Relay on / off detection system and method for charging protection device of new energy vehicle

Abstract

The present invention relates to a relay on / off detection system and method for a new energy vehicle charging protection device in the field of circuit detection technology, based on a dual-relay charging device comprising an L-pole relay and an N-pole relay. A first feedback circuit is set between the input end of the L-pole relay and the output end of the N-pole relay, and a second feedback circuit is set between the input end of the N-pole relay and the output end of the L-pole relay. By detecting the conduction and cutoff of these two circuits, the on / off of the two relays can be determined. This allows the system to self-detect relay failures and increase user safety.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit detection, and in particular to a relay on / off detection system and method for a charging protection device of a new energy vehicle. Background Art

[0002] As new energy vehicles become more and more popular, the safety requirements for charging guns and charging piles are getting higher and higher. There are two relays in the control board of the charging gun box and the charging pile, which control the on and off of the L and N circuits respectively.

[0003] The existing technology only controls the on and off of the relay through the control system, and does not check and verify the actual on and off results of each relay. This not only fails to self-locate the fault, but also brings certain hidden dangers to the safety of users. Once a relay fails, if it cannot be connected normally, it cannot be charged normally; if it is stuck and cannot be disconnected, it will bring the risk of electric shock to the user. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings and defects of the prior art and provide a relay on-off detection system and method for a new energy vehicle charging protection device, which can detect the on-off results of the two circuits L and N separately.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A relay on-off detection system for a new energy vehicle charging protection device comprises a dual-relay charging device including an L-pole relay and an N-pole relay. A first feedback circuit is connected between the input end of the L-pole relay and the output end of the N-pole relay, and a second feedback circuit is connected between the output end of the L-pole relay and the input end of the N-pole relay.

[0007] Specifically, the components in the first feedback circuit include a first diode, a first photocoupler and a first transistor, the input end of the L-pole relay is electrically connected to the positive electrode of the first diode, the negative electrode of the first diode is electrically connected to the output end of the N-pole relay through the connecting surface of the first photocoupler, the output surface of the first photocoupler is electrically connected to the base of the first transistor, and the emitter of the first transistor is electrically connected to the MCU.

[0008] Specifically, the components in the second feedback circuit include a second diode, a second photocoupler and a second transistor, the input end of the N-pole relay is electrically connected to the anode of the second diode, the cathode of the second diode is electrically connected to the output end of the L-pole relay through the connection surface of the second photocoupler, the output surface of the second photocoupler is electrically connected to the base of the first transistor, and the emitter of the first transistor is electrically connected to the CPU.

[0009] Specifically, the collector of the first transistor is provided with a bias circuit connected to the base and connected to an external voltage at the same time, and the emitter of the first transistor is grounded and electrically connected to the MCU at the same time.

[0010] Specifically, the collector of the second transistor is provided with a bias circuit connected to the base and connected to an external voltage at the same time, and the emitter of the second transistor is grounded and electrically connected to the MCU at the same time.

[0011] Specifically, the first feedback circuit and the second feedback circuit further include a plurality of protection resistors.

[0012] A method for detecting the on-off of a relay of a charging protection device of a new energy vehicle utilizes the on-off detection system of a relay of a charging protection device of a new energy vehicle to detect the on-off of a dual-relay charging device.

[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0014] (1) The present invention provides a method for detecting the on-off results of two circuits, L and N, separately. Each relay is designed as a single relay circuit inside the control board, and the on-off of the circuit is detected by a photocoupler and a triode. Thus, the purpose of detecting whether the relay is on and off properly is achieved.

[0015] (2) Through the present invention, the control system can know exactly whether the relay is on and off properly, thereby improving the self-detection capability of the product and providing users with the greatest safety protection. This patented technology is not only applicable to automobile charging protection devices, but also to charging protection devices for battery vehicles and other products, and can also be applied to other protection devices that require dual relays to control power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a circuit connection diagram of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "provided with, connected", etc. should be understood in a broad sense; the terms "first, second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0019] like Figure 1 As shown, the specific implementation process of the present invention is as follows:

[0020] The present invention relates to a relay on-off detection system for a new energy vehicle charging protection device in the field of circuit detection technology. The invention is a circuit on-off detection system for a dual relay charging device provided with an L-pole relay PL1 for controlling the L-pole and an N-pole relay PL2 for controlling the N-pole. In the two relays, the two ends of the L-pole relay for controlling the L-pole are respectively an input end L_in and an output end L_out; the two ends of the N-pole relay for controlling the N-pole are respectively an input end N_in and an output end N_out. A first feedback circuit is designed between L_in and N_out, and a second feedback circuit is designed between N_in and L_out. By detecting the conduction and cutoff of these two circuits, the on-off of the two relays can be determined. This allows the system to self-detect relay failures and increase user safety.

[0021] Specifically, L_in and L_out are arranged at two ends of the L-pole relay switch, and N_in and N_out are arranged at two ends of the N-pole relay switch.

[0022] The components in the first feedback circuit include a first diode D1, a first photocoupler U1 and a first transistor Q1. The input terminal L_in of the L-pole relay RL1 is electrically connected to the anode of the first diode D1, the cathode of the first diode D1 is electrically connected to the output terminal N_out of the N-pole relay RL2 through the connection surface of the first photocoupler U1, the output surface of the first photocoupler U1 is electrically connected to the base of the first transistor Q1, and the emitter of the first transistor is electrically connected to the MCU.

[0023] Specifically, in the first feedback circuit, a protection resistor R1 is connected in series between L_in and N_out, a bias circuit is set for the first transistor Q1, an external voltage VDD is added to the collector, the emitter is connected to the output end of the photocoupler U1 to form a ground loop, and is electrically connected to the MCU through the data socket.

[0024] The components in the second feedback circuit include a second diode D2, a second photocoupler U2 and a second transistor Q2. The input terminal N_in of the N-pole relay RL2 is electrically connected to the anode of the second diode D2. The cathode of the second diode D2 is electrically connected to the output terminal L_out of the L-pole relay RL1 through the connection surface of the second photocoupler U2. The output surface of the second photocoupler U2 is electrically connected to the base of the second transistor Q2. The emitter of the second transistor Q2 is electrically connected to the CPU.

[0025] Specifically, in the first feedback circuit, a protection resistor R4 is connected in series between L_in and N_out, a bias circuit is set for the second transistor Q2, an external voltage VDD is added to the collector, the emitter is connected to the output end of the photocoupler U2 to form a ground loop, and is electrically connected to the CPU through the data socket.

[0026] Specifically, in order for the transistor amplifier to amplify the signal voltage without distortion, it is necessary to ensure that the emitter junction of the transistor is forward biased and the collector junction is reverse biased, that is, to set its operating point. The base, emitter and collector of the transistor are at the required potential VDD through the setting of the external circuit, and the value of VDD is obtained according to calculation.

[0027] Among them, the most common function of the diode is to allow current to pass in only one direction (called forward bias) and to block the current in the reverse direction (called reverse bias). Therefore, the diode can be understood as an electronic version of a check valve. When the L-pole relay PL1 and the N-pole relay PL2 work normally, the first feedback circuit and the second feedback circuit are powered on at the same time, and the MCU or CPU receives the electrical signal. Otherwise, the MCU or CPU cannot receive the electrical signal.

[0028] The transistor has a current amplification function, and its essence is that the transistor can control a larger change in collector current with a small change in base current. This is the most basic and important characteristic of the transistor. In the present invention, the first transistor Q1 and the second transistor Q2 are PNP-type crystal transistors, which can amplify the small current input by the base, and transmit the electrical signal to the MCU or CPU by the emitter.

[0029] The CPU is a data processing unit. The MCU generally includes a CPU, but in addition to the data processing unit, there are other peripheral modules, such as RAM, ROM, timers, counters, and various I / O interfaces. In other words, the MCU is a micro control unit that integrates the CPU and other peripheral modules.

[0030] The specific implementation of the present invention is:

[0031] Start the dual relay charging device equipped with the detection circuit designed by the present invention. When both the L-pole relay and the N-pole relay can work normally, the first feedback circuit and the second feedback circuit form a loop, a forward current passes through the first diode, the light-emitting diode in the first photocoupler emits light and converts it into an electrical signal and transmits it to the first transistor, and the emitter of the first transistor feeds back the electrical signal to the MCU; similarly, a forward current passes through the second diode D2, the light-emitting diode in the second photocoupler U2 emits light and converts it into an electrical signal and transmits it to the second transistor Q2, and the emitter of the second transistor Q2 feeds back the electrical signal to the CPU. The information that the equipment is operating normally can be obtained.

[0032] When one or both of the L-pole relay PL1 and the N-pole relay PL2 fail to work properly, the first feedback circuit and the second feedback circuit cannot form a loop, and there is no forward current that can pass through the diode in the feedback circuit connected to the input end of the faulty relay. Information that the equipment is not operating normally can be obtained, so that the user can deal with the abnormal situation in time.

[0033] The above-mentioned embodiments only express the implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A detection method for a relay on / off detection system of a charging protection device for a new energy vehicle, characterized in that: The detection system comprises a dual-relay charging device of an L-pole relay and an N-pole relay, wherein a first feedback circuit is connected to the input end of the L-pole relay and the output end of the N-pole relay, and a second feedback circuit is connected to the output end of the L-pole relay and the input end of the N-pole relay; The components in the first feedback circuit include a first diode, a first photocoupler and a first transistor, the input end of the L-pole relay is electrically connected to the anode of the first diode, the cathode of the first diode is electrically connected to the output end of the N-pole relay through the connection surface of the first photocoupler, the output surface of the first photocoupler is electrically connected to the base of the first transistor, and the emitter of the first transistor is electrically connected to the MCU; The components in the second feedback circuit include a second diode, a second photocoupler and a second triode, the input end of the N-pole relay is electrically connected to the anode of the second diode, the cathode of the second diode is electrically connected to the output end of the L-pole relay through the connection surface of the second photocoupler, the output surface of the second photocoupler is electrically connected to the base of the first triode, and the emitter of the second triode is electrically connected to the CPU; The collector of the first transistor is provided with a bias circuit connected to the base and connected to an external voltage at the same time, and the emitter of the first transistor is grounded and electrically connected to the MCU at the same time; The collector of the second transistor is provided with a bias circuit and connected to the base, and is connected to an external voltage at the same time; the emitter of the second transistor is grounded and is electrically connected to the CPU; The detection method comprises the following steps: When the L-pole relay and the N-pole relay work normally, the first feedback circuit and the second feedback circuit form a loop, a forward current passes through the first diode, the light-emitting diode in the first photocoupler emits light and converts it into an electrical signal and transmits it to the first transistor, and the emitter of the first transistor feeds back the electrical signal to the MCU; similarly, a forward current passes through the second diode, the light-emitting diode in the second photocoupler emits light and converts it into an electrical signal and transmits it to the second transistor, and the emitter of the second transistor feeds back the electrical signal to the CPU, thereby obtaining information that the device is operating normally; When one or both of the L-pole relay and the N-pole relay fail to work properly, the first feedback circuit and the second feedback circuit cannot form a loop, and there is no forward current that can pass through the diode in the feedback circuit connected to the input end of the faulty relay, so that the information that the equipment is not operating normally is obtained, so that the user can deal with the abnormal situation in time.

2. The detection method of the relay on-off detection system of the new energy vehicle charging protection device according to claim 1 is characterized in that: The first feedback circuit and the second feedback circuit further include a plurality of protection resistors.

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