Energy storage converter charging circuit and energy storage converter

Abstract

The utility model provides an energy storage converter charging circuit and an energy storage converter. The energy storage converter charging circuit comprises a detection circuit which generates different level state information according to different states of a normally open contact; the contactor is connected with the detection circuit and is used for triggering the state conversion of the normally open contact; one end of the relay is connected with the contactor; and the control circuit is respectively connected with the detection circuit and the other end of the relay. According to the exemplary embodiment, the detection circuit and the execution control are arranged, so that the locking function of closing control of the charging contactor and the main contactor of the energy storage converter is realized, and the safety of the energy storage converter is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of energy storage systems, and in particular, to an energy storage converter charging circuit and an energy storage converter. BACKGROUND

[0002] The energy storage converter is a core component of the electrochemical energy storage system, which converts the alternating current power of the power grid into direct current power stored in the energy storage battery, or converts the direct current power of the energy storage battery into alternating current power fed back to the power grid or directly supplied to the power equipment. The energy storage converter is divided into voltage source type energy storage converter and current source type energy storage converter, and the energy storage converter usually refers to the voltage source type energy storage converter.

[0003] The direct current input end of the energy storage converter has a parallel capacitor for voltage stabilization and filtering. In the case that there is no current limiting measure, directly closing the direct current terminal contactor of the energy storage converter to connect the energy storage battery and the parallel capacitor of the direct current input end of the energy storage converter will cause a problem similar to short circuit at the initial moment of charging the parallel capacitor of the direct current input end of the energy storage converter by the energy storage battery, and a very large capacitor charging inrush current will be generated. This inrush current will cause damage to the overcurrent protection device of the direct current input end of the energy storage converter, overcurrent impact or damage to the direct current terminal contactor of the energy storage converter, and health damage to the energy storage battery.

[0004] It should be noted that the statements herein only provide background information related to the present disclosure, and do not necessarily constitute the prior art. CONTENT OF THE INVENTION

[0005] In view of the above problems, an energy storage converter charging circuit and an energy storage converter are proposed to overcome the above problems or at least partially solve the above problems.

[0006] The embodiments of the present disclosure adopt the following technical solutions:

[0007] In a first aspect, an energy storage converter charging circuit is provided, comprising: a detection circuit configured to generate different level state information according to different states of a normally open contact; a contactor connected with the detection circuit and configured to trigger state conversion of the normally open contact; a relay having one end connected with the contactor; and a control circuit connected with the detection circuit and the other end of the relay, respectively.

[0008] Optionally, the detection circuit comprises a first detection circuit and a second detection circuit, the first detection circuit comprises a first normally open contact, and the second detection circuit comprises a second normally open contact.

[0009] Optionally, the contactors include a first contactor associated with the first normally open contact and a second contactor associated with the second normally open contact.

[0010] Optionally, the relays include a first relay having one end connected to the first contactor and the other end connected to the control circuit, and a second relay having one end connected to the second contactor and the other end connected to the control circuit.

[0011] Optionally, the normally open contacts include a normally open main contact and a normally open auxiliary contact. The circuit is disposed on a unit control board.

[0012] In a second aspect, there is provided an energy storage converter including a controller and a charging circuit as described in any of the first aspect.

[0013] The above at least one technical solution adopted by the exemplary embodiments can achieve the following beneficial effects:

[0014] According to the exemplary embodiments of the present disclosure, the working state of the contactor is monitored by the detection circuit, and the locking function of the DC end charging contactor and the main contactor closing control of the energy storage converter is realized by the cooperation of the unit circuits.

[0015] It should be understood that the summary section is not intended to identify key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0016] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which:

[0017] Figure 1 The schematic diagram of the DC end charging circuit of the energy storage converter in the embodiments of the present disclosure is shown in FIG. 1.

[0018] Figure 2 The control schematic diagram of the DC end charging circuit of the energy storage converter in the embodiments of the present disclosure is shown in FIG. 2. DETAILED DESCRIPTION

[0019] The principles of the present disclosure will now be described with reference to some embodiments. It should be understood that the description of these embodiments is merely intended to be illustrative and help the skilled person understand and implement the present disclosure, and does not impose any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in a manner different from that described below.

[0020] In the following description and claims, unless otherwise specified, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0021] Reference throughout this disclosure to "one embodiment", "an embodiment", "exemplary embodiment", or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

[0022] It should be understood that, although the terms "first" and "second" and the like can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the example embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed terms.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "set of elements" or "collection of elements" is intended to include one or more elements. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", when used herein, specify the presence of stated features, elements and / or components etc. but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0024] As used in this disclosure, the term "circuitry" can refer to one or more or all of the following:

[0025] (a) hardware-only circuit implementations (such as implementations in analog and / or digital circuitry)

[0026] (b) combinations of hardware circuits and software, such as (as applicable):

[0027] (i) combinations of analog and / or digital hardware circuit(s) with software / firmware

[0028] (ii) any portions of hardware processor(s) with software (including digital signal processors); and

[0029] (c) hardware circuitry and / or a processor, e.g., a microprocessor(s) or a portion of microprocessor(s), that requires software (e.g., firmware) for operation, but need not necessarily have software (e.g., firmware) present.

[0030] The definition of circuit applies to all uses of this term in this disclosure, including in any claims. As another example, as used in this disclosure, the term circuitry also includes implementations involving only hardware circuitry or processors (or multiple processors), or hardware circuitry or processors in combination with accompanying software and / or firmware, as appropriate for the particular claim element. The term circuitry also includes, for example, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or network device, as appropriate for the particular claim element.

[0031] In the exemplary embodiments, in view of the situation that the contactor misoperation may occur in the working of the DC terminal capacitor of the energy storage converter in the related art, a charging circuit with strong universality for the energy storage converter is designed. The charging circuit reduces the mis-triggering operation in the working of the energy storage converter by setting a detection circuit and a latching scheme.

[0032] The technical solutions provided by the embodiments of the present disclosure are described in detail below with reference to the drawings.

[0033] The disclosed embodiments provide an energy storage converter charging circuit and an energy storage converter. As shown in Figure 1 A schematic diagram of the DC terminal charging circuit of the energy storage converter in the disclosed embodiments is provided.

[0034] The DC terminal charging contactor KM1 of the energy storage converter is closed, and the energy storage battery charges the DC terminal parallel capacitor C1 of the energy storage converter through the charging current limiting circuit. After the DC terminal parallel capacitor C1 of the energy storage converter is charged to a voltage close to that of the energy storage battery, the second contactor KM2 of the DC terminal of the energy storage converter is closed, bypassing the DC terminal charging contactor KM1 and the current limiting resistor R1, and connecting the energy storage battery and the DC terminal parallel capacitor C1 of the energy storage converter. In the process of charging the DC terminal parallel capacitor by the energy storage battery controlled by the energy storage converter, the contactor KM1 may be mis-closed. Therefore, a contactor closing latching control scheme needs to be set.

[0035] To achieve the above charging control, the present disclosure provides an energy storage converter charging circuit, as shown in Figure 2 The charging circuit includes: a detection circuit, which generates different level state information according to different states of the normally open contact; a contactor connected with the detection circuit, used to trigger the state conversion of the normally open contact; a relay, one end of which is connected with the contactor; and a control circuit, the other end of the relay being connected with the control circuit.

[0036] As shown in Figure 2 , the detection circuit includes a first detection circuit (contactor KM1 closing detection circuit) and a second detection circuit (contactor KM2 closing detection circuit), the first detection circuit includes a first normally open contact, and the second detection circuit includes a second normally open contact.

[0037] The contactor includes a first contactor (contactor KM1) associated with the first normally open contact and a second contactor (contactor KM2) associated with the second normally open contact. It can be understood that the association includes triggering operation caused by electromagnetic induction of the two.

[0038] The relay includes a first relay (KA1) connected to the first contactor (contactor KM1) at one end and connected to the control circuit (core circuit) at one end, and a second relay (KA2) connected to the second contactor at one end and connected to the control circuit (core circuit) at the other end.

[0039] The normally open contact includes a normally open main contact and a normally open auxiliary contact. Each of the detection circuits includes a normally open main contact and a normally open auxiliary contact.

[0040] The control circuit is used to realize the related functions of the charging circuit. The charging circuit is arranged on the unit control board, and the unit control board interacts with the energy storage converter controller through a communication line.

[0041] In order to clearly illustrate the implementation scheme of the energy storage converter charging circuit in the present disclosure, the charging circuit will be described in detail.

[0042] As shown in Figure 2 , when the energy storage converter is working, the output end DC circuit breaker QF1 of the energy storage battery is closed. The controller of the energy storage converter sends the closing instruction of the first contactor KM1 of the DC end of the energy storage converter, and the control circuit in the charging circuit receives the closing instruction of the first contactor KM1 of the DC end of the energy storage converter, and controls the relay KA1 to close. The normally open contact of the relay KA1 is closed, so that the control coil of the first contactor KM1 of the DC end of the energy storage converter is powered. After the normally open main contact of the first contactor KM1 of the DC end of the energy storage converter is closed, the energy storage battery charges the parallel capacitor C1 of the DC end of the energy storage converter through the current limiting resistor R1. It should be noted that the normally open contact includes a normally open main contact and a normally open auxiliary contact, and the two operate synchronously.

[0043] As shown in Figure 2As shown, when the normally open main contact of the DC-side first contactor KM1 of the energy storage converter is not closed, the output state of the closing detection circuit (first detection circuit) of the DC-side first contactor KM1 is high, and the closing allow interlocking signal of the DC-side second contactor KM2 of the control circuit remains invalid; that is, when the normally open main contact of the first contactor KM1 is not closed, the second contactor KM2 is prohibited from performing a closing operation. Simultaneously with the closing of the normally open main contact of the DC-side first contactor KM1 of the energy storage converter, its normally open auxiliary contact also closes, and the output state of the closing detection circuit (first detection circuit) of the DC-side first contactor KM1 of the control circuit changes from high to low.

[0044] After the second contactor KM2 on the DC side of the control circuit closes, the output state of the closing detection circuit of the first contactor KM1 changes from high level to low level, and the timing starts. In one example, within a preset time period, such as 5 seconds, the blocking signal for the closing of the second contactor KM2 on the DC side remains invalid. That is, the operation of the second contactor KM2 is invalid during the 5 seconds when the first detection circuit is low. After 5 seconds of closing the second contactor KM2 on the DC side, the relevant operation commands of the second contactor KM2 on the DC side will be conditionally executed.

[0045] The controller of the energy storage converter detects the terminal voltage of the parallel capacitor C1 at the DC end of the energy storage converter. When the terminal voltage of the parallel capacitor C1 reaches the threshold that allows the closing of the second contactor KM2 at the DC end of the energy storage converter, the controller issues a closing command to the second contactor KM2. It can be understood that the controller's command for the second contactor KM2 is valid only when both the blocking duration threshold and the capacitor voltage threshold are met.

[0046] like Figure 2 As shown, after the control circuit receives the closing command of the second contactor KM2 on the DC side of the energy storage converter, if the closing allow interlocking signal of the second contactor KM2 on the DC side is valid, the control relay KA2 will close, the normally open contact of the relay KA2 will close, the control coil of the second contactor KM2 on the DC side of the energy storage converter will be energized, the normally open main contact of the second contactor KM2 on the DC side of the energy storage converter will close, bypassing the first contactor KM1 on the DC side of the energy storage converter and the current limiting resistor R1. The charging process of the energy storage battery to the parallel capacitor C1 on the DC side of the energy storage converter through the current limiting circuit ends.

[0047] The control circuit detects the closing state of the second contactor KM2 of the DC end of the energy storage converter and uploads it to the controller of the energy storage converter. It should be noted that when the normally open main contact of the second contactor KM2 of the DC end of the energy storage converter is closed, the normally open auxiliary contact is also closed, the output state of the closing detection circuit (second detection circuit) of the second contactor KM2 of the DC end of the control circuit is converted from high level to low level, and the unit control board uploads the output state of the closing detection circuit of the second contactor KM2 of the DC end to the controller of the energy storage converter.

[0048] After the energy storage converter detects the closing state of the second contactor KM2 of the DC end of the energy storage converter, it issues a closing instruction of the first contactor KM1 of the DC end of the energy storage converter after a fixed delay, and after the control circuit receives the closing instruction of the first contactor KM1 of the DC end of the energy storage converter, the unit control board controls the relay KA1 to open, the normally open contact of the relay KA1 is opened, the control coil of the first contactor KM1 of the DC end of the energy storage converter loses power, and the normally open main contact of the first contactor KM1 of the DC end of the energy storage converter is opened.

[0049] It should be understood that monitoring the state of the contactor through the detection circuit can reduce the misoperation caused by the abnormality of the interaction instruction; by setting the closing and opening conditions of the contactor (latch control), the operation timing of the contactor can be comprehensively judged, and the running stability of the energy storage converter can be improved.

[0050] The embodiment of the present disclosure also provides an energy storage converter comprising the charging circuit described above. For other parts of the energy storage converter, refer to the prior art, which will not be described herein.

[0051] It should be noted that in the description of the present application, the terms "first", "second" and the like are only used for descriptive purposes and should not be construed as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0052] In the present application, unless otherwise specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or electrical connection or communication with each other; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specified. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] In the present application, unless specifically stated and limited otherwise, a first feature "on" or "under" a second feature can be directly in contact with the second feature, or indirectly in contact with the second feature through an intermediate medium. Also, a first feature "over", "above" and "on top of" a second feature can mean the first feature is directly above or obliquely above the second feature, or simply means the first feature is horizontally higher than the second feature. A first feature "under", "below" and "underneath" a second feature can mean the first feature is directly below or obliquely below the second feature, or simply means the first feature is horizontally lower than the second feature.

[0054] Any process or method descriptions or blocks in flow charts described herein and elsewhere in this specification can be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process. Alternate implementations are included within the scope of the preferred embodiments of this application in which the functions performed by the various processes described herein and elsewhere in this specification are executed out of order from the described ordering, including substantially concurrently or in reverse order. Implementations have been described as related to the best mode implementation of the application, it is understood that various omissions and substitutions have been made without departing from the spirit of the application. This application is defined solely by the scope of the following claims.

[0055] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary, and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A charging circuit for an energy storage converter, characterized in that, include: The detection circuit generates different level status information based on the different states of the normally open contact; A contactor, connected to the detection circuit, is used to trigger the state transition of the normally open contact; A relay, one end of which is connected to the contactor; The control circuit is connected to the detection circuit and the other end of the relay.

2. The circuit as described in claim 1, characterized in that, The detection circuit includes a first detection circuit and a second detection circuit. The first detection circuit includes a first normally open contact, and the second detection circuit includes a second normally open contact.

3. The circuit as described in claim 2, characterized in that, The contactor includes a first contactor and a second contactor, the first contactor being associated with a first normally open contact and the second contactor being associated with a second normally open contact.

4. The circuit as described in claim 3, characterized in that, The relay includes a first relay and a second relay. One end of the first relay is connected to the first contactor, and the other end is connected to the control circuit; one end of the second relay is connected to the second contactor, and the other end is connected to the control circuit.

5. The circuit as described in any one of claims 1-4, characterized in that, The normally open contacts include normally open main contacts and normally open auxiliary contacts.

6. The circuit as described in any one of claims 1-4, characterized in that, The circuit is located on the unit control board.

7. An energy storage converter, comprising a controller and a charging circuit as described in any one of claims 1-6.

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