Constant current source high-voltage loop interlocking detection circuit

Abstract

The utility model discloses a constant-current source high-voltage loop interlocking detection circuit, which comprises a controller and is characterized by comprising a switch module communicated with a signal output end of the controller; the signal input end of the voltage follower is communicated with the output end of the switch module; one end of the high-voltage connector is connected with the output end of the voltage follower, and the two ends of the high-voltage connector are connected with a constant-current power supply; the controller is connected with the input end and the output end of the high-voltage connector and used for detecting the voltage of the input end and the output end of the high-voltage connector.

Description

TECHNICAL FIELD

[0001] The utility model relates to high pressure loop interlock detection circuit technical field, specifically a constant current source high pressure loop interlock detection circuit. BACKGROUND

[0002] High Voltage Inter-lock, abbreviated as HVIL, is high voltage interlock or high voltage interlock loop, which uses low voltage signal to monitor the continuity of all high voltage loops (battery system, motor controller, connector, DC / DC, high voltage box, etc.) connected to the high voltage bus on the electric vehicle. High voltage interlock is a safety design measure function of hybrid and pure electric vehicles, which aims to protect personnel at any stage of the life cycle of electric vehicles (during vehicle assembly, repair, maintenance and operation).

[0003] When the high voltage interlock loop is connected or disconnected, the controller receiving end receives the feedback signal, and the on-off of the high voltage loop is controlled by the feedback signal. The high voltage loop must ensure that the entire high voltage loop is electrically connected before the vehicle can be powered by high voltage, thereby improving the safety of the vehicle; if the integrity of the vehicle high voltage system is accidentally damaged, the entire high voltage loop is disconnected and discharged; to avoid the occurrence of electric leakage or fire accidents.

[0004] The existing market mainstream scheme mainly includes two categories, the first category is a direct current source scheme, and the second category is a PWM scheme.

[0005] The direct current source scheme outputs direct current at one end of the controller, forms a loop at the other end, detects the voltage at the output and input points, then compares the collected voltage value with the corresponding threshold value under different interface states (normal, short ground, short power supply, open circuit), and determines the current state of the high voltage loop interlock loop. This scheme has high cost and is highly dependent on integrated chips, and once a chip shortage occurs, it will be difficult to continue.

[0006] The PWM scheme is that the controller sends out a PWM wave, which passes through multiple high voltage interlock connectors and finally returns to the controller, and the integrity of the high voltage loop interlock loop is determined according to the duty cycle of the received PWM wave. This scheme cannot detect the case where the impedance in the high voltage loop interlock loop becomes large due to oxidation of the plug-in metal pins (generally, the industry currently uses a loop impedance of 200Ω or less to consider it normal), which has a safety hazard. INVENTION CONTENTS

[0007] The utility model aims at providing a constant current source high voltage loop interlock detection circuit to solve the problems in the background art.

[0008] To achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0009] A constant current source high voltage loop interlock detection circuit, comprising a controller, comprising:

[0010] A switch module in communication with the signal output of the controller;

[0011] A voltage follower in communication with the output of the switch module;

[0012] A high voltage connector connected at one end to the output of the voltage follower, and having a constant current source connected across the two ends thereof;

[0013] The controller is connected to the input and output of the high voltage connector for detecting the voltage at the input and output of the high voltage connector.

[0014] By providing the voltage follower, the constant current source is provided for the high voltage connector through the power follower, thereby reducing the cost.

[0015] As a further aspect of the present application, the switch module comprises a triode Q1, the base resistor of the triode Q1 is in communication with the signal output port I / O of the controller, and the collector of the triode Q1 is in communication with the voltage input end of the voltage follower.

[0016] As the input voltage circuit of the voltage follower, the triode Q1 can realize the opening or closing of the voltage follower circuit.

[0017] As a further aspect of the present application, the voltage input end of the voltage follower is connected to a power supply.

[0018] The input power supply is provided for the voltage follower.

[0019] As a further aspect of the present application, the output end of the voltage follower is connected to a triode Q2, and the base of the triode Q2 is in communication with the voltage output end of the power follower.

[0020] The voltage follower processing circuit, the voltage of the emitter of the triode Q2 is equal to the voltage sum of the voltage of the same phase input end of the voltage follower U1 and the PN junction voltage between the emitter and the collector of Q2, and the constant current source generated by the triode Q2 can be transmitted to the high voltage connector.

[0021] As a further aspect of the present application, the triode collector Q2 is in communication with the output end of the high voltage connector through a diode D1.

[0022] The constant current source generated by the voltage follower is transmitted to the high voltage connector through the diode D1.

[0023] As a further scheme of the utility model: the output end of high voltage connector is connected with capacitor C1, and the end of capacitor C1 away from high voltage connector is grounded.

[0024] As a further scheme of the utility model: the input end of high voltage connector is connected with capacitor C2, and the end of capacitor C2 away from high voltage connector is grounded.

[0025] By connecting capacitor at the input end and output end of high voltage connector, noise interference is filtered out, and electrostatic protection is carried out.

[0026] As a further scheme of the utility model: the voltage detection port AN1 of controller is in communication with the output end of high voltage connector.

[0027] As a further scheme of the utility model: the voltage detection port AN2 of controller is in communication with the input end of high voltage connector.

[0028] The voltage of input end and output end is detected by controller, and then the collected voltage value is compared with the corresponding threshold value under different interface states (normal, short ground, short power supply, open circuit), so that the current state of high voltage loop interlocking circuit is determined.

[0029] As a further scheme of the utility model: common mode inductor L1 is connected between the input end and output end of high voltage connector.

[0030] By setting common mode inductor L1, common mode interference is inhibited, misjudgment is avoided, common mode electromagnetic interference is effectively inhibited.

[0031] Compared with the prior art, the utility model has the beneficial effects that:

[0032] 1, the application can realize constant current high voltage detection by setting follower and triode, so that the cost is low.

[0033] 2, the application is provided with common mode inductor L1, common mode interference is inhibited, misjudgment is avoided, common mode electromagnetic interference is effectively inhibited. DETAILED DESCRIPTION

[0034] Figure 1 It is the circuit diagram of the embodiment;

[0035] Figure 2 It is the circuit diagram working flow chart of the embodiment;

[0036] In the drawing: 1 - controller, 2 - voltage follower, 3 - switch module, 4 - high voltage connector. DETAILED DESCRIPTION

[0037] Clearly and completely describe the technical scheme in the embodiments of the utility model with reference to the drawings in the embodiments of the utility model, obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the utility model.

[0038] Please refer to Figure 1 In the embodiments of the utility model, a constant current source high voltage loop interlock detection circuit comprises a controller 1, comprising:

[0039] A switching module 3 is in communication with the signal output end of the controller 1, in this embodiment, the switching module 3 comprises a triode Q1, the base electrode of the triode Q1 is in communication with the signal output port I / O of the controller 1, and the collector of the triode Q1 is in communication with the voltage input end of the voltage follower 2.

[0040] The voltage follower 2 is connected with a power supply at the voltage input end, and the signal input end of the voltage follower 2 is in communication with the output end of the switching module 3; the output end of the voltage follower 2 is connected with a triode Q2, the base electrode of the triode Q2 is in communication with the voltage output end of the voltage follower, the voltage processing circuit of the voltage follower 2, the voltage of the emitter of the triode Q2 is equal to the voltage sum of the voltage of the non-inverting input end of the voltage follower 2 U1 and the PN junction voltage between the emitter and the collector of Q2, and then the generated constant current source can be transmitted to the high voltage connector 4 through the triode Q2, and the triode collector Q2 is in communication with the output end of the high voltage connector 4 through the diode D1.

[0041] The high voltage connector 4 is connected with the output end of the voltage follower 2 at one end, and the high voltage connector 4 is connected with a constant current power supply at two ends, the output end of the high voltage connector 4 is connected with a capacitor C1, the end of the capacitor C1 away from the high voltage connector 4 is grounded, the input end of the high voltage connector 4 is connected with a capacitor C2, the end of the capacitor C2 away from the high voltage connector 4 is grounded, and the input end and the output end of the high voltage connector 4 are connected with a common mode inductor L1. By arranging the common mode inductor L1, common mode interference is suppressed, false judgment is avoided, and common mode electromagnetic interference is effectively suppressed.

[0042] The input end and the output end of the high voltage connector 4 are connected with the controller 1 for detecting the voltage of the input end and the output end of the high voltage connector 4, in this embodiment, the voltage detection port AN1 of the controller 1 is in communication with the output end of the high voltage connector 4, and the voltage detection port AN2 of the controller 1 is in communication with the input end of the high voltage connector 4.

[0043] In use, as Figure 2As shown, the signal output port I / O of the controller 1 outputs high level, and the voltage values of HVIL-OUT-AD and HVIL-IN-AD detected by the voltage detection ports AN1 and AN2 of the controller 1 are read.

[0044] Firstly, it is judged whether the detected voltage value of HVIL-OUT-AD is in the interval a and whether the voltage value of HVIL-IN-AD is in the interval a'. If yes, the high voltage interlocking loop is connected normally, and the high voltage is allowed to be applied. In this embodiment, a=a', and the value range of a is 0.5-1.5V.

[0045] If not in the above range, it is judged whether the detected voltage value of HVIL-OUT-AD is in the interval b and whether the voltage value of HVIL-IN-AD is in the interval b'. If yes, the high voltage interlocking loop is open, and the high voltage is not allowed to be applied. In this embodiment, b=b', and the value range of b is 4V>b>2V.

[0046] Then, it is judged whether the detected voltage value of HVIL-OUT-AD is in the interval c and whether the voltage value of HVIL-IN-AD is in the interval c'. If yes, the high voltage interlocking loop is shorted, and the high voltage is not allowed to be applied. In this embodiment, c=c', and the value range of c is c>4V.

[0047] Finally, it is judged whether the detected voltage value of HVIL-OUT-AD is in the interval d and whether the voltage value of HVIL-IN-AD is in the interval d'. If yes, the high voltage interlocking loop is shorted, and the high voltage is not allowed to be applied. In this embodiment, d=d', and the value range of d is d<0.1V.

[0048] Embodiment 1

[0049] The signal output port I / O of the controller 1 outputs high level, and the voltage values of HVIL-OUT-AD and HVIL-IN-AD detected by the voltage detection ports AN1 and AN2 of the controller 1 are read. In this embodiment, the read voltage values of HVIL-OUT-AD and HVIL-IN-AD are both 1V. Firstly, it is judged whether 3V is in the range of a. Through comparison, it is in the range, so it can be judged by detection in this embodiment that the high voltage interlocking loop is connected normally, and the high voltage is allowed to be applied.

[0050] Embodiment 2

[0051] The signal output port I / O of the controller 1 outputs a high level, reads the voltage values of HVIL-OUT-AD and HVIL-IN-AD detected by the voltage detection ports AN1 and AN2 of the controller 1, in this embodiment, the read voltage values of HVIL-OUT-AD and HVIL-IN-AD are both 3V, first determine whether 3V is in the range of a, through comparison, it is not, then continue to compare whether it is in the range of b, after comparison, it is in the range of b, further, the high voltage interlock loop is in an open circuit state, and high voltage is not allowed to be applied at this time.

[0052] Embodiment 3

[0053] The signal output port I / O of the controller 1 outputs a high level, reads the voltage values of HVIL-OUT-AD and HVIL-IN-AD detected by the voltage detection ports AN1 and AN2 of the controller 1, in this embodiment, the read voltage values of HVIL-OUT-AD and HVIL-IN-AD are both 5V, first determine whether 5V is in the range of a, through comparison, it is not, then continue to compare whether it is in the range of b, after comparison, it is not in the range of b, then continue to compare whether it is in the range of c, after comparison, it is in the range of c, further, the high voltage interlock loop is in an open circuit state, and high voltage is not allowed to be applied at this time.

[0054] Embodiment 4

[0055] The signal output port I / O of the controller 1 outputs a high level, reads the voltage values of HVIL-OUT-AD and HVIL-IN-AD detected by the voltage detection ports AN1 and AN2 of the controller 1, in this embodiment, the read voltage values of HVIL-OUT-AD and HVIL-IN-AD are both 0.05V, first determine whether 0.05V is in the range of a, through comparison, it is not, then continue to compare whether it is in the range of b, after comparison, it is not in the range of b, then continue to compare whether it is in the range of c, after comparison, it is also in the range of c, then compare whether it is in the range of d, after comparison, it is in the range of c, further, the high voltage interlock loop is in an open circuit state, and high voltage is not allowed to be applied at this time.

[0056] It is apparent for a person skilled in the art that the present application is not limited to the details of the above-described exemplary embodiments, but that it can be implemented in other concrete forms without departing from the spirit or the essential characteristics of the present application. Therefore, the embodiments should be considered as exemplary and non-limiting, the scope of the present application being defined by the claims appended hereto rather than by the above description, and all the changes which fall within the meaning and the scope of the equivalent elements of the claims are intended to be embraced therein. Any reference signs in the claims should not be construed as limiting the claims to the figures in which the reference signs are used.

[0057] Furthermore, it should be understood that although the present specification describes exemplary embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this way only for the sake of clarity, and a person skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that a person skilled in the art can understand.

Claims

1. A constant current source high voltage loop interlock detection circuit comprising a controller (1), characterized in that, The utility model relates to a high-voltage detection circuit, including: Switch module (3) with the signal output of controller (1) intercommunication; Voltage follower (2) with the output of switch module (3) intercommunication; High-voltage connector (4) one end is connected with the output of voltage follower (2), and both ends of high-voltage connector (4) are connected with constant-current power supply; The controller (1) is connected with the input and output of high-voltage connector (4) for detecting the voltage of input and output of high-voltage connector (4).

2. The constant current source high voltage loop interlock detection circuit of claim 1, wherein, The switch module (3) includes triode Q1, and the base resistance of triode Q1 is connected with the signal output port I / O of controller (1), and the collector of triode Q1 is connected with the voltage input of voltage follower (2).

3. The constant current source high voltage loop interlock detection circuit of claim 1, wherein, The voltage input of voltage follower (2) is connected with power supply.

4. The constant current source high voltage loop interlock detection circuit of claim 1, wherein, The output of voltage follower (2) is connected with triode Q2, and the base of triode Q2 is connected with the voltage output of voltage follower.

5. The constant current source high voltage loop interlock detection circuit of claim 4, wherein, The electrode of triode Q2 is connected with the output of high-voltage connector (4) through diode D1.

6. The constant current source high voltage loop interlock detection circuit of claim 1, wherein, The output of high-voltage connector (4) is connected with capacitor C1, and one end of capacitor C1 away from high-voltage connector (4) is grounded.

7. The constant current source high voltage loop interlock detection circuit of claim 1, wherein, The input of high-voltage connector (4) is connected with capacitor C2, and one end of capacitor C2 away from high-voltage connector (4) is grounded.

8. The constant current source high voltage loop interlock detection circuit of claim 1, wherein, The voltage detection port AN1 of controller (1) is connected with the output of high-voltage connector (4).

9. The constant current source high voltage loop interlock detection circuit of claim 1, wherein, The voltage detection port AN2 of controller (1) is connected with the input of high-voltage connector (4).

10. The constant current source high voltage loop interlock detection circuit of claim 1, wherein, The common mode inductance L1 is connected between the input and output of high-voltage connector (4).

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