Power switching system, switch cabinet, and power switching method

Abstract

The present invention discloses a power switching system, a switch cabinet, and a power switching method. The power switching system includes: a first busbar, connected to a first power source through a first ultra-high-speed circuit breaker CSV1; a second busbar, connected to a second power source through a second ultra-high-speed circuit breaker CSV2; a third ultra-high-speed circuit breaker CSV3 and a pulse reactor connected in series, located between the first busbar and the second busbar, wherein the pulse reactor is connected in parallel with a fourth ultra-high-speed circuit breaker CSV4; a soft-cut controller, respectively connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3, and the fourth ultra-high-speed circuit breaker CSV4. Through the present invention, switching under different power supply conditions can be achieved to achieve disturbance-free rapid switching between power sources.

Description

Technical Field

[0001] The present invention relates to the technical field of power switching, and in particular to a power switching system, a switch cabinet, and a power switching control method. Background Art

[0002] Unstable power supply to industrial enterprises will bring about relatively large economic losses. For example, large and medium-sized industrial enterprises such as new materials, petrochemicals, and metallurgy often experience abnormal power outages, large voltage fluctuations, or short-term power outages (called "voltage sags" in the standard) due to failures or abnormalities in the external power grid or internal power supply network. Due to the particularity of the process flow of new materials, petrochemicals, and metallurgical enterprises, power outages or abnormalities often cause equipment shutdown or idling, process interruptions, or waste production, resulting in economic losses.

[0003] At present, the main way for industrial enterprises to solve the problem of power supply reliability is to use dual or multi-circuit power supply in the primary system, supplemented by the use of automatic backup power supply devices in the secondary system. For general industrial enterprises, although the automatic backup power supply devices have inherent delays, since most enterprises are discrete enterprises, short-term interruptions in production will not have a significant impact on product quality and production equipment. Therefore, automatic backup power supply can already meet the electricity requirements of enterprises. However, in continuous production process enterprises such as new materials, petrochemicals, and metallurgy, the use of automatic backup power supply cannot meet production requirements. The reason is that the main power load of these enterprises is asynchronous motor. When the incoming line or main transformer is disconnected due to a fault, although the bus has lost power, due to the existence of the motor feedback voltage, the bus voltage cannot immediately reach the starting condition of the standby automatic switch. Generally, the voltage loss setting value of the standby automatic switch device is 65-75% of the rated voltage, and it takes hundreds of milliseconds or even several levels of time from the power failure to the voltage drop to the voltage loss value. In addition, the inherent delay of the standby automatic switch (such as the standby automatic switch on the high-voltage side of the total step-down, the power supply company generally requires the setting of the reclosing time, the reclosing time is generally greater than 0.5 seconds, and the standby automatic switch of the lower substation increases the delay step by step). When the standby automatic switch successfully operates and the power supply is restored, there is already a delay of 1-2 seconds from the power failure. The delay time of the device substation is even longer, causing production interruption and adverse effects on product quality. For a 400V system, low voltage will cause the contactor to trip and the inverter to stop working, which will also cause production interruption.

[0004] In addition to the "voltage sag" accident caused by the loss of voltage due to a fault, which cannot be quickly resolved by the backup automatic switch, there is also a "voltage sag" accident caused by a voltage drop due to a fault in the substation on the opposite side of the external power grid, which the backup automatic switch cannot solve well. Because this type of voltage drop "voltage sag" causes a large voltage fluctuation, but the voltage does not necessarily drop below the backup automatic switch voltage loss setting value. Therefore, the backup automatic switch will not start, but when the voltage drops below 80%, the low-voltage contactor has begun to trip one after another; or although the bus voltage has dropped to the backup automatic switch starting voltage, due to the fixed time delay of the backup automatic switch, it will inevitably cause some low-voltage motors to be cut off.

[0005] In summary, the problem of power interruption during power switching in related technologies urgently requires providing industrial enterprises, such as new materials, petrochemical, and metallurgical enterprises, with a solution that overcomes the inherent deficiencies of standby automatic switching devices, ensures continuous power supply, and achieves "zero power outage" for the enterprise. Summary of the invention

[0006] The present invention provides a power switching system, a switch cabinet, and a power switching method, which are used to solve the problem of power supply interruption during power switching in the related art.

[0007] According to one aspect of the present invention, there is provided a power switching system, comprising: a first busbar, connected to a first power source via a first ultra-high-speed circuit breaker CSV1; a second busbar, connected to a second power source via a second ultra-high-speed circuit breaker CSV2; a third ultra-high-speed circuit breaker CSV3 and a pulse reactor connected in series, located between the first busbar and the second busbar, wherein the pulse reactor is connected in parallel with a fourth ultra-high-speed circuit breaker CSV4; and a soft-cutting controller, respectively connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4.

[0008] Preferably, the first power supply and the second power supply are redundant with each other, wherein, when the first power supply and the second power supply are working normally, the first ultra-high-speed circuit breaker CSV1 is closed, the second ultra-high-speed circuit breaker CSV2 is closed, and the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are opened.

[0009] Preferably, in the event of a failure of the first power supply or the second power supply, the soft switching controller controls the ultra-high-speed circuit breaker corresponding to the faulty power supply to open, and controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to close in sequence.

[0010] Preferably, after switching from the faulty power supply to the non-faulty power supply for power supply, the soft switching controller controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to be disconnected in sequence.

[0011] Preferably, the soft switching controller is connected to the first power source via a voltage transformer (PT for short) PT1; the soft switching controller is connected to the second power source via a voltage transformer PT2.

[0012] According to another aspect of the present invention, a switch cabinet is also provided, including: a microcomputer comprehensive protection, a soft-cut controller, a first ultra-high-speed circuit breaker CSV1, a second ultra-high-speed circuit breaker CSV2, a third ultra-high-speed circuit breaker CSV3, a fourth ultra-high-speed circuit breaker CSV4 and a pulse reactor; wherein the first ultra-high-speed circuit breaker CSV1 connects the first power supply to the first bus; the second ultra-high-speed circuit breaker CSV2 connects the second power supply to the second bus; the third ultra-high-speed circuit breaker CSV3 and the pulse reactor connected in series are located between the first bus and the second bus, wherein the pulse reactor is connected in parallel with the fourth ultra-high-speed circuit breaker CSV4; the soft-cut controller is respectively connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4.

[0013] According to another aspect of the present invention, a power switching method is also provided, comprising: a soft-cut controller detects that a first power supply or a second power supply fails, wherein the first power supply and the second power supply are redundant with each other, the first power supply is connected to a first busbar via a first ultra-high-speed circuit breaker CSV1, and the second power supply is connected to a second busbar via a second ultra-high-speed circuit breaker CSV2; the soft-cut controller controls the ultra-high-speed circuit breaker corresponding to the faulty power supply to disconnect; the soft-cut controller controls a third ultra-high-speed circuit breaker CSV3 and a fourth ultra-high-speed section circuit breaker CSV4 to close in sequence, wherein the third ultra-high-speed circuit breaker CSV3 and a pulse reactor are connected in series between the first busbar and the second busbar, wherein the pulse reactor is connected in parallel with the fourth ultra-high-speed circuit breaker CSV4; wherein the soft-cut controller is respectively connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4.

[0014] Preferably, when the first power supply and the second power supply work normally, the first ultra-high-speed circuit breaker CSV1 is closed, the second ultra-high-speed circuit breaker CSV2 is closed, and the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are opened.

[0015] Preferably, after switching from the faulty power supply to the non-faulty power supply for power supply, the soft switching controller controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to be disconnected in sequence.

[0016] Preferably, the soft switching controller is connected to the first power supply via a voltage transformer PT1; the soft switching controller is connected to the second power supply via a voltage transformer PT2.

[0017] The present invention provides a power switching system and a power switching method, in which the backup power supply can be put into use before the critical voltage, thereby solving the problem of power interruption during power switching, achieving disturbance-free switching of the power supply, and ensuring the continuity of the production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of power switching in the related art. Figure 1 ;

[0020] Figure 2 It is a schematic diagram of the change trajectory of the residual voltage vector of the power-off bus voltage caused by power switching in the related art;

[0021] Figure 3 is a schematic diagram of a power switching system according to an embodiment of the present invention Figure 1 ;

[0022] Figure 4 The process of the power switching method according to the embodiment of the present invention is Figure 1 ;

[0023] Figure 5 The process of the power switching method according to the embodiment of the present invention is Figure 2 ;

[0024] Figure 6 is a schematic diagram of a power switching system according to an embodiment of the present invention Figure 2 . DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] This embodiment provides a power switching system. Figure 3 is a schematic diagram of a power switching system according to an embodiment of the present invention. Figure 3 As shown, the power switching system includes: a first busbar, connected to the first power source through a first ultra-high-speed circuit breaker CSV1; a second busbar, connected to the second power source through a second ultra-high-speed circuit breaker CSV2; a third ultra-high-speed circuit breaker CSV3 and a pulse reactor connected in series, located between the first busbar and the second busbar, wherein the pulse reactor is connected in parallel with a fourth ultra-high-speed circuit breaker CSV4; and a soft-cut controller, respectively connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4.

[0027] In the related art, during the power switching process, if the first power fails, the first power and the first bus lose power, the motor will coast. Figure 1 As shown, for example: when the incoming line 1 is switched to the incoming line 2, the bus 1 loses power after the 1DL is tripped, and the motor will coast. Since most of the loads are asynchronous motors, for a single motor, the stator current of the motor becomes zero after the power is cut off, and the rotor current gradually decays. Due to mechanical inertia, the rotor speed will gradually slow down from the rated value, and the rotor current magnetic field will reversely induce potential in the stator winding to form a feedback voltage. Figure 2 It is a schematic diagram of the change trajectory of the residual voltage vector of the power failure mother voltage caused by the power switching in the related art, such as Figure 2 As shown in the figure, when multiple asynchronous motors are connected to the same bus, due to the different capacities and loads of each motor, during the coasting process, some asynchronous motors will show the characteristics of asynchronous generators, while others will show the characteristics of asynchronous motors. The bus voltage is the synthetic feedback voltage of many motors, commonly known as residual voltage, and the frequency and amplitude of the residual voltage will gradually decay. Generally, the larger the total capacity of the motor, the slower the decay rate of the residual voltage frequency and amplitude. In order to achieve rapid switching of power supply, it is necessary to accurately judge the frequency, voltage, and phase quantity of the power supply at both ends, and automatically track and measure them, and the calculation is relatively complicated.

[0028] The technical solution in this embodiment uses a pulse inductor and utilizes the pulse inductor's characteristic of suppressing current mutations to avoid the influence of frequency, voltage, and phase quantity. The existence of the pulse inductor does not require accurate judgment of the frequency, voltage, and phase quantity of the power supplies at both ends for automatic tracking and measurement. The transition inductor is used to limit the current and establish a network connection, which reduces the requirements of the power switching process for angle difference, amplitude difference, and frequency difference, and can achieve switching under different power supply conditions to achieve disturbance-free and rapid switching between power supplies.

[0029] As a preferred implementation, the first power supply and the second power supply are mutually redundant, wherein, when the first power supply and the second power supply are in normal operation, the first ultra-high-speed circuit breaker CSV1 is closed, the second ultra-high-speed circuit breaker CSV2 is closed, and the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are disconnected. In this embodiment, when the first power supply and the second power supply are in normal operation, the first power supply is connected to the first busbar through the first ultra-high-speed circuit breaker CSV1, the first ultra-high-speed circuit breaker CSV1 is closed, and the first power supply and the first busbar are connected. The second power supply is connected to the second busbar through the second ultra-high-speed circuit breaker CSV2, the second ultra-high-speed circuit breaker CSV2 is closed, the second power supply and the second busbar are connected, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are disconnected, and the pulse reactor is not connected to the power grid to maintain the stability of the power grid.

[0030] As another preferred embodiment, in the case of a fault in the first power supply or the second power supply, the soft-cut controller controls the ultra-high-speed circuit breaker corresponding to the faulty power supply to be disconnected, and controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to be closed in sequence. In this embodiment, in the case of a fault, the soft-cut controller disconnects the ultra-high-speed circuit breaker (the first ultra-high-speed circuit breaker CSV3 or the second ultra-high-speed circuit breaker CSV2) corresponding to the faulty power supply (the first power supply or the second power supply), and then controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to be closed in sequence, and connects the pulse reactor to the power grid. Through the pulse reactor, the pulse reactor's characteristic of suppressing current mutation is used to avoid the influence of frequency, voltage, and phase quantity. The existence of the pulse reactor does not require accurate judgment of the frequency, voltage, and phase quantity of the power supplies at both ends for automatic tracking and measurement. The transition inductor is used to limit the current and establish a network connection, which reduces the requirements of the power switching process for angle difference, amplitude difference, and frequency difference, and can achieve switching under different power supply conditions to achieve disturbance-free rapid switching between power supplies.

[0031] As another preferred implementation, after switching from the faulty power supply to the non-faulty power supply for power supply, the soft-cut controller controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to be disconnected in sequence. In this embodiment, after the faulty power supply is switched to the non-faulty power supply for power supply. For example, the first power supply fails, and the second power supply fails. After a period of time, after the second power supply is stably supplied, the soft-cut controller can disconnect the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 in sequence, and return to the initial stage of power switching. If the power grid fails again, the soft-cut controller can control the pulse reactor to be connected to the power grid again to achieve disturbance-free power switching.

[0032] In implementation, the soft switching controller is connected to the first power supply through the voltage transformer PT1, and is connected to the second power supply through the voltage transformer PT2. The soft switching controller is connected to the first power supply and the second power supply through the voltage transformers, respectively, to sample the voltage signals of the two power supplies.

[0033] In practice, the industrial field environment becomes more and more complex. When a power failure occurs, the fault section system is in an island operation state, and the change in bus voltage is the result of the combined effect of all loads. This requires that the device can start quickly and accurately in various complex operating environments in addition to starting by loss of voltage. Those skilled in the art can adopt a variety of methods to start according to actual needs. In the power switching system and power switching method of the present application, the soft-cut controller starts the switching in the following ways: protection start, no-current start, reverse power start, switch false trip start, and loss of voltage start. The starting method is described in detail below:

[0034] (1) Protection start: When the incoming line differential protection (or main transformer differential protection) is activated, a pair of protection output contacts is specially arranged to be connected to the ultra-high-speed switching device. In this way, when a fault occurs and the protection output is activated, although the incoming line switch has not yet tripped, the ultra-high-speed switching has already started, thus seizing the initiative.

[0035] (2) No-current start: When there is no optical fiber longitudinal differential protection set for the incoming line, the incoming line fault will cause the opposite side switch to trip, and there will be no current in the incoming line. When the device detects that there is no current in the incoming line, and combines other auxiliary criteria to confirm that the working bus and the backup power supply are disconnected, the ultra-high-speed switching will be started. Since the no-current criterion can also start the ultra-high-speed switching when the opposite side switch is tripped due to other reasons (not short circuit, line break fault), it is a very effective starting criterion in many occasions.

[0036] (3) Reverse power starting criteria: It is very effective in solving the problem of power fluctuation in the external power grid.

[0037] Frequency and voltage abnormality judgment criteria: It is mainly applicable to situations where there is a generator on the bus or at the rear end of the bus, and other judgment criteria cannot be used normally. Of course, it is also applicable to other situations.

[0038] It should be noted that the criteria for no-current starting, reverse power starting, abnormal frequency and voltage starting, etc. are new criteria specially proposed for the application of ultra-high-speed switching in substations.

[0039] (4) Switch false tripping start: When the system is operating normally, the switch in the closed position trips due to various reasons (including human error) and starts the ultra-high-speed switching device.

[0040] (5) Loss-pressure starting: This is the starting method used by the backup automatic starter. Ultra-high-speed switching retains it as a backup starting method.

[0041] This embodiment provides a power switching method. Figure 4 The process of the power switching method according to the embodiment of the present invention is Figure 1 ,like Figure 1 As shown, the method includes the following steps S401 to S408, which are described in detail below.

[0042] Step S401, start.

[0043] Step S402, detect the state of the power grid. If the power grid state is detected to be normal, proceed to step S404. If the power grid state is detected to be abnormal, return to step S402.

[0044] Step S404, fault detection. If a fault is detected, go to step S406, if no fault is detected, return to step S402. In this step, the soft switching controller determines the nature of the fault within a preset time (eg, 12 ms).

[0045] Step S406, if the grid state is detected as a fault, the switching action is initiated. In this step, when a fault is detected and the power supply switching is met, a trip command is issued, and the network connection is established by using the transition inductor to limit the current, without the need for synchronous capture and other long judgment time.

[0046] Step S408, power switching is completed. In this step, the backup line is immediately switched on when the faulty line is removed, and the entire switching time can be less than 18ms.

[0047] Step S410: manually start the power switching action.

[0048] It should be noted that step S410 is not a necessary step. In the actual power grid operation process, the standby automatic switching device does not have a normal switching function. In some maintenance or post-accident recovery situations, manual start-up and correct switching operation can ensure the stability of the power grid and the safety of equipment such as transformers.

[0049] Step S408 in this embodiment can adopt the power switching system in the above embodiment and its preferred implementation mode, and realize the power switching operation through the control operation of the soft-cut controller. And through the pulse reactor, the characteristic of suppressing current mutation of the pulse reactor is adopted to avoid the influence of frequency, voltage and phase quantity. The existence of the pulse reactor does not need to accurately judge the frequency, voltage and phase quantity of the power supply at both ends for automatic tracking and measurement. The transition inductor is used to limit the current and establish a network connection, which reduces the requirements of the power switching process for angle difference, amplitude difference and frequency difference, and can realize switching under different power supply conditions to realize disturbance-free rapid switching between power supplies.

[0050] This embodiment can avoid external power failure of the system and internal short circuit of the system, which may cause the voltage of the entire distribution network to sag for too long, resulting in the failure of low voltage ride-through of a fatal device and the need for mediation, thus affecting safe production.

[0051] This embodiment provides a power switching system. In this embodiment, the 10kV system of the 110kV A station supplies power to multiple companies. The 10kV line can be a mixed line of cables and overhead lines. Once a fault occurs in any part of the 10kV system, it may cause voltage fluctuations in the entire 10kV system. The 10kV V incoming power supply of the X company comes from the 10kV system of the 110kV A station. There are 8 external network voltage drops in one year, which have repeatedly affected the tripping of sensitive equipment in the system, resulting in process interruption or waste, causing huge economic losses.

[0052] In this embodiment, Figure 6 is a schematic diagram of a power switching system according to an embodiment of the present invention Figure 2 ,like Figure 6 As shown, in order to solve the problem of power outage of X enterprise, the V incoming line switch can be replaced with the connecting incoming line cabinet 1#, the VI incoming line switch can be replaced with the connecting incoming line cabinet 2#, and the mother coupling cabinet can be replaced with the parallel soft-cut cabinet, and the parallel soft-cut cabinet is provided with a soft-cut controller, wherein the connecting incoming line cabinet 1# is provided with an ultra-high-speed vacuum circuit breaker, and the connecting incoming line cabinet 2# is also provided with an ultra-high-speed vacuum circuit breaker. This embodiment adopts the soft-cut controller in the above embodiment and its preferred implementation mode, and the two power supply lines of the switch station operate in a one-in-one-standby mode. When the voltage of the power supply line drops due to an external fault, the soft-cut controller cuts off the voltage drop power supply within 18ms, and puts in another standby power supply to ensure that the voltage drop time of the power system is less than 18ms.

[0053] It should be noted that the control system of the above power supply system can be assembled into a separate panel cabinet.

[0054] In implementation, one-for-one and two-for-standby and dual incoming lines being mutually redundant can be equivalent to the above technical solution.

[0055] It should be noted that, in this embodiment, the power supply capacity of the V incoming line of Company X and the VI incoming line of Company X are both greater than the load capacity of the two switch stations.

[0056] As a preferred implementation method, in actual operation, the V incoming line switch cabinet of X Company can be transformed into an ultra-high-speed vacuum circuit breaker CSV; or a switching incoming line switch cabinet can be placed in front of the original incoming line switch cabinet.

[0057] In this embodiment, a soft-cut controller of an ultra-high-speed circuit breaker in parallel with a pulse inductor is used, which is connected in series to the lower position of the main circuit breaker. The transition inductance is used to limit the current and establish a network connection, which reduces the requirements of the switching process for angle difference, amplitude difference, and frequency difference, and can be switched under different power supply conditions.

[0058] In this embodiment, the ultra-high-speed inductive soft switching device starts in advance by predicting the occurrence of voltage loss, and can adopt protection starting, no-current starting, reverse power starting, switch false tripping starting, voltage loss starting and other starting switching.

[0059] It should be noted that through parallel switching, the power supply is briefly connected in parallel and then transitions through the reactor during the switching process, which can avoid the expansion of accidents and the existence of phase difference, voltage difference, and frequency difference between the two power supplies.

[0060] In this embodiment, the switching switch adopts a CSV ultra-high-speed vacuum circuit breaker, with an opening time of less than 2ms and a closing time of less than 5ms.

[0061] Through this embodiment, no matter the voltage sag is caused by the external network or the voltage sag is caused by a fault in the system, the power supply can be switched within 18ms to ensure the voltage stability of the power supply system.

[0062] The present embodiment provides a switch cabinet, including: a microcomputer comprehensive protection, a soft-cut controller, a first ultra-high-speed circuit breaker CSV1, a second ultra-high-speed circuit breaker CSV2, a third ultra-high-speed circuit breaker CSV3, a fourth ultra-high-speed circuit breaker CSV4 and a pulse reactor; wherein the first ultra-high-speed circuit breaker CSV1 connects a first power supply to a first bus; the second ultra-high-speed circuit breaker CSV2 connects a second power supply to a second bus; the third ultra-high-speed circuit breaker CSV3 and the pulse reactor connected in series are located between the first bus and the second bus, wherein the pulse reactor is connected in parallel with the fourth ultra-high-speed circuit breaker CSV4; the soft-cut controller is respectively connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4.

[0063] This embodiment provides a power switching method. Figure 5 The process of the power switching method according to the embodiment of the present invention is Figure 2 ,like Figure 5 As shown, the method includes the following steps S502 to S510.

[0064] In step S502, the soft-cut controller detects that the first power supply or the second power supply fails, wherein the first power supply and the second power supply are redundant with each other, the first power supply is connected to the first bus through the first ultra-high-speed circuit breaker CSV1, and the second power supply is connected to the second bus through the second ultra-high-speed circuit breaker CSV2.

[0065] Step S504: the soft switching controller controls the ultra-high-speed circuit breaker corresponding to the faulty power source to disconnect.

[0066] Step S506: the soft switching controller controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to close in sequence.

[0067] The third ultra-high-speed circuit breaker CSV3 and the pulse reactor are connected in series between the first bus and the second bus, wherein the pulse reactor is connected in parallel with the fourth ultra-high-speed circuit breaker CSV4.

[0068] The technical solution in this embodiment uses a pulse inductor and utilizes the pulse inductor's characteristic of suppressing current mutations to avoid the influence of frequency, voltage, and phase quantity. The existence of the pulse inductor does not require accurate judgment of the frequency, voltage, and phase quantity of the power supplies at both ends for automatic tracking and measurement. The transition inductor is used to limit the current and establish a network connection, which reduces the requirements of the power switching process for angle difference, amplitude difference, and frequency difference, and can achieve switching under different power supply conditions, thereby realizing disturbance-free rapid switching between power supplies.

[0069] In this embodiment, the soft switching controller is respectively connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4.

[0070] As a preferred implementation, when the first power supply and the second power supply are working normally, the first ultra-high-speed circuit breaker CSV1 is closed, the second ultra-high-speed circuit breaker CSV2 is closed, and the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are disconnected. In this embodiment, when the first power supply and the second power supply are working normally, the first power supply is connected to the first bus through the first ultra-high-speed circuit breaker CSV1, the first ultra-high-speed circuit breaker CSV1 is closed, and the first power supply and the first bus are connected. The second power supply is connected to the second bus through the second ultra-high-speed circuit breaker CSV2, the second ultra-high-speed circuit breaker CSV2 is closed, the second power supply and the second bus are connected, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are disconnected, and the pulse reactor is not connected to the power grid to maintain the stability of the power grid.

[0071] Preferably, after switching from the faulty power supply to the non-faulty power supply for power supply, the soft-cut controller controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to be disconnected in sequence. In this embodiment, after the faulty power supply is switched to the non-faulty power supply for power supply. For example, the first power supply fails, and the second power supply fails. After a period of time, after the second power supply is stably supplied, the soft-cut controller can disconnect the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 in sequence, and return to the initial stage of power switching. If the power grid fails again, the soft-cut controller can control the pulse reactor to be connected to the power grid again to achieve disturbance-free power switching.

[0072] In implementation, the soft switching controller is connected to the first power supply through the voltage transformer PT1, and is connected to the second power supply through the voltage transformer PT2. The soft switching controller is connected to the first power supply and the second power supply through the voltage transformers, respectively, to sample the voltage signals of the two power supplies.

[0073] In this application, as the core component of the power switching system and the power switching method, the ultra-high-speed vacuum circuit breaker is described in detail below:

[0074] The ultra-high-speed vacuum circuit breaker CSV adopts an ultra-high-speed electromagnetic induction drive mechanism and a built-in phase-controlled ultra-high-speed short-circuit protection controller. The circuit breaker can realize ultra-high-speed breaking at the first power frequency zero crossing point of the short-circuit current, and can also cooperate with other protection devices such as microcomputer comprehensive protection, and accept commands from other protection devices such as microcomputer comprehensive protection to perform ultra-high-speed closing and opening operations. The circuit breaker opening speed reaches 5m / s, the opening time is less than 2ms, the closing speed reaches 3m / s, and the closing time is less than 5ms, and ultra-high-speed inductive soft switching and other devices can be used.

[0075] In this application, the ultra-high-speed vacuum circuit breaker meets the following conditions:

[0076] (1) Ultra-high-speed closing and opening: The ultra-high-speed opening mechanism driven by electromagnetic principle has an opening speed of 5m / s and an opening time of less than 2ms. The three-phase arc extinguishing chamber can perform accurate phase-splitting operation to achieve ultra-high-speed phase-controlled zero-crossing breaking in the true sense. The closing speed reaches 3m / s and the closing time is less than 5ms, which can achieve ultra-high-speed closing and is suitable for occasions such as fast power cutting.

[0077] (2) Bistable holding: The unique bistable holding mechanism is used to ensure reliable holding and accurate positioning, so that the circuit breaker can be reliably kept in the closing and opening positions even during ultra-high-speed movement. During the entire closing and opening process, the force curve during the closing and opening process is optimized through analysis to reduce contact collision.

[0078] Through the above embodiments and preferred implementations, a power switching system, a switch cabinet, and a power switching method are provided, which can achieve the following beneficial effects:

[0079] The pulse reactor's characteristic of suppressing sudden current changes is used to avoid the influence of frequency, voltage and phase quantity. The existence of the pulse reactor does not require accurate judgment of the frequency, voltage and phase quantity of the power supplies at both ends for automatic tracking and measurement. The transition inductor is used to limit the current and establish a network connection, which reduces the requirements of the power switching process for angle difference, amplitude difference and frequency difference, and can achieve switching under different power supply conditions, realizing disturbance-free and rapid switching between power supplies.

[0080] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A power switching system, characterized in that: include: A first busbar connected to a first power source via a first ultra-high-speed circuit breaker CSV1; A second busbar connected to a second power source via a second ultra-high-speed circuit breaker CSV2, wherein the first power source and the second power source are redundant to each other; A third ultra-high-speed circuit breaker CSV3 and a pulse reactor connected in series are located between the first bus and the second bus, wherein the pulse reactor is connected in parallel with a fourth ultra-high-speed circuit breaker CSV4, wherein the pulse reactor uses a transition inductor to limit the current and establish a network connection, thereby reducing the requirements of the power switching process on the angle difference, amplitude difference, and frequency difference; as well as A soft switching controller, connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 respectively; Wherein, when the first power supply and the second power supply are working normally, the first ultra-high-speed circuit breaker CSV1 is closed, the second ultra-high-speed circuit breaker CSV2 is closed, and the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are opened; In the event of a failure of the first power supply or the second power supply, the soft switching controller controls the ultra-high-speed circuit breaker corresponding to the failed power supply to open, and controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to close in sequence.

2. The power switching system according to claim 1, characterized in that: After switching from the faulty power supply to the non-faulty power supply for power supply, the soft switching controller controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to be disconnected in sequence.

3. The power switching system according to any one of claims 1 to 2, characterized in that The soft switching controller is connected to the first power supply via a voltage transformer PT1; The soft switching controller is connected to the second power supply via a voltage transformer PT2.

4. A switch cabinet, characterized in that: include: Microcomputer comprehensive protection, soft cut controller, first ultra-high-speed circuit breaker CSV1, second ultra-high-speed circuit breaker CSV2, third ultra-high-speed circuit breaker CSV3, fourth ultra-high-speed circuit breaker CSV4 and pulse reactor; among them, A first ultra-high speed circuit breaker CSV1 connects the first power source to the first bus; A second ultra-high-speed circuit breaker CSV2 connects a second power source to a second bus, wherein the first power source and the second power source are redundant to each other; A third ultra-high-speed circuit breaker CSV3 and a pulse reactor connected in series are located between the first bus and the second bus, wherein the pulse reactor is connected in parallel with a fourth ultra-high-speed circuit breaker CSV4, wherein the pulse reactor uses transition inductance current limiting and establishes a network connection, thereby reducing the requirements of the power switching process on the angle difference, amplitude difference, and frequency difference; and A soft switching controller, connected to the first ultra-high-speed circuit breaker CSV1, the second ultra-high-speed circuit breaker CSV2, the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 respectively; Wherein, when the first power supply and the second power supply are working normally, the first ultra-high-speed circuit breaker CSV1 is closed, the second ultra-high-speed circuit breaker CSV2 is closed, and the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are opened; In the event of a failure of the first power supply or the second power supply, the soft switching controller controls the ultra-high-speed circuit breaker corresponding to the failed power supply to open, and controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to close in sequence.

5. A power switching method, characterized in that: include: The soft switching controller detects that a first power supply or a second power supply fails, wherein the first power supply and the second power supply are redundant with each other, the first power supply is connected to the first bus through a first ultra-high-speed circuit breaker CSV1, and the second power supply is connected to the second bus through a second ultra-high-speed circuit breaker CSV2; The soft-cut controller controls the ultra-high-speed circuit breaker corresponding to the faulty power supply to disconnect; The soft-cut controller controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to close in sequence, wherein the third ultra-high-speed circuit breaker CSV3 and the pulse inductor are connected in series between the first bus and the second bus, wherein the pulse inductor is connected in parallel with the fourth ultra-high-speed circuit breaker CSV4, wherein the pulse inductor uses transition inductance to limit current and establish a network connection, thereby reducing the requirements of the power switching process on angle difference, amplitude difference, and frequency difference.

6. The power switching method according to claim 5, characterized in that: When the first power supply and the second power supply work normally, the first ultra-high-speed circuit breaker CSV1 is closed, the second ultra-high-speed circuit breaker CSV2 is closed, and the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 are opened.

7. The power switching method according to claim 6, characterized in that: After switching from the faulty power supply to the non-faulty power supply for power supply, the soft switching controller controls the third ultra-high-speed circuit breaker CSV3 and the fourth ultra-high-speed circuit breaker CSV4 to be disconnected in sequence.

8. The power switching method according to claim 6 or 7, characterized in that: The soft switching controller is connected to the first power supply via a voltage transformer PT1; The soft switching controller is connected to the second power supply via a voltage transformer PT2.

Images