Anti-electricity shaking and overcurrent protection linkage control device and control method thereof

Abstract

The present invention relates to an anti-power sway and overcurrent protection linkage control device and a control method thereof, which are suitable for performing overcurrent protection on the load side and anti-power sway control on the power supply side of electric equipment. The device comprises a main power supply module connected to the power supply side, a backup power supply module connected to the main power supply module and charging the main power supply module, a CPU module connected to the main power supply module, a voltage and current signal acquisition and processing module connected to the CPU module, a relay switch and circuit breaker module connected to the CPU module, and a FRAM storage module connected to the CPU module. The device has the advantages of effectively preventing the influence of power sway on the load side equipment on the system side, and preventing the voltage sway on the power supply side caused by the inability to timely remove the fault due to a fault on the load side. The device will not affect the safe operation of the adjacent side equipment, and is beneficial to improving the selectivity and reliability of the current anti-power sway device, and preventing the influence of the anti-power sway device on the rapid removal of the faulty component of the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of relay protection for electric power systems, and particularly relates to a method for

[0002] The invention relates to an anti-sway and overcurrent protection linkage control device and a control method thereof, which performs overcurrent protection on the load side and anti-sway control on the power supply side. Background Art

[0003] During the operation of the power system, due to lightning strikes, short-circuit fault reclosing, internal and external power grid failures, and the start-up of large equipment, the voltage may fluctuate instantly or be cut off for a short time and then restored. This phenomenon is usually called "power shaking". The basic types of power shaking generated in the power supply system are: voltage sag, swell, short-term power outage, and voltage flicker. Voltage swell refers to a voltage rise or fall of 110~180% of the nominal voltage with a duration of 0.5 cycle to 1min. Voltage sag / sag refers to one of the power quality events in which the effective value of the voltage drops to 10% to 90% of the nominal value (Nominal Value) and lasts for 10ms to 1min (typical duration is 10ms~600ms). Short-term power outage refers to a power interruption lasting from 0.5 cycle to 3s (such as standby automatic switching, reclosing, etc.). Voltage flicker refers to the regular change of the voltage waveform envelope or a series of random changes in the voltage amplitude, which is generally manifested as the visual perception of the human eye caused by abnormal lighting caused by voltage fluctuations.

[0004] With the increasing expansion of grid connection and ring network, and the increase of distribution circuits due to the increase of feeder transformer capacity, the phenomenon of instantaneous power loss, i.e. "power shaking", is becoming more and more frequent. The reason is that the probability of voltage fluctuation caused by adjacent circuit faults has increased. The longest duration is generally the removal time of the fault protection, which is about 200 milliseconds or less. There are also special cases of "transient" instantaneous power loss when the protection element does not have time to act. The general requirements for AC contactor electrical retention are: the voltage is not less than 45% or the power loss time is not more than 60 milliseconds. Conventional microprocessor self-starting equipment is powerless to deal with this type of contactor release caused by "power shaking" because the fault time is less than the voltage acquisition cycle time of the microprocessor and cannot be identified.

[0005] Since the power system is equipped with surge protectors, lightning arresters and detuning devices, the impact caused by normal production loads will not be very large. The power grid shaking is mainly caused by external power grid or internal power grid failures of enterprises, among which voltage sag (Class A) and short-term voltage interruption (Class C) account for the majority. Generally speaking, a voltage drop within 20% will not have much impact on equipment operation. When the voltage drop exceeds 20%, it is easy to cause the equipment controlled by the AC contactor to trip and shut down.

[0006] At the same time, the power shaking phenomenon caused by the fault on the power supply side and the power supply line seriously affects the smooth and safe operation of the equipment on the load side. Severe power shaking accidents may cause the machine speed to swing unsteadily, the control switch circuit breaker to trip, the power supply to be interrupted, and the machine to be forced to stop and restart after the power is restored, etc., endangering the safety and stable operation of the equipment on the load side. In order to prevent the fluctuation of the load side equipment caused by power shaking, the control circuit breaker on the load side is disconnected with a delay. Although it can prevent the circuit breaker from tripping due to power shaking on the power supply side, it implies that the power shaking and equipment overcurrent accidents caused by the short circuit fault on the load side cannot be removed in time, which expands the accidents caused by the fault on the load side.

[0007] Chinese patent publication number CN 109474206 A discloses a "device and method for intelligent restarting after power swing of beam pumping unit with industrial frequency direct start", which can accurately identify the forward and reverse rotation process of the motor after it is disconnected from the grid, and close the switch when it is stopped or at the time of forward swing. The starting current is small. When power swing occurs, the stop position, swing direction and swing time of the crank balance block of the beam pumping unit are different. The device can be intelligently restarted based on analysis of various data, and has thermal overload protection, rotor blocking protection, zero-sequence overcurrent protection, etc. However, it still has limitations and cannot be widely used in power equipment. The linkage control function of its anti-power swing and overcurrent protection is low, and it cannot improve the anti-power swing capability on the power supply side and the overcurrent protection capability on the equipment load side. Summary of the invention

[0008] The purpose of the present invention is to overcome the shortcomings of existing anti-electrical sway devices and provide an anti-electrical sway and overcurrent protection linkage control device and its control method, so as to improve the anti-electrical sway capability on the power supply side and the overcurrent protection capability on the equipment load side, and can be applied to the anti-electrical sway and overcurrent protection of power equipment at the same time.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A power shaking prevention and overcurrent protection linkage control device, comprising a main power module connected to the power supply side, a backup power module connected to the main power module and charging the main power module, a CPU module connected to the main power module, a voltage and current signal acquisition and processing module connected to the CPU module, a relay switch and circuit breaker module connected to the CPU module, and a FRAM storage module connected to the CPU module;

[0011] The CPU module includes a CPU device and its peripheral circuits;

[0012] The main power supply module includes an AC-AC step-down circuit, an AC-DC step-down rectifier circuit, and a DC-DC step-down module circuit;

[0013] The backup power supply module includes a supercapacitor and a charging module circuit of the supercapacitor, and a DC-AC boost circuit;

[0014] The voltage and current signal acquisition and processing module includes a power supply side voltage signal acquisition module, a load side current signal acquisition module and a voltage and current signal processing module; the power supply side voltage acquisition module converts the sampling signal into an AC signal of 0-3.3V by measuring the voltage transformer and the operational amplifier circuit; the load side current signal acquisition module converts the sampling required signal into an AC signal of 0-3.3V by measuring the current transformer and the operational amplifier circuit; the voltage and current signal processing module includes an A / D chip and a voltage reference chip;

[0015] The relay switch and circuit breaker module includes a switch control circuit of the main power switch K1, a switch control circuit of the backup power charging switch K2, a switch control circuit of the backup power supply switch K3, an overcurrent control switch control circuit and a closing and opening coil;

[0016] The FRAM storage module includes a storage device and a peripheral circuit.

[0017] Further, the CPU module uses STM32F103C8T6 as the core processor, and uses the processor STM32F103C8T6 of the ARM architecture Cortex-M0 core to realize the operation of various functions. The CPU module has 48 pins, is powered by 3.3V voltage, is externally connected to an 8M quartz crystal oscillator, has an internal 12-bit ADC, SW2 is an external hardware reset button, and SWD is an interface for program download, which is used to realize data calculation and storage as well as control and interaction functions of other modules; in the peripheral circuit of the CPU, its 1, 24, 36, 48, and 9 pins are all 3.3V power access pins, 3.3V on pin 1 is connected to a Schottky diode MBR0520, and 3.3V on pin 9 is connected to two filter capacitors C132, C133, the other end is connected to pins 24, 36, 48 through magnetic bead L11, and these three pins are connected with 100nf filter capacitors C135, C136, C137 respectively; its 23, 35, 47, 8 pins are the ground pins of the CPU, and pins 5 and 6 are connected to pins 1 and 2 of a crystal oscillator Y6, and then to two capacitors C130 and C140 before connecting to the ground; port P19 is the serial port connected to pins 30 and 31 respectively, and P20 is the program burning port, which is connected to pull-up resistor R106 and pull-down resistor R108 respectively and then to pins 34 and 37; the reset button is connected to pin 7 of the CPU, with an external pull-up resistor R98, and a decoupling capacitor C120 connected to the ground; pins 20 and 44 of the CPU are connected to the ground respectively, and other used pins are brought out, and unused pins are retained.

[0018] Furthermore, the AC-AC step-down circuit includes a connector P15 for connecting the step-down circuit to a 380V-10KV power grid, an adjustable transformer T1 of model Trans Adj connected to the connector P15, and a connector P16 connected to the adjustable transformer T1. The 380V-10KV AC voltage is converted into a stable AC voltage of 220V through the step-down output of the adjustable transformer T1 through the connector P16.

[0019] Furthermore, the AC-DC step-down rectifier circuit is used to connect the 220V stable AC voltage to the fuse F1 and one side of the common-mode inductor Lf1 through the 2nd pin of the connector P17, and then connect it to the 1st pin of the rectifier module U1. The rectifier module U1 adopts the HenL AC220S12DC-20W rectifier module, and the 220V voltage is rectified to +12V through the rectifier module U1; wherein the 1st pin of the connector P17 is connected in parallel with the filter capacitors C94, C95 and the varistor Rv1, and the line connected to the 1st and 2nd pins of the rectifier module U1 is connected in parallel with the filter capacitor C91 and the varistor Rv2; the 4th pin of the rectifier module U1 is connected together with the inductor L8, the resistor R74, and the cathode end of the diode D11 through the diode D9; the models of the diodes D9 and D11 are IN4 007; Pin 5 of the rectifier module U1 is directly grounded, and the forward end of the diode D11 outputs a +12V voltage signal; a reversely connected diode D10 is connected between pins 4 and 5 of the rectifier module U1. The model of the voltage stabilizing diode D10 is 1N4742, and the rated power is +12V, which plays a role in stabilizing the output voltage; Pins 4 and 5 of the rectifier module U1 output a stable +12V DC voltage, which is input into the DC-DC buck circuit and the energy storage control circuit after filtering and protection by the inductor, resistor and diode.

[0020] Furthermore, the DC-DC step-down module circuit includes a main chip of model RT7272BGSP and an LDO linear voltage regulator circuit. Pin 8 of the main chip is connected to 12V, pin 7 is connected to a pull-down resistor R83 and then to ground, and then three 10uF filter capacitors C102, C100, and C101 are connected in parallel between pins 7 and 8; a 100nFC99 capacitor and a 24K resistor R85 are connected in series between pin 6 and ground; pin 5 is connected to an 11.8K pull-down resistor R84; pin 4 is directly grounded; pin 3 is connected to a 100K pull-up resistor R79 and then to 12V; pin 2 is connected in series with a 100nF capacitor C98 and then connected to pin 1, and then connected in series with a 6.8uH power inductor L9, and then connected to a 62K pull-down resistor R82. At this time, the voltage has dropped to 5V, and then two filter capacitors C103 and C101 are connected to ground. 04 and TVS diode D12; then two capacitors C112 and C111 are connected in parallel, and finally connected to pins 3 and 1 of chip AMS1117-3.3 respectively; this circuit reduces the DC 12V voltage to a stable DC 5V voltage, and outputs it to the lower-level LDO linear voltage regulator circuit, which has a buffering effect on other circuits; the LDO linear voltage regulator circuit includes a voltage regulator chip of model AMS1117-3.3, and pins 2 and 4 of the voltage regulator chip are connected in series. At this time, the voltage has been converted to 3.3V, and a voltage regulator diode D13 is connected in parallel with the ground. The two filter capacitors C113 and C114 are finally connected in parallel with the power indicator light D14, and the indicator light is connected in series with a voltage divider resistor R93. The final output voltage of this circuit is used to provide stable power supply to the CPU module and other modules, which can ensure the normal and stable operation of the circuit.

[0021] Furthermore, the backup power supply module includes a supercapacitor and a charging module circuit of the supercapacitor. In order to ensure the safety, stability and efficiency of charging the supercapacitor, a LT3741DC-DC chip is used as a buffer. The input pin VIN of the chip is powered by 12V, and two conventional capacitors are connected in parallel between the pin and the ground for filtering protection; the gate drive signal pin HG is connected to a MOS tube with 12V to buffer the voltage, and CTRL2 is externally connected to a pull-down resistor for reducing the thermal control input of the regulating current level; the soft start pin SS is grounded through an external capacitor to limit the regulating current; the RT pin is externally connected to a pull-down resistor to set the switching frequency at 200KHz to 1MHz The current limit of this pin is 60μA; the VC pin is connected to a 47.5K compensation resistor and a 4.7nF compensation capacitor; the above external circuit is the limitation and protection circuit of the module; the following circuit is the output circuit, the CBOOT pin provides a 5V regulated power supply for the high-end FET driver, and when the switch pin is close to the ground, the CBOOT capacitor is charged from the VIN pin to the CBOOT pin through an external Schottky diode; LG is the ground FET gate drive signal, and an external MOS tube is used to control the state of the low-side external power FET; SENSE+ is the inverting input of the average current mode error amplifier, and this pin is connected to the detection resistor R71; SENSE The voltage drop between + and SENSE generates the input voltage of the current regulation loop; SENSE– is the non-inverting input loop error amplifier of the average current mode; the reference current based on CTRL1 or CTRL2 flows out of the pin and flows to the output side of the detection resistor R71; FB is the feedback pin for voltage regulation and overvoltage protection. The feedback voltage is 1.21V. Overvoltage is also detected through the FB pin. When the feedback voltage exceeds 1.5V, the overvoltage lock will prevent switching for 13μs to allow the inductor current to discharge. The stepped-down electrical signal flowing through the detection resistor charges the supercapacitor through two 150uf filter capacitors.

[0022] Furthermore, in the DC-AC boost circuit, when the power supply shakes, the backup power supply needs to perform DC-AC boost to supply power to the load. The 5V DC power is connected to the 15 and 13 pins of the boost chip CW3525A through an electric fuse to supply power to the chip and then directly pass through the sliding transformer; IN-, IN+, V-REF, Rt, Ct, SS, and COMP are used as protection circuits and limiting circuits to connect external pull-down resistors and capacitors respectively. OUT-A and OUT-B are the output ends of the chip to convert the voltage from DC to AC and transmit it to the sliding resistor with a small boost. The sliding transformer has obtained 220V AC according to the required adjustment, and the rectifier bridge filters out the DC power, so that the 220V AC power generated by the module is a purer sine wave.

[0023] Furthermore, the power supply side voltage signal acquisition module includes a signal conversion and signal processing module. The 220V AC is connected to the 1 and 2 pins of the voltage transformer T2 through four identical resistors R99, R100, R102, and R103. The converted signal comes out from the 3 and 4 pins of the voltage transformer. On the one hand, the 3 pin is connected to the ground through the 0 ohm resistor R107, and on the other hand, it is connected to the 2 pin of the operational amplifier AD623 through the resistor R105. The 4 pin is connected to the pin 3 of the operational amplifier AD623 through the resistor R101. A decoupling capacitor C122 is added between the 3 and 4 pins of the voltage transformer T2, and is connected to the 1 and 2 pins of the operational amplifier AD623 respectively. Filter capacitors C121 and C124 are connected to ground; pin 7 of operational amplifier AD623 is connected to a 3.3V voltage, pin 4 is grounded, and an adjustable resistor RP2 is connected between pins 8 and 1; pin 6 is an output pin, and the sorted signal is output to the signal processing circuit through a resistor R104 and a capacitor C123; this circuit uses a voltage transformer to reduce the signal of 220V AC, and then an operational amplifier AD623 is used to sort the signal. After the voltage signal is input, the signal is filtered by a low-pass filter, and the output end of the operational amplifier is connected to the ADC acquisition chip, and the adjustable resistor adjusts the signal amplification factor.

[0024] Further, in the load side current signal acquisition module, the port of connector P21 receives the current signal after passing through the current transformer, the resistor R112 is a sampling resistor, the pin 1 of connector P21 is connected to the pin 1 of the operational amplifier LMV358 through the RC filter circuit and the resistor R111, the current signal passes through the RC filter circuit, and then passes through the resistor R111 to the pin 1 of the operational amplifier LMV358; the pin 2 of connector P21 passes through the RC filter circuit and the 0 ohm resistor to the ground; the operational amplifier LMV358 enables the generated signal to be raised and amplified, its pin 8 is powered by a 5V power supply, and the pin 4 is grounded, and the 5V DC power passes through two filter capacitors C138 and C139 to the ground on the one hand, and passes through the inductor L12 and the resistor R117 to the operational amplifier on the other hand. Put it on pin 5 of LMV358, and pin 5 is connected to the ground by two identical resistors R118 and R119 and a capacitor C134. Pins 6 and 7 are directly connected and output to pin 3 through an RC filter. Pin 2 is connected to pin 1 through resistor R109 in series with resistor R111 and parallel with capacitor C126, and superimposed with the current signal, and output to the signal acquisition circuit through resistor R114 and parallel with capacitor C129; the first stage of the operational amplifier in this circuit is a voltage follower, and the next stage is a Sallen-Key filter. The rightmost wire is the input interface of the leakage current, and resistor R54 is a sampling resistor. After the current signal is input, it is filtered by a low-pass filter, and then superimposed with the DC voltage of the operational amplifier to raise the negative half axis of the signal to the positive half axis.

[0025] Furthermore, in the voltage and current signal processing module, pins 2 and 3 of the electrical signal processing chip TM7705 are used to connect the crystal oscillator module, first a 1M resistor R89 ​​is connected in parallel, then a 4.9152M crystal oscillator is connected in parallel, and finally a 30pF capacitor is connected in series and then grounded, pins 7 and 8 are connected to the voltage signal acquisition module, pins 6 and 11 are connected to the current signal acquisition module, a 1K pull-up resistor R80 is connected in series between pin 5 and the 3.3V voltage, and a 10nF pull-down capacitor GND is connected in series between pin 5 and the ground, pins 16 and 10 are grounded, pins 9 and 15 are connected to 3.3V, pins 1, 4, 14, and 13 are used as SPI communication, only pin 4 is connected to the pull-down resistor to default the communication mode to SPI, and the rest are connected to pins 26, 28, and 27 of the central processor STM32F103C8T6, pin 12 is connected to pin 25 of the central processor, and the voltage reference chip REF3033 Pin 1 is connected to 5V and then a 10uF / 16V electrolytic capacitor +CE2 is connected between it and the ground; pin 2 is connected to 3.3V and then a 10nF filter capacitor C118 is connected between it and the ground; three 10nF decoupling capacitors C115, C116, and C117 are connected in parallel between 5V and the ground; this circuit consists of a voltage reference chip REF3033 and an ADC chip TM7705. The voltage reference chip can stabilize the reference voltage of the ADC at a fixed value.

[0026] Furthermore, in the FRAM storage module, pins 1, 2, 3, 4, and 7 of the FRAM storage chip FM24CL64 are all grounded, pin 8 is connected to a 3.3V power supply, and a 100nF filter capacitor C83 is connected in series between the power supply and the ground of the storage chip; pins 5 and 6 are respectively connected to pins 42 and 43 of the central processor STM32F103C8T6 and are each connected to a 4.7K pull-up resistor R69 and R70; this circuit uses a FRAM storage chip FM24CL64 to store the collected signal waveform and other data. The FRAM storage chip FM24CL64 is powered by an external 3.3V DC voltage and uses the IIC communication protocol to exchange data with the CPU. The chip can be erased an unlimited number of times, and the saved data will not be lost during power failure. The storage size is 64KBit.

[0027] Furthermore, the relay switch and circuit breaker module includes four relay modules JQC-3FF-SZ, which are used as a controllable switch to control the on and off of DC and AC power using the GPIO pins of the single-chip microcomputer; they are respectively used as the operating power control switch K1, the backup power charging switch K2, the backup power discharging switch K3, and the overcurrent control switch; at the same time, the circuit breaker is used to control the on and off of the power supply of the equipment. If the equipment encounters an overcurrent situation, the CPU controls the relay switch to disconnect the coil power supply controlled by the circuit breaker, and then controls the main contacts of the circuit breaker to disconnect.

[0028] A method for controlling the linkage between power sway protection and overcurrent protection, comprising the following steps:

[0029] Step 1), in normal operation, the K1 switch that controls the operating power supply of the circuit breaker in the anti-power sway module is closed, the operating power supply is powered normally, the K2 that controls the charging of the backup power supply is closed, the backup charging power supply is charged normally, and the K3 that connects the operating power supply with the backup charging power supply is disconnected;

[0030] Step 2), calculate the effective value of the voltage on the power supply side and the effective value of the current on the load side. If the voltage change on the power supply side exceeds the value, the anti-power sway module is activated; if the voltage change on the power supply side does not exceed the value but the current change on the load side exceeds the value, the overcurrent protection module is activated;

[0031] Step 3), after starting the anti-power sway module, immediately and quickly put the backup charging power supply K3 connected to the operating power supply into use, put the backup power supply into use as the operating power supply of the circuit breaker, and quickly disconnect the K1 control switch of the operating power supply and the K2 charging switch of the charging power supply, turn on the backup charging power supply input timer for timing, and then determine whether the load side current value exceeds the value. If the load side current does not exceed the value, the backup charging power supply continues to be put into operation, and the timer continues to count. After reaching a reasonably set time limit, the backup charging power supply is automatically returned, the timer returns to zero, and the anti-power sway counter records the number of times, and returns to step 1) to continue monitoring and diagnosis; if the fault characteristics on the load side are obvious and the current value exceeds the set value, the circuit breaker is immediately tripped, and the control switch K3 is disconnected to exit the backup charging power supply, completing the protection of the load side once, the protection counter is increased by 1, and the protection alarm locking function is started, and returns to step 1) to continue monitoring and diagnosis;

[0032] Step 4) After starting the overcurrent protection module, continuously calculate and determine whether the fault characteristics and overcurrent value on the load side exceed the set value and the corresponding protection time limit. If it exceeds the value, the protection immediately disconnects the circuit breaker, starts the protection alarm locking function, and returns to step 1) to continue calculation and judgment; if it does not exceed the value or the time limit is not reached, keep the fault start mark, return to step 1) to continue calculation and judgment.

[0033] Furthermore, in step 2), the calculation criterion for the voltage change is:

[0034] (1)

[0035] is the relative change in voltage, is the rated value of the power supply line, is the RMS calculation value of the current voltage half cycle, is the allowable value of voltage fluctuation, It is the duration of continuous shaking after the voltage exceeds the value. It is the set value for the allowed time of continuous voltage fluctuation after the voltage exceeds the value.

[0036] Furthermore, in step 3), after the anti-power-sway module is started, the duration of automatic switching on of the backup power supply is set according to the characteristics of the load.

[0037] Furthermore, in step 4), after the protection module is started, the criterion for the protection output tripping is:

[0038] (2) or (3)

[0039] The current effective value of the current is: The minimum short-circuit current value at the end of the load line when the power supply system is in the minimum operating mode. Reliability coefficient, All load current values ​​of this load line when the power supply system is in maximum operation mode, Overload reliability factor, Exceeding the set value After the duration, Exceeding the set value The allowed duration setting after.

[0040] The present invention has the following positive effects:

[0041] The present invention discloses a linkage control device for preventing power sway and overcurrent protection and a control method thereof. The device can monitor the voltage characteristics of the power supply side and the current characteristics of the load side. When power sway occurs on the power supply side, in order to maintain the continuity of the load side voltage and prevent the circuit breaker operating circuit from tripping due to power sway, the anti-power sway conversion part is immediately put into operation, and the backup charging power supply is automatically switched to provide operating power to the circuit breaker. At the same time, it is immediately detected and determined whether there are fault characteristics on the load side. If there are no fault characteristics, the anti-power sway conversion part continues to be put into operation. If there are fault characteristics and it is determined that the power sway is caused by the load side, the anti-power sway conversion part is immediately tripped, and the circuit breaker is immediately tripped, so as to avoid the failure to cut off the fault in time due to the delayed tripping of the anti-power sway circuit breaker, resulting in greater fault damage on the load side and causing the power supply on the system side to shake. When there is no power sway on the power supply but it is detected that there are fault characteristics on the load side and the fault current exceeds the value, the circuit breaker is immediately tripped to cut off the faulty equipment.

[0042] Therefore, the present invention has the advantages of effectively preventing the influence of power swings on the system side on the equipment on the load side, and also preventing the voltage swing on the power supply side caused by the inability to timely eliminate the fault on the load side. It will not affect the safe operation of the equipment on the adjacent side, and is beneficial to improving the selectivity and reliability of the current anti-power swing device, and preventing the influence of the anti-power swing device on the system's rapid elimination of faulty components. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural block diagram and wiring diagram of the load-side overcurrent protection and power-side anti-sway control device of the present invention.

[0044] Figure 2 It is a control program determination flow chart of the present invention.

[0045] Figure 3 It is a schematic diagram of the control circuit structure of the present invention.

[0046] Figure 4 It is a peripheral circuit diagram of the CPU of the present invention.

[0047] Figure 5 It is the AC-AC step-down circuit diagram of the present invention.

[0048] Figure 6 The AC-DC step-down rectifier circuit diagram of the present invention.

[0049] Figure 7 This is a circuit diagram of a DC-DC step-down module of the present invention.

[0050] Figure 8 This is the LDO linear voltage stabilization circuit diagram of the present invention.

[0051] Fig. 9 It is a circuit diagram of the supercapacitor of the backup power module and the charging module of the supercapacitor of the present invention.

[0052] Fig.10 This is a diagram of a DC-AC boost circuit (220V AC inverter circuit) of the present invention.

[0053] Fig.11 This is a circuit control diagram of the power supply side voltage signal acquisition module of the present invention.

[0054] Fig.12 This is a circuit control diagram of the load side current signal acquisition module of the present invention.

[0055] Fig.13 This is a circuit control diagram of the voltage and current signal processing module of the present invention.

[0056] Fig.14 FIG. 4 is a storage circuit diagram of the FRAM storage module of the present invention.

[0057] Fig.15 It is a schematic diagram of a circuit breaker in the relay switch control and circuit breaker control circuit of the present invention.

[0058] Fig.16 It is a schematic diagram of the operating power switch K1 in the relay switch control and circuit breaker control circuit of the present invention.

[0059] Fig.17It is a schematic diagram of the backup power supply charging switch K2 in the relay switch control and circuit breaker control circuit of the present invention.

[0060] Fig.18 It is a schematic diagram of the standby power supply discharge switch K3 in the relay switch control and circuit breaker control circuit of the present invention.

[0061] Fig.19 It is a schematic diagram of an overcurrent control switch in a relay switch control and circuit breaker control circuit of the present invention. DETAILED DESCRIPTION

[0062] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0063] Embodiment 1, as Figure 1 , 3 As shown, the present invention discloses an anti-power shaking and overcurrent protection linkage control device, comprising a main power module connected to the power supply side, a backup power module connected to the main power module and charging the main power module, a CPU module connected to the main power module, a voltage and current signal acquisition and processing module connected to the CPU module, a relay switch and circuit breaker module connected to the CPU module, and a FRAM storage module connected to the CPU module.

[0064] The CPU module includes a CPU device and its peripheral circuits;

[0065] The main power supply module includes an AC-AC step-down circuit, an AC-DC step-down rectifier circuit, and a DC-DC step-down module circuit;

[0066] The backup power supply module includes a supercapacitor and a charging module circuit of the supercapacitor, and a DC-AC boost circuit;

[0067] The voltage and current signal acquisition and processing module includes a power supply side voltage signal acquisition module, a load side current signal acquisition module and a voltage and current signal processing module; the power supply side voltage acquisition module converts the sampling signal into an AC signal of 0-3.3V by measuring the voltage transformer and the operational amplifier circuit; the load side current signal acquisition module converts the sampling required signal into an AC signal of 0-3.3V by measuring the current transformer and the operational amplifier circuit; the voltage and current signal processing module includes an A / D chip and a voltage reference chip;

[0068] The relay switch and circuit breaker module includes a switch control circuit of the main power switch K1, a switch control circuit of the backup power charging switch K2, a switch control circuit of the backup power supply switch K3, an overcurrent control switch control circuit and a closing and opening coil;

[0069] The FRAM storage module includes a storage device and a peripheral circuit.

[0070] like Figure 4 As shown, the CPU module uses STM32F103C8T6 as the core processor, and uses the processor STM32F103C8T6 of the ARM architecture Cortex-M0 core to realize the operation of various functions. The CPU module has 48 pins, is powered by a 3.3V voltage, is externally connected to an 8M quartz crystal oscillator, has an internal 12-bit ADC, SW2 is an external hardware reset button, and SWD is an interface for program download, which is used to realize data calculation, processing and storage as well as control and interaction functions of other modules; in the peripheral circuit of the CPU, its 1, 24, 36, 48, and 9 pins are all 3.3V power access pins, 3.3V on pin 1 is connected to a Schottky diode MBR0520, and 3.3V on pin 9 is connected to two filter capacitors C 132, C133, the other end is connected to the 24, 36, 48 pins through the magnetic bead L11, and these 3 pins are respectively connected with 100nf filter capacitors C135, C136, C137; its 23, 35, 47, 8 pins are the ground pins of the CPU, and the 5 and 6 pins are connected to the 1 and 2 pins of a crystal oscillator Y6, and then to two capacitors C130 and C140 and then to the ground; the P19 port is the serial port connected to the 30 and 31 pins respectively, and the P20 is the program burning port, which is respectively connected to the pull-up resistor R106 and the pull-down resistor R108 and then to the 34 and 37 pins; the reset button is connected to the 7 pin of the CPU, and an external pull-up resistor R98 is connected, and a decoupling capacitor C120 is connected to the ground; the 20 and 44 pins of the CPU are connected to the ground respectively, and the other used pins are brought out, and the unused pins are retained.

[0071] like Figure 5 As shown, the AC-AC step-down circuit includes a connector P15 for connecting the step-down circuit to a 380V-10KV power grid, an adjustable transformer T1 of model Trans Adj connected to the connector P15, and a connector P16 connected to the adjustable transformer T1. The 380V-10KV AC voltage is converted into a stable AC voltage of 220V through the step-down output of the adjustable transformer T1 through the connector P16.

[0072] like Figure 6As shown, the AC-DC step-down rectifier circuit is used to connect the 220V stable AC voltage to the fuse F1 and one side of the common mode inductor Lf1 through the 2nd pin of the connector P17, and then connect it to the 1st pin of the rectifier module U1. The rectifier module U1 adopts the HenL AC220S12DC-20W rectifier module, and the 220V voltage is rectified to +12V through the rectifier module U1; wherein the 1st pin of the connector P17 is connected in parallel with the filter capacitors C94, C95 and the varistor Rv1, and the line connected to the 1st and 2nd pins of the rectifier module U1 is connected in parallel with the filter capacitor C91 and the varistor Rv2; the 4th pin of the rectifier module U1 is connected together with the inductor L8, the resistor R74, and the cathode end of the diode D11 through the diode D9; the models of the diodes D9 and D11 are IN4 007; Pin 5 of the rectifier module U1 is directly grounded, and the forward end of the diode D11 outputs a +12V voltage signal; a reversely connected diode D10 is connected between pins 4 and 5 of the rectifier module U1. The model of the voltage stabilizing diode D10 is 1N4742, and the rated power is +12V, which plays a role in stabilizing the output voltage; Pins 4 and 5 of the rectifier module U1 output a stable +12V DC voltage, which is input into the DC-DC buck circuit and the energy storage control circuit after filtering and protection by the inductor, resistor and diode.

[0073] like Figure 7 As shown, the DC-DC step-down module circuit includes a main chip of model RT7272BGSP and an LDO linear voltage regulator circuit. The 8th pin of the main chip is connected to 12V, the 7th pin is connected to the pull-down resistor R83 and then to the ground, and then three 10uF filter capacitors C102, C100, and C101 are connected in parallel between the 7th and 8th pins; a 100nFC99 capacitor and a 24K resistor R85 are connected in series between the 6th pin and the ground; the 5th pin is connected to the 11.8K pull-down resistor R84; the 4th pin is directly grounded; the 3rd pin is connected to the 100K pull-up resistor R79 and then to 12V; the 2nd pin is connected in series A 100nF capacitor C98 is connected to pin 1, and then connected in series with a 6.8uH power inductor L9, and then connected to a 62K pull-down resistor R82. At this time, the voltage has dropped to 5V, and then two filter capacitors C103 and C104 and a TVS diode D12 are connected between the ground; then two capacitors C112 and C111 are connected in parallel, and finally connected to pins 3 and 1 of the chip AMS1117-3.3 respectively; this circuit reduces the DC 12V voltage to a stable DC 5V voltage, and outputs it to the lower-level LDO linear voltage regulator circuit, which has a buffering effect on other circuits;

[0074] like Figure 8As shown, the LDO linear voltage regulator circuit includes a voltage regulator chip model AMS1117-3.3. Pin 2 and pin 4 of the voltage regulator chip are connected in series. At this time, the voltage has been converted to 3.3V. A voltage regulator diode D13 is connected in parallel with the ground. Two filter capacitors C113 and C114 are finally connected in parallel with the power indicator light D14, and the indicator light is connected in series with a voltage divider resistor R93. The final output voltage of this circuit is used to provide stable power supply to the CPU module and other modules, which can ensure the normal and stable operation of the circuit.

[0075] like Fig. 9 As shown, the backup power supply module includes a supercapacitor and a charging module circuit of the supercapacitor. In order to ensure the safety, stability and efficiency of charging the supercapacitor, a LT3741DC-DC chip is used as a buffer. The input pin VIN of the chip is powered by 12V, and two conventional capacitors are connected in parallel between the pin and the ground for filtering protection; the gate drive signal pin HG is connected to a MOS tube with 12V to buffer the voltage, and CTRL2 is externally connected to a pull-down resistor for reducing the thermal control input of the adjustment current level; the soft start pin SS is grounded through an external capacitor to limit the adjustment current; the RT pin is externally connected to a pull-down resistor to set the switching frequency between 200KHz and 1MHz The current limit of this pin is 60μA; the VC pin is connected to a 47.5K compensation resistor and a 4.7nF compensation capacitor; the above external circuit is the limitation and protection circuit of the module; the following circuit is the output circuit, the CBOOT pin provides a 5V regulated power supply for the high-end FET driver, and when the switch pin is close to the ground, the CBOOT capacitor is charged from the VIN pin to the CBOOT pin through an external Schottky diode; LG is the ground FET gate drive signal, and an external MOS tube is used to control the state of the low-side external power FET; SENSE+ is the inverting input of the average current mode error amplifier, and this pin is connected to the detection resistor R71; SENSE The voltage drop between + and SENSE generates the input voltage of the current regulation loop; SENSE– is the non-inverting input loop error amplifier of the average current mode; the reference current based on CTRL1 or CTRL2 flows out of the pin and flows to the output side of the detection resistor R71; FB is the feedback pin for voltage regulation and overvoltage protection. The feedback voltage is 1.21V. Overvoltage is also detected through the FB pin. When the feedback voltage exceeds 1.5V, the overvoltage lock will prevent switching for 13μs to allow the inductor current to discharge. The stepped-down electrical signal flowing through the detection resistor charges the supercapacitor through two 150uf filter capacitors.

[0076] like Fig.10As shown, in the DC-AC boost circuit, when the power supply shakes, the backup power supply needs to perform DC-AC boost to supply power to the load. The 5V DC is connected to the 15 and 13 pins of the boost chip CW3525A through an electric fuse to supply power to the chip and then directly pass through the sliding transformer; IN-, IN+, V-REF, Rt, Ct, SS, COMP are used as protection circuits and limiting circuits to connect external pull-down resistors and capacitors respectively. OUT-A and OUT-B are the output ends of the chip to convert the voltage from DC to AC and transmit it to the sliding resistor with a small boost. The sliding transformer has obtained 220V AC according to the required adjustment, and the rectifier bridge filters out the DC, so that the 220V AC generated by the module is a purer sine wave.

[0077] like Fig.11 As shown, the power supply side voltage signal acquisition module includes a signal conversion and signal processing module. The 220V AC is connected to the 1 and 2 pins of the voltage transformer T2 through four identical resistors R99, R100, R102, and R103. The converted signal comes out from the 3 and 4 pins of the voltage transformer. On the one hand, the 3 pin is connected to the ground through the 0 ohm resistor R107, and on the other hand, it is connected to the 2 pin of the operational amplifier AD623 through the resistor R105. The 4 pin is connected to the pin 3 of the operational amplifier AD623 through the resistor R101. A decoupling capacitor C122 is added between the 3 and 4 pins of the voltage transformer T2, and is connected to There are filter capacitors C121 and C124 connected to the ground; pin 7 of the operational amplifier AD623 is connected to a 3.3V voltage, pin 4 is grounded, and an adjustable resistor RP2 is connected between pins 8 and 1; pin 6 is an output pin, and the sorted signal is output to the signal processing circuit through a resistor R104 and a capacitor C123; this circuit uses a voltage transformer to reduce the signal of 220V AC, and then an operational amplifier AD623 is used to sort the signal. After the voltage signal is input, the signal is filtered by a low-pass filter, and the output end of the operational amplifier is connected to the ADC acquisition chip, and the adjustable resistor adjusts the signal amplification factor.

[0078] like Fig.12As shown, in the load side current signal acquisition module, the port of connector P21 receives the current signal after passing through the current transformer, the resistor R112 is a sampling resistor, the 1-pin of connector P21 is connected to the 1-pin of the operational amplifier LMV358 through the RC filter circuit and the resistor R111, the current signal passes through the RC filter circuit, and then passes through the resistor R111 to the 1-pin of the operational amplifier LMV358; the 2-pin of connector P21 passes through the RC filter circuit and the 0 ohm resistor to the ground; the operational amplifier LMV358 enables the generated signal to be raised and amplified, its 8-pin is powered by a 5V power supply, and the 4-pin is grounded, and the 5V DC power passes through two filter capacitors C138 and C139 to the ground on the one hand, and passes through the inductor L12 and the resistor R117 to the operational amplifier on the other hand. Pin 5 of LMV358 is connected to the ground by two identical resistors R118 and R119 and a capacitor C134. Pins 6 and 7 are directly connected and output to pin 3 through an RC filter. Pin 2 is connected to pin 1 through resistor R109 in series with resistor R111 and in parallel with capacitor C126, where it is superimposed with the current signal and output to the signal acquisition circuit through resistor R114 and in parallel with capacitor C129. The first stage of the operational amplifier in this circuit is a voltage follower, and the second stage is a Sallen-Key filter. The rightmost wire is the input interface of the leakage current. Resistor R54 is a sampling resistor. After the current signal is input, it is filtered by a low-pass filter and then superimposed with the DC voltage of the operational amplifier to raise the negative half axis of the signal to the positive half axis.

[0079] like Fig.13As shown, in the voltage and current signal processing module, the 2nd and 3rd pins of the electrical signal processing chip TM7705 are used to connect the crystal oscillator module, first connect a 1M resistor R89 ​​in parallel, then connect a 4.9152M crystal oscillator in parallel, and finally connect a 30pF capacitor in series and then ground, the 7th and 8th pins are connected to the voltage signal acquisition module, the 6th and 11th pins are connected to the current signal acquisition module, the 5th pin is connected in series with the 3.3V voltage with a 1K pull-up resistor R80, and the ground is connected in series with a 10nF pull-down capacitor GND, the 16th and 10th pins are grounded, the 9th and 15th pins are connected to 3.3V, the 1st, 4th, 14th and 13th pins are used as SPI communication, only the 4th pin is connected to the pull-down resistor to set the communication mode to SPI by default, the rest are connected to the 26th, 28th and 27th pins of the central processor STM32F103C8T6, the 12th pin is connected to the 25th pin of the central processor, and the voltage reference chip REF3033 Pin 1 is connected to 5V and then a 10uF / 16V electrolytic capacitor +CE2 is connected between it and the ground; pin 2 is connected to 3.3V and then a 10nF filter capacitor C118 is connected between it and the ground; three 10nF decoupling capacitors C115, C116, and C117 are connected in parallel between 5V and the ground; this circuit consists of a voltage reference chip REF3033 and an ADC chip TM7705. The voltage reference chip can stabilize the reference voltage of the ADC at a fixed value.

[0080] like Fig.14 As shown, in the FRAM storage module, pins 1, 2, 3, 4, and 7 of the FRAM storage chip FM24CL64 are all grounded, pin 8 is connected to a 3.3V power supply, and a 100nF filter capacitor C83 is connected in series between the power supply and the ground of the storage chip; pins 5 and 6 are respectively connected to pins 42 and 43 of the central processor STM32F103C8T6 and are each connected to a 4.7K pull-up resistor R69 and R70; this circuit uses a FRAM storage chip FM24CL64 to store the collected signal waveform and other data. The FRAM storage chip FM24CL64 is powered by an external 3.3V DC voltage and uses the IIC communication protocol to exchange data with the CPU. The chip can be erased an unlimited number of times, and the saved data will not be lost when the power is off. The storage size is 64K Bit.

[0081] like Figure 15-19As shown, the relay switch and circuit breaker module includes four relay modules JQC-3FF-SZ, which are used as a controllable switch to control the on and off of DC and AC power using the GPIO pins of the single-chip microcomputer; they are respectively used as the operating power control switch K1, the backup power charging switch K2, the backup power discharging switch K3, and the overcurrent control switch; at the same time, the circuit breaker is used to control the on and off of the power supply of the equipment. If the equipment encounters an overcurrent situation, the CPU controls the relay switch to disconnect the coil power supply controlled by the circuit breaker, thereby controlling the main contacts of the circuit breaker to be disconnected.

[0082] like Figure 2 , 3 As shown, a method for controlling the linkage between power sway protection and overcurrent protection includes the following steps:

[0083] Step 1), in normal operation, the K1 switch that controls the operating power supply of the circuit breaker in the anti-power sway module is closed, the operating power supply is powered normally, the K2 that controls the charging of the backup power supply is closed, the backup charging power supply is charged normally, and the K3 that connects the operating power supply with the backup charging power supply is disconnected;

[0084] Step 2), calculate the effective value of the voltage on the power supply side and the effective value of the current on the load side. If the voltage change on the power supply side exceeds the value, the anti-power sway module is activated; if the voltage change on the power supply side does not exceed the value but the current change on the load side exceeds the value, the overcurrent protection module is activated;

[0085] Step 3), after starting the anti-power sway module, immediately and quickly put the backup charging power supply K3 connected to the operating power supply into use, put the backup power supply into use as the operating power supply of the circuit breaker, and quickly disconnect the K1 control switch of the operating power supply and the K2 charging switch of the charging power supply, turn on the backup charging power supply input timer for timing, and then determine whether the load side current value exceeds the value. If the load side current does not exceed the value, the backup charging power supply continues to be put into operation, and the timer continues to count. After reaching a reasonably set time limit, the backup charging power supply is automatically returned, the timer returns to zero, and the anti-power sway counter records the number of times, and returns to step 1) to continue monitoring and diagnosis; if the fault characteristics on the load side are obvious and the current value exceeds the set value, the circuit breaker is immediately tripped, and the control switch K3 is disconnected to exit the backup charging power supply, completing the protection of the load side once, the protection counter is increased by 1, and the protection alarm locking function is started, and returns to step 1) to continue monitoring and diagnosis;

[0086] Step 4) After starting the overcurrent protection module, continuously calculate and determine whether the fault characteristics and overcurrent value on the load side exceed the set value and the corresponding protection time limit. If it exceeds the value, the protection immediately disconnects the circuit breaker, starts the protection alarm locking function, and returns to step 1) to continue calculation and judgment; if it does not exceed the value or the time limit is not reached, keep the fault start mark, return to step 1) to continue calculation and judgment.

[0087] In step 2), the calculation criterion for the voltage change is:

[0088] (1)

[0089] is the relative change in voltage, is the rated value of the power supply line, is the RMS calculation value of the current voltage half cycle, is the allowable value of voltage fluctuation, It is the duration of continuous shaking after the voltage exceeds the value. It is the set value for the allowed time of continuous voltage fluctuation after the voltage exceeds the value.

[0090] In step 3), after the anti-power sway module is started, the duration of automatic switching on of the backup power supply is set according to the characteristics of the load.

[0091] In step 4), after the protection module is started, the criterion for the protection output tripping is:

[0092] (2) or (3)

[0093] The current effective value of the current is: The minimum short-circuit current value at the end of the load line when the power supply system is in the minimum operating mode. Reliability coefficient, All load current values ​​of this load line when the power supply system is in maximum operation mode, Overload reliability factor, Exceeding the set value After the duration, Exceeding the set value The allowed duration setting after.

[0094] The present invention adopts STM32F103C8T6 as a core processor, and adds a main power module circuit, a backup power module part, a voltage signal acquisition part, a current signal acquisition part, a voltage and current signal processing part (also called an ADC acquisition part), a relay control switch part, and a FRAM storage part circuit to form a system that can realize protection against power shaking and overcurrent.

[0095] During normal operation, the high voltage of the main power supply is converted into 220V AC through an adjustable transformer. On the one hand, this voltage is converted into 12V DC through the AC-DC chip and its peripheral circuits, and then stepped down to 5V through the DC-DC and LDO chips. The 3.3V DC is used to power the CPU and other circuits normally. On the other hand, this voltage is converted into a small AC signal through a voltage transformer, which enables the ADC acquisition circuit to detect whether a power shake occurs. When a power shake occurs on the main power supply side, the CPU detects that there is a power shake, and the CPU quickly disconnects the operation control switch K1 and the backup power supply charging switch K2, closes the backup power supply discharge switch K3, and stores the collected power shake data in the FRAM. When an overcurrent occurs on the load side, the ADC detects that the current is too large and transmits it to the CPU. The CPU quickly disconnects the overcurrent control switch, and the coil power supply in the circuit breaker is cut off. At the same time, the main contacts of the circuit breaker will be disconnected, cutting off the main power supply.

[0096] The CPU module uses the STM32F103C8T6 processor with the ARM Cortex-M0 core to implement the operation of various functions. The CPU has 48 pins, is powered by a 3.3V voltage, is externally connected to an 8M quartz crystal oscillator, has an internal 12-bit ADC, SW2 is an external hardware reset button, and SWD is the interface for program downloading;

[0097] The main power module uses an adjustable transformer to convert the voltage of 380V-10KV to 220V, and then converts the 220V AC power to 12V DC power through an AC-DC chip AC220S12DC-20W and its peripheral circuits. Finally, the DC-DC chip RT7272B and the LDO chip AMS1117-3.3 are used to reduce the 12V voltage to 5V and 3.3V to power the CPU and other IC modules; the backup power module uses a supercapacitor as a backup power source. When charging the supercapacitor, a DC-DC chip LT3741E that can generate a large current and its peripheral circuits are used to reduce the 12V DC voltage to 5V DC voltage. When discharging, a DC-AC chip CW3525A and its peripheral circuits convert the 5V DC power into 220V AC power to power the circuit breaker or equipment end. The 12V-2 voltage here is derived from the 12V-1 DC power generated by the main power supply. The relay switch is used to control their conduction to control when the capacitor is charged and discharged. The relay switch control module uses four relay modules JQC-3FF-SZ, which can be used as a controllable switch. The GPIO pins of the microcontroller can control the on and off of DC and AC power. They are used as the operating power control switch K1, the backup power charging switch K2, the backup power discharging switch K3, and the overcurrent control switch. The circuit also involves a circuit breaker to control the on and off of the power supply of the equipment. If the equipment encounters an overcurrent situation, the CPU controls the relay switch to disconnect the power supply of the coil controlled by the circuit breaker, and then controls the main contacts of the circuit breaker to disconnect; the voltage acquisition module uses a voltage transformer to reduce the signal of 220V AC, and then an operational amplifier AD623 is used to sort the signal. After the small voltage signal is input, the low-pass filter filters the signal, and the output end of the operational amplifier is connected to the ADC acquisition chip. The RP1 adjustable resistor can adjust the amplification factor; the current acquisition module is composed of LMV358 and peripheral devices, and its power supply voltage uses an external 5V DC voltage. The first stage of the operational amplifier is a voltage follower, and the next stage is a filter. The rightmost wire is the input interface of the leakage current, and the R54 resistor is a sampling resistor. After the current signal is input, it is filtered by a low-pass filter, and then superimposed with the DC voltage of the op amp to raise the negative half axis of the signal to the positive half axis, and then output to the ADC sampling circuit; the voltage and current signal processing module consists of a voltage reference chip (REF3033) and an ADC chip (TM7705). The voltage reference chip can stabilize the reference voltage of the ADC at a fixed value.The ADC chip is a 16-bit precision dual-channel differential input interface. The signal is input to the ADC chip in differential form to improve accuracy. Its communication protocol is SPI, and an external 4.9152 crystal oscillator is used to provide a clock signal. The FRAM storage module uses a FRAM chip FM24CL64 to store the collected signal waveform and other data. The chip is powered by an external 3.3V DC voltage and uses the IIC communication protocol to exchange data with the CPU. The two resistors R are external pull-up resistors, and the capacitor C is a filter capacitor. The chip can be erased unlimited times, and the saved data will not be lost when the power is off. The storage size is 64K Bit.

[0098] CPU peripheral circuits such as Figure 4 As shown, pins 1, 24, 36, 48, and 9 are all 3.3V power supply access pins. The 3.3V on pin 1 is connected to a Schottky diode MBR0520. The 3.3V on pin 9 is connected to pins 24, 36, and 48 through two filter capacitors C132 and C133. The other end is connected to pins 24, 36, and 48 through a magnetic bead L11. These three pins are connected to a 100nf filter capacitor C135, C136, and C137 respectively. Pins 23, 35, 47, and 8 are the ground pins of the CPU. Pins 5 and 6 are connected to pins 1 and 2 of a crystal oscillator Y6 and then connected to two capacitors C130 and C140 to the ground. Port P19 is a serial port connected to pins 30 and 31 respectively. P20 is a program burning port connected to a pull-up resistor R106 and a pull-down resistor R108 respectively and then connected to pins 34 and 37. The reset button is connected to the 7th pin of the CPU, and an external pull-up resistor R98 is connected, and a decoupling capacitor C120 is connected to the ground. The 20th and 44th pins of the CPU are connected to the ground respectively, and the other used pins are brought out and the unused ones are reserved. The CPU uses the STM32F103C8T6 processor with the ARM architecture cortex-M0 core. It has 48 pins and is powered by 3.3V voltage to realize data calculation, processing and storage as well as control and interaction with other modules.

[0099] AC-AC step-down circuit and AC-DC step-down rectifier circuit such as Figure 5 , 6As shown, the step-down circuit includes a connector P15 for connecting the step-down circuit to the 380V-10KV power grid, and the step-down output of the adjustable transformer T1 (Trans Adj) is converted into a stable voltage of 220V through the connector P16. The AC-DC step-down circuit is used to connect the 220V AC voltage to the fuse F1 and one side of the common mode inductor Lf1 through the 2nd pin of the P17 connector, and is connected to the 1st pin of the rectifier module U1. The rectifier module adopts an AC220S12DC-20W rectifier module, and the 220V voltage is rectified to +12V through the rectifier module. The 1st pin of the connector P17 is connected in parallel with the filter capacitor C94, C95 and the varistor Rv1, and the line connected to the 1st and 2nd pins of the rectifier module U1 is connected in parallel with the filter capacitor C91 and the varistor Rv2. The 4th pin of the rectifier module U1 is connected to the inductor L8, the resistor R74, and the cathode end of the diode D11 through the diode D9. The model of the diodes D9 and D11 is IN4007. The 5th pin of the rectifier module U1 is directly grounded, and the positive end of D11 outputs a +12V voltage signal. : A reverse-connected diode D10 is connected between the 4th and 5th pins of the rectifier module U1. The model of the voltage stabilizing diode D10 is 1N4742, and the rated power is +12V, which plays a role in stabilizing the output voltage. The 4th and 5th pins of U1 output a stable +12V DC voltage, which is input into the DC-DC buck circuit and the energy storage control circuit after filtering and protection by the inductor, resistor and diode.

[0100] DC-DC step-down module circuit Figure 7 As shown, the 8th pin of the main chip RT7272BGSP is connected to 12V, the 7th pin is connected to the pull-down resistor R83 and then to the ground, and then three 10uF filter capacitors C102, C100, and C101 are connected between the 7th and 8th pins. A 100nFC99 capacitor and a 24K resistor R85 are connected in series between the 6th pin and the ground. The 5th pin is connected to the 11.8K pull-down resistor R84. The 4th pin is directly connected to the ground. The 3rd pin is connected to the 100K pull-up resistor R79 and then to 12V. The 2nd pin is connected in series with a 100nF capacitor C98 and connected to the 1st pin, and then connected in series with the 6.8uH power inductor L9, and then connected to the 62K pull-down resistor R82. At this time, the voltage has dropped to 5V, and then two filter capacitors C103 and C104 and TVS diode D12 are connected to the ground, and then two capacitors C1123 and C111 are connected in parallel, and finally connected to the 3rd pin and 1st pin of the chip AMS1117-3.3 respectively. This circuit reduces the DC 12V voltage to a stable DC 5V voltage and outputs it to the downstream LDO linear voltage regulator circuit, which has a buffering effect on other circuits.

[0101] LDO linear voltage regulator circuit Figure 8As shown, the 2nd and 4th pins of the voltage regulator chip AMS1117-3.3 are connected in series. At this time, the voltage has been converted to 3.3V and a voltage regulator diode D13 is connected in parallel with the ground. The two filter capacitors C113 and C114 are finally connected in parallel with the power indicator light D14, and the indicator light needs to be connected in series with a voltage divider resistor R93. The final output voltage of this circuit is used to provide stable power supply to the CPU module and other modules, which can ensure the normal and stable operation of the circuit.

[0102] like Fig. 9 The figure shows the charging module circuit of the supercapacitor of the backup power supply. In order to ensure the safety, stability and efficiency of charging the supercapacitor, the commonly used DC-DC chip LT3741 is used as a buffer. The input pin VIN of the chip is powered by 12V, and two conventional capacitors are connected in parallel between this pin and the ground for filtering protection. The gate drive signal pin HG is connected to a MOS tube with 12V to buffer the large voltage. A large pull-down resistor is connected to CTRL2 to reduce the thermal control input of the regulation current level. The soft start pin SS connects an external capacitor to ground under the startup condition to limit the regulation current. The external pull-down resistor of the RT pin sets the switching frequency between 200KHz and 1MHz, and the current limit of this pin is 60μA. The VC pin is connected to a 47.5K compensation resistor and a 4.7nF compensation capacitor. Most of the external circuits described above are the limitation and protection circuits of this module. The following is mostly a description of the output circuit module. The CBOOT pin provides a 5V regulated power supply for the high-side FET drive. When the switch pin is close to ground, an external Schottky diode is required from the VIN pin to the CBOOT pin to charge the CBOOT capacitor. LG is the ground FET gate drive signal, and an external MOS tube is required to control the state of the low-side external power FET. SENSE+ is the inverting input of the average current mode error amplifier, and this pin is connected to the sense resistor R71. The voltage drop between SENSE+ and SENSE produces the input voltage of the current regulation loop. SENSE– is the non-inverting input loop error amplifier of the average current mode. The reference current based on CTRL1 or CTRL2 flows out of the pin and flows to the output side of the sense resistor R71. FB is the feedback pin for voltage regulation and overvoltage protection. The feedback voltage is 1.21V. Overvoltage is also detected through the FB pin. When the feedback voltage exceeds 1.5V, the overvoltage lockout will prevent switching for 13μs to allow the inductor current to discharge. The stepped-down electrical signal flowing through the sense resistor charges the supercapacitor through two 150uf filter capacitors.

[0103] 220V AC inverter circuit Fig.10As shown in the figure, when the power supply is shaken, the backup power supply needs to be DC-AC boosted to supply power to the load. 5V DC is connected to the 15 and 13 pins of the boost chip CW3525A through an electric fuse to power the chip and then directly pass through the sliding transformer. IN-, IN+, V-REF, Rt, Ct, SS, COMP are used as protection circuits and limiting circuits to connect pull-down resistors and capacitors respectively. OUT-A and OUT-B are the output ends of the chip, which convert the voltage from DC to AC and boost it slightly to the sliding resistor. The sliding transformer can be adjusted appropriately according to the needs to obtain 220V AC, and the rectifier bridge can filter out the DC, so that the 220V AC generated by the module is a purer sine wave.

[0104] Voltage signal acquisition Fig.11 As shown, including signal conversion and signal processing, 220V AC is connected to pins 1 and 2 of voltage transformer T2 through four identical resistors R99, R100, R102, and R103. The converted signal comes out from pins 3 and 4 of the voltage transformer. Pin 3 is connected to the ground through a 0 ohm resistor on the one hand, and connected to pin 2 of op amp AD623 through resistor R105 on the other hand. Pin 4 is connected to pin 3 of AD623 through resistor R101. A decoupling capacitor C122 is added between pins 3 and 4 of the voltage transformer and a filter capacitor C121 and C124 are connected to the ground respectively. Pin 7 of op amp AD623 is connected to a 3.3V voltage, pin 4 is grounded, an adjustable resistor RP2 is connected between pins 8 and 1, and pin 6 is the output pin. Through a small resistor R104 and a capacitor C123, the sorted signal is output to the signal processing circuit. This circuit uses a voltage transformer to reduce the signal of 220V AC, and then an operational amplifier AD623 is used to sort the signal. After the small voltage signal is input, the low-pass filter filters the signal, and the output end of the operational amplifier is connected to the ADC acquisition chip. The adjustable resistor can adjust the signal amplification factor.

[0105] Current signal acquisition Fig.12As shown, the P21 port is the current signal after passing through the current transformer, and the resistor R112 is a sampling resistor. One end of the current signal passes through the RC filter circuit, and then passes through the resistor R111 to the 1 pin of the op amp LMV358, which is also the output pin; the other end also passes through the RC filter circuit and the 0 ohm resistor to the ground. For the op amp LMV358, in order to raise and amplify the generated signal, the 8-pin 5V power supply is used, the 4-pin is grounded, and the 5V DC passes through two filter capacitors C138 and C139 to the ground on the one hand, and passes through the inductor L12 and the resistor R117 to the 5-pin. The 5-pin is connected to two identical resistors R118 and R119 and a capacitor C134 to the ground end. The 6-pin and 7-pin are directly connected to the output through the RC filter to the 3-pin, and the 2-pin passes through the resistor R109 in series with the resistor R111 and the capacitor C126 in parallel to the 1-pin, and is superimposed with the current signal, and is output to the signal acquisition circuit through the resistor R114 and the capacitor C129 in parallel. The first stage of the circuit is composed of a voltage follower, and the second stage is a Sallen-Key filter. The rightmost wire is the input interface of the leakage current, and the R54 resistor is a sampling resistor. After the current signal is input, it is filtered by a low-pass filter, and then superimposed with the DC voltage of the op amp to raise the negative half axis of the signal to the positive half axis.

[0106] Voltage and current signal processing module such as Fig.13 As shown, the 2nd and 3rd pins of the TM7705 electrical signal processing chip are used to connect the crystal oscillator module. First, a 1M large point group R89 is connected in parallel, and then a 4.9152M crystal oscillator is connected in parallel. Finally, a 30pF capacitor is connected in series and then grounded. Pins 7 and 8 are connected to the voltage signal acquisition module, and pins 6 and 11 are connected to the current signal acquisition module. A 1K pull-up resistor R80 is connected in series between pin 5 and the 3.3V voltage, and a 10nF pull-down capacitor GND is connected in series between the ground. Pins 16 and 10 are grounded, and pins 9 and 15 are connected to 3.3V. Pins 1, 4, 14, and 13 are used as SPI communication. Only pins 4 are connected to the pull-down resistor to default the communication mode to SPI. The rest are connected to pins 26, 28, and 27 of the central processor STM32F103C8T6, and pin 12 is connected to pin 25 of the central processor. The 1 pin of the voltage reference chip REF3033 is connected to 5V and then to the ground with a 10uF / 16V electrolytic capacitor +CE2. The 2 pin is connected to 3.3V and then to the ground with a 10nF filter capacitor C118. Three 10nF decoupling capacitors C115, C116, and C117 are connected in parallel between 5V and the ground. This circuit consists of a voltage reference chip (REF3033) and an ADC chip (TM7705). The voltage reference chip can stabilize the reference voltage of the ADC at a fixed value. The ADC chip is a 16-bit precision dual-channel differential input interface. The signal is input to the ADC chip in differential form to improve accuracy.

[0107] Data storage circuits such as Fig.14 As shown, the 1, 2, 3, 4, and 7 pins of the FM24CL64 memory chip are all grounded, the 8 pin is connected to a 3.3V power supply, and a 100nF filter capacitor C83 is connected in series between the power supply and the ground of the memory chip. The 5 and 6 pins are respectively connected to the 42 and 43 pins of the central processor STM32F103C8T6 and each is connected to a 4.7K pull-up resistor R69 and R70. This circuit uses a FRAM chip FM24CL64 to store the collected signal waveform and other data. The chip is powered by an external 3.3V DC voltage and uses the IIC communication protocol to exchange data with the CPU. The chip can be erased an unlimited number of times, and the saved data will not be lost when the power is off. The storage size is 64K Bit.

[0108] Relay switch control and circuit breaker control circuit such as Figure 15-19 As shown, it includes four relay modules JQC-3FF-SZ, which can be used as a controllable switch. The GPIO pins of the microcontroller can be used to control the on and off of DC and AC power. They are used as the operating power control switch K1, the backup power charging switch K2, the backup power discharge switch K3, and the overcurrent control switch. The circuit breaker is also involved to control the on and off of the power supply of the equipment. If the equipment encounters an overcurrent situation, the CPU controls the relay switch to disconnect the coil power supply controlled by the circuit breaker, and then controls the main contact of the circuit breaker to disconnect.

Claims

1. A control device for preventing power sway and overcurrent protection linkage, comprising a main power module connected to the power supply side, a backup power module connected to the main power module and charging the main power module, a CPU module connected to the main power module, a voltage and current signal acquisition and processing module connected to the CPU module, a relay switch and circuit breaker module connected to the CPU module, and a FRAM storage module connected to the CPU module, characterized in that: The CPU module includes a CPU device and its peripheral circuits; The main power supply module includes an AC-AC step-down circuit, an AC-DC step-down rectifier circuit, and a DC-DC step-down module circuit; The backup power supply module includes a supercapacitor and a charging module circuit of the supercapacitor, and a DC-AC boost circuit; The voltage and current signal acquisition and processing module includes a power supply side voltage signal acquisition module, a load side current signal acquisition module and a voltage and current signal processing module; the power supply side voltage signal acquisition module converts the sampling signal into an AC signal of 0-3.3V by measuring the voltage transformer and the operational amplifier circuit; the load side current signal acquisition module converts the sampling required signal into an AC signal of 0-3.3V by measuring the current transformer and the operational amplifier circuit; the voltage and current signal processing module includes an A / D chip and a voltage reference chip; The relay switch and circuit breaker module includes a switch control circuit of the main power switch K1, a switch control circuit of the backup power charging switch K2, a switch control circuit of the backup power supply switch K3, an overcurrent control switch control circuit and a closing and opening coil; The FRAM storage module includes a storage device and a peripheral circuit; The CPU module uses STM32F103C8T6 as the core processor and adopts the processor STM32F103C8T6 of the ARM architecture Cortex-M0 core to realize the operation of various functions. The CPU module has 48 pins, is powered by 3.3V voltage, is externally connected to an 8M quartz crystal oscillator, has an internal 12-bit ADC, SW2 is an external hardware reset button, SWD is an interface for program download, which is used to realize data calculation, processing and storage as well as control and interaction functions of other modules; in the peripheral circuit of the CPU, its 1, 24, 36, 48, and 9 pins are all 3.3V power access pins, 3.3V on pin 1 is connected to a Schottky diode MBR0520, and 3.3V on pin 9 is connected to two filter capacitors C13 2. C133, the other end is connected to pins 24, 36, and 48 through a magnetic bead L11, and these three pins are connected to 100nf filter capacitors C135, C136, and C137 respectively; its pins 23, 35, 47, and 8 are the ground pins of the CPU, and pins 5 and 6 are connected to pins 1 and 2 of a crystal oscillator Y6, and then connected to two capacitors C130 and C140 before being connected to the ground; port P19 is the serial port connected to pins 30 and 31 respectively, and P20 is the program burning port, which is connected to pull-up resistors R106 and pull-down resistors R108 respectively and then connected to pins 34 and 37; the reset button is connected to pin 7 of the CPU, and an external pull-up resistor R98 is connected, and a decoupling capacitor C120 is connected to the ground; pins 20 and 44 of the CPU are connected to the ground respectively, and other used pins are led out, and unused pins are retained; The AC-AC step-down circuit includes a connector P15 for connecting the step-down circuit to a 380V-10KV power grid, an adjustable transformer T1 of model Trans Adj connected to the connector P15, and a connector P16 connected to the adjustable transformer T1. The 380V-10KV AC voltage is converted into a stable AC voltage of 220V through the step-down output of the adjustable transformer T1 through the connector P16.

2. The anti-power sway and overcurrent protection linkage control device according to claim 1 is characterized in that: The AC-DC step-down rectifier circuit is used to connect the 220V stable AC voltage to the fuse F1 and one side of the common mode inductor Lf1 through the 2nd pin of the connector P17, and then connect it to the 1st pin of the rectifier module U1. The rectifier module U1 adopts the HenL AC220S12DC-20W rectifier module, and the 220V voltage is rectified to +12V through the rectifier module U1; wherein the 1st pin of the connector P17 is connected in parallel with the filter capacitors C94, C95 and the varistor Rv1, and the line connected to the 1st and 2nd pins of the rectifier module U1 is connected in parallel with the filter capacitor C91 and the varistor Rv2; the 4th pin of the rectifier module U1 is connected to the inductor L8, the resistor R74, and the cathode end of the diode D11 through the diode D9; the models of the diodes D9 and D11 are IN 4007; Pin 5 of the rectifier module U1 is directly grounded, and the forward end of the diode D11 outputs a +12V voltage signal; a reversely connected diode D10 is connected between pins 4 and 5 of the rectifier module U1. The model of the diode D10 is 1N4742, and the rated power is +12V, which plays a role in stabilizing the output voltage; Pins 4 and 5 of the rectifier module U1 output a stable +12V DC voltage, which is input into the DC-DC buck circuit and the energy storage control circuit after filtering and protection by the inductor, resistor and diode.

3. The anti-power sway and overcurrent protection linkage control device according to claim 1 is characterized in that: The DC-DC step-down module circuit includes a main chip of model RT7272BGSP and an LDO linear voltage regulator circuit. Pin 8 of the main chip is connected to 12V, pin 7 is connected to a pull-down resistor R83 and then to ground, and then three 10uF filter capacitors C102, C100, and C101 are connected in parallel between pins 7 and 8; a 100nFC99 capacitor and a 24K resistor R85 are connected in series between pin 6 and ground; pin 5 is connected to an 11.8K pull-down resistor R84; pin 4 is directly grounded; pin 3 is connected to a 100K pull-up resistor R79 and then to 12V; pin 2 is connected in series with a 100nF capacitor C98 and then to pin 1, and then a 6.8uH power inductor L9 is connected in series, and then a 62K pull-down resistor R82 is connected. At this time, the voltage has dropped to 5V, and then two filter capacitors C103 and C104 are connected between the pin and the ground. and TVS diode D12; then two capacitors C112 and C111 are connected in parallel, and finally connected to pins 3 and 1 of chip AMS1117-3.3 respectively; this circuit reduces the DC 12V voltage to a stable DC 5V voltage, and outputs it to the lower-level LDO linear voltage regulator circuit, which has a buffering effect on other circuits; the LDO linear voltage regulator circuit includes a voltage regulator chip of model AMS1117-3.3, and pins 2 and 4 of the voltage regulator chip are connected in series. At this time, the voltage has been converted to 3.3V, and a voltage regulator diode D13 is connected in parallel with the ground. The two filter capacitors C113 and C114 are finally connected in parallel with the power indicator light D14, and the indicator light is connected in series with a voltage divider resistor R93. The final output voltage of this circuit is used to provide stable power supply to the CPU module and other modules, which can ensure the normal and stable operation of the circuit.

4. The anti-power sway and overcurrent protection linkage control device according to claim 1, characterized in that: The backup power supply module includes a supercapacitor and a charging module circuit of the supercapacitor. In order to ensure the safety, stability and efficiency of charging the supercapacitor, a LT3741DC-DC chip is used as a buffer. The input pin VIN of the chip is powered by 12V, and two conventional capacitors are connected in parallel between the pin and the ground for filtering protection; the gate drive signal pin HG is connected to a MOS tube with 12V to buffer the voltage, and CTRL2 is externally connected to a pull-down resistor for reducing the thermal control input of the adjustment current level; the soft start pin SS is grounded through an external capacitor to limit the adjustment current; the RT pin is externally connected to a pull-down resistor to set the switching frequency between 200KHz and 1MHz, and the current limit of the pin is 60μA; the VC pin is externally connected to a 47.5K compensation resistor and a 4.7nF compensation capacitor; the CBOOT pin provides a 5V regulated power supply for the high-end FET driver. When the switch pin is close to the ground, the voltage from the VIN pin to the CBOOT pin is connected. The CBOOT capacitor is charged through an external Schottky diode; LG is the ground FET gate drive signal, and an external MOS tube is used to control the state of the low-side external power FET; SENSE+ is the inverting input of the average current mode error amplifier, and the pin is connected to the detection resistor R71; the voltage drop between SENSE+ and SENSE generates the input voltage of the current regulation loop; SENSE– is the non-inverting input loop error amplifier of the average current mode; the reference current based on CTRL1 or CTRL2 flows out of the pin and flows to the output side of the detection resistor R71; FB is the feedback pin for voltage regulation and overvoltage protection, the feedback voltage is 1.21V, and overvoltage is also detected through the FB pin. When the feedback voltage exceeds 1.5V, the overvoltage lock will prevent switching for 13μs to allow the inductor current to discharge, and the stepped-down electrical signal flowing through the detection resistor charges the supercapacitor through two 150uf filter capacitors.

5. The anti-power sway and overcurrent protection linkage control device according to claim 1, characterized in that: In the DC-AC boost circuit, when the power supply is shaken, the backup power supply needs to perform DC-AC boost to supply power to the load. The 5V DC is connected to the 15 and 13 pins of the boost chip CW3525A through an electric fuse to supply power to the chip and then directly pass through the sliding transformer; IN-, IN+, V-REF, Rt, Ct, SS, COMP are used as protection circuits and limiting circuits to connect external pull-down resistors and capacitors respectively. OUT-A and OUT-B are the output ends of the chip to convert the voltage from DC to AC and transmit it to the sliding resistor with a small boost. The sliding transformer has obtained 220V AC according to the required adjustment, and the rectifier bridge filters out the DC, so that the 220V AC generated by the module is a purer sine wave.

6. The anti-power sway and overcurrent protection linkage control device according to claim 1, characterized in that: The power supply side voltage signal acquisition module includes a signal conversion and signal processing module. The 220V AC is connected to the 1 and 2 pins of the voltage transformer T2 through four identical resistors R99, R100, R102, and R103. The converted signal comes out from the 3 and 4 pins of the voltage transformer. The 3 pin is connected to the ground through a 0 ohm resistor R107 on the one hand, and connected to the 2 pin of the operational amplifier AD623 through a resistor R105 on the other hand. The 4 pin is connected to the pin 3 of the operational amplifier AD623 through a resistor R101. A decoupling capacitor C122 is added between the 3 and 4 pins of the voltage transformer T2, and is respectively connected to Filter capacitors C121 and C124 are connected to ground; pin 7 of operational amplifier AD623 is connected to a 3.3V voltage, pin 4 is grounded, and an adjustable resistor RP2 is connected between pins 8 and 1; pin 6 is an output pin, and the sorted signal is output to the signal processing circuit through a resistor R104 and a capacitor C123; this circuit uses a voltage transformer to reduce the signal of 220V AC, and then an operational amplifier AD623 sorts the signal. After the voltage signal is input, a low-pass filter filters the signal, and the output end of the operational amplifier is connected to the ADC acquisition chip, and the adjustable resistor adjusts the signal amplification factor.

7. The anti-power sway and overcurrent protection linkage control device according to claim 1, characterized in that: In the load side current signal acquisition module, the port of connector P21 receives the current signal after passing through the current transformer, resistor R112 is a sampling resistor, pin 1 of connector P21 is connected to pin 1 of op amp LMV358 through RC filter circuit, resistor R111, the current signal passes through the RC filter circuit, and then passes through resistor R111 to pin 1 of op amp LMV358; pin 2 of connector P21 passes through the RC filter circuit and 0 ohm resistor to ground; op amp LMV358 enables the generated signal to be raised and amplified, and its pin 8 is powered by a 5V power supply. , pin 4 is grounded, 5V DC passes through two filter capacitors C138 and C139 to the ground on the one hand, and passes through inductor L12 and resistor R117 to pin 5 of op amp LMV358 on the other hand. Pin 5 is connected to the ground by two identical resistors R118 and R119 and a capacitor C134. Pins 6 and 7 are directly connected and output through the RC filter to pin 3. Pin 2 passes through resistor R109 in series with resistor R111 and parallel with capacitor C126 to pin 1, where it is superimposed with the current signal and output to the signal acquisition circuit through resistor R114 and parallel with capacitor C129; The first stage of the circuit is composed of a voltage follower, and the second stage is a Sallen-Key filter. The rightmost wire is the input interface of the leakage current. Resistor R54 is a sampling resistor. After the current signal is input, it is filtered by a low-pass filter and then superimposed with the DC voltage of the op amp to raise the negative half axis of the signal to the positive half axis.

8. The anti-power shaking and overcurrent protection linkage control device according to claim 1 is characterized in that: In the voltage and current signal processing module, pins 2 and 3 of the electrical signal processing chip TM7705 are used to connect the crystal oscillator module. First, a 1M resistor R89 ​​is connected in parallel, and then a 4.9152M crystal oscillator is connected in parallel. Finally, a 30pF capacitor is connected in series and then grounded. Pins 7 and 8 are connected to the voltage signal acquisition module, and pins 6 and 11 are connected to the current signal acquisition module. A 1K pull-up resistor R80 is connected in series between pin 5 and the 3.3V voltage, and a 10nF pull-down capacitor GND is connected in series between pin 5 and the ground. Pins 16 and 10 are grounded, pins 9 and 15 are connected to 3.3V, and pins 1, 4, 14, and 13 are used as SPI communication. Only pin 4 is connected to the pull-down resistor to set the communication mode to default. It is SPI, and the rest are connected to the 26, 28, and 27 pins of the central processor STM32F103C8T6 respectively, and the 12th pin is connected to the 25th pin of the central processor. The 1st pin of the voltage reference chip REF3033 is connected to 5V and then connected to a 10uF / 16V electrolytic capacitor +CE2 between the ground, and the 2nd pin is connected to 3.3V and then connected to a 10nF filter capacitor C118 between the ground; three 10nF decoupling capacitors C115, C116, and C117 are connected in parallel between 5V and the ground; this circuit consists of the voltage reference chip REF3033 and the ADC chip TM7705. The voltage reference chip can stabilize the reference voltage of the ADC at a fixed value.

9. The anti-power sway and overcurrent protection linkage control device according to claim 1, characterized in that: In the FRAM storage module, pins 1, 2, 3, 4, and 7 of the FRAM storage chip FM24CL64 are all grounded, pin 8 is connected to a 3.3V power supply, and a 100nF filter capacitor C83 is connected in series between the power supply and the ground of the storage chip; pins 5 and 6 are respectively connected to pins 42 and 43 of the central processor STM32F103C8T6 and are respectively connected to a 4.7K pull-up resistor R69 and R70; this circuit uses a FRAM storage chip FM24CL64 to store the collected signal waveform and other data. The FRAM storage chip FM24CL64 is powered by an external 3.3V DC voltage and uses the IIC communication protocol to exchange data with the CPU. The chip can be erased unlimited times, and the saved data will not be lost when the power is off. The storage size is 64K Bit.

10. The anti-power sway and overcurrent protection linkage control device according to claim 1, characterized in that: The relay switch and circuit breaker module includes four relay modules JQC-3FF-SZ, which are used as a controllable switch to control the on and off of DC and AC power using the GPIO pins of the single-chip microcomputer; they are respectively used as the operating power control switch K1, the backup power charging switch K2, the backup power discharging switch K3, and the overcurrent control switch; at the same time, the circuit breaker is used to control the on and off of the power supply of the equipment. If the equipment encounters an overcurrent situation, the CPU controls the relay switch to disconnect the coil power supply controlled by the circuit breaker, thereby controlling the main contacts of the circuit breaker to be disconnected.

11. A method for performing linkage control of power sway protection and overcurrent protection using a linkage control device for power sway protection and overcurrent protection according to any one of claims 1 to 10, characterized in that: The following steps are involved: Step 1), in normal operation, the K1 switch that controls the operating power supply of the circuit breaker in the anti-power sway module is closed, the operating power supply is powered normally, the K2 that controls the charging of the backup power supply is closed, the backup charging power supply is charged normally, and the K3 that connects the operating power supply with the backup charging power supply is disconnected; Step 2) Calculate the effective value of the voltage on the power supply side and the effective value of the current on the load side. If the voltage change on the power supply side exceeds the value, start the anti-power sway module; If the voltage change on the power supply side does not exceed the value but the current change on the load side exceeds the value, the overcurrent protection module is activated; Step 3), after starting the anti-power sway module, immediately and quickly put the backup charging power supply K3 connected with the operating power supply into use, put the backup power supply into use as the operating power supply of the circuit breaker, and quickly disconnect the K1 control switch of the operating power supply and the K2 charging switch of the charging power supply, turn on the backup charging power supply input timer for timing, and then determine whether the load side current value exceeds the value. If the load side current does not exceed the value, the backup charging power supply continues to be put into operation, and the timer continues to count. After reaching a reasonably set time limit, the backup charging power supply is automatically returned, the timer returns to zero, and the anti-power sway counter records the number of times, and returns to step 1) to continue monitoring and diagnosis; if the fault characteristics on the load side are obvious and the current value exceeds the set value, the circuit breaker is immediately tripped, and the control switch K3 is disconnected to exit the backup charging power supply, completing the protection of the load side once, the protection counter is increased by 1, and the protection alarm locking function is started, and returns to step 1) to continue monitoring and diagnosis; Step 4) After starting the overcurrent protection module, continuously calculate and determine whether the fault characteristics and overcurrent value on the load side exceed the set value and the corresponding protection time limit. If exceeded, the protection immediately disconnects the circuit breaker, starts the protection alarm locking function, and returns to step 1) to continue calculation and determination; if not exceeded or the time limit is not reached, keep the fault start mark, return to step 1) to continue calculation and determination.

12. The method for controlling the linkage between power shaking prevention and overcurrent protection according to claim 11, characterized in that: In step 2), the calculation criterion formula of the voltage change is: Δu is the relative change of voltage, u n is the rated value of the power supply line, u i is the RMS value of the current voltage half cycle, u D is the allowable value of voltage fluctuation, Δt is the duration of voltage fluctuation after exceeding the value, T ΔuD It is the set value for the allowed time of continuous voltage fluctuation after the voltage exceeds the value.

13. The method for controlling the linkage between power shaking prevention and overcurrent protection according to claim 11, characterized in that: In step 3), after the anti-power-sway module is started, the duration of automatic switching on of the backup power supply is set according to the characteristics of the load.

14. The method for controlling the linkage between power shaking prevention and overcurrent protection according to claim 11, characterized in that: In step 4), after the protection module is started, the criterion for the protection output tripping is: i d ≥k1I D1 (2) or i d The current effective value of the running current, I D1 The minimum short-circuit current value at the end of the load line when the power supply system is in the minimum operating mode, k1 reliability coefficient, I D2 When the power supply system is in the maximum operation mode, all load current values ​​of the load line, k2 overload reliability coefficient, Δt exceeds the set value k2I D2 The duration after, T D2 Exceeding the set value k2I D2 The allowed duration setting after.

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