TWI648934B - Power system and power factor control method thereof - Google Patents

Abstract

A power system and a power factor control method thereof. The power system includes an AC power network, a green power generation device, an inverter, a load terminal, a measuring device, and a controller. The AC power network is used to provide the first AC power source. The green power generation unit provides green power. The inverter is coupled to the green energy generating device for converting the green energy source into the second alternating current power source. The load side is used to provide power consumption. The measuring device is coupled between the inverter, the load end and the AC power network to measure the sum total power factor of the second AC power source and the power consumption. The controller is coupled to the measuring device and the inverter to control the inverter according to the target power factor of the first alternating current power source to adjust the second alternating current power source, so that the sum power factor is greater than or equal to the target power factor.

Description

Power system and its power factor control method

The present invention relates to a power grid management technique, and more particularly to a power system and a power factor control method thereof.

The power calculation of the power system includes active power (represented by P) and apparent power (represented by S), and power factor (PF) is the ratio of active power to apparent power. Where the apparent power and active power, reactive power (represented by Q) satisfy the following vector relationship S ² =P ² +Q ² .

In general, when an inverter in a power system feeds additional energy, such as green energy, into the grid (such as buying electricity or selling electricity), because the inverter supplies active power to the power system, it causes The overall power factor of the power system is reduced, which affects the power quality at the end of the power grid. Therefore, how to reduce the impact of the power factor of the power system has become one of the main topics of power control technology in power systems.

Embodiments of the present invention provide a power system and a power factor control method thereof, which can improve the power factor of the power system as a whole, and the target power factor of the original power system can be improved under the condition that the apparent power of the inverter output is constant. The impact is reduced.

Embodiments of the present invention provide a power system including an AC power network, a green power generation device, an inverter, a load terminal, a gauge, and a controller. The AC power network is used to provide the first AC power source. The green power generation unit provides green power. The inverter is coupled to the green energy generating device for converting the green energy source into the second alternating current power source. The load side is used to provide power consumption. The measuring device is coupled between the inverter, the load end and the AC power network to measure the sum total power factor of the second AC power source and the power consumption. The controller is coupled to the measuring device and the inverter to control the inverter according to the target power factor of the first alternating current power source to adjust the second alternating current power source, so that the sum power factor is greater than or equal to the target power factor.

Embodiments of the present invention provide a power factor control method for a power system, wherein a power system converts a green power source provided by a green power generation device into a second AC power source through an inverter to transmit to a load terminal and provide a first AC power source The AC power network, the power factor control method includes: measuring a total power factor of the second AC power source and the power consumption through the measuring device; and controlling the inverter to adjust the second according to the target power factor of the first AC power source through the controller The AC power source causes the sum power factor to be greater than or equal to the target power factor.

Based on the above, the power system of the embodiment of the present invention and its power are controlled by numerical control The method, the total AC power factor of the second AC power source and the power consumption measured according to the amount of the measuring device, and the controller controls the inverter according to the target power factor of the first AC power source to adjust the second AC power source, thereby causing the sum power factor It is greater than or equal to the target power factor, so that the influence of the target power factor of the original power system can be reduced.

The above described features and advantages of the invention will be apparent from the following description.

100, 600‧‧‧ power system

110‧‧‧AC power network

120‧‧‧Green power generation unit

130‧‧‧Inverter

140‧‧‧Load side

150‧‧‧ Controller

160‧‧‧Measurer

170‧‧‧ Energy storage equipment

210‧‧‧ line segment (representing a positive angle threshold greater than or equal to the target power factor)

212‧‧‧ line segment (representing a negative angle threshold greater than or equal to the target power factor)

220‧‧‧ line segment (representing the load vector)

234, 244, 334, 344, 434, 444, 634, 644‧‧‧ sum power factor

232, 242, 332, 342, 432, 442, 632, 642‧‧ ‧ apparent power output from the inverter

646‧‧‧ Energy storage equipment vector

NP‧‧‧ grid

PAC1‧‧‧First AC power supply

PAC2‧‧‧Second AC power supply

PGE‧‧‧Green Power

P‧‧‧Active power

Q‧‧‧Reactive power

θ, θ1~θ9‧‧‧sum total power factor angle

S510~S570, S810~S830, S910, S920‧‧‧ steps

1 is a system diagram of a power system in accordance with an embodiment of the present invention.

2A is a schematic diagram of power transmission of a power system in accordance with an embodiment of the present invention.

2B is a schematic diagram of power compensation of a power system according to an embodiment of the invention.

3A-3D are schematic diagrams of power compensation of a power-on state of a power system according to an embodiment of the invention.

4A-4B are schematic diagrams of power compensation of a power selling state of a power system according to an embodiment of the invention.

FIG. 5 is a flow chart showing an embodiment of a power system according to an embodiment of the invention.

6 is a system diagram of a power system in accordance with another embodiment of the present invention.

FIG. 7A is a schematic diagram of power transmission of a power system according to another embodiment of the present invention.

7B and 7C are respectively schematic diagrams of power compensation of a power system according to another embodiment of the present invention.

FIG. 8 is a flow chart showing an embodiment of a power system according to another embodiment of the present invention.

9 is a flow chart of a power factor control method for a power system in accordance with an embodiment of the present invention.

1 is a system diagram of a power system in accordance with an embodiment of the present invention. 2A is a schematic diagram of power transmission of a power system in accordance with an embodiment of the present invention. Referring to FIG. 1 and FIG. 2A , in the embodiment, the power system 100 includes an AC power network 110 , a green power generation device 120 , an inverter 130 , a load terminal 140 , a controller 150 , and a measuring device 160 , wherein the AC power network The road 110 is used to provide a first AC power source PAC1, and the green power generation device 120 is used to provide a green power source PGE, for example, using solar power. The manner in which the green power source PGE is generated is not limited to the present invention. The load terminal 140 is coupled to the AC power network 110 and the green power generating device 120 for providing power consumption.

Specifically, the inverter 130 is coupled to the green power generation device 120, the AC power network 110, and the load terminal 140 for converting the green power source PGE provided by the green power generation device 120 into the second AC power source PAC2 for feeding. The grid NP is connected to the AC power network 110. The measuring device 160 is coupled between the inverter 130, the load terminal 140 and the AC power network 110 for measuring the second converted by the inverter 130. The sum total power factor of the power consumption of the AC power source PAC2 and the load terminal 140. The controller 150 is coupled to the measuring device 160 and the inverter 130 to control the inverter 130 according to the target power factor of the first AC power source PAC1 to adjust the second AC power source PAC2, so that the second AC power source PAC2 and the load terminal 140 are The sum power factor of the power consumption is greater than or equal to the target power factor of the first AC power source PAC1. The following examples will be explained in more detail.

2B is a schematic diagram of power compensation of a power system according to an embodiment of the invention. Referring to FIG. 1, FIG. 2A and FIG. 2B, the horizontal axis represents the active power P, and the vertical axis represents the reactive power Q. Here, an embodiment of the power system of the present invention will be exemplarily described. In this embodiment, the power system 100 converts the green power source PGE provided by the green power generation device 120 into the second AC power source PAC2 through the inverter 130 to be transmitted to the load terminal 140 and provide the communication of the first AC power source PAC1. The power network 110, wherein the target power factor value of the power system 100 represents a positive angle threshold value greater than or equal to a target power factor value (eg, 0.8) in line segment 210 of FIG. 2B, and line segment 212 represents a target power factor value (eg, 0.8) greater than or equal to Negative angle threshold. In this embodiment, the power consumption of the load terminal 140 (as indicated by line segment 220) is between line segments 210 and 212, indicating that the power factor of the power consumption of load terminal 140 (ie, line segment 220) is greater than the target power factor value. Here, the transmission measurer 160 can measure the sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140, that is, |cos θ1|.

Since the inverter 130 is originally supplied to the power grid NP is active power, such as the broken line 232, the sum of the power consumption of the second AC power source PAC2 and the load terminal 140 provided by the inverter 130 is indicated by a broken line 234. Since the dotted line 234 is beyond the line segment Between 210 and 212, the sum total power factor of the summed electrical energy indicated by the dashed line 234 is less than the target power factor value. At this time, the inverter 130 of the embodiment can change the reactive power of the second AC power source PAC2 and the load terminal 140 by adjusting the reactive power of the second AC power source PAC2, and the second AC power source PAC2 is viewed. The value of the power remains unchanged.

According to the above, the controller 150 can control the inverter 130 according to the target power factor, for example, increase or decrease the output reactive power. In the embodiment of FIG. 2B, the controller 150 can increase the output of the inverter 130. The reactive power of the AC power source PAC2 causes the inverter 130 to provide the corrected second AC power source PAC2 (as indicated by line segment 242), wherein the line segment 242 can be considered as the downwardly rotated line segment 232, that is, the value of the line segment 242 ( That is, the length is the same as the value of the line segment 232 (ie, the length). Correspondingly, the adjusted sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 is as shown by the line segment 244. Since the line segment 244 overlaps with the line segment 210, the power consumption of the second AC power source PAC2 and the load terminal 140 is indicated. The adjusted sum power factor will be equal to the target power factor value, that is, the adjusted sum power factor of the second AC power source PAC2 and the load terminal 140 power consumption will be not less than the target power factor.

In addition, in this embodiment, since the line segments 210 and 212 are smaller than the target power factor, the controller 150 can determine the sum of the power consumption of the second AC power source PAC2 and the load terminal 140 (eg, the angle θ1). The shown) is a positive or negative value to determine the manner in which the second AC power source PAC2 of the inverter 130 is adjusted. Further, when the sum function power angle (as indicated by the angle θ1) is positive and the sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 is smaller than the target In the power factor, the controller 150 can control the inverter 130 to increase the reactive power of the second AC power source PAC2, so that the second AC power source PAC2 rotates downward until the power consumption of the second AC power source PAC2 and the load terminal 140 is adjusted. The post-sum power factor is not less than the target power factor; when the sum power factor angle (as indicated by the angle θ1) is negative and the sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 is less than the target power factor, the control The inverter 130 can reduce the reactive power of the second AC power source PAC2, so that the second AC power source PAC2 is rotated upward until the adjusted power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 is not less than the target power. Factor. In addition, the controller 150 can also determine that the power consumption of the second AC power source PAC2 and the load terminal 140 is a power-on state or a power-selling state, wherein the embodiment shown in FIG. 2B is the second AC power source PAC2 and the load terminal 140. The power consumption is in the state of buying power. In addition, when the power consumption of the second AC power source PAC2 and the load terminal 140 is in a power selling state, that is, the total power energy overflows, the controller 150 may determine that the sum function power angle (as indicated by the angle θ1) is positive or negative. The adjustment method of the second AC power source PAC2 of the inverter 130 is determined.

Please refer to FIG. 3A to FIG. 5. 3A-3D are schematic diagrams of power compensation of a power-on state of a power system according to an embodiment of the invention. 4A-4B are schematic diagrams of power compensation of a power selling state of a power system according to an embodiment of the invention. FIG. 5 is a flow chart showing an embodiment of a power system according to an embodiment of the invention. The power system 100 of Figure 1 can be applied to any of the embodiments of Figures 3A-5. Where the same or similar elements are given the same or similar reference numerals, but different embodiments are shown in the different drawings.

After the power system 100 starts operating (step S510), the controller 150 determines that the power consumption of the second alternating current power source PAC2 and the load terminal 140 is a power-on state or a power-sell state (step S520).

In the embodiment of Figures 3A-3D, power system 100 is assumed to be in a power-on state, i.e., the sum power is not overflowed, and line segment 210 represents a positive angle threshold greater than or equal to a target power factor (e.g., 0.8), and line 212 represents A negative angle threshold greater than or equal to the target power factor (eg, 0.8), and the load vector of the load terminal 140 (ie, power consumption) is represented by line segment 220. When the power system 100 is in the power-on state, the controller 150 may determine whether the sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 is greater than or equal to the target power factor (ie, between the line segments 210 and 212) ( Step S530).

Referring to the embodiment of FIG. 3A and FIG. 3B, when the controller 150 determines that the original sum power factor of the power system 100 is greater than the target power factor (ie, the line segment 334 between the line segments 210 and 212), the controller 150 can control the inverse. The power factor of the second AC power source PAC2 outputted by the transformer 130 is corrected to 1.0. Further, in the embodiment of FIG. 3A, the sum function power angle θ2 is greater than 0 degrees (which is a positive value), and the controller 150 controls the inverter 130 to reduce the reactive power of the output second AC power source PAC2 to The power factor of the second AC power source PAC2 is corrected to 1.0 (step S550). As shown in FIG. 3A, after correction, the vector of the second AC power source PAC2 is rotated from the line segment 332 to the line segment 342, but the corrected sum power factor (as indicated by the line segment 344) is still between the line segments 210 and 212. That is, the corrected sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 is still greater than or equal to the target power factor. number.

In the embodiment of FIG. 3B, the sum of the power factor angle θ3 is less than 0 degrees (which is a negative value), and the controller 150 can control the power factor of the second AC power source PAC2 output by the inverter 130 to be corrected to 1.0, after being corrected. The vector of the second AC power source PAC2 is rotated from the line segment 332 to the line segment 342, but the corrected sum power factor (as indicated by line segment 344) is still greater than or equal to the target power factor (step S550).

When the controller 150 determines that the sum power factor is less than the target power factor, the controller 150 further determines that the sum function power angle is a positive value or a negative value (step S540). In the embodiment of FIG. 3C, the sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 (as indicated by line segment 334) is beyond the line segments 210 and 212, indicating that the target power factor is less than the target power factor of the first AC power source PAC1. After the controller 150 determines that the total power factor angle θ4 is greater than 0 degrees, the controller 150 controls the inverter 130 to increase the reactive power of the second alternating current power source PAC2, so that the line segment 332 indicating the second alternating current power source PAC2 is rotated downward. The line segment 342 is changed until the adjusted sum power factor (shown by line segment 344) of the power consumption of the second AC power source PAC2 and the load terminal 140 is greater than or equal to the target power factor (step S560).

In the embodiment of FIG. 3D, the sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 (as indicated by line segment 334) is beyond the line segments 210 and 212, indicating that the target power factor is less than the target power factor of the first AC power source PAC1. And the controller 150 first determines that the total power factor angle θ5 is a negative value, and the controller 150 controls the inverter 130 to reduce the output amount of the reactive power of the second alternating current power source PAC2 (step S570). The inverter 130 provides the corrected second AC power source PAC2 (eg, line segment 342) As shown, the summed power factor (as indicated by line segment 344) of the corrected power consumption of the second AC power source PAC2 and the load terminal 140 may be greater than or equal to the target power factor.

In the embodiment of FIGS. 4A-4B, power system 100 is assumed to be in a power-selling state, and line segment 210 represents a positive angle threshold greater than or equal to a target power factor (eg, 0.8), and line segment 212 represents a target power factor greater than or equal to (eg, The negative angle threshold of 0.8), and the load vector of the load terminal 140 (ie, power consumption) is represented by line segment 220. When the controller 150 determines that the power consumption of the second AC power source PAC2 and the load terminal 140 is an electric energy overflow state (step S520), the power system 100 is in a power selling state, and the controller 150 further determines that the sum function power angle is positive or negative. Value (step S540).

In the embodiment of FIG. 4A, when the controller 150 determines that the sum of the power factor of the power system 100 (as indicated by the line segment 434) is positive, the second AC power source originally output by the inverter 130 The power vector of the PAC2 is as shown by the line segment 432. The controller 150 controls the inverter 130 to increase the output of the reactive power of the second AC power source PAC2. The vector of the second AC power source PAC2 is rotated from the line segment 432 to the line segment 442, so that the correction is made. The resulting sum power factor is corrected to 1.0, i.e., corrected by line segment 434 to line segment 444. In the present embodiment, the corrected power vector 442 of the second AC power source PAC2 may cause the power system 100 to have a total power factor close to 1.0 in the power-selling state.

In the embodiment of FIG. 4B, when controller 150 determines that the sum power factor θ7 of the sum power factor of power system 100 (as indicated by line segment 434) is negative, control The controller 150 can control the inverter 130 to reduce the output of the reactive power of the second alternating current power source PAC2 such that the power vector of the second alternating current power source PAC2 is rotated from the line segment 432 to the line segment 442, so that the summed power of the modified power system 100 The factor (as indicated by line 444) is corrected to 1.0, and the sum power factor of power system 100 is near 1.0 in the power selling state.

6 is a system diagram of a power system in accordance with another embodiment of the present invention. Referring to FIG. 6, in the present embodiment, the power system 600 is similar to the embodiment of the power system 100, but includes an energy storage device 170 as compared to the power system 100. The energy storage device 170 is coupled to the green power generation device 120 and the controller 150 to be controlled by the controller 150 to charge or discharge using the green power source PGE. Those skilled in the art will be able to obtain relevant teachings, suggestions, or implementations in accordance with the description of the embodiments of Figures 1 through 5.

7A is a schematic diagram of power transmission of a power system according to another embodiment of the present invention, FIG. 7B and FIG. 7C are respectively schematic diagrams of power compensation of a power system according to another embodiment of the present invention, and FIG. 8 is a schematic diagram of another embodiment of the present invention. Schematic diagram of the implementation of the power system. Next, with reference to FIG. 6 , referring to FIG. 7A to FIG. 8 , after the power system 600 starts operating (step S810 ), the controller 150 determines that the second AC power source PAC2 and the power consumption are in a power-on state or a power-sell state (steps). S812). When the second AC power source PAC2 and the power consumption are in the power-on state, the controller 150 determines whether the sum power factor of the power system 600 is greater than or equal to the target power factor of the first AC power source PAC1 (S814) to determine to increase or decrease the energy storage device. 170 charging power.

Referring to FIG. 7B, the power system 600 is assumed to be in a power-on state. When the controller 150 determines that the sum power factor of the power consumption of the second AC power source PAC2 and the load terminal 140 (as indicated by the line segment 634) is less than the target power factor ( That is, outside the line segments 210 and 212, the controller 150 further determines whether the energy storage device 170 reaches the maximum charging power (step S822). When the energy storage device 170 does not reach the maximum charging power, the controller 150 can control the energy storage device 170. The charging power is increased (step S824). Specifically, the controller 150 can control the inverter 130 and adjust the output of the reactive power of the second AC power source PAC2 (as indicated by the line segment 642), and the controller 150 can also control the energy storage device 170 to utilize the green power source PGE. Charging is performed (as shown by energy storage device vector 646 in Figure 7B) such that the corrected sum power factor (as indicated by line 644) overlaps line segment 210, indicating power consumption of second AC power source PAC2 and load terminal 140. The corrected sum power factor is still not less than the target power factor. In this embodiment, the power system 600 is in a power-on state, and the total power factor angle θ8 is a positive value. However, in another embodiment, the sum power factor angle θ8 may also be a negative value, which is generally available to those skilled in the art. The above embodiments have been given sufficient teachings and will not be described again.

7C is a schematic diagram of power compensation of a power system according to another embodiment of the present invention. Referring to FIG. 7C, the power system 600 is assumed to be in a power-on state. When the controller 150 determines that the sum power factor of the power system 600 (as indicated by line 634) is less than the target power factor, that is, the line segment 634 is outside the area sandwiched by the line segments 210 and 212, and the energy storage device 170 has reached the maximum charging power. At this time, on behalf of the energy storage device 170, the power can not be further adjusted. Therefore, the controller 150 can determine that the total power factor angle θ9 is a positive value or a negative value to determine whether to increase or decrease the output of the inverter 130. The reactive power of the AC power source PAC2 (step S826). In this embodiment, the sum of the work power angle θ9 is a positive value, the controller 150 controls the inverter 130 to increase the reactive power outputting the second AC power source PAC2, and the vector of the second AC power source PAC2 is rotated from the line segment 632 to the line segment 642. (Step S828), so that the corrected sum power factor (as indicated by line 644) is not less than the target power factor. Similar to the above embodiment, in addition, when the sum function angle θ9 is a negative value, the controller 150 controls the inverter 130 to reduce the reactive power outputting the second AC power source PAC2 (step S830), with respect to a specific embodiment, Those skilled in the art can obtain sufficient teachings according to the embodiments of the embodiments of FIG. 1 to FIG. 7B, and details are not described herein again.

It should be noted that, in the above embodiments, the magnitude of the sum of the power angles is only an example and is not intended to limit the present invention.

In addition, in the embodiment of FIG. 8, when the sum power factor of the power system 600 is greater than or equal to the target power factor (ie, located in the area sandwiched by the target power factors 210 and 212), the controller 150 may also determine the inverse Whether the inverter 130 outputs the reactive power of the second alternating current power source PAC2 (step S816). When the inverter 130 does not output the reactive power of the second AC power source PAC2, the charging power representing the energy storage device 170 is too high, and the controller 130 can control the energy storage device 170 to reduce the charging power and even discharge (ie, Negative charging power) (step S820), and when the inverter 130 outputs the reactive power of the second alternating current power source PAC2, the controller 150 can control the inverter 130 to consume the power of the second alternating current power source PAC2 and the load terminal 140. The sum power factor is corrected to 1.0 (step S818). The details of steps S826, S828, and S830 can be referred to the embodiment of FIG. 1 to FIG. 5, and details are not described herein again.

Please refer to FIG. 9. FIG. 9 is a flowchart of a power factor control method for a power system according to an embodiment of the invention. In this embodiment, the power system converts the green energy power provided by the green power generation device into a second alternating current power source through the inverter, and transmits the power to the load terminal and the alternating current power network that provides the first alternating current power source, and the power factor of the power system. The control method includes the following steps. In step S910, the sum total power factor of the second alternating current power source and the power consumption is measured through the measuring device. Next, in step S920, the controller controls the inverter according to the target power factor of the first alternating current power source to adjust the second alternating current power source, so that the sum power factor is greater than or equal to the target power factor. For details of the steps S910 and S920, reference may be made to the teachings in the foregoing embodiments, and details are not described herein again.

In summary, the power system and the power factor control method thereof according to the embodiment of the present invention can measure the sum power factor of the second AC power source and the power consumption through the measuring device, and pass the controller according to the target of the first AC power source. The power factor controls the inverter to adjust the second AC power source such that the sum power factor is greater than or equal to the target power factor, so that the influence of the target power factor of the original power system can be reduced.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

Claims (15)

An electric power system comprising: an alternating current power network for providing a first alternating current power source; a green power generating device for providing a green energy source; and an inverter coupled to the green power generating device for the green The power source is converted into a second AC power source; a load end is used to provide a power consumption; a measuring device is coupled between the inverter, the load end and the AC power network for measuring the power a second AC power source and a sum total power factor consumed by the power source; and a controller coupled to the meter and the inverter to control the inverter to adjust according to a target power factor of the first AC power source The second AC power source causes the sum power factor to be greater than or equal to the target power factor, wherein the controller determines that the second AC power source and the power source are in a power-on state or a power-selling state, when the second AC power source is When the power consumption is in the power selling state, the controller determines that the sum of the power consumption of the second AC power source and the power source is a positive value or a negative value. The power system of claim 1, wherein the controller controls the inverter to increase a reactive power of the second alternating current power source when the total power factor is the positive value, when the total power is When the angle is the negative value, the inverter is controlled to reduce the reactive power of the second alternating current power source. The power system of claim 2, wherein when the second AC power source and the power source are in the power-on state, the controller determines whether the sum power factor is greater than or equal to the target power factor, when the sum When the power factor is less than the target power factor, the controller determines whether the sum power factor is the positive value or the negative value. The power system of claim 3, wherein when the sum power factor is greater than or equal to the target power factor, the controller controls the inverter to correct a power factor of the inverter to 1.0. The power system of claim 2, further comprising an energy storage device coupled to the green power generation device and the controller to be controlled by the controller to charge or discharge the green energy source, When the second AC power source and the power source are in the power-on state, the controller determines whether the sum power factor is greater than or equal to the target power factor to determine that the energy storage device is charging or discharging. The power system of claim 5, wherein when the sum power factor is less than the target power factor, the controller determines whether the energy storage device reaches a maximum charging power, and when the energy storage device does not reach the The controller controls the energy storage device to increase a charging power when the charging power is maximum. The power system of claim 6, wherein when the energy storage device reaches the maximum charging power, the controller determines whether the total power factor is the positive value or the negative value. The power system of claim 5, wherein when the sum power factor is greater than or equal to the target power factor, the controller determines whether the inverter outputs the reactive power, when the inverter does not output the The controller controls the energy storage device to reduce a charging power when reactive power is used. The power system of claim 8, wherein when the inverter outputs the reactive power, the controller controls the inverter to correct a power factor of the inverter to 1.0. A power factor control method for a power system, wherein the power system converts a green power source provided by a green power generation device into a second AC power source through an inverter to transmit to a load terminal and provide a first communication An AC power network of the power supply, the power factor control method includes: measuring, by a measuring device, a total power factor consumed by the second AC power source and a power source; and transmitting, by a controller, a target power of the first AC power source Controlling the inverter to adjust the second AC power source, such that the sum power factor is greater than or equal to the target power factor; and determining, by the controller, that the second AC power source and the power source are in a state of buying power or selling power a state, wherein when the second AC power source and the power source are consumed in the power selling state, the controller determines that a sum of the power consumption angles of the second AC power source and the power source is a positive value or a negative value. The power factor control method according to claim 10, wherein the step of determining, by the controller, the total AC power consumption angle of the second AC power source and the power source is the positive value or the negative value comprises: when the sum When the power factor angle is the positive value, the inverter is controlled by the controller to increase a reactive power of the second alternating current power source; and when the sum power angle is the negative value, controlling the inverter to reduce the The reactive power of the second alternating current power source. The power factor control method according to claim 10, wherein the step of determining, by the controller, the second AC power source and the power consumption as the power-on state or the power-selling state comprises: when the second AC power source And when the power consumption is in the power-on state, the controller determines whether the sum power factor is greater than or equal to the target power factor; when the sum power factor is less than the target power factor, the controller determines that the sum power factor is The positive value or the negative value; and when the sum power factor is greater than or equal to the target power factor, the inverter is controlled by the controller to correct a power factor of the inverter to 1.0. The power factor control method according to claim 10, wherein the step of determining, by the controller, the second AC power source and the power consumption as the power-on state or the power-selling state comprises: When the second AC power source and the power source are in the power-on state, the controller determines whether the sum power factor is greater than or equal to the target power factor to determine whether an energy storage device is charging or discharging. The power factor control method of claim 13, wherein the step of determining that the energy storage device is charging or discharging comprises: determining, by the controller, the storage when the sum power factor is less than the target power factor Whether the device reaches a maximum charging power; when the energy storage device does not reach the maximum charging power, the energy storage device is controlled to increase a charging power through the controller; and when the energy storage device reaches the maximum charging power, The controller determines whether the sum function angle is the positive value or the negative value. The power factor control method of claim 13, wherein the step of determining that the energy storage device is charging or discharging comprises: determining, by the controller, when the sum power factor is greater than or equal to the target power factor Whether the inverter outputs a reactive power of the second alternating current power source; when the inverter does not output the reactive power, the energy storage device is controlled by the controller to reduce a charging power; and when the inverter outputs In the reactive power, the inverter is controlled by the controller to correct a power factor of the inverter to 1.0.