CN1169537A

CN1169537A - Electric quantity computer-controlled monitoring instrument

Info

Publication number: CN1169537A
Application number: CN 96106712
Authority: CN
Inventors: 潘峥嵘; 王继曾; 张熙德; 秦云
Original assignee: High-New Tech Industry General Co Gansu Polytechnique Univ
Current assignee: High-New Tech Industry General Co Gansu Polytechnique Univ
Priority date: 1996-06-26
Filing date: 1996-06-26
Publication date: 1998-01-07

Abstract

The computer monitoring instrument for quantity of electricity mainly comprises current collecting circuit, urrent detection circuit, voltage detection circuit, phase-shortage detection circuit, real-time clock circuit, memory, monolithic computer chip and data transmission circuit, in which a current transformer is connected in the front of connecting terminal of the monitoring instrument and another current transformer is connected with input end of watt-hour meter. The connection of both current transformers is implemented by using positive-negative opposition method, so that the current is amplified by amplifier, detected, integrated and compared by comparator, then phase-reversibly fed into the monolithic computer chip, and analyzed, processed and recorded by said monolithic computer to define phase-shortage and breakaway and can find and prevent improper use of electricity.

Description

A kind of electric quantity computer-controlled monitoring instrument

The present invention is a kind of electric quantity computer-controlled monitoring instrument, and it belongs to the electronics metering field.

Watt-hour meter of the prior art adopts a net timer, be connected on respectively on the normally closed contact of two relays, and the A that these two relays are connected to watt-hour meter voltage mutual inductor PT input end respectively mutually with C mutually, when voltage transformer pt insurance is opened circuit or had a power failure, it is the meter voltage coil dead electricity, then connect corresponding timer, the time of the dead electricity of accumulative total meter voltage coil.

The defective of above-mentioned watt-hour meter of the prior art is:

1, it adds up the voltage transformer pt no-voltage, but also adds up for normal power failure (having a power failure for the maintenance circuit as power supply department), and therefore being hard to tell is to belong to normal or improper power failure;

2, it but is at a complete loss as to what to do at connection terminal short circuit (being the meter current coil dead electricity) to current transformer CT, and the most direct method of professional stealing is exactly short circuit current transformer CT.

The objective of the invention is automatically A, B, the C three-phase voltage of voltage transformer pt to be monitored, determine phase shortage and power down time, automatically current transformer CT is monitored, find and prevent professional stealing.

The present invention is a kind of electric quantity computer-controlled monitoring instrument, by current acquisition circuit 1, current detection circuit 2, voltage detecting circuit 3, lack detection circuit 4, power circuit 5, power backup circuit 6, real time clock circuit 7, storer 8, singlechip chip 9 and data transmission circuit 10 are formed, power backup circuit 6 is by diode D3, D4, resistance R 5, capacitor C 9, electrochemical capacitor E1, capacitor C 10, backup battery EE constitutes, power circuit 5 is by inductance B1, B2, diode D11, D12, D13, D14, D15, D16, D1, D2, electrochemical capacitor E3, singlechip chip U7, electrochemical capacitor E4, capacitor C 24 constitutes, feature of the present invention is: current transformer I1 is connected on monitor connection terminal L1 front end, current transformer I3 is connected on the input end A1 of watt-hour meter KWH, I1 and the reversal connection of I3 both positive and negative polarity, each self-induced electromotive force addition of I1 and I3, via resistance R 8, R9, capacitor C 12, diode D6, D7, resistance R 7, capacitor C 11, chip U6:A, the amplifier that potentiometer P2 forms amplifies, through diode D5 detection, again through capacitor C 13, resistance R 16 integrations, again via resistance R 11, capacitor C 14, Led2, resistance R 12, electric capacity U6:E, the comparer that resistance R 13 is formed compares, after U5:A is anti-phase, the P1.0 that sends into the U3 chip is analyzed by single-chip microcomputer, handle, and record; Lack detection circuit 4 is made up of resistance R 1, P3, capacitor C 22, U5:D, when appointing, a, b, c lack a phase time, through the three phase full bridge rectification that D11～D16 forms, the B point voltage is through resistance R 1, potentiometer P3 dividing potential drop, the pulsation that the A point promptly produces 100Hz, through the U5:C shaping, anti-phase through U5:D again, send into the T0 mouth of U3 chip, count, judge its non-full-phase state, and record; Power-fail detection circuit is made up of electrochemical capacitor E2, resistance R 2, potentiometer P4, capacitor C 23, U5:F, U5:E, when power down takes place, the D point voltage descends, through resistance R 2, potentiometer P4 dividing potential drop, the C point voltage is dropped rapidly to the following threshold values of Schmidt trigger U5:F, makes Schmidt trigger U5:F upset, through the U5:E shaping, provide one along interrupting, by the circuit record power down time of U3 for the INT0 of U3 chip.A pad 12 is equipped with in end at the housing 11 of above-mentioned monitor, on pad 12, have a

rectangular chute

13,3 of E in its circuit, F, G link to each other with three

spring

15a, 15b, 15c of protruding housing 11,

spring

15a, 15b, 15c are contained on three slide plate 14a, the 14b that can move in chute 13, the 14c with insulating respectively, and

spring

15a, 15b, 15c are inserted in respectively on the socket on the watt-hour meter KWH.

Current transformer I1 and the reversal connection of I3 both positive and negative polarity, when the electric current that flows through I1, I3 equated, the electromotive force of responding among I1, the I3 equated that direction is opposite, cancels out each other the amplifier no signal; When stealing or power down take place when, flow through I1, the electric current of I3 is unequal, I1 then, the electromotive force of responding among the I3 is also unequal, can not cancel out each other, amplifier has signal, via resistance R 8, R9, capacitor C 12, diode D6, D7, resistance R 7, capacitor C 11, chip U6:A, the amplifier that potentiometer P2 forms amplifies, through diode D5 detection, again through capacitor C 13, resistance R 16 integrations, again via resistance R 11, capacitor C 14, Led2, resistance R 12, electric capacity U6:E, the comparer that resistance R 13 is formed compares, after U5:A is anti-phase, the P1.0 that sends into the U3 chip is analyzed by single-chip microcomputer, handle, and record; Acting as of lack detection circuit: lack a phase time when a, b, c appoint, by the three phase full bridge rectification that resistance R is formed through D11～D16, the waveform bar number that the B point shows on voltage table becomes 4 by original 6, and the following threshold values of U5:C is reduced in voltage fluctuation in one-period, the voltage of ordering at B is through resistance R 1, potentiometer P3 dividing potential drop, the pulsation that the A point promptly produces 100Hz, through the U5:C shaping, anti-phase through U5:D again, send into the T0 mouth of U3 chip, count, judge its non-full-phase state, and record.

Fig. 1 is a circuit block diagram of the present invention;

Fig. 2 is a circuit diagram of the present invention;

Fig. 3 is the appearance assumption diagram of most preferred embodiment of the present invention;

Fig. 4 is the monitoring installation diagram of most preferred embodiment of the present invention.

The model that singlechip chip U3 among Fig. 2 adopts is 8751, and the model of U2 is 373, and the model of U1 is 6116, and the model of U4 is 146818.As shown in Figure 3, Figure 4, when measuring electric weight, the watchcase of the bottom of watt-hour meter KWH is unloaded, with of the present utility model three respectively with Fig. 2 in the vertical socket that inserts on the watt-hour meter KWH of

spring

15a, 15b, 15c that links of 3 of E, F, G on, by two screws on the pad 12 the present invention is installed in the bottom of watt-hour meter KWH with two bolts.

The present invention adopts more advanced in the world MCS series monolithic system, has achieved digitizing, computerization, can analyze any accident information of electric power system, record; It can automatically be monitored the three-phase voltage of voltage transformer (VT), can carry out record to the concrete time that phase shortage and power down begin and finish, for the powered operation man analysis.It also can be monitored the electric current of current transformer, can write down actual current and analyze and record with the input unequal concrete time of current watt-hour meter.Because of adopting the non-contact type current collection, need not change the load of current transformer CT; It need not reequip the ammeter cabinet, can directly be plugged on the watt-hour meter to monitor.

Claims

1, a kind of electric quantity computer-controlled monitoring instrument, by current acquisition circuit 1, current detection circuit 2, voltage detecting circuit 3, lack detection circuit 4, power circuit 5, power backup circuit 6, real time clock circuit 7, storer 8, singlechip chip 9 and data transmission circuit 10 are formed, power backup circuit 6 is by diode D3, D4, resistance R 5, capacitor C 9, electrochemical capacitor E1, capacitor C 10, backup battery EE constitutes, power circuit 5 is by inductance B1, B2, diode D11, D12, D13, D14, D15, D16, D1, D2, electrochemical capacitor E3, singlechip chip U7, electrochemical capacitor E4, capacitor C 24 constitutes, feature of the present invention is: current transformer I1 is connected on monitor connection terminal L1 front end, current transformer I3 is connected on the input end A1 of watt-hour meter KWH, I1 and the reversal connection of I3 both positive and negative polarity, each self-induced electromotive force addition of current transformer I1 and I3, via resistance R 8, R9, capacitor C 12, diode D6, D7, resistance R 7, capacitor C 11, chip U6:A, the amplifier that potentiometer P2 forms amplifies, through diode D5 detection, again through capacitor C 13, resistance R 16 integrations, again via resistance R 11, capacitor C 14, Led2, resistance R 12, electric capacity U6:E, the comparer that resistance R 13 is formed compares, after U5:A is anti-phase, the P1.0 that sends into the U3 chip is analyzed by single-chip microcomputer, handle, and record;

2, by the described electric quantity computer-controlled monitoring instrument of claim 1, it is characterized in that: lack detection circuit 4 is made up of resistance R 1, P3, capacitor C 22, U5:D, lacks a phase time when a, b, c appoint, through the three phase full bridge rectification of D11～D16 composition, the B point voltage is through resistance R 1, potentiometer P3 dividing potential drop, the pulsation that the A point promptly produces 100Hz, through the U5:C shaping, anti-phase through U5:D again, send into the T0 mouth of U3 chip, count, judge its non-full-phase state, and record;

3, by the described electric quantity computer-controlled monitoring instrument of claim 1, it is characterized in that: power-fail detection circuit is made up of electrochemical capacitor E2, resistance R 2, potentiometer P4, capacitor C 23, U5:F, U5:E, when power down takes place, the D point voltage descends, and through resistance R 2, potentiometer P4 dividing potential drop, the C point voltage is dropped rapidly to the following threshold values of Schmidt trigger U5:F, make Schmidt trigger U5:F upset, through the U5:E shaping, provide one along interrupting, by the circuit record power down time of U3 for the INT0 of U3 chip.

4, by the described electric quantity computer-controlled monitoring instrument of claim 1, its feature also is: a pad 12 is housed in the end of its housing 11, on pad 12, have a rectangular chute 13, three spring 15a, 15b, the 15c of 3 of the E in its circuit, F, G and protruding housing 11, spring 15a, 15b, 15c are contained on three slide plate 14a, the 14b that can move in chute 13, the 14c with insulating respectively, and spring 15a, 15b, 15c are inserted in respectively on the socket on the watt-hour meter KWH.