Voltage monitoring system

Abstract

The utility model discloses a voltage monitoring system, which relates to the technical field of electric power systems and is used for monitoring the voltage of the alternating current side of a generator. The system comprises a monitoring controller, a network switch and at least one voltage monitoring unit, each voltage monitoring unit comprises a voltage collector and an electric field induction mutual inductor arranged on the alternating current side of the generator, and the electric field induction mutual inductor is used for collecting the phase voltage value of the alternating current side of the generator and sending the phase voltage value to the voltage collector; the network switch is respectively connected with the monitoring controller and the voltage collector of each voltage monitoring unit, and is used for establishing communication connection between the monitoring controller and the voltage collector; the monitoring controller is used for receiving the phase voltage value from the voltage collector through the network switch and monitoring the voltage of the alternating current side of the generator based on the phase voltage value. According to the technical scheme disclosed by the utility model, the capability of monitoring the transient overvoltage of the alternating current side of the generator can be obviously enhanced.

Description

Technical Field

[0001] The utility model relates to the technical field of power systems, in particular to a voltage monitoring system. Background Art

[0002] As more and more renewable energy generators are connected to the power grid system, the power grid system often experiences excessive overvoltage at the generator end due to faults in the generator's transmission line, causing the generator to go offline. Especially in offshore wind farms, the transmission line of the wind turbine is a long-distance submarine cable. After a fault-free load shedding occurs on the land side of the submarine cable, the wind turbine and the submarine cable form a series resonant circuit of reactance and capacitance, which often causes excessive transient overvoltage at the wind turbine end, seriously threatening the safety of power electronic equipment. Among them, transient overvoltage refers to the phenomenon that the voltage value exceeds the normal operating voltage in a very short time due to some sudden changes or operations in the power grid system. At present, excessive transient overvoltage at the wind turbine end is the main factor causing wind turbines to go offline. It is necessary to monitor the voltage on the AC side of the wind turbine in real time to detect whether the wind turbine has transient overvoltage at the machine end.

[0003] Currently, existing transient overvoltage monitoring systems rely on capacitive or electromagnetic voltage transformers to collect and monitor the phase voltage values ​​on the AC side of the wind turbine to detect transient overvoltages at the turbine end. However, the voltage transformer's response frequency band is insufficient to meet the requirements for collecting transient overvoltage spectra, and its sampling frequency is too low, resulting in poor monitoring effectiveness and insufficient monitoring capability for transient overvoltages on the AC side of the generator. Utility Model Content

[0004] In view of this, the present invention provides a voltage monitoring system, the main purpose of which is to solve the technical problem that the response frequency band of the voltage transformer in the existing transient overvoltage monitoring system is difficult to meet the acquisition requirements of the transient overvoltage spectrum, resulting in insufficient monitoring capability of the transient overvoltage on the AC side of the generator.

[0005] To achieve the above object, the present invention first provides a voltage monitoring system for monitoring the voltage of a generator, wherein the voltage monitoring system includes a monitoring controller, a network switch, and at least one voltage monitoring unit;

[0006] Each of the voltage monitoring units includes a voltage collector and an electric field induction transformer provided on the AC side of the generator, wherein the electric field induction transformer is used to collect the phase voltage value of the AC side of the generator and send the phase voltage value to the voltage collector;

[0007] The network switch is connected to the monitoring controller and the voltage collector of each voltage monitoring unit respectively, and is used to establish a communication connection between the monitoring controller and the voltage collector;

[0008] The monitoring controller is used to receive the phase voltage value from the voltage collector via the network switch, and monitor the voltage of the AC side of the generator based on the phase voltage value.

[0009] In one embodiment of the present invention, the voltage collector includes a data collector and a data manager; the input end of the data collector is connected to the output end of the electric field induction transformer, for obtaining the phase voltage value, and based on the phase voltage value, calculating the positive sequence voltage value of the AC side; the output end of the data collector is connected to the input end of the data manager, for sending the phase voltage value and the positive sequence voltage value to the data manager; the interaction end of the data manager is connected to the first signal interaction end of the network switch, for sending the phase voltage value and the positive sequence voltage value to the monitoring controller through the network switch.

[0010] In one embodiment of the present invention, the voltage collector also includes a filtering device; the input end of the filtering device is connected to the electric field induction transformer, and the output end of the filtering device is connected to the input end of the data collector, for receiving the phase voltage value, performing harmonic filtering on the phase voltage value, and sending the phase voltage value after harmonic filtering to the data collector.

[0011] In one embodiment of the present invention, the filtering device includes a first second-order filter, a second second-order filter and a third second-order filter; the input end of the first second-order filter is connected to the electric field induction mutual inductor, the output end of the first second-order filter is connected to the input end of the second second-order filter, the output end of the second second-order filter is connected to the input end of the third second-order filter, and the output end of the third second-order filter is connected to the input end of the data collector; the quality factor of the first second-order filter is smaller than the quality factor of the second second-order filter, and the quality factor of the second second-order filter is smaller than the quality factor of the third second-order filter.

[0012] In one embodiment of the present invention, the voltage collector also includes an analog-to-digital converter; the input end of the analog-to-digital converter is connected to the output end of the data collector, and the output end of the analog-to-digital converter is connected to the input end of the data manager, for receiving the phase voltage value and the positive-sequence voltage value in the form of analog signals, and performing analog-to-digital conversion on the phase voltage value and the positive-sequence voltage value in the form of analog signals to obtain the phase voltage value and the positive-sequence voltage value in the form of digital signals, and sending the phase voltage value and the positive-sequence voltage value in the form of digital signals to the data manager.

[0013] In one embodiment of the present invention, the data collector includes a high-speed data collector and a mathematical operator; the input end of the high-speed data collector is connected to the output end of the filtering device for obtaining the phase voltage value; the input end of the mathematical operator is connected to the output end of the high-speed data collector, and the output end of the mathematical operator is connected to the input end of the analog-to-digital converter for obtaining the phase voltage value, and based on the phase voltage value, calculate the positive-sequence voltage value, and send the phase voltage value and the positive-sequence voltage value to the analog-to-digital converter.

[0014] In one embodiment of the present invention, the data manager is a field programmable gate array device.

[0015] In one embodiment of the present invention, the field programmable gate array device has a storage unit for storing the phase voltage value and the positive sequence voltage value.

[0016] In one embodiment of the present invention, the interaction end of the data manager includes a synchronization signal interaction end and a data acquisition interaction end; the monitoring controller has a synchronization signal transceiver end and a data transceiver end; the synchronization signal transceiver end of the monitoring controller is connected to the synchronization signal interaction end of the data manager through the network switch, and is used to send a synchronization signal to the data manager; the data transceiver end of the monitoring controller is connected to the data acquisition interaction end of the data manager through the network switch, and is used to receive the phase voltage value and the positive sequence voltage value from the data manager.

[0017] In one embodiment of the present invention, the monitoring controller has a remote communication port for connecting to a remote host computer.

[0018] The present invention provides a voltage monitoring system that installs a voltage monitoring unit on the AC side of each generator at a new energy station. The voltage monitoring unit's electric field induction transformer collects the phase voltage values ​​on the generator's AC side. The electric field induction transformer measures the potential of a charged body based on the principle of electric field coupling. By placing electric field induction transformers around the generator's AC side, non-contact measurement of the generator's AC phase voltage is achieved, reducing the complexity of insulation design and improving equipment safety. Furthermore, the electric field induction transformer has a high response frequency band and can collect the generator's AC phase voltage values ​​at an extremely high sampling rate. Furthermore, a monitoring controller can be connected to each voltage monitoring unit via a network switch to receive the phase voltage values ​​collected by all voltage monitoring units, enabling monitoring of the generator's AC phase voltage values ​​for transient overvoltages. The embodiments provided herein can significantly enhance the monitoring capability of transient overvoltages on the generator's AC side.

[0019] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 One of the structural diagrams of a voltage monitoring system provided by an embodiment of the present utility model is shown;

[0022] Figure 2 One of the structural diagrams of a voltage collector provided by an embodiment of the present utility model is shown;

[0023] Figure 3 The second structural diagram of a voltage collector provided by an embodiment of the present utility model is shown;

[0024] Figure 4 The second structural diagram of a voltage monitoring system provided by an embodiment of the present utility model is shown;

[0025] Figure 5 A structural diagram of a data manager provided by an embodiment of the present utility model is shown. DETAILED DESCRIPTION

[0026] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0027] To further illustrate the technical means and effects employed by the present invention to achieve its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention is provided in conjunction with the accompanying drawings and preferred embodiments. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0028] The following combination Figures 1 to 5 A voltage monitoring system according to some embodiments of the present invention is described.

[0029] like Figure 1 As shown, an embodiment of the present invention proposes a voltage monitoring system for monitoring the voltage of a generator. Here, the voltage monitoring system can monitor the phase voltage value on the AC side of the generator, taking the phase voltage value on the AC side of the generator as the monitoring object, to determine whether the generator has a transient overvoltage at the machine end. Furthermore, the voltage monitoring system includes a monitoring controller, a network switch, and at least one voltage monitoring unit. Here, the number of voltage monitoring units can be determined based on the number of generators that need to be monitored in the station, and a voltage monitoring unit can be set on the AC side of each generator that needs to be monitored. Furthermore, the monitoring controller has a remote communication port for connecting to a remote host computer. The host computer can be a computer device such as a control terminal, and relevant staff can connect to the monitoring controller based on the host computer to remotely control the monitoring controller.

[0030] Specifically, each of the voltage monitoring units includes a voltage collector and an electric field induction transformer arranged on the AC side of the generator. The electric field induction transformer is used to collect the phase voltage value of the AC side of the generator and send the phase voltage value to the voltage collector. Here, the electric field induction transformer measures the potential of the charged body based on the principle of electric field coupling. By utilizing the principle that the electric field strength around a conductor is proportional to the conductor's potential, placing an electric field induction transformer around the AC side of the generator can achieve non-contact measurement of the phase voltage on the AC side of the generator, reducing the complexity of the insulation design and improving the safety factor of the equipment. Furthermore, the electric field induction transformer has the characteristics of a high response frequency band and can collect the phase voltage value of the AC side of the generator at an extremely high sampling rate. Furthermore, the voltage monitoring unit can send the phase voltage value to the monitoring controller via the network switch in the form of a high-frequency transient voltage signal.

[0031] Furthermore, an electric field sensing transformer can be installed near the port where the power output cable is drawn from the AC side of the generator to determine the phase voltage value on the AC side of the generator based on the electric field at the port where the power output cable is drawn. Here, the electric field sensing transformer can collect the transient phase voltage value of the AC side of the generator during each sampling period. Furthermore, the electric field sensing transformer can include multiple pairs of sensing nodes, through which the phase voltage value of the AC side of the generator is collected.

[0032] Furthermore, the network switch is respectively connected to the monitoring controller and the voltage collector of each voltage monitoring unit, and is used to establish a communication connection between the monitoring controller and the voltage collector. Specifically, the data interaction port of the voltage collector of each voltage monitoring unit can be connected to different first-side ports of the network switch via optical fiber, and the interaction port of the monitoring controller can be connected to the second-side port of the network switch via optical fiber, so that the voltage monitoring unit can send the high-frequency transient voltage signal carrying information about the phase voltage value to the monitoring controller via the network switch; further, the control command of the monitoring controller can also be sent to each voltage monitoring unit via the network switch. In this way, the high voltage of the voltage monitoring unit of the primary system can be effectively isolated from the monitoring controller of the operation data analysis system, ensuring the safety of the monitoring system and operation and maintenance personnel. In addition, the speed of optical fiber data transmission is fast, ensuring the accurate acquisition of high-frequency transient voltage signals.

[0033] Furthermore, the monitoring controller is configured to receive the phase voltage values ​​from the voltage collector via the network switch and monitor the voltage on the AC side of the generator based on the phase voltage values. The monitoring controller can be a server that performs monitoring functions and can be connected to a display device to display the acquired phase voltage values ​​collected by each voltage monitoring unit, thereby enabling generator-side overvoltage monitoring using the phase voltage values ​​of the generator where the voltage monitoring unit is located as the monitoring target. Furthermore, a monitoring program can be configured within the monitoring controller to monitor the generator for transient overvoltages using the phase voltage values ​​as the monitoring target.

[0034] It should be noted that the selection of the monitoring controller, network switch and voltage monitoring unit and the connection method of the internal circuit of the module can be determined according to the actual situation, and this embodiment does not make specific restrictions. In addition, the connection method of each device can be determined according to the specific selection of the device, and this embodiment does not make specific restrictions. The functions of the voltage monitoring system provided by this embodiment are mainly realized through the circuit connection relationship between each module, and do not rely on the implementation of the program module in a certain module. In addition, each module in the voltage monitoring system can be implemented by an analog circuit or a digital circuit, and for circuit modules that can be implanted with program modules, the implementation of their module functions can be achieved through the program modules provided by the prior art.

[0035] The voltage monitoring system proposed in the embodiment of the present invention can be implemented by setting a voltage monitoring unit on the AC side of each generator at a new energy station, and collecting the phase voltage value on the AC side of the generator through the electric field induction transformer of the voltage monitoring unit. Furthermore, the monitoring controller can be connected to each voltage monitoring unit through a network switch to receive the phase voltage values ​​collected by all voltage monitoring units, thereby monitoring the voltage value on the AC side of the generator. The embodiment provided by the present application can significantly enhance the monitoring capability of transient overvoltage on the AC side of the generator.

[0036] In one embodiment, Figure 2 As shown, the voltage collector includes a data collector and a data manager.

[0037] Specifically, the input end of the data collector is connected to the output end of the electric field induction transformer, and is used to obtain the phase voltage value and calculate the positive sequence voltage value of the AC side based on the phase voltage value. Here, the data collector can be a computing device with certain computing capabilities, such as a single chip microcomputer or a digital signal processor. Furthermore, the current common method of calculating the positive sequence voltage based on the phase voltage is: first, determine the phase voltage and convert the phase voltage into a phasor form; then, based on the symmetrical component method, decompose the phase voltage into positive sequence, negative sequence, and zero sequence voltage components; finally, calculate the positive sequence voltage amplitude and convert the positive sequence voltage amplitude into the line voltage to obtain the positive sequence voltage value. Here, the method of calculating the positive sequence voltage based on the phase voltage can be determined according to actual conditions and is also applicable to this embodiment.

[0038] Furthermore, the output end of the data collector is connected to the input end of the data manager, and is used to send the phase voltage value and the positive-sequence voltage value to the data manager. Furthermore, the interactive end of the data manager is connected to the first signal interactive end of the network switch, and is used to send the phase voltage value and the positive-sequence voltage value to the monitoring controller through the network switch, so that the monitoring controller can display the phase voltage value and the positive-sequence voltage value, so that relevant personnel can monitor the voltage value of the AC side of the generator to perform transient overvoltage monitoring. Furthermore, a relevant monitoring program can also be set in the monitoring controller, and the higher voltage value of the phase voltage value and the positive-sequence voltage value is used as the monitoring object to perform transient overvoltage monitoring on the generator. The embodiment provided in this application can calculate the positive-sequence voltage of the generator based on the phase voltage of the generator, and use the higher voltage of the phase voltage and the positive-sequence voltage on the AC side of the generator as the monitoring object, thereby realizing simultaneous monitoring of the phase voltage and the positive-sequence voltage, meeting the requirements of different overvoltage protection settings at the machine end of the new energy generator, and determining whether the generator has a machine end transient overvoltage.

[0039] In one embodiment, Figure 3 As shown, the voltage collector also includes a filtering device; specifically, the input end of the filtering device is connected to the electric field induction transformer, and the output end of the filtering device is connected to the input end of the data collector, for receiving the phase voltage value, performing harmonic filtering on the phase voltage value, and sending the phase voltage value after harmonic filtering to the data collector. Specifically, the filtering device can receive a high-frequency transient voltage signal representing the phase voltage value from the electric field induction transformer, perform harmonic filtering on the high-frequency transient voltage signal, filter out useless harmonics of 50 Hz and other frequencies, and send the high-frequency transient voltage signal after harmonic filtering to the data collector, so that the data collector can obtain the phase voltage value based on the high-frequency transient voltage signal and perform further processing.

[0040] The embodiment provided in the present application can filter the signal output by the electric field induction transformer to the data collector to improve the quality of the signal received by the data collector, thereby improving the accuracy of the voltage monitoring system in monitoring the transient overvoltage at the generator end.

[0041] In one embodiment, the filtering device includes a first second-order filter, a second second-order filter, and a third second-order filter with unity gain; wherein the first second-order filter, the second second-order filter, and the third second-order filter are connected in cascade.

[0042] Specifically, the input end of the first second-order filter is connected to the electric field induction transformer, the output end of the first second-order filter is connected to the input end of the second second-order filter, the output end of the second second-order filter is connected to the input end of the third second-order filter, and the output end of the third second-order filter is connected to the input end of the data collector.

[0043] Furthermore, the quality factor of the first second-order filter is smaller than the quality factor of the second second-order filter, and the quality factor of the second second-order filter is smaller than the quality factor of the third second-order filter. In the embodiment provided by the present application, a filtering device is obtained by cascading three unit-gain second-order filters. The quality factors of the three second-order filters are increased, and a sixth-order low-pass filter can be finally realized. The useless harmonics can be filtered out, and only the high-speed transient signal representing the phase voltage value is retained, thereby improving the signal quality received by the data collector and thereby improving the accuracy of the voltage monitoring system in monitoring the generator end transient overvoltage.

[0044] In one embodiment, the data manager is a field programmable gate array (FPGA) device. The FPGA device may be pre-programmed with a program to receive phase voltage values ​​and positive-sequence voltage values ​​and control the voltage acquisition and processing process of the voltage monitoring unit. Furthermore, the FPGA device includes a storage unit for storing the phase voltage values ​​and the positive-sequence voltage values.

[0045] Further, such as Figure 3 As shown, the voltage collector further includes an analog-to-digital converter; specifically, the input end of the analog-to-digital converter is connected to the output end of the data collector, and the output end of the analog-to-digital converter is connected to the input end of the data manager, for receiving the phase voltage value and the positive-sequence voltage value in the form of analog signals, performing analog-to-digital conversion on the phase voltage value and the positive-sequence voltage value in the form of analog signals, obtaining the phase voltage value and the positive-sequence voltage value in the form of digital signals, and sending the phase voltage value and the positive-sequence voltage value in the form of digital signals to the data manager. Here, the analog-to-digital converter can obtain a voltage analog signal carrying the phase voltage value and the positive-sequence voltage value from the data collector, perform analog-to-digital conversion on the voltage analog signal, obtain a voltage digital signal carrying the phase voltage value and the positive-sequence voltage value, and send the voltage digital signal to the data manager, so that the data manager obtains the voltage digital signal and further obtains the phase voltage value and the positive-sequence voltage value.

[0046] The embodiment provided in the present application can convert the analog signal emitted by the data collector into a digital signal based on an analog-to-digital converter, and send the digital signal to the FPGA device serving as a data manager, so that the FPGA device can process the received phase voltage value and positive sequence voltage value, and utilize the powerful processing capability of the FPGA device to meet the high sampling frequency in the transient overvoltage monitoring process, solve the problem of massive data processing, storage and transmission, and improve the monitoring capability of the voltage monitoring system.

[0047] In one embodiment, the data collector includes a high-speed data collector and a mathematical operator. Specifically, the input of the high-speed data collector is connected to the output of the filtering device to obtain the phase voltage value. The high-speed data collector uses a 14-bit dual-channel collector with a maximum rotation speed of 4 MHz and a maximum clock frequency of 80 MHz, which can achieve a high sampling rate for obtaining the phase voltage value from the electric field induction transformer.

[0048] Furthermore, the input end of the mathematical operator is connected to the output end of the high-speed data collector, and the output end of the mathematical operator is connected to the input end of the analog-to-digital converter, for obtaining the phase voltage value, and calculating the positive-sequence voltage value based on the phase voltage value, and sending the phase voltage value and the positive-sequence voltage value to the analog-to-digital converter. The mathematical operator is a computing device with a certain computing capability, such as a single-chip microcomputer or a digital signal processor, which can calculate the positive-sequence voltage based on the phase voltage. The embodiment provided by the present application can collect phase voltage values ​​at high speed based on a high-speed data collector, and calculate the positive-sequence voltage value based on the mathematical operator, thereby improving the voltage monitoring efficiency of the voltage monitoring system.

[0049] In one embodiment, Figure 4 As shown, the interaction end of the data manager includes a synchronization signal interaction end and a data acquisition interaction end; the monitoring controller has a synchronization signal transceiver end and a data transceiver end.

[0050] The synchronization signal transceiver of the monitoring controller is connected to the synchronization signal interaction terminal of the data manager via the network switch, and is used to send a synchronization signal to the data manager. In order to synchronously sample the distributed voltage monitoring units and assign accurate timestamps to the data, a satellite synchronization clock method can be used within the monitoring controller, which can receive Beidou satellite signals for time synchronization and use a high-stability constant-temperature crystal oscillator to ensure the accuracy and stability of synchronization and sampling. In actual operation, the monitoring controller outputs a synchronization signal from the synchronization signal transceiver, so that the synchronization signal is sent to the synchronization signal interaction terminal of the data manager of each voltage monitoring unit via the network switch, so that the digital sampling signal of the voltage monitoring unit is strictly synchronized with the Beidou second pulse to ensure data consistency. Furthermore, the monitoring controller can also output sampling command information including sampling time and sampling length from the synchronization signal transceiver, so that the sampling command information is sent to the synchronization signal interaction terminal of the data manager of each voltage monitoring unit via the network switch, so that each voltage monitoring unit performs voltage sampling according to the sampling time and sampling length. Furthermore, the data transceiver end of the monitoring controller is connected to the data acquisition interaction end of the data manager through the network switch, and is used to receive the phase voltage value and the positive sequence voltage value from the data manager.

[0051] Further, such as Figure 5 As shown, the data manager also includes a sampling control module, a communication control module and a synchronous clock control module. The synchronous clock control module is connected to the communication control module and the sampling control module, and the storage unit is connected to the sampling control module and the communication control module respectively.

[0052] During actual operation, the monitoring controller can send synchronization signals and sampling command information to the data manager of each voltage monitoring unit, causing the data manager of each voltage monitoring unit to begin high-frequency voltage sampling, obtain phase voltage and positive-sequence voltage, and store the obtained phase voltage and positive-sequence voltage in a storage unit. Furthermore, the monitoring controller sends a read data command from the data transceiver to each voltage monitoring unit. After receiving the read data command, the data manager of each voltage monitoring unit sends the positive-sequence voltage and phase voltage to the monitoring controller via the data acquisition interaction terminal. Furthermore, the monitoring controller can display the positive-sequence voltage and phase voltage on a display device connected to it, allowing relevant personnel to monitor the voltage value on the AC side of the generator for transient overvoltage monitoring. Furthermore, a relevant monitoring program can also be set up in the monitoring controller to monitor the higher voltage value of the phase voltage and positive-sequence voltage as the monitoring object to perform transient overvoltage monitoring on the generator.

[0053] Furthermore, data analysis software can be pre-installed within the monitoring controller. This software primarily includes a login interface and displays real-time waveform curves of phase transient overvoltage and positive-sequence transient overvoltage for each voltage monitoring unit. Furthermore, the software can use pattern recognition technology to determine whether a transient overvoltage has occurred based on preset thresholds and a waveform feature library. The overvoltage's location and propagation path can be analyzed and diagnosed based on timestamp information. Furthermore, the software can analyze and determine the safety threshold for overvoltage tripping at the renewable energy generator end of each node based on the collected phase voltage and positive-sequence voltage waveforms.

[0054] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A voltage monitoring system for monitoring the voltage of a generator, characterized in that: The voltage monitoring system includes a monitoring controller, a network switch and at least one voltage monitoring unit; Each of the voltage monitoring units includes a voltage collector and an electric field induction transformer provided on the AC side of the generator, wherein the electric field induction transformer is used to collect the phase voltage value of the AC side of the generator and send the phase voltage value to the voltage collector; The network switch is connected to the monitoring controller and the voltage collector of each voltage monitoring unit respectively, and is used to establish a communication connection between the monitoring controller and the voltage collector; The monitoring controller is used to receive the phase voltage value from the voltage collector via the network switch, and monitor the voltage of the AC side of the generator based on the phase voltage value.

2. The voltage monitoring system according to claim 1, wherein: The voltage collector includes a data collector and a data manager; The input end of the data collector is connected to the output end of the electric field induction transformer, and is used to obtain the phase voltage value and calculate the positive sequence voltage value of the AC side based on the phase voltage value; The output end of the data collector is connected to the input end of the data manager, and is used to send the phase voltage value and the positive sequence voltage value to the data manager; The interactive end of the data manager is connected to the first signal interactive end of the network switch, and is used to send the phase voltage value and the positive sequence voltage value to the monitoring controller through the network switch.

3. The voltage monitoring system according to claim 2, characterized in that: The voltage collector also includes a filtering device; The input end of the filtering device is connected to the electric field induction transformer, and the output end of the filtering device is connected to the input end of the data collector, for receiving the phase voltage value, performing harmonic filtering on the phase voltage value, and sending the phase voltage value after harmonic filtering to the data collector.

4. The voltage monitoring system according to claim 3, characterized in that: The filtering device includes a first second-order filter, a second second-order filter and a third second-order filter; The input end of the first second-order filter is connected to the electric field induction mutual inductor, the output end of the first second-order filter is connected to the input end of the second second-order filter, the output end of the second second-order filter is connected to the input end of the third second-order filter, and the output end of the third second-order filter is connected to the input end of the data collector; The quality factor of the first second-order filter is smaller than the quality factor of the second second-order filter, and the quality factor of the second second-order filter is smaller than the quality factor of the third second-order filter.

5. The voltage monitoring system according to claim 3, wherein: The voltage collector also includes an analog-to-digital converter; The input end of the analog-to-digital converter is connected to the output end of the data collector, and the output end of the analog-to-digital converter is connected to the input end of the data manager, for receiving the phase voltage value and the positive-sequence voltage value in the form of analog signals, and performing analog-to-digital conversion on the phase voltage value and the positive-sequence voltage value in the form of analog signals to obtain the phase voltage value and the positive-sequence voltage value in the form of digital signals, and sending the phase voltage value and the positive-sequence voltage value in the form of digital signals to the data manager.

6. The voltage monitoring system according to claim 5, characterized in that: The data collector includes a high-speed data collector and a mathematical operator; The input end of the high-speed data collector is connected to the output end of the filtering device for obtaining the phase voltage value; The input end of the mathematical operator is connected to the output end of the high-speed data collector, and the output end of the mathematical operator is connected to the input end of the analog-to-digital converter, for obtaining the phase voltage value, and based on the phase voltage value, calculating the positive-sequence voltage value, and sending the phase voltage value and the positive-sequence voltage value to the analog-to-digital converter.

7. The voltage monitoring system according to claim 2, wherein: The interactive end of the data manager includes a synchronous signal interactive end and a data acquisition interactive end; the monitoring controller has a synchronous signal transceiver end and a data transceiver end; The synchronization signal transceiver of the monitoring controller is connected to the synchronization signal interaction terminal of the data manager via the network switch, and is used to send a synchronization signal to the data manager; The data transceiver end of the monitoring controller is connected to the data acquisition interaction end of the data manager through the network switch, and is used to receive the phase voltage value and the positive sequence voltage value from the data manager.

8. The voltage monitoring system according to claim 2, wherein: The data manager is a field programmable gate array device.

9. The voltage monitoring system according to claim 8, characterized in that: The field programmable gate array device has a storage unit for storing the phase voltage value and the positive sequence voltage value.

10. The voltage monitoring system according to claim 1, wherein: The monitoring controller has a remote communication port for connecting to a remote host computer.

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