Protection device suitable for distribution line with distributed power supply

Abstract

The utility model discloses a protection device suitable for a distribution line with a distributed power supply, which relates to the technical field of electric power control and protection devices and comprises a control module based on chip control and a power supply protection module integrating various distribution lines. The control module based on chip control can be applied to segments, branches and common connection points of the distributed power supplies on a distribution line with the distributed power supplies and can also be applied to segments and branches of traditional and conventional distribution lines, on one hand, linkage among all the modules can be effectively achieved through the control module based on chip control, on the other hand, expandability is achieved, and the control module based on chip control can be applied to the distribution line. The device is convenient to expand so as to adapt to more forms of power distribution networks, one set of protection device adapts to strategies of various power distribution networks, a power distribution line manager does not need to distinguish types and models of the device, and engineering installation, operation and maintenance and management are easier.

Description

Technical Field

[0001] This utility model relates to the field of power control and protection device technology, specifically, to a protection device suitable for power distribution lines with distributed power sources. Background Technology

[0002] Various small-scale clean energy sources, balancing cost and convenience, often choose to connect to the distribution network via 10kV lines, changing the original simple radial network operation mode into a multi-source network. Simultaneously, with the development of regional economies, the number of dedicated line users is constantly increasing, and the original power flow will also change. The power supply and consumption model has undergone tremendous changes, and traditional distribution line protection devices are generally only suitable for a certain type of distribution network, making it difficult to accommodate multiple distribution lines. Utility Model Content

[0003] The purpose of this invention is to provide a protection device suitable for distributed power distribution lines, solving the problem that traditional power distribution line protection devices are difficult to adapt to the operation scenarios of distributed power distribution lines.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A protection device suitable for power distribution lines with distributed power sources includes a control module, a distributed power source grid-connected management module, and a power distribution line protection module. The control module is connected to the distributed power source grid-connected management module. The control module includes a power supply module, an input / output module, a communication module, and a CPU module. The CPU module is connected to the power supply module, the input / output module, and the communication module. The distributed power source grid-connected management module includes a power distribution line protection device basic module and a distributed power source grid-connected protection monitoring module. The protection common module includes a signal acquisition module, a data calculation module, and... The protection judgment basic module includes a distributed power grid-connected protection monitoring module comprising a power quality detection module, a loop-closing synchronization module, and a source-side voltage-controlled closing interlocking module. The distribution line protection module includes a single-phase grounding protection module and a line break protection module. The signal acquisition module is installed on the distribution line. The data calculation module is connected to the protection judgment basic module, the power quality detection module, the loop-closing synchronization module, the source-side voltage-controlled closing interlocking module, the single-phase grounding protection module, and the line break protection module. The CPU module is connected to the signal acquisition module and the data calculation module.

[0006] Traditional protection devices for power distribution lines are generally only suitable for single-radial distribution networks, making it difficult to meet the requirements of multi-source distribution networks. The protection device proposed in this solution is chip-controlled and integrates multiple power distribution line protection modules. It can be applied to sections, branches, and common connection points of distributed power sources on power distribution lines, as well as to sections and branches of conventional power distribution lines. The chip-controlled modules effectively enable linkage between modules and are scalable, facilitating device expansion and adaptability to more types of power distribution networks. This strategy of adapting one protection device to multiple power distribution networks eliminates the need for power distribution line managers to distinguish between different device types and models, making engineering installation, operation, and management easier.

[0007] Furthermore, the protection device is installed at the point of common coupling (PCC) between the distributed power source and the distribution network. In a power system, protection devices in different parts may have different protection settings and strategies. If these are not properly configured and verified, malfunctions or failures to operate may occur. Installing the protection device at the PCC enables management and grid connection protection of distributed power sources, ensuring the stable operation of the power system. Simultaneously, equipment in different locations may have different management methods and systems. If unified management is not implemented, it will lead to management chaos. If the models and types of protection devices in various locations of the power system can be standardized, unified management of equipment in different locations can be achieved, improving the management efficiency and level of the power system. The PCC installation also provides dual protection for both the distributed power source and the distribution network. If a fault occurs on one side, the protection device can quickly disconnect the fault path, preventing the fault from spreading to the other side.

[0008] Furthermore, the protection device also includes a setting preset device, which is used to preset the settings of the protection device. The setting preset device communicates wirelessly with the control module. For each functional module of the protection device to perform timely and correct operations, its relevant values ​​need to be preset. This solution achieves this effect by utilizing the setting preset device. The setting preset can set different protection actions for different operating modes, such as overcurrent protection, undervoltage protection, and overvoltage protection. When an abnormal situation occurs, the protection device will perform corresponding actions according to the preset settings, thereby protecting the stability and reliability of distributed power sources and the power system. In addition, the setting preset can be flexibly adjusted and modified according to actual needs to meet the protection requirements in different scenarios.

[0009] Furthermore, the protection device also includes a bidirectional current protection module, which comprises a current protection device and a directional element, and is connected to the data calculation module. Traditional current protection activates based on the current magnitude and operates after a protection time limit. Directional overcurrent protection with a directional element only protects the forward-direction line, ignoring the reverse line. The bidirectional current protection in this invention can provide forward-direction protection, reverse-direction protection, or simultaneous forward and reverse-direction protection according to user settings.

[0010] Furthermore, the protection device also includes a switching module, through which the control module is connected to the distributed power grid management module and the power distribution line protection module. When dealing with different types of power distribution networks, the protection device needs to switch to the corresponding mode. Through the switching module, based on the relevant parameter settings of the power distribution network and the coordinated control of the control module, mode switching can be achieved more quickly and conveniently.

[0011] Furthermore, the distributed power grid connection management module also includes an anti-islanding protection module and a reverse power protection module, and the data calculation module is connected to the anti-islanding protection module and the reverse power protection module. When an unplanned island forms in the power system, the load within the island and the capacity of the distributed power source are mismatched, which can lead to the burning of electrical appliances by users within the island, and even threaten grid maintenance personnel. When islanding occurs, the anti-islanding protection device can quickly disconnect the distributed power source, ensuring the power safety of users and the life safety of maintenance personnel. At the same time, the power supply between the distributed power source and the grid is generally unidirectional, and there are often power supply requirements; therefore, a reverse power protection function should be configured to control the direction and power threshold.

[0012] Furthermore, the anti-islanding protection module includes an anti-islanding protection device and an execution device. The execution device includes a fault handling unit and a signal processing unit, which are connected in series. Islanding detection methods are mainly divided into passive detection and active detection. This invention adopts a passive detection method, which has no impact on power quality, thereby reducing the impact on the power grid. At the same time, the anti-islanding protection module only needs to detect whether the voltage, frequency, and other parameters of the grid-connected distributed power source are disconnected from the power grid to make a judgment. Therefore, its structure is relatively simple and its cost is relatively low.

[0013] Furthermore, the communication module includes a serial communication protocol interface, a network communication protocol interface, and a mobile communication interface. The communication module contains multiple interfaces, making information transmission and interaction between the control module and other modules and external systems more flexible and selective.

[0014] Furthermore, the control module also includes a debugging and monitoring module, which includes a debugging and monitoring interface and a debugging and monitoring device, with the CPU module, the debugging and monitoring interface, and the debugging and monitoring device connected in series. During the operation of the protection device, its operating status needs to be monitored to understand its working status in a timely manner. The debugging and monitoring module can monitor the system's operating status in real time, record various system operating data, and provide rapid early warnings when system anomalies or faults occur.

[0015] Furthermore, the control module also includes an indicator module, which comprises an indicator interface and an indicator device, with the CPU module, the indicator interface, and the indicator device connected in series. When the protection device is in operation, the operating status of each module needs to be displayed intuitively. The indicator module can better display the operating status and function execution of each module.

[0016] One or more technical solutions provided by this utility model have at least the following technical effects or advantages:

[0017] This power distribution line protection device is based on chip control and integrates multiple power distribution line protection function modules. It can be applied to sections, branches, and common connection points of distributed power sources on power distribution lines with distributed power sources, as well as to sections and branches of traditional conventional single-radial power distribution lines. The chip-based control module can effectively realize the linkage between various modules and has scalability, which facilitates the expansion of the device and adapts to power distribution networks with more operating modes. The strategy of one protection device adapting to multiple power distribution networks eliminates the need for power distribution line managers to distinguish between different types and models of devices, making engineering installation, operation and maintenance easier. Attached Figure Description

[0018] The accompanying drawings, which are provided to further illustrate the embodiments of the present invention and constitute a part of the present invention, do not constitute a limitation thereof.

[0019] Figure 1 This is a schematic diagram of a grid connection structure for a protection device applicable to a distributed power distribution line in this utility model.

[0020] Figure 2 This is a schematic diagram of a distributed power distribution line structure that includes a protection device, according to this utility model.

[0021] Figure 3 This is a structural schematic diagram of the protection device of this utility model, which includes an anti-islanding protection module, a reverse power protection module, a bidirectional current protection module, and a switching module;

[0022] Figure 4This is a structural diagram of the control module, which includes a debugging and monitoring module and an indication module, as well as a preset value device. Detailed Implementation

[0023] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, where there is no conflict, the embodiments of this utility model and the features within them can be combined with each other.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0025] Example 1

[0026] Please refer to Figure 1 and Figure 2This utility model provides a protection device suitable for distributed power distribution lines, comprising a control module, a distributed power grid management module, and a distribution line protection module. The protection device is installed at the common connection point between the distributed power source and the distribution network. The distributed power source can be a solar photovoltaic power source or a wind power source. The control module includes a power module, an input / output module, a communication module, and a CPU module. The power module can be a BUCK step-down DC-DC converter or a W78 series linear regulator. The input modules in the input / output module can be optocouplers or diodes. The output module can be a transistor or a field-effect transistor. The input-output module is used for input signal acquisition and output opening / closing and energy storage operations. The communication module includes a serial communication protocol interface, a network communication protocol interface, and a mobile communication interface. The serial communication protocol interface can be RS232 or RS485. The network communication protocol interface can be an RJ45 interface or an SFP interface. The mobile communication interface can be a SIM800L series GPRS module or an M590 series GPRS module. The communication module is used to receive and send the data and signals required by the protection device when it is working. The CPU can be an ARM Cortex-M series microprocessor or a Huada HC32F4A0 series chip. The CPU is mounted on a circuit board substrate. The input / output module and power module are connected to the CPU via terminals, which can be pins or sockets. The communication module is mounted on the circuit board substrate and connected to the CPU via a circuit. The control module receives various data signals from the power distribution line and various functional module devices through the input / output module and transmits and distributes the various data signals to the corresponding functional modules. The various data signals are received through a network port or serial port. The various data signals include power parameters in the power distribution line and operating parameters of each functional module device. The CPU contains a control program written according to the actual working conditions. The control program is an existing program and can be written in C or C++. The control program is used for the transmission and distribution of data and signals.

[0027] The distributed power grid connection management module includes a basic module for power distribution line protection devices and a distributed power grid connection protection monitoring module. The basic module for power distribution line protection devices includes a signal acquisition module, a data calculation module, and a protection judgment module. The signal acquisition module can be a current transformer or a voltage transformer, and the data calculation module can be a DSP digital signal processor or an ARM processor. The protection judgment module includes a logic processing unit and a protection action execution unit. The logic processing unit can be software or a program, and the protection action execution unit can be a circuit breaker or a relay. Based on the software and program, the protection judgment module processes and analyzes the current and voltage signals on the line collected by the protection device, and determines the type and location of the fault based on this data, thereby protecting the power distribution line with distributed power sources. For example, when the current on the line exceeds a set value, the logic processing unit triggers a corresponding protection action, such as tripping or disconnecting the faulty section. The signal acquisition module is connected to the power distribution line and acquires the current and voltage signals on the line from the installation point of the protection device. The signal acquisition module is connected to the data calculation module, and the connection method can be wired or wireless. The circuit board substrate on which the CPU module is installed is connected to the signal acquisition module and the data calculation module through terminals. The terminals can be sockets or outlets. The terminals are connected to the CPU through a circuit. The data calculation module is connected to the protection judgment basic module and can perform data communication. The data communication method can be wired or wireless.

[0028] The distributed power grid-connected protection and monitoring module is applied to sections, branches, and common connection points between distributed power sources and the public power grid on distribution lines with distributed power sources. The module includes a power quality detection module, a loop-connection synchronization module, and a source-side voltage-controlled closing interlocking module. The power quality detection module can be a PMC-680M online power quality monitoring device or an HZDZ-T power quality analyzer. The loop-connection synchronization module can be a SYZ-550 microcomputer-based automatic quasi-synchronization device or an FJX-3815B intelligent synchronization verification device. The source-side voltage-controlled closing interlocking module can be a PS-3815B intelligent electronic interlocking device or an SDL-300 electromagnetic lock interlocking device. The data calculation module is connected to the power quality detection module, the loop-connection synchronization module, and the source-side voltage-controlled closing interlocking module. The connection method can be a wired connection via terminals on a circuit board or a wireless connection based on a wireless communication protocol, such as Wi-Fi or Bluetooth. The protection device can also be applied to the segmented branches of conventional power distribution lines. The power distribution line protection module in the protection device includes a single-phase grounding protection module and a line break protection module. The single-phase grounding protection module can be a DPR-100 or DPR-200 single-phase grounding protection device, and the line break protection module can be a DL-100 or DL-200 line break protection device. The data calculation module is connected to both the single-phase grounding protection module and the line break protection module. The connection method can be a wired connection via terminals on a circuit board or a wireless connection based on a wireless communication protocol, such as Wi-Fi or Bluetooth. Based on the control of the control module, and in conjunction with the various modules of the protection device, the protection function of the distributed power distribution line is realized.

[0029] In this invention, the chips or modules are all existing modules in the prior art, and the programs or codes stored in the chips are all existing programs or codes. The methods corresponding to these codes are also existing methods in the prior art. This invention is a utility model that utilizes these existing chips and applies them to protection devices suitable for distributed power distribution lines.

[0030] Example 2

[0031] Please refer to Figure 3This utility model provides a protection device suitable for distributed power distribution lines, based on Embodiment 1. The distributed power grid management module of the protection device further includes an anti-islanding protection module and a reverse power protection module. A data calculation module is connected to the anti-islanding protection module and the reverse power protection module. The anti-islanding protection module includes an anti-islanding protection device and an execution device. The anti-islanding protection device performs the anti-islanding protection function in the distribution line through the execution device. The anti-islanding protection module is connected to the execution device. The execution device includes a fault handling unit and a signal processing unit. The fault handling unit can be a vacuum circuit breaker or sulfur hexafluoride. The circuit breaker, wherein the signal processing unit can be a DSP digital signal processor or an ARM processor, and the anti-islanding protection device can be an ACLT-38160H islanding effect protection device or an ACLT-31000 islanding effect protection device, wherein one end of the anti-islanding protection device is connected to the common connection point of the distribution line and the distribution network, and the other end of the anti-islanding protection device, the signal processing unit, and the fault handling unit are sequentially connected, wherein the connection method can be a wired connection through the terminal block on the circuit board or a wireless connection based on a wireless communication protocol, wherein the wireless communication protocol can be a Wi-Fi communication protocol or a Bluetooth communication protocol. When the anti-islanding protection device of the anti-islanding protection module detects an abnormal situation such as islanding operation in the distributed power system, the signal processing unit judges and processes according to the preset protection logic and outputs a corresponding control signal, thereby driving the fault handling unit to act, disconnecting the distributed power source from the main power grid, thereby avoiding the impact of islanding operation. The reverse power protection module can be an HPD300 reverse power protection relay or a Sungrow SG320HX inverter. Distributed power sources and the grid generally supply power in one direction and often have power requirements. By configuring a reverse power protection module, the direction and power threshold can be controlled.

[0032] The protection device also includes a bidirectional current protection module, which comprises a current protection device and a directional element. The data calculation module is connected to the bidirectional current protection module. The connection method can be a wired connection via a terminal block on a circuit board or a wireless connection based on a wireless communication protocol, such as Wi-Fi or Bluetooth. The current protection device can be an electromagnetic protection relay or an inductive protection relay, and the directional element can be an inductive power directional relay or a transistor relay. The directional element and the current protection device combine to form the bidirectional current protection module. The bidirectional current protection module adds a directional element to the current protection, which can determine the direction of the fault. The bidirectional current protection can provide forward, reverse, or simultaneous forward and reverse protection according to user settings.

[0033] The protection device also includes a switching module, which is an electromagnetic relay. Depending on the actual application, when the protection device is used in sections, branches, or common connection points of distributed power sources on power distribution lines, the electromagnetic relay can be manually switched to the distributed power grid-connected protection scenario via a button. This establishes a path between the power distribution line protection module, the distributed power grid-connected protection monitoring module, the anti-islanding protection module, the reverse power protection module, and the bidirectional current protection module, thus adapting to the application scenario. When the application scenario is a section or branch of a conventional power distribution line, the electromagnetic relay can be manually switched to the conventional protection application scenario via a button. This establishes a path between the power distribution line protection module, the power distribution line protection module, and the bidirectional current protection module, thus adapting to the application scenario. The switching module can also switch via wireless network signal transmission to control the electromagnetic relay. The electromagnetic relay can be a JQX-13F electromagnetic relay or a JT3-11 / 1 220V electromagnetic relay.

[0034] Example 3

[0035] Please refer to Figure 4 This utility model provides a protection device suitable for distributed power distribution lines, based on Embodiment 1. The control module further includes a debugging and monitoring module and an indication module. The control module is connected to the debugging and monitoring module through a debugging and monitoring interface, which can be an RS232 serial port or an RS485 serial port. The debugging and monitoring module can be an RCL-0923 distributed power coordination monitoring device or an RCL-0924 distributed power coordination monitoring device. During the operation of the protection device, the debugging and monitoring module monitors the operating status of the system in real time, records various data of the system operation, and provides rapid early warning when the system malfunctions or fails. The control module is connected to the indicator device via an indicator interface, which can be an RS232 serial port or an RS485 serial port. The indicator module can be an LCD screen or an LED light. When the protection device is in working condition, the indicator module displays various parameters of the protection device and the working status of each protection function module in real time. These parameters can be electrical parameters such as current or voltage, which are obtained through a voltage transformer or current transformer and transmitted to the indicator module via a cable. Alternatively, they can be the device operation status of each module. For example, the opening and closing status of the circuit breaker in the closing loop detection synchronization module can be transmitted to the indicator module in the form of an electrical signal through a circuit breaker position sensor. The transmission method can be cable transmission or wireless network transmission. The indicator module uses the lighting and extinguishing of LED lights to indicate the closing and opening of the circuit breaker.

[0036] The protection device also includes a setting preset device, which communicates wirelessly with the control module. The wireless communication method can be Wi-Fi or Bluetooth. The setting preset device can be a tablet computer or an industrial computer. It can store various settings required by the protection device, including bidirectional current protection settings, open-circuit protection settings, grounding protection settings, anti-islanding protection settings, reverse power protection settings, loop synchronizing settings, and source-side voltage-enabled closing lockout values. The control module can receive these settings wirelessly and transmit them to various modules. This transmission can be via cable or wireless network. Each module acquires the settings based on its own components to determine and execute its protection function.

[0037] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0038] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A protection device for a power distribution line having a distributed power source, characterized by comprising: The protection device comprises a control module, a distributed power grid-connected management module, a protection common module and a power distribution line protection module, the control module is connected with the distributed power grid-connected management module, the control module comprises a power module, an input / output module, a communication module and a CPU module, the CPU module is connected with the power module, the input / output module and the communication module, the distributed power grid-connected management module comprises a power distribution line protection device basic module and a distributed power grid-connected protection monitoring module, the protection common module comprises a signal acquisition module, a data calculation module and a protection judgment basic module, the distributed power grid-connected protection monitoring module comprises an electric energy quality detection module, a loop closing detection synchronization module and a source side voltage closing locking module, the power distribution line protection module comprises a single-phase grounding protection module and a wire breaking protection module, the signal acquisition module is installed on a power distribution line, the data calculation module is connected with the protection judgment basic module, the electric energy quality detection module, the loop closing detection synchronization module, the source side voltage closing locking module, the single-phase grounding protection module and the wire breaking protection module, and the CPU module is connected with the signal acquisition module and the data calculation module.

2. The protection device for distribution lines with distributed generation according to claim 1, characterized in that, The protection device is installed at a common connection point of a distributed power source and a power distribution network.

3. The protection device for distribution lines with distributed generation according to claim 1, characterized in that, The protection device further comprises a fixed value preset device, which is used for pre-setting fixed values of the protection device, and the fixed value preset device and the control module are in wireless communication.

4. The protection device for distribution lines with distributed generation according to claim 1, characterized in that, The protection device further comprises a bidirectional current protection module, which comprises a current protection device and a direction element, and the bidirectional current protection module is connected with the data calculation module.

5. The protection device for distribution lines with distributed generation according to claim 1, characterized in that, The protection device further comprises a switching module, and the control module is connected with the distributed power grid-connected management module and the power distribution line protection module through the switching module.

6. The protection device for distribution lines with distributed generation according to claim 1, characterized in that, The distributed power grid-connected management module further comprises an anti-islanding protection module and an inverse power protection module, and the data calculation module is connected with the anti-islanding protection module and the inverse power protection module.

7. The protection device for distribution lines with distributed generation according to claim 6, characterized in that, The anti-islanding protection module comprises an anti-islanding protection device and an execution device, the execution device comprises a fault processing unit and a signal processing unit, and the fault processing unit, the signal processing unit and the anti-islanding protection device are connected in series.

8. The protection device for distribution lines with distributed generation according to claim 1, characterized in that, The communication module comprises a serial communication protocol interface, a network communication protocol interface and a mobile communication interface.

9. The protection device for distribution lines with distributed generation according to claim 1, characterized in that, The control module further comprises a debugging monitoring module, the debugging monitoring module comprises a debugging monitoring interface and a debugging monitoring device, and the CPU module, the debugging monitoring interface and the debugging monitoring device are connected in series.

10. The protection device for distribution lines with distributed generation according to claim 9, characterized in that, The control module further comprises an indication module, the indication module comprises an indication interface and an indication device, and the CPU module, the indication interface and the indication device are connected in series.

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