Microgrid and assembly thereof, and supporting electrical appliance and adapter thereof

Abstract

A microgrid and an assembly thereof, and a supporting appliance and an adapter thereof, in particular a microgrid having a wide application range and high safety. The microgrid comprises a main line V1 used for supplying power and a main line V2 used for arc extinguishing, wherein a pulse current provided by means of the main line V2 realizes arc extinguishing of a device connected to the main line V1 (V2). The present invention is raional in design and has the advantages of a wide application range and high safety.

Description

Technical Field

[0001] The present invention relates to a microgrid and components thereof, electrical apparatuses adapted for use with the microgrid and adapters therefor, and more particularly to a microgrid having a wide range of applications and a high level of safety, and components, electrical apparatuses and adapters therefor that facilitate convenient use. Background Art

[0002] In a direct-current (alternating-current) electric control system (microgrid), connection devices (microgrid components) such as switches connected to a power supply line generate an electric arc during operation, causing problems such as short electrical life, sticking, combustion and explosion of the connection devices, thereby posing serious risks to the safe and stable operation of the system. Although existing electronic arc-extinguishing technologies have relatively good arc-extinguishing effects, their application scenarios are limited and their technical solutions lack versatility, making it difficult to establish unified technical standards and achieve widespread application on a large scale. Conventional microgrids and components thereof can hardly meet the requirements of social development. Summary of the Invention

[0003] The object of the present invention is to solve the problems described in the background art and to provide a microgrid with a wide range of applications and high safety, as well as easy-to-use associated components, electrical appliances, and adapters therefor.

[0004] The object of the present invention is achieved by the following technical solutions:

[0005] A microgrid, as shown in FIG. 1, comprises a main line V1 and a main line V2, with the main line V1 configured for power supply and the main line V2 configured for arc extinction.

[0006] Operating principle: A pulse current provided by the main line V2 achieves arc extinction for a device connected to the main line V1 (V2).

[0007] The present invention has a rational design and provides the advantages of a wide range of applications and high safety. Brief Description of the Drawings

[0008] FIG. 1 is a schematic diagram of the microgrid of the present invention.

[0009] FIG. 2 is a first schematic diagram of an embodiment of the microgrid and components thereof of the present invention.

[0010] FIG. 3 is a second schematic diagram of an embodiment of the microgrid and components thereof of the present invention.

[0011] FIG. 4 is a first schematic diagram of an embodiment of a connection device of the microgrid of the present invention.

[0012] FIG. 5 is a second schematic diagram of an embodiment of the connection device for the microgrid of the present invention.

[0013] FIG. 6 is a first schematic diagram of an embodiment of a unidirectional device for the microgrid of the present invention.

[0014] FIG. 7 is a second schematic diagram of an embodiment of the unidirectional device for the microgrid of the present invention.

[0015] FIG. 8 is a third schematic diagram of an embodiment of the unidirectional device for the microgrid of the present invention.

[0016] FIG. 9 is a fourth schematic diagram of an embodiment of the unidirectional device for the microgrid of the present invention.

[0017] FIG. 10 is a fifth schematic diagram of an embodiment of the unidirectional device for the microgrid of the present invention.

[0018] FIG. 11 is a schematic diagram of an embodiment of a control device for the microgrid of the present invention.

[0019] FIG. 12 is a first schematic diagram of an embodiment of an electrical apparatus for the microgrid of the present invention.

[0020] FIG. 13 is a second schematic diagram of an embodiment of the electrical apparatus for the microgrid of the present invention.

[0021] FIG. 14 is a schematic diagram of an adapter for the electrical apparatus of the microgrid for the present invention. Detailed Description of the Embodiments

[0022] Embodiments of the present invention:

[0023] As shown in FIG. 2 and FIG. 3, a microgrid and components thereof comprise a control device C (providing a pulse current), a main line V1, a main line V2, connection devices (S1, S2, S3, S4, S5, S6, configured to establish an electrical connection, abbreviated herein as S1-S6), and unidirectional devices D (being semiconductor unidirectional conducting devices; the unidirectional devices D shown in FIG. 3 are placed inside the connection devices). The electrical energy of the main line V1 (optional) and the main line V2 is provided by a power source V through the control device C (a built-in switch). The main line V2 is configured to perform arc extinction on the connection devices. An electrode P1 of each connection device is connected to the main line V1. An electrode P2 of each connection device (S1-S6) is connected to the main line V2 through a unidirectional device D. The unidirectional device D and the electrode P2 are connected to form a selection switch. During the disconnection process of the connection device, break points K1 and K2 form between electrode P1, electrode P2, and electrode P3. Each unidirectional device D is connected to the main line V2 in a common-anode connection (in practical applications, a common-cathode connection may also be adopted according to line requirements; both common-cathode and common-anode connections are defined as same-polarity connections).

[0024] Control device C: By detecting a current (voltage, i.e., a potential difference of V2 relative to V1 or the power source V) signal on the main line V2, the control device detects a disconnection action of the connection device. When current (arc current) exists on the main line V2, the current through break point K1 drops to zero, achieving arc extinction at the break point K1. Then control device C turns off the current in main line V2, achieving arc extinction at break point K2. Subsequently, the control device supplies electrical energy to the main line V2 again, entering the next operating cycle. If the current is detected again, the preceding working process is repeated. When the control device detects that the current of the main line V2 exceeds a set time range, it may determine that the grid is abnormal and turn off the electrical energy of the main line V1 (optional) and the main line V2 (or the power source V). During a period when the control device C does not supply electrical energy to the main line V2, it may also be configured to detect the voltage of the main line V2, so as to detect whether a breakdown condition exists in the unidirectional device D. The control device C is connected to the main line V1 (preferably) and is configured to detect an electric signal of the main line V1. When control device C simultaneously detects and controls the main lines V1 and V2, the microgrid's fault-arc detection accuracy can be greatly improved, further ensuring microgrid safety. When the control device C simultaneously detects the electric signal of the main line V1 and the electric signal of the main line V2, it may also serve the following purposes: When the main line V1 experiences a power loss (power loss defined herein in the present invention is: current is zero, or voltage drops, manifesting as the potential difference between the main line V2 and the main line V1 satisfying the condition for driving the unidirectional device D to conduct) and a current appears on the main line V2, it indicates that no arc exists in the connection device and the main line V1 undergoes a voltage sag (power loss). At this time, maintaining power supply to the main line V2 can effectively suppress the voltage sag (power loss), thereby preventing an accident in a load connected to the connection device. When main line V1 and main line V2 use the same power source, the working process is as follows: The control device C first performs bypass arc extinction at break point K1 through main line V2 and the unidirectional device D, and then performs series arc extinction at break point K2.

[0025] Specific implementations of the connection devices (S1-S6) are as follows:

[0026] S1 is a switch with a bridge-contact structure, and the electrode P2 is a contact bridge. S2 and S5 are conventional switches with a linkage structure (Note: they are double-pole switches connected in series; two sets of switches with a bridge-contact structure as shown in S1 may also be connected in series, with the same principle, and the common node of the two series-connected components is the electrode P2). The break point K1 (junction, contact) formed by electrode P1 and electrode P2 of S1 and S2, and the break point K2 (junction, contact) formed by electrode P2 and electrode P3, form a series circuit. The main line V1 supplies power through this series circuit (in a connected state). S3 is a sliding-contact switch. S4 is a linked switch.

[0027] S5 is a switch comprising electrode P1, electrode P2, electrode P3, and electrode P4. The electrode P3 is configured to connect to the power ground G. The electrode P1 and the electrode P2 form the break point K1. The electrode P3 and the electrode P4 form the break point K2, i.e., the electrode P2 forms the break point K2 with the electrode P3 through a connection object (a load, or a battery).

[0028] S6 is a socket, comprising electrodes P1, P2 and P3. The electrode P3 is configured to connect to the power ground G. The electrode P1 and the electrode P2 form the break point K1 (with a connection object, plug PL). Electrode P2 forms the break point K2 with electrode P3 through the connecting object (plug PL). During insertion, an electrode P5 of the plug PL is first connected to electrode P2, and then the plug PL is connected to electrode P1 and electrode P3. During withdrawal, the plug PL is first disconnected from electrode P1 and electrode P3, and then disconnected from electrode P2. The structure of S6 is advantageous for preventing the unidirectional device D from conducting current for a long time due to incomplete plugging and unplugging of the plug. When S6 is changed to a single-wire socket, reference is made to the structure of S3: the electrode P3 is a plug, and the socket comprises the electrode P1 and the electrode P2, which can be established.

[0029] As shown in FIG. 3, a connection device S7 is a double-pole switch, configured to perform double-wire control on the main line V1 and the power ground G. The electrode P1 of the connection devices (S4, S5, S6) and the electrode P3 of the connection devices (S4, S5, S6) are connected to the main line V1 and the power ground G through the connection device S7. While the main line V2 achieves arc extinction for the connection devices (S4, S5, S6), it may also be configured for arc extinction of the connection device S7 and any number of connection devices (a plurality of S7 connected in series). S4 connected in series with S7 may also be of any type selected from S1-S3.

[0030] The connection devices (S1, S2, S5, S6, S7) are capable of synchronous breaking (synchronous making). The connection devices (S3, S4) are connection devices capable of asynchronous breaking (K1 breaks before K2; asynchronous making). The asynchronous time of the connection device in the S4 structure is greater than the power-off time of the main line V2 (i.e., the time during which the control device C stops supplying power to the main line V2), to prevent arc-extinguishing failure for S4.

[0031] As shown in FIG. 3, the microgrid and components thereof comprise a power distribution unit (distribution box) U. The power distribution unit comprises the control device C and circuit breakers (B1, B2). The circuit breakers at least comprise a first-pole switch L1 and a second-pole switch L2. The connection devices are connected to the main line V1 through the first-pole switch L1. The connection devices are connected to the main line V2 through the second-pole switch L2 by using a common node of the unidirectional devices D. When it is required that the control device C performs arc extinction on the circuit breakers (B1, B2, switches), the first-pole switch L1 (equivalent to the break point K1) may be configured to break before the second-pole switch L2 (equivalent to the break point K2), and the asynchronous time is greater than the power-off time of the main line V2. The control device C is configured to detect the leakage current and insulation resistance of the main line V1, the main line V2, and the power ground G to earth E. The main line V2 may be configured to detect the leakage current (insulation). When an abnormality is detected, the power source of main line V1 and main line V2 (or power source V) is turned off. FIG. 3 shows a control device with relatively comprehensive functions. In practical applications, the functions of the control device C may be simplified according to requirements.

[0032] At present, in direct-current systems, circuit breakers (switches) generally adopt a multi-pole series configuration. The solution of FIG. 4 may be adopted. The main line V2 is connected to the unidirectional device D (electrode P2) of the next-stage connection device (S1-S6) through the second-pole switch L2 (when P4 is connected to P2, the main line V2 first passes through the unidirectional device D). When dual control of a load (such as a lamp) is required, the wiring solution shown in FIG. 5 may be adopted (the diode D of S1-2 shown in FIG. 5 may be eliminated, and only the diode D of S1-1 is used).

[0033] The unidirectional devices D shown in FIG. 2, FIG. 3, FIG. 4 and FIG. 5 adopt diodes (uncontrolled devices; a plurality of diodes may be connected in series to increase the conduction voltage threshold and reverse withstand voltage). This solution not only has the advantages of simple wiring, good frequency characteristics (supporting a higher arc-extinguishing frequency), strong overcurrent capability, high cost-effectiveness, and no leakage current, but also can utilize the main line V2 to detect the break point between the electrode P2 and the main line V1 (node V1) (when the electrode P1 is connected in series with a fuse, arc extinction for the fuse and detection of the state of the fuse can be achieved) and faults such as overcurrent of the connection devices (which can be determined by detecting the duration of the arc-extinguishing pulse current of the main line V2; in addition, FIG. 6 also supports this function). When a plurality of connection devices in a dispersed arrangement are in a connected state and the working current of the main line V1 is relatively large, the line voltage drop between the connection device connected at the end of the grid and the main line V1 (power source end, power source V) may cause the main line V2 to generate a current. To prevent this phenomenon, when the main line V2 does not pass an arc-extinguishing current and the connection device is connected, the unidirectional device D connected to the connection device is reverse-biased. The potential difference (absolute value) of the main line V1 (power source end, power source V) relative to the main line V2 is greater than the maximum allowable working voltage drop (absolute value, generally 5% of the working voltage) of the main line V1. The conduction voltage threshold of the control device C is not less than this voltage drop.

[0034] When the unidirectional device D is changed to adopt a thyristor (semi-controlled device), several elements may be simply added. Reference is made to the circuits shown in FIG. 6, FIG. 7 and FIG. 8. Each thyristor D is in common-anode connection. As shown in FIG. 6 (the difference from the solution adopting an uncontrolled device lies in that it is easier to increase the conduction voltage threshold, and the on-state voltage drop value can be less than the conduction voltage threshold), the control electrode of the thyristor D is connected to the anode (terminal) of the thyristor D through a display device LED (optional), a resistor R (optional), a voltage detection device ZA (Zener diode, optional, configured to adjust the conduction voltage threshold of the unidirectional device), and a diode DA (rectifier diode) (Note: alternatively, the diode DA may also be connected in series with the anode or the cathode of the thyristor, and the control electrode of the thyristor is connected to the anode of the thyristor). The cathode of the thyristor is connected to the electrode P2. This solution is configured to avoid false conduction of the unidirectional device (such as when an uncontrolled device is adopted) caused by the voltage drop of the main line V1 under special conditions. As shown in FIG. 7, the control electrode of thyristor D is connected to electrode P1 through resistor R, and electrode P2 is connected to the cathode of thyristor D, with the advantage of no leakage current. As shown in FIG. 8, the control electrode of thyristor D is connected to electrode P2 through resistor R, and the cathode of thyristor D is connected to electrode P3. Compared with other solutions of the present invention, the key difference is that the main circuit of the unidirectional device D is not connected in series with electrode P2. During the arc-extinguishing process, the control device C performs bypass (parallel) arc extinction on the series circuit comprising the break point K1 and the break point K2 through the main line V2 and the unidirectional device D. In addition, when the connection device is disconnected due to an external impact or a voltage sag, the main line V2 may be utilized to supply power to the load for a short time, so as to prevent an accident from occurring. This solution has the advantages of fast arc breaking and good arc-extinguishing effect. The control electrode of the thyristor D shown in FIG. 7 may also be modified to be connected to the electrode P3 through a resistor R, so as to achieve fast arc breaking. The resistor R shown in FIG. 7 and FIG. 8 shall not be replaced with a capacitor, because during the disconnection process of the connection device, the main line V2 is in a power-off state, and the capacitor will be fully charged very quickly. When the main line V2 transitions to a high level, it cannot drive the thyristor D to conduct for arc extinction. In addition, the break-point bouncing of the connection device will also cause the problem that arc extinction cannot be achieved if a capacitor is adopted. When the unidirectional device D adopts a thyristor, under the condition that the connection device connected thereto is in a connected state, a working mode in which the unidirectional device is forward-biased (or near equipotential) may be adopted by utilizing the potential difference of the main line V2 relative to the main line V1, so as to obtain a larger arc-extinguishing current, which is suitable for high-current arc-extinguishing scenarios. When a unidirectional device and a connection device are selected to form a three-terminal selection switch, it is recommended that the unidirectional device and related elements (such as resistors, diodes, etc., optional) be installed as close as possible to the connection device, or be built into the connection device, so as to reduce the length of connection wires and improve the anti-interference capability.

[0035] If the main line V1 is negative or is configured for current collection, and a three-terminal selection switch technical solution needs to be selected, considering that current unidirectional thyristors are difficult to meet the requirements of special scenarios, as shown in FIG. 9, implementation is achieved by connecting a unidirectional device D (uncontrolled device, diode) in series with a bidirectional thyristor. Each unidirectional device D is in common-cathode connection. The anode of the unidirectional device D is connected to a second anode of a bidirectional thyristor T. A first anode of the bidirectional thyristor T is connected to the electrode P2. A control electrode of the bidirectional thyristor T is connected to the electrode P3 or the electrode P1 through a resistor R. Alternatively, it is configured such that the first anode of the bidirectional thyristor T is connected to the electrode P3, and the control electrode of the bidirectional thyristor T is connected to the electrode P2 through a resistor R.

[0036] In the above embodiments, the electrode P2 may be connected in series with a display device LED so that a user can know whether the connection device is normally connected to the main line V2. As shown in FIG. 6, the electrode P2 is connected in series with the unidirectional device D, and the control electrode of the unidirectional device D is connected in series with the LED. When the unidirectional device D comprises a plurality of diodes connected in series, as shown in FIG. 10, a series circuit (display unit) comprises a resistor RA, a diode DB and a display device LED, which may be connected in parallel with the unidirectional device D.

[0037] FIG. 11 is a cost-effective implementation of the control device for the microgrid of the present invention: It comprises a circuit breaker BK (optional, capable of electrically controlled breaking and manual closing), a control unit M, a switch Q1 (a fully controlled device, a semiconductor device, configured to output a pulse signal, being a field effect transistor, an IGBT, or a BJT), and a detection unit A (a four-terminal circuit). The power source V supplies power to the main line V1, the main line V2 and the control unit M (the control unit M may also adopt an independent power supply solution according to actual working conditions) through the circuit breaker BK. The control unit M is connected to the circuit breaker BK, the switch Q1 and the detection unit A. The switch Q1 is connected in series with the detection unit A and the main line V2. The detection unit A is configured to detect an electric signal of the main line V2.

[0038] Detection unit A: It comprises a current detection unit CT and a voltage detection unit VT (trigger switch). The voltage detection unit VT is connected in series with the current detection unit CT.

[0039] Current detection unit CT: It comprises a voltage detection device Z1 (comprising a plurality of diodes connected in series), a resistor R1 (optional), and an optocoupler OPT1. An input terminal of the optocoupler OPT1 forms a parallel circuit with the voltage detection device Z1 through the resistor R1. An output terminal of the optocoupler OPT1 is connected to the control unit M. A resistor R4 and a display device LED1 form a series circuit connected in parallel with Z1. LED1 is configured to display the arc-extinguishing action process.

[0040] Voltage detection unit VT: It is configured to detect a potential difference between the main line V2 and the main line V1, or between the main line V2 and the power source V. It comprises a thyristor SCR1, a resistor R2 (optional), and a voltage detection device Z2. A control electrode of the thyristor SCR1 is connected to the voltage detection device Z1 through the resistor R2 and the voltage detection device Z2 (it can be connected to a common node between the diodes inside Z1). The current detection unit CT is connected in series with an anode of the thyristor SCR1. This connection mode can effectively improve the stability of current detection, and has a current detection capability at the milliampere level.

[0041] The detection unit A of this embodiment detects (through the switch Q1) the potential difference of the main line V2 relative to the main line V1 (i.e., the power source V), and achieves that the on-state voltage drop of the detection unit A (control device C) is less than its conduction threshold (the voltage threshold or current threshold of the output current of the control device C is mainly determined by the conduction voltage threshold or current threshold of the detection unit A). It offers high cost-effectiveness, low loss, and strong output-current capability. The detection unit A may also be completed by circuits of other forms. When the unidirectional device D adopts a semi-controlled device or another device with a high conduction threshold, or is applied to a project with a small required arc-extinguishing current and short lines, the detection unit A only needs to detect the current of the main line V2, and it is sufficient to retain the current detection unit CT. If it is necessary to quantitatively measure the current, the CT in FIG. 11 may be changed to another current sensor. The output terminal (main line V2) of the detection unit A may be connected to a diode to the power ground to eliminate a reverse potential generated by the line connected to the main line V2. If the main line V1 is negative or is configured for current collection, the polarity direction of relevant components may be adjusted.

[0042] The voltage detection device (ZA, Z1, Z2) defined in the present invention is a semiconductor device that conducts when the voltage across its two terminals reaches its conduction voltage threshold, and can recover to a high-impedance state or a cut-off state when the voltage across its two terminals is lower than its conduction voltage threshold. The voltage detection device may comprise a plurality of ordinary diodes connected in series. The voltage detection device may be a transient voltage suppressor, a Zener diode, a trigger diode or a varistor, or another equivalent device.

[0043] The socket defined in the present invention and the plug PL connected thereto are in a mutual reference relationship, and the definitions may be interchanged in practical applications.

[0044] Working principle: The circuit breaker BK is closed for power-on, and the control device C performs a self-test (if an abnormality occurs, the BK is controlled to break). The control unit M provides a turn-on control signal for the switch Q1. When the potential difference between the main line V2 and the main line V1 (power source V) reaches the conduction-voltage (current) threshold of detection unit A, detection unit A conducts. The control unit M obtains relevant information through the optocoupler OPT1, and then controls (delay control) the switch Q1 to turn off. Then the voltage of node N2 is detected (the voltage of the main line V2 is detected through the internal loop of detection unit A) to determine whether switch Q1 is completely off and whether the unidirectional device D is damaged. If normal, the turn-on control signal for switch Q1 is provided again, and the next operating cycle begins. When an abnormality (such as arc-extinguishing abnormality, overcurrent, leakage, etc.) occurs during operation, the circuit breaker BK is controlled to break. Note: An overvoltage suppression device RV (optional, being a varistor, or adopting a transient voltage suppressor, etc.) connected to the switch Q1 is configured for overvoltage protection. A resistor R3 (optional) serves as current sampling for overcurrent protection.

[0045] For scenarios where power loss is not allowed, such as aircraft and automobiles, the circuit breaker BK may be omitted, and the control unit M provides relevant information. When high-speed protection is required, the circuit breaker BK may adopt a semiconductor switch.

[0046] In the above embodiments, the control device C first provides a direct-current voltage to the main line V2, and after detecting a current, turns off the current, thereby achieving arc extinction. It has detection and arc-extinction functions. To improve response speed, the control unit M includes a built-in (or external) pull-down circuit (applying reverse bias to the unidirectional device D and discharging charges on the main line V2), cooperating with switch Q1 to achieve push-pull output. For working conditions with stringent cost requirements, the control device may adopt a pulse generator as a pulse power source, which is equivalent to the control device controlling a high-level and low-level voltage signal output to the main line V2.

[0047] Arc extinction defined in the present invention means preventing an electric arc from being generated, or extinguishing an electric arc that has already been generated. The break point K1 (K2) defined in the present invention is not limited to a specific single junction (break point), and may be a plurality of junctions (break points, i.e., a group of break points) connected in series or in parallel.

[0048] The component for the microgrid of the present invention includes a switch or socket including the unidirectional device D (or further including components connected thereto), which greatly facilitates connection with the microgrid of the present invention.

[0049] When the connection devices (S1-S6) are switches, they may be manual mechanical switches (such as flip switches, toggle switches, push buttons, rocker switches, etc.), limit switches, circuit breakers, or may be electromagnetic switches such as contactors and relays.

[0050] The connection devices (S1-S6) in the above embodiments may also be connection devices inside an electrical apparatus (such as a power strip) or an electrical appliance (a water heater, an air conditioner, a kitchen appliance).

[0051] The number of connection devices (S1-S6) connected to the main line V1 and the main line V2 is two or more. The types of the connection devices represented by S1-S6 can be selected individually or in combination. When the connection devices are installed close to each other, the control device C is installed close to each connection device, and the unidirectional device D and the electrode P2 form a two-terminal selection switch; the main line V2 and the unidirectional device D can be integrated into the control device C.

[0052] The connection devices of the present invention may be connected in parallel, in series (i.e., main circuits of a plurality of connection devices are connected in series), or in hybrid connection, with the advantage of flexibility and convenience.

[0053] When the connection device of the present invention is a linkage structure, a mechanical linkage structure (preferred) or an electrical linkage structure is adopted.

[0054] The phrase "unidirectional device D is connected to the main line V2 in common-anode or common-cathode" defined in the microgrid of the present invention includes the meaning of "the unidirectional device D is directly connected to the main line V2 in common-anode (or common-cathode)", and also includes the meaning of "the unidirectional device D is connected to the main line V2 in common-anode (or common-cathode) through another component (or element, or device)", such as placing the unidirectional device D connected to the connection device S4 between the electrode P3 and the break point K2, i.e., in the connected state of the break point K2, the unidirectional device D is connected to the main line V2 in common-anode (or common-cathode) through the electrode P2.

[0055] The unidirectional device D of the microgrid of the present invention is preferably an uncontrolled device (diode), or a semi-controlled device (thyristor, not limited to a traditional thyristor). Adopting a non-fully-controlled device has the advantages of high withstand voltage, good overcurrent capability, low cost, and simple circuit. The connection devices (S1-S6) sharing one control device are extremely cost-effective.

[0056] The present invention utilizes the electrode P2 of the connection device connected to the unidirectional device D to form a selection switch. In the connected state of the connection device, the electrode P2, the electrode P1 and the electrode P3 are in an electrically connected state, which is advantageous for the main line V2 to detect the working state of the connection device in real time (achieving overcurrent detection, arc detection, arc extinction, etc., capable of detecting an arc current at the milliampere level and stably performing arc extinction). In the disconnected state of the connection device connected to a load, the electrode P2, the electrode P1 and the electrode P3 are in a disconnected state, and the unidirectional device D connected to the electrode P2 is in an open-circuit state (main circuit open-circuit state, or control circuit open-circuit state), effectively preventing the false conduction of the unidirectional device from affecting the load. It has extremely high anti-interference capability, meeting the use requirements of various complex working condition environments.

[0057] In the above embodiments, when the electrode P3 (if the connection device is S5, then the electrode P2 and the electrode P4) is connected to an electrical appliance, the microgrid is a distribution grid. When configured for current collection, the electrode P3 (if the connection device is S5, then the electrode P2 and the electrode P4) is configured to connect to each branch power source, and the microgrid is a current collection grid, suitable for scenarios such as photovoltaic current collection, charging piles, electrical energy storage, and battery current collection.

[0058] To facilitate the microgrid of the present invention in performing arc extinction on an electrical apparatus connected thereto, the plug PL shown in FIG. 2, FIG. 3, FIG. 12 and FIG. 13 further comprises an electrode P6 configured to connect to the electrode P2 of S6 (Note: the electrodes of S6 and PL may be adjusted according to the engineering layout of an actual product). The main line V2 achieves arc extinction for a connection device S8 inside an electrical apparatus RL6.

[0059] The electrical apparatus RL6 is connected to the electrode P1 and the electrode P3 of the connection device S6 through the plug PL. The electrode P6 of the plug PL is connected to the electrode P2 of the connection device S6. The main line V2 is configured to perform arc extinction on the connected electrical apparatus. The electrical apparatus further comprises a fuse F1, and the fuse F1 is connected to the electrode P4.

[0060] To improve the compatibility and flexibility of the electrical apparatus of the present microgrid when used with other direct-current grids, an adapter for other direct-current grids is shown in FIG. 14, comprising an arc-extinguishing device AS, an electrode PA and an electrode PB configured to connect to a power source and the electrical apparatus, and an electrode PC configured to perform arc extinction on the electrical apparatus. The arc-extinguishing device AS is connected to the electrode PA, the electrode PB and the electrode PC. The electrode PA, the electrode PB and the electrode PC are configured to connect to the plug PL.

[0061] Direct-current grids have the advantages of low loss and high transmission efficiency. However, since direct current has no zero-crossing point, its arc is difficult to extinguish, which is a technical bottleneck that makes it difficult to popularize direct-current power distribution in places such as buildings at present. By adopting the microgrid and components thereof of the present invention, traditional alternating-current switches that are technologically mature and have an extremely wide variety can, according to the wiring mode of the present invention, break direct current at least 1.414 times (the peak value of alternating-current voltage) of their alternating-current rated voltage (switch nominal value), and simultaneously can achieve an electrical life far higher than that under alternating-current working conditions (up to 10 times or more). The arcing time of a traditional alternating-current switch can reach 10 milliseconds (calculated based on 50 Hz, half a cycle time). The arcing time of the present invention can be controlled within 10 milliseconds. The recommended arcing time is less than 1 / 4 cycle time, preferably not greater than 1 millisecond. This solves the problems existing in current direct-current switches, such as long arcing time, short electrical life and mechanical life, and relatively limited product variety, and can greatly accelerate the popularization and application of direct-current power supply. To change an existing three-phase alternating-current control unit to direct-current control, as long as the microgrid of the present invention is used, there is no need to replace switches such as contactors, relays, and push buttons; it is only necessary to adjust the wiring and add a unidirectional device. For existing switches (when applied to a direct-current switch that itself has arc-breaking capability), its electrical life can be greatly improved by simply adding a unidirectional device (or externally). For sockets (or plugs, or connectors), it is also only necessary to add the electrode P2 and a unidirectional device (or externally) to produce a compliant product conveniently connected to the microgrid of the present invention. The control device and connection devices of the present microgrid can be independently produced in a standardized manner by different manufacturers, which is advantageous for cultivating an industrial ecosystem and accelerating the development of direct-current applications. It is particularly suitable for use in systems of various specification voltage levels within the current range of 1800 V (such as 1500 V, 750 V, 375 V, 270 V, 110 V, etc.).

[0062] For the microgrid of the novel architecture of the present invention, through industry or national relevant institutions, parameters such as the arc-extinguishing current pulse width of the main line V2 and the pulse width of stopping power supply to the main line V2 (the preferred recommended values of the two pulse widths are in the range of 0.05 milliseconds to 1 millisecond, not greater than 5 milliseconds, i.e., the arc-extinguishing frequency is controlled in the range of 100 Hz-10 kHz, and appropriate parameters are formulated according to the system current, voltage and line length), the potential difference of the main line V1 (power source end) relative to the main line V2 (for example, when the unidirectional device D is a diode, it is greater than the allowable voltage drop of the main line V1, preferably with an absolute value greater than 5 V and less than 30 V), the conduction voltage threshold of the unidirectional device D, and other parameters can be standardized, thereby standardizing the technical standards for tests related to the electrical life of the connection devices and the technical standards for the control device, which is advantageous for popularizing electronic arc extinction and standardizing market management.

[0063] For the microgrid of the novel architecture of the present invention, a single node (the main line V2, one bus) can achieve long-distance detection and arc extinction for connection devices of various current levels, with an unlimited number, in a dispersed arrangement. This is advantageous for the miniaturisation, lightweight and intelligence of the system. While greatly improving economy, it has very high safety and compatibility, and is suitable for application scenarios such as buildings (household, industrial, commercial, etc.), ships, automobiles, aircraft (airplanes, etc.), locomotives, and various equipment (charging piles, combiner boxes, machine control equipment, power distribution cabinets, etc.).

[0064] The connection device of the microgrid of the present invention may be a load (an electrical appliance, a connection device inside a refrigerator, a water heater, an air conditioner, a kitchen appliance, etc.), i.e., the main line V2 achieves arc extinction for the electrical appliance, which is advantageous for reducing the cost of the electrical appliance and improving product safety. In advanced applications, an internal circuit of the electrical appliance may be utilized to detect the main line V2 (achieving the detection purpose by driving a semiconductor switch to perform pulse discharge on V2). For example, if the main line V2 operates normally, the connection device inside the load is allowed to connect and enter normal operation.

[0065] In the above embodiments, for ease of understanding, a direct-current (unidirectional) microgrid is taken as an example. When bidirectional arc extinction for direct current or alternating current is required, it is sufficient to add only several components.

[0066] The present invention has a rational design and has the advantages of a wide application range and high safety.

Claims

1. A microgrid, comprising a main line (V1), the main line (V1) being configured for power supply, characterized in that: the microgrid further comprises a main line (V2), the main line (V2) being configured for arc extinction.

2. The microgrid according to claim 1, characterized in that: when a current appears on the main line (V2), the current of the main line (V2) is turned off, and then electrical energy is supplied to the main line (V2) again.

3. The microgrid according to claim 1, characterized in that: the microgrid is a building grid, or a ship grid, or a locomotive grid, or an aircraft grid, or an automobile grid, or an equipment grid.

4. The microgrid according to claim 1, characterized in that: the microgrid further comprises a control device (C), the control device (C) is connected to the main line (V2), and the control device (C) is configured to provide the main line (V2) with electrical energy.

5. The microgrid according to claim 4, characterized in that: the control device (C) is configured to detect the current of the main line (V2).

6. The microgrid according to claim 4, characterized in that: the control device (C) is configured to detect the voltage of the main line (V2).

7. The microgrid according to claim 4, characterized in that: when the main line (V1) experiences a power loss and a current appears on the main line (V2), the control device (C) maintains power supply to the main line (V2).

8. The microgrid according to claim 4, characterized in that: the control device (C) is configured to detect a fault arc.

9. The microgrid according to claim 4, characterized in that: the control device (C) is configured to detect a leakage current.

10. The microgrid according to claim 4, characterized in that: the microgrid further comprises connection devices (S1-S6) which are connected to the main line (V1) and the main line (V2), the number of the connection devices (S1-S6) being two or more, the connection devices (S1-S6) at least comprising an electrode (P1) and an electrode (P2), a break point (K1) and a break point (K2) being formed among the electrode (P1), the electrode (P2) and anelectrode (P3), the electrode (P1) being connected to the main line (V1), the electrode (P2) being connected to a unidirectional device (D) to form a selection switch, and each of the unidirectional devices (D) being connected to the main line (V2) with the same polarity; in a connected state of the connection devices (S1-S6), the electrode (P1), the electrode (P2) and the electrode (P3) are in an electrically connected state.

11. The microgrid according to claim 10, characterized in that: the connection device is a sliding contact, or a bridge-contact structure, or a linkage structure.

12. The microgrid according to claim 10, characterized in that: the electrode (P3) is connected to a fuse.

13. The microgrid according to claim 10, characterized in that: the electrode (P1) and the electrode (P2), or the electrode (P1) and the electrode (P3) form the break point (K1), and the electrode (P2) and the electrode (P3) form the break point (K2).

14. The microgrid according to claim 13, characterized in that: the electrode (P1) and the electrode (P2) form the break point (K1), and the electrode (P2) forms the break point (K2) with the electrode (P3) through an object connected thereto.

15. The microgrid according to claim 10, characterized in that: the connection device (S6) is a socket, and further comprises the electrode (P3), the electrode (P3) being configured to connect to a power ground (G), the electrode (P2) and a plug (PL) form the break point (K1) with the electrode (P1), and the electrode (P3) and the plug (PL) form the break point (K2).

16. The microgrid according to claim 15, characterized in that: during an insertion process, an electrode (P5) of the plug (PL) is first connected to the electrode (P2), and then the plug (PL) is connected to the electrode (P1) and the electrode (P3); during a withdrawal process, the plug (PL) is first disconnected from the electrode (P1) and the electrode (P3), and then disconnected from the electrode (P2).

17. The microgrid according to claim 15, characterized in that: the plug (PL) further comprises an electrode (P6) configured to connect to the electrode (P2).

18. The microgrid according to claim 10, characterized in that: the connection device (S5) is a switch, and further comprises the electrode (P3) and an electrode (P4), the electrode (P3) being configured to connect to the power ground (G), the electrode (P1) and the electrode (P2) forming the break point (K1), the electrode (P3) and the electrode (P4) forming the break point (K2), and the electrode (P2) and the electrode (P4) being configured to connect to aconnection object.

19. The microgrid according to claim 10, 15 or 18, characterized in that: the microgrid further comprises a connection device (S7), the electrode (P1) of the connection devices (S4, S5, S6) and the electrode (P3) of the connection devices (S4, S5, S6) are connected to the main line (V1) and the power ground (G) through the connection device (S7), and the main line (V2) is configured for arc extinction of the connection device (S7).

20. The microgrid according to claim 10, characterized in that: the unidirectional device (D) is an uncontrolled device.

21. The microgrid according to claim 20, characterized in that: a conduction voltage threshold of an output current of the control device (C) is not less than an allowable voltage drop of the main line (V1).

22. The microgrid according to claim 20, characterized in that: an on-state voltage drop of the control device (C) is less than the conduction voltage threshold of the control device (C).

23. The microgrid according to claim 20, characterized in that: the microgrid further comprises a bidirectional thyristor (T), the unidirectional device (D) is connected to a second anode of the bidirectional thyristor (T), a first anode of the bidirectional thyristor (T) is connected to the electrode (P2), and a control electrode of the bidirectional thyristor (T) is connected to the electrode (P3) or the electrode P1 through a resistor (R).

24. The microgrid according to claim 20, characterized in that: the microgrid further comprises a bidirectional thyristor (T), the unidirectional device (D) is connected to the second anode of the bidirectional thyristor (T), the first anode of the bidirectional thyristor (T) is connected to the electrode (P3), and the control electrode of the bidirectional thyristor (T) is connected to the electrode (P2) through a resistor (R).

25. The microgrid according to claim 10, characterized in that: the unidirectional device (D) is a semi-controlled device, each of the semi-controlled devices is in common-anode connection, a control electrode of the semi-controlled device is connected to an anode of the semi-controlled device, a cathode of the semi-controlled device is connected to the electrode (P2), and the semi-controlled device is connected in series with a diode (DA).

26. The microgrid according to claim 25, characterized in that: the control electrode of the semi-controlled device is connected to the anode of the semi-controlled device through a voltage detection device (ZA) and the diode (DA).

27. The microgrid according to claim 20 or 25, characterized in that: the control device (C) detects an overcurrent of the connection devices (S1-S6) by detecting the current of the main line (V2).

28. The microgrid according to claim 10, characterized in that: the unidirectional device (D) is a semi-controlled device, each of the semi-controlled devices is in common-anode connection, a control electrode of the semi-controlled device is connected to the electrode (P1) through a resistor (R), and a cathode of the semi-controlled device is connected to the electrode (P2).

29. The microgrid according to claim 10, characterized in that: the unidirectional device (D) is a semi-controlled device, each of the semi-controlled devices is in common-anode connection, a control electrode of the semi-controlled device is connected to the electrode (P2) through a resistor (R), and a cathode of the semi-controlled device is connected to the electrode (P3).

30. The microgrid according to claim 10, characterized in that: the unidirectional device (D) is a semi-controlled device, each of the semi-controlled devices is in common-anode connection, a control electrode of the semi-controlled device is connected to the electrode (P3) through a resistor (R), and a cathode of the semi-controlled device is connected to the electrode (P2).

31. The microgrid according to claim 10, characterized in that: the connection devices (S1-S6) are switches, or sockets, or plugs, or connectors.

32. The microgrid according to claim 10, characterized in that: the electrode (P2) isconnected in series with a display device (LED).

33. The microgrid according to claim 4, characterized in that: the microgrid furthercomprises a power distribution unit (U), the power distribution unit (U) comprises the control device (C) and circuit breakers (B1, B2) including a first-pole switch (L1) and a second-poleswitch (L2), the main line (V1) outputs through the first-pole switch (L1), and the main line(V2) outputs through the second-pole switch (L2).

34. A component based on the microgrid according to claim 4 or 10, characterized in that: the component is the control device (C), the control device (C) comprises a control unit (M), a fully controlled device (Q1) and a detection unit (A), the control unit (M) is connected to the fully controlled device (Q1) and the detection unit (A), and the fully controlled device (Q1), the detection unit (A) and the main line (V2) are connected in series.

35. The component for the microgrid according to claim 34, characterized in that: the detection unit (A) comprises a current detection unit (CT).

36. The component for the microgrid according to claim 35, characterized in that: the control device (C) further comprises a voltage detection unit (VT) configured to detect a potential difference of the main line (V2) relative to the main line (V1) or a power source (V), and the voltage detection unit (VT) is connected in series with the current detection unit (CT).

37. The component for the microgrid according to claim 36, characterized in that: the current detection unit (CT) comprises a voltage detection device (Z1) and an optocoupler (OPT1), the voltage detection unit (VT) comprising a thyristor (SCR1) and a voltage detection device (Z2), an input terminal of the optocoupler (OPT1) and the voltage detection device (Z1) form a parallel circuit, an output terminal of the optocoupler (OPT1) is connected to the control unit (M), the parallel circuit is connected in series with an anode of the thyristor (SCR1), and a trigger electrode of the thyristor (SCR1) is connected to the voltage detection device (Z1) through the voltage detection device (Z2).

38. The component for the microgrid according to claim 35, characterized in that: the current detection unit comprises a voltage detection device (Z1) and an optocoupler (OPT1), the voltage detection device (Z1) and an input terminal of the optocoupler (OPT1) are connected in parallel, and the optocoupler (OPT1) is configured to output a signal.

39. The component for the microgrid according to claim 34, characterized in that: the control device (C) further comprises a circuit breaker (BK), the power source (V) supplies power to the main line (V1) and the main line (V2) through the circuit breaker, and the circuit breaker (BK) is connected to the control unit (M).

40. A component based on the microgrid according to claim 10, characterized in that: the component is the connection devices (S1-S6).

41. A component for the microgrid according to claim 26, characterized in that: the connection devices (S1-S6) further comprise the semi-controlled device, the voltage detection device (ZA) and the diode (DA).

42. The component for the microgrid according to claim 41, characterized in that: the connection devices (S1-S6) further comprise a display device (LED), and the display device (LED) is connected in series with the control electrode.

43. A component for the microgrid according to any one of claims 28 to 30, characterized inthat: the component is the connection devices (S1-S6), and the connection devices (S1-S6) further comprise the semi-controlled device (D) and the resistor (R).

44. A component for the microgrid according to claim 20, characterized in that: the connection devices (S1-S6) comprise the unidirectional device (D).

45. The component for the microgrid according to claim 44, characterized in that: the connection devices (S1-S6) further comprise a resistor (RA), a diode (DB) and a display device (LED), and a series circuit comprising the resistor (RA), the diode (DB) and the display device (LED) is connected in parallel with the unidirectional device (D).

46. A component for the microgrid according to claim 33, characterized in that: the component is the power distribution unit (U).

47. An electrical apparatus for the microgrid according to claim 17, characterized in that: the electrical apparatus is connected to the electrode (P1) and the electrode (P3) of the connection device (S6) through the plug (PL), and the electrode (P6) is configured to connect to the electrode (P2) of the connection device (S6).

48. The electrical apparatus for the microgrid according to claim 47, characterized in that: the electrical apparatus further comprises a fuse (F1), and the fuse (F1) is connected to the electrode (P4) of the plug (PL).

49. The electrical apparatus for the microgrid according to claim 47, characterized in that: the electrical apparatus is an electrical appliance, or a power strip.

50. An adapter for the electrical apparatus of the microgrid according to claim 48, characterized in that: the adapter comprises an arc-extinguishing device (AS), an electrode (PA) and an electrode (PB) configured to connect to a power source and the electrical apparatus, and an electrode (PC) configured to perform arc extinction on the electrical apparatus, the arc-extinguishing device (AS) is connected to the electrode (PA), the electrode (PB) and the electrode (PC), and the electrode (PA), the electrode (PB) and the electrode (PC) are configured to connect to the plug (PL).

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