Network construction power distribution switch controller and control system

Abstract

The utility model discloses a network construction power distribution switch controller and a control system, relates to the technical field of power distribution network automation, and mainly aims to solve the problem that the existing anti-islanding circuit breaker fails when the new energy output capacity is close to or greater than a load. The network construction power distribution switch controller comprises an electric signal detection assembly, a central control assembly and a switch opening and closing execution assembly. The central control assembly is electrically connected with the electric signal detection assembly and the switch opening and closing execution assembly. The switch opening and closing execution assembly is electrically connected with a control contact of the low-voltage distribution circuit breaker. The electric signal detection assembly is used for collecting electric signals of a low-voltage distribution power supply side. And the central control assembly is used for controlling the switch opening and closing execution assembly to drive the low-voltage power distribution circuit breaker to be opened under the condition that the electric signal flows from the electricity load to the power supply side so as to cut off the connection between the low-voltage power distribution device and the new energy inverter. The method is used for controlling a power distribution switch in a new energy grid-connected power grid.

Description

Technical Field

[0001] The present application relates to the technical field of power distribution network automation, and in particular to a network distribution switch controller and control system. Background Art

[0002] With the grid connection of new energy systems (such as photovoltaic power generation systems, wind power generation systems, etc.), power islanding has also occurred, which has caused great harm to distribution equipment. In order to solve this problem, the power supply company requires the installation of an anti-islanding (switch) circuit breaker on the new energy access side. The working principle is that when the main distribution grid is out of power, the over-(under) voltage protection and over-(under) frequency protection of the grid voltage are used to detect the power failure of the grid voltage, thereby automatically tripping the anti-islanding circuit breaker to prevent the occurrence of the islanding effect.

[0003] The existing anti-islanding circuit breaker can only be triggered to disconnect when the voltage is lower than the set value and the frequency is lower than the set value, that is, there is a significant imbalance between the power output of the new energy system and the power demand of the power grid. However, when the difference between the active power and reactive power consumed by the load and the power provided by the photovoltaic system is very small or the output capacity of the grid-connected new energy is greater than the load, the voltage outage information in the grid will not be detected, and the anti-islanding circuit breaker will not disconnect, resulting in the failure of the anti-islanding circuit breaker. Utility Model Content

[0004] In view of this, the utility model provides a grid distribution switch controller and control system, the main purpose of which is to improve the problem of failure of existing anti-islanding circuit breakers when the output capacity of new energy is close to or greater than the load.

[0005] According to one aspect of the utility model, a network distribution switch controller is provided, comprising an electrical signal detection component, a central control component and a switch opening and closing execution component;

[0006] The central control component is electrically connected to the electrical signal detection component and the switch opening and closing execution component respectively, and the switch opening and closing execution component is electrically connected to the control contact of the low-voltage distribution circuit breaker;

[0007] The electrical signal detection component is used to collect electrical signals from the low-voltage power distribution power supply side;

[0008] The central control component is used to control the switch opening and closing execution component to drive the low-voltage distribution circuit breaker to open when the direction of flow of the electrical signal is from the power load to the power supply side, so as to cut off the connection between the low-voltage distribution device and the new energy inverter.

[0009] Preferably, the switch opening and closing actuator comprises a relay;

[0010] The normally open contact terminal of the relay is electrically connected to the central control component;

[0011] The output end of the relay is electrically connected to the short-circuit opening control contact of the low-voltage power distribution circuit breaker.

[0012] Preferably, the relay comprises a fast-acting relay or a DC relay.

[0013] Preferably, the central control component includes a central chip and a carrier communication module;

[0014] The central chip is electrically connected to the normally open contact terminal of the relay;

[0015] The carrier communication module is communicatively connected to an anti-islanding circuit breaker in a power supply line.

[0016] Preferably, the electrical signal detection component comprises: a voltage transformer and a current transformer;

[0017] The current transformer is electrically connected to the central chip, and the voltage transformer is electrically connected to the central chip;

[0018] The current transformer is used to collect the current signal on the low-voltage power distribution power supply side;

[0019] The voltage transformer is used to collect the voltage signal on the low-voltage power distribution power supply side.

[0020] Preferably, the voltage transformer is also used to detect the voltage on the low-voltage distribution power supply side after driving the low-voltage distribution circuit breaker to open.

[0021] Preferably, the carrier communication module is used to send an instruction to instruct the anti-islanding circuit breaker in the power supply line to disconnect the switch when the voltage is greater than a preset voltage value, so as to disconnect the connection between the new energy power supply end and the power load before the low-voltage distribution circuit breaker delays reclosing.

[0022] Preferably, the switch opening and closing actuator further comprises a button, and the button comprises a capacitive touch button or a mechanical button;

[0023] The button is electrically connected to the short-circuit opening control contact of the low-voltage power distribution circuit breaker.

[0024] Preferably, the grid-building power distribution switch controller further comprises: a display screen or an indicator light;

[0025] The display screen is electrically connected to the central chip; or the indicator light is electrically connected to the central chip.

[0026] According to another aspect of the utility model, a network distribution switch control system is provided, the system including a new energy power supply, a new energy inverter, an anti-islanding circuit breaker, a power load, a low-voltage distribution circuit breaker, a main power grid distribution transformer and the above-mentioned network distribution switch controller.

[0027] By means of the above technical solution, the technical solution provided by the embodiment of the utility model has at least the following advantages:

[0028] The utility model provides a network distribution switch controller and control system, the network distribution switch controller includes: an electric signal detection component, a central control component and a switch opening and closing execution component; the central control component is electrically connected to the electric signal detection component and the switch opening and closing execution component respectively, and the switch opening and closing execution component is electrically connected to the control contact of the low-voltage distribution circuit breaker. The network distribution switch control system includes: a new energy power supply, a new energy inverter, an anti-islanding circuit breaker, a power load, a low-voltage distribution circuit breaker, a main power grid distribution transformer and a network distribution switch controller. Compared with the prior art, the embodiment of the utility model collects the electrical signal on the low-voltage distribution power supply side through the electrical signal detection component; the central control component, when the flow direction of the electrical signal is from the power load to the power supply side, controls the switch opening and closing execution component to drive the low-voltage distribution circuit breaker to open, so as to cut off the connection between the low-voltage distribution device and the new energy inverter, and timely discover the situation that the main power grid is out of power and the anti-islanding circuit breaker fails, and controls the low-voltage distribution circuit breaker to open, so as to disconnect the connection between the distribution main grid power supply and the new energy inverter, and prevent the islanding phenomenon from occurring. At the same time, by driving the low-voltage distribution circuit breaker through the switch opening and closing execution component, it also avoids the modification of the original distribution network lines and components, and reduces the cost of improvement.

[0029] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limiting of the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0031] Figure 1 A schematic diagram showing the structure of a network distribution switch controller provided by an embodiment of the utility model is shown;

[0032] Figure 2A schematic diagram of a wiring circuit in the application process of a network distribution switch controller provided by an embodiment of the utility model is shown;

[0033] Figure 3 A schematic diagram showing the structure of another network distribution switch controller provided by an embodiment of the utility model is shown;

[0034] Figure 4 A schematic diagram of the structural composition of a network distribution switch control system provided by an embodiment of the utility model is shown. DETAILED DESCRIPTION

[0035] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0036] The utility model embodiment provides a network distribution switch controller, such as Figure 1 As shown, it includes: an electrical signal detection component 11, a central control component 12 and a switch opening and closing execution component; the central control component 12 is electrically connected to the electrical signal detection component 11 and the switch opening and closing execution component 13 respectively, and the switch opening and closing execution component 13 is electrically connected to the control contacts of the low-voltage distribution circuit breaker.

[0037] Among them, the electrical signal detection component 11 is used to collect electrical signals on the low-voltage power distribution power supply side, and the electrical signals include data such as the amplitude, frequency, and phase of voltage and current. The electrical signal detection component 11 may include a voltage sensor and a current sensor, or a current measuring instrument and a voltage measuring instrument, or a voltage transformer and a current transformer, etc., which are not specifically limited in the embodiments of the present utility model. Preferably, the electrical signal detection component 11 includes: a voltage transformer and a current transformer; the current transformer is electrically connected to the central chip, and the voltage transformer is electrically connected to the central chip; the current transformer is used to collect current signals on the low-voltage power distribution power supply side; the voltage transformer is used to collect voltage signals on the low-voltage power distribution power supply side. Figure 2As shown, the current and voltage transformer collects the electrical signal data of the three-phase electrical circuit on the power supply side of the main grid, and sends it to the central chip. The central chip sends instructions to the switch opening and closing execution component to drive the low-voltage distribution circuit breaker to open. By collecting the voltage phase, voltage amplitude, current phase and current amplitude of each phase in the three-phase electrical circuit on the power supply side of the main grid, it can be determined whether the total current of the current line flows from the power supply side of the main grid to the power load side, or from the power load side to the power supply side of the main grid, and timely discovers the failure of the anti-islanding circuit breaker, and the electric energy output by the new energy inverter is reversely supplying power to the power supply side of the main grid that is out of power. In addition, the use of voltage transformers and current transformers as electrical signal detection components 11 can make the network distribution switch controller have a smaller size and lower cost while ensuring the accuracy of electrical signal collection.

[0038] Among them, the central control component 12 is used to collect the electrical signal according to the electrical signal detection component 11 and determine the flow direction of the electrical signal. When the flow direction of the electrical signal is from the power load to the power supply side, by sending a control instruction, the switch opening and closing execution component 13 is controlled to drive the low-voltage distribution circuit breaker to open, so as to cut off the connection between the low-voltage distribution device and the new energy inverter. The switch opening and closing execution component 13 is used to receive the control signal of the central control component 12, and execute the driving action according to the control signal to drive the low-voltage distribution circuit breaker to open. Preferably, the switch opening and closing execution component 13 includes a relay; the normally open contact terminal of the relay is electrically connected to the central control component 12; and the output end of the relay is electrically connected to the short-circuit opening control contact of the low-voltage distribution circuit breaker. Preferably, the relay is a quick-acting relay or a DC relay. By electrically connecting the output end of the relay to the short-circuit opening control contact of the low-voltage distribution circuit breaker, when the relay receives the control command, the normally open contact closes, the low-voltage distribution circuit breaker control contact is short-circuited, and the low-voltage distribution circuit breaker is triggered to open, thereby disconnecting the connection between the new energy inverter and the power load. When the output capacity of the new energy is close to or greater than the power load, the anti-islanding circuit breaker between the new energy inverter and the power load is not opened. In this case, by disconnecting the low-voltage distribution circuit breaker, the reverse charging of the distribution equipment on the main power grid side can be avoided and the safety of the power grid equipment can be protected. It can also enable new energy to supply power to the power load and improve the absorption capacity of new energy. At the same time, it provides technical support for the transformation of the grid-following mode of new energy grid connection to the grid-building mode. In addition, by connecting the relay to the short-circuit opening control contact of the low-voltage distribution circuit breaker, the function of the circuit breaker in the existing power grid is fully utilized, the workload of line changes and installation of network distribution switch controllers is minimized, and the convenient installation and removal of the island distribution switch controller is achieved, thereby improving the convenience of operation.

[0039] In the embodiments of the present application, Figure 3As shown, the central control component 12 includes a central chip 1201 and a carrier communication module 1202; the central chip 1201 is electrically connected to the normally open contact terminal of the relay; and the carrier communication module 1202 is communicatively connected to the anti-islanding circuit breaker in the power supply line. When the network distribution switch controller is actually used in the power grid, it is installed on the power supply side of the low-voltage distribution circuit breaker, which is far away from the anti-islanding circuit breaker on the new energy inverter side. By configuring the carrier communication module in the central control component, the anti-islanding circuit breaker can be controlled, thereby achieving flexible selectivity and comprehensiveness of the low-voltage distribution switch control.

[0040] Among them, after driving the low-voltage distribution circuit breaker to open, the voltage transformer detects the voltage on the low-voltage distribution power supply side. After the main grid is abnormal or the power outage demand is lifted, it will be reconnected to the power supply network for power supply. By detecting the voltage on the low-voltage distribution power supply side through the voltage transformer, it can be timely known whether the main grid power supply is powered. The carrier communication module is used to send an instruction to the anti-islanding circuit breaker in the power supply line to indicate the disconnection of the switch when the voltage is greater than the preset voltage value, so as to disconnect the connection between the new energy power supply end and the power load before the low-voltage distribution circuit breaker is delayed and reclosed. Since the anti-islanding circuit breaker is not disconnected after the power outage on the main grid side, the new energy inverter has been supplying power to the power load, and the electrical signal reference of the main grid is lost, and the phase and frequency of the new energy electrical signal will deviate. After the low-voltage distribution circuit breaker is delayed and reclosed, the power supply pace of the new energy and the main grid is inconsistent, resulting in power grid fires, power grid shocks, etc. The voltage transformer is used to detect whether the main grid is receiving power. When power is detected, the carrier communication module sends a trip control command to the anti-islanding circuit breaker along the power supply line. This can disconnect the power supply of new energy before the low-voltage distribution circuit breaker is closed and the main grid is connected to the power load. This can effectively avoid the power supply of new energy and the main grid being out of step, which may cause abnormal power grid conditions. The preset voltage value can be configured according to the actual application scenario, such as 220V, 380V, etc.

[0041] In the embodiment of the present application, the switch opening and closing actuator 13 also includes a button, which includes a capacitive touch button or a mechanical button; the button is electrically connected to the short-circuit opening control contact of the low-voltage distribution circuit breaker. By configuring a manual button in the switch opening and closing actuator 13, the need for manual intervention is met, and when the relay of the switch opening and closing actuator 13 fails and automatic control cannot be achieved, the opening of the low-voltage distribution circuit breaker is controlled by manual intervention, thereby improving the reliability of the network distribution switch controller.

[0042] In an embodiment of the present application, the network distribution switch controller also includes: a display screen or an indicator light; the display screen is electrically connected to the central chip; or the indicator light is electrically connected to the central chip. By configuring the display screen or the indicator light, the execution status of the switch opening and closing execution component 13 and the signal sending status of the carrier communication module can be displayed. For example, the prompt "the switch opening and closing execution component action is successful (failed)" is displayed on the display screen; when the switch opening and closing execution component and the carrier communication module are working normally, the indicator light is green; when any of the switch opening and closing execution component and the carrier communication module is working abnormally, the indicator light is red, so as to realize the visualization of the control process and facilitate the monitoring and inspection of the inspection personnel.

[0043] The utility model provides a network distribution switch controller, which includes: an electric signal detection component, a central control component and a switch opening and closing execution component; the central control component is electrically connected to the electric signal detection component and the switch opening and closing execution component respectively, and the switch opening and closing execution component is electrically connected to the control contact of the low-voltage distribution circuit breaker. Compared with the prior art, the embodiment of the utility model collects the electric signal on the low-voltage distribution power supply side through the electric signal detection component; the central control component, when the flow direction of the electric signal is from the power load to the power supply side, controls the switch opening and closing execution component to drive the low-voltage distribution circuit breaker to open, so as to cut off the connection between the low-voltage distribution device and the new energy inverter and timely discover the situation that the main power grid is out of power and the anti-islanding circuit breaker fails, and controls the low-voltage distribution circuit breaker to open, so as to disconnect the connection between the distribution main power grid power supply and the new energy inverter to prevent the islanding phenomenon from occurring. At the same time, by driving the low-voltage distribution circuit breaker through the switch opening and closing execution component, the modification of the original distribution network lines and components is also avoided, and the cost of improvement is reduced.

[0044] In another aspect of the present invention, the present invention provides a network distribution switch control system, such as Figure 4 As shown, the system includes: a network distribution switch controller 1, a low-voltage distribution circuit breaker 2, an anti-islanding circuit breaker 3, an electrical load 4, a new energy inverter 5, a new energy power supply 6 and a main power distribution transformer 7. Among them, the low-voltage distribution circuit breaker 2 is in the low-voltage distribution cabinet, and the new energy power supply 6 can be a photovoltaic panel, a wind turbine, a chemical energy generator, etc. The embodiment of the utility model is not specifically limited. The new energy power supply 6, the new energy inverter 5, the anti-islanding circuit breaker 3, the electrical load 4, the low-voltage distribution circuit breaker 2, and the main power distribution transformer 7 are all existing equipment in the power supply network. Among them, the low-voltage distribution circuit breaker has a delayed reclosing function of reclosing after a certain delay after a power outage. The network distribution switch controller is installed between the low-voltage distribution circuit breaker and the distribution transformer. Since the complexity of the power line on the power supply side and the number of power devices are much smaller than those on the power load side, the difficulty of wiring installation can be reduced and the convenience can be improved.

[0045] The utility model provides a network distribution switch control system, which collects electrical signals from the low-voltage distribution power supply side through an electrical signal detection component; the central control component, when the flow direction of the electrical signal is from the power load to the power supply side, controls the switch opening and closing execution component to drive the low-voltage distribution circuit breaker to open, so as to cut off the connection between the low-voltage distribution device and the new energy inverter, and timely discover the situation that the main power grid is out of power and the anti-islanding circuit breaker fails, and controls the low-voltage distribution circuit breaker to open, so as to disconnect the connection between the distribution main grid power supply and the new energy inverter, and prevent the islanding phenomenon from occurring. At the same time, by driving the low-voltage distribution circuit breaker through the switch opening and closing execution component, it is also avoided to change the original distribution network lines and components, and the cost of improvement is reduced.

[0046] In the description of the present invention, "plurality" means two or more than two, unless otherwise clearly and specifically defined.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A network distribution switch controller, characterized in that: include: Electrical signal detection components, central control components and switch opening and closing execution components; The central control component is electrically connected to the electrical signal detection component and the switch opening and closing execution component respectively, and the switch opening and closing execution component is electrically connected to the control contact of the low-voltage distribution circuit breaker; The electrical signal detection component is used to collect electrical signals from the low-voltage power distribution power supply side; The central control component is used to control the switch opening and closing actuator to drive the low-voltage distribution circuit breaker to open when the direction of the electrical signal flows from the power load to the power supply side, so as to cut off the connection between the low-voltage distribution device and the new energy inverter; The switch opening and closing execution component includes a relay; The normally open contact terminal of the relay is electrically connected to the central control component; The output end of the relay is electrically connected to the short-circuit opening control contact of the low-voltage distribution circuit breaker; The relay comprises a fast-acting relay or a DC relay; The central control component includes a central chip and a carrier communication module; The central chip is electrically connected to the normally open contact terminal of the relay; The carrier communication module is communicatively connected with the anti-islanding circuit breaker in the power supply line; The electrical signal detection component includes: a voltage transformer and a current transformer; The current transformer is electrically connected to the central chip, and the voltage transformer is electrically connected to the central chip; The current transformer is used to collect the current signal on the low-voltage power distribution power supply side; The voltage transformer is used to collect the voltage signal on the low-voltage power distribution power supply side; The voltage transformer is also used to detect the voltage on the low-voltage distribution power supply side after driving the low-voltage distribution circuit breaker to open; The carrier communication module is used to send an instruction to the anti-islanding circuit breaker in the power supply line to instruct the switch to be disconnected when the voltage is greater than a preset voltage value, so as to disconnect the connection between the new energy power supply end and the power load before the low-voltage distribution circuit breaker delays reclosing.

2. The network distribution switch controller according to claim 1, characterized in that: The switch opening and closing actuator further comprises a button, and the button comprises a capacitive touch button or a mechanical button; The button is electrically connected to the short-circuit opening control contact of the low-voltage power distribution circuit breaker.

3. The network distribution switch controller according to claim 1, characterized in that: The grid-building power distribution switch controller further includes: a display screen or an indicator light; The display screen is electrically connected to the central chip; or the indicator light is electrically connected to the central chip.

4. A network distribution switch control system, characterized in that: The system comprises: a new energy power supply, a new energy inverter, an anti-islanding circuit breaker, a power load, a low-voltage distribution circuit breaker, a main power grid distribution transformer and a network distribution switch controller as described in any one of claims 1-3.

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