CN104716902B - Device and method for measuring maximum power of photovoltaic module and method for measuring generated energy - Google Patents

Abstract

The embodiment of the invention provides a device and a method for measuring the maximum power of a photovoltaic module and a method for measuring the power generation amount, wherein the device for measuring the maximum power of the photovoltaic module comprises the following components: one end of the voltage measuring circuit is connected with the anode of the photovoltaic module, and the other end of the voltage measuring circuit is connected with the cathode of the photovoltaic module, and the voltage measuring circuit is used for measuring the open-circuit voltage and the discharge voltage of the photovoltaic module in the current environment; and the controller is connected with the voltage measuring circuit and is used for acquiring the second maximum power of the photovoltaic module under the current environment according to the first maximum power under the standard environment, the working voltage and the working current corresponding to the first maximum power point, the open-circuit voltage and the discharge voltage. The device and the method for measuring the maximum power of the photovoltaic module and the method for measuring the generated energy can measure the maximum power and the generated energy of the photovoltaic module, improve the measurement accuracy, and have the advantages of simple structure, high reliability and low cost.

Description

The peak power measurement apparatus of photovoltaic module, method and generating measuring method

Technical field

The present invention relates to technical field of photovoltaic power generation, more particularly to a kind of peak power measurement apparatus, the side of photovoltaic module Method and generating measuring method.

Background technology

Solar energy is more and more paid close attention to as a kind of new forms of energy of clean environment firendly by people.In the fortune of photovoltaic plant In row, generated energy is the key index for evaluating its performance.In prior art, mainly there are two methods：

One is mathematical model method：Ambient parameter is acquired using temperature sensor and light intensity sensor, then in conjunction with The Mathematical Modeling of photovoltaic battery panel, calculates the output power value of photovoltaic cell under the ambient parameter.The deficiency of the method is Mathematical Modeling is complex, needs a large amount of site environments with electric parameter to correct wherein parameter, reduces its engineering practicability.

Two is look-up table：The method according to the thought of piece-wise linearization, initially set up photovoltaic cell peak power output with Relation table between temperature and light intensity, the then method by testing measures in relation table photovoltaic electric at each temperature and light intensity The peak power output in pond, and insert in table, as the reference of power prediction in future.The deficiency of the method is to set up light When volt battery peak power output is with temperature and the Relationship of Light intensity table, need to gather the power output under various environment, its workload Larger, in addition the foundation of relation table is acquired and tests in photovoltaic cell site, and works as photovoltaic cell site When changing, the relation table set up has been no longer desirable for current location, therefore the method adaptability is not strong, is such as still based on building The relation table for having stood goes to obtain peak power output, and the peak power output degree of accuracy that may result in acquisition is not high.

The content of the invention

Embodiments of the invention provide a kind of peak power measurement apparatus of photovoltaic module, method and generating measuring Method, it is possible to increase the peak power of measurement photovoltaic module and the degree of accuracy of generated energy.

For achieving the above object, The embodiment provides a kind of peak power for photovoltaic module is measured Device, described device includes：Tension measuring circuit, described tension measuring circuit one end is connected with the positive pole of the photovoltaic module Connect, the other end is connected with the negative pole of the photovoltaic module, for measuring the open-circuit voltage of the photovoltaic module of current environment And discharge voltage；Controller, is connected with the tension measuring circuit, for according to the first peak power under standard environment with And the first corresponding operating voltage of maximum power point and operating current, the open-circuit voltage and discharge voltage, obtain current environment Under the photovoltaic module the second peak power.

Embodiments of the invention additionally provide a kind of peak power measuring method for photovoltaic module, methods described bag Include：The open-circuit voltage and discharge voltage of the photovoltaic module of measurement current environment；According to the first maximum work under standard environment Rate and the corresponding operating voltage of the first maximum power point and operating current, the open-circuit voltage and discharge voltage, obtain current Second peak power of the photovoltaic module under environment.

Embodiments of the invention additionally provide a kind of generating measuring method for photovoltaic module, and methods described includes： In predetermined time period, with the peak power measurement side for photovoltaic module that setting time interval utilizes above-described embodiment Method, obtains the corresponding peak power of each time interval under current environment；Length according to predetermined time period, setting when Between interval and the corresponding peak power of described each time interval the generated energy of the photovoltaic module is calculated by following formula：

Wherein, W_PVFor the generated energy of the photovoltaic module, Δ T is setting time interval, and i is the sequence number of time interval, and N is Number comprising time interval, P ' in predetermined amount of time_MPPI () is corresponding peak power in i-th time interval.

The peak power measurement apparatus of photovoltaic module provided in an embodiment of the present invention, method and generating measuring method, tool There is following technique effect：

On the one hand, the present invention is the maximum work of the open-circuit voltage and discharge voltage acquisition photovoltaic module obtained based on measurement Rate, for mathematical model method in prior art, open-circuit voltage and the degree of accuracy of discharge voltage measured value in the present invention be high, Error is little, and so as to improve the degree of accuracy of measurement photovoltaic module peak power, and engineering practicability is strong；

On the other hand, open-circuit voltage and discharge voltage belong to the electric signal parameter inside photovoltaic module, compared to existing skill Art is done indirectly using external environment condition parameter (temperature and light intensity) and the relation table of power output to the power output of photovoltaic module For prediction, its parameter form is more nearly the power output of photovoltaic module, and used as internal electric signal parameter, it more can body Reveal the electrology characteristic of tested photovoltaic module, therefore, the photovoltaic module obtained based on the open-circuit voltage and discharge voltage it is defeated Going out power can more accurately, and workload is little, strong adaptability.

Description of the drawings

Fig. 1 is the schematic diagram of the VA characteristic curve of photovoltaic module；

Fig. 2 is the structural representation of the peak power measurement apparatus for photovoltaic module of the embodiment of the present invention one；

Fig. 3 is the structural representation of the peak power measurement apparatus for photovoltaic module of the embodiment of the present invention two；

Fig. 4 is the schematic flow sheet of the peak power measuring method for photovoltaic module of the embodiment of the present invention three；

Fig. 5 is the schematic flow sheet of the generating measuring method for photovoltaic module of the embodiment of the present invention four.

Specific embodiment

It is used for peak power measurement apparatus, method and the generated energy of photovoltaic module to the embodiment of the present invention below in conjunction with the accompanying drawings Measuring method is described in detail.

The peak power measurement apparatus for photovoltaic module of the present invention, method and generating measuring method know-why are Measure the open-circuit voltage and discharge voltage of photovoltaic module under current environment using tension measuring circuit, then based on the open-circuit voltage and The first peak power and the corresponding operating voltage of the first maximum power point and operating current under discharge voltage, standard environment, It is calculated the peak power of photovoltaic module.

For the ease of understanding the embodiment of the present invention, accompanying drawing is combined the maximum work of photovoltaic module to be used for the embodiment of the present invention Before rate measurement apparatus, method and generating measuring method are described in detail, following technical term is explained.

[I. photovoltaic module]

Photovoltaic module (also referred to as solar panel) is the core in solar power system, is also solar electrical energy generation Most important part in system.Its effect is to convert solar energy into electrical energy.

[II. the VA characteristic curve of photovoltaic module]

Fig. 1 is the schematic diagram of the VA characteristic curve of photovoltaic module, with reference to Fig. 1, by the photovoltaic module of illumination, certain At irradiation level and temperature and different external circuit loads, the electric current of inflow and the relation curve of photovoltaic module terminal voltage.

(i) short circuit current (I_SC), under certain irradiation level and temperature conditionss, photovoltaic module is defeated when terminal voltage is zero Go out electric current.

(ii) open-circuit voltage (V_OC), under certain irradiation level and temperature conditionss, photovoltaic module end in the case of an open circuit Voltage.

(iii) peak power (P_M), under certain irradiation level and temperature conditionss, the power vs. voltage curve of photovoltaic module On maximum power value；Or on the VA characteristic curve of photovoltaic module electric current and voltage product maximum.

(iv) maximum power point (maximum power point, MPP), right on the VA characteristic curve of photovoltaic module Answer the point of peak power, also referred to as best operating point.

Corresponding operating current (the I of (v) maximum power point_MPP), the maximum power point on the VA characteristic curve of photovoltaic module Corresponding electric current.

(vi) the corresponding operating voltage (V of maximum power point_MPP), the peak power on the VA characteristic curve of photovoltaic module The corresponding voltage of point.

Embodiment one

Fig. 2 for the embodiment of the present invention one the peak power measurement apparatus for photovoltaic module structural representation, such as Fig. 2 Shown, the peak power measurement apparatus for photovoltaic module of the embodiment of the present invention include：Tension measuring circuit 11, voltage measurement Circuit on one side is connected with the positive pole of photovoltaic module, and the other end is connected with the negative pole of photovoltaic module, for measuring current environment Photovoltaic module open-circuit voltage and discharge voltage；Controller 12, is connected with tension measuring circuit 11, for according to standard ring The first peak power and the corresponding operating voltage of the first maximum power point and operating current, open-circuit voltage and electric discharge electricity under border Pressure, obtains the second peak power of the photovoltaic module under current environment.

Specifically, the tension measuring circuit is nonpolarity, only need to draw two ends, positive pole respectively with photovoltaic module, negative pole phase Connection.Controller control voltage measuring circuit measures the open-circuit voltage and discharge voltage of photovoltaic module under current environment, and Controller is fed back to, controller refers again to the first maximum work under standard environment according to the open-circuit voltage and discharge voltage of feedback Rate and the corresponding operating voltage of the first maximum power point and operating current, so as to get current environment under photovoltaic module Second peak power.

Peak power measurement apparatus for photovoltaic module provided in an embodiment of the present invention, by the positive and negative of photovoltaic module The open-circuit voltage and discharge voltage of pole connection tension measuring circuit measurement current environment, based on the open-circuit voltage and discharge voltage, The first peak power and the corresponding operating voltage of the first maximum power point and operating current under standard environment just can be obtained The peak power of photovoltaic module.And prior art typically obtains temperature, light intensity parameter using temperature sensor and light intensity sensor, The peak power of photovoltaic module is predicted using these ambient parameters.

Can show that the technical scheme of the present embodiment has the following technical effect that by comparative analysis：

1) the present embodiment is based on the peak power for measuring the open-circuit voltage and discharge voltage acquisition photovoltaic module for obtaining, phase For mathematical model method in prior art, open-circuit voltage and the degree of accuracy of the discharge voltage measured value height in the present invention, error It is little such that it is able to improve the degree of accuracy of measurement photovoltaic module peak power, and improve engineering practicability.Contrary prior art A large amount of site environments are larger with measurement of electric parameter difficulty, and error is also very high, poor practicability, based on the photovoltaic that these parameters are obtained The degree of accuracy of component peak power it is difficult to ensure that.

2) open-circuit voltage and discharge voltage belong to the electric signal parameter inside photovoltaic module, compared to tabling look-up in prior art For method, parameter form of the present invention is more nearly the power output of photovoltaic module, and used as internal electric signal parameter, it more can The electrology characteristic of tested photovoltaic module is embodied, therefore, the photovoltaic module obtained based on the open-circuit voltage and discharge voltage Power output can more accurately, and workload is little, strong adaptability.Contrary prior art is setting up photovoltaic cell peak power output Need to gather the power output under various environment during with temperature and the Relationship of Light intensity table, workload is larger, and adaptability is not strong, causes The peak power output degree of accuracy of acquisition is low.

Embodiment two

Fig. 3 for the embodiment of the present invention two the peak power measurement apparatus for photovoltaic module structural representation, such as Fig. 3 Shown, the peak power measurement apparatus for photovoltaic module of the embodiment of the present invention include：Tension measuring circuit 21, voltage measurement Circuit on one side is connected with the positive pole of photovoltaic module, and the other end is connected with the negative pole of photovoltaic module, for measuring current environment Photovoltaic module open-circuit voltage and discharge voltage；Controller 22, is connected with tension measuring circuit 21, for according to standard ring The first peak power and the corresponding operating voltage of the first maximum power point and operating current, open-circuit voltage and electric discharge electricity under border Pressure, obtains the second peak power of the photovoltaic module under current environment.

With reference to Fig. 3, tension measuring circuit is illustrated that in dotted line frame, tension measuring circuit 21 may include discharging resistor 211st, switching device 212 and voltmeter 213, wherein, discharging resistor 211 is composed in series series arm with switching device 212, electricity Pressure table 213 is in parallel with series arm, the control signal that switching device 212 sends in response to controller 22, controls series arm It is opened or closed, when series arm disconnects, voltmeter 213 measures the open-circuit voltage of photovoltaic module, and is sent to controller 22, When series arm is closed, the discharge voltage when measurement photovoltaic module of voltmeter 213 discharges discharging resistor 211, and send To controller 22.The tension measuring circuit simple structure and reliability height.

Specifically, switching device can be specifically, but be not limited to, relay or contactor.Also can be using other derailing switches Part replaces, for example, controller sends control signal, and control relay disconnects, voltmeter measure photovoltaic module open circuit Voltage；Controller sends control signal, control relay closure, after current stabilization, voltmeter measure photovoltaic module to putting Discharge voltage when electric resistor discharges.

Further, tension measuring circuit can also include inductance, and one end of the inductance is connected with discharging resistor, electricity The other end of sense is connected with switching device, for the moment impact electric current for avoiding switching device from producing when closing.

In embodiments of the present invention, discharging resistor is the sufficiently small resistance of resistance, after series arm closure, light Volt component is discharged by the discharging resistor, so as to voltage will be produced at the discharging resistor two ends, after current stabilization, Voltmeter can measure voltage when photovoltaic module discharges discharging resistor, i.e. discharge voltage, due to the resistance of discharging resistor Value is sufficiently small, and it is short circuit current that can be approximately considered and flow through the electric current of resistance, therefore can be by discharge voltage value and discharging resistor Computing the resistor value obtain short-circuit current value.

Tension measuring circuit in the device of the present embodiment is simply made up of inductance, resistance and voltmeter etc., is not required to The external equipments such as relatively expensive temperature sensor and light intensity sensor are configured, therefore, the complexity of structure is reduced, while Reduce cost.

Further, after short-circuit current value is obtained, by analysis may be used using the Practical model of photovoltaic module Know, the ratio of the short circuit current under the conditions of varying environment is equal with the ratio of the corresponding operating current of maximum power point, varying environment bar The ratio of the open-circuit voltage under part is equal with the ratio of the corresponding operating voltage of maximum power point, concrete such as formula (1) and formula (2)：

I′_SC/I″_SC=I '_MPP/I″_MPP... ... ... ... ... ... ... ... ... ... ... ... formula (1)

V′_OC/V″_OC=V '_MPP/V″_MPP... ... ... ... ... ... ... ... ... ... ... ... formula (2)

Wherein, I '_SCFor the short circuit current under the first environment, I '_MPPIt is corresponding for the maximum power point under the first environment Operating current, V '_OCFor the open-circuit voltage under the first environment, V '_MPPFor the corresponding work of maximum power point under the first environment Voltage, I "_SCFor the short circuit current under second environment, I "_MPPFor the corresponding work electricity of maximum power point under second environment Stream, V "_OCFor the open-circuit voltage under second environment, V "_MPPFor the corresponding operating voltage of maximum power point under second environment.

Here, it should be noted that different environmental conditions generally refers to the irradiation level and environment temperature of photovoltaic module, light The power of volt component is mainly affected by irradiation level and environment temperature.

So, it is assumed that the first environment is current environment, second environment is that standard environment, i.e. irradiation level are 1000W/ m², environment temperature is 25 DEG C, the first peak power and the corresponding operating voltage of the first maximum power point under standard environment Known numeric value is with operating current, controller just can be by below equation (3) and formula (4) according to first under standard environment Peak power and the corresponding operating voltage of the first maximum power point and operating current, open-circuit voltage and discharge voltage, obtain and work as Second peak power of the photovoltaic module under front environment：

... ... ... ... ... ... ... ... ... ... ... ... ... ... formula (3)

... ... ... ... ... ... ... ... ... ... ... ... formula (4)

Wherein, V '_SCThe discharge voltage of photovoltaic module under to measure the current environment that obtains, R is discharge resistance, I '_SCIt is to work as The short circuit current of photovoltaic module, V ' under front environment_OCThe open-circuit voltage of photovoltaic module, P ' under to measure the current environment for obtaining_MPPFor Second peak power of photovoltaic module, P_MPPNFor the first peak power under standard environment, V_OCNIt is maximum under standard environment first The corresponding operating voltage of power points, I_SCNFor the corresponding operating current of the first maximum power point under standard environment.

In the present embodiment, the discharge voltage for directly being measured based on tension measuring circuit is calculated short circuit current, and Using standard environment as on the premise of one of which environmental condition, under the conditions of varying environment, short circuit current and peak power Put proportionate relationship, the proportionate relationship of open-circuit voltage operating voltage corresponding with maximum power point and the mark of corresponding operating current The parameter of photovoltaic module under quasi, it becomes possible to obtain the peak power of current environment photovoltaic module, its calculation is easy, and And the degree of accuracy of the photovoltaic module peak power for finally giving is high.With reference to specific example, further more intuitively to say The concrete application of the bright embodiment of the present invention once.

5 kinds of photovoltaic battery panels are chosen, power grade is 210W-300W.The use specifications of photovoltaic battery panel give mark The maximum power value P of floating screed part (1000W/m2,25 DEG C) and non-standard condition (800W/m2,20 DEG C) under the conditions of both_MPPNWith P_MPP。

Using the device of the embodiment of the present invention, the open-circuit voltage and discharge voltage under non-standard condition is measured, by measuring Discharge voltage be calculated short circuit current, photovoltaic battery panel under non-standard condition can be obtained by aforementioned computing formula (4) Peak power, then will obtain the non-standard condition provided in the peak power and specifications of photovoltaic battery panel under non-standard condition The peak power of lower photovoltaic battery panel is contrasted, as a result as shown in table 1 below：

Table 1

Sequence number

PMPPN

PMPP

V′OC

I′SC

P′MPP

Error (%)

1

210W

152.1W

28.6V

7.13A

157.85W

3.78

2

220W

160.5W

28.1V

7.19A

164.35W

2.40

3

240W

175.1W

34.8V

6.81A

178.68W

2.04

4

250W

182.4W

34.2V

7.01A

186.50W

2.25

5

260W

189.7W

34.4V

7.25A

194.27W

2.41

6

280W

204.2W

36.7V

7.76A

209.36W

2.53

7

290W

211.5W

41.9V

7.16A

216.85W

2.53

8

300W

218.8W

42.7V

7.10A

223.40W

2.10

From the error result in table 1, the maximum of the photovoltaic battery panel obtained using the device of the embodiment of the present invention Power control errors within 5%, can comply fully with the standard of engineer applied.

Embodiment three

Fig. 4 for the embodiment of the present invention three the peak power measuring method for photovoltaic module schematic flow sheet, such as Fig. 4 Shown, the peak power measuring method for photovoltaic module includes：

Step 301：The open-circuit voltage and discharge voltage of the photovoltaic module of measurement current environment.

Step 302：According to the first peak power under standard environment and the corresponding operating voltage of the first maximum power point With the open-circuit voltage and discharge voltage under operating current, current environment, the second maximum of photovoltaic module under current environment is obtained Power.Specifically, according to the first peak power under standard environment and the corresponding operating voltage of the first maximum power point and work Make the open-circuit voltage and discharge voltage under electric current, current environment, obtain the second peak power of the photovoltaic module under current environment Process using following formula (5) and formula (6) realization：

... ... ... ... ... ... ... ... ... ... ... ... ... ... formula (5)

... ... ... ... ... ... ... ... ... ... ... ... formula (6)

Wherein, V '_SCThe discharge voltage of photovoltaic module under to measure the current environment that obtains, R is discharge resistance, I '_SCIt is to work as The short circuit current of photovoltaic module, V ' under front environment_OCThe open-circuit voltage of photovoltaic module, P ' under to measure the current environment for obtaining_MPPFor Second peak power of photovoltaic module, P_MPPNFor the first peak power under standard environment, V_OCNIt is maximum under standard environment first The corresponding operating voltage of power points, I_SCNFor the corresponding operating current of the first maximum power point under standard environment.

Peak power measuring method for photovoltaic module provided in an embodiment of the present invention, by measuring opening for current environment Road voltage and discharge voltage, based on the first peak power and first under the open-circuit voltage and discharge voltage, standard environment most The corresponding operating voltage of high-power point and operating current can just obtain the peak power of photovoltaic module.Compared with prior art, Have the following technical effect that：

1) the present embodiment is based on the peak power for measuring the open-circuit voltage and discharge voltage acquisition photovoltaic module for obtaining, phase For mathematical model method in prior art, the open-circuit voltage of the present invention and discharge voltage measured value degree of accuracy height, error are little, So as to improve the degree of accuracy of measurement photovoltaic module peak power.

2) the present embodiment measurement is obtained open-circuit voltage and discharge voltage can directly reflect the electricity of tested photovoltaic module Characteristic, relative to look-up table in prior art, and using external environment condition parameter and the relation table of power output, to photovoltaic module Power output is done and is indirectly predicted, the present embodiment does further power calculation based on the open-circuit voltage and discharge voltage can be more Accurately.

3) the present embodiment is to be calculated short circuit current based on the discharge voltage for directly measuring, and using varying environment condition Under, the proportionate relationship of short circuit current operating current corresponding with maximum power point, open-circuit voltage work corresponding with maximum power point Make the parameter of photovoltaic module under the proportionate relationship and standard environment of voltage, so as to obtain the maximum work of current environment photovoltaic module Rate, its accuracy of measurement is high, and calculation is easy.Improve engineering practicability, and strong adaptability.

Example IV

Fig. 5 is the schematic flow sheet of the generating measuring method for photovoltaic module of the embodiment of the present invention four, such as Fig. 5 institutes Show, the generating measuring method for photovoltaic module includes：

Step 401：In predetermined time period, with setting time interval utilize as described in embodiment three for photovoltaic group The peak power measuring method of part, obtains the corresponding peak power of each time interval under current environment.

Step 402：Length, the time interval of setting and each time interval according to predetermined time period is corresponding most The high-power generated energy that photovoltaic module is calculated by following formula (7)：

... ... ... ... ... ... ... ... ... ... ... ... formula (7)

Wherein, W_PVFor the generated energy of photovoltaic module, Δ T is setting time interval, and i is the sequence number of time interval, and N is predetermined Number comprising time interval, P ' in time period_MPPI () is corresponding peak power in i-th time interval.Specifically, illustrate For, if predetermined amount of time is one day, i.e., 24 hour, each time interval was obtained with 5 seconds Fixed Time Intervals corresponding most It is high-power, then, cumulative summation is carried out to generated energy with Fixed Time Interval, you can obtain same day generated energy.

The generating measuring method for photovoltaic module of the present invention, by predetermined time period, with setting time Interval utilizes the peak power measuring method for photovoltaic module described in embodiment three, obtains each time under current environment Corresponding peak power is spaced, then cumulative summation is carried out to the generated energy tried to achieve by peak power with Fixed Time Interval, so as to The generated energy of photovoltaic module is calculated, the degree of accuracy of measurement photovoltaic module generated energy is improve.

The above, the only specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, any Those familiar with the art the invention discloses technical scope in, change or replacement can be readily occurred in, all should contain Cover within protection scope of the present invention.Therefore, protection scope of the present invention should be defined by the scope of the claims.

Claims (8)

1. a kind of peak power measurement apparatus for photovoltaic module, it is characterised in that described device includes：

Tension measuring circuit, described tension measuring circuit one end is connected with the positive pole of the photovoltaic module, the other end with it is described The negative pole of photovoltaic module is connected, described for measuring the open-circuit voltage and discharge voltage of the photovoltaic module of current environment Tension measuring circuit includes discharging resistor；

Controller, is connected with the tension measuring circuit, for the electric discharge electricity obtained according to the tension measuring circuit measurement The resistance of pressure and discharging resistor obtains the short circuit current of the photovoltaic module, and according to the first peak power under standard environment And the first corresponding operating voltage of maximum power point and operating current, the open-circuit voltage and short circuit current, acquisition works as front ring Second peak power of the photovoltaic module under border.

2. peak power measurement apparatus according to claim 1, it is characterised in that the tension measuring circuit also includes opening Device and voltmeter are closed, the resistance of the discharging resistor is sufficiently small so that flow through the electric current of the discharging resistor be close to short Road electric current；

The discharging resistor is composed in series series arm with the switching device, and the voltmeter is with the series arm simultaneously Connection, the control signal that the switching device sends in response to the controller controls being opened or closed for the series arm, when When the series arm disconnects, the open-circuit voltage of the voltmeter measurement photovoltaic module is simultaneously sent to the controller, when described When series arm is closed, the voltmeter measures discharge voltage when photovoltaic module discharges the discharging resistor and is sent to The controller.

3. peak power measurement apparatus according to claim 2, it is characterised in that the tension measuring circuit also includes electricity Sense, one end of the inductance is connected with the discharging resistor, and the other end of the inductance is connected with the switching device, For the moment impact electric current for avoiding the switching device from producing when closing.

4. peak power measurement apparatus according to Claims 2 or 3, it is characterised in that the switching device be specially after Electrical equipment or contactor.

5. peak power measurement apparatus according to claim 1, it is characterised in that the controller is held by below equation Row is according to the first peak power under standard environment and the corresponding operating voltage of the first maximum power point and operating current, described Open-circuit voltage and short circuit current, the process of the second peak power of the photovoltaic module under acquisition current environment：

$I_{SC}^{\′}=\frac{V_{SC}^{\′}}{R},P_{MPP}^{\′}=P_{MPPN}\frac{V_{OC}^{\′}{I}_{SC}^{\′}}{V_{OCN}{I}_{SCN}},$

Wherein, V '_SCThe discharge voltage of photovoltaic module under to measure the current environment that obtains, R is discharge resistance, I '_SCIt is to work as front ring The short circuit current of photovoltaic module, V ' under border_OCThe open-circuit voltage of photovoltaic module, P ' under to measure the current environment for obtaining_MPPFor described Second peak power of photovoltaic module, P_MPPNFor the first peak power under standard environment, V_OCNIt is maximum under standard environment first The corresponding operating voltage of power points, I_SCNFor the corresponding operating current of the first maximum power point under standard environment.

6. a kind of peak power measuring method for photovoltaic module, it is characterised in that methods described includes：

The open-circuit voltage and discharge voltage of the photovoltaic module of measurement current environment；

The short circuit current of the photovoltaic module is obtained according to the discharge voltage, and according to the first peak power under standard environment And the first corresponding operating voltage of maximum power point and operating current, the open-circuit voltage and short circuit current, acquisition works as front ring Second peak power of the photovoltaic module under border.

7. peak power measuring method according to claim 6, it is characterised in that it is described according under standard environment first Peak power and the corresponding operating voltage of the first maximum power point and operating current, the open-circuit voltage and short circuit current, obtain The process for taking the second peak power of the photovoltaic module under current environment is realized using following formula：

$I_{SC}^{\′}=\frac{V_{SC}^{\′}}{R},P_{MPP}^{\′}=P_{MPPN}\frac{V_{OC}^{\′}{I}_{SC}^{\′}}{V_{OCN}{I}_{SCN}},$

Wherein, V '_SCThe discharge voltage of photovoltaic module under to measure the current environment that obtains, R is discharge resistance, I '_SCIt is to work as front ring The short circuit current of photovoltaic module, V ' under border_OCThe open-circuit voltage of photovoltaic module, P ' under to measure the current environment for obtaining_MPPFor described Second peak power of photovoltaic module, P_MPPNFor the first peak power under standard environment, V_OCNIt is maximum under standard environment first The corresponding operating voltage of power points, I_SCNFor the corresponding operating current of the first maximum power point under standard environment.

8. a kind of generating measuring method for photovoltaic module, it is characterised in that methods described includes：

In predetermined time period, the maximum for photovoltaic module for utilizing as claimed in claims 6 or 7 is spaced with setting time Power measurement method, obtains the corresponding peak power of each time interval under current environment；

Length, the time interval of setting and the corresponding peak power of described each time interval according to predetermined time period is logical Cross the generated energy that following formula calculates the photovoltaic module：

$W_{PV}=\underset{i=1}{\overset{N}{\Σ}}(\mathrm{\Δ}T\·P_{MPP}^{\′}(i\left)\right),$

Wherein, W_PVFor the generated energy of the photovoltaic module, Δ T is setting time interval, and i is the sequence number of time interval, and N is predetermined Number comprising time interval, P ' in time period_MPPI () is corresponding peak power in i-th time interval.