Overcurrent monitoring and early warning control system in power station room

Abstract

The present invention provides an overcurrent monitoring and early warning control system for a power station room, comprising a current detection unit, a power supply unit, a processing chip U1, a battery BAT, a voltage conversion circuit and a battery switching unit; the current detection unit is used to detect the current of the live power line L of the power station room, and output a control signal to the switch control circuit and the processing chip when the current increases, the positive input end and the negative input end of the rectifier circuit Z2 are respectively connected to the live power line L and the neutral power line N, the positive output end of the rectifier circuit is connected to the input end of the switch control circuit, the negative output end of the rectifier circuit is grounded, the second output end of the switch control circuit is connected to the input end of the voltage conversion circuit, the voltage conversion circuit supplies power to the processing chip, and the processing chip is connected to the above-mentioned host; through the above-mentioned structure, the voltage and current of the live power line of the power station room can be monitored.

Description

Technical Field

[0001] The invention relates to a power supply monitoring system for a power station, and in particular to an overcurrent monitoring and early warning control system for a power station machine room. Background Art

[0002] The power station machine room is an essential equipment for power places such as substations. Various communication equipment is installed in the power station machine room to collect, store and upload monitoring information of substations and other places. The equipment in the power station machine room is generally powered by 220V during operation. During the power supply process of the power station machine room, due to the different states of various equipment, when these devices are working, once a short circuit or other fault occurs in a certain device, the current on the power supply live wire will increase, thereby causing an impact on other electrical equipment. In the prior art, there is no effective means to monitor and warn the power supply status of the power station machine room.

[0003] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the invention

[0004] In view of this, the present invention provides a power station machine room overcurrent monitoring and early warning control system, which can monitor the voltage and current of the power supply live wire of the power station machine room, and output corresponding detection signals in time when the current is overcurrent and the voltage is overvoltage, so as to provide timely early warning and ensure the stable operation of the entire system.

[0005] The present invention provides a power station room overcurrent monitoring and early warning control system, comprising a current detection unit, a power supply unit, a processing chip U1, a battery BAT, a voltage conversion circuit and a battery switching unit;

[0006] The power supply unit includes a rectifier circuit Z2 and a switch control circuit;

[0007] The current detection unit is used to detect the current of the live power line L of the power station room, and output a control signal to the switch control circuit and the processing chip when the current increases. The positive input terminal and the negative input terminal of the rectifier circuit Z2 are respectively connected to the live power line L and the neutral power line N. The positive output terminal of the rectifier circuit is connected to the input terminal of the switch control circuit, and the negative output terminal of the rectifier circuit is grounded. The second output terminal of the switch control circuit is connected to the input terminal of the voltage conversion circuit. The voltage conversion circuit supplies power to the processing chip, and the processing chip is connected to the above-mentioned host;

[0008] The positive pole of the battery BAT is connected to the input end of the battery switching unit, the output end of the battery switching unit is connected to the input end of the voltage conversion circuit, the control output end of the battery switching unit is connected to the input end of the processing chip, the control end of the battery switching unit is connected to the first output end of the switch control circuit, and the control input end of the switch control circuit is connected to the output end of the current detection unit.

[0009] Further, the current detection unit includes a current transformer T1, a rectifier circuit Z1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a matching resistor RL, a resistor R14, a resistor R15, a transistor Q4, a transistor Q5, an inductor L1, a capacitor C3 and a voltage regulator DW3;

[0010] The primary winding of the current transformer T1 is connected in series to the live power line L, the positive end of the secondary winding of the current transformer T1 is connected to the positive input end of the rectifier circuit Z1, the negative input end of the rectifier circuit Z1 and the negative output end of the secondary winding of the current transformer T1 are grounded, one end of the resistor R1 is connected to the positive output end of the rectifier circuit Z1, the negative output end of the rectifier circuit is grounded, the other end of the resistor R1 is connected to one end of the inductor L1, and the other end of the inductor L1 is grounded through a matching load RL;

[0011] A common connection point between the inductor L1 and the resistor R1 is connected to the emitter of the transistor Q4 through the resistor R2, the collector of the transistor Q4 is grounded through the resistor R15, the collector of the transistor Q4 is grounded through the capacitor C3, the collector of the transistor Q4 is connected to the negative electrode of the voltage regulator DW3, the positive electrode of the voltage regulator DW3 is grounded, the collector of the transistor Q4 is connected to one end of the resistor R14, the other end of the resistor R14 serves as the output end of the current detection unit, the base of the transistor Q4 is connected to the collector of the transistor Q5, the base of the transistor Q5 is connected to the common connection point between the inductor L1 and the matching load RL through the resistor R4, and the emitter of the transistor Q5 is connected to the common connection point between the inductor L1 and the matching load RL through the resistor R3.

[0012] Further, the switch control circuit includes a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R16, a capacitor C1, a capacitor C2, a voltage regulator DW1, a voltage regulator DW2, a transistor Q2, a transistor Q3, a PMOS tube M1 and a diode D1;

[0013] One end of the resistor R6 is connected to the positive output end of the rectifier circuit Z2, the other end of the resistor R6 is connected to the source of the PMOS tube M1 through the resistor R7, the common connection point between the resistor R6 and the resistor R7 is grounded through the capacitor C1, the common connection point between the resistor R6 and the resistor R7 is connected in series with the resistor R8 and the resistor R9 and then grounded, the common connection point between the resistor R8 and the resistor R9 is connected to the negative electrode of the voltage regulator tube DW1, the positive electrode of the voltage regulator tube DW1 is connected to the base of the transistor Q2 through the resistor R10, the emitter of the transistor Q2 is grounded, the collector of the transistor Q2 is connected to the base of the transistor Q3, and the base of the transistor Q3 is connected to the source of the PMOS tube M1 through the resistor R11. The source of the PMOS tube M1 is connected to the gate of the PMOS tube M1 through the resistor R12, the gate of the PMOS tube M1 is connected to the collector of the transistor Q3, the emitter of the transistor Q3 is grounded through the resistor R13, the drain of the PMOS tube M1 is connected to the anode of the diode D1 through the resistor R16, the cathode of the diode D1 serves as the second output end of the switch control circuit, the anode of the diode D1 serves as the first output end of the switch control circuit, the drain of the PMOS tube M1 is grounded through the capacitor C2, the drain of the PMOS tube M1 is connected to the cathode of the voltage regulator tube DW2, and the anode of the voltage regulator tube DW2 is grounded; the base of the transistor Q2 serves as the control input end of the switch control circuit.

[0014] Further, the battery switching unit includes a resistor R17, a resistor R18, a resistor R19, a resistor R5, a transistor Q1, and a diode D2;

[0015] One end of resistor R17 serves as a control input end of the battery switching unit, the other end of resistor R17 is connected to the base of transistor Q1, the emitter of transistor Q1 is connected to one end of resistor R5, the other end of resistor R5 serves as an input end of the battery switching unit, the collector of transistor Q1 is connected to the positive electrode of diode D2 through resistor R8, the negative electrode of diode D2 serves as an output end of the battery switching unit, the collector of transistor Q1 is connected to one end of resistor R19, the other end of resistor R19 serves as a control output end of the battery switching unit, wherein transistor Q1 is a P-type transistor.

[0016] Furthermore, the voltage conversion circuit is a LM7805 chip.

[0017] Furthermore, the processing chip is an AT89C2051 chip.

[0018] Furthermore, the battery is a lithium battery.

[0019] Beneficial effects of the present invention: Through the present invention, the voltage and current of the power supply live wire of the power station room can be monitored, and the corresponding detection signal can be output in time when the current is overcurrent and the voltage is overvoltage, so that timely warning can be given, and the whole system works stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0021] Figure 1 It is a principle block diagram of the present invention.

[0022] Figure 2 It is a circuit schematic diagram of the present invention. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0024] The present invention provides a power station room overcurrent monitoring and early warning control system, comprising a current detection unit, a power supply unit, a processing chip U1, a battery BAT, a voltage conversion circuit and a battery switching unit;

[0025] The power supply unit includes a rectifier circuit Z2 and a switch control circuit;

[0026] The current detection unit is used to detect the current of the live power line L of the power station room, and outputs a control signal to the switch control circuit and the processing chip when the current increases. The positive input terminal and the negative input terminal of the rectifier circuit Z2 are respectively connected to the live power line L and the neutral power line N, the positive output terminal of the rectifier circuit is connected to the input terminal of the switch control circuit, the negative output terminal of the rectifier circuit is grounded, the second output terminal of the switch control circuit is connected to the input terminal of the voltage conversion circuit, the voltage conversion circuit supplies power to the processing chip, and the processing chip is connected to the above-mentioned host; the processing chip and the upper host can be connected through an existing wireless communication module, such as a 4G communication module, a Bluetooth module, etc., or can be connected through a CAN bus; the voltage conversion circuit is an LM7805 chip, the processing chip is an AT89C2051 chip, and the battery is a lithium battery.

[0027] The positive pole of the battery BAT is connected to the input end of the battery switching unit, the output end of the battery switching unit is connected to the input end of the voltage conversion circuit, the control output end of the battery switching unit is connected to the input end of the processing chip, the control end of the battery switching unit is connected to the first output end of the switch control circuit, and the control input end of the switch control circuit is connected to the output end of the current detection unit; through the above structure, the voltage and current of the power supply live wire of the power station room can be monitored, and the corresponding detection signal can be output in time when the current is overcurrent and the voltage is overvoltage, so that timely warning can be given, and the whole system works stably.

[0028] In this embodiment, the current detection unit includes a current transformer T1, a rectifier circuit Z1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a matching resistor RL, a resistor R14, a resistor R15, a transistor Q4, a transistor Q5, an inductor L1, a capacitor C3 and a voltage regulator DW3;

[0029] The primary winding of the current transformer T1 is connected in series to the live power line L, the positive end of the secondary winding of the current transformer T1 is connected to the positive input end of the rectifier circuit Z1, the negative input end of the rectifier circuit Z1 and the negative output end of the secondary winding of the current transformer T1 are grounded, one end of the resistor R1 is connected to the positive output end of the rectifier circuit Z1, the negative output end of the rectifier circuit is grounded, the other end of the resistor R1 is connected to one end of the inductor L1, and the other end of the inductor L1 is grounded through a matching load RL;

[0030] The common connection point of the inductor L1 and the resistor R1 is connected to the emitter of the transistor Q4 through the resistor R2, the collector of the transistor Q4 is grounded through the resistor R15, the collector of the transistor Q4 is grounded through the capacitor C3, the collector of the transistor Q4 is connected to the negative electrode of the voltage regulator DW3, the positive electrode of the voltage regulator DW3 is grounded, the collector of the transistor Q4 is connected to one end of the resistor R14, the other end of the resistor R14 serves as the output end of the current detection unit, the base of the transistor Q4 is connected to the collector of the transistor Q5, and the transistor Q5 The base of transistor Q4 is connected to the common connection point between inductor L1 and matching load RL through resistor R4, and the emitter of transistor Q5 is connected to the common connection point between inductor L1 and matching load RL through resistor R3. Among them, transistor Q4 and transistor Q5 are both P-type transistors, and the resistance of resistor R2 is equal to that of resistor R3 or the resistance of resistor R2 is greater than that of resistor R3. In general, the resistance of resistor R2 is greater than that of resistor R3. The resistance difference between resistor R2 and resistor R3 can be adjusted according to actual needs. The resistance value is also At the current fluctuation amplitude adjustment point, the resistance value of resistor R3 is less than that of resistor R4. Among them, the current transformer T1 is used to collect the current of the live wire L. After being rectified by the rectifier circuit Z1, a loop is formed through the resistor R1, the inductor L1 and the matching load RL. For stable DC, the inductor L1 is equivalent to a wire. Therefore, there is no induced electromotive voltage at both ends of the inductor L1. At this time, the transistor Q5 is turned on and the transistor Q4 is turned off. When the current suddenly increases, the left end of the inductor L1 induces a high voltage, and the voltage at the left end of the inductor L1 Greater than the right end voltage, at this time, the emitter voltage of transistor Q4 is greater than the base voltage, transistor Q4 is turned on, and there is an output at the collector of transistor Q4, forming a detection signal. On the one hand, the detection signal is transmitted to the processing chip, and then uploaded to the upper host by the processing chip. The upper host issues an alarm through an alarm, a display, etc., informing the staff to conduct inspection and troubleshooting, and to determine whether power-off control is needed. On the other hand, the detection signal is transmitted to the switch control circuit to cut off the online power supply and supply power to the battery.

[0031] In this embodiment, the switch control circuit includes a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R16, a capacitor C1, a capacitor C2, a voltage regulator DW1, a voltage regulator DW2, a transistor Q2, a transistor Q3, a PMOS tube M1 and a diode D1;

[0032] One end of the resistor R6 is connected to the positive output end of the rectifier circuit Z2, the other end of the resistor R6 is connected to the source of the PMOS tube M1 through the resistor R7, the common connection point between the resistor R6 and the resistor R7 is grounded through the capacitor C1, the common connection point between the resistor R6 and the resistor R7 is connected to the ground after being connected in series with the resistor R8 and the resistor R9, the common connection point between the resistor R8 and the resistor R9 is connected to the negative electrode of the voltage regulator tube DW1, the positive electrode of the voltage regulator tube DW1 is connected to the base of the transistor Q2 through the resistor R10, the emitter of the transistor Q2 is grounded, and the collector of the transistor Q2 is connected to the positive electrode of the transistor Q2. The base of the transistor Q3 is connected to the base of the transistor Q3, the base of the transistor Q3 is connected to the source of the PMOS tube M1 through the resistor R11, the source of the PMOS tube M1 is connected to the gate of the PMOS tube M1 through the resistor R12, the gate of the PMOS tube M1 is connected to the collector of the transistor Q3, the emitter of the transistor Q3 is grounded through the resistor R13, the drain of the PMOS tube M1 is connected to the anode of the diode D1 through the resistor R16, the cathode of the diode D1 serves as the second output end of the switch control circuit, and the anode of the diode D1 serves as the first output end of the switch control circuit , the drain of the PMOS tube M1 is grounded through the capacitor C2, the drain of the PMOS tube M1 is connected to the negative electrode of the voltage regulator tube DW2, and the positive electrode of the voltage regulator tube DW2 is grounded; the base of the transistor Q2 serves as the control input end of the switch control circuit; through the above structure, the PMOS tube M1 is a switch tube, which is turned on by the conduction of the transistor Q3. When the power is just turned on, the direct current output by the rectifier circuit is filtered by the capacitor, and the transistor Q3 is turned on through the resistors R6, R7 and R11. The conduction of Q3 makes the gate voltage of the PMOS tube M1 lower, and the source voltage When the voltage is greater than the gate voltage, it is turned on, thereby supplying power to the subsequent circuits. When the voltage fluctuates and exceeds the safety voltage, the voltage regulator DW1 is turned on, thereby turning on the transistor Q2, and then controlling the transistor Q3 to be turned off, and the PMOS tube M1 is turned off accordingly, thereby playing the role of overvoltage protection. When the voltage returns to normal, the voltage regulator DW1 is turned off again, the transistor Q2 is also turned off, the transistor Q3 is turned on, and the PMOS tube is then turned on for power supply. When the current detection circuit outputs a detection signal, the transistor Q2 is also turned on, thereby turning off the PMOS tube to form a protection mechanism.

[0033] In this embodiment, the battery switching unit includes a resistor R17, a resistor R18, a resistor R19, a resistor R5, a transistor Q1, and a diode D2;

[0034] One end of the resistor R17 is used as the control input end of the battery switching unit, the other end of the resistor R17 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to one end of the resistor R5, the other end of the resistor R5 is used as the input end of the battery switching unit, the collector of the transistor Q1 is connected to the positive electrode of the diode D2 through the resistor R8, the negative electrode of the diode D2 is used as the output end of the battery switching unit, the collector of the transistor Q1 is connected to one end of the resistor R19, the other end of the resistor R19 is used as the control output end of the battery switching unit, wherein the transistor Q1 is a P-type transistor, when the current detection circuit and the voltage regulator DW1 are normal, the transistor Q1 has a gate voltage greater than the emitter voltage. The transistor Q1 is cut off when the PMOS tube is cut off, and the transistor Q1 is turned on, so that the battery supplies power to the processing chip to ensure that the processing chip can upload the alarm information. The processing chip U1 determines whether it is overcurrent or overvoltage according to the output signal of the resistor R19 and the signal output by the resistor R14. When the resistor R14 has no output, but the resistor R19 has an output, it is judged that the power supply of the computer room is overvoltage. When both the resistor R14 and the resistor R19 have outputs, it is judged as overcurrent. Although overcurrent and overvoltage may occur at the same time, it is also attributed to the overcurrent state. The processing chip uploads the alarm information (including the computer room number or detection location, alarm content (overcurrent or overvoltage)), etc.) to the upper host.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A power station room overcurrent monitoring and early warning control system, characterized in that: It includes a current detection unit, a power supply unit, a processing chip U1, a battery BAT, a voltage conversion circuit and a battery switching unit; The power supply unit includes a rectifier circuit Z2 and a switch control circuit; The current detection unit is used to detect the current of the live power line L of the power station room, and output a control signal to the switch control circuit and the processing chip when the current increases. The positive input terminal and the negative input terminal of the rectifier circuit Z2 are respectively connected to the live power line L and the neutral power line N. The positive output terminal of the rectifier circuit is connected to the input terminal of the switch control circuit, and the negative output terminal of the rectifier circuit is grounded. The second output terminal of the switch control circuit is connected to the input terminal of the voltage conversion circuit. The voltage conversion circuit supplies power to the processing chip, and the processing chip is connected to the upper host; The positive electrode of the battery BAT is connected to the input end of the battery switching unit, the output end of the battery switching unit is connected to the input end of the voltage conversion circuit, the control output end of the battery switching unit is connected to the input end of the processing chip, the control end of the battery switching unit is connected to the first output end of the switch control circuit, and the control input end of the switch control circuit is connected to the output end of the current detection unit; The current detection unit includes a current transformer T1, a rectifier circuit Z1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a matching resistor RL, a resistor R14, a resistor R15, a transistor Q4, a transistor Q5, an inductor L1, a capacitor C3 and a voltage regulator DW3; The primary winding of the current transformer T1 is connected in series to the live power line L, the positive end of the secondary winding of the current transformer T1 is connected to the positive input end of the rectifier circuit Z1, the negative input end of the rectifier circuit Z1 and the negative output end of the secondary winding of the current transformer T1 are grounded, one end of the resistor R1 is connected to the positive output end of the rectifier circuit Z1, the negative output end of the rectifier circuit is grounded, the other end of the resistor R1 is connected to one end of the inductor L1, and the other end of the inductor L1 is grounded through a matching load RL; A common connection point between the inductor L1 and the resistor R1 is connected to the emitter of the transistor Q4 through the resistor R2, the collector of the transistor Q4 is grounded through the resistor R15, the collector of the transistor Q4 is grounded through the capacitor C3, the collector of the transistor Q4 is connected to the negative electrode of the voltage-regulating tube DW3, the positive electrode of the voltage-regulating tube DW3 is grounded, the collector of the transistor Q4 is connected to one end of the resistor R14, the other end of the resistor R14 serves as the output end of the current detection unit, the base of the transistor Q4 is connected to the collector of the transistor Q5, the base of the transistor Q5 is connected to the common connection point between the inductor L1 and the matching load RL through the resistor R4, and the emitter of the transistor Q5 is connected to the common connection point between the inductor L1 and the matching load RL through the resistor R3; The switch control circuit includes a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R16, a capacitor C1, a capacitor C2, a voltage regulator DW1, a voltage regulator DW2, a transistor Q2, a transistor Q3, a PMOS tube M1 and a diode D1; One end of the resistor R6 is connected to the positive output end of the rectifier circuit Z2, the other end of the resistor R6 is connected to the source of the PMOS tube M1 through the resistor R7, the common connection point between the resistor R6 and the resistor R7 is grounded through the capacitor C1, the common connection point between the resistor R6 and the resistor R7 is connected to the ground after being connected in series with the resistor R8 and the resistor R9, the common connection point between the resistor R8 and the resistor R9 is connected to the negative electrode of the voltage regulator tube DW1, the positive electrode of the voltage regulator tube DW1 is connected to the base of the transistor Q2 through the resistor R10, the emitter of the transistor Q2 is grounded, the collector of the transistor Q2 is connected to the base of the transistor Q3, the base of the transistor Q3 is connected to the source of the PMOS tube M1 through the resistor R11, the source of the PMOS tube M1 is connected to the gate of the PMOS tube M1 through the resistor R12, the gate of the PMOS tube M1 is connected to the collector of the transistor Q3, the emitter of the transistor Q3 is grounded through the resistor R13, The drain of the PMOS tube M1 is connected to the positive electrode of the diode D1 through the resistor R16, the negative electrode of the diode D1 serves as the second output terminal of the switch control circuit, the positive electrode of the diode D1 serves as the first output terminal of the switch control circuit, the drain of the PMOS tube M1 is grounded through the capacitor C2, the drain of the PMOS tube M1 is connected to the negative electrode of the voltage regulator tube DW2, and the positive electrode of the voltage regulator tube DW2 is grounded; the base of the transistor Q2 serves as the control input terminal of the switch control circuit; The battery switching unit includes a resistor R17, a resistor R18, a resistor R19, a resistor R5, a transistor Q1, and a diode D2; One end of resistor R17 serves as a control input end of the battery switching unit, the other end of resistor R17 is connected to the base of transistor Q1, the emitter of transistor Q1 is connected to one end of resistor R5, the other end of resistor R5 serves as an input end of the battery switching unit, the collector of transistor Q1 is connected to the positive electrode of diode D2 through resistor R8, the negative electrode of diode D2 serves as an output end of the battery switching unit, the collector of transistor Q1 is connected to one end of resistor R19, the other end of resistor R19 serves as a control output end of the battery switching unit, wherein transistor Q1 is a P-type transistor.

2. According to claim 1, the power station room overcurrent monitoring and early warning control system is characterized by: The voltage conversion circuit is a LM7805 chip.

3. The power station room overcurrent monitoring and early warning control system according to claim 1 is characterized by: The processing chip is an AT89C2051 chip.

4. The power station room overcurrent monitoring and early warning control system according to claim 1 is characterized by: The storage battery is a lithium battery.

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