A power quality compensation control method and apparatus based on D-STATCOM

Abstract

This invention relates to a power quality compensation control method and apparatus based on D-STATCOM, comprising: controlling the power quality at point PCC... a_pcc v b_pcc and v c_pcc Convert to v α and v β ; to the nonlinear load side i La i Lb and i Lc Convert to i α and i β According to v α and v β i α and i β Calculations are performed to obtain p and q; q is then filtered to obtain the AC component, and the DC voltage reference value V is obtained. cdc_ref DC side voltage value V in D-STATCOM cdc V cdc_ref and V cdc The input is processed by the PI controller to obtain the PI control output; based on p and the PI control output, the active power reference value p is obtained. ref and reactive power reference value q ref According to p ref q ref v α and v β Calculate the reference value i α_ref and i β_ref ;change i α_ref and i β_ref The quantity i of abc transforming from a two-phase orthogonal coordinate system to a three-phase coordinate system s_aref i s_bref and i s_cref ;change i s_aref i s_bref and i s_cref The three-phase measured current value i in D-STATCOM ac_dst_a i ac_dst_b and i ac_dst_c A PWM pulse signal is generated through comparison and then output to the D-STATCOM. This invention can meet the needs of large reactive power compensation in subway stations.

Description

Technical Field

[0001] This invention relates to the field of urban rail transit power supply system technology, specifically to a power quality compensation control method and device based on D-STATCOM. Background Technology

[0002] Urban rail transit power supply systems consist of multiple AC-DC hybrid subsystems. The extensive use of nonlinear power electronic devices, transformers, power factor correction capacitors, and capacitive loads in low-voltage power distribution systems generates harmonics and causes both insufficient and excessive reactive power. In addition to the conventional system harmonics and reactive power demand issues, the harmonic resonance problem between multiple subsystems and the AC power grid at certain characteristic frequencies is also becoming increasingly prominent in urban rail transit.

[0003] As the proportion of power electronic devices in urban power supply systems increases, the interaction and coupling effects between grid-connected converters and urban power supply systems become more complex. The presence of strong capacitive characteristic impedance in subway stations may also trigger the risk of harmonic amplification, which may lead to damage to key system equipment and cause subway shutdowns.

[0004] Traditional system compensation schemes eliminate system characteristic harmonics and compensate reactive power by installing active power filters (APFs) and static synchronous compensation (STATCOMs). Currently, although STATCOMs and APFs belong to different application areas, there is functional overlap; moreover, APF devices typically have smaller capacities, capable of only suppressing system harmonics but unable to meet the large reactive power compensation needs of subway stations. Summary of the Invention

[0005] The purpose of this invention is to propose a power quality compensation control method based on D-STATCOM, which adopts Distributed Static Synchronous Compensation (D-STATCOM). It can solve complex power quality problems by adjusting the equipment control strategy, thereby improving equipment utilization and meeting the needs of large reactive power compensation in subway stations.

[0006] To achieve the above objectives, embodiments of the present invention propose a power quality compensation control method based on D-STATCOM, comprising the following steps:

[0007] Obtain the three-phase measured voltage value v at point PCC a_pcc v b_pcc and v c_pcc and the va_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β ;

[0008] Obtain the three-phase measured current value i on the nonlinear load side. La i Lb and i Lc and the i La i Lb and i Lc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and i β ;

[0009] According to the v α and v β The i α and i β The instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated.

[0010] The instantaneous reactive power q is input into a high-pass filter for filtering to obtain the AC component of the instantaneous reactive power.

[0011] Obtain DC voltage reference value V cdc_ref and the DC side voltage value V in D-STATCOM cdc , will the V cdc_ref and V cdc The input is processed by the PI controller to obtain the PI control output.

[0012] According to the p, The active power reference value p is obtained from the PI control output. ref and reactive power reference value q ref ;

[0013] According to the active power reference value p ref Reactive power reference value q ref v α and v β Calculate the reference value i for αβ α_ref and i β_ref ;

[0014] i α_ref and i β_ref The quantity i of abc transforming from a two-phase orthogonal coordinate system to a three-phase coordinate system s_aref i s_bref and i s_cref ;

[0015] Obtain the three-phase measured current value i from D-STATCOM ac_dst_a i ac_dst_b and i ac_dst_c , will the i s_aref i s_bref and i s_cref and the i ac_dst_a i ac_dst_b and i ac_dst_c The comparison is performed, and a corresponding PWM pulse signal is generated based on the comparison result. The PWM pulse signal is then output to the D-STATCOM.

[0016] Preferably, the v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β ,include:

[0017] According to the transfer function T abc_αβ v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β As shown in the formula below:

[0018]

[0019] Preferably, the step of placing the i La i Lb and i Lc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and i β ,include:

[0020] According to the transfer function T abc_αβ i La i Lb and i Lc The αβ quantity i transforms from a three-phase coordinate system to a two-phase orthogonal coordinate system α and i β As shown in the formula below:

[0021]

[0022] Preferably, the step according to the v α and v β The i α and i βThe instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated as follows:

[0023]

[0024] Preferably, the high-pass filter is as shown in the following formula:

[0025] Y(t) = L -1 [(K _hpf *[s / ω c ])*X(s) / (1+2*ξ*(s / ω c )+(s / ω c ) 2 )]

[0026] Where Y(t) is the filter output, X(s) is the filter input, and K... _hpf It is the HPF gain; ω c It is the characteristic frequency; ξ is the set damping ratio; s represents the Laplace operator; L -1 It is the inverse Laplace transform.

[0027] Preferably, the step of basing the active power reference value p ref Reactive power reference value q ref v α and v β Calculate the reference value i for αβ α_ref and i β_ref As shown in the formula below:

[0028]

[0029] Embodiments of the present invention also propose a power quality compensation control device based on D-STATCOM, used to implement the above-mentioned power quality compensation control method based on D-STATCOM, comprising:

[0030] The voltage acquisition module is used to acquire the three-phase measured voltage value v at the PCC point. a_pcc v b_pcc and v c_pcc and the v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β ;

[0031] The current acquisition module is used to acquire the three-phase measured current value i on the nonlinear load side. La i Lb and i Lc and the i Lai Lb and i Lc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and i β ;

[0032] Instantaneous power calculation module, used to calculate power based on the v α and v β The i α and i β The instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated.

[0033] A high-pass filter module is used to input the instantaneous reactive power q into a high-pass filter for filtering to obtain the AC component of the instantaneous reactive power.

[0034] The PI control module is used to obtain the DC voltage reference value V. cdc_ref and the DC side voltage value V in D-STATCOM cdc , will the V cdc_ref and V cdc The input is processed by the PI controller to obtain the PI control output.

[0035] The power reference value calculation module is used to calculate the power reference value based on the p, The active power reference value p is obtained from the PI control output. ref and reactive power reference value q ref ;

[0036] The current reference value calculation module is used to calculate the active power reference value p. ref Reactive power reference value q ref v α and v β Calculate the reference value i for αβ α_ref and i β_ref ;

[0037] The current value conversion module is used to convert the i α_ref and i β_ref The quantity i of abc transforming from a two-phase orthogonal coordinate system to a three-phase coordinate system s_aref i s_bref and i s_cref ;

[0038] The PWM module is used to acquire the three-phase measured current value i from the D-STATCOM. ac_dst_a i ac_dst_b and i ac_dst_c , will the i s_aref i s_bref and i s_cref and the iac_dst_a i ac_dst_b and i ac_dst_c The comparison is performed, and a corresponding PWM pulse signal is generated based on the comparison result. The PWM pulse signal is then output to the D-STATCOM.

[0039] Compared with the prior art, the embodiments of the present invention have at least the following advantages:

[0040] This invention proposes a power quality compensation control strategy based on D-STATCOM suitable for subway stations. This strategy, based on instantaneous power, can effectively reduce the harmonic current content of the D-STATCOM grid-connected AC bus, achieve dynamic reactive power compensation, and improve the system power factor. Furthermore, considering the potential harmonic amplification problem caused by the strong capacitive characteristics of harmonic impedance, the D-STATCOM-based power quality compensation control strategy can effectively improve the system's harmonic impedance.

[0041] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of a power quality compensation control method based on D-STATCOM in an embodiment of the present invention.

[0044] Figure 2 This is a schematic diagram of a power quality compensation control method based on D-STATCOM in an embodiment of the present invention.

[0045] Figure 3 This is a schematic diagram of the connection between the subway traction power supply system and D-STATCOM in an embodiment of the present invention.

[0046] Figure 4 This is a schematic diagram of the device-level control principle for reactive power compensation and harmonic suppression based on D-STATCOM in an embodiment of the present invention.

[0047] Figure 5 This is a structural diagram of a power quality compensation control device based on D-STATCOM in an embodiment of the present invention. Detailed Implementation

[0048] The various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. Furthermore, numerous specific details are set forth in the following detailed embodiments to better illustrate the invention. Those skilled in the art will understand that the invention can be practiced without certain specific details. In some instances, means well known to those skilled in the art have not been described in detail in order to highlight the spirit of the invention.

[0049] An embodiment of the present invention proposes a power quality compensation control method based on D-STATCOM. Figure 1 This is a flowchart of the method in this embodiment. Figure 2 This is a schematic diagram of the method in this embodiment. Figure 3 This is a connection diagram of the D-STATCOM subway traction power supply system in the method of this embodiment. Specifically, in Figure 2 In the middle, L s and R s It refers to the inductance and resistance of the AC cable. L c and R c Representing the equivalent inductance and resistance on the AC side of the STATCOM, nonlinear loads include traction power supply system loads and low-voltage distribution system loads, such as single-phase and three-phase rectified loads and 24-pulse rectified locomotive sets. The operating resistance R of the three-phase conversion load. dc_n Capacitor C dc_n Representing electrical equipment and PFC power rectifiers, A / D is a digital-to-analog converter that measures AC voltage and current and converts them into digital signals for transmission to the controller.

[0050] PWM is a generated pulse signal used to control the switching on and off of the transistors in the D-STATCOM. ac_dst This is the three-phase AC current value measured at the PCC point; i ac_st This is the three-phase AC current value measured at the D-STATCOM port; I dc_st This refers to the DC-side current value of the D-STATCOM device; inL_3pl, inL_1pl, inL_tpss, and Idc_tpss represent the AC current values ​​of the three-phase load, the AC current value of the single-phase load, the AC current value of the traction power supply load, and the DC-side current value of the traction power supply load, respectively. (In the symbols, L stands for Load, 3pl for three-phase load, 1pl for single-phase load, tpss for traction power supply system, and dc for DC).

[0051] The method in this embodiment mainly involves measuring the nonlinear load-side hybrid current i. La i Lb and i Lc and PCC voltage va_pcc v b_pcc and v c_pcc To determine the harmonic current suppression benchmark and reactive power compensation benchmark, a PWM pulse signal is output to the D-STATCOM, which then performs the corresponding compensation.

[0052] See Figure 1-3 As can be seen, the method in this embodiment includes the following steps:

[0053] Step S1: Obtain the three-phase measured voltage value v at point PCC. a_pcc v b_pcc and v c_pcc and the v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β ;

[0054] Specifically, step S1 includes:

[0055] According to the transfer function T abc _ α β will the v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β As shown in formula (1) below:

[0056]

[0057] Step S2: Obtain the three-phase measured current value i on the nonlinear load side. La i Lb and i Lc and the i La i Lb and i Lc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and i β ;

[0058] Specifically, step S2 includes:

[0059] According to the transfer function T abc_αβ i La i Lb and i Lc The αβ quantity i transforms from a three-phase coordinate system to a two-phase orthogonal coordinate system α and i β As shown in formula (2) below:

[0060]

[0061] Step S3, according to the v α and v β The i α and i β The instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated.

[0062] Specifically, according to the v α and v β The i α and i β The instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated as follows:

[0063]

[0064] Step S4: Input the instantaneous reactive power q into a high-pass filter for filtering to obtain the AC component of the instantaneous reactive power.

[0065] Specifically, the high-pass filter is defined by the following formula:

[0066] Y(t) = L -1 [(K _hpf *[s / ω c ])*X(s) / (1+2*ξ*(s / ω c )+(s / ω c ) 2 (4)

[0067] Where Y(t) is the filter output, X(s) is the filter input, and K... _hpf It is the HPF gain; ω c It is the characteristic frequency; ξ is the set damping ratio; s represents the Laplace operator; L -1 It is the inverse Laplace transform;

[0068] Specifically, both the instantaneous real power p and the instantaneous imaginary power q of a nonlinear load have a DC component. and high-frequency communication components Right now Among them, the DC component It is the reactive power reference that is needed, and the AC component. p This is the part that needs to be suppressed by the D-STATCOM. Therefore, in this embodiment, it is filtered by a high-pass filter. In this embodiment, the high-pass filter used for the parallel D-STATCOM is a second-order filter, as shown in the above formula (4).

[0069] Step S5: Obtain the DC voltage reference value V cdc_ref and the DC side voltage value V in D-STATCOM cdc , will the V cdc_ref and V cdc The input is processed by the PI controller to obtain the PI control output.

[0070] Specifically, Figure 2 Zhong K p T and s are predefined coefficients of the DC voltage regulation PI controller;

[0071] Step S6, according to p, The active power reference value p is obtained from the PI control output. ref and reactive power reference value q ref ;

[0072] Specifically, the PI controller's function is to regulate the DC-side voltage of the D-STATCOM to remain constant. ref =p, Control the output amount;

[0073] Step S7: Based on the active power reference value p ref Reactive power reference value q ref v α and v β Calculate the reference value i for αβ α_ref and i β_ref ;

[0074] Specifically, step S7 is as shown in the following formula (5):

[0075]

[0076] Step S8, place the i α_ref and i β_ref The quantity i of abc transforming from a two-phase orthogonal coordinate system to a three-phase coordinate system s_aref i s_bref and i s_cref ;

[0077] Specifically, the conversion principle is the same as formula (2) in step S2, only the conversion is reversed;

[0078] Step S9: Obtain the three-phase measured current value i in D-STATCOM ac_dst_a i ac_dst_b and i ac_dst_c , will the i s_aref i s_bref and i s_cref and the i ac_dst_a i ac_dst_b and iac_dst_c The comparison is performed, and a corresponding PWM pulse signal is generated based on the comparison result. The PWM pulse signal is then output to the D-STATCOM.

[0079] Specifically, the PWM pulse signal is used to control the switching on and off of the switching transistors in the D-STATCOM, so that the three-phase current value in the D-STATCOM is i. s_aref i s_bref and i s_cref .

[0080] Specifically, such as Figure 4 The diagram shown is a schematic of the device-level control principle for reactive power compensation and harmonic suppression based on D-STATCOM. Figure 4 In the middle, Z s It is the equivalent impedance of the power supply, Z c It is the equivalent impedance of the parallel D-STATCOM, Z l The equivalent impedance representing the nonlinear load, once the installed D-STATCOM device is activated, the controllable voltage source V... c When the system is in operation, the harmonics caused by the nonlinear load in the subway station are compensated and suppressed by D-STATCOM.

[0081] Specifically, an equivalent virtual resistance G _D-STATCOM It will be connected in series with the equivalent impedance of the power supply, as shown in equation (6) below.

[0082] I s_(b)＝ I l *Z l Z c / (Z l Z c +Z l (Z s +G _DSTATCOM )+Z s Z c (6)

[0083] Therefore, by adjusting G _D-STATCOM The set value can simultaneously achieve the system's impedance reconstruction function, ultimately avoiding resonance and harmonic amplification between multiple systems. The calculated PWM pulse signal is transmitted to the D-STATCOM controller to initiate the next stage of converter valve-level control, ultimately achieving the comprehensive requirements of reactive power regulation, characteristic harmonic suppression, and system capacitance impedance reconstruction; G _D-STATCOM The set value can be modified by adjusting the gain K of the filter in the D-STATCOM control loop. _hpf It's the HPF gain, or adding an additional gain stage. Because the actual value of the D-STATCOM three-phase current output is i... ac_st_a i ac_st_b iac_st_c Follow current signal reference value i s_aref i s_bref i s_cref Furthermore, by adjusting the gain, the reference value i of the three-phase current signal of D-STATCOM can be indirectly achieved. s_aref i s_bref i s_cref Through adjustment, impedance reconfiguration function is ultimately achieved.

[0084] See Figure 5 The embodiments of the present invention also propose a power quality compensation control device based on D-STATCOM, used to implement the power quality compensation control method based on D-STATCOM described in the above embodiments, including the following functional modules:

[0085] Voltage acquisition module 1 is used to acquire the three-phase measured voltage value v at the PCC point. a_pcc v b_pcc and v c_pcc and the v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β ;

[0086] Current acquisition module 2 is used to acquire the three-phase measured current value i on the nonlinear load side. La i Lb and i Lc and the i La i Lb and i Lc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and i β ;

[0087] Instantaneous power calculation module 3, used to calculate power based on the v α and v β The i α and i β The instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated.

[0088] High-pass filter module 4 is used to input the instantaneous reactive power q into the high-pass filter for filtering to obtain the AC component of the instantaneous reactive power.

[0089] PI control module 5 is used to obtain the DC voltage reference value V. cdc_ref and the DC side voltage value V in D-STATCOM cdc , will the Vcdc_ref and V cdc The input is processed by the PI controller to obtain the PI control output.

[0090] Power reference value calculation module 6 is used to calculate the power reference value based on the p, The active power reference value p is obtained from the PI control output. ref and reactive power reference value q ref ;

[0091] Current reference value calculation module 7 is used to calculate the active power reference value p based on the current reference value p. ref Reactive power reference value q ref v α and v β Calculate the reference value i for αβ α_ref and i β_ref ;

[0092] Current value conversion module 8 is used to convert the i α_ref and i β_ref The quantity i of abc transforming from a two-phase orthogonal coordinate system to a three-phase coordinate system s_aref i s_bref and i s_cref ;

[0093] PWM module 9 is used to acquire the three-phase measured current value i from the D-STATCOM. ac_dst_a i ac_dst_b and i ac_dst_c , will the i s_aref i s_bref and i s_cref and the i ac_dst_a i ac_dst_b and i ac_dst_c The comparison is performed, and a corresponding PWM pulse signal is generated based on the comparison result. The PWM pulse signal is then output to the D-STATCOM.

[0094] The apparatus in this embodiment corresponds to the method in the above embodiments. Therefore, any details not described in the apparatus of this embodiment can be obtained by referring to the method in the above embodiments, and will not be elaborated here.

[0095] As described in the above embodiments, the embodiments of the present invention propose a power quality compensation control strategy based on D-STATCOM suitable for subway stations. This control strategy, based on instantaneous power, can effectively reduce the harmonic current content of the D-STATCOM grid-connected AC bus, achieve dynamic reactive power compensation, and improve the system power factor. Furthermore, considering the potential harmonic amplification problem caused by the strong capacitive characteristics of harmonic impedance, the power quality compensation control strategy based on D-STATCOM can effectively improve the system harmonic impedance.

[0096] The embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles of the embodiments, their practical application, or their technological improvements in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A power quality compensation control method based on D-STATCOM, characterized in that, Includes the following steps: Obtain the three-phase measured voltage value v at point PCC a_pcc v b_pcc and v c_pcc and the v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β ; Obtain the three-phase measured current value i on the nonlinear load side. La i Lb and i Lc and the i La i Lb and i Lc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and i β ; According to the v α and v β The i α and i β The instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated. The instantaneous reactive power q is input into a high-pass filter for filtering to obtain the AC component of the instantaneous reactive power. Obtain DC voltage reference value V cdc_ref and the DC side voltage value V in D-STATCOM cdc , will the V cdc_ref and V cdc The input is processed by the PI controller to obtain the PI control output. According to the p, The active power reference value p is obtained from the PI control output. ref and reactive power reference value q ref ; According to the active power reference value p ref Reactive power reference value q ref v α and v β Calculate the reference value i for αβ α_ref and i β_ref ; i α_ref and i β_ref The quantity i of abc transforming from a two-phase orthogonal coordinate system to a three-phase coordinate system s_aref i s_bref and i s_cref ; Obtain the three-phase measured current value i from D-STATCOM ac_dst_a i ac_dst_b and i ac_dst_c , will the i s_aref i s_bref and i s_cref and the i ac_dst_a i ac_dst_b and i ac_dst_c The comparison is performed, and a corresponding PWM pulse signal is generated based on the comparison result. The PWM pulse signal is then output to the D-STATCOM.

2. The power quality compensation control method based on D-STATCOM as described in claim 1, characterized in that, The v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β ,include: According to the transfer function T abc_αβ v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β As shown in the formula below:

3. The power quality compensation control method based on D-STATCOM as described in claim 1, characterized in that, The i La i Lb and i Lc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and i β ,include: According to the transfer function T abc_αβ i La i Lb and i Lc The αβ quantity i transforms from a three-phase coordinate system to a two-phase orthogonal coordinate system α and i β As shown in the formula below:

4. The power quality compensation control method based on D-STATCOM as described in claim 1, characterized in that, According to the v α and v β The i α and i β The instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated as follows:

5. The power quality compensation control method based on D-STATCOM as described in claim 1, characterized in that, The high-pass filter is shown in the following formula: Y(t)=L -1 [(K _hpf *[s / ω c ])*X(s) / (1+2*ξ*(s / ω c )+(s / ω c ) 2 )] Where Y(t) is the filter output, X(s) is the filter input, and K... _hpf It is the HPF gain; ω c It is the characteristic frequency; ξ is the set damping ratio; s represents the Laplace operator; L -1 It is the inverse Laplace transform.

6. The power quality compensation control method based on D-STATCOM as described in claim 1, characterized in that, The active power reference value p ref Reactive power reference value q ref v α and v β Calculate the reference value i for αβ α_ref and i β_ref As shown in the formula below:

7. A power quality compensation control device based on D-STATCOM, characterized in that, The power quality compensation control method based on D-STATCOM according to any one of claims 1-6 includes: The voltage acquisition module is used to acquire the three-phase measured voltage value v at the PCC point. a_pcc v b_pcc and v c_pcc and the v a_pcc v b_pcc and v c_pcc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and v β ; The current acquisition module is used to acquire the three-phase measured current value i on the nonlinear load side. La i Lb and i Lc and the i La i Lb and i Lc The abc components of the three-phase coordinate system are transformed into the αβ components of the two-phase orthogonal coordinate system. α and i β ; Instantaneous power calculation module, used to calculate power based on the v α and v β The i α and i β The instantaneous active power p and instantaneous reactive power q on the nonlinear load side are calculated. A high-pass filter module is used to input the instantaneous reactive power q into a high-pass filter for filtering to obtain the AC component of the instantaneous reactive power. The PI control module is used to obtain the DC voltage reference value V. cdc_ref and the DC side voltage value V in D-STATCOM cdc , will the V cdc_ref and V cdc The input is processed by the PI controller to obtain the PI control output. The power reference value calculation module is used to calculate the power reference value based on the p, The active power reference value p is obtained from the PI control output. ref and reactive power reference value q ref ; The current reference value calculation module is used to calculate the active power reference value p. ref Reactive power reference value q ref v α and v β Calculate the reference value i for αβ α_ref and i β_ref ; The current value conversion module is used to convert the i α_ref and i β_ref The quantity i of abc transforming from a two-phase orthogonal coordinate system to a three-phase coordinate system s_aref i s_bref and i s_cref ; The PWM module is used to acquire the three-phase measured current value i from the D-STATCOM. ac_dst_a i ac_dst_b and i ac_dst_c , will the i s_aref i s_bref and i s_cref and the i ac_dst_a i ac_dst_b and i ac_dst_c The comparison is performed, and a corresponding PWM pulse signal is generated based on the comparison result. The PWM pulse signal is then output to the D-STATCOM.

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