Power system and power system control device
The power system addresses impedance-related control failures by calculating and controlling active and reactive power differences for each AC/DC converter, ensuring stable power distribution and offset management.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KK TOYOTA CHUO KENKYUSHO
- Filing Date
- 2025-05-28
- Publication Date
- 2026-06-18
Smart Images
Figure JP2025019294_18062026_PF_FP_ABST
Abstract
Description
Power systems and control devices for power systems 【0001】 The present invention relates to a power system and a control device for a power system. 【0002】 A method for autonomously and distributedly controlling the balance of current and power of inverter power supplies connected to an AC bus line has been disclosed (Japanese Patent Publication No. 2019-161868). In this technology, the average values of the active current and reactive current are obtained via communication, and the active current and reactive current of each inverter power supply are controlled to be equal to the average value. 【0003】 In AC microgrids independent of the power grid, distributed power sources such as stationary batteries, electric vehicles, and solar panels are considered promising as grid-controlled power sources. It is envisioned that multiple distributed power sources will be connected to a single microgrid via AC / DC converters. 【0004】 Incidentally, if there is variation in the impedance of the wiring between each AC / DC converter and the grid of the AC bus line, the output voltages of each AC / DC converter will not be equal even if the active current and reactive current are equal. This can lead to significant variations in active power and reactive power. 【0005】 Furthermore, it is desirable to be able to change the distribution ratio of active power and reactive power according to the rated power of the inverter power supply and the capacity of the battery connected to the inverter power supply. However, the conventional technology described above assumes a power system in which the same power supply is connected in parallel, and is configured to follow the average value of the active current and reactive current, making it impossible to change the power distribution ratio. 【0006】 Furthermore, in order to control the charging and discharging of batteries connected to the inverter power supply in accordance with the amount of charge (SOC) and usage schedule, it is desirable to be able to individually adjust the offset amounts of the active power and reactive power of each AC / DC converter. However, in the conventional technology described above, power offset control is impossible because the system is configured to follow the average value of the active current and reactive current. 【0007】Furthermore, in the conventional technology described above, instantaneous voltage control is performed by determining the phase using the active current deviation and the voltage amplitude using the reactive current deviation. However, when the wiring impedance is small, such as in short-distance wiring, the current change in response to phase and voltage changes becomes large, making control prone to failure. 【0008】 As shown in Figure 12, a simulation was conducted when two AC / DC converters applying the above prior art were operated in a power system with wiring impedance assuming short-distance wiring of about 5 to 10 m in length. At the start of the simulation, the units were operated without load, and 10 seconds after the start, the switches were turned on and a load of 10 + j 10 Ω was connected to the AC bus line. Figure 13 shows the simulation results of the active power (P1, P2) and reactive power (Q1, Q2) of each AC / DC converter. The control failed because it was not possible to control the active power and reactive power to be equal to the average value of the two AC / DC converters. 【0009】 Another existing method for controlling load sharing between AC / DC converters is droop control. This method controls the voltage amplitude based on the active power of the AC / DC converters and the frequency based on the reactive power, under the condition that the wiring impedance is resistive. However, a problem with this control is that if the wiring resistance between each AC / DC converter and the AC bus line is mismatched, the output voltages from each AC / DC converter will be different, resulting in errors in the distribution of active power. 【0010】One aspect of the present invention is a power system comprising an AC / DC converter having an AC / DC converter input / output controller, and an AC bus in which a plurality of devices having power supplies capable of input and output are connected in parallel, wherein the power system calculates the difference between the effective active power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted effective active power offset value for each of the AC / DC converters, and the difference between the effective reactive power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted reactive power offset value for each of the AC / DC converters. The control controller comprises a first control unit, a second control unit that calculates a first target value which is the difference between the average active power value and the average active power offset value obtained based on the calculation results of the first control unit, and a second target value which is the difference between the average reactive power value and the average reactive power offset value, and a third control unit that determines a voltage control target value from the difference between the first target value and the effective active power value of the AC / DC converter, and the difference between the second target value and the effective reactive power value of the AC / DC converter, and controls the active power and reactive power of the AC / DC converter by commanding each of the AC / DC converters with the voltage control target value. 【0011】Another aspect of the present invention is a power system comprising an AC / DC converter having an AC / DC converter input / output controller, and an AC bus in which multiple devices having power supplies capable of input and output are connected in parallel, wherein the power system comprises a first control unit that calculates the effective value of active power calculated from the voltage and current for each of the AC / DC converters, and the effective value of reactive power calculated from the voltage and current for each of the AC / DC converters, and a first target value obtained by weighting the average value of active power obtained based on the effective value of active power by the number of AC / DC converters and an arbitrary active power distribution ratio, and reactive power obtained based on the effective value of reactive power The control controller comprises: a second control unit that calculates a second target value weighted by the number of AC / DC converters and an arbitrary reactive power distribution ratio with respect to the average power value; and a third control unit that determines a voltage control target value from the difference between the first target value weighted by the active power distribution ratio and the effective active power value of each AC / DC converter, and the difference between the second target value weighted by the reactive power distribution ratio and the effective reactive power value of each AC / DC converter; and controls the active power and reactive power of each AC / DC converter by commanding the voltage control target value to each AC / DC converter. 【0012】Another aspect of the present invention is a power system comprising an AC / DC converter having an AC / DC converter input / output controller, and an AC bus in which a plurality of devices having power supplies capable of input and output are connected in parallel, wherein the power system comprises a first control unit that calculates the difference between the effective active power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted effective active power offset value for each of the AC / DC converters, and the difference between the effective reactive power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted reactive power offset value for each of the AC / DC converters, and the difference between the average effective power value and the average effective power offset value obtained based on the calculation results of the first control unit for the AC / DC converters The control controller comprises: a first target value weighted by the number and an arbitrary active power distribution ratio; a second control unit that calculates a second target value weighted by the number and an arbitrary reactive power distribution ratio based on the difference between the average reactive power value and the average reactive power offset value obtained from the calculation results of the first control unit; and a third control unit that determines a voltage control target value from the difference between the first target value weighted by the active power distribution ratio and the effective active power value of each of the AC / DC converters, and the difference between the second target value weighted by the reactive power distribution ratio and the effective reactive power value of each of the AC / DC converters, and controls the active power and reactive power of each of the AC / DC converters by commanding the AC / DC converters with the voltage control target value. 【0013】Another aspect of the present invention is a control device for a power system, comprising an AC / DC converter having an AC / DC converter input / output controller, and an AC bus in which a plurality of devices having power supplies capable of input and output are connected in parallel, wherein the control device for a power system comprises the difference between the effective active power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted effective active power offset value for each of the AC / DC converters, and the effective reactive power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted reactive power offset value for each of the AC / DC converters. The system comprises a first control unit that calculates the difference between the average active power value and the average active power offset value, a second control unit that calculates a first target value which is the difference between the average active power value and the average active power offset value obtained based on the calculation results of the first control unit, a second target value which is the difference between the average reactive power value and the average reactive power offset value, and a third control unit that determines a voltage control target value from the difference between the first target value and the effective active power value of the AC / DC converter, and the difference between the second target value and the effective reactive power value of the AC / DC converter, and controls the active power and reactive power of the AC / DC converter by commanding each of the AC / DC converters with the voltage control target value. 【0014】Another aspect of the present invention is a control device for a power system, comprising an AC / DC converter having an AC / DC converter input / output controller, and an AC bus in which a plurality of devices having power supplies capable of input and output are connected in parallel, wherein the control device for a power system comprises: a first control unit that calculates the effective value of active power calculated from the voltage and current for each of the AC / DC converters, and the effective value of reactive power calculated from the voltage and current for each of the AC / DC converters; a first target value obtained by weighting the average value of active power obtained based on the effective value of active power by the number of AC / DC converters and an arbitrary active power distribution ratio; and the reactive power The system includes a second control unit that calculates a second target value by weighting the average reactive power value obtained based on the effective value with the number of AC / DC converters and an arbitrary reactive power distribution ratio, and a third control unit that determines a voltage control target value from the difference between the first target value weighted by the effective power distribution ratio and the effective effective value of each AC / DC converter, and the difference between the second target value weighted by the reactive power distribution ratio and the effective effective value of each AC / DC converter, and controls the active power and reactive power of each AC / DC converter by commanding the voltage control target value to each AC / DC converter. 【0015】Another aspect of the present invention is a power system control device comprising: an AC / DC converter having an AC / DC converter input / output controller; and an AC bus in which a plurality of devices having power supplies capable of input and output are connected in parallel, the power system control device comprising: a first control unit that calculates the difference between the effective active power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted effective active power offset value for each of the AC / DC converters; and the difference between the effective reactive power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted reactive power offset value for each of the AC / DC converters, and the difference between the average effective power value and the average effective power offset value obtained based on the calculation results of the first control unit, and the A The system includes a second control unit that calculates a second target value weighted by the number of AC / DC converters and an arbitrary reactive power distribution ratio, based on a first target value weighted by the number of AC / DC converters and an arbitrary active power distribution ratio, and the difference between the average reactive power value and the average reactive power offset value obtained based on the calculation results of the first control unit; and a third control unit that determines a voltage control target value from the difference between the first target value weighted by the active power distribution ratio and the effective active power value of each AC / DC converter, and the difference between the second target value weighted by the reactive power distribution ratio and the effective reactive power value of each AC / DC converter. The system controls the active power and reactive power of each AC / DC converter by commanding the AC / DC converters with the voltage control target value. 【0016】 According to the present invention, it is possible to provide a power system and a control device for the power system that can arbitrarily control the active power and reactive power of an AC / DC converter. 【0017】This figure shows the configuration of a power system in an embodiment of the present invention. This figure shows the configuration of a control controller for a power system in an embodiment of the present invention. This figure shows the configuration of a control controller for a power system in an embodiment of the present invention. This figure shows the configuration during simulation of a power system in an embodiment of the present invention. This figure shows the results of a simulation of a power system in an embodiment of the present invention. This figure shows the results of a simulation of a power system in an embodiment of the present invention. This figure shows the configuration of a control controller for a power system in a modified example 1. This figure shows the configuration of a control controller for a power system in a modified example 2. This figure shows the configuration of a control controller for a power system in a modified example 3. This figure shows the configuration of a control controller for a power system in a modified example 4. This figure shows a specific example of a power system configuration in a modified example 5. This figure shows a specific example of a conventional power system configuration. This figure shows the results of a simulation of a conventional power system. 【0018】 As shown in Figure 1, the power system 100 in the embodiment of the present invention comprises an ADC converter 10 (10a to 10n), input / output controllers 12 (12a to 12n), current controllers 14 (14a to 14n), and a power reference value calculation unit 16. The current controllers 14 (14a to 14n) and the power reference value calculation unit 16 together function as a control controller 18. 【0019】 The number of input / output controllers 12 and current controllers 14 is equal to the number of ACDC converters 10 that are to be controlled. In the example of the power system 100 shown in Figure 1, each of the n ACDC converters 10 (10a to 10n) is provided with an input / output controller 12 (12a to 12n) and a current controller 14 (14a to 14n). 【0020】In the following description, for the power, voltage, and current related to the first AC-DC converter 10a, input / output controller 12a, and current controller 14a, a number 1 is attached to the symbol for indication. Similarly, for the power, voltage, and current related to the nth AC-DC converter 10n, input / output controller 12n, and current controller 14n, the symbol is attached with n for indication. Also, when explaining the common functions, the nth AC-DC converter 10n, input / output controller 12n, current controller 14n, and power reference value calculation unit 16 are described as representatives. 【0021】 The AC-DC converter 10n is a circuit that performs AC-DC conversion between the DC power supply and the AC bus connected thereto. The DC power supply is not particularly limited, and for example, it can be a secondary battery, a solar cell, a fuel cell, or the like. 【0022】 The input / output controller 12n controls the output voltage V ｒｅｆｎ and the output current I ＡＣＤＣｎ output from the AC-DC converter 10n based on the current target value I ｒｅｆｎ input from the current controller 14n so that the output current I ＡＣＤＣｎ becomes the current target value I ＡＣＤＣｎ . Alternatively, when the current controller 14n is not provided, the input / output controller 12n controls the output voltage V ｒｅｆｎ and the output current I ＡＣＤＣｎ output from the AC-DC converter 10n based on the target voltage value V ｒｅｆｎ input from the power reference value calculation unit 16 so that the output voltage V ＡＣＤＣｎ becomes the target voltage value V ＡＣＤＣｎ . 【0023】 The current controller 14n receives the detected values of the output voltage V ＡＣＤＣｎ and the output current I ＡＣＤＣｎ from the AC-DC converter 10n and outputs these values to the power reference value calculation unit 16. Also, upon receiving the target voltage value V ｒｅｆｎ from the power reference value calculation unit 16, the current controller 14n generates a current target value I ｒｅｆｎ corresponding to the target voltage value V ｒｅｆｎ and outputs it to the input / output controller 12n. Note that the target voltage value V ｒｅｆｎIn a configuration where the ACDC converter 10n is controlled based on this, the current controller 14n is not required. 【0024】 The power reference value calculation unit 16 calculates the output voltage V ＡＣＤＣｎ and output current I ＡＣＤＣｎ Based on the detected value, a target voltage value V for controlling the ADC converter 10n ｒｅｆｎ The process for generating the power reference value is described below. 【0025】 [Configuration and Function of Control Controller] Figure 2 is a diagram showing the configuration of the power system 100, with a detailed view of the configuration of the power reference value calculation unit 16. The power reference value calculation unit 16 is composed of a first control unit 16-1 (16-1a to 16-1n), a second control unit 16-2 (16-2p, 16-2q), and a third control unit 16-3 (16-3a to 16-3n). 【0026】 The first control unit 16-1 and the third control unit 16-3 are provided in the same number as the ACDC converter 10 to be controlled. In the example of the power system 100 shown in Figure 2, the first control unit 16-1 (16-1a to 16-1n) and the third control unit 16-3 (16-3a to 16-3n) are provided for each of the n ACDC converters 10 (10a to 10n). 【0027】 The power reference value calculation unit 16 is configured to achieve the distribution of active and reactive power according to a desired power distribution ratio and power offset, regardless of the wiring impedance of the power system 100. 【0028】 In the first control unit 16-1n, the output voltage V of the ACDC converter 10n ＡＣＤＣｎ and output current I ＡＣＤＣｎ The effective power output P depends on the measured value. ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎ To determine the effective power output P. Also, when setting a power offset at the output of the ADC converter 10n, ＡＣＤＣｎ From the active power offset value P ｒｅｆｎ Subtracting this, the reactive power output Q ＡＣＤＣｎ The reactive power offset value Q ｒｅｆｎ The process involves subtracting the active power offset value P. ｒｅｆｎand reactive power output Q ＡＣＤＣｎ These can each be independently set to a positive or negative value. The first control unit 16-1n determines the effective power output P ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎ This is output to the second control unit 16-2 and the third control unit 16-3n. 【0029】 The second control unit 16-2 is configured to include an active power reference value calculation unit 16-2p and a reactive power reference value calculation unit 16-2q. 【0030】 The active power reference value calculation unit 16-2p calculates the active power output P obtained by the first control unit 16-1 (16-1a to 16-1n) corresponding to each of the ACDC converters 10 (10a to 10n). ＡＣＤＣ (P ＡＣＤＣ１ ~P ＡＣＤＣｎ ) and the effective power output P is calculated using formula (1). ＡＣＤＣ (P ＡＣＤＣ１ ~P ＡＣＤＣｎ Calculate the first target value, weighted according to ). 【0031】 Here, the average value of the active power output P ｍｅａｎ and the average value of the active power offset P ｒｅｆｍｅａｎ These are expressed by equations (2) and (3), respectively. Also, the coefficient K ｐｋ These are the active power outputs P, respectively. ＡＣＤＣｋ This is a weighting coefficient for setting the active power distribution ratio. 【0032】 The active power reference value calculation unit 16-2p outputs the calculated first target value to the third control units 16-3 (16-3a to 16-3n) corresponding to each of the ACDC converters 10 (10a to 10n). 【0033】 Furthermore, the reactive power reference value calculation unit 16-2q calculates the reactive power output Q obtained by the first control unit 16-1 (16-1a to 16-1n) corresponding to each of the ACDC converters 10 (10a to 10n). ＡＣＤＣ (Q ＡＣＤＣ１ ~Q ＡＣＤＣｎ ) and the reactive power output Q is calculated using formula (4). ＡＣＤＣ (Q ＡＣＤＣ１ ~QＡＣＤＣｎ A second target value is calculated, weighted according to the following criteria. 【0034】 Here, the average value of the reactive power output Q ｍｅａｎ and reactive power offset average value Q ｒｅｆｍｅａｎ These are expressed by equations (5) and (6), respectively. Also, the coefficient K ｑｋ These are the reactive power outputs Q, respectively. ＡＣＤＣｋ This is a weighting coefficient for setting the reactive power distribution ratio. 【0035】 The reactive power reference value calculation unit 16-2q outputs the calculated second target value to the third control units 16-3 (16-3a to 16-3n) corresponding to each of the ACDC converters 10 (10a to 10n). 【0036】 When the third control unit 16-3n receives the first target value and the second target value from the second control unit 16-2, it outputs an effective power output P for each of them. ＡＣＤＣｋ Weighting coefficient K for setting the active power distribution ratio ｐｋ and reactive power output Q ＡＣＤＣｋ Weighting coefficient K for setting the reactive power distribution ratio ｑｋ The value obtained by multiplying by the first control unit 16-1n is the effective power output P ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎ The process involves subtracting from to find the difference. Furthermore, the obtained difference value is input to the PI controller, and the voltage target value V is set. ｒｅｆｎ The third control unit 16-3n calculates the calculated voltage target value V. ｒｅｆｎ This is output to the input / output controller 12n. 【0037】 As described above, the input / output controller 12n receives the target voltage value V from the power reference value calculation unit 16. ｒｅｆｎ Based on this, the output voltage V output from the ACDC converter 10n is V. ＡＣＤＣｎ The target voltage value V ｒｅｆｎ Output voltage V ＡＣＤＣｎ and output current I ＡＣＤＣｎ Control. 【0038】As described above, the power system 100 in this embodiment can accurately distribute active and reactive power according to a desired power distribution ratio and power offset, regardless of the wiring impedance. 【0039】 Furthermore, as shown in Figure 3, the control controller 18 may also include current controllers 14 (14a to 14n). The number of current controllers 14 is equal to the number of ACDC converters 10 that are to be controlled. In the example of the power system 100 shown in Figure 3, a current controller 14 (14a to 14n) is provided for each of the n ACDC converters 10 (10a to 10n). 【0040】 The current controller 14n receives the target voltage value V from the third control unit 16-3n. ｒｅｆｎ Based on this, the target voltage value V ｒｅｆｎ Output voltage V ＡＣＤＣｎ After subtracting that value, the difference is input to the PI controller to set the current target value I ｒｅｆｎ The current controller 14n outputs the calculated current target value I. ｒｅｆｎ This is output to the input / output controller 12n. 【0041】 The input / output controller 12n receives the current target value I from the control controller 18. ｒｅｆｎ Based on this, the output current I output from the ACDC converter 10n ＡＣＤＣｎ Current target value I ｒｅｆｎ Output voltage V ＡＣＤＣｎ and output current I ＡＣＤＣｎ Control. 【0042】 Circuit simulations were performed to confirm that the desired power distribution could be achieved with the configuration of the power system 100 shown in Figures 1 and 3. Figure 4 shows the circuit diagram used in the simulation. 【0043】 Two ACDC converters 10 are connected to the AC bus with different wiring impedances (0.1 + j0.1Ω, 0.2 + j0.2Ω). At the start of the simulation, there was no load, and 10 seconds after the start, the switch was turned on and a load of 10 + j10Ω was connected to the AC bus and the simulation was performed. Also, the active power distribution ratio was (K ｐ１ , Kｐ２ ) = (1, 2), with respect to the reactive power distribution ratio (K ｑ１ , K ｑ２ ) = (1, 2). 【0044】 Figure 5 shows the active power (P1, P2) and reactive power (Q1, Q2) of ACDC converter 10a and ACDC converter 10b, respectively. After 15 seconds, when the load was connected to the AC bus and the active and reactive powers stabilized, the ratio of active power P1:P2 = 1:2 and the ratio of reactive power Q1:Q2 = 1:2 respectively, achieving the desired power distribution ratio. 【0045】 Furthermore, regarding the active power offset values of each of the ACDC converters 10a and 10b (P ｒｅｆ１ , P ｒｅｆ２ ) = (1000, 0), regarding the reactive power offset value (Q ｒｅｆ１ Q ｒｅｆ２ The simulation was performed with ) = (1000, 0). Figure 6 shows the active power (P1, P2) and reactive power (Q1, Q2) of ACDC converter 10a and ACDC converter 10b, respectively. Both the active power and reactive power were offset by 1000W. 【0046】 As described above, it has been confirmed that the power system 100 in the embodiment of the present invention performs the desired operation. 【0047】 [Modification 1] Figure 7 shows the configuration of the power system 100 when no power distribution settings are made in the multiple ACDC converters 10. 【0048】 The power reference value calculation unit 16 is composed of a first control unit 16-1 (16-1a to 16-1n), a second control unit 16-2 (16-2p, 16-2q), and a third control unit 16-3 (16-3a to 16-3n). The first control unit 16-1 and the third control unit 16-3 are provided in the same number as the ACDC converter 10 to be controlled. 【0049】 In the first control unit 16-1n, the output voltage V of the ACDC converter 10n ＡＣＤＣｎ and output current I ＡＣＤＣｎ The effective power output P depends on the measured value. ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎFind it. Also, when setting a power offset for the output of the AC-DC converter 10n, the active power output P ＡＣＤＣｎ subtracts the active power offset value P ｒｅｆｎ from it, and performs a process of subtracting the reactive power offset value Q ＡＣＤＣｎ from the reactive power output Q ｒｅｆｎ . The active power offset value P ｒｅｆｎ and the reactive power output Q ＡＣＤＣｎ can be set independently to positive or negative values respectively. The first control unit 16-1n outputs the obtained active power output P ＡＣＤＣｎ and the reactive power output Q ＡＣＤＣｎ to the second control unit 16-2 and the third control unit 16-3n. 【0050】 The second control unit 16-2 is configured to include an active power reference value calculation unit 16-2p and a reactive power reference value calculation unit 16-2q. 【0051】 The active power reference value calculation unit 16-2p receives the active power output P ＡＣＤＣ (P ＡＣＤＣ１ to P ＡＣＤＣｎ ) obtained by the first control unit 16-1 (16-1a to 16-1n) corresponding to each of the AC-DC converters 10 (10a to 10n), and calculates its average value P ｍｅａｎ . Further, it calculates the average value P ｒｅｆｎ of the active power offset value P ｒｅｆｍｅａｎ . Then, as the difference value of these values, it subtracts the average value P ｍｅａｎ of the active power offset value from the average value P ｒｅｆｍｅａｎ of the active power output, and outputs it to the third control unit 16-3 (16-3a to 16-3n) as the first target value. 【0052】 The reactive power reference value calculation unit 16-2q receives the reactive power output Q ＡＣＤＣ (Q ＡＣＤＣ１ to Q ＡＣＤＣｎ ) obtained by the first control unit 16-1 (16-1a to 16-1n) corresponding to each of the AC-DC converters 10 (10a to 10n), and calculates its average value Q ｍｅａｎ . Further, it calculates the average value Q ｒｅｆｎ of the reactive power offset value Q ｒｅｆｍｅａｎ . Then, as the difference value of these values, the average value Qｍｅａｎ From the average value of the reactive power offset Q ｒｅｆｍｅａｎ This value is subtracted and output as the second target value to the third control unit 16-3 (16-3a to 16-3n). 【0053】 The third control unit 16-3n determines the first target value and the second target value of the active power output P obtained by the first control unit 16-1n. ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎ The process involves subtracting from to find the difference. Furthermore, the obtained difference value is input to the PI controller, and the voltage target value V is set. ｒｅｆｎ The third control unit 16-3n calculates the calculated voltage target value V. ｒｅｆｎ This is output to the input / output controller 12n. 【0054】 As described above, the input / output controller 12n receives the target voltage value V from the power reference value calculation unit 16. ｒｅｆｎ Based on this, the output voltage V output from the ACDC converter 10n is V. ＡＣＤＣｎ The target voltage value V ｒｅｆｎ Output voltage V ＡＣＤＣｎ and output current I ＡＣＤＣｎ Control. 【0055】 Furthermore, as shown in Figure 3, current controllers 14 (14a to 14n) are provided to set the target voltage value V ｒｅｆｎ From current target value I ｒｅｆｎ It may also be configured to calculate and output the current target value I input from the control controller 18. In this case, the input / output controller 12n receives the current target value I from the control controller 18. ｒｅｆｎ Based on this, the output current I output from the ACDC converter 10n ＡＣＤＣｎ Current target value I ｒｅｆｎ Output voltage V ＡＣＤＣｎ and output current I ＡＣＤＣｎ Control. 【0056】 [Modification 2] Figure 8 shows the configuration of the power system 100 when no power offset is set in the multiple ACDC converters 10. 【0057】The power reference value calculation unit 16 is composed of a first control unit 16-1 (16-1a to 16-1n), a second control unit 16-2 (16-2p, 16-2q), and a third control unit 16-3 (16-3a to 16-3n). The first control unit 16-1 and the third control unit 16-3 are provided in the same number as the ACDC converter 10 to be controlled. 【0058】 In the first control unit 16-1n, the output voltage V of the ACDC converter 10n ＡＣＤＣｎ and output current I ＡＣＤＣｎ The effective power output P depends on the measured value. ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎ The first control unit 16-1n determines the effective power output P. ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎ This is output to the second control unit 16-2 and the third control unit 16-3n. 【0059】 The second control unit 16-2 is configured to include an active power reference value calculation unit 16-2p and a reactive power reference value calculation unit 16-2q. In this modified example 2, the active power reference value calculation unit 16-2p and the reactive power reference value calculation unit 16-2q perform the same processing as the power system 100 shown in Figure 2. The third control unit 16-3n processes the first target value and the second target value input from the second control unit 16-2. In this modified example 2, the third control unit 16-3n performs the same processing as the power system 100 shown in Figure 2. The input / output controller 12n then processes the target voltage value V input from the power reference value calculation unit 16. ｒｅｆｎ Based on this, the output voltage V output from the ACDC converter 10n is V. ＡＣＤＣｎ The target voltage value V ｒｅｆｎ Output voltage V ＡＣＤＣｎ and output current I ＡＣＤＣｎ Control. 【0060】 Furthermore, as shown in Figure 3, current controllers 14 (14a to 14n) are provided to set the target voltage value V ｒｅｆｎ From current target value I ｒｅｆｎ It may also be configured to calculate and output the current target value I input from the control controller 18. In this case, the input / output controller 12n receives the current target value I from the control controller 18. ｒｅｆｎ Based on this, the output current I output from the ACDC converter 10nＡＣＤＣｎ Current target value I ｒｅｆｎ Output voltage V ＡＣＤＣｎ and output current I ＡＣＤＣｎ Control. 【0061】 [Modification 3] Figure 9 shows the configuration of the power system 100 in Modification 3. In the power system 100 of Modification 3, the control controller 18 is configured to include a first control unit 16-1 (16-1a to 16-1n), a second control unit 16-2 (16-2p, 16-2q), and a third control unit 16-3 (16-3a to 16-3n). 【0062】 In the power system 100 of the modified example 3, information is exchanged between the second control unit 16-2 (16-2p, 16-2q), the first control unit 16-1 (16-1a to 16-1n), and the third control unit 16-3 (16-3a to 16-3n) via a communication line (CL). In communication via the communication line (CL), the information may be digitized before communication, or it may be communicated as an analog signal. 【0063】 The processing in the first control unit 16-1 (16-1a to 16-1n), the second control unit 16-2 (16-2p, 16-2q), and the third control unit 16-3 (16-3a to 16-3n) is the same as that of the power system 100 shown in Figure 2, so no explanation is provided. Furthermore, as shown in Figure 3, a current controller 14 (14a to 14n) is provided to control the target voltage value V ｒｅｆｎ From current target value I ｒｅｆｎ You may also perform control by seeking this value. 【0064】 In the present configuration, a communication line is used, but the second control unit 16-2 is provided in common for multiple ACDC converters 10 (10a to 10n), which reduces the manufacturing cost of the power system 100. 【0065】[Modification 4] Figure 10 shows the configuration of the power system 100 in Modification 4. In the power system 100 of Modification 3, the control controller 18 is configured to include a first control unit 16-1 (16-1a to 16-1n), a second control unit 16-2 (16-2a to 16-2n: 16-2p, 16-2q), and a third control unit 16-3 (16-3a to 16-3n). 【0066】 In the power system 100 of modified example 4, a second control unit 16-2 (16-2a to 16-2n: 16-2p, 16-2q) is provided for each of the ACDC converters 10 (10a to 10n). That is, in the power system 100 of modified example 4, the second control units 16-2n are distributed for each of the ACDC converters 10n. 【0067】 Information is exchanged between the first control unit 16-1 (16-1a to 16-1n) and the second control unit 16-2 (16-2p, 16-2q) via a communication line (CL). In communication via the communication line (CL), the information may be digitized before communication, or it may be communicated as an analog signal. 【0068】 The first control unit 16-1n outputs an active power output P to each of the second control units 16-2 (16-2a to 16-2n) via the communication line (CL). ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎ The second control unit 16-2n communicates the active power output P from all first control units 16-1 (16-1a to 16-1n). ＡＣＤＣｎ and reactive power output Q ＡＣＤＣｎ Receives and processes the data. 【0069】 The processing in the first control unit 16-1 (16-1a to 16-1n), the second control unit 16-2 (16-2a to 16-2n: 16-2p, 16-2q), and the third control unit 16-3 (16-3a to 16-3n) is the same as that of the power system 100 shown in Figure 2, so no explanation is given. Furthermore, as shown in Figure 3, a current controller 14 (14a to 14n) is provided to control the target voltage value V ｒｅｆｎ From current target value I ｒｅｆｎ You may also perform control by seeking this value. 【0070】In this way, by using a communication line and providing a second control unit 16-2 for each of the ACDC converters 10 (10a to 10n), distributed control including the second control unit 16-2 can be realized. Distributed control reduces the computational load on the second control unit 16-2, which is the higher-level controller, and eliminates the need for high-frequency communication. 【0071】 [Modification 5] Figure 10 shows the configuration of the power system 100 in Modification 5. In the power system 100 of Modification 5, the ADC converters 10 (10a to 10n) and the control controller 18 are connected by a communication device (communication line). In communication via the communication device (communication line), information may be digitized before communication, or it may be communicated as an analog signal. 【0072】 The configuration of the control controller 18 includes a current controller 14 (14a to 14n) and a power reference value calculation unit 16. The power reference value calculation unit 16 may be configured in the same way as in any of the above embodiments and modified examples, and includes a first control unit 16-1 (16-1a to 16-1n), a second control unit 16-2 (16-2a to 16-2n: 16-2p, 16-2q), and a third control unit 16-3 (16-3a to 16-3n). Note that the configuration may also be configured without the current controller 14. 【0073】 [Technical Effects] According to the power systems in the embodiments and variations of the present invention, it is possible to provide a power system and a control device (control controller) for the power system that can arbitrarily control the active power and reactive power of an AC / DC converter. That is, the control loop includes control terms that can control the power distribution ratio and power offset of the active power and reactive power, respectively, so that the distribution ratio and offset of the active power and reactive power of the AC / DC converter can be arbitrarily controlled. 【0074】 Furthermore, the power systems in the embodiments and various modifications of the present invention are applicable to AC microgrids using various types of power sources. 【0075】Furthermore, within the control of the ADC converter, a control system including an integrator determines the current command value based on the voltage command value. This suppresses current changes in response to changes in phase and voltage amplitude command values, even in systems with low wiring impedance, enabling stable control. 【0076】 10 (10a to 10n) ADC converter, 12 (12a to 12n) Input / output controller, 14 (14a to 14n) Current controller, 16 Power reference value calculation unit, 16-2p Active power reference value calculation unit, 16-2q Reactive power reference value calculation unit, 18 Control controller, 100 Power system.
Claims
1. A power system comprising: an AC / DC converter having an AC / DC converter input / output controller; and an AC bus in which multiple devices having power supplies capable of input and output are connected in parallel, wherein the power system comprises: a first control unit that calculates the difference between the effective active power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted effective active power offset value for each of the AC / DC converters, and the difference between the effective reactive power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted reactive power offset value for each of the AC / DC converters; a second control unit that calculates a first target value which is the difference between the average effective active power value and the average effective power offset value obtained based on the calculation results of the first control unit, and a second target value which is the difference between the average reactive power value and the average reactive power offset value; and a third control unit that determines a voltage control target value from the difference between the first target value and the effective active power value of the AC / DC converter, and the difference between the second target value and the effective reactive power value of the AC / DC converter. The system includes a control controller that controls the active and reactive power of the AC / DC converters by commanding each of the AC / DC converters with the aforementioned voltage control target value.
2. A power system comprising: an AC / DC converter having an AC / DC converter input / output controller; and an AC bus in which multiple devices having power supplies capable of input and output are connected in parallel, the power system comprising: a first control unit that calculates the effective active power value and the effective reactive power value of each of the AC / DC converters calculated from the voltage and current; a second control unit that calculates a first target value obtained by weighting the average active power value obtained from the effective active power value by the number of AC / DC converters and an arbitrary active power distribution ratio; a second target value obtained by weighting the average reactive power value obtained from the effective reactive power value by the number of AC / DC converters and an arbitrary reactive power distribution ratio; and a third control unit that determines a voltage control target value from the difference between the first target value weighted by the active power distribution ratio and the effective active power value of each of the AC / DC converters, and the difference between the second target value weighted by the reactive power distribution ratio and the effective reactive power value of each of the AC / DC converters. The system includes a control controller that controls the active power and reactive power of each AC / DC converter by commanding the aforementioned voltage control target value to each AC / DC converter.
3. A power system comprising: an AC / DC converter having an AC / DC converter input / output controller; and an AC bus in which multiple devices having power supplies capable of input and output are connected in parallel, wherein the power system comprises: a first control unit that calculates the difference between the effective active power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted effective active power offset value for each of the AC / DC converters, and the difference between the effective reactive power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted reactive power offset value for each of the AC / DC converters; a first target value obtained by weighting the difference between the average active power value and the average active power offset value obtained based on the calculation results of the first control unit by the number of AC / DC converters and an arbitrary active power distribution ratio; and a second target value obtained by weighting the difference between the average reactive power value and the average reactive power offset value obtained based on the calculation results of the first control unit by the number of AC / DC converters and an arbitrary reactive power distribution ratio. The system includes a third control unit that determines a voltage control target value from the difference between the first target value weighted by the active power distribution ratio and the effective active power value of each of the AC / DC converters, and the difference between the second target value weighted by the reactive power distribution ratio and the effective reactive power value of each of the AC / DC converters, and a control controller that controls the active power and reactive power of each of the AC / DC converters by commanding the AC / DC converters with the voltage control target value.
4. A power system according to claim 3, comprising: a single centralized control controller on which the second control unit is implemented; and distributed control controllers equal to the number of AC / DC converters on which the first control unit and the third control unit are implemented, wherein the centralized control controller and the distributed control controllers are each connected to a communication line; each of the distributed control controllers transmits to the centralized control controller the difference between the effective value of the active power and the effective power offset value, and the difference between the effective value of the reactive power and the reactive power offset value; the centralized control controller transmits to each of the distributed control controllers a weighted value of the difference between the average value of the active power and the average value of the active power offset, and a weighted value of the difference between the average value of the reactive power and the average value of the reactive power offset; each of the AC / DC converter input / output controllers transmits to the centralized control controller voltage and current for each of the AC / DC converters; and the centralized control controller transmits to each of the AC / DC converter input / output controllers the voltage control target value or the current control target value obtained from the voltage control target value.
5. The power system according to claim 3, comprising a distributed control controller equal to the number of AC / DC converters on which the first control unit, the second control unit, and the third control unit are implemented, wherein the distributed control controllers are connected by communication lines, and each of the distributed control controllers transmits the effective active power value and the effective reactive power value for each of the AC / DC converters to the other distributed control controllers.
6. A power system according to claim 3, further comprising a fourth control unit which determines a current control target value using a controller which includes a voltage control target value determined by the third control unit and an integrator determined from the voltage for each of the AC / DC converters, and a control controller which controls the active power and reactive power for each of the AC / DC converters by commanding each of the AC / DC converters with respect to the current control target value.
7. A control device for a power system comprising: an AC / DC converter having an AC / DC converter input / output controller; and an AC bus in which multiple devices having power supplies capable of input and output are connected in parallel, the control device comprising: a first control unit that calculates the difference between the effective active power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted effective active power offset value for each of the AC / DC converters, and the difference between the effective reactive power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted reactive power offset value for each of the AC / DC converters; a second control unit that calculates a first target value which is the difference between the average effective active power value and the average effective power offset value obtained based on the calculation results of the first control unit, and a second target value which is the difference between the average reactive power value and the average reactive power offset value; and a third control unit that determines a voltage control target value from the difference between the first target value and the effective active power value of the AC / DC converter, and the difference between the second target value and the effective reactive power value of the AC / DC converter, The active power and reactive power of the AC / DC converters are controlled by commanding each of the AC / DC converters with the aforementioned voltage control target value.
8. A control device for a power system comprising: an AC / DC converter having an AC / DC converter input / output controller; and an AC bus in which multiple devices having power supplies capable of input / output are connected in parallel, the control device comprising: a first control unit that calculates the effective active power value and the effective reactive power value of each of the AC / DC converters calculated from the voltage and current; a second control unit that calculates a first target value obtained by weighting the average active power value obtained from the effective active power value by the number of AC / DC converters and an arbitrary active power distribution ratio; a second target value obtained by weighting the average reactive power value obtained from the effective reactive power value by the number of AC / DC converters and an arbitrary reactive power distribution ratio; and a third control unit that determines a voltage control target value from the difference between the first target value weighted by the active power distribution ratio and the effective active power value of each of the AC / DC converters, and the difference between the second target value weighted by the reactive power distribution ratio and the effective reactive power value of each of the AC / DC converters. The active power and reactive power are controlled for each of the AC / DC converters by commanding the aforementioned voltage control target value to each AC / DC converter.
9. A control device for a power system, comprising an AC / DC converter having an AC / DC converter input / output controller, and an AC bus in which multiple devices having power supplies capable of input / output are connected in parallel, wherein the control device comprises: a first control unit that calculates the difference between the effective active power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted effective active power offset value for each of the AC / DC converters, and the difference between the effective reactive power value calculated from the voltage and current for each of the AC / DC converters and an arbitrary weighted reactive power offset value for each of the AC / DC converters; a first target value obtained by weighting the difference between the average active power value and the average active power offset value obtained based on the calculation results of the first control unit by the number of AC / DC converters and an arbitrary active power distribution ratio; and a second target value obtained by weighting the difference between the average reactive power value and the average reactive power offset value obtained based on the calculation results of the first control unit by the number of AC / DC converters and an arbitrary reactive power distribution ratio. The system includes a third control unit that determines a voltage control target value from the difference between the first target value weighted by the active power distribution ratio and the effective active power value of each of the AC / DC converters, and the difference between the second target value weighted by the reactive power distribution ratio and the effective reactive power value of each of the AC / DC converters, and controls the active power and reactive power of each of the AC / DC converters by commanding the AC / DC converters with the voltage control target value.