WO2016201968A1

WO2016201968A1 - Low-voltage power distribution voltage-regulating device

Info

Publication number: WO2016201968A1
Application number: PCT/CN2016/070462
Authority: WO
Inventors: 施博一; 夏文; 孟领刚; 王新明; 夏武; 王春生; 冯国伟; 王宗臣
Original assignee: 江苏现代电力科技股份有限公司
Priority date: 2015-06-16
Filing date: 2016-01-08
Publication date: 2016-12-22
Also published as: CN104882891A; CN104882891B

Abstract

A low-voltage power distribution voltage-regulating device, comprising the following constituent parts: an incoming line apparatus (4) provided with an incoming line busbar (7), which is connected to an incoming line power supply line, and an incoming line line breaker (6); an outgoing line apparatus (6) provided with an outgoing line busbar (12) connected to a load line; a regulating autotransformer (2); an action execution mechanism (4) comprising a plurality of contactors (15, 16, 17, 18), wherein one end of each contactor is connected to an input end of the regulating autotransformer and the other end is respectively connected to a knob-position of a primary winding of the regulating autotransformer corresponding to a different number of turn; and a control unit (22), wherein the action execution mechanism is connected to the control unit. The voltage-regulating device can be connected to a power grid conveniently, and in the case of not adding a 10 kV line, not newly adding a power distribution transformer and not changing a low-voltage line, can solve the problem that a terminal voltage in a low-voltage line of an electrical transformer district in a rural area does not qualify and perform voltage compensation on a low voltage at the terminal of the power grid.

Description

Low-voltage power distribution regulator

Technical field

The invention relates to the technical field of electric engineering, in particular to a low voltage distribution network voltage regulating device.

Background technique

In the existing distribution network, because the line radius is too long, the line diameter is too small, causing the voltage line loss to be too large, resulting in a low terminal voltage of the user, and the electrical equipment cannot operate normally. In rural areas such as remote mountainous areas, low voltage is particularly common, and the peak period of power consumption is particularly significant. There are several general governance measures to solve this problem:

1) Low-voltage line reactive power compensation boost, improve power factor and reduce line loss, but it is greatly affected by power factor, and the voltage regulation effect is limited;

2) Increase the output voltage of the transformer in the station, but it will cause the voltage of the user at the head end of the power distribution to be high, which will affect the service life of the electrical equipment. At the same time, it cannot fundamentally solve the problem of low voltage caused by the long radius of the line;

3) New distribution transformers, but with high cost and long cycle.

Summary of the invention

The technical purpose of the present invention is to provide a low-voltage power distribution voltage regulating device that can directly connect to a power grid without modifying an existing low-voltage line, in view of the problems existing in the prior art.

To achieve the above technical purpose, the technical solution disclosed by the present invention is:

A low-voltage power distribution voltage regulating device, characterized in that it comprises the following components:

a line-in device with an incoming busbar and an incoming circuit breaker connected to the incoming line supply line;

An outlet device having an outlet busbar connected to the load line;

An autotransformer transformer, the input end of which is connected to the output end of the incoming line device, the output end of which is connected to the input end of the outlet device, and the incoming line breaker is connected in series to the input end of the auto-transformer transformer On the connection line with the incoming line device;

An action actuator comprising a plurality of contactors, one end of each contactor being connected to the input end of the auto-transformer transformer, the connection point being located on the outgoing side of the line breaker, and the other end of each contact being connected to the auto-coupling The primary coil of the transformer transformer corresponds to a different number of gear positions;

A control unit is connected to the action actuator, and the control action actuator performs on/off of each contactor.

Based on the above, further improvements include:

The control unit includes a rectifying circuit, and the external alternating current power source is connected to the action executing mechanism through the rectifying circuit, and the converted electric energy is used as a driving power source of the action executing mechanism.

The rectifier circuit is provided with a capacitor C1, a rectifier diode and a filter capacitor C2, and the capacitor C1 is connected in series On one of the incoming lines of the external AC power supply, the two sides of the capacitor C1 are short-circuited by a circuit, and each of the contactors is respectively connected to the circuit in a normally closed contact. When the contactors of the action actuator are in the off state, the main contact is disconnected, the normally closed contact (auxiliary contact) of the contactor is in a closed state, the capacitor C1 is short-circuited, and the AC voltage is rectified by the diode to output a DC high. Piezoelectric drive action actuator contactor pull-in, when any contactor is closed, its normally closed contact is open, then the circuit of short-circuit capacitor C1 is disconnected, then the capacitor C1 supplies power to the diode, at this time the diode The rectified DC voltage is small, and only the capacitor C2 maintains a DC low voltage to supply power to the coil of the actuator of the actuator, maintains the contact state of the contactor, and ensures reliable engagement of the actuator. In this way, a conventional 220V AC contactor can be used, which can save costs compared to using a low voltage DC contactor.

The low-voltage power distribution voltage regulating device of the present invention is provided with a contactor coil interlocking structure, the contactor coil interlocking structure includes an interlocking circuit corresponding to each contactor coil; and the interlocking circuit is connected in series with a contactor a normally open contact (auxiliary contact) of the coil and the contactor, and a normally closed contact (auxiliary contact) of the other contactors, and the interlock circuit of each contactor coil is connected in parallel and then connected to the action actuator Drive the power circuit. When the contactor coil on any of the interlock circuits is energized, the normally open contact of the contactor on the interlock circuit is closed, and the normally closed contact of the contactor on the other interlock circuit is disconnected, thereby making each contact The coils of the device cannot be energized at the same time to achieve interlocking between the coils.

Further, the control unit is further provided with a power supply interlocking structure for the action executing mechanism, wherein the power supply interlocking structure is provided with a control module corresponding to each contactor, and each control module includes a driving action mechanism for connecting the action actuators. a first switch corresponding to the interlock circuit of the contactor coil, a second switch serially connected to the other contactor interlock circuits, and a jog electromagnetic driving mechanism for controlling the first switch and the second switch to be turned on and off; The first switch and the second switch in each mode control module are interlocking switches. When the electromagnetic drive mechanism coil is not energized, the first switch of each control module is connected to the action actuator driving power supply and the contactor coil interlocking circuit. The line is in the off state, the second switch is in the on state on the interlock circuit thereof; after the electromagnetic drive mechanism coil is energized, the first switch is turned on, and the second switch is turned off.

The outlet device is provided with a manual bypass circuit breaker for short-circuiting the auto-coupled voltage-regulating transformer. When an auto-coupling voltage-regulating transformer or other component fails to be repaired, the line-breaking circuit breaker must be manually disconnected to cut off the line power supply. Power supply, close the manual bypass circuit breaker to temporarily isolate the auto-coupled voltage regulating transformer, and then put it into operation after the fault is recovered.

The contactor of the action actuator includes an automatic bypass contactor. After the automatic bypass contactor is engaged, the input voltage of the auto-coupled voltage regulating transformer is equal to the output voltage.

Further, the low-voltage power distribution voltage regulating device of the present invention further comprises a capacitor and a low-voltage power distribution measuring and controlling device, wherein the low-voltage power distribution measuring and controlling device is connected to the control unit to perform information interaction; the capacitor is set in an auto-coupling The output side of the voltage regulating transformer is connected to the low-voltage power distribution measuring and controlling device, and the low-voltage power distribution measuring and controlling device inputs and cuts the capacitor according to the lack of reactive power.

The incoming line device is provided with an incoming line transformer for monitoring an electrical signal of the incoming line power supply line, and the outgoing line device is provided with an outgoing line transformer for monitoring the electrical signal of the load line, wherein the incoming line transformer and the outgoing line transformer respectively Connected to the control unit, the control unit automatically inputs an auto-coupled voltage regulating transformer according to the current/voltage condition of the power supply side or the load side or cuts the auto-coupled voltage regulating transformer into a reasonable gear position.

A lightning arrester is disposed in the line feeding device and the outlet device.

The low-voltage power distribution voltage regulating device of the invention can be conveniently connected to the power grid, and effectively solves the terminal voltage in the low-voltage line of the rural distribution station without increasing the 10kV line, adding the distribution transformer, and not modifying the low-voltage line. Qualified problem, voltage compensation for low voltage at the end of the power grid is a more economical way to solve the terminal voltage in rural power grid. On the basis of further technical solutions, the low-voltage power distribution voltage regulating device of the invention can be safe and reliable. Running.

DRAWINGS

Figure 1 is a schematic view of the structure of the present invention;

2 is a schematic diagram of a circuit structure of an autotransformer transformer and a contactor;

3 is a schematic structural view of a rectifier circuit of a control unit;

4 is a schematic circuit diagram of shorting the capacitor C1 of FIG. 3;

Figure 5 is a schematic structural view of a power supply interlocking structure;

Figure 6 is a schematic view showing the structure of the interlocking structure of the contactor coil.

detailed description

In order to clarify the technical solutions and technical objects of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

A low-voltage power distribution voltage regulating device as shown in FIG. 1 includes a cooling fan 1, an incoming line device 4, an outlet device 9, an auto-coupled voltage transformer 2, an action actuator 4, a smart capacitor 19, and a detection control alarm device 20, etc. Several components. The incoming line device 4 is provided with an incoming current transformer 5, an incoming circuit breaker 6, an incoming busbar 7, and an incoming lightning arrester 8. The outlet device 9 is provided with an outgoing current transformer 10, a manual bypass breaker 11, an outgoing busbar 12, and an outgoing lightning arrester 13. The detection control alarm device 20 is provided with a low-voltage power distribution measuring and controlling device 21, a control unit 22 with a microprocessor as a core, and an operating status indicator lamp 23. An infrared temperature measuring sensor 3 is disposed on the auto-coupled voltage regulating transformer 2. The motion actuator 14 is provided with a voltage output 1st contactor 16 (hereinafter replaced by KM1), a voltage output 2nd contactor 17 (hereinafter replaced by KM2), and a voltage output 3rd contactor 18 (hereinafter replaced by KM3) And automatic bypass contactor 15 (hereinafter replaced by KM4).

The voltage regulation principle of the autotransformer 2 is as shown in FIG. 2, and the input end of the autotransformer 2 is connected to the output end of the line feeder 4, and the line breaker 6 (hereinafter referred to K1 instead) is connected in series with the connection line One end of each contactor KM1, KM2, KM3, KM4 of the action actuator 14 is connected to the outgoing side of the line breaker 6, and the other end is connected to the gear of the primary coil of the autotransformer corresponding to different turns. Above, when the incoming circuit breaker 6 is closed, the auto-coupled voltage regulating transformer 2 is thus connected to the incoming power supply line.

In Figure 2:

When K1 is closed, the input voltage Uin is equal to the output voltage Uout when KM4 is pulled;

When K1 is closed, the output voltage Uout of KM1 is equal to the sum of the input voltage Uin and the first induced voltage dU of the auto-transformer transformer;

When K1 is closed, KM2 and KM3 are similar to the voltage when KM1 is pulled in, but only change the turns ratio of the primary and secondary coils of the transformer to obtain a larger induced voltage dU.

The incoming lightning arrester 8 and the outgoing lightning arrester 13 function as lightning protection and surge protection. The incoming lightning arrester 8 and the outgoing lightning arrester 13 are respectively connected with the incoming busbar 7 and the outgoing busbar 12, and the grounding terminal and the grounding wire are connected. connection.

The action actuator 14 adopts DC high voltage pull-in, and the control unit 22 includes a rectifier circuit. The external AC power source is connected to the action actuator 14 through the rectifier circuit, and the converted DC high voltage power is used as the drive of the action actuator 14. power supply.

As shown in FIG. 3, the rectifier circuit is provided with a capacitor C1, a plurality of rectifier diodes, and a filter capacitor C2. The capacitor C1 is connected in series to an incoming line connected to an external AC power source, and both sides of the capacitor C1 pass through FIG. One of the circuits shown is shorted, and each contactor is respectively connected with a normally closed contact (auxiliary contact) KMA1, KMA2, KMA3, KMA4 in the circuit. When the contactors of the action actuator 14 are all in the off state, KMA1, KMA2, KMA3, and KMA4 are all in a closed state. In the figure, the KA5 terminal is directly connected to the UAIN terminal of the external AC power source, and the capacitor C1 is short-circuited, and the AC voltage passes through the diode. The rectification of the DC high voltage drive action actuator is engaged. When any contactor is closed, the corresponding normally closed contact KMA1/KMA2/KMA3/KMA4 is disconnected, and UAIN supplies power to KA5 through C1. At this time, the DC voltage rectified by the diode is small, and only the capacitor C2 maintains a DC low voltage. The coil of the pull-in contactor is energized to maintain the pull-in state of the contactor, ensuring reliable engagement of the actuator actuator 14 at low voltages.

The four-speed switch position of the action actuator 14 needs to be interlocked, and only one pull-in, multi-stage protection, including the interlocking of the coils between the contactors, the power supply interlock of the control unit, and the interlocking of the output lines of the software.

The contactor coil interlocking structure is as shown in FIG. 6, and includes four parallel interlocking circuits, a coil of any contactor of the action actuator 14 and a normally open contact (auxiliary contact) of the contactor, and other contactors. A normally closed contact (auxiliary contact) is connected in series to form one of the interlock circuits, and the interlock circuit corresponding to each contactor is connected in parallel to the driving power supply circuit of the action actuator 14. As shown in FIG. 6, taking the interlock circuit of the corresponding voltage output 1st contactor 16 as an example, the KM1 coil is connected to the power input terminal OT1 through the normally closed contacts of KM2, KM3, and KM4, and when the OT1 has DC high voltage, KM1 When the coil is turned on, the KM1 normally open contact is closed, and the normally closed contacts of all KM1 are disconnected, then the KM2 coil, the KM3 coil, and the KM4 coil are de-energized, and the interlock circuits of other contactor coils work similarly.

The power supply interlocking structure of the control unit 22 for the motion actuator 14 is as shown in FIG. 5, and a control module is provided corresponding to each contactor, and each control module includes a driving action power supply KZUA end and a corresponding contactor coil. a first switch of the interlock circuit, three second switches serially connected to the other contactor interlock circuits, and a jog electromagnetic drive mechanism for controlling the first switch and the second switch to be turned on and off, in each control module The first switch and the second switch are interlocking switches.

Taking the first control module in which the corresponding voltage output 1st gear contact 16 is taken as an example, the jog electromagnetic driving mechanism includes a 12V power supply and a coil J1, and the first switch located between "8-4-12" is located at " Pulling or disconnecting the three second switches between 5-1-9", "6-2-10", and "7-3-11", when the coil J1 is energized, the first switch is pulled, so that The KZUA terminal is connected to the KC1 terminal, and the three second switches are disconnected, so that the J2-8 connection J3-10, the J3-8 connection J2-10, and the J4-8 connection J2-11 are disconnected, so that the OT2 and the OT3 are disconnected. If the OT4 cannot be powered, the power supply circuit of the other contactor coils is cut off. J2-8 in the first control module indicates that the point is connected to the position 8 in the second module, J3-8 indicates that the point is connected to the position 8 in the third module, and J4-8 indicates the point and the fourth module Position 8 is connected, and the explanations for other symbols such as J3-10, J2-11, etc. are the same as above. After the KZUA end of the first control module is connected to the KC1 end, the KC1 end is located at the second switch between the "5-1-9" by the second control module, and is located in the third control module "5-1-9". The second switch between the second switch, the second switch between the fourth control module "5-1-9" is connected to the OT1 end of the contactor coil interlock circuit, so that the OT1 terminal in FIG. 6 has DC high voltage, KM1 When the coil is turned on, the KM1 normally open contact is closed. When the KM1 normally open contact is closed, the coil of the jog electromagnetic drive mechanism is de-energized, and the first switch of the first control module is restored to the off state, and the second switch Resume the closed state. Other control modules work the same way.

The infrared temperature sensor 3 detects the real-time temperature of the auto-transformer transformer 2 and transmits it to the control unit 22. The control unit 22 drives the heat-dissipating fan 1 according to the temperature, thereby effectively reducing the heat inside the device, improving the operational reliability of the device, and prolonging the service life.

The smart capacitor 19 is connected to the voltage output side of the auto-transformer transformer 2, and is connected to the low-voltage power distribution measuring and controlling device 21, and the low-voltage power distribution measuring and controlling device 21 performs the input and the cutting of the smart capacitor 19 according to the vacancy of the reactive power. When the voltage regulating transformer 2 adjusts the voltage, reasonable reactive power compensation is performed to reduce the line loss.

The low-voltage power distribution measuring and controlling device 21 is connected to the control unit 22, and the operating state, power distribution parameters, and the like of the components in the device are obtained through information interaction. The low-voltage power distribution measurement and control device 21 can remotely monitor the operation status of the user side of the distribution network and the remote adjustment of the voltage by logging in to the server background.

The operation status indicator 23 is convenient for running on-site monitoring, and outputs a protection signal when the protection occurs, reminding the worker Maintenance in time. The voltage regulating device of the invention comprises various protection modes, such as output overcurrent protection, overvoltage protection, undervoltage protection, autotransformation transformer 2 over temperature protection, lightning protection, surge protection, main circuit, secondary circuit short circuit Protection and so on.

The manual bypass circuit breaker 11 is used when the invention fails to repair the fault, and only needs to manually disconnect the incoming circuit breaker 6 to cut off the incoming power supply, and close the manual bypass breaker 11 to short the T1 outgoing coil to achieve voltage loss. The output can completely isolate the core components of the low-voltage power distribution voltage regulating device of the present invention, and does not affect the normal use of the rear-side users. The automatic bypass contactor 15 is used to control the pull-in automatic bypass contactor 15 through the low control unit 22 when the temporary fault occurs in the present invention, temporarily isolating the voltage regulating function of the auto-coupled voltage regulating transformer, and when the fault is recovered, it can be immediately put into service.

The control unit 22 can detect the line voltage (incoming side) of the low voltage side of the autotransformer 2 through the transformer, and automatically input the different gears of the autotransformer 2 when the line voltage is lower than the set input threshold. When the line voltage is higher than the cut-off threshold, the auto-transformer transformer 2 is automatically cut into a reasonable gear position, so that the line voltage reaches the qualified range, so that the voltage quality on the user side is effectively improved.

According to the use occasion, the low-voltage power distribution voltage regulating device of the invention can be divided into single-phase voltage regulation, three-phase voltage regulation and phase separation voltage regulation. In the single-phase and three-phase voltage regulation, the pressure regulating action actuator 14 only needs to include a set of contactors 15-18, and the split-phase pressure regulating action actuator 14 needs to include exactly the same three sets of contactors 15-18.

The basic principles, main features, and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited by the foregoing embodiments, and that the present invention is only described in the foregoing description and the description of the present invention, without departing from the spirit and scope of the invention. The scope of the invention is defined by the appended claims, the description and the equivalents thereof.

Claims

A low-voltage power distribution voltage regulating device, characterized in that it comprises the following components:

An incoming line device (4) is provided with an incoming busbar (7) and an incoming circuit breaker (6) connected to the incoming power supply line;

a outlet device (9) having an outlet busbar (12) connected to the load line;

An autotransformer transformer (2) having an input connected to an output of the line feed device (4) and an output connected to an input of the outlet device (9), the line breaker ( 6) serially connected to the connection line of the input end of the auto-transformer transformer (2) and the line-in device (4);

An action actuator (14) includes a plurality of contactors, one end of each contactor is connected to the input end of the auto-transformer transformer (2), and the connection point is located on the outgoing side of the line breaker (6), each contact The other ends of the device are respectively connected to the gears of the primary coil of the auto-transformer transformer corresponding to different turns;

A control unit (22) is connected to the action actuator (14), and the control action actuator (14) performs on/off of each contactor.
The low-voltage power distribution voltage regulating device according to claim 1, wherein the control unit (22) comprises a rectifying circuit, and the external alternating current power source is connected to the action executing mechanism (14) through the rectifying circuit, and is converted The subsequent electric energy is used as a driving power source for the action actuator (14).
The low-voltage power distribution voltage regulating device according to claim 2, wherein the rectifier circuit is provided with a capacitor C1, a rectifier diode and a filter capacitor C2, and the capacitor C1 is connected in series with an external AC power supply. On the line, both sides of the capacitor C1 are short-circuited by a circuit, and each contactor is respectively connected to the circuit in a normally closed contact.
A low-voltage power distribution voltage regulating device according to claim 1, wherein a contactor coil interlocking structure is provided, and the contactor coil interlocking structure includes an interlock circuit corresponding to each contactor coil;

The interlock circuit is connected in series with a coil of the contactor and a normally open contact of the contactor, and a normally closed contact of the other contactors, and the interlocking circuit of each contactor coil is connected in parallel and the access action is performed. In the drive power circuit of the mechanism (14).
A low-voltage power distribution voltage regulating device according to claim 4, wherein said control unit (22) is provided with a power supply interlocking structure for the action actuator (14), said power supply interlocking structure Corresponding to each contactor, a control module is provided, and each control module includes a first switch that connects the driving power supply of the action actuator with an interlock circuit corresponding to the contactor coil, and is connected in series with the interlock circuit of the other contactor coils. a second switch and a jog electromagnetic driving mechanism for controlling the first switch and the second switch to be turned on and off;

The first switch and the second switch in each mode control module are interlocking switches. When the electromagnetic drive mechanism coil is not energized, the first switch of each control module is connected to the action actuator driving power supply and the contactor coil interlocking circuit. The line is in the off state, the second switch is in the on state on the interlock circuit thereof; after the electromagnetic drive mechanism coil is energized, the first switch is turned on, and the second switch is turned off.
The low-voltage power distribution voltage regulating device according to claim 1, characterized in that the outlet device (9) is provided with a manual bypass breaker (12) for shorting the auto-transformer transformer (2) .
A low-voltage power distribution voltage regulating device according to claim 1, wherein the contactor of the action actuator (14) includes an automatic bypass contactor (15), the automatic bypass contactor (15) After the pull-in, the input voltage of the auto-coupled voltage transformer (2) is equal to the output voltage.
The low-voltage power distribution voltage regulating device according to any one of claims 1 to 7, characterized in that: a capacitor and a low-voltage power distribution measuring and controlling device (21), the low-voltage power distribution measuring and controlling device (21) Connected to the control unit (22) for information interaction; the capacitor is disposed on the output side of the auto-coupled voltage regulating transformer (2), connected to the low-voltage power distribution measuring and controlling device (21), and controlled by the low-voltage power distribution The device (21) performs input and cut-out of the capacitor in accordance with the vacancy of the reactive power.
The low-voltage power distribution voltage regulating device according to any one of claims 1 to 7, characterized in that the incoming line device (4) is provided with an incoming line transformer for monitoring the electrical signal of the incoming power supply line The outlet device (9) is provided with an outlet transformer for monitoring the electrical signal of the load line, and the two transformers are respectively connected with the control unit (22).
The low-voltage power distribution voltage regulating device according to any one of claims 1 to 7, characterized in that the lightning arresting device (4) and the outlet device (9) are provided with lightning arresters.