CN104459303B - A kind of adaptively sampled line selection apparatus of double-bus - Google Patents

Abstract

The invention discloses a double-bus self-adaptive sampling line selection device, which includes a first bus, a second bus, a first voltage transformer, a second voltage transformer, a first switch circuit, a second switch circuit, a current transformer, The first analog signal acquisition circuit, the second analog signal acquisition circuit, the third analog signal acquisition circuit, the main controller and the main transformer can automatically collect and calculate reactive power through the control of the switch circuit and the main controller. The double-bus self-adaptive sampling and line selection device of the present invention can correctly and reliably realize the reactive power acquisition and calculation of the main transformer, ensure the correctness and effectiveness of subsequent power quality management, and provide accurate assistance for effectively reducing the loss of transmission lines Calculate and measure.

Description

A dual-bus self-adaptive sampling line selection device

technical field

The invention relates to a bus adaptive sampling line selection device, in particular to an adaptive sampling line selection device for calculating the reactive power of double bus bars.

Background technique

In a 220KV substation, there are generally multiple buses and multiple main transformers, and each bus has its own PT. A specific main transformer can be connected to a specific busbar as required. The reactive power compensation controller generally needs to compensate the reactive power of a certain main transformer, so it needs to sample and calculate the reactive power flowing through the main transformer.

At present, the controllers of reactive power compensation manufacturers generally only have a set of PCC point voltage sampling capabilities, so there will be sampling misalignment. In order to avoid this kind of situation, some manufacturers design external manual electrical switching switches to realize PT switching of main transformer voltage sampling. The manual switching method has problems such as many connection points, large device size, high cost, poor reliability, and short-circuit phenomenon during the switching process, which is no longer suitable for the operation requirements of unattended substations.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a double-bus self-adaptive sampling and line selection device, which can automatically sample the voltage on the double-bus, is not prone to sampling errors, and has high reliability.

The technical solution adopted by the present invention to solve the technical problem is: a double-bus self-adaptive sampling line selection device, including a first bus, a second bus, a first voltage transformer, a second voltage transformer, a first switch circuit, A second switch circuit, a current transformer, a first analog signal acquisition circuit, a second analog signal acquisition circuit, a third analog signal acquisition circuit, a main controller and a main transformer;

The main controller includes a first digital processing module, a second digital processing module, a third digital processing module, a logic judgment module and a reactive power calculation module; the logic judgment module includes a first switch and a second switch; the The output of the first digital processing module is connected to the reactive power calculation module after passing through the first switch; the output of the second digital processing module is connected to the reactive power calculation module after passing through the second switch; the output terminal of the third digital processing module Connected to the reactive power calculation module;

The input end of the first voltage transformer is connected to the first bus bar, the output end of the first voltage transformer is connected to the input end of the first analog signal acquisition circuit; the output of the first analog signal acquisition circuit terminal is connected with the input terminal of the first digital processing module in the main controller; the first voltage transformer converts the first voltage on the first bus into the first measurement voltage; the first analog signal acquisition circuit collects The first measurement voltage output by the first voltage transformer, and output the first voltage analog quantity to the first digital processing module in the main controller; the first digital processing module converts the first voltage analog quantity into Calculated first voltage digital quantity;

The input end of the second voltage transformer is connected to the second bus bar, and the output end of the second voltage transformer is connected to the input end of the second analog signal acquisition circuit; the output of the second analog signal acquisition circuit The end is connected with the input end of the second digital processing module in the main controller; the second voltage transformer converts the second voltage on the second bus into a second measurement voltage; the second analog signal acquisition circuit collects The second measurement voltage output by the second voltage transformer, and output the second voltage analog quantity to the first digital processing module in the main controller; the second digital processing module converts the second voltage analog quantity into Calculated first voltage digital quantity;

The input end of the first switch circuit is connected to the first bus bar; the output end of the first switch circuit is connected to the first input end of the logic judgment module in the main controller, and the first switch circuit The switch status information of the switch is transmitted to the logic judgment module of the main controller;

The input end of the second switch circuit is connected to the second bus bar, the output end of the second switch circuit is connected to the second input end of the logic judgment module in the main controller, and the second switch circuit The switch status information of the switch is transmitted to the logic judgment module of the main controller;

The node where the output end of the first switch circuit is connected to the output end of the second switch circuit is connected to the input end of the current transformer; the output end of the current transformer is connected to the third analog signal acquisition circuit connected to the input terminal; the output terminal of the third analog signal acquisition circuit is connected to the input terminal of the third digital processing module in the main controller; when the first switch circuit is closed and the second switch circuit is disconnected, the The current transformer converts the first current output by the first bus bar into a first measurement current; the third analog signal acquisition circuit collects the first measurement current output by the current transformer, and outputs the first current analog quantity to the main control The third digital processing module in the device; the third digital processing module converts the first current analog quantity into a first current digital quantity that can be calculated; when the first switch circuit is disconnected and the second switch circuit is closed, the The current transformer converts the second current output by the second bus bar into a second measurement current; the third analog signal acquisition circuit collects the second measurement current output by the current transformer, and outputs the second current analog quantity to the main A third digital processing module in the controller; the third digital processing module converts the second current analog quantity into a second current digital quantity available for calculation;

The main transformer is connected to the output end of the current transformer;

Wherein, the logic judgment module in the main controller includes an interlock algorithm processing unit, so that the first switch and the second switch in the main controller will not be closed at the same time; when the first switch circuit is closed, the second switch circuit is open , the logic judgment module controls the first switch to be closed and the second switch to be turned off, so that the first voltage digital quantity and the first current digital quantity are transmitted to the reactive power calculation module to calculate the reactive power on the first bus; When the second switch circuit is closed and the first switch is open, the logic judgment module controls the second switch to close and the first switch to open, so that the second voltage digital quantity and the second current digital quantity are transmitted to the reactive power The calculation module calculates the reactive power on the second bus.

Preferably, the first digital processing module, the second digital processing module and the third digital processing module in the main controller perform digital discrete sampling on the collected analog quantities; the calculation formula adopted by the reactive power calculation module for:

Among them, Q _sampling is the reactive power calculated by the reactive power calculation module, N is the number of sampling points in each cycle of voltage signal and current signal, u(n+N/4) is the instantaneous value of voltage sampling, i(n ) is the instantaneous value of current sampling.

Preferably, the logic judgment module in the main controller further includes a redundant logic processing unit, and when the first switch circuit and the second switch circuit are closed at the same time, the logic control module compulsorily controls one of the first switch and the second switch One is closed and the other is open.

Preferably, the main controller further includes an alarm module, which sends an alarm when the first switch circuit and the second switch circuit are closed at the same time.

Preferably, the first digital processing module, the second digital processing module and the third digital processing module in the main controller all use a chip of the model ADS8364, and the logic judgment module and the reactive power calculation module all use a TMS32F2812 chip .

The beneficial effects of the present invention are:

1. There will be no sampling misalignment caused by voltage transformer switching;

2. Small footprint, low cost and high reliability.

3. The reactive power compensation controller using this technology can correctly and reliably realize the reactive power collection and calculation of the main transformer, ensuring the correctness and effectiveness of subsequent power quality management. Correct and effective power quality management can effectively reduce the loss of transmission lines, expand the transmission capacity of transmission lines, and reduce the phase-advancing operation pressure of power plants.

The present invention will be described in further detail below with reference to the accompanying drawings and embodiments; however, the dual-bus adaptive sampling line selection device of the present invention is not limited to the embodiments.

Description of drawings

Fig. 1 is a functional structure block diagram of the present invention.

detailed description

Example

Referring to Fig. 1, a double-bus adaptive sampling line selection device of the present invention includes a first bus 101, a second bus 102, a first voltage transformer 201, a second voltage transformer 202, and a first switch circuit 401 , the second switch circuit 402, the current transformer 50, the first analog signal acquisition circuit 301, the second analog signal acquisition circuit 302, the third analog signal acquisition circuit 303, the main controller 70 and the main transformer 60;

The main controller 70 includes a first digital processing module 701, a second digital processing module 702, a third digital processing module 703, a logic judgment module 704 and a reactive power calculation module 705; the logic judgment module 704 includes a first switch 7041 and the second switch 7042; the output of the first digital processing module 701 is connected to the reactive power calculation module 705 after passing through the first switch 7041; the output of the second digital processing module 702 is connected to the reactive power after passing through the second switch 7042 A power calculation module 705; the output of the third digital processing module 703 is connected to the reactive power calculation module 705;

The input end of the first voltage transformer 201 is connected to the first bus bar 101, and the output end of the first voltage transformer 201 is connected to the input end of the first analog signal acquisition circuit 301; the first analog signal The output end of the acquisition circuit 301 is connected to the input end of the first digital processing module in the main controller 70; the first voltage transformer 201 converts the first voltage on the first bus 101 into a first measurement voltage; The first analog signal acquisition circuit 301 acquires the first measurement voltage output by the first voltage transformer 201, and outputs the first voltage analog quantity to the first digital processing module 701 in the main controller 70; the first digital The processing module 701 converts the first voltage analog quantity into a computable first voltage digital quantity;

The input end of the second voltage transformer 202 is connected to the second bus bar 102, and the output end of the second voltage transformer 202 is connected to the input end of the second analog signal acquisition circuit 301; the second analog signal The output end of the acquisition circuit 301 is connected to the input end of the second digital processing module 702 in the main controller 70; the second voltage transformer 202 converts the second voltage on the second bus 102 into a second measurement voltage; The second analog signal acquisition circuit 302 acquires the second measurement voltage output by the second voltage transformer 202, and outputs the second voltage analog quantity to the first digital processing module in the main controller 70; the second digital The processing module 702 converts the second voltage analog quantity into a computable first voltage digital quantity;

The input terminal of the first switch circuit 401 is connected to the first bus bar 101; the output terminal of the first switch circuit 401 is connected to the first input terminal of the logic judgment module in the main controller 70, and the The switch state information of the first switch circuit 401 is transmitted to the logic judgment module 704 of the main controller 70;

The input terminal 402 of the second switch circuit is connected to the second bus bar 102, the output terminal of the second switch circuit 402 is connected to the second input terminal of the logic judgment module 704 in the main controller 70, and the The switch status information of the second switch circuit 402 is transmitted to the logic judgment module 704 of the main controller 70;

The node where the output end of the first switch circuit 401 is connected to the output end of the second switch circuit 402 is connected to the input end of the current transformer 50; the output end of the current transformer 50 is connected to the third The input end of the analog signal acquisition circuit 303 is connected; the output end of the third analog signal acquisition circuit 303 is connected with the input end of the third digital processing module 703 in the main controller 70; when the first switch circuit 401 is closed, the second When the second switch circuit 402 is disconnected, the current transformer 50 converts the first current output by the first bus bar 101 into a first measurement current; the third analog signal acquisition circuit 303 acquires the first measurement output by the current transformer 50 current, and output the first current analog quantity to the third digital processing module 703 in the main controller 70; the third digital processing module 703 converts the first current analog quantity into a first current digital quantity that can be calculated ; When the first switch circuit 401 is disconnected and the second switch circuit is closed 402, the current transformer 50 converts the second current output by the second bus bar 102 into a second measurement current; the third analog signal acquisition circuit 303 Collect the second measurement current output by the current transformer 50, and output the second current analog quantity to the third digital processing module 703 in the main controller 70; the third digital processing module 703 converts the second current analog quantity is the second current digital quantity available for calculation;

The main transformer 60 is connected to the output end of the current transformer 50;

Wherein, the logic judgment module 704 in the main controller 70 includes an interlocking algorithm processing unit, so that the first switch 7041 and the second switch 7042 in the main controller 70 will not be closed at the same time; when the first switch circuit 401 is closed, When the second switch circuit 402 is disconnected, the logic judgment module 704 controls the first switch 7041 to be closed and the second switch 7042 to be disconnected, so that the first voltage digital quantity and the first current digital quantity are transmitted to the reactive power calculation module 705 calculates the reactive power on the first bus 101; when the second switch circuit 402 is closed and the first switch circuit 401 is open, the logic judgment module 704 controls the second switch 7042 to be closed and the first switch 7041 to be open, so that The second voltage digital quantity and the second current digital quantity are transmitted to the reactive power calculation module 705 to calculate the reactive power on the second bus 102 .

Furthermore, the first digital processing module 701, the second digital processing module 702 and the third digital processing module 703 in the main controller 70 perform digital discrete sampling on the collected analog quantities; the reactive power calculation The calculation formula adopted by module 705 is:

Wherein, Q _sampling is the reactive power calculated by the reactive power calculation module 705, N is the number of sampling points in each cycle of the voltage signal and the current signal, u(n+N/4) is the instantaneous value of the voltage sampling, i( n) is the instantaneous value of current sampling.

Furthermore, the logic judgment module 704 in the main controller 70 also includes a redundant logic processing unit, and when the first switch circuit 401 and the second switch circuit 402 are closed at the same time, the logic control module 704 compulsorily controls the first switch One of the 7041 and the second switch 7042 is in the closed state and the other is in the open state.

Furthermore, the main controller 70 also includes an alarm module, which sends an alarm when the first switch circuit 401 and the second switch circuit 402 are closed at the same time.

Furthermore, the first digital processing module 701, the second digital processing module 702 and the third digital processing module 703 in the main controller 70 all adopt the chip model ADS8364, and the logic judgment module 704 and reactive power The computing modules 705 all use the TMS32F2812 chip.

The above-mentioned embodiment is only used to further illustrate a kind of dual-bus self-adaptive sampling line selection device of the present invention, but the present invention is not limited to the embodiment, any simple modification made to the above embodiment according to the technical essence of the present invention, is equivalent to Changes and modifications all fall within the protection scope of the technical solutions of the present invention.

Claims (5)

1. A dual-bus self-adaptive sampling line selection device, characterized in that it comprises a first bus, a second bus, a first voltage transformer, a second voltage transformer, a first switch circuit, a second switch circuit, a current transformer device, a first analog signal acquisition circuit, a second analog signal acquisition circuit, a third analog signal acquisition circuit, a main controller and a main transformer; The main controller includes a first digital processing module, a second digital processing module, a third digital processing module, a logic judgment module and a reactive power calculation module; the logic judgment module includes a first switch and a second switch; the The output of the first digital processing module is connected to the reactive power calculation module after passing through the first switch; the output of the second digital processing module is connected to the reactive power calculation module after passing through the second switch; the output terminal of the third digital processing module Connected to the reactive power calculation module; The input end of the first voltage transformer is connected to the first bus bar, the output end of the first voltage transformer is connected to the input end of the first analog signal acquisition circuit; the output of the first analog signal acquisition circuit terminal is connected with the input terminal of the first digital processing module in the main controller; the first voltage transformer converts the first voltage on the first bus into the first measurement voltage; the first analog signal acquisition circuit collects The first measurement voltage output by the first voltage transformer, and output the first voltage analog quantity to the first digital processing module in the main controller; the first digital processing module converts the first voltage analog quantity into Calculated first voltage digital quantity; The input end of the second voltage transformer is connected to the second bus bar, and the output end of the second voltage transformer is connected to the input end of the second analog signal acquisition circuit; the output of the second analog signal acquisition circuit The end is connected with the input end of the second digital processing module in the main controller; the second voltage transformer converts the second voltage on the second bus into a second measurement voltage; the second analog signal acquisition circuit collects The second measurement voltage output by the second voltage transformer, and output the second voltage analog quantity to the first digital processing module in the main controller; the second digital processing module converts the second voltage analog quantity into Calculated first voltage digital quantity; The input end of the first switch circuit is connected to the first bus bar; the output end of the first switch circuit is connected to the first input end of the logic judgment module in the main controller, and the first switch circuit The switch status information of the switch is transmitted to the logic judgment module of the main controller; The input end of the second switch circuit is connected to the second bus bar, the output end of the second switch circuit is connected to the second input end of the logic judgment module in the main controller, and the second switch circuit The switch state information is transmitted to the logic judgment module of the main controller; The node where the output end of the first switch circuit is connected to the output end of the second switch circuit is connected to the input end of the current transformer; the output end of the current transformer is connected to the third analog signal acquisition circuit connected to the input terminal; the output terminal of the third analog signal acquisition circuit is connected to the input terminal of the third digital processing module in the main controller; when the first switch circuit is closed and the second switch circuit is disconnected, the The current transformer converts the first current output by the first bus bar into a first measurement current; the third analog signal acquisition circuit collects the first measurement current output by the current transformer, and outputs the first current analog quantity to the main control The third digital processing module in the device; the third digital processing module converts the first current analog quantity into a first current digital quantity that can be calculated; when the first switch circuit is disconnected and the second switch circuit is closed, the The current transformer converts the second current output by the second bus bar into a second measurement current; the third analog signal acquisition circuit collects the second measurement current output by the current transformer, and outputs the second current analog quantity to the main A third digital processing module in the controller; the third digital processing module converts the second current analog quantity into a second current digital quantity available for calculation; The main transformer is connected to the output end of the current transformer; Wherein, the logic judgment module in the main controller includes an interlock algorithm processing unit, so that the first switch and the second switch in the main controller will not be closed at the same time; when the first switch circuit is closed, the second switch circuit is open , the logic judgment module controls the first switch to be closed and the second switch to be turned off, so that the first voltage digital quantity and the first current digital quantity are transmitted to the reactive power calculation module to calculate the reactive power on the first bus; When the second switch circuit is closed and the first switch is open, the logic judgment module controls the second switch to close and the first switch to open, so that the second voltage digital quantity and the second current digital quantity are transmitted to the reactive power The calculation module calculates the reactive power on the second bus. 2. A kind of dual-bus self-adaptive sampling line selection device according to claim 1, characterized in that: the first digital processing module, the second digital processing module and the third digital processing module in the master controller collect The analog quantity that arrives carries out digital discretization sampling; The calculation formula that described reactive power calculation module adopts is: Among them, Q _sampling is the reactive power calculated by the reactive power calculation module, N is the number of sampling points in each cycle of voltage signal and current signal, u(n+N/4) is the instantaneous value of voltage sampling, i(n ) is the instantaneous value of current sampling. 3. A dual-bus self-adaptive sampling line selection device according to claim 1, characterized in that: the logic judgment module in the main controller also includes a redundant logic processing unit, when the first switch circuit and the second When the switch circuits are closed at the same time, the logic control module forcibly controls one of the first switch and the second switch to be in a closed state and the other to be in an open state. 4. A kind of dual-bus self-adaptive sampling line selection device according to claim 3, characterized in that: the main controller also includes an alarm module, and when the first switch circuit and the second switch circuit are closed simultaneously, the alarm module Alert. 5. A kind of dual-bus self-adaptive sampling line selection device according to claim 1, characterized in that: the first digital processing module, the second digital processing module and the third digital processing module in the main controller all adopt The chip model is ADS8364, and the logic judgment module and the reactive power calculation module both use the TMS32F2812 chip.