Active power control method and system connected with DRU-HVDC networking converter

Abstract

The invention discloses an active power control method and an active power control system connected with a DRU-HVDC network construction converter, which are applied to a new energy station comprising n converters, and each converter is connected to a DRU sending end converter station through a collection line after passing through a transformer at a respective outlet; the specific implementation of the method comprises the following steps: collecting high-voltage side three-phase voltage instantaneous values of transformers at all converter outlets; calculating the high-voltage side voltage amplitude of the corresponding transformer based on the acquired high-voltage side three-phase voltage instantaneous value; and performing active power control based on the calculated high-voltage side voltage amplitude to obtain a d-axis reference value of the output voltage of the converter. According to the method, the converter can be well helped to quickly construct the voltage, and static errors caused by proportional control can be effectively reduced by collecting the high-voltage side voltage and sending the high-voltage side voltage to the converter as a voltage correction reference due to the fact that the wind power converter, the photovoltaic converter and other converters can only collect the low-voltage side voltage of the transformer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of network configuration converter control, and particularly to an active power control method and system for connecting DRU-HVDC network configuration converters, a storage medium and a computing device. BACKGROUND

[0002] With the development of Diode Rectifier Unit-High Voltage Direct Current (DRU-HVDC) in recent years, wind power and photovoltaic power have also developed corresponding network configuration control to adapt to the DRU sending end converter station. For example, in patent CN118508499A, a diode rectifier sending system and its network configuration control method and starting method are disclosed, in which the active power control and voltage control both use proportional integral (hereinafter referred to as PI) control. However, the active power and voltage control are cascaded, and the PI controller parameters are difficult to coordinate, and there is a static error problem. SUMMARY

[0003] The first object of the present application is to overcome the shortcomings and deficiencies of the prior art, and to provide an active power control method for connecting DRU-HVDC network configuration converters, which can help the converter to quickly build voltage. Since wind power, photovoltaic power and other converters can only collect the low-voltage side voltage of the transformer, this method collects the high-voltage side voltage and sends it to the converter as a voltage correction reference, which can effectively reduce the static error caused by proportional control.

[0004] The second object of the present application is to provide an active power control system for connecting DRU-HVDC network configuration converters.

[0005] The third object of the present application is to provide a storage medium.

[0006] The fourth object of the present application is to provide a computing device.

[0007] The first object of the present application is achieved by the following technical solution: an active power control method for connecting DRU-HVDC network configuration converters, applied to a new energy field station containing n converters, each converter is connected to the DRU sending end converter station through the collection line after passing through the transformer at the outlet of each converter; the specific implementation of the active power control method includes:

[0008] Collecting the high-voltage side three-phase voltage instantaneous value of the transformer at the outlet of all converters;

[0009] Based on the collected high-voltage side three-phase voltage instantaneous value, calculating the high-voltage side voltage amplitude of the corresponding transformer;

[0010] Based on the calculated high-voltage side voltage amplitude, active power control is performed to obtain the d-axis reference value of the converter output voltage, helping the converter to quickly build voltage.

[0011] Further, the high-voltage side three-phase voltage instantaneous value U a1 ,b1,c1,U a2 ,b2,c2,…,U an ,bn,cn of all transformers at the converter outlet is collected by the field station control system of the new energy field station.

[0012] Further, the high-voltage side three-phase voltage instantaneous value U ai ,bi,ci of the transformer at the outlet of the i-th converter is obtained according to the Clarke transformation to obtain the voltage and current in the static two-phase coordinate system U αi ,U βi , as shown in the following formula:

[0013]

[0014] In the formula, U ai ,U bi ,U ci are the A-phase, B-phase, and C-phase voltages of the high-voltage side three-phase voltage instantaneous value U ai ,bi,ci.

[0015] The high-voltage side voltage amplitude U coi of the transformer at the outlet of the i-th converter is represented as:

[0016]

[0017] In the formula, K Ti is the transformation ratio of the transformer at the outlet of the i-th converter.

[0018] Further, the field station control system sends the calculated high-voltage side voltage amplitudes U co1 ,U co2 ,…,U coi ,…,U con of all transformers to the corresponding converters.

[0019] Further, the control logic of the active power control of the i-th converter is shown in the following formula:

[0020] U gd_refi = U coi + K pi (P refi -P gi )

[0021] In the formula, K piP is an active power control proportional coefficient refi P is an active power reference value gi U is an active power actual value gd_refi U is a converter output voltage gi of the d-axis reference value.

[0022] Further, in the active power control, the value of U coi does not have to be updated in each control period, and the update period can be set according to the actual situation.

[0023] The second object of the application is achieved by the following technical solution: an active power control system connected to a DRU-HVDC network converter, used to implement the active power control method of the DRU-HVDC network converter described above, comprising:

[0024] A voltage signal acquisition module is used to acquire the high-voltage side three-phase voltage instantaneous value of the transformer at the outlet of all converters.

[0025] A voltage amplitude calculation module is used to calculate the high-voltage side voltage amplitude of the corresponding transformer based on the acquired high-voltage side three-phase voltage instantaneous value.

[0026] An active power control module is used to perform active power control based on the calculated high-voltage side voltage amplitude, to obtain the d-axis reference value of the converter output voltage, and to help the converter quickly build voltage.

[0027] The third object of the application is achieved by the following technical solution: a storage medium storing a program, which is executed by a processor to implement the active power control method of the DRU-HVDC network converter described above.

[0028] The fourth object of the application is achieved by the following technical solution: a computing device comprising a processor and a memory for storing a program executable by the processor, wherein the processor executes the program stored in the memory to implement the active power control method of the DRU-HVDC network converter described above.

[0029] Compared with the prior art, the application has the following advantages and beneficial effects:

[0030] 1. The application can help the converter quickly build voltage.

[0031] 2. The application can effectively reduce the problem of difficult coordination design of control parameters caused by the cascade PI of active power control and voltage control.

[0032] 3. The application can effectively reduce the static error problem caused by proportional control while simplifying the controller design.

[0033] 4. The present invention is easy to implement, efficient and reliable, has practical application value, and is worthy of promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the wind power transmission system via DRU-HVDC.

[0035] Figure 2 Schematic diagram of the converter network control connected to DRU-HVDC.

[0036] Figure 3 This is an architecture diagram of the system of the present invention. DETAILED DESCRIPTION

[0037] The present invention will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0038] Example 1

[0039] This embodiment discloses a method for controlling active power of a DRU-HVDC network converter. Figure 1 As shown in the figure, it is applied to a new energy station containing n converters. Each converter is connected to the DRU sending end converter station through a collection line after passing through the transformer at its own outlet. Figure 2 As shown, the specific implementation of the active power control method is as follows:

[0040] 1) The station control system of the new energy station (referred to as the station control) collects the instantaneous value U of the three-phase voltage on the high-voltage side of the transformer at all converter outlets. a1 ,b1,c1,U a2 ,b2,c2,…,U an ,bn,cn, where the subscripts 1, 2,…, n are the numbers of the converters.

[0041] 2) For the instantaneous value of the three-phase voltage on the high-voltage side of the transformer at the output of the i-th converter, U ai ,bi,ci,i∈[1,2,…,n], the voltage and current U in the stationary two-phase coordinate system are obtained according to Clarke transformation αi 、U βi , as shown below:

[0042]

[0043] Where U ai 、U bi 、U ci is the instantaneous value of the three-phase voltage on the high-voltage side U ai ,bi,ci phase A, B, and C voltages;

[0044] The voltage amplitude U on the high side of the transformer at the output of the i-th convertercoi is expressed as:

[0045]

[0046] wherein K Ti is the transformer ratio of the transformer at the outlet of the i-th converter;

[0047] The station control system sends the calculated voltage amplitudes U co1 ,U co2 ,…,U coi ,…,U con of the high-voltage side of all transformers to the corresponding converters.

[0048] 3) Based on the calculated voltage amplitudes U co1 ,U co2 ,…,U coi ,…,U con of the high-voltage side, active power control is performed to obtain the d-axis reference value of the converter output voltage, helping the converter to quickly build voltage; wherein for the i-th converter, the control logic of the active power control is as follows:

[0049] U gd_refi = U coi + K pi (P refi -P gi )

[0050] wherein K pi is the active power control proportionality coefficient, P refi is the active power reference value, P gi is the actual value of the active power, and U gd_refi is the d-axis reference value of the converter output voltage U gi .

[0051] In the active power control, the value of U coi does not have to be updated in each control period, and the update period can be set according to the actual situation.

[0052] Embodiment 2

[0053] The embodiment discloses an active power control system connected to a DRU-HVDC network converter, which is used to implement the active power control method of the DRU-HVDC network converter as described in Embodiment 1, as shown in Figure 3 , comprising the following functional modules:

[0054] A voltage signal acquisition module is configured to acquire the high-voltage side three-phase voltage instantaneous values of the transformers at the outlets of all converters.

[0055] The voltage amplitude calculation module calculates the high-voltage side voltage amplitude of the corresponding transformer based on the collected high-voltage side three-phase voltage instantaneous value.

[0056] The active power control module performs active power control based on the calculated high-voltage side voltage amplitude, obtains the d-axis reference value of the converter output voltage, and helps the converter to quickly build voltage.

[0057] Embodiment 3

[0058] The embodiment discloses a storage medium, which stores a program. When the program is executed by a processor, the active power control method for connecting a DRU-HVDC network converter is realized.

[0059] The storage medium in the embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a U disk, a mobile hard disk, and the like.

[0060] Embodiment 4

[0061] The embodiment discloses a computing device, which comprises a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the active power control method for connecting a DRU-HVDC network converter is realized.

[0062] The computing device in the embodiment can be a desktop computer, a notebook computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with a processor function.

[0063] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above embodiments, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application should be equivalent replacement methods, which are all included in the protection scope of the present application.

Claims

1. A method for controlling active power of a DRU-HVDC network converter, characterized in that: Applied to a new energy station containing n converters, each converter is connected to the DRU sending-end converter station via a collection line after passing through its own output transformer. The specific implementation of this active power control method includes: Collect the instantaneous three-phase voltage values ​​on the high-voltage side of the transformer at all converter outlets; Calculate the voltage amplitude on the high-voltage side of the corresponding transformer based on the collected instantaneous values ​​of the three-phase voltage on the high-voltage side; Active power control is performed based on the calculated high-voltage side voltage amplitude, and the d-axis reference value of the converter output voltage is obtained, helping the converter to quickly build voltage.

2. The active power control method of a DRU-HVDC network converter according to claim 1, characterized in that: The station control system of the new energy station collects the instantaneous value U of the three-phase voltage on the high-voltage side of the transformer at all converter outlets. a1,b1,c1 ,U a2,b2,c2 ,…,U an,bn,cn , where the subscripts 1, 2,…, n are the numbers of the converters.

3. The active power control method of a DRU-HVDC network converter according to claim 2, characterized in that: For the instantaneous value of the three-phase voltage on the high-voltage side of the transformer at the output of the i-th converter, U ai,bi,ci ,i∈[1,2,…,n],according to Clarke transformation, the voltage and current U in the stationary two-phase coordinate system are obtained αi 、U βi , as shown below: Where U ai 、U bi 、U ci is the instantaneous value of the three-phase voltage on the high-voltage side U ai,bi,ci Phase A, phase B, and phase C voltages; The voltage amplitude U on the high side of the transformer at the output of the i-th converter coi Expressed as: Where K Ti is the transformation ratio of the transformer at the output of the i-th converter.

4. The active power control method of a DRU-HVDC network converter according to claim 3, characterized in that: The station control system calculates the high-voltage side voltage amplitude U of all transformers co1 ,U co2 ,…,U coi ,…,U con Sent to the corresponding converter.

5. The active power control method of a DRU-HVDC network converter according to claim 4, characterized in that: The control logic of active power control of the i-th converter is as follows: IN gd_refi =U coi +K pi (P refi -P gi ) Where K pi is the active power control proportional coefficient, P refi is the active power reference value, P gi is the actual value of active power, U gd_refi is the converter output voltage U gi The d-axis reference value.

6. The active power control method of a DRU-HVDC network converter according to claim 5, characterized in that: In active power control, U coi The value does not need to be updated in every control cycle, and the update cycle can be set according to actual conditions.

7. An active power control system connected to a DRU-HVDC grid converter, characterized in that: The method for controlling active power of a DRU-HVDC network converter according to any one of claims 1 to 6 comprises: Voltage signal acquisition module, used to collect the instantaneous value of the three-phase voltage on the high-voltage side of the transformer at all converter outlets; The voltage amplitude calculation module calculates the voltage amplitude of the high-voltage side of the corresponding transformer based on the collected instantaneous value of the three-phase voltage on the high-voltage side; The active power control module performs active power control based on the calculated high-voltage side voltage amplitude, obtains the d-axis reference value of the converter output voltage, and helps the converter quickly build voltage.

8. A storage medium storing a program, characterized in that: When the program is executed by a processor, the active power control method of a DRU-HVDC network converter connected to any one of claims 1 to 6 is implemented.

9. A computing device comprising a processor and a memory for storing a program executable by the processor, characterized in that: When the processor executes the program stored in the memory, the active power control method of the DRU-HVDC network converter connected to any one of claims 1 to 6 is implemented.

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