CN106856331B - Grid-connected performance testing method for wind-solar combined power generation system - Google Patents

Abstract

The invention relates to a method for testing the grid-connected performance of a wind-solar combined power generation system, which comprises the following steps: step 1: determining a test point for field test of the wind-solar combined power generation system; step 2: determining a test condition of field detection of the wind-solar combined power generation system; and step 3: determining the test content of the scene detection of the wind-solar combined power generation system; and 4, step 4: and testing the grid-connected point performance of the wind-solar combined power generation system. The technical scheme provided by the invention solves the problem of field detection of the grid-connected performance of the power generation system, and has very important significance for improving the standardization and the accuracy of the field test of the wind power combined power generation system.

Description

A method for testing the grid-connected performance of wind-solar combined power generation systems

technical field

The invention relates to a method for testing new energy access and control, in particular to a method for testing grid-connected performance of a wind-solar combined power generation system.

Background technique

Wind-solar combined power generation system is a wind-solar hybrid power system that comprehensively utilizes wind and solar energy, and is a reasonable power system. It not only opens up a new way to solve the current energy crisis and environmental pollution problems, but also effectively improves the stability and reliability of the system when wind power and photovoltaic power generation independently output power.

A separate solar or wind energy system, due to time and geographical constraints, is difficult to utilize solar and wind energy resources around the clock. And solar energy and wind energy have strong complementarity in time and region. When the light is strong during the day, the wind is small, and when the light is weak at night, the wind energy is enhanced due to the large change in the surface temperature difference. The complementarity of solar energy and wind energy in time is scenery. The best match of complementary power generation system in resource utilization.

The wind and wind combined power generation system is mainly composed of wind power generation units and photovoltaic power generation units. Wind power units utilize wind turbines to convert wind energy into electrical output. Photovoltaic power generation units use photovoltaic panels of the required scale to convert sunlight energy into electrical output. The two power generation methods of wind power and photovoltaic complement each other in energy collection, and at the same time have their own characteristics: photovoltaic power generation has reliable power supply, low operation and maintenance cost, but high cost; wind power generation has high power generation, low cost and operation and maintenance cost, but reliable low sex.

Wind-solar combined power generation system utilizes the natural complementarity of wind energy and solar energy, such as sufficient solar energy during the day and sufficient wind energy at night; sufficient solar energy in summer and sufficient wind energy in winter, which can improve the economy and reliability of the system. In Northwest my country, North China and other regions, wind energy and solar energy resources are complementary. The wind is strong in winter and spring, and the solar radiation is strong in summer and autumn. Therefore, the use of wind energy/solar complementary power generation can well overcome wind energy and solar energy to provide energy. The shortcomings of randomness and intermittentness can realize uninterrupted power supply.

The access of the wind-solar combined power generation system has a certain impact on the peak regulation, stable operation and power quality of the power grid, and the fluctuation of wind and light makes the output power of the wind-solar combined power generation system fluctuate, which is difficult to the wind-solar combined power generation like conventional power sources. The system develops and implements accurate power generation plans. Power fluctuations may cause problems such as voltage fluctuations, frequency fluctuations, and transmission power fluctuations of transmission lines in the power grid. Large power shocks may also cause power oscillations between synchronous generator sets in the power grid. In severe cases, the stable operation of the power grid will be destroyed. Grid security has a direct impact. With the development of wind-solar combined power generation systems, it is urgent to carry out research on the grid-connected performance test and detection technology of wind-solar combined power generation systems to ensure the safe and stable operation of the power system after the wind-solar combined power generation system is connected to the grid.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for testing the grid-connected performance of a wind-solar combined power generation system, which is of great significance for improving the standardization and accuracy of on-site testing of the wind-power combined power generation system.

The purpose of this invention is to adopt following technical scheme to realize:

The present invention provides a method for testing the grid-connected performance of a wind-solar combined power generation system. The improvement lies in that the testing method includes the following steps:

Step 1: Determine the test points for on-site inspection of the wind-solar combined power generation system;

Step 2: Determine the test conditions for the on-site inspection of the wind-solar combined power generation system;

Step 3: Determine the test content of the on-site inspection of the wind-solar combined power generation system;

Step 4: Test the performance of the grid connection point of the wind-solar combined power generation system.

Further, in the step 1, the test points are determined according to the wiring mode of the wind-solar combined power generation system; the grid-connected test points of the 220kV or 110kV level and the 35kV level are included; the electrical collection points of the wind-solar combined power generation system include: the main transformer high-voltage 220kV three-phase voltage on the side, 220kV three-phase current on the high-voltage side of the main transformer, 35kV three-phase voltage on the low-voltage side of the main transformer, 35kV three-phase current on the low-voltage side of the main transformer, 35kV three-phase voltage at the grid connection point of the wind power branch, 35kV three-phase voltage at the grid connection point of the wind power branch Phase current, 35kV three-phase voltage of photovoltaic branch grid connection point and 35kV three-phase current of photovoltaic branch grid connection point.

Further, in the step 2, the test conditions for the on-site detection of the wind-solar combined power generation system are: stable grid-connected operation capability, and independent wind power generation operation, photovoltaic independent power generation operation, and wind-solar combined power generation operation; during the test, the wind speed is required to have 3-15m/s working condition to ensure that the output power of the fan is in the range of 0 to 95% Pn; the light radiation amount is required to meet 0-7500MJ/m ² to ensure that the output power of the photovoltaic power station is in the range of 0 to rated power.

Further, in the step 3, the test content of the on-site detection of the wind-solar combined power generation system includes: according to the operation characteristics of the wind-solar combined power generation system, without affecting the power generation, the following three operating modes are tested, and the collected The power quality parameters of flicker, harmonics and power change rate are calculated and analyzed (the calculation is obtained according to the formula in the national standard GB/T12326-2008):

(1) The wind power is running normally, and the photovoltaic has no output, that is, the test is performed in the dark and windy time period at night;

(2) Photovoltaic is running normally, and wind power has no output, that is, the test is performed during the day when there is light and no wind;

(3) The normal operation of wind power and photovoltaics, that is, the test is carried out under the conditions that both wind and solar power are available during the day.

Further, the step 4 includes:

① The wind power and photovoltaic power generation units in the wind and wind combined power generation system are operating normally, and are collected separately, and the sampling frequency is not less than 4kHz;

②The wind power is running normally, and the photovoltaic has no output: the output power of the wind power is from 0 to 95% of the rated power, with 10% of the rated power as the interval, and at least five 10-min time series instantaneous voltages of the grid-connected points of the wind farm are collected for each power interval and each phase. and measurement of instantaneous current value;

③ Normal operation of photovoltaics, no output from wind power: starting from the minimum power of the photovoltaic power station for continuous normal operation, take 10% of the total rated power of the inverters equipped with the photovoltaic power station as an interval, and measure the data twice for 10 minutes in each interval ;

④ Normal operation of wind power and photovoltaic: wind and solar output power is from 0 to 95% of rated power, with 10% of rated power as the interval, at least 5 10min time series instantaneous voltage and instantaneous voltage of wind farm grid connection point are collected for each power interval and each phase. Measured value of current value.

Further, the step 4 includes: according to the national standard "GB/T 12326-2008 Power Quality, Voltage Fluctuation and Flicker", by calculating and analyzing the collected data, obtaining flicker, harmonics and power change rate electric energy quality parameters, so as to judge the performance of the grid connection point of the wind-solar combined power generation system under test.

Compared with the closest prior art, the technical solution provided by the present invention has the following excellent effects:

(1) The design of the test plan is reasonable: this test considers the independent operation mode of wind power, the independent operation mode of photovoltaic, the operation mode of wind power and photovoltaic combined power generation, and the division of these three operation modes is conducive to analyzing the performance indicators of grid connection under different modes. .

(2) Comprehensive consideration of the on-site operation mode: Due to the different operation modes of the wind power combined power generation system in the actual field, the mutual influence between wind power generation and photovoltaic power generation is also different. It is necessary to consider different operation modes as much as possible.

(3) Reasonable selection of on-site test points: The test points are selected at grid-connected points of different voltage levels, which can more truly reflect the grid-connected performance indicators of different power generation units.

Description of drawings

1 is a schematic diagram of a simple wiring method collection point provided by the present invention;

2 is a schematic diagram of a plurality of photovoltaic branch collection points provided by the present invention;

3 is a schematic diagram of a collection point of a complex wiring method provided by the present invention;

FIG. 4 is a flowchart of a method for testing the grid-connected performance of a wind-solar combined power generation system provided by the present invention.

Detailed ways

The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

The following description and drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. The examples are only representative of possible variations. Unless explicitly required, individual components and functions are optional and the order of operations may vary. Portions and features of some embodiments may be included in or substituted for those of other embodiments. The scope of embodiments of the invention includes the full scope of the claims, along with all available equivalents of the claims. These embodiments of the invention may be referred to herein by the term "invention," individually or collectively, for convenience only and not to automatically limit the application if more than one invention is in fact disclosed. The scope is any single invention or inventive concept.

Based on the operating characteristics of the wind-solar combined power generation system, the present invention provides a method for testing the grid-connected performance of the power generation system, including test points, test conditions, test contents and test methods for the on-site detection of the wind-solar combined power generation system, and solves the problem of the power generation system. The problem of on-site detection of system grid-connected performance. The flow chart of the grid-connected performance testing method of the wind-solar combined power generation system provided by the present invention is shown in FIG. 4 :

Step 1: Determine the test points for on-site inspection of the wind-solar combined power generation system:

According to the wiring method of the wind-solar combined power generation system, the test points are also different.

(1) As shown in Figure 1, the schematic diagram is a relatively simple wiring method. The grid-connected test points of 220kV or 110kV and 35kV are marked in the figure. The following table lists the specific electrical quantities that need to be collected.

Table 1 The electrical collection points of the wind-solar combined power generation system in Fig. 1

serial number Collection point 1 220kV three-phase voltage on the high-voltage side of the main transformer 2 Main transformer high voltage side 220kV three-phase current 3 35kV three-phase voltage on the low-voltage side of the main transformer 4 35kV three-phase current on the low-voltage side of the main transformer 5 35kV three-phase voltage at grid connection point of wind power branch 6 35kV three-phase current at grid connection point of wind power branch 7 35kV three-phase voltage of photovoltaic branch grid connection point 8 35kV three-phase current of photovoltaic branch grid connection point

(2) As shown in FIG. 2 , the schematic diagram shows a wiring method with multiple photovoltaic power generation branches. Due to the differences in the performance indicators of the entire grid connection point between multiple photovoltaic units, it is necessary to analyze the test points of this connection method separately.

Table 2 The electrical collection points of the wind-solar combined power generation system in Fig. 2

(3) As shown in FIG. 3 , the schematic diagram represents a relatively complicated wiring method.

Table 3 The electrical collection points of the wind-solar combined power generation system in Fig. 3

serial number Collection point 1 The first main transformer high-voltage side 220kV three-phase voltage 2 The first main transformer high voltage side 220kV three-phase current 3 The first main transformer low-voltage side 35kV three-phase voltage 4 The first main transformer low-voltage side 35kV three-phase current 5 35kV three-phase voltage at the grid connection point of the first wind power branch 6 35kV three-phase current at the grid connection point of the first wind power branch 7 35kV three-phase voltage at the grid connection point of the first photovoltaic branch 8 35kV three-phase current at the grid connection point of the first photovoltaic branch 9 The second main transformer high voltage side 220kV three-phase voltage 10 220kV three-phase current on the high voltage side of the second main transformer 11 35kV three-phase voltage on the low-voltage side of the second main transformer 12 35kV three-phase current on the low-voltage side of the second main transformer 13 35kV three-phase voltage at the grid connection point of the second wind power branch 14 35kV three-phase current at the grid connection point of the second wind power branch 15 35kV three-phase voltage at the grid connection point of the second photovoltaic branch 16 35kV three-phase current at the grid connection point of the second photovoltaic branch

Step 2: Determine the test conditions for the on-site inspection of the wind-solar combined power generation system:

The wind-solar combined power generation system to be tested should have stable grid-connected operation capability, and be capable of independent wind power generation operation, photovoltaic independent power generation operation, and wind-solar combined power generation operation. The test requires reasonable wind and light conditions.

Step 3: Determine the test content of the on-site inspection of the wind-solar combined power generation system:

According to the operating characteristics of the wind-solar combined power generation system, the following three operating modes can be tested without affecting the power generation, and the power quality parameters such as flicker, harmonics, and power change rate can be calculated and analyzed through the collected data. :

(1) The wind power is running normally, and the photovoltaic has no output (tested in the dark and windy time period at night)

(2) Photovoltaic operates normally, and wind power has no output (tested during the day with light and no wind)

(3) Normal operation of wind power and photovoltaics (tested under the conditions that both wind and solar power are available during the day)

Step 4: Determine the test method for on-site inspection of the wind-solar combined power generation system: According to the national standard "GB/T 12326-2008 Power Quality, Voltage Fluctuation and Flicker", through calculation and analysis of the collected data, flicker, harmonics are obtained. and power change rate power quality parameters, so as to judge the performance of the grid connection point of the wind-solar combined power generation system under test.

The wind power and photovoltaic power generation units in the wind-solar combined power generation system operate normally, and are collected separately, and the sampling frequency is not lower than 4kHz.

Wind power is running normally, but photovoltaics have no output. The output power of wind power is from 0 to 95% of the rated power, with 10% of the rated power as the interval. In each power interval and each phase, at least five 10-min time series instantaneous voltage and instantaneous current values are collected at the grid-connected point of the wind farm.

Photovoltaic operates normally, and wind power has no output. Starting from the minimum power of the photovoltaic power station for continuous normal operation, take 10% of the total rated power of the inverters equipped with the photovoltaic power station as an interval, and measure the data twice for 10 minutes in each interval.

Wind power and photovoltaics are operating normally. The wind and solar output power is from 0 to 95% of the rated power, with 10% of the rated power as the interval. At least five 10-min time series instantaneous voltage and instantaneous current values of the wind farm grid connection point are collected for each power interval and each phase.

The invention provides the field test content and method of the wind-solar combined power generation system, mainly including flicker, harmonic and high-frequency components, and power control capability. The invention has great significance for improving the standardization and accuracy of the field test of the wind power combined power generation system.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still modify or equivalently replace the specific embodiments of the present invention. , any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are all within the protection scope of the claims of the present invention for which the application is pending.

Claims (3)

1. A method for testing grid-connected performance of a wind and light combined power generation system is characterized by comprising the following steps:

step 1: determining a test point for field test of the wind-solar combined power generation system;

step 2: determining a test condition of field detection of the wind-solar combined power generation system;

and step 3: determining the test content of the scene detection of the wind-solar combined power generation system;

and 4, step 4: testing the grid-connected point performance of the wind-solar combined power generation system;

in the step 2, the test conditions of the field test of the wind-solar hybrid power generation system are as follows: the system has stable grid-connected operation capability, and has wind power independent power generation operation, photovoltaic independent power generation operation and wind-light combined power generation operation; during testing, the wind speed is required to have a working condition of 3-15m/s, so that the output power of the fan is ensured to be in a range of 0-95% of rated power; the light irradiation quantity is required to meet 0-7500MJ/m²Ensuring that the output power of the photovoltaic power station is in a range from 0 to rated power;

in step 3, the test content of the field test of the wind-solar hybrid power generation system includes: according to the operation characteristics of the wind-solar combined power generation system, under the condition of not influencing power generation, the following three operation modes are tested, and through the collected data, flicker, harmonic wave and power change rate electric energy quality parameters are obtained through calculation and analysis:

(1) the wind power normally runs, and the photovoltaic is free of output, namely the test is carried out in the period of no light and wind at night;

(2) the photovoltaic operation is normal, and the wind power does not output power, namely the test is carried out in the time period of light and no wind in the daytime;

(3) normally running wind power and photovoltaic power, namely testing under the condition that wind and light are available at the same time in the daytime;

the step 4 comprises the following steps:

firstly, wind power and photovoltaic power generation units in the wind-solar combined power generation system normally operate and respectively collect the wind power and the photovoltaic power, and the sampling frequency is not lower than 4 kHz;

wind power normally runs, and photovoltaic power does not output: the wind power output power is from 0 to 95% of rated power, 10% of rated power is taken as an interval, and at least measured values of 5 10min time sequence instantaneous voltage and instantaneous current values of a wind power plant grid-connected point are collected in each power interval and each phase;

photovoltaic normal operating, wind-powered electricity generation does not exert oneself: starting from the minimum power of the continuous normal operation of the photovoltaic power station, taking 10% of the total rated power of an inverter allocated to the photovoltaic power station as an interval, and respectively measuring data for 10min for 2 times in each interval;

wind power and photovoltaic normal operation: the wind and light output power is from 0 to 95% of rated power, 10% of rated power is taken as an interval, and at least 5 measured values of 10min time sequence instantaneous voltage and instantaneous current values of a wind power plant grid-connected point are collected in each power interval and each phase.

2. The grid-connected performance test method according to claim 1, wherein in the step 1, the test point is determined according to a connection mode of the wind-solar hybrid power generation system; the method comprises the steps of (1) grid-connected test points of 220kV or 110kV grade and 35kV grade; the electric collection point of the wind-solar combined power generation system comprises: the main transformer high-voltage side 220kV three-phase voltage, the main transformer high-voltage side 220kV three-phase current, the main transformer low-voltage side 35kV three-phase voltage, the main transformer low-voltage side 35kV three-phase current, the wind power branch grid-connected point 35kV three-phase voltage, the wind power branch grid-connected point 35kV three-phase current, the photovoltaic branch grid-connected point 35kV three-phase voltage and the photovoltaic branch grid-connected point 35kV three-phase current.

3. The grid-connection performance test method according to claim 1, wherein the step 4 includes: according to the GB/T12326-2008 electric energy quality, voltage fluctuation and flicker, calculating and analyzing the collected data to obtain flicker, harmonic wave and power change rate electric energy quality parameters, so as to judge the grid-connected point performance of the tested wind-light combined power generation system;

the wind power and photovoltaic power generation units in the wind-solar combined power generation system normally operate and respectively collect the wind power and photovoltaic power generation units, and the sampling frequency is not lower than 4 kHz;

the wind power normally runs, and the photovoltaic power does not output power; the wind power output power is from 0 to 95% of rated power, 10% of rated power is taken as an interval, and at least measured values of 5 10min time sequence instantaneous voltage and instantaneous current values of a wind power plant grid-connected point are collected in each power interval and each phase;

the photovoltaic power generation system normally operates, and the wind power generation system does not output power; starting from the minimum power of the continuous normal operation of the photovoltaic power station, taking 10% of the total rated power of an inverter allocated to the photovoltaic power station as an interval, and respectively measuring data for 10min for 2 times in each interval;

wind power and photovoltaic normally operate; the wind and light output power is from 0 to 95% of rated power, 10% of rated power is taken as an interval, and at least 5 measured values of 10min time sequence instantaneous voltage and instantaneous current values of a wind power plant grid-connected point are collected in each power interval and each phase.

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