Power distribution protection system and method thereof

Abstract

The invention relates to a power distribution protection system and a method thereof. The system includes: a main input unit receiving an AC power input; the main loop electronic switch is connected in series with the main input unit; the controllable mechanical isolation switch is connected in series with the main loop electronic switch; the main output unit is connected in series with the controllable mechanical isolation switch and outputs alternating current power; the main circuit self-checking unit is used for detecting electrical parameters output by the main circuit electronic switch when the controllable mechanical isolation switch is in an off state; the main control unit is used for judging whether the state of the main loop electronic switch is normal or not based on the electrical parameter information detected by the main circuit self-detection unit; the auxiliary power supply unit provides a working power supply for the main control unit and the main circuit self-checking unit; when the main loop electronic state of the main loop electronic switch unit is normal, the controllable mechanical isolation switch is closed, and then the main loop electronic switch is closed. And when the state of the main loop electronic switch is abnormal, the controllable mechanical isolation switch is kept disconnected under the control of the main control unit.

Description

Technical Field

[0001] The present disclosure relates to a power distribution protection system and method, and more particularly to a protection system and method for power-on and circuit-breaking processes of alternating current power distribution. Background Art

[0002] There are various forms of AC power distribution input, such as single-phase (any 2P) AC input wiring, standard three-phase live wire AC input wiring, standard three-phase missing phase AC input wiring, dual live wire + N wire AC input wiring and other application scenarios.

[0003] At the same time, with the development of power electronics technology and Internet of Things technology, the branch protection of the distribution system is required to have not only functions such as overload, short circuit, and leakage protection, but also functions such as fault status indication, remote communication, and customizable protection curves. In addition, the switching devices in the branch protection of the distribution system are required to be able to respond and cut off the faulty branch on a us time scale.

[0004] Moreover, due to the particularity of AC power distribution systems in applications such as data centers, it is necessary to perform self-checks on the functions of the solid-state circuit breaker power electronic switch devices in the AC power distribution system (that is, before closing the mechanical switch of the AC power distribution system each time the power is turned on, or after the overcurrent and short-circuit protection abnormalities are eliminated, before closing the mechanical switch when the power is turned on again, it is necessary to ensure that the solid-state circuit breaker power electronic switch in the AC power distribution system is in a good state before the closing command can be executed) to prevent the main circuit from being closed in the event of a failure of the electronic switch device, resulting in the inability to quickly cut off the circuit power supply later, creating a safety risk.

[0005] Therefore, in view of the above problems, it is urgent to propose a comprehensive and intelligent protection solution for the power-on and circuit-breaking processes of AC power distribution. Summary of the invention

[0006] According to one aspect of the present disclosure, a power distribution protection system is provided, comprising: a main input unit for receiving an AC power input; a main circuit electronic switch unit connected in series with the main input unit; a controllable mechanical isolating switch connected in series with the main circuit electronic switch unit; a main output unit connected in series with the controllable mechanical isolating switch for outputting AC power; a main circuit self-test unit for detecting the output electrical parameters of the main circuit electronic switch unit when the controllable mechanical isolating switch is disconnected; a main control unit for determining whether the state of the main circuit electronic switch of the main circuit electronic switch unit is normal based on the electrical parameter information detected by the main circuit self-test unit; an auxiliary power supply unit for providing working power to the main control unit and the main circuit self-test unit based on the AC power input received by the main input unit; wherein, when the state of the main circuit electronic switch of the main circuit electronic switch unit is normal, the controllable mechanical isolating switch is closed under the control of the main control unit, and then the main circuit electronic switch of the main circuit electronic switch unit is closed again; when the state of the main circuit electronic switch of the main circuit electronic switch unit is abnormal, the controllable mechanical isolating switch remains disconnected under the control of the main control unit.

[0007] The power distribution protection system further includes: an input state detection unit, which is used to detect the electrical parameters of the AC power input received by the main input unit; wherein, the main control unit, based on the electrical parameter information detected by the input state detection unit, determines whether the AC power input is in a "specific wiring form AC power input abnormal" state or in a "specific wiring form AC power input normal" state; when the AC power input is in a "specific wiring form AC power input normal" state, further based on the electrical parameter information detected by the main circuit self-test unit, determines whether the state of the main circuit electronic switch of the main circuit electronic switch unit is normal; wherein, the auxiliary power supply unit, based on the AC power input received by the main input unit, also provides working power to the input state detection unit; wherein, when the AC power input is in a "specific wiring form AC power input abnormal" state, the main circuit electronic switch of the main circuit electronic switch unit is disconnected, and the controllable mechanical isolating switch is disconnected under the control of the main control unit; when the AC power input is in a "specific wiring form AC power input normal" state and when the state of the main circuit electronic switch of the main circuit electronic switch unit is normal, the controllable mechanical isolating switch is closed under the control of the main control unit, and then the main circuit electronic switch of the main circuit electronic switch unit is closed again.

[0008] The power distribution protection system further includes: a detection and drive unit: when the main circuit electronic switch of the main circuit electronic switch unit is closed and the controllable mechanical isolating switch is closed, the output current of the main circuit electronic switch unit is detected, wherein the auxiliary power supply unit provides working power for the detection and drive unit; wherein the main control unit determines whether the main circuit is in an "overcurrent or overload or leakage" state based on the current detected by the detection and drive unit, and when it is determined that the main circuit is in an "overcurrent or overload or leakage" state, if the main control unit determines that the abnormal current detected by the detection and drive unit reaches an instantaneous tripping level , the main circuit electronic switch of the main circuit electronic switch unit is disconnected through the detection and drive unit, and the main control unit controls the controllable mechanical isolating switch to be disconnected; when it is determined that the main circuit is in the "overcurrent or overload or leakage" state, if the main control unit determines that the abnormal current detected by the detection and drive unit has not reached the instantaneous tripping level, the main control unit performs delay processing. If the main circuit is still in the "overcurrent or overload or leakage" state when the delay expires, the main circuit electronic switch of the main circuit electronic switch unit is disconnected through the detection and drive unit, and the main control unit controls the controllable mechanical isolating switch to be disconnected.

[0009] The power distribution protection system also includes: when the main circuit electronic switch of the main circuit electronic switch unit is closed and the controllable mechanical isolating switch is closed, the input state detection unit detects the voltage of the AC power received by the main input unit; wherein the main control unit determines whether the AC power is in an "overvoltage or undervoltage" state based on the voltage detected by the input state detection unit; when it is determined that the AC power is in an "overvoltage or undervoltage" state, the main circuit electronic switch of the main circuit electronic switch unit is disconnected through the detection and driving unit, and the main control unit controls the controllable mechanical isolating switch to disconnect.

[0010] Among them, the AC power input of the specific wiring form includes the wiring form of 3-phase live wire AC input, the wiring form of single-phase AC input, the wiring form of standard 3-phase missing phase AC input, and the wiring form of dual live wire + N wire AC input.

[0011] The electrical parameter information is at least one of voltage amplitude, frequency, and phase.

[0012] The power distribution protection system also includes: an input overvoltage absorption unit, which is used to absorb the residual energy of the upper circuit after the main circuit electronic switch or the controllable mechanical isolating switch of the main circuit electronic switch unit is disconnected, or the input surge energy when the controllable mechanical isolating switch is closed; an output overvoltage absorption unit, which is used to absorb the residual energy of the lower circuit after the main circuit electronic switch or the controllable mechanical isolating switch of the main circuit electronic switch unit is disconnected, or the output surge energy when the controllable mechanical isolating switch is closed; a communication and display unit, which exchanges electrical parameters and control information with the main control unit, inputs switch quantity information to the main control unit, and displays fault information.

[0013] According to one aspect of the present disclosure, a method for a power distribution protection system is provided, wherein the power distribution protection system includes a main circuit electronic switch unit and a controllable mechanical isolating switch, and the method includes: detecting electrical parameters of the output of the main circuit electronic switch unit when the controllable mechanical isolating switch is in an off state; determining whether the state of the main circuit electronic switch of the main circuit electronic switch unit is normal based on the detected electrical parameter information; when the state of the main circuit electronic switch of the main circuit electronic switch unit is normal, closing the controllable mechanical isolating switch, and then closing the main circuit electronic switch of the main circuit electronic switch unit again; when the state of the main circuit electronic switch of the main circuit electronic switch unit is abnormal, keeping the controllable mechanical isolating switch open.

[0014] The method also includes: detecting electrical parameters of the AC power input; based on the detected electrical parameter information of the AC power input, determining whether the AC power input is in a "specific wiring form AC power input abnormal" state or in a "specific wiring form AC power input normal" state; when the AC power input is in a "specific wiring form AC power input normal" state, further determining whether the state of the main circuit electronic switch of the main circuit electronic switch unit is normal based on the detected output electrical parameter information of the main circuit electronic switch unit; when the AC power input is in a "specific wiring form AC power input abnormal" state, the main circuit electronic switch of the main circuit electronic switch unit is disconnected, and the controllable mechanical isolating switch is disconnected; when the AC power input is in a "specific wiring form AC power input normal" state and when the state of the main circuit electronic switch of the main circuit electronic switch unit is normal, the controllable mechanical isolating switch is closed, and then the main circuit electronic switch of the main circuit electronic switch unit is closed again.

[0015] The method further comprises: when the main circuit electronic switch of the main circuit electronic switch unit is closed and the controllable mechanical isolating switch is closed, detecting the output current of the main circuit electronic switch unit; and judging whether the main circuit is in an "overcurrent or overload or leakage" state based on the detected output current of the main circuit electronic switch unit. When the main circuit is judged to be in an "overcurrent or overload or leakage" state, if it is determined that the abnormal current of the output of the detected main circuit electronic switch unit reaches the instantaneous tripping level, the main circuit electronic switch of the main circuit electronic switch unit is disconnected, and the controllable mechanical isolating switch is controlled to be disconnected at the same time; when the main circuit is judged to be in an "overcurrent or overload or leakage" state, if it is determined that the abnormal current of the output of the detected main circuit electronic switch unit does not reach the instantaneous tripping level, delay processing is performed, and if the main circuit is still in an "overcurrent or overload or leakage" state when the delay expires, the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected, and the controllable mechanical isolating switch is controlled to be disconnected at the same time.

[0016] The method further includes: detecting the voltage of the AC power when the main circuit electronic switch of the main circuit electronic switch unit is closed and the controllable mechanical isolating switch is closed; determining whether the AC power is in an "overvoltage or undervoltage" state based on the voltage detected by the input state detection unit; when it is determined that the AC power is in an "overvoltage or undervoltage" state, disconnecting the main circuit electronic switch of the main circuit electronic switch unit and controlling the controllable mechanical isolating switch to disconnect.

[0017] Among them, the AC power input of the specific wiring form includes the wiring form of 3-phase live wire AC input, the wiring form of single-phase AC input, the wiring form of standard 3-phase missing phase AC input, and the wiring form of dual live wire + N wire AC input.

[0018] The electrical parameter information is at least one of voltage amplitude, frequency, and phase.

[0019] Wherein, the method also includes: absorbing the residual energy of the upper circuit after the main circuit electronic switch or the controllable mechanical isolating switch of the main circuit electronic switch unit is disconnected or the input surge energy when the main circuit electronic switch unit or the controllable mechanical isolating switch is closed; absorbing the residual energy of the lower circuit after the main circuit electronic switch or the controllable mechanical isolating switch of the main circuit electronic switch unit is disconnected or the output surge energy when the main circuit electronic switch unit or the controllable mechanical isolating switch is closed; interactive electrical parameters and control information, switch quantity information, and display fault information.

[0020] The features and technical advantages of the examples according to the present disclosure have been summarized quite broadly above so that the following detailed description will be better understood. Other features and advantages will be described below. The disclosed concepts and specific examples can be easily used as the basis for modifying or designing other structures for achieving the same purpose of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. When the following description is considered in conjunction with the accompanying drawings, the features of the concepts disclosed herein, their organization and method of operation, and the associated advantages will be better understood. Each figure is provided for the purpose of illustration and description rather than as a definition of the limitations of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The aspects, features and advantages of the present disclosure will become clearer and easier to understand through the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0022] Figure 1 A block diagram of an AC power distribution protection system according to an embodiment of the present disclosure is shown;

[0023] Figure 2 An exemplary circuit diagram of each unit of the AC power distribution protection system according to an embodiment of the present disclosure is shown;

[0024] Figure 3 A flow chart of a method for an AC power distribution protection system according to an embodiment of the present disclosure is shown;

[0025] Figure 4 1 is a diagram showing a typical power supply waveform supported by the AC power distribution protection system according to an embodiment of the present disclosure;

[0026] Figure 5 An example waveform of a non-abnormal state detected by the main circuit electronic switch self-test unit 6 before the controllable mechanical isolating switch 9 is closed in the AC power distribution protection system according to an embodiment of the present disclosure is shown;

[0027] Figure 6 An example waveform of an abnormal state detected by the main circuit electronic switch self-test unit 6 before the controllable mechanical isolating switch 9 is closed in the AC power distribution protection system according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0028] The present disclosure will be described in detail below with reference to exemplary embodiments of the present disclosure. However, the present disclosure is not limited to the embodiments described herein, and it can be implemented in many different forms. The described embodiments are only used to make the present disclosure thorough and complete, and to fully convey the concept of the present disclosure to those skilled in the art. The features of the various embodiments described can be combined or replaced with each other, unless explicitly excluded or should be excluded according to the context.

[0029] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] Figure 1 FIG. 1 is a block diagram of an AC power distribution protection system according to an embodiment of the present disclosure. Figure 1 According to the embodiment of the present disclosure, the AC power distribution protection system is composed of 13 units, including: a main input unit 1, an input overvoltage absorption unit 10, a main circuit electronic switch unit 3, a controllable mechanical isolating switch 9, an output overvoltage absorption unit 11, and a main output unit 2, which are sequentially connected in series in the main circuit; Figure 1 The auxiliary power supply unit 4 shown provides working power to each unit that needs working power; a detection and driving unit 5 for driving the electronic switch of the main circuit electronic switch unit 3 and detecting the current on the main circuit electronic switch unit 3; a main circuit electronic switch self-test unit 6 for detecting the state of the electronic switch of the main circuit electronic switch unit 3; an input state detection unit 12 for detecting the state of the input voltage; a main control unit 8 for comprehensive control; a communication and display unit 7 for communicating and displaying interactively with the main control unit 8; and a mechanical switch driving unit 13 for driving the action of the controllable mechanical isolating switch 9.

[0031] The main input unit 1 includes a 3P terminal for receiving AC power input, which can support the wiring form of 3-phase live wire AC input, single-phase (any 2P) AC input, standard 3-phase missing phase AC input, and dual live wire + N wire AC input.

[0032] The main output unit 2 includes a 3P terminal for outputting AC power. Based on the AC power input received by the main input unit 1, it can correspondingly support the wiring form of 3-phase live wire AC output, the wiring form of single-phase (any 2P) AC output, the wiring form of standard 3-phase missing phase AC output, and the wiring form of dual live wire + N wire AC output.

[0033] The electronic switch of the main circuit electronic switch unit 3 may be a main circuit power electronic switch device such as MOSFET / IGBT.

[0034] The auxiliary power supply unit 4 is Figure 1 Each unit that needs working power is provided with working power. For example, the auxiliary power supply unit 4 provides working power for the detection and drive unit 5, the main circuit electronic switch self-test unit 6, the communication and display unit 7, the main control unit 8, the input state detection unit 12, and the mechanical switch drive unit 13.

[0035] Detection and drive unit 5: generates a drive signal for driving the electronic switch of the main circuit electronic switch unit 3 under the control of the main control unit 8; detects the electrical parameter information of the main circuit overload, overcurrent (in the case of short circuit), and leakage fault by detecting the current on the electronic switch of the main circuit electronic switch unit 3, generates corresponding protection information, and sends the protection information to the main control unit 8.

[0036] Before the controllable mechanical isolating switch 9 is closed, the main circuit electronic switch self-test unit 6 performs a self-test on the state of the electronic switch of the main circuit electronic switch unit 3. When the state of the electronic switch of the main circuit electronic switch unit 3 is normal, the self-test normal information is sent to the main control unit 8, and then the main control unit 8 sends an instruction to close the controllable mechanical isolating switch 9 to the mechanical switch drive unit 13. In this way, the controllable mechanical isolating switch 9 can be avoided from being closed in the fault state of the main circuit electronic switch. After receiving the instruction to close the controllable mechanical isolating switch 9, the mechanical switch drive unit 13 drives the controllable mechanical isolating switch 9 to close.

[0037] Communication and display unit 7: exchanges electrical parameters and control information with the main control unit 8, inputs switch quantity information, and displays fault information; the communication and display unit 7 can also exchange electrical parameters and control information with an external power management device or other devices in the system (not shown).

[0038] The main control unit 8 receives the switch quantity information of the input wiring form indicated by the communication and display unit 7, the detection result information from the input state detection unit 12, the detection and drive unit 5, and the main circuit electronic switch self-test unit 6, performs electrical parameter processing, and based on the electrical parameter processing results and the switch quantity information, (1) determines the wiring form of the AC power input; (2) determines whether there is an overcurrent, overload or leakage fault in the main circuit, and (3) completes the self-test and protection logic processing of the controllable mechanical isolation switch 9. Under normal circumstances, a drive signal for driving the relevant switch is sent to the detection and drive unit 5 and the mechanical isolation switch drive unit 13. At the same time, the main control unit 8 exchanges information with the communication and display unit 7.

[0039] The controllable mechanical isolating switch 9 is used to reliably close or open under the control of the main control unit 8. The execution speed is slower than the power electronic switch of the main circuit electronic switch unit 3 and has the ability to independently break current.

[0040] The input overvoltage absorption unit 10 is used to absorb the residual energy of the upper circuit after the circuit breaker protection of the main circuit electronic switch unit 3 or the controllable mechanical isolating switch 9, or the input surge energy when the controllable mechanical isolating switch 9 is closed.

[0041] The output overvoltage absorption unit 11 is used to absorb the residual energy of the lower circuit after the circuit breaker protection of the main circuit electronic switch unit 3 or the controllable mechanical isolating switch 9, or the output surge energy when the controllable mechanical isolating switch 9 is closed.

[0042] The input state detection unit 12 is used to detect the state of the input voltage, determine whether it is overvoltage, undervoltage, or phase loss, and identify the wiring form of the input voltage.

[0043] Figure 2 An example circuit diagram of each unit of the AC power distribution protection system according to an embodiment of the present disclosure is shown. Figure 2 , which shows the Figure 1 An example of a circuit implementation corresponding to the functional unit of the AC power distribution protection system according to an embodiment of the present disclosure. The circuit implementation of the present application is not limited to Figure 2 The example shown. Within the scope of knowledge of ordinary technicians in this field, it is obvious that there are many circuit implementations of this application, all of which are within the protection scope of this application.

[0044] Figure 2In the figure, the main input unit 1, the input overvoltage absorption unit 10, the main circuit electronic switch unit 3, the controllable mechanical isolating switch 9, the output overvoltage absorption unit 11, and the main output unit 2 are sequentially connected in series in the main circuit. The input ends of the auxiliary power supply unit 4 and the input state detection unit 12 are respectively connected to the main input unit 1 to receive the input AC distribution voltage. The detection and drive unit 5 is connected to the main circuit electronic switch unit 3 and the main control unit 8. The detection and drive unit 5 detects the leakage fault of the main circuit through the Hall sensor and detects the overcurrent and overload faults through the phase current monitoring. The detection and drive unit 5 sends a drive signal to the main circuit electronic switch unit 3 based on the control signal of the main control unit 8. The main circuit electronic switch self-test unit 6 detects the electrical parameters of the main circuit between the main circuit electronic switch unit 3 and the controllable mechanical isolating switch 9. The main control unit 8 determines whether the state of the electronic switch of the main circuit electronic switch unit 3 is normal based on the electrical parameter detection result of the main circuit electronic switch self-test unit 6.

[0045] Figure 3 A flow chart of a method for an AC power distribution protection system according to an embodiment of the present disclosure is shown. Figure 3 In the initial state, the electronic switch of the main circuit electronic switch unit 3 and the controllable mechanical isolating switch 9 are both in the disconnected state.

[0046] In step S310, the AC power distribution input is connected via the main input unit 1.

[0047] In step S312, the auxiliary power supply unit 4 is started, and can provide working power to the detection and drive unit 5, the main circuit electronic switch self-test unit 6, the communication and display unit 7, the main control unit 8, the input state detection unit 12, and the mechanical switch drive unit 13.

[0048] In step S314, the main control unit 8 determines whether the AC power input of a specific wiring form is normal or abnormal based on the electrical parameters detected by the input state detection unit 12 (such as the input voltage amplitude, frequency and phase information detected by the input state detection unit 12) and the switch quantity information of the input form indicated by the communication and display unit 7. The main control unit 8 determines whether the main circuit is in an abnormal state of "leakage" based on the electrical parameters detected by the detection and drive unit 5 (such as the leakage current information detected by the detection and drive unit 5).

[0049] When the judgment result of step S314 is that there is no abnormality, the process proceeds to step S316, in which the communication and display unit 7 reports the wiring form of the AC power input to the superior device, and then proceeds to step S318.

[0050] When the judgment result of step S314 is abnormal, jump to step S332.

[0051] In step S318, the detection and driving unit 5, under the control of the main control unit 8, turns on the electronic switch ( Figure 2 At this time, the main control unit 8 determines whether each main electronic switch in Q1-Q6 is abnormal based on the electrical parameters detected by the main circuit electronic switch self-test unit 6 (for example, the periodic voltage information detected by the main circuit electronic switch self-test unit 6).

[0052] When the judgment result of step S318 is abnormal, jump to step S332.

[0053] When the result of step S318 is that there is no abnormality, the process proceeds to step S320, step S322, step S324, step S326, and step S328 in sequence. In step S322, the mechanical switch drive unit 13 drives the controllable mechanical isolating switch 9 to close under the control of the main control unit 8. In step S324, the detection and drive unit 5, under the control of the main control unit 8, turns the electronic switch ( Figure 2 In step S326, after receiving the closed drive signal from the detection and drive unit 5, the electronic switch of the main circuit electronic switch unit 3 is closed. In step S328, the main output unit 2 outputs AC power distribution.

[0054] Next, proceed to S330. In step S330, the input state detection unit 12 continues to cyclically detect electrical parameters, such as overvoltage / undervoltage information of the input voltage; the detection and drive unit 5 continues to cyclically detect electrical parameters, such as leakage current information, overload information and overcurrent information of the main circuit; the main control unit 8 determines whether there is an overvoltage / undervoltage, leakage current, overload and overcurrent fault state in the main circuit based on the electrical parameters detected by the input state detection unit 12 and the detection and drive unit 5.

[0055] When the judgment result of step S330 is failure, go to step S332.

[0056] In step S332, the main control unit 8 sends a shut-off drive signal to the detection and drive unit 5. Then, steps S334, S336, S338, and S340 are sequentially executed.

[0057] In step S334, the detection and driving unit 5 turns on the electronic switch ( Figure 2 Q1-Q6 of the main circuit sends a shutdown drive signal, and the electronic switch of the main circuit electronic switch unit 3 is turned off.

[0058] In step S336, the main control unit 8 sends a shutdown drive signal to the mechanical switch drive unit 13.

[0059] In step S338, the mechanical switch driving unit 13 sends a shutoff driving signal to the controllable mechanical isolating switch 9, and the controllable mechanical isolating switch 9 is shut off.

[0060] In step S340, the communication and display unit 7 reports the fault information to the superior device and displays the fault information.

[0061] When the judgment result of step S330 is normal, step S330 is looped.

[0062] When the detection and drive unit 5 detects overcurrent, overload, and leakage current information (leakage current detection in step S314, leakage current, overload, and overcurrent detection in step 330), if the abnormal current reaches the instantaneous tripping level, the hardware of the detection and drive unit 5 is directly used to perform wave sealing (disconnection) processing, so that the switch tube of the main circuit electronic switch unit 3 is sealed, and the controllable mechanical isolating switch 9 is driven to disconnect. After that, the alarm information is processed by the main control unit 8, and the fault information is reported and a fault indication is given through the communication and display unit 7.

[0063] When the detection and drive unit 5 detects overcurrent, overload, and leakage information (leakage detection in step S314, leakage, overload, and overcurrent detection in step 330), if the abnormal current does not reach the instantaneous tripping level, the main control unit 8 performs long delay and short delay logic processing. If the overcurrent, overload, and leakage are still not eliminated after the long delay or short delay, the hardware of the detection and drive unit 5 performs wave sealing processing to seal the switch tube of the main circuit electronic switch unit 3, and at the same time drive the controllable mechanical isolating switch 9 to disconnect. After that, the alarm information is processed by the main control unit 8, and the fault information is reported and a fault indication is given through the communication and display unit 7.

[0064] When the main control unit 8 determines whether there is an overvoltage / undervoltage fault state in the main circuit based on the voltage of the AC power detected by the input state detection unit 12 in step S330, the electronic switch of the main circuit electronic switch unit 3 is disconnected through the detection and drive unit 5, and the main control unit 8 controls the controllable mechanical isolation switch 9 to be disconnected. Thereafter, the main control unit 8 processes the alarm information, and reports the fault information and performs a fault indication through the communication and display unit 7.

[0065] Figure 4 Graph 1 shows a typical power supply waveform supported by the AC power distribution protection system according to an embodiment of the present disclosure.

[0066] exist Figure 1 , 2In the process, the input state detection unit 12 detects the electrical parameters of the AC power distribution input of the main input unit 1, such as voltage amplitude, frequency, phase, etc. This information is transmitted to the main control unit 8 together with the switch quantity information in the form of indication input of the communication and display unit 7 to perform logic judgment in the form of logic input wiring, and judge whether the AC power input is over-voltage, under-voltage, phase loss, etc.

[0067] The main control unit 8 performs logical judgment based on the typical characteristics of the 2P\3P power supply form that can be supported by the embodiment of the present disclosure. The judgment result may be, for example, "AC power input in a specific wiring form is abnormal" or "AC power input in a specific wiring form is abnormal".

[0068] Through the above judgment, it can be identified Figure 4 The typical power supply waveform supported by the AC power distribution protection system according to the embodiment of the present disclosure is shown. Figure 4 (1) shows a typical power supply waveform of a standard 3P input and a 220V phase voltage (i.e., a wiring form of a 3-phase live wire AC input); Figure 4 (2) shows a typical power supply waveform of 3P input with phase A missing and 220V phase voltage (i.e., the wiring form of standard 3-phase missing AC input); Figure 4 (3) shows a typical power supply waveform of 2P input (L to A, N to B, C none) and 220V phase voltage (i.e., single-phase AC input wiring form); Figure 4 (4) shows the typical power supply waveform of 3P split phase (L1 to A, L2 to C, N to B) and 120V phase voltage (i.e., the wiring form of double live wire + N wire AC input).

[0069] Figure 5 An example waveform of a non-abnormal state detected by the main circuit electronic switch self-test unit 6 before the controllable mechanical isolating switch 9 is closed in the AC power distribution protection system according to an embodiment of the present disclosure is shown. Figure 6 An example waveform of an abnormal state detected by the main circuit electronic switch self-test unit 6 before the controllable mechanical isolating switch 9 is closed in the AC power distribution protection system according to an embodiment of the present disclosure is shown.

[0070] Return to reference Figure 1 , 2 When the main input unit 1 starts to input power, the controllable mechanical isolation switch 9 is not closed. Under the control of the main control unit 8, the detection and drive unit 5 switches the electronic switch ( Figure 2At this time, the main circuit electronic switch self-test unit 6 samples the voltages of C1, C2, and C3, and performs waveform and amplitude analysis to determine the switches of the main circuit electronic switch unit 3 ( Figure 2 Q1-Q6) is in an abnormal state. If there is no abnormality, the controllable mechanical isolating switch 9 is ready to receive the closing drive signal and perform the closing action. If a switch of the main circuit electronic switch unit 3 is in an abnormal state, no matter what command is executed, the closing drive signal will be in an invalid state, and the switch of the main circuit electronic switch unit 3 will remain in an open state. Feedback fault signal to the operator indicates that there is a fault. The controllable mechanical isolating switch 9 can only receive the closing drive signal and perform the closing action after the abnormal fault is eliminated and the automatic detection results performed by the main circuit electronic switch self-test unit 6 and the main control unit 8 are normal.

[0071] Figure 5 The figure shows the voltage waveforms of C1, C2, and C3 sampled by the main circuit electronic switch self-test unit 6 when the switches Q1, Q2, Q3, Q4, Q5, and Q6 of the main circuit electronic switch unit 3 are in good condition under the normal power supply input of the standard 3P input and 220V phase voltage of the main input unit 1. Before the controllable mechanical isolating switch 9 is closed, the voltage waveforms of Vca_out, Vab_out, and Vbc_out are symmetrical with a phase angle of 120° and equal in amplitude when the switches Q1, Q2, Q3, Q4, Q5, and Q6 of the main circuit electronic switch unit 3 are in good condition.

[0072] Figure 6 The figure shows the voltage waveforms of C1, C2, and C3 sampled by the main circuit electronic switch self-test unit 6 when the switches Q1, Q2, Q3, Q4, Q5, and Q6 of the main circuit electronic switch unit 3 are faulty under the normal power supply input of the standard 3P input and 220V phase voltage of the main input unit 1. Before the controllable mechanical isolating switch 9 is closed, the switches Q1 and Q2 of the main circuit electronic switch unit 3 have already failed, and the voltage waveforms of Vca_out, Vab_out, and Vbc_out are symmetrical, but the waveform amplitudes are obviously very different.

[0073] Fault judgment method of other branch switches of main circuit electronic switch unit 3 and Figure 6 Same as shown.

[0074] In this way, through the voltage waveforms of C1, C2, and C3 sampled by the main circuit electronic switch self-test unit 6, the main control unit 8 can compare the periodic voltage magnitudes of the above voltage waveforms, and then determine which switch of the main circuit electronic switch unit 3 is abnormal, or whether all the electronic switches of the main circuit electronic switch unit 3 are normal.

[0075] The AC power distribution protection system and method according to the embodiments of the present disclosure may be applied to an AC power distribution system including a solid-state circuit breaker and / or a mechanical isolating switch.

[0076] According to the AC power distribution protection system and method of the embodiments of the present disclosure, when the mechanical isolating switch is powered on and closed with load, it can be predicted whether the main circuit electronic switch of the solid-state circuit breaker is faulty.

[0077] According to the AC power distribution protection system and method of the embodiments of the present disclosure, when the mechanical isolating switch is powered on and closed with load, the main circuit electronic switch is in a good state, but the load is already in a short-circuit state, the detection and drive unit can completely turn off the main circuit electronic switch after power-on, thereby avoiding electrical accidents.

[0078] According to the AC power distribution protection system and method of the embodiment of the present disclosure, when a fault occurs before closing the mechanical isolating switch, the operator can be informed. When a fault is detected, no matter what command is executed, the mechanical isolating switch cannot perform the closing action until the fault is eliminated and the closing command can be accepted and the closing action can be performed.

[0079] According to the AC power distribution protection system and method of the disclosed embodiment, it is ensured that the main circuit electronic switch is intact and in a fault-free state before each power-on, ensuring safe and reliable use by customers and avoiding other unpredictable electrical safety problems caused by the customer's inability to judge when using the circuit breaker due to circuit breaker failure.

[0080] According to the AC power distribution protection system and method of the embodiments of the present disclosure, customers can use solid-state circuit breakers safely and reliably to a greater extent. At the same time, when a fault is detected in the main circuit electronic switch, the fault location and pre-set number can be accurately determined, which greatly reduces the difficulty of troubleshooting for maintenance personnel, greatly shortens maintenance time, improves maintenance efficiency and customer experience, and meets the current market development and customer demand for intelligence.

[0081] According to the AC power distribution protection system and method of the disclosed embodiment, a 3P solid-state protection scheme suitable for the AC power distribution system is implemented. By detecting the input electrical characteristics, the input power supply form can be identified, and then it can be determined whether the input wiring is abnormal. It can support and operate normally for 2P applications or special forms of 3P application scenarios, so that the protection device can be compatible with input 2P / 3P application scenarios. In addition, the input power supply form can be reported to the host computer for energy management and alarm indication of the corresponding power supply form, which can meet customer applications to the greatest extent.

[0082] According to the AC power distribution protection system and method of the embodiments of the present disclosure, a solid-state circuit breaker design scheme suitable for the AC system is realized, which has overload, short circuit and leakage protection functions, and adopts power electronic devices such as MOSFET / IGBT as the main circuit power-off device (main circuit electronic switch), and the protection time is in the microsecond level; at the same time, it can realize self-checking of the main circuit electronic switch to prevent the safety risks caused by closing the mechanical isolation switch of the main circuit in the state of device failure; in order to meet the application requirements to the greatest extent, according to the solid-state circuit breaker design scheme of the embodiments of the present disclosure, the input wiring form can be detected so that the input can be compatible with 2P / 3P applications; for abnormal information such as input wiring error or device failure, it can inform the host computer or operator through communication or status indication to eliminate the fault in time.

[0083] The hardware computing device described in the present disclosure may be implemented in its entirety or in parts thereof by various suitable hardware means, including but not limited to FPGA, ASIC, SoC, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0084] The block diagrams of circuits, devices, apparatuses, equipment, and systems involved in the present disclosure are only illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these circuits, devices, apparatuses, equipment, and systems may be connected, arranged, or configured in any manner as long as the desired purpose can be achieved.

[0085] Those skilled in the art should understand that the above-mentioned specific embodiments are merely examples and not limitations, and various modifications, combinations, partial combinations and replacements may be made to the embodiments of the present disclosure according to design requirements and other factors. As long as they are within the scope of the attached claims or their equivalents, they belong to the scope of rights to be protected by the present disclosure.

Claims

1. A power distribution protection system, comprising: A main input unit (1) for receiving AC power input; A main circuit electronic switch unit (3) is connected in series with the main input unit (1); A controllable mechanical isolating switch (9) is connected in series with the main circuit electronic switch unit (3); A main output unit (2) is connected in series with the controllable mechanical isolating switch (9) and is used to output AC power; A main circuit self-test unit (6) is used to detect the output electrical parameters of the main circuit electronic switch unit (3) when the controllable mechanical isolating switch (9) is in the disconnected state; The main control unit (8) determines whether the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is normal based on the electrical parameter information detected by the main circuit self-detection unit (6); An auxiliary power supply unit (4) provides working power to a main control unit (8) and a main circuit self-checking unit (6) based on the AC power input received by the main input unit (1); When the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is normal, the controllable mechanical isolating switch (9) is closed under the control of the main control unit (8), and then the main circuit electronic switch of the main circuit electronic switch unit (3) is closed again; When the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is abnormal, the controllable mechanical isolating switch (9) remains disconnected under the control of the main control unit (8).

2. A power distribution protection system according to claim 1, further comprising: An input state detection unit (12) is used to detect electrical parameters of the AC power input received by the main input unit (1); The main control unit (8) determines whether the AC power input is in a "specific wiring form AC power input abnormal" state or a "specific wiring form AC power input normal" state based on the electrical parameter information detected by the input state detection unit (12); when the AC power input is in a "specific wiring form AC power input normal" state, the main control unit (8) determines whether the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is normal based on the electrical parameter information detected by the main circuit self-checking unit (6); The auxiliary power supply unit (4) also provides working power to the input state detection unit (12) based on the AC power input received by the main input unit (1); When the AC power input is in the state of "AC power input abnormality in a specific wiring form", the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected, and the controllable mechanical isolating switch (9) is disconnected under the control of the main control unit (8); When the AC power input is in the "normal AC power input of a specific wiring form" state and when the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is normal, the controllable mechanical isolating switch (9) is closed under the control of the main control unit (8), and then the main circuit electronic switch of the main circuit electronic switch unit (3) is closed again.

3. The power distribution protection system according to claim 1 or 2, further comprising: The detection and drive unit (5) detects the output current of the main circuit electronic switch unit (3) when the main circuit electronic switch of the main circuit electronic switch unit (3) is closed and the controllable mechanical isolating switch (9) is closed, wherein the auxiliary power supply unit (4) provides working power for the detection and drive unit (5); The main control unit (8) determines whether the main circuit is in an "overcurrent or overload or leakage" state based on the current detected by the detection and driving unit (5). When it is determined that the main circuit is in an "overcurrent or overload or leakage" state, if the main control unit (8) determines that the abnormal current detected by the detection and drive unit (5) reaches an instantaneous trip level, the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected through the detection and drive unit (5), and at the same time, the main control unit (8) controls the controllable mechanical isolation switch (9) to disconnect; When it is determined that the main circuit is in an "overcurrent or overload or leakage" state, if the main control unit (8) determines that the abnormal current detected by the detection and drive unit (5) has not reached the instantaneous tripping level, the main control unit (8) performs a delay process, and if the main circuit is still in the "overcurrent or overload or leakage" state when the delay expires, the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected through the detection and drive unit (5), and at the same time, the main control unit (8) controls the controllable mechanical isolation switch (9) to disconnect.

4. The power distribution protection system according to claim 3, further comprising: When the main circuit electronic switch of the main circuit electronic switch unit (3) is closed and the controllable mechanical isolating switch (9) is closed, the input state detection unit (12) detects the voltage of the AC power received by the main input unit (1); Wherein, the main control unit (8) determines whether the AC power is in an "overvoltage or undervoltage" state based on the voltage detected by the input state detection unit (12); When it is determined that the AC power is in an "overvoltage or undervoltage" state, the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected through the detection and drive unit (5), and at the same time, the main control unit (8) controls the controllable mechanical isolation switch (9) to be disconnected.

5. The power distribution protection system according to claim 1 or 2, wherein The specific wiring forms of AC power input include the wiring form of 3-phase live wire AC input, the wiring form of single-phase AC input, the wiring form of standard 3-phase missing phase AC input, and the wiring form of dual live wire + N wire AC input.

6. The power distribution protection system according to claim 1 or 2, wherein The electrical parameter information is at least one of voltage amplitude, frequency, and phase.

7. The power distribution protection system according to claim 1 or 2, further comprising: An input overvoltage absorption unit (10) is used to absorb residual energy of an upper circuit after the main circuit electronic switch or the controllable mechanical isolating switch (9) of the main circuit electronic switch unit (3) is disconnected, or input surge energy when the controllable mechanical isolating switch (9) is closed; An output overvoltage absorption unit (11) is used to absorb residual energy of a lower circuit after the main circuit electronic switch of the main circuit electronic switch unit (3) or the controllable mechanical isolating switch (9) is disconnected, or output surge energy when the controllable mechanical isolating switch (9) is closed; The communication and display unit (7) exchanges electrical parameters and control information with the main control unit (8), inputs switch quantity information to the main control unit (8), and displays fault information.

8. A method for a power distribution protection system, wherein the power distribution protection system comprises a main circuit electronic switch unit (3) and a controllable mechanical isolating switch (9), the method comprising: When the controllable mechanical isolating switch (9) is in the disconnected state, the output electrical parameters of the main circuit electronic switch unit (3) are detected; Based on the detected electrical parameter information, determining whether the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is normal; When the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is normal, the controllable mechanical isolating switch (9) is closed, and then the main circuit electronic switch of the main circuit electronic switch unit (3) is closed again; When the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is abnormal, the controllable mechanical isolating switch (9) remains disconnected.

9. The method of claim 8, further comprising: Detecting electrical parameters of AC power input; Based on the detected electrical parameter information of the AC power input, determining whether the AC power input is in a "specific wiring form AC power input abnormal" state or in a "specific wiring form AC power input normal" state; when the AC power input is in a "specific wiring form AC power input normal" state, further determining whether the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is normal based on the detected output electrical parameter information of the main circuit electronic switch unit (3); When the AC power input is in the "AC power input abnormality of a specific wiring form" state, the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected, and the controllable mechanical isolating switch (9) is disconnected; When the AC power input is in the "normal AC power input of a specific wiring form" state and when the state of the main circuit electronic switch of the main circuit electronic switch unit (3) is normal, the controllable mechanical isolating switch (9) is closed, and then the main circuit electronic switch of the main circuit electronic switch unit (3) is closed again.

10. The method according to claim 8 or 9, further comprising: When the main circuit electronic switch of the main circuit electronic switch unit (3) is closed and the controllable mechanical isolating switch (9) is closed, detecting the output current of the main circuit electronic switch unit (3); Based on the detected output current of the main circuit electronic switch unit (3), it is determined whether the main circuit is in an "overcurrent or overload or leakage" state, When it is determined that the main circuit is in an "overcurrent or overload or leakage" state, if it is determined that the abnormal current outputted by the detected main circuit electronic switch unit (3) reaches an instantaneous trip level, the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected, and the controllable mechanical isolating switch (9) is controlled to be disconnected at the same time; When it is determined that the main circuit is in the "overcurrent or overload or leakage" state, if it is determined that the abnormal current output by the detected main circuit electronic switch unit (3) has not reached the instantaneous tripping level, a delay process is performed. If the main circuit is still in the "overcurrent or overload or leakage" state when the delay expires, the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected, and the controllable mechanical isolating switch (9) is controlled to be disconnected.

11. The method of claim 10, further comprising: When the main circuit electronic switch of the main circuit electronic switch unit (3) is closed and the controllable mechanical isolating switch (9) is closed, the voltage of the AC power is detected; Wherein, based on the voltage detected by the input state detection unit (12), it is determined whether the AC power is in an "overvoltage or undervoltage" state; When it is determined that the AC power is in an "overvoltage or undervoltage" state, the main circuit electronic switch of the main circuit electronic switch unit (3) is disconnected, and the controllable mechanical isolating switch (9) is controlled to be disconnected at the same time.

12. The method of claim 8 or 9, wherein The specific wiring forms of AC power input include the wiring form of 3-phase live wire AC input, the wiring form of single-phase AC input, the wiring form of standard 3-phase missing phase AC input, and the wiring form of dual live wire + N wire AC input.

13. The method of claim 8 or 9, wherein The electrical parameter information is at least one of voltage amplitude, frequency, and phase.

14. The method of claim 8 or 9, further comprising: Absorbing residual energy of the upper circuit after the main circuit electronic switch or the controllable mechanical isolating switch (9) of the main circuit electronic switch unit (3) is disconnected or input surge energy when the main circuit electronic switch unit (3) or the controllable mechanical isolating switch (9) is closed; Absorbing residual energy of a lower circuit after the main circuit electronic switch or the controllable mechanical isolating switch (9) of the main circuit electronic switch unit (3) is disconnected or output surge energy when the main circuit electronic switch unit (3) or the controllable mechanical isolating switch (9) is closed; Interactive electrical parameters and control information, switch quantity information, and display fault information.

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