KR101197040B1 - Weather-Load Simulator - Google Patents

Abstract

The present invention relates to a weather-load simulator for simulating a device under test. And a signal processing processor for sampling and outputting the sampled information to a test simulator (including wind power simulator, solar cell simulator, load simulator, and EMS). It is effective to provide load information.

Weather-load simulator, signal processor, memory, real-time clock, communication port, A / D converter, D / A converter, external sensor, test simulator, input computer

Description

Weather-load simulator for simulating equipment under test {Weather-Load Simulator}

The present invention relates to a weather-load simulator for simulating a device under test, and more particularly, to a test simulator including a wind simulator, a solar cell simulator, a load simulator, and an energy management system (EMS) for microgrids. A weather-load simulator for simulating equipment under test that provides weather and loading conditions at the same level as actual operating conditions.

The test equipment of the power conditioning system (PCS) used in solar power or wind power generation is a function for producing the maximum power under a given solar radiation and wind speed conditions, that is, the so-called maximum power point tracking control ( Maximum Power Tracking (hereinafter referred to as 'MPPT') is an important function in terms of energy use efficiency. However, during the development and testing of the product, it is very difficult and time consuming to actually test under various insolation and wind speed conditions. Therefore, the PCS for photovoltaic power generation uses a solar cell simulator, which is a direct current power supply that realizes the voltage-current characteristics of the solar cell array, or performs a simple test using a simple direct current power supply. Wind turbines are simulated using a generator (commonly called a MG set).

In addition, the microgrid system, which is a new power grid composed of renewable energy such as solar, wind, geothermal and hydropower, and energy storage devices such as cogeneration and gas engine cogeneration, has a variety of energy sources. It has energy storage devices and load devices, and installs and operates an energy management system (EMS) to manage, monitor and control them collectively. The EMS is generally installed for the purpose of optimally operating the power generation and heat and power loads of distributed generators such as solar and wind under given weather conditions, and for starting and stopping operation and optimal operation of controllable power sources such as gas engine generators. It performs various functions such as economic power supply, load and power generation forecasting which determine the output set point of the generator. Therefore, in order to develop and test the EMS, a simulated test is performed by inputting virtual data on a separate weather and load in the EMS.

However, in the case of the simulation test of the PCS and the wind generator for photovoltaic power generation according to the prior art, there is still a very difficult problem to implement the actual solar radiation or fluctuation conditions of the wind speed. In particular, in the case of wind speed model, a simplified mathematical model is used, or in the case of solar radiation, the solar radiation is randomly input to the simulator, but this also does not reflect the weather conditions that change according to time and ambient conditions, and thus tests the complete function. There is a problem that cannot be done.

In addition, even in the case of the development test of the EMS according to the prior art, it is difficult to reflect in real time the meteorological characteristics of the area where the microgrid and the EMS will be installed and the heat and power load characteristics of the customer in real time and difficult to pre-analyze the effect. there is a problem. In addition, there is a problem of excessive engineering time in actual application.

The present invention has been proposed to solve the problems of the prior art, and the development and / or development of a test simulator 530 including an EMS (Energy Management System), a wind simulator, a solar cell simulator and a load simulator for microgrid (Microgrid) The objective is to provide a weather-load simulator for the EUT to provide weather and load information at the same level as the weather and load conditions, which are the actual operating conditions in the test.

In addition, another object of the present invention is to provide a simulated weather-load simulator for the EUT to minimize the engineering and application time in the field for the installation and operation of the EMS.

In addition, another object of the present invention is to provide a weather-load simulator for simulating the device under test, which can accurately simulate the economic benefit or payback period of the customer to be installed the microgrid system.

In addition, another object of the present invention is to provide a weather-load simulator for simulating a test apparatus that can simulate a variety of new and renewable energy sources and loads for test simulators such as wind simulators, solar cell simulators and load simulators. There is.

In order to solve the above technical problem, the simulated weather-load simulator according to the present invention includes a predetermined period of weather information including measured temperature, insolation and wind speed, and load information including power, voltage, and current. And a signal processing processor for sampling to (T) and outputting the sampled information to a test simulator (including wind power simulator, solar cell simulator, load simulator, and EMS).

The apparatus for simulated weather-load simulator may further include a memory configured to store information sampled by the signal processing processor, and output the sampled information stored in the memory to the test simulator.

The weather information and load information may be measured by an external sensor including an insolation measurement sensor, a temperature measurement sensor, a wind speed measurement sensor, and a power or voltage / current measurement sensor and input to the signal processing processor.

The wake-up simulator may further include a real-time clock for providing a reference time for the predetermined period T to the signal processing processor.

The weather-load simulator may further include an A / D converter configured to convert weather information and load information output from the external sensor into digital signals and input them to the signal processing processor.

Here, the weather-load simulator may include one or more D / A converters, which are analog output channels, and one or more communication ports, which are digital output channels, to output information sampled by the signal processor to the test simulator. .

In addition, the weather-load simulator stores weather data including temperature and insolation or wind speed of a specific measured area and load data including electricity usage of a load, and stores information sampled by the signal processing processor in the communication port. The computer may further include an input computer configured to receive and store the received data and information through the communication port or the D / A converter.

The weather-load simulator for simulating the apparatus under test according to the present invention having the above-described configuration generates the weather information and load information of the same level as the actual operating conditions in real time in PCS for solar and wind power generation and EMS for microgrid systems. It can shorten the performance test and development period of PCS for photovoltaic and wind power generation and EMS for microgrid system and realize the optimal function.

In addition, there is an effect that can minimize the engineering and application time in the field for the installation and operation of the EMS.

In addition, it is possible to simulate in advance the economic benefits and the payback period of the customer to which the EMS for the microgrid system will be installed, and it can be used as a preliminary economic evaluation tool.

In addition, there is an effect that can simulate a variety of real and renewable energy sources and loads for solar cell simulators, wind simulators, load simulators and the like.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same reference numerals will be used for components having the same functions and functions when describing the embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention provides weather information including temperature, insolation, wind speed, and the like for the development and testing of a test simulator 530 including an EMS (Energy Management System) for microgrids, a wind simulator, a solar cell simulator, and a load simulator. By generating load information including heat and power usage in real time and applying it to the test simulator 530, the apparatus under test 550 for developing and testing the test simulator efficiently and easily simulates the meteorological load It's about the simulator.

First, the load characteristic curve for the weather information of the solar cell and the wind power generator corresponding to the apparatus under test 550 will be described.

As a characteristic curve representing the relationship between the meteorological information and the load information of the solar cell, FIG. 1A shows a temperature dependency of voltage-current, FIG. 1B shows a voltage-current characteristic according to the amount of insolation at the same temperature, and FIG. Characteristic curve showing the voltage-output characteristic according to the amount of insolation at the same temperature.

As shown in FIG. 1A, the voltage-current characteristics of the solar cell are different when the ambient temperature is the high temperature 100 and the low temperature 20. That is, the temperature is reduced and the current is increased as the high temperature 10 increases, and the voltage is increased and the current is decreased as the low temperature 20 increases.

Voltage-current characteristics and voltage-output characteristics according to the same temperature (eg, 25 degrees Celsius) of the solar cell are different from each other depending on the amount of insolation, as shown in FIGS. 1B and 1C. In particular, the maximum output point 50 at the same temperature is changed as shown in Figure 1c as the amount of solar radiation increases.

As a characteristic curve representing the relationship between the meteorological information and the load information of the wind generator, FIG. 2 shows a characteristic of the output-turbine speed of the wind generator that varies according to the magnitude of the wind speed (for example, V1 <V2 <V3). That is, when the wind speed is low (V1 curve), at the intermediate speed (V2 curve), at the rated speed (V3 curve), the maximum output point 70 is changed, and the output P also has the same wind speed. Conditions vary depending on the rotational speed ω of the turbine.

3 to 6 show the construction or operation principle of the test simulator 530.

As shown in FIG. 3, the microgrid system includes three networks, that is, a heat supply network 110, a power supply network 120, and a communication network 160. In addition, the microgrid includes a load 130, a distributed generator 140, and an energy storage device 150, and each of the components is an energy management system that is the test simulator 530 through the communication network 160. EMS, 200) is integrated, managed, monitored and controlled.

The microgrid may be operated in connection with a commercial power grid 180, and may independently supply power and / or heat to the load 130 when there is no power in the commercial power grid 180 due to a power failure. have.

The energy management system (EMS) 200 of the microgrid includes heat and / or power, which is information of the load 130 in the microgrid, and power generation information of the distributed generation 140 such as solar, wind, and fuel cells, and the energy. The distributed generation 140 and the energy storage device for economical operation such as minimizing the energy cost of the customer through the state information of the storage device 150 or optimizing or suppressing the maximum purchase power from the commercial power grid 180. 150) to control the device.

4 is a functional flowchart showing the function and flow of the microgrid energy management system (EMS) 200.

In order to operate the microgrid, the energy management system (EMS) 200 first establishes a power generation plan 210. An input for establishing the power generation plan 210 may be largely divided into power generation-load prediction information 220 and an operation constraint 230. The generation amount-load prediction information 220 includes a generation amount prediction 221, a load prediction 222, and a heat load prediction 223, and the driving constraint 230 includes an institutional condition 231 including transaction conditions, etc., Price information, including electricity charges, fuel costs (such as gas), maintenance costs, etc.Target (costs, 233) and various technical constraints (234) ) Is considered.

At this time, the generation amount prediction 221 of the distributed power source performs a function of predicting the generation amount from weather information such as wind speed, temperature, solar radiation amount according to the weather prediction information 240. In addition, the power load prediction 222 and the heat load prediction 223 may be performed according to the weather forecast information 240. On the other hand, the load prediction 222 and the heat load prediction 223 is a conventional operation DB 241 storing the operation data for the existing load and / or heat demand and the like / weekly / monthly operation DB storing the weekly / monthly operation data You can also use

Next, the operation plan 250 for the component device 100 of each microgrid should be established according to the established power generation plan 210. The operation plan 250 refers to determining the start and / or stop of the device at each time interval, the operation set value, etc. in order to supply optimal energy according to the target value according to the load prediction 222 and the heat load prediction 223. .

At this time, inconsistencies in the load and power generation that are different from the predicted values in the actual operation process occur, so measures must be taken to compensate for this. Predictive uncertainty compensation 251 means to correct the starting and / or stopping and setting values by comparing the set values presented in the operation plan 250 and the collected actual operating measurement data 252 to compensate for the inconsistency. . In this case, the collected measurement data 252 uses the communication network 160 connected between the microgrid components 100 and the energy management system (EMS) 200.

In addition, in actual microgrid operation, additional functions 260 according to an operation mode, such as compensation of power quality or control of output, may be added, and the operation command 270 may be configured to reflect the additional functions. The device 100 transmits the data through the communication network.

In the microgrid operation method as described above, the input of the weather forecast information 240 is the most important condition of the development plan.

5 is a configuration diagram of a solar cell simulator that is an example of the test simulator 530.

Hereinafter, the configuration / operation principle of the solar cell simulator will be described with reference to FIG. 5.

The solar cell simulator is a power supply device that converts the voltage-current characteristics (see FIG. 1B) of the solar cells according to ambient temperature and / or solar radiation conditions into actual voltage-current characteristics.

Parameters such as ambient temperature and / or solar radiation conditions can be input or modified by the user arbitrarily in the parameter input unit 330 to perform a test of a photovoltaic power converter (PCS) that becomes the device under test 550. Help make it easier At this time, the test can be conducted using the actual solar cell, but time and cost problems such as installation cost and natural dependence of solar radiation are caused.

Since the voltage-current characteristic of the solar cell (see FIG. 1B) is DC, first, the AC power supply 300 is rectified through the rectifier 311 to be converted into DC, and the first capacitor is used to reduce the pulsation of the rectified DC. 312 is installed in parallel with the rectifier 311. The direct current smoothed by the first capacitor 312 is a voltage Vo and a current Io output by the power semiconductor switch 313 connected in parallel to the rectifier 311 and the first capacitor 312. To control.

The output voltage Vo and output current Io are detected by respective voltage and current sensors and input to the controller 320. The controller 320 determines the output current command from the voltage-current characteristic curve (see FIG. 1B) of the solar cell using the inputted output voltage Vo, and the detected output current Io is outputted. Current control is performed by the current controller 321 to be the same as the current command. At this time, the output of the current controller 321 outputs the actual current by turning on and / or off the switch 313 through a pulse width modulation (PWM) 322. .

At this time, the pulsation of the output voltage Vo by the on / off of the switch 313 is smoothed by a filter composed of the reactor 315 and the second capacitor 316. In addition, the current sensor 314 in front of the reactor 315 is used for the overcurrent protection of the switch 313.

Figure 6 is an illustration of the configuration of a wind turbine simulator which is another example of the test simulator.

Hereinafter, the configuration / operation principle of the wind turbine simulator will be described with reference to FIG. 6.

In the configuration of the wind turbine simulator, instead of the wind turbine, a variable speed electric motor 410 driven by an inverter 480 is used as the wind generator 420 directly connected to the shaft. At this time, the speed detection sensor 430 for detecting the speed is installed on the shaft directly connected to the variable speed motor 410 and the wind generator 420.

The wind generator 420 converts the mechanical axial force of the variable speed electric motor 410 into electric power. When the permanent magnet wind generator 420 is used, the output voltage and frequency of the wind generator 420 are rotated at a rotational speed. Since it is directly proportional, the output of the wind generator 420 may not be directly connected to the power source 490 of the power system. Therefore, a power converter (PCS) 440 for grid linkage is used.

The power converter (PCS) 440 has a structure in which a three-phase bridge type first converter 441 and a second converter 442 are connected in series. In this case, the first converter 441 which is the wind generator side converter performs a function of rectifying the AC voltage of the wind generator 420, and the second converter 442 that is the converter on the power source 490 side is converted. The DC power is linked to the power source 490. The first and second converters 441 and 442 are provided with an input voltage sensor 443 and an input current sensor 444, an output voltage sensor 445, and an output current sensor 446, respectively. The voltage is transmitted to the PCS controller 447 for wind power generation.

The wind power PCS controller 447 performs the necessary control while following the maximum output and outputs the pulse width modulation (PWM) signals 448 and 449 to the corresponding converters 441 and 442. In addition, the wind power PCS controller 447 calculates an electrical output 450 of the wind generator 420 and transmits it to the wind turbine simulator controller 450.

The wind turbine simulator controller 460 receives wind speed data from the parameter input unit 470 and outputs velocity information from the speed detection sensor 430 and electrical output 450 from the power converter PCS 440. Calculates the output corresponding to the speed-output curve 60 of the wind turbine, outputs the torque reference value 461 of the drive inverter 480, and drives the variable speed motor 410 to the same speed as the actual wind turbine. Output characteristics are obtained.

The wind turbine simulator as the test simulator 530 enables the same operation as the actual turbine runs on the side of the wind generator 420 without the actual wind turbine. However, the wind turbine simulator controller 460 may be operated in the same manner as the actual wind speed condition when the wind speed data is input from the parameter input unit 470 from the outside, so a separate parameter input method is required.

The simulated weather-load simulator for a device under test according to the present invention extracts a specific pattern using weather information including actual temperature, insolation, wind speed, and load information including power, voltage, and current. By outputting to the simulator 530, it is possible to evaluate the performance of the optimization program implemented in the test simulator by providing weather information and load information of various patterns in real time for the development of test simulators such as microgrid EMS and functional tests. This can shorten trial and error and engineering time.

7 is a configuration diagram of a weather-load simulator for simulating an apparatus under test according to the present invention.

Hereinafter, a preferred embodiment of the vapor-load simulator for simulating the apparatus under test of the present invention will be described in detail with reference to FIG. 7.

The weather-load simulator 510 of the present invention includes various peripheral devices mainly on the signal processing processor 511. The peripheral devices include weather information including measured temperature, solar radiation, wind speed, and the like, such as power, voltage, and current. A memory 512 for storing load information is included.

That is, it includes a signal processing processor for sampling the measured weather information and load information at a predetermined period (T) and outputs the sampling information to the test simulator 530.

In this case, the weather-load simulator further includes a memory 512 for storing weather information and load information sampled at regular intervals, and the information stored in the memory 512 is stored through the signal processing processor 511. It is output to the test simulator 530.

At this time, the weather information and load information is output from the external sensor 520, the external sensor 520 is a solar radiation measuring sensor 521, temperature measuring sensor 522, wind speed measuring sensor 523 and power or voltage / Including the current measuring sensor 524 and performs the function of collecting weather information and load information of a specific region and a specific time zone.

In this case, the weather information and the load information is filtered by the signal processor 514 as measured data from the external sensor 520, and then converted into an analog signal to a digital signal through the A / D converter 515 It is input to the signal processing processor 511.

In addition, the weather-load simulator further includes a real time clock 513 associated with the signal processing processor 511, wherein the real time clock 513 is weather information and load information input from the external sensor 520. Performs a function of providing a reference time to allow a to be sampled at a constant period (T).

The information sampled by the weather-load simulator is input to the test simulator 530 through a communication port 517 or a D / A converter for converting a digital signal into an analog signal.

At this time, a communication UART (Universal Asynchronous Receiver / Transmitter) 516 is installed between the communication port 517 and the signal processing processor 511.

The signal processor 511 and the D / A converter 519 further include an insulation unit 518 that insulates the information sampled by the signal processor 511 from weather information and load information.

That is, the communication port 517 transmits weather information and load information sampled by the signal processing processor 511 to the test simulator 530, and the test simulator 530 supports communication. If not, the D / A converter 519 may transmit the analog signal. That is, the output method from the weather-load simulator to the test simulator 530 is analogous through the communication port 517 or the D / A converter 519 according to the interface method of the test simulator 530. It can be an output. In some cases, the test may be performed while directly exporting data input through the signal processor 514 through the D / A converter 519.

8 is an exemplary diagram in which the weather-load simulator for simulating the apparatus under test according to the present invention is applied to a wind power simulator.

8 and 6, the overall configuration and operation principle of the weather-load simulator of the present invention linked to the wind simulator will be described.

In the case of the wind turbine simulator described in FIG. 6, the wind turbine simulator controller 460 is variable by using the inverter 480 to vary the rotational speed of the wind turbine according to temporally changing wind speed data. The torque reference value 461 corresponding to the speed-output characteristic curve 60 of the turbine rotation is transmitted to the inverter 480.

At this time, the wind turbine simulator controller 460 inputs wind speed information sampled by the weather-load simulator 510, rotation speed information of the electric motor 410 detected by the speed detection sensor 430, and power conversion. The output power information of the wind generator 420 output from the device PCS 440 is used.

In addition, the weather-load simulator 510 transmits the measured and stored real-time wind speed data 512-1 to the wind turbine simulator controller 460.

Through the above configuration, the wind generator 420 and the power converter (PCS) 440 may be tested in the same manner as the actual wind speed condition.

9 is an exemplary diagram in which the apparatus under test simulated weather-load simulator according to the present invention is applied to a load simulator.

Hereinafter, referring to FIG. 9, the configuration and operation principle of the weather-load simulator of the present invention linked to the load simulator 610 will be described.

The load simulator 610, which is an electronic load device, is a power converter that absorbs the electrical output of the device under test 550 and regenerates the power system 620.

At this time, when the output of the device under test 550 is alternating current, such as an alternator, two three-phase bridge type converters 611 and 612 are used in series, and a filter capacitor 613 is installed in the middle thereof. .

In this case, first and second filters 614 and 615 including reactor-capacitors are installed on left and right sides of the converters 611 and 612, respectively, and voltages are provided on the side of the device under test 550 of the first filter 611. The sensor 616 and the current sensor 617 are respectively provided.

The load controller 618 controls the currents of the two converters 614 and 615. The current control of the converter 611 on the side of the device under test 550 is controlled by the load applied to the device under test 550. Depending on the type, it is designed to control not only active and reactive currents but also nonlinear load currents. In addition, the converter 612 on the side of the power system 620 increases the DC voltage due to the current regenerated from the device under test 550 and maintains the current as much as necessary to maintain it at a constant level. 620), and in general, the power factor is controlled to be 1.

The load simulator 610 is generally operated by setting a reference value of the active power or the reactive power applied to the apparatus under test 550, and the magnitude of the reference value is also changed over time in the form of a lookup table or a ramp function. It is often designed to be variable. However, when a complex load such as the microgrid described above is present at the same time, the simulation of the load is not easy, and it is more difficult to simulate the load pattern 512-2 that varies with various types of nonlinearity or time. Accordingly, the weather-load simulator 510 of the present invention outputs the actual load data measured in advance in real time in order to simulate loads varying with time, thereby realizing the function of the load simulator 610 more realistically. It is effective to test for a long time close to the load of.

It will be apparent to those skilled in the art that various modifications and changes can be made in the present invention without departing from the spirit or scope of the present invention as defined by the appended claims. It will be appreciated that such modifications and variations are intended to fall within the scope of the following claims.

Figure 1a is a characteristic curve showing the temperature dependence of the voltage-current for solar cells

1b is a voltage-current characteristic curve according to the solar radiation amount for a solar cell

Figure 1c is the voltage-output characteristic curve according to the solar radiation amount for the solar cell

2 is a characteristic curve of output-turbine speed of a wind generator

3 is a schematic configuration diagram of a microgrid

4 is a functional flow diagram of an EMS for a microgrid system

5 is a configuration diagram of a solar cell simulator

6 is a configuration diagram of a wind turbine simulator

7 is an overall configuration diagram of a weather-load simulator according to a preferred embodiment of the present invention.

8 is an exemplary diagram in which the weather-load simulator according to the present invention is applied to a wind power simulator.

9 is an exemplary diagram in which the weather-load simulator according to the present invention is applied to a load simulator.

[Description of Code for Major Parts of Drawing]

320: solar cell simulator controller 410: variable speed motor

420: wind generator 430: speed detection sensor

440: power converter (PCS) 447: pcs controller for wind power generation

460: wind turbine simulator controller 480: inverter

510: weather-load simulator 511: signal processing processor

512: memory 513: real time clock

514: signal processing unit 515: A / D conversion unit

516: UART 517: communication port

518: insulation section 519: D / A conversion section

520: external sensor 521: solar radiation measuring sensor

522: temperature measuring sensor 523: wind speed measuring sensor

524: power or voltage / current measuring sensor 530: test simulator

540: input computer 550: device under test

610: load simulator 618: load controller

Claims (8)

Receives the weather information from the meteorological measurement sensor that measures the weather information including temperature, solar radiation and wind speed, and processes it by sampling at regular intervals to generate processed weather information data, and simulates the characteristics of the solar cell according to real-time weather conditions. A signal processing processor that sets the real-time weather state to be input to the wind turbine simulator simulating the characteristics of a solar cell simulator or a wind turbine as the weather information data; And And a communication port for outputting the weather information data to the solar cell simulator or the wind turbine simulator. The method of claim 1, The signal processing processor, Energy management system (EMS: Energy) that receives the measured energy usage from the energy measurement sensor that measures energy usage including heat or electricity, samples it at regular intervals, generates processed energy usage information data, and manages real-time energy usage. Set the real-time energy usage to be input to the load simulator associated with the management system as the energy usage information data, The communication port, And a weather-load simulator for simulating the device under test, wherein the energy usage information data is output to the load simulator. The method of claim 2, And a memory for storing the meteorological data or the energy usage information data of the signal processing processor. The method according to claim 2 or 3, And a real-time clock that provides the signal processing processor with a reference time for the predetermined period for sampling. 5. The method of claim 4, And an A / D changer for converting a signal output from the meteorological measurement sensor or the energy measurement sensor into a digital signal and inputting the digital signal to the signal processing processor. The signal processing processor may simulate digital weather information or digital energy usage information from the A / D conversion unit at regular intervals to generate digital weather information data or digital energy usage information data. Load simulator. 6. The method of claim 5, Converts the digital weather information data or the digital energy usage information data into an analog signal, outputs the analog weather information data to the solar cell simulator or the wind turbine simulator, and outputs the analog energy usage information data to the load simulator; A weather-load simulator for simulating the device under test, further comprising an A converter. 5. The method of claim 4, The signal processing processor, Extracting weather information and energy usage of a specific pattern for each of the weather information and energy usage sampled at regular intervals, and generating the weather information data and energy usage information data using the extracted weather information and energy usage, respectively. Weather-load simulator for simulated EUT. delete

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