Construction distribution box intelligent safety energy-saving control system based on multi-source perception

Abstract

The invention discloses a construction distribution box intelligent safety energy-saving control system based on multi-source sensing, and particularly relates to the field of construction distribution box intelligent safety energy saving, which comprises a multi-source sensing module, an edge computing gateway, a dynamic compensation module and a safety execution module. The multi-source sensing module collects electrical parameters, environmental parameters and equipment working conditions, and obtains information such as a power factor, a current high-frequency component amplitude, temperature, smoke concentration and a motor starting event. The edge computing gateway generates a security event instruction through the security risk judgment unit, the energy-saving control decision unit calculates the capacity of the capacitor bank, the collaboration arbitration unit executes the instruction according to the priority, and the security instruction compulsively covers energy-saving control; the dynamic compensation module realizes capacitor bank switching and pre-compensation; and the safety execution module completes open circuit opening and multi-stage alarm. Safety and energy-saving cooperative control is achieved, the early warning accuracy is improved, the problem of traditional compensation lag is solved, and power utilization safety of a construction site is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of intelligent safety and energy-saving technology for construction distribution boxes, and more specifically, to an intelligent safety and energy-saving control system for construction distribution boxes based on multi-source sensing. Background Technology

[0002] Currently, safety and energy-saving control technologies for distribution boxes have been developed in the construction industry. In terms of safety, some distribution boxes are equipped with current and voltage monitoring devices to detect basic faults such as overloads and short circuits, while a few integrate temperature sensors to monitor the internal temperature. Regarding energy saving, most systems rely on manual or timed control of equipment start-up and shutdown, with some systems manually switching capacitor banks for reactive power compensation based on power factor.

[0003] However, it still has some shortcomings in actual use: on the one hand, the existing technology has a single sensing dimension, only monitoring safety through single parameters such as current and temperature, without considering the high-frequency current characteristics of arc faults; its reactive power compensation relies on timed switching, which cannot respond to the dynamic reactive power demand of motor starting, resulting in compensation lag. On the other hand, existing technologies rely on manual or fixed logic, cannot dynamically adjust compensation strategies according to the motor's starting conditions, and lack a pre-compensation mechanism, resulting in limited energy-saving effects. Existing technologies operate independently of safety and energy-saving controls without a coordination mechanism. When safety risks occur, energy-saving controls may continue to operate, posing potential hazards. Furthermore, existing technology decisions rely on cloud processing, which is affected by network latency, leading to delayed responses to emergencies. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a smart safety and energy-saving control system for construction power distribution boxes based on multi-source sensing, which solves the problems mentioned in the background art through the following scheme.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a smart safety and energy-saving control system for construction power distribution boxes based on multi-source sensing, comprising: Multi-source sensing module: includes an electrical parameter acquisition unit, an environmental parameter acquisition unit, and an equipment condition identification unit; the electrical parameter acquisition unit is used to collect the instantaneous values ​​of three-phase voltage and current of the main circuit of the primary distribution box at the target construction site in real time, and analyze the power factor and the amplitude of the high-frequency component of the current; the environmental parameter acquisition unit is used to monitor the temperature, humidity, smoke concentration inside the distribution box and the opening and closing status of the distribution box door in real time; the equipment condition identification unit is used to identify motor starting and pre-start events; Edge computing gateway: includes a security risk judgment unit, an energy-saving control decision unit, and a collaborative arbitration unit; calculates the capacitor bank switching capacity based on data from multi-source sensing modules, and generates security event instructions and power-off priority instructions respectively; Dynamic compensation module: includes capacitor bank switching response unit and pre-compensation execution unit; the capacitor bank switching response unit switches capacitor bank combinations, and the pre-compensation execution unit performs pre-compensation during the motor start-up preparation stage; Safety execution module: includes circuit breaker drive unit and multi-level alarm unit, responds to safety event commands and power outage priority commands, drives the circuit breaker to trip through the circuit breaker drive unit and triggers corresponding alarm actions through the multi-level alarm unit.

[0006] Preferably, the power factor is analyzed in the following way: The instantaneous value of the three-phase voltage U is synchronously acquired at a sampling frequency of 50kHz. a U b U c and the instantaneous value of three-phase current I a I b I c Power factor , where P avg Q is the average active power. avg Average reactive power; The average active power Where T is the sampling period; the average reactive power .

[0007] Preferably, the high-frequency component amplitude of the current is analyzed in the following way: At a sampling frequency of 50kHz, the current I of phase A is... a Perform a 2-100kHz bandpass filter and calculate the high-frequency energy mutation rate within a 1ms time window. E t E represents the root mean square value of the high-frequency current signal within the current time window. t-1 This is the root mean square value of the high-frequency current signal within the previous 1ms time window; The root mean square value of the high-frequency current signal in the time window k is the starting sampling point number of the current window, and N is the number of sampling points within the window. For discretized high-frequency current signal sequences; The discretized high-frequency current signal sequence is obtained by analyzing the A-phase current I. a A discretized high-frequency current signal sequence is obtained by performing a 2-100kHz bandpass filter. , where n is the sampling point number of the signal sequence, f low f represents the lower cutoff frequency of the bandpass filter. high This indicates the upper limit frequency of the bandpass filter.

[0008] Preferably, the equipment operating condition identification unit determines the motor starting event by calculating the current rise rate in real time. When the current rise rate is greater than 100A / ms and the duration is greater than 0.5s, the motor starting event is recorded. When the current rise rate is greater than 100A / ms and the duration is greater than 10ms, it is only marked as the starting preparation stage. The rate of rise of current , For time intervals, Time interval The change in current within.

[0009] Preferably, the rule for the security risk judgment unit to generate security event instructions is as follows: An arc fault command is generated when the amplitude of the high-frequency component of the current is greater than 5A and the high-frequency energy mutation rate within the time window is greater than 300%; when the temperature inside the box is greater than 60℃, sampling is accelerated; when the temperature inside the box is greater than 65℃, an overheat alarm command is generated; when the smoke concentration is greater than 5%LEL, sampling is accelerated; when the smoke concentration is greater than 15%LEL, a fire linkage command is generated; when the power factor is lower than the target threshold or a motor starting event is detected, an energy-saving control command is generated.

[0010] The target threshold is a power factor threshold preset in the safety risk judgment unit, with a value of 0.9 under normal load scenarios and a value of 0.85 under scenarios with inductive loads.

[0011] Preferably, the energy-saving control decision unit calculates the switching capacity of the capacitor bank after receiving the energy-saving control command: The specific analysis method for the switching capacity of the capacitor bank is as follows: Basic compensation capacity , where P a The average active power for the previous minute, PF is the power factor, and k1 is the target power factor compensation coefficient; dynamic correction term. Where k2 is the motor starting compensation coefficient, N s The number of motor starting events is used; finally, the switching capacity of the capacitor bank is obtained by summing the basic compensation capacity and the dynamic correction term.

[0012] Preferably, the collaborative arbitration unit performs operation scheduling according to the priority of the security event instruction; when the security event instruction generated by the security risk judgment unit is triggered, the energy-saving control signal path is cut off through the hardware relay, and a power-off priority instruction is generated, which is sent to the circuit breaker drive unit in the security execution module. The priority of the event commands is as follows: fire linkage command > arc fault command > overheat alarm command > energy saving control command.

[0013] Preferably, the capacitor bank switching response unit receives the capacitor bank capacity output by the energy-saving control decision unit and switches the closest capacitor bank combination. When the effective value of the total current is less than 30A and lasts for 10 seconds, the compensation function is automatically locked. The pre-compensation execution unit monitors the current rise rate in real time. When the current rise rate is greater than 100A / ms, lasts for more than 10ms, and the voltage drop rate is greater than 5% per millisecond, it activates the preset capacity. , where k c To compensate for efficiency and safety margin factors, k s k is the starting current multiplier. c k s The specific value is determined based on the type of motor; I r X is the rated current of the motor. c U is the reference value for capacitive reactance. n The system rated voltage is assumed to be the standard voltage at the construction site, with 380 being the reference voltage.

[0014] Preferably, the circuit breaker drive unit receives a power failure priority command, drives the magnetic latching relay, and causes the circuit breaker to trip. The multi-level alarm unit triggers audible and visual alarms and remotely pushes alarm information to the management platform upon receiving an arc fault command; it triggers the cabinet alarm upon receiving an overheat alarm command and simultaneously pushes overheat warning information to the management platform; and it activates the inert gas extinguishing system inside the cabinet and links the on-site fire protection system upon receiving a fire linkage command.

[0015] The technical effects and advantages of this invention are as follows: 1. This invention integrates electrical parameters, environmental parameters, and equipment operating conditions through a multi-source sensing module to achieve comprehensive monitoring of safety risks such as arc faults, overheating, and fires. The safety risk judgment unit, based on multi-parameter threshold linkage analysis, significantly improves the accuracy of safety warnings, reduces false alarms and missed alarms, and provides multiple safeguards for electrical safety at construction sites. 2. This invention uses an energy-saving control decision unit to dynamically calculate the switching capacity of the capacitor bank by combining the power factor and the motor starting frequency, thus solving the problem of traditional compensation lag; the pre-compensation execution unit intervenes in advance before the equipment starts, reducing startup losses; 3. The collaborative arbitration unit of this invention ensures that the safety event command forcibly overrides the energy-saving control decision, and cuts off the energy-saving signal path through the hardware relay and generates a power-off priority command to realize the safety-first control logic. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the collaborative arbitration unit execution process structure of the present invention.

[0018] Figure 3 Schematic diagram of the process structure of the dynamic compensation module of the present invention. Specific implementation manners

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] As Figure 1-3 shown, a smart safety and energy-saving control system for a construction distribution box based on multi-source perception includes: A multi-source perception module, an edge computing gateway, a dynamic compensation module, and a safety execution module. The multi-source perception module is connected to the edge computing gateway: the electrical parameter acquisition unit is connected to the gateway after being connected to the data acquisition card through USB, the environmental parameter acquisition unit is connected to the gateway through the I²C bus, and the equipment condition identification unit is connected to the gateway through the SPI bus. The edge computing gateway is connected to the dynamic compensation module: connected through the RS485 bus Modbus-RTU protocol, and the GPIO pin of the gateway is connected to the pre-compensation execution unit. The edge computing gateway is connected to the safety execution module: connected through the Ethernet TCP / IP protocol, and the hardware relay and pulse output terminal of the gateway are connected to the breaker drive unit. The dynamic compensation module is connected to the safety execution module: connected through dry contacts to achieve status feedback and linkage control.

[0021] The multi-source perception module: includes an electrical parameter acquisition unit, an environmental parameter acquisition unit, and an equipment condition identification unit; the electrical parameter acquisition unit is used to collect the instantaneous values of the three-phase voltage and current of the main circuit of the primary distribution box at the target construction site in real time, and analyze to obtain the power factor and the amplitude of the high-frequency component of the current; the environmental parameter acquisition unit is used to monitor the internal temperature, humidity, smoke concentration, and the opening and closing state of the distribution box door of the distribution box in real time; the equipment condition identification unit is used to identify motor startup and pre-start events; The electrical parameter acquisition unit selects 3 0.5S-class current transformers with a range of 0-600A, which are connected in series to the incoming line terminals of phases A, B, and C, and 3 voltage sensors with a range of 0-500V, which are connected in parallel between the three-phase live wires and the neutral wire; the sensor signals are connected to the data acquisition card PCI-6251 through shielded twisted pair, with a built-in 128MB cache, and the 50kHz raw data is packaged and compressed every 100ms and transmitted to the edge computing gateway. The data acquisition card is fixed to the back panel of the distribution box.

[0022] It should be noted in particular that the electrical parameter acquisition synchronously acquires the three-phase voltage U at a sampling frequency of 50kHz aU b U c and current I a I b I c Discrete data sequences are generated every 1ms; the power factor is obtained by integrating the average active power and average reactive power; the A-phase current is subjected to a 2-100kHz bandpass filter; the high-frequency energy mutation rate within the 1ms time window is calculated; and the amplitude of the high-frequency component of the current (E) is extracted. t (Maximum value).

[0023] It should be noted that the power factor is analyzed in the following way: Power factor , where P avg Q is the average active power. avg The average reactive power; the average active power Where T is the sampling period, and the average reactive power is... .

[0024] It should be noted that the specific analysis method for the amplitude of the high-frequency component of the current is as follows: Perform a 2-100kHz bandpass filter on the phase A current Ia and calculate the high-frequency energy mutation rate within a 1ms time window. E t E represents the root mean square value of the high-frequency current signal within the current time window. t-1 This is the root mean square value of the high-frequency current signal within the previous 1ms time window; It should be noted that the root mean square value of the high-frequency current signal within the time window... k is the starting sampling point number of the current window, and N is the number of sampling points within the window. It is a discretized high-frequency current signal sequence; N is 50 at a sampling frequency of 50kHz.

[0025] It should be noted that the discretized high-frequency current signal sequence is obtained by analyzing the A-phase current I. a A 2-100kHz bandpass filter is applied to obtain a discretized high-frequency current signal sequence. , where n is the sampling point number of the signal sequence, f low f represents the lower cutoff frequency of the bandpass filter. high This indicates the upper limit frequency of the bandpass filter.

[0026] The environmental parameter acquisition unit includes a temperature and humidity sensor installed inside the distribution box, above and away from heat-generating components; a smoke sensor fixed to the center of the top of the distribution box; and a door magnetic sensor installed at the junction of the door and the box body. All environmental sensors are connected to the edge computing gateway expansion interface via an I²C bus.

[0027] It should be noted that the temperature and humidity sensor collects data every 100ms, and the sampling interval is shortened to 10ms when the temperature is ≥60℃; the smoke sensor monitors the smoke concentration in real time, and starts continuous sampling at 1s interval when the smoke concentration is ≥5%LEL; the door magnetic sensor monitors the door status every 500ms, and generates an abnormal log if it is open for more than 30 seconds.

[0028] The equipment operating condition identification unit has a current rise rate monitoring chip connected to the secondary side of the A-phase current transformer, and its output signal is connected to the GPIO interface of the edge computing gateway, configured to trigger an interrupt on the rising edge.

[0029] It should be noted that the equipment operating condition identification calculates the current rise rate every 10ms. When the current rise rate is >100A / ms and the duration is >0.5s, it is determined to be a valid start-up event; when the current rise rate is >100A / ms, the duration is >10ms and the voltage drop rate is >5% / ms, it is determined to be the start-up preparation stage, and a pre-compensation trigger signal is output.

[0030] It is important to note the rate of current rise. , This is the time interval, with a value of 10ms. Time interval The change in current within the voltage range. Voltage sag rate. U0 is the initial voltage, and U1 is the current voltage.

[0031] It should be noted that the edge computing gateway includes a security risk judgment unit, an energy-saving control decision unit, and a collaborative arbitration unit; it calculates the switching capacity of the capacitor bank based on data from the multi-source sensing module and generates security event instructions and power-off priority instructions respectively. The edge computing gateway is an industrial-grade EC200S edge gateway with a quad-core ARM Cortex-A53 processor, 2GB of memory, and is fixed in the control cabinet. It connects to the multi-source sensing module via an RS485 bus and to the dynamic compensation module and the security execution module via an Ethernet connection. It is pre-installed with a Linux system and edge computing software developed in Python, which supports data parsing, threshold judgment, instruction generation, and automatic startup.

[0032] The safety risk judgment unit generates safety event instructions according to the following rules: receiving and verifying multi-source parameters and eliminating outliers; generating an arc fault instruction when the amplitude of the high-frequency current component is >5A and the mutation rate is >300%; reducing the sampling frequency from 100ms to 10ms when the internal temperature is >60℃, and generating an overheat alarm instruction when the temperature is >65℃; reducing the sampling frequency from 100ms to 10ms when the smoke concentration is >5%LEL, and generating a fire linkage instruction when the smoke concentration is >15%LEL; generating an energy-saving control instruction when the power factor is below the target threshold or a motor start-up event is detected; the instruction format is code + timestamp + checksum, and is sent to the collaborative arbitration unit.

[0033] The energy-saving control decision unit calculates the switching capacity of the capacitor bank after receiving the energy-saving control command. The specific analysis method for the switching capacity of the capacitor bank is as follows: Basic compensation capacity , where P a The average active power for the previous minute, PF is the power factor, and k1 is the target power factor compensation coefficient; dynamic correction term. Where k2 is the motor starting compensation coefficient, N s The number of motor starting events is used; finally, the switching capacity of the capacitor bank is obtained by summing the basic compensation capacity and the dynamic correction term.

[0034] It should be noted that when the distribution box is mainly loaded with welding machines, lighting, and small motors, the power factor fluctuates between 0.7 and 0.85, the motor starts 10-20 times a day, and the load type is stable, k1 is 0.95 and k2 is 0.15. When the distribution box is connected to equipment driven by frequency converters or high-frequency welding equipment, the power factor fluctuates greatly between 0.6 and 0.8 due to the influence of harmonics. When the motor starts with harmonic impact and the load is dynamic, k1 takes a value of 0.92 and k2 takes a value of 0.2. The priority order of the collaborative arbitration unit is fire linkage command > arc fault command > overheat alarm command > energy saving control command. When any safety event command exists, the hardware relay is triggered to cut off the energy saving control signal path, generate a high-level pulse with a voltage greater than 5V and a pulse width of 10 microseconds, and send it to the circuit breaker drive unit. If the triggered command is a fire command, the fire linkage mechanism is activated at the same time.

[0035] It should be noted that the dynamic compensation module includes a capacitor bank switching response unit and a pre-compensation execution unit; the capacitor bank switching response unit switches the capacitor bank combination, and the pre-compensation execution unit performs pre-compensation during the motor start-up preparation stage. The capacitor bank switching response unit uses 10 self-healing capacitors, model BSMJ0.45-5-3, 5kvar, installed in two groups on the compensation circuit busbar; each capacitor is connected in series with a thyristor module, model TCSC-40A, with a response ≤10ms, and the control terminal is connected to the gateway relay interface via an optocoupler; a current transformer, model LMZJ1-0.5, 0-100A, is installed at the main input terminal of the compensation circuit to monitor the effective value of the total current.

[0036] It should be noted that the capacitor bank switching response unit receives the capacitor bank capacity output by the energy-saving control decision unit, parses it into switching combinations, and executes the instructions by the thyristor module. The switching time is ≤10ms and the inrush current is ≤1.5 times the rated value. It also monitors the effective value of the total current in real time. When the effective value of the total current is <30A and lasts for 10s, it automatically locks out compensation and cuts off all capacitors.

[0037] The pre-compensation execution unit has an independent thyristor switching module, a shared capacitor bank, and receives pre-compensation commands through a GPIO interface; it also has a series current sensor with a range of 0-50A to monitor the motor starting current.

[0038] It should be noted that the pre-compensation execution unit monitors the current rise rate in real time. When the current rise rate is greater than 100A / ms, lasts for more than 10ms, and the voltage drop rate is greater than 5% per millisecond, the preset capacity is activated. , where k c To compensate for efficiency and safety margin factors, k s k is the starting current multiplier. c k s The specific value is determined based on the type of motor; I r X is the rated current of the motor. c U is the reference value for capacitive reactance. n The system rated voltage is assumed to be the standard voltage at the construction site, with 380 being the reference voltage.

[0039] It should be noted that during the initial start-up phase of the motor, the amplitude I of the current rising to a steady state during the motor start-up process is recorded in real time. max Based on I max get Every 24 hours, the calculated I r The mean value is updated to adapt to parameter changes during long-term operation of the motor, ensuring the accuracy of the pre-compensation capacity calculation.

[0040] It should be noted that when the motor is a common Y-series motor, the starting current multiple is within 6-8 times, the load is general construction machinery, the power supply system is stable, and there are no special harmonics or voltage fluctuations.

[0041] At this time, when a conventional motor starts, reactive power compensation needs to cover 90%-95% of the reactive power deficit, while reserving a 5%-10% safety margin to avoid capacitor damage due to overcurrent. c The value is set to 0.92, which ensures that the compensation efficiency covers 92% of the reactive power demand, while also avoiding the risk of capacitor overload caused by the starting current surge through an 8% margin.

[0042] The starting current multiple of standard asynchronous motors is concentrated between 6 and 8, so we take the middle value k. s A value of 7 is suitable for the starting characteristics of most conventional motors, ensuring that the pre-compensation capacity matches the actual starting reactive power demand, thus avoiding overcompensation due to an excessively high value or undercompensation due to an excessively low value.

[0043] When an electric motor drives heavy-duty equipment, the starting current is more than 8 times the rated current and the starting time is long, greater than 2 seconds. The voltage of the power supply bus is prone to drop due to the impact of the large current.

[0044] During heavy-load startup, the reactive power surge is prolonged and has a high amplitude, requiring improved compensation efficiency to cover 95% of the reactive power deficit. However, the safety margin needs to be increased because bus voltage fluctuations may cause capacitor overvoltage. Therefore, k is chosen as... c The compensation efficiency is increased to 90% with a value of 0.9, while a 10% margin is reserved to balance compensation needs and equipment safety.

[0045] The starting current multiple of heavy-duty motors is significantly higher than that of conventional motors, k s In scenarios where the starting current multiple is 8-10, the pre-compensation capacity is sufficient to offset the reactive power impact of heavy-load startup and suppress bus voltage drop.

[0046] When a motor is soft-started by a frequency converter, the starting current multiple is no more than 2, but the current contains high-order harmonics, and the capacitor is prone to overheating due to harmonic overcurrent.

[0047] At this point, the reactive power impact of soft starting is small, but harmonics will cause an increase in the actual capacitor current, requiring a reduction in compensation efficiency and an increase in safety margin. c The value is set to 0.85, which reduces the compensation efficiency to 85%, reduces the capacitor capacity, and avoids the risk of harmonic resonance; the 15% margin is used to buffer harmonic current impact.

[0048] The variable frequency soft start current multiple is low, k s A value of 3 is chosen to suit scenarios with a starting current multiple of 1.5-3, avoiding issues caused by k. s Excessive pre-compensation capacity leads to overcapacity, while also covering the small reactive power demand during the initial soft-start phase.

[0049] When the insulation of a motor ages and the winding resistance increases, the starting current multiple becomes highly variable, potentially reaching 10 times the normal value due to local short circuits. The reactive power loss during startup is 10%-20% higher than that of a new motor, and the probability of failure increases.

[0050] At this point, the old motor has high reactive power loss and unstable characteristics, requiring a reduction in compensation efficiency, but the safety margin must be maximized. c The value is set to 0.8, with a compensation efficiency of 80% and a 20% margin to cope with abnormal current surges caused by motor failures, protecting the capacitors and power supply system.

[0051] Considering the dispersion of the starting current multiple of the aging motor, k s The value is set to 8, covering the possible range of starting current multiples of 6-10, ensuring that the pre-compensation capacity is still adaptable to abnormally high starting currents and avoiding compensation failure due to individual differences in motors.

[0052] It should be noted that the safety execution module includes a circuit breaker drive unit and a multi-level alarm unit. It responds to safety event commands and power outage priority commands, drives the circuit breaker to trip through the circuit breaker drive unit, and triggers corresponding alarm actions through the multi-level alarm unit.

[0053] The circuit breaker drive unit uses a magnetic latching relay, model JQX-60F-1C, 250A / 380V, installed next to the main switch. The coil is connected to the gateway pulse interface through the drive circuit (ULN2003). The normally open contact of the relay is connected in series in the circuit breaker trip coil circuit. The trip coil voltage is DC24V and the trip time is ≤200ms.

[0054] It should be noted that the circuit breaker drive unit drives the magnetic latching relay to operate by receiving the power failure priority command, which energizes the trip coil and drives the circuit breaker to trip. After tripping, it maintains the energized state, and the circuit breaker can be closed manually by pressing and holding the reset button for 3 seconds.

[0055] The multi-level alarm unit uses an audible and visual alarm installed on the surface of the distribution box and connected to the gateway relay interface; the remote communication module is installed in the control cabinet and connected to the gateway via UART (115200bps); the inert gas fire extinguishing device (FM-200, 2L) is installed in the corner of the box, and the solenoid valve (DC24V) is connected to the gateway relay, with dry contact linkage to the fire protection system.

[0056] It should be noted that when the multi-level alarm unit receives an arc fault command, it triggers an audible and visual alarm and pushes information including the fault time and current waveform to the management platform via NB-IoT; when the multi-level alarm unit receives an overheat alarm command, it triggers the yellow LED light of the enclosure alarm to flash; when the multi-level alarm unit receives a fire linkage command, it starts inert gas fire extinguishing spray for 10 seconds and links the fire pump and smoke exhaust fan.

[0057] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other. In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A smart safety and energy-saving control system for construction power distribution boxes based on multi-source sensing, characterized in that, include: Multi-source sensing module: includes electrical parameter acquisition unit, environmental parameter acquisition unit and equipment operating condition identification unit; The electrical parameter acquisition unit is used to acquire the instantaneous values ​​of three-phase voltage and current of the main circuit of the primary distribution box at the target construction site in real time, and analyze the power factor and the amplitude of the high-frequency component of the current. The environmental parameter acquisition unit is used to monitor the temperature, humidity, smoke concentration and opening / closing status of the distribution box door in real time; the equipment operating condition identification unit is used to identify motor starting and pre-start events. Edge computing gateway: includes a security risk judgment unit, an energy-saving control decision unit, and a collaborative arbitration unit; calculates the capacitor bank switching capacity based on data from multi-source sensing modules, and generates security event instructions and power-off priority instructions respectively; Dynamic compensation module: includes capacitor bank switching response unit and pre-compensation execution unit; the capacitor bank switching response unit switches capacitor bank combinations, and the pre-compensation execution unit performs pre-compensation during the motor start-up preparation stage; Safety execution module: includes circuit breaker drive unit and multi-level alarm unit, responds to safety event commands and power outage priority commands, drives the circuit breaker to trip through the circuit breaker drive unit and triggers corresponding alarm actions through the multi-level alarm unit.

2. The intelligent safety and energy-saving control system for construction power distribution boxes based on multi-source sensing according to claim 1, characterized in that: The specific analysis method for the power factor is as follows: The instantaneous value of the three-phase voltage U is synchronously acquired at a sampling frequency of 50kHz. a U b U c and the instantaneous value of three-phase current I a I b I c Power factor , where P avg For average active power, Q avg Average reactive power; The average active power Where T is the sampling period; the average reactive power .

3. The intelligent safety and energy-saving control system for construction distribution boxes based on multi-source sensing according to claim 1, characterized in that: The specific analysis method for the amplitude of the high-frequency component of the current is as follows: At a sampling frequency of 50kHz, the A-phase current I a Perform a 2-100kHz bandpass filter and calculate the high-frequency energy mutation rate within a 1ms time window. E t E represents the root mean square value of the high-frequency current signal within the current time window. t-1 This is the root mean square value of the high-frequency current signal within the previous 1ms time window; The root mean square value of the high-frequency current signal in the time window k is the starting sampling point number of the current window, and N is the number of sampling points within the window. For discretized high-frequency current signal sequences; The discretized high-frequency current signal sequence is obtained by analyzing the A-phase current I. a A discretized high-frequency current signal sequence is obtained by performing a 2-100kHz bandpass filter. , where n is the sampling point number of the signal sequence, f low f represents the lower cutoff frequency of the bandpass filter. high This indicates the upper limit frequency of the bandpass filter.

4. The intelligent safety and energy-saving control system for construction distribution boxes based on multi-source sensing according to claim 1, characterized in that: The equipment operating condition identification unit determines the motor start event by calculating the current rise rate in real time. When the current rise rate is greater than 100A / ms and the duration is greater than 0.5s, the motor start event is recorded. When the current rise rate is greater than 100A / ms and the duration is greater than 10ms, it is only marked as the start preparation stage. The rate of rise of current , For time intervals, Time interval The change in current within.

5. The intelligent safety and energy-saving control system for construction distribution boxes based on multi-source sensing according to claim 1, characterized in that: The rules for generating security event instructions by the security risk judgment unit are as follows: When the amplitude of the high-frequency component of the current is greater than 5A and the high-frequency energy mutation rate within the time window is greater than 300%, an arc fault command is generated; when the temperature inside the box is greater than 60℃, sampling is accelerated; when the temperature inside the box is greater than 65℃, an overheat alarm command is generated; when the smoke concentration is greater than 5%LEL, sampling is accelerated; when the smoke concentration is greater than 15%LEL, a fire linkage command is generated; when the power factor value is lower than the target threshold or a motor starting event is detected, an energy-saving control command is generated. The target threshold is a power factor threshold preset in the safety risk judgment unit, with a value of 0.9 under normal load scenarios and a value of 0.85 under scenarios with inductive loads.

6. The intelligent safety and energy-saving control system for construction distribution boxes based on multi-source sensing according to claim 1, characterized in that: The energy-saving control decision unit calculates the switching capacity of the capacitor bank after receiving the energy-saving control command. The specific analysis method for the switching capacity of the capacitor bank is as follows: Basic compensation capacity , where P a The average active power for the previous minute, PF is the power factor, and k1 is the target power factor compensation coefficient; dynamic correction term. Where k2 is the motor starting compensation coefficient, N s The number of motor starting events is used; finally, the switching capacity of the capacitor bank is obtained by summing the basic compensation capacity and the dynamic correction term.

7. The intelligent safety and energy-saving control system for construction distribution boxes based on multi-source sensing according to claim 1, characterized in that: The collaborative arbitration unit performs operation scheduling based on the priority of security event instructions; when a security event instruction generated by the security risk judgment unit is triggered, the energy-saving control signal path is cut off through a hardware relay, and a power-off priority instruction is generated, which is sent to the circuit breaker drive unit in the security execution module. The priority of the event commands is as follows: fire linkage command > arc fault command > overheat alarm command > energy saving control command.

8. The intelligent safety and energy-saving control system for construction distribution boxes based on multi-source sensing according to claim 1, characterized in that: The capacitor bank switching response unit receives the capacitor bank capacity output by the energy-saving control decision unit and switches the closest capacitor bank combination. When the effective value of the total current is less than 30A and lasts for 10s, the compensation function is automatically locked. The pre-compensation execution unit monitors the current rise rate in real time. When the current rise rate is greater than 100A / ms, lasts for more than 10ms, and the voltage drop rate is greater than 5% per millisecond, it activates the preset capacity. , where k c To compensate for efficiency and safety margin factors, k s k is the starting current multiplier. c k s The specific value is determined based on the type of motor; I r X is the rated current of the motor. c U is the reference value for capacitive reactance. n The system rated voltage is assumed to be the standard voltage at the construction site, with 380 being the reference voltage.

9. A smart safety and energy-saving control system for construction distribution boxes based on multi-source sensing according to claim 1, characterized in that: The circuit breaker drive unit receives a power outage priority command, drives the magnetic latching relay, and causes the circuit breaker to trip. The multi-level alarm unit triggers audible and visual alarms upon receiving arc fault commands and remotely pushes alarm information to the management platform. Upon receiving an overheat alarm command, the cabinet alarm is triggered, and an overheat warning message is pushed to the management platform; upon receiving a fire linkage command, the inert gas extinguishing system inside the cabinet is activated and the on-site fire protection system is activated.

Images