Transformer substation relay protection intelligent monitoring circuit

Abstract

The invention discloses a transformer substation relay protection intelligent monitoring circuit, and relates to the field of electric signal acquisition, and the transformer substation relay protection intelligent monitoring circuit comprises a voltage acquisition module which is used for acquiring a voltage signal of a transformer substation, obtaining a sampling voltage, and outputting the sampling voltage to a voltage judgment module; the voltage judgment module is used for setting different threshold voltages in the peak period, the gentle period and the valley period of power utilization, and outputting a driving signal to the alarm protection module when the sampling voltage is greater than the threshold voltages; the alarm protection module is used for giving an alarm after receiving the driving signal and controlling a switch at a three-phase live wire of the transformer substation to be switched off to stop power supply; compared with the prior art, the method has the beneficial effects that different threshold voltages are set on the basis of the power utilization peak period, the smooth period and the valley period, the different threshold voltages are matched with the fault voltages of the transformer substation in the power utilization peak period, the smooth period and the valley period, and the voltage fault of the transformer substation is detected more accurately.

Description

Technical Field

[0001] The invention relates to the field of electric signal acquisition, in particular to an intelligent monitoring circuit for relay protection of a transformer substation. Background Art

[0002] The voltage of the substation is usually different during peak and valley periods. This difference is mainly affected by the change in grid load. During peak periods, the grid load increases, and a large amount of current passes through the transmission lines and transformers. Since the lines and transformers have a certain impedance, the increase in current will cause the line voltage drop to increase. In contrast, during valley periods, the grid load decreases, and the amount of current passing through the transmission lines and transformers also decreases accordingly. Therefore, the line voltage drop will decrease. Therefore, the voltage at the substation is different during peak, flat, and valley periods.

[0003] Existing substation voltage monitoring often sets a fixed voltage threshold to determine whether the substation voltage is abnormal. When an abnormality occurs, the control relay disconnects the power supply circuit to avoid losses caused by abnormal voltage. Setting a fixed voltage threshold is not accurate enough for different power consumption periods and needs to be improved. Summary of the invention

[0004] The purpose of the present invention is to provide a transformer substation relay protection intelligent monitoring circuit to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A transformer substation relay protection intelligent monitoring circuit, comprising:

[0007] The voltage acquisition module is used to collect the voltage signal of the substation, obtain the sampled voltage, and output it to the voltage judgment module;

[0008] The voltage judgment module is used to set different threshold voltages (first threshold voltage, second threshold voltage, third threshold voltage) during peak power consumption period, flat period and valley period, and output a driving signal to the alarm protection module when the sampled voltage is greater than the threshold voltage;

[0009] The alarm protection module is used to give an alarm prompt after receiving the driving signal, and control the switch at the three-phase live wire of the substation to disconnect and stop the power supply;

[0010] The timing control module is used to detect the timing change, and based on the timing change, output a peak power consumption control signal or a level-slow power consumption control signal or a valley power consumption control signal (at common points A1, A2, and A3, respectively) to the voltage judgment module, so that the voltage judgment module sets different threshold voltages;

[0011] The output end of the voltage acquisition module is connected to the first input end of the voltage judgment module, the output end of the voltage judgment module is connected to the input end of the alarm protection module, and the output end of the timing control module is connected to the second input end of the voltage judgment module.

[0012] As a further solution of the present invention: the voltage acquisition module includes a mutual inductor, a first resistor, a first diode, a second resistor, and a first capacitor. The mutual inductor detects the voltage on the live line of the substation. One end of the mutual inductor is grounded, and the other end of the mutual inductor is connected to one end of the first resistor. The other end of the first resistor is connected to the positive electrode of the first diode, and the negative electrode of the first diode is connected to one end of the second resistor, one end of the first capacitor, and the first input end of the voltage judgment module. The other end of the second resistor is grounded, and the other end of the first capacitor is grounded.

[0013] As a further solution of the present invention: the voltage judgment module includes a first MOS tube, a second MOS tube, a third MOS tube, a first amplifier, a second amplifier, and a third amplifier. The D pole of the first MOS tube is connected to the output end of the voltage acquisition module, the D pole of the second MOS tube, and the D pole of the third MOS tube. The G pole of the first MOS tube is connected to the output end of the timing control module, the S pole of the first MOS tube is connected to the in-phase end of the first amplifier, and the inverting end of the first amplifier is connected to the first threshold voltage. The output end of the first amplifier is connected to the output end of the second amplifier, the output end of the third amplifier, and the input end of the alarm protection module. The G pole of the second MOS tube is connected to the output end of the timing control module, the S pole of the second MOS tube is connected to the in-phase end of the second amplifier, and the inverting end of the second amplifier is connected to the second threshold voltage. The G pole of the third MOS tube is connected to the output end of the timing control module, the S pole of the third MOS tube is connected to the in-phase end of the third amplifier, and the inverting end of the third amplifier is connected to the third threshold voltage.

[0014] As a further solution of the present invention: the alarm protection module includes a third resistor, a first thyristor, a second diode, a fourth resistor, a first relay, a third diode, and a buzzer, one end of the third resistor is connected to the power supply voltage, the other end of the third resistor is connected to the positive electrode of the first thyristor, the control electrode of the first thyristor is connected to the output end of the voltage judgment module, the negative electrode of the first thyristor is connected to the positive electrode of the second diode, one end of the buzzer, one end of the first relay, and the negative electrode of the third diode, the other end of the buzzer is grounded, the other end of the first relay is grounded, the positive electrode of the third diode is grounded, the negative electrode of the second diode is connected to one end of the fourth resistor, and the other end of the fourth resistor is grounded.

[0015] As a further solution of the present invention: the timing control module includes:

[0016] A fixed timing unit is used to output a timing signal to the timing output unit and the self-circulating control unit every 8 hours;

[0017] A timing output unit is used to output an 8-hour peak power consumption control signal to the voltage judgment module when receiving a first timing signal, output an 8-hour flat power consumption control signal to the voltage judgment module when receiving a second timing signal, and output an 8-hour valley power consumption control signal to the voltage judgment module when receiving a third timing signal;

[0018] A self-circulation control unit is used to control the timing output unit and the self-circulation control unit to restore the initial state after receiving three timing signals, and wait for the next cycle of the peak period, the flat period, and the valley period of electricity consumption;

[0019] The output end of the fixed timing unit is connected to the first input end of the timing output unit and the input end of the self-circulation control unit, the output end of the self-circulation control unit is connected to the second input end of the timing output unit, and the output end of the timing output unit is connected to the second input end of the voltage judgment module.

[0020] As a further solution of the present invention: the fixed timing unit includes a fifth resistor, a first potentiometer, a second capacitor, a fourth diode, and a fourth transistor, one end of the fifth resistor is connected to the power supply voltage, the other end of the fifth resistor is connected to one end of the first potentiometer, the other end of the first potentiometer is connected to one end of the second capacitor, the cathode of the fourth diode, and the collector of the fourth transistor, the other end of the second capacitor is grounded, the emitter of the fourth transistor is grounded, and the anode of the fourth diode is connected to the base of the fourth transistor and the common point A4.

[0021] As a further solution of the present invention: the timing output unit includes a sixth triode, a seventh MOS tube, an eighth triode, a second thyristor, a ninth triode, a third thyristor, a tenth triode, an eleventh MOS tube, a fourth thyristor, and a twelfth triode, the emitter of the sixth triode is grounded, the base of the sixth triode is connected to the cathode of the fifth diode and the cathode of the sixth diode, the anode of the fifth diode is connected to the common point A2, the anode of the sixth diode is connected to the common point A3, the collector of the sixth triode is connected to the common point A1 and one end of the seventh resistor, and the other end of the seventh resistor is connected to the supply voltage;

[0022] The D pole of the seventh MOS tube is connected to one end of the third capacitor and one end of the ninth resistor, the other end of the third capacitor is grounded, the other end of the ninth resistor is connected to the power supply voltage through the eighth resistor, the G pole of the seventh MOS tube is connected to the common point A4, the S pole of the seventh MOS tube is connected to the control pole of the second thyristor, the positive pole of the second thyristor is connected to one end of the tenth resistor and the collector of the eighth transistor, the other end of the tenth resistor is connected to the power supply voltage, the emitter of the eighth transistor is grounded, the base of the eighth transistor is connected to the common point A5, the negative pole of the second thyristor is connected to the common point A2, the collector of the ninth transistor, and the control pole of the third thyristor, the emitter of the ninth transistor is grounded, and the base of the ninth transistor is connected to the common point A3;

[0023] The positive electrode of the third thyristor is connected to one end of the eleventh resistor and the collector of the twelfth transistor, the other end of the eleventh resistor is connected to the power supply voltage, the emitter of the twelfth transistor is grounded, and the base of the twelfth transistor is connected to the common point A5, the negative electrode of the third thyristor is connected to one end of the twelfth resistor, the other end of the twelfth resistor is connected to one end of the fourth capacitor and the D electrode of the eleventh MOS tube, the other end of the fourth capacitor is grounded, the G electrode of the eleventh MOS tube is connected to the common point A4, the S electrode of the eleventh MOS tube is connected to the control electrode of the fourth thyristor, the negative electrode of the fourth thyristor is connected to the common point A3, the positive electrode of the fourth thyristor is connected to one end of the thirteenth resistor and the collector of the twelfth transistor, the other end of the thirteenth resistor is connected to the power supply voltage, the emitter of the twelfth transistor is grounded, and the base of the twelfth transistor is connected to the common point A5.

[0024] As a further solution of the present invention: the self-circulation control unit includes a counter, a sixth resistor, and a fifth transistor, the input end of the counter is connected to the common point A4, the output end of the counter is connected to the common point A5 and the base of the fifth transistor, the emitter of the fifth transistor is grounded, the collector of the fifth transistor is connected to one end of the sixth resistor and the power supply end of the counter, and the other end of the sixth resistor is connected to the supply voltage.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention sets different threshold voltages based on peak, flat and valley periods of electricity consumption; the different threshold voltages match the fault voltages of the substation during peak, flat and valley periods of electricity consumption, making the detection of substation voltage faults more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The schematic diagram is a schematic diagram of an intelligent monitoring circuit for relay protection in a substation.

[0027] Figure 2 This is the schematic diagram of the timing control module.

[0028] Figure 3 It is the circuit diagram of the voltage acquisition module, voltage judgment module and alarm protection module.

[0029] Figure 4 This is the circuit diagram of the timing control module. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0031] See also Figure 1 , a substation relay protection intelligent monitoring circuit, comprising:

[0032] The voltage acquisition module 1 is used to collect the voltage signal of the substation, obtain the sampled voltage, and output it to the voltage judgment module 2;

[0033] The voltage judgment module 2 is used to set different threshold voltages (first threshold voltage VREF1, second threshold voltage VREF2, third threshold voltage VREF3) during the peak period, flat period and valley period of electricity consumption, and output a driving signal to the alarm protection module 3 when the sampled voltage is greater than the threshold voltage;

[0034] The alarm protection module 3 is used to give an alarm prompt after receiving the driving signal, and control the switch at the three-phase live wire of the substation to disconnect and stop power supply;

[0035] The timing control module 4 is used to detect the timing change, and based on the timing change, output a peak power consumption control signal or a level-slow power consumption control signal or a valley power consumption control signal (at the common points A1, A2, and A3, respectively) to the voltage judgment module 2, so that the voltage judgment module 2 sets different threshold voltages;

[0036] The output end of the voltage acquisition module 1 is connected to the first input end of the voltage judgment module 2 , the output end of the voltage judgment module 2 is connected to the input end of the alarm protection module 3 , and the output end of the timing control module 4 is connected to the second input end of the voltage judgment module 2 .

[0037] In this example: See Figure 3The voltage acquisition module 1 includes a mutual inductor X, a first resistor R1, a first diode D1, a second resistor R2, and a first capacitor C1. The mutual inductor X detects the voltage on the live line of the substation. One end of the mutual inductor X is grounded, and the other end of the mutual inductor X is connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the positive electrode of the first diode D1, and the negative electrode of the first diode D1 is connected to one end of the second resistor R2, one end of the first capacitor C1, and the first input end of the voltage judgment module 2. The other end of the second resistor R2 is grounded, and the other end of the first capacitor C1 is grounded.

[0038] The voltage on the live line of the substation is proportionally output through the transformer X, rectified and filtered by the first diode D1 and the first capacitor C1, and a sampling voltage is formed on the second resistor R2, which is output to the voltage judgment module 2.

[0039] In another embodiment: the voltage on the live line of the substation is obtained through the transformer X, and the voltage on the live line of the substation can also be obtained through a plurality of resistors connected in series. The resistance value of the series resistors needs to be large enough to make the final sampled voltage suitable.

[0040] In this example: See Figure 3 The voltage judgment module 2 includes a first MOS tube V1, a second MOS tube V2, a third MOS tube V3, a first amplifier U1, a second amplifier U2, and a third amplifier U3. The D pole of the first MOS tube V1 is connected to the output end of the voltage acquisition module 1, the D pole of the second MOS tube V2, and the D pole of the third MOS tube V3. The G pole of the first MOS tube V1 is connected to the output end of the timing control module 4. The S pole of the first MOS tube V1 is connected to the in-phase end of the first amplifier U1. The inverting end of the first amplifier U1 is connected to the first threshold voltage VREF1. The first amplifier U1 The output end of is connected to the output end of the second amplifier U2, the output end of the third amplifier U3, and the input end of the alarm protection module 3, the G pole of the second MOS tube V2 is connected to the output end of the timing control module 4, the S pole of the second MOS tube V2 is connected to the in-phase end of the second amplifier U2, the inverting end of the second amplifier U2 is connected to the second threshold voltage VREF2, the G pole of the third MOS tube V3 is connected to the output end of the timing control module 4, the S pole of the third MOS tube V3 is connected to the in-phase end of the third amplifier U3, and the inverting end of the third amplifier U3 is connected to the third threshold voltage VREF3.

[0041] When the live line voltage of the substation is normal, the sampling voltage will be lower than the different threshold voltages corresponding to the peak period, flat period and valley period of electricity consumption (the first threshold voltage VREF1, the second threshold voltage VREF2, the third threshold voltage VREF3), and the first amplifier U1 or the second amplifier U2 or the third amplifier U3 will not output a high level, and will not trigger the alarm protection module 3 to work; otherwise, the first amplifier U1 or the second amplifier U2 or the third amplifier U3 will output a high level, triggering the alarm protection module 3 to work.

[0042] In another embodiment, only one amplifier may be used, and three MOS tubes are connected in parallel to the inverting terminal of the amplifier, and provide a first threshold voltage VREF1, a second threshold voltage VREF2, and a third threshold voltage VREF3 respectively when they are turned on.

[0043] In this example: See Figure 3 The alarm protection module 3 includes a third resistor R3, a first thyristor Z1, a second diode D2, a fourth resistor R4, a first relay J1, a third diode D3, and a buzzer BUZZ. One end of the third resistor R3 is connected to the power supply voltage VCC, the other end of the third resistor R3 is connected to the positive electrode of the first thyristor Z1, the control electrode of the first thyristor Z1 is connected to the output end of the voltage judgment module 2, the negative electrode of the first thyristor Z1 is connected to the positive electrode of the second diode D2, one end of the buzzer BUZZ, one end of the first relay J1, and the negative electrode of the third diode D3. The other end of the buzzer BUZZ is grounded, the other end of the first relay J1 is grounded, the positive electrode of the third diode D3 is grounded, the negative electrode of the second diode D2 is connected to one end of the fourth resistor R4, and the other end of the fourth resistor R4 is grounded.

[0044] The first amplifier U1 or the second amplifier U2 or the third amplifier U3 outputs a high level, the first thyristor Z1 is turned on, the first relay J1 is energized and works, the first switch S1 is controlled to be disconnected, the live line of the substation is disconnected, the power supply is stopped, and the buzzer BUZZ sounds to alert the staff.

[0045] In another embodiment, the second diode D2 can be omitted. The second diode D2 is used as a light emitting diode to play an indicating role.

[0046] In this example: See Figure 2 and Figure 4 , the timing control module 4 includes:

[0047] A fixed timing unit 41 is used to output a timing signal to the timing output unit 42 and the self-circulation control unit 43 every 8 hours;

[0048] The timing output unit 42 is used to output an 8-hour peak power consumption control signal to the voltage judgment module 2 when receiving the first timing signal, output an 8-hour flat power consumption control signal to the voltage judgment module 2 when receiving the second timing signal, and output an 8-hour valley power consumption control signal to the voltage judgment module 2 when receiving the third timing signal;

[0049] The self-cycle control unit 43 is used to control the timing output unit 42 and the self-cycle control unit 43 to restore the initial state after receiving the three timing signals, and wait for the next cycle of the peak period, the flat period, and the valley period of electricity consumption;

[0050] The output end of the fixed timing unit 41 is connected to the first input end of the timing output unit 42 and the input end of the self-circulation control unit 43, the output end of the self-circulation control unit 43 is connected to the second input end of the timing output unit 42, and the output end of the timing output unit 42 is connected to the second input end of the voltage judgment module 2.

[0051] In this example: See Figure 4 The fixed timing unit 41 includes a fifth resistor R5, a first potentiometer RP1, a second capacitor C2, a fourth diode D4, and a fourth transistor V4. One end of the fifth resistor R5 is connected to the power supply voltage VCC, the other end of the fifth resistor R5 is connected to one end of the first potentiometer RP1, the other end of the first potentiometer RP1 is connected to one end of the second capacitor C2, the cathode of the fourth diode D4, and the collector of the fourth transistor V4, the other end of the second capacitor C2 is grounded, the emitter of the fourth transistor V4 is grounded, and the anode of the fourth diode D4 is connected to the base of the fourth transistor V4 and the common point A4.

[0052] After power-on, the supply voltage VCC charges the second capacitor C2 through the fifth resistor R5 and the first potentiometer RP1. By adjusting the resistance of the first potentiometer RP1, the second capacitor C2 is charged to a time sufficient to turn on the fourth diode D4 for 8 hours. 8 hours after power-on, the fourth diode D4 is turned on, a high level appears at the common point A4, the fourth transistor V4 is turned on, and the voltage on the second capacitor C2 is quickly discharged, so that the fixed timing unit 41 returns to the initial state. After waiting for another 8 hours, a high level appears at the common point A4 again, and this goes on and on. A high level is output at the common point A4 every 8 hours.

[0053] In another embodiment, other devices such as time relays may be used to output a high level every 8 hours.

[0054] In this example: See Figure 4The timing output unit 42 includes a sixth transistor V6, a seventh MOS transistor V7, an eighth transistor V8, a second thyristor Z2, a ninth transistor V9, a third thyristor Z3, a tenth transistor V10, an eleventh MOS transistor V11, a fourth thyristor Z4, and a twelfth transistor V12. The emitter of the sixth transistor V6 is grounded, the base of the sixth transistor V6 is connected to the cathode of the fifth diode D5 and the cathode of the sixth diode D6, the anode of the fifth diode D5 is connected to the common point A2, the anode of the sixth diode D6 is connected to the common point A3, the collector of the sixth transistor V6 is connected to the common point A1 and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the power supply voltage VCC;

[0055] The D pole of the seventh MOS tube V7 is connected to one end of the third capacitor C3 and one end of the ninth resistor R9, the other end of the third capacitor C3 is grounded, the other end of the ninth resistor R9 is connected to the power supply voltage VCC through the eighth resistor R8, the G pole of the seventh MOS tube V7 is connected to the common point A4, the S pole of the seventh MOS tube V7 is connected to the control pole of the second thyristor Z2, the positive pole of the second thyristor Z2 is connected to one end of the tenth resistor R10 and the collector of the eighth transistor V8, the other end of the tenth resistor R10 is connected to the power supply voltage VCC, the emitter of the eighth transistor V8 is grounded, the base of the eighth transistor V8 is connected to the common point A5, the negative pole of the second thyristor Z2 is connected to the common point A2, the collector of the ninth transistor V9, and the control pole of the third thyristor Z3, the emitter of the ninth transistor V9 is grounded, and the base of the ninth transistor V9 is connected to the common point A3;

[0056] The positive electrode of the third thyristor Z3 is connected to one end of the eleventh resistor R11 and the collector of the thirteenth MOS tube V10, the other end of the eleventh resistor R11 is connected to the power supply voltage VCC, the emitter of the thirteenth MOS tube V10 is grounded, the base of the thirteenth MOS tube V10 is connected to the common point A5, the negative electrode of the third thyristor Z3 is connected to one end of the twelfth resistor R12, the other end of the twelfth resistor R12 is connected to one end of the fourth capacitor C4 and the D pole of the eleventh MOS tube V11, and the other end of the fourth capacitor C4 is connected to the D pole of the fourth capacitor C4. grounded, a G pole of the eleventh MOS tube V11 is connected to a common point A4, an S pole of the eleventh MOS tube V11 is connected to a control pole of a fourth thyristor Z4, a cathode of the fourth thyristor Z4 is connected to a common point A3, a cathode of the fourth thyristor Z4 is connected to one end of a thirteenth resistor R13 and a collector of a twelfth transistor V12, the other end of the thirteenth resistor R13 is connected to a power supply voltage VCC, an emitter of the twelfth transistor V12 is grounded, and a base of the twelfth transistor V12 is connected to a common point A5.

[0057] The peak period of electricity consumption (9:00-17:00), the flat period (17:00-1:00), and the valley period (1:00-9:00) are alternately explained for 8 hours. When the power is turned on, it is 9:00. At this time, the common point A1 is at a high level, triggering the first MOS tube V1 to turn on. At this time, the sampled voltage is compared with the first threshold voltage VREF1 corresponding to the peak period of electricity consumption to determine whether the live line voltage of the substation is abnormal; after 8 hours, it reaches the flat period of electricity consumption, and the common point A4 has a high level. The seventh MOS tube V7 is turned on instantaneously, triggering the second thyristor Z2 to turn on, and the common point A2 becomes a high level, triggering the third thyristor Z3 to turn on, and the sixth transistor V6 is turned on at the same time. Grounded, common point A1 becomes low level, triggering the second MOS tube V2 to turn on, at this time, the sampling voltage is compared with the second threshold voltage VREF2 corresponding to the power consumption period, and it is judged whether the live line voltage of the substation is abnormal; after another 8 hours, it reaches the power consumption valley period, and common point A4 appears a high level again. Based on the fact that the third thyristor Z3 has been turned on, the eleventh MOS tube V11 is turned on, triggering the fourth thyristor Z4 to turn on, common point A3 becomes high level, the sixth triode V6 and the ninth triode V9 are turned on and grounded, and common points A1 and A2 become low level. At this time, the sampling voltage is compared with the third threshold voltage VREF3 corresponding to the power consumption valley period, and it is judged whether the live line voltage of the substation is abnormal. The initial 9.00 power-on can be controlled by the microcontroller timing, or it can be powered on manually.

[0058] In another embodiment, the seventh MOS transistor V7 and the eleventh MOS transistor V11 can be replaced with other types of switch transistors.

[0059] In this example: See Figure 4 The self-circulation control unit 43 includes a counter U4, a sixth resistor R6, and a fifth transistor V5. The input end of the counter U4 is connected to the common point A4, the output end of the counter U4 is connected to the common point A5 and the base of the fifth transistor V5, the emitter of the fifth transistor V5 is grounded, the collector of the fifth transistor V5 is connected to one end of the sixth resistor R6 and the power supply end of the counter U4, and the other end of the sixth resistor R6 is connected to the power supply voltage VCC.

[0060] At the end of the low power consumption period, when the common point A4 outputs a high level for the third time, the counter U4 is set as a ternary counter U4. After receiving three high levels at the input end, the output end outputs a high level, and the common point A5 becomes a high level, so that the eighth triode V8, the tenth triode V10, the twelfth triode V12, and the fifth triode V5 are turned on and grounded, and the second thyristor Z2, the third thyristor Z3, and the fourth thyristor Z4 are restored to the non-conducting state. The power supply end of the counter U4 is grounded and stops working. After the high level of the common point A5 ends, the timing output unit 42 and the self-circulation control unit 43 are restored to the initial state, and the next peak power consumption period, flat period, and low period are alternately cycled for 8 hours. Here, 8 hours is used as an example, but it is not limited to 8 hours in actual use.

[0061] In another embodiment, the supply voltage VCC can be obtained by processing the voltage obtained from the transformer X, or by powering a battery.

[0062] The working principle of the present invention is: the voltage acquisition module 1 is used to collect the voltage signal of the substation, obtain the sampled voltage, and output it to the voltage judgment module 2; the voltage judgment module 2 is used to set different threshold voltages (first threshold voltage VREF1, second threshold voltage VREF2, third threshold voltage VREF3) during the peak period, flat period, and valley period of electricity consumption, and when the sampled voltage is greater than the threshold voltage, output a drive signal to the alarm protection module 3; the alarm protection module 3 is used to give an alarm prompt after receiving the drive signal, and control the switch at the three-phase live wire of the substation to disconnect and stop power supply; the timing control module 4 is used to detect timing changes, and based on the timing changes, output a peak power consumption control signal or a flat power consumption control signal or a valley power consumption control signal (at common points A1, A2, and A3, respectively) to the voltage judgment module 2, so that the voltage judgment module 2 sets different threshold voltages.

[0063] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered as exemplary and non-restrictive in all respects.

[0064] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A substation relay protection intelligent monitoring circuit, characterized in that: The substation relay protection intelligent monitoring circuit includes: The voltage acquisition module is used to collect the voltage signal of the substation, obtain the sampled voltage, and output it to the voltage judgment module; The voltage judgment module is used to set different threshold voltages during peak, flat and valley periods of electricity consumption. When the sampled voltage is greater than the threshold voltage, it outputs a driving signal to the alarm protection module. The alarm protection module is used to give an alarm prompt after receiving the driving signal, and control the switch at the three-phase live wire of the substation to disconnect and stop the power supply; A timing control module is used to detect timing changes, and based on the timing changes, output a peak power consumption control signal, a level-delay control signal, or a valley power consumption control signal to the voltage judgment module, so that the voltage judgment module sets different threshold voltages; The output end of the voltage acquisition module is connected to the first input end of the voltage judgment module, the output end of the voltage judgment module is connected to the input end of the alarm protection module, and the output end of the timing control module is connected to the second input end of the voltage judgment module.

2. The intelligent monitoring circuit for relay protection of a substation according to claim 1, characterized in that: The voltage acquisition module includes a mutual inductor, a first resistor, a first diode, a second resistor, and a first capacitor. The mutual inductor detects the voltage on the live line of the substation. One end of the mutual inductor is grounded, and the other end of the mutual inductor is connected to one end of the first resistor. The other end of the first resistor is connected to the positive electrode of the first diode, and the negative electrode of the first diode is connected to one end of the second resistor, one end of the first capacitor, and the first input end of the voltage judgment module. The other end of the second resistor is grounded, and the other end of the first capacitor is grounded.

3. The intelligent monitoring circuit for relay protection of a substation according to claim 1, characterized in that: The voltage judgment module includes a first MOS tube, a second MOS tube, a third MOS tube, a first amplifier, a second amplifier, and a third amplifier. The D pole of the first MOS tube is connected to the output end of the voltage acquisition module, the D pole of the second MOS tube, and the D pole of the third MOS tube. The G pole of the first MOS tube is connected to the output end of the timing control module. The S pole of the first MOS tube is connected to the in-phase end of the first amplifier. The inverting end of the first amplifier is connected to the first threshold voltage. The output end of the first amplifier is connected to the output end of the second amplifier, the output end of the third amplifier, and the input end of the alarm protection module. The G pole of the second MOS tube is connected to the output end of the timing control module, the S pole of the second MOS tube is connected to the in-phase end of the second amplifier, the inverting end of the second amplifier is connected to the second threshold voltage, the G pole of the third MOS tube is connected to the output end of the timing control module, the S pole of the third MOS tube is connected to the in-phase end of the third amplifier, and the inverting end of the third amplifier is connected to the third threshold voltage.

4. The intelligent monitoring circuit for relay protection of a substation according to claim 1, characterized in that: The alarm protection module includes a third resistor, a first thyristor, a second diode, a fourth resistor, a first relay, a third diode, and a buzzer. One end of the third resistor is connected to the power supply voltage, the other end of the third resistor is connected to the positive electrode of the first thyristor, the control electrode of the first thyristor is connected to the output end of the voltage judgment module, the negative electrode of the first thyristor is connected to the positive electrode of the second diode, one end of the buzzer, one end of the first relay, and the negative electrode of the third diode. The other end of the buzzer is grounded, the other end of the first relay is grounded, the positive electrode of the third diode is grounded, the negative electrode of the second diode is connected to one end of the fourth resistor, and the other end of the fourth resistor is grounded.

5. The intelligent monitoring circuit for relay protection of a substation according to claim 1, characterized in that: The timing control module includes: A fixed timing unit is used to output a timing signal to the timing output unit and the self-circulating control unit every 8 hours; A timing output unit is used to output an 8-hour peak power consumption control signal to the voltage judgment module when receiving a first timing signal, output an 8-hour flat power consumption control signal to the voltage judgment module when receiving a second timing signal, and output an 8-hour valley power consumption control signal to the voltage judgment module when receiving a third timing signal; A self-circulation control unit is used to control the timing output unit and the self-circulation control unit to restore the initial state after receiving three timing signals, and wait for the next cycle of the peak period, the flat period, and the valley period of electricity consumption; The output end of the fixed timing unit is connected to the first input end of the timing output unit and the input end of the self-circulation control unit, the output end of the self-circulation control unit is connected to the second input end of the timing output unit, and the output end of the timing output unit is connected to the second input end of the voltage judgment module.

6. The intelligent monitoring circuit for relay protection of substation according to claim 5, characterized in that: The fixed timing unit includes a fifth resistor, a first potentiometer, a second capacitor, a fourth diode, and a fourth transistor. One end of the fifth resistor is connected to the supply voltage, the other end of the fifth resistor is connected to one end of the first potentiometer, the other end of the first potentiometer is connected to one end of the second capacitor, the cathode of the fourth diode, and the collector of the fourth transistor, the other end of the second capacitor is grounded, the emitter of the fourth transistor is grounded, and the anode of the fourth diode is connected to the base of the fourth transistor and the common point A4.

7. The intelligent monitoring circuit for relay protection of a substation according to claim 5, characterized in that: The timing output unit includes a sixth triode, a seventh MOS tube, an eighth triode, a second thyristor, a ninth triode, a third thyristor, a tenth triode, an eleventh MOS tube, a fourth thyristor, and a twelfth triode, the emitter of the sixth triode is grounded, the base of the sixth triode is connected to the cathode of the fifth diode and the cathode of the sixth diode, the anode of the fifth diode is connected to the common point A2, the anode of the sixth diode is connected to the common point A3, the collector of the sixth triode is connected to the common point A1 and one end of the seventh resistor, and the other end of the seventh resistor is connected to the power supply voltage; The D pole of the seventh MOS tube is connected to one end of the third capacitor and one end of the ninth resistor, the other end of the third capacitor is grounded, the other end of the ninth resistor is connected to the power supply voltage through the eighth resistor, the G pole of the seventh MOS tube is connected to the common point A4, the S pole of the seventh MOS tube is connected to the control pole of the second thyristor, the positive pole of the second thyristor is connected to one end of the tenth resistor and the collector of the eighth transistor, the other end of the tenth resistor is connected to the power supply voltage, the emitter of the eighth transistor is grounded, the base of the eighth transistor is connected to the common point A5, the negative pole of the second thyristor is connected to the common point A2, the collector of the ninth transistor, and the control pole of the third thyristor, the emitter of the ninth transistor is grounded, and the base of the ninth transistor is connected to the common point A3; The positive electrode of the third thyristor is connected to one end of the eleventh resistor and the collector of the twelfth transistor, the other end of the eleventh resistor is connected to the power supply voltage, the emitter of the twelfth transistor is grounded, and the base of the twelfth transistor is connected to the common point A5, the negative electrode of the third thyristor is connected to one end of the twelfth resistor, the other end of the twelfth resistor is connected to one end of the fourth capacitor and the D electrode of the eleventh MOS tube, the other end of the fourth capacitor is grounded, the G electrode of the eleventh MOS tube is connected to the common point A4, the S electrode of the eleventh MOS tube is connected to the control electrode of the fourth thyristor, the negative electrode of the fourth thyristor is connected to the common point A3, the positive electrode of the fourth thyristor is connected to one end of the thirteenth resistor and the collector of the twelfth transistor, the other end of the thirteenth resistor is connected to the power supply voltage, the emitter of the twelfth transistor is grounded, and the base of the twelfth transistor is connected to the common point A5.

8. The substation relay protection intelligent monitoring circuit according to any one of claims 5 to 7, characterized in that: The self-circulation control unit includes a counter, a sixth resistor, and a fifth transistor. The input end of the counter is connected to the common point A4, the output end of the counter is connected to the common point A5 and the base of the fifth transistor, the emitter of the fifth transistor is grounded, the collector of the fifth transistor is connected to one end of the sixth resistor and the power supply end of the counter, and the other end of the sixth resistor is connected to the supply voltage.

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