A ring main unit secondary control circuit integration device

Abstract

A ring main unit secondary control circuit integration device comprises a shell and a control module, wherein the control module comprises a control circuit, a power circuit with a +12V output meeting electromagnetic compatibility level 4, an input circuit, a control circuit, an open-in circuit, and an open-out circuit; the power circuit, the input circuit, the open-in circuit, and the open-out circuit are all electrically connected to the control circuit; the shell is a shell with a high protection level, the shell consists of a body and a cover plate covering the body and adopts a dustproof sealing structure, after the control module is fixed in the body, the electronic device glue completely seals the control module, and only the wiring terminals, LED lamps, and a debugging port are exposed in the body; the wiring terminals and the debugging port use waterproof sockets; after the cover plate is connected to the body, only the wiring terminals and the LED lamps are exposed, the debugging port is hidden under the cover plate, and is sealed by a rubber gasket.

Description

Technical Field

[0001] The utility model relates to the technical field of electric power equipment, in particular to a secondary control loop integration device for a ring network cabinet. Background Art

[0002] Prior art such as CN202021238314.2 discloses a ring main unit secondary chamber, a ring main unit and a ring main unit system. The secondary chamber of the ring main unit of the present application includes: a secondary box, a switch assembly, a distribution terminal and a first aviation plug. The secondary chamber of the ring main unit provided is provided with the distribution terminal in the accommodating cavity in the secondary box. The input end of the distribution terminal is connected to the signal of the switch assembly, and the output end of the distribution terminal is used to connect to the distribution master station. The signal of the switch assembly is preliminarily processed by the distribution terminal and then uploaded to the distribution master station.

[0003] Ring main unit is an important equipment in the urban distribution network. The stability and safety of its secondary control circuit directly affect the normal operation of the power system. However, the existing secondary control circuit of the ring main unit has problems such as low protection level and poor integration. It is easily affected by the external environment, resulting in equipment failure and even power accidents. Utility Model Content

[0004] The purpose of this utility model is to develop an integrated device for the secondary control circuit of a ring main unit. The traditional contactor, time relay, and thermal relay are integrated into a device that meets the IP55 protection level and has full input and output isolation, which can meet the use of scenes with high wind and sand, high temperature and humidity, and complex electromagnetic environments. At the same time, it has timeout, overcurrent and other protection functions, which greatly improves the reliability of the secondary control circuit of the ring main unit.

[0005] The technical scheme of the utility model is a ring network cabinet secondary control circuit integrated device, comprising a housing, a control module, the control module comprising a control circuit, a power circuit of +12V output meeting the electromagnetic compatibility level 4, an input circuit composed of a plurality of photoelectric coupling isolation circuits, a microprocessor control circuit composed of a microprocessor based on STM32G070 and its peripheral circuits, an open-in circuit connected to a position signal input connected to an external ring network cabinet and a control command end, a closing and opening coil composed of a relay drive circuit, a MOS tube drive circuit, and a current sampling circuit, and an open-out circuit of an energy storage motor; the power circuit, the input circuit, the open-in circuit, and the open-out circuit are all electrically connected to the control circuit;

[0006] The power supply circuit comprises a surge suppression circuit, a rectifier filter circuit, an isolation step-down circuit and an LDO unit.

[0007] The shell is a high-protection-level shell, which consists of a main body and a cover plate covering the main body and adopts a dust-proof sealing structure. After the control module is fixed in the main body, the electronic device glue completely seals the control module, and only the wiring terminals, LED lights and debugging ports are exposed in the main body;

[0008] The wiring terminals and the debugging port use waterproof sockets; after the cover plate is connected to the body, only the wiring terminals and the LED lamp are exposed, and the debugging port is hidden under the cover plate and sealed by a rubber gasket.

[0009] The open-in circuit is a circuit connected to the position signal and control command end of the external ring network cabinet input. The open-out circuit connected to the ring network cabinet opening and closing coil and energy storage motor, as well as the control circuit between the open-in circuit and the open-out circuit are all connected to the control circuit input and output ends of the control module.

[0010] Specifically, a housing of a secondary control circuit integrated device of a ring main unit is a housing with a high protection level, and adopts dustproof and waterproof technology and structure to prevent moisture and dust from invading the device. The main body includes a fastening structure for fixing the control module. After the control module is fixed in the main body, the control module is completely sealed in the main body by a glue dedicated to electronic devices, and only components such as wiring terminals, LED lights, and debugging ports are exposed. The wiring terminals and debugging ports all use waterproof sockets. After the cover is connected to the main body, only the wiring terminals, LED lights, etc. are exposed, and the debugging port is hidden under the cover to facilitate later program maintenance.

[0011] The control module is connected to a +12V output power circuit that meets the fourth level of electromagnetic compatibility, an input circuit composed of several photoelectric coupling isolation circuits, a microprocessor control circuit composed of a microprocessor based on STM32G070 and its peripheral circuits, a closing and opening coil composed of a relay drive circuit, a MOS tube drive circuit, and a current sampling circuit, and an opening and closing circuit of an energy storage motor; and a human-computer interaction interface composed of a reset button and an LED light can also be installed.

[0012] After the input power enters the power circuit, the power circuit of the +12V output that meets the electromagnetic compatibility level 4 will first pass through the EMC suppression circuit composed of thermistors, varistors, common-mode inductors and safety capacitors to protect the input power so that it can be stably output to the rectifier circuit; the rectifier filter circuit is implemented by a rectifier bridge and an electrolytic capacitor to adjust the input power to a smooth and stable DC power supply to meet the requirements of the step-down circuit, and the isolation step-down circuit isolates and steps down the input power to a +12V DC output. At the same time, the LDO unit steps down the +12V to +3.3V to power the control circuit and the logic output unit. The working principle of the LDO unit (a low voltage difference linear regulator chip) can refer to the principle of the AMS1117 chip.

[0013] The input circuit is composed of several photoelectric coupling isolation circuits. Each photoelectric coupling isolation circuit includes at least one photoelectric coupler and a voltage divider circuit connected to the input end of the photoelectric coupler, the voltage divider circuit includes a general diode, a voltage stabilizing diode, and a voltage divider current limiting resistor, and the output end of the photoelectric coupler is connected to the input end of the microprocessor.

[0014] The open-circuit includes an open-circuit composed of a MOS tube and a relay, which includes a switch-on and switch-off control circuit, an energy storage motor control circuit, etc. Each control circuit at least includes a MOS tube, a relay, and a drive circuit for driving the MOS tube and the relay. In particular, the motor drive circuit also includes an isolated current sampling current circuit.

[0015] The relay drive circuit is composed of an AND gate and a NAND gate of a NAND gate logic processing unit. The two input ends of the NAND gate are connected to the output end of the microprocessor, the output end of the NAND gate is connected to one input end of the AND gate, and the other end of the AND gate is connected to the output end of the microprocessor. The output end of the AND gate is connected to the base of the NPN transistor. The high and low levels of the output end are changed by the microprocessor to determine the high and low output of the AND gate.

[0016] The MOS tube driving circuit is composed of an optocoupler control chip that drives the MOS tube, an NMOS tube, pull-up and pull-down resistors, and a current-limiting resistor. The optocoupler control chip receives a PWM modulation signal from a microprocessor to drive the on and off of the MOS tube to control the energy storage motor and the opening and closing coil.

[0017] The current sampling circuit is connected in series in the motor circuit, and includes a current sampling chip based on a Hall sensor and a filter circuit matched therewith. The voltage signal output by the current sampling chip is connected to the ADC acquisition port of the microprocessor after passing through the filter circuit. During the operation of the motor, if the current value exceeds the preset value, the motor control circuit will be immediately cut off to ensure the safe operation of the ring network cabinet.

[0018] The human-machine interface is composed of a reset button and a plurality of LED lights. The LED lights are used to indicate the current operating status and alarm information of the ring network cabinet, and the reset button is used to reset the alarm signal.

[0019] Beneficial effect: Compared with the existing secondary control circuit of the ring main unit, the integrated device of the secondary control circuit of the ring main unit proposed in the utility model solves the pain points of numerous split components and complex wiring through integrated design, and improves the stability of the secondary control circuit. At the same time, the shell structure design meets the IP55 protection level to prevent the influence of the external environment on the equipment. At the same time, the control circuit based on the high-performance microprocessor collects the operating status of the ring main unit in real time, and timely protects when problems occur to avoid the expansion of the fault range of the ring main unit, thereby improving the operating stability of the ring main unit. The embodiment of the present application solves the current technical problem of low signal processing efficiency in the secondary chamber of the ring main unit by providing the distribution terminal, thereby achieving the technical effect of improving the signal processing efficiency of the secondary chamber of the ring main unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a block diagram of the device principle of the utility model;

[0021] Figure 2 This is the principle diagram of the photoelectric coupling isolation circuit of the utility model;

[0022] Figure 3 This is a principle block diagram of the isolated output loop circuit of the utility model;

[0023] Figure 4 It is a structural schematic diagram of the utility model;

[0024] Figure 5 It is a schematic diagram of the main body of the utility model. DETAILED DESCRIPTION

[0025] The utility model will be further described below in conjunction with the accompanying drawings.

[0026] like Figure 1 , Figure 2 , Figure 3 As shown, a secondary control circuit integrated device of a ring main unit includes a housing with a high protection level, an open-in circuit connected to the position signal, control command, etc. of the external ring main unit, an open-out circuit connected to the opening and closing coils, energy storage motor, etc. of the ring main unit, and a control circuit between the open-in circuit and the open-out circuit.

[0027] Specifically, Figure 4 , Figure 5In the figure, the main body 1, the LED indicator 2, the cover 3, the wiring terminal 4, the burning port 5, and the rubber pad 6; the shell of the ring main unit secondary control circuit integrated device includes dustproof and waterproof processes and structures to prevent moisture and dust from invading the device. The shell consists of two parts: the main body and the cover. The main body includes a fastening structure for fixing the control module. After the control module is fixed in the main body, the control module is completely sealed in the main body by a special glue for electronic devices, and only the wiring terminals, LED lights, and debugging ports are exposed. The wiring terminals and debugging ports are waterproof sockets. After the cover is connected to the main body, only the wiring terminals, LED lights, etc. are exposed, and the debugging port is hidden under the cover to facilitate later program maintenance.

[0028] The control module includes a +12V output power supply circuit that meets the fourth level of electromagnetic compatibility, an input circuit composed of several photoelectric coupling isolation circuits, a microprocessor control circuit composed of a microprocessor based on STM32G070 and its peripheral circuits, a closing and opening coil composed of a relay drive circuit, a MOS tube drive circuit, and a current sampling circuit, an opening and closing circuit of an energy storage motor, and a human-computer interaction interface composed of a reset button and an LED light.

[0029] After the input power enters the power circuit, the power circuit of the +12V output that meets the electromagnetic compatibility level 4 will first pass through the EMC suppression circuit composed of thermistors, varistors, common-mode inductors and safety capacitors to protect the input power so that it can be stably output to the rectifier circuit; the rectifier filter circuit is implemented by a rectifier bridge and an electrolytic capacitor to adjust the input power to a smooth and stable DC power supply to meet the requirements of the step-down circuit, and the isolated step-down circuit steps down the input power to an isolated +12V DC output. At the same time, the LDO unit steps down the +12V to +3.3V to power the control circuit and the logic output unit. The working principle of the LDO unit (a low voltage difference linear regulator chip) can refer to the principle of the AMS1117 chip.

[0030] The input circuit is composed of several photoelectric coupling isolation circuits. Each photoelectric coupling isolation circuit includes at least one photoelectric coupler and a voltage divider circuit connected to the input end of the photoelectric coupler, the voltage divider circuit includes a general diode, a voltage stabilizing diode, and a voltage divider current limiting resistor, and the output end of the photoelectric coupler is connected to the input end of the microprocessor.

[0031] The open-circuit includes an open-circuit composed of a MOS tube and a relay, which includes a switch-on and switch-off control circuit, an energy storage motor control circuit, etc. Each control circuit at least includes a MOS tube, a relay, and a drive circuit for driving the MOS tube and the relay. In particular, the motor drive circuit also includes an isolated current sampling current circuit.

[0032] The relay drive circuit is composed of an AND gate and a NAND gate of a NAND gate logic processing unit. The two input ends of the NAND gate are connected to the output end of the microprocessor, the output end of the NAND gate is connected to one input end of the gate, and the other end of the AND gate is connected to the output end of the microprocessor. The output end of the AND gate is connected to the base of the NPN transistor. The high and low levels of the output end are changed by the microprocessor to determine the high and low output of the AND gate.

[0033] The MOS tube driving circuit is composed of an optocoupler control chip that drives the MOS tube, an NMOS tube, pull-up and pull-down resistors, and a current-limiting resistor. The optocoupler control chip receives a PWM modulation signal from a microprocessor to drive the on and off of the MOS tube to control the energy storage motor and the opening and closing coil.

[0034] The current sampling circuit is connected in series in the motor circuit, and includes a current sampling chip based on a Hall sensor and a filter circuit matched therewith. The voltage signal output by the current sampling chip is connected to the ADC acquisition port of the microprocessor after passing through the filter circuit. During the operation of the motor, if the current value exceeds the preset value, the motor control circuit will be immediately cut off to ensure the safe operation of the ring network cabinet.

[0035] The human-machine interface is composed of a reset button and a plurality of LED lights. The LED lights are used to indicate the current operating status and alarm information of the ring network cabinet, and the reset button is used to reset the alarm signal.

[0036] Take the energy storage motor control as an example. Its control principle is: after the device auxiliary power supply is powered on, the entire device is powered through the power supply circuit. After the initialization is completed, the device will input all the switch inputs to the microprocessor through the isolation input circuit. The microprocessor collects all the switch data in real time and performs logical calculations. When all conditions are met and the energy storage signal is received, the isolation output circuit will be driven to drive the motor. When the isolation switch drives the energy storage motor, the microprocessor will first drive the relay control circuit. After the relay is attracted and maintained, the microprocessor will drive the MOS tube control circuit. When the PWM control is used, the MOS tube is turned on, thereby turning on the entire isolation output circuit to control the energy storage motor. At startup, the soft start function is realized through PWM to avoid the inrush current at the moment of motor startup from damaging the device. At the same time, the current sampling circuit collects current data and collects it through the ADC port of the microprocessor. The internal timer of the microprocessor counts the energy storage time. When the energy storage is overcurrent or timed out or the energy storage completion signal is received, the microprocessor first stops driving the MOS tube, cuts off the isolation output circuit through the MOS tube, and then stops driving the relay, thereby realizing the energy storage operation of the energy storage motor.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A ring main unit secondary control circuit integration device, characterized in that: It comprises a housing and a control module, wherein the control module comprises a control circuit, a power circuit with a +12V output meeting the electromagnetic compatibility level 4, an input circuit composed of a plurality of photoelectric coupling isolation circuits, a control circuit which is a microprocessor control circuit composed of a microprocessor based on an STM32G070 and its peripheral circuits, an open-in circuit connected to a position signal input connected to an external ring network cabinet and a control command terminal, a closing and opening coil composed of a relay drive circuit, a MOS tube drive circuit, and a current sampling circuit, and an open-out circuit of an energy storage motor; the power circuit, the input circuit, the open-in circuit, and the open-out circuit are all electrically connected to the control circuit; The shell is a high-protection-level shell, which consists of a main body and a cover plate covering the main body and adopts a dust-proof sealing structure. After the control module is fixed in the main body, the electronic device glue completely seals the control module, and only the wiring terminals, LED lights and debugging ports are exposed in the main body; The wiring terminals and the debugging port use waterproof sockets; after the cover plate is connected to the body, only the wiring terminals and the LED lamp are exposed, and the debugging port is hidden under the cover plate and sealed by a rubber gasket.

2. The ring main unit secondary control circuit integration device according to claim 1 is characterized in that: The power supply circuit comprises a surge suppression circuit, a rectifier filter circuit, an isolation step-down circuit and an LDO unit.

3. The ring main unit secondary control circuit integration device according to claim 1 is characterized in that: In the input circuit composed of several photoelectric coupling isolation circuits, each photoelectric coupling isolation circuit includes at least one photoelectric coupler and a voltage divider circuit connected to the input end of the photoelectric coupler, the voltage divider circuit includes a general diode, a voltage regulator diode, and a voltage divider current limiting resistor, and the output end of the photoelectric coupler is connected to the input end of the microprocessor.

4. The ring main unit secondary control circuit integration device according to claim 1 is characterized in that: The output loop includes a MOS tube and a relay; the control loop includes a MOS tube, a relay, and a drive circuit for driving the MOS tube and the relay; the drive circuit includes a motor drive loop, and the motor drive loop also includes an isolated current sampling current loop.

5. The ring main unit secondary control circuit integration device according to claim 1 is characterized in that: The relay driving circuit is composed of an AND gate and a NAND gate of a NAND gate logic processing unit; the two input ends of the NAND gate are connected to the output end of the microprocessor, the output end of the NAND gate is connected to one input end of the AND gate, and the other end of the AND gate is connected to the output end of the microprocessor; the output end of the AND gate is connected to the base of the NPN transistor.

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