KR100794197B1 - The method for controlling operation using hybrid distributed generation system - Google Patents

Abstract

The present invention relates to a driving control method using a hybrid distributed power generation system. Determining whether the first distributed power supply unit is set to a boosted or charged mode based on the result; (g) When the boosting or charging mode is set as a result of the determination in step (f), the integrated monitoring controller increases the counter Cnt and compares the value of the increased counter with the set value to determine whether the set value is greater than or equal to the set value. step; (h) when the determination result of step (g) is greater than or equal to the set value, that is, when a predetermined time has elapsed, the integrated monitoring controller sets the counter to 0 and executes the boost or charge mode; (i) determining whether the integrated monitoring control unit is in a boost mode; (j) in the boosting mode, as a result of the determination in step (i), setting, by the integrated monitoring controller, a voltage reference value as an intermediate value between the highest voltage (Vdc_max) and the lowest voltage (Vdc-min); And (k) the integrated monitoring controller inspecting the state of charge of the battery and executing a boost operation. It consists of.

Hybrid, Distributed Power, Output Leveling

Description

The method for controlling operation using hybrid distributed generation system

1 is a block diagram of a hybrid distributed power generation system according to an embodiment of the present invention.

2 is a detailed configuration diagram of a hybrid distributed power generation system according to an embodiment of the present invention.

3 is a flowchart illustrating an output control method of a hybrid distributed power generation system according to an embodiment of the present invention.

4 is a flowchart illustrating an output leveling algorithm according to an embodiment of the present invention.

5 is a flowchart illustrating an operation control method of a hybrid distributed power generation system according to an embodiment of the present invention.

6 is a view showing a plurality of distributed power supply unit is applied to a hybrid distributed power generation system according to an embodiment of the present invention.

The present invention relates to a driving control method using a hybrid distributed power generation system, and more particularly, a power generation system capable of using a combination of renewable energy sources such as wind, solar, fuel cells, and diesel engine or gas engine synchronous power generation. The present invention relates to a method for controlling operation using a hybrid distributed power generation system combined with a system.

In general, a power supply system using a synchronous generator driven by a diesel engine in an island area or a remote area may operate a plurality of generators in parallel in preparation for a load variation or an increase in a load. At this time, the solar power or wind power generation may be operated in combination for reasons such as fuel cost reduction. In particular, the wind power generator has a characteristic that the output varies widely and rapidly according to the wind speed condition. This can cause a sudden change in generated power, which can cause voltage and frequency fluctuations in a small power system and, in extreme cases, can lead to an outage of the entire synchronous generator.

On the other hand, in order to overcome these problems, conventionally, by using a storage battery, or by supplying the output of the diesel generator to the load through a power converter such as an inverter to prevent the sudden change of the output. However, there is a concern that the life of the battery due to frequent charging and discharging may be shortened, and there is a problem that the capacity of the battery must be increased in order to supply power stably. In addition, when a common inverter is used by connecting a wind power and solar power generation system and a diesel or gas engine synchronous power generation system to a single DC stage, the inverter requires the same rated capacity as the total power generation capacity. There was a problem with stable power supply, and if the inverter failed, there was a problem that the power supply was cut off as a whole.

The present invention has been made to solve the above problems, the first object is to separate the power generation system using renewable energy from the diesel power generation system, by adding wind or solar power generation to the existing diesel generator Even if there is a characteristic purpose to provide an operation control method using a hybrid distributed power generation system that can stably supply power.

In addition, the second object is to provide an operation control method using a hybrid distributed power generation system that can prevent the operation stop due to shortening the life of the battery by frequent charging / discharging by monitoring the remaining capacity of the energy storage device, such as a battery. Is in.

The present invention relates to a hybrid distributed power generation system, comprising: a first distributed power supply unit converting direct current power of a wind power generator (wt) and a solar cell (pv) into maximum power; An inverter unit for outputting DC power input through the common DC bus from the first distributed power supply unit as AC power; A second distributed power supply unit comprising a diesel engine and a driving synchronous generator; And an integrated monitoring control unit integrally monitoring and controlling the first distributed power supply unit, the inverter unit, and the second distributed power supply unit. Including, but the AC power output from the inverter unit and the output power of the second distributed power supply unit is connected to the AC common bus is characterized in that it is supplied to the load (L).

Preferably, the first distributed power supply unit, AC-DC converter connected to the wind power generator for converting the output of the wind power generator to the maximum power; A boost converter connected to the solar cell to convert the output of the solar cell into maximum power; A DC-DC converter connected to the battery for discharging or charging surplus or insufficient power in the battery; And a capacitor bank for storing power of the first distributed power supply unit. Including, but by the integrated monitoring control unit monitors the state of charge of the battery, it characterized in that to maintain a constant state of charge of the battery.

Also preferably, the inverter unit may include: a DC-AC converter converting DC power input from the first distributed power supply unit into AC power; A reactor and a filter capacitor for filtering harmonics included in an output of the DC-AC converter; And a switch for opening and closing a distributed power supply of the first distributed power supply unit converted into AC power through the DC-AC converter. Characterized in that it comprises a.

Also preferably, the inverter unit may include: a voltage / current detector for controlling the output of the DC-AC converter; It characterized in that it further comprises.

And preferably the second distributed power supply unit, a synchronous generator driven by a diesel engine; A governor controller for controlling the speed, the effective power, and the frequency of the diesel engine; A voltage regulator controlling a voltage and reactive power of the synchronous generator; And a second switch for opening and closing the distributed power supply of the second distributed power supply unit. Characterized in that it comprises a.

On the other hand, the present invention relates to an output control method using a hybrid distributed power generation system, wherein (a) the inverter unit outputs the power (Pwt, Ppv) values output from an AC-DC converter connected to a wind generator and a solar cell and a boost converter. Calculating a current reference value i ^* _qe based on the result; (b) determining whether the inverter reads the voltage Vdc of the DC common bus A1 to be greater than the DC terminal minimum voltage Vdc_min; (c) determining whether the inverter unit is smaller than the DC terminal maximum voltage Vdc_max when the voltage Vdc of the DC common bus A1 is large as a result of the determination of step (b); (d) When the determination result of step (c) indicates that the voltage Vdc of the DC common bus A1 is small, the inverter determines that the DC terminal voltage does not exceed the allowable operating range. Operating at the calculated current reference value i ^* _qe ; And (e) the inverter performing continuous steady current control. Characterized in that it comprises a.

Preferably, when the determination result of step (b) indicates that the voltage Vdc of the DC common bus A1 is small, the inverter determines whether the boost operation is being executed, and as a result of the determination, the boost operation is performed. If so, the inverter unit 120 to perform the normal current control with a current reference value (i ^* _qe) and, if it is not the step-up operation is performed, subtracting the values (Δi) is set based on the current reference value (i ^* _qe) as Reducing the output; It characterized in that it further comprises.

Preferably, when the determination result of step (c) indicates that the maximum flow voltage (Vdc_max) is small, the inverter unit determines whether the charging operation is being executed, and when the determination result is performed, the inverter Thereby, the values (Δi) is set based on the current reference value (i ^* _qe) performs when the normal current control in additional current reference value (i ^* _qe), the charging operation is not being executed, the step of increasing the output; It characterized in that it further comprises.

Preferably, the output current reference value i ^* _qe calculates a molecular value using the maximum value of the output power and the current of each of the AC-DC converter and the boost converter, and calculates the line-to-line voltage of the AC common bus A2. The denominator value is calculated using the magnitude value, and is calculated as the ratio.

On the other hand, the present invention relates to an operation control method using a hybrid distributed power generation system, wherein (f) the integrated monitoring control unit controls the voltage (Vdc) value of the DC common bus (A1), the DC voltage maximum voltage (Vdc_max), and the minimum voltage (Vdc_min). Determining whether the first distributed power supply unit is set to a boosted or charged mode based on the basis; (g) When the boosting or charging mode is set as a result of the determination in step (f), the integrated monitoring controller increases the counter Cnt and compares the value of the increased counter with the set value to determine whether the set value is greater than or equal to the set value. step; (h) when the determination result of step (g) is greater than or equal to the set value, that is, when a predetermined time has elapsed, the integrated monitoring controller sets the counter to 0 and executes the boost or charge mode; (i) determining whether the integrated monitoring control unit is in a boost mode; (j) in the boosting mode, as a result of the determination in step (i), setting, by the integrated monitoring controller, a voltage reference value as an intermediate value between the highest voltage (Vdc_max) and the lowest voltage (Vdc-min); And (k) the integrated monitoring controller inspecting the state of charge of the battery and executing a boost operation. Characterized in that it comprises a.

And preferably, when the determination result of the step (i), if not in the boosting mode, the integrated monitoring control unit determines the charging mode to check the state of charge of the battery and to execute the charging operation; It characterized in that it further comprises.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are defined in the technical spirit of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. It should be interpreted to mean meanings and concepts. In addition, when it is determined that the detailed description of the known function and its configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, it should be noted that the detailed description is omitted.

Hereinafter, an operation control method using a hybrid distributed power generation system according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the hybrid distributed power generation system 100 includes a first distributed power supply unit 110, an inverter unit 120, a second distributed power supply unit 130, and an integrated monitoring controller 140, and FIG. 2. Looking at the detailed configuration with reference to, the first distributed power supply unit 110 is connected to the wind generator (wt) AC-DC converter 111 for converting the output of the wind generator to the maximum power, and the solar cell (pv Step-up converter 112 to convert the output of the solar cell to the maximum power connected to), and direct current-direct current converter 113 is connected to the storage battery (B) to discharge or charge the excess or insufficient power to the storage battery, And a capacitor bank 114 storing power of the first distributed power supply unit, wherein the DC power output through the AC-DC converter, the boost converter, the DC-DC converter, and the capacitor bank is a DC common bus (A1). Inverter unit (1) described below through 20).

In addition, the inverter unit 120 performs a function of outputting the DC power input through the DC common bus A1 from the first distributed power supply unit to the AC power, and the DC-AC converter converts the input DC power into AC power. A reactor 122 and a filter capacitor 123 for filtering harmonics included in the output of the DC-AC converter and a distributed power supply of the first distributed power supply unit converted into AC power; The switch 124 may further include a voltage / current detector 125 that controls the output of the DC-AC converter 121.

In addition, the second distributed power supply unit 130 includes a synchronous generator (G) 131 driven by the diesel engine (E), a governor controller 132 for controlling the speed, active power and frequency of the diesel engine, and the synchronous generator The voltage regulator 133 for controlling the voltage and the reactive power of the second, and the second switch 134 for opening and closing the distributed power supply of the second distributed power supply. In the present embodiment, the second distributed power supply unit is set as a synchronous generator driven by a diesel engine and a diesel engine. However, the present invention is not limited thereto, and may be set as a synchronous generator driven by a gas engine and a gas engine.

At this time, the distributed power of the first distributed power supply unit 110 and the second distributed power supply unit 130 is opened and closed by the first and second switch 124, 134, respectively, the AC output is connected to the common AC bus (A2) And the load L is supplied.

In addition, the integrated monitoring controller 140 is integrated with the first distributed power supply unit 110, the inverter unit 120, and the second distributed power supply unit 130 to perform a function of integrally monitoring and controlling.

In detail, the integrated monitoring controller 140 is connected to each of the power converters 111, 112, and 113 of the first distributed power supply unit to read operation state information of each power converter, that is, information such as output power and voltage, and the second distributed unit. It is connected to the governor controller 132 of the power supply unit and transmits the output command value of the diesel engine, and is connected to the voltage regulator 133 to transmit and receive the voltage reference value of the synchronous generator. In addition, the controller receives the output information of the second distributed power supply unit and the state information of the load and transmits an opening / closing control signal to the first and second switches 124 and 134.

On the other hand, with respect to the hybrid distributed power generation system control method using a system consisting of the first distributed power supply unit 110, the inverter unit 120, the second distributed power supply unit 130 and the integrated monitoring control unit 140 described above with reference to FIGS. Referring to the following.

As described above, by separately configuring a power generation system using renewable energy and a diesel power generation system, it is a characteristic object of the present invention to stably supply power even if wind or solar power is added to an existing diesel generator. To describe the output control flow of the hybrid distributed power generation system to achieve this.

Referring to FIG. 3, the output control flow of the inverter unit 120 according to a characteristic aspect of the present invention is an AC-DC converter 111 connected to a wind generator and a solar cell, respectively. The power Pwt and Ppv values output from the boost converter 112 are calculated as average values for [T] seconds, and the current reference value i ^* _qe is calculated based on the sum of the calculated average values ( S100).

The inverter unit 120 reads the voltage Vdc value of the DC common bus A1 and determines whether the inverter unit 120 is greater than the DC terminal minimum voltage Vdc_min (S200). As a result of determination, when the voltage Vdc of the DC common bus A1 is large, it is determined whether the inverter unit 120 is smaller than the DC terminal maximum voltage Vdc_max (S300). When the voltage Vdc of A1 is small, the inverter unit 120 determines that the DC terminal voltage does not exceed the allowable operating range, and operates the current reference value i ^* _qe calculated in the step S100 (S100). S400). At this time, since a separate step-up or step-down operation is not necessary, the inverter unit 120 performs continuous normal current control (S500).

As a result of the determination in step S300, when the DC terminal maximum voltage Vdc_max is small, the inverter unit 120 determines whether the charging operation is being performed (S400a), and when it is determined that the charging operation is being executed, the inverter The unit 120 performs normal current control with the current reference value i ^* _qe , and when the charging operation is not being executed, the inverter unit 120 sets a predetermined value Δi at the current reference value i ^* _qe . By adding, the output is increased (S500a).

When the voltage Vdc of the DC common bus A1 is small, the inverter unit 120 determines whether the boost operation is being performed (S300b). When the operation is being executed, that is, as the voltage drops as the output of the inverter portion is greater than the output of the first distributed power supply portion, the battery B and the DC-DC converter 113 compensate for the DC common bus A1. In the case of performing the operation of compensating the voltage of the inverter), the inverter unit 120 performs the normal current control with the current reference value (i ^* _qe ), and when the boost operation is not executed, the inverter unit 120 performs the current reference value. By subtracting the predetermined value Δi from (i ^* _qe ), the output is reduced (S400b).

The output leveling algorithm of step S100 according to an embodiment of the present invention will be described with reference to FIG. 4 as follows.

The inverter unit 120 receives the respective output powers Pwt and Ppv from the AC-DC converter 111 connected to the wind generator wt and the boost converter 112 connected to the solar cell pv (S110). ). The inverter unit 120 that receives the output power calculates an average value of the respective output powers for [T] seconds and sums the calculated respective average values (S120). Thereafter, the inverter unit 120 divides the sum of the values by the line voltage of the AC common bus A2 and multiplies the maximum value of the current to extract the output current reference value i ^* _qe of the inverter unit 120 (S130). .

The advantage of the above-described output leveling algorithm is that it is possible to make full use of the generated energy without actually measuring environmental conditions such as solar radiation and wind speed affecting the output of wind power and photovoltaic power generation. This prevents the output from changing suddenly, thereby minimizing the influence of disturbance on the output of the engine generator, providing more stable power to the load and preventing unnecessary engine output control.

In addition, as described above, by monitoring the remaining capacity of the energy storage device, such as a battery, the hybrid dispersion to achieve the characteristic object of the present invention to prevent the shutdown due to the shortening of the life of the battery by frequent charging / discharging The operation control flow of the power generation system will be described.

The operation control flow of the hybrid distributed power generation system according to an embodiment of the present invention will be described with reference to FIG. 5, wherein the integrated monitoring controller 140 includes the voltage Vdc value of the DC common bus A1 and the DC voltage peak voltage. Based on the Vdc_max and the lowest voltage Vdc_min, it is determined whether the first distributed power supply unit is set to the boosted or charged mode (S210). When the boosted or charged mode is set, the integrated monitoring controller 140 counts the counters. (Cnt) is increased (S220), and the value of the increased counter is compared with the set value to determine whether or not the set value (S230).

As a result of the determination in step S230, when the set value is equal to or greater than a predetermined time, the integrated monitoring controller 140 sets the counter to 0 (S240) and executes the boost or charge mode (S250).

At this time, the integrated monitoring controller 140 determines whether the driving operation is in the boost mode (S260), and as a result of the determination, in the boost mode, the integrated monitoring controller 140 sets the voltage reference values as the highest voltage (Vdc_max) and the lowest voltage. Set to the intermediate value of (Vdc-min) (S270), and check the state of charge of the battery and performs the boost operation (S280). As a result of the determination in step S260, when it is not in the boosted mode, the integrated monitoring controller 140 determines the charging mode, checks the state of charge of the battery, and executes the charging operation (S280a).

FIG. 6 is a diagram illustrating a plurality of distributed power supply units applied to a hybrid distributed power generation system. As shown in FIG. 6, an input capacitance that is connected to a DC common bus A1 regardless of the number of first distributed power supply units is increased and thus increased. The inverter section which handles this is extended. In addition, an additional second distributed power supply unit may be connected to the AC common bus A2 as the load increases.

As described above and described with reference to a preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as described above, it is a deviation from the scope of the technical idea It will be understood by those skilled in the art that many modifications and variations can be made to the invention without departing from the scope of the invention. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

According to the present invention as described above, by separately configuring a power generation system using a renewable energy, and a diesel power generation system, there is an effect that can be stably supplied power even if wind or solar power is added to the existing diesel generator.

In addition, by monitoring the remaining capacity of the battery, it is possible to prevent the operation stop due to the shortening of the battery life due to frequent charging and discharging, and to stably supply power even in case of sudden changes in output due to natural conditions such as wind or solar light. have.

Claims (11)

delete delete delete delete delete delete delete delete delete In the operation control method using a hybrid distributed power generation system, (f) The integrated monitoring control unit 140 operates the first distributed power supply unit in the boosted or charged mode based on the voltage Vdc value of the DC common bus A1, the DC voltage highest voltage Vdc_max, and the lowest voltage Vdc_min. Determining whether it is set; (g) When the boosting or charging mode is set as a result of the determination in step (f), the integrated monitoring controller 140 increases the counter Cnt and compares the value of the increased counter with the set value to determine whether it is greater than or equal to the set value. Determining whether or not; (h) when the determination result of step (g) is greater than or equal to a set value, that is, when a predetermined time has elapsed, the integrated monitoring controller 140 sets the counter to 0 and executes a boost or charge mode; (i) determining whether the integrated surveillance controller 140 is in a boost mode; (j) in the boosting mode, as a result of the determination in step (i), the integrated monitoring controller 140 setting the voltage reference value as an intermediate value between the highest voltage Vdc_max and the lowest voltage Vdc-min; And (k) checking, by the integrated monitoring controller 140, the state of charge of the battery and performing a boost operation; Operation control method using a hybrid distributed power generation system comprising a. The method of claim 10, As a result of the determination of step (i), When not in the boosted mode, the integrated monitoring control unit 140 determines the charging mode to check the state of charge of the battery and to execute the charging operation; Operation control method using a hybrid distributed power generation system, characterized in that it further comprises.

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