CN110061501A - A kind of power distribution network intelligence cyclization switch - Google Patents

Abstract

The invention relates to an intelligent loop closing switch for a distribution network, including a loop closing switch for opening or closing a distribution loop network, and an intelligent regulator for controlling the opening or closing of the loop closing switch. The intelligent regulator includes A communication module communicating with the ring main unit of each node of the distribution ring network, a power supply adjusting module and a controller for adjusting the voltage difference between the two ends of the loop closing switch, and the controller is respectively connected with the communication module, the power supply adjusting module and the loop closing switch . The beneficial effects of the invention are as follows: the intelligent regulator of the distribution network intelligent loop closing switch of the patent is composed of two alternating current power sources, a series power supply and a parallel power supply, the series power supply is directly connected in series in the distribution network line, and the output voltage is adjusted by adjusting the output voltage. The amplitude and phase are directly superimposed on the line power supply, so that the amplitude and phase of the voltage difference between the two ends of the loop closing point meet the design requirements of the loop closing operation, and the loop closing switch is closed to realize the closed loop operation of the line.

Description

An intelligent loop closing switch for distribution network

technical field

The invention relates to the technical field of distribution network, in particular to an intelligent loop closing switch of distribution network.

Background technique

In recent years, with the development of economy and society, people have higher and higher requirements for the reliability of power supply. The distribution network is directly oriented to users, and its impact on the reliability of power supply cannot be ignored. After long-term development of my country's distribution network, the power supply mode of "closed-loop design, open-loop operation" has generally been formed, and on this basis, measures such as distribution automation, equipment management, load transfer, power outage management, and transformer load management are implemented to ensure Reliable power supply. Although these measures have helped a lot to improve the reliability of power supply of the distribution network, the open-loop power supply mode still cannot avoid short-term power outages caused by the switch-off operation during line maintenance or faults, and cannot meet the requirements of high-tech industries and financial centers. and other important users have strict demand for power supply. In addition, distributed power sources represented by solar energy and wind energy are increasingly connected to the distribution network, which brings many impacts and impacts on the operation and control of existing systems. Radiating and open-loop operation modes are difficult to adapt to new operation and control requirements, and cannot give full play to the performance of distributed power sources. The open-loop operation mode limits the improvement of power supply reliability to a certain extent. In order to reduce the power outage time and improve the power supply reliability rate, many experts and scholars have studied the feasibility of the distribution network loop closure. At present, the research on the loop closure problem of distribution network mainly includes two aspects: distribution network loop closure transfer power supply and distribution network loop closure operation problem.

In the mode of "closed-loop design, open-loop operation", many loads distributed on the distribution line are powered by a single power supply, and different lines are connected by normally open tie switches to form an open-loop operation mode. During line maintenance and load reversal, the reliability of power supply will be reduced if the power is switched off after the power failure. Adopting the closed loop operation without power failure to reduce the power failure time has become a common method for power supply enterprises.

However, if there is a voltage difference on both sides of the loop closing point or the short-circuit impedance on both sides is different, a circulating current will be generated after the loop is closed, and a large inrush current will appear at the moment of the loop closing, which may cause a protection action and affect the safe and stable operation of the power grid. If the operator only judges whether the loop can be closed based on the operating experience, and lack of test or simulation verification, it may cause the protection to malfunction due to the excessive current of the closed loop, thereby causing a wider range of power outages.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above problems existing in the prior art, and to provide an intelligent loop closing switch for a distribution network.

In order to realize the above-mentioned technical purpose and achieve the above-mentioned technical effect, the present invention is realized through the following technical solutions:

An intelligent loop closure switch for a distribution network, comprising a loop closure switch for opening or closing a distribution loop network, an intelligent regulator for controlling the opening or closing of the loop closure switch, the intelligent regulator comprising a A communication module connected to the ring network cabinet of each node of the ring network, a power supply adjustment module for adjusting the voltage difference between the two ends of the loop closing switch, and a controller, the controllers are respectively connected with the communication module, the power supply adjustment module and the loop closing switch.

Wherein, the power conditioning module includes a series power supply connected in series with the distribution ring network, a parallel power supply connected in parallel with the distribution ring network, and a filter capacitor, and the series power supply and the parallel power supply are connected in parallel with the filter capacitor.

The series power supply includes a series transformer, a series power inverter, a second series power inverter, a third series power inverter, and a fourth series power inverter, and the parallel power source includes a parallel transformer and a parallel power inverter. Transformer one, parallel power inverter two, parallel power inverter three, parallel power inverter four, the primary winding of the series transformer is connected in series with the distribution ring network, and the first end of the series power inverter one is inversely connected to the series power source. The first end of the inverter two is connected in parallel with the first end of the secondary winding of the series transformer, and the first end of the series power inverter three is connected in parallel with the first end of the series power inverter four and then connected to the second end of the series transformer. The second end of the secondary winding is connected in series; the primary winding of the parallel transformer is connected in parallel with the distribution ring network, and the first end of the parallel power inverter one is connected in parallel with the first end of the parallel power inverter two and then connected to the secondary winding of the parallel transformer. The first end of the parallel power inverter 3 is connected in parallel with the first end of the parallel power inverter 4 and then connected in series with the second end of the secondary winding of the parallel transformer; the second end of the series power inverter 1 Two terminals, the second terminal of the series power inverter three, the second terminal of the parallel power inverter one, the second terminal of the parallel power inverter three, and the first terminal of the filter capacitor are connected in parallel; the series power inverter two The second end of the series power inverter four, the second end of the parallel power inverter two, the second end of the parallel power inverter four, and the second end of the filter capacitor are connected in parallel.

Wherein, the communication module is an optical fiber communication module, and the optical fiber communication module adopts optical fiber to communicate with the ring network cabinet of each node of the distribution ring network, and the communication optical fiber transmits the received voltage signal detected in the ring network cabinet to the controller .

Wherein, the controller is a PLC controller.

Wherein, the closed loop switch is a circuit breaker.

The beneficial effects of the invention are: the intelligent regulator of the distribution network intelligent loop closing switch of the patent is composed of two AC power sources, a series power supply and a parallel power supply, the series power supply is directly connected in series in the distribution network line, and the output voltage is adjusted by adjusting the output voltage. The amplitude and phase are directly superimposed on the line power supply, so that the amplitude and phase of the voltage difference between the two ends of the loop closing point meet the design requirements of the loop closing operation, and the loop closing switch is closed to realize the closed loop operation of the line. The parameters control the current of the loop closing point and the flow of the loop network; the parallel power supply takes the regulation of the series power supply as the control point, and operates in the load mode and the power mode to realize the series superposition and energy transmission.

Description of drawings

The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of the connection relationship between a controller, a communication module, a ring network cabinet, a power conditioning module, and a loop closing switch in an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a power conditioning module in an embodiment of the present invention.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

In the description of the present invention, it is to be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "around", etc. Indicates the orientation or positional relationship, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, are constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention .

As shown in FIGS. 1 to 3 , an intelligent loop closing switch 200 for a distribution network includes a loop closing switch 220 for opening or closing the distribution ring network 100 , a loop closing switch 220 for controlling the opening or closing of the loop closing switch 220 An intelligent regulator, the intelligent regulator includes a communication module 210 that communicates with the ring main unit 101 of each node of the distribution ring network 100, a power supply adjustment module 240 that adjusts the voltage difference between the two ends of the loop closing switch 220, a controller 230, and the controller 230 They are respectively connected with the communication module 210 , the power conditioning module 240 and the loop closing switch 220 .

The power conditioning module 240 includes a series power supply connected in series with the distribution ring network 100, a parallel power supply connected in parallel with the distribution ring network 100, and a filter capacitor 2430. The series power supply and the parallel power supply are connected in parallel with the filter capacitor 2430.

The series power supply includes series transformer 2411, series power inverter one 2412, series power inverter two 2413, series power inverter three 2414, series power inverter four 2415, parallel power supply includes parallel transformer 2421, parallel power inverter Transformer one 2422, parallel power inverter two 2423, parallel power inverter three 2424, parallel power inverter four 2425, the primary winding of the series transformer 2411 is connected in series with the distribution ring network 100, and the series power inverter one 2412 The first end is connected in parallel with the first end of the series power inverter two 2413 and then connected in series with the first end of the secondary winding of the series transformer 2411. The first end of the series power inverter three 2414 is connected with the series power inverter four 2415 The first end of the parallel transformer 2411 is connected in parallel with the second end of the secondary winding of the series transformer 2411; the primary winding of the parallel transformer 2421 is connected in parallel with the distribution ring network 100, and the first end of the parallel power inverter 2422 is connected to the parallel power inverter. The first end of the second inverter 2423 is connected in parallel with the first end of the secondary winding of the parallel transformer 2421, and the first end of the parallel power inverter 2424 is connected in parallel with the first end of the parallel power inverter 4 2425 and then connected in parallel. The second end of the secondary winding of the transformer 2421 is connected in series; the second end of the series power inverter one 2412, the second end of the series power inverter three 2414, the second end of the parallel power inverter one 2422, the parallel power supply The second end of inverter three 2424 and the first end of filter capacitor 2430 are connected in parallel; the second end of series power inverter two 2413, the second end of series power inverter four 2415, the parallel power inverter two 2423 The second end of the parallel power inverter four 2425 and the second end of the filter capacitor 2430 are connected in parallel.

The series transformer 2411 and the parallel transformer 2421 mainly adjust the voltage to meet the operating parameters of the closed loop of the distribution line; the series power inverter 1 2412, the series power inverter 2 2413, the series power inverter 3 2414, the series power inverter Four 2415, parallel power inverter one 2422, parallel power inverter two 2423, parallel power inverter three 2424, parallel power inverter four 2425 realize the control of series power supply and parallel power supply.

The parallel transformer 2421 reduces the voltage of the distribution network to the allowable voltage value of the inverter. When the series power supply superimposes a positive voltage, the parallel power supply inputs power. When the series power supply superimposes a negative voltage, the parallel power supply feeds back the power to the grid, and the parallel power supply The inverter transmits stable DC voltage through power, and the output voltage of the series power inverter is superimposed with the line voltage through the series transformer, so that the voltage vector difference between the two ends of the loop closing switch is less than the allowable value of the loop closing operation, and the output signal closes the loop closing switch.

The controller 230 calculates and determines whether the voltage difference between the two ends of the loop closing switch 220 meets the loop closing condition according to the following formula, (ū ₁ +Δū)−ū _{2 ≤ūallow} . In the formula, ū ₁ is the voltage at the first end of the loop closure switch 220 , ū ₂ is the voltage at the second end of the loop closure switch 220 , and ū _allow is the allowable voltage difference between the two ends of the loop closure switch 220 when the loop closure switch 220 is closed , Δū is the voltage of the series power supply superimposed in the distribution ring network 100 at the first end of the loop closing switch 220 .

The communication module 210 is an optical fiber communication module. The optical fiber communication module uses optical fiber to communicate with the ring main unit 101 of each node of the distribution ring network 100. The communication optical fiber transmits the received voltage signal detected in the ring main unit 101 to the controller. The controller 230 is a PLC controller. The closed loop switch 220 is a circuit breaker.

The intelligent regulator of the distribution network intelligent loop switch of this patent is composed of two AC power sources, a series power supply and a parallel power supply. The series power supply is directly connected in series in the distribution network line, and the amplitude and phase of the output voltage are adjusted to directly superimpose. On the line power supply, the amplitude and phase of the voltage difference between the two ends of the loop closure point meet the design requirements of the loop closure operation, the loop closure switch is closed to realize the closed loop operation of the line, and the loop closure point current and The flow of the ring network; the parallel power supply takes the regulation of the series power supply as the control point, and operates in the load mode and the power supply mode to realize the series superposition and energy transmission.

In the description of this specification, description with reference to the terms "one embodiment," "example," "specific example," etc. means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one aspect of the present invention. in one embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above-mentioned embodiments, and the descriptions in the above-mentioned embodiments and the description are only to illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have Various changes and modifications fall within the scope of the claimed invention.

Claims (6)

1. An intelligent loop closing switch for a distribution network, characterized in that: comprising a loop closing switch for opening or closing a distribution loop network, an intelligent regulator for controlling the opening or closing of the loop closing switch, and the intelligent The regulator includes a communication module connected to the ring network cabinet of each node of the distribution ring network, a power supply adjustment module and a controller for adjusting the voltage difference between the two ends of the closed loop switch, and the controller is respectively connected with the communication module, the power supply adjustment module, and the switch. Ring switch connection. 2. The intelligent loop closing switch of the distribution network according to claim 1, wherein the power supply adjustment module comprises a series power supply connected in series with the distribution ring network, a parallel power supply connected in parallel with the distribution ring network, and a filter capacitor, The series power supply and the parallel power supply are connected in parallel with the filter capacitor. 3 . The intelligent loop closing switch of the distribution network according to claim 2 , wherein the series power supply comprises a series transformer, a series power inverter one, a series power inverter two, a series power inverter three, 3 . The fourth series power inverter, the parallel power source includes a parallel transformer, a parallel power inverter 1, a parallel power inverter 2, a parallel power inverter 3, and a parallel power inverter 4. The primary winding of the series transformer is connected with the distribution The electric ring network is connected in series, the first end of the series power inverter one is connected in parallel with the first end of the series power inverter two and then connected in series with the first end of the secondary winding of the series transformer, and the first end of the series power inverter three is connected in series. The terminal is connected in parallel with the first terminal of the series power inverter four and then connected in series with the second terminal of the secondary winding of the series transformer; the primary winding of the parallel transformer is connected in parallel with the distribution ring network, and the first terminal of the parallel power inverter one is connected to the second terminal of the series transformer. The first end of the parallel power inverter two is connected in parallel with the first end of the secondary winding of the parallel transformer, and the first end of the parallel power inverter three is connected in parallel with the first end of the parallel power inverter four. The second end of the secondary winding of the transformer is connected in series; the second end of the series power inverter one, the second end of the series power inverter three, the second end of the parallel power inverter one, the parallel power inverter three The second end of the series power inverter and the first end of the filter capacitor are connected in parallel; the second end of the series power inverter two, the second end of the series power inverter four, the second end of the parallel power inverter two, the parallel power inverter two The second end of the device 4 and the second end of the filter capacitor are connected in parallel. 4. The intelligent loop-closing switch for distribution network according to claim 1, wherein the communication module is an optical fiber communication module, and the optical fiber communication module adopts optical fiber to communicate with the ring network cabinet of each node of the distribution ring network. , the communication fiber transmits the received voltage signal detected in the ring main unit to the controller. 5 . The intelligent loop closing switch of the distribution network according to claim 1 , wherein the controller is a PLC controller. 6 . 6 . The intelligent loop closing switch of the distribution network according to claim 1 , wherein the loop closing switch is a circuit breaker. 7 .