WO2017014372A1 - System for controlling output voltage of three-phase induction generator by varying self-excitation capacitance - Google Patents

System for controlling output voltage of three-phase induction generator by varying self-excitation capacitance Download PDF

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Publication number
WO2017014372A1
WO2017014372A1 PCT/KR2015/013253 KR2015013253W WO2017014372A1 WO 2017014372 A1 WO2017014372 A1 WO 2017014372A1 KR 2015013253 W KR2015013253 W KR 2015013253W WO 2017014372 A1 WO2017014372 A1 WO 2017014372A1
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Prior art keywords
capacitor
induction generator
phase induction
semiconductor switch
inductor
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PCT/KR2015/013253
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French (fr)
Korean (ko)
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염성도
김응석
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주식회사 그랜드
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Publication of WO2017014372A1 publication Critical patent/WO2017014372A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
    • H02P9/46—Control of asynchronous generator by variation of capacitor

Definitions

  • the present invention relates to an output voltage control system of a three-phase induction generator for varying the capacity of the magnetic excitation capacitor to control the magnitude and power factor of the output voltage of the three-phase induction generator.
  • induction generators take an excitation current that is 90 degrees out of phase in the system, so the capacitors are connected in parallel to improve the power factor.
  • the conventional induction generator is fixed in the capacity of the magnetic excitation capacitor.
  • the induction generator has a rotational speed at which power generation starts depending on the capacity of the capacitor.
  • the capacity of the self-exciting capacitor is fixed according to the rated speed of the generator, so that the power generation output is generated only when the speed of the generator is higher than the rated speed.
  • the conventional induction generator has a limit that does not generate power at a rotation speed below the rated speed.
  • the rotational speed of the generator is too high after the start of power generation exceeds the rated speed, there is a problem that the system is damaged by outputting the generated voltage exceeding the maximum allowable voltage range of the power converter such as converter, inductor, rectifier, etc. .
  • the self-excitation capacity control system of the three-phase induction generator disclosed in the patent document is characterized by adjusting the capacitance of the capacitor by adjusting the firing angle of the thyristors connected to the auxiliary winding.
  • the impedance of the capacitor It can be expressed as. here Means frequency Means self-excited capacitor value.
  • variable value of impedance in the fixed state is a technical feature set forth in the prior art, but it is noted that the shape of the waveform can be changed by adjusting the firing angle of the thyristors.
  • the change range of the in switching frequency is small. Therefore, in the adjustment of the firing angle of the thyristors, the range in which the capacitance can be controlled is very limited due to the small fluctuation in the impedance value of the self-exciting capacitor. That is, it is difficult to adjust the induction generator output voltage range as desired because the variable range of the capacitor capacity is limited.
  • the conventional self-excitation capacity control system is applied to a single-phase induction generator, there is a problem that can not be applied to a three-phase induction generator consisting of three-phase main winding without the auxiliary winding because the auxiliary winding capacity control unit is connected to the auxiliary winding. .
  • the present inventors have focused on the above problem that the capacity of the magnetic excitation capacitor is not sufficiently controlled by the thyristors, and through the other technical solutions that can vary the magnetic excitation capacity as desired, We have devised a system that can efficiently control the magnitude and phase of the output voltage which varies with rotation speed.
  • the present invention is to provide a self-excitation capacity control system of a three-phase induction generator capable of varying the capacity of the magnetic excitation capacitor according to the rotational speed of the three-phase induction generator or the magnitude of the generated voltage. More specifically, the present invention is to provide an output voltage control system of an induction generator capable of varying the capacitance of the capacitor by connecting the semiconductor switch in parallel with the capacitor to control the switching frequency.
  • the present invention is to provide an output voltage control system of a three-phase induction generator capable of controlling the output voltage of the three-phase induction generator to a desired size by improving the control range of the capacitor capacity by the switching frequency control.
  • the present invention relates to an output voltage control system of a three-phase induction generator, comprising: a capacitor connected in parallel to the auxiliary winding of the three-phase induction generator; An auxiliary circuit unit having an inductor electrically connected in parallel with the capacitor and electrically resonating, and having a semiconductor switch intermittent with the current flowing through the inductor or varying the direction of the current flowing through the inductor to vary the capacitance of the capacitor at an on / off frequency of the semiconductor switch; And a control unit for controlling the switching frequency of the semiconductor switch by measuring the rotational speed of the three-phase induction generator or the magnitude of the generated voltage of the three-phase induction generator.
  • the first semiconductor switch may bias the current flowing through the inductor in the forward direction
  • the second semiconductor switch may bias the current flowing through the inductor in the reverse direction.
  • the plurality of capacitors may have different capacities and may be connected in parallel to the auxiliary windings, respectively.
  • the output voltage control system of the three-phase induction generator according to the present invention may further include a relay switch for selectively connecting the plurality of capacitors to the auxiliary winding to select the capacitance of the capacitor.
  • control unit may control to decrease the capacity of the capacitor when the rotational speed of the three-phase induction generator is increased, and to increase the capacity of the capacitor when the rotational speed of the three-phase induction generator is reduced.
  • control unit can control the other semiconductor switch on-off in the state of turning off any one of the semiconductor switch of the pair.
  • the capacity of the self-exciting capacitor is varied according to the rotational speed of the three-phase induction generator or the magnitude of the generated voltage, so that generation of the generated voltage is possible even when the rotational speed of the generator is lower than the rated speed, and the rotational speed of the generator Even if it is excessively increased, there is an advantage of maintaining the optimum voltage generation efficiency.
  • the impedance of the capacitor is varied as the frequency is adjusted by the semiconductor switch of the auxiliary circuit portion connected in parallel.
  • the present invention can easily control the magnetic excitation capacity by the desired size by controlling the ON / OFF of the semiconductor switch in inverse proportion to the generator rotation speed.
  • the present invention when the capacitor capacitance control range by the switching frequency control is exceeded, there is an advantage that the relay switch can control the output voltage of the desired size by connecting the capacitor of the other capacitor connected in parallel.
  • the present invention does not require a separate winding for the control of the magnetic excitation capacity, it is possible to configure the circuit in the main winding of three phases. Accordingly, it is possible to provide a power generation facility that does not require a mechanical braking device with a minimum element and low manufacturing cost.
  • the present invention is simple in the configuration of the auxiliary circuit portion for varying the capacitance of the capacitor, and the weight of the system is light, thereby making it easy to carry. Accordingly, it is possible to provide a power generation facility that does not require a mechanical braking device with a minimum element and a low manufacturing cost.
  • a mechanical braking device with a minimum element and a low manufacturing cost.
  • the performance of the permanent magnet deteriorates with time, but the performance is degraded.
  • the power generation equipment equipped with the magnetic excitation capacity control system according to the present invention is remarkably easy to maintain and replace the synchronous generator.
  • FIG. 1 is a block diagram of an output voltage control system of a three-phase induction generator according to an embodiment of the present invention.
  • Figure 2 shows the relationship between the speed of self-excited capacitance of the induction generator.
  • FIG 3 shows an auxiliary circuit according to an embodiment of the present invention.
  • FIG. 4 is a diagram illustrating a connection of a semiconductor switch according to an exemplary embodiment of the present invention.
  • FIG. 5 is a semiconductor switch ( , ) Shows the frequency conversion by the ON / OFF state and the current flow chart of the auxiliary circuit.
  • FIG. 6 shows a method of controlling the output voltage of a three-phase induction generator according to an embodiment of the present invention.
  • Fig. 8 shows an excitation capacitance control circuit using a thyristor and a circuit diagram embodying the present invention.
  • FIG. 9 shows a result waveform according to each control in FIG. 8.
  • an output voltage control system 1 of a three-phase induction generator 1 includes an induction generator 10, an AC-DC converter 13, a DC-AC converter 15, a capacitor 20, and an auxiliary circuit unit 30. ) And the controller 40.
  • the induction generator 10 may be connected to the turbine 11, and may be provided with three phase main windings 18 arranged near the rotor and the rotor to induce a voltage.
  • the turbine 11 refers to a prime mover that rotates the rotor by turbines of various generators such as wind power, water wheels, and the like.
  • the turbine 11 refers to a prime mover that rotates the rotor by turbines of various generators such as wind power, water wheels, and the like.
  • the rotation of the rotor induces a voltage on each main winding of the three phases.
  • the three-phase induction generator takes an excitation current that is 90 ° out of phase in the system 17, it is common to connect the capacitors 20 in parallel to improve the power factor.
  • the capacitance of the capacitor 20 has generally been fixed and used.
  • FIG. 2 shows the relationship between the speed of self-excited capacitance of the three-phase induction generator 10.
  • the graph of FIG. 2 is a result derived by binding capacitors having different capacitances in each experiment speed section of the three-phase induction generator 10.
  • the capacity of the capacitor 20 is inversely proportional to the rotational speed of the induction generator 10. Accordingly, it is possible to check the power generation start speed of the induction generator 10 according to the change of the self-excitation capacitance in the graph of FIG. 2. As the self-excitation capacitance of the capacitor 20 increases, the power generation start rate decreases. In this case, the output voltage (generation voltage) of the induction generator 10 is also lowered. That is, in order to control the magnitude and phase of the power generation voltage of the induction generator 10, the capacity of the capacitor 20 for self-excitation must be variable in inverse proportion to the rotational speed of the induction generator 10.
  • the self-excited capacitance control system 1 adjusts the capacitance of the self-excited capacitor connected to each terminal of (a, b), (b, c), and (a, c) output terminals of the induction generator. It is technical feature
  • the capacitor 20 may be connected in three phases to the three-phase winding of the induction generator 10.
  • the capacitor 20 is the first capacitor 201 connected to the (b, c) terminal, the second capacitor 203 connected to the (a, c) terminal, and the third capacitor 205 connected to the (a, b) terminal.
  • the capacitor 20 may use the first capacitor 201, the second capacitor 203, or the third capacitor 205. Can mean.
  • the voltage between the phases of the output terminal of the induction generator 10 is applied to the capacitor 20.
  • the capacity of the capacitor 20 is preferably set to the maximum capacity that is matched to the lowest speed at which the induction generator 10 starts to generate power.
  • the accurate calculation of the maximum capacity according to the lowest speed at which the induction generator 10 starts to generate power is difficult to find without driving the generator.
  • one or more capacitors 20: 201 or 203 or 205 connected to each of the three phase windings may be used to appropriately set the capacity of the initial capacitor 20. , ,... , 3) to implement.
  • the auxiliary circuit unit 30 may vary the capacitance of the capacitor 20.
  • 3 shows the auxiliary circuit unit 30 according to the embodiment of the present invention.
  • the auxiliary circuit unit 30 may include an inductor 301, a pair of diodes, and a semiconductor switch 303.
  • the auxiliary circuit unit 30 may be connected in parallel with the capacitor 201.
  • the capacitor 20 includes a plurality of capacitors (n) having different capacitances for setting the initial capacitance. , ,... , Is preferably connected in parallel. In this case, the capacitor is connected to the output terminal of each phase. , , 0, Relay switch for selecting the capacity of FIG. , , 0, , 305 may be further included.
  • the relay switch 305 properly sets the capacity of the initial capacitor 20 to prevent damage to the system at the start of power generation, and when the capacity adjustment range of the selected capacitor 201 is exceeded, another capacitor connected in parallel ( , ,... , ) Can control the output voltage of the desired size by connecting or disconnecting the circuit.
  • the inductor 301 may electrically resonate with the magnetic excitation capacitor 201.
  • the inductor 301 enables self-excited power generation according to the LC resonance phenomenon with the capacitor 201. At this time, the capacity of the capacitor 201 to generate the LC resonance depends on the rotational speed of the generator.
  • the semiconductor switch 303 may be connected in series with the inductor 301.
  • a plurality of semiconductor switches 303 may be provided.
  • the semiconductor switch 303 has a pair ( , ) May be provided.
  • the semiconductor switch 303 may interrupt a flow flowing in the inductor 301.
  • the semiconductor switch 303 may change the direction of the current flowing through the inductor 301.
  • the auxiliary circuit unit 30 may vary the capacitance of the capacitor 201 at the on / off frequency of the semiconductor switch 303. In this regard, it will be described later with reference to FIG.
  • the IGBT may be used as the semiconductor switch 303.
  • the auxiliary circuit unit 30 may be configured by connecting two or more unidirectional semiconductor switches in series or in parallel.
  • the output voltage control system 1 of the three-phase induction generator is implemented as a pair of semiconductor switches 303, and the first semiconductor switch ( ) And the second semiconductor switch ( ) Shows the form d) connected in parallel.
  • the first semiconductor switch ( ) And the second semiconductor switch ( ) Should be wired so that the bias direction is symmetrical.
  • the auxiliary circuit unit 30 is a semiconductor switch ( , ) May include diodes connected in series in the same bias direction.
  • the pair of semiconductor switches 303 may include a first semiconductor switch ( ) Biases the current flowing in the inductor 301 in the forward direction, and the second semiconductor switch ( ) May be connected to bias the current flowing in the inductor 301 in the reverse direction.
  • the forward direction and the reverse direction are terms used to distinguish the directions of different currents and do not limit the directions of the currents.
  • the auxiliary circuit unit 30 may vary the capacitance of the capacitor 20 at the on / off frequency of the semiconductor switch 303.
  • the auxiliary circuit unit 30 has a switching frequency of the semiconductor switch 303 ( ) By controlling the impedance values of the capacitor 20 and the inductor 301.
  • the impedance of the self-exciting capacitance of the capacitor 20 is It can be expressed as. here Means frequency Denotes the value of the self-exciting capacitor. To change the impedance Should be changed. In the present embodiment, by the on-off operation of the semiconductor switch 303 As is changed, the impedance of the self-exciting capacitance can be controlled.
  • the self-excited capacitive impedance ( ) By controlling the number of switching pulses in the on / off operation of the semiconductor switch 303, the ON / OFF control may be performed irrespective of the polarity of the power to which the frequency is applied. Therefore, both the method of adjusting the size of the switching frequency and the number of switching pulses n and the method of controlling the amount of current charged and discharged in the capacitor 20 can be applied. do. In addition, since the size of the switching pulse can be adjusted, even if the physical size of the capacitor 20 for repeating charging and discharging is small, it can be controlled so that charge and discharge can be clearly generated.
  • the controller 40 may control the switching frequency of the semiconductor switch 303 by measuring the rotational speed of the three-phase induction generator 10 or the magnitude of the generated voltage of the three-phase induction generator 10.
  • the controller 40 may be used as a reference value for controlling the switching frequency of the semiconductor switch 303 by measuring the rotational speed of the three-phase induction generator 10 or the magnitude of the output voltage of the three-phase induction generator 10.
  • the controller 40 transmits information such as the rotational speed of the induction generator 10, the generated AC voltage, the generated AC current, the rectifier output voltage, the rectifier output current, the AC-DC converter output voltage, the AC-DC converter output current, and the phase. I can receive it.
  • the controller 40 may receive and monitor a grid current and voltage from the grid 17.
  • the controller 40 may control the auxiliary circuit unit 30, the AC-DC converter 13, and the DC-AC converter 15 by monitoring the voltage currents of the induction generator 10 and the system 17.
  • the controller 40 reduces the capacity of the capacitor 20 when the speed of rotation of the induction generator 10 increases, and increases the capacity of the capacitor 20 when the speed of rotation of the induction generator 10 decreases. Can be.
  • the controller 40 may be any one of a pair of semiconductor switches 303 ( or ) With the remaining semiconductor switch ( or ) You can control On / Off. Detailed operation will be described later with reference to FIG. 4.
  • the controller 40 may control the capacity of the capacitor 20 to the maximum value at the lowest rotational speed at which the induction generator 10 can start generating power.
  • the controller 40 may control the capacitance of the capacitor 20 to a minimum value when the generated voltage of the induction generator 10 is outside the allowable range set by the user. In this case, even if the rotational speed of the induction generator 10 is out of the allowable range, while the range of the generated output voltage is maintained within the allowable range, it is possible to generate the generated voltage even if the rotational speed of the induction generator 10 is less than the allowable range. Do.
  • the controller 40 measures the rotational speed of the induction generator 10 in the graph of FIG. 2 to control the self-excitation capacity so that the generator corresponds to the stable region region.
  • the semiconductor switch 303 which is easy to control and has low installation and manufacturing cost is a capacitor.
  • the controller 40 controls the magnitude and phase of the power generation voltage by monitoring the rotational speed of the induction generator 10 to adjust the capacity of the capacitor 20. Accordingly, stable operation is possible even with a change in the rotational speed of the induction generator 10.
  • 5 shows a current flow chart of the auxiliary circuit unit 30 according to the charge / discharge mode of the self-excited capacitor 20.
  • 5A shows that the control unit 40 in the case where the output voltage of the three-phase inductor To OFF, When repeating ON / OFF at a specific frequency, Indicates the current flow in the capacitor 20 when is ON state.
  • 5B shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave type is in a positive state To OFF, When repeating ON / OFF at a specific frequency, Shows a current flow chart of the capacitor 20 when is ON state.
  • 5C shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave type is in a positive state To OFF, When repeating ON / OFF at a specific frequency, Shows a current flow of the capacitor 20 when is OFF.
  • the three-phase induction generator 10 is operated in a charge mode and the capacitor , ,... ,
  • the current supplied to the load may be reduced and supplied by the amount of the current charged in the self-exciting capacitor 20.
  • 5D shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave type is in a positive state To OFF, When repeating ON / OFF at a specific frequency, Shows the current flow of the capacitor 20 when is OFF. At this time, it operates in discharge mode and capacitor , ,... , When the voltage charged in the is greater than the input voltage, the current supplied to the load is increased by the amount of current emitted from the self-exciting capacitor 20 and supplied.
  • 5E shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave form is in the negative state. OFF When repeating ON / OFF at a specific frequency, Shows a current flow chart of the capacitor 20 when is ON state.
  • 5F shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave form is in the negative state.
  • OFF When repeating ON / OFF at a specific frequency, Shows a current flow of the capacitor 20 when is OFF.
  • the three-phase induction generator (1) is operated in the charge mode and the capacitor , ,... ,
  • the current supplied to the load side is reduced and supplied by the amount of the current charged in the capacitor 20.
  • 5G shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave form is in a negative state.
  • OFF When repeating ON / OFF at a specific frequency, Shows a current flow of the capacitor 20 when is OFF.
  • the three-phase induction generator 10 is operated in the discharge mode and the capacitor , ,... , In the case where the voltage charged in is greater than the input voltage, the current supplied to the load side is increased by the amount of the current emitted from the capacitor 20.
  • FIG. 6 shows an output voltage control method of a three-phase induction generator 10 according to an embodiment of the present invention.
  • the first step S10 of receiving the rotation speed or the generation voltage of the induction generator 10, the rotation speed or the generation voltage of the induction generator 10.
  • a step S50 and a fourth step S70 of controlling the self-exciting capacitance of the capacitor 20 may be included.
  • control unit 40 may receive the rotational speed or power generation voltage of the three-phase induction generator 10 to the ADC of the controller.
  • the controller 40 may calculate the impedance value by calculating the self-exciting capacity of the capacitor 20 corresponding to the rotational speed or the generation voltage received in the first step S10. Looking at the process of calculating the impedance at the rotational speed of the three-phase induction generator as follows.
  • Equation 1) represents the rotation frequency and the synchronous speed of the induction machine. At this time, if a slight time delay occurs between the frequencies of the generated alternating current voltage with respect to the actual rotational speed of the rotor of the inductor, slip ('s' in Equation 2) occurs.
  • Rotational angular velocity ( ) And the capacitive reactance ( ) are inversely related to each other. In other words, This holds true.
  • the controller 40 modifies the impedance calculated in the second step S30.
  • Semiconductor switching frequency value from (rad / s) can be converted.
  • the control unit 40 compares the rotational speed or the generated voltage of the three-phase induction generator 10 with the maximum reference value or the minimum reference value to change the converted frequency value of the self-exciting capacity of the capacitor 20.
  • the maximum reference value of the rotational speed means a case where the rotational speed of the three-phase induction generator 10 exceeds the rated speed.
  • the minimum reference value of the rotational speed means that the rotational speed of the three-phase induction generator 10 is less than the rated speed.
  • the switching frequency of the semiconductor switch 303 may be adjusted in a direction in which the impedance of the capacitor 20 decreases.
  • the switching frequency of the semiconductor switch 303 may be adjusted in a direction in which the impedance of the capacitor 20 increases.
  • the on / off pulse time of the semiconductor switch 303 may be controlled and output based on the adjusted frequency value.
  • the control process of the fourth step S70 is as described above with reference to FIG. 4. Briefly summarized the control section of the control unit 40 is as follows. The larger the rotational speed of the induction rotor, the smaller the capacitive reactance of the self-excited capacitor that can start generating power. On the contrary, the smaller the speed of the induction rotor, the larger the self-excited capacitor capacitive reactance that can start generating. .
  • the rotational angular velocity of the induction machine ( ), The capacitive reactance ( Switching frequency of By adjusting the size of), the size of the capacitive reactance can be adjusted. That is, the inductor rotational angular velocity ( ) Increases, the capacitive reactance ( Decrease). This requires a switching frequency ( Increase). In addition, the inductor rotational angular velocity ( Decreases, the capacitive reactance ( To increase the switching frequency ( ) Is reduced.
  • the capacitance of the capacitor 20 is variable according to the switching frequency adjusted by the controller 40. Accordingly, the three-phase induction generator 10 can output a high efficiency generation voltage even at or above the rated speed.
  • the self-excited dose control system described above is more effective than the method of controlling the excitation dose using a thyristor.
  • a technique of controlling the self-exciting capacity of a capacitor by the firing angle control using a thyristor has been described above in the background art.
  • the semiconductor switch 303 according to the present embodiment has different characteristics and functions of the thyristor and the device. Looking at the above differences in more detail summarizes the differences from the prior art as follows.
  • FIG. 7 shows the basic operation of the thyristor circuit.
  • a thyristor applies an ON pulse to a gate
  • the thyristor becomes conductive at that moment, and a load current flows, which lasts until the polarity (+,-) of the power supply voltage is changed.
  • the firing angle control for turning on the thyristor is possible. That is, there is no separate control operation to turn off, and it is OFF when the polarity of the input waveform is changed.
  • FIG. 8 shows an excitation capacitance control circuit using a thyristor and a circuit diagram of the present invention according to the present invention. As shown in FIG. 8, when both of them are implemented as actual circuit diagrams and output result waveforms according to control are shown in FIG. 9.
  • the frequency of the current waveform does not change even if the polarity of the applied power is changed and the thyristor is re-ignited.
  • the circuit configuration of the present invention can be seen that the switching current is changed in proportion to the switching pulse is applied.
  • the capacitor's capacity must be relatively large, but the larger the capacitor's capacity, the greater the physical time required for charging and discharging. As a result, the thyristor has a limit in that it cannot adjust the charge / discharge time interval to control the electrical capacity of the capacitor.
  • the capacitive reactance Frequency by adjusting the number of switching pulses You can control ON / OFF irrespective of polarity of applied power.
  • switching frequency And the number of switching pulses n ( ) And the method of controlling the amount of current charged and discharged in the capacitor can be applied, so that the range for adjusting the capacitance of the reactance becomes significantly larger.
  • the size of the switching pulse can be adjusted, even if the physical size of the capacitor for repeating the charging and discharging can be controlled so that the charge and discharge can be clearly generated.
  • control unit 40 control unit

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Abstract

The present invention relates to a system for controlling the output voltage of a three-phase induction generator, comprising: a capacitor connected in parallel to an auxiliary winding of a three-phase induction generator; an auxiliary circuit unit which includes an inductor connected in parallel to the capacitor to induce electrical resonance and a pair of semiconductor switches for controlling the current flowing through the inductor or changing the direction of the current flowing through the inductor, so as to vary the capacitance of the capacitor with the on/off frequencies of the semiconductor switches; and a control unit which measures the rotation speed of the three-phase induction generator or the magnitude of generated voltage of the three-phase induction generator, so as to control the switching frequencies of the semiconductor switches. The present invention has advantages in that the capacitance of a self-excited capacitor can vary according to the rotation speed or the magnitude of generated voltage of a three-phase induction generator, so that the generated voltage can be generated even when the rotation speed of the generator does not exceed a rated speed, and optimal voltage generation efficiency can be maintained even when the rotation speed of the generator is excessively increased.

Description

자기 여자 용량을 가변하는 3상 유도 발전기의 출력전압 제어 시스템Output voltage control system of three-phase induction generator with variable magnetic excitation capacity
본 발명은 자기 여자 커패시터의 용량을 가변하여 3상 유도 발전기의 출력전압 크기와 역률을 제어하는 3상 유도 발전기의 출력전압 제어 시스템에 관한 것이다. The present invention relates to an output voltage control system of a three-phase induction generator for varying the capacity of the magnetic excitation capacitor to control the magnitude and power factor of the output voltage of the three-phase induction generator.
일반적으로 유도 발전기는 계통에서 위상이 90도 뒤쳐진 여자 전류를 취하기 때문에 커패시터를 병렬로 접속하여 역률개선을 하게 된다. 이 경우, 기존의 유도 발전기는 자기 여자 커패시터의 용량이 고정된다. 이러한 유도 발전기는 최초에 정해진 커패시터의 용량에 따라 발전개시 회전속도가 정해지게 된다. 대개의 경우, 발전기의 정격 속도에 맞춰서 자기 여자 커패시터의 용량을 고정시키고 있기 때문에 발전기의 회전속도가 정격 속도 이상일 때에만 발전 출력이 발생하게 된다. Typically, induction generators take an excitation current that is 90 degrees out of phase in the system, so the capacitors are connected in parallel to improve the power factor. In this case, the conventional induction generator is fixed in the capacity of the magnetic excitation capacitor. The induction generator has a rotational speed at which power generation starts depending on the capacity of the capacitor. In most cases, the capacity of the self-exciting capacitor is fixed according to the rated speed of the generator, so that the power generation output is generated only when the speed of the generator is higher than the rated speed.
즉, 종래의 유도 발전기는 정격 속도 이하의 회전속도에서 발전이 되지 않는 한계가 있다. 또한, 발전개시 이후 발전기의 회전속도가 지나치게 높아지게 되어 정격 속도를 초과하는 경우 컨버터, 인덕터, 정류기 등의 전력변환장치가 갖는 최대 허용 전압범위를 초과하는 발전전압이 출력되어 시스템이 파손되는 문제점이 있다.That is, the conventional induction generator has a limit that does not generate power at a rotation speed below the rated speed. In addition, if the rotational speed of the generator is too high after the start of power generation exceeds the rated speed, there is a problem that the system is damaged by outputting the generated voltage exceeding the maximum allowable voltage range of the power converter such as converter, inductor, rectifier, etc. .
따라서, 종래와 같이 유도 발전기의 정격 회전속도에 맞추어 커패시터의 용량을 고정하여 설치하는 경우에는 유도 발전기의 회전속도가 허용범위를 벗어나지 않도록 주의하여 운용해야 한다. 발전기가 허용범위의 회전속도를 초과하여 회전한다면, 발전기의 출력전압이 과전압이 되어 시스템 파손 및 전기화재 등의 대형사고가 야기될 수 있다. 이와는 반대로, 발전기가 허용범위의 회전속도 이하에서 회전하게 된다면 출력전압이 발생하지 않거나 효율이 현저히 저하된다. 이에 따라 종래의 유도 발전기는 오히려 전기를 소비하는 전동기로 작동하게 되는 문제점이 있다.Therefore, when the fixed capacity of the capacitor is installed in accordance with the rated rotational speed of the induction generator as in the prior art, care must be taken to ensure that the rotational speed of the induction generator does not deviate from the allowable range. If the generator rotates in excess of the allowable rotation speed, the output voltage of the generator may be overvoltage, which may cause system damage and major accidents such as electric fire. On the contrary, if the generator rotates below the allowable rotational speed, no output voltage is generated or the efficiency is significantly reduced. Accordingly, there is a problem in that the conventional induction generator is operated by a motor that consumes electricity.
전술한 문제점에 따라, 종래에는 자기 여자 방식의 유도 발전기 회전속도를 제어하기 위해서 기계적인 기어비를 조절하거나 제동장치를 작동하여 허용범위를 초과하는 회전속도에서는 발전기의 회전축을 정지시켰다. 따라서, 종래에는 시스템의 설치비용, 관리 및 운전 비용 등 전체적인 비용의 상승을 초래하는 문제점이 있으며, 별도의 제동장치는 소용량의 발전시스템 설치 및 보급에 저해되는 요소로 작용되었다. In accordance with the above-described problems, conventionally, in order to control the rotation speed of the induction generator of the self-excited manner, the mechanical shaft ratio is adjusted or the braking device is operated to stop the rotation axis of the generator at a rotation speed exceeding an allowable range. Therefore, in the related art, there is a problem of raising the overall cost such as installation cost, management and operation cost of the system, and a separate braking device acts as a detrimental factor in installing and distributing a small capacity power generation system.
최근, 상기 문제점에 착안하여 3상 유도 발전기의 자기 여자 용량을 가변함으로써 발전기의 회전속도가 정격 속도 이하인 경우에도 전압을 생성하고, 회전속도가 정격 속도 이상에서도 전압 생성 효율을 유지하는 특허문헌이 개시되었다(한국등록특허 제10-1506206호).Recently, in view of the above problems, a patent document for generating a voltage even when the rotational speed of the generator is below the rated speed by varying the self-excitation capacity of the three-phase induction generator, and maintaining the voltage generation efficiency even if the rotational speed is above the rated speed is disclosed. (Korean Patent No. 10-1506206).
상기 특허문헌에 개시된 3상 유도 발전기의 자기 여자 용량 제어 시스템은, 보조권선에 연결된 사이리스터의 점호각을 조정함으로써 커패시터의 용량을 조절하는 것을 기술적 특징으로 한다. The self-excitation capacity control system of the three-phase induction generator disclosed in the patent document is characterized by adjusting the capacitance of the capacitor by adjusting the firing angle of the thyristors connected to the auxiliary winding.
한편, 자기 여자 용량을 제어하기 위해선 커패시터의 임피던스 값을 가변시킬 수 있어야 한다. 커패시터의 임피던스는
Figure PCTKR2015013253-appb-I000001
로 표현될 수 있다. 여기서
Figure PCTKR2015013253-appb-I000002
는 주파수를 의미하며
Figure PCTKR2015013253-appb-I000003
는 자기 여자 커패시터 값을 의미한다. On the other hand, in order to control the self-exciting capacitance, it is necessary to be able to vary the impedance value of the capacitor. The impedance of the capacitor
Figure PCTKR2015013253-appb-I000001
It can be expressed as. here
Figure PCTKR2015013253-appb-I000002
Means frequency
Figure PCTKR2015013253-appb-I000003
Means self-excited capacitor value.
Figure PCTKR2015013253-appb-I000004
값은 고정된 상태에서 임피던스의 값을 가변시키는 것이 종래의 선행특허에서 제시된 기술적 특징이나, 사이리스터의 점호각 조정으로는 파형의 형태를 변화시킬 수 있음은 별론으로 하고
Figure PCTKR2015013253-appb-I000005
인 스위칭 주파수의 변화폭이 작다. 따라서, 사이리스터의 점호각 조정으로는 자기 여자 커패시터의 임피던스 값의 변동폭이 적어서 용량을 제어할 수 있는 범위가 매우 제한적이다. 즉, 커패시터 용량의 가변 범위가 제한적이기 때문에 유도 발전기 출력전압 범위를 원하는 만큼 조절하는 것이 어렵다.
Figure PCTKR2015013253-appb-I000004
The variable value of impedance in the fixed state is a technical feature set forth in the prior art, but it is noted that the shape of the waveform can be changed by adjusting the firing angle of the thyristors.
Figure PCTKR2015013253-appb-I000005
The change range of the in switching frequency is small. Therefore, in the adjustment of the firing angle of the thyristors, the range in which the capacitance can be controlled is very limited due to the small fluctuation in the impedance value of the self-exciting capacitor. That is, it is difficult to adjust the induction generator output voltage range as desired because the variable range of the capacitor capacity is limited.
또한, 종래의 자기 여자 용량 제어 시스템은 단상 유도 발전기에 적용되는 것으로서, 보조권선 용량 조절부가 보조권선에 연결되기 때문에 보조권선이 없이 3상의 주권선으로 이루어지는 3상 유도 발전기에 적용될 수 없는 문제점이 있다. In addition, the conventional self-excitation capacity control system is applied to a single-phase induction generator, there is a problem that can not be applied to a three-phase induction generator consisting of three-phase main winding without the auxiliary winding because the auxiliary winding capacity control unit is connected to the auxiliary winding. .
이에 따라, 본 출원인은 사이리스터로는 자기 여자 커패시터의 용량이 충분히 제어되지 않는 상기의 문제점에 착안하여 자기 여자 용량을 원하는 만큼 가변할 수 있는 다른 기술적 해결 수단을 통해 전기적인 방식으로 3상 유도 발전기의 회전속도에 따라 변동하는 출력전압의 크기와 위상을 효율적으로 제어할 수 있는 시스템을 고안하게 되었다.Accordingly, the present inventors have focused on the above problem that the capacity of the magnetic excitation capacitor is not sufficiently controlled by the thyristors, and through the other technical solutions that can vary the magnetic excitation capacity as desired, We have devised a system that can efficiently control the magnitude and phase of the output voltage which varies with rotation speed.
[선행기술문헌][Preceding technical literature]
[특허문헌][Patent Documents]
한국등록특허 제10-1506206호(등록일 2015년 03월 20일)Korea Patent Registration No. 10-1506206 (Registration Date March 20, 2015)
본 발명은 3상 유도 발전기의 회전속도 또는 발전전압의 크기에 따라 자기 여자 커패시터의 용량을 가변시킬 수 있는 3상 유도 발전기의 자기 여자 용량 제어 시스템을 제공하고자 한다. 보다 상세하게, 본 발명은 반도체 스위치를 커패시터와 병렬로 연결하여 스위칭 주파수를 제어함으로써 커패시터의 용량을 가변할 수 있는 유도 발전기의 출력전압 제어 시스템을 제공하고자 한다. The present invention is to provide a self-excitation capacity control system of a three-phase induction generator capable of varying the capacity of the magnetic excitation capacitor according to the rotational speed of the three-phase induction generator or the magnitude of the generated voltage. More specifically, the present invention is to provide an output voltage control system of an induction generator capable of varying the capacitance of the capacitor by connecting the semiconductor switch in parallel with the capacitor to control the switching frequency.
또한 본 발명은, 스위칭 주파수 제어에 의한 커패시터 용량의 조절 범위가 향상되어 3상 유도 발전기의 출력전압을 원하는 크기로 제어할 수 있는 3상 유도 발전기의 출력전압 제어 시스템을 제공하고자 한다.In addition, the present invention is to provide an output voltage control system of a three-phase induction generator capable of controlling the output voltage of the three-phase induction generator to a desired size by improving the control range of the capacitor capacity by the switching frequency control.
상기 목적을 달성하기 위하여 본 발명은, 3상 유도 발전기의 출력전압 제어 시스템에 관한 것으로, 3상 유도 발전기의 보조 권선에 병렬로 연결된 커패시터; 커패시터와 병렬로 연결되어 전기적으로 공진하는 인덕터, 인덕터에 흐르는 전류를 단속 또는 인덕터에 흐르는 전류의 방향을 가변하는 반도체 스위치를 구비하여 반도체 스위치의 온오프 주파수로 상기 커패시터의 용량을 가변하는 보조 회로부; 및 3상 유도 발전기의 회전속도 또는 3상 유도 발전기의 발전전압의 크기를 측정하여 반도체 스위치의 스위칭 주파수를 제어하는 제어부를 포함한 것을 특징으로 한다.In order to achieve the above object, the present invention relates to an output voltage control system of a three-phase induction generator, comprising: a capacitor connected in parallel to the auxiliary winding of the three-phase induction generator; An auxiliary circuit unit having an inductor electrically connected in parallel with the capacitor and electrically resonating, and having a semiconductor switch intermittent with the current flowing through the inductor or varying the direction of the current flowing through the inductor to vary the capacitance of the capacitor at an on / off frequency of the semiconductor switch; And a control unit for controlling the switching frequency of the semiconductor switch by measuring the rotational speed of the three-phase induction generator or the magnitude of the generated voltage of the three-phase induction generator.
바람직하게, 본 발명에 따른 반도체 스위치는 복수개일 수 있다. 이 경우, 제1 반도체 스위치가 인덕터에 흐르는 전류를 정방향으로 바이어스시키고, 제2 반도체 스위치가 인덕터에 흐르는 전류를 역방향으로 바이어스 시킬 수 있다.Preferably, there may be a plurality of semiconductor switches according to the present invention. In this case, the first semiconductor switch may bias the current flowing through the inductor in the forward direction, and the second semiconductor switch may bias the current flowing through the inductor in the reverse direction.
바람직하게, 본 발명에 따른 커패시터는 복수개이고, 복수개의 커패시터는 서로 다른 용량을 갖고 보조권선에 각각 병렬로 연결될 수 있다.Preferably, there are a plurality of capacitors according to the present invention, and the plurality of capacitors may have different capacities and may be connected in parallel to the auxiliary windings, respectively.
바람직하게, 본 발명에 따른 3상 유도 발전기의 출력전압 제어 시스템은 복수개의 커패시터를 보조권선에 선택적으로 접속하여 커패시터의 용량을 선택하는 릴레이 스위치를 더 포함할 수 있다.Preferably, the output voltage control system of the three-phase induction generator according to the present invention may further include a relay switch for selectively connecting the plurality of capacitors to the auxiliary winding to select the capacitance of the capacitor.
바람직하게, 본 발명에 따른 제어부는 3상 유도 발전기의 회전속도가 증가되면 커패시터의 용량을 감소시키고, 3상 유도 발전기의 회전속도가 감소되면 커패시터의 용량을 증가시키도록 제어할 수 있다.Preferably, the control unit according to the present invention may control to decrease the capacity of the capacitor when the rotational speed of the three-phase induction generator is increased, and to increase the capacity of the capacitor when the rotational speed of the three-phase induction generator is reduced.
바람직하게, 본 발명에 따른 제어부는 한 쌍의 반도체 스위치 중 어느 하나의 반도체 스위치를 오프한 상태에서 나머지 반도체 스위치를 온오프 제어할 수 있다.Preferably, the control unit according to the present invention can control the other semiconductor switch on-off in the state of turning off any one of the semiconductor switch of the pair.
본 발명에 따르면, 3상 유도 발전기의 회전속도 또는 발전전압의 크기에 따라 자기여자 커패시터의 용량을 가변하여, 발전기의 회전속도가 정격 속도 이하인 경우에도 발전전압의 생성이 가능하고, 발전기의 회전속도가 과도하게 증가되어도 최적의 전압 생성 효율을 유지할 수 있는 이점이 있다. According to the present invention, the capacity of the self-exciting capacitor is varied according to the rotational speed of the three-phase induction generator or the magnitude of the generated voltage, so that generation of the generated voltage is possible even when the rotational speed of the generator is lower than the rated speed, and the rotational speed of the generator Even if it is excessively increased, there is an advantage of maintaining the optimum voltage generation efficiency.
또한 본 발명은, 병렬로 연결된 보조 회로부의 반도체 스위치에 의해서 주파수가 조절됨에 따라 커패시터의 임피던스가 가변된다. 특히, 본 발명은 제어부가 발전기 회전속도에 반비례하여 반도체 스위치의 ON/OFF를 조절함으로써 자기 여자 용량을 손쉽게 원하는 크기만큼 제어할 수 있다. In addition, in the present invention, the impedance of the capacitor is varied as the frequency is adjusted by the semiconductor switch of the auxiliary circuit portion connected in parallel. In particular, the present invention can easily control the magnetic excitation capacity by the desired size by controlling the ON / OFF of the semiconductor switch in inverse proportion to the generator rotation speed.
또한 본 발명은, 스위칭 주파수 제어에 의한 커패시터 용량 조절 범위가 초과될 경우, 릴레이 스위치가 병렬로 연결된 다른 용량의 커패시터를 회로적으로 연결하여 원하는 크기의 출력전압을 제어할 수 있는 이점이 있다.In addition, the present invention, when the capacitor capacitance control range by the switching frequency control is exceeded, there is an advantage that the relay switch can control the output voltage of the desired size by connecting the capacitor of the other capacitor connected in parallel.
또한 본 발명은 자기 여자 용량의 제어를 위한 별도의 권선이 요구되지 않고 3상의 주권선에 회로의 구성이 가능하다. 이에 따라 최소한의 소자 및 저렴한 제조 단가로 기계적 제동 장치가 요구되지 않는 발전 설비의 제공이 가능하다.In addition, the present invention does not require a separate winding for the control of the magnetic excitation capacity, it is possible to configure the circuit in the main winding of three phases. Accordingly, it is possible to provide a power generation facility that does not require a mechanical braking device with a minimum element and low manufacturing cost.
또한 본 발명은, 커패시터의 용량을 가변하는 보조 회로부의 구성이 간단하여 시스템의 중량이 가벼워짐으로써 휴대가 용이해진다. 이에 따라, 최소한의 소자 및 저렴한 제조 단가로 기계적 제동 장치가 요구되지 않는 발전 설비의 제공이 가능하다. 고가의 영구자석 동기발전기의 경우, 시간의 흐름에 따라 영구자석이 열화되어 성능이 저하되나 본 발명에 따른 자기 여자 용량 제어 시스템이 구비된 발전 설비는 유지보수가 현저히 용이하고, 동기발전기를 대신하여 저렴한 3상 유도 발전기의 사용을 가능하게 하여 전체 발전기 시스템의 가격을 낮추고 소형화 및 보급 확산에 기여할 수 있다.In addition, the present invention is simple in the configuration of the auxiliary circuit portion for varying the capacitance of the capacitor, and the weight of the system is light, thereby making it easy to carry. Accordingly, it is possible to provide a power generation facility that does not require a mechanical braking device with a minimum element and a low manufacturing cost. In the case of an expensive permanent magnet synchronous generator, the performance of the permanent magnet deteriorates with time, but the performance is degraded. However, the power generation equipment equipped with the magnetic excitation capacity control system according to the present invention is remarkably easy to maintain and replace the synchronous generator. By enabling the use of inexpensive three-phase induction generators, the price of the entire generator system can be lowered, contributing to miniaturization and spread of the supply.
도 1은 본 발명의 실시예에 따른 3상 유도 발전기의 출력전압 제어 시스템의 블록 구성도를 나타낸다.1 is a block diagram of an output voltage control system of a three-phase induction generator according to an embodiment of the present invention.
도 2는 유도 발전기의 자기여자 정전용량 대비 속도의 관계도를 나타낸다.Figure 2 shows the relationship between the speed of self-excited capacitance of the induction generator.
도 3은 본 발명의 실시예에 따른 보조 회로부를 나타낸다.3 shows an auxiliary circuit according to an embodiment of the present invention.
도 4는 본 발명의 실시예에 따른 반도체 스위치의 연결 예시도이다.4 is a diagram illustrating a connection of a semiconductor switch according to an exemplary embodiment of the present invention.
도 5는 본 발명의 실시예에 따른 반도체 스위치(
Figure PCTKR2015013253-appb-I000006
,
Figure PCTKR2015013253-appb-I000007
)의 ON/OFF상태에 의한 주파수 변환과 보조 회로부의 전류 흐름도를 나타낸다.5 is a semiconductor switch (
Figure PCTKR2015013253-appb-I000006
,
Figure PCTKR2015013253-appb-I000007
) Shows the frequency conversion by the ON / OFF state and the current flow chart of the auxiliary circuit.
도 6은 본 발명의 실시예에 따른 3상 유도 발전기의 출력전압 제어 방법을 나타낸다.6 shows a method of controlling the output voltage of a three-phase induction generator according to an embodiment of the present invention.
도 7은 사이리스터의 기본 동작을 나타낸다.7 shows the basic operation of the thyristor.
도 8은 사이리스터를 이용한 여자 용량 제어회로와 본 발명을 구현한 회로도면을 나타낸다.Fig. 8 shows an excitation capacitance control circuit using a thyristor and a circuit diagram embodying the present invention.
도 9는 도 8에서의 각각의 제어에 따른 결과 파형을 나타낸다.FIG. 9 shows a result waveform according to each control in FIG. 8.
이하, 첨부된 도면들에 기재된 내용들을 참조하여 본 발명을 상세히 설명한다. 다만, 본 발명이 예시적 실시 예들에 의해 제한되거나 한정되는 것은 아니다. 각 도면에 제시된 동일 참조부호는 실질적으로 동일한 기능을 수행하는 부재를 나타낸다.Hereinafter, with reference to the contents described in the accompanying drawings will be described in detail the present invention. However, the present invention is not limited or limited by the exemplary embodiments. Like reference numerals in the drawings denote members that perform substantially the same function.
본 발명의 목적 및 효과는 하기의 설명에 의해서 자연스럽게 이해되거나 보다 분명해 질 수 있으며, 하기의 기재만으로 본 발명의 목적 및 효과가 제한되는 것은 아니다. 또한, 본 발명을 설명함에 있어서 본 발명과 관련된 공지 기술에 대한 구체적인 설명이, 본 발명의 요지를 불필요하게 흐릴 수 있다고 판단되는 경우에는 그 상세한 설명을 생략하기로 한다.The objects and effects of the present invention may be naturally understood or more apparent from the following description, and the objects and effects of the present invention are not limited only by the following description. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.
도 1은 본 발명의 실시예에 따른 3상 유도 발전기의 출력전압 제어 시스템(1)의 블록 구성도를 나타낸다. 도 1을 참조하면, 3상 유도 발전기의 출력전압 제어 시스템(1)은 유도 발전기(10), AC-DC 컨버터(13), DC-AC 컨버터(15), 커패시터(20), 보조 회로부(30) 및 제어부(40)를 포함할 수 있다.1 shows a block diagram of an output voltage control system 1 of a three-phase induction generator according to an embodiment of the present invention. Referring to FIG. 1, an output voltage control system 1 of a three-phase induction generator 1 includes an induction generator 10, an AC-DC converter 13, a DC-AC converter 15, a capacitor 20, and an auxiliary circuit unit 30. ) And the controller 40.
유도 발전기(10)는 터빈(11)과 연결될 수 있고, 회전자와 회전자의 인근에 배치되어 전압을 유도하는 3상의 주권선(18)이 구비될 수 있다. 터빈(11)은 풍력, 수차, 등 각종 발전기의 터빈으로 회전자를 회전시키는 원동기를 의미한다. 터빈(11)은 풍력, 수차, 등 각종 발전기의 터빈으로 회전자를 회전시키는 원동기를 의미한다. 회전자의 회전으로 3상의 주권선에는 각 상별로 전압이 유도된다. The induction generator 10 may be connected to the turbine 11, and may be provided with three phase main windings 18 arranged near the rotor and the rotor to induce a voltage. The turbine 11 refers to a prime mover that rotates the rotor by turbines of various generators such as wind power, water wheels, and the like. The turbine 11 refers to a prime mover that rotates the rotor by turbines of various generators such as wind power, water wheels, and the like. The rotation of the rotor induces a voltage on each main winding of the three phases.
3상 유도 발전기는 계통(17)에서 위상이 90° 뒤쳐진 여자 전류를 취하기 때문에 커패시터(20)를 병렬로 접속하여 역률을 개선하는 것이 보통이다. 커패시터(20)의 용량은 일반적으로 고정되어 사용되어 왔다.Since the three-phase induction generator takes an excitation current that is 90 ° out of phase in the system 17, it is common to connect the capacitors 20 in parallel to improve the power factor. The capacitance of the capacitor 20 has generally been fixed and used.
도 2는 3상 유도 발전기(10)의 자기여자 정전용량 대비 속도의 관계도를 나타낸다. 도 2의 그래프는 3상 유도 발전기(10)의 매 실험속도 구간마다 정전 용량이 각각 다른 커패시터를 결속하여 실험함에 따라 도출된 결과이다.2 shows the relationship between the speed of self-excited capacitance of the three-phase induction generator 10. The graph of FIG. 2 is a result derived by binding capacitors having different capacitances in each experiment speed section of the three-phase induction generator 10.
도 2를 참조하면, 커패시터(20)의 용량은 유도 발전기(10)의 회전속도와 반비례하는 특성이 존재한다. 이에 따라, 도 2의 그래프에서 자기 여자 정전용량의 변화에 따른 유도 발전기(10)의 발전 개시 속도를 확인할 수 있다. 커패시터(20)의 자기여자 정전용량이 증가함에 따라 발전개시 속도는 낮아진다. 이 경우, 유도 발전기(10)의 출력전압(발전전압)도 낮아지게 된다. 즉, 유도 발전기(10)의 발전전압의 크기와 위상을 제어하기 위해서는 자기 여자를 위한 커패시터(20)의 용량이 유도 발전기(10)의 회전속도에 반비례하여 가변될 수 있어야 한다. Referring to FIG. 2, the capacity of the capacitor 20 is inversely proportional to the rotational speed of the induction generator 10. Accordingly, it is possible to check the power generation start speed of the induction generator 10 according to the change of the self-excitation capacitance in the graph of FIG. 2. As the self-excitation capacitance of the capacitor 20 increases, the power generation start rate decreases. In this case, the output voltage (generation voltage) of the induction generator 10 is also lowered. That is, in order to control the magnitude and phase of the power generation voltage of the induction generator 10, the capacity of the capacitor 20 for self-excitation must be variable in inverse proportion to the rotational speed of the induction generator 10.
본 실시예에 따른 자기 여자 용량 제어 시스템(1)은, 유도 발전기의 출력단인 (a, b), (b, c), (a, c)의 단자별로 연결된 자기 여자 커패시터의 용량을 조절하는 것을 기술적 특징으로 한다The self-excited capacitance control system 1 according to the present embodiment adjusts the capacitance of the self-excited capacitor connected to each terminal of (a, b), (b, c), and (a, c) output terminals of the induction generator. It is technical feature
커패시터(20)는 유도 발전기(10)의 3상 권선에 3상으로 연결될 수 있다. 커패시터(20)는 (b, c)단자에 연결된 제1 커패시터(201), (a, c)단자에 연결된 제2 커패시터(203), (a, b)단자에 연결된 제3 커패시터(205)로 표현될 수 있다. 이하 3상 중 어느 한 상을 기준으로 그 동작원리를 설명한다. 본 명세서에서는 각 상에 연결된 커패시터(201, 203, 205) 중 한 상을 기준으로 설명함에 따라 커패시터(20)가 제1 커패시터(201) 또는 제2 커패시터(203) 또는 제3 커패시터(205)를 의미할 수 있다. 커패시터(20)에는 유도 발전기(10) 출력 단자의 상간 전압이 인가된다. The capacitor 20 may be connected in three phases to the three-phase winding of the induction generator 10. The capacitor 20 is the first capacitor 201 connected to the (b, c) terminal, the second capacitor 203 connected to the (a, c) terminal, and the third capacitor 205 connected to the (a, b) terminal. Can be expressed. The operation principle will be described below with reference to any one of the three phases. In the present specification, as described with reference to one of the capacitors 201, 203, and 205 connected to each phase, the capacitor 20 may use the first capacitor 201, the second capacitor 203, or the third capacitor 205. Can mean. The voltage between the phases of the output terminal of the induction generator 10 is applied to the capacitor 20.
커패시터(20)의 용량은 유도 발전기(10)의 발전 개시 최저속도에 맞춰진 최대 용량으로 설정됨이 바람직하다. 다만, 현실적으로 유도 발전기(10)의 발전 개시 최저속도에 따른 최대 용량의 정확한 계산은 발전기의 구동없이 알아내기 어려운 문제점이 있다. The capacity of the capacitor 20 is preferably set to the maximum capacity that is matched to the lowest speed at which the induction generator 10 starts to generate power. However, in reality, the accurate calculation of the maximum capacity according to the lowest speed at which the induction generator 10 starts to generate power is difficult to find without driving the generator.
이에 따라, 초기 커패시터(20)의 용량을 잘못 설정하게 되면 과전압으로 시스템의 손상 또는 전기화재가 발생될 수 있다. 본 실시예에서는 초기 커패시터(20)의 용량을 적절하게 설정할 수 있도록, 3상의 각 권선에 연결된 커패시터(20 : 201 또는 203 또는 205)를 하나 이상(
Figure PCTKR2015013253-appb-I000008
,
Figure PCTKR2015013253-appb-I000009
, …,
Figure PCTKR2015013253-appb-I000010
, 도 3)으로 제공하여 구현한다. Accordingly, if the capacity of the initial capacitor 20 is incorrectly set, damage to the system or electric fire may occur due to overvoltage. In this embodiment, one or more capacitors 20: 201 or 203 or 205 connected to each of the three phase windings may be used to appropriately set the capacity of the initial capacitor 20.
Figure PCTKR2015013253-appb-I000008
,
Figure PCTKR2015013253-appb-I000009
,… ,
Figure PCTKR2015013253-appb-I000010
3) to implement.
보다 상세하게, 3상의 각 권선에는 초기 과전압을 방지하기 위하여, 사용자가 설정할 수 있도록 서로 다른 용량을 갖는 커패시터가 연결된 것이 바람직하다. 즉, 실시예로서 도 1에는 (b, c)단자에 연결된 제1 커패시터(201)가 한 개로 도시되었으나, 도 3의 실시예와 같이 제1 커패시터(201)는 서로 다른 용량을 갖는 복수개의 커패시터(
Figure PCTKR2015013253-appb-I000011
,
Figure PCTKR2015013253-appb-I000012
, …,
Figure PCTKR2015013253-appb-I000013
, 도 3, m=1, 2, 3 각 상을 표시)로 제공될 수 있다. 이 경우, 복수개의 커패시터(
Figure PCTKR2015013253-appb-I000014
,
Figure PCTKR2015013253-appb-I000015
, …,
Figure PCTKR2015013253-appb-I000016
, 도 3, m=1, 2, 3 각 상을 표시)는 모두 병렬로 연결된 것이 바람직하다. More specifically, it is preferable that capacitors having different capacitances are connected to each of the three phase windings so as to be set by the user in order to prevent initial overvoltage. That is, in FIG. 1, the first capacitor 201 connected to the (b, c) terminals is illustrated as one embodiment. However, as shown in the embodiment of FIG. 3, the first capacitor 201 has a plurality of capacitors having different capacities. (
Figure PCTKR2015013253-appb-I000011
,
Figure PCTKR2015013253-appb-I000012
,… ,
Figure PCTKR2015013253-appb-I000013
3, m = 1, 2, 3 each phase) can be provided). In this case, a plurality of capacitors (
Figure PCTKR2015013253-appb-I000014
,
Figure PCTKR2015013253-appb-I000015
,… ,
Figure PCTKR2015013253-appb-I000016
3, m = 1, 2, 3 each phase) is preferably connected in parallel.
보조 회로부(30)는 커패시터(20)의 용량을 가변시킬 수 있다. 도 3은 본 발명의 실시예에 따른 보조 회로부(30)를 나타낸다. 도 3을 참조하면, 보조 회로부(30)는 인덕터(301), 한 쌍의 다이오드 및 반도체 스위치(303)를 포함할 수 있다. 보조 회로부(30)는 커패시터(201)와 병렬로 연결될 수 있다.The auxiliary circuit unit 30 may vary the capacitance of the capacitor 20. 3 shows the auxiliary circuit unit 30 according to the embodiment of the present invention. Referring to FIG. 3, the auxiliary circuit unit 30 may include an inductor 301, a pair of diodes, and a semiconductor switch 303. The auxiliary circuit unit 30 may be connected in parallel with the capacitor 201.
커패시터(20)는 전술한 바와 같이 초기 용량의 설정을 위해서 서로 다른 용량을 갖는 복수개(n개)의 커패시터(
Figure PCTKR2015013253-appb-I000017
, , …,
Figure PCTKR2015013253-appb-I000019
)가 병렬로 연결됨이 바람직하다. 이 경우, 각 상의 출력 단자에 연결되어 커패시터(
Figure PCTKR2015013253-appb-I000020
,
Figure PCTKR2015013253-appb-I000021
, 0,
Figure PCTKR2015013253-appb-I000022
, 도 3)의 용량을 선택하기 위한 릴레이 스위치(
Figure PCTKR2015013253-appb-I000023
,
Figure PCTKR2015013253-appb-I000024
, 0,
Figure PCTKR2015013253-appb-I000025
, 305)가 더 포함될 수 있다.As described above, the capacitor 20 includes a plurality of capacitors (n) having different capacitances for setting the initial capacitance.
Figure PCTKR2015013253-appb-I000017
, ,… ,
Figure PCTKR2015013253-appb-I000019
Is preferably connected in parallel. In this case, the capacitor is connected to the output terminal of each phase.
Figure PCTKR2015013253-appb-I000020
,
Figure PCTKR2015013253-appb-I000021
, 0,
Figure PCTKR2015013253-appb-I000022
Relay switch for selecting the capacity of FIG.
Figure PCTKR2015013253-appb-I000023
,
Figure PCTKR2015013253-appb-I000024
, 0,
Figure PCTKR2015013253-appb-I000025
, 305 may be further included.
릴레이 스위치(305)는 초기 커패시터(20) 용량을 적절히 설정하여 발전개시시 시스템의 손상을 방지할 뿐만 아니라 선택된 커패시터(201)의 용량 조절 범위가 초과될 경우, 병렬로 연결된 다른 커패시터(
Figure PCTKR2015013253-appb-I000026
,
Figure PCTKR2015013253-appb-I000027
, …,
Figure PCTKR2015013253-appb-I000028
)를 회로적으로 연결하거나 끊어줌으로써 원하는 크기의 출력전압을 제어할 수 있다.The relay switch 305 properly sets the capacity of the initial capacitor 20 to prevent damage to the system at the start of power generation, and when the capacity adjustment range of the selected capacitor 201 is exceeded, another capacitor connected in parallel (
Figure PCTKR2015013253-appb-I000026
,
Figure PCTKR2015013253-appb-I000027
,… ,
Figure PCTKR2015013253-appb-I000028
) Can control the output voltage of the desired size by connecting or disconnecting the circuit.
인덕터(301)는 자기 여자 커패시터(201)와 전기적으로 공진할 수 있다. 인덕터(301)는 커패시터(201)와 LC 공진 현상에 따라 자기 여자 발전을 가능하게 한다. 이때, LC 공진을 발생시키기 위한 커패시터(201)의 용량은 발전기의 회전속도에 따라 달라진다. The inductor 301 may electrically resonate with the magnetic excitation capacitor 201. The inductor 301 enables self-excited power generation according to the LC resonance phenomenon with the capacitor 201. At this time, the capacity of the capacitor 201 to generate the LC resonance depends on the rotational speed of the generator.
반도체 스위치(303)는 인덕터(301)와 직렬로 연결될 수 있다. 반도체 스위치(303)는 복수개 제공될 수 있다. 본 실시예로 반도체 스위치(303)는 한 쌍(
Figure PCTKR2015013253-appb-I000029
,
Figure PCTKR2015013253-appb-I000030
)으로 제공될 수 있다. 반도체 스위치(303)는 인덕터(301)에 흐르는 류를 단속할 수 있다. 또한, 반도체 스위치(303)는 인덕터(301)에 흐르는 전류의 방향을 가변시킬 수 있다. 보조 회로부(30)는 반도체 스위치(303)의 온오프(ON/OFF) 주파수로 커패시터(201)의 용량을 가변할 수 있다. 이와 관련, 도 5를 통해 후술한다.The semiconductor switch 303 may be connected in series with the inductor 301. A plurality of semiconductor switches 303 may be provided. In this embodiment, the semiconductor switch 303 has a pair (
Figure PCTKR2015013253-appb-I000029
,
Figure PCTKR2015013253-appb-I000030
) May be provided. The semiconductor switch 303 may interrupt a flow flowing in the inductor 301. In addition, the semiconductor switch 303 may change the direction of the current flowing through the inductor 301. The auxiliary circuit unit 30 may vary the capacitance of the capacitor 201 at the on / off frequency of the semiconductor switch 303. In this regard, it will be described later with reference to FIG.
본 실시예로 반도체 스위치(303)로는 IGBT가 사용될 수 있으며, 도 4와 같이 보조 회로부(30)는 두 개 이상의 단방향 반도체 스위치를 직렬 또는 병렬로 연결하여 구성될 수 있다.  In this embodiment, the IGBT may be used as the semiconductor switch 303. As shown in FIG. 4, the auxiliary circuit unit 30 may be configured by connecting two or more unidirectional semiconductor switches in series or in parallel.
본 실시예에서는 3상 유도 발전기의 출력전압 제어 시스템(1)을 한 쌍의 반도체 스위치(303)로 구현하였고, 제1 반도체 스위치(
Figure PCTKR2015013253-appb-I000031
)와 제2 반도체 스위치(
Figure PCTKR2015013253-appb-I000032
)가 병렬로 연결된 d)형태를 도시하였다. 단방향의 반도체 스위치를 사용할 경우, 제1 반도체 스위치(
Figure PCTKR2015013253-appb-I000033
)와 제2 반도체 스위치(
Figure PCTKR2015013253-appb-I000034
)의 바이어스 방향이 대칭되도록 결선되어야 한다. 이 경우, 보조 회로부(30)는 반도체 스위치(
Figure PCTKR2015013253-appb-I000035
,
Figure PCTKR2015013253-appb-I000036
)와 각각 동일한 바이어스 방향으로 직렬 연결된 다이오드가 포함될 수 있다. In the present embodiment, the output voltage control system 1 of the three-phase induction generator is implemented as a pair of semiconductor switches 303, and the first semiconductor switch (
Figure PCTKR2015013253-appb-I000031
) And the second semiconductor switch (
Figure PCTKR2015013253-appb-I000032
) Shows the form d) connected in parallel. When using a unidirectional semiconductor switch, the first semiconductor switch (
Figure PCTKR2015013253-appb-I000033
) And the second semiconductor switch (
Figure PCTKR2015013253-appb-I000034
) Should be wired so that the bias direction is symmetrical. In this case, the auxiliary circuit unit 30 is a semiconductor switch (
Figure PCTKR2015013253-appb-I000035
,
Figure PCTKR2015013253-appb-I000036
) May include diodes connected in series in the same bias direction.
한 쌍의 반도체 스위치(303)는 제1 반도체 스위치(
Figure PCTKR2015013253-appb-I000037
)가 인덕터(301)에 흐르는 전류를 정방향으로 바이어스시키고, 제2 반도체 스위치(
Figure PCTKR2015013253-appb-I000038
)가 인덕터(301)에 흐르는 전류를 역방향으로 바이어스 시키도록 연결될 수 있다. 여기서, 정방향과 역방향은 서로 다른 전류의 방향을 구분하기 위한 용어적 표현이며 전류의 방향을 한정하는 것은 아니다.The pair of semiconductor switches 303 may include a first semiconductor switch (
Figure PCTKR2015013253-appb-I000037
) Biases the current flowing in the inductor 301 in the forward direction, and the second semiconductor switch (
Figure PCTKR2015013253-appb-I000038
) May be connected to bias the current flowing in the inductor 301 in the reverse direction. Here, the forward direction and the reverse direction are terms used to distinguish the directions of different currents and do not limit the directions of the currents.
보조 회로부(30)는 반도체 스위치(303)의 온오프(On/OFF) 주파수로 커패시터(20)의 용량을 가변할 수 있다. 보조 회로부(30)는 반도체 스위치(303)의 스위칭 주파수(
Figure PCTKR2015013253-appb-I000039
)를 변화함으로써 커패시터(20)와 인덕터(301)의 임피던스 값을 제어한다.The auxiliary circuit unit 30 may vary the capacitance of the capacitor 20 at the on / off frequency of the semiconductor switch 303. The auxiliary circuit unit 30 has a switching frequency of the semiconductor switch 303 (
Figure PCTKR2015013253-appb-I000039
) By controlling the impedance values of the capacitor 20 and the inductor 301.
커패시터(20)의 자기여자 용량의 임피던스는
Figure PCTKR2015013253-appb-I000040
로 표현될 수 있다. 여기서
Figure PCTKR2015013253-appb-I000041
는 주파수를 의미하며
Figure PCTKR2015013253-appb-I000042
는 자기여자 커패시터 값을 의미한다. 임피던스를 변화시키기 위해서는
Figure PCTKR2015013253-appb-I000043
가 변화되어야 한다. 본 실시예에서는 반도체 스위치(303)의 온오프 동작에 의해서
Figure PCTKR2015013253-appb-I000044
가 가변됨에 따라 자기여자 용량의 임피던스가 제어될 수 있다. The impedance of the self-exciting capacitance of the capacitor 20 is
Figure PCTKR2015013253-appb-I000040
It can be expressed as. here
Figure PCTKR2015013253-appb-I000041
Means frequency
Figure PCTKR2015013253-appb-I000042
Denotes the value of the self-exciting capacitor. To change the impedance
Figure PCTKR2015013253-appb-I000043
Should be changed. In the present embodiment, by the on-off operation of the semiconductor switch 303
Figure PCTKR2015013253-appb-I000044
As is changed, the impedance of the self-exciting capacitance can be controlled.
따라서 본 실시예에 따르면, 자기여자 용량성 임피던스(
Figure PCTKR2015013253-appb-I000045
)를 조절하기 위한 요소 중 반도체 스위치(303)의 온오프 동작으로 스위칭 펄스 개수를 조절함으로써 주파수를 인가하는 전원의 극성과 무관하게 ON/OFF 제어할 수 있다. 따라서, 스위칭 주파수 의 크기 및 스위칭 펄스의 개수 n을 조절하는 방법과 커패시터(20)에 충방전되는 전류량을 조절하는 방법을 모두 적용할 수 있으므로 자기여자 임피던스의 용량을 조절할 수 있는 범위가 현저히 커지게 된다. 또한, 스위칭 펄스의 크기도 조절이 가능하므로 충방전을 반복하기 위한 커패시터(20)의 물리적인 크기가 작더라도 충전과 방전이 명확하게 발생될 수 있도록 제어할 수 있다.Therefore, according to this embodiment, the self-excited capacitive impedance (
Figure PCTKR2015013253-appb-I000045
) By controlling the number of switching pulses in the on / off operation of the semiconductor switch 303, the ON / OFF control may be performed irrespective of the polarity of the power to which the frequency is applied. Therefore, both the method of adjusting the size of the switching frequency and the number of switching pulses n and the method of controlling the amount of current charged and discharged in the capacitor 20 can be applied. do. In addition, since the size of the switching pulse can be adjusted, even if the physical size of the capacitor 20 for repeating charging and discharging is small, it can be controlled so that charge and discharge can be clearly generated.
제어부(40)는 3상 유도 발전기(10)의 회전속도 또는 3상 유도 발전기(10)의 발전전압의 크기를 측정하여 반도체 스위치(303)의 스위칭 주파수를 제어할 수 있다. 제어부(40)는 3상 유도 발전기(10)의 회전속도 또는 3상 유도 발전기(10) 출력전압의 크기를 측정하여 반도체 스위치(303)의 스위칭 주파수를 제어하기 위한 기준값으로 사용할 수 있다. The controller 40 may control the switching frequency of the semiconductor switch 303 by measuring the rotational speed of the three-phase induction generator 10 or the magnitude of the generated voltage of the three-phase induction generator 10. The controller 40 may be used as a reference value for controlling the switching frequency of the semiconductor switch 303 by measuring the rotational speed of the three-phase induction generator 10 or the magnitude of the output voltage of the three-phase induction generator 10.
제어부(40)는 유도 발전기(10)의 회전속도, 발전 교류 전압, 발전 교류 전류, 정류기 출력전압, 정류기 출력 전류, AC-DC 컨버터 출력전압, AC-DC 컨버터 출력 전류, 위상 등의 정보를 전달 받을 수 있다. 또한, 제어부(40)는 계통(17)으로부터 계통 전류 및 전압을 전달 받아 모니터링할 수 있다. 제어부(40)는 유도 발전기(10) 및 계통(17)의 전압 전류를 모니터링하여 보조 회로부(30), AC-DC 컨버터(13) 및 DC-AC 컨버터(15)를 제어할 수 있다.The controller 40 transmits information such as the rotational speed of the induction generator 10, the generated AC voltage, the generated AC current, the rectifier output voltage, the rectifier output current, the AC-DC converter output voltage, the AC-DC converter output current, and the phase. I can receive it. In addition, the controller 40 may receive and monitor a grid current and voltage from the grid 17. The controller 40 may control the auxiliary circuit unit 30, the AC-DC converter 13, and the DC-AC converter 15 by monitoring the voltage currents of the induction generator 10 and the system 17.
제어부(40)는 유도 발전기(10)의 회전속도가 증가하는 경우, 커패시터(20)의 용량을 감소시키고, 유도 발전기(10)의 회전속도가 감소되는 경우, 커패시터(20)의 용량을 증가시킬 수 있다. The controller 40 reduces the capacity of the capacitor 20 when the speed of rotation of the induction generator 10 increases, and increases the capacity of the capacitor 20 when the speed of rotation of the induction generator 10 decreases. Can be.
이 경우, 제어부(40)는 한 쌍의 반도체 스위치(303) 중 어느 하나의 반도체 스위치(
Figure PCTKR2015013253-appb-I000046
or
Figure PCTKR2015013253-appb-I000047
)를 오프한 상태에서 나머지 반도체 스위치(
Figure PCTKR2015013253-appb-I000048
or
Figure PCTKR2015013253-appb-I000049
)를 On/Off 제어할 수 있다. 상세한 동작 과정은 도 4를 통해 후술한다.In this case, the controller 40 may be any one of a pair of semiconductor switches 303 (
Figure PCTKR2015013253-appb-I000046
or
Figure PCTKR2015013253-appb-I000047
) With the remaining semiconductor switch (
Figure PCTKR2015013253-appb-I000048
or
Figure PCTKR2015013253-appb-I000049
) You can control On / Off. Detailed operation will be described later with reference to FIG. 4.
제어부(40)는 유도 발전기(10)의 발전 개시가 가능한 가장 낮은 회전속도에서 커패시터(20) 용량을 최대값으로 제어할 수 있다. 또한, 제어부(40)는 유도 발전기(10)의 발전전압이 사용자가 설정해놓은 허용범위를 벗어나려는 경우 커패시터(20)의 용량을 최소값으로 제어할 수 있다. 이와 같은 경우, 유도 발전기(10)의 회전속도가 허용범위를 벗어나더라도 발전 출력전압의 범위는 허용범위 내에서 유지되면서, 유도 발전기(10)의 회전속도가 허용범위 이하일 지라도 발전전압의 생성이 가능하다.The controller 40 may control the capacity of the capacitor 20 to the maximum value at the lowest rotational speed at which the induction generator 10 can start generating power. In addition, the controller 40 may control the capacitance of the capacitor 20 to a minimum value when the generated voltage of the induction generator 10 is outside the allowable range set by the user. In this case, even if the rotational speed of the induction generator 10 is out of the allowable range, while the range of the generated output voltage is maintained within the allowable range, it is possible to generate the generated voltage even if the rotational speed of the induction generator 10 is less than the allowable range. Do.
즉, 제어부(40)는 도 2의 그래프에서 유도 발전기(10)의 회전속도를 측정하여 발전기가 Stable region 영역에 해당하도록 자기 여자 용량을 제어한다. That is, the controller 40 measures the rotational speed of the induction generator 10 in the graph of FIG. 2 to control the self-excitation capacity so that the generator corresponds to the stable region region.
종래에는 유도 발전기의 회전속도를 제어하기 위해 기계적인 기어비를 조절하거나 별도의 제동장치를 작동하여 회전속도를 허용범위 내에 들어가도록 제어하였다. 제동장치는 기어비의 조절에도 회전속도가 허용범위를 벗어날 경우 시스템 파손을 방지하기 위하여 발전기를 정지시키도록 작동하였다. 종래와 같이 기계적인 제어로는 한계가 있으며 설치비용의 과다, 관리 및 운전 비용 상승등의 문제점이 발생함에 따라, 본 실시예에서는 제어가 용이하고 설치 및 제조단가가 저렴한 반도체 스위치(303)를 커패시터(20)와 병렬 구성함으로써 전기적인 방식으로 발전기의 회전속도가 아닌 커패시터(20)의 용량을 조절한다. Conventionally, in order to control the rotational speed of the induction generator, by controlling the mechanical gear ratio or by operating a separate braking device to control the rotational speed within the allowable range. The braking system was operated to stop the generator in order to prevent damage to the system if the rotational speed is outside the allowable range even when the gear ratio is adjusted. As the conventional mechanical control has limitations and problems such as excessive installation cost, management and operation cost increase, in the present embodiment, the semiconductor switch 303 which is easy to control and has low installation and manufacturing cost is a capacitor. By configuring in parallel with (20) to adjust the capacity of the capacitor 20, not the rotational speed of the generator in an electrical manner.
제어부(40)는 유도 발전기(10)의 회전속도를 모니터링하여 커패시터(20)의 용량을 조절함으로써 발전전압의 크기 및 위상을 제어한다. 이에 따라, 유도 발전기(10)의 회전속도의 변화에도 안정적인 운용이 가능하다. The controller 40 controls the magnitude and phase of the power generation voltage by monitoring the rotational speed of the induction generator 10 to adjust the capacity of the capacitor 20. Accordingly, stable operation is possible even with a change in the rotational speed of the induction generator 10.
도 5는 자기 여자 커패시터(20)의 충방전 모드에 따른 보조 회로부(30)의 전류 흐름도를 나타낸다. 도 5a는 정현파 형태의 3상 유도기 출력전압이 (+) 상태인 경우에 제어부(40)가
Figure PCTKR2015013253-appb-I000050
를 OFF 시키고,
Figure PCTKR2015013253-appb-I000051
를 특정한 주파수로 ON/OFF를 반복하는 경우에 있어서,
Figure PCTKR2015013253-appb-I000052
가 ON 상태일 때의 커패시터(20)의 전류 흐름을 나타낸다.5 shows a current flow chart of the auxiliary circuit unit 30 according to the charge / discharge mode of the self-excited capacitor 20. 5A shows that the control unit 40 in the case where the output voltage of the three-phase inductor
Figure PCTKR2015013253-appb-I000050
To OFF,
Figure PCTKR2015013253-appb-I000051
When repeating ON / OFF at a specific frequency,
Figure PCTKR2015013253-appb-I000052
Indicates the current flow in the capacitor 20 when is ON state.
도 5b는 정현파 형태의 3상 유도기 출력전압이 (+) 상태인 경우에 제어부(40)가
Figure PCTKR2015013253-appb-I000053
를 OFF 시키고,
Figure PCTKR2015013253-appb-I000054
를 특정한 주파수로 ON/OFF를 반복하는 경우에 있어서,
Figure PCTKR2015013253-appb-I000055
가 ON 상태일 때의 커패시터(20)의 전류 흐름도를 나타낸다.5B shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave type is in a positive state
Figure PCTKR2015013253-appb-I000053
To OFF,
Figure PCTKR2015013253-appb-I000054
When repeating ON / OFF at a specific frequency,
Figure PCTKR2015013253-appb-I000055
Shows a current flow chart of the capacitor 20 when is ON state.
도 5c는 정현파 형태의 3상 유도기 출력전압이 (+) 상태인 경우에 제어부(40)가
Figure PCTKR2015013253-appb-I000056
를 OFF 시키고,
Figure PCTKR2015013253-appb-I000057
를 특정한 주파수로 ON/OFF를 반복하는 경우에 있어서,
Figure PCTKR2015013253-appb-I000058
가 OFF 상태일 때의 커패시터(20)의 전류 흐름도를 나타낸다. 이 때, 3상 유도 발전기(10)는 충전모드로 작동하게 되며 커패시터
Figure PCTKR2015013253-appb-I000059
,
Figure PCTKR2015013253-appb-I000060
, …,
Figure PCTKR2015013253-appb-I000061
에 충전된 전압이 입력전압보다 작은 경우에 부하에 공급되는 전류는 자기여자 커패시터(20)에 충전되는 전류의 크기 만큼 저감되어 공급될 수 있다. 5C shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave type is in a positive state
Figure PCTKR2015013253-appb-I000056
To OFF,
Figure PCTKR2015013253-appb-I000057
When repeating ON / OFF at a specific frequency,
Figure PCTKR2015013253-appb-I000058
Shows a current flow of the capacitor 20 when is OFF. At this time, the three-phase induction generator 10 is operated in a charge mode and the capacitor
Figure PCTKR2015013253-appb-I000059
,
Figure PCTKR2015013253-appb-I000060
,… ,
Figure PCTKR2015013253-appb-I000061
When the voltage charged in the is smaller than the input voltage, the current supplied to the load may be reduced and supplied by the amount of the current charged in the self-exciting capacitor 20.
도 5d는 정현파 형태의 3상 유도기 출력전압이 (+) 상태인 경우에 제어부(40)가
Figure PCTKR2015013253-appb-I000062
를 OFF 시키고,
Figure PCTKR2015013253-appb-I000063
를 특정한 주파수로 ON/OFF를 반복하는 경우에 있어서,
Figure PCTKR2015013253-appb-I000064
가 OFF 상태일 때의 커패시터(20)의 전류 흐름도를 나타내고 있다. 이 때, 방전모드로 작동하게 되며 커패시터
Figure PCTKR2015013253-appb-I000065
,
Figure PCTKR2015013253-appb-I000066
, …,
Figure PCTKR2015013253-appb-I000067
에 충전된 전압이 입력전압보다 큰 경우에 부하에 공급되는 전류는 자기여자 커패시터(20)에서 방출되는 전류의 크기 만큼 증가되어 공급된다.5D shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave type is in a positive state
Figure PCTKR2015013253-appb-I000062
To OFF,
Figure PCTKR2015013253-appb-I000063
When repeating ON / OFF at a specific frequency,
Figure PCTKR2015013253-appb-I000064
Shows the current flow of the capacitor 20 when is OFF. At this time, it operates in discharge mode and capacitor
Figure PCTKR2015013253-appb-I000065
,
Figure PCTKR2015013253-appb-I000066
,… ,
Figure PCTKR2015013253-appb-I000067
When the voltage charged in the is greater than the input voltage, the current supplied to the load is increased by the amount of current emitted from the self-exciting capacitor 20 and supplied.
도 5e는 정현파 형태의 3상 유도기 출력전압이 (-) 상태인 경우에 제어부(40)가
Figure PCTKR2015013253-appb-I000068
를 OFF 시키고
Figure PCTKR2015013253-appb-I000069
를 특정한 주파수로 ON/OFF를 반복하는 경우에 있어서,
Figure PCTKR2015013253-appb-I000070
가 ON 상태일 때의 커패시터(20)의 전류 흐름도를 나타낸다.5E shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave form is in the negative state.
Figure PCTKR2015013253-appb-I000068
OFF
Figure PCTKR2015013253-appb-I000069
When repeating ON / OFF at a specific frequency,
Figure PCTKR2015013253-appb-I000070
Shows a current flow chart of the capacitor 20 when is ON state.
도 5f는 정현파 형태의 3상 유도기 출력전압이 (-) 상태인 경우에 제어부(40)가
Figure PCTKR2015013253-appb-I000071
를 OFF 시키고
Figure PCTKR2015013253-appb-I000072
를 특정한 주파수로 ON/OFF를 반복하는 경우에 있어서,
Figure PCTKR2015013253-appb-I000073
가 OFF 상태일 때의 커패시터(20)의 전류 흐름도를 나타낸다. 이 때, 3상 유도 발전기(1)는 충전모드로 작동하게 되며 커패시터
Figure PCTKR2015013253-appb-I000074
,
Figure PCTKR2015013253-appb-I000075
, …,
Figure PCTKR2015013253-appb-I000076
에 충전된 전압이 입력전압보다 작은 경우에 부하측에 공급되는 전류는 커패시터(20)에 충전되는 전류의 크기 만큼 저감되어 공급된다.5F shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave form is in the negative state.
Figure PCTKR2015013253-appb-I000071
OFF
Figure PCTKR2015013253-appb-I000072
When repeating ON / OFF at a specific frequency,
Figure PCTKR2015013253-appb-I000073
Shows a current flow of the capacitor 20 when is OFF. At this time, the three-phase induction generator (1) is operated in the charge mode and the capacitor
Figure PCTKR2015013253-appb-I000074
,
Figure PCTKR2015013253-appb-I000075
,… ,
Figure PCTKR2015013253-appb-I000076
When the voltage charged in the circuit is smaller than the input voltage, the current supplied to the load side is reduced and supplied by the amount of the current charged in the capacitor 20.
도 5g는 정현파 형태의 3상 유도기 출력전압이 (-) 상태인 경우에 제어부(40)가
Figure PCTKR2015013253-appb-I000077
를 OFF 시키고,
Figure PCTKR2015013253-appb-I000078
를 특정한 주파수로 ON/OFF를 반복하는 경우에 있어서,
Figure PCTKR2015013253-appb-I000079
가 OFF 상태일 때의 커패시터(20)의 전류 흐름도를 나타낸다. 이 때, 3상 유도 발전기(10)는 방전모드로 작동하게 되며 커패시터
Figure PCTKR2015013253-appb-I000080
,
Figure PCTKR2015013253-appb-I000081
, …,
Figure PCTKR2015013253-appb-I000082
에 충전된 전압이 입력전압보다 큰 경우로서 부하측에 공급되는 전류는 커패시터(20)로부터 방출되는 전류의 크기 만큼 증가되어 공급된다.5G shows that the control unit 40 in the case where the three-phase inductor output voltage of the sine wave form is in a negative state.
Figure PCTKR2015013253-appb-I000077
To OFF,
Figure PCTKR2015013253-appb-I000078
When repeating ON / OFF at a specific frequency,
Figure PCTKR2015013253-appb-I000079
Shows a current flow of the capacitor 20 when is OFF. At this time, the three-phase induction generator 10 is operated in the discharge mode and the capacitor
Figure PCTKR2015013253-appb-I000080
,
Figure PCTKR2015013253-appb-I000081
,… ,
Figure PCTKR2015013253-appb-I000082
In the case where the voltage charged in is greater than the input voltage, the current supplied to the load side is increased by the amount of the current emitted from the capacitor 20.
도 6은 본 발명의 실시예에 따른 3상 유도 발전기(10)의 출력전압 제어 방법을 나타낸다. 도 6을 참조하면, 유도 3상 발전기(10)의 자기 여자 용량 제어 방법은 유도 발전기(10)의 회전속도 또는 발전전압을 입력 받는 제1 단계(S10), 유도 발전기의 회전속도 또는 발전전압에 부합하는 커패시터(20) 용량 및 이에 부합하는 임피던스를 계산하는 제2 단계(S30), 제2 단계(S30)에서 계산된 임피던스 값을 기준으로 반도체 스위치(303)의 스위칭 주파수 값을 환산하는 제3 단계(S50) 및 커패시터(20)의 자기 여자 용량을 제어하는 제4 단계(S70)를 포함할 수 있다.6 shows an output voltage control method of a three-phase induction generator 10 according to an embodiment of the present invention. Referring to FIG. 6, in the self-excitation capacity control method of the induction three-phase generator 10, the first step S10 of receiving the rotation speed or the generation voltage of the induction generator 10, the rotation speed or the generation voltage of the induction generator 10. A third step of calculating a switching frequency value of the semiconductor switch 303 based on a second step S30 of calculating a matching capacitor 20 capacity and an impedance corresponding thereto, and an impedance value calculated in a second step S30. A step S50 and a fourth step S70 of controlling the self-exciting capacitance of the capacitor 20 may be included.
제1 단계(S10)에서는 제어부(40)가 3상 유도 발전기(10)의 회전속도 또는 발전전압을 제어기의 ADC로 입력받을 수 있다.In the first step S10, the control unit 40 may receive the rotational speed or power generation voltage of the three-phase induction generator 10 to the ADC of the controller.
제2 단계(S30)에서는 제어부(40)가 제1 단계(S10)에서 입력받은 회전속도 또는 발전전압에 부합하는 커패시터(20)의 자기 여자 용량을 계산하여 임피던스 값을 산출할 수 있다. 3상 유도 발전기의 회전속도로 임피던스가 산출되는 과정을 살펴보면 다음과 같다.In the second step S30, the controller 40 may calculate the impedance value by calculating the self-exciting capacity of the capacitor 20 corresponding to the rotational speed or the generation voltage received in the first step S10. Looking at the process of calculating the impedance at the rotational speed of the three-phase induction generator as follows.
1) 동기 속도:
Figure PCTKR2015013253-appb-I000083
[rpm]1) Synchronous Speed:
Figure PCTKR2015013253-appb-I000083
[rpm]
2) 슬립:
Figure PCTKR2015013253-appb-I000084
2) slip:
Figure PCTKR2015013253-appb-I000084
여기서,
Figure PCTKR2015013253-appb-I000085
: 주파수,
Figure PCTKR2015013253-appb-I000086
: 극수,
Figure PCTKR2015013253-appb-I000087
: 회전 속도[rpm]here,
Figure PCTKR2015013253-appb-I000085
: frequency,
Figure PCTKR2015013253-appb-I000086
: Number of poles,
Figure PCTKR2015013253-appb-I000087
: Rotation speed [rpm]
Figure PCTKR2015013253-appb-I000088
[rpm]
Figure PCTKR2015013253-appb-I000088
[rpm]
상기의 식1)은 유도기의 회전주파수와 동기속도를 나타내고 있다. 이때 유도기의 회전자의 실제 회전 속도에 대해 발전 교류 전압의 주파수 간에는 약간의 시간지연이 발생하게 되면 슬립(식2)의 's')이 발생하게 된다. Equation 1) represents the rotation frequency and the synchronous speed of the induction machine. At this time, if a slight time delay occurs between the frequencies of the generated alternating current voltage with respect to the actual rotational speed of the rotor of the inductor, slip ('s' in Equation 2) occurs.
회전각속도(
Figure PCTKR2015013253-appb-I000089
)와 자기여자 커패시터의 용량성 리액턴스(
Figure PCTKR2015013253-appb-I000090
)의 상관 관계는 서로 반비례 관계가 있다. 즉,
Figure PCTKR2015013253-appb-I000091
이 성립한다. Rotational angular velocity (
Figure PCTKR2015013253-appb-I000089
) And the capacitive reactance (
Figure PCTKR2015013253-appb-I000090
) Are inversely related to each other. In other words,
Figure PCTKR2015013253-appb-I000091
This holds true.
제3 단계(S50)에서는 제어부(40)가 제2 단계(S30)에서 산출된 임피던스의 수식
Figure PCTKR2015013253-appb-I000092
로부터 반도체 스위칭 주파수 값
Figure PCTKR2015013253-appb-I000093
(rad/s)을 환산할 수 있다.In the third step S50, the controller 40 modifies the impedance calculated in the second step S30.
Figure PCTKR2015013253-appb-I000092
Semiconductor switching frequency value from
Figure PCTKR2015013253-appb-I000093
(rad / s) can be converted.
제4 단계(S70)에서는 제어부(40)가 3상 유도 발전기(10)의 회전속도 또는 발전전압을 최대 기준치 또는 최소 기준치와 비교하여 환산된 주파수 값을 가변함에 따라 커패시터(20)의 자기 여자 용량을 제어하게 된다. 여기서, 회전속도의 최대 기준치란 3상 유도 발전기(10)의 회전속도가 정격속도를 넘어서는 경우를 의미한다. 회전속도의 최소 기준치란 3상 유도 발전기(10)의 회전속도가 정격속도 이하인 경우를 의미한다. In the fourth step (S70), the control unit 40 compares the rotational speed or the generated voltage of the three-phase induction generator 10 with the maximum reference value or the minimum reference value to change the converted frequency value of the self-exciting capacity of the capacitor 20. To control. Here, the maximum reference value of the rotational speed means a case where the rotational speed of the three-phase induction generator 10 exceeds the rated speed. The minimum reference value of the rotational speed means that the rotational speed of the three-phase induction generator 10 is less than the rated speed.
제4 단계(S70)에서는 3상 유도 발전기(10)의 회전속도가 최대 기준치보다 빠를 경우, 반도체 스위치(303)의 스위칭 주파수를 커패시터(20)의 임피던스가 감소하는 방향으로 조절할 수 있다. In the fourth step S70, when the rotation speed of the three-phase induction generator 10 is faster than the maximum reference value, the switching frequency of the semiconductor switch 303 may be adjusted in a direction in which the impedance of the capacitor 20 decreases.
이와는 반대로, 제4 단계(S70)에서는 3상 유도 발전기(10)의 회전속도가 최소 기준치보다 느릴 경우, 반도체 스위치(303)의 스위칭 주파수를 커패시터(20)의 임피던스가 증가하는 방향으로 조절할 수 있다. On the contrary, in the fourth step S70, when the rotation speed of the three-phase induction generator 10 is lower than the minimum reference value, the switching frequency of the semiconductor switch 303 may be adjusted in a direction in which the impedance of the capacitor 20 increases. .
제4 단계(S70)는 전술한 과정을 수행한 후 조절된 주파수 값을 기준으로 반도체 스위치(303)의 On/Off 펄스 시간을 제어하여 출력할 수 있다. 제4 단계(S70)의 제어 과정은 도 4에서 전술한 바와 같다. 제어부(40)의 제어과장을 간략히요약하면 다음과 같다. 유도기 회전자의 회전속도가 증가할수록 발전개시가 가능한 자기여자 커패시터의 용량성 리액턴스의 크기는 작아도 되며, 반대로 유도기 회전자의 속도가 감소할수록 발전개시가 가능한 자기여자 커패시터 용량성 리액턴스의 크기는 커져야 한다. In the fourth step S70, after performing the above-described process, the on / off pulse time of the semiconductor switch 303 may be controlled and output based on the adjusted frequency value. The control process of the fourth step S70 is as described above with reference to FIG. 4. Briefly summarized the control section of the control unit 40 is as follows. The larger the rotational speed of the induction rotor, the smaller the capacitive reactance of the self-excited capacitor that can start generating power. On the contrary, the smaller the speed of the induction rotor, the larger the self-excited capacitor capacitive reactance that can start generating. .
이러한 기본 원칙에 입각하여, 유도기의 회전각속도(
Figure PCTKR2015013253-appb-I000094
)의 증감에 따라 자기여자 커패시터의 용량성 리액턴스(
Figure PCTKR2015013253-appb-I000095
)의 스위칭 주파수(
Figure PCTKR2015013253-appb-I000096
)의 크기를 조절함으로써 용량성 리액턴스의 크기를 조절할 수 있다. 즉, 유도기 회전각속도(
Figure PCTKR2015013253-appb-I000097
)가 증가하면 용량성 리액턴스(
Figure PCTKR2015013253-appb-I000098
)를 감소시킨다. 이를 위해서는 스위칭 주파수(
Figure PCTKR2015013253-appb-I000099
)를 증가시키면 된다. 또한, 유도기 회전각속도(
Figure PCTKR2015013253-appb-I000100
)가 감소하면 용량성 리액턴스(
Figure PCTKR2015013253-appb-I000101
)를 증가시키기 위해서 스위칭 주파수(
Figure PCTKR2015013253-appb-I000102
)를 감소시키면 된다.Based on these basic principles, the rotational angular velocity of the induction machine (
Figure PCTKR2015013253-appb-I000094
), The capacitive reactance (
Figure PCTKR2015013253-appb-I000095
Switching frequency of
Figure PCTKR2015013253-appb-I000096
By adjusting the size of), the size of the capacitive reactance can be adjusted. That is, the inductor rotational angular velocity (
Figure PCTKR2015013253-appb-I000097
) Increases, the capacitive reactance (
Figure PCTKR2015013253-appb-I000098
Decrease). This requires a switching frequency (
Figure PCTKR2015013253-appb-I000099
Increase). In addition, the inductor rotational angular velocity (
Figure PCTKR2015013253-appb-I000100
Decreases, the capacitive reactance (
Figure PCTKR2015013253-appb-I000101
To increase the switching frequency (
Figure PCTKR2015013253-appb-I000102
) Is reduced.
제어부(40)가 조절한 스위칭 주파수에 따라 커패시터(20)의 용량은 가변되며, 이에 따라 3상 유도 발전기(10)는 정격속도 이상 또는 정격속도 이하에서도 높은 효율의 발전전압을 출력할 수 있다.The capacitance of the capacitor 20 is variable according to the switching frequency adjusted by the controller 40. Accordingly, the three-phase induction generator 10 can output a high efficiency generation voltage even at or above the rated speed.
이상에서와 같이 설명한 자기 여자 용량 제어 시스템은 사이리스터를 이용하여 여자 용량을 제어하는 방법보다 효과가 현저하다. 종래기술로서, 사이리스터를 이용한 점호각 제어로 커패시터의 자기 여자 용량을 제어하는 기술을 배경기술에서 전술한 바 있다. 본 실시예에 따른 반도체 스위치(303)는 사이리스터와 소자의 특성 및 기능이 상이하다. 상기의 차이점을 보다 상세히 살펴 종래기술과의 차이점을 정리하면 하기와 같다.The self-excited dose control system described above is more effective than the method of controlling the excitation dose using a thyristor. As a related art, a technique of controlling the self-exciting capacity of a capacitor by the firing angle control using a thyristor has been described above in the background art. The semiconductor switch 303 according to the present embodiment has different characteristics and functions of the thyristor and the device. Looking at the above differences in more detail summarizes the differences from the prior art as follows.
a. 사이리스터와 반도체 스위치의 작동 방법 및 기능상 차이점a. Differences in Operation and Functionality of Thyristors and Semiconductor Switches
도 7은 사이리스터 회로의 기본 동작을 나타낸다. 도 7을 참조하면, 사이리스터는 게이트에 ON 펄스를 인가하면 그 순간 도통이 되어 부하전류가 흐르게 되며, 이는 전원전압의 극성(+, -)이 바뀔때까지 지속되는 특성이 있다. 결국, 사이리스터 회로의 경우 사이리스터를 ON시키는 점화각(firing angle) 제어만 가능하다. 즉, OFF시키기 위한 별도의 제어동작은 없으며 입력파형의 극성(polarity)이 바뀌어야 OFF가 되는 성질을 갖는다.7 shows the basic operation of the thyristor circuit. Referring to FIG. 7, when a thyristor applies an ON pulse to a gate, the thyristor becomes conductive at that moment, and a load current flows, which lasts until the polarity (+,-) of the power supply voltage is changed. As a result, in the case of the thyristor circuit, only the firing angle control for turning on the thyristor is possible. That is, there is no separate control operation to turn off, and it is OFF when the polarity of the input waveform is changed.
도 8은 사이리스터를 이용한 여자 용량 제어 회로와 본원 제1항 발명을 실제 구현한 회로도면을 나타낸다. 도 8과 같이 양자를 실제 회로도면으로 구현하여 각각 제어에 따른 결과파형을 출력하면 도 9와 같다.8 shows an excitation capacitance control circuit using a thyristor and a circuit diagram of the present invention according to the present invention. As shown in FIG. 8, when both of them are implemented as actual circuit diagrams and output result waveforms according to control are shown in FIG. 9.
도 9를 참조하면, 사이리스터 회로의 파형에서, 인가된 전원의 극성이 바뀌고 사이리스터를 재점화시켰더라도 전류파형의 주파수가 변하지 않는 것을 볼 수 있다. 반면 본원 발명의 회로 구성은 스위칭 펄스가 인가되는 것에 비례하여 스위칭 전류가 바뀌는 것을 확인할 수 있다. 본원 발명과 같이 IGBT 또는 MOSFET 종류의 반도체 스위칭 소자를 사용할 경우, 이는 사이리스터와 달리 인가되는 전원 파형의 극성과 무관하게 ON/OFF 시간 간격을 제어할 수 있다. 이러한 특성은 스위칭 펄스의 ON 시간동안 커패시터가 충전을 하고, 스위칭 펄스의 OFF 시간동안 커패시터가 방전을 한다는 점을 생각하면, 커패시터의 충방전 간격을 짧게 할 수 있으므로 커패시터 용량 조절 범위를 사이리스터에 비해 현저히 크게 조절할 수 있는 것으로 이해될 수 있다. Referring to FIG. 9, in the waveform of the thyristor circuit, it can be seen that the frequency of the current waveform does not change even if the polarity of the applied power is changed and the thyristor is re-ignited. On the other hand, the circuit configuration of the present invention can be seen that the switching current is changed in proportion to the switching pulse is applied. When using a semiconductor switching device of the IGBT or MOSFET type as in the present invention, it is possible to control the ON / OFF time interval, regardless of the polarity of the power waveform applied to the thyristors. Considering that the capacitor charges during the ON time of the switching pulse and discharges the capacitor during the OFF time of the switching pulse, it is possible to shorten the charge / discharge interval of the capacitor. It can be understood that it can be greatly adjusted.
b. 사이리스터와 반도체 스위치의 효과상 차이점b. Differences in the Effects of Thyristors and Semiconductor Switches
사이리스터로는 용량성 리액턴스(
Figure PCTKR2015013253-appb-I000103
)를 조절하기위한 요소 중 스위칭 주파수
Figure PCTKR2015013253-appb-I000104
를 변경하는 것이 거의 불가능하다. 이는 전술한 바와 같이 사이리스터의 특성항 한번 점화각 신호를 인가하여 사이리스터가 ON되면 인가 전원의 극성이 바뀔때까지는 OFF시키는 것이 불가능하기 때문이다. 따라서, 점화각 제어를 통해서는 커패시터에 충방전되는 전류량의 조절만으로 리액턴스의 용량을 제어해야 한다. 결국, 그 조절 범위가 극히 제한적이게 된다.With thyristors, capacitive reactance (
Figure PCTKR2015013253-appb-I000103
Switching frequency among the elements for regulating
Figure PCTKR2015013253-appb-I000104
It is almost impossible to change it. This is because, as described above, when the ignition angle signal of the thyristor is applied once and the thyristor is turned on, it is impossible to turn it off until the polarity of the applied power is changed. Therefore, through the ignition angle control, it is necessary to control the reactance capacity only by adjusting the amount of current charged and discharged in the capacitor. As a result, the adjustment range becomes extremely limited.
만일 회전 주파수가 낮은 지점에서 유도기의 발전개시를 얻기를 원한다면, 커패시터의 용량이 상대적으로 커야하는데, 커패시터의 용량이 크면 충전과 방전에 소요되는 물리적인 시간이 절대적으로 커져야 한다. 결국 사이리스터는 커패시터의 전기적인 용량을 제어하기 위해 충방전 시간 간격을 조절할 수 없는 한계가 있다.If one wants to get the inductor to start generating at a low rotational frequency, the capacitor's capacity must be relatively large, but the larger the capacitor's capacity, the greater the physical time required for charging and discharging. As a result, the thyristor has a limit in that it cannot adjust the charge / discharge time interval to control the electrical capacity of the capacitor.
반면, 본원 제1항 발명의 경우, 용량성 리액턴스(
Figure PCTKR2015013253-appb-I000105
)를 조절하기 위한 요소 중 스위칭 펄스 개수를 조절함으로써 주파수
Figure PCTKR2015013253-appb-I000106
를 인가되는 전원의 극성과 무관하게 ON/OFF 제어할 수 있다. 따라서, 스위칭 주파수
Figure PCTKR2015013253-appb-I000107
의 크기 및 스위칭 펄스의 개수 n(
Figure PCTKR2015013253-appb-I000108
)을 조절하는 방법과 커패시터에 충방전되는 전류량을 조절하는 방법을 모두 적용할 수 있으므로 리액턴스의 용량을 조절할 수 있는 범위가 현저히 커지게 된다. 또한, 스위칭 펄스의 크기도 조절이 가능하므로 충방전을 반복하기 위한 커패시터의 물리적인 크기가 작더라도 충전과 방전이 명확하게 발생될 수 있도록 제어할 수 있다.On the other hand, in the case of claim 1 of the present invention, the capacitive reactance (
Figure PCTKR2015013253-appb-I000105
Frequency by adjusting the number of switching pulses
Figure PCTKR2015013253-appb-I000106
You can control ON / OFF irrespective of polarity of applied power. Thus, switching frequency
Figure PCTKR2015013253-appb-I000107
And the number of switching pulses n (
Figure PCTKR2015013253-appb-I000108
), And the method of controlling the amount of current charged and discharged in the capacitor can be applied, so that the range for adjusting the capacitance of the reactance becomes significantly larger. In addition, since the size of the switching pulse can be adjusted, even if the physical size of the capacitor for repeating the charging and discharging can be controlled so that the charge and discharge can be clearly generated.
이상에서 대표적인 실시예를 통하여 본 발명을 상세하게 설명하였으나, 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자는 상술한 실시예에 대하여 본 발명의 범주에서 벗어나지 않는 한도 내에서 다양한 변형이 가능함을 이해할 것이다. 그러므로 본 발명의 권리 범위는 설명한 실시예에 국한되어 정해져서는 안 되며, 후술하는 특허청구범위뿐만 아니라 특허청구범위와 균등 개념으로부터 도출되는 모든 변경 또는 변형된 형태에 의하여 정해져야 한다.  Although the present invention has been described in detail through the representative embodiments above, it will be understood by those skilled in the art that various modifications can be made without departing from the scope of the present invention with respect to the above-described embodiments. will be. Therefore, the scope of the present invention should not be limited to the embodiments described, but should be defined by all changes or modifications derived from the claims and the equivalent concepts as well as the following claims.
[부호의 설명][Description of the code]
1: 3상 유도 발전기의 출력전압 제어 시스템1: Output voltage control system of three-phase induction generator
10: 유도 발전기10: induction generator
11: 원동력 터빈11: motive power turbine
13: AC-DC 컨버터13: AC-DC Converter
15: DC-AC 컨버터15: DC-AC Converter
17: 계통17: system
18: 주권선18: Sovereignty
19: 보조권선19: auxiliary winding
20: 커패시터20: capacitor
30: 보조 회로부30: auxiliary circuit
301: 인덕터301: inductor
303: 반도체 스위치303: semiconductor switch
40: 제어부40: control unit
305: 릴레이 스위치305: relay switch

Claims (6)

  1. 3상 유도 발전기의 3상 권선에 각각 병렬로 연결된 커패시터;Capacitors connected in parallel to the three-phase windings of the three-phase induction generator, respectively;
    상기 커패시터와 병렬로 연결되어 전기적으로 공진하는 인덕터, 상기 인덕터에 흐르는 전류를 단속 또는 상기 인덕터에 흐르는 전류의 방향을 가변하는 반도체 스위치를 구비하여 상기 반도체 스위치의 온오프 주파수로 상기 커패시터의 용량을 가변하는 보조 회로부; 및 An inductor connected in parallel with the capacitor to electrically resonate, and a semiconductor switch intermittent with the current flowing through the inductor or varying the direction of the current flowing through the inductor to vary the capacitance of the capacitor at an on / off frequency of the semiconductor switch. An auxiliary circuit unit; And
    상기 3상 유도 발전기의 회전속도 또는 상기 3상 유도 발전기의 발전전압의 크기를 측정하여 상기 반도체 스위치의 스위칭 주파수를 제어하는 제어부를 포함하고,It includes a control unit for controlling the switching frequency of the semiconductor switch by measuring the rotational speed of the three-phase induction generator or the magnitude of the generated voltage of the three-phase induction generator,
    상기 제어부는,The control unit,
    상기 3상 유도 발전기의 회전속도 또는 발전전압에 부합하는 상기 커패시터의 용량과 임피던스를 계산하여 계산된 임피던스 값을 기준으로 상기 반도체 스위치의 스위칭 주파수 값을 환산하여 상기 릴레이 스위치 또는 상기 반도체 스위치를 제어하는 것을 특징으로 하는 3상 유도 발전기의 출력전압 제어 시스템.Controlling the relay switch or the semiconductor switch by converting the switching frequency value of the semiconductor switch on the basis of the impedance value calculated by calculating the capacitance and impedance of the capacitor corresponding to the rotational speed or generation voltage of the three-phase induction generator Output voltage control system of a three-phase induction generator, characterized in that.
  2. 제 1 항에 있어서,The method of claim 1,
    상기 반도체 스위치는 복수개이고,The semiconductor switch is a plurality,
    제1 반도체 스위치가 상기 인덕터에 흐르는 전류를 정방향으로 바이어스시키고, 제2 반도체 스위치가 상기 인덕터에 흐르는 전류를 역방향으로 바이어스 시키는 것을 특징으로 하는 3상 유도 발전기의 출력전압 제어 시스템.The first semiconductor switch biases the current flowing in the inductor in the forward direction, and the second semiconductor switch biases the current flowing in the inductor in the reverse direction.
  3. 제 1 항에 있어서,The method of claim 1,
    3상의 각 권선에 연결된 상기 커패시터는 복수개이고,A plurality of capacitors connected to each of the three phase windings,
    복수개의 커패시터는 서로 다른 용량을 갖고 병렬로 연결된 것을 특징으로 하는 3상 유도 발전기의 출력전압 제어 시스템.The output voltage control system of a three-phase induction generator, characterized in that the plurality of capacitors having a different capacity and connected in parallel.
  4. 제 3 항에 있어서,The method of claim 3, wherein
    상기 복수개의 커패시터를 상기 보조권선에 선택적으로 접속하여 상기 커패시터의 용량을 선택하는 릴레이 스위치를 더 포함한 것을 특징으로 하는 3상 유도 발전기의 출력전압 제어 시스템.And a relay switch for selectively connecting the plurality of capacitors to the auxiliary winding to select a capacity of the capacitor.
  5. 제 1 항에 있어서,The method of claim 1,
    상기 제어부는,The control unit,
    상기 3상 유도 발전기의 회전속도가 증가되면 상기 커패시터의 용량을 감소시키고, 상기 3상 유도 발전기의 회전속도가 감소되면 상기 커패시터의 용량을 증가시키는 것을 특징으로 하는 유도 발전기의 출력전압 제어 시스템.The output voltage control system of the induction generator characterized in that the capacity of the capacitor is reduced when the rotational speed of the three-phase induction generator is increased, and the capacity of the capacitor is increased when the rotational speed of the three-phase induction generator is reduced.
  6. 제 1 항에 있어서,The method of claim 1,
    상기 반도체 스위치는 복수개이고,The semiconductor switch is a plurality,
    상기 제어부는, The control unit,
    상기 반도체 스위치 중 어느 하나의 반도체 스위치를 오프한 상태에서 나머지 반도체 스위치를 온오프 제어하는 것을 특징으로 하는 3상 유도 발전기의 출력전압 제어 시스템.The output voltage control system of the three-phase induction generator, characterized in that for controlling the other semiconductor switch on and off in the state of turning off any one of the semiconductor switch.
PCT/KR2015/013253 2015-07-20 2015-12-04 System for controlling output voltage of three-phase induction generator by varying self-excitation capacitance WO2017014372A1 (en)

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Citations (4)

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JP2005168113A (en) * 2003-12-01 2005-06-23 Meidensha Corp Setting method for capacity of compensating capacitor of induction generator
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KR101506206B1 (en) 2014-03-19 2015-03-26 김철진 System for controlling self excitation capacitance of single phase induction generator

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JP2005168113A (en) * 2003-12-01 2005-06-23 Meidensha Corp Setting method for capacity of compensating capacitor of induction generator
US20090134812A1 (en) * 2007-11-26 2009-05-28 Zheng-Kun Zhang Exhaust fan for showing variable characters
JP2010045934A (en) * 2008-08-18 2010-02-25 Takaoka Electric Mfg Co Ltd Device for controlling output of power generator
KR20130001049A (en) * 2011-06-24 2013-01-03 엘지이노텍 주식회사 System and method for controlling induction motor of eps(electronic power steering) in vehicle using adaptive backstepping controller

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