Feeder terminal residual voltage detection system

Abstract

The invention relates to a feeder terminal residual voltage detection system, and belongs to the technical field of feeder terminals. The main control chip module is added on the basis of an existing detection system, the MCU module is in communication connection with the main control chip module, detected residual voltage is sent to the main control chip module, reverse incoming call closing in the fault recovery process is prevented, and therefore equipment and line safety is protected; when the residual voltage value detected by the MCU module is smaller than the residual voltage fixed value or the duration time that the residual voltage value is not smaller than the residual voltage fixed value exceeds a set time fixed value, the residual voltage detection system considers that no residual voltage occurs, the main control chip module turns off power supply of the MCU module, and the residual voltage detection system stops running, so that after the residual voltage detection task is completed, the residual voltage detection system is started to work. By turning off the power supply of the MCU module, the problem of high power consumption of the whole machine during normal operation of the system is solved.

Description

Technical Field

[0001] The invention relates to a feeder terminal residual voltage detection system, belonging to the technical field of feeder terminals. Background Art

[0002] With the development of economy, the construction of power grid is becoming more and more perfect, and distribution automation plays an important role. With the increase of power load, higher requirements are put forward for the power supply reliability of power grid. Feeder automation is one of the cores of building distribution automation. The distribution network can isolate the faulty section and restore the power supply of the non-faulty section through the mutual cooperation between terminals, thus reducing the power outage time of users and improving the reliability of power grid.

[0003] The distribution terminal has software and hardware residual voltage detection functions. In the power-off state (when the feeder terminal has no backup power supply), it can realize the recognition and memory of residual voltage pulses with a time of not less than 60ms and a residual voltage value of not less than 50%Un; after the terminal is powered on, the recognized residual voltage pulse can be involved in the fault handling logic calculation, thereby improving the reliability and stability of the power supply of the power grid and improving the accuracy of distribution automation.

[0004] Since the residual voltage detected occurs instantaneously when the switch is turned off, when the residual voltage detection task is completed, the current residual voltage detection method will keep the system in operation for the next residual voltage fault detection. Although this detection method is conducive to real-time detection of residual voltage, it will inevitably cause the problem of increased power consumption of the entire machine. Summary of the invention

[0005] The object of the present invention is to provide a feeder terminal residual voltage detection system to solve the problem in the prior art that after the residual voltage detection task is completed, the residual voltage detection system is still in operation, thereby increasing the power consumption of the entire machine.

[0006] To achieve the above object, the solution of the present invention includes: A feeder terminal residual voltage detection system of the present invention includes a rectifier and buck module and an MCU module. The MCU module is connected to the output end of the rectifier and buck module through a sampling branch. The input end of the rectifier and buck module is used to connect the feeder to detect the residual voltage on the feeder. The system also includes a main control chip module. The MCU module is communicatively connected to the main control chip module and is used to send the detected residual voltage situation to the main control chip module. The main control chip module is also used to shut off the power supply of the MCU module when no residual voltage situation occurs, so that the MCU module stops running. The no residual voltage situation refers to that the detected residual voltage value is less than the residual voltage set value or the residual voltage value is not less than the residual voltage set value for a duration exceeding a set time set value.

[0007] Furthermore, the MCU module is powered by a power conversion module, and the input end of the power conversion module is connected to the output end of the rectifier and buck module, so as to convert the voltage output by the rectifier and buck module into the power supply voltage required by the MCU module.

[0008] Furthermore, the power conversion module adopts a power conversion chip, and a controllable switch device is arranged between the enable pin of the power conversion chip and the ground. The control end of the controllable switch device is connected to the IO pin of the main control chip module. When no residual voltage occurs, the main control chip module controls the controllable switch device to be turned on through the IO pin, thereby cutting off the power supply of the power conversion chip to the MCU module.

[0009] Furthermore, the controllable switch device is a triode or a thyristor.

[0010] Furthermore, the sampling branch adopts a resistor voltage divider circuit, and the output voltage of the rectifier and buck module is reduced to within the collection range of the MCU module through the resistor voltage divider circuit.

[0011] Furthermore, the rectifier and step-down module includes a transformer, a rectifier module and an energy storage capacitor. The transformer is used to achieve voltage level conversion; the rectifier module is used to convert the alternating current converted by the transformer into direct current.

[0012] Furthermore, the main control chip module is connected to the MCU module for communication via a serial port.

[0013] Furthermore, the MCU module integrates FLASH for recording the detected residual pressure data.

[0014] Furthermore, the MCU module detects the high and low levels output by the sampling branch through the IO level detection module.

[0015] Furthermore, the time setting value is sent from the main control chip module to the MCU module, and the residual pressure setting value is determined by hardware.

[0016] The beneficial effects of the present invention are as follows: as an improved invention, the present invention adds a main control chip module on the basis of the existing detection system, and the MCU module is communicatively connected with the main control chip module, and the detected residual voltage is sent to the main control chip module to prevent the occurrence of reverse power closing during the fault recovery process, thereby protecting the safety of equipment and lines; when the residual voltage value detected by the MCU module is less than the residual voltage setting value or the residual voltage value is not less than the residual voltage setting value for a duration exceeding the set time setting value, the residual voltage detection system considers that no residual voltage occurs, and the main control chip module turns off the power supply of the MCU module to stop the residual voltage detection system from running. Therefore, after the residual voltage detection task is completed, the present invention solves the problem of high power consumption of the whole machine during normal operation of the system by turning off the power supply of the MCU module. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the overall architecture diagram of the residual pressure detection system; Figure 2 This is the schematic diagram of the rectifier and voltage reduction module of the residual voltage detection system; Figure 3 This is the schematic diagram of the power conversion module of the residual voltage detection system; Figure 4 It is the software flow chart of the residual pressure detection system. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail in a clear and complete manner in conjunction with the accompanying drawings and embodiments.

[0019] System Example: The idea of ​​the present invention is that the system adds a main control chip module on the basis of the existing detection system. The main control chip module is communicated with the MCU module. When the residual pressure value detected by the MCU module is less than the residual pressure set value (the residual pressure set value is determined by hardware) or the residual pressure value is not less than the residual pressure set value and the duration exceeds the set time set value, the main control chip module cuts off the power supply of the MCU module to stop the residual pressure detection system from running.

[0020] like Figure 1 The overall architecture diagram of the residual voltage detection system shown includes a rectifier and buck module, a power conversion module, an MCU module and a main control chip module. The input end of the rectifier and buck module is used to connect the feeder to detect the residual voltage on the feeder, and the output end of the rectifier and buck module is connected to the MCU module; the MCU module is connected to the main control chip module through a serial port, and the MCU module integrates FLASH and IO level detection modules on the chip. The FLASH is used to record the detected residual voltage data, and the IO level detection module is used to detect the high and low output levels of the sampling branch; the input end of the power conversion module is connected to the output end of the rectifier and buck module, and is used to convert the output voltage of the rectifier and buck module into the power supply voltage required by the MCU module. The control end of the power conversion module is connected to the main control chip module. When there is no residual voltage (the detected residual voltage value is less than the residual voltage set value or the residual voltage value is not less than the residual voltage set value for a duration that exceeds the set time set value), the main control chip module controls the power conversion module to shut down the power supply to the MCU, so that the residual voltage detection system stops running. Specifically, like Figure 2The schematic diagram of the rectifier and step-down module is shown. The module adopts an integrated chip, including transformers T9 and T10, a rectifier module, energy storage capacitors C2, C4 and C5, and a sampling branch. The module draws power from the feeder terminal PT side. The 220V AC power of VAB1 and VCB1 is reduced to AC 24V through transformers T9 and T10, and then the AC power is converted into DC power VAB+ and VCB+ through a rectifier bridge and a 20V DC voltage is output. VAB+ and VCB+ are then reduced to VAB_+ and VCB_+ through the resistor voltage divider on the sampling branch to be detected through the IO level detection port. In order to ensure that the residual voltage detection system can still detect the residual voltage in the power-off state (when the feeder terminal has no backup power supply), the energy storage capacitor C5 is set in the schematic diagram to store the electric energy, supporting the MCU to complete the detection and storage of the residual voltage signal.

[0021] like Figure 3 The schematic diagram of the power conversion module is shown. The module reduces the DC 20V voltage output by the rectifier and step-down module to 3.3V through the U19 power conversion chip to provide working power for the MCU; the Q1 transistor is used as a switch, and its base is connected to PWROFF (the signal comes from the main control chip), the emitter is grounded, and the collector is connected to the 4th pin (enable pin) of U19. When the pin is high, the chip U19 works normally, and when the pin is grounded to a low level, the chip U19 does not work; when the feeder terminal system is operating normally and there is no residual pressure, the main control chip turns on the transistor Q1 through PWROFF, grounding the 4th pin, and U19 does not work, thereby cutting off the power supply of the MCU and reducing the power consumption of the entire feeder terminal. In this embodiment, the switching device set between the 4th pin and the ground is a transistor. As other implementation methods, the transistor can also be replaced by other controllable switching devices, such as MOS tubes, thyristors, etc.

[0022] The MCU core module uses a highly integrated MCU chip. The MCU comes with FLASH and IO level detection modules, which saves PCB layout area. The module completes the voltage sampling, residual voltage detection judgment, and stores the residual voltage detection data in the on-chip FLASH and sends it to the main control chip module. In this embodiment, in order to improve the detection efficiency, the IO level detection module is used to detect the voltage on the sampling branch. As another implementation method, the ADC sampling module can also be integrated on the MCU to detect the voltage on the sampling branch through the ADC sampling module.

[0023] On the one hand, the main control chip module controls the switch of the power conversion module through the PWROFF signal. When the system is operating normally and there is no residual voltage, the main control chip turns on the transistor Q1 by outputting the PWROFF signal, so that the No. 4 pin of the power conversion chip U19 is grounded, U19 does not work, and then cuts off the power supply of the MCU, stops the residual voltage detection system from running, and reduces the power consumption of the whole feeder terminal; on the other hand, it is responsible for communicating with the MCU, receiving the residual voltage sent from the MCU module, sending serial port instructions to the MCU core module, and setting the time constant. The specific flow chart is as follows Figure 4 shown.

[0024] like Figure 4 The figure shows the software flow chart of the residual pressure detection system. When the MCU is powered on normally, the system is initialized first, and then the serial port interrupt and timer interrupt are set, and the serial port interrupt is set to a high priority; then the GPIO, timer and serial port are initialized; the MCU reads the internal FLASH of the STM32 and takes out the time constant sent by the main control chip; if there is a residual pressure record, the data of the residual pressure record is framed and sent to the main control chip through the serial port. If the MCU receives a successful reception instruction from the main control chip, it stops sending and clears the residual pressure record in the FLASH. If no successful reception instruction is received, the residual pressure record data is framed and sent until the main control chip receives it successfully; if there is no residual pressure record , or after the main control chip successfully receives the last residual voltage record and has cleared the last residual voltage record in the FLASH, the MCU module detects the level of UAB and UCB through the IO port; if there is a residual voltage situation (the duration of the residual voltage does not exceed the set time value and the residual voltage value is greater than the set residual voltage value), the residual voltage data is written into the MCU on-chip FLASH, and the data is sent to the main control chip through the serial port after the next normal operation of the system to prevent reverse power from closing during the fault recovery process, thereby protecting the safety of the equipment and lines; otherwise, the main control chip controls the transistor Q1 of the power conversion module to turn on through the IO pin to turn off the power of the residual voltage detection module and reduce the power consumption of the whole machine.

Claims

1. A feeder terminal residual voltage detection system, comprising a rectifier and buck module and an MCU module, wherein the MCU module is connected to the output end of the rectifier and buck module through a sampling branch, and the input end of the rectifier and buck module is used to connect the feeder to detect the residual voltage on the feeder, characterized in that: It also includes a main control chip module, and the MCU module is communicatively connected to the main control chip module, and is used to send the detected residual voltage situation to the main control chip module; the main control chip module is also used to cut off the power supply of the MCU module when no residual voltage situation occurs, so that the MCU module stops running; the no residual voltage situation is that the detected residual voltage value is less than the residual voltage set value or the residual voltage value is not less than the residual voltage set value for a duration exceeding the set time set value.

2. The feeder terminal residual voltage detection system according to claim 1, characterized in that: The MCU module is powered by a power conversion module, the input end of which is connected to the output end of the rectifier and buck module, and is used to convert the voltage output by the rectifier and buck module into the power supply voltage required by the MCU module.

3. The feeder terminal residual voltage detection system according to claim 2, characterized in that: The power conversion module adopts a power conversion chip, and a controllable switch device is arranged between the enable pin of the power conversion chip and the ground. The control end of the controllable switch device is connected to the IO pin of the main control chip module. When no residual voltage occurs, the main control chip module controls the controllable switch device to be turned on through the IO pin, and cuts off the power supply from the power conversion chip to the MCU module.

4. The feeder terminal residual voltage detection system according to claim 3, characterized in that: The controllable switch device is a triode or a thyristor.

5. The feeder terminal residual voltage detection system according to claim 1, characterized in that: The sampling branch adopts a resistor voltage divider circuit, and the output voltage of the rectifier and buck module is reduced to within the collection range of the MCU module through the resistor voltage divider circuit.

6. The feeder terminal residual voltage detection system according to claim 1, characterized in that: The rectifier and step-down module includes a transformer, a rectifier module and an energy storage capacitor. The transformer is used to achieve voltage level conversion; the rectifier module is used to convert the alternating current converted by the transformer into direct current.

7. The feeder terminal residual voltage detection system according to claim 1, characterized in that: The main control chip module is connected to the MCU module through the serial port.

8. The feeder terminal residual voltage detection system according to claim 1, characterized in that: The MCU module integrates FLASH for recording the detected residual pressure data.

9. The feeder terminal residual voltage detection system according to claim 1, characterized in that: The MCU module detects the high and low levels output by the sampling branch through the IO level detection module.

10. The feeder terminal residual voltage detection system according to claim 1, characterized in that: The time constant is sent from the main control chip module to the MCU module, and the residual pressure constant is determined by hardware.

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