A Design Method for an Automatic Anti-Fooling Circuit for Industrial-Level High-Voltage Monitoring

Abstract

The present invention discloses a design method for an industrial-grade high-voltage monitoring automatic anti-fooling circuit, which relates to the technical field of photovoltaic cell module monitoring. The automatic anti-fooling circuit includes a high-voltage screening circuit, a high-voltage disconnection circuit, and a high-voltage comparison circuit. The number of stages of the three circuits is determined by the series number i of the photovoltaic cell modules in the series photovoltaic power station, and the voltage input ends of the series-connected photovoltaic cell modules are in a disordered state. The high-voltage screening circuit has i stages, and each stage of the high-voltage screening circuit is used to screen out the maximum value of all input voltages that have not been disconnected at this stage. The high-voltage disconnection circuit has i-1 stages, and each stage of the high-voltage disconnection circuit is used to automatically disconnect all high-voltage inputs greater than or equal to the maximum value voltage screened out by the previous stage of the high-voltage screening circuit and not participate in the high-voltage maximum value comparison at this stage. The high-voltage comparison circuit has i-1 stages, and each stage of the high-voltage comparison circuit is used to screen out all voltage values except those lower than the voltage of the previous stage and participate in the maximum value voltage comparison at this stage.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cell module monitoring, and particularly to a design method for an industrial-grade high-voltage monitoring automatic anti-fooling circuit. Background Art

[0002] At present, during the refined management of a photovoltaic power station, it is necessary to monitor the voltage and current of each battery panel, the temperature before and after the panel, and the on-site wind speed. These data are important bases for monitoring the operating status and fault determination of the photovoltaic power station. Photovoltaic modules can allow short-term shading, but long-term local shading will produce a heat island effect, and the battery panels will heat up. The long-term accumulation of heat may physically damage the photovoltaic solar modules. These characteristics will affect the output power and voltage of a single photovoltaic module. Therefore, it is necessary to monitor the voltage of photovoltaic cell modules.

[0003] In the field of photovoltaic power station operation, to meet the power generation requirements, multiple groups of solar photovoltaic modules are often connected in series for power generation. In order to monitor the operating status of each photovoltaic module at all times, it is necessary to collect the operating voltage of each solar photovoltaic module in real time. In the actual engineering practice process, the monitoring voltage acquisition heads of each photovoltaic solar cell module are usually placed in a disorderly manner. Once the connection order of the acquisition heads of a series circuit in the monitoring acquisition circuit is disordered, the consequences will be very serious. Summary of the Invention

[0004] In view of the above technical problems, the present invention provides a design method for an industrial-grade high-voltage monitoring automatic anti-fooling circuit, which is mainly used for the situation where the monitoring heads are disorderly sorted in the voltage monitoring of series-connected photovoltaic modules in a series-connected group of battery modules.

[0005] To solve the above technical problems, the technical solution proposed by the present invention is as follows:

[0006] A design method for an industrial-grade high-voltage monitoring automatic anti-fooling circuit includes a high-voltage screening circuit, a high-voltage disconnection circuit, and a high-voltage comparison circuit. The number of stages of the high-voltage screening circuit, the high-voltage disconnection circuit, and the high-voltage comparison circuit is determined by the number of series stages i of the photovoltaic cell modules in the series-connected photovoltaic power station, where i is an integer, and the voltage input ends of the series-connected photovoltaic cell modules are in a disordered state;

[0007] The high-voltage screening circuit has i stages, and each stage of the high-voltage screening circuit is used to screen out the maximum value of all input voltages that have not been disconnected at this stage;

[0008] The high-voltage disconnection circuit has i - 1 stages, and each stage of the high-voltage disconnection circuit is used to disconnect all high-voltage inputs greater than or equal to the maximum value voltage screened out by the previous stage of the high-voltage screening circuit, and does not participate in the high-voltage maximum value comparison at this stage;

[0009] The high-voltage comparison circuit has i - 1 levels. Each level of the high-voltage comparison circuit is used to include in the maximum voltage comparison at this level all voltage values that are lower than the maximum voltage value screened out by the previous-level high-voltage screening circuit.

[0010] As a further improvement of the above technical solution:

[0011] Preferably, the anti-fooling circuit includes an i-level high-voltage screening circuit, an i - 1-level high-voltage disconnection circuit, and an i - 1-level high-voltage comparison circuit. The first-level high-voltage screening circuit independently screens out the maximum value of all input voltages. Each subsequent level of the high-voltage screening circuit is connected to the corresponding high-voltage disconnection circuit, and each level of the high-voltage disconnection circuit is connected to the corresponding level of the high-voltage comparison circuit. The first-level high-voltage disconnection circuit is connected to the second-level high-voltage screening circuit, and so on, until the i - 1-level high-voltage disconnection circuit is connected to the i-level high-voltage screening circuit. The series disordered input voltages of the photovoltaic modules in the photovoltaic power station are connected to the first-level high-voltage screening circuit, and are also connected to the reverse input terminal of each level of the high-voltage comparison circuit and each level of the high-voltage disconnection circuit;

[0012] The high-voltage comparison circuit at this level will screen out all input voltages that are lower than the extremely high voltage of the previous level, and control the output voltage of the emitter follower drive circuit through the output voltage value of the voltage comparator, so as to control the closing or opening of the high-voltage disconnection circuit at this level, allowing all voltages lower than the extremely high voltage of the previous level to perform voltage magnitude comparison at this level, and disconnecting the voltage input terminals of all voltages greater than or equal to the extremely high voltage value of the previous level to prohibit them from participating in the maximum voltage comparison at this level.

[0013] Preferably, the i-level high-voltage screening circuit includes i diodes and a resistor. All the diodes are connected in parallel with a common cathode. After the i diodes are connected in parallel, their common cathode is connected in series with the resistor. The anodes of the diodes in the first-level high-voltage screening circuit are respectively connected to the series disordered input voltages of the photovoltaic modules, and the anodes of the diodes in the remaining high-voltage screening circuits are respectively connected to the time relay delay closing contacts of the corresponding high-voltage disconnection circuits.

[0014] Preferably, each level of the high-voltage comparison circuit includes i high-voltage proportional reduction circuits, i voltage comparators, and i emitter follower drive combinations. Among them, the high-voltage proportional reduction circuit is used to reduce all high voltages in proportion and then perform voltage magnitude comparison through the voltage comparator; the emitter follower drive combination is used to drive the corresponding high-voltage disconnection circuit at the subsequent level; one high-voltage proportional reduction circuit, one voltage comparator, and one emitter follower drive combination constitute a sub-high-voltage comparison circuit, and their inputs respectively correspond to different disordered input voltages and the maximum voltage value output by the previous-level high-voltage screening circuit.

[0015] Preferably, the high-voltage proportional reduction circuit includes two sets of proportionally reduced resistors, each set containing two resistors connected in series. The input end of one set of series resistors is connected to the extremely high voltage output by the previous-stage high-voltage screening circuit, and the other end is grounded. The center connection point of the two series resistors is connected to the non-inverting input terminal of the voltage comparator. The input end of the other set of series resistors is connected to any non-repeating and unordered voltage input terminal, and the other end is grounded. The center connection point of the two series resistors is connected to the inverting input terminal of the voltage comparator. The positive power input terminal of the voltage comparator is connected to the positive pole of the power supply, the negative power input terminal is grounded, and a pull-up resistor is connected between the pin of the positive power input terminal and the output terminal pin.

[0016] Preferably, the emitter follower drive combination includes a transistor, a zener diode, and two resistors. One end of one resistor is connected to the output terminal of the voltage comparator, and the other end is respectively connected to the cathode of the zener diode and the base of the transistor. The anode of the zener diode is grounded. The collector of the transistor is connected to the power supply, the emitter of the transistor is connected to the other resistor and then grounded, and at the same time, the emitter is also connected to one end of the control coil of the i-th time relay of the corresponding stage of the high-voltage disconnection circuit of this stage.

[0017] Preferably, each stage of the high-voltage disconnection circuit includes i time relays. One end of the control coil of each time relay is connected to the emitter of the transistor of the emitter follower drive combination of the i-th stage in the high-voltage comparison circuit of the same stage, and the other end is grounded. One end of the delayed closing contact of each time relay is connected to any non-repeating and unordered voltage input terminal, and the other end of the delayed closing contact is respectively connected to the anode of the diode of the corresponding subsequent-stage high-voltage screening circuit.

[0018] Preferably, the anti-fooling circuit is also provided with its own power supply circuit, and the power supply circuit is supplied by an emitter follower. The emitter follower is composed of one zener diode, one transistor, and two resistors. The negative pole of the zener diode is respectively connected to one of the resistors and the base of the transistor. The positive pole of the zener diode is grounded. The negative pole of the zener diode is connected to the resistor and then connected to the highest voltage terminal output by the first-stage high-voltage screening circuit. The emitter of the transistor is connected to the other resistor and then grounded, and the emitter of the transistor is also connected to the output terminal, and the output is the positive pole of the power supply for the overall circuit. The collector of the transistor is connected to the highest voltage terminal output by the first-stage high-voltage screening circuit.

[0019] The design method of the industrial-grade high-voltage monitoring automatic anti-fooling circuit provided by the present invention has the following advantages compared with the prior art:

[0020] (1) The design method of the industrial-grade high-voltage monitoring automatic fool-proof circuit of the present invention automatically sorts and outputs the high-voltage monitoring heads of disordered series-connected photovoltaic modules in descending order of voltage value. The overall circuit is not affected by the number of series-connected stages, and there is no upper limit on the maximum peak value of the total series voltage. It can be applied to large-scale centralized photovoltaic power stations or small-scale distributed photovoltaic power stations, and its application can be extended to any application occasions that require series-connected monitoring of battery groups.

[0021] (2) The design method of the industrial-grade high-voltage monitoring automatic fool-proof circuit of the present invention can accurately output the voltage value of each node of the series photovoltaic module circuit in sequence after the identification and sorting of the fool-proof circuit, regardless of how the connection sequence of the connectors is disordered. The present invention has universal applicability, and by adjusting the number of stages of the identification circuit, it can adapt to any series high-voltage battery group circuit with a single-stage voltage higher than 12V. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the disordered voltage input circuit of the present invention.

[0023] Figure 2 This is the circuit diagram of the first-level high-voltage screening circuit of the present invention.

[0024] Figure 3 This is an emitter follower circuit diagram of the power supply of the present invention.

[0025] Figure 4 This is the circuit diagram of the first high-voltage comparison circuit of the present invention.

[0026] Figure 5 This is a circuit diagram of the first high-voltage comparison circuit of the second part of the present invention.

[0027] Figure 6 This is the circuit diagram of the first high-voltage comparison circuit of the third part of the present invention.

[0028] Figure 7 This is the circuit diagram of the fourth first high-voltage comparison circuit of the present invention.

[0029] Figure 8 This is a diagram of the first high-voltage disconnection circuit and the second high-voltage automatic screening circuit of the present invention. DETAILED DESCRIPTION

[0030] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the described embodiments are part of the present invention, not all of them. Based on these examples, those skilled in the art can understand and implement all other possible embodiments of the present technical solution without creative work, and these embodiments also belong to the protection scope of the present technical solution. The protection of the present technical solution is not limited to the specific embodiments described in the text, but also includes all equivalent embodiments, which are all organic components of the present invention.

[0031] The present invention provides a design method for an industrial-grade high-voltage monitoring automatic anti-fooling circuit. The anti-fooling circuit includes a high-voltage screening circuit, a high-voltage disconnection circuit, and a high-voltage comparison circuit. The number of stages of the high-voltage screening circuit, the high-voltage disconnection circuit, and the high-voltage comparison circuit is determined by the number of stages of the photovoltaic cell modules in the series photovoltaic power station. If there are i-stage battery modules in series, the high-voltage screening circuit is i-stage, the high-voltage disconnection circuit is i - 1 stage, and the high-voltage comparison circuit is i - 1 stage.

[0032] As Figure 1 shown, since the circuit of the present invention has universality in applicable occasions, this embodiment takes a 4-stage 12V serial anti-fooling circuit as an example for illustration, and the working principles of the other circuits are similar to this circuit. All component labels mentioned below in this embodiment are components involved in 4-stage - 12V.

[0033] Let V5, V6, V7, and V8 be 4 series-connected photovoltaic cell modules of the battery, and K69, K70, K71, and K72 be single-pole four-throw switches. The disordered input voltage of the photovoltaic modules in the photovoltaic power station is controlled by the disordered combination of the switches K69, K70, K71, and K72 for input.

[0034] In this embodiment, the high-voltage screening circuit has four stages, and each stage of the high-voltage screening circuit is used to screen out the maximum value of all the input voltages that have not been disconnected at this stage. The high-voltage disconnection circuit has three stages. The previous stage of the high-voltage screening circuit screens out the maximum voltage value max x , and each stage of the high-voltage disconnection circuit is used to automatically disconnect all high-voltage inputs ≥ max x , and they do not participate in the high-voltage maximum value comparison at this stage. The high-voltage comparison circuit has three stages. First, select the voltage value lower than the voltage of the previous stage, remove this voltage value, and the remaining voltage values pass through the high-voltage comparison circuit of the current stage and participate in the maximum value voltage comparison at this stage, that is, each stage of the high-voltage comparison circuit only allows the voltage signal with the input voltage < the maximum value screened out by the previous stage to participate in the maximum value comparison at this stage.

[0035] In this embodiment, the disordered input voltage of the photovoltaic modules in the photovoltaic power station is controlled by the disordered combination of switches K69, K70, K71, and K72; the disordered input voltage is represented by four voltages v0, v1, v2, and v3. The same v0 is a voltage value, and similarly, the same v1, the same v2, and the same v3 are all the same voltage value.

[0036] The four-level high-voltage screening circuits are the first high-voltage screening circuit, the second high-voltage screening circuit, the third high-voltage screening circuit, and the fourth high-voltage screening circuit, and they have the same structure.

[0037] As Figure 2 shown, the first high-voltage screening circuit is taken as an example for illustration. The first high-voltage screening circuit includes diodes and resistors. S43, S51, S53, and S61 are four diodes, and they are connected in parallel with a common cathode; after the 4 diodes S43, S51, S53, and S61 are connected in parallel, their common cathode is connected in series with the resistor R3.

[0038] In any high-voltage screening circuit, assuming that the forward conduction voltage drop of all diodes is 0, the highest input voltage is vx, the diode connected to vx is Sx, and at the same time, there is a voltage value vy smaller than vx that first conducts through the diode Sy connected to vy, then the cathode voltage of the Sy terminal is vy. Since the cathode of Sx is short-circuited with the cathode of Sy, in this case, the cathode voltage of Sx must also be vy, and because vx is greater than vy, Sx must conduct. At this time, the cathode voltage of Sx immediately rises to the maximum voltage vx, and since vx > vy, Sy must be cut off, and the input voltage of vy is cut off by the reverse cut-off of Sy. The common cathode output voltage of the diodes Sx and Sy must be the maximum voltage vx. Here, x and y represent numbers.

[0039] Therefore, after the non-repetitive disordered voltage passes through the first high-voltage screening circuit composed of S43, S51, S53, S61, and R3, the highest voltage max0 will be output.

[0040] As Figure 8 shown, the high-voltage disconnection circuit is provided with a first high-voltage disconnection circuit, a second high-voltage disconnection circuit, and a third high-voltage disconnection circuit. The first high-voltage disconnection circuit is taken as an example for illustration. The first high-voltage disconnection circuit includes time relays J29, J36, J43, and J50. One end of the control coil of each time relay is connected to the emitter of the crystal triode of the high-voltage comparison circuit, and the other end is grounded. At the same time, one end of the delay closing contact of each time relay is connected to the non-repetitive disordered voltage input terminal in series with any photovoltaic cell module in the photovoltaic power station, and the other end of the delay closing contact is respectively connected to the anodes of the diodes S40, S48, S58, and S66 of the corresponding second high-voltage screening circuit.

[0041] The high-voltage comparison circuit is provided with a first high-voltage comparison circuit, a second high-voltage comparison circuit, and a third high-voltage comparison circuit, which have the same structure. The first high-voltage comparison circuit will be taken as an example for illustration. As Figures 4 to 7 shown, the first high-voltage comparison circuit includes 4 high-voltage proportional reduction circuits, 4 voltage comparators, and 4 emitter follower drive combinations. The function of the high-voltage proportional reduction circuit is to step down all high voltages and then compare the voltage magnitudes through the voltage comparators. Otherwise, the voltage comparator chip will be directly burned out. The emitter follower drive combination is used to drive the control coil of the time relay in the corresponding high-voltage disconnection circuit at the subsequent stage. One high-voltage proportional reduction circuit, one voltage comparator, and one emitter follower drive combination constitute a sub-first high-voltage comparison circuit. In this embodiment, there are 4 levels of unordered input voltages, so there are 4 high-voltage sub-comparison circuits in each level. Their structures are similar, and the only difference lies in that the voltages connected to the inverting input terminal of the voltage comparator are the unordered input voltages v0, v1, v2, v3 respectively, and the high-voltage disconnection circuits driven by the emitter of the triode in the emitter follower drive combination are different.

[0042] Furthermore, as Figure 4 shown, each high-voltage proportional reduction circuit contains 2 groups of proportional resistors. The proportional reduction ratio of the voltage at the inverting input terminal is the same as that of the voltage at the non-inverting input terminal. Each group contains 2 series-connected resistors. One group of series-connected resistors R42 and R75 has its input terminal connected to the highest voltage max0 output by the first high-voltage screening circuit, and the other end is grounded. The center of the two series-connected resistors is connected to the non-inverting input terminal of the voltage comparator U1A. The input terminal of the other group of series-connected resistors R125 and R192 is connected to the non-repetitive unordered voltage input terminal in series with any photovoltaic cell module. In this embodiment, the sub-first high-voltage comparison circuit is connected to v0; the other end is grounded. The center of the two series-connected resistors R125 and R192 is connected to the inverting input terminal of the voltage comparator U1A. The positive power supply input terminal of the voltage comparator U1A is connected to the power supply vcc, the negative power supply input terminal is grounded, and a pull-up resistor R59 is connected between the pin of the positive power supply input terminal and the output terminal pin to ensure the normal operation of the operational amplifier.

[0043] The emitter follower drive combination includes a crystal triode Q2, a zener diode D2, a resistor R76, and a resistor R153; one end of the resistor R76 is connected to the output terminal of the voltage comparator U1A, and the other end is respectively connected to the cathode of the zener diode D2 and the base of the crystal triode Q2; the anode of the zener diode D2 is grounded, the collector of the crystal triode Q2 is connected to the positive pole vcc of the power supply, the emitter of the crystal triode Q2 is grounded (GND) through the resistor R153. At the same time, the emitter is also connected to one end of the control coil of the time relay in the corresponding first high-voltage disconnection circuit, and the other end of the corresponding time relay control coil is grounded.

[0044] In this embodiment, the coils of the four normally open time relays J29, J36, J43, and J50 of the first high-voltage disconnect circuit are respectively controlled by four first high-voltage comparison circuits. Only when the voltage value of the disordered input voltages v0, v1, v2, and v3 is lower than the maximum voltage value max0, the corresponding normally open time relays will produce a power-on delay attraction action, that is, the voltage participating in the voltage comparison of this level is always controlled to be smaller than the maximum voltage of the previous level.

[0045] like Figure 3 As shown, the foolproof circuit is also provided with its own power supply circuit, the working voltage of which is supplied by an emitter follower, which is composed of R1, R2, D1, and Q1, wherein the cathode of the voltage zener diode D1 is connected to the resistor R1 and the base of the transistor Q1, the anode of the voltage zener diode D1 is grounded, the emitter of the transistor Q1 is connected to the resistor R2 and then to the ground, and the emitter of the transistor Q1 is also connected to the power supply voltage of its own circuit, and outputs the power supply vcc. The collector of the transistor Q1 is connected to the highest voltage terminal max0 output by the first high-voltage screening circuit; the cathode of the voltage zener diode D1 is connected to the resistor R1 and then to the highest voltage output terminal max0 of the first high-voltage screening circuit.

[0046] When the foolproof circuit of the present invention is used, Figure 1 As shown, assuming that the output voltage of K69 is v2, the output voltage of K70 is v0, the output voltage of K71 is v3, and the output voltage of K72 is v1, the output ends of the four disordered switch combinations K69, K70, K71, and K72 are respectively connected to the anodes of diodes S43, S51, S53, and S61. Through the first high-voltage screening circuit, the highest voltage max0 can be output at the cathodes of the four diodes and output at the non-grounded end of the resistor R3. The other end of the resistor R3 is connected to the common cathode of the common cathode diodes S43, S51, S53, and S61.

[0047] The disordered input voltage will output the highest voltage max0 after passing through the first high-voltage screening circuit composed of S43, S51, S53, S61, and R3, that is, the highest voltage max0 is separated. The max0 voltage passes through the emitter follower composed of R1, D1, Q1, and R2, and outputs a stable DC voltage vcc to power the foolproof circuit itself.

[0048] Further, after isolating the maximum voltage max0, the input non-repeating and unordered voltages are passed through 4 high-voltage scaling circuits and voltage comparators and then compared with the maximum voltage max0. Only the voltage comparators connected to the three unordered input voltages smaller than the highest voltage max0 will output a high level, thereby driving the transistors in the emitter-follower drive combination connected thereto to conduct, causing the normally-open time relays in the corresponding high-voltage screening circuits to close; while the transistors in the emitter-follower drive combination corresponding to the input voltage terminal equal to max0 will be cut off, and then the output at its emitter terminal will be at a low level, thus unable to drive the time relay control coil of the high-voltage disconnection circuit connected thereto to work. Therefore, only the other 3 input voltages lower than max0 participate in the first-stage comparison, and then through the second high-voltage screening circuit, the second-highest voltage value max1 lower than max0 is compared and screened out.

[0049] During the screening process of the second high voltage, first, all voltages lower than max0 are selected through the first high-voltage comparison circuit, and then by controlling the voltage level at the emitter of the transistors in the emitter-follower drive combination of the corresponding high-voltage comparison circuit, the on / off of the control coil of the time relay in the first high-voltage disconnection circuit is controlled, and then the closing of the delayed closing contacts of the corresponding time relays in the first high-voltage disconnection circuit is controlled, so as to achieve the purpose of performing a second-stage comparison on all voltages smaller than the voltage value of max0. Finally, the second-highest voltage value max1 lower than max0 is screened out through the second high-voltage screening circuit.

[0050] Similarly, the third high-voltage screening circuit screens out the third-highest voltage value max2 lower than max1. By keeping the two normally-open time relays connected to the voltage value greater than or equal to max1 in the open state, their participation in the third-stage voltage comparison is prohibited, and the third-highest voltage value max2 is compared and screened out. The fourth high-voltage screening circuit screens out the fourth-highest voltage value max3 lower than max2. Therefore, the final voltage output result of the entire circuit is max0 > max1 > max2 > max3.

[0051] Through the anti-fooling circuit of the present invention, the high-voltage monitoring heads of the disordered series-connected photovoltaic modules can be automatically sorted and output in descending order of voltage value. The overall circuit is not affected by the number of series-connected photovoltaic modules, and there is no upper limit for the maximum peak value of the series total voltage. It can be applied to centralized large-scale photovoltaic power stations or distributed small-scale photovoltaic power stations, and the application can be extended to any application scenarios where battery packs need to be monitored in series.

[0052] The above embodiments are only preferred embodiments of the present invention and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Therefore, any simple modifications, equivalent changes, and decorations made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A design method for an industrial-grade high-voltage monitoring automatic fool-proofing circuit, characterized in that: The design content of the foolproof circuit includes the design of a high-voltage screening circuit, a high-voltage disconnection circuit, and a high-voltage comparison circuit. The number of the high-voltage screening circuit, the high-voltage disconnection circuit, and the high-voltage comparison circuit is determined by the number of series-connected photovoltaic cell modules of the photovoltaic power station, i, where i is an integer, and the voltage input end of the photovoltaic cell modules connected in series is in a disordered state; The high-voltage screening circuit is provided with i levels, and each level of the high-voltage screening circuit is used to screen out the maximum value of all input voltages that are not disconnected at this level; The high-voltage disconnection circuit is provided with i-1 levels, and each level of the high-voltage disconnection circuit is used to disconnect all high-voltage inputs that are greater than or equal to the maximum voltage value screened out by the previous level of high-voltage screening circuit, and do not participate in the high-voltage maximum value comparison of this level; The high-voltage comparison circuit is provided with i-1 stages, and each stage of the high-voltage comparison circuit is used to screen out all voltage values ​​lower than the maximum voltage screened out by the previous stage of the high-voltage screening circuit to participate in the maximum voltage comparison of this stage; The high-voltage screening circuit of the first stage independently screens out the maximum value of all input voltages, and each subsequent high-voltage screening circuit is connected to the corresponding high-voltage disconnect circuit, and each high-voltage disconnect circuit is connected to the corresponding high-voltage comparison circuit of the first stage, and the high-voltage disconnect circuit of the first stage is connected to the high-voltage screening circuit of the second stage, and so on, until the high-voltage disconnect circuit of the i-1 stage is connected to the high-voltage screening circuit of the i stage.

2. The design method of the industrial-grade high-voltage monitoring automatic fool-proofing circuit according to claim 1 is characterized in that: The foolproof circuit includes an i-level high-voltage screening circuit, an i-1-level high-voltage disconnection circuit and an i-1-level high-voltage comparison circuit. The series disordered input voltage of the photovoltaic modules of the photovoltaic power station is connected to the first-level high-voltage screening circuit, and is connected to the reverse input end of each level of the high-voltage comparison circuit and the high-voltage disconnection circuit of each level; The high-voltage comparison circuit of this stage will screen out all input voltages lower than the extremely high voltage of the previous stage, and control the output voltage of the emitter follower drive circuit through the output voltage value of the voltage comparator, thereby controlling the closing or opening of the high-voltage disconnect circuit of this stage, allowing all voltages lower than the extremely high voltage of the previous stage to be compared with the voltage of this stage, and disconnecting all voltage input terminals that are greater than or equal to the extremely high voltage value of the previous stage, prohibiting them from participating in the comparison of the maximum voltage of this stage.

3. The design method of the industrial-grade high-voltage monitoring automatic fool-proofing circuit according to claim 2 is characterized in that: The i-th level high-voltage screening circuit includes i diodes and a resistor. All diodes have a common cathode connected in parallel. After the i diodes are connected in parallel, their common cathode is connected in series with the resistor. The anodes of the diodes in the first-level high-voltage screening circuit are respectively connected to the series disordered input voltage of the photovoltaic module, and the anodes of the remaining high-voltage screening circuit diodes are respectively connected to the delayed closing contacts of the time relays of the corresponding high-voltage disconnect circuits.

4. The design method of the industrial-grade high-voltage monitoring automatic fool-proofing circuit according to claim 3 is characterized in that: The high-voltage comparison circuit of each stage includes i high-voltage proportional reduction circuits, i voltage comparators, and i groups of emitter follower drive combinations, wherein the high-voltage proportional reduction circuit is used to proportionally reduce all high voltages and then compare the voltages through the voltage comparator; the emitter follower drive combination is used to drive the corresponding high-voltage disconnection circuit of the subsequent stage; 1 high-voltage proportional reduction circuit, 1 voltage comparator, and 1 group of emitter follower drive combinations constitute a high-voltage comparison circuit, whose inputs correspond to different disordered input voltages and the maximum voltage output by the previous stage high-voltage screening circuit.

5. The design method of the industrial-grade high-voltage monitoring automatic fool-proofing circuit according to claim 4 is characterized in that: The high-voltage proportional reduction circuit includes two groups of proportional reduction resistors, each group includes two resistors connected in series, the input end of one group of series resistors is connected to the extremely high voltage output by the high-voltage screening circuit of the previous stage, the other end is grounded, and the center connection point of the two series resistors is connected to the same-phase input end of the voltage comparator; the input end of the other group of series resistors is connected to any non-repetitive disordered voltage input end, the other end is grounded, and the center connection point of the two series resistors is connected to the inverting input end of the voltage comparator; the positive power supply input end of the voltage comparator is connected to the positive pole of the power supply, the negative power supply input end is grounded, and a pull-up resistor is connected between the pin of the positive power supply input end and the pin of the output end.

6. The design method of the industrial-grade high-voltage monitoring automatic fool-proofing circuit according to claim 4 is characterized in that: The emitter follower drive combination includes a transistor, a voltage regulator diode, and two resistors; one end of one of the resistors is connected to the output end of the voltage comparator, and the other end is respectively connected to the cathode of the voltage regulator diode and the base of the transistor; the anode of the voltage regulator diode is grounded, the collector of the transistor is connected to the power supply, the emitter of the transistor is connected to another resistor and then to the ground, and the emitter is also connected to one end of the control coil of the i-th level time relay of the corresponding high-voltage disconnect circuit of this level.

7. The design method of the industrial-grade high-voltage monitoring automatic fool-proofing circuit according to claim 3 is characterized in that: Each level of the high-voltage disconnect circuit includes i time relays, one end of the control coil of each time relay is connected to the emitter of the i-th level emitter follower drive combination transistor in the high-voltage comparison circuit of the same level, and the other end is grounded; one end of the delayed closing contact of each time relay is connected to any non-repetitive disordered voltage input terminal, and the other end of the delayed closing contact is respectively connected to the diode anode of the high-voltage screening circuit of the corresponding next level.

8. The design method of the industrial-grade high-voltage monitoring automatic fool-proofing circuit according to claim 2 is characterized in that: The fool-proofing circuit is also provided with its own power supply circuit, which is supplied by an emitter follower. The emitter follower is composed of a voltage-stabilizing diode, a transistor and two resistors. The cathode of the voltage-stabilizing diode is respectively connected to one of the resistors and the base of the transistor, the anode of the voltage-stabilizing diode is grounded, and the cathode of the voltage-stabilizing diode is connected to the resistor and then connected to the highest voltage end of the output of the first-level high-voltage screening circuit; the emitter of the transistor is connected to another resistor and then grounded, and the emitter of the transistor is also connected to the output end, which is the positive electrode of the power supply of the overall circuit, and the collector of the transistor is connected to the highest voltage end of the output of the first-level high-voltage screening circuit.

Images