An intelligent system for measuring phase quantities under load in an expanded and renovated substation based on phase regulation

Abstract

The present invention discloses an intelligent system for measuring phase quantities under load in an expanded or renovated substation based on phase regulation, comprising: a current output main machine, a reference acquisition slave machine, a secondary measurement slave machine, and an image recognition slave machine; the current output main machine is used for receiving wireless sensor network signals sent by the reference acquisition slave machine, the secondary measurement slave machine, and the image recognition slave machine; the reference acquisition slave machine is used for collecting the reference reference phase and sending it to the current output main machine through the wireless sensor network; the secondary measurement slave machine is used for collecting the amplitude and phase of the secondary current of the current transformer and sending them to the current output main machine through the wireless sensor network; the image recognition slave machine is used for identifying the sampled values displayed by the protection device and sending them to the current output main machine through the wireless sensor network. The present invention can achieve the acquisition of the voltage and current reference phases of the operating equipment in the substation, conduct primary current injection with the reference phase as a reference, complete the simulation of the phase quantity measurement test under load, and change the existing acceptance mode of the secondary circuit of the current transformer.

Description

Technical Field

[0001] The present invention belongs to the technical field of relay protection in power systems, and particularly relates to an intelligent system for measuring phase vectors under load in a reconstructed and expanded substation based on phase regulation. Background Art

[0002] In the on-site commissioning and acceptance of the secondary circuit of current transformers in substations, conventional methods such as using a small direct current to check the secondary polarity of current transformers, measuring the resistance of the secondary circuit to ensure connectivity, and secondary line checking to check the correctness of wiring are usually adopted. The inspection process is complex and the phenomena are not intuitive. In the test of measuring phase vectors under load of current transformers, the reconstructed and expanded equipment is connected to the operating power grid to verify the correctness of the secondary circuit of current transformers with actual loads. In actual production, the accuracy of the test results of measuring phase vectors under load is restricted by various influencing factors, and there is a risk of misjudging the correctness; during the test of measuring phase vectors under load of newly commissioned equipment, errors in the secondary circuit of current transformers may cause maloperation of relay protection, affecting operating equipment and endangering personal safety. Therefore, before the reconstructed and expanded equipment is put into operation, it is advisable to conduct a simulated test of measuring phase vectors under load to ensure the correctness of the secondary circuit of current transformers. Summary of the Invention

[0003] To solve the above technical problems, the present invention proposes an intelligent system for measuring phase vectors under load in a reconstructed and expanded substation based on phase regulation, which can collect the reference phase of voltage and current of operating equipment in the substation, conduct a primary current injection with the reference phase as a reference, complete the simulated test of measuring phase vectors under load, and change the existing acceptance mode of the secondary circuit of current transformers.

[0004] To achieve the above object, the present invention provides an intelligent system for measuring phase vectors under load in a reconstructed and expanded substation based on phase regulation, including:

[0005] A current output main machine, a reference acquisition slave machine, a secondary measurement slave machine, and an image recognition slave machine;

[0006] The current output main machine is configured to receive wireless sensor network signals sent by the reference acquisition slave machine, the secondary measurement slave machine, and the image recognition slave machine;

[0007] The reference acquisition slave machine is configured to collect the reference reference phase and send it to the current output main machine through the wireless sensor network;

[0008] The secondary measurement slave machine is configured to collect the amplitude and phase of the secondary current of the current transformer and send it to the current output main machine through the wireless sensor network;

[0009] The image recognition slave machine is configured to identify the sampled values displayed by the protection device and send them to the current output main machine through the wireless sensor network.

[0010] According to the intelligent system for measuring phasors with load in the reconstructed and expanded substation based on phase regulation provided by the present invention, the system further includes a communication extension module, which is used to receive the wired sensor network signals sent by the reference acquisition slave, the secondary measurement slave, and the image recognition slave, and communicate with the current output host through a wireless sensor network.

[0011] According to the intelligent system for measuring phasors with load in the reconstructed and expanded substation based on phase regulation provided by the present invention, the working process of the reference acquisition slave includes:

[0012] The reference acquisition slave collects the system voltage and the operating interval current in a non-contact manner;

[0013] Taking the system voltage as the first reference value and sending it to the current output host to simulate the phasor measurement in the line no-load charging state during conventional power transmission;

[0014] Taking the operating interval current as the second reference value and sending it to the current output host to simulate the repeated phasor measurement in the line loaded state during conventional power transmission.

[0015] According to the intelligent system for measuring phasors with load in the reconstructed and expanded substation based on phase regulation provided by the present invention, the working process of the secondary measurement slave includes:

[0016] The secondary measurement slave collects the magnitudes and phases of the secondary currents of each group of current transformers in the simulated phasor measurement with load test, and synchronously sends the secondary current sampling values to the current output host through a wireless sensor network.

[0017] According to the intelligent system for measuring phasors with load in the reconstructed and expanded substation based on phase regulation provided by the present invention, the working process of the current output host includes:

[0018] The current output host receives the reference reference phase returned by the reference acquisition slave, controls the full-bridge full-wave high-frequency link inverter circuit by means of unipolar phase shift, outputs the current with the maximum effective value to the primary equipment, and keeps the output primary current synchronized and relatively fixed with the received reference reference phase. The current with the maximum effective value is converted into secondary current by the current transformer and enters the relay protection device, and the information is returned by the secondary measurement slave and the image recognition slave to intelligently judge the correctness of the phasor.

[0019] According to the intelligent system for measuring phasors with load in the reconstructed and expanded substation based on phase regulation provided by the present invention, the process of the reference acquisition slave collecting the system voltage and the operating interval current in a non-contact manner includes:

[0020] An improved non-contact voltage measurement principle based on topological transformation is adopted. An induction probe is used for non-contact measurement of the voltage terminal. Electrical coupling is carried out through the parasitic capacitance between the voltage terminal and the measuring device, and a topological transformation algorithm is used for parameter calculation to obtain the system voltage as the first reference value;

[0021] A clamp ammeter using the conventional electromagnetic induction principle is used for acquisition to obtain the operating interval current as the second reference value.

[0022] According to the intelligent system for measuring phase vectors under load of an expanded and renovated substation based on phase regulation provided by the present invention, the communication between the current output host and each slave through the sensing network specifically includes:

[0023] The delay measurement time synchronization algorithm is adopted for signal synchronization. By embedding the local time at the sending end and sending it together with the message, after the receiving end receives the message, it calculates the transmission time delay between the receiving time and the sending time, and changes the local time of the receiving end to the sum of the transmission delay time and the sending moment, so as to realize synchronous communication between the host and each slave.

[0024] The technical effect of the present invention: The present invention discloses an intelligent system for measuring phase vectors under load of an expanded and renovated substation based on phase regulation, in which the current output host is independent of the above-mentioned reference acquisition slave, secondary measurement slave and image recognition slave, and the host communicates synchronously with the three slaves respectively through the wireless sensing network. The current output host has the function of outputting primary current, receives the reference value sent by the reference acquisition slave, outputs the primary current and self-checks the phase relationship and synchronization with the reference benchmark; the current output host receives the reference benchmark value and current sampling value sent by the secondary measurement slave, back-checks the synchronization of the output primary current, secondary measurement current and the received reference benchmark, and performs phasor logic operation to intelligently judge the correctness of the phasor; the current output host receives the sampling value information sent by the image recognition slave, performs phasor logic operation, and intelligently judges the correctness of the phasor. This system is applicable to the simulation of the test for measuring phase vectors under load of an expanded and renovated substation, and improves the work efficiency and accuracy of the commissioning, acceptance and start-up of the expanded and renovated substation. Description of the Drawings

[0025] The drawings constituting a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0026] Figure 1 It is a schematic flow chart of an intelligent system for measuring phase vectors under load of an expanded and renovated substation based on phase regulation according to an embodiment of the present invention;

[0027] Figure 2 It is a schematic diagram of the extension of the communication between the host and each slave according to an embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the application of the intelligent system for measuring phase quantities with load in the reconstructed and expanded substation based on phase regulation according to an embodiment of the present invention;

[0029] Figure 4 Structural diagram of the full-bridge full-wave high-frequency link inverter circuit according to an embodiment of the present invention;

[0030] Figure 5 Schematic diagram of non-contact voltage measurement according to an embodiment of the present invention;

[0031] Figure 6 Schematic diagram of signal synchronization of the wireless sensor network according to an embodiment of the present invention. Detailed implementation manners

[0032] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0033] It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0034] As Figure 1 shown, in this embodiment, an intelligent system for measuring phase quantities with load in the reconstructed and expanded substation based on phase regulation is provided, including: a current output host, a reference acquisition slave, a secondary measurement slave, and an image recognition slave; the current output host is configured to receive wireless sensor network signals sent by the reference acquisition slave, the secondary measurement slave, and the image recognition slave; the reference acquisition slave is configured to collect a reference reference phase and send it to the current output host through the wireless sensor network; the secondary measurement slave is configured to collect the amplitude and phase of the secondary current of the current transformer CT and send it to the current output host through the wireless sensor network; the image recognition slave is configured to identify the sampled values displayed by the protection device and send them to the current output host through the wireless sensor network.

[0035] As Figure 2 shown, the current output host communicates with each slave through a wireless sensor network. To address the problem of signal shielding in some substation protection rooms, a communication extension module is added. The slaves in the protection room are connected to the communication extension module through a wired network, extended outside the protection room, and then communicate with the current output host through the wireless sensor network.

[0036] As Figure 3 shown, an application scenario of an intelligent system for measuring phase quantities with load in the reconstructed and expanded substation based on phase regulation for simulating the test of measuring phase quantities with load.

[0037] The reference acquisition slave first acquires the system voltage and the operating interval current respectively.

[0038] When using the system voltage as the reference, it is used in the protection room or the outdoor voltage transformer terminal box. The system voltage is acquired in a non-contact manner as the reference value and sent to the current output host, simulating the phase measurement under the line no-load charging state during conventional power transmission.

[0039] When using the operating interval current as the reference, it is used in the protection room or the outdoor circuit breaker terminal box. The operating interval current is acquired as the reference value and sent to the current output host, simulating the re-measurement of the phase under the line loaded state during conventional power transmission.

[0040] The secondary measurement slave is used in the protection room to acquire the amplitude and phase of the secondary current of each group of current transformers (CTs) in the simulated load-bearing phase measurement test, and synchronously send the secondary current sampling values to the host through the wireless sensor network.

[0041] The image recognition slave recognizes the sampling values displayed by the protection device, sends them to the current output host through the wireless sensor network, assists in judging the correctness of the phase, and is applied to the load-bearing phase measurement test.

[0042] The current output host receives the reference phase returned by the reference acquisition slave, controls the full-bridge full-wave high-frequency link inverter circuit using a single-polarity phase-shifting method, outputs a current with a maximum effective value of 1000A to the primary equipment, and keeps the output primary current synchronized and relatively fixed with the received reference phase. The large current is converted into secondary current by the current transformer (CT) and enters the relay protection device. Information is returned by the secondary measurement slave and the image recognition slave to intelligently judge the correctness of the phase.

[0043] As Figure 4 shown, for the function of the current output host to output the primary current, it is powered by 220V AC. First, the 220V AC is rectified and boosted to 400V DC voltage through a half-bridge power factor correction circuit, then the harmonics in the 400V DC voltage are filtered through a filter, and then the 400V DC voltage is input into the full-bridge full-wave high-frequency link inverter circuit. The function of the full-bridge full-wave high-frequency link inverter circuit is to convert the 400V DC voltage into an AC current with an effective value of 250A, and an AC current with an effective value of 1000A required for testing is obtained through the circuit structure in which the primary sides of four transformers are connected in series and four cycle conversion circuit modules are connected in parallel.

[0044] As Figure 5As shown in the figure, the reference acquisition slave unit acquires the system voltage and the operating interval current in a non-contact manner. For the system voltage, an improved non-contact voltage measurement principle based on topological transformation is adopted. An induction probe is used to perform non-contact measurement on the voltage terminal, and electrical coupling is carried out through the parasitic capacitance between the voltage terminal and the measuring device. Then, the topological transformation algorithm is used for parameter calculation to obtain the system voltage as the reference benchmark. For the operating interval current, a clamp ammeter based on the conventional electromagnetic induction principle is used for acquisition. The entire process of reference benchmark acquisition does not come into contact with the operating equipment and circuits.

[0045] As Figure 6 shown in the figure, the current output host communicates with each slave unit through a sensing network. The delay measurement time synchronization algorithm is used for signal synchronization. The local time is embedded at the sending end and sent together with the message. After the receiving end receives the message, it calculates the transmission time delay between the receiving time and the sending time. Finally, the local time of the receiving end is changed to the sum of the transmission delay time and the sending moment to ensure the communication synchronization between the host and each slave unit.

[0046] In the intelligent system for measuring phase quantities under load in the reconstructed and expanded substation based on phase regulation provided in an embodiment, the specific implementation includes the following steps:

[0047] Step 1: After the installation of the reconstructed and expanded primary equipment is completed and the secondary wiring is finished, a simulated phase quantity measurement test under load is carried out. The test line of the current output host is connected to the primary side of the new current transformer CT.

[0048] Step 2: Carry out a phase quantity measurement test under the condition of simulating the line being charged without load. Use the reference acquisition slave unit to acquire the system voltage as the reference value and send it to the current output host through the wireless sensing network (if there is signal shielding in the relay protection room, the reference acquisition slave unit needs to be connected to the communication extension module).

[0049] Step 3: The current output host receives the system voltage as the reference, regulates the trigger phase of the full-bridge full-wave high-frequency link inverter circuit, and outputs a capacitive current with a fixed frequency and a phase following the reference value to simulate the phase quantity measurement test under the condition of the line being charged without load.

[0050] Step 4: The secondary measurement slave unit measures the amplitude and phase of each group of secondary currents of the current transformer CT and synchronously sends the sampled values to the current output host through the wireless sensing network (if there is signal shielding in the relay protection room, the secondary measurement slave unit needs to be connected to the communication extension module).

[0051] Step 5: The current output host receives the measurement values returned by the secondary measurement slave unit and intelligently judges the correctness of the phase quantity measurement test under the condition of simulating the line being charged without load.

[0052] Step 6: Conduct a phasor measurement test under the simulated line closed-loop state. Use the reference acquisition slave to collect the current of the operating interval as the reference value and send it to the current output host through the wireless sensor network (if there is signal shielding in the protection room, the reference acquisition slave needs to be connected to the communication extension module);

[0053] Step 7: The current output host receives the current of the operating interval as the reference, regulates the trigger phase of the full-bridge full-wave high-frequency link inverter circuit, and outputs a load current with a fixed frequency and a phase following the reference value to simulate the phasor measurement test under the line closed-loop state;

[0054] Step 8: The secondary measurement slave measures the amplitude and phase of the secondary current of each group of current transformers CT, and synchronously sends the sampled values to the current output host through the wireless sensor network (if there is signal shielding in the protection room, the secondary measurement slave needs to be connected to the communication extension module);

[0055] Step 9: The current output host receives the measurement values returned by the secondary measurement slave, intelligently judges the correctness of the phasor measurement test under the simulated line closed-loop state, and the phasor measurement test with load simulation ends;

[0056] Step 10: After the renovated and expanded equipment actually carries the load, the image recognition slave takes pictures and recognizes the sampled values of the protection device, synchronously sends them to the current output host through the wireless sensor network, and intelligently judges the correctness of the phasor test.

[0057] The present invention discloses an intelligent system for phasor measurement with load in a renovated and expanded substation based on phase regulation. The current output host is independent of the above-mentioned reference acquisition slave, secondary measurement slave, and image recognition slave. The host conducts synchronous communication with the three slaves respectively through the wireless sensor network. The current output host has the function of primary current output, receives the reference value sent by the reference acquisition slave, outputs the primary current, and self-checks the phase relationship and synchronization with the reference benchmark; the current output host receives the reference benchmark value and current sampled values sent by the secondary measurement slave, back-checks the synchronization of the output primary current, secondary measurement current with the received reference benchmark, and performs phasor logic operations to intelligently judge the phasor correctness; the current output host receives the sampled value information sent by the image recognition slave, performs phasor logic operations, and intelligently judges the phasor correctness. This system is applicable to the phasor measurement test with load simulation in renovated and expanded substations, improving the work efficiency and accuracy of substation renovation, commissioning, acceptance, and startup.

[0058] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An intelligent system for measuring phase quantities on load in a substation for renovation and expansion based on phase control, characterized in that: include: Current output master, reference acquisition slave, secondary measurement slave and image recognition slave; The current output host is used to receive the wireless sensor network signal sent by the reference acquisition slave, the secondary measurement slave and the image recognition slave. The working process of the current output host includes: The current output host receives the reference reference phase transmitted back by the reference acquisition slave, uses a unipolar phase shift method to control the full-bridge full-wave high-frequency chain inverter circuit, outputs the maximum effective value current to pass into the primary device, and keeps the output primary current synchronized with the received reference reference phase and relatively fixed. The maximum effective value current is converted into a secondary current through a current transformer and enters the relay protection device. The secondary measurement slave and the image recognition slave transmit information back to intelligently judge the correctness of the phase quantity. The reference acquisition slave is used to acquire the reference phase and send it to the current output host through the wireless sensor network. The working process of the reference acquisition slave includes: The reference acquisition slave collects the system voltage and the operating interval current in a non-contact manner: adopts an improved non-contact voltage measurement principle based on topological transformation, uses an induction probe to perform non-contact measurement on the voltage terminal, performs electrical coupling through the parasitic capacitance between the voltage terminal and the measuring device, uses a topological transformation algorithm to perform parameter calculation, and obtains the system voltage as the first reference value; uses a conventional clamp ammeter based on the principle of electromagnetic induction to collect, and obtains the operating interval current as the second reference value; The system voltage is used as a first reference value and sent to the current output host to simulate the phase measurement in the line empty and charged state in conventional power transmission; The operating interval current is used as a second reference value and sent to the current output host to simulate the re-measurement of the phase quantity under the load state of the line in conventional power transmission; The secondary measurement slave is used to collect the secondary current amplitude and phase of the current transformer and send them to the current output host through the wireless sensor network; The image recognition slave is used to recognize the sampled value displayed by the protection device and send it to the current output host through the wireless sensor network; The communication between the current output host and each slave through the sensor network specifically includes: using a delay measurement time synchronization algorithm to synchronize signals, embedding the local time at the sending end and sending it together with the message, and after the receiving end receives the message, calculating the transmission time delay between the receiving time and the sending time, and changing the local time of the receiving end to the sum of the transmission delay time and the sending time, thereby realizing synchronous communication between the host and each slave.

2. The intelligent system for measuring phase quantities with load in a substation for renovation and expansion based on phase control as claimed in claim 1 is characterized in that: The system further comprises a communication extension module, which is used to receive wired sensor network signals sent by the reference acquisition slave, the secondary measurement slave and the image recognition slave, and communicate with the current output host through a wireless sensor network.

3. The intelligent system for measuring phase quantities of load in a substation under reconstruction and expansion based on phase control according to claim 1 is characterized in that: The working process of the secondary measurement slave includes: The secondary measurement slave collects the secondary current amplitude and phase of each group of current transformers in the simulated load phase measurement test, and synchronously sends the secondary current sampling values ​​to the current output host through the wireless sensor network.

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