LED fault identification device and LED driving system

Abstract

The utility model discloses an LED fault identification device and an LED driving system, and relates to the field of fault identification, the LED fault identification device is arranged in an LED driving power supply, when the corresponding LED driving power supply has an electric leakage condition, a detection module in the device receives a voltage transmitted by a current acquisition module and generates a fault signal, and the fault signal is sent to the LED driving power supply. When a fault occurs, the time-delay identification module keeps the fault signal unchanged within a preset time, the switch module turns off power supply of the corresponding LED driving power supply after receiving the fault signal, so that the LED lamp correspondingly connected with the LED driving power supply is turned off, and the time-delay identification module delays on and off of the LED lamp corresponding to the fault power supply. Therefore, a maintainer can judge whether the LED driving power supply has an electric leakage fault or not according to the on-off condition of the LED lamp, the maintainer does not need to overhaul each LED driving power supply one by one for troubleshooting, and the overhaul difficulty and the labor cost are greatly reduced.

Description

Technical Field

[0001] The utility model relates to the field of fault identification, in particular to an LED fault identification device and an LED driving system. Background Technique

[0002] Existing electrical equipment, such as the lighting system of an LED (Light-Emitting Diode) lamp, drives multiple groups of LED loads (LED lamps) through multiple LED driving power supplies to form an LED driving system. In the LED driving system, the existing leakage protection circuit is connected to the input side of all LED driving power supplies. As Figure 1 shown, when a leakage fault is detected in the LED driving system, the input power of the LED driving system is cut off in time, that is, all LED driving power supplies are cut off, so as to achieve the function of leakage protection.

[0003] However, this leakage protection method has the problem of difficult maintenance. For example, in a high-power lighting system, which includes several LED driving power supplies, if only one of the LED driving power supplies has a leakage fault, under this leakage protection method, all LED driving power supplies are cut off. At this time, maintenance personnel need to check each LED driving power supply one by one to troubleshoot the fault, which increases the difficulty of maintenance and the labor cost. Content of the Utility Model

[0004] The purpose of the utility model is to provide an LED fault identification device and an LED driving system. Through the delay identification module in this solution, the on and off of the LED lamp corresponding to the faulty power supply is delayed, so that maintenance personnel can judge whether there is a leakage fault in the LED driving power supply according to the on and off situation of the LED lamp, without the need for maintenance personnel to check each LED driving power supply one by one to troubleshoot the fault, greatly reducing the difficulty of maintenance and the labor cost.

[0005] To solve the above technical problems, the utility model provides an LED fault identification device, which is arranged in the LED driving power supply and includes: a current acquisition module, a detection module, a delay identification module and a switch module;

[0006] The input end of the current acquisition module is connected to the L line and the N line on the input side of the LED driving power supply connected in one-to-one correspondence, and is used to collect the leakage current on the L line and the N line on the input side of the LED driving power supply to obtain a voltage positively correlated with the leakage current; the L line and the N line on the input side of the LED driving power supply are connected to the output end of the total leakage protection circuit, and the input end of the total leakage protection circuit is connected to the power grid;

[0007] The input end of the detection module is connected to the output end of the current acquisition module and is used to generate a fault signal;

[0008] The delay identification module, the input end of the delay identification module is connected to the output end of the detection module, and the output end is connected to the control end of the switch module, and is used for delaying the fault signal generated by the detection module by a preset time so that the fault signal remains valid within the delay time;

[0009] The input end of the switch module is connected to the L line and the N line on the input side of the corresponding LED drive power supply, the output end is connected to the corresponding LED drive power supply, and the power supply end is connected to the DC power supply, and is used for closing when the fault signal is less than the preset voltage value; cutting off when the fault signal is greater than or equal to the preset voltage value.

[0010] Optionally, the current acquisition module is a zero-sequence current transformer, and the zero-sequence current transformer includes: an iron core, a first winding, a second winding and a third winding, and the first winding, the second winding and the third winding are all wound on the iron core;

[0011] The first end of the first winding is connected to the N line on the input side of the LED drive power supply, and the second end is connected to the LED drive power supply;

[0012] The first end of the second winding is connected to the L line on the input side of the LED drive power supply, and the second end is connected to the LED drive power supply, and the number of turns of the first winding and the second winding is the same;

[0013] The first end and the second end of the third winding are both connected to the input end of the detection module, and are used for obtaining a voltage positively correlated with the leakage current when the first winding and the second winding collect the leakage current on the L line and the N line on the input side of the LED drive power supply, and the number of turns of the first winding and the third winding is different.

[0014] Optionally, the detection module is a first resistor, and the first resistor is connected to the output end of the current acquisition module, and is used for taking the obtained voltage as the fault signal and transmitting the fault signal to the delay identification module.

[0015] Optionally, the detection module further includes: a second resistor, a third resistor and an operational amplifier;

[0016] The first end of the second resistor is connected to the negative input end of the operational amplifier, and the second end is respectively connected to the second end of the first resistor and the input end of the delay identification module;

[0017] The first end of the third resistor is connected to the negative input end of the operational amplifier, and the second end is connected to the output end of the operational amplifier;

[0018] The non-inverting input terminal of the operational amplifier is connected to the first end of the first resistor, the output terminal is connected to the input terminal of the delay identification module, and the power supply terminal is connected to the DC power supply.

[0019] Optionally, the switch module includes: a comparator, a triode, and a relay;

[0020] The inverting input terminal of the comparator is connected to a preset voltage, the non-inverting input terminal is connected to the output terminal of the delay identification module, and the power supply terminal is connected to the DC power supply;

[0021] The base of the triode is connected to the output terminal of the comparator, the collector is connected to the output terminal of the delay identification module, and the emitter is connected to the first end of the coil of the relay, and is used to conduct when the voltage at the non-inverting input terminal of the comparator is greater than the voltage at the inverting input terminal of the comparator;

[0022] The second end of the coil of the relay is connected to the DC power supply, the first stationary contact is connected to the first input terminal of the corresponding LED drive power supply, the second stationary contact is connected to the second input terminal of the LED drive power supply, the first moving contact is connected to the N line on the input side of the LED drive power supply, and the second moving contact is connected to the L line on the input side of the LED drive power supply, and is used to cut off the power of the coil when the triode is turned off, disconnect the first moving contact and the first stationary contact, and disconnect the second moving contact and the second stationary contact.

[0023] Optionally, it further includes: a rectification module and a buck module;

[0024] The input terminal of the rectification module is connected to the L line and the N line on the input side of the LED drive power supply connected in one-to-one correspondence, and the output terminal is connected to the input terminal of the buck module, and is used to convert the AC power transmitted by the power grid into corresponding DC power and transmit the DC power to the buck module;

[0025] The output terminal of the buck module is connected to the power supply terminal of the switch module, and is used to perform corresponding bucking on the total DC voltage corresponding to the DC power so that the bucked first DC voltage can supply power to the switch module.

[0026] Optionally, the delay identification module includes: a second capacitor and a fourth resistor;

[0027] The second capacitor is connected in parallel with the fourth resistor. The first end of the second capacitor and the first end of the fourth resistor are connected to the positive output terminal of the detection module, the second end of the second capacitor and the second end of the fourth resistor are connected to the negative output terminal of the detection module, and at the same time, the first end of the second capacitor and the first end of the fourth resistor are both connected to the control terminal of the switch module.

[0028] Optionally, the delay recognition module further includes:

[0029] A one-way conduction module, the input end of the one-way conduction module is connected to the output end of the detection module, and the output end is respectively connected to the first end of the second capacitor and the first end of the fourth resistor.

[0030] Optionally, the one-way conduction module is a diode, the anode of the diode is connected to the output end of the detection module, and the cathode is respectively connected to the first end of the second capacitor and the first end of the fourth resistor.

[0031] To solve the above technical problems, the present invention also provides an LED driving system, including: a power grid, a total leakage protection circuit, the LED fault recognition device as described above, and a corresponding LED driving power supply. The LED fault recognition device is respectively connected to the total leakage protection circuit and each LED driving power supply, and the total leakage protection circuit is connected to the power grid.

[0032] The purpose of the present invention is to provide an LED fault recognition device and system. The LED fault recognition device is arranged in the LED driving power supply. When a leakage occurs in the corresponding LED driving power supply, the detection module in the device will receive the voltage transmitted by the current acquisition module and generate a fault signal. The delay recognition module will keep the fault signal unchanged within a preset time. After receiving the fault signal, the switch module will cut off the power supply of the corresponding LED driving power supply, so that the LED lamp connected to the LED driving power supply is turned off. By forming a delay in the on and off of the LED lamp corresponding to the faulty power supply through the delay recognition module, maintenance personnel can judge whether there is a leakage fault in the LED driving power supply according to the on and off situation of the LED lamp, without the need for maintenance personnel to check each LED driving power supply one by one to troubleshoot the fault, greatly reducing the difficulty of maintenance and labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0034] Figure 1 A schematic structural diagram of an existing LED driving system provided by the present invention;

[0035] Figure 2 A schematic structural diagram of an LED fault recognition device provided by the present invention;

[0036] Figure 3 Schematic structural diagram of an improved LED driving system provided by the present utility model;

[0037] Figure 4 Schematic structural diagram of a detection module, a delay identification module and a switch module provided by the present utility model. Detailed implementation manners

[0038] The core of the present utility model is to provide an LED fault identification device. In this solution, the delay identification module forms a time delay for the on and off of the LED lights corresponding to the faulty power supply, enabling maintenance personnel to judge whether there is a leakage fault in the LED driving power supply according to the on and off conditions of the LED lights, without the need for maintenance personnel to check each LED driving power supply one by one to troubleshoot faults, greatly reducing the difficulty of troubleshooting and labor costs.

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0040] Please refer to Figure 2 , Figure 2 Schematic structural diagram of an LED fault identification device provided by the present utility model. The LED fault identification device is arranged in the LED driving power supply. When there are multiple LED driving power supplies in the LED driving system, the connection manners of the multiple LED fault identification devices are as Figure 2 shown.

[0041] The LED fault identification device includes: a current acquisition module 1, a detection module 2, a delay identification module 3 and a switch module 4;

[0042] The input end of the current acquisition module 1 is connected to the L line and the N line on the input side of the LED driving power supply connected in one-to-one correspondence, and is used to collect the leakage current on the L line and the N line on the input side of the LED driving power supply to obtain a voltage positively correlated with the leakage current; the L line and the N line on the input side of the LED driving power supply are connected to the output end of the total leakage protection circuit, and the input end of the total leakage protection circuit is connected to the power grid;

[0043] The input end of the detection module 2 is connected to the output end of the current acquisition module 1, and is used to generate a fault signal;

[0044] The delay recognition module 3, the input end of the delay recognition module 3 is connected to the output end of the detection module 2, and the output end is connected to the control end of the switch module 4, which is used to delay the fault signal generated by the detection module 2 for a preset time, so that the fault signal remains valid within the delay time;

[0045] The input end of the switch module 4 is connected to the L line and the N line on the input side of the LED driving power supply connected in one-to-one correspondence, the output end is connected to the corresponding LED driving power supply, and the power supply end is connected to the DC power supply, which is used to close when the fault signal is less than the preset voltage value; cut off when the fault signal is greater than or equal to the preset voltage value.

[0046] In the present utility model, the LED fault recognition device includes a current acquisition module 1, a detection module 2, a delay recognition module 3 and a switch module 4. Among them, when there is a leakage situation in the corresponding LED driving power supply, the current acquisition module 1 can collect the leakage current on the L line and the N line on the input side of the LED driving power supply, and obtain a voltage that is positively correlated with the leakage current. The detection module 2 will generate a fault signal. When it is recognized in the switch module 4 that the fault signal is greater than the preset voltage value, the switch module 4 in the LED fault recognition device disconnects, and under the action of the delay recognition module 3, the fault signal is maintained for the delay set time, then the switch module 4 will also maintain the disconnected state within the delay set time. When the LED driving system re-obtains the input power, the aforementioned disconnected state remains unchanged. Then, the detected faulty LED driving power supply does not work due to power off, and the connected LED lamp is in the off state, while the other undetected faulty LED driving power supplies work normally, and the connected LED lamps are in the on state. In this way, through the on / off state of the LED lamps, it can be judged whether the corresponding LED driving power supply is in a leakage fault state, without the need for maintenance personnel to check each LED driving power supply one by one to troubleshoot the fault, greatly reducing the difficulty of maintenance and labor costs.

[0047] It should be noted that a LED driving system includes multiple LED driving power supplies, and the multiple LED driving power supplies are commonly connected to a total leakage protection circuit, and an LED fault recognition device is provided inside each LED driving power supply. The LED fault recognition device can be provided with a current acquisition module 1, a detection module 2, a delay recognition module 3, an auxiliary power source acquisition module and a switch module 4, and the structure is as Figure 3 shown. The auxiliary power source acquisition module includes a rectification module and a step-down module. The input end of the auxiliary power source acquisition module is connected to the front stage of the switch module 4, and its output end outputs an auxiliary power supply Vcc to provide an auxiliary power supply for the active devices in the detection module 2 and the switch module 4, that is, to supply power to the operational amplifier U1 and the comparator C1, so that the fault signal continues to be delayed for the set time under the action of the delay recognition circuit, and further controls the switch module 4 to continuously disconnect within the set time. Figure 3The input end of the auxiliary source acquisition module in is connected to the front stage of the switch module 4. It can be as Figure 3 connected to the rear stage of the first winding and the second winding of the zero-sequence current transformer as in, or can be connected to the front stage of the first winding and the second winding of the zero-sequence current transformer, that is, the front and rear connections of the auxiliary source acquisition module and the zero-sequence current transformer are not restricted, as long as it is ensured to be in the front stage of the switch module 4.

[0048] It should also be noted that since the first winding and the second winding of the zero-sequence current transformer are respectively wound with the same number of turns by the two input lines of the LED drive power supply, and both ends of the third winding are used as the input end of the detection module 2, therefore, during normal operation (when there is no leakage current), the currents flowing through the first and second windings are equal and the voltages cancel each other out. When a leakage current occurs, a current deviation (flux deviation) appears at both ends of the first winding and the second winding, and a voltage corresponding to the turns ratio is induced in the third winding. The voltage signal on the third winding is used as a fault signal for detecting the leakage current and is input into the switch module 4 through the detection module 2, causing the switch module 4 to disconnect. Since the switch module 4 disconnects, the LED drive power supply of this path will lose the power input, and it is very likely that the fault detection and switch function cannot continue. Therefore, an auxiliary source acquisition module is provided and connected to the front stage of the switch module 4 to ensure the normal operation of the detection module 2 and the switch module 4 when the switch module 4 is disconnected.

[0049] It should also be noted that in the LED fault identification device of the present application, when one or several LED drive power supplies are leaking, the switches at the input ends of the corresponding LED drive power supplies are timely cut off through the detection module 2, the delay identification module 3, and the switch module 4; and since the input end of the auxiliary source acquisition module is connected to the front stage of the switch module 4, the detection module 2 and the switch module 4 in the faulty LED drive power supply have the power provided by the auxiliary power supply, so that the detection module 2 and the switch module 4 can continue to work when the switch module 4 is cut off; therefore, when power is applied again, through the action of the delay identification module 3, the switch module 4 at the input end of the faulty LED drive power supply continues to maintain the cut-off state, making the LED lamp at its output end in the off state, while the other LED drive power supplies without leakage faults work normally and the load LED lamps at their rear stages are in the on state, which is convenient for users to identify and repair.

[0050] It should also be noted that in Figure 1Among them, the signs of the L wire and the N wire on the input side of the LED driving power supply are L and N respectively. The total leakage protection circuit is connected to the front stage of the L wire and the N wire on the input side of the LED driving power supply. The input terminals of the total leakage protection circuit are marked as the L' wire and the N' wire, which are the input wires connected to the grid side. The function of the total leakage protection circuit is to cut off its input loop after detecting the leakage current at the input end of the LED driving system to protect the LED driving system from leakage faults.

[0051] It should also be noted that since the LED fault identification device designed in this application is arranged inside the LED driving power supply, the manufacturers who produce and sell the driving power supply will only mark the current threshold of the LED fault identification device inside it, and will not participate in the design of the total leakage protection in the LED driving system. Therefore, in the LED driving system, it is very likely that the current thresholds of the total leakage protection circuit and the LED fault identification device in each LED driving power supply are different. The LED fault identification device of this application can achieve the function of identifying leakage faults regardless of the following situations.

[0052] In addition, before introducing the working conditions of the driving system in two situations, first define the current protection threshold:

[0053] The total leakage protection circuit has a current protection threshold, that is, when the leakage current increases to this threshold, the protection is started, the total leakage switch is disconnected, and the LED driving power supplies connected to the L wire and the N wire at the rear stage cannot work, as Figure 3 shown. The current threshold in the total leakage protection circuit is used as the first current threshold;

[0054] In the LED fault identification device inside each LED driving power supply, there is also a current protection threshold, that is, the preset voltage value in the switch module 4 defines the current threshold in the corresponding LED driving power supply, which is used as the second current threshold.

[0055] Next, through the working principles of the total leakage protection circuit and the LED fault identification device in each driving power supply, it is explained how the LED fault identification device of this application realizes the identification of leakage faults:

[0056] When the first current threshold of the total leakage protection circuit is greater than the second threshold of each LED driver power supply, assuming that a certain LED driver power supply has a leakage fault and the leakage current has reached the second threshold, the LED fault identification device inside the LED driver power supply starts to work. The detection module 2 controls the switch module 4 to disconnect through the delay identification module 3. The faulty LED driver power supply cuts off its input power and stops working. At the same time, due to the delay effect of the delay identification module 3, the switch module 4 remains in the disconnected state within the set delay time. Since the first current threshold is greater than the second current threshold, the total leakage protection circuit does not work. In this way, in the LED driver system, other non-faulty LED driver power supplies work normally. That is, in the lamp system driven by this LED driver system, only the lamp connected to the faulty LED driver power supply is in the off state, and the lamps connected to other non-faulty LED driver power supplies are in the on state. In this case, it is easy for maintenance personnel to identify the faulty power supply and carry out maintenance work.

[0057] When the first current threshold of the total leakage protection circuit is equal to the second threshold of each LED driver power supply, assuming that a certain LED driver power supply has a leakage fault and the leakage current has reached the second threshold, both the total leakage protection circuit and the fault identification device inside the faulty LED driver power supply start to work. The input power of the LED driver system is cut off. When the total leakage protection circuit is restarted and the LED driver system regains the input power, it is described in two cases:

[0058] In the first case, at the moment of restart, if the delay time of the delay identification module 3 in the LED fault identification device that detected the leakage fault has not ended, then at the moment of restart, all non-faulty LED driver power supplies work normally, and the subsequent LED load lamps are in the on state. However, due to the effect of the delay identification circuit, the switch module 4 of the faulty LED driver power supply remains continuously disconnected, and its subsequent load lamp is in the off state. In this case, it is easy for maintenance personnel to identify the faulty power supply and carry out maintenance work;

[0059] In the second case, at the moment of restart, if the delay time of the delay identification module 3 in the LED fault identification device that detected the leakage fault has ended, then at the moment of the first restart, both the total leakage protection circuit and the fault identification device inside the faulty LED driver power supply start to work, and all driver power supplies cut off the input power and do not work. In the faulty LED driver power supply, the delay identification module 3 works to keep the switch module 4 continuously disconnected. If it is restarted again in a short time so that the delay time does not end within the interval between the two restarts, it will return to the first case. In this case, it is easy for maintenance personnel to identify the faulty power supply and carry out maintenance work.

[0060] This embodiment provides an LED fault identification device. The LED fault identification device is arranged in the LED drive power supply. When the corresponding LED drive power supply has a leakage situation, the detection module 2 in the device will receive the voltage transmitted by the current acquisition module 1 and generate a fault signal. The delay identification module 3 will keep the fault signal unchanged within a preset time. After receiving the fault signal, the switch module 4 will cut off the power supply of the corresponding LED drive power supply, so that the LED lamp connected to the LED drive power supply is turned off. By forming a delay in the on / off state of the LED lamp corresponding to the faulty power supply through the delay identification module 3, maintenance personnel can judge whether there is a leakage fault in the LED drive power supply according to the on / off state of the LED lamp, without the need for maintenance personnel to check each LED drive power supply one by one to troubleshoot the fault, greatly reducing the difficulty of troubleshooting and labor costs.

[0061] Based on the above embodiment:

[0062] As an optional embodiment, the current acquisition module 1 is a zero-sequence current transformer. The zero-sequence current transformer includes: an iron core, a first winding, a second winding, and a third winding. The first winding, the second winding, and the third winding are all wound around the iron core;

[0063] The first end of the first winding is connected to the N line on the input side of the LED drive power supply, and the second end is connected to the LED drive power supply;

[0064] The first end of the second winding is connected to the L line on the input side of the LED drive power supply, and the second end is connected to the LED drive power supply. The number of turns of the first winding and the second winding is the same;

[0065] Both the first end and the second end of the third winding are connected to the input end of the detection module 2, and are used to obtain a voltage positively correlated with the leakage current when the first winding and the second winding collect the leakage current on the L line and the N line on the input side of the LED drive power supply. The number of turns of the first winding and the third winding is different.

[0066] In the present utility model, the current acquisition module 1 is a zero-sequence current transformer, and the zero-sequence current transformer is provided with an iron core, a first winding, a second winding and a third winding, and the first winding, the second winding and the third winding are all wound around the iron core. Since the first winding and the second winding in the current transformer are respectively connected to the L line and the N line on the input side of the LED driving power supply and the LED driving power supply, and the number of turns of the first winding and the second winding is the same, when there is no leakage fault in the LED driving power supply, the currents flowing through the first winding and the second winding are equal, and the voltages cancel each other out. At this time, the third winding cannot sense the voltage value. On the contrary, when there is a leakage fault in the LED driving power supply, that is, when a leakage current is generated, a current deviation (flux deviation) appears at both ends of the first winding and the second winding. Because the number of turns of the first winding and the third winding is different, a voltage corresponding to the turns ratio will be induced in the third winding at this time. The advantage of the zero-sequence current transformer is high sensitivity, which can accurately detect small-amplitude zero-sequence current, is more convenient for detecting leakage current, and improves the accuracy of fault detection. In addition, the zero-sequence current transformer also has the advantages of fast response, easy installation and maintenance.

[0067] It should be noted that, as Figure 3 shown, the L and N lines are the input lines input to a certain LED driving power supply in the LED driving system. The three windings of the zero-sequence current transformer include T1 (the first winding), T2 (the second winding) and T3 (the third winding). T1 and T2 are coils wound by the L and N lines respectively, and T3 is wound as a separate coil.

[0068] As an alternative embodiment, the detection module 2 is a first resistor. The first resistor R1 is connected to the output end of the current acquisition module 1, and is used to take the obtained voltage as a fault signal and transmit the fault signal to the delay identification module 3.

[0069] In the present utility model, the detection module 2 is the first resistor R1. Since the first resistor R1 is arranged at the output end of the current acquisition module 1, when there is a leakage fault in the corresponding LED driving power supply, the first resistor R1 can receive the voltage transmitted by the current acquisition module 1, and the first resistor R1 will take the voltage as a fault signal and transmit it to the delay identification module 3. The reason for using a resistor as the detection module 2 is that the resistor has the advantages of small volume and low cost.

[0070] As an alternative embodiment, the detection module 2 further includes: a second resistor R2, a third resistor R3 and an operational amplifier U1;

[0071] The first end of the second resistor R2 is connected to the negative input terminal of the operational amplifier U1, and the second end is respectively connected to the second end of the first resistor and the input terminal of the delay identification module 3;

[0072] The first end of the third resistor R3 is connected to the negative input terminal of the operational amplifier U1, and the second end is connected to the output terminal of the operational amplifier U1;

[0073] The positive input terminal of the operational amplifier U1 is connected to the first end of the first resistor R1, the output terminal is connected to the input terminal of the delay identification module 3, and the power supply terminal is connected to the DC power supply.

[0074] In the present utility model, as Figure 4 shown, the detection module 2 is further provided with: a second resistor R2, a third resistor R3, and an operational amplifier U1. Among them, the second resistor R2, the third resistor R3, and the operational amplifier U1 realize the function of a voltage follower circuit. By impedance matching, the voltages on both sides of the third winding are not affected by the subsequent circuit. The voltage follower circuit can increase the input impedance and decrease the output impedance, reduce the influence of the input signal (fault signal), and improve the accuracy of the solution.

[0075] It should be noted that in practical applications, the voltage follower circuit may be provided with a second resistor R2, a third resistor R3, and an operational amplifier U1 or other voltage follower devices.

[0076] As an optional embodiment, the switch module 4 includes: a comparator C1, a triode, and a relay;

[0077] The negative input terminal of the comparator C1 is connected to a preset voltage, the positive input terminal is connected to the output terminal of the delay identification module 3, and the power supply terminal is connected to the DC power supply;

[0078] The base of the triode is connected to the output terminal of the comparator C1, the collector is connected to the output terminal of the delay identification module 3, and the emitter is connected to the first end of the coil of the relay, and is used to conduct when the voltage at the positive input terminal of the comparator C1 is greater than the voltage at the negative input terminal of the comparator C1;

[0079] The second end of the coil of the relay is connected to the DC power supply. The first stationary contact is connected to the first input terminal of the corresponding LED driving power supply, the second stationary contact is connected to the second input terminal of the LED driving power supply, the first moving contact is connected to the N line on the input side of the LED driving power supply, and the second moving contact is connected to the L line on the input side of the LED driving power supply, and is used to cut off the power supply of the coil when the triode is turned off, disconnect the first moving contact and the first stationary contact, and disconnect the second moving contact and the second stationary contact.

[0080] In the present utility model, a comparator C1, a triode, and a relay K1 are provided in the switch module 4, and the triode is a P-type triode. Since the negative-phase input terminal of the comparator C1 is connected to a preset voltage and the positive-phase input terminal is connected to the output terminal of the detection module 2, only when a leakage fault occurs in the corresponding LED drive power supply will the positive-phase input terminal of the comparator C1 receive the voltage corresponding to the fault signal. Therefore, only when the voltage corresponding to the fault signal is less than the preset voltage, for example: ideally, when the LED drive power supply does not have a leakage fault, the voltage at the positive-phase input terminal of the comparator C1 should be zero. On the contrary, when the LED drive power supply has a leakage fault, the voltage corresponding to the fault signal should be greater than zero; when the LED drive power supply does not have a leakage fault, the comparator C1 will output a low level to turn on the P-type triode. When the triode is turned on, the coil of the relay K1 is energized, the first static contact and the first moving contact are closed, and the second static contact and the second moving contact are closed, and the LED drive power supply is normally energized; on the contrary, when the LED drive power supply has a leakage fault, the comparator C1 will output a high level to turn off the P-type triode. When the triode is turned off, the coil of the relay K1 is not energized, the first static contact and the first moving contact are disconnected, and the second static contact and the second moving contact are disconnected, and the LED drive power supply cannot be energized, accurately realizing the work of fault detection.

[0081] It should be noted that in practical applications, the comparator C1 can be replaced by other comparison circuits, such as a comparison circuit implemented by a triode. In addition, the electrical energy corresponding to the DC power supply can be obtained from the output of the auxiliary source acquisition module, or an eligible power supply can be additionally connected or an eligible battery can be built in.

[0082] As an optional embodiment, it further includes: a rectification module and a buck module;

[0083] The input terminal of the rectification module is connected to the L line and the N line on the input side of the LED drive power supply connected in one-to-one correspondence, and the output terminal is connected to the input terminal of the buck module, and is used to convert the AC electrical energy transmitted by the power grid into corresponding DC electrical energy and transmit the DC electrical energy to the buck module;

[0084] The output terminal of the buck module is connected to the power supply terminal of the switch module 4, and is used to perform corresponding bucking on the total DC voltage corresponding to the DC electrical energy, so that the bucked first DC voltage can supply power to the switch module 4.

[0085] In the present utility model, a rectification module and a step-down module are further provided in the LED fault identification device. Among them, the rectification module can convert the alternating current energy transmitted by the power grid into corresponding direct current energy, and transmit the direct current energy to the step-down module. After receiving the direct current energy, the step-down module will perform corresponding voltage conversion to supply power to the switch module 4. The purpose of setting the rectification module and the step-down module is to reasonably utilize the alternating current energy transmitted by the power grid, and there is no need to connect other power sources to supply power to the switch module 4. As long as the power grid remains powered on, the switch module 4 can always remain in the powered-on state.

[0086] It should be noted that Figure 3 The auxiliary source acquisition module in includes a rectification module and a step-down module. First, rectification is performed in the auxiliary source acquisition module. The rectification method is not limited and can be any rectification such as half-wave rectification, full-bridge rectification, etc. After rectification, any auxiliary power generation method can be used to output direct current, such as realized by DC-DC (such as Buck topology), a three-terminal voltage regulator circuit, such as a zener diode voltage regulator circuit, etc., to obtain direct current with a stable voltage value.

[0087] It should also be noted that in practical applications, when an operational amplifier U1 is provided in the detection module 2, considering the magnitude relationship between the current threshold of the total leakage protection circuit and the current threshold of the fault identification device, it is necessary to keep the comparator C1 and the operational amplifier U1 in the switch module 4 in the powered-on state. At this time, the comparator C1 and the operational amplifier U1 can be connected to a direct current power supply, and the direct current power supply can be either built-in in the LED fault identification device or externally connected; in addition, the comparator C1 and the operational amplifier U1 can also be connected to the output end of the step-down module, and the step-down module's voltage reduction process is used to supply power to the comparator C1 and the operational amplifier U1 respectively.

[0088] As an optional embodiment, the delay identification module 3 includes: a second capacitor and a fourth resistor;

[0089] The second capacitor is connected in parallel with the fourth resistor. The first end of the second capacitor and the first end of the fourth resistor are connected to the positive output end of the detection module, and the second end of the second capacitor and the second end of the fourth resistor are connected to the negative output end of the detection module 2. At the same time, the first end of the second capacitor and the first end of the fourth resistor are both connected to the control end of the switch module 4.

[0090] In the present utility model, a capacitor C and a fourth resistor R4 are provided in the circuit of the delay identification module 3. Among them, the capacitor C and the fourth resistor R4 form an RC filtering circuit, which plays a filtering role. However, the capacitor C also has a charging function. That is, when a leakage fault occurs in the corresponding LED driving power supply, the detection module 2 will transmit the fault signal to the capacitor C and continuously charge the capacitor C. After the capacitor C is fully charged, the fault signal will be transmitted to the switch module 4, accurately realizing the function of time delay. Moreover, the delay identification module 3 uses fewer electronic components, has a simple structure, a small volume, and a low cost.

[0091] As an alternative embodiment, the delay identification module 3 further includes:

[0092] A unidirectional conduction module, the input end of the unidirectional conduction module is connected to the output end of the detection module 2, and the output end is respectively connected to the first end of the second capacitor and the first end of the fourth resistor.

[0093] In the present utility model, a unidirectional conduction module is also provided in the delay identification module 3. The unidirectional conduction module is arranged between the output end of the detection module 2 and the control end of the switch module 4, which can prevent the occurrence of current backflow in the loop and improve the safety of the solution.

[0094] It should be noted that in practical applications, the unidirectional conduction module can be replaced by a resistor, which can also achieve the charging function and maintain a certain voltage value on the capacitor C; making the fault signal last for a certain period of time. The unidirectional conduction module can be a diode D or other unidirectional conduction devices.

[0095] As an alternative embodiment, the unidirectional conduction module is a diode. The anode of the diode is connected to the output end of the detection module 2, and the cathode is respectively connected to the first end of the second capacitor and the first end of the fourth resistor.

[0096] In the present utility model, the unidirectional conduction module is a diode D because the diode D has the function of unidirectional conduction, and the diode D also has the advantages of low driving voltage, small working current, strong anti-vibration and impact resistance, small volume, high reliability, low power consumption, and long service life.

[0097] The present utility model also provides an embodiment corresponding to an LED driving system, including: a power grid, a total leakage protection circuit, the LED fault identification device as described above, and a plurality of LED driving power supplies. The LED fault identification device is respectively connected to the total leakage protection circuit and each LED driving power supply, and the total leakage protection circuit is connected to the power grid.

[0098] The LED driving system provided in this embodiment corresponds to the above-mentioned LED fault identification device, so it has the same beneficial effects as the above-mentioned LED fault identification device. Therefore, for the embodiments of the LED driving system, please refer to the descriptions of the embodiments of the LED fault identification device, which will not be elaborated here for the time being.

[0099] It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0100] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An LED fault identification device, characterized in that: The LED fault identification device is arranged in the LED driving power supply, and includes: a current acquisition module, a detection module, a delay identification module and a switch module; The input end of the current acquisition module is connected to the L line and the N line on the input side of the LED driving power supply, which are connected one by one, and is used to collect the leakage current on the L line and the N line on the input side of the LED driving power supply, and obtain a voltage that is positively correlated with the leakage current; the L line and the N line on the input side of the LED driving power supply are connected to the output end of the total leakage protection circuit, and the input end of the total leakage protection circuit is connected to the power grid; The input end of the detection module is connected to the output end of the current acquisition module to generate a fault signal; The delay identification module, the input end of the delay identification module is connected to the output end of the detection module, and the output end is connected to the control end of the switch module, and is used to delay the fault signal generated by the detection module for a preset time so that the fault signal remains valid within the delay time; The input end of the switch module is connected to the L line and the N line on the input side of the LED driving power supply which are connected one by one, the output end is connected to the corresponding LED driving power supply, and the power supply end is connected to the DC power supply, and is used to close when the fault signal is less than the preset voltage value; and cut off when the fault signal is greater than or equal to the preset voltage value.

2. The LED fault identification device according to claim 1, characterized in that: The current acquisition module is a zero-sequence current transformer, which includes: an iron core, a first winding, a second winding and a third winding, wherein the first winding, the second winding and the third winding are all wound on the iron core; The first end of the first winding is connected to the N line at the input side of the LED driving power supply, and the second end is connected to the LED driving power supply; A first end of the second winding is connected to the L line at the input side of the LED driving power supply, and a second end is connected to the LED driving power supply, and the number of turns of the first winding and the second winding is the same; The first end and the second end of the third winding are both connected to the input end of the detection module, and are used to obtain a voltage positively correlated with the leakage current when the first winding and the second winding collect the leakage current on the L line and the N line on the input side of the LED driving power supply, and the number of turns of the first winding and the third winding are different.

3. The LED fault identification device according to claim 1, characterized in that: The detection module is a first resistor, which is connected to the output end of the current acquisition module and is used to use the acquired voltage as the fault signal and transmit the fault signal to the delay identification module.

4. The LED fault identification device according to claim 3, characterized in that: The detection module further includes: a second resistor, a third resistor and an operational amplifier; The first end of the second resistor is connected to the negative phase input terminal of the operational amplifier, and the second end is respectively connected to the second end of the first resistor and the input terminal of the delay identification module; A first end of the third resistor is connected to the negative phase input terminal of the operational amplifier, and a second end of the third resistor is connected to the output terminal of the operational amplifier; The non-inverting input terminal of the operational amplifier is connected to the first end of the first resistor, the output terminal is connected to the input terminal of the delay identification module, and the power supply terminal is connected to the DC power supply.

5. The LED fault identification device according to claim 1, characterized in that: The switch module includes: a comparator, a triode and a relay; The negative phase input terminal of the comparator is connected to a preset voltage, the positive phase input terminal is connected to the output terminal of the delay identification module, and the power supply terminal is connected to the DC power supply; The base of the transistor is connected to the output end of the comparator, the collector is connected to the output end of the delay identification module, and the emitter is connected to the first end of the coil of the relay, and is used to be turned on when the voltage of the positive input end of the comparator is greater than the voltage of the negative input end of the comparator; The second end of the coil of the relay is connected to the DC power supply, the first static contact is connected to the corresponding first input end of the LED driving power supply, the second static contact is connected to the second input end of the LED driving power supply, the first moving contact is connected to the N line on the input side of the LED driving power supply, and the second moving contact is connected to the L line on the input side of the LED driving power supply, so that when the transistor is turned off, the coil is powered off, the first moving contact and the first static contact are disconnected, and the second moving contact and the second static contact are disconnected.

6. The LED fault identification device according to claim 1, characterized in that: Also includes: Rectifier module and step-down module; The input end of the rectifier module is connected to the L line and the N line of the input side of the LED driving power supply connected one by one, and the output end is connected to the input end of the step-down module, for converting the AC power transmitted by the power grid into corresponding DC power, and transmitting the DC power to the step-down module; The output end of the step-down module is connected to the power supply end of the switch module, and is used to step down the total DC voltage corresponding to the DC power, so that the stepped-down first DC voltage can power the switch module.

7. The LED fault identification device according to any one of claims 1 to 6, characterized in that: The delay identification module includes: a second capacitor and a fourth resistor; The second capacitor is connected in parallel with the fourth resistor, the first end of the second capacitor and the first end of the fourth resistor are connected to the positive output end of the detection module, the second end of the second capacitor and the second end of the fourth resistor are connected to the negative output end of the detection module, and the first end of the second capacitor and the first end of the fourth resistor are both connected to the control end of the switch module.

8. The LED fault identification device according to claim 7, characterized in that: The delay identification module further includes: A one-way conducting module, wherein the input end of the one-way conducting module is connected to the output end of the detection module, and the output end is respectively connected to the first end of the second capacitor and the first end of the fourth resistor.

9. The LED fault identification device according to claim 8, characterized in that: The one-way conducting module is a diode, an anode of the diode is connected to the output end of the detection module, and a cathode of the diode is respectively connected to the first end of the second capacitor and the first end of the fourth resistor.

10. An LED driving system, characterized in that: include: A power grid, a total leakage protection circuit, an LED fault identification device as described in any one of claims 1 to 9 and a corresponding LED driving power supply, wherein the LED fault identification device is respectively connected to the total leakage protection circuit and each of the LED driving power supplies, and the total leakage protection circuit is connected to the power grid.

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