Pre-charging circuit with ultra-low impact current input at high voltage

Abstract

The utility model discloses a pre-charging circuit for high-voltage input ultra-low impact current. The pre-charging circuit comprises a main power contactor K1, a pre-charging contactor KP, a pre-charging resistor KR, a filter non-polar capacitor C, a filtering common-mode inductor L, an auxiliary power supply unit U1 and a filtering resistor R, adjusting auxiliary power supply to the rear end of the pre-charging resistor; fusing the pre-charging circuit into an input filter; the filter resistor R is connected in series with the filter capacitor C. According to the circuit, the space of the filter is reasonably utilized under the condition that high-voltage direct-current safe access is achieved, the pre-charging circuit and the filter circuit are designed in a fusion mode, and system electromagnetic compatibility and power supply safety are achieved.

Description

Technical Field

[0001] The utility model relates to a high-voltage direct current power supply, in particular to a pre-charging circuit with high-voltage input and ultra-low impact current. Background Art

[0002] With the rapid development of high-voltage energy storage technology, related products have been widely used in defense, aerospace, consumer electronics, communications, new energy, inverter and other industries. Among them, high-voltage DC is more used in the field of vehicle and ship, and the proportion of input power supply is gradually increasing. In some use environments, the high-voltage DC bus improves the system safety on the one hand, and reduces the difficulty of laying power supply cables on the other. The high-voltage DC bus is used for power supply in the system design, and there are large capacitors on its DC bus. We know that when the capacitor is connected in parallel at both ends of the power supply, when the power is turned on, the voltage at both ends of the capacitor will not change suddenly, but the current at both ends of the capacitor will change suddenly. At the moment the power is turned on, the two ends of the capacitor are equivalent to a short circuit, which is determined by the working principle of the capacitor. Therefore, the high-voltage DC access must be designed with a pre-charging circuit, which plays a role in limiting the charging current of the capacitor at the moment the power is turned on, and reducing the equipment startup impact current.

[0003] The existing high-voltage DC power supply access circuit takes the system electromagnetic compatibility into consideration and is basically designed at the back end of the filter. Auxiliary power supply and non-polarized capacitors of the high-voltage DC filter are not considered, resulting in a certain amount of instantaneous impact current when high-voltage DC is connected. When multiple devices are started at the same time during system integration, the superimposed surge current is larger and lasts longer, seriously affecting the power supply safety of the system.

[0004] Therefore, it is necessary to study the design of a new type of impulse current system with high-voltage DC input, which can not only solve the power supply safety but also take into account the electromagnetic compatibility of the system.

[0005] In view of this, the present utility model is proposed. Utility Model Content

[0006] The utility model aims to provide a pre-charging circuit with high voltage input and ultra-low impact current to solve the above technical problems existing in the prior art.

[0007] The purpose of this utility model is achieved through the following technical solutions:

[0008] The utility model provides a pre-charging circuit with high-voltage input and ultra-low impact current, including a main power contactor K1, a pre-charging contactor KP, a pre-charging resistor KR, a filter non-polarized capacitor C, a filter common-mode inductor L, an auxiliary power supply unit U1, and a filter resistor R, wherein:

[0009] The main power contactor K1 is at the circuit input end, one end of the main power contactor K1 is connected to the positive input end of the high voltage DC, and the other end is connected to the positive input end of the filter inductor L;

[0010] The pre-charging contactor KP is in the middle of the circuit, the input end of the pre-charging contactor KP is connected to the output end of the pre-charging resistor KR, and the output end is connected to the other end of the main power contactor K1;

[0011] The pre-charging resistor KR is at the circuit input end, the input end of the pre-charging resistor KR is connected to the high-voltage DC input positive end, and the input end is connected to the input end of the pre-charging contactor KP and the auxiliary power supply unit U1 high-voltage input positive end;

[0012] The filter non-polar capacitor C is at the output end of the circuit, one end of the filter non-polar capacitor C is connected to the positive end of the filter common-mode inductor, and the other end is connected to one end of the filter resistor R;

[0013] The filter common mode inductor L is at the output end of the circuit, the filter common mode inductor L input positive end is connected to the output end of the main power contactor, the filter common mode inductor output positive end is connected to the filter non-polarized capacitor C, the filter common mode inductor input negative end is connected to the high voltage input negative end, and the filter common mode inductor output negative end is connected to one end of the filter resistor;

[0014] The filter resistor R is at the output end of the circuit, one end of the filter resistor R is connected to one end of the filter non-polarized capacitor C, and the other end is connected to the output negative end of the filter common mode inductor L;

[0015] The auxiliary power supply unit U1 is at the output end of the circuit, the positive input end of the auxiliary power supply unit U1 is connected to the output end of the pre-charging resistor KR, and the negative input end of the auxiliary power supply unit U1 is connected to the negative input end of the high-voltage direct current.

[0016] Compared with the prior art, the high-voltage input ultra-low impact current pre-charging circuit provided by the utility model reasonably utilizes the filter space while realizing safe access to high-voltage direct current, and integrates the pre-charging circuit and the filter circuit to achieve system electromagnetic compatibility and power supply safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a pre-charging circuit structure with high voltage input and ultra-low impact current provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0018] The following is a clear and complete description of the technical solutions in the embodiments of the utility model in conjunction with the drawings in the embodiments of the utility model; it is obvious that the described embodiments are only part of the embodiments of the utility model, not all of the embodiments, which does not constitute a limitation of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the utility model.

[0019] First, the terms that may be used in this article are explained as follows:

[0020] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0021] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0022] The contents not described in detail in the examples of the present utility model belong to the prior art known to professionals in the field. If no specific conditions are specified in the examples of the present utility model, the conditions are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments used in the examples of the present utility model are not specified, they are all conventional products that can be purchased commercially.

[0023] The utility model provides a pre-charging circuit with high-voltage input and ultra-low impact current, including a main power contactor K1, a pre-charging contactor KP, a pre-charging resistor KR, a filter non-polarized capacitor C, a filter common-mode inductor L, an auxiliary power supply unit U1, and a filter resistor R, wherein:

[0024] The main power contactor K1 is at the circuit input end, one end of the main power contactor K1 is connected to the positive input end of the high voltage DC, and the other end is connected to the positive input end of the filter inductor L;

[0025] The pre-charging contactor KP is in the middle of the circuit, the input end of the pre-charging contactor KP is connected to the output end of the pre-charging resistor KR, and the output end is connected to the other end of the main power contactor K1;

[0026] The pre-charging resistor KR is at the circuit input end, the input end of the pre-charging resistor KR is connected to the high-voltage DC input positive end, and the input end is connected to the input end of the pre-charging contactor KP and the auxiliary power supply unit U1 high-voltage input positive end;

[0027] The filter non-polar capacitor C is at the output end of the circuit, one end of the filter non-polar capacitor C is connected to the positive end of the filter common-mode inductor, and the other end is connected to one end of the filter resistor R;

[0028] The filter common mode inductor L is at the output end of the circuit, the filter common mode inductor L input positive end is connected to the output end of the main power contactor, the filter common mode inductor output positive end is connected to the filter non-polarized capacitor C, the filter common mode inductor input negative end is connected to the high voltage input negative end, and the filter common mode inductor output negative end is connected to one end of the filter resistor;

[0029] The filter resistor R is at the output end of the circuit, one end of the filter resistor R is connected to one end of the filter non-polarized capacitor C, and the other end is connected to the output negative end of the filter common mode inductor L;

[0030] The auxiliary power supply unit U1 is at the output end of the circuit, the positive input end of the auxiliary power supply unit U1 is connected to the output end of the pre-charging resistor KR, and the negative input end of the auxiliary power supply unit U1 is connected to the negative input end of the high-voltage direct current.

[0031] Adjust the auxiliary power supply to the rear end of the pre-charge resistor;

[0032] Integrate the pre-charge circuit into the input filter;

[0033] The filter resistor R is connected in series with the filter non-polarized capacitor C.

[0034] In summary, it can be seen that the high-voltage input ultra-low impact current pre-charging circuit of the embodiment of the utility model, while achieving safe access to high-voltage DC, reasonably utilizes the filter space, integrates the pre-charging circuit and the filter circuit into a design, and realizes system electromagnetic compatibility and power supply safety.

[0035] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the embodiments of the present invention are described in detail with specific embodiments below.

[0036] Example 1

[0037] like Figure 1 As shown:

[0038] A schematic diagram of a pre-charging circuit design for a high-voltage input ultra-low impact current is provided for an embodiment of the utility model. The pre-charging circuit includes a main power contactor K1, a pre-charging contactor KP, a pre-charging resistor KR, a filter non-polarized capacitor C, a filter common-mode inductor L, an auxiliary power supply unit U1, and a filter resistor R, wherein:

[0039] The main power contactor K1 is at the circuit input end, one end of the main power contactor K1 is connected to the positive input end of the high voltage DC, and the other end is connected to the positive input end of the filter inductor L;

[0040] The pre-charging contactor KP is in the middle of the circuit, the input end of the pre-charging contactor KP is connected to the output end of the pre-charging resistor KR, and the output end is connected to the other end of the main power contactor K1;

[0041] The pre-charging resistor KR is at the input end of the circuit, and the input end of the pre-charging resistor KR is connected to the positive end of the high-voltage DC input, and the input end is connected to the input end of the pre-charging contactor KP and the positive end of the high-voltage input of the auxiliary power supply unit U1;

[0042] The filter non-polar capacitor C is at the output end of the circuit, one end of the filter non-polar capacitor C is connected to the positive end of the filter common-mode inductor, and the other end is connected to one end of the filter resistor R;

[0043] The filter common mode inductor L is at the output end of the circuit, the filter common mode inductor L input positive end is connected to the output end of the main power contactor, the filter common mode inductor output positive end is connected to the filter non-polarized capacitor C, the filter common mode inductor input negative end is connected to the high voltage input negative end, and the filter common mode inductor output negative end is connected to one end of the filter resistor;

[0044] The filter resistor R is at the output end of the circuit, one end of the filter resistor R is connected to one end of the filter non-polarized capacitor C, and the other end is connected to the output negative end of the filter common mode inductor L;

[0045] The auxiliary power supply unit U1 is at the output end of the circuit, the positive input end of the auxiliary power supply unit U1 is connected to the output end of the pre-charging resistor KR, and one end of the negative input end of the auxiliary power supply unit U1 is connected to the negative input end of the high-voltage DC;

[0046] After inputting DC620V, the auxiliary power supply unit U1 is connected through the pre-charging resistor KR, which not only suppresses the impact current of the auxiliary power supply unit, but also ensures the normal operation of the auxiliary power supply; after receiving the high-voltage access control command, the pre-charging contactor KP is turned on, and the DC620V is connected to the filter. The filter resistor R is connected in series with the filter non-polar capacitor to limit its impact current. After a delay of 3 seconds, the main power contactor K1 is connected, and the pre-charging contactor KP is closed. The DC620V is safely connected, the impact current during the access process is small, and the electromagnetic compatibility requirements are met.

[0047] In summary, the circuit described in the embodiment of the utility model has the following advantages:

[0048] 1) Adjust the auxiliary power supply to the rear end of the pre-charging resistor to reduce the auxiliary power supply starting impact current, and ensure that the auxiliary power supply unit works synchronously with the high-voltage input to meet the system power supply requirements;

[0049] 2) Integrate the pre-charge circuit into the input filter design to suppress the impact current of the filter's non-polar capacitor, which not only solves the electromagnetic compatibility problem but also improves the reliability of high-voltage DC access;

[0050] 3) Increase the filter resistance R and connect the filter non-polar capacitor C in series to suppress the impact current of the filter non-polar capacitor.

[0051] The above is only a preferred specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the utility model, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A pre-charging circuit with high voltage input and ultra-low impact current, It is characterized in that It includes a main power contactor (K1), a pre-charge contactor (KP), a pre-charge resistor (KR), a filter non-polar capacitor (C), a filter common mode inductor (L), an auxiliary power supply unit (U1), and a filter resistor (R), wherein: The main power contactor (K1) is at the circuit input end, one end of the main power contactor (K1) is connected to the positive input end of the high-voltage direct current, and the other end is connected to the positive input end of the filter inductor (L); The pre-charging contactor (KP) is in the middle of the circuit, the input end of the pre-charging contactor (KP) is connected to the output end of the pre-charging resistor (KR), and the output end is connected to the other end of the main power contactor (K1); The pre-charging resistor (KR) is at the circuit input end, the input end of the pre-charging resistor (KR) is connected to the high-voltage DC input positive end, and the input end is connected to the input end of the pre-charging contactor (KP) and the auxiliary power supply unit (U1) high-voltage input positive end; The filter non-polar capacitor (C) is at the output end of the circuit, one end of the filter non-polar capacitor (C) is connected to the positive end of the filter common-mode inductor, and the other end is connected to one end of the filter resistor (R); The filter common mode inductor (L) is at the output end of the circuit, the filter common mode inductor (L) input positive end is connected to the output end of the main power contactor, the filter common mode inductor output positive end is connected to the filter non-polarized capacitor (C), the filter common mode inductor input negative end is connected to the high voltage input negative end, and the filter common mode inductor output negative end is connected to one end of the filter resistor; The filter resistor (R) is at the output end of the circuit, one end of the filter resistor (R) is connected to one end of the filter non-polarized capacitor (C), and the other end is connected to the output negative end of the filter common mode inductor (L); The auxiliary power supply unit (U1) is at the output end of the circuit, the positive input end of the auxiliary power supply unit (U1) is connected to the output end of the pre-charging resistor (KR), and the negative input end of the auxiliary power supply unit (U1) is connected to the negative input end of the high-voltage direct current.

2. The pre-charging circuit of high voltage input ultra-low impact current according to claim 1, Features: Adjust the auxiliary power supply to the rear end of the pre-charge resistor; Integrate the pre-charge circuit into the input filter; The filter resistor (R) is connected in series with the filter non-polarized capacitor (C).

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