A dual power supply switching device

Abstract

This application provides a dual-power switch switching device, comprising a main contact branch and a main thyristor branch. A main magnetic switch and a thyristor QN1 are respectively installed on the main contact branch and the main thyristor branch. A main current transformer CTN1 is installed on either the main contact branch or the main thyristor branch. A spare contact branch and a spare thyristor branch are also provided, each equipped with a spare magnetic switch and a thyristor QN2. A spare current transformer CTN2 is installed on either the spare contact branch or the spare thyristor branch. Both the main current transformer CTN1 and the spare current transformer CTN2 are connected to a contact break detection circuit. A current detection device is installed on the output side of the main power switch circuit and the spare power switch circuit. This application directly detects the line current using the current transformer in conjunction with the contact break detection circuit, accurately determining whether a break has occurred.

Description

Technical Field

[0001] This application relates to the field of switch technology, specifically to a dual-power switch switching device. Background Technology

[0002] A dual power switch is an electrical component that connects two circuits simultaneously and can switch between them. When one circuit fails, the dual power switch can switch to the other circuit to ensure that the load continues to work stably. Therefore, a dual power switch is an indispensable and important component in a power supply system.

[0003] Currently, the low-voltage field mainly adopts two types of technical solutions: mechanical transfer switches (ATS) and static transfer switches (STS). However, both have significant technical limitations. The response time of traditional ATS is usually more than 100ms, which is difficult to meet the high stability requirements of power supply for highly sensitive loads such as data centers and medical equipment. STS achieves contactless switching based on power electronic devices, but due to high manufacturing and maintenance costs and complex heat dissipation design, it is difficult to apply on a large scale in ordinary industrial and civil scenarios.

[0004] Currently, the industry is attempting to improve switching speed to the 10-30ms range by optimizing the mechanical structure of ATS (Automatic Switching System). However, this faces two major challenges: First, the natural extinguishing of the arc during contact separation still requires at least 10ms, directly limiting further reduction in switching speed. Second, in the timing of dual-power switching, accurate judgment of the main contact status is a prerequisite for ensuring reliable execution of the switching action. Existing ATSs rely on mechanical auxiliary contacts to indirectly detect the main contact status. These mechanical auxiliary contacts cannot provide synchronous feedback of the main contact status. Furthermore, under long-term vibration and temperature changes, mechanical transmission components are prone to deformation or displacement, leading to inaccurate contact position feedback signals. If the feedback is delayed, the backup power supply closing command will be delayed, resulting in a longer switching time. If the feedback is premature, the backup power supply will close prematurely, causing a short-term parallel connection between the main and backup power supplies, potentially leading to a short circuit. Therefore, unreliable feedback of the main contact status not only limits the optimization potential of switching speed but also directly threatens system operational safety, becoming a key bottleneck for achieving millisecond-level fast switching.

[0005] To solve the above-mentioned technical problems, the present invention aims to accurately determine the state of the main contacts through current detection. After searching, no relevant prior art was found.

[0006] Therefore, a new technical solution is needed to solve the above-mentioned technical problems. Summary of the Invention

[0007] This application provides a dual power supply switch switching device, including...

[0008] The main power switch circuit includes a main contact branch and a main thyristor branch arranged in parallel. A main magnetic switch is provided on the main contact branch, and a thyristor QN1 is provided on the main thyristor branch. A main current transformer CTN1 is provided on the main contact branch or the main thyristor branch. The main current transformer CTN1 is connected to a contact break detection circuit.

[0009] A backup power switch circuit includes a backup contact branch and a backup thyristor branch connected in parallel. A backup magnetic switch is provided on the backup contact branch, and a thyristor QN2 is provided on the backup thyristor branch. A backup current transformer CTN2 is provided on the backup contact branch or the backup thyristor branch, and the backup current transformer CTN2 is connected to a contact separation detection circuit.

[0010] A current detection device is installed on the output side of the main power switch circuit and the backup power switch circuit.

[0011] As a preferred embodiment, the current detection device employs an output current transformer.

[0012] As a preferred embodiment, the main power switch circuit adopts three main power switch circuits connected in parallel. Three linked main contacts QF1 are provided on the three main contact branches, and the three linked main contacts QF1 are located inside the main magnetic control switch. Thyristors QN1 are respectively provided on the three main thyristor branches, with N=A, B, and C. Main current transformers CTN1 are respectively provided on the three main contact branches or the three main thyristor branches, with N=A, B, and C.

[0013] As a preferred embodiment, the backup power switch circuit adopts three backup power switch circuits connected in parallel. Three main contacts QF2 are set on the three backup contact branches, and the three main contacts QF2 are set in the backup magnetic control switch. A thyristor QN2 is set on each of the three backup thyristor branches, and N=A, B, C. A backup current transformer CTN2 is set on each of the three backup contact branches or the three backup thyristor branches, and N=A, B, C.

[0014] As a preferred embodiment, the contact separation detection circuit includes a sampling resistor R1 connected to both ends of a thyristor CN1 or a thyristor CN2. The sampling resistor R1 is connected to an amplifier circuit, which is connected to a low-pass filter circuit one. The low-pass filter circuit one is connected to a window comparison circuit, which is connected to a low-pass filter circuit two.

[0015] As a preferred embodiment, the amplifier circuit includes a resistor R1, one end of which is connected to one end of a resistor R2, the other end of which is connected to one end of a resistor R3 and the inverting input terminal of an operational amplifier U1, the other end of which is connected to the output terminal of the operational amplifier U1, and the other end of which is connected to the non-inverting input terminal of the operational amplifier U1.

[0016] As a preferred embodiment, the low-pass filter circuit includes a resistor R4, the output terminal of the operational amplifier U1 is connected to one end of the resistor R4, the other end of the resistor R4 is connected to the window comparator circuit, and a capacitor C1 is provided between the resistor R4 and the window comparator circuit, with one end of the capacitor C1 grounded.

[0017] As a preferred embodiment, the window comparator circuit includes resistors R5, R6, R7, and R8, operational amplifiers U2.1 and U2.2. One end of resistor R4 is connected to the inverting input of operational amplifier U2.1 and the non-inverting input of operational amplifier U2.2, respectively. The non-inverting input of operational amplifier U2.1 is connected to one end of resistor R7 via a first wire, and the other end of resistor R7 is grounded. The inverting input of operational amplifier U2.2 is connected to one end of resistor R5 via a second wire, and the other end of resistor R5 is connected to the positive power supply. Resistor R6 is placed between the first and second wires. The output of operational amplifier U2.1 is connected to the anode of diode D1, and the output of operational amplifier U2.2 is connected to the anode of diode D2. The cathodes of diodes D1 and D2 are connected to a second low-pass filter circuit.

[0018] As a preferred embodiment, the low-pass filter circuit includes a resistor R8 connected to the cathodes of diodes D1 and D2. The resistor R8 is connected to the output terminal OUT via a wire three. The wire three is connected to one end of capacitor C2, and the other end of capacitor C2 is grounded.

[0019] This application has the following advantages:

[0020] 1. Compared with the traditional method that relies on the physical separation of mechanical auxiliary contacts to determine whether the contact has just broken, which has a large error, the hardware circuit directly detects the line current through a current transformer and a contact breaking detection circuit, which can accurately determine whether the contact has just broken.

[0021] 2. This dual power supply switch switching device can realize both contact break detection and current zero-crossing detection, without relying on algorithm judgment, with fast response and high reliability;

[0022] 3. Significant cost advantages: It eliminates the need for high-cost power electronic devices and high energy consumption in STS (Search Engine Technology). Performance breakthroughs are achieved through optimized mechanical switch control logic, making it suitable for large-scale industrial deployment. Attached Figure Description

[0023] Figure 1 This is the circuit diagram of this application;

[0024] Figure 2 It is a waveform diagram of the dual-power supply closing process;

[0025] Figure 3 This is the circuit diagram of the contact separation detection circuit. Attached image description:

[0027] 1. Main contact branch; 2. Main thyristor branch; 3. Spare contact branch; 4. Spare thyristor branch; 5. Wire 1; 6. Wire 2; 7. Wire 3. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1 , 2 Section 3 provides a detailed description of specific embodiments of the present invention. It should be noted that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0029] Example 1:

[0030] like Figure 1 This embodiment provides a dual power switch switching device, including:

[0031] This application provides a dual power supply switch switching device, comprising:

[0032] The main power switch circuit includes a main contact branch 1 and a main thyristor branch 2 connected in parallel. A main magnetic switch is installed on the main contact branch 1, which is a conventional magnetic switch such as an electromagnetic relay or a magnetic latching relay. A thyristor QN1 is installed on the main thyristor branch 2. A main current transformer CTN1 is installed on either the main contact branch 1 or the main thyristor branch 2. The current transformer CTN1 is connected to a contact break detection circuit. When the main current transformer CTN1 is installed on the main contact branch 1, it works with the contact break detection circuit to measure the contact current of the main power switch circuit. When the main current transformer CTN1 is installed on the main thyristor branch 2, it works with the contact break detection circuit to measure the thyristor current. Both circuits can achieve circulating current detection.

[0033] In this embodiment, the main power switch circuit includes three branches representing three-phase electricity connected in parallel, namely three main contact branches 1 and three main thyristor branches 2 connected in parallel. Three linked main contacts QF1 are provided on the three main contact branches 1, and the three linked main contacts QF1 are located inside the main magnetic switch. Thyristors QN1 are provided on the three main thyristor branches 2, where N = A, B, C, that is, thyristors QA1, QB1, and QC1 are provided on the three main thyristor branches 2. A main current transformer CTN1 is provided on the three main contact branches 1 or the three main thyristor branches 2, where N = A, C, that is, CTA1, CTB1, and CTC1 are provided on the three main contact branches 1 or the three main thyristor branches 2. CTA1, CTB1, and CTC1 are respectively connected to a contact separation detection circuit.

[0034] A backup power switch circuit includes a backup contact branch 3 and a backup thyristor branch 4 connected in parallel. A backup magnetic switch is installed on the backup contact branch 3, and a thyristor QN2 is installed on the backup thyristor branch 4. A backup current transformer CTN2 is installed on either the backup contact branch 3 or the backup thyristor branch 4. The current transformer CTN2 is connected to a contact break detection circuit. When the backup current transformer CTN2 is installed on the backup contact branch 3, it works with the current detection circuit to measure the contact current of the backup power switch circuit. When the backup current transformer CTN2 is installed on the backup thyristor branch 4, it works with the contact break detection circuit to measure the thyristor current. Both circuits can achieve circulating current detection.

[0035] In this embodiment, the backup power switch circuit includes three branches representing three-phase electricity connected in parallel, namely three backup contact branches 3 and backup thyristor branches 4 connected in parallel. Three linked main contacts QF2 are provided on the three backup contact branches 3, and the three linked main contacts QF2 are located inside the backup magnetic control switch. Thyristors QN2 are provided on the three backup thyristor branches 4 respectively, where N = A, B, C, that is, thyristors QA2, QB2, and QC2 are provided on the three backup thyristor branches 4 respectively. Main current transformers CTN2 are provided on the three backup contact branches 3 or the three backup thyristor branches 4 respectively, where N = A, B, C, that is, CTA2, CTB2, and CTC2 are provided on the three backup contact branches 3 or the three backup thyristor branches 4 respectively. CTA1, CTB1, and CTC1 are respectively connected to contact separation detection circuits.

[0036] A current detection device is installed on the output side of the main power switch circuit and the backup power switch circuit. The current detection device adopts an output current transformer. In this embodiment, the UA output side of the main power switch circuit and the backup power switch circuit is equipped with an output current transformer CTA, the UB output side is equipped with an output current transformer CTB, and the UC output side is equipped with an output current transformer CTC. The output current transformers CTA, CTB, and CTC are used to measure the output current, that is, to measure the load current.

[0037] The working principle of this application is explained as follows: taking the primary side as the main power switch circuit and the backup side as the backup power switch circuit as an example, the working principle is explained as follows:

[0038] When a problem occurs in the main power switch circuit, the controller outputs the opening signal of the main magnetic switch of the main power switch circuit and triggers the thyristors QA1, QB1, and QC1. It delays for the pulse width required for the main contact QF1 to open, typically 0.6–1 ms, waiting for the main contact QF1 to just open. After the main contact QF1 has just opened, the trigger signals of the thyristors QA1, QB1, and QC1 are turned off. After a delay of 4–5 ms, the controller outputs the closing signal of the backup magnetic switch of the backup power switch circuit to determine the main current of the main power switch circuit. If the current is zero, the closing signal is maintained, typically for 10-15ms. If it is not zero, the closing reversible window of the backup magnetic switch of the backup power supply is checked to see if it is about to end. The criterion for checking if it is about to end is whether the time from time T1 is less than or equal to 0.3ms. If it is, it means that it is about to end. If the closing reversible window is about to end, the closing signal of the backup magnetic switch of the backup power supply is canceled, and the closing is terminated to avoid short circuit and loop between the two power supplies. Otherwise, the main current of the original power supply is checked to see if it is zero.

[0039] In addition, taking the primary side as the main power switch circuit and the backup side as the backup power switch circuit as an example, the reversible closing window period of the main contact QF2 is explained, such as... Figure 2 The diagram shows the waveforms during the dual-power-supply closing process, where CH1 is the coil current of the standby magnetic switch, and CH2 is the closing signal of the main contact QF2 of the standby magnetic switch. Figure 2It can be seen that the closing process is divided into four time points: T0, T1, T2, and T3. From the time the closing command is issued at T0 to the start point of the main contact QF2's action at T1, the coil of the standby magnetic switch is energized and begins to magnetize. This stage is the reversible closing window period. The main contact QF2 has not yet undergone physical displacement. If the main current is not zero or other abnormal signals are detected, the closing signal can be immediately turned off, the magnetization process can be terminated, and the closing command can be completely canceled. The typical reversible closing window period is 5-6ms. From the start point of the main contact QF2's action at T1 to the time the main contact QF2 is closed at T2, the magnetic control mechanism completes the magnetization, and the main contact QF2 begins to accelerate under the electromagnetic driving force to complete the closing of the main contact QF2. From the time the main contact QF2 is closed at T2 to the time the closing signal is turned off at T3, the closing signal output is maintained during this stage to maintain the stability of the closing.

[0040] Example 2:

[0041] This embodiment provides a detailed description of the contact separation detection circuit:

[0042] The contact separation detection circuit includes a sampling resistor R1 connected to the two ends of either the thyristor CN1 or CN2. The sampling resistor R1 is connected to an amplifier circuit, which amplifies the voltage across the sampling resistor R1. The amplifier circuit is also connected to a low-pass filter circuit, which filters out high-frequency interference. The low-pass filter circuit is connected to a window comparison circuit, which compares the output signal of the preceding amplifier circuit to detect zero and non-zero current flowing through the current transformer. The window comparison circuit is also connected to a second low-pass filter circuit, which achieves a delayed output to ensure that the measured current is zero.

[0043] like Figure 3 As shown, specifically: the amplifier circuit consists of resistor R2, resistor R3, and operational amplifier U1. One end of resistor R1 is connected to one end of resistor R2, the other end of resistor R2 is connected to one end of resistor R3 and the inverting input terminal of operational amplifier U1, the other end of resistor R3 is connected to the output terminal of operational amplifier U1, and the other end of resistor R1 is connected to the non-inverting input terminal of operational amplifier U1.

[0044] The low-pass filter circuit consists of a resistor R4 and a capacitor C1. The output terminal of the operational amplifier U1 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the window comparator circuit. A capacitor C1 is placed between the resistor R4 and the window comparator circuit, and one end of the capacitor C1 is grounded.

[0045] The resistors R5, R6, R7, and R8, along with operational amplifiers U2.1 and U2.2, form a window comparator circuit. Specifically, one end of resistor R4 is connected to the inverting input of operational amplifier U2.1 and the non-inverting input of operational amplifier U2.2. The non-inverting input of operational amplifier U2.1 is connected to one end of resistor R7 via wire 5, and the other end of resistor R7 is grounded. The inverting input of operational amplifier U2.2 is connected to one end of resistor R5 via wire 6, and the other end of resistor R5 is connected to the positive power supply. Resistor R6 is placed between wire 5 and wire 6. The output of operational amplifier U2.1 is connected to the anode of diode D1, and the output of operational amplifier U2.2 is connected to the anode of diode D2. The cathodes of diodes D1 and D2 are connected to the second low-pass filter circuit.

[0046] The second low-pass filter circuit includes a resistor R8 connected to the cathodes of diodes D1 and D2. The resistor R8 is connected to the output terminal OUT through a wire 7. The wire 7 is connected to one end of capacitor C2, and the other end of capacitor C2 is grounded.

[0047] Taking the example of a main current transformer CTN1 installed on the main thyristor branch 2 and a backup current transformer CTN2 installed on the backup thyristor branch 4, the following is an explanation of the contact break detection circuit:

[0048] The thyristors and magnetic switches operate in parallel. When a problem occurs on the main power supply side, the main magnetic switch on the main power supply side trips, triggering the conduction of thyristors QA1, QB1, and QC1. At the instant the main contact QF1 of the main magnetic switch breaks, an arc is generated between the contacts, increasing the resistance between them. The current automatically commutates to the main thyristor branch 2 connected in parallel. The main current transformers CTA1, CTB1, and CTC1 induce an electromotive force, which is sampled by the sampling resistor R1. After being amplified by operational amplifier U1, the signal is low-pass filtered by R4 and C1 before being output to the next stage. The window comparator circuit detects that the input signal is outside the upper and lower threshold windows and outputs a high level, indicating that the contacts are open. At this time, the trigger signals of thyristors QA1, QB1, and QC1 are turned off. Because the thyristor holding circuit exists, thyristors QA1, QB1, and QC1 continue to be in the conducting state. When the current of thyristors QA1, QB1, and QC1 crosses zero, the main current transformers CTA1, CTB1, and CTC1 no longer have induced voltage. The input signal of the window comparator enters the upper and lower threshold windows and outputs a low level, indicating that the main switch current is zero.

[0049] Alternatively, if the main current transformers CTA1, CTB1, and CTC1 are installed in the main contact branch 1 and the spare contact branch 3, the detection logic is the opposite of the above. Before the main contact QF1 of the main magnetic switch breaks, it outputs a high level, and after the contact breaks, it outputs a low level. This scheme determines the contact state through current detection, does not rely on mechanical contacts, has a fast response, and provides accurate and reliable judgment conditions for switching timing.

[0050] In summary, due to the adoption of the above technical solution, this application has the following advantages:

[0051] 1. Compared with the traditional method that relies on the physical separation of mechanical auxiliary contacts to determine whether the contact has just broken, which has a large error, the hardware circuit directly detects the line current through the cooperation of current transformer and contact breaking detection circuit, which can accurately determine whether the contact has just broken.

[0052] 2. This dual power supply switch switching device can realize both contact break detection and current zero-crossing detection, without relying on algorithm judgment, with fast response and high reliability;

[0053] 3. Significant cost advantages: It eliminates the need for high-cost power electronic devices and high energy consumption in STS (Search Engine Technology). Performance breakthroughs are achieved through optimized mechanical switch control logic, making it suitable for large-scale industrial deployment.

[0054] The devices and connections not specifically described above are all prior art, and will not be described in detail here.

[0055] The preferred embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0056] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the various possible combinations in this application will not be described separately.

[0057] Furthermore, various different implementations of this application can be combined in any way, as long as they do not violate the spirit of this application, and such combinations should also be regarded as the content disclosed in this application.

Claims

1. A dual-power switch switching device, characterized in that, include: The main power switch circuit includes a main contact branch (1) and a main thyristor branch (2) connected in parallel. A main magnetic switch is provided on the main contact branch (1), and a thyristor QN1 is provided on the main thyristor branch (2). A main current transformer CTN1 is provided on the main contact branch (1) or the main thyristor branch (2). The main current transformer CTN1 is connected to a contact separation detection circuit. The backup power switch circuit includes a backup contact branch (3) and a backup thyristor branch (4) connected in parallel. A backup magnetic switch is provided on the backup contact branch (3), and a thyristor QN2 is provided on the backup thyristor branch (4). A backup current transformer CTN2 is provided on the backup contact branch (3) or the backup thyristor branch (4). The backup current transformer CTN2 is connected to a contact separation detection circuit. A current detection device is installed on the output side of the main power switch circuit and the backup power switch circuit.

2. The dual power supply switch switching device according to claim 1, characterized in that, The current detection device uses an output current transformer.

3. The dual power supply switch switching device according to claim 1, characterized in that, The main power switch circuit adopts three main power switch circuits connected in parallel. Three main contact branches (1) are equipped with three linked main contacts QF1, which are located inside the main magnetic control switch. Three main thyristor branches (2) are equipped with thyristors QN1, N = A, B, C. Three main contact branches (1) or three main thyristor branches (2) are equipped with main current transformers CTN1, N = A, B, C.

4. The dual power supply switch switching device according to claim 3, characterized in that, The backup power switch circuit adopts three backup power switch circuits connected in parallel. Three main contacts QF2 are set on the three backup contact branches (3). The three main contacts QF2 are set in the backup magnetic control switch. Three thyristors QN2 are set on the three backup thyristor branches (4), respectively. N = A, B, C. Backup current transformers CTN2 are set on the three backup contact branches (3) or the three backup thyristor branches (4), respectively. N = A, B, C.

5. The dual power supply switch switching device according to claim 1, characterized in that, The contact separation detection circuit includes a sampling resistor R1 connected to both ends of a thyristor CN1 or a thyristor CN2. The sampling resistor R1 is connected to an amplifier circuit, which is connected to a low-pass filter circuit one. The low-pass filter circuit one is connected to a window comparison circuit, and the window comparison circuit is connected to a low-pass filter circuit two.

6. The dual power supply switch switching device according to claim 5, characterized in that, The amplifier circuit consists of resistor R2, resistor R3, and operational amplifier U1. One end of resistor R1 is connected to one end of resistor R2, the other end of resistor R2 is connected to one end of resistor R3 and the inverting input terminal of operational amplifier U1, the other end of resistor R3 is connected to the output terminal of operational amplifier U1, and the other end of resistor R1 is connected to the non-inverting input terminal of operational amplifier U1.

7. The dual power supply switch switching device according to claim 6, characterized in that, The low-pass filter circuit consists of a resistor R4 and a capacitor C1. The output terminal of the operational amplifier U1 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the window comparator circuit. A capacitor C1 is placed between the resistor R4 and the window comparator circuit, and one end of the capacitor C1 is grounded.

8. The dual power supply switch switching device according to claim 7, characterized in that, The window comparator circuit includes resistors R5, R6, R7, and R8, operational amplifiers U2.1 and U2.

2. One end of resistor R4 is connected to the inverting input of operational amplifier U2.1 and the non-inverting input of operational amplifier U2.

2. The non-inverting input of operational amplifier U2.1 is connected to one end of resistor R7 via wire 1 (5), and the other end of resistor R7 is grounded. The inverting input of operational amplifier U2.2 is connected to one end of resistor R5 via wire 2 (6), and the other end of resistor R5 is connected to the positive power supply. Resistor R6 is provided between wire 1 (5) and wire 2 (6). The output of operational amplifier U2.1 is connected to the anode of diode D1, and the output of operational amplifier U2.2 is connected to the anode of diode D2. The cathodes of diode D1 and diode D2 are connected to low-pass filter circuit 2.

9. The dual power supply switch switching device according to claim 8, characterized in that, The low-pass filter circuit includes a resistor R8 connected to the cathode of diode D1 and the cathode of diode D2. The resistor R8 is connected to the output terminal OUT through wire three (7). Wire three (7) is connected to one end of capacitor C2, and the other end of capacitor C2 is grounded.

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