Bypass circuit of converter, unit control board and converter
By employing a bypass circuit design with fully controlled power electronic switches and voltage divider resistors in a cascaded multilevel converter, the problems of high cost and poor adaptability of bypass circuits are solved, achieving a low-cost and highly adaptable bypass circuit.
Patent Information
- Application Number
- CN202411721739.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-03-07
AI Technical Summary
In the existing technology, the bypass circuit of the cascaded multilevel converter has high hardware cost, is not easy to adjust, and has poor adaptability.
Design a bypass circuit for a converter. By combining the power supply circuit and the control circuit, a fully controlled power electronic switch is used as the closing control switch for the contactor. A voltage divider resistor and a Zener diode are used to provide power to the contactor, reducing the number of components and material costs.
A reliable closing power supply and closing control circuit were achieved, reducing circuit complexity, lowering component costs, and improving circuit adaptability.
Smart Images
Figure CN119582117A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of energy storage technology, and in particular to a bypass circuit of a converter, a unit control board and a converter. Background Art
[0002] Cascaded multilevel converters with bypass function usually use contactors as bypass devices of cascaded multilevel converters. Vacuum contactors can be manually opened and closed, electrically controlled, and permanently magnetically maintained. They have the advantages of small size, small closing power supply capacity, simple control circuit, and mechanically maintained closing.
[0003] In the related art, the bypass circuit of the converter has high hardware cost, is difficult to adjust after the circuit is determined, and has poor adaptability.
[0004] It should be noted that the statements herein merely provide background information related to the present disclosure and do not necessarily constitute prior art. Summary of the invention
[0005] In view of the above problems, a bypass circuit of a converter, a unit control board and a 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, a bypass circuit of a converter is provided, wherein the converter comprises a plurality of cascade unit modules, each of the cascade unit modules comprises a support capacitor; the bypass circuit comprises: a power supply circuit and a control circuit, the power supply circuit and the control circuit are respectively connected in parallel with the support capacitor; in response to the charging process of the support capacitor, the power supply circuit stores electricity to provide working power for the control circuit.
[0008] Preferably, the bypass circuit also includes a switching circuit, the power supply circuit includes at least a first power supply circuit and a second power supply circuit, and the first power supply circuit and the second power supply circuit are connected in series; the control circuit includes at least a trigger circuit and an execution circuit, and the trigger circuit and the execution circuit are connected in series; in response to the closing operation of the switching circuit, after the first power supply circuit supplies power to the trigger circuit, the second power supply circuit supplies power to the execution circuit to close the contactor in the cascade unit module so that the cascade unit module is bypassed.
[0009] Preferably, the power supply circuit further includes a first resistor, a first diode, and a second diode, and the first resistor, the first diode, and the second diode are connected in series and in parallel with the support capacitor;
[0010] The first power supply circuit is connected in parallel with the second diode, and the second power supply circuit is connected in parallel with a series circuit of the first diode and the second diode.
[0011] Preferably, the first power supply circuit includes a first capacitor, the second power supply circuit includes a third capacitor and a fifth resistor, and the third capacitor and the fifth resistor are connected in parallel.
[0012] Preferably, the power supply circuit further includes a third diode, a second resistor and a second capacitor, and the third diode, the second resistor and the second capacitor are connected in series and then in series with the fifth resistor.
[0013] Preferably, the control circuit includes a trigger circuit and an execution circuit, the trigger circuit includes a fully-controlled power electronic switch, the fully-controlled power electronic switch includes an IGBT, the first end of the IGBT is connected to one end of the first capacitor through a third resistor, and the second end of the IGBT is connected to the other end of the first capacitor.
[0014] Preferably, the execution circuit includes a control coil and a fourth diode, the fourth diode is connected in parallel with the control coil, the control coil is connected to the third end of the IGBT through a fourth resistor, and the second end of the control coil is connected to one end of the second capacitor.
[0015] Preferably, the power supply circuit further includes a normally closed auxiliary contact, and the normally closed auxiliary contact is connected in parallel with the second capacitor.
[0016] Preferably, the switch circuit comprises a relay normally open contact, and the relay normally open contact is arranged between the third resistor and the first capacitor.
[0017] In a second aspect, a unit control board is provided, comprising a bypass circuit as described in any one of the first aspects.
[0018] According to a third aspect, a converter is provided, comprising the unit control board according to the second aspect.
[0019] At least one of the above technical solutions adopted by the exemplary embodiment can achieve the following beneficial effects:
[0020] In an exemplary embodiment of the present disclosure, the bypass circuit of the converter provides a reliable closing power supply, a closing control loop power supply and a simple control circuit; the bypass circuit uses a small number of components, and the component materials are low in cost and easy to obtain.
[0021] It should be understood that the invention summary is not intended to identify the 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 easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of some embodiments of the present disclosure in the accompanying drawings, in which:
[0023] Figure 1 Schematic diagram of a bypass circuit of a converter in an embodiment of the present disclosure;
[0024] Figure 2 4 is a circuit diagram of a bypass circuit of a converter in an embodiment of the present disclosure. Figure 3 Schematic diagram of bypass circuit connection of the converter in the embodiment of the present disclosure; Figure 4 The figure shows the connection relationship between the unit control board and the converter controller in the embodiment of the present disclosure. DETAILED DESCRIPTION
[0025] The principle of the present disclosure will now be described with reference to some embodiments. It should be understood that the description of these embodiments is only for illustrative purposes, and helps those skilled in the art to understand and implement the present disclosure, without any limitation to the scope of the present disclosure. The disclosure described herein can be implemented in a manner different from that described below.
[0026] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.
[0027] References in this disclosure to "one embodiment," "an embodiment," "an exemplary embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an exemplary embodiment, whether or not explicitly described, those skilled in the art will recognize that such feature, structure, or characteristic affects incorporation into other embodiments.
[0028] It should be understood that although the terms "first" and "second" etc. may be used to describe various elements herein, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term "and / or" as used herein includes any and all combinations of one or more of the listed terms.
[0029] The terms used herein are only for describing specific embodiments, rather than for limiting exemplary embodiments. The singular forms "one", "an", and "the" used herein also include plural forms, unless the context clearly indicates otherwise. "A group of elements" or "element set" used herein is intended to include one or more elements. It should also be understood that the terms "include", "comprise", "have", "have", "include" and / or "include", when used herein, specify the presence of the features, elements and / or parts, etc., but do not exclude the presence or addition of one or more other features, elements, parts and / or combinations thereof.
[0030] As used in this disclosure, the term "circuitry" may refer to one or more or all of the following:
[0031] (a) Hardware circuit implementation only (e.g., implementation only in analog and / or digital circuits)
[0032] (b) a combination of hardware circuitry and software, such as (where applicable):
[0033] (i) a combination of analog and / or digital hardware circuits and software / firmware; and
[0034] (ii) any portion of a hardware processor (including a digital signal processor) with software, software and memory that work together to enable a device such as a mobile phone or server to perform various functions, and
[0035] (c) A hardware circuit and / or processor, such as a microprocessor or portion of a microprocessor, that requires software (e.g., firmware) to operate, but where software is not required for operation, the software may not be present.
[0036] This definition of circuitry 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 merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware implementation. The term circuitry also includes, for example, if applicable to the particular claim element, 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 network device.
[0037] Cascaded multilevel converters have the advantages of high output voltage level, high output power level, low output current harmonic content, modular structure, high redundancy, and easy expansion. They are widely used in high-voltage frequency converters, cascaded energy storage converters, high-voltage static VAR generators, high-voltage active filters, AC flexible transmission, and high-voltage DC transmission.
[0038] Cascaded multilevel converters generally use single-phase full-bridge or half-bridge topology as the core topology of cascaded unit module power electronics. Several unit modules are cascaded to form a single-phase converter, and three single-phase converters are connected in star or delta connection to form a three-phase converter. The number of power devices in cascaded multilevel converters is large, which increases the number of fault points; the failure of the power device of the cascaded unit module will affect the normal operation of the converter.
[0039] In order to achieve high reliability of the cascaded multilevel converter, a bypass device is connected in parallel to the AC output end of the cascade unit module to bypass the cascade unit module when a fault occurs, so as to ensure that the cascaded multilevel converter continues to operate normally.
[0040] Commonly used bypass technology solutions include: anti-parallel thyristors or bidirectional thyristors, rectifier bridge thyristors, reverse series IGBTs, anti-parallel IGBTs in series with diodes, anti-parallel diodes in series with thyristors, contactors, etc.
[0041] When the bypass technology solution uses power electronic devices as core components, it is not only necessary to configure a dedicated control circuit to achieve the bypass function, but also to configure a heat dissipation device to ensure that the power electronic devices operate within the allowable temperature range. The use of semi-controlled power electronic devices also has the problem of current discontinuity.
[0042] The bypass technology solution of cascaded multilevel converter uses contactor as the core component, and the power supply modes applied to high-voltage inverter are:
[0043] 1. The input side of the single-phase isolation transformer is connected to the AC input terminal of the cascade unit module, and the output of the single-phase isolation transformer is directly used for the control coil power supply of the contactor.
[0044] 2. The input side of the single-phase isolation transformer is connected to the AC input terminal of the cascade unit module, and the output side of the single-phase isolation transformer is connected to the input terminal of the AC / DC conversion circuit. The output of the AC / DC conversion circuit is used for the control coil power supply of the contactor.
[0045] The contactor power supply modes used in high-voltage frequency converters, high-voltage static VAR generators, etc. are:
[0046] 1. The DC support capacitor voltage of the cascade unit module is converted by the power module and used as the control coil power supply of the contactor;
[0047] 2. The DC support capacitor voltage of the cascaded unit module is converted by the auxiliary power circuit and used for the control coil power supply of the contactor and the unit module control board power supply.
[0048] The above technical solution has the following disadvantages:
[0049] 1. The material cost is relatively high when using a single-phase isolation transformer or a single-phase isolation transformer plus an AC / DC conversion circuit.
[0050] 2. The power supply mode in which the power module or the auxiliary source circuit is connected in parallel at both ends of the DC support capacitor of the cascade unit module has high material cost, and the output of the power module or the auxiliary source circuit is difficult to adjust after being determined, and has poor adaptability.
[0051] In the exemplary embodiments disclosed herein, in view of the current situation in the related art that the bypass circuit of the converter is of high cost, difficult to adjust and has poor adaptability, a bypass circuit of the converter with strong universality is designed. The bypass circuit of the converter reduces the complexity of the circuit, reduces the circuit cost and improves the adaptability of the circuit through the combination of the power supply circuit and the control circuit.
[0052] The technical solutions provided by various embodiments of the present disclosure are described in detail below in conjunction with the accompanying drawings.
[0053] The disclosed embodiments provide a bypass circuit of a converter, a unit control board and a converter. Figure 1 As shown, a schematic diagram of a bypass circuit 100 of a converter in an embodiment of the present disclosure is provided, wherein the converter includes a plurality of cascade unit modules 110, each of which includes a support capacitor; the bypass circuit includes: a power supply circuit 120, a control circuit 130, and a switch circuit 140, wherein the power supply circuit 120 and the control circuit 130 are connected in parallel with the support capacitor; the power supply circuit 120 includes at least a first power supply circuit 1201 and a second power supply circuit 1202. The support capacitor is a DC support capacitor C0, reference Figure 3 .
[0054] When the converter is in shutdown state, the terminal voltage U of the converter's DC support capacitor C0 is C0 is 0V, the converter changes from shutdown state to running state, and the terminal voltage U of the converter's DC support capacitor C0 is C0 It gradually increases from 0V to the working voltage set by the converter. The terminal voltage U of the DC support capacitor C0 of the converter C0 In the process of gradually increasing from 0V to the working voltage set by the converter, the DC support capacitor C0 supplies power to the first power supply circuit and the second power supply circuit respectively, and the first power supply circuit and the second power supply circuit store power.
[0055] When the converter switches from the running state to the shutdown state, the terminal voltage U C0 The rated working voltage is gradually reduced to 0V, and the power supply circuit releases the stored electric energy to ensure the safety of the bypass circuit.
[0056] In response to the closing operation of the switch circuit 140, after the first power supply circuit 1201 supplies power to the trigger circuit 1301 in the control circuit, the second power supply circuit 1202 supplies power to the execution circuit 1302 in the control circuit, and the trigger circuit is used to start the execution circuit, and the execution circuit is used to close the contactor so that the cascade unit module is bypassed.
[0057] like Figure 2 , Figure 3 As shown, the power supply circuit also includes a first resistor R1, a first diode D1, and a second diode D2. The first resistor R1, the first diode D1, and the second diode D2 are connected in series and then connected in parallel with the (DC) support capacitor; the first power supply circuit 1201 is connected in parallel with the second diode D2, and the second power supply circuit 1202 is connected in parallel with the series circuit of the first diode D1 and the second diode D2. Among them, the first diode D1 and the second diode D2 are voltage-stabilizing diodes. The first diode D1 and the second diode D2 are reversely connected in the circuit. R1 is a current-limiting resistor, D1 is a voltage-stabilizing diode, and C1 is an energy storage capacitor. The DC support capacitor C0 charges the energy storage capacitor C1 through the current-limiting resistor R1 and the voltage-stabilizing diode D1. The breakdown voltage of D1 is greater than the breakdown voltage of D2.
[0058] Continue to refer Figure 2 , the first power supply circuit 1201 includes a first capacitor C1, and the second power supply circuit 1202 includes a third capacitor C3 and a fifth resistor R5, and the third capacitor C3 and the fifth resistor R5 are connected in parallel. The power supply circuit 120 also includes a third diode D3, a second resistor R2 and a second capacitor C2, and the third diode D3, the second resistor R2 and the second capacitor C2 are connected in series with the fifth resistor R5. Among them, C2 is a fire extinguishing capacitor, which is used to prevent the contact from sparking when the normally closed contact of the contactor turns normally open, D3 is an anti-reverse diode, R2 is a current limiting resistor, and C3 is an energy storage capacitor. The DC support capacitor C0 charges the energy storage capacitor C3 through the current limiting resistor R1, the anti-reverse diode D3, the current limiting resistor R2 and the normally closed auxiliary contact of the bypass contactor KM1.
[0059] The control circuit 130 includes a trigger circuit 1301 and an execution circuit 1302. The trigger circuit 1301 includes a fully controlled power electronic switch (IGBT) Q1. The first end of the IGBT is connected to one end of the first capacitor C1 through a third resistor R3, and the second end of the IGBT is connected to the other end of the first capacitor C1.
[0060] The execution circuit 1302 includes a (contactor KM1) control coil and a fourth diode D4, the fourth diode D4 is connected in parallel with the control coil, the control coil is connected to the third end of the IGBT through a fourth resistor R4, and the second end of the control coil is connected to one end of the second capacitor C2. The power supply circuit 120 also includes a (KM1) normally closed auxiliary contact, the normally closed auxiliary contact is connected in parallel with the second capacitor C2. The switch circuit 140 includes a relay (KA1) normally open contact, the relay normally open contact is arranged between the third resistor R3 and the first capacitor C1. Among them, Q1 is a fully controlled power electronic switch (IGBT), C3 is a storage capacitor, and R4 is a current limiting resistor. When the relay control circuit controls relay KA1 to close, the energy storage capacitor C1 applies gate voltage to the fully controlled power electronic switch Q1 through the current limiting resistor R3, and the fully controlled power electronic switch Q1 is turned on. The energy storage capacitor C3 applies closing voltage to the closing coil of the bypass contactor KM1 through the current limiting resistor R4 and the fully controlled power electronic switch Q1. The current limiting resistor R4 limits the closing current of the closing coil, and the normally open main contact of the bypass contactor KM1 is closed and remains in a closed state.
[0061] It can be understood that in the bypass circuit in the disclosed embodiment, the power supply circuit and the control circuit are connected in parallel at the positive bus terminal and the negative bus terminal of the supporting capacitor of the cascade unit module, and a voltage-dividing resistor and two voltage-stabilizing diodes with different breakdown voltages are connected in series for voltage division. An energy storage capacitor is connected in parallel at both ends of the voltage-stabilizing diode with a low breakdown voltage to store electrical energy as the power supply for the closing control circuit of the bypass contactor. After the high breakdown voltage diode and the low breakdown voltage diode are connected in series, the energy storage capacitor is charged through a current-limiting resistor to store energy as the power supply for the closing coil of the bypass contactor. The closing control circuit of the bypass contactor uses a fully controlled power electronic device as a switch, which is connected in series between the contactor closing power supply and the contactor coil. The power supply circuit and the control circuit of the bypass contactor use a small number of components and low material cost, which can provide the bypass contactor with a reliable closing power supply, a closing control circuit power supply and a simple control circuit.
[0062] In the present disclosure, the working principle of the power supply circuit 120 is as follows:
[0063] 1. When the (cascaded multilevel) converter is in shutdown state, the terminal voltage U of the DC support capacitor C0 of the converter is C0 The terminal voltage U of the energy storage capacitor C1 in the power supply circuit of the bypass contactor is 0V. C1 is 0V and the terminal voltage U of the energy storage capacitor C3 C3 is 0V.
[0064] 2. When the cascaded multilevel converter switches from shutdown state to running state, the terminal voltage U of the DC support capacitor C0 of the converter C0 Gradually increase from 0V to the working voltage set by the converter:
[0065] 2.1、Terminal voltage U of the DC support capacitor C0 of the converter C0 In the process of gradually increasing from 0V to the working voltage set by the converter, the DC support capacitor C0 charges the energy storage capacitor C1 through the current limiting resistor R1 and the voltage stabilizing diode D1. The terminal voltage U C1 Gradually increases; the terminal voltage U of the energy storage capacitor C1 C1 Higher than the breakdown voltage V of Zener diode D2 BR(D2) When the voltage-stabilizing diode D2 remains in breakdown state, the terminal voltage of the energy storage capacitor C1 and the voltage-stabilizing diode D2 remains V BR(D2) , the terminal voltage U of the energy storage capacitor C1 C1 It is within the gate turn-on voltage range allowed by the power electronic switching device Q1.
[0066] 2.2. The terminal voltage U of the DC support capacitor C0 of the converter C0 In the process of gradually increasing from 0V to the working voltage set by the converter, the DC support capacitor C0 charges the energy storage capacitor C3 through the current limiting resistor R1, the anti-reverse diode D3, the current limiting resistor R2 and the normally closed auxiliary contact of the bypass contactor KM1. The terminal voltage U C3 Gradually increases; the terminal voltage U of the current limiting resistor R1 R1 , the voltage drop of the anti-reverse diode D3 is V D3 , the terminal voltage U of the current limiting resistor R2 R2 and the terminal voltage U of the energy storage capacitor C3 C3 The sum of the voltages is higher than the breakdown voltage V of Zener diode D1 BR(D1) and the breakdown voltage of Zener diode D2 V BR(D2) When the sum of the voltages of the Zener diodes D1 and D2 is reached, the Zener diodes D1 and D2 remain in breakdown state, and the terminal voltage of the Zener diodes D1 and D2 connected in series remains V BR(D1) With V BR(D2) The total terminal voltage U of the energy storage capacitor C3 C3 No longer increases, the terminal voltage U C3 It is within the closing voltage range required by bypass contactor KM1.
[0067] 3. When the cascaded multilevel converter switches from the running state to the shutdown state, the terminal voltage U of the DC support capacitor C0 of the converter C0 From the rated working voltage gradually reduced to 0V:
[0068] 3.1、Terminal voltage U of DC support capacitor C0 C0 Higher than the breakdown voltage of Zener diode D1 V BR(D1) and the breakdown voltage of Zener diode D2 V BR(D2) The sum of the phases, the terminal voltage U of the energy storage capacitor C3C3 Remains unchanged; the terminal voltage U of the DC support capacitor C0 C0 Not higher than the breakdown voltage of the Zener diode D1 V BR(D1) and the breakdown voltage of Zener diode D2 V BR(D2) In the summation stage, the electric energy stored in the energy storage capacitor C3 is consumed by the resistor R5, and its terminal voltage U C3 Gradually decrease to 0V.
[0069] 3.2. Terminal voltage U of DC support capacitor C0 C0 Higher than the breakdown voltage V of Zener diode D2 BR(D2) In the stage, the terminal voltage U of the energy storage capacitor C1 C1 Remains unchanged; the terminal voltage U of the DC support capacitor C0 C0 Not higher than the breakdown voltage V of the Zener diode D2 BR(D2) In the stage, the terminal voltage U of the energy storage capacitor C1 C1 Gradually decrease to 0V.
[0070] In the present disclosure, the working principle of the control circuit 130 is as follows:
[0071] 1. When the cascade multilevel converter operates normally, the bypass contactor of the converter remains in the open state. The bypass contactor control signal sent by the converter controller to the unit control board is an open signal. After the unit control board decodes the bypass contactor control signal sent by the controller, the relay control circuit controls the relay KA1 to remain in the open state, and the normally open contact of the relay KA1 remains in the open state.
[0072] 2. During the operation of the cascaded multilevel converter, when the controller detects that a bypassable fault occurs in the cascaded unit module, the controller sends a bypass contactor closing control signal to the unit control board. After the unit control board decodes the bypass contactor control signal sent by the controller, the relay control circuit controls the relay KA1 to close, and the energy storage capacitor C1 applies a gate voltage to the fully controlled power electronic switch Q1 through the current limiting resistor R3. The fully controlled power electronic switch Q1 is turned on, and the energy storage capacitor C3 applies a closing voltage to the closing coil of the bypass contactor KM1 through the current limiting resistor R4 and the fully controlled power electronic switch Q1. The current limiting resistor R4 limits the closing current of the closing coil, and the normally open main contact of the bypass contactor KM1 is closed and remains closed. The bypass contactor KM1 bypasses the faulty unit, and the cascaded multilevel converter continues to operate.
[0073] 3. The unit-controlled contactor KM1 status detection circuit detects the contactor KM1 status and uploads the status information to the controller.
[0074] It can be understood that the power supply circuit and control circuit of the bypass circuit for the bypass contactor are connected in parallel at the positive bus terminal and negative bus terminal of the DC support capacitor of the cascade unit module, and two voltage regulator diodes with different breakdown voltages are used in series for voltage division. The energy storage capacitor connected in parallel at both ends of the low breakdown voltage voltage regulator diode stores electrical energy as the control power supply of the fully controlled power electronic switch of the bypass contactor closing control circuit. The voltage divided by the high breakdown voltage diode and the low breakdown voltage diode in series charges the energy storage capacitor through the current limiting resistor to store energy as the power supply of the bypass contactor closing coil; the closing control switch of the bypass contactor uses a fully controlled power electronic device, and the gate drive voltage of the fully controlled power electronic device is low, and the capacity requirement of the power supply is small. The power supply circuit and the control circuit can provide a reliable closing power supply, a closing control circuit power supply and a simple control circuit for the bypass contactor. The bypass circuit uses a small number of components, and the cost of the component materials is low and easy to obtain. The two power supply voltages of the power supply circuit and the control circuit are easy to adjust, and the selection of the voltage regulator diode and the working voltage of the energy storage capacitor can be adjusted.
[0075] The present disclosure also provides a unit control board, comprising any bypass circuit as described in the first aspect. Figure 4 As shown, the bypass circuit is integrated on the unit control board and exchanges information with the converter controller. The working process of the unit control board can be referred to the above description.
[0076] The present disclosure also provides a converter, including the above-mentioned unit control board. For other parts of the converter, please refer to the prior art, which will not be described here.
[0077] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.
[0078] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0079] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0080] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.
[0081] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0082] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A bypass circuit of a converter, characterized in that: The converter comprises a plurality of cascade unit modules, each of which comprises a supporting capacitor; The bypass circuit comprises: A power supply circuit and a control circuit, wherein the power supply circuit and the control circuit are respectively connected in parallel with the support capacitor; In response to the charging process of the support capacitor, the power supply circuit stores electricity to provide working power for the control circuit.
2. The bypass circuit according to claim 1, characterized in that: The bypass circuit further includes a switch circuit, the power supply circuit includes at least a first power supply circuit and a second power supply circuit, the first power supply circuit and the second power supply circuit are connected in series; the control circuit includes at least a trigger circuit and an execution circuit, the trigger circuit and the execution circuit are connected in series; In response to the closing operation of the switch circuit, after the first power supply circuit supplies power to the trigger circuit, the second power supply circuit supplies power to the execution circuit to close the contactor in the cascade unit module so that the cascade unit module is bypassed.
3. The bypass circuit according to claim 2, characterized in that: The power supply circuit further includes a first resistor, a first diode, and a second diode, wherein the first resistor, the first diode, and the second diode are connected in series and in parallel with the support capacitor; The first power supply circuit is connected in parallel with the second diode, and the second power supply circuit is connected in parallel with a series circuit of the first diode and the second diode.
4. The bypass circuit as claimed in claim 3, characterized in that: The first power supply circuit includes a first capacitor, and the second power supply circuit includes a third capacitor and a fifth resistor, and the third capacitor and the fifth resistor are connected in parallel.
5. The bypass circuit according to claim 4, characterized in that: The power supply circuit further includes a third diode, a second resistor and a second capacitor. The third diode, the second resistor and the second capacitor are connected in series and then connected in series with the fifth resistor.
6. The bypass circuit according to claim 5, characterized in that: The control circuit includes a trigger circuit and an execution circuit. The trigger circuit includes a fully-controlled power electronic switch. The fully-controlled power electronic switch includes an IGBT. The first end of the IGBT is connected to one end of the first capacitor through a third resistor, and the second end of the IGBT is connected to the other end of the first capacitor.
7. The bypass circuit according to claim 6, characterized in that: The execution circuit includes a control coil and a fourth diode, the fourth diode is connected in parallel with the control coil, the control coil is connected to the third end of the IGBT through a fourth resistor, and the second end of the control coil is connected to one end of the second capacitor.
8. The bypass circuit according to claim 5, characterized in that: The power supply circuit further includes a normally closed auxiliary contact, which is connected in parallel with the second capacitor; the switch circuit includes a relay normally open contact, which is arranged between the third resistor and the first capacitor.
9. A unit control panel, characterized in that: Comprising a bypass circuit as claimed in any one of claims 1-8.
10. A converter, characterized in that: Comprising the unit control board as claimed in claim 9.