A multi-power source on-site and remote synchronization grid-connected access device and method

Abstract

This invention discloses a multi-power source local and remote synchronous grid connection device and method. The device includes a local device and a remote device that communicate with each other. The local device is installed between the local load power supply line and the remote load power supply line, and the remote device is connected in parallel with a remote circuit breaker. This invention eliminates the need for traditional emergency power vehicles. Through the cooperation of the local and remote devices, it can achieve uninterrupted power supply for users during the entire process of primary synchronous connection of the local power source when the remote power source is operating normally, complete transfer of power from the local power source to the remote load when the remote power source is disconnected, and secondary remote synchronous connection of the remote power source after maintenance.

Description

Technical Field

[0001] This invention relates to a device and method for simultaneous local and remote grid connection of multiple power sources, belonging to the field of power distribution technology. Background Technology

[0002] During transformer maintenance or replacement work in the distribution area, in order to ensure uninterrupted power supply to users, low-voltage emergency power vehicles are usually used for temporary power supply. However, this method has the following limitations: the synchronization and disconnection operation is restricted. Specifically, some emergency power vehicles equipped with low-voltage synchronization grid connection can achieve primary synchronization grid connection, but since the secondary synchronization point and the primary synchronization point are often not in the same location, and the distance between them is often greater than 50m, remote secondary synchronization connection cannot be achieved. The power supply of the power vehicle must be disconnected before the low-voltage outgoing line switch of the secondary synchronization point can be closed, which requires a power outage. Most ordinary emergency power vehicles or diesel generators do not have the function of synchronization grid connection, and two power outage processes are required for connection and disconnection. Summary of the Invention

[0003] This invention provides a device and method for simultaneous local and remote grid connection of multiple power sources, which solves the problems disclosed in the background art.

[0004] According to one aspect of this application, a multi-power source local and remote synchronous grid connection access device is provided, including a local device and a remote device that communicate with each other; the local device is disposed between the local load power supply line and the remote load power supply line, and the remote device is connected in parallel with a remote circuit breaker; wherein, the remote circuit breaker is a circuit breaker between the remote power source and the second load power supply line. During local synchronous grid connection, the local device adjusts the power parameters of the local load power supply line according to the voltage at the first connection point and the voltage at the second connection point until the adjusted voltage and the voltage at the second connection point meet the first preset loop closing condition, and then controls the local load power supply line to connect with the remote load power supply line; wherein, the voltage at the first connection point is the voltage at the connection point with the local load power supply line, and the voltage at the second connection point is the voltage at the connection point with the remote load power supply line. During remote secondary synchronous grid connection, the remote device remotely controls the local device to adjust the power parameters of the local load power supply line according to the voltage at both ends of the remote circuit breaker, until the voltage at both ends of the remote circuit breaker meets the second preset loop closing condition, and then controls the bypass connection at both ends of the remote circuit breaker.

[0005] Furthermore, the local device includes a locally installed synchronization control terminal, a synchronization adjustment device, and a first synchronization switch; The synchronizing device is used to adjust the power parameters of the local load power supply line, and the first synchronizing switch is used to control the connection and disconnection between the local load power supply line and the remote load power supply line. The control terminals of the synchronizing device and the first synchronizing switch are both connected to the synchronizing control terminal. The synchronizing control terminal communicates with the remote device. One end of the synchronizing device is connected to one end of the first synchronizing switch, and the other end of the synchronizing device is connected to the local load power supply line. The other end of the first synchronizing switch is connected to the remote load power supply line.

[0006] Furthermore, the synchronization control terminal, synchronization adjustment device, and first synchronization switch are housed within the first housing, and the dimensions of the first housing meet the requirements for small cargo vehicle transportation.

[0007] Furthermore, the synchronous regulation device is a voltage regulation device based on the voltage compensation principle of partial power conversion or an AC-DC-AC device based on full power energy conversion.

[0008] Furthermore, the remote device includes a remotely installed data acquisition and transmission terminal and a second synchronizing switch; the second synchronizing switch is used to control the bypass switching at both ends of the remote circuit breaker; the control terminal of the second synchronizing switch is connected to the data acquisition and transmission terminal, the data acquisition and transmission terminal communicates with the local device, and the second synchronizing switch is connected in parallel with the remote circuit breaker.

[0009] Furthermore, the data acquisition and transmission terminal and the second synchronization switch are installed inside the second housing, which is a trolley box type housing.

[0010] Furthermore, both local and remote devices use quick-connect cable connections to connect to the power supply lines.

[0011] According to another aspect of this application, a grid connection method is provided, which uses the above-mentioned device for grid connection. The method includes a local synchronous grid connection method implemented on the local device side and a remote secondary synchronous grid connection method implemented on the remote device side. Local synchronous grid connection methods include: Collect the voltage at the first connection point and the voltage at the second connection point; If the voltage at the first connection point and the voltage at the second connection point meet the first preset loop closing condition, control the connection between the local load power supply line and the remote load power supply line. If the voltage at the first connection point and the voltage at the second connection point do not meet the first preset loop closing condition, the power parameters of the local load power supply line are adjusted. When the adjusted voltage and the voltage at the second connection point meet the first preset loop closing condition, the local load power supply line is connected to the remote load power supply line. Remote secondary synchronous grid connection methods include: Collect the voltage across the remote circuit breaker; If the voltage at both ends of the remote circuit breaker meets the second preset loop closing condition, control the bypass connection at both ends of the remote circuit breaker. If the voltage across the remote circuit breaker does not meet the second preset closing condition, the remote control local device adjusts the power parameters of the local load power supply line until the voltage across the remote circuit breaker meets the second preset closing condition, and then controls the bypass connection across the remote circuit breaker.

[0012] The beneficial effects achieved by this invention are as follows: This invention abandons the traditional emergency power vehicle and, through the cooperation of local and remote devices, can realize the uninterrupted power supply for users by: firstly synchronizing the local power supply when the remote power supply is running normally, completely transferring the power from the local power supply to the remote load when the remote power supply is disconnected, and secondly synchronizing the remote power supply after maintenance. In the entire process of firstly synchronizing the power supply, transferring the power, and secondly synchronizing the remote power supply, the power supply user is not interrupted. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the grid-connected device; Figure 2 This is a front view of the local device; Figure 3 This is a reverse view of the local device; Figure 4 This is a schematic diagram of the structure of the remote device; Figure 5 A flowchart for the local synchronous grid connection method; Figure 6 This is a flowchart of the remote secondary synchronous grid connection method. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0015] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application.

[0016] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0017] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0018] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0019] It should be noted that similar symbols and letters in the accompanying drawings represent similar items; therefore, once an item is defined in one accompanying drawing, it does not need to be discussed further in subsequent accompanying drawings.

[0020] Furthermore, in the description of the embodiments of this application, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. Therefore, features defined with "first" or "second" may explicitly or implicitly include one or more features.

[0021] To address the power outage issues encountered during the initial synchronization, transfer, and secondary remote synchronization processes of existing emergency power vehicles, this application provides a multi-power source local and remote synchronous grid connection device. This device includes at least a local device 1 and a remote device 2 that communicate with each other. The local device 1 is installed between the local load power supply line and the remote load power supply line, while the remote device 2 is connected in parallel with a remote circuit breaker. The remote circuit breaker is the circuit breaker between the remote power source and the second load power supply line. The local device 1 is installed locally, and the remote device 2 is installed remotely. The communication between the two can employ wired and wireless methods specific to power distribution networks, not limited to existing communication methods such as HPLC, RJ45, RS-485, LoRa, and fiber optics. This use of one or more hybrid communication methods improves communication reliability and expands applicability to complex scenarios.

[0022] During local synchronous grid connection, the local device 1 adjusts the power parameters of the local load power supply line according to the voltage at the first connection point and the voltage at the second connection point until the adjusted voltage and the voltage at the second connection point meet the first preset loop closing condition, and then controls the local load power supply line to connect with the remote load power supply line; during remote secondary synchronous grid connection, the remote device 2 remotely controls the local device 1 to adjust the power parameters of the local load power supply line according to the voltage at both ends of the remote circuit breaker until the voltage at both ends of the remote circuit breaker meets the second preset loop closing condition, and then controls the bypass connection at both ends of the remote circuit breaker; wherein, the voltage at the first connection point is the voltage at the connection point with the local load power supply line, and the voltage at the second connection point is the voltage at the connection point with the remote load power supply line.

[0023] In some embodiments, see Figure 1The local device 1 may include at least a locally installed synchronization control terminal 1-1, a synchronization adjustment device 1-2, and a first synchronization switch 1-3 (some common accessories in this device, such as protection or equipment bypass, will not be described in detail). The synchronization adjustment device 1-2 is used to adjust the power parameters of the local load power supply line, and the first synchronization switch 1-3 is used to control the connection and disconnection between the local load power supply line and the remote load power supply line. The control terminals of the synchronization adjustment device 1-2 and the first synchronization switch 1-3 are both connected to the synchronization control terminal 1-1. The synchronization control terminal 1-1 communicates with the remote device 2. One end of the synchronization adjustment device 1-2 is connected to one end of the first synchronization switch 1-3, and the other end of the synchronization adjustment device 1-2 is connected to the local load power supply line. The other end of the first synchronization switch 1-3 is connected to the remote load power supply line.

[0024] It should be noted that the synchronization control terminal 1-1 of the local device 1 can be a control terminal with a display, which facilitates real-time display of grid connection status and makes it convenient for operators to use. The synchronization regulation device 1-2 can be a voltage regulation device based on the voltage compensation principle of partial power conversion or an AC-DC-AC device based on full power energy conversion, and the product solution has wide applicability.

[0025] In some embodiments, for easy and quick connection, the local device 1 uses a quick-connect cable connection structure to connect to the power supply line.

[0026] In some embodiments, the synchronization control terminal 1-1, the synchronization adjustment device 1-2, and the first synchronization switch 1-3 are installed in the first housing. The size of the first housing meets the requirements of small cargo vehicle transportation, such as the loading and transportation requirements of conventional pickup trucks. By miniaturizing the local device 1, the device can be suitable for handling and use in confined spaces and is easy to cooperate with small cargo vehicles. It is suitable for situations with narrow roads and limited parking spaces, and will not cause problems such as emergency power vehicles being unable to directly reach the access point due to their large size.

[0027] Miniaturized local device 1 can be seen Figure 2 and Figure 3 The components are installed in layers within the first housing, as shown in the figure. The synchronization control terminal 1-1 and the synchronization adjustment device 1-2 are installed at the bottom, and the synchronization control terminal 1-1 is located at the front for easy viewing of the display screen by the operator. The first synchronization switch 1-3 is installed at the top, and multiple quick-connect cable connection structures are also installed on the front top.

[0028] The remote device 2 may include at least a remotely installed data acquisition and transmission terminal 2-1 and a second synchronous switch 2-2 (some common accessories in this device, such as protection or equipment bypass, will not be described in detail); the second synchronous switch 2-2 is used to control the bypass on and off at both ends of the remote circuit breaker; the control terminal of the second synchronous switch 2-2 is connected to the data acquisition and transmission terminal 2-1, the data acquisition and transmission terminal 2-1 communicates with the local device 1, and the second synchronous switch 2-2 is connected in parallel with the remote circuit breaker.

[0029] It should be noted that the data acquisition and transmission terminal 2-1 is similar to the synchronous control terminal 1-1, and can also be a control terminal with a display. Similarly, in order to facilitate quick connection, the remote device 2 also adopts a quick-connect cable connection structure to connect the power supply line.

[0030] Since the secondary synchronization point and the primary synchronization point are often not in the same location and the distance between them is often greater than 50m but not too far, in some embodiments, the remote device 2 is also miniaturized. Specifically, the acquisition and transmission terminal 2-1 and the second synchronization switch 2-2 are installed in the second housing. The second housing adopts a trolley box type housing, which is convenient for the remote device 2 to be transported on site.

[0031] Miniaturized remote sensing device 2 can be seen Figure 4 The components are installed in layers inside the second housing, as shown in the figure. The data acquisition and transmission terminal 2-1 is installed at the bottom, and the display screen is located at the front for easy viewing by the operator. The second synchronous switch 2-2 is installed at the top, and multiple quick-connect cable connection structures are also installed on the front of the top.

[0032] The above-mentioned device abandons the traditional emergency power vehicle. Through the cooperation of local device 1 and remote device 2, it can realize the following three processes: when the remote power is running normally, the local power (which can be from the same source as the remote power, or it can be a conventional emergency generator or emergency power vehicle) can be connected to the local power source for the first time, disconnect the remote power source and completely transfer the power to the remote load from the local power source, and after maintenance, the remote power source can be connected to the remote power source for the second time for uninterrupted power supply. The device can achieve uninterrupted power supply to the user in the three processes of primary connection, transfer, and secondary remote connection.

[0033] Based on the above-described apparatus, this application provides a grid connection method using the above-described grid connection apparatus. The method may include at least a local synchronous grid connection method and a remote secondary synchronous grid connection method.

[0034] The local synchronous grid connection method is implemented on the local device 1 side, specifically on the synchronous control terminal 1-1, and the method may include: Step 1: Collect the voltage at the first connection point and the voltage at the second connection point; Step 2: If the voltage at the first connection point and the voltage at the second connection point meet the first preset loop closing condition, control the local load power supply line to connect with the remote load power supply line; if the voltage at the first connection point and the voltage at the second connection point do not meet the first preset loop closing condition, adjust the power parameters of the local load power supply line. When the adjusted voltage and the voltage at the second connection point meet the first preset loop closing condition, control the local load power supply line to connect with the remote load power supply line.

[0035] by Figure 1 Taking the structure as an example, the local synchronous grid connection method can be found in [reference]. Figure 5 First, check that the first synchronizing switch 1-3 is in the open state. Connect the local load power supply line and the remote load power supply line to the synchronizing adjustment device 1-2 and the first synchronizing switch 1-3 respectively. Turn on the synchronizing control terminal 1-1 and observe the voltage U1 at the first connection and the voltage U3 at the second connection through the display screen. If the frequency difference, voltage amplitude difference, and voltage phase difference between U1 and U3 meet the first preset closing conditions (specifically, the frequency difference is less than 0.01Hz, the amplitude difference is less than 3V, and the phase difference is less than 1 degree), the display screen of the synchronizing control terminal 1-1 will show that synchronizing can be performed. The synchronizing control terminal 1-1 will automatically or manually close the first synchronizing switch 1-3 to perform one synchronizing operation, completing one synchronization operation. However, when U1 and U3 are closed, the voltage U1 at the first connection is closed, the voltage U1 at the second connection is closed, and the voltage U3 at the third connection is closed, completing one synchronization operation. When the frequency difference, voltage amplitude difference, and voltage phase difference between U2 and U3 do not meet the first preset closing condition, the display screen of the synchronization control terminal 1-1 will show that synchronous closing is not possible. The synchronization control terminal 1-1 will send a control signal to the synchronization adjustment device 1-2 according to the frequency difference, voltage amplitude difference, and voltage phase difference, and control the synchronization adjustment device 1-2 to adjust the power parameters. The adjustment feedback process can go through one or more times until the frequency difference, voltage amplitude difference, and voltage phase difference between the adjusted voltages U2 and U3 meet the first preset closing condition. The display screen of the synchronization control terminal 1-1 will show that synchronous closing is possible. The synchronization control terminal 1-1 will automatically or manually close the first synchronization switch 1-3 to perform one synchronous closing, completing one synchronization.

[0036] The remote secondary synchronization grid connection method is implemented on the remote device 2 side, specifically at the data acquisition and transmission terminal 2-1, and the method may include: S1) Collect the voltage across the remote circuit breaker.

[0037] S2) If the voltage at both ends of the remote circuit breaker meets the second preset closing condition, control the bypass connection at both ends of the remote circuit breaker; if the voltage at both ends of the remote circuit breaker does not meet the second preset closing condition, remote control local device 1 adjusts the power parameters of the local load power supply line until the voltage at both ends of the remote circuit breaker meets the second preset closing condition, then controls the bypass connection at both ends of the remote circuit breaker.

[0038] Or with Figure 1Taking the structure as an example, the remote secondary synchronous grid connection method can be found in [reference needed]. Figure 6 First, check that the first synchronizing switch 1-3 is in the closed state, and the second synchronizing switch 2-2 and the remote circuit breaker are in the open state. Connect the local load power supply line and the remote load power supply line to the synchronizing adjustment device 1-2 and the first synchronizing switch 1-3 respectively. Connect the second synchronizing switch 2-2 in parallel with the remote circuit breaker. Turn on the data acquisition and transmission terminal 2-1 and observe the voltages U4 and U5 displayed on the screen. When the frequency difference, voltage amplitude difference, and voltage phase difference between U4 and U5 meet the second preset closing conditions (specifically, the frequency difference is less than 0.01Hz, the amplitude difference is less than 3V, and the phase difference is less than 1 degree), the display screen of the data acquisition and transmission terminal 2-1 will show that secondary synchronizing closing is possible. Secondary synchronizing closing can be performed by automatically or manually controlling the second synchronizing switch 2-2 through the data acquisition and transmission terminal 2-1 to complete the secondary synchronizing. However, when the frequency difference, voltage amplitude difference, and voltage phase difference between U4 and U5 meet the second preset closing conditions (specifically, the frequency difference is less than 0.01Hz, the amplitude difference is less than 3V, and the phase difference is less than 1 degree), the display screen of the data acquisition and transmission terminal 2-1 will show that secondary synchronizing closing is possible. Secondary synchronizing closing can be performed by automatically or manually controlling the second synchronizing switch 2-2 through the data acquisition and transmission terminal 2-1 to complete the secondary synchronizing. When the position difference does not meet the second preset closing condition, the display screen of the acquisition and transmission terminal 2-1 will show that secondary synchronous closing is not possible. At this time, the acquisition and transmission terminal 2-1 will communicate with the synchronization control terminal 1-1. The synchronization control terminal 1-1 will send a control signal to the synchronization adjustment device 1-2 according to the frequency difference, voltage amplitude difference, and voltage phase difference measured by the communication, and control the synchronization adjustment device 1-2 to adjust the power parameters, that is, through U2, it will affect U5. The acquisition and transmission terminal 2-1 will feed back the adjustment result to determine whether secondary synchronous closing is possible. The adjustment feedback process can go through one or more times until the frequency difference, voltage amplitude difference, and voltage phase difference between U5 and U4 meet the second preset closing condition. At this time, the display screen of the acquisition and transmission terminal 2-1 will show that secondary synchronous closing is possible. The second synchronization switch 2-2 can be closed for secondary synchronous closing through automatic control or manual control of the acquisition and transmission terminal 2-1 to complete the secondary synchronization.

[0039] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A multi-power source local and remote synchronous grid connection device, characterized in that, It includes local and remote devices that communicate with each other; the local device is installed between the local load power supply line and the remote load power supply line, and the remote device is connected in parallel with the remote circuit breaker; wherein, the remote circuit breaker is the circuit breaker between the remote power supply and the second load power supply line. During local synchronous grid connection, the local device adjusts the power parameters of the local load power supply line according to the voltage at the first connection point and the voltage at the second connection point until the adjusted voltage and the voltage at the second connection point meet the first preset loop closing condition, and then controls the local load power supply line to connect with the remote load power supply line; wherein, the voltage at the first connection point is the voltage at the connection point with the local load power supply line, and the voltage at the second connection point is the voltage at the connection point with the remote load power supply line. During remote secondary synchronous grid connection, the remote device remotely controls the local device to adjust the power parameters of the local load power supply line according to the voltage at both ends of the remote circuit breaker, until the voltage at both ends of the remote circuit breaker meets the second preset loop closing condition, and then controls the bypass connection at both ends of the remote circuit breaker.

2. The apparatus according to claim 1, characterized in that, The local device includes a locally installed synchronization control terminal, a synchronization adjustment device, and a first synchronization switch; The synchronizing device is used to adjust the power parameters of the local load power supply line, and the first synchronizing switch is used to control the connection and disconnection between the local load power supply line and the remote load power supply line. The control terminals of the synchronizing device and the first synchronizing switch are both connected to the synchronizing control terminal. The synchronizing control terminal communicates with the remote device. One end of the synchronizing device is connected to one end of the first synchronizing switch, and the other end of the synchronizing device is connected to the local load power supply line. The other end of the first synchronizing switch is connected to the remote load power supply line.

3. The apparatus according to claim 2, characterized in that, The synchronization control terminal, synchronization adjustment device and first synchronization switch are installed in the first housing, and the size of the first housing meets the requirements of small cargo vehicle transportation.

4. The apparatus according to claim 2, characterized in that, The synchronous regulation device is a voltage regulation device based on the voltage compensation principle of partial power conversion or an AC-DC-AC device based on full power energy conversion.

5. The apparatus according to claim 1, characterized in that, The remote device includes a remotely installed data acquisition and transmission terminal and a second synchronous switch; the second synchronous switch is used to control the bypass on / off of both ends of the remote circuit breaker; the control terminal of the second synchronous switch is connected to the data acquisition and transmission terminal, the data acquisition and transmission terminal communicates with the local device, and the second synchronous switch is connected in parallel with the remote circuit breaker.

6. The apparatus according to claim 5, characterized in that, The data acquisition and transmission terminal and the second synchronization switch are located inside the second housing, which is a pull-along box type housing.

7. The apparatus according to any one of claims 1 to 6, characterized in that, Both local and remote devices use quick-connect cable connections to the power supply lines.

8. A grid connection method, characterized in that, The method of grid connection using the device according to any one of claims 1 to 7 includes a local synchronous grid connection method implemented on the local device side and a remote secondary synchronous grid connection method implemented on the remote device side. Local synchronous grid connection methods include: Collect the voltage at the first connection point and the voltage at the second connection point; If the voltage at the first connection point and the voltage at the second connection point meet the first preset loop closing condition, control the connection between the local load power supply line and the remote load power supply line. If the voltage at the first connection point and the voltage at the second connection point do not meet the first preset loop closing condition, the power parameters of the local load power supply line are adjusted. When the adjusted voltage and the voltage at the second connection point meet the first preset loop closing condition, the local load power supply line is connected to the remote load power supply line. Remote secondary synchronous grid connection methods include: Collect the voltage across the remote circuit breaker; If the voltage at both ends of the remote circuit breaker meets the second preset loop closing condition, control the bypass connection at both ends of the remote circuit breaker. If the voltage across the remote circuit breaker does not meet the second preset closing condition, the remote control local device adjusts the power parameters of the local load power supply line until the voltage across the remote circuit breaker meets the second preset closing condition, and then controls the bypass connection across the remote circuit breaker.

Images