Dual power supply switching circuit and method and emergency power supply system

Abstract

The invention particularly relates to a dual-power-supply switching circuit and method and an emergency power supply system, and the circuit is characterized in that the first end of a first switch assembly is connected with a first AC power supply, the second end of the first switch assembly is connected with a second AC power supply, and the third to fifth ends of the first switch assembly are connected with the first to third ends of a second switch assembly respectively; the sixth end of the first switch assembly is connected with a load; the control and detection system is connected with the first AC power supply, the second AC power supply, the first switch assembly and the second switch assembly, and is used for determining a target switch state of the second switch assembly according to a first fundamental wave voltage amplitude determined by the first AC power supply and a second fundamental wave voltage amplitude determined by the second AC power supply. And when the second switch assembly is in a fault state, the first switch assembly is switched to supply power to the load. Therefore, the problems of low dual-power-supply switching speed, inaccurate fault judgment and the like in related technologies are solved, and rapid and stable switching of the main power supply and the auxiliary power supply is realized.

Description

Technical Field

[0001] The present application relates to the field of emergency power supply technology, and in particular to a dual power supply switching circuit, method and emergency power supply system. Background Art

[0002] For sensitive and critical loads, power supply continuity and stability are crucial factors among the many factors that influence power quality. For example, some military and defense departments provide two single-phase power supplies to critical loads. During power switching, the system must maintain a power interruption time of less than 4ms. Furthermore, the system must accurately identify power anomalies and rapidly switch power even under poor power quality conditions.

[0003] In related technologies, dual-power switching time can be divided into two parts: the first is the fault determination time; the second is the actuator action time. When fault determination is performed on power supplies experiencing frequency fluctuations, voltage fluctuations, phase jumps, or high levels of harmonics, existing single-phase voltage amplitude anomaly determination methods, such as the voltage peak method, Fourier transform, wavelet transform, dq transform (Direct-Quadrature-Zero Transform), and pqr transform, suffer from insufficient accuracy and real-time performance. Furthermore, current dual-power switching switches mostly use traditional mechanical switches or thyristor switches.

[0004] However, mechanical circuit breakers operate at speeds of tens of milliseconds or even seconds due to structural limitations. Using high-speed bidirectional thyristors as actuators can result in total response times exceeding the 8ms switching delay due to their reverse shutdown time, making them unable to meet the uninterrupted power supply requirements of some critical single-phase loads. Summary of the Invention

[0005] The present application provides a dual power switching circuit, method and emergency power supply system to solve the problems of slow dual power switching and inaccurate fault judgment in related technologies, and to achieve fast and smooth switching between main and auxiliary power supplies.

[0006] A first embodiment of the present application provides a dual power switching circuit, comprising: a control and detection system, a first switch component, and a second switch component, wherein:

[0007] The first end of the first switch assembly is connected to a first AC power source, the second end of the first switch assembly is connected to a second AC power source, the third to fifth ends of the first switch assembly are connected to the first to third ends of the second switch assembly, respectively, and the sixth end of the first switch assembly is connected to a load;

[0008] The control and detection system is respectively connected to the first AC power supply, the second AC power supply, the first switch assembly and the second switch assembly, and is used to determine the target switching state of the second switch assembly based on the first fundamental voltage amplitude determined by the first AC power supply and the second fundamental voltage amplitude determined by the second AC power supply, and when the second switch assembly is in a fault state, switch to the first switch assembly to power the load.

[0009] Optionally, the second switch assembly includes: a first power electronic switch, a second power electronic switch and a drive protection circuit, wherein:

[0010] The first power electronic switch includes: a first IGBT, a first diode, a second IGBT, and a second diode, wherein the drain of the first IGBT is connected to the cathode of the first diode, the source of the first IGBT is connected to the drain of the second IGBT, the source of the second IGBT is connected to the anode of the second diode, and the cathode of the second diode is connected to the anode of the first diode;

[0011] The second power electronic switch includes: a third IGBT, a third diode, a fourth IGBT and a fourth diode, the source of the third IGBT is connected to the anode of the third diode, the drain of the third IGBT is connected to the source of the fourth IGBT, the drain of the fourth IGBT is connected to the cathode of the fourth diode, and the cathode of the third diode is connected to the anode of the fourth diode;

[0012] The cathode of the third diode is connected to the connection node between the anode of the fourth diode, the cathode of the second diode, and the anode of the first diode, respectively.

[0013] Optionally, the first switch assembly includes: a first incoming switch, a second incoming switch, a first bypass switch, a second bypass switch and an outgoing switch, wherein:

[0014] One end of the first incoming line switch is connected to the output end of the first AC power supply, and the other end of the first incoming line switch is connected to a connection node between the source of the first IGBT and the drain of the second IGBT;

[0015] One end of the second incoming line switch is connected to the output end of the second AC power supply, and the other end of the second incoming line switch is connected to the connection node between the drain of the third IGBT and the source of the fourth IGBT;

[0016] One end of the first bypass switch is connected to one end of the first incoming line switch, and the other end of the first bypass switch is connected to the load;

[0017] One end of the second bypass switch is connected to one end of the second incoming line switch, and the other end of the second bypass switch is connected to the load;

[0018] One end of the outgoing line switch is connected to a connection node between the first power electronic switch and the second power electronic switch, and the other end of the outgoing line switch is connected to the load.

[0019] Optionally, the control and detection system includes:

[0020] an extraction unit, configured to extract a first fundamental voltage of the first AC power supply and a second fundamental voltage of the second AC power supply based on a frequency adaptive biquad generalized integrator frequency locked loop strategy, and extract a third fundamental voltage of the first AC power supply and a fourth fundamental voltage of the second AC power supply after a preset delay angle;

[0021] a calculation unit, configured to obtain the first fundamental voltage amplitude according to the first fundamental voltage and the third fundamental voltage, and to obtain the second fundamental voltage amplitude according to the second fundamental voltage and the fourth fundamental voltage;

[0022] a first control unit, configured to control the first power electronic switch to be disconnected when the first AC power supply is determined to be abnormal based on the first fundamental voltage amplitude; to control the second power electronic switch to be disconnected when the second AC power supply is determined to be abnormal based on the second fundamental voltage amplitude; to control the second power electronic switch to be disconnected when the first AC power supply is a main power supply and the second AC power supply is a backup power supply, and the first AC power supply is determined to be normal based on the first fundamental voltage amplitude, and to control the second power electronic switch to be disconnected, and to control the first power electronic switch to be connected after a delay of a first preset time or a setting of a first phase angle of the first AC power supply; and to control the first power electronic switch to be disconnected when the first AC power supply is a backup power supply and the second AC power supply is a main power supply, and the second AC power supply is determined to be normal based on the second fundamental voltage amplitude, and to control the second power electronic switch to be connected after a delay of a second preset time or a setting of a second phase angle of the second AC power supply.

[0023] Optionally, the control and detection system includes:

[0024] a second control unit, configured to, when it is determined based on the first power electronic switch state information that the first power electronic switch state is abnormal, control the first power electronic switch and the second bypass switch to be disconnected, and control the first bypass switch to be opened; and, when it is determined based on the second power electronic switch state information that the second power electronic switch state is abnormal, control the second power electronic switch and the first bypass switch to be disconnected, and control the second bypass switch to be opened.

[0025] Optionally, the control and detection system further includes:

[0026] The absorption snubber circuit is used to absorb overvoltage and overcurrent generated during the switching process of power electronic switches.

[0027] Optionally, the dual power switching circuit further includes:

[0028] A human-computer interaction system is connected to the control and detection system and is used to complete parameter setting of the control and detection system.

[0029] A second embodiment of the present application provides an emergency power supply system, including: a dual power supply switching circuit as described in any one of the above items.

[0030] A third aspect of the present application provides a dual power switching method, using any of the above-described dual power switching circuits, including the following steps:

[0031] Obtaining a first fundamental voltage amplitude determined by the first AC power source and a second fundamental voltage amplitude determined by the second AC power source;

[0032] The target switching state of the second switch component is determined according to the first fundamental voltage amplitude and the second fundamental voltage amplitude, and when the second switch component is in a fault state, the first switch component is switched to supply power to the load.

[0033] Optionally, obtaining a first fundamental voltage amplitude determined by the first AC power source and a second fundamental voltage amplitude determined by the second AC power source includes:

[0034] Extracting a first fundamental voltage of the first AC power supply and a second fundamental voltage of the second AC power supply based on a frequency adaptive biquad generalized integrator frequency locked loop strategy;

[0035] After a preset delay angle, extracting the third fundamental voltage of the first AC power supply and the fourth fundamental voltage of the second AC power supply;

[0036] The first fundamental voltage amplitude is obtained according to the first fundamental voltage and the third fundamental voltage, and the second fundamental voltage amplitude is obtained according to the second fundamental voltage and the fourth fundamental voltage.

[0037] Optionally, determining the target switching state of the second switch component according to the first fundamental voltage amplitude and the second fundamental voltage amplitude includes:

[0038] When it is determined that the first AC power source is abnormal based on the first fundamental voltage amplitude, controlling the first power electronic switch to be disconnected;

[0039] When it is determined that the second AC power supply is abnormal based on the second fundamental voltage amplitude, controlling the second power electronic switch to be disconnected;

[0040] When the first AC power source is a main power source and the second AC power source is a backup power source, and the first AC power source is determined to be normal based on the first fundamental voltage amplitude, controlling the second power electronic switch to be off, and controlling the first power electronic switch to be on after delaying for a first preset time or setting a first phase angle of the first AC power source;

[0041] When the first AC power source is a backup power source and the second AC power source is a main power source, and the second AC power source is determined to be normal based on the second fundamental voltage amplitude, the first power electronic switch is controlled to be disconnected, and after a delay of a second preset time or a setting of a second phase angle of the second AC power source, the second power electronic switch is controlled to be turned on.

[0042] Optionally, determining the target switching state of the second switch component according to the first fundamental voltage amplitude and the second fundamental voltage amplitude includes:

[0043] When it is determined that the state of the first power electronic switch is abnormal based on the first power electronic switch state information, the first power electronic switch and the second bypass switch are controlled to be disconnected, and the first bypass switch is controlled to be opened; when it is determined that the state of the second power electronic switch is abnormal based on the second power electronic switch state information, the second power electronic switch and the first bypass switch are controlled to be disconnected, and the second bypass switch is controlled to be opened.

[0044] Optionally, the dual power switching method further includes:

[0045] The overvoltage and overcurrent generated during the switching process of the power electronic switch are absorbed by the absorption buffer circuit.

[0046] Optionally, the dual power switching method further includes:

[0047] The parameter setting of the control and detection system is completed through the human-computer interaction system.

[0048] Thus, the first end of the first switch assembly is connected to the first AC power source, the second end of the first switch assembly is connected to the second AC power source, the third to fifth ends of the first switch assembly are respectively connected to the first to third ends of the second switch assembly, and the sixth end of the first switch assembly is connected to the load. The control and detection system is respectively connected to the first AC power source, the second AC power source, the first switch assembly, and the second switch assembly, and is used to determine the target switching state of the second switch assembly based on the first fundamental voltage amplitude determined by the first AC power source and the second fundamental voltage amplitude determined by the second AC power source, and when the second switch assembly is in a fault state, switch to the first switch assembly to power the load. This solves the problems of slow dual power supply switching and inaccurate fault judgment in the related art, and achieves fast and smooth switching between the main and auxiliary power supplies.

[0049] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0051] Figure 1 1 is a block diagram of a dual power switching circuit provided according to an embodiment of the present application;

[0052] Figure 2 A schematic diagram of a dual power switching circuit according to an embodiment of the present application;

[0053] Figure 3 This is an electrical schematic diagram of a main circuit of a dual power switching circuit provided according to one embodiment of the present application;

[0054] Figure 4 A schematic diagram of a fundamental voltage detection method for a dual power switching circuit according to an embodiment of the present application;

[0055] Figure 5 A schematic diagram of a method for calculating the fundamental wave amplitude of a dual-power switching circuit according to one embodiment of the present application;

[0056] Figure 6 This is a control flow chart of a dual power switching circuit provided according to one embodiment of the present application;

[0057] Figure 7 This is a flowchart of a dual power switching circuit provided according to one embodiment of the present application;

[0058] Figure 8 The figure is a flow chart of a dual power switching method provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0059] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0060] The following describes a dual power switching circuit, method, and emergency power supply system according to an embodiment of the present application with reference to the accompanying drawings. In response to the problems of slow dual power switching and inaccurate fault judgment in the related art mentioned in the background technology above, the present application provides a dual power switching circuit, comprising: a control and detection system, a first switch component, and a second switch component, wherein the first end of the first switch component is connected to the first AC power source, the second end of the first switch component is connected to the second AC power source, the third to fifth ends of the first switch component are respectively connected to the first to third ends of the second switch component, and the sixth end of the first switch component is connected to the load; the control and detection system is respectively connected to the first AC power source, the second AC power source, the first switch component, and the second switch component, and is configured to determine the target switching state of the second switch component based on the first fundamental voltage amplitude determined by the first AC power source and the second fundamental voltage amplitude determined by the second AC power source, and when the second switch component is in a fault state, switch to the first switch component to supply power to the load. Thus, the problems of slow dual power switching and inaccurate fault judgment in the related art are solved, and the main and auxiliary power supplies are switched quickly and smoothly.

[0061] Specifically, Figure 1 A block diagram of a dual power switching circuit provided in an embodiment of the present application.

[0062] like Figure 1 As shown, the dual power switching circuit 10 includes: a control and detection system 100 , a first switch component 200 and a second switch component 300 .

[0063] In which, the first end of the first switch assembly 200 is connected to the first AC power supply 400, the second end of the first switch assembly 200 is connected to the second AC power supply 500, the third to fifth ends of the first switch assembly 200 are respectively connected to the first to third ends of the second switch assembly 300, and the sixth end of the first switch assembly 200 is connected to the load 600; the control and detection system 100 is respectively connected to the first AC power supply 400, the second AC power supply 500, the first switch assembly 200 and the second switch assembly 300, and is used to determine the target switching state of the second switch assembly 300 based on the first fundamental voltage amplitude determined by the first AC power supply 400 and the second fundamental voltage amplitude determined by the second AC power supply 500, and when the second switch assembly 300 is in a fault state, switch to the first switch assembly 200 to power the load 600.

[0064] The target switch state is an ideal working state set by the control and detection system 100 for the second switch component 300 according to the power state and the fault judgment result.

[0065] Specifically, through the coordinated work of the first switch component 200, the second switch component 300 and the control and detection system 100, the control and detection system 100 can quickly and accurately determine power failures by monitoring the power status and switch status in real time, and switch to the first switch component 200 for power supply when the second switch component 300 fails, thereby achieving rapid and smooth switching between dual power supplies and ensuring continuous power supply to the load 600.

[0066] Optionally, in some embodiments, the second switch component 300 includes: a first power electronic switch, a second power electronic switch and a drive protection circuit, wherein the first power electronic switch includes: a first IGBT, a first diode, a second IGBT and a second diode, the drain of the first IGBT is connected to the cathode of the first diode, the source of the first IGBT is connected to the drain of the second IGBT, the source of the second IGBT is connected to the anode of the second diode, and the cathode of the second diode is connected to the anode of the first diode; the second power electronic switch includes: a third IGBT, a third diode, a fourth IGBT and a fourth diode, the source of the third IGBT is connected to the anode of the third diode, the drain of the third IGBT is connected to the source of the fourth IGBT, the drain of the fourth IGBT is connected to the cathode of the fourth diode, and the cathode of the third diode is connected to the anode of the fourth diode; the cathode of the third diode is respectively connected to the connection nodes between the anode of the fourth diode, the cathode of the second diode and the anode of the first diode.

[0067] It is understandable that if Figure 2 As shown, Figure 2This is a schematic diagram of a dual power switching circuit according to an embodiment of the present application, comprising a control and detection system 100, a human-computer interaction system, a power electronic switch (i.e., a first switch component 200), and a mechanical switch (i.e., a second switch component 300). The control and detection system 100 collects real-time data on the input voltage of two AC power supplies and the output voltage and current data of the switching switch, monitors the status information of the power electronic switch and the mechanical switch in real time, and analyzes the data for fault diagnosis, thereby realizing the switching action of the power electronic switch and the mechanical switch; the human-computer interaction system completes functions such as parameter setting, data and status feedback of the control system and the detection system; the first switch component 200 is composed of an IGBT, a diode, and a corresponding drive protection circuit to realize rapid switching of the power supply circuit; and the second switch component 300 performs electrical isolation and bypass switching of the power supply after a power electronic switch fault.

[0068] Optionally, in some embodiments, the first switch assembly 200 includes: a first incoming switch, a second incoming switch, a first bypass switch, a second bypass switch and an outgoing switch, wherein one end of the first incoming switch is connected to the output end of the first AC power supply 400, and the other end of the first incoming switch is connected to the connection node between the source of the first IGBT and the drain of the second IGBT; one end of the second incoming switch is connected to the output end of the second AC power supply 500, and the other end of the second incoming switch is connected to the connection node between the drain of the third IGBT and the source of the fourth IGBT; one end of the first bypass switch is connected to one end of the first incoming switch, and the other end of the first bypass switch is connected to the load 600; one end of the second bypass switch is connected to one end of the second incoming switch, and the other end of the second bypass switch is connected to the load 600; one end of the outgoing switch is connected to the connection node between the first power electronic switch and the second power electronic switch, and the other end of the outgoing switch is connected to the load 600.

[0069] Optionally, in some embodiments, the control and detection system 100 further includes: an absorption buffer circuit for absorbing overvoltage and overcurrent generated during the switching process of the power electronic switch.

[0070] It is understandable that if Figure 3 As shown, Figure 3This is an electrical schematic diagram of the main circuit of a dual power switching circuit according to one embodiment of the present application. K1 is the first incoming line switch, K2 is the second incoming line switch, K3 is the first bypass switch, K4 is the second bypass switch, and K5 is the outgoing line switch. The mechanical switches K3 and K4 are interlocked and cannot be opened simultaneously. R1 and C1 are connected in series to form the absorption and snubber circuit of the first AC power source 400, R2 and C2 are connected in series to form the absorption and snubber circuit of the second AC power source 500, and R3 and C3 are connected in series to form the output-side absorption and snubber circuit of the first switch assembly 200. Q1-Q4 are IGBT devices, and D1-D4 are diode devices. Q1 and D1 are connected in reverse series to form a loop, Q2 and D2 are connected in reverse series to form a loop, and the two loops are connected in reverse parallel to form the power electronic switch of the first AC power source 400. Q3 and D3 are connected in reverse series to form a loop, and Q4 and D4 are connected in reverse series to form a loop, and the two loops are connected in reverse parallel to form the power electronic switch of the second AC power source 500. The input side of K5 is connected to the output side of the power electronic switch, and the output side of K5 is connected to the load 600. The phase line L1 of the first AC power source 400 is connected to K1 and K3 respectively, and the phase line L2 of the second AC power source 500 is connected to the mechanical switches K2 and K4 respectively. The neutral line N of the first AC power source 400 and the second AC power source 500 are simultaneously connected to the load 600.

[0071] Optionally, in some embodiments, the control and detection system 100 includes: an extraction unit for extracting the first fundamental voltage of the first AC power supply 400 and the second fundamental voltage of the second AC power supply 500 based on a frequency adaptive dual second-order generalized integrator frequency locked loop strategy, and extracting the third fundamental voltage of the first AC power supply 400 and the fourth fundamental voltage of the second AC power supply 500 after a preset delay angle; a calculation unit for obtaining a first fundamental voltage amplitude according to the first fundamental voltage and the third fundamental voltage, and obtaining a second fundamental voltage amplitude according to the second fundamental voltage and the fourth fundamental voltage; a first control unit for controlling the first power electronic switch to disconnect when it is determined that the first AC power supply 400 is abnormal based on the first fundamental voltage amplitude; and when it is determined that the first AC power supply 400 is abnormal based on the second fundamental voltage amplitude. When the amplitude determines that the second AC power supply 500 is abnormal, the second power electronic switch is controlled to be disconnected; when the first AC power supply 400 is the main power supply and the second AC power supply 500 is the backup power supply, and the first AC power supply 400 is determined to be normal based on the first fundamental voltage amplitude, the second power electronic switch is controlled to be disconnected, and after delaying for a first preset time or setting a first phase angle of the first AC power supply 400, the first power electronic switch is controlled to be opened; when the first AC power supply 400 is the backup power supply and the second AC power supply 500 is the main power supply, and the second AC power supply 500 is determined to be normal based on the second fundamental voltage amplitude, the first power electronic switch is controlled to be disconnected, and after delaying for a second preset time or setting a second phase angle of the second AC power supply 500, the second power electronic switch is controlled to be opened.

[0072] Optionally, in some embodiments, the control and detection system 100 includes: a second control unit, configured to control the first power electronic switch and the second bypass switch to be disconnected, and control the first bypass switch to be opened, when it is determined that the state of the first power electronic switch is abnormal based on the first power electronic switch state information; and to control the second power electronic switch and the first bypass switch to be disconnected, and control the second bypass switch to be opened, when it is determined that the state of the second power electronic switch is abnormal based on the second power electronic switch state information.

[0073] Among them, the first preset time length, the second preset time length, the first phase angle and the second phase angle can be thresholds set in advance by the user, can be thresholds obtained through a limited number of experiments, or can be thresholds obtained through a limited number of computer simulations, and are not specifically limited here.

[0074] Specifically, the system extracts the fundamental voltages of the two AC power sources based on a frequency-adaptive dual-second-order generalized integrator frequency-locked loop strategy and extracts the fundamental voltages again after a preset delay to avoid harmonic interference. The fundamental voltage amplitudes of the two AC power sources are calculated based on the extracted fundamental voltages. If the fundamental voltage amplitude of one power source is abnormal, the corresponding power electronic switch is disconnected. The system monitors the status of the two AC power sources in real time and controls the on / off of the power electronic switches based on the configuration of the primary and backup power sources and the normal fundamental voltage amplitudes. Switching is completed after a set delay or phase angle, ensuring smoothness and stability in the primary and backup power source switching process and preventing impacts on load 600. A second control unit is primarily used to perform corresponding protection operations when the power electronic switch status is abnormal, including disconnecting the abnormal power electronic switch and controlling the on / off of the bypass switch to ensure continuous power supply to load 600. This fast response and high reliability design improves the safety and stability of the system.

[0075] It is understandable that if Figures 4 to 6 As shown, Figure 4 This is a schematic diagram of a fundamental voltage detection method for a dual-power switching circuit according to an embodiment of the present application. The fundamental voltage component is obtained through the transfer function G1(s), and the orthogonal component of the fundamental voltage is obtained through the transfer function G2(s). The phase angle of the fundamental voltage is calculated from the fundamental voltage component and the orthogonal component of the fundamental voltage. The frequency is adaptively adjusted by a given reference angular frequency and an error transfer function to obtain the fundamental voltage angular frequency.

[0076]

[0077]

[0078] Among them, u is the power supply voltage signal of the sampling detection, x1 is the fundamental voltage component, k is the proportional coefficient, s is the Lagrangian operator, V is the fundamental voltage amplitude, is the initial phase of the fundamental wave, x2 is the orthogonal component of the fundamental wave voltage, θ is the phase angle of the fundamental wave voltage, ω c is the given reference angular frequency, E(s) is the error transfer function, e(s) is the error function, and ω′ is the fundamental voltage angular frequency.

[0079] Figure 5 This is a schematic diagram of a method for calculating the fundamental amplitude of a dual power switching circuit according to an embodiment of the present application; according to the fundamental voltage component x1, the phase angle difference δ is given by the two-point sampling interval time requirement, and its sine value and cosine value are calculated, and the delay Δt is used to obtain x 1′ Substitute into the formula to calculate the fundamental voltage amplitude V.

[0080]

[0081] Δt=δ / ω′;

[0082]

[0083] Among them, Δt is the delay time, δ is the phase angle difference, x1 is the fundamental voltage component sampled at the first point, and x 1′ is the fundamental voltage component sampled at the second point after the delay, V is the fundamental voltage amplitude, z -k For the delay link.

[0084] Furthermore, if Figure 6 As shown, Figure 6This is a control flow chart of a dual power switching circuit according to an embodiment of the present application, wherein power supply 1 is a first AC power supply 400, power supply 2 is a second AC power supply 500, power supply IGBT 1 is a first power electronic switch, power supply IGBT 2 is a second power electronic switch, power supply bypass switch 1 is a first bypass switch, and power supply bypass switch 2 is a second bypass switch; the input voltages of the first AC power supply 400 and the second AC power supply 500 are sampled in real time, and the voltage fundamental waveform signals are extracted by the frequency adaptive second-order generalized integrator frequency locked loop with zero phase shift, while the power supply voltage fundamental frequency and phase are tracked in real time; the phase difference angle of the voltage waveforms at two points is set according to the sampling interval requirement, the current voltage fundamental wave data is obtained by the extracted voltage fundamental wave waveform signal, the voltage fundamental wave data at the second point is obtained after the phase difference angle is delayed, and the voltage is divided into the following steps: The voltage fundamental amplitudes of the first AC power supply 400 and the second AC power supply 500 are calculated separately; the first AC power supply 400 and the second AC power supply 500 are defined as primary and backup through settings, with the primary power supply having a high priority; the primary power supply determines in real time whether the voltage fundamental amplitude meets the power supply demand, and if so, turns off the backup power electronic switch and turns on the primary power electronic switch; if not, determines whether the backup power supply meets the power supply demand, and if so, turns off the primary power electronic switch and turns on the backup power electronic switch; if the voltage fundamental amplitudes of both the primary and backup power supplies do not meet the power supply demand, the dual power switching device alarms; the status information of the power electronic switch and the mechanical switch is monitored in real time, and if the power electronic switch of the power supply circuit fails, the power electronic switch of its own power supply is promptly turned off, and the mechanical bypass switch of the corresponding circuit is activated. The dual power switching device monitors the output voltage of the power electronic switch, that is, the load 600 input voltage, in real time. During the switching of the power electronic switch, it can delay the set fixed time for fast switching, or it can switch at the phase angle point set by the power supply according to the requirements of different load types, and can achieve zero voltage, zero current and other state switching.

[0085] Optionally, in some embodiments, Figure 2 As shown, the dual power switching circuit 10 further includes a human-computer interaction system, wherein the human-computer interaction system is connected to the control and detection system 100 and is used to complete parameter setting of the control and detection system 100 .

[0086] As can be appreciated, the human-computer interaction system significantly improves the operability and maintenance ease of the dual-power switching circuit 10 through its structured parameter configuration interface and real-time status visualization. Its modular design also allows for flexible configuration based on actual application requirements, facilitating user operation and monitoring. Through the human-computer interaction system, users can easily adjust the device's operating parameters, view the power input and output status in real time, and obtain various system operation information, ensuring a secure and stable power supply.

[0087] In order to facilitate those skilled in the art to further understand the dual power switching circuit of the embodiment of the present application, the following takes the dual power switching method as an example, combined with Figure 7 The illustrated embodiment is described in detail.

[0088] S701: Real-time acquisition of two-way AC power input voltage data and switch output voltage data, and real-time monitoring of power electronic switch and mechanical switch status information;

[0089] S702: The voltage fundamental wave signals of the two input voltage data are extracted by using a frequency-adaptive second-order generalized integrator frequency-locked loop to obtain two-point waveform data, and the amplitude, phase angle, and frequency of the two fundamental wave voltages are calculated respectively;

[0090] S703: Based on the preset parameter indicators, determine the fault status such as undervoltage, overvoltage, power failure, etc. through the fundamental voltage amplitude;

[0091] S704: The two power supplies are preset as the main power supply and the backup power supply, respectively. If the fundamental voltage amplitude of the main power supply meets the requirements, the main power supply will be used for power supply. If it does not meet the requirements and the fundamental voltage amplitude of the backup power supply meets the requirements, the backup power supply will be used for power supply. If both do not meet the requirements, the dual power supply switch device will alarm.

[0092] S705: The power supply switching process is as follows: first, the power electronic switch of the power supply that does not need power supply is turned off, and according to the preset switching mode, the fixed time delay or the power phase angle setting point is applied, and the power electronic switch of the power supply that needs power supply is turned on to supply power from the corresponding power supply;

[0093] S706: Detect the output voltage and current of the switch in real time, and monitor the operating status of the power electronic switch of the current power supply. If the power electronic switch works abnormally, switch to the corresponding mechanical bypass switch to bypass power supply.

[0094] Therefore, the dual power switching circuit of the embodiment of the present application adopts IGBT to realize power supply circuit switching, and its switching speed can reach microsecond level, which is much faster than mechanical switch and thyristor switch (ms level), and can realize millisecond or even microsecond switching between dual power supplies. In addition, IGBT has low conduction voltage drop and switching loss, long service life, and is suitable for frequent switching scenarios. The embodiment of the present application adopts a frequency-adaptive second-order generalized integrator frequency-locked loop to extract the power supply voltage fundamental signal, and calculates the voltage fundamental amplitude through a single-phase voltage two-point detection method; when a serious power quality problem occurs in the single-phase power supply voltage, the amplitude of the fundamental voltage signal can be obtained quickly and accurately, and fault judgments such as undervoltage, overvoltage, and power failure can be made. The delay time can be less than 1ms, meeting the requirements of accuracy and real-time performance; at the same time, the quality of the power supply power can be analyzed and evaluated, including harmonics, voltage deviation, frequency deviation, etc. The dual power switching circuit of the embodiment of the present application uses power electronic switches and mechanical switches to form a hybrid switch main circuit, ensuring the real-time and reliability of the system; the power supply switching mode can be selected according to the load type, and zero voltage, zero current and other state switching can be achieved, reducing the impact of power failure and switching process on the load working conditions, and further improving the switching stability of the dual power switching equipment.

[0095] According to the dual power switching circuit proposed in the embodiment of the present application, the first end of the first switch component is connected to the first AC power source, the second end of the first switch component is connected to the second AC power source, the third to fifth ends of the first switch component are respectively connected to the first to third ends of the second switch component, and the sixth end of the first switch component is connected to the load; the control and detection system is respectively connected to the first AC power source, the second AC power source, the first switch component, and the second switch component, and is used to determine the target switching state of the second switch component based on the first fundamental voltage amplitude determined by the first AC power source and the second fundamental voltage amplitude determined by the second AC power source, and when the second switch component is in a fault state, switch to the first switch component to power the load. This solves the problems of slow dual power switching speed and inaccurate fault judgment in the related art, and realizes fast and smooth switching between the main and auxiliary power supplies.

[0096] An embodiment of the present application also provides an emergency power supply system, comprising any of the above-mentioned dual power supply switching circuits.

[0097] Next, a dual power switching method proposed according to an embodiment of the present application is described with reference to the accompanying drawings, using any of the above-mentioned dual power switching circuits.

[0098] Figure 8 Flowchart of the dual power switching method according to an embodiment of the present application.

[0099] like Figure 8 As shown, the dual power switching method includes the following steps:

[0100] In step S801 , a first fundamental voltage amplitude determined by a first AC power source and a second fundamental voltage amplitude determined by a second AC power source are acquired.

[0101] In step S802, the target switching state of the second switch component is determined according to the first fundamental voltage amplitude and the second fundamental voltage amplitude, and when the second switch component is in a fault state, the first switch component is switched to supply power to the load.

[0102] Optionally, in some embodiments, obtaining a first fundamental voltage amplitude determined by the first AC power supply and a second fundamental voltage amplitude determined by the second AC power supply includes: extracting the first fundamental voltage of the first AC power supply and the second fundamental voltage of the second AC power supply based on a frequency-adaptive dual-second-order generalized integrator frequency-locked loop strategy; extracting the third fundamental voltage of the first AC power supply and the fourth fundamental voltage of the second AC power supply after a preset delay angle; obtaining the first fundamental voltage amplitude based on the first fundamental voltage and the third fundamental voltage, and obtaining the second fundamental voltage amplitude based on the second fundamental voltage and the fourth fundamental voltage.

[0103] Optionally, in some embodiments, the target switching state of the second switch component is determined based on the first fundamental voltage amplitude and the second fundamental voltage amplitude, including: when the first AC power supply is determined to be abnormal based on the first fundamental voltage amplitude, controlling the first power electronic switch to be disconnected; when the second AC power supply is determined to be abnormal based on the second fundamental voltage amplitude, controlling the second power electronic switch to be disconnected; when the first AC power supply is the main power supply, the second AC power supply is the backup power supply, and the first AC power supply is determined to be normal based on the first fundamental voltage amplitude, controlling the second power electronic switch to be disconnected, and after delaying for a first preset time or setting a first phase angle of the first AC power supply, controlling the first power electronic switch to be turned on; when the first AC power supply is the backup power supply, the second AC power supply is the main power supply, and when the second AC power supply is determined to be normal based on the second fundamental voltage amplitude, controlling the first power electronic switch to be disconnected, and after delaying for a second preset time or setting a second phase angle of the second AC power supply, controlling the second power electronic switch to be turned on.

[0104] Optionally, in some embodiments, the target switch state of the second switch component is determined based on the first fundamental voltage amplitude and the second fundamental voltage amplitude, including: when the state of the first power electronic switch is determined to be abnormal based on the first power electronic switch state information, controlling the first power electronic switch and the second bypass switch to be disconnected, and controlling the first bypass switch to be opened; when the state of the second power electronic switch is determined to be abnormal based on the second power electronic switch state information, controlling the second power electronic switch and the first bypass switch to be disconnected, and controlling the second bypass switch to be opened.

[0105] Optionally, in some embodiments, the dual power switching method further includes: absorbing overvoltage and overcurrent generated during the switching process of the power electronic switch by an absorption buffer circuit.

[0106] Optionally, in some embodiments, the dual power switching method further includes: completing parameter setting of the control and detection system through a human-computer interaction system.

[0107] It should be noted that the aforementioned explanation of the dual power switching circuit embodiment is also applicable to the dual power switching method of this embodiment, and will not be repeated here.

[0108] The dual power switching method proposed in an embodiment of the present application obtains a first fundamental voltage amplitude determined by a first AC power source and a second fundamental voltage amplitude determined by a second AC power source; determines the target switching state of the second switch component based on the first and second fundamental voltage amplitudes; and switches to the first switch component to supply power to the load when the second switch component is in a faulty state. This solves the problems of slow dual power switching and inaccurate fault diagnosis in related technologies, achieving fast and smooth switching between the primary and secondary power sources.

[0109] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0110] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0111] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0112] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0113] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

Claims

1. A dual power switching circuit, characterized in that: include: A control and detection system, a first switch component and a second switch component, wherein: The first end of the first switch assembly is connected to a first AC power source, the second end of the first switch assembly is connected to a second AC power source, the third to fifth ends of the first switch assembly are connected to the first to third ends of the second switch assembly, respectively, and the sixth end of the first switch assembly is connected to a load; The control and detection system is respectively connected to the first AC power supply, the second AC power supply, the first switch assembly and the second switch assembly, and is used to determine the target switching state of the second switch assembly based on the first fundamental voltage amplitude determined by the first AC power supply and the second fundamental voltage amplitude determined by the second AC power supply, and when the second switch assembly is in a fault state, switch to the first switch assembly to power the load.

2. The dual power switching circuit according to claim 1, wherein: The second switch assembly includes: a first power electronic switch, a second power electronic switch and a drive protection circuit, wherein: The first power electronic switch includes: a first IGBT, a first diode, a second IGBT, and a second diode, wherein the drain of the first IGBT is connected to the cathode of the first diode, the source of the first IGBT is connected to the drain of the second IGBT, the source of the second IGBT is connected to the anode of the second diode, and the cathode of the second diode is connected to the anode of the first diode; The second power electronic switch includes: a third IGBT, a third diode, a fourth IGBT and a fourth diode, the source of the third IGBT is connected to the anode of the third diode, the drain of the third IGBT is connected to the source of the fourth IGBT, the drain of the fourth IGBT is connected to the cathode of the fourth diode, and the cathode of the third diode is connected to the anode of the fourth diode; The cathode of the third diode is connected to the connection node between the anode of the fourth diode, the cathode of the second diode, and the anode of the first diode, respectively.

3. The dual power switching circuit according to claim 2, wherein: The first switch assembly includes: a first incoming switch, a second incoming switch, a first bypass switch, a second bypass switch and an outgoing switch, wherein: One end of the first incoming line switch is connected to the output end of the first AC power supply, and the other end of the first incoming line switch is connected to a connection node between the source of the first IGBT and the drain of the second IGBT; One end of the second incoming line switch is connected to the output end of the second AC power supply, and the other end of the second incoming line switch is connected to the connection node between the drain of the third IGBT and the source of the fourth IGBT; One end of the first bypass switch is connected to one end of the first incoming line switch, and the other end of the first bypass switch is connected to the load; One end of the second bypass switch is connected to one end of the second incoming line switch, and the other end of the second bypass switch is connected to the load; One end of the outgoing line switch is connected to a connection node between the first power electronic switch and the second power electronic switch, and the other end of the outgoing line switch is connected to the load.

4. The dual power switching circuit according to claim 3, wherein: The control and detection system comprises: an extraction unit, configured to extract a first fundamental voltage of the first AC power supply and a second fundamental voltage of the second AC power supply based on a frequency adaptive biquad generalized integrator frequency locked loop strategy, and extract a third fundamental voltage of the first AC power supply and a fourth fundamental voltage of the second AC power supply after a preset delay angle; a calculation unit, configured to obtain the first fundamental voltage amplitude according to the first fundamental voltage and the third fundamental voltage, and to obtain the second fundamental voltage amplitude according to the second fundamental voltage and the fourth fundamental voltage; a first control unit, configured to control the first power electronic switch to be disconnected when the first AC power supply is determined to be abnormal based on the first fundamental voltage amplitude; to control the second power electronic switch to be disconnected when the second AC power supply is determined to be abnormal based on the second fundamental voltage amplitude; to control the second power electronic switch to be disconnected when the first AC power supply is a main power supply and the second AC power supply is a backup power supply, and the first AC power supply is determined to be normal based on the first fundamental voltage amplitude, and to control the second power electronic switch to be disconnected, and to control the first power electronic switch to be connected after a delay of a first preset time or a setting of a first phase angle of the first AC power supply; and to control the first power electronic switch to be disconnected when the first AC power supply is a backup power supply and the second AC power supply is a main power supply, and the second AC power supply is determined to be normal based on the second fundamental voltage amplitude, and to control the second power electronic switch to be connected after a delay of a second preset time or a setting of a second phase angle of the second AC power supply.

5. The dual power switching circuit according to claim 4, wherein: The control and detection system comprises: a second control unit, configured to, when it is determined based on the first power electronic switch state information that the first power electronic switch state is abnormal, control the first power electronic switch and the second bypass switch to be disconnected, and control the first bypass switch to be opened; and, when it is determined based on the second power electronic switch state information that the second power electronic switch state is abnormal, control the second power electronic switch and the first bypass switch to be disconnected, and control the second bypass switch to be opened.

6. The dual power switching circuit according to claim 1, wherein: The control and detection system further includes: The absorption snubber circuit is used to absorb overvoltage and overcurrent generated during the switching process of power electronic switches.

7. The dual power switching circuit according to claim 1, wherein: Also includes: A human-computer interaction system is connected to the control and detection system and is used to complete parameter setting of the control and detection system.

8. An emergency power supply system, characterized in that: include: The dual power switching circuit according to any one of claims 1 to 7.

9. A dual power switching method, characterized in that: The method comprises the following steps: Obtaining a first fundamental voltage amplitude determined by the first AC power source and a second fundamental voltage amplitude determined by the second AC power source; The target switching state of the second switch component is determined according to the first fundamental voltage amplitude and the second fundamental voltage amplitude, and when the second switch component is in a fault state, the first switch component is switched to supply power to the load.

10. The dual power switching method according to claim 9, wherein: The obtaining of a first fundamental voltage amplitude determined by the first AC power source and a second fundamental voltage amplitude determined by the second AC power source includes: Extracting a first fundamental voltage of the first AC power supply and a second fundamental voltage of the second AC power supply based on a frequency adaptive biquad generalized integrator frequency locked loop strategy; After a preset delay angle, extracting the third fundamental voltage of the first AC power supply and the fourth fundamental voltage of the second AC power supply; The first fundamental voltage amplitude is obtained according to the first fundamental voltage and the third fundamental voltage, and the second fundamental voltage amplitude is obtained according to the second fundamental voltage and the fourth fundamental voltage.

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