples, as shown in fig. 2, the first processing circuit may include a power supply module, a voltage acquisition module, and a control module. The control module may be communicatively coupled to the controller to interact with the controller. The control module can control the power supply module to supply working current to the Hall element

The control module can control the voltage acquisition module to acquire the Hall voltage of the Hall element

The hall voltage that the magnetic induction subassembly that this application embodiment provided is favorable to confirming the surplus magnetic induction intensity of transformer to in the electric power system of being convenient for, according to the surplus magnetic induction intensity of transformer, adjust the operating voltage that provides to the transformer, restrain the excitation inrush current. The magnetic induction component provided by the embodiment of the application can become a magnetic induction component based on the Hall effect.

In the embodiment of the present application, the residual magnetic induction strength of the transformer is used as an external magnetic field as an example, and is only used to describe the operation process of the magnetic induction component, and is not specifically limited to an application scenario of the magnetic induction component or a transformer as a detection object. The magnetic induction component provided by the embodiment of the application can also be applied to other scenes or detection objects.

Based on the magnetic induction assembly provided by the above embodiments, the embodiments of the present application provide a magnetic induction detection apparatus, which can be applied to the magnetic induction intensity of an external magnetic field, for example, to detect the residual magnetic induction intensity of a transformer. As shown in fig. 4, the magnetic induction detection apparatus may include a first magnetic induction assembly and a first controller. The Hall element of the first magnetic induction assembly is arranged on a magnetic core of the transformer or in an air gap of the magnetic core.

The first magnetic induction component is used for sending a first voltage, and the first voltage represents the voltage formed by the working current in the Hall element under the action of the residual magnetic induction intensity of the transformer

I.e. the hall voltage across the aforementioned hall element. And the residual magnetic induction intensity of the transformer represents the magnetic induction intensity of the transformer when the transformer does not work.

The controller may receive the first voltage, and then determine, based on a relationship among the set voltage of the hall element, the operating current of the hall element, and the magnetic induction density, the magnetic induction density corresponding to the first voltage as the residual magnetic induction density of the transformer.

E.g. voltage, holter of the Hall element arrangedThe relationship between the operating current and the magnetic induction of the element may be

is the operating current of the hall element,

in order to be the voltage of the hall,

the residual magnetic induction strength of the transformer.

The controller can determine the first voltage according to the set relation among the voltage of the Hall element, the working current of the Hall element and the magnetic induction intensity

Corresponding magnetic induction

I.e. the residual magnetic induction strength of the transformer

In a possible implementation manner, the first magnetic induction component in the magnetic induction detection apparatus may be any one of the magnetic induction components based on the hall effect provided in the foregoing embodiments.

In some possible embodiments, the controller may be communicatively coupled to the first magnetic induction assembly to interact with parameters of the hall element in the first magnetic induction assembly, such as hall coefficient, thickness, operating current, and the like. Or the controller may pre-store parameters of the hall element in the first magnetic induction assembly.

The magnetic induction intensity detection device provided by the embodiment of the application can detect the residual magnetic induction intensity of the transformer, so that the working voltage provided by the transformer can be adjusted conveniently according to the residual magnetic induction intensity of the transformer in a power system, and the magnetizing inrush current is restrained. The internal structure of the existing transformer does not need to be adjusted, and a resistor for weakening the magnetizing inrush current does not need to be connected in parallel outside the transformer.

In the embodiment of the present application, the residual magnetic induction strength of the transformer is taken as an external magnetic field as an example, which is only used for describing the operation process of the magnetic induction detection device, and is not specifically limited as an application scenario of the magnetic induction detection device or a detection object is the transformer. The magnetic induction intensity detection device provided by the embodiment of the application can also be applied to other scenes or detection objects.

The present application provides another magnetic induction assembly comprising a magnetoresistive circuit and a second processing circuit. The reluctance circuit is arranged on a magnetic core of the transformer or in an air gap of the magnetic core. The magnetoresistive circuit may have a wheatstone bridge configuration. As shown in fig. 5, the magnetoresistive circuit may include a first series branch formed by a series connection of a first magnetoresistive (R4) and a second magnetoresistive (R3), and a second series branch formed by a series connection of a third magnetoresistive (R2) and a fourth magnetoresistive (R1).

The first end of the first series branch is connected with the first end of the second series branch, and the second end of the first series branch and the second end of the second series branch are respectively grounded. The first end of the first series branch is configured to receive an operating voltage provided by the processing circuit.

The magneto-resistance in the magneto-resistance circuit may be one or more of a tunnel magnetoresistive sensor magneto-resistance (TMR), an anisotropic magneto-resistance (AMR), and a giant magneto-resistance (GMR). In some scenarios, the first magnetoresistance (R4), the second magnetoresistance (R3), the third magnetoresistance (R2), and the fourth magnetoresistance (R1) may all be TMR, or AMR, or GMR. In other scenarios the first magneto-resistance (R4), the second magneto-resistance (R3), the third magneto-resistance (R2) and the fourth magneto-resistance (R1) may be different types of magneto-resistances in TMR, AMR, GMR, respectively.

In the embodiments of the present application, the magnetic resistance may also be referred to as a magneto-resistor, and may refer to an element based on a magneto-sensitive effect. For example, the resistance value of the element changes under the influence of an external magnetic field. The resistance value of a component is usually linearly related to the magnetic induction of an external magnetic field, e.g. the residual magnetic induction of a transformer, e.g. the resistance value of a component

k is a constant associated with the element.

In the magnetic induction component, the equivalent resistance Ry of the magnetic resistance circuit and the residual magnetic induction intensity of the transformer also have a linear relation,

when the magnetic induction component is not subjected to an external magnetic field, the equivalent resistance of the magnetoresistive circuit can be recorded as Rm, and the value is equal to B0 in the linear relation. Residual magnetic induction intensity of the reluctance circuit in the transformer

The equivalent resistance value of the magnetoresistive circuit becomes Ry. At this time, the amount of change in the equivalent resistance of the magnetoresistive circuit is denoted as Δ R, where Δ R is Ry-Rm. Residual magnetic induction intensity of transformer

It can be seen that by determining the amount of change in the equivalent resistance of the magnetoresistive circuit, the residual induction strength of the transformer can be determined.

The second processing circuit may set the operating voltage Vcc to the first end of the first series branch. The second processing circuit can collect the voltage difference

The voltage difference

A first voltage at one end (S1) of the first reluctance (R4) and the second reluctance (R3) connected

A second voltage of one terminal (S2) connected with the third magnetic resistance (R2) and the fourth magnetic resistance (R1)

The difference of (a). The variation delta R of the equivalent resistance of the magneto-resistive circuit, the voltage difference collected

And the relation between the operating voltages VCC is

It can be seen that the voltage difference collected by the second processing circuit

The residual magnetic induction intensity of the reluctance circuit in the transformer can be determined by combining the working voltage VCC

The change amount Δ R of the equivalent resistance of the magnetoresistive circuit. Then combining the residual magnetic induction intensity of the transformer

And the amount of change in the equivalent resistance of the magnetoresistive circuit. Thereby determining the residual magnetic induction intensity of the transformer

To improve the detection accuracy or detection effect, the magnetic resistance circuit in the magnetic induction assembly may be disposed on the magnetic core of the transformer, or the hall element may be disposed in the air gap of the magnetic core. In some scenarios, as shown in fig. 6, the magnetic induction component may be disposed on the magnetic core of the transformer, or within the air gap of the magnetic core.

In one possible implementation, the second processing circuit may be communicatively coupled to a controller (or processor). The controller may be a controller of an electric power system to which the magnetic induction component belongs, or may be a controller of a magnetic induction intensity detection apparatus to which the magnetic induction component belongs. The controller may pre-acquire parameters of the magneto resistive circuit in the magnetic induction component, and the parameters of the magneto resistive circuit may include, but are not limited to, parameters characterizing a linear relationship between an equivalent resistance of the magneto resistive circuit and a residual magnetic induction strength of the transformer, such as k in the foregoing embodiment. The controller may obtain parameters of the magneto-resistive circuit by interacting with the magnetic induction assembly. Alternatively, the controller may pre-store parameters of the magnetoresistive circuit. The embodiment of the present application does not excessively limit the manner in which the controller obtains the parameters of the magnetoresistive circuit.

In some examples, the second processing circuit may include a power supply module, a voltage acquisition module, and a control module. The control module may be communicatively coupled to the controller to interact with the controller. The control module may control the power supply module to provide the set operating voltage Vcc to the second end of the first reluctance (R4). The control module may control the voltage acquisition module to acquire a voltage difference between the second end of the first magnetic resistance and the second end of the third magnetic resistance

The magnetic induction assembly that this application embodiment provided provides the voltage difference, is favorable to confirming the surplus magnetic induction intensity of transformer to be convenient for adjust the operating voltage that provides to the transformer according to the surplus magnetic induction intensity of transformer, restrain the excitation inrush current. In some scenarios, the voltage difference provided by the magnetic induction component may be referred to as a voltage parameter. The magnetic induction component provided by the embodiment of the application can become a magnetic induction component based on a magnetic induction effect.

Based on the magnetic induction component based on the magnetosensitive effect provided by the above embodiments, the present application provides another magnetic induction detection apparatus, which can be applied to the magnetic induction intensity of an external magnetic field, for example, to detect the residual magnetic induction intensity of a transformer. As shown in fig. 7, the magnetic induction detection apparatus may include a second magnetic induction assembly and a second controller. The reluctance circuit of the magnetic induction assembly may be arranged on the core of the transformer or in the air gap of the core.

The second magnetic induction component is used for sending voltage parameters; the equivalent resistance of the reluctance circuit is changed under the action of the residual magnetic induction intensity of the transformer, wherein the change quantity delta R of the equivalent resistance of the reluctance circuit is equal to the voltage parameter

The ratio of the operating voltage VCC of the magnetoresistive circuit is the same. It can be seen that the relationship between the amount of change in the equivalent resistance of the magnetoresistive circuit, the voltage parameter, and the operating voltage of the magnetoresistive circuit may be

For example, the second magnetic induction element may be a magnetic induction element with any one of the magnetic sensitive effects provided in the foregoing embodiments, and the connection relationship of the magnetic resistance circuit in the magnetic induction element may refer to the magnetic resistance circuit in the magnetic induction element with any one of the magnetic sensitive effects provided in the foregoing embodiments, which is not described herein again. The voltage parameter sent by the second magnetic induction component

May be a voltage difference between a second terminal of the first magnetic resistance and a second terminal of the third magnetic resistance.

The second controller may receive the voltage parameter, and determine a variation Δ R of the equivalent resistance of the magnetoresistive circuit in the second magnetic induction component according to a relationship between a variation of the equivalent resistance of the magnetoresistive circuit, the voltage parameter, and the operating voltage of the magnetoresistive circuit. And then determining the magnetic induction intensity corresponding to the variable quantity as the residual magnetic induction intensity of the transformer based on the set linear relation between the variable quantity of the equivalent resistance of the magnetic resistance circuit and the magnetic induction intensity. For example, variation of the equivalent resistance of the magnetoresistive circuit providedThe linear relationship of the quantity to the magnetic induction,

wherein Δ R is a variation amount of an equivalent resistance of the magnetoresistive circuit, k is a constant relating to the magnetoresistive circuit,

the magnetic induction, e.g. the residual magnetic induction of a transformer, is characterized. The second controller may control the magnetic induction intensity corresponding to the variation of the equivalent resistance of the magnetoresistive circuit

The residual magnetic induction strength of the transformer is determined.

In some examples, after receiving the voltage parameter, the second controller may determine the remaining magnetic induction of the transformer, that is, the remaining magnetic induction of the transformer based on the variation of the equivalent resistance of the magnetoresistive circuit, the relationship between the voltage parameter and the operating voltage of the magnetoresistive circuit, and the linear relationship between the variation of the equivalent resistance of the magnetoresistive circuit and the magnetic induction

In some possible designs, the second controller may be communicatively coupled to the second magnetic induction component, and interact with parameters of the magnetic resistance circuit in the second magnetic induction component, such as a constant k in a linear relationship between an equivalent resistance change amount of the magnetic resistance circuit and a magnetic induction intensity. Or the second controller may pre-store parameters of the magneto resistive circuit in the second magnetic induction assembly.

It should be noted that, in the embodiment of the present application, the magnetic field to be detected is taken as the residual magnetic induction intensity of the transformer as an example, and is only used to introduce the working process of the magnetic induction detection apparatus, and is not taken as a specific limitation that an application scene of the magnetic induction detection apparatus or a detection object is the transformer. The magnetic induction intensity detection device provided by the embodiment of the application can also be applied to other scenes or detection objects.

In addition, the embodiment of the application further provides an electric power system. As shown in fig. 8, the power system may include a first switch, a transformer, a magnetic induction assembly, and a first control circuit. The first switch has a first terminal coupled to a first power source and a second terminal coupled to an electrical load through the transformer. The first power source may provide alternating current to the power system.

The first power source includes one or more of an ac power grid or a first energy conversion device. The first energy conversion device is used for converting non-electric energy into alternating current electric energy, and for example, the first energy conversion device may be an oil engine, such as a diesel generator. In some examples, referring back to fig. 8, the first power source may include an ac power grid and a first energy conversion device. In the power system provided by the embodiment of the application, the working frequency of the transformer may be the same as the working frequency of the alternating current provided by the first power supply. The power system may be implemented as a microgrid system.

In one possible design, in a scenario where the first power source includes an ac power grid and the first energy conversion device, the power system may further include a switching module capable of switching ac power input to the bypass module, for example, the switching module may output ac power provided by the ac power grid to the first switch or output ac power provided by the first energy device to the bypass module. The first switch may include, but is not limited to, a power electronic switch and a mechanical switch. In some scenarios, the switching module may be implemented as an Automatic Transfer Switch (ATS). The first switch is typically a contactor.

The power system provided by the embodiment of the application can further comprise a protection device. The protection device can be used for breaking the circuit between the power supply side and the electric load under the conditions of overcurrent, overload, short circuit and the like on the user load side. The protection devices may include, but are not limited to, circuit breakers, fuses, air switches, and the like. The magnetizing inrush current may cause malfunction of the protection device, which affects the operational reliability and safety of the power system.

The magnetic induction component can generate a voltage parameter under the induction of the residual magnetic induction intensity of the transformer, and report the voltage parameter to the first control circuit, and the voltage parameter can be used for the first control circuit to determine the residual magnetic induction intensity of the transformer based on the voltage parameter. The magnetic induction assembly may be disposed on the core of the transformer, or within an air gap of the core.

In a possible embodiment, the magnetic induction assembly may be a magnetic induction assembly based on the hall effect, and the hall element in the magnetic induction assembly may be disposed on the magnetic core of the transformer or in the air gap of the magnetic core. The voltage parameters reported by the magnetic induction assembly can represent the Hall voltage formed by the working current in the Hall element of the magnetic induction assembly under the action of the residual magnetic induction intensity of the transformer.

The first control circuit can determine the magnetic induction intensity corresponding to the voltage parameter, namely the residual magnetic induction intensity of the transformer according to the set relation among the voltage of the Hall element, the working current of the Hall element and the magnetic induction intensity. For example, the relation of the voltage of the hall element, the operating current of the hall element and the magnetic induction intensity may be set

Wherein,

is the residual magnetic induction strength of the transformer,

is a voltage parameter received by the first control circuit, Rh is a hall coefficient of the hall element, d is a thickness of the hall element,

is the operating current of the hall element. In this relationship, the coefficient of the hall element, the thickness of the hall element, and the operating current of the hall element may be fixed values.

The first control circuit may acquire parameters of the hall element such as a coefficient of the hall element, a thickness of the hall element, and a working current of the hall element in advance. The way in which the first control circuit obtains the parameters of the hall element in advance may include, but is not limited to, obtaining by interacting with a magnetic induction assembly, or storing the parameters of the hall element in advance. The examples of the present application are not intended to be limiting.

In another possible embodiment, the magnetic induction component may be a magnetic induction component based on the magnetosensitive effect, and the magnetic induction component may include a magnetoresistive circuit. The reluctance circuit may be arranged on the core of the transformer or in the air gap of the core.

The equivalent resistance of the reluctance circuit is changed under the action of the residual magnetic induction intensity of the transformer, wherein the change quantity delta R of the equivalent resistance of the reluctance circuit is equal to the voltage parameter

The first control circuit may receive the voltage parameter, and determine a variation Δ R of the equivalent resistance of the magnetoresistive circuit in the second magnetic induction component according to a relationship between a variation of the equivalent resistance of the magnetoresistive circuit, the voltage parameter, and the operating voltage of the magnetoresistive circuit. Then, based on the set linear relation between the variation of the equivalent resistance of the magnetic resistance circuit and the magnetic induction intensity, determining the magnetic induction intensity corresponding to the variation as the residual magnetic induction of the transformerThe strength should be. For example, the linear relationship between the variation of the equivalent resistance of the magnetic resistance circuit and the magnetic induction intensity is set,

the magnetic induction, e.g. the residual magnetic induction of a transformer, is characterized. The first control circuit may control the magnetic induction intensity corresponding to the variation of the equivalent resistance of the magnetoresistive circuit

The residual magnetic induction strength of the transformer is determined.

In some examples, after the first control circuit receives the voltage parameter, the remaining magnetic induction of the transformer may be determined directly based on the variation of the equivalent resistance of the magnetoresistive circuit, the relationship between the voltage parameter and the operating voltage of the magnetoresistive circuit, and the linear relationship between the variation of the equivalent resistance of the magnetoresistive circuit and the magnetic induction, that is, the remaining magnetic induction of the transformer is determined

The first control circuit may determine at least one target input voltage based on a relationship between a set voltage of the input transformer and a magnetic induction generated by the transformer, wherein a first magnetic induction corresponding to the target input voltage is the same as and opposite to the residual magnetic induction. The first control circuit may control the first switch based on any one of the target input voltages so that an initial voltage of the ac input transformer provided by the first power supply is the target input voltage.

The relationship between the voltage of the input transformer and the magnetic induction intensity generated by the transformer can be determined based on the condition that the magnetic induction intensity generated by the transformer is changed along with the voltage of the input transformer under the action of the periodic first alternating current in the condition that the magnetic core of the transformer is magnetized. Wherein the amplitude and the operating frequency of the first alternating current may be the same as the amplitude and the operating frequency of the alternating current supplied from the first power supply, respectively. Since the voltage waveform of the alternating current supplied by the first power supply is generally sinusoidal, the voltage and the phase of the alternating current satisfy a sine function relationship. The voltage of the alternating current varies with the variation of the phase angle θ, and the voltage of the alternating current supplied by the first power supply varies with the variation of the phase angle θ, such as the voltage U-Asin (ω t), where a is the amplitude, the phase angle θ is ω t, ω is a fixed value, ω is 2 pi × fm, and fm is the operating frequency of the alternating current supplied by the first power supply.

For the unmagnetized transformer, the relationship between the voltage input to the transformer and the magnetic induction generated by the transformer is recorded as a first relationship. For a magnetized transformer, a second relationship between the voltage input to the transformer and the magnetic induction generated by the transformer is provided. The person skilled in the art knows that the first relation and the second relation are different. And the transformer generates magnetizing inrush current when put into operation, usually because the transformer has residual magnetic induction intensity. The transformer has residual magnetic induction which reflects that the transformer is magnetized. In view of this, the transformer in the power system provided in the embodiments of the present application may be referred to as a magnetized transformer.

The first control circuit may store the set voltage of the input transformer in relation to the magnetic induction generated by the transformer, or the first control circuit may receive the set voltage of the input transformer in relation to the magnetic induction generated by the transformer.

In the embodiment of the present application, the first magnetic induction intensity is the same as the residual magnetic induction intensity of the transformer, and the directions are opposite. Under the action of target input voltage corresponding to the first magnetic induction intensity, the magnetic induction intensity generated by the transformer is the first magnetic induction intensity. At this time, the total magnetic induction of the transformer is the sum of the first magnetic induction and the remaining magnetic induction. The first magnetic induction intensity is equal to the residual magnetic induction intensity in magnitude and opposite in direction. The first magnetic induction can counteract the residual magnetic induction, so that the total magnetic induction of the transformer is zero. Therefore, the total magnetic induction intensity of the transformer is smaller than the saturation magnetic induction intensity of the transformer when the transformer is put into use, the situation that the magnetic induction intensity of the transformer is supersaturated can be avoided, and therefore the generation of excitation inrush current is avoided.

When the transformer is applied to a power system, the physical structure of the transformer is kept unchanged, so that the magnetic circuit physical structure of the transformer is kept unchanged. Voltage U of input transformer_inThe relationship between Asin (ω t) and the magnetic induction B generated by the transformer may satisfy:

wherein f is the working frequency of the transformer, N is the number of turns of the primary winding of the transformer, S is the cross-sectional area of the magnetic core of the transformer, and t is time. The working frequency, the number of turns and the cross-sectional area of the magnetic core of the transformer are fixed values.

Is related to the sign of Asin (ω t). For example, when Asin (ω t) is a positive number,

is the first direction. Where Asin (ω t) is negative,

in a direction opposite to said first direction.

In one example, the voltage input to the transformer is a periodic alternating current, which may be an alternating current provided by the first power source. Taking a period as an example, as shown in fig. 9, the voltage amplitude of the alternating current input to the transformer varies with time in the period as shown in the thin solid line curve. Under the action of the alternating current, the variation of the magnetic induction intensity generated by the transformer along with time can be seen in a thick solid curve.

The thin dashed line in fig. 9 shows the first magnetic induction. Within a period, there is at least one time at which the magnetic induction of the transformer is the first magnetic induction, i.e. the same as the residual magnetic induction of the transformer, and the opposite direction. Assume that the magnetic induction of the transformer at time ta in the period is the first magnetic induction, and the magnetic induction at time tb is also the first magnetic induction.

The first control circuit may control the voltage of the alternating current corresponding to the time ta

Determining the voltage of the AC corresponding to the time tb as the target input voltage

Is determined as the target input voltage. Voltage of

When the transformer is input, the transformer is at voltage

The magnetic induction generated by (a) is b (ta), that is, the first magnetic induction. Voltage of

When the transformer is input, the transformer is at voltage

The magnetic induction generated under the action of (a) is b (tb), namely the first magnetic induction.

The first control circuit can make the initial voltage of the alternating current output transformer provided by the first power supply be equal to the initial voltage of the alternating current output transformer provided by the first power supply by determining the time ta or the time tb as the closing time of the first switch and making the first switch be in a conducting state at the time ta or the time tb

Or

That is to sayThe aforementioned target input voltage. The transformer generates a first magnetic induction intensity under the action of the target input voltage. At this time, the total magnetic induction of the transformer is the sum of the first magnetic induction and the remaining magnetic induction, i.e. is zero.

In the embodiment of the present application, when the first control circuit controls the first switch, a phase of the alternating current provided by the first power supply when the first switch is switched from the open state to the conducting state may be recorded as an initial closing phase angle θ m of the first switch. The phase angle of the alternating current at the closing time is ω ta or ω tb, that is, the initial closing phase angle of the first switch may be ω ta or ω tb. The first control circuit controls the first switch to be in a conducting state at the closing moment, and the initial voltage input by the alternating current to the transformer can be any target input voltage in at least one target input voltage. At the moment, the sum of the magnetic induction intensity generated by the transformer under the action of the alternating current and the residual magnetic induction intensity is zero.

The magnetizing inrush current can heat the magnetic core of the transformer, which affects the service life of the transformer. And the magnetizing inrush current contains a large amount of higher harmonics, which affects the power quality of the power system. In the power system that this application embodiment provided, magnetic induction component can be based on hall effect, detects the voltage parameter of hall voltage that self hall element produced because of transformer surplus magnetic induction intensity. The magnetic induction component can also detect a voltage parameter which can reflect the variation of the equivalent resistance of the magnetic induction component on the basis of a magnetosensitive effect. The magnetic induction component reports the voltage parameters to the control circuit, so that the first control circuit can determine the residual magnetic induction intensity of the transformer. The first control circuit may determine a residual magnetic induction strength of the transformer, and control the first switch based on the determined residual magnetic induction strength so that the ac power input to the transformer becomes the target input voltage. When the transformer is put into operation, the magnetic induction intensity generated under the action of the target input voltage is the same as the residual magnetic induction intensity of the transformer, and the directions are opposite, so that the total magnetic induction intensity of the transformer is zero, the situation that the magnetic induction intensity of the transformer is greater than the saturated magnetic induction intensity is avoided, and the generation of inhibiting the magnetizing inrush current is realized.

An embodiment of the present application further provides an electric power system, as shown in fig. 10, the electric power system may include a transformer, an inverter circuit, a magnetic induction component, and a second control circuit. One end of the transformer is coupled with the inverter circuit, and the other end of the transformer is coupled with an electric load. The transformer may convert power of the ac power supplied from the inverter and supply the converted ac power to the electric load. The inverter circuit may output an alternating current under the control of the second control circuit.

In the embodiment of the present application, the inverter circuit may include, but is not limited to, a dc-to-ac circuit. The inverter circuit can also comprise an alternating current to direct current circuit, so that the inverter circuit has a bidirectional inversion function or capacity. In some possible application scenarios, the inverter circuit may be implemented as a Power Control System (PCS).

In some possible scenarios, the power system may also include a second power source. The input side of the inverter circuit is coupled to a second power supply, and the output side of the inverter circuit is coupled to the transformer; the second power source is capable of providing direct current. The inverter circuit may convert the direct current supplied from the second power source into an alternating current under the control of the second control circuit. In some examples, the second power source includes one or more of a second energy conversion device and an energy storage device. The second energy conversion device may convert non-electrical energy into direct current electrical energy, for example, the second energy conversion device may be a photovoltaic power generation device. The energy storage device can store electric energy and output direct current electric energy.

The magnetic induction component can generate a voltage parameter under the induction of the residual magnetic induction intensity of the transformer and send the voltage parameter to the second control circuit. When the magnetic induction assembly comprises a Hall element, the voltage parameter represents the voltage formed by the working current in the Hall element under the action of the residual magnetic induction intensity of the transformer; or, when the magnetic induction component comprises a magnetic resistance circuit, the equivalent resistance of the magnetic resistance circuit is changed under the action of the residual magnetic induction intensity of the transformer, wherein the ratio of the working voltage of the magnetic resistance circuit to the voltage parameter represents the variation of the equivalent resistance of the magnetic resistance circuit.

The second control circuit may determine a residual magnetic induction of the transformer based on the voltage parameter. Here, the process or manner of determining the residual magnetic induction strength of the transformer by the second control circuit may refer to the related description of determining the residual magnetic induction strength of the transformer in the foregoing embodiments, and will not be described herein again.

The second control circuit may determine a target output voltage based on a set relationship between a voltage input to the transformer and a magnetic induction generated by the transformer, wherein a second magnetic induction corresponding to the target output voltage is a maximum magnetic induction of the transformer

And the difference from the residual magnetic induction strength. For example, if the residual magnetic induction is + Br, the second magnetic induction is a difference between the maximum magnetic induction + Bm and the residual magnetic induction + Br in the same direction as the residual magnetic induction, that is, + (Bm-Br). For another example, if the residual magnetic induction is-Br, the second magnetic induction is the difference between the maximum magnetic induction-Bm and the residual magnetic induction-Br in the same direction as the residual magnetic induction, that is, — Bm-Br.

Maximum magnetic induction intensity of transformer

May be preset. And maximum magnetic induction

Less than the saturation induction of the transformer. Maximum magnetic induction of transformer

The maximum magnetic induction intensity of the transformer during operation can be characterized.

In the embodiment of the present application, the relationship between the voltage of the input transformer and the magnetic induction intensity generated by the transformer may be referred to the description in the foregoing embodiments, and details are not described here. The second control circuit may store the relationship between the set voltage of the input transformer and the magnetic induction intensity generated by the transformer, or may obtain the relationship between the set voltage of the input transformer and the magnetic induction intensity generated by the transformer in advance.

When the transformer is switched in, that is, when the inverter circuit supplies voltage to the transformer, the second control circuit may control the initial voltage of the alternating current output by the inverter circuit to be the target output voltage. And the magnetic induction intensity generated by the transformer under the action of the target output voltage is the second magnetic induction intensity. And the second magnetic induction is the difference value between the maximum magnetic induction and the residual magnetic induction of the transformer, and then the sum of the second magnetic induction and the residual magnetic induction is the maximum magnetic induction of the transformer. Therefore, when the transformer is put into use, the total magnetic induction intensity of the transformer is the maximum magnetic induction intensity, and the magnetic induction intensity of the transformer is not saturated because the total magnetic induction intensity does not exceed the saturated magnetic induction intensity. Thereby avoiding the generation of a magnetizing inrush current. The safety and the reliability of the operation of the power system are improved, and the protection device can be prevented from being triggered due to excitation inrush current in the power system. And the service life of the transformer can be prolonged.

The second magnetic induction can also be referred to as an excitation space Δ B of the transformer. The excitation space of the transformer can be understood as the maximum value of the magnetic induction intensity which can be generated when the transformer is put into use, and if the sum of the maximum value of the magnetic induction intensity generated when the transformer is put into use and the residual magnetic induction intensity reaches the saturated magnetic induction intensity of the transformer, the phenomenon of magnetic saturation of the transformer can occur. In the embodiment of the present application, the sum of the residual magnetic induction of the excitation space and the transformer is the maximum magnetic induction of the transformer during operation, and is less than the saturation magnetic induction. Therefore, the second control circuit controls the inverter circuit to input the voltage to the transformer so that the magnetic induction intensity generated by the transformer is the excitation space, and the total magnetic induction intensity of the transformer does not reach the saturation magnetic induction intensity.

The second control circuit may be pre-acquired or storedVoltage U of storage input transformer_inAnd the magnetic induction intensity generated by the transformer

In relation to each other, e.g.

Wherein f is the working frequency of the transformer, N is the number of turns of the transformer, and S is the cross-sectional area of the magnetic core of the transformer, wherein the working frequency, the number of turns and the cross-sectional area of the magnetic core are fixed values.

The second control circuit can determine the voltage corresponding to the excitation space based on the relationship between the input voltage of the transformer and the magnetic induction intensity generated by the transformer, and the voltage is recorded as the target output voltage U_outWherein, U_out4.44 × f × N × S × Δ B. The second control circuit may be based on the target output voltage U_outControlling the inverter circuit to make the initial voltage of the alternating current output by the inverter circuit be the target output voltage U_outIt is to be understood that the magnitude of the initial voltage is the same as the magnitude of the target output voltage and the phase of the initial voltage is the same as the phase of the target output voltage. Thus, when the transformer is put into operation, the initial voltage of the alternating current output by the inverter circuit is the target output voltage U_outThe magnetic induction generated by the transformer may be Δ B. At this time, the total amount of the magnetic induction intensity generated by the transformer and the residual magnetic induction intensity of the transformer does not exceed the maximum magnetic induction intensity of the transformer, that is, the transformer does not have a magnetic saturation phenomenon, so that the magnetizing inrush current in the power system is restrained.

In some possible cases, the voltage waveform of the alternating current provided by the inverter circuit is generally sinusoidal, that is, the voltage and the phase of the alternating current satisfy a sinusoidal function relationship. The voltage of the alternating current changes with the change of the phase angle θ, such as the voltage U-Asin (ω t), where the phase angle θ is ω t, ω is a fixed value, ω is 2 pi × fm, and fm is the operating frequency of the alternating current provided by the inverter circuit.

The second control circuit can control the initial voltage of the alternating current output by the inverter circuit to be a targetStandard output voltage U_out. At this time, the number of the initial phase angles θ x of the inverter circuit outputting the alternating current may be at least one. The relation between any initial phase angle and the target output voltage satisfies U_outAsin (θ x). The second control circuit can control the inverter circuit based on the amplitude A of the alternating current and any initial phase angle theta x, so that the initial value of the alternating current output by the inverter circuit is the target output voltage U_out。

An embodiment of the present application further provides an electric power system, as shown in fig. 11, the electric power system may include a first power supply branch, a second power supply branch, a first switch, a second switch, a transformer, a magnetic induction component, and a third control circuit.

The first power supply branch is coupled with a first power supply, and the first power supply branch is coupled with a user load through the first switch. The first power supply is capable of providing a first alternating current to the first power supply branch. The first power supply branch may transmit the first alternating current to the first switch. The alternating current provided by the first power supply branch to the user load is recorded as a first alternating current, and the alternating current provided by the second power supply direct current to the user load is recorded as a second alternating current.

The second power supply branch is coupled with a second power supply. The second power supply branch is coupled with one end of the transformer through the second switch. The other end of the transformer is coupled to the user load. The second power supply is capable of providing a first direct current to the second supply direct current. The second power supply branch is used for converting the first direct current into second alternating current and then transmitting the second alternating current to the second switch.

The magnetic induction component is arranged on the magnetic core of the transformer or in an air gap of the magnetic core and used for reporting a voltage parameter to the third control circuit, and the voltage parameter is used for the third control circuit to determine the residual magnetic induction intensity of the transformer. In the embodiment of the present application, the third control circuit determines the remaining magnetic induction intensity of the transformer according to the description in the foregoing embodiment, and details are not described here.

In a possible scenario where the first power supply supplies power and the first power supply branch supplies alternating current to the user load, the third control circuit may determine at least one target input voltage based on a set relationship between a voltage input to the transformer and a magnetic induction generated by the transformer, wherein the target input voltage corresponds to a first magnetic induction having a same magnitude and an opposite direction to the residual magnetic induction. And controlling the first switch to enable the initial voltage of the alternating current input into the transformer to be any one of the at least one target input voltage.

In the embodiment of the present application, the relationship between the voltage of the input transformer and the magnetic induction intensity generated by the transformer may be referred to the description in the foregoing embodiments, and details are not described here. The third control circuit may store the relationship between the voltage of the input transformer and the magnetic induction generated by the transformer, or may obtain the relationship between the voltage of the input transformer and the magnetic induction generated by the transformer in advance.

When the transformer is put into operation, the magnetic induction intensity generated by the transformer is the first magnetic induction intensity under the action of the target input voltage, and the total magnetic induction intensity of the transformer is the sum of the first magnetic induction intensity and the residual magnetic induction intensity, namely zero. Because the total magnetic induction intensity of the transformer is zero and does not exceed the maximum magnetic induction intensity of the transformer, the magnetizing inrush current cannot be generated. The safety and the reliability of the power system are improved, harmonic waves in the excitation inrush current are prevented from entering the first power supply side, the power quality is improved, and the operation stability of the power system can be improved.

In yet another possible scenario, in which the second power supply supplies power and the second power supply branch supplies ac power to the user load, the third control circuit may determine a target output voltage of the second power supply branch based on a relationship between the set voltage input to the transformer and the magnetic induction generated by the transformer, wherein the second magnetic induction corresponding to the target output voltage is a difference between the maximum magnetic induction and the residual magnetic induction of the transformer. And the third control circuit controls the second power supply branch circuit to enable the initial voltage of the alternating current output by the second power supply branch circuit to be the target output voltage.

The third control circuit may control the second switch to be in a conducting state before the second power supply branch outputs the alternating current. The second switch may also be controlled to be in a conducting state after the second power supply branch outputs the alternating current.

Because the initial voltage of the alternating current output by the second power supply branch circuit is the target output voltage, when the transformer is put into use, the magnetic induction intensity generated by the transformer is the second magnetic induction intensity under the action of the target output voltage, and the total magnetic induction intensity of the transformer is the sum of the second magnetic induction intensity and the residual magnetic induction intensity, namely the maximum magnetic induction intensity. Therefore, the total magnetic induction intensity does not exceed the maximum magnetic induction intensity when the transformer is put into operation, so that the excitation inrush current cannot be generated. The safety and the reliability of the power system are improved, harmonic waves in the excitation inrush current are prevented from entering the first power supply side, the power quality is improved, and the operation stability of the power system can be improved.

In embodiments of the present application, the first switch may comprise one or more of a power electronic switch and a mechanical switch. The third control circuit may control the power electronic switch and the mechanical switch. In scenarios where the first power source comprises an ac power grid, the first switch may generally comprise a power electronic switch and a mechanical switch, based on grid-side safety code requirements for fault disengagement. In this case, the initial closing phase angle of the power electronic switch and the mechanical switch may be the same. Or the power electronic switch may be in a conducting state before the mechanical switch, and then the initial closing phase angle of the mechanical switch may be the initial closing phase angle determined by the third control circuit. Or, the mechanical switch may be in the conduction-change state before the power electronic switch, and then the initial closing phase angle of the power electronic switch may be the initial closing phase angle determined by the third control circuit.

Referring again to fig. 11, the power system may further include the first power source. The first power source may include an ac power grid and a first energy conversion device. The first power branch may include a transmission line that may transmit the ac power provided by the first power source to the first switch. In the power system provided by the embodiment of the application, the operating frequency of the transformer may be the same as the operating frequency of the alternating current provided by the first power supply. The power system may be implemented as a microgrid system.

In a possible design, in a scenario where the first power source includes an ac power grid and the first energy conversion device, the first power supply branch may further include a switching module, and the switching module may be capable of switching ac power input to the first switch, for example, the switching module may output ac power provided by the ac power grid to the first switch or output ac power provided by the first energy device to the first switch. In some scenarios, the switching module may be implemented as an ATS.

In one possible design, the second power source includes one or more of a second energy conversion device and an energy storage device. The second energy conversion device may convert non-electrical energy into direct current electrical energy, for example, the second energy conversion device may be a photovoltaic power generation device. The energy storage device can store electric energy and output direct current electric energy.

In a possible design, the magnetic induction component in the power system provided by the embodiment of the present application may be any one of the magnetic induction components in the foregoing embodiments, and may send the voltage parameter to the control circuit. For example, the magnetic induction assembly is communicatively coupled to the control circuit. In the embodiment of the present application, the communication connection may include, but is not limited to, a wireless communication connection and a wired communication connection. The wireless communication may be a communication method implemented based on any wireless communication technology. Wired communications include, but are not limited to, bus communications.

As shown in fig. 12, the magnetic induction assembly may send a voltage parameter for determining the residual magnetic induction of the transformer to the third control circuit, facilitating the control circuit to determine the residual magnetic induction of the transformer based on the voltage parameter. The third control circuit may determine that the power supply branch supplying power to the electrical load is the first power supply branch or the second power supply branch based on the set power supply manner. For example, the set power supply mode may be a first power supply mode, and the first power supply mode may be characterized by supplying power to the user load by the first power supply branch. For another example, the set power supply mode may be a second power supply mode, and the second power supply mode may be characterized by supplying power to the user load by the second power supply branch.

The third control circuit may control the first switch to be in a conducting state based on the first power supply manner, so that the first power supply branch supplies power to the user load. The third control circuit determines at least one target input voltage based on a set relation between the voltage input to the transformer and the magnetic induction intensity generated by the transformer in the operation of controlling the first switch, wherein the first magnetic induction intensity corresponding to the target input voltage is the same as the residual magnetic induction intensity in magnitude and opposite in direction. The third control circuit may determine a phase angle of any one of the at least one target input voltage as a switching initial phase angle of the first switch, and then control the first switch to be in a conducting state based on the switching initial phase angle, so that an initial voltage of the first alternating current input to the transformer is the any one target input voltage.

The third control circuit may control the inverter circuit and the second switch based on the second power supply manner, so that the second power supply branch supplies power to the user load. Wherein the third control circuit may determine the target output voltage of the inverter circuit based on the set relationship between the voltage input to the transformer and the magnetic induction intensity generated by the transformer in controlling the operation of the inverter circuit and the second switch. And the second magnetic induction intensity corresponding to the target output voltage is the difference value between the maximum magnetic induction intensity of the transformer and the residual magnetic induction intensity. This second magnetic induction can also be referred to as excitation space. The third control circuit may control the inverter circuit based on the target output voltage so that an initial voltage of the second alternating current output by the inverter circuit becomes the target output voltage. The amplitude of the initial voltage is the same as the amplitude of the target output voltage, and the phase of the initial voltage is the same as the phase of the target output voltage.

The third control circuit may control the second switch to be in a conductive state before controlling the inverter circuit to output the second alternating current. Alternatively, the third control circuit may control the second switch to be in the on state after controlling the inverter circuit to output the second alternating current. And then the third control circuit can control the amplitude range of the second alternating current output by the inverter circuit to gradually increase.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. An electrical power system comprising a first switch, a transformer, a magnetic induction assembly, and a control circuit; a first terminal of the first switch is coupled to a first power source, and a second terminal of the first switch is coupled to an electrical load through the transformer; the first power source is capable of providing alternating current to the power system;

the magnetic induction component is used for generating a voltage parameter under the induction of the residual magnetic induction intensity of the transformer and sending the voltage parameter to the control circuit, wherein the voltage parameter is used for the control circuit to determine the residual magnetic induction intensity of the transformer;

the control circuit is configured to:

determining at least one target input voltage based on a set relation between the voltage input into the transformer and the magnetic induction generated by the transformer, wherein the first magnetic induction corresponding to the target input voltage is the same as the residual magnetic induction in magnitude and opposite in direction;

and controlling the first switch to enable the initial voltage of the alternating current input into the transformer to be any one of the at least one target input voltage.

2. The system of claim 1, wherein when the magnetic induction assembly comprises a hall element, the voltage parameter characterizes a voltage developed by an operating current in the hall element under the influence of a residual magnetic induction of the transformer; or

When the magnetic induction component comprises a magnetic resistance circuit, the equivalent resistance of the magnetic resistance circuit is changed under the action of the residual magnetic induction intensity of the transformer, wherein the ratio of the working voltage of the magnetic resistance circuit to the voltage parameter represents the variation of the equivalent resistance of the magnetic resistance circuit.

3. The system of claim 2, wherein the magnetic induction assembly comprises a hall element; the control circuit is further configured to:

and determining the magnetic induction intensity corresponding to the voltage parameter as the residual magnetic induction intensity of the transformer based on the set relation among the voltage of the Hall element, the working current and the magnetic induction intensity.

4. The system of claim 2, wherein the magnetic induction component comprises a magnetoresistive circuit; the control circuit is further configured to:

based on the set relation between the variation of the equivalent resistance of the magnetic resistance circuit and the magnetic induction intensity, determining the magnetic induction intensity corresponding to the target variation as the residual magnetic induction intensity of the transformer, wherein the target variation is the ratio of the voltage parameter to the working voltage of the magnetic resistance circuit.

5. The system of any of claims 1-4, wherein the control circuit is further to:

after the at least one target input voltage is determined and before a first switch is controlled, determining the closing time of the first switch, wherein the initial voltage of the alternating current at the closing time is the same as any target input voltage;

when the control circuit controls the first switch, the control circuit is specifically configured to:

and controlling the first switch to be in a conducting state at the closing moment.

6. A power system is characterized by comprising a transformer, an inverter circuit, a magnetic induction assembly and a control circuit; one end of the transformer is coupled with the inverter circuit, and the other end of the transformer is coupled with an electric load;

the inverter circuit is used for outputting alternating current under the control of the control circuit;

the transformer is used for converting power of the alternating current provided by the inverter circuit and then providing the converted alternating current to the power load;

the control circuit is configured to:

determining a target output voltage based on a set relation between the voltage input into the transformer and the magnetic induction intensity generated by the transformer, wherein a first magnetic induction intensity corresponding to the target output voltage is a difference value between the maximum magnetic induction intensity and the residual magnetic induction intensity of the transformer, and the maximum magnetic induction intensity of the transformer is smaller than the saturation magnetic induction intensity of the transformer;

and controlling the inverter circuit to enable the initial voltage of the alternating current output by the inverter circuit to be the target output voltage.

7. The system of claim 6, wherein when the magnetic induction assembly comprises a hall element, the voltage parameter is indicative of a voltage developed by an operating current in the hall element as a function of a residual magnetic induction of the transformer; or,

8. The system of claim 7, wherein the magnetic induction assembly comprises a hall element; the control circuit is further configured to:

9. The system of claim 7, wherein the magnetic induction component comprises a magnetoresistive circuit; the control circuit is further configured to:

10. An electrical power system, comprising: the power supply device comprises a first power supply branch, a second power supply branch, a first switch, a second switch, a transformer, a magnetic induction assembly and a control circuit;

the first power supply branch is coupled with a first power supply, and the first power supply branch is coupled with a user load through the first switch; the first power supply is capable of providing a first alternating current to the first power supply branch; the first power supply branch is used for transmitting the first alternating current to the first switch;

the second power supply branch is coupled with a second power supply; the second power supply branch is coupled with one end of the transformer through the second switch; the other end of the transformer is coupled with the user load; the second power supply is capable of providing a first direct current to the second supply direct current; the second power supply branch is used for converting the first direct current into a second alternating current and then transmitting the second alternating current to the second switch;

the control circuit is configured to:

determining at least one target input voltage based on a set relation between the voltage input into the transformer and the magnetic induction intensity generated by the transformer, wherein the first magnetic induction intensity corresponding to the target input voltage is the same as the residual magnetic induction intensity in size and opposite in direction; controlling the first switch to enable the initial voltage of the first alternating current input into the transformer to be any one target input voltage in the at least one target input voltage; or,

determining a target output voltage of the second power supply branch circuit based on the set relationship between the voltage input into the transformer and the magnetic induction intensity generated by the transformer, wherein the second magnetic induction intensity corresponding to the target output voltage is the difference value between the maximum magnetic induction intensity of the transformer and the residual magnetic induction intensity, and the maximum magnetic induction intensity of the transformer is smaller than the saturation magnetic induction intensity of the transformer; and controlling the second power supply branch to enable the initial voltage of the second alternating current output by the second power supply branch to be the target output voltage.

11. The system of claim 10, wherein the first power source comprises one or more of an ac power grid or a first energy conversion device; the first energy conversion device is used for converting non-electric energy into alternating current electric energy.

12. The system of claim 10 or 11, wherein when the first power source comprises the ac power grid and the first energy conversion device, the first power supply branch further comprises a switching module;

the switching module is coupled to the ac power grid and the first energy conversion device, and coupled to the first switch, respectively, and is configured to output the first ac power provided by the ac power grid or the first ac power provided by the first energy conversion device to the first switch.

13. The system of claim 10 or 11, wherein the second power supply branch comprises an inverter circuit;

the inverter circuit is used for converting the direct current provided by the second power supply into the second alternating current.

14. The system of claim 13, wherein the second power source comprises one or more of a second energy conversion device and an energy storage device;

the second energy conversion device is used for converting non-electric energy into direct current and supplying the direct current to the inverter circuit;

and the energy storage device is used for providing direct current to the inverter circuit.

15. A magnetic induction component is characterized by comprising a Hall element and a processing circuit; the Hall element is arranged on a magnetic core of the transformer or in an air gap of the magnetic core;

the processing circuitry to:

providing a set working current to the Hall element; the current direction of the working current is vertical to the magnetic induction intensity direction of the transformer during working, and the working current forms a first voltage at the Hall element under the action of the residual magnetic induction intensity of the transformer; a first ratio of the first voltage to the working current has a linear relation with the residual magnetic induction intensity;

sending the first voltage to a controller communicatively coupled to the processing circuit, wherein the first voltage is used by the controller to determine a residual magnetic induction of the transformer.

16. The assembly of claim 15, wherein a ratio of the first ratio to the residual magnetic induction is the same as a second ratio of a hall coefficient of the hall element to a thickness of the hall element.

17. A magnetic induction assembly, comprising: the magnetic resistance circuit is arranged on a magnetic core of the transformer or in an air gap of the magnetic core; the magnetic resistance circuit comprises a first series branch formed by connecting a first magnetic resistance and a second magnetic resistance in series and a second series branch formed by connecting a third magnetic resistance and a fourth magnetic resistance in series;

the first end of the first series branch is connected with the first end of the second series branch, and the second end of the first series branch and the second end of the second series branch are respectively grounded; the first end of the first series branch is configured to receive an operating voltage provided by the processing circuit;

the processing circuitry to:

providing a set operating voltage to the magnetoresistive circuit;

collecting a voltage difference, wherein the voltage difference is a difference value between a first voltage at one end connected with the first magnetic resistance and the second magnetic resistance and a second voltage at one end connected with the third magnetic resistance and the fourth magnetic resistance; the equivalent resistance of the reluctance circuit is changed under the action of the residual magnetic induction intensity of the transformer, and the variation of the equivalent resistance of the reluctance circuit is the same as the ratio of the voltage difference to the working voltage; the variation and the residual magnetic induction intensity have a linear relation;

sending the voltage difference to a controller communicatively coupled to the processing circuit, the voltage difference being used by the controller to determine a residual magnetic induction of the transformer.

18. The assembly of claim 17, wherein the magnetoresistive circuit comprises one or more of a tunnel magnetoresistive sensor magnetoresistive TMR, anisotropic magnetoresistive AMR, and giant magnetoresistive GMR.

19. A magnetic induction intensity detection device is characterized by comprising a magnetic induction component and a controller; the Hall element of the magnetic induction assembly is arranged on a magnetic core of the transformer or in an air gap of the magnetic core;

the magnetic induction component is used for sending a first voltage, and the first voltage represents a voltage formed by working current in the Hall element under the action of residual magnetic induction of the transformer;

the controller is configured to:

receiving the first voltage;

and determining the magnetic induction intensity corresponding to the first voltage as the residual magnetic induction intensity of the transformer based on the set relation among the voltage of the Hall element, the working current and the magnetic induction intensity.

20. The magnetic induction detection apparatus of claim 19 wherein the magnetic induction assembly is the magnetic induction assembly of claim 15 or 16.

21. A magnetic induction intensity detection device is characterized by comprising a magnetic induction component and a controller; the magnetic resistance circuit of the magnetic induction assembly is arranged on a magnetic core of the transformer or in an air gap of the magnetic core;

the magnetic induction component is used for sending voltage parameters; the equivalent resistance of the reluctance circuit is changed under the action of the residual magnetic induction intensity of the transformer, wherein the variation of the equivalent resistance of the reluctance circuit is the same as the ratio of the voltage parameter to the working voltage of the reluctance circuit;

the controller is configured to:

receiving the voltage parameter;

and determining the magnetic induction intensity corresponding to the variable quantity as the residual magnetic induction intensity of the transformer based on the set linear relation between the variable quantity of the equivalent resistance of the magnetic resistance circuit and the magnetic induction intensity.

22. The apparatus of claim 21, wherein the magnetic induction assembly is the magnetic induction assembly of any of claims 17 or 18.

23. A transformer comprising a magnetic core, a primary winding, a secondary winding, and the magnetic induction detecting means according to any one of claims 19 to 22;

the primary winding and the secondary winding are respectively wound on the magnetic core to realize power conversion;

and part or all of the magnetic induction intensity detection device is arranged on the magnetic core, or is arranged in an air gap of the magnetic core and is used for detecting the magnetic induction intensity of the magnetic core.