CN206211650U - For the power circuit of distribution line failure positioner - Google Patents

Abstract

The utility model discloses a power supply circuit for a power distribution line fault location device, which comprises a power-taking current transformer, a voltage stabilizing circuit, a main loop charging circuit, a farad capacitor discharging circuit, a farad capacitor, a backup battery, and a backup loop charging circuit , the control unit and the switching switch; the power-taking current transformer is connected to the switching switch through the voltage stabilizing circuit; the backup battery is connected to the switching switch, and the farad capacitor is connected to the backup circuit charging circuit; the voltage stabilizing circuit is connected to the farad capacitor through the main circuit charging circuit; The switching switch is connected through a farad capacitor discharge circuit; the control unit controls the operation of the power supply circuit. The utility model achieves the purpose of providing common power supply and instantaneous high current power supply for the load through the combination of the three groups of power supplies of the farad capacitor, the current transformer and the backup battery, and the power supply load capacity is strong, safe, stable and reliable, and the power supply circuit can also be applied for various types of electronic equipment.

Description

Power circuit for distribution line fault location device

technical field

The utility model specifically relates to a power circuit used for a power distribution line fault location device.

Background technique

With the development of economy and technology and the improvement of people's living standards, electric energy has been widely used in people's production and life, and plays a huge role. At the same time, with the rise of the smart grid and the application of automatic control technology, the automatic fault location of the power grid is gradually applied to the power grid.

The distribution line fault location device is used on the distribution line to quickly locate line faults, and its performance is directly related to the accuracy and reliability of line fault location. At present, the power supply circuits of traditional distribution line fault location devices all use current transformers to take power and supply them to the system after voltage stabilization. The excess energy is stored in farad capacitors, and disposable batteries are used as backup power sources. When the energy supply of the inverter is insufficient, the Farad capacitor and the disposable battery provide energy for the system at one time. As the function of the fault location device becomes more complicated and its performance improves, the power management becomes more stringent, and the power supply current becomes larger. In order to meet the requirements of long life, ordinary disposable batteries have a small discharge current, and it is difficult to meet the power requirements of more advanced distribution line fault location devices. If rechargeable batteries or other forms of batteries are used, it will have a huge impact on the life of the device. , while security and reliability are difficult to be guaranteed. And if farad capacitors are used, although farad capacitors have the characteristics of large capacity and low internal resistance, and can provide a large current for the load in a short time, they also have the disadvantage of large leakage current. In addition, the disposable batteries used in traditional fault location devices for distribution lines are mostly energy-type lithium sub-batteries with a carbon pack structure inside, which has the advantages of high energy density, long life, and good safety performance. The current is small. However, it cannot meet the requirements of the new fault location device for instantaneous high-current discharge. The power type lithium sub-battery has a winding structure inside. Compared with the energy type, the energy density is small and the safety performance is poor, but the internal resistance is small and the discharge current is large. It is also difficult to meet the requirements of long life, high reliability, safety and stability required by the new distribution line fault location device.

Utility model content

The purpose of the utility model is to provide a safe, stable and reliable power supply circuit for a power distribution line fault location device with strong load capacity.

The power supply circuit for the distribution line fault location device provided by the utility model includes a power-taking current transformer, a voltage stabilizing circuit, a main loop charging circuit, a farad capacitor discharging circuit, a farad capacitor, a backup battery, and a backup loop charging circuit , a control unit and a switching switch; the power-taking current transformer takes power from the power grid line, and supplies the power supply of the main circuit after the voltage stabilization circuit stabilizes; The loop charging circuit is connected to the farad capacitor and does not supply power to the farad capacitor; the backup battery constitutes a backup power supply circuit alone, and is directly connected to the external load and supplies power through the transfer switch, and is also connected to the farad capacitor through the backup loop charging circuit; the farad capacitor passes through the farad capacitor at the same time The discharge circuit is connected to the main power supply circuit and is directly connected to the switch to supply power to the external load; the control unit outputs control signals to control the main circuit charging circuit, the backup circuit charging circuit, the farad capacitor discharging circuit and the switch.

The backup battery is a lithium sub-battery with a disposable energy type carbon pack structure.

The voltage stabilizing circuit includes a rectifier bridge, a switch tube, a protection diode, a voltage comparator, a voltage sampling circuit and a filter capacitor; The active end of the switch tube is connected in parallel between the positive and negative poles of the output; the positive pole of the rectifier bridge is forwardly connected in series with a diode and used as the output terminal of the voltage stabilizing circuit; the voltage sampling circuit and the filter capacitor are connected in parallel, and both are connected to the output terminal of the voltage stabilizing circuit and the output negative pole of the rectifier bridge; one end of the input end of the voltage comparator is connected to the reference voltage, and the other end is connected to the output end of the voltage sampling circuit.

The main loop charging circuit includes a main loop charging switch tube and a current limiting resistor; the active end of the main loop charging switch tube and the current limiting resistor are connected in series between the output end of the voltage stabilizing circuit and the output end of the Farah capacitor; the main loop The control terminal of the charging switch tube is connected with the control unit.

The farad capacitor discharge circuit includes a farad capacitor discharge switch tube; the movable end of the farad capacitor discharge switch tube is connected in series between the output terminal of the farad capacitor and the output terminal of the voltage stabilizing circuit, and the control terminal of the farad capacitor discharge switch tube is connected to control unit.

The backup loop charging circuit includes a backup loop charging switch tube and a current limiting resistor; the active end of the backup loop charging switch tube and the current limiting resistor are connected in series between the output end of the backup battery and the output end of the farad capacitor; the backup loop charging The control end of the switch tube is connected with the control unit.

The changeover switch includes a first switching tube, a second switching tube, a third switching tube, a first protection diode and a second protection diode; the output terminal of the voltage stabilizing circuit is connected to the first protection diode connected in series in forward direction. One end of the movable end of a switch tube; the other end of the movable end of the first switch tube is connected to the movable end of the third switch tube, which is also the output end of the switch; the control end of the first switch tube is connected to the active end of the second switch tube The control ends of the second switch tube and the third switch tube are short-circuited and connected to the control unit; the other end of the movable end of the second switch tube is connected to the other end of the movable end of the third switch tube through the second protection diode in forward series one end.

The power supply circuit used for the distribution line fault location device provided by the utility model achieves the purpose of providing ordinary power supply and instantaneous high-current power supply for the load through the combination of three groups of power supplies including farad capacitors, current transformers and backup batteries. Moreover, the power supply load capacity is strong, safe, stable and reliable. In addition, the power supply circuit provided by the utility model is not only suitable for fault location devices of distribution lines, but also obviously suitable for various types of electronic equipment that need power supply, including various types of measuring instruments (such as electric energy meters, water meters, gas Meters, heat meters, etc.), power management terminals, power distribution terminals, power quality monitoring equipment, power grid automation terminals, collection terminals, concentrators, data collectors, meter hand-written devices, etc.

Description of drawings

Fig. 1 is a functional block diagram of the power supply circuit of the present invention.

Fig. 2 is a schematic circuit diagram of the power supply circuit of the present invention.

detailed description

As shown in Figure 1, it is a functional block diagram of the power supply circuit of the present utility model: the power supply circuit provided by the utility model for the distribution line fault location device includes a power-taking current transformer, a voltage stabilizing circuit, and a main circuit charging circuit, a Farad capacitor discharge circuit, a Farad capacitor, a backup battery, a backup loop charging circuit, a control unit and a switch; the power-taking current transformer takes power from the power grid line, and supplies power to the main circuit after being stabilized by a voltage stabilizing circuit; After the voltage stabilizing circuit outputs a stable power supply, it is connected to the load through the switch, and at the same time, it is also connected to the Farad capacitor through the main circuit charging circuit to supply power to the Farad capacitor; the backup battery alone constitutes a backup power supply circuit, and is directly connected to the external load through the transfer switch and supplies power. It is also connected to the farad capacitor through the backup circuit charging circuit; the farad capacitor is connected to the main power supply circuit through the farad capacitor discharge circuit at the same time, and is directly connected to the switch to supply power for the external load; the control unit outputs control signals to control the main circuit charging circuit and the backup The loop charging circuit, the farad capacitor discharging circuit and the work of the switch. The backup battery can be a lithium sub-battery with a disposable energy-type carbon pack structure, which has the characteristics of high energy density, high safety performance, and long life. It can greatly improve the safety and reliability of the device and circuit, and prolong the service life of the equipment. .

As shown in Figure 2 is the circuit schematic diagram of the power supply circuit of the present utility model: the voltage stabilizing circuit consists of a rectifier bridge D1, a switch tube Q1, a protection diode D2, a voltage comparator U1, a voltage sampling circuit (R1 and R2) and a filter capacitor C1 The main circuit charging circuit is composed of the main circuit charging switch tube Q2 and the current limiting resistor R3; the farad capacitor discharge circuit is composed of the farad capacitor discharging switch tube Q3; the backup circuit charging circuit is composed of the backup circuit charging switch tube Q5 and the current limiting resistor R4 The switching switch is composed of the first switch tube Q4, the second switch tube Q6, the third switch tube Q7, the first protection diode D4 and the second protection diode D5; the load takes power from the signal output terminal VCC described in the figure and Work.

The output terminal of the electric current transformer is connected to the rectifier bridge, and after being rectified into direct current by the rectifier bridge, the active end of the switch tube is connected in parallel between the output positive pole and the negative pole of the rectifier bridge; The output terminal of the circuit; the voltage sampling circuit and the filter capacitor are connected in parallel, and both are connected between the output terminal of the voltage stabilizing circuit and the output negative pole of the rectifier bridge; one end of the input terminal of the voltage comparator is connected to the reference voltage, and the other end is connected to the voltage sampling circuit. Output terminal; the active terminal of the main circuit charging switch tube and the current limiting resistor are connected in series between the output terminal of the voltage stabilizing circuit and the output terminal of the Farad capacitor; the control terminal of the main circuit charging switch tube is connected to the control unit; the Farad capacitor discharge switch The active end of the tube is connected in series between the output end of the farad capacitor and the output end of the voltage stabilizing circuit, the control end of the farad capacitor discharge switch tube is connected to the control unit; the active end of the backup circuit charging switch tube and the current limiting resistor are connected in series in the backup Between the output terminal of the battery and the output terminal of the farad capacitor; the control terminal of the charging switch tube of the backup circuit is connected to the control unit; the output terminal of the voltage stabilizing circuit is connected to the activity of the first switch tube through the first protection diode connected in series in the forward direction One end; the other end of the movable end of the first switch tube is connected to the movable end of the third switch tube, which is also the output end of the switch; the control end of the first switch tube is connected to the movable end of the second switch tube; The control terminals of the switching tube and the third switching tube are short-circuited and connected to the control unit; the other end of the movable end of the second switching tube is connected to the other end of the active end of the third switching tube through the second protective diode connected in series.

Claims (7)

1. a kind of power circuit for distribution line failure positioner, it is characterised in that including power taking current transformer, surely Volt circuit, major loop charging circuit, farad capacitor discharge circuit, farad capacitor, backup battery, standby loop charging circuit, control Unit processed and switching are switched；The power taking current transformer is led back from power network line power taking by being supplied after mu balanced circuit voltage stabilizing The power supply on road；By switching switch connection load after mu balanced circuit output stabilized power source, simultaneously also by major loop charging circuit Connection farad capacitor not power by farad capacitor；Backup battery is separately formed backup loop, and directly passes through change-over switch It is connected with external loading and is powered, is connected with farad capacitor simultaneously also by standby loop charging circuit；Farad capacitor is simultaneously logical Cross farad capacitor discharge circuit and access main current supply circuit, and be directly connected to be powered for external loading with switching switch；Control unit Output control signal, controls major loop charging circuit, standby loop charging circuit, farad capacitor discharge circuit and switching to open respectively The work of pass.

2. the power circuit for distribution line failure positioner according to claim 1, it is characterised in that described Backup battery is the lithium Asia battery of disposable energy type charcoal bag structure.

3. the power circuit for distribution line failure positioner according to claim 1 and 2, it is characterised in that described Mu balanced circuit include rectifier bridge, switching tube, protection diode, voltage comparator, voltage sampling circuit and filter capacitor；Power taking The output end connection rectifier bridge of current transformer, after rectifier bridge rectification is direct current, the output cathode and negative pole of rectifier bridge Between paralleling switch pipe movable end；As the output end of mu balanced circuit after the output cathode forward direction series diode of rectifier bridge； Voltage sampling circuit and filter capacitor are in parallel, and are both connected between the output end of mu balanced circuit and the output negative pole of rectifier bridge； Input one end connection reference voltage of voltage comparator, the other end connects the output end of voltage sampling circuit.

4. the power circuit for distribution line failure positioner according to claim 1 and 2, it is characterised in that described Major loop charging circuit include major loop charge switch pipe and current-limiting resistance；The movable end and current limliting of major loop charge switch pipe Resistance is serially connected between the output end of mu balanced circuit and the output end of farad capacitor；The control end of major loop charge switch pipe and control Unit connection processed.

5. the power circuit for distribution line failure positioner according to claim 1 and 2, it is characterised in that described Farad capacitor discharge circuit include farad capacitor discharge switch pipe；The movable end of farad capacitor discharge switch pipe is serially connected in farad Between the output end of electric capacity and the output end of mu balanced circuit, the control end connection control unit of farad capacitor discharge switch pipe.

6. the power circuit for distribution line failure positioner according to claim 1 and 2, it is characterised in that described Standby loop charging circuit include standby loop charge switch pipe and current-limiting resistance；The movable end of standby loop charge switch pipe And current-limiting resistance is serially connected between the output end of backup battery and the output end of farad capacitor；The control of standby loop charge switch pipe End processed is connected with control unit.

7. the power circuit for distribution line failure positioner according to claim 1 and 2, it is characterised in that described Switching switch include first switch pipe, second switch pipe, the 3rd switching tube, the first protection diode and second protect two poles Pipe；The output end of mu balanced circuit is connected to movable end one end of first switch pipe by the first protection diode of positive concatenation； The other end of the movable end of first switch pipe connects movable end one end of the 3rd switching tube, while being also the output of switching switch End；The control end of first switch pipe connects movable end one end of second switch pipe；The control of second switch pipe and the 3rd switching tube End short circuit is simultaneously connected to control unit；The movable end other end of second switch pipe is connected by the second protection diode of positive series connection Connect the movable end other end of the 3rd switching tube.