阅读说明：本技术 一种直流照明供电中应对线路漏电的处理系统及处理方法 (Processing system and processing method for dealing with line leakage in direct-current lighting power supply ) 是由 黄白羽 徐大海 吴昌华 符君 胡祥 毛文静 宋定南 梁子东 于 2021-08-13 设计创作，主要内容包括：本发明涉及一种直流照明供电中应对线路漏电的处理系统及处理方法,直流供电柜、供电线缆、DC-DC驱动器和灯具组成直流照明供电系统中应对线路漏电的处理系统,DC-DC驱动器的将输入的直流电转换为灯具所需的电压和电流,DC-DC驱动器包括MCU微处理器及与MCU微处理器相连接的输入电压侦测电路、PWM变换电路、PWM控制电路、输入端故障反馈电路和输出端故障反馈控制电路；由于直流系统保护灵敏,因此线路漏电很容易造成直流系统的过载保护,导致灭灯。本发明通过DC-DC驱动器侦测输入电压的方式,自适应调整输出功率,在线路漏电时通过减轻灯具负载功率,使得直流电源柜负载变化减小,大大减小其过载保护的概率。(The invention relates to a processing system and a processing method for dealing with line leakage in direct current lighting power supply, wherein a direct current power supply cabinet, a power supply cable, a DC-DC driver and a lamp form the processing system for dealing with the line leakage in the direct current lighting power supply system, the DC-DC driver converts input direct current into voltage and current required by the lamp, and the DC-DC driver comprises an MCU microprocessor, and an input voltage detection circuit, a PWM conversion circuit, a PWM control circuit, an input end fault feedback circuit and an output end fault feedback control circuit which are connected with the MCU microprocessor; because the direct current system is protected sensitively, therefore the circuit electric leakage very easily causes the overload protection of the direct current system, lead to turning off the light. The invention adaptively adjusts the output power by detecting the input voltage through the DC-DC driver, reduces the load change of the DC power supply cabinet by reducing the load power of the lamp when the circuit leaks electricity, and greatly reduces the overload protection probability.)

1. A processing system for dealing with line leakage in direct current lighting power supply is applied to a road tunnel lighting system with direct current power supply, the lighting system comprises a plurality of groups of lamps, a direct current power supply cabinet for outputting direct current and a power supply cable for transmitting the direct current to the lamps, and is characterized in that a DC-DC driver is arranged on a connecting line between the direct current power supply cabinet and the lamps; the DC-DC driver comprises an MCU microprocessor, and an input voltage detection circuit, a PWM conversion circuit, a PWM control circuit, an input end fault feedback circuit and an output end fault feedback control circuit which are connected with the MCU microprocessor; the lighting system is provided with a plurality of groups of lamps, a DC-DC driver is arranged on a connecting line between each group of lamps and the DC power supply cabinet, the DC-DC drivers convert the DC power input by the DC power supply cabinet into the voltage and the current required by the lamps, detect the input voltage and adaptively adjust the output power, and the processing system for dealing with the line leakage in the DC lighting power supply is formed.

2. The system of claim 1, wherein the DC-DC driver further comprises an input and filter circuit coupled to the DC input, and an output rectifier and filter circuit coupled to the voltage output, the PWM converter circuit being disposed between the input and filter circuit and the output rectifier and filter circuit.

3. The system of claim 2, wherein the DC-DC driver further comprises a protection circuit and an isolation circuit I.

4. The system for handling line leakage in a dc lighting power supply of claim 3, wherein the protection circuit is connected to the PWM control circuit.

5. The system according to claim 3, wherein the isolation circuit I is connected to the PWM control circuit at one end and to the output end fault feedback control circuit at the other end, and the output end fault feedback control circuit is disposed between the MCU and the voltage output terminal.

6. The system of claim 3, wherein the DC-DC driver further comprises an isolation circuit II, and the isolation circuit II is disposed between the MCU and the input end fault feedback circuit.

7. The system of claim 6, wherein the DC-DC driver further comprises an isolation circuit III, and the isolation circuit III is disposed between the input voltage detection circuit and the MCU.

8. The system of claim 1, wherein the input voltage detection circuit is connected to the isolation circuit III at one end and to the input fault feedback circuit and the input and filter circuit at the other end.

9. The system for processing line leakage in direct current lighting power supply according to claim 1, wherein one end of the PWM control circuit is connected to the protection circuit and the isolation circuit I, and the other end is connected to the PWM conversion circuit.

10. A method for processing line leakage in dc lighting power supply, which employs the system according to any one of claims 1 to 9, and comprises:

the direct current power supply cabinet outputs direct current, the power supply cable is responsible for transmitting the direct current, the DC-DC driver and the lamp are used as loads, the DC-DC driver converts the input direct current into voltage and current required by the lamp, and the DC-DC driver comprises an MCU microprocessor, an input voltage detection circuit, a PWM conversion circuit, a PWM control circuit, an input end fault feedback circuit and an output end fault feedback control circuit, wherein the input voltage detection circuit, the PWM conversion circuit, the PWM control circuit, the input end fault feedback circuit and the output end fault feedback control circuit are connected with the MCU microprocessor;

the DC-DC driver records the stable input voltage value of the current line in a good insulation state by detecting the input voltage; when the circuit has poor insulation leakage, the circuit leakage is in the output current range of the direct current power supply cabinet, which is equivalent to that the direct current power supply cabinet not only has lamp load, but also increases the load of the circuit leakage, and the overload protection is easily triggered to cause the lamp to be turned off, based on the above, when the circuit insulation is good, each DC-DC driver in the system records the input voltage in the state, when the circuit insulation is poor to generate leakage, the system increases the load, the load current is increased, the circuit voltage drop is increased, then the input voltage of each DC-DC driver at the moment is lower than the input voltage recorded before when the circuit insulation is good, according to the difference, the DC-DC driver reduces the output current according to a certain proportion, so that the current of the whole load lamp becomes smaller, at the moment, for the direct current power supply cabinet, the lamp load becomes smaller, the circuit leakage current is increased, and the whole load change is equal to the lamp load plus the circuit leakage, when the load is increased or decreased, the whole load change value is greatly reduced, and the possibility of generating overload protection becomes lower;

the DC-DC driver is provided with an input voltage detection circuit, and in a DC power supply system with a 290Vdc DC power supply cabinet, the output current dimming proportion of the DC-DC driver automatically changes along with the input voltage;

in the input voltage range of 260 Vdc-290 Vdc, the dimming proportion of the DC-DC driver is kept at 100% and does not change along with the change of the input voltage, when the input voltage of the DC-DC driver is reduced to below 260V due to poor insulation of a line, the output dimming proportion of the DC-DC driver is reduced along with the reduction of the input voltage, and when the input voltage is only 200V, the DC-DC driver is directly shut down, and at the moment, the leakage current of the line is overlarge, so that power-off protection is implemented.

Technical Field

The invention relates to a highway tunnel lighting power supply system, in particular to a system and a method for processing line leakage in direct-current lighting power supply.

Background

In the existing highway tunnel lighting, the direct current power supply has the advantages of safety, energy conservation, intelligence and the like, and can be conveniently connected into energy storage power supply systems such as photovoltaic systems, so that the direct current power supply gradually becomes the development trend of the current highway tunnel lighting power supply.

In dc lighting, the insulation requirements for the lines are high. Because the number of line nodes is very large and the working environment is complex and severe, the situation of line low current leakage often occurs. If insulating decline, there is the risk of electrocution on the one hand, and on the other hand also can cause the waste of electric quantity, simultaneously because direct current system protection sensitivity is higher, and it is bad very easily to cause the system protection malfunction, leads to going out the lamp, forms the traffic safety hidden danger from this.

Aiming at the problem of line insulation, the main measure at present is to monitor the line insulation, but the method is only a detection and early warning means and cannot deal with the problems of load increase and system protection caused by electric leakage after poor insulation.

Therefore, it is necessary to provide a system and a method capable of adaptively reducing the load, so as to ensure that the direct current system is protected from shutdown as much as possible and the tunnel illumination is normally turned on while the line insulation monitoring alarm is performed.

Disclosure of Invention

In view of the above mentioned problem, the insulation monitoring function of the existing dc power supply system only has an early warning function, and after the early warning, before the fault point is manually cleared, the shunt circuit with poor insulation is directly turned off, so as to ensure that the whole system can still supply power normally, which may cause the lamp of the shunt load lamp to be turned off. The invention provides a processing system for dealing with line leakage in direct current lighting power supply and a method for dealing with line leakage in direct current lighting power supply by adopting the system, aiming at self-adaptively reducing the brightness of a load lamp of a leakage shunt circuit under the condition of small leakage current caused by poor insulation, and ensuring that the shunt circuit can still be lightened before a fault point is subsequently manually checked.

In order to achieve the above object, the present invention adopts the following technical solutions.

The invention provides a processing system for dealing with line leakage in direct-current lighting power supply of a road tunnel lighting system with direct-current power supply, wherein the lighting system comprises a plurality of groups of lamps, a direct-current power supply cabinet for outputting direct current and a power supply cable for transmitting the direct current to the lamps; a DC-DC driver is arranged on a connecting line of the DC power supply cabinet and the lamp; the DC-DC driver comprises an MCU microprocessor, and an input voltage detection circuit, a PWM conversion circuit, a PWM control circuit, an input end fault feedback circuit and an output end fault feedback control circuit which are connected with the MCU microprocessor; the lighting system is provided with a plurality of groups of lamps, a DC-DC driver is arranged on a connecting line between each group of lamps and the DC power supply cabinet, the DC-DC drivers convert the DC power input by the DC power supply cabinet into the voltage and the current required by the lamps, detect the input voltage and adaptively adjust the output power, and the processing system for dealing with the line leakage in the DC lighting power supply is formed.

Preferably, the DC-DC driver further includes an input and filter circuit connected to the DC input terminal, and an output rectifying and filter circuit connected to the voltage output terminal, and the PWM conversion circuit is disposed between the input and filter circuit and the output rectifying and filter circuit.

In any of the above technical solutions, preferably, the DC-DC driver further includes a protection circuit and an isolation circuit I, the protection circuit is connected to the PWM control circuit, one end of the isolation circuit I is connected to the PWM control circuit, the other end of the isolation circuit I is connected to the output end fault feedback control circuit, and the output end fault feedback control circuit is disposed between the MCU microcontroller and the voltage output end.

In any of the above technical solutions, preferably, the DC-DC driver further includes an isolation circuit II, and the isolation circuit II is disposed between the MCU microcontroller and the input end fault feedback circuit.

In any of the above technical solutions, preferably, the DC-DC driver further includes an isolation circuit III, and the isolation circuit III is disposed between the input voltage detection circuit and the MCU microcontroller.

In any of the above technical solutions, preferably, one end of the input voltage detection circuit is connected to the isolation circuit III, and the other end of the input voltage detection circuit is connected to the input end fault feedback circuit and the input and filter circuit.

In any of the above technical solutions, preferably, one end of the PWM control circuit is connected to the protection circuit and the isolation circuit I, and the other end is connected to the PWM conversion circuit.

The invention also provides a processing method for dealing with the line electric leakage in the direct current lighting power supply, which adopts the processing system for dealing with the line electric leakage in the direct current lighting power supply to process the line electric leakage in the direct current lighting power supply, and the processing method comprises the following steps:

the direct current power supply cabinet outputs direct current, the power supply cable is responsible for transmitting the direct current, the DC-DC driver and the lamp are used as loads, the DC-DC driver converts the input direct current into voltage and current required by the lamp, and the DC-DC driver comprises an MCU microprocessor, an input voltage detection circuit, a PWM conversion circuit, a PWM control circuit, an input end fault feedback circuit and an output end fault feedback control circuit, wherein the input voltage detection circuit, the PWM conversion circuit, the PWM control circuit, the input end fault feedback circuit and the output end fault feedback control circuit are connected with the MCU microprocessor;

the DC-DC driver records the stable input voltage value of the current line in a good insulation state by detecting the input voltage; when the circuit has poor insulation leakage, the circuit leakage is in the output current range of the direct current power supply cabinet, which is equivalent to that the direct current power supply cabinet not only has lamp load, but also increases the load of the circuit leakage, and the overload protection is easily triggered to cause the lamp to be turned off, based on the above, when the circuit insulation is good, each DC-DC driver in the system records the input voltage in the state, when the circuit insulation is poor to generate leakage, the system increases the load, the load current is increased, the circuit voltage drop is increased, then the input voltage of each DC-DC driver at the moment is lower than the input voltage recorded before when the circuit insulation is good, according to the difference, the DC-DC driver reduces the output current according to a certain proportion, so that the current of the whole load lamp becomes smaller, at the moment, for the direct current power supply cabinet, the lamp load becomes smaller, the circuit leakage current is increased, and the whole load change is equal to the lamp load plus the circuit leakage, when the load is increased or decreased, the whole load change value is greatly reduced, and the possibility of generating overload protection becomes lower;

the DC-DC driver is provided with an input voltage detection circuit, and in a DC power supply system with a 290Vdc DC power supply cabinet, the output current dimming proportion of the DC-DC driver automatically changes along with the input voltage;

in the input voltage range of 260 Vdc-290 Vdc, the dimming proportion of the DC-DC driver is kept at 100% and does not change along with the change of the input voltage, when the input voltage of the DC-DC driver is reduced to below 260V due to poor insulation of a line, the output dimming proportion of the DC-DC driver is reduced along with the reduction of the input voltage, and when the input voltage is only 200V, the DC-DC driver is directly shut down, and at the moment, the leakage current of the line is overlarge, so that power-off protection is implemented.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

because the direct current system is protected sensitively, therefore the circuit electric leakage very easily causes the overload protection of the direct current system, lead to turning off the light. The invention adaptively adjusts the output power by detecting the input voltage by the DC-DC driver, reduces the load change of the DC power supply cabinet by reducing the load power of the lamp when the circuit leaks electricity, greatly reduces the probability of overload protection, and the lamp of the leakage shunt circuit still normally lights at the moment, but the brightness of the lamp is correspondingly reduced because the current value is reduced by dimming.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic system structure diagram of a processing system for dealing with line leakage in dc lighting power supply according to a preferred embodiment of the present invention;

fig. 2 is a schematic diagram of a DC-DC driver structure and an operation principle of a processing system for dealing with line leakage in DC lighting power supply according to a preferred embodiment of the present invention;

fig. 3 is a schematic diagram of a load shedding curve of a DC-DC driver according to a preferred embodiment of a system for handling line leakage in a DC lighting power supply according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Aiming at the problem that the insulation monitoring function only has an early warning function in the existing direct current power supply system, and after early warning, before a fault point is eliminated manually, a shunt circuit with poor insulation is directly switched off so as to ensure that the whole system can still normally supply power, and the shunt circuit load lamp is turned off. The embodiment of the invention provides a system for processing line leakage in direct-current lighting power supply and a method for processing the line leakage in the direct-current lighting power supply by adopting the system, aiming at adaptively reducing the brightness of a load lamp of a leakage shunt circuit under the condition of low leakage current caused by poor insulation, and ensuring that the shunt circuit can still be lightened before a fault point is manually checked subsequently.

The principle, technical features and specific processing procedure of the processing system for dealing with the line leakage in the dc lighting power supply described in this embodiment are described below with reference to fig. 1 to 3.

The lighting system includes a plurality of sets of lamps, a DC power supply cabinet for outputting DC power, and a power supply cable for transmitting the DC power to the lamps, in the embodiment, the processing system for dealing with line leakage in the DC lighting power supply is provided with a DC-DC driver on a connection line between the DC power supply cabinet and the lamps, as shown in fig. 1; the DC-DC driver comprises an MCU microprocessor, and an input voltage detection circuit, a PWM conversion circuit, a PWM control circuit, an input end fault feedback circuit and an output end fault feedback control circuit which are connected with the MCU microprocessor; the lighting system is provided with a plurality of groups of lamps, a DC-DC driver is arranged on a connecting circuit of each group of lamps and the DC power supply cabinet, the DC-DC drivers convert the direct current input by the DC power supply cabinet into the voltage and the current required by the lamps, detect the input voltage and adaptively adjust the output power, and the processing system for dealing with the line leakage in the DC lighting power supply is formed.

In the processing system of this embodiment, as shown in fig. 1, the DC-DC driver further includes an input and filter circuit connected to the DC input terminal, and an output rectifying and filter circuit connected to the voltage output terminal, and the PWM conversion circuit is disposed between the input and filter circuit and the output rectifying and filter circuit.

In the processing system of this embodiment, as shown in fig. 1, the DC-DC driver further includes a protection circuit and an isolation circuit I; the protection circuit is connected with the PWM control circuit; and one end of the isolation circuit I is connected with the PWM control circuit, the other end of the isolation circuit I is connected with the output end fault feedback control circuit, and the output end fault feedback control circuit is arranged between the MCU microcontroller and the voltage output end.

In the processing system of this embodiment, as shown in fig. 1, the DC-DC driver further includes an isolation circuit II, and the isolation circuit II is disposed between the MCU microcontroller and the input end fault feedback circuit.

In the processing system of this embodiment, as shown in fig. 1, the DC-DC driver further includes an isolation circuit III, and the isolation circuit III is disposed between the input voltage detection circuit and the MCU microcontroller.

In the processing system of this embodiment, as shown in fig. 1, one end of the input voltage detection circuit is connected to the isolation circuit III, and the other end is connected to the input end fault feedback circuit and the input and filter circuit.

In the processing system described in this embodiment, as shown in fig. 1, one end of the PWM control circuit is connected to the protection circuit and the isolation circuit I, and the other end is connected to the PWM conversion circuit.

A typical direct-current lighting power supply system is shown in a schematic diagram in fig. 1, and comprises a direct-current power supply cabinet, a power supply cable, a lamp and a DC-DC driver; the direct current power supply cabinet outputs direct current, the power supply cable is responsible for transmitting the direct current, the DC-DC driver and the lamp are used as loads, and the DC-DC driver is arranged to convert the input direct current into voltage and current required by the lamp, so that the treatment of line electric leakage in direct current lighting power supply is realized.

Due to the resistance of the power supply cable, a line voltage drop is formed when current flows through the power supply cable. Therefore, the closer the DC power supply cabinet is, the higher the input DC voltage of the DC-DC driver is, and the lower the DC input voltage of the DC-DC driver is. When the power supply cable is well insulated, the input voltage of each DC-DC driver is also kept stable because the voltage of the DC power supply cabinet, the resistance (voltage drop) of the power supply cable and the load lamp are kept unchanged. The DC-DC driver has the function of detecting the input voltage, and can record the stable input voltage value of the current line in a good insulation state.

In the implementation, when the poor insulation leakage occurs in the line, there are 3 cases:

case 1: the line leaks slightly (the leakage current is milliampere level), and the insulation monitoring function can trigger an alarm at the moment, but because the leakage current is very small, the protection of the direct current power supply cabinet cannot be caused (but the leakage relates to the personal electric shock safety, and the inspection treatment is still needed as soon as possible).

Case 2: the circuit has serious electric leakage and is nearly short-circuited, and at the moment, because the load current is sharply increased, overcurrent or short-circuit protection can be directly triggered, and even a protection switch is triggered to act. The lamp is inevitably turned off.

Case 3: the line leakage is in the output current range of the direct current power supply cabinet, which is equivalent to the direct current power supply cabinet, not only the lamp load is provided, but also the load of the line leakage is increased, and the overload protection is easily triggered to cause the lamp to be turned off.

For the case 3, the technical measures adopted by the invention are as follows: when the line insulation is good, each DC-DC driver records the input voltage in the state, and when the line insulation is poor and electric leakage is generated, the system increases the load, the load current increases, and the line voltage drop increases. For each DC-DC driver, the input voltage at this time becomes lower than the previously recorded input voltage when the line insulation is good, and depending on the difference, the DC-DC driver can reduce the output current by a certain proportion, so that the current of the entire load fixture becomes smaller. At this moment, for the direct current power supply cabinet, the lamp load becomes smaller, the line leakage current increases, the whole load change is equal to the lamp load plus the line leakage current, the change value of the whole load is greatly reduced by increasing and decreasing, and the possibility of generating overload protection becomes lower.

Because the direct current system is protected sensitively, therefore the circuit electric leakage very easily causes the overload protection of the direct current system, lead to turning off the light. The invention adaptively adjusts the output power by detecting the input voltage through the DC-DC driver, reduces the load change of the DC power supply cabinet by reducing the load power of the lamp when the circuit leaks electricity, and greatly reduces the overload protection probability.

At this time, the lamp of the leakage shunt still normally lights, and only because the current value is reduced by dimming, the brightness of the lamp is correspondingly reduced.

In one embodiment, as shown in fig. 2, an input voltage detecting circuit is designed in the DC-DC driver. In a dc power supply system with a dc power cabinet of 290Vdc, the output current dimming ratio thereof automatically varies with the input voltage as shown in fig. 3, for example.

Since the input voltage allows a maximum voltage drop of 10% in the design standard of the DC power supply, the dimming ratio of the DC-DC driver is kept at 100% in the input voltage range of 260 Vdc-290 Vdc and does not change with the change of the input voltage (note: it still responds to the dimming command at this time). When the input voltage of the DC-DC driver is reduced to below 260V due to poor insulation of a line, the output dimming proportion of the DC-DC driver is reduced along with the reduction of the input voltage, and when the input voltage is only 200V, the DC-DC driver is directly shut down. At this time, the leakage current of the line is too large, and power-off protection is required.

The foregoing is merely illustrative of the preferred embodiments of the present invention and is not to be construed as limiting the scope of the invention; the above description is only for the specific embodiment of the present invention, and is not intended to limit the scope of the present invention; any modification, equivalent replacement, improvement and the like of the technical solution of the present invention by a person of ordinary skill in the art without departing from the design spirit of the present invention shall fall within the protection scope determined by the claims of the present invention.