Automatic switching protection circuit module

Abstract

The utility model discloses an automatic switching protection circuit module, which comprises an effective value converter, a current transformer, an upper and lower limit comparison circuit, a relay selection circuit and a buzzer alarm circuit, and is characterized in that the effective value converter is used for detecting the voltage effective value of a power grid in real time; detecting the output current of the photovoltaic inverter by using a current transformer; through an upper and lower limit comparison circuit, according to a power grid voltage effective value and a detection result output by an upper and lower limit comparator of an inverter output current, a relay selection circuit controls on-off of a corresponding relay so as to realize power supply switching. When the output of the power grid and the output of the inverter are detected to be abnormal, an alarm signal is sent out through the buzzer alarm circuit. According to the automatic switching protection circuit module, the states of a power grid and an inverter can be monitored in real time, a power supply is automatically switched, and the problems of equipment damage and unstable power supply are avoided; and meanwhile, alarm prompt is performed under abnormal conditions, so that a user can conveniently process faults in time, and the reliability and safety of a power system are improved.

Description

Technical Field

[0001] The utility model relates to a circuit module, in particular to an automatic switching protection circuit module. Background Art

[0002] With the rapid development of photovoltaic power generation technology, photovoltaic inverters are increasingly widely used in power systems. However, due to reasons such as grid voltage fluctuations and inverter failures, it may lead to unstable power supply in the power system and even damage to equipment. Therefore, it is of great significance to design a circuit module that can monitor the states of the grid and the inverter in real time and perform automatic switching and alarm in case of abnormalities. Summary of the Invention

[0003] To solve the problem that the power supply mode cannot be switched in time when the device encounters grid faults or inverter faults during operation, resulting in device abnormalities or damage, the utility model needs to provide an automatic switching protection circuit module.

[0004] The utility model provides the following technical solutions:

[0005] An automatic switching protection circuit module includes an effective value converter, a current transformer, an upper and lower limit comparison circuit, a relay selection circuit, and a buzzer alarm circuit;

[0006] The effective value converter is used to detect the effective value of the grid voltage in real time; the current transformer is used to detect the output current of the photovoltaic inverter;

[0007] The upper and lower limit comparison circuit outputs a detection result according to the comparison of the effective value of the grid voltage and the upper and lower limits of the output current of the inverter; the power supply is switched by controlling the on and off of the corresponding relay through the relay selection circuit;

[0008] When it is detected that both the grid and the inverter output are abnormal, an alarm signal is sent through the buzzer alarm circuit.

[0009] Further, the effective value converter adopts the AD637 model; the current transformer adopts the FC-ACT25-50A-1000T-1T model.

[0010] Further, the upper and lower limit comparison circuit includes a plurality of inverters and a plurality of comparators. The input end of the inverter is connected to the comparator, and the output end of the comparator is connected to a binary-to-quaternary decoder.

[0011] Further, the binary-to-quaternary decoder adopts the 74LS139 model, the comparator adopts the LM339 model; the inverter adopts the 74LS04 model.

[0012] Further, the relay selection circuit includes a first current relay and a second voltage relay. The first current relay is connected to the first terminal, and the second voltage relay is connected to the second terminal.

[0013] Further, the buzzer alarm circuit includes a triode and a buzzer. The collector of the triode is connected to the buzzer, and the base of the triode is connected to the binary-to-quaternary decoder.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows: The automatic switching protection circuit module of the present utility model can monitor the status of the power grid and the inverter in real time, automatically switch the power supply, and avoid problems such as equipment damage and unstable power supply; at the same time, it gives an alarm prompt in case of abnormalities, facilitating users to handle faults in a timely manner and improving the reliability and safety of the power system. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the principle of the present utility model.

[0016] Figure 2 It is a schematic diagram of the upper and lower limit comparison circuit of the present utility model.

[0017] Figure 3 It is a schematic diagram of the relay selection circuit of the present utility model.

[0018] Figure 4 It is a schematic diagram of the buzzer alarm circuit of the present utility model.

[0019] In the figure, 1. RMS converter; 2. Current transformer; 3. Upper and lower limit comparison circuit, 4. Relay selection circuit, 5. Buzzer alarm circuit. Detailed Embodiments

[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0021] Please refer to Figure 1 , an automatic switching protection circuit module of the present utility model includes an RMS converter 1, a current transformer 2, an upper and lower limit comparison circuit 3, a relay selection circuit 4, and a buzzer alarm circuit 5.

[0022] Use the RMS converter 1 to detect the RMS value of the grid voltage in real time; use the current transformer 2 to detect the output current of the photovoltaic inverter.

[0023] Through the upper and lower limit comparison circuit 3, according to the detection results output by the upper and lower limit comparators of the effective value of the grid voltage and the inverter output current, the on-off of the corresponding relay is controlled through the relay selection circuit 4 to achieve power supply switching;

[0024] When it is detected that both the grid and the inverter output are abnormal, an alarm signal is sent through the buzzer alarm circuit 5.

[0025] The effective value converter 1 uses the AD637 model;

[0026] The current transformer uses the FC-ACT25-50A-1000T-1T model.

[0027] Figure 2 As shown, the upper and lower limit comparison circuit 3 includes multiple inverters and multiple comparators. The input end of the inverter is connected to the comparator, and the output end of the comparator is connected to the binary-to-quaternary decoder.

[0028] The multiple inverters are respectively inverter U3A, inverter U4A, and inverter U3B;

[0029] The multiple comparators are respectively comparator U2A, comparator U2B, comparator U2C, and comparator U2D. The output end of comparator U2A is connected to the input end of inverter U3A, the output end of comparator U2B is connected to the input end of inverter U3A, the output ends of comparator U2C and comparator U2D are both connected to the input end of inverter U3B, and the output end of inverter U3B is connected to the input end of inverter U4A;

[0030] The output end of inverter U4A and the output end of inverter U3A are connected to the binary-to-quaternary decoder U1A.

[0031] The binary-to-quaternary decoder uses the 74LS139 model. The models used for comparator U2A, comparator U2B, comparator U2C, and comparator U2D are LM339; the models used for inverter U3A, inverter U4A, and inverter U3B are 74LS04.

[0032] The standard stipulates that the effective value fluctuation range of the grid voltage is +7%, -10%. If it exceeds this range, it can be considered that the effective value of the grid voltage is abnormal. Through the grid effective value detection circuit, the current effective value of the grid voltage is obtained and compared with the pre-set upper and lower limits of the grid voltage comparison circuit to determine whether the current voltage effective value is within the specified range. When the current effective value of the grid voltage is within this range, a high level is output, otherwise a low level is output. The detection of the inverter output current is the same, but the output result is inverted by the inverter. The two-way outputs are used as input signals to enter the binary-to-quaternary decoder, and the output control signal controls the operation of the relay selection circuit and the buzzer alarm circuit.

[0033] Figure 3As shown, the relay selection circuit 4 includes a first current relay and a second voltage relay. The first current relay is connected to the first terminal JP1, and the second voltage relay is connected to the second terminal JP2.

[0034] Figure 4 As shown, the buzzer alarm circuit 5 includes a triode Q1 and a buzzer LS1. The collector of the triode Q1 is connected to the buzzer LS1, and the base of the triode Q1 is connected to the Y1 pin of the binary-to-quaternary decoder U1A.

[0035] The Y0 pin of the binary-to-quaternary decoder U1A is connected to the first current relay, and the Y3 pin of the binary-to-quaternary decoder U1A is connected to the second voltage relay.

[0036] The utility model can monitor the power grid and inverter status in real time, automatically switch the power supply, and avoid problems such as equipment damage and unstable power supply. At the same time, it gives an alarm prompt in case of abnormalities, which is convenient for users to handle faults in time and improves the reliability and safety of the power system.

[0037] Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. An automatic switching protection circuit module, characterized in that: It includes an effective value converter (1), a current transformer (2), an upper and lower limit comparison circuit (3), a relay selection circuit (4), and a buzzer alarm circuit (5); The effective value converter (1) is used to detect the effective value of the grid voltage in real time; the current transformer (2) is used to detect the output current of the photovoltaic inverter; The upper and lower limit comparison circuit (3) compares the detection results output by the upper and lower limit comparators based on the effective value of the grid voltage and the output current of the inverter; the power supply switching is realized by controlling the on and off of the corresponding relay through the relay selection circuit (4); When it is detected that both the grid and the inverter output are abnormal, an alarm signal is sent through the buzzer alarm circuit (5).

2. The automatic switching protection circuit module according to claim 1, wherein: The effective value converter (1) uses the AD637 model; the current transformer (2) uses the FC-ACT25-50A-1000T-1T model.

3. The automatic switching protection circuit module according to claim 1, wherein: The upper and lower limit comparison circuit (3) includes a plurality of inverters and a plurality of comparators. The input end of the inverter is connected to the comparator, and the output end of the comparator is connected to a two-to-four decoder.

4. The automatic switching protection circuit module according to claim 3, wherein: The two-to-four decoder uses the 74LS139 model, the comparator uses the LM339 model, and the inverter uses the 74LS04 model.

5. An automatic switching protection circuit module according to claim 1, characterized in that: The relay selection circuit (4) includes a first-path current relay and a second-path voltage relay. The first-path current relay is connected to the first terminal, and the second-path voltage relay is connected to the second terminal.

6. The automatic switching protection circuit module according to claim 1, wherein: The buzzer alarm circuit (5) includes a triode and a buzzer. The collector of the triode is connected to the buzzer, and the base of the triode is connected to the two-to-four decoder.

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