KR101834487B1 - Apparatus for power control - Google Patents

Abstract

The present invention relates to a power control device used in a frequency conversion mode or a frequency fixation mode in accordance with a load amount. The power control device comprises: at least one electricity generating unit configured to output alternating current power; a main bus bar connected to a first load unit; a high load wire configured to connect between the electricity generating unit and the main bus bar; a power conversion module configured to receive power from the electricity generating unit to convert the power, and provide the converted power to a first load unit or a second load unit having a larger consumption power amount than the first load unit; and a switch board configured to switch power transfer among the electricity generating unit, the high load wire and the power conversion module.

Description

Apparatus for power control < RTI ID = 0.0 >

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power control apparatus, and more particularly, to a power control apparatus that varies a driving speed of a generator according to a load to output a power source and converts or fixes the frequency of the output power source.

The power grid is composed of a plurality of generators, a power conversion module, and a switchboard, as well as a load with a high power consumption and a small load. Such a power grid is essential for ships, as well as for power control devices such as wind turbines. For example, U.S. Patent No. 6,856,038 discloses a power system for controlling a motor. The power network that controls power can be configured in various types according to the purpose and purpose of the use.

Typically, the grid consists of a high-load grid used to drive high loads and a low-load grid used to drive low loads. The high-load power grid and the low-load power grid are installed in the majority of the vessels and improve the efficiency of the ship according to the operating conditions. However, the majority of ships currently use only high-load power networks, which are useful for driving high loads because of the inability to switch between high and low-load power networks.

Therefore, a large amount of fuel is consumed even in a low-load operation section, and the generator is unnecessarily driven to shorten the life span of the generator and to carry out a lot of maintenance work.

United States Patent 6,856,038 (Feb. 15, 2005)

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above problems, and it is an object of the present invention to provide a frequency conversion method and a frequency conversion method, Mode power control apparatus.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a power control apparatus including at least one power generating unit for outputting an AC power, a main bus bar connected to a first load unit, a high load wiring connecting the power generation unit and the main bus bar, A power conversion module that receives the AC power from the power generation unit and converts the AC power into a first load unit or a second load unit that consumes a larger amount of power than the first load unit; And a switch board for switching power transmission therebetween.

The power conversion module may further include a circulation wiring to which one end is connected to the input end of the power conversion module and the other end is connected to the main bus bar.

Wherein the power generation unit includes a control module for controlling a frequency of the AC power to be output, the switch board including a first switch for switching the power generation unit and the high load wiring, a second switch for switching the power conversion module and the circulation wiring, Switches,

The main bus bar may include a third switch for switching the power conversion module and the first load unit and the second load unit.

Wherein the power conversion module converts and outputs the applied AC power when the frequency of the output power of the power conversion module is less than the frequency of the AC power, And an output terminal of the power conversion module is connected to the main bus bar,

Wherein one end of the generator is connected to one end of the high load wiring when the frequency of the output power of the power conversion module is higher than the frequency of the AC power, May be connected to the second load unit.

The control module may control the first switch, the second switch, and the third switch by measuring and calculating AC power of the generator and output power of the power conversion module.

The power control apparatus according to the present invention can reduce the amount of fuel that is unnecessarily consumed in the operation of the generator by preventing the generator from being driven at a constant speed even when the generator is driven at a low speed in accordance with the amount of load to be driven. Further, by adjusting the driving speed of the generator according to the situation, the load applied to the generator can be reduced, and the life of the generator can be extended.

1 is a diagram illustrating a power control apparatus according to an embodiment of the present invention.
Fig. 2 is a diagram showing one-phase voltage waveforms output from the generator of Fig. 1. Fig.
3 is a diagram showing a voltage waveform output from the DC link portion of the power conversion module of FIG.
FIG. 4 is a diagram illustrating a voltage waveform that the power conversion module of FIG. 1 operates in PWM mode and outputs. FIG.
5 is a diagram showing a state in which the apparatus is driven in the frequency conversion mode when the load is small.
FIG. 6 is a diagram illustrating a state in which the power control apparatus of FIG. 1 is driven in the frequency fixed mode when the load is large.

Brief Description of the Drawings The advantages and features of the present invention and methods of achieving them can be made clear with reference to the embodiments described below in detail with reference to the accompanying drawings.

The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. To fully disclose the scope of invention to a person skilled in the art, and the invention is only defined by the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a power control apparatus and a power control apparatus according to an embodiment of the present invention will be described in detail with reference to FIG. The voltage output from the generator, the DC link unit, and the inverter unit constituting the power control apparatus will be described with reference to Figs. 2 to 4. Fig.

FIG. 1 is a diagram illustrating a power control apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing one-phase voltage waveforms output from the generator of FIG. 1, And the voltage waveform output from the link unit. 4 is a diagram illustrating a voltage waveform that the power conversion module of FIG. 1 operates in PWM mode and outputs. FIG.

The power control apparatus 1 according to an embodiment of the present invention uses the control module 12 to detect the driving state of the loads and the voltage output from the generator 11 and the power conversion module 30 in real time. Then, based on the sensed value, it controls the path of the current output from the generator 11 and the path of the current output from the power conversion module 30 to operate in the frequency conversion mode or the frequency fixed mode, Stable electricity is applied. At this time, the frequency conversion mode is an operation mode in which the generator 11 is driven at a low speed less than the commercial frequency, the frequency is less than 60 Hz, the power is converted to 60 Hz, and then the first power is applied to the first load 71. The frequency fixing mode is a mode in which the generator 12 is driven at a constant speed corresponding to the commercial frequency and outputs a power source having a frequency of 60 Hz to the first load section 71 to maintain and convert the output power, (72).

Therefore, the power control apparatus 1 drives the generator 11 at a low speed so as to consume less fuel under a low load condition by changing the driving speed of the generator 11 according to the load, The first load section 71 and the second load section 72 are controlled so that the first load section 71 is stably driven and the generator 11 is driven at a constant speed under a high load condition to output the commercial frequency alternating current power, All are driven stably. The power control apparatus 1 can adjust the driving speed of the generator 11 according to the load to reduce the load applied to the generator 11 and increase the service life of the generator 11 and the maintenance period.

The power control device 1 includes a power generation unit 10 for outputting an AC power supply, a main bus bar 40 for supplying the applied power to the connected devices, a power supply unit 10 for connecting the power generation unit 10 and the main bus bar 40 A power conversion module 50 for converting the frequency and magnitude of the input power source, a switch board 20 for changing the current path and a power conversion module 50 for converting the current between the main bus bar 40 and the power conversion module 50 And circulating wiring 60 for circulating.

Hereinafter, each component of the power control device 1 and the waveforms of voltages input and output through the respective components will be described in more detail.

The power generation section 10 outputs a three-phase power source outputting voltages of R phase, S phase, and T phase in different phases, that is, each phase difference is 120 degrees. The R phase of the voltage output from the three-phase power source may be a voltage as shown in FIG. The power generation section 10 includes at least one generator 11 for outputting AC power, a control module 12 for controlling the operation of the generator 11, and the like.

The control module 12 includes a plurality of sensors 13 and a micro control unit to control the driving states of the first load unit 71 and the second load unit 72 and the output voltage of the generator 11 and the power conversion module 50 and calculates the phase difference between the output voltage of the generator 11 and the output voltage of the power conversion module 50. [ The frequency of the output voltage of the generator 11 and the frequency of the output voltage of the power conversion module 50 are variously adjusted on the basis of the calculated values to change the path of the output voltage of the generator 11. For example, the control module 12 can control the generator 11 so that the frequency of the output voltage of the generator 11 is 30 Hz to 60 Hz, and the output voltage of the power conversion module 50 is 60 Hz. And can control the components of the conversion module 50. It is also possible to control the switches connected to the switch board 20 and the main bus bar 40, which form various current paths.

The switch board 20 forms a current path so that the AC power applied from the power generation section 10 can be applied to either the high load wiring 30 or the power conversion module 50. That is, the switch board 20 switches the power between the power generation unit 10 and the high-load wiring 30 and the power conversion module 50. The switch board 20 includes a first switch 221 and a second switch 222 connected to the bus bar 21 and the bus bar 21 and controlled by the control module 12. And is connected to one end of the high load wiring (30). The first switch 221 switches the power generation unit 11 and the high load wiring 30 under the control of the control module 12 to form a current path and the second switch 222 is connected to the power conversion module 50 The circulating wiring 60 is switched to form a current path.

The high load wiring 30 has one end connected to the switch board 20 and the other end connected to the main bus bar 40 so that the AC power output from the power generating unit 11 is supplied to the main bus bar (40). The power generation unit 11 and the high load wiring 30 are directly connected to each other through the first switch 221 of the switch board 20 in order to simplify the connection relationship between the high load wiring 30 and the power generation unit 11. [ Respectively. However, this is merely an example, and the present invention is not limited to this in connection with the connection between the high-load wiring 30 and the power generation section 11, and a structure in which the power generation section 11 is transferred to the high- And can be variously modified.

The main bus bar 40 connects the AC power applied through the high load wiring 30 or the power conversion module 50 to the first load part 71 and the circulating wiring 60 connected to one side of the main bus bar 40 Supply. The main bus bar 40 includes a third switch 43 and is connected between the power conversion module 50 and the first load part 71 through a current path or between the power conversion module 50 and the second load part 72 To form a current path. The third switch 43 switches the power conversion module 50 and the first load portion 71 and the second load portion 72 under the control of the control module 11 and forms a current path. One end of the circulation wiring 60 is connected to the input terminal of the power conversion module 50 and the other end of the circulation wiring 60 is connected to the main bus bar 40. Thus, (50). The high load wiring 30 including the circulating wiring 60 may be formed of a wire of a single wire type and the thickness of the high load wiring 30 may be determined by the thickness of the first load portion 41 and the power conversion module 50, Of a maximum load current of 1.25 times or more of the maximum load current.

The power conversion module 50 is connected to the generator 11 or the circulation wiring 60 according to the operation of the second switch 222 and receives the AC power from the generator 11, And converts the frequency and the magnitude of the magnitude by outputting the AC power from the bar 40. Then, the converted power is stably provided to the first load unit 71 and the second load unit 72. The power conversion module 50 may include a converter section 51 for rectifying an AC current into a DC current, a DC link section 52 for storing a DC current, an inverter section 53 for converting a DC current into an AC current, and the like. Here, the converter unit 51 rectifies the AC power input from the generator 11 as shown in FIG. The converter unit 51 is formed in a structure in which the first diode unit formed by connecting the upper diode Di and the lower diode Db in series, the second diode unit, and the third diode unit are connected in parallel to each other. Here, the first diode portion is connected to the R phase of the three-phase power source, the second diode portion is connected to the S phase, and the third diode portion is connected to the T phase, .

The DC link unit 52 stores electricity corresponding to the pulsating current rectified by the converter unit 51 and suppresses voltage fluctuation due to the ripple voltage applied by the converter unit 51 as shown in FIG. That is, the DC link unit 52 reduces the magnitude of the voltage ripple. The DC link unit 52 may be a capacitor capable of storing and outputting a voltage of 3000V. Therefore, when the stored electricity is discharged, the DC link unit 52 emits a waveform close to DC to apply a constant voltage to the inverter unit 53.

The inverter unit 53 is connected in parallel with the DC link unit 52 to synthesize a voltage applied from the DC link unit 52 with a desired magnitude and frequency to output the AC voltage. The inverter unit 53 includes semiconductor switches T1 to T6 for controlling the flow of signals by the input value or voltage or current and diodes D1 to D6 connected in anti-parallel to the semiconductor switches T1 to T6, ≪ / RTI >

Here, the first semiconductor switch T1 to the sixth semiconductor switch T6 are elements having the same electrical characteristics. The first semiconductor switch T1 to the sixth semiconductor switch T6 may be any one of various power semiconductors forming the current path on the circuit, that is, IGBT, IEGT, MOSFET, ICGT, GCT, SGCT and GTO. However, in this specification, an IGBT which is simple to drive and has high efficiency at high voltage and large current will be described as an example of semiconductor switches T1 to T6. The IGBT has a gate, an emitter and a collector terminal, and a gate terminal is provided in the control module 11 so that a reference signal (RW, see FIG. 4) and a carrier signal (see FIG. 4) . At this time, the IGBT is operated in the on state or the non-operation state by comparing the magnitude of the carrier signal CW of a certain period and the reference signal RW of the output voltage, And outputs a square wave voltage having the same value. Therefore, the first semiconductor switch T1 to the sixth semiconductor switch T6 are turned on or off so that the output current of the inverter section 53 is set to a specific value, that is, a frequency capable of driving the load It is possible to output a sinusoidal voltage having In other words, the inverter unit 53 is controlled so that the power conversion module 50 outputs electricity that stably drives the first load unit 71 and the second load unit 72. [ The operation in which the third switch 43 is switched between the inverter unit 53 of the power conversion module 50 and the first load unit 71 and the second load unit 72 will be described later.

Hereinafter, with reference to Figs. 5 and 6, a description will be given of a state in which the power control apparatus 1 is switched from the frequency conversion mode to the frequency fixing mode and operated according to the load amount.

FIG. 5 is a diagram illustrating a state in which the power control apparatus of FIG. 1 is driven in the frequency conversion mode when the load is small, FIG. 6 is a diagram illustrating a state in which the power control apparatus of FIG. Fig.

When the amount of power consumed by the load is small, the control module 12 drives the generator 11 slowly to output AC power less than the commercial frequency. The sensor 13 measures the frequency of the AC power of the generator 11 The frequency of the output power of the power conversion module 50 is measured in real time. The control module 12 calculates a value measured by the sensor 13 so that the first switch 221 is switched so that the output power of the generator 11 is transmitted to the switch board 20, The output power of the generator 11 applied to the switch board 20 is transferred to the power conversion module 50 and the output of the power conversion module 50 is connected to the main bus bar 40 So that the output power of the generator 11 is applied to the power conversion module 50. Thereafter, the control module 12 controls the turn-on and turn-off of the first semiconductor switch T1 to the sixth semiconductor switch T6 to change the frequency of the power source applied by the power conversion module 50 To be output to a power source of a commercial frequency. That is, the control module 12 controls the first switch 221 and the second switch 222 to form an electric path to be applied to the power conversion module 50 in a situation where the amount of power consumed by the load is small, The semiconductor switch T1 to the sixth semiconductor switch T6 are controlled to output the alternating current at the frequency suitable for the first load section 71, that is, 60 Hz. That is, the control module 12 enables the AC power output from the generator 11 to be stably applied to the first load portion 72 via the power conversion module 50. [

Here, the first load unit 71 may be one device or a plurality of devices that have a relatively lower power consumption than the second load unit 72. The second load portion 72 may be one device or a plurality of devices that have a relatively higher power consumption than the first load portion 71. [ For example, the first load portion 71 may be formed of additional devices such as a motor and an LED consuming less than 40% of the power generation amount of the generator 11, and the second load portion 72 may be formed of a load Can be a thruster consuming at least 40% of the power generation amount of the generator 11. [

On the other hand, when the amount of power consumed by the load is large, the control module 12 calculates the frequency of the AC power source of the generator 11 and the frequency of the output power of the power conversion module 50 in real time from the sensor 13 And gradually drives the generator 11 at a constant speed. The control module 12 controls the generator 11 to be driven at a constant speed and the first switch 221 is connected to the output power of the generator 11, The second switch 222 is switched so that the input terminal of the power conversion module 50 and one end of the circulating wiring 60 are connected to each other and the third switch 43 is connected to one end of the high- So that the output terminal of the power conversion module 50 is connected to the second load portion 72. Thereafter, the control module 12 controls the turn-on and turn-off of the first semiconductor switch T1 to the sixth semiconductor switch T6 to maintain or change the power applied to the power conversion module 50 To the second load section (72).

In other words, the control module 12 controls the first switch 221 in a situation where a large amount of power is consumed in the load, so that the AC power of the generator 11 forms a current path directly applied to the main bus bar 40 And controls the second switch 222 to form a current path circulated to the power conversion module 50 through the electricity applied to the main bus bar 40. And controls the third switch 43 so that the alternating current output from the power conversion module 50 forms a current path to be applied to the second load portion 72. That is, the control module 12 allows the AC power outputted from the generator 11 to be applied to the first load portion 71, and the AC outputted from the power conversion module 50 is supplied to the second load portion 72, As shown in FIG.

Thus, the power control device 1 drives the generator 11 at a low speed in a low load condition, outputs a low frequency power, converts the low frequency power to a commercial frequency through the power conversion module 50, . Then, in a situation where the load is large, the generator 11 is driven at a constant speed to output a commercial frequency power, then the output power is applied to the first load part 71 and the power output to the power conversion module 50 is converted And then applied to the second load section 72.

In this way, the power control apparatus 1 switches from the frequency-locked mode or the frequency-locked mode to the frequency-converted mode according to the load, and the generator 11 is driven at a low speed to be driven at a constant speed It is possible to reduce the amount of fuel unnecessarily consumed in the generator 11 and to stably drive both the first load portion 71 and the second load portion 72 with the power output from the generator 11. [

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You can understand that you can. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1: Power controller 10: Power generator
11: Generator 12: Control module
13: Sensor 20: Switch board
21: bus bar 221: first switch
222: second switch 30: high load wiring
40: main bus bar 43: third switch
50: power conversion module 51: converter section
52: DC link unit 53: Inverter unit
60: circulating wiring 71: first load section
72: second load section

Claims (5)

At least one power generator for outputting AC power;
A main bus bar to which the first load section is connected;
A high load wiring connecting the power generation unit and the main bus bar;
A power conversion module that receives the AC power from the power generation unit and converts the AC power to provide the first load unit or a second load unit having a higher power consumption than the first load unit; And
And a switch board for transferring power between the power generation unit and the power conversion module. The power control apparatus according to claim 1, further comprising a circulation wiring whose one end is connected to the input terminal of the power conversion module and the other end is connected to the main bus bar. The power conversion apparatus according to claim 2, wherein the power generation section includes a control module for controlling a frequency of the AC power to be output, the switch board including a first switch for switching the power generation section and the high- And a second switch for switching wiring,
Wherein the main bus bar comprises a third switch that forms a current path between the power conversion module and the first load section or between the power conversion module and the second load section. 3. The power conversion apparatus according to claim 2, wherein the power conversion module converts and outputs the applied AC power, and when the frequency of the output power of the power conversion module is less than the frequency of the AC power, Is connected to the switch board and the output terminal of the power conversion module is connected to the main bus bar,
Wherein one end of the power generation unit is connected to one end of the high load wiring when the frequency of the output power of the power conversion module is equal to or greater than the frequency of the alternating current power supply and one end of the circulation wiring is connected to the input end of the power conversion module, And an output end of the module is connected to the second load portion. The power control apparatus according to claim 3, wherein the control module controls the first switch, the second switch, and the third switch by measuring and calculating AC power of the power generation unit and output power of the power conversion module.

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