CN117978084A - Method for reducing non-shielding electric quantity loss - Google Patents
Method for reducing non-shielding electric quantity loss Download PDFInfo
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- CN117978084A CN117978084A CN202311523682.XA CN202311523682A CN117978084A CN 117978084 A CN117978084 A CN 117978084A CN 202311523682 A CN202311523682 A CN 202311523682A CN 117978084 A CN117978084 A CN 117978084A
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Abstract
The invention relates to the field of photovoltaic optimizers, and discloses a method for reducing non-shielding electric quantity loss, which comprises the following steps: detecting current photovoltaic module electrical parameters, wherein the current photovoltaic module electrical parameters comprise current voltage V1, current I1 and current power P1; calculating the change trend of the electrical parameters of the photovoltaic module, and subtracting the initial electrical parameters of the photovoltaic module before the unit time T from the current electrical parameters of the photovoltaic module to obtain the change trend of the electrical parameters of the photovoltaic module; the initial photovoltaic module electrical parameters comprise an initial voltage V0, an initial current I0 and an initial power P0; the photovoltaic module electrical parameter variation trend comprises a voltage variation trend V=v1-V0, a current variation trend I=i1-I0 and a power variation trend P=P1-P0; step three, judging the change trend of the electrical parameters of the photovoltaic module, and selecting and controlling the working state of the photovoltaic optimizer; the working state of the photovoltaic optimizer comprises: stopping working and outputting normally. The invention can effectively reduce the electric quantity loss of the non-blocking photovoltaic component.
Description
Technical Field
The invention relates to the field of photovoltaic optimizers, in particular to a method for reducing non-shielding electric quantity loss.
Background
In a photovoltaic system, a photovoltaic array is generally formed by connecting a plurality of photovoltaic modules in series, so that solar energy can be utilized to the maximum extent to generate electric energy. However, such a serial array structure inevitably causes a certain power loss. Because the currents of the series circuits are equal, one component in the series is partially shielded or damaged, and the like, the output power of the whole system is reduced, and the electric quantity loss is large. The mounting of the photovoltaic optimizer is the most direct and effective method for solving the electric quantity loss at present.
The mounting photovoltaic optimizer can effectively solve the problem of electric quantity loss caused by shielding and the like, but another problem occurs along with the fact that: without shielding, the mounting optimizer would instead lose a small portion of its power. The reason for this is that the power consumption (about 10W) is generated when the optimizer itself works, and the larger the current is, the larger the power consumption is. The loss is not as much as from the single optimizer level, but the more the number, the more the loss is doubled (100 is 1000W). Another aspect is that the photovoltaic optimizer device itself cannot fully (about 95%) deliver the output of the photovoltaic module to the inverter, and can cause about 5% loss.
Disclosure of Invention
The invention aims to provide a method for reducing the non-shielding electric quantity loss so as to solve the problem that a certain electric quantity loss still exists even if a photovoltaic power optimizer is mounted.
In order to solve the problems, the invention adopts the following technical scheme:
A method for reducing non-blocking power loss, comprising the steps of:
Step one, detecting current photovoltaic module electrical parameters, wherein the current photovoltaic module electrical parameters comprise current voltage V1, current I1 and current power P1;
calculating the change trend of the electrical parameters of the photovoltaic module, and subtracting the initial electrical parameters of the photovoltaic module before the unit time T from the current electrical parameters of the photovoltaic module to obtain the change trend of the electrical parameters of the photovoltaic module; the initial photovoltaic module electrical parameters comprise an initial voltage V0, an initial current I0 and an initial power P0;
The photovoltaic module electrical parameter variation trend comprises a voltage variation trend V=v1-V0, a current variation trend I=i1-I0 and a power variation trend P=P1-P0;
Step three, judging the change trend of the electrical parameters of the photovoltaic module, and selecting and controlling the working state of the photovoltaic optimizer; the working state of the photovoltaic optimizer comprises: stopping working and outputting normally.
And in the third step, judging whether the corresponding photovoltaic module is shielded according to the variation trend of the electrical parameters of the photovoltaic module, if so, controlling the photovoltaic optimizer to enter a normal output working state, and if not, controlling the photovoltaic optimizer to enter a stop working state.
Further, the method for judging whether the corresponding photovoltaic module is shielded according to the change trend of the electrical parameter of the photovoltaic module comprises the following steps:
When the current change trend I is negative and smaller than 20% of the initial current I0 or when the power change trend P is negative and smaller than 15% of the initial power, the photovoltaic module is considered to have shielding;
When the current change trend I is positive and more than or equal to the initial current I0 or when the power change trend P is positive and more than or equal to the initial power P0, and meanwhile, the duty ratio exceeds the set threshold, the power component is considered to have no shielding.
Further, the set threshold is 90%.
Further, when judging whether the photovoltaic module is shielded or not, before judging the change trend of the electrical parameter, judging the working environment temperature and the illumination intensity of the working environment of the current photovoltaic module to judge whether the photovoltaic module is in a normal working environment or not; when the working environment temperature is greater than-15 degrees and smaller than 55 degrees, and the illumination intensity is greater than 300 lux and smaller than 500 lux, judging that the photovoltaic module is in a normal working environment, and judging whether the corresponding photovoltaic module is shielded or not according to the change trend of the electrical parameters of the photovoltaic module.
Further, if the photovoltaic module is considered to have no shielding when the operating environment temperature is equal to or less than-15 ° and the illumination intensity is equal to or less than 50 lux and is equal to or less than 300 lux, when the current variation trend I is negative and the absolute value is equal to or less than 40% of the initial current I0 or when the power variation trend P is negative and the absolute value is equal to or less than 35% of the initial power, and the duty ratio exceeds the set threshold.
Further, if the photovoltaic module is when the working environment temperature is greater than or equal to 55 ° and the illumination intensity is greater than 300 lux, when the current variation trend I is positive and its absolute value is greater than or equal to 55% of the initial current I0 or when the power variation trend P is positive and its absolute value is greater than or equal to 50% of the initial power, and at the same time, the duty ratio exceeds the set threshold, then it is considered that there is no shielding of the power module.
Furthermore, a controllable switch is added on a hardware circuit, and acquisition of the electrical parameters of the photovoltaic module is completed through AD sampling.
The controllable switch can be a diode, a triode or a thyristor with a switching function, and the MOS tube is selected as the controllable switch in the scheme.
The principle and the advantages of the scheme are as follows: according to the scheme, the controllable switch is added on the hardware structure of the photovoltaic optimizer, meanwhile, the selection and switching control of the working state of the photovoltaic optimizer are completed through the controllable switch controlled by a software method, the optimizer serves as a midpoint station between the photovoltaic module and the inverter, when the photovoltaic module is shielded, the photovoltaic module is output to the inverter by the optimizer, and when the photovoltaic module is not shielded, the photovoltaic module is directly output to the inverter, so that the loss caused by transition of the optimizer is reduced. The method can solve the electric quantity loss caused by shielding and the electric quantity loss caused by the self power consumption of the optimizer.
Drawings
Fig. 1 is a flowchart of a first embodiment of the present invention.
Detailed Description
The following is a further detailed description of the embodiments:
Example 1
An example is substantially as shown in figure 1: the method for reducing the non-shielding electric quantity loss in the embodiment comprises the following steps:
firstly, adding a controllable switch on a hardware circuit, and completing acquisition of electric parameters of the photovoltaic module through AD sampling. Detecting current photovoltaic module electrical parameters, wherein the current photovoltaic module electrical parameters comprise current voltage V1, current I1 and current power P1;
Calculating the change trend of the electrical parameters of the photovoltaic module, and subtracting the initial electrical parameters of the photovoltaic module before the unit time T from the current electrical parameters of the photovoltaic module to obtain the change trend of the electrical parameters of the photovoltaic module; the initial photovoltaic module electrical parameters comprise an initial voltage V0, an initial current I0 and an initial power P0;
The photovoltaic module electrical parameter variation trend comprises a voltage variation trend V=v1-V0, a current variation trend I=i1-I0 and a power variation trend P=P1-P0;
thirdly, judging the change trend of the electrical parameters of the photovoltaic module, and selecting and controlling the working state of the photovoltaic optimizer; the working state of the photovoltaic optimizer comprises: stopping working and outputting normally.
Judging whether the corresponding photovoltaic module is shielded or not according to the change trend of the electrical parameters of the photovoltaic module, if so, controlling the photovoltaic optimizer to enter a normal output working state, and if not, controlling the photovoltaic optimizer to enter a stop working state.
When judging whether the photovoltaic module is shielded or not, before judging the change trend of the electrical parameters, judging the working environment temperature and the illumination intensity of the working environment of the current photovoltaic module so as to judge whether the photovoltaic module is in a normal working environment or not; when judging whether the photovoltaic module is shielded or not, before judging the change trend of the electrical parameters, judging the working environment temperature and the illumination intensity of the working environment of the current photovoltaic module so as to judge whether the photovoltaic module is in a normal working environment or not; when the working environment temperature is greater than-15 degrees and smaller than 55 degrees, and the illumination intensity is greater than 300 lux and smaller than 500 lux, judging that the photovoltaic module is in a normal working environment, and judging whether the corresponding photovoltaic module is shielded or not according to the change trend of the electrical parameters of the photovoltaic module.
Specifically, the method for judging whether the corresponding photovoltaic module is shielded according to the change trend of the electrical parameter of the photovoltaic module comprises the following steps:
When the current change trend I is negative and smaller than 20% of the initial current I0 or when the power change trend P is negative and smaller than 15% of the initial power, the photovoltaic module is considered to have shielding;
When the current change trend I is positive and more than or equal to the initial current I0 or when the power change trend P is positive and more than or equal to the initial power P0, and meanwhile, the duty ratio exceeds the set threshold, the power component is considered to have no shielding.
Wherein the set threshold is 90%.
When the photovoltaic module is not in the normal working environment, judging whether the photovoltaic module is shielded according to the following content, and further judging whether to start or close the photovoltaic optimizer:
If the temperature of the working environment of the photovoltaic module is less than or equal to minus 15 degrees and the illumination intensity is greater than 50 lux and less than or equal to 300 lux, when the current change trend I is negative and the absolute value is less than or equal to 40% of the initial current I0 or when the power change trend P is negative and the absolute value is less than or equal to 35% of the initial power, and meanwhile, the duty ratio exceeds a set threshold, the power module is considered to be free from shielding. If the working environment temperature of the photovoltaic module is greater than or equal to 55 degrees and the illumination intensity is greater than 300 lux, when the current change trend I is positive and the absolute value of the current change trend I is greater than or equal to 55% of the initial current I0 or when the power change trend P is positive and the absolute value of the power change trend P is greater than or equal to 50% of the initial power, and meanwhile, the duty ratio exceeds a set threshold, the power module is considered to be free from shielding.
In the scheme, a controllable switch is added on a hardware structure of the photovoltaic optimizer, wherein the controllable switch can be a diode, a triode or a thyristor with a switching function, and an MOS tube is selected as the controllable switch in the embodiment; meanwhile, the controllable switch is controlled by a software method to complete the selection and switching control of the working state of the photovoltaic optimizer, the optimizer is used as a midpoint station between the photovoltaic module and the inverter, when the photovoltaic module is shielded, the photovoltaic module is output to the optimizer by the control switch, and when the photovoltaic module is not shielded, the photovoltaic module is directly output to the inverter, so that the loss caused by transition of the optimizer is reduced. The method can solve the electric quantity loss caused by shielding and the electric quantity loss caused by the self power consumption of the optimizer.
According to the embodiment, a controllable switch tube is added on a hardware circuit design, software detects voltage, current or power change of a photovoltaic module through AD sampling, a switch is controlled according to a change trend, the switch determines whether current passes through an optimizer power circuit, when current or power is detected to be reduced by a certain proportion, the photovoltaic module is considered to be shielded, at the moment, the current is reduced by the optimizer power circuit to rise and flow, normal output of a system is ensured, if the current or power is detected to rise by a certain proportion, and the duty ratio exceeds a set threshold, no shielding is considered, at the moment, the switch can be controlled to enable the current to be directly input into an inverter, and the optimizer power circuit is shielded, so that power consumption is reduced. Compared with the prior art, the loss of the photovoltaic optimizer can be reduced by more than 10%, the energy consumption can be effectively reduced on the premise that the normal operation of the photovoltaic optimizer is not affected, and the service life of the photovoltaic optimizer can be prolonged.
The foregoing is merely exemplary of the present application, and specific technical solutions and/or features that are well known in the art have not been described in detail herein. It should be noted that, for those skilled in the art, several variations and modifications can be made without departing from the technical solution of the present application, and these should also be regarded as the protection scope of the present application, which does not affect the effect of the implementation of the present application and the practical applicability of the patent. The protection scope of the present application is subject to the content of the claims, and the description of the specific embodiments and the like in the specification can be used for explaining the content of the claims.
Claims (8)
1. The method for reducing the non-shielding electric quantity loss is characterized by comprising the following steps of:
Step one, detecting current photovoltaic module electrical parameters, wherein the current photovoltaic module electrical parameters comprise current voltage V1, current I1 and current power P1;
calculating the change trend of the electrical parameters of the photovoltaic module, and subtracting the initial electrical parameters of the photovoltaic module before the unit time T from the current electrical parameters of the photovoltaic module to obtain the change trend of the electrical parameters of the photovoltaic module; the initial photovoltaic module electrical parameters comprise an initial voltage V0, an initial current I0 and an initial power P0;
The photovoltaic module electrical parameter variation trend comprises a voltage variation trend V=v1-V0, a current variation trend I=i1-I0 and a power variation trend P=P1-P0;
Step three, judging the change trend of the electrical parameters of the photovoltaic module, and selecting and controlling the working state of the photovoltaic optimizer; the working state of the photovoltaic optimizer comprises: stopping working and outputting normally.
2. The method for reducing non-shielding electric quantity loss according to claim 1, wherein in the third step, whether the corresponding photovoltaic module is shielded is judged according to the change trend of the electric parameters of the photovoltaic module, if the corresponding photovoltaic module is shielded, the photovoltaic optimizer is controlled to enter a normal output working state, and if the corresponding photovoltaic module is not shielded, the photovoltaic optimizer is controlled to enter a stop working state.
3. The method for reducing non-shielding electric quantity loss according to claim 2, wherein the step of judging whether the corresponding photovoltaic module is shielded according to the trend of the change of the electric parameter of the photovoltaic module comprises the following steps:
When the current change trend I is negative and smaller than 20% of the initial current I0 or when the power change trend P is negative and smaller than 15% of the initial power, the photovoltaic module is considered to have shielding;
When the current change trend I is positive and more than or equal to the initial current I0 or when the power change trend P is positive and more than or equal to the initial power P0, and meanwhile, the duty ratio exceeds the set threshold, the power component is considered to have no shielding.
4. A method of reducing shadowless power loss as set forth in claim 3 wherein said threshold is 90%.
5. The method for reducing non-shielding electric quantity loss according to claim 3, wherein when judging whether the photovoltaic module is shielded, before judging the trend of electric parameter change, it is necessary to judge the current working environment temperature and the working environment illumination intensity of the photovoltaic module so as to judge whether the photovoltaic module is in a normal working environment; when the working environment temperature is greater than-15 degrees and smaller than 55 degrees, and the illumination intensity is greater than 300 lux and smaller than 500 lux, judging that the photovoltaic module is in a normal working environment, and judging whether the corresponding photovoltaic module is shielded or not according to the change trend of the electrical parameters of the photovoltaic module.
6. The method according to claim 5, wherein if the photovoltaic module has a working environment temperature of-15 ° or less and an illumination intensity of 50 lux or more and 300 lux or less, the power module is considered to have no shielding when the current variation trend I is negative and the absolute value is 40% or less of the initial current I0 or when the power variation trend P is negative and the absolute value is 35% or less of the initial power, and the duty ratio exceeds the set threshold.
7. The method according to claim 5, wherein if the photovoltaic module has a working environment temperature of 55 ° or higher and an illumination intensity of 300 lux or higher, the power module is considered to have no shielding when the current variation trend I is positive and its absolute value is 55% or higher of the initial current I0 or when the power variation trend P is positive and its absolute value is 50% or higher of the initial power, and the duty ratio exceeds the set threshold.
8. The method for reducing non-blocking electric quantity loss according to claim 1, wherein the acquisition of the electric parameters of the photovoltaic module is completed through AD sampling by adding a controllable switch on a hardware circuit.
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| CN202311523682.XA CN117978084A (en) | 2023-11-14 | 2023-11-14 | Method for reducing non-shielding electric quantity loss |
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