Residual current protective device with continuous power function for residual current test

Abstract

This invention discloses a residual current protection device with uninterrupted power supply during residual current testing. The residual current protection device includes a residual current circuit breaker, an electric operating module for reclosing the circuit breaker, a bypass connected in parallel with the residual current circuit breaker, and a controller for controlling the bypass. The controller is connected to the electric operating module. A bypass contactor is connected in series in the bypass, and the control terminal of the bypass contactor is connected to the controller. The overload current I3 that the bypass contactor can withstand within time t1 is greater than the rated current I1 of the residual current circuit breaker, and the time t1 is greater than the residual current test time t2. Compared with the prior art, this invention has the advantages of simple structure, flexible configuration, low cost, and wide applicability.

Description

Technical Field

[0001] This invention relates to a residual current protection device, and more particularly to a residual current protection device with an uninterrupted power supply function during residual current testing. Background Technology

[0002] Installing residual current circuit breakers (RCCBs) in low-voltage power distribution systems is an effective measure to prevent direct and indirect electric shock accidents, and also a technical measure to prevent electrical fires and equipment damage caused by grounding faults in electrical lines or equipment. During the use of RCCBs, the residual current protection function must be tested regularly to ensure its proper functioning. Currently, RCCB testing is done manually, requiring live measurements before and after testing to determine if it meets normal operating conditions. During the entire testing process, the RCCB may trip due to triggering the protection action, causing power outages on the user side, which is inconvenient for users. For enterprises with high power quality requirements, restarting machinery after a power outage can result in significant and direct economic losses. Therefore, it is necessary to design a RCCB with an uninterrupted power supply testing function to ensure uninterrupted power supply to the user side during RCCB testing. However, current products on the market are relatively expensive, which does not meet the requirements of economical product development. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a residual current protection device with a residual current test uninterrupted power supply function and low cost, which can still ensure uninterrupted power supply to the user side during the residual current protection function test.

[0004] The present invention specifically adopts the following technical solutions to solve the above-mentioned technical problems: A residual current protection device with uninterrupted power supply function during residual current testing includes a residual current protection circuit breaker and an electric operating module for reclosing the circuit breaker. The device also includes a bypass connected in parallel with the residual current protection circuit breaker for supplying power to the load during residual current testing, and a controller for controlling the bypass. The controller is connected to the electric operating module. A bypass contactor is connected in series in the bypass. The control terminal of the bypass contactor is connected to the controller. The overload current I2 that the bypass contactor can withstand within time t1 is greater than the rated current I1 of the residual current protection circuit breaker. Time t1 is greater than the residual current test time t2. The residual current test time t2 includes the entire time period from when the residual current protection circuit breaker receives the requirement to conduct a residual current test, controlling the bypass contactor to close, the residual current test circuit breaker to open, the circuit breaker to reclose, and the bypass contactor to disconnect.

[0005] Preferably, the bypass further includes a cable inlet and a cable outlet, with the two ends of the cable inlet connected to the power supply terminal and the bypass contactor respectively via high-current crimp terminals, and the two ends of the cable outlet connected to the load terminal and the bypass contactor respectively via high-current crimp terminals.

[0006] Furthermore, the residual current protection circuit breaker includes a control circuit, a detection circuit, and a power supply circuit.

[0007] Preferably, the detection circuit includes a zero-sequence current transformer, a residual current sampling amplification circuit, a current sampling amplification circuit, and a voltage sampling amplification circuit, wherein the zero-sequence current transformer includes a measuring coil and a test coil.

[0008] More preferably, the power supply circuit is directly powered by the main line, or it is powered by drawing power from the main line through a current transformer.

[0009] Preferably, the controller is a controller within the residual current circuit breaker or an external controller.

[0010] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: This invention achieves load power supply during residual current simulation tests by setting a controllable bypass for the residual current circuit breaker. The overload current I2 that the bypass contactor can withstand within time t1 is greater than the rated current I1 of the residual current circuit breaker, and time t1 is greater than the residual current test time t2. It has the advantages of simple structure, flexible configuration, and low cost. The technical solution of this invention can be achieved by simple modification of various existing residual current circuit breakers, and has extremely wide applicability, which meets the requirements of economic development. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a block diagram illustrating the structural principle of the present invention; Figure 3 This is a block diagram of a specific implementation of a residual current protection circuit breaker in a specific embodiment of the present invention; Figure 4 This is a flowchart illustrating the residual current test performed by the residual current protection device of the present invention without power interruption. Detailed Implementation

[0012] To address the problem that residual current testing in existing technologies can cause power outages at the user end, the present invention proposes to set up a controllable bypass on the basis of the existing residual current protection circuit breaker to provide load power during residual current simulation testing. This bypass can then supply power to the load during residual current testing, thereby achieving the function of uninterrupted residual current testing.

[0013] Specifically, the present invention provides a residual current protection device with an uninterrupted power supply function during residual current testing, comprising a residual current protection circuit breaker and an electric operating module for reclosing the circuit breaker. The device also includes a bypass connected in parallel with the residual current protection circuit breaker for supplying power to the load during residual current testing, and a controller for controlling the bypass. The controller is connected to the electric operating module. A bypass contactor is connected in series in the bypass. The control terminal of the bypass contactor is connected to the controller. The overload current I2 that the bypass contactor can withstand within time t1 is greater than the rated current I1 of the residual current protection circuit breaker. Time t1 is greater than the residual current test time t2. The residual current test time t2 includes the entire time period from when the residual current protection circuit breaker receives the requirement to conduct a residual current test, controlling the bypass contactor to close, the residual current test circuit breaker to open, the circuit breaker to reclose, and the bypass contactor to disconnect.

[0014] To facilitate public understanding, the technical solution of the present invention will be described in detail below through a specific embodiment and in conjunction with the accompanying drawings: The residual current protection device in this embodiment, such as Figure 1 , 2 As shown, the circuit includes a residual current circuit breaker 1, an electric operating module 4, a bypass contactor 2, and a connecting wire 3. The bypass contactor 2 is connected in parallel with the residual current circuit breaker 1 through the connecting wire 3 to form a bypass. The control terminal of the bypass contactor 2 is connected to a controller, and the electric operating module 4 is also connected to the controller. The controller can be an internal controller of the residual current circuit breaker or an external controller. This invention takes the internal controller of the residual current circuit breaker as an example. The control coil 21 of the bypass contactor 2 is connected to the controller of the residual current circuit breaker 1 and is used to control the circuit to open / close before / after the residual current test by the controller of the residual current circuit breaker 1. During the residual current test, the bypass is opened to ensure that the circuit load is not de-energized, thus achieving uninterrupted power supply during the residual current test. The electric operating module is used to control the reclosing of the circuit breaker through the controller after the residual current test. The electric operating module can be built into the residual current circuit breaker or placed externally. The connecting wire 3 includes a cable inlet 31 and a cable outlet 32. The two ends of the cable inlet 31 are connected to the power supply end and the bypass contactor 2 respectively through high-current crimp terminals. The two ends of the cable outlet 32 ​​are connected to the load end and the bypass contactor 2 respectively through high-current crimp terminals.

[0015] The residual current protection circuit breaker 1 can be any existing type of residual current protection circuit breaker. Figure 3The diagram shows one type of residual current circuit breaker 1, used in molded case circuit breakers with residual current protection function. It can be installed inside the molded case circuit breaker or spliced ​​to the outside of the molded case circuit breaker. The bypass section of this invention is installed outside the molded case circuit breaker, side by side with the molded case circuit breaker, and connected in parallel with the residual current circuit breaker 1 inside the molded case circuit breaker.

[0016] like Figure 3 As shown, the electric operation module is built into the residual current circuit breaker 1. The controller of the residual current protection circuit breaker 1 includes a control circuit, a detection circuit, a power supply circuit, and the electric operation module. The control circuit includes an MCU circuit, a human-machine interface, an alarm circuit, a residual current test circuit, a communication circuit, an interface circuit, and a tripping circuit. The residual current test circuit includes a residual current function test button and is electrically connected to the MCU circuit, allowing for remote control of the residual current test. The interface circuit is electrically connected to the control coil 21 of the contactor 2 of the bypass switch 2. The tripping circuit controls the tripping mechanism to complete the tripping of the residual current protection circuit breaker. The human-machine interface displays the operating status of the residual current protection circuit breaker, prompts the operation steps for the residual current protection function test, and displays the final test results. The communication module, when connected to a host computer, allows for remote control of the residual current protection function test. The detection circuit includes a zero-sequence current transformer, a residual current sampling amplification circuit, a current sampling amplification circuit, and a voltage sampling amplification circuit. The zero-sequence current transformer includes a measuring coil and a test coil. The power supply circuit can be directly powered by the phase line voltage, or it can be powered by the current transformer from the main line, or it can be powered by an external +24V supply, or it can be powered by a handheld device. The electric operation module includes a reclosing circuit and a geared synchronous motor. The reclosing circuit is electrically connected to the MCU circuit and is used to control the rotation of the geared synchronous motor to achieve the reclosing function. When the electric operating module is placed outside the residual current circuit breaker 1, it can communicate with the controller of the residual current circuit breaker to receive the reclosing signal of the residual current circuit breaker 1, and connect to the electric operating mechanism through the control output circuit of the electric operating module to control the reclosing of the residual current circuit breaker.

[0017] The process of performing a residual current test on the residual current protection device is as follows: Figure 4 As shown, the specific steps include: 1) When a residual current test is required, after the controller receives the signal that a residual current test is required, it first controls the control coil 21 of the bypass contactor 2 to conduct, and the bypass contactor 2 closes. After the controller receives the closing signal of the bypass contactor 2, it sends a residual current simulation signal to cause the residual current protection circuit breaker to trip. 2) After the residual current protection circuit breaker 1 trips, it is reclosed through the electric operation module, so that the residual current protection circuit breaker 1 is closed again, and the circuit breaker is closed within about 40s±10s. 3) After the residual current protection circuit breaker 1 is closed again, the controller controls the control coil 21 of the bypass contactor 2 to de-energize, causing the bypass contactor 2 to open. 4) Confirm that the residual current protection circuit breaker 1 has resumed power supply to the load and complete the residual current protection test function test process.

[0018] The overload current I2 that the bypass contactor of the residual current protection device can withstand within time t1 is greater than the rated current I1 of the residual current protection circuit breaker. Time t1 is greater than the residual current test time t2. The residual current test time t2 includes the entire time period from when the residual current protection circuit breaker receives the requirement to conduct a residual current test, controlling the bypass contactor to close, conducting the residual current test, the circuit breaker to open, the circuit breaker to reclose, the bypass contactor to open, and the residual current protection to restart. Time t2 is within 60 seconds.

[0019] This invention, employing the above-mentioned scheme, features a simple structure, few components, ingenious control, and low cost. It ensures uninterrupted power supply to the user side during residual current circuit breaker functional testing. When equipped with a residual current circuit breaker with reclosing function, the test operation can be completed remotely via a host computer, eliminating the need for on-site operation by maintenance personnel and reducing their workload. An optional alarm module can also be added to indicate whether the test function was successful.

Claims

1. A residual current protection device with uninterrupted power supply function during residual current testing, comprising a residual current protection circuit breaker and an electrically operated module for reclosing the circuit breaker, characterized in that, The device also includes a bypass connected in parallel with the residual current circuit breaker for supplying power to the load during the residual current test, and a controller for controlling the bypass. The controller is connected to the electric operation module. A bypass contactor is connected in series in the bypass. The control terminal of the bypass contactor is connected to the controller. The overload current I2 that the bypass contactor can withstand within time t1 is greater than the rated current I1 of the residual current circuit breaker. The time t1 is greater than the residual current test time t2. The residual current test time t2 includes the entire time period from when the residual current circuit breaker receives the requirement to conduct a residual current test, controlling the bypass contactor to close, the residual current test circuit breaker to open, the circuit breaker to reclose, and the bypass contactor to disconnect.

2. The residual current protection device with uninterrupted power supply function during residual current testing as described in claim 1, characterized in that, The bypass also includes a cable inlet and a cable outlet. The two ends of the cable inlet are connected to the power supply end and the bypass contactor respectively through high-current crimp terminals, and the two ends of the cable outlet are connected to the load end and the bypass contactor respectively through high-current crimp terminals.

3. The residual current protection device with uninterrupted power supply function during residual current testing as described in claim 1, characterized in that, The residual current protection circuit breaker includes a control circuit, a detection circuit, and a power supply circuit.

4. The residual current protection device with uninterrupted power supply function during residual current testing as described in claim 3, characterized in that, The detection circuit includes a zero-sequence current transformer, a residual current sampling amplification circuit, a current sampling amplification circuit, and a voltage sampling amplification circuit. The zero-sequence current transformer includes a measuring coil and a test coil.

5. The residual current protection device with uninterrupted power supply function during residual current testing as described in claim 3, characterized in that, The power supply circuit is directly powered by the main line, or it draws power from the main line through a current transformer.

6. The residual current protection device with uninterrupted power supply function during residual current testing as described in claim 1, characterized in that, The controller is either a controller within the residual current circuit breaker or an external controller.

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