Contactor detection circuit, energy storage converter and energy storage system

Abstract

The utility model relates to a contactor detection circuit, an energy storage converter and an energy storage system, and the contactor detection circuit comprises a first divider resistor, a second divider resistor, a first rectification circuit, a second rectification circuit, and an isolation circuit. A first detection point of the contactor is connected with the first rectifying circuit through a first divider resistor, a second detection point of the contactor is connected with the second rectifying circuit through a second divider resistor, output current of the contactor is rectified by the first rectifying circuit and the second rectifying circuit, and a direct current signal is output to the isolating circuit; and the isolation circuit is respectively connected with the first rectification circuit and the second rectification circuit and is used for isolating the direct current signal and outputting a voltage signal. The output current of the contactor can be rectified through the divider resistor and the rectifying circuit, the voltage signal is isolated and output through the isolating circuit, the circuit is simple, an additional power supply is not needed, and the problem that an existing detection circuit is complex in design is solved.

Description

Technical Field

[0001] The present application relates to the technical field of power energy storage, and in particular, to a contactor detection circuit, an energy storage converter, and an energy storage system. Background Art

[0002] The state of the contactor is an important link to ensure the safe operation of the system. The detection circuit of the contactor can timely detect whether the contactor can cut off the circuit normally. If the contactor fails to cut off in time, it may cause the current to continue to pass through, leading to faults such as system short circuit and overload, and may even damage other electrical equipment.

[0003] The existing contactor detection circuits usually rely on complex hardware structures and high-power consumption designs. For example, an additional power supply is required. The complex detection circuit not only increases the system cost, but also may cause continuous heating and potential safety hazards.

[0004] In view of the problem of complex design of the detection circuit in the related art, no effective solution has been proposed yet. Summary of the Utility Model

[0005] Based on this, it is necessary to provide a contactor detection circuit, an energy storage converter, and an energy storage system with a simple design for the above technical problems.

[0006] In a first aspect, in the present embodiment, a contactor detection circuit is provided, including: a first voltage-dividing resistor, a second voltage-dividing resistor, a first rectifying circuit, a second rectifying circuit, and an isolation circuit;

[0007] A first detection point of the contactor is connected to the first rectifying circuit through the first voltage-dividing resistor, a second detection point of the contactor is connected to the second rectifying circuit through the second voltage-dividing resistor, and the output current of the contactor is rectified by the first rectifying circuit and the second rectifying circuit, and a DC signal is output to the isolation circuit;

[0008] The isolation circuit, which is respectively connected to the first rectifying circuit and the second rectifying circuit, is configured to isolate the DC signal and output a voltage signal.

[0009] In some embodiments, the contactor includes an AC contactor and / or a DC contactor.

[0010] In some embodiments, the first voltage-dividing resistor and the second voltage-dividing resistor each include a plurality of resistors connected in series;

[0011] The number of resistors connected in series in the first voltage-dividing resistor and the second voltage-dividing resistor is the same, and the resistance value of each resistor is equal.

[0012] In some of these embodiments, the isolation circuit includes an optocoupler.

[0013] In some of these embodiments, both the first rectifier circuit and the second rectifier circuit include a first diode and a second diode. The anode of the first diode is connected to the cathode of the second diode and is simultaneously connected to the first voltage-dividing resistor or the second voltage-dividing resistor. The cathode of the first diode and the anode of the second diode are respectively connected to both ends of the input terminal of the optocoupler.

[0014] In some of these embodiments, it further includes: a first protection circuit connected in parallel between the two rectifier circuits and the isolation circuit;

[0015] The first protection circuit includes a first resistor and a first capacitor connected in parallel across both ends of the input terminal of the optocoupler.

[0016] In some of these embodiments, it further includes: a second protection circuit;

[0017] The second protection circuit includes a second resistor and a second capacitor connected in parallel. One end of the second protection circuit is connected to the output terminal of the optocoupler, and the other end is grounded.

[0018] In some of these embodiments, it further includes: a processor;

[0019] The output terminal of the isolation circuit is connected to the interrupt interface of the processor, and the processor is configured to trigger an interrupt service when an abnormal voltage is output by the isolation circuit.

[0020] In a second aspect, in the present embodiment, a power storage converter is provided, including: at least one contactor, and a contactor detection circuit as described in the first aspect;

[0021] The contactor detection circuit is connected in parallel with the contactor and is configured to detect the voltage signal of the contactor.

[0022] In a third aspect, in the present embodiment, a power storage system is provided, including: a power storage converter as described in the second aspect;

[0023] The power storage converter is connected to a power storage battery and the power grid and is configured to perform bidirectional conversion between direct current and alternating current.

[0024] Compared with the related art, the contactor detection circuit, energy storage converter, and energy storage system provided in this embodiment include: a first voltage-dividing resistor, a second voltage-dividing resistor, a first rectifying circuit, a second rectifying circuit, and an isolation circuit; a first detection point of the contactor is connected to the first rectifying circuit through the first voltage-dividing resistor, a second detection point of the contactor is connected to the second rectifying circuit through the second voltage-dividing resistor, the output current of the contactor is rectified by the first rectifying circuit and the second rectifying circuit, and a DC signal is output to the isolation circuit; the isolation circuit is respectively connected to the first rectifying circuit and the second rectifying circuit, and is used to isolate the DC signal and output a voltage signal. Through this embodiment, the output current of the contactor can be rectified by the voltage-dividing resistor and the rectifying circuit, isolated by the isolation circuit and a voltage signal is output, and the detection of the contactor can be realized through a simple circuit without an additional power supply, solving the problem of complex design of the current detection circuit.

[0025] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0027] Figure 1 is a structural block diagram of a contactor detection circuit in an embodiment;

[0028] Figure 2 is a schematic diagram of a contactor detection circuit in an embodiment;

[0029] Figure 3 is a schematic diagram of an energy storage converter in an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] To more clearly understand the purpose, technical solution, and advantages of the present application, the present application will be described and illustrated below with reference to the drawings and embodiments.

[0031] Unless otherwise defined, technical terms or scientific terms involved in this application shall have the general meanings understood by those with ordinary skills in the technical field to which this application belongs. In this application, words such as "a", "an", "one kind", "the", "these", etc. do not indicate a limitation in quantity, and they can be singular or plural. The terms "including", "comprising", "having" and any variants thereof involved in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product or device including a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent in these processes, methods, products or devices. The terms "connected", "coupled", etc. involved in this application do not limit to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "plurality" involved in this application means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. Usually, the character " / " indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0032] In an energy storage system, the state of the contactor is an important link to ensure the safe operation of the system. The detection circuit of the contactor can timely detect whether the contactor cuts off the circuit normally. If the contactor fails to cut off in time, it may cause the current to continue to flow through, leading to faults such as system short circuit and overload, and may even damage other electrical equipment.

[0033] Existing contactor detection circuits usually rely on complex hardware structures and high-power consumption designs. For example, an additional power supply is required. The complex detection circuit not only increases the system cost, but also may cause continuous heating and potential safety hazards.

[0034] In this embodiment, a contactor detection circuit is provided. Figure 1 is the structural block diagram of the contactor detection circuit in this embodiment, as Figure 1 shown, the contactor detection circuit includes: a first voltage-dividing resistor, a second voltage-dividing resistor, a first rectifying circuit, a second rectifying circuit, and an isolation circuit;

[0035] The first detection point of the contactor is connected to the first rectifying circuit through the first voltage-dividing resistor, the second detection point of the contactor is connected to the second rectifying circuit through the second voltage-dividing resistor, and the output current of the contactor is rectified by the first rectifying circuit and the second rectifying circuit and outputs a DC signal to the isolation circuit;

[0036] An isolation circuit, which is connected to the first rectification circuit and the second rectification circuit respectively, is used to isolate the DC signal and output a voltage signal.

[0037] Among them, the contactor detection circuit is connected in parallel across the contactor. One end of the first detection point of the contactor is connected to one contact of the contactor, and the other end is sequentially connected to the first voltage-dividing resistor and the first rectification circuit; one end of the second detection point of the contactor is connected to the other contact of the contactor, and the other end is sequentially connected to the second voltage-dividing resistor and the second rectification circuit.

[0038] The output current of the contactor includes a positive-phase current and a negative-phase current. After being voltage-divided by the first voltage-dividing resistor and the second voltage-dividing resistor respectively, and passing through the first rectification circuit and the second rectification circuit, the positive and negative phase currents of the contactor are both converted into positive-voltage DC signals, and the DC signals are output to the isolation circuit. The input ends of the isolation circuit are respectively connected to the output ends of the first rectification circuit and the second rectification circuit. Signal isolation is achieved through the isolation circuit, and the output end of the isolation circuit outputs a voltage signal, which can reflect whether the contactor is normally closed and opened. Among them, the first rectification circuit and the second rectification circuit are used to rectify the positive voltage and negative voltage of the contactor. Specifically, a detection diode, a rectification diode, or other diode circuits with rectification functions can be used; the isolation circuit includes any one of an optocoupler, a capacitive isolator, a magnetic isolator, and a digital isolator, all of which can achieve the function of the isolation circuit and ensure the safe transmission of signals.

[0039] Through the contactor detection circuit implemented by voltage-dividing resistors and diode rectification in this embodiment to convert the positive-phase current and negative-phase current output by the contactor into DC signals, and then output a voltage signal through the isolation circuit, the positive-phase current and negative-phase current of the contactor can be detected. It has the advantages of few components and no need for an additional power supply, simplifies the design of the detection circuit, and solves the problem of complex design of the detection circuit.

[0040] In some of these embodiments, the contactor includes an AC contactor and / or a DC contactor.

[0041] Specifically, the output current of the AC contactor includes a positive-phase current and a negative-phase current, and the output current of the DC contactor includes a positive-phase current. The above contactor detection circuit is applicable to both AC contactors and DC contactors, and the positive and negative phase currents output can be rectified through voltage-dividing resistors and rectification circuits to output positive-voltage DC signals.

[0042] In some of these embodiments, the isolation circuit includes an optocoupler.

[0043] Among them, the optocoupler is based on the photoelectric effect and realizes the isolation and conversion of electrical signals through the transmission of light. The optocoupler mainly consists of two parts: a light-emitting device (such as a light-emitting diode LED) and a light-receiving device (such as a phototransistor, a photoresistor, etc.). The two parts are optically coupled through a transparent insulating material (such as an optical fiber, air, etc.) to achieve the isolated transmission of electrical signals.

[0044] Optionally, an optocoupler is used as the isolation circuit, and the optimal model of the optocoupler is selected to ensure the integrity and response speed of signal transmission.

[0045] In some of the embodiments, both the first rectifying circuit and the second rectifying circuit include a first diode and a second diode. The anode of the first diode is connected to the cathode of the second diode and is simultaneously connected to the first voltage-dividing resistor or the second voltage-dividing resistor. The cathodes of the first diode and the anodes of the second diode are respectively connected to both ends of the input terminal of the optocoupler.

[0046] Specifically, the first diode and the second diode form a diac.

[0047] Optionally, the first diode and the second diode adopt Schottky diodes with high efficiency and low forward voltage drop to improve the rectification efficiency and reduce the system heat loss.

[0048] Figure 2 is a schematic diagram of a contactor detection circuit in an embodiment. The contactor detection circuit includes: a first voltage-dividing resistor, a second voltage-dividing resistor, a first rectifying circuit, a second rectifying circuit, and an optocoupler.

[0049] Among them, the first detection point P1(+) is sequentially connected to the first voltage-dividing resistor and the first rectifying circuit, the second detection point P(+) is sequentially connected to the second voltage-dividing resistor and the second rectifying circuit. The output terminals of the first rectifying circuit and the second rectifying circuit are connected to the optocoupler U1. The output terminal JFC of the optocoupler U1 outputs a voltage signal, and a 5V voltage is used as the driving voltage of the optocoupler U1. Among them, the first rectifying circuit includes a first diode D1 and a second diode D2, the second rectifying circuit includes a first diode D3 and a second diode D4. The anodes of the first diodes D1 and D3 are respectively connected to the cathodes of the second diodes D2 and D4 and are simultaneously connected to the first voltage-dividing resistor or the second voltage-dividing resistor. The cathodes of the first diodes D1 and D3 and the anodes of the second diodes D2 and D4 are respectively connected to both ends of the input terminal of the optocoupler.

[0050] In some of the embodiments, the first voltage-dividing resistor and the second voltage-dividing resistor respectively include a plurality of resistors connected in series; the number of resistors connected in series in the first voltage-dividing resistor and the second voltage-dividing resistor is the same, and the resistance value of each resistor is equal.

[0051] Such as Figure 2As shown, the first voltage-dividing resistor includes resistors R1, R2, and R3 connected in series, and the second voltage-dividing resistor includes resistors R4, R5, and R6 connected in series. Connecting multiple resistors in series can reduce the voltage across a single resistor. The selection criteria for the resistors include the withstand voltage rating and accuracy requirements.

[0052] Furthermore, the number of resistors connected in series in the first voltage-dividing resistor and the second voltage-dividing resistor is the same, and the resistance value of each resistor is equal to ensure that the voltage across each resistor is consistent. Optionally, the resistance value of the resistor is 10K. Assuming the DC voltage is 1000V, each of the six resistors in the first voltage-dividing resistor and the second voltage-dividing resistor divides 167V. If the resistance values of each resistor are different, the voltage across some resistors exceeds 167V, which easily damages the resistors.

[0053] In this embodiment, the first voltage-dividing resistor and the second voltage-dividing resistor respectively include a number of resistors connected in series, and by setting the same number and resistance value of the resistors, the safety can be improved and resistor damage can be avoided.

[0054] In some of these embodiments, the contactor detection circuit further includes: a first protection circuit connected in parallel between the two rectifier circuits and the isolation circuit; the first protection circuit includes a first resistor and a first capacitor connected in parallel across the two ends of the input terminal of the optocoupler.

[0055] As Figure 2 shown, the first protection circuit includes a first resistor R8 and a first capacitor C1 connected in parallel across the two ends of the input terminal of the optocoupler U1. The first resistor R8 is connected in parallel with the two rectifier circuits, and the first capacitor C1 and the optocoupler U1 are connected in parallel. Among them, the first resistor R8 is used to limit the current flowing into the input terminal (LED) of the optocoupler U1, protect the LED from exceeding the rated current and prevent damage, and the first capacitor C1 is used to buffer the voltage change in the circuit and provide a more stable voltage supply for the LED to avoid unnecessary responses of the LED due to voltage fluctuations.

[0056] Through the setting of the first protection circuit in this embodiment, it is possible to avoid damage to the LED in the backend optocoupler due to current or unnecessary responses due to voltage fluctuations.

[0057] In some of these embodiments, it further includes: a second protection circuit;

[0058] The second protection circuit includes a second resistor and a second capacitor connected in parallel. One end of the second protection circuit is connected to the output terminal of the optocoupler, and the other end is grounded.

[0059] As Figure 2As shown, the second protection circuit includes a second resistor R9 and a second capacitor C2 connected in parallel. Optionally, the resistance value of the second resistor R9 is 3K. One end of the second resistor R9 in the second protection circuit is connected to the output end of the isolation circuit optocoupler U1, and the other end is grounded (GND). One end of the second capacitor C2 is connected to the output end of the isolation circuit optocoupler U1, and the other end is grounded (GND). Among them, the second resistor R9 is a current-limiting resistor, which is used to protect the LED part of the optocoupler U1 to prevent damage to the LED caused by excessive current. The second capacitor C2 is a noise reduction capacitor, which is used to reduce circuit noise and stabilize the signal, ensure the normal operation of the optocoupler U1, and improve the reliability of the circuit.

[0060] Through the setting of the second protection circuit in this embodiment, the normal operation of the optocoupler can be ensured, and the reliability of the detection circuit can be improved.

[0061] In some of these embodiments, the contactor detection circuit further includes: a processor;

[0062] The output end of the isolation circuit is connected to the interrupt interface of the processor, and the processor is used to trigger an interrupt service when the isolation circuit outputs an abnormal voltage.

[0063] Specifically, the processor can adopt a DSP (Digital Signal Processing) chip; the rectifier circuit on the primary side of the isolation circuit is used to judge whether there is a voltage between the first detection point and the second detection point. When there is a voltage between the first detection point and the second detection point, the isolation circuit starts, and the voltage signal at the output end of the isolation circuit is connected to the interrupt interface of the processor. The voltage signal at the output end JFC of the isolation circuit is judged in the processor, such as judging the level of the voltage signal. When an abnormal voltage is judged, the processor can quickly process the abnormal voltage and trigger an interrupt service, such as the system stops running.

[0064] By connecting the output end of the isolation circuit in this embodiment to the interrupt interface of the processor, an interrupt service can be triggered when it is judged that the isolation circuit outputs an abnormal voltage, ensuring the safety and reliability of the circuit.

[0065] In some of these embodiments, it further includes: a pre-charge circuit connected in parallel with the contactor; the pre-charge circuit includes a pre-charge switch and a pre-charge resistor connected in series.

[0066] Specifically, since the input voltage of the circuit is a high voltage, the pre-charge circuit is used to slowly charge the large capacitor in the circuit to prevent the instantaneous large current impact generated during direct connection, which may damage the circuit or device. When closing the contactor, first close the pre-charge switch to reduce the current, then close the contactor, and disconnect the pre-charge switch to avoid directly closing the contactor, causing a risk of arcing due to too large an instantaneous current; when disconnecting the contactor, it is also necessary to first close the pre-charge switch, then disconnect the contactor and the pre-charge switch. Among them, the switch includes a relay or a contactor.

[0067] Through the setting of the pre-charge circuit in this embodiment, the power-on impact can be reduced, and the safety of the overall circuit can be improved.

[0068] Since it is necessary to control the contactor to be attracted and disconnected when detecting the contactor, in the case of heavy load operation of the circuit, the contactor and the pre-charge switch may fail, so it is necessary to perform detection during light load or startup.

[0069] The voltage signal at the output end JFC of the isolation circuit can reflect whether the contactor is normally closed and disconnected. Specifically, it includes the following situations:

[0070] When controlling the contactor to close, if the contactor is normally closed, the voltage across the contactor is 0, and the output end of the optocoupler JFC in the detection circuit is at a low level of 0V; if the contactor cannot be normally closed and the pre-charge switch is still in the closed state, at this time, there is voltage across the contactor, and the output end of the optocoupler JFC in the detection circuit is at a high level of 5V, which is judged as an abnormal voltage.

[0071] When controlling the contactor to disconnect, if the contactor is normally disconnected, the voltage across the contactor is still 0, and the output end of the optocoupler JFC in the detection circuit is at a low level of 0V; if the contactor cannot be normally disconnected and the pre-charge switch is still in the closed state, at this time, there is voltage across the contactor, and the output end of the optocoupler JFC in the detection circuit is at a high level of 5V.

[0072] Therefore, in the processor, it is possible to judge whether it is an abnormal voltage according to the high and low levels at the output end of the optocoupler JFC, and trigger an interrupt service when it is judged as an abnormal voltage.

[0073] The following describes and illustrates this embodiment through preferred embodiments.

[0074] This embodiment provides a contactor detection circuit, as Figure 2 shown, the circuit includes: a first voltage-dividing resistor, a second voltage-dividing resistor, a first rectifying circuit, a second rectifying circuit, a first protection circuit, a second protection circuit, and an isolation circuit.

[0075] Among them, the first detection point P1(+) of the contactor is sequentially connected to the first voltage-dividing resistor and the first rectifying circuit. The first voltage-dividing resistor includes resistors R1, R2, and R3 connected in series, and the first rectifying circuit includes the first diode D1 and the second diode D2. The second detection point P(+) of the contactor is sequentially connected to the second voltage-dividing resistor and the second rectifying circuit. The second voltage-dividing resistor includes resistors R4, R5, and R6 connected in series, and the second rectifying circuit includes the first diode D3 and the second diode D4.

[0076] The contactor includes an AC contactor and a DC contactor. After the output current of the contactor is divided by the first voltage-dividing resistor and the second voltage-dividing resistor, it is rectified by the first rectifying circuit and the second rectifying circuit to output a DC signal.

[0077] The first protection circuit includes a first resistor R8 and a first capacitor C1 connected in parallel. The first resistor R8 is connected in parallel with the two rectifying circuits, and the first resistor R8 and the first capacitor C1 are connected in parallel across the two ends of the input of the optocoupler U1. The first protection circuit is used to prevent the LED in the subsequent optocoupler from being damaged by current or generating unnecessary responses due to voltage fluctuations.

[0078] The isolation circuit is the optocoupler U1, and a 5V voltage is used as the driving voltage of the optocoupler U1. The output end JFC of the optocoupler U1 outputs a voltage signal, and the output end is connected to the interrupt interface of the DSP processor. When the isolation circuit outputs an abnormal voltage, it triggers the interrupt service of the DSP processor.

[0079] The second protection circuit includes a second resistor R9 and a second capacitor C2 connected in parallel. One end of the second resistor R9 in the second protection circuit is connected to the output end of the isolation circuit optocoupler U1, and the other end is grounded (GND). One end of the second capacitor C2 is connected to the output end of the isolation circuit optocoupler U1, and the other end is grounded (GND). The second protection circuit is used to ensure the normal operation of the optocoupler U1.

[0080] The contactor detection circuit provided in this embodiment can convert both the positive-phase current and the negative-phase current output by the contactor into DC signals through voltage-dividing resistors and diode rectification, and then output a voltage signal through the isolation circuit to implement the contactor detection circuit. It can detect the positive-phase current and the negative-phase current of the contactor, and has the advantages of few components and no need for an additional power supply, simplifies the design of the detection circuit, and solves the problem of complex detection circuit design. Further, the processor can determine whether it is an abnormal signal according to the level of the voltage signal output by the isolation circuit, and can quickly process the abnormal signal.

[0081] This embodiment provides an energy storage converter, including: at least one contactor, and the contactor detection circuit in the above embodiment.

[0082] Figure 3 It is a schematic diagram of the energy storage converter in this embodiment, asFigure 3 As shown, it includes DC contactors S2, S4 on the battery side (BAT+ and BAT-), and AC contactors S6, S8, S10 on the grid / load side (U, V, W). Each contactor is connected in parallel with a pre-charge circuit and a contactor detection circuit (only the detection points P1(+) and P(+) of one contactor are shown in the figure). The pre-charge circuit includes pre-charge switches S1, S3, S5, S7, S9 connected in series and pre-charge resistors R1 to R5.

[0083] Among them, IGBTs (Insulate-Gate Bipolar Transistors) VT1 to VT12 are used for the inversion of DC voltage to AC voltage. The IGBT module converts DC power into AC power through high-speed switching operations, or performs the opposite conversion. Diodes D1 to D6 are connected in parallel with the IGBTs to provide freewheeling for reverse current, prevent the IGBTs from being damaged by reverse voltage, and also help improve the efficiency of the system.

[0084] The capacitor banks C1 to C4 between the DC input and the IGBTs are used for filtering and stabilizing the DC voltage, reducing voltage fluctuations, so as to ensure that the IGBTs operate at a stable voltage level.

[0085] The AC power output by the IGBTs usually contains high-frequency switching noise and harmonics. The filter composed of inductors L1 to L6 and capacitors C9 to C11 is used to eliminate these high-frequency components, obtaining a purer sinusoidal AC output that meets the requirements of the grid or the load.

[0086] The three-phase AC output (U, V, W) is usually connected to the grid or the load. Through the control of the IGBTs, the DC power is converted into standard three-phase AC power and output through these ports.

[0087] It also includes a series of protection measures, such as current sensors CT1 to CT7, fuses FU, etc., which are used to monitor current and voltage to protect the system from overcurrent, short circuit or other faults.

[0088] Through the energy storage converter provided in this embodiment, the AC contactors and DC contactors in the energy storage converter are detected through the contactor detection circuit, improving the overall safety and reliability.

[0089] This embodiment provides an energy storage system, including: the energy storage converter in the above embodiment; the energy storage converter is connected to the energy storage battery and the grid and is used for the bidirectional conversion of DC power and AC power.

[0090] Specifically, when the energy storage battery is being charged, the system receives alternating current from the power grid. The energy storage converter operates in the rectification mode, converting the alternating current into direct current, which is then filtered and used to charge the energy storage battery. When the energy storage battery discharges, the energy storage battery provides direct current, and the energy storage converter converts the direct current into alternating current and outputs it to the power grid or the load.

[0091] In addition, the system can synchronize the output voltage and frequency of the inverter IGBT with the power grid through control, thereby achieving grid connection operation. In the grid-connected state, the energy storage battery can discharge at high electricity prices or charge at low electricity prices, playing a role in peak shaving and valley filling.

[0092] When the power grid is powered off or unstable, the system can automatically switch to the island mode, generating alternating current by itself to supply power to local loads and ensuring continuous power supply to important loads.

[0093] Through the energy storage system in this embodiment, it is possible to effectively manage the flow of energy, achieve stable power output and efficient utilization of electricity.

[0094] It should be understood that the specific embodiments described here are only used to explain this application, rather than to limit it. According to the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0095] Obviously, the drawings are only some examples or embodiments of this application. For those of ordinary skill in the art, this application can also be applied to other similar situations based on these drawings without creative efforts. In addition, it can be understood that although the work done during this development process may be complex and time-consuming, for those of ordinary skill in the art, certain design, manufacturing, or production changes based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient disclosure of this application.

[0096] The term "embodiment" in this application means that the specific features, structures, or characteristics described in connection with the embodiment may be included in at least one embodiment of this application. The phrase appears in various positions in the specification does not necessarily mean the same embodiment, nor does it mean being independent or alternative to other embodiments and mutually exclusive. Those of ordinary skill in the art can clearly or implicitly understand that the embodiments described in this application can be combined with other embodiments without conflict.

[0097] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of patent protection. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. Contactor detection circuit, characterized in that, include: A first voltage-dividing resistor, a second voltage-dividing resistor, a first rectifier circuit, a second rectifier circuit, and an isolation circuit; The first detection point of the contactor is connected to the first rectifier circuit through the first voltage-dividing resistor, the second detection point of the contactor is connected to the second rectifier circuit through the second voltage-dividing resistor, the output current of the contactor is rectified by the first rectifier circuit and the second rectifier circuit, and a DC signal is output to the isolation circuit; The isolation circuit is connected to the first rectifier circuit and the second rectifier circuit respectively, and is used to isolate the DC signal and output a voltage signal.

2. The contactor detection circuit according to claim 1, characterized in that: The contactor includes an AC contactor and / or a DC contactor.

3. The contactor detection circuit according to claim 1, characterized in that: The first voltage-dividing resistor and the second voltage-dividing resistor respectively include a plurality of resistors connected in series; The number of resistors connected in series in the first voltage-dividing resistor and the second voltage-dividing resistor is the same, and the resistance value of each resistor is equal.

4. The contactor detection circuit according to claim 1, characterized in that: The isolation circuit includes an optocoupler.

5. The contactor detection circuit according to claim 4, characterized in that: The first rectifier circuit and the second rectifier circuit both include a first diode and a second diode, the anode of the first diode is connected to the cathode of the second diode, and are simultaneously connected to the first voltage-dividing resistor or the second voltage-dividing resistor, and the cathode of the first diode and the anode of the second diode are respectively connected to the two ends of the optocoupler input end.

6. The contactor detection circuit according to claim 4, characterized in that: Also includes: A first protection circuit connected in parallel between the two rectifier circuits and the isolation circuit; The first protection circuit includes a first resistor and a first capacitor connected in parallel at both ends of the optocoupler input terminal.

7. The contactor detection circuit according to claim 4, characterized in that: Also includes: A second protection circuit; The second protection circuit includes a second resistor and a second capacitor connected in parallel, one end of the second protection circuit is connected to the output end of the optocoupler, and the other end is grounded.

8. The contactor detection circuit according to claim 1, characterized in that: Also includes: processor; The output end of the isolation circuit is connected to the interrupt interface of the processor, and the processor is used to trigger an interrupt service when the isolation circuit outputs an abnormal voltage.

9. An energy storage converter, characterized in that: include: At least one contactor, and a contactor detection circuit as claimed in any one of claims 1 to 8; The contactor detection circuit is connected in parallel with the contactor and is used for detecting a voltage signal of the contactor.

10. An energy storage system, characterized in that: include: The energy storage converter according to claim 9; The energy storage converter is connected to the energy storage battery and the power grid, and is used for bidirectional conversion between direct current and alternating current.

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