Contactor interlocking circuit based on hardware feedback protection

Abstract

The invention relates to the technical field of smart parking lots, and discloses a contactor interlocking circuit based on hardware feedback protection, which comprises a contactor control circuit, a contactor contact feedback circuit and a hardware logic interlocking protection circuit, and is characterized in that the contactor control circuit adopts an NMOS tube NTD5865NLT4G; and the contactor feedback circuit adopts feedback contact signals of the direct current contactor. The contactor interlocking circuit based on hardware feedback protection is simple in wiring and convenient to construct, contactor hardware interlocking protection is integrated on the PCBA board, integral forming is achieved, troubles caused by complex wiring are reduced, the safety protection performance is high, and by means of a pure hardware interlocking mode, the reliability of the circuit is improved. According to the utility model, the control abnormity of the contactor caused by the abnormal operation of software BUG or master control is completely eradicated, the condition of abnormal short circuit is avoided, the charging efficiency is high, the outputs of the power modules can be effectively combined together through the hardware interlocking circuit, and the safety fault caused by the abnormal access of another gun is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of smart parking lots, and in particular to a contactor interlocking circuit based on hardware feedback protection. Background Art

[0002] A charging pile is a device that provides electric energy for electric vehicles. Its function is similar to that of a gas pump in a gas station. The charging pile can be fixed on the ground or on the wall and installed in public buildings (such as charging stations, shopping malls, public parking lots, etc.) and parking lots in residential areas. It can charge various types of electric vehicles by adjusting the voltage and current. The input end of the charging pile is directly connected to the AC power grid, and the output end is equipped with a charging plug for charging electric vehicles. Charging piles generally provide two charging methods: conventional charging and fast charging. People can use a specific charging card to swipe the card on the human-computer interaction interface provided by the charging pile to perform corresponding charging operations and print cost data.

[0003] Currently, the DC charging piles on the market mainly include 60kW / 120kW / 180kW / 400kW, etc. When high-power output is required to achieve faster and more efficient charging, the DC contactor of the first charging gun and the DC contactor of the second charging gun need to be short-circuited together through the power distribution mother contactor. However, when the first charging gun and the second charging gun are separately charging new energy vehicles of different models, different voltages, and different powers, short-circuiting the outputs of the first charging gun and the second charging gun will cause risks.

[0004] The existing charging piles have complex wiring and are difficult to install. When using electrical parts interlocking, the cost is high, the wiring is complex, the production and processing are difficult, and the safety level is low. When using software function interlocking, due to software bugs or crashes, all DC contactors are energized, the charging gun output will be short-circuited, causing risks, output power reduction, and affecting charging efficiency. If the output of the power modules cannot be safely and effectively combined together, the output charging power of a single gun will be reduced and the charging efficiency will be reduced by half. Summary of the invention

[0005] The purpose of the present invention is to provide a contactor interlocking circuit based on hardware feedback protection to solve the problems proposed in the above background technology that the existing charging piles have complex wiring and are difficult to install. When using electrical parts for interlocking, the cost is high, the wiring is complex, the production and processing are difficult, and the safety level is low. When using software function interlocking, due to software BUG or crash, all DC contactors are energized, the output of the charging gun will be short-circuited, causing risks, and the output power will be reduced, affecting the charging efficiency. If the output of the power module cannot be safely and effectively combined together, the output charging power of a single gun will be reduced, and the charging efficiency will be reduced by half.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a contactor interlocking circuit based on hardware feedback protection, comprising a contactor control circuit, a contactor contact feedback circuit, and a hardware logic interlocking protection circuit, wherein the contactor control circuit adopts an NMOS tube NTD5865NLT4G;

[0007] The contactor feedback circuit uses the feedback contact signal of the DC contactor.

[0008] The hardware logic interlock protection circuit adopts a diode, an OR gate and an AND gate.

[0009] Preferably, the contactor control circuit includes a DC contactor 1+ and a DC contactor 1-, and the DC contactor 1+ and the DC contactor 1- are respectively connected to two groups of logic switching level conversion units through a control feedback unit, the two groups of logic switching level conversion units are connected to a logic switching hardware interlocking unit, and the logic switching hardware interlocking unit is connected to the DC contactor 3+ control output.

[0010] Preferably, the contactor control circuit includes a DC contactor 2+ and a DC contactor 2-, and the DC contactor 2+ and the DC contactor 2- are respectively connected to two groups of logic switching level conversion units through a control feedback unit, the two groups of logic switching level conversion units are connected to a logic switching hardware interlocking unit, and the logic switching hardware interlocking unit is connected to a DC contactor 3- control output.

[0011] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0012] First, the wiring of the present invention is simple and the construction is convenient. The contactor hardware interlock protection is integrated on the PCBA board and is integrally formed, which reduces the troubles caused by complex wiring. It has high safety protection performance. Through pure hardware interlocking, it eliminates contactor control abnormalities caused by software bugs or abnormal operation of the main control, avoids abnormal short circuits, and has high charging efficiency. Through the hardware interlocking circuit, the power module outputs can be effectively merged together to avoid safety failures caused by abnormal access to another gun. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is the system architecture diagram of the product of the present invention. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] See also Figure 1 A contactor interlocking circuit based on hardware feedback protection mainly includes a contactor control circuit, a contactor contact feedback circuit, and a hardware logic interlocking protection circuit. The contactor control circuit adopts an NMOS tube NTD5865NLT4G, the contactor feedback circuit adopts the feedback contact signal of the DC contactor, and the hardware logic interlocking protection circuit adopts a diode (BAT54A), an OR gate (SN74AHC1G32DBVR) and an AND gate (SN74AHC1G08DBVR).

[0016] In this embodiment, the DC charging piles currently on the market mainly include 60kW / 120kW / 180kW / 400kW, etc. When high-power output is required to achieve faster and more efficient charging, the DC contactor of the first charging gun and the DC contactor of the second charging gun need to be short-connected together through the power distribution mother contactor. However, when the first charging gun and the second charging gun are separately charged for new energy vehicles of different models, different voltages, and different powers, the short-circuiting of the outputs of the first charging gun and the second charging gun will cause risks. For example, when the first charging gun provides 800V voltage to charge car A, and the second charging gun provides 600V voltage to charge car B, when the power distribution DC contactor is closed due to misoperation, the outputs of the first charging gun and the second charging gun will be short-circuited, causing the output voltage of the second charging gun to be raised to 800V, and car B does not support charging at an 800V voltage level. Overvoltage causes damage to car B, affecting the safe charging of car B. Therefore, a hardware interlocking protection circuit for the DC contactor of the DC charging pile charging gun is designed to achieve separate, safe, and high-performance charging of the two guns.

[0017] In this embodiment, a charging gun contactor interlocking circuit with a hardware feedback protection function is implemented. Because the DC contactor of the first charging gun is connected to the DC contactor of the second charging gun and the output of the main DC contactor of the power distribution, when the three DC contactors are energized at the same time, the output ends of the two charging guns will be short-circuited, posing a risk to the new energy vehicle being charged. Therefore, this patent provides a DC contactor interlocking protection circuit based on a hardware feedback protection function.

[0018] In this embodiment, according to the charging gun DC contactor interlocking circuit of the present application, by detecting the control and feedback signals of the first charging gun DC contactor, the second charging gun DC contactor and the main DC contactor of the power distribution, it can be determined whether the first charging gun DC contactor, the second charging gun DC contactor and the power distribution DC contactor are in the energized state or the off state. At the same time, when the contactors corresponding to the two control / feedback signals are energized, the charging gun DC contactor interlocking circuit controls the other DC contactor to remain disconnected, thereby realizing pure hardware interlocking, greatly reducing the risk of short circuit at the output end, and forming protection. Since it is a pure hardware interlocking method, it can avoid relay control abnormalities caused by abnormal conditions such as software bugs or freezes, and avoid the risk of output short circuit and burning new energy vehicles.

[0019] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A contactor interlocking circuit based on hardware feedback protection, comprising a contactor control circuit, a contactor contact feedback circuit, and a hardware logic interlocking protection circuit, characterized in that: The contactor control circuit adopts NMOS tube NTD5865NLT4G; The contactor feedback circuit uses the feedback contact signal of the DC contactor; The hardware logic interlock protection circuit adopts a diode, an OR gate and an AND gate.

2. A contactor interlocking circuit based on hardware feedback protection according to claim 1, characterized in that: The contactor control circuit includes a DC contactor 1+ and a DC contactor 1-, and the DC contactor 1+ and the DC contactor 1- are respectively connected to two groups of logic switching level conversion units through a control feedback unit, the two groups of logic switching level conversion units are connected to a logic switching hardware interlocking unit, and the logic switching hardware interlocking unit is connected to the DC contactor 3+ control output.

3. A contactor interlocking circuit based on hardware feedback protection according to claim 1, characterized in that: The contactor control circuit includes a DC contactor 2+ and a DC contactor 2-, and the DC contactor 2+ and the DC contactor 2- are respectively connected to two groups of logic switching level conversion units through a control feedback unit, the two groups of logic switching level conversion units are connected to a logic switching hardware interlocking unit, and the logic switching hardware interlocking unit is connected to a DC contactor 3- control output.

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