Excitation power supply and power converter

Abstract

The utility model discloses an excitation power supply and a power converter, and relates to the technical field of excitation fusing. According to the excitation power supply, when the switch is switched off, the energy storage element can be charged through the conversion circuit, so that the storage of electric energy is realized. When the switch is closed, the energy storage element can discharge electricity to the excitation fuse connected with the energy storage element through the switch, an ignition tube in the excitation fuse is ignited, and the fusing function of the excitation fuse is further achieved. Namely, the discharge of the energy storage element can satisfy the transient power required by the action of the ignition tube. Moreover, the electric energy received by the ignition tube is stored by the energy storage element instead of being directly output by the conversion circuit; therefore, the output response speed of the excitation power supply is greatly improved, and the rated power of the conversion circuit can be far less than the transient maximum power, so that the volume and no-load loss of the excitation power supply can be greatly reduced, and the cost of the excitation power supply can also be reduced.

Description

Technical Field

[0001] This application relates to the technical field of excitation fusing, and particularly to an excitation power supply and a power converter. Background Art

[0002] For a power converter, the protection of its DC side can be achieved by using an excitation fuse. Currently, for the excitation power supply used to control the breaking of the excitation fuse, in order to ensure that it can provide the large transient power required for the excitation fuse to operate, it is generally designed according to the transient maximum power. As a result, the volume and cost of this excitation power supply are greatly increased, and the no-load loss becomes larger, and the overall efficiency of the power converter decreases. Summary of the Utility Model

[0003] In view of the above problems, this application provides an excitation power supply and a power converter to avoid the problems of large volume, high cost, and large no-load loss caused by meeting the transient power requirements. The specific solutions are as follows:

[0004] In the first aspect of this application, an excitation power supply is provided, including: a conversion circuit, an energy storage element, and a switch; wherein,

[0005] The input side of the conversion circuit, as the input side of the excitation power supply, receives the supplied electric energy;

[0006] The energy storage element is connected between the positive and negative poles of the output side of the conversion circuit;

[0007] The connection point of the energy storage element and at least one pole of the output side of the conversion circuit is connected to the corresponding pole of the output side of the excitation power supply through the corresponding switch;

[0008] The output side of the excitation power supply is used to provide the electric energy for igniting the ignition tube in the excitation fuse;

[0009] The control end of the switch, as the control end of the excitation power supply, receives the trigger signal of the excitation fuse.

[0010] In a possible implementation, the energy storage element is a capacitor or a battery.

[0011] In a possible implementation, the number of the energy storage elements is greater than 1, and the number of the switches is greater than 1;

[0012] There are at least two paths of interfaces on the output side of the conversion circuit, and are respectively connected to the corresponding path of interfaces on the output side of the excitation power supply through the corresponding energy storage element and the switch;

[0013] Each of the energy storage elements is respectively connected between the positive and negative poles of the corresponding path of interfaces on the output side of the conversion circuit;

[0014] Between each of the energy storage elements and the corresponding path interfaces on the output side of the excitation power supply, there is respectively provided at least one corresponding switch.

[0015] In a possible implementation, the path interfaces on the output side of the conversion circuit are isolated from each other.

[0016] In a possible implementation, the conversion circuit is an isolated topology, and the isolated topology includes: a transformer, a primary circuit, and a secondary circuit;

[0017] The primary winding of the transformer is connected to the input side of the conversion circuit through the primary circuit;

[0018] The secondary winding of the transformer is connected to the output side of the conversion circuit through the secondary circuit.

[0019] In a possible implementation, the number of the secondary circuits in the isolated topology is greater than 1. The input ends of the secondary circuits are respectively connected to the corresponding secondary windings in the transformer, and the output ends of the secondary circuits are respectively connected to the corresponding path interfaces on the output side of the conversion circuit.

[0020] In a possible implementation, the excitation power supply further includes: a diode;

[0021] The diode is arranged in the discharge path of the energy storage element to the output side of the excitation power supply, and the conduction direction of the diode is the discharge direction of the energy storage element.

[0022] In a possible implementation, the excitation power supply further includes: a current limiting resistor;

[0023] The current limiting resistor is arranged in the charging path of the output side of the conversion circuit to the energy storage element.

[0024] In a possible implementation, the conversion circuit is: an AC / DC conversion circuit, or a DC / DC conversion circuit;

[0025] The AC side of the AC / DC conversion circuit serves as the input side of the conversion circuit; the DC side of the AC / DC conversion circuit serves as the output side of the conversion circuit;

[0026] Both sides of the DC / DC conversion circuit respectively serve as the input side and the output side of the conversion circuit.

[0027] In a possible implementation, the switch is a switching tube, a relay, or a contactor.

[0028] In a possible implementation, a corresponding switch is provided between the positive electrode of the energy storage element and the positive electrode on the output side of the excitation power supply;

[0029] Alternatively, a corresponding switch is provided between the negative electrode of the energy storage element and the negative electrode of the output side of the excitation power supply;

[0030] Or, a corresponding switch is respectively provided between the positive electrode of the energy storage element and the positive electrode of the output side of the excitation power supply, and between the negative electrode of the energy storage element and the negative electrode of the output side of the excitation power supply.

[0031] The second aspect of the present application provides a power converter, including: a main circuit, an excitation fuse, a current sampling device, a sampling trigger circuit, and an excitation power supply as described in the first aspect or any implementation form of the first aspect; wherein,

[0032] The power supply side of the main circuit is connected to the corresponding path interface of the power supply side of the power converter through at least one transmission branch;

[0033] In the transmission branch, a corresponding excitation fuse and a current sampling device are provided;

[0034] The igniter tube in the excitation fuse is ignited when the excitation power supply outputs electric energy;

[0035] The output end of the current sampling device is connected to the input end of the sampling trigger circuit;

[0036] The output end of the sampling trigger circuit is connected to the control end of the excitation power supply to output a trigger signal.

[0037] In a possible implementation, at least two transmission branches are connected to the power supply side of the main circuit; one side of each transmission branch is connected in parallel to the power supply side of the main circuit; the other side of each transmission branch is respectively connected to the corresponding path interface of the power supply side of the power converter;

[0038] And / or,

[0039] Only a corresponding excitation fuse is provided in the positive branch of the transmission branch, or only a corresponding excitation fuse is provided in the negative branch of the transmission branch, or corresponding excitation fuses are respectively provided in the positive branch and the negative branch of the transmission branch.

[0040] In a possible implementation, the two excitation fuses in the same transmission branch are connected to the same excitation power supply;

[0041] Or, when the number of transmission branches is greater than 1, the excitation fuses in at least two transmission branches are connected to the same excitation power supply.

[0042] In a possible implementation, the sampling trigger circuit includes: a bidirectional current sampling circuit, a forward trigger circuit, and a reverse trigger circuit;

[0043] The input terminal of the bidirectional current sampling circuit serves as the input terminal of the sampling trigger circuit;

[0044] The output terminal of the bidirectional current sampling circuit is respectively connected to the inverting input terminal of the forward trigger circuit and the non-inverting input terminal of the reverse trigger circuit;

[0045] The non-inverting input terminal of the forward trigger circuit receives a forward reference voltage;

[0046] The inverting input terminal of the reverse trigger circuit receives a reverse reference voltage;

[0047] The output terminals of the forward trigger circuit and the reverse trigger circuit are both connected to the output terminal of the sampling trigger circuit.

[0048] In a possible implementation, the forward reference voltage and / or the reverse reference voltage is an adjustable voltage.

[0049] With the above technical solution, for the excitation power supply provided in this application, when the switch is off, its energy storage element can receive charging through the conversion circuit to achieve electrical energy storage. When the switch is on, the energy storage element can discharge through the switch to the connected excitation fuse, ignite the igniter in the excitation fuse, and then enable the excitation fuse to achieve the fusing function; that is, the discharge of the energy storage element can meet the transient power required for the operation of the igniter. Moreover, the electrical energy received by the igniter comes from the storage of the energy storage element, rather than directly from the output of the conversion circuit; therefore, the output response speed of the excitation power supply is greatly improved, and at the same time, the rated power of the conversion circuit can be much smaller than the transient maximum power, thereby greatly reducing the volume and no-load loss of the excitation power supply, and also reducing the cost of the excitation power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In combination with the accompanying drawings and with reference to the following specific embodiments, the above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the original components and elements are not necessarily drawn to scale.

[0051] Figure 1 It is a schematic structural diagram of the excitation power supply provided by the embodiment of the present application;

[0052] Figure 2 It is another schematic structural diagram of the excitation power supply provided by the embodiment of the present application;

[0053] Figure 3Another structural schematic diagram of the excitation power supply provided by the embodiment of the present application;

[0054] Figure 4 Another structural schematic diagram of the excitation power supply provided by the embodiment of the present application;

[0055] Figure 5 Another structural schematic diagram of the excitation power supply provided by the embodiment of the present application;

[0056] Figure 6 Another structural schematic diagram of the excitation power supply provided by the embodiment of the present application;

[0057] Figure 7 Another structural schematic diagram of the excitation power supply provided by the embodiment of the present application;

[0058] Figure 8 Another structural schematic diagram of the excitation power supply provided by the embodiment of the present application;

[0059] Figure 9 Another structural schematic diagram of the excitation power supply provided by the embodiment of the present application;

[0060] Figure 10 Another structural schematic diagram of the excitation power supply provided by the embodiment of the present application;

[0061] Figure 11 A structural schematic diagram of a power converter provided by the embodiment of the present application;

[0062] Figure 12 Another structural schematic diagram of a power converter provided by the embodiment of the present application;

[0063] Figure 13 A structural schematic diagram of a sampling trigger circuit in a power converter provided by the embodiment of the present application. Detailed implementation manners

[0064] The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. The terms used in the embodiment part of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0065] The embodiments of the present application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application. As those of ordinary skill in the art can know, with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0066] In the description, claims and the above-mentioned drawings of this application, the terms "first", "second", etc. are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, which is merely a way of distinguishing objects with the same attributes when describing embodiments of this application. In addition, the terms "comprise", "include" and any of their variants are intended to cover non-exclusive inclusion, so that a process, method, system, product or device including a series of units does not have to be limited to those units, but may include other units not clearly listed or inherent to these processes, methods, products or devices.

[0067] An embodiment of this application provides an excitation power supply to avoid problems such as large volume, high cost and large no-load loss caused by meeting transient power requirements. The specific solution is as follows:

[0068] See Figure 1 , the excitation power supply 12 includes: a conversion circuit 101, an energy storage element 102 and a switch S; where:

[0069] The input side of the conversion circuit 101, as the input side of the excitation power supply 12, receives the supplied electric energy. The supplied electric energy can be DC electric energy or AC electric energy, which is not limited here and depends on its specific application environment; when the supplied electric energy is DC electric energy, the conversion circuit 101 is a DC / DC conversion circuit, and its two sides are respectively used as the input side and the output side of the conversion circuit 101: when the supplied electric energy is AC electric energy, the conversion circuit 101 is an AC / DC conversion circuit 101, its AC side is used as the input side of the conversion circuit 101, and its DC side is used as the output side of the conversion circuit 101. Moreover, the supplied electric energy can come from any position of the device where the excitation power supply 12 is located, such as the DC side or the AC side, which is not limited here either.

[0070] The energy storage element 102 is connected between the positive and negative poles of the output side of the conversion circuit 101, and can store the electric energy output by the conversion circuit 101 and release its own stored electric energy. Specifically, the energy storage element 102 can be a capacitor, but is not limited thereto; in practical applications, the energy storage element 102 can also use a battery, etc.; as long as it can store and release electric energy, it is within the protection scope of this application.

[0071] The connection point of the energy storage element 102 and at least one pole of the output side of the conversion circuit 101 is connected to the corresponding pole of the output side of the excitation power supply 12 through the corresponding switch S. That is, as Figure 1 shown in, only one switch S can be provided between the positive pole of the energy storage element 102 and the positive pole of the output side of the excitation power supply 12; or, as Figure 2As shown, a switch S' may also be provided only between the negative electrode of the energy storage element 102 and the negative electrode of the output side of the excitation power supply 12; or, as Figure 3 shown, a switch S may also be provided between the positive electrode of the energy storage element 102 and the positive electrode of the output side of the excitation power supply 12, and at the same time, a switch S' may be provided between the negative electrode of the energy storage element 102 and the negative electrode of the output side of the excitation power supply 12.

[0072] The control terminal of this switch (such as S shown in Figure 1 , or S' shown in Figure 2 , or S and S' shown in Figure 3 ) serves as the control terminal of the excitation power supply 12 and receives the trigger signal of the excitation fuse FU. In practical applications, this switch can be implemented by an electronic switch such as a switching tube, for example, a MOS (Metal Oxide Semiconductor) transistor. Moreover, when implemented with a MOS transistor, for Figure 1 and Figure 3 , the switch S can be implemented by a PMOS transistor, while for Figure 2 and Figure 3 , the switch S' shown needs to be implemented by an NMOS transistor; <s Figure 4 Taking Figure 1 as an example for illustration, when the trigger signal controls the PMOS transistor to conduct, the switch S closes; when the trigger signal controls the PMOS transistor to turn off, the switch S opens. Additionally, Figures 1 to 3 , the switches shown can also be implemented by mechanical switches such as relays or contactors, depending on their specific application environments, and all are within the protection scope of this application.

[0073] The output side of the excitation power supply 12 is used to provide the electrical energy for igniting the ignition tube in the excitation fuse FU, and then, after the ignition tube is ignited, it can push the grid pieces in the excitation fuse FU to act, realizing the active breaking of the excitation fuse FU, thereby achieving effective protection for the position where the excitation fuse FU is located; the internal structure of the excitation fuse FU can refer to the prior art and will not be elaborated here.

[0074] Taking Figure 1 as an example for illustration, the specific working principle of the excitation power supply 12 is as follows:

[0075] The conversion circuit 101 can convert the power supply electrical energy received on its input side into direct current electrical energy, and when the switch S is open, output the direct current electrical energy to the energy storage element 12 to charge the energy storage element 12, so that a certain amount of electrical energy is stored in the energy storage element 12.

[0076] When the switch S is closed under the control of a trigger signal, the electric energy stored in the energy storage element 12 can be quickly transmitted through the switch S to the excitation fuse FU, igniting the igniter tube in the excitation fuse FU, and then pushing the grid pieces of the excitation fuse FU to achieve a breaking action. The response speed is fast, and reliable transient energy support can be provided for the excitation fuse FU.

[0077] The excitation power supply 12 provided in this embodiment enables the excitation fuse FU to break by the above principle, and can meet the transient power required for the action of the igniter tube. Moreover, the electric energy received by the igniter tube comes from the storage of the energy storage element 102, rather than directly from the output of the conversion circuit 101; therefore, the output response speed of the excitation power supply is greatly improved, and at the same time, the rated power of the conversion circuit 101 can be much smaller than the transient maximum power, thereby greatly reducing the volume and no-load loss of the excitation power supply 12, and also reducing the cost of the excitation power supply 12.

[0078] In practical applications, the device where the excitation power supply 12 is located can be a battery energy storage converter, that is, the excitation power supply 12 can be applied to a battery energy storage converter; that is, when the side of the battery energy storage converter connected to the battery is protected by an excitation fuse, these excitation fuses can obtain the electric energy required for the action of the igniter tube through the excitation power supply 12 provided in this embodiment.

[0079] In addition, for a photovoltaic inverter, when its DC side is protected by a traditional gPV (indicating that it has fusing ability within the entire range in a photovoltaic power generation system, where g indicates the fusing ability range of the fuse and PV indicates the application range is a photovoltaic power generation system) fuse, there is a problem of slow response speed. Therefore, the DC side of the photovoltaic inverter can also use an excitation fuse to replace the traditional gPV fuse for protection. However, the action time of the igniter tube in the excitation fuse is generally within 1 ms, the transient power requirement is large, usually above 100 W, but the total energy requirement is small. If the output power of the excitation power supply used for the excitation fuse is small, the power support provided within the action time is insufficient, resulting in the inability of the excitation fuse to break reliably. And if the excitation power supply is designed according to the transient maximum power, it will lead to a significant increase in its volume and cost, and the no-load loss becomes larger, reducing the overall efficiency of the photovoltaic inverter. Therefore, the excitation fuse on the DC side of the photovoltaic inverter can also use the excitation power supply 12 provided in this embodiment to provide the electric energy required for the action of the igniter tube; at this time, the rated power of the excitation power supply 12 can be designed to be very small, such as about 5 W, greatly reducing the volume, cost and no-load loss of the excitation power supply 12 compared with the scheme designed according to the transient maximum power above 100 W.

[0080] The excitation power supply 12 can also be applied to other devices, such as other power converters in any scenario; this embodiment does not limit the devices to which the excitation power supply 12 is applied, and any device equipped with an excitation fuse can use the excitation power supply 12 to provide the electrical energy required for the ignitron to operate; it can be determined according to its specific application environment, and all are within the protection scope of this application.

[0081] Based on the previous embodiment, this embodiment gives another description of the structure of the excitation power supply 12. For example, there can be multiple interfaces on its output side; at this time, the number of energy storage elements 102 is greater than 1, and the number of switches is greater than 1, such as Figure 5 (taking the structure shown in Figure 1 as an example for display), the numbers of both can be n, where n is an integer greater than 1.

[0082] At this time, there are at least two paths ( Figure 5 taking n paths as an example for display) on the output side of the conversion circuit 101, and they are respectively connected to the corresponding path interfaces on the output side of the excitation power supply 12 through the corresponding energy storage elements 102 and switches.

[0083] Specifically, each energy storage element 102 is respectively connected between the positive and negative poles of the corresponding path interface on the output side of the conversion circuit 101. And between each energy storage element 102 and the corresponding path interface on the output side of the excitation power supply 12, there is respectively provided at least one switch; Figure 5 taking that between each energy storage element 102 and the corresponding path interface on the output side of the excitation power supply 12, there is respectively provided a corresponding one switch (such as Figure 5 the corresponding one among S1 to Sn shown in Figure 3 as an example for display); in actual application, when the excitation power supply 12 realizes multiple interfaces on the output side based on the structure shown in

[0084] In one example, the interfaces on the output side of each path of the conversion circuit 101 can be isolated from each other, thereby avoiding mutual interference between the excitation fuses (such as Figure 5 FU1 to FUn shown in

[0085] In an application scenario, on the DC side of a photovoltaic inverter, multiple photovoltaic power sources can be connected through multiple transmission branches respectively, and corresponding excitation fuses can be arranged in both the positive and negative branches of each transmission branch; for a centralized photovoltaic inverter, the voltage difference between the positive electrode PV+ and the negative electrode PV- of the connected photovoltaic power source can usually reach more than 1000V, such as 1500V. Therefore, for the excitation power supply 12 connecting multiple excitation fuses, the interfaces on the output side of each path not only need to isolate between each path of photovoltaic power source, but also need to isolate between the positive electrode PV+ and the negative electrode PV- of the same path of photovoltaic power source. In this embodiment, the interfaces on the output side of the conversion circuit 101 are isolated from each other, which can achieve the isolation between the positions of all the excitation fuses it connects, and avoid mutual interference between these positions.

[0086] In order to achieve the mutual isolation between the interfaces on the output side of the conversion circuit 101, the conversion circuit 101 can adopt an isolated topology; see Figure 6 (taking the structure shown in Figure 1 as an example for display), the isolated topology includes: a transformer T, a primary circuit 111 and a secondary circuit 112; among them, the primary winding P of the transformer T S , is connected to the input side of the conversion circuit 101 through the primary circuit 111; the secondary winding N of the transformer T S , is connected to the output side of the conversion circuit 101 through the secondary circuit 112.

[0087] In an example, the number of secondary circuits 112 in the isolated topology is greater than 1, see Figure 7 (taking the structure shown in Figure 5 as an example for display), the input ends of each secondary circuit 112 are respectively connected to the corresponding secondary windings in the transformer T (such as Figure 7 the N shown in S1 to Sn corresponding one), and the output ends of each secondary circuit 112 are respectively connected to the corresponding path interfaces on the output side of the conversion circuit 101.

[0088] The output side of the conversion circuit 101 adopts a multi-winding method, and different windings meet the safety requirements. It can not only achieve the mutual isolation between the interfaces on the output side of the conversion circuit 101, but also, in the application equipment of the excitation power supply 12, such as an energy storage converter or a photovoltaic inverter, when there are at least two transmission branches connecting batteries or photovoltaic power sources on the DC side, the excitation fuses in multiple transmission branches (such as Figure 7 the n excitation fuses FU1 to FUn shown in

[0089] For example, for a photovoltaic inverter, when multiple DC-side photovoltaic power sources are connected in parallel through corresponding transmission branches and multiple excitation fuses are used, the output side of the excitation power supply 12 is set to adopt the multi-winding method provided in this embodiment. The safety regulations requirements are met between different windings, which can avoid mutual interference between the poles of each photovoltaic power source and reduce the number of excitation power supplies 12 required by the photovoltaic inverter.

[0090] In practical applications, for an excitation fuse, in addition to being able to achieve external breaking control through the excitation power supply 12, it usually also has a self-excitation signal fuse inside. The maximum voltage difference across the two ends when the self-excitation signal fuse operates can reach 1500V, and it is directly connected to the output side of the excitation power supply 12. Therefore, the high-voltage transient impact caused by the operation of this signal fuse is extremely likely to damage the excitation power supply 12.

[0091] To avoid this problem, this embodiment provides another excitation power supply 12 on the basis of the above embodiment, such as Figure 8 (shown by taking Figure 7 as an example). As shown, the excitation power supply 12 further includes: diodes (such as Do1 to Don shown in Figure 8 ); the diodes are arranged in the discharge path of the energy storage element 102 to the output side of the excitation power supply 12, and the conduction direction of the diodes is the discharge direction of the energy storage element 102. As shown in Figure 8 , the output-side interfaces of each path of the conversion circuit 101 are respectively connected to the corresponding path interfaces of the output side of the excitation power supply 12 through corresponding energy storage elements 102, switches (a corresponding one of S1 to Sn), and diodes (a corresponding one of Do1 to Don).

[0092] For example, in a photovoltaic inverter, high-voltage diodes with a voltage of more than 1500V can be connected in series to the output side of its excitation power supply 12 (such as Do1 to Don shown in Figure 8 ). When the self-excitation signal fuse inside the excitation fuse (such as at least one of FU1 to FUn shown in Figure 8 ) operates, the generated voltage polarity is opposite to that of the corresponding diode (such as at least one of Do1 to Don corresponding in Figure 8 ), making the corresponding diode operate in the reverse cut-off state, which can effectively protect the low-voltage electronic devices inside the output side of the excitation power supply 12.

[0093] In practical applications, the diode can be arranged between the corresponding energy storage element 102 and the positive pole of the corresponding path interface of the output side of the excitation power supply 12 (such as in Figure 8shown), or can be disposed between the corresponding energy storage element 102 and the negative pole of the corresponding path interface on the output side of the excitation power supply 12 (not shown). As long as the conduction state of the diode is in the discharge direction of the corresponding energy storage element 102 and can achieve the above protection, it is within the protection scope of this application.

[0094] In addition, the excitation power supply 12 can also be as Figure 9 (taking Figure 8 as an example for display on the basis of Figure 9 ), which further includes, on the basis of the above embodiments: current limiting resistors (such as Rt1 to Rtn shown in Figure 9 ); the current limiting resistors are disposed in the charging path of the energy storage element 102 on the output side of the conversion circuit 101. The existence of the current limiting resistors can limit the current during the charging process of the corresponding energy storage element 102, thereby reducing the impact of the large current at the moment of charging the energy storage element 102 on the excitation power supply 12.

[0095] Figure 10 On the basis of Figure 9 , taking the conversion circuit 101 adopting a flyback isolation conversion topology and the energy storage element 102 adopting a capacitor (such as Cs1 to Csn shown in the figure) as an example for display, the sources of the trigger signals 1 to n are also shown, that is, n sampling trigger circuits (such as sampling trigger circuits #1 to n shown in the figure) 11; the specific working principle is:

[0096] Figure 10 The current acquisition signals 1 to n shown in are respectively the current acquisition signals in the branches where the excitation fuses FU1 to FUn are located; taking a photovoltaic inverter as an example, assuming that n / 2 paths of photovoltaic power supplies are connected to the DC side, and corresponding excitation fuses are respectively arranged in the positive and negative branches of the transmission branch of each path of photovoltaic power supply, that is, FU1 to FUn shown in the figure; then the current acquisition signal 1 can be the current acquisition signal in the branch where the excitation fuse FU1 is located, the current acquisition signal 2 can be the current acquisition signal in the branch where the excitation fuse FU2 is located,..., and the current acquisition signal n can be the current acquisition signal in the branch where the excitation fuse FUn is located.

[0097] The excitation power supply 12 can obtain the power supply electrical energy from the DC side of the photovoltaic inverter, output n paths of stable voltages through the conversion circuit 101, and the requirements of system safety regulations are met between each output.

[0098] Each output of the conversion circuit 101 charges the capacitor through the corresponding current limiting resistor; for example, the first output of the conversion circuit 101 charges the capacitor Cs1 through the current limiting resistor Rt1; the current limiting function of the current limiting resistor Rt1 can reduce the impact of the large current at the moment of charging the capacitor Cs1.

[0099] Each sampling trigger circuit 11 respectively obtains the corresponding current acquisition signal, and determines whether there is an abnormality in the corresponding branch according to the obtained current acquisition signal; for example, for sampling trigger circuit #1, when the obtained current acquisition signal 1 exceeds the corresponding threshold, it determines that the current in the branch where the excitation fuse FU1 is located is abnormal, and then controls the switch S1 to close by outputting a trigger signal 1. The capacitor Cs1 provides transient energy support externally, thereby igniting the igniter tube inside the excitation fuse FU1, causing the excitation fuse FU1 to perform active breaking; in addition, a high-voltage diode Do1 is added to the output side of the switch S1 to protect against the high-voltage impact generated inside the excitation fuse FU1.

[0100] The working principles of other branches are similar to the above process and will not be elaborated one by one.

[0101] The excitation power supply 12 provided in this embodiment can achieve a fast response to the trigger signal through the above principle, and can provide sufficient transient output power, enabling the rated power of the conversion circuit 101 to be greatly reduced, with small size, low no-load loss, and low cost; moreover, the conversion circuit 101 uses multiple windings to achieve multiple outputs, which can reduce the number of excitation power supplies 12, and the windings meet the system safety regulations requirements, avoiding mutual interference between the branches where each excitation fuse is located; in addition, the output side of the excitation power supply 12 has strong resistance to external high-voltage impact, which can effectively protect the low-voltage components inside the excitation power supply 12.

[0102] Another embodiment of this application also provides a power converter, as Figure 11 shown in, including: a main circuit 10, excitation fuses (such as FU1 to FU2m shown in the figure), current sampling devices (such as CT1 to CTm shown in the figure), sampling trigger circuits 11, and excitation power supplies (such as excitation power supply #1 to m) 12; where:

[0103] The power supply side of the main circuit 10 is connected to the corresponding path interface on the power supply side of the power converter through at least one transmission branch; for example, referring to Figure 11 , the power supply side of the main circuit 10 is connected with at least two transmission branches; one side of each transmission branch is connected in parallel to the power supply side of the main circuit 10; the other side of each transmission branch is respectively connected to the corresponding path interface on the power supply side of the power converter. In practical applications, the path interfaces on the power supply side of this power converter can be connected to corresponding power supplies, such as photovoltaic power supplies, batteries, or wind turbines, etc., which are not limited here; moreover, the power supplies connected to the path interfaces on the power supply side can be the same or different, depending on its specific application environment, and all are within the protection scope of this application. Taking this power converter as a photovoltaic inverter as an example for illustration, the path interfaces on its power supply side are respectively connected to the corresponding path photovoltaic power supplies; Figure 11In the figure, PV1+ represents the positive electrode of the first photovoltaic power source PV1, PV1- represents the negative electrode of the first photovoltaic power source PV1, ..., PVm+ represents the positive electrode of the m-th photovoltaic power source PVm, and PVm- represents the negative electrode of the m-th photovoltaic power source PVm.

[0104] The transmission branch is provided with corresponding excitation fuses and current sampling devices. In practical applications, corresponding excitation fuses can be provided in the positive and negative branches of the transmission branch, respectively. For example, the first transmission branch is provided with excitation fuses FU1 and FU2 and current sampling device CT1. The other transmission branches are similar. For details, please refer to Figure 11 Alternatively, the transmission branch can also be provided with a corresponding excitation fuse only in its positive branch, that is, the corresponding excitation fuse is removed. Figure 11 Alternatively, the transmission branch may also be provided with a corresponding excitation fuse only in its negative branch, that is, removing Figure 11 FU1, FU3, ..., FU2m-1; it depends on the specific application environment and is within the protection scope of this application.

[0105] The ignition tube in the excitation fuse is ignited when the excitation power supply 12 outputs electrical energy. The structure and working principle of the excitation power supply 12 can be found in the above embodiment and will not be described in detail here.

[0106] The output end of the current sampling device is connected to the input end of the sampling trigger circuit 11; the output end of the sampling trigger circuit 11 is connected to the control end of the excitation power supply 12 to output a trigger signal. Figure 11 The sampling trigger circuit #1 corresponding to the first photovoltaic power source is only shown as an example. Its input end is connected to the output end of the current sampling device CT1 in the first transmission branch, and its output end outputs the trigger signal 1 to the control end of the excitation power source #1. The other transmission branches are similar to this. For details, please refer to Figure 11 , I will not go into details one by one.

[0107] In one example, two excitation fuses can be set in the same transmission branch and connected to the same excitation power supply 12; Figure 11 As shown in FIG, the two excitation fuses FU1 and FU2 in the first transmission branch are connected to the same excitation power supply #1; the two excitation fuses FU3 and FU4 in the second transmission branch are connected to the same excitation power supply #2; and the two excitation fuses FU2m-1 and FU2m in the m-th transmission branch are connected to the same excitation power supply #m. In this case, the output side of the conversion circuit 101 of each excitation power supply 12 can be provided with two mutually isolated interfaces, for example, the transformer T can be provided with two secondary windings, that is, Figure 5 、 Figures 7 to 10where n = 2 to achieve isolation and breaking control of different excitation fuses in the positive and negative branches of the same transmission branch, avoiding interference to the positive and negative branches.

[0108] In another example, when the number of transmission branches is greater than 1, it is also possible to set that each excitation fuse in at least two transmission branches is connected to the same excitation power supply 12. Figure 12 Based on Figure 11 as an example for modification, refer to Figure 12 , the four excitation fuses FU1 to FU4 in the first and second-round transmission branches are connected to the same excitation power supply #1; at this time, n = 4 in the excitation power supply #1; and, the sampling trigger circuit #2 can be omitted, and this sampling trigger circuit #1 can only receive the current sampling signal 1 output by the current sampling device CT1 (as shown in Figure 12 ), or can only receive the current sampling signal 2 output by the current sampling device CT2, or can also receive both the current sampling signal 1 and 2 and control the four excitation fuses FU1 to FU4 to break equally when at least one of them exceeds the corresponding threshold; or, this excitation power supply #1 can also be connected to the sampling trigger circuits #1 and 2 at the same time and control the four excitation fuses FU1 to FU4 to break equally when receiving at least one of the trigger signals 1 and 2. In practical applications, the number of excitation fuses connected to the same excitation power supply 12 is not limited, and moreover, the number of excitation fuses connected to different excitation power supplies 12 can be the same or different, and this is not limited here either. In the case where there are corresponding excitation fuses only in one pole branch of the transmission branch, it can be deduced by analogy, and the corresponding excitation fuses in each positive or negative branch in Figure 12 and the connecting cables between them and the corresponding excitation power supply 12 can be removed, and will not be shown one by one.

[0109] In addition, it is also possible to set that all excitation fuses (such as FU1 to FU2m shown in Figure 11 ) are connected to the same excitation power supply 12. At this time, the setting of the sampling trigger circuit 11 can refer to the description in the previous paragraph and will not be repeated; in this structure, each excitation fuse FU1 to FU2m will act simultaneously.

[0110] For the corresponding setting between each excitation fuse and the excitation power supply 12, it can be set according to the actual application environment, and no limitation is made here. As long as the electrical energy when the igniter tube in the excitation fuse is ignited is provided by the excitation power supply 12 shown in the above embodiments, the advantages of small volume, low no-load loss, and low cost can be achieved; moreover, when the conversion circuit 101 uses multiple windings to achieve multiple outputs, the number of excitation power supplies 12 can be reduced, and the windings meet the system safety requirements, which can avoid mutual interference between the branches where each excitation fuse is located; in addition, the output side of the excitation power supply 12 has strong resistance to external high-voltage impact and can effectively protect the low-voltage components inside the excitation power supply 12.

[0111] It should be noted that in a photovoltaic system, due to the uncertainty of the short-circuit point position, the corresponding short-circuit current direction is bidirectional; and with the change of the on-site weather, the magnitude of the short-circuit current is also random. Therefore, on the basis of the above embodiments, this embodiment provides another implementation form of the power converter. For example, its sampling trigger circuit 11 includes Figure 13 as shown in: a bidirectional current sampling circuit 121, a forward trigger circuit 123, and a reverse trigger circuit 124; where:

[0112] The input end of the bidirectional current sampling circuit 121 serves as the input end of the sampling trigger circuit 11; the output end of the bidirectional current sampling circuit 121 is respectively connected to the inverting input end of the forward trigger circuit 123 and the non-inverting input end of the reverse trigger circuit 124; in practical applications, the output end of the bidirectional current sampling circuit 121 can be output through a filtering circuit 122, such as Figure 13 the RC filtering circuit shown in, but not limited thereto.

[0113] The non-inverting input end of the forward trigger circuit 123 receives a forward reference voltage Vref1; the inverting input end of the reverse trigger circuit 124 receives a reverse reference voltage Vref2. In practical applications, the forward reference voltage Vref1 can be an adjustable voltage, the reverse reference voltage Vref2 can also be an adjustable voltage, or both can be set as adjustable voltages; their values can be determined according to the specific application environment, and no limitation is made here.

[0114] The output ends of the forward trigger circuit 123 and the reverse trigger circuit 124 are both connected to the output end of the sampling trigger circuit 11 to output corresponding trigger signals.

[0115] With the above settings, the sampling trigger circuit 11 can collect bidirectional short-circuit current, and the fault current threshold for triggering, i.e., the above two reference voltages Vref1 and Vref2, is adjustable, enabling full-range protection of the current for different application scenarios; that is, the power converter can detect bidirectional short-circuit current, with fast response speed, strong transient support ability, small size, low loss, and the ability to withstand high external voltage impacts.

[0116] For the various embodiments in this specification, the same or similar parts can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for a system or system embodiment, since it is basically similar to a method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative efforts.

[0117] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Skilled professionals can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0118] Regarding the above description of the disclosed embodiments, the features recorded in each embodiment of this specification can be replaced or combined with each other, enabling those skilled in the art to implement or use this application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An excitation power supply, characterized in that, Comprising: A conversion circuit, an energy storage element, and a switch; wherein, The input side of the conversion circuit, as the input side of the excitation power supply, receives supply electric energy; The energy storage element is connected between the positive and negative poles of the output side of the conversion circuit; The connection point between the energy storage element and at least one pole of the output side of the conversion circuit is connected to the corresponding pole of the output side of the excitation power supply through the corresponding switch; The output side of the excitation power supply is used to provide the electric energy for igniting the ignition tube in the excitation fuse; The control end of the switch, as the control end of the excitation power supply, receives the trigger signal of the excitation fuse.

2. The excitation power supply according to claim 1, wherein The energy storage element is a capacitor or a battery.

3. The excitation power supply according to claim 1, characterized in that, The number of the energy storage elements is greater than 1, and the number of the switches is greater than 1; There are at least two interfaces on the output side of the conversion circuit, and are respectively connected to the corresponding interfaces of the output side of the excitation power supply through the corresponding energy storage elements and switches; Each of the energy storage elements is respectively connected between the positive and negative poles of the corresponding interface on the output side of the conversion circuit; Between each of the energy storage elements and the corresponding interface of the output side of the excitation power supply, at least one corresponding switch is respectively provided.

4. The excitation power supply according to claim 3, characterized in that, The interfaces on each path of the output side of the conversion circuit are isolated from each other.

5. The excitation power supply according to claim 1, wherein The conversion circuit is an isolated topology, and the isolated topology includes: a transformer, a primary circuit, and a secondary circuit; The primary winding of the transformer is connected to the input side of the conversion circuit through the primary circuit; The secondary winding of the transformer is connected to the output side of the conversion circuit through the secondary circuit.

6. The excitation power supply according to claim 5, characterized in that The number of the secondary circuits in the isolated topology is greater than 1, the input ends of each of the secondary circuits are respectively connected to the corresponding secondary windings in the transformer, and the output ends of each of the secondary circuits are respectively connected to the corresponding interfaces of the output side of the conversion circuit.

7. The excitation power supply according to any one of claims 1 to 6, characterized in that Further comprising: A diode; The diode is arranged in the discharge path of the energy storage element to the output side of the excitation power supply, and the conduction direction of the diode is the discharge direction of the energy storage element.

8. The excitation power supply according to any one of claims 1 to 6, characterized in that Further comprising: A current-limiting resistor; The current-limiting resistor is arranged in the charging path of the output side of the conversion circuit to the energy storage element.

9. The excitation power supply according to any one of claims 1 to 6, characterized in that, The conversion circuit is: an AC / DC conversion circuit, or a DC / DC conversion circuit; The AC side of the AC / DC conversion circuit is used as the input side of the conversion circuit; the DC side of the AC / DC conversion circuit is used as the output side of the conversion circuit; Both sides of the DC / DC conversion circuit are respectively used as the input side and the output side of the conversion circuit.

10. The exciting power supply according to any one of claims 1 to 6, characterized in that, The switch is a switching tube, a relay, or a contactor.

11. The exciting power supply according to any one of claims 1 to 6, characterized in that, A corresponding switch is provided between the positive pole of the energy storage element and the positive pole of the output side of the excitation power supply; Or, a corresponding switch is provided between the negative pole of the energy storage element and the negative pole of the output side of the excitation power supply; Or, corresponding switches are respectively provided between the positive pole of the energy storage element and the positive pole of the output side of the excitation power supply, and between the negative pole of the energy storage element and the negative pole of the output side of the excitation power supply.

12. A power converter, characterized in that, Comprising: A main circuit, an excitation fuse, a current sampling device, a sampling trigger circuit, and an excitation power supply according to any one of claims 1 to 11; wherein, The power supply side of the main circuit is connected to the corresponding path interface on the power supply side of the power converter through at least one transmission branch; In the transmission branch, the corresponding excitation fuse and the current sampling device are provided; The ignitron in the excitation fuse is ignited when the excitation power supply outputs electric energy; The output end of the current sampling device is connected to the input end of the sampling trigger circuit; The output end of the sampling trigger circuit is connected to the control end of the excitation power supply to output a trigger signal.

13. The power converter according to claim 12, characterized in that, The power supply side of the main circuit is connected with at least two transmission branches; on one side of each transmission branch, they are connected in parallel to the power supply side of the main circuit; on the other side of each transmission branch, they are respectively connected to the corresponding path interface on the power supply side of the power converter; And / or, In the transmission branch, the corresponding excitation fuse is only provided in its positive branch, or the corresponding excitation fuse is only provided in its negative branch, or the corresponding excitation fuses are respectively provided in the positive branch and the negative branch of the transmission branch.

14. The power converter according to claim 13, wherein, The two excitation fuses in the same transmission branch are connected to the same excitation power supply; Or, when the number of the transmission branches is greater than 1, there are at least two transmission branches in which each excitation fuse is connected to the same excitation power supply.

15. The power converter according to any one of claims 12 to 14, characterized in that The sampling trigger circuit includes: a bidirectional current sampling circuit, a forward trigger circuit, and a reverse trigger circuit; The input end of the bidirectional current sampling circuit serves as the input end of the sampling trigger circuit; The output end of the bidirectional current sampling circuit is respectively connected to the inverting input end of the forward trigger circuit and the non-inverting input end of the reverse trigger circuit; The non-inverting input end of the forward trigger circuit receives a forward reference voltage; The inverting input end of the reverse trigger circuit receives a reverse reference voltage; The output ends of the forward trigger circuit and the reverse trigger circuit are both connected to the output end of the sampling trigger circuit.

16. The power converter according to claim 15, characterized in that, The forward reference voltage and / or the reverse reference voltage is an adjustable voltage.

Images