CN116937597B - Low-voltage ride through control method for multiport energy router - Google Patents
Low-voltage ride through control method for multiport energy router Download PDFInfo
- Publication number
- CN116937597B CN116937597B CN202311179530.2A CN202311179530A CN116937597B CN 116937597 B CN116937597 B CN 116937597B CN 202311179530 A CN202311179530 A CN 202311179530A CN 116937597 B CN116937597 B CN 116937597B
- Authority
- CN
- China
- Prior art keywords
- voltage
- value
- current
- power grid
- controller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 37
- 230000002457 bidirectional effect Effects 0.000 claims abstract description 26
- 238000005070 sampling Methods 0.000 claims description 4
- 230000009466 transformation Effects 0.000 claims description 2
- 238000004870 electrical engineering Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 10
- 238000004146 energy storage Methods 0.000 description 8
- 238000004891 communication Methods 0.000 description 3
- 230000035515 penetration Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/388—Islanding, i.e. disconnection of local power supply from the network
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses a multi-port energy router low-voltage ride through control method, which belongs to the technical field of electrical engineering and comprises the steps of collecting power grid voltage and calculating power grid voltage drop depth M according to the power grid voltage; selecting a module cascade converter operation mode according to the power grid voltage drop depth M: when the power grid voltage drop depth M is not smaller than a threshold value, the operation mode of the module cascading converter is a control mode when the power grid voltage is normal; when the voltage drop depth M of the power grid is smaller than a threshold value, the operation mode of the module cascading converter is a control mode in low voltage ride through; when the operation mode of the module cascading converter is a control mode in low voltage ride through, the bidirectional DC/DC and the three-phase half-bridge inverter control the DC bus in sequence according to the voltage of the DC bus. The method is used for solving the problem that the bus voltage cannot be stably controlled when the existing method for controlling the bus voltage to be stable fails, and the method can ensure the stability of the intermediate bus voltage during low-voltage ride through.
Description
Technical Field
The invention belongs to the technical field of electrical engineering, and particularly relates to a low-voltage ride-through control method of a multiport energy router.
Background
When the ports of the energy routers with voltage class above 10kV are connected in a grid, the energy routers have low voltage ride through capability. However, when the multiport energy router performs low voltage ride through, the voltage of the direct current bus is shifted, and when the voltage shift exceeds the allowable range, the system cannot operate normally.
Patent application with publication number CN110323781A and named as low voltage ride through control method of modularized multi-level power electronic transformer, as shown in figure 1, the topology structure of the energy router system consists of a high voltage input stage, an intermediate isolation stage, a low voltage output stage and an energy storage DC/DC. The control scheme is as follows: when the power grid voltage drops, if the direct current bus voltage is higher than a reference value, the bidirectional DC/DC converter works in a Buck mode to charge the energy storage system, and energy flows from the direct current side to the energy storage system, so that the direct current bus voltage is reduced; otherwise, if the voltage of the direct current bus is lower than the reference value, the bidirectional DC/DC converter works in a Boost mode to discharge the energy storage system, and energy flows from the energy storage system to the direct current bus, so that the voltage of the direct current bus is increased.
In the prior art, the voltage of the direct current bus is stabilized by controlling the energy storage DC/DC, but when the voltage of the direct current bus is higher and the SOC of the battery is larger than the upper limit value, the energy storage system cannot charge, so that the voltage of the direct current bus is unstable; otherwise, when the voltage of the direct current bus is lower and the battery SOC is smaller than the lower limit value, the energy storage system cannot discharge, and the voltage of the direct current bus is unstable. Under the two conditions, the method for controlling the bus voltage stabilization in the prior art can fail, the bus voltage cannot be controlled stably, and the prior art needs to rely on communication among the port controllers, so that the complexity of a control system is increased, and the reliability of the system is reduced.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a multi-port energy router low-voltage ride-through control method, which is used for solving the problem that the bus voltage cannot be stably controlled when the existing bus voltage stabilizing control method in the background art fails.
In order to achieve the above purpose, the present invention provides the following technical solutions:
a multi-port energy router low voltage ride through control method comprises the following steps:
collecting power grid voltage, and calculating power grid voltage drop depth M according to the power grid voltage;
selecting a module cascade converter operation mode according to the power grid voltage drop depth M: when the power grid voltage drop depth M is not smaller than a threshold value, the operation mode of the module cascading converter is a control mode when the power grid voltage is normal; when the voltage drop depth M of the power grid is smaller than a threshold value, the operation mode of the module cascading converter is a control mode in low voltage ride through;
when the operation mode of the module cascading converter is a control mode in low voltage ride through, the bidirectional DC/DC and the three-phase half-bridge inverter control the DC bus in sequence according to the voltage of the DC bus.
Preferably, when the operation mode of the module cascading converter is a control mode in low voltage ride through, the bidirectional DC/DC controls the voltage of the direct current bus; when the SOC of the bidirectional DC/DC link battery exceeds the SOC limit, the three-phase half-bridge inverter controls the voltage of the DC bus.
Preferably, the threshold is 0.85.
Preferably, the bidirectional DC/DC is controlled by a second-order direct-current voltage deviation, and specifically includes: set point udref+du of up-deviation PI controller 1 The difference value obtained by making a difference with the DC bus voltage feedback value udc_ fdb is used for obtaining the integral lower limit value of the lower deviation PI controller through the upper deviation PI controller; the integral upper limit value of the upper deviation PI controller is a DC/DC discharge current given value idc_dis;
set point udc_ref-dU of lower deviation PI controller 1 The difference value obtained by differencing the feedback value udc_ fdb of the voltage of the direct current bus is obtained by a lower deviation PI controllerThe stream setpoint idc_ref;
let the current set point idc_ref and (F) SOC +F idc ) Multiplying the absolute value of/2 and then obtaining a difference value by the difference between the absolute value and the DC/DC current feedback value idc_ fdb, wherein F SOC Is the zone bit of the battery SOC value, F idc A flag bit for DC/DC discharge current;
the difference value is obtained by a current PI controller, and the control quantity is subjected to voltage control of a direct current bus by a PWM signal of a switching tube obtained by a PWM generation link.
Preferably, the three-phase half-bridge inverter adopts second-order direct-current voltage deviation control, and specifically includes: set point udref+du of up-deviation PI controller 2 The difference value obtained by making a difference with the DC bus voltage feedback value udc_ fdb is used for obtaining the integral lower limit value of the lower deviation PI controller through the upper deviation PI controller; the integral upper limit value of the upper deviation PI controller is a discharge current given value id_dis_L of the three-phase half-bridge inverter;
set point udc_ref-dU of lower deviation PI controller 2 The difference value obtained by making a difference with the feedback value udc_ fdb of the direct-current bus voltage is obtained by an up-down deviation PI controller; the d-axis current given value id_ref_L is different from the d-axis current feedback value id_ fdb _L of the three-phase half-bridge inverter, and the d-axis control quantity is obtained through a current PI controller;
the q-axis current given value iq_ref_L is differenced with the q-axis current feedback value iq_ fdb _L of the three-phase half-bridge inverter, and then the q-axis control quantity is obtained through a current PI controller;
the d-axis control quantity and the q-axis control quantity are subjected to dq/abc coordinate transformation, and then a PWM generation link is used for obtaining PWM signals for controlling the switching tube to control the voltage of the direct current bus.
Further, the voltage deviation value range formula of the upper deviation PI controller and the lower deviation PI controller is:
wherein DeltaU sam Absolute value of voltage sampling error; dU (dU) 1 Is the voltage deviation value I; dU (dU) 2 Is the voltage deviation value two.
Preferably, the calculation formula of the grid voltage drop depth M is as follows:
wherein u is d+ Is the positive sequence d-axis component of the power grid voltage, u q+ Is the positive sequence q-axis component of the grid voltage, U N Is the rated value of the voltage amplitude of the power grid.
Preferably, when the operation mode of the module cascading converter is a control mode in low voltage ride through, d-axis current in low voltage ride through is differenced with d-axis current feedback value id_ fdb _M, and d-axis control quantity is obtained through a d-axis current loop PI controller;
the q-axis current and the q-axis current feedback value iq_ fdb _M are differenced during low voltage ride through, and then q-axis control quantity is obtained through a q-axis current loop PI controller;
the d-axis control quantity and the q-axis control quantity are transformed through dq/abc coordinates, PWM signals for controlling the switching tube are obtained through PWM generation links, and the control module cascades the converter to output reactive power to the power grid voltage.
Further, the d-axis current formula at the time of low voltage ride through is:
wherein i is d0 The d-axis current before low voltage ride through, M is the voltage drop depth of the power grid,for the q-axis current,as a sign function.
Further, the q-axis current at the time of low voltage ride through is expressed as:
in the method, in the process of the invention,is q-axis current.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention provides a low-voltage ride through control method of a multiport energy router, which is characterized in that the power grid voltage drop depth is calculated by collecting power grid voltage information, so that the direct-current bus voltage is controlled through a bidirectional DC/DC and a three-phase half-bridge inverter during low-voltage ride through, and the stability of the direct-current bus voltage of the multiport energy router during low-voltage ride through can be ensured; the controller of the bidirectional DC/DC and three-phase half-bridge inverter adopts a second-order direct-current voltage deviation control method, the control right of the direct-current bus voltage can be switched between the bidirectional DC/DC and the three-phase half-bridge inverter, complex logic of a central controller is not needed, the workload of communication is reduced, the control scheme of the invention is easy to realize and high in reliability, and the stable operation of the system is maintained to the maximum extent on the premise of not increasing the complexity of control.
Drawings
FIG. 1 is a diagram of a prior art system topology;
FIG. 2 is a diagram of a topology of a multiport energy router system;
FIG. 3 is a flow chart of a method for controlling low voltage ride through of a multiport energy router according to the present invention;
fig. 4 is a control block diagram of a modular cascaded converter;
FIG. 5 is a control block diagram of bi-directional DC/DC;
fig. 6 is a control block diagram of a three-phase half-bridge inverter.
Detailed Description
The invention will now be described in further detail with reference to specific examples, which are intended to illustrate, but not to limit, the invention.
As shown in fig. 2, the multi-port energy router system topology comprises three ports, wherein a module cascading converter is connected with an alternating current 10kV power grid and a direct current bus, and adopts a topology structure that a dual active bridge converter (DAB) +cascading H bridge (CHB) is connected with a high-voltage side in series and a low-voltage side in parallel; the three-phase half-bridge inverter is connected with an alternating-current 0.4kV power grid and a direct-current bus, the bidirectional DC/DC is connected with a battery and the direct-current bus, and the bidirectional DC/DC adopts a bidirectional Buck topology.
When the power grid is normal, the direct current bus voltage is stabilized by the 10kV module cascading converter on the right side in fig. 2, and when the power grid voltage drops, the control target of the 10kV module cascading converter is changed into a supporting power grid voltage, the direct current voltage cannot be stabilized, and the control right is transferred to the other two ports, namely the bidirectional DC/DC and the three-phase half-bridge inverter.
As shown in fig. 3, the low voltage ride through control method of the multiport energy router of the present invention, includes the following processes,
and collecting the power grid voltage, and calculating the power grid voltage drop depth M according to the power grid voltage.
Selecting a module cascading converter operation mode according to the power grid voltage drop depth M; when the voltage drop depth M of the power grid is more than or equal to 0.85, the operation mode of the module cascading converter is a control mode when the voltage of the power grid is normal; when the voltage drop depth M of the power grid is less than 0.85, the operation mode of the module cascading converter is a control mode when the voltage passes through.
When the operation mode of the module cascading converter is a control mode in low voltage ride through, the bidirectional DC/DC and the three-phase half-bridge inverter adopt second-order direct-current voltage deviation control, and the control right of the direct-current bus is selected according to the voltage of the direct-current bus, so that the low voltage ride through control of the multiport energy router is completed.
Specifically, the module cascading converter determines an operation mode according to the grid voltage drop depth M, in fig. 3, the grid voltage is collected, and a positive sequence d-axis component u of the grid voltage is calculated d+ And a positive sequence q-axis component u q+ And calculating the grid voltage drop depth M according to the grid voltage.
The calculation of M is shown in equation (1),
（1）
wherein u is d+ For mains voltagePositive order d-axis component of (u) q+ Is the positive sequence q-axis component of the grid voltage, U N Is the rated value of the voltage amplitude of the power grid.
The operation mode of the module cascading converter comprises an operation mode 0 and an operation mode 1, wherein the operation mode 0 corresponds to a control mode when the power grid voltage is normal, and the operation mode 1 corresponds to a control mode when the power grid voltage passes through. Determining an operation mode of the module cascading converter according to the power grid voltage drop depth M, wherein when M is more than or equal to 0.85, the operation mode is 0; when M <0.85, the operation mode is 1.0.85 is determined according to national standard GBT40097 section 7.3.3.2.
When the power grid voltage is normal, the module cascading converter stabilizes the direct current bus voltage, d-axis current is determined by the output of a direct current voltage outer ring, and the given value of q-axis current is generally 0. The q-axis current and the d-axis current are formed by decomposing alternating current of a 10kV power grid according to coordinates by a module cascading converter.
During low voltage ride through, the module cascading converter needs to output reactive power to support power grid voltage, the power grid current is proportional to the power grid voltage drop depth M, and a given value of q-axis current in the power grid current is shown in a formula (2). In order to reduce the change of the active power, the given value of the d-axis current is reduced by M times as much as the d-axis current value before low penetration, and the d-axis current before low penetration is shown as a formula (3), wherein P 0 、i d0 、u d0 The active power before low pass, the d-axis current and the positive sequence d-axis component of the grid voltage are respectively.
In order to prevent the overcurrent of the current transformer, the given value of the d-axis current needs to be limited, and the given value of the d-axis current is finally obtained as shown in a formula (4).
（2）
（3）
（4）
Wherein i is d0 The d-axis current before low voltage ride through, M is the voltage drop depth of the power grid,for the q-axis current,is a sign function; />Is q-axis current; />Is d-axis current; p (P) 0 Is low in active power before wearing, u d0 Is a low pre-grid voltage positive sequence d-axis component.
As shown in fig. 4, the control block diagram of the modular cascaded converter is as follows: udc_ref represents a direct current bus voltage given value, udc_ fdb represents a direct current bus voltage feedback value, a d-axis current given value in an operation mode 0 is obtained through a voltage ring PI controller after the two values are differenced, a d-axis current given value in the operation mode 1 is obtained through a formula (4), and d-axis control quantity is obtained through a d-axis current ring PI controller after the two values are differenced with a d-axis current feedback value id_ fdb _M; the q-axis current given value is obtained by the formula (2), and the q-axis control quantity is obtained through the q-axis current loop PI controller after the q-axis current given value is differenced with the q-axis current feedback value iq_ fdb _M. The d-axis control quantity and the q-axis control quantity are transformed through dq/abc coordinates, and PWM signals for controlling the switching tube are obtained through PWM generation links.
The bidirectional DC/DC adopts a second-order direct-current voltage deviation control method, the charge and discharge current value of the battery is determined by the voltage value of a direct-current bus, meanwhile, the current is limited by considering the SOC condition of the battery, and F is defined SOC Definition F as shown in equation (5) idc As shown in equation (6). A control block diagram of the bi-directional DC/DC is shown in fig. 5. Wherein dU is 1 Is the voltage deviation value one.
（5）
（6）
Wherein F is SOC Is the zone bit of the battery SOC value, F idc A flag bit for DC/DC discharge current; SOC is the state of charge of the battery;is the upper limit value of the charge state of the battery; />Is the lower limit value of the charge state of the battery; />Is a current given value; />As a sign function.
As shown in fig. 5, the control block diagram of the bidirectional DC/DC is as follows: dU (dU) 1 For a voltage deviation value of one, udref+du 1 The given value of the upper deviation PI controller is obtained through the upper deviation PI controller after the given value of the upper deviation PI controller is differenced with the feedback value udc_ fdb of the DC bus voltage, wherein the given value idc_dis of the DC/DC discharge current is the integral lower limit value of the upper deviation PI controller; udc_ref-dU 1 For the given value of the lower deviation PI controller, the current given value idc_ref is obtained by the lower deviation PI controller after the difference is made with the feedback value udc_ fdb of the DC bus voltage, and the current given value idc_ref is equal to (F) SOC +F idc ) And multiplying the absolute value of/2, then, carrying out difference with a DC/DC current feedback value idc_ fdb to obtain a difference value, obtaining a control quantity by a current PI controller, and finally obtaining a PWM signal of the switching tube by a PWM generating link.
The three-phase half-bridge inverter adopts a second-order direct-current voltage deviation control method, and a control block diagram is shown in fig. 6. Wherein dU is 2 Is the voltage deviation value two.
When low voltage passes through, the module cascading converter is switched to an operation mode 1, the voltage of the direct current bus is out of control, the voltage rises or falls, and the bidirectional DC/DC automatically takes over the direct current bus under the action of the controllerAnd (3) controlling voltage, wherein when the battery SOC exceeds the SOC limit value and the bidirectional DC/DC cannot stabilize the direct-current voltage, the three-phase half-bridge inverter can autonomously take over the control of the direct-current bus voltage. In order to achieve the control objective, the voltage deviation values of the upper and lower deviation PI controllers should satisfy the requirement of formula (7), wherein Δu sam Is the absolute value of the voltage sampling error.
（7）
Wherein DeltaU sam Absolute value of voltage sampling error; dU (dU) 1 Is the voltage deviation value I; dU (dU) 2 Is the voltage deviation value two.
As shown in fig. 6, the control block diagram of the three-phase half-bridge inverter is as follows: dU (dU) 2 For voltage deviation value two, udc_ref+du 2 The method comprises the steps that a given value of an upper deviation PI controller is obtained, and an integral lower limit value of the lower deviation PI controller is obtained through the upper deviation PI controller after the given value is differenced with a feedback value udc_ fdb of a direct current bus voltage, wherein a given value id_dis_L of a discharge current of a three-phase half-bridge inverter is an integral upper limit value of the upper deviation PI controller; udc_ref-dU 2 The d-axis current given value id_ref_L is obtained through the lower deviation PI controller after the given value is differenced with the DC bus voltage feedback value udc_ fdb, the d-axis current given value id_ fdb _L is differenced with the d-axis current feedback value of the three-phase half-bridge inverter, and the d-axis control quantity is obtained through the current PI controller; the q-axis current given value iq_ref_l is differenced from the q-axis current feedback value iq_ fdb _l of the three-phase half-bridge inverter, and then the q-axis control quantity is obtained through a current PI controller. The d-axis control quantity and the q-axis control quantity are transformed through dq/abc coordinates, and PWM signals for controlling the switching tube are obtained through PWM generation links.
The control method provided by the invention can ensure the stability of the DC bus voltage of the multiport energy router during low voltage ride-through, the controllers of the bidirectional DC/DC and three-phase half-bridge inverter adopt a second-order DC voltage deviation control method, the control right of the DC bus voltage can be automatically switched among the controllers, complex central controller logic is not needed, the communication workload is reduced, the control scheme is easy to realize and has strong reliability, and the stable operation of the system is maintained to the maximum extent on the premise of not increasing the control complexity.
The control method for the low pass time of the module cascade converter can ensure reactive power support to a power grid, simultaneously reduce active change as much as possible and ensure that the converter is not excessively excessive. According to the invention, the bidirectional DC/DC is controlled by adopting second-order direct-current voltage deviation, so that the control of the direct-current bus voltage can be automatically taken over in low-pass time, and the current is limited according to the state of the battery SOC, so that the battery SOC is ensured to be within the limit value. The three-phase half-bridge inverter adopts second-order direct-current voltage deviation control, and independently takes over the control of the direct-current bus voltage when the bidirectional DC/DC cannot control the direct-current bus voltage.
Claims (8)
1. A method for controlling low voltage ride through of a multiport energy router, comprising:
collecting power grid voltage, and calculating power grid voltage drop depth M according to the power grid voltage;
selecting a module cascade converter operation mode according to the power grid voltage drop depth M: when the power grid voltage drop depth M is not smaller than a threshold value, the operation mode of the module cascading converter is a control mode when the power grid voltage is normal; when the voltage drop depth M of the power grid is smaller than a threshold value, the operation mode of the module cascading converter is a control mode in low voltage ride through;
when the operation mode of the module cascading converter is a control mode in low voltage ride through, the bidirectional DC/DC controls the voltage of the direct current bus; when the SOC of the bidirectional DC/DC connection battery exceeds the SOC limit value, the three-phase half-bridge inverter controls the voltage of the direct current bus by adopting a second-order direct current voltage deviation control method;
the module cascading converter is connected with an alternating current 10kV power grid and a direct current bus, the three-phase half-bridge inverter is connected with an alternating current 0.4kV power grid and the direct current bus, and the bidirectional DC/DC is connected with a battery and the direct current bus;
the bidirectional DC/DC adopts second-order direct-current voltage deviation control, and specifically comprises the following steps: set point udref+du of up-deviation PI controller 1 The difference value obtained by differencing the feedback value udc_ fdb of the DC bus voltage obtains the lower deviation through an upper deviation PI controllerAn integral lower limit value of the PI controller; the integral upper limit value of the upper deviation PI controller is a DC/DC discharge current given value idc_dis;
set point udc_ref-dU of lower deviation PI controller 1 The difference value obtained by making a difference with the feedback value udc_ fdb of the voltage of the direct current bus is used for obtaining a current given value idc_ref through a lower deviation PI controller;
let the current set point idc_ref and (F) SOC +F idc ) Multiplying the absolute value of/2 and then obtaining a difference value by the difference between the absolute value and the DC/DC current feedback value idc_ fdb, wherein F SOC Is the zone bit of the battery SOC value, F idc A flag bit for DC/DC discharge current;
the difference value is obtained by a current PI controller, and the control quantity is subjected to voltage control of a direct current bus by a PWM signal of a switching tube obtained by a PWM generation link.
2. The method of claim 1, wherein the threshold is 0.85.
3. The method for controlling low voltage ride through of a multiport energy router according to claim 1, wherein the three-phase half-bridge inverter is controlled by a second-order dc voltage deviation, and the method specifically comprises: set point udref+du of up-deviation PI controller 2 The difference value obtained by making a difference with the DC bus voltage feedback value udc_ fdb is used for obtaining the integral lower limit value of the lower deviation PI controller through the upper deviation PI controller; the integral upper limit value of the upper deviation PI controller is a discharge current given value id_dis_L of the three-phase half-bridge inverter;
set point udc_ref-dU of lower deviation PI controller 2 The difference value obtained by making a difference with the feedback value udc_ fdb of the direct-current bus voltage is obtained by a lower deviation PI controller to obtain a d-axis current given value id_ref_L; the d-axis current given value id_ref_L is different from the d-axis current feedback value id_ fdb _L of the three-phase half-bridge inverter, and the d-axis control quantity is obtained through a current PI controller;
the q-axis current given value iq_ref_L is differenced with the q-axis current feedback value iq_ fdb _L of the three-phase half-bridge inverter, and then the q-axis control quantity is obtained through a current PI controller;
the d-axis control quantity and the q-axis control quantity are subjected to dq/abc coordinate transformation, and then a PWM generation link is used for obtaining PWM signals for controlling the switching tube to control the voltage of the direct current bus.
4. The method of claim 1, wherein the voltage deviation value range formula of the upper deviation PI controller and the lower deviation PI controller is as follows:
wherein DeltaU sam Absolute value of voltage sampling error; dU (dU) 1 Is the voltage deviation value I; dU (dU) 2 Is the voltage deviation value two.
5. The method for controlling low voltage ride through of a multiport energy router according to claim 1, wherein the calculation formula of the power grid voltage sag depth M is:
wherein u is d+ Is the positive sequence d-axis component of the power grid voltage, u q+ Is the positive sequence q-axis component of the grid voltage, U N Is the rated value of the voltage amplitude of the power grid.
6. The method for controlling low voltage ride through of a multiport energy router according to claim 1, wherein when the operation mode of the modular cascaded converter is a control mode in low voltage ride through, d-axis current in low voltage ride through is differenced from d-axis current feedback value id_ fdb _m, and d-axis control quantity is obtained by a d-axis current loop PI controller;
the q-axis current and the q-axis current feedback value iq_ fdb _M are differenced during low voltage ride through, and then q-axis control quantity is obtained through a q-axis current loop PI controller;
the d-axis control quantity and the q-axis control quantity are transformed through dq/abc coordinates, PWM signals for controlling the switching tube are obtained through PWM generation links, and the control module cascades the converter to output reactive power to the power grid voltage.
7. The method for controlling low voltage ride through of a multiport energy router according to claim 6, wherein the d-axis current formula at the time of low voltage ride through is:
wherein i is d0 The d-axis current before low voltage ride through, M is the voltage drop depth of the power grid,for q-axis current, ">As a sign function.
8. The method of claim 6, wherein the q-axis current at the time of low voltage ride through is expressed as:
in the method, in the process of the invention,is q-axis current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311179530.2A CN116937597B (en) | 2023-09-13 | 2023-09-13 | Low-voltage ride through control method for multiport energy router |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311179530.2A CN116937597B (en) | 2023-09-13 | 2023-09-13 | Low-voltage ride through control method for multiport energy router |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116937597A CN116937597A (en) | 2023-10-24 |
| CN116937597B true CN116937597B (en) | 2023-12-19 |
Family
ID=88382853
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311179530.2A Active CN116937597B (en) | 2023-09-13 | 2023-09-13 | Low-voltage ride through control method for multiport energy router |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116937597B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104821595A (en) * | 2015-04-30 | 2015-08-05 | 许继集团有限公司 | DC voltage hybrid control strategy for multi-terminal flexible DC power transmission system |
| CN105610336A (en) * | 2016-01-27 | 2016-05-25 | 东南大学 | Dual-capacitor module based MMC type multi-port power electronic transformer |
| CN108767843A (en) * | 2018-07-02 | 2018-11-06 | 上海大周能源技术有限公司 | Multiport energy router |
| CN110323781A (en) * | 2019-07-03 | 2019-10-11 | 国网江苏省电力有限公司电力科学研究院 | A kind of low voltage traversing control method of modular multilevel electric power electric transformer |
| CN110690731A (en) * | 2019-08-20 | 2020-01-14 | 东南大学 | Power electronic transformer applicable to hybrid micro-grid and coordination control and mode switching method thereof |
| CN112448414A (en) * | 2020-11-17 | 2021-03-05 | 清华大学 | Four-port electric energy router and low voltage ride through control method thereof |
| CN113258562A (en) * | 2021-04-21 | 2021-08-13 | 湖南大学 | Energy router operation control method and system |
| WO2022262191A1 (en) * | 2021-06-16 | 2022-12-22 | 南方电网科学研究院有限责任公司 | Dc fault clearing control method and device for hybrid mmc, and storage medium |
-
2023
- 2023-09-13 CN CN202311179530.2A patent/CN116937597B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104821595A (en) * | 2015-04-30 | 2015-08-05 | 许继集团有限公司 | DC voltage hybrid control strategy for multi-terminal flexible DC power transmission system |
| CN105610336A (en) * | 2016-01-27 | 2016-05-25 | 东南大学 | Dual-capacitor module based MMC type multi-port power electronic transformer |
| CN108767843A (en) * | 2018-07-02 | 2018-11-06 | 上海大周能源技术有限公司 | Multiport energy router |
| CN110323781A (en) * | 2019-07-03 | 2019-10-11 | 国网江苏省电力有限公司电力科学研究院 | A kind of low voltage traversing control method of modular multilevel electric power electric transformer |
| CN110690731A (en) * | 2019-08-20 | 2020-01-14 | 东南大学 | Power electronic transformer applicable to hybrid micro-grid and coordination control and mode switching method thereof |
| CN112448414A (en) * | 2020-11-17 | 2021-03-05 | 清华大学 | Four-port electric energy router and low voltage ride through control method thereof |
| CN113258562A (en) * | 2021-04-21 | 2021-08-13 | 湖南大学 | Energy router operation control method and system |
| WO2022262191A1 (en) * | 2021-06-16 | 2022-12-22 | 南方电网科学研究院有限责任公司 | Dc fault clearing control method and device for hybrid mmc, and storage medium |
Non-Patent Citations (3)
| Title |
|---|
| Low-voltage ride through of multi-port power electronic transformer;Wusong Wen et al.;《iEnergy》;第1卷(第2期);第243-256页 * |
| VSC-HVDC受端换流器参与电网调频的VSG控制及其改进算法;姚为正等;《中国电机工程学报》;第37卷(第2期);第525-533、S19页 * |
| 四端口电力电子变压器高压交流端口的低电压穿越功能;聂浩哲等;《清华大学学报》;第61卷(第10期);第1097-1105页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116937597A (en) | 2023-10-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11431263B2 (en) | Solid-state transformer having uninterrupted operation ability under AC/DC fault and control method thereof | |
| CN109842142B (en) | Hybrid three-terminal high-voltage direct-current power transmission system and direct-current fault rapid current limiting method thereof | |
| CN106849148B (en) | Alternating current fault ride-through control method for rectifying station of hybrid direct current transmission system | |
| CN107681877B (en) | A kind of mixed type MMC starting method of the submodule containing full-bridge | |
| CN113964836B (en) | Direct-current flexible loop closing control device for power grid and control method thereof | |
| CN103997033B (en) | A kind of HVDC transmission system possessing DC Line Fault ride-through capability | |
| CN110912208B (en) | Flexible direct current transmission converter control method based on improved droop controller | |
| CN112165127A (en) | Energy control method of multi-port alternating current-direct current hybrid micro-grid system | |
| CN115224717A (en) | Sending-end alternating current fault ride-through method of new energy island power grid sending-out system | |
| CN107465192A (en) | Mix the variable power control and DC voltage control method of microgrid | |
| CN115693731A (en) | Energy storage system, grid-connected and off-grid switching method and energy storage converter | |
| CN114825414B (en) | High-voltage direct-current fault ride-through control method and system for energy router | |
| CN113991670A (en) | Alternating-current flexible loop closing control device for power grid and control method thereof | |
| CN112217193A (en) | Photovoltaic hydrogen production power station, direct-current coupling photovoltaic off-grid hydrogen production system and control method thereof | |
| CN116937597B (en) | Low-voltage ride through control method for multiport energy router | |
| CN116316852A (en) | Multi-photovoltaic power supply fault ride-through coordination method | |
| Chong et al. | A Power Conversion System For Large-Scale Reversible SOFC Energy Storage System | |
| CN112117784B (en) | Operation control method of virtual transformer | |
| CN115207980A (en) | Direct-current fault self-clearing method of new energy island power grid sending-out system | |
| CN112600239A (en) | Wind power grid-connected control method | |
| CN209731103U (en) | A kind of novel VIENNA rectifier control system | |
| CN221408445U (en) | Control system of wind power flexible direct current grid-connected system on double polar sea | |
| CN115296332B (en) | Method for reducing no-load loss of energy router by SRC boosting technology | |
| CN115377992B (en) | Power converter fault ride-through control method suitable for wide-range flexible hydrogen production | |
| CN113497552B (en) | Island starting method for converter of flexible direct current transmission system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |