CN102590586B - Photoelectric Current Transformer Powered by Transmission Line Insulator - Google Patents

Abstract

The invention discloses a photoelectric current transformer for supplying power for a transmission line insulator. The photoelectric current transformer comprises a current photoelectric measuring system; a high-voltage current photoelectric data measuring and transmitting module makes use of an electromagnetic induction principle to measure the current of a current busbar at a low-voltage side and converts the current information into a photoelectric signal, and the current information is transmitted to a current measurement secondary processing module arranged at the low-voltage side to perform data processing. The photoelectric current transformer is characterized in that an active photoelectric current transformer further comprises a high frequency drive power supply arranged at the low-voltage side, a high frequency transmission line insulator core and an alternating current (AC)/direct current (DC) power supply converter arranged at the high-frequency side; the high frequency transmission insulator core transmits high frequency AC electric energy with a specific frequency produced by the high frequency driving power supply from the low-voltage side to the high-voltage side through the liquid crystal (LC) high frequency electromagnetic resonance, and the high frequency AC electric energy is converted into DC electric energy by the AC/DC power supply converter, thereby supplying power for the high-voltage current measurement data photoelectric transmission module in the current photoelectric measuring system.

Description

Photoelectric Current Transformer Powered by Transmission Line Insulator

technical field

The invention relates to an active photoelectric current transformer.

Background technique

The current transformer plays a very important role in the power system and is a core device in the power system. With the development of power system and the construction of smart grid, especially the development of ultra-high voltage transmission, the power system has higher and higher requirements for current transformers. Traditional electromagnetic current transformers have ferromagnetic saturation, low frequency response, and high voltage Insurmountable shortcomings such as poor insulation capacity and many operating accidents have been unable to meet the development requirements of the power system. It is an urgent need for the development of smart grid to develop current transformers with good linear performance, wide frequency range and strong high-voltage insulation ability. Optical fiber current transformer (OCT) has broad application prospects due to its good anti-electromagnetic interference performance, high measurement accuracy, large dynamic range, wide frequency response range, small size, light weight, cheap price, and convenient interface with digital devices. It has become the development trend of high-voltage current transformers. Fiber optic current transformers mainly include pure optical current transformers (passive photoelectric transformers) and photoelectric hybrid current transformers (active photoelectric transformers). Pure optical current transformers are affected by factors such as ambient temperature and vibration The stability of its performance is the main difficulty that plagues its practical application; the photoelectric hybrid current transformer uses the electromagnetic measurement principle of a low-power current transformer or (Rogowski) coil to measure current, and uses optical fiber communication to transmit measurement information, which overcomes the problem of no The problem of poor stability of the source photoelectric transformer, good stability has made it develop rapidly, and has entered the practical stage at present. However, the measurement, data processing and photoelectric information transmission systems on the high-voltage side of active photoelectric transformers require power supplies. " and "pneumatic power supply" and other power supply methods. "Electromagnetic induction power supply with primary current on the high-voltage side" has insufficient power supply energy when the primary current is relatively small, forming a power supply dead zone that cannot work. When the primary current is large and short-circuited, there is too much power supply energy, which makes it difficult to discharge and damage the power supply circuit. ;Although the performance of laser and ultrasonic energy supply is stable, it can well meet the stability requirements of power supply, but the power supply energy is relatively small, and the energy saving and anti-interference requirements for measurement and photoelectric transmission systems are very high, and the price is too expensive. Long-term operation The service life cannot meet the requirements; the pneumatic energy supply also has gas leakage and the long-term operation life cannot meet the requirements. The high-voltage side energy supply of the photoelectric hybrid current transformer is the core technical problem that plagues its practical application.

Contents of the invention

Aiming at the shortcomings of existing active photoelectric current transformer high voltage side power supply methods, the present invention provides an active photoelectric current transformer powered by transmission line insulators, which can realize the active photoelectric current transformer through high-frequency electromagnetic resonance energy transfer. The power module on the high-voltage side of the photoelectric current transformer or other high-voltage online detection and monitoring equipment supplies energy.

To achieve the above object, the present invention is achieved by taking the following technical solutions:

A photoelectric current transformer powered by transmission line insulators, including a current photoelectric measurement system composed of a high-voltage current measurement photoelectric data transmission module, a communication optical fiber, and a current measurement data secondary processing module. The high-voltage current measurement photoelectric data transmission module uses the principle of electromagnetic induction Measure the current of the current bus on the high-voltage side, convert the current information into a photoelectric signal, and transmit the current information to the current measurement secondary processing module on the low-voltage side through the communication optical fiber for data processing; it is characterized in that the active photoelectric current transformer It also includes a high-frequency driving power placed on the low-voltage side, a high-frequency transmission line insulator core, and an AC/DC power converter placed on the high-voltage side. The high-frequency transmission line insulator core converts high-frequency The high-frequency alternating current energy of a specific frequency generated by the drive power supply is transmitted from the low-voltage side to the high-voltage side, and then converted into direct current energy by the AC/DC power converter to supply power to the high-voltage current measurement data photoelectric transmission module in the current photoelectric measurement system.

In the above solution, the high-frequency transmission line insulator core includes two capacitor columns, each capacitor column is composed of parallel plate capacitors with the same geometric size and capacitance in series, and the pitch of the same height between the two capacitor columns is There are several inductors L connected to each other, the output of the high-frequency drive power supply is connected to the two electrodes of the low-voltage end of the two capacitor columns, and the two electrodes of the high-voltage end of the two capacitor columns are connected to the input of the AC/DC power converter 4 .

The two capacitor columns can be installed side by side, or one of them can be made into a cylinder, and the other can be made into a cylinder, and then set with concentric axes.

The high-frequency drive power supply includes an AC-DC conversion circuit, a signal generator, a phase-locked frequency tracker, a power amplifier and a first transformer, and the output of the AC-DC conversion circuit is connected to the signal generator, phase-locked Frequency tracker and power amplifier; the high-frequency signal output by the signal generator is connected to the power amplifier, the output of the power amplifier is connected to the input of the first transformer, and the output of the first transformer is connected to the two capacitor columns at the low-voltage end of the high-frequency transmission line insulator core. electrodes are connected.

The AC/DC power converter includes a second transformer connected to the two electrodes of the high-voltage ends of the two capacitor columns, the output of the second transformer is connected to the input of a high-frequency rectification circuit, and the output of the high-frequency rectification circuit is connected to a The input of the filter circuit and the output of the filter circuit are stabilized and transformed by a DC-DC converter to output a stable DC power supply, which supplies power to the high-voltage current measurement data photoelectric transmission module.

The photoelectric current transformer powered by the transmission line insulator of the present invention uses high-frequency electric energy to transmit the power supply energy from the low-voltage side to the high-voltage side through the high-frequency transmission line insulator core, and converts the high-frequency electric energy into DC electric energy on the high-voltage side to realize the active The high-voltage side of the photoelectric current transformer is powered by a power unit. In this way, the power frequency electrical isolation between the high voltage and low voltage sides of the power supply system is complete. This power supply system has strong high-voltage insulation capability, large power supply energy transmission, stable performance, and is not affected and restricted by environmental factors. It has a long service life and has little influence on the electromagnetic interference generated by the measurement and data processing systems on the high voltage side.

Compared with the prior art, the present invention has the following advantages:

1) It is not limited by the current of the primary busbar on the high-voltage side, there is no "power supply dead zone", and it is not affected by the impact of large currents, and the power supply energy is very stable.

2) It can provide relatively large power supply energy, and can provide continuous and reliable power supply for a long time. The energy saving and anti-interference requirements for the measurement system of the active photoelectric transformer and the photoelectric transmission system are very low.

3) The performance is very stable, the environmental adaptability is strong, it is not limited by factors such as temperature changes, and the service life is long, which can meet the requirements of the power system for safety, reliability and long service life.

Description of drawings

Fig. 1 is a schematic structural diagram of a photoelectric current transformer powered by a transmission line insulator of the present invention.

FIG. 2 is a block diagram of the functional structure of the high-frequency driving power supply 3 on the low-voltage side in FIG. 1 .

FIG. 3 is a functional structural block diagram of the AC-DC power converter 4 on the high voltage side in FIG. 1 .

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Referring to Figure 1, the high-frequency drive power supply 3 is used on the low-voltage side L to convert the 50HZ industrial frequency AC power supply into the high-frequency power supply required to drive the high-frequency transmission line insulator core, and the high-frequency output generated by the high-frequency drive power supply is connected to the high-frequency transmission line insulator The two electrodes of the low-voltage end (lower end surface) of the two capacitor columns 1 and 2 in the core, and the high-frequency driving power supply 3 drive the high-frequency transmission line insulator core to generate high-frequency electromagnetic energy to be transmitted. The high-frequency transmission line insulator core includes two series capacitor columns 1 and 2 and an inductance L connected between the two capacitor columns. The capacitor columns 1 and 2 are stacked in series by several parallel plate capacitors of the same geometric size and capacitance. The two capacitor columns 1 and 2 can be installed side by side, or the capacitor column 1 can be made into a cylinder, and the capacitor column 2 can be made into a cylinder, and then they can be packaged with concentric axes. The parallel plate capacitor can be a high-voltage ceramic capacitor. When the electrodes of the parallel plate capacitor are stacked in series to form capacitor columns 1 and 2, the mutual gap between the capacitors shall be minimized, and the height of the corresponding capacitor between the two capacitor columns 1 and 2 shall be kept the same and the electrodes shall be parallel. The two capacitor columns 1 The inductance L is connected between the electrodes of the capacitor at the same pitch height as 2, the pitch height, the number of inductances and the inductance are determined by the frequency of the high-frequency drive power supply 3, the series capacitors of the two capacitor columns 1 and 2 and These inductors L form a high-frequency transmission line insulator core. The insulator core has AC and DC high-voltage insulation capabilities and can transmit high-frequency power at a specific frequency (10KHZ-1MHZ) from the low-voltage side L to the high-voltage side H. The input of the AC/DC power converter 4 is connected to the two electrodes of the high-voltage end (upper end face) of the two capacitor columns 1 and 2 in the high-frequency transmission line insulator core, and converts the high-frequency power output from the high-voltage end of the high-frequency transmission line insulator core The DC power is supplied to the high-voltage current measurement photoelectric data transmission module 6 in the current photoelectric measurement system of the photoelectric current transformer, so as to realize the photoelectric measurement of the high voltage current.

The current photoelectric measurement system includes a high-voltage current measurement photoelectric data transmission module 6 , a communication optical fiber 7 and a current measurement secondary processing module 8 . The high-voltage current measurement photoelectric data transmission module uses the principle of electromagnetic induction to measure the high-voltage current in the high-voltage current bus 5, converts the current information into a photoelectric signal, and transmits the current information to the current measurement secondary processing module 8 on the low-voltage side L through the communication optical fiber 7 , carry out data processing to realize the measurement of high voltage current.

As shown in Figure 2, the high-frequency drive power supply 3 on the low-voltage side includes an AC----DC conversion circuit, a signal generator, a phase-locked frequency tracker, a power amplifier and a transformer. The 50HZ industrial frequency AC power supply is converted into DC voltage by the AC----DC conversion circuit, and the output of the AC-DC conversion circuit is connected to the DC bias circuit of the signal generator, phase-locked frequency tracker and power amplifier to provide DC bias for them Voltage; the high-frequency signal output by the signal generator is connected to the power amplifier for power amplification to generate high-frequency power voltage. The frequency of the high-frequency signal is the same as the LC electromagnetic resonance frequency in the high-frequency transmission line insulator core; the output of the power amplifier is connected to the input of the transformer , the output of the transformer is connected to the two electrodes of the low-voltage end of the two capacitor columns 1 and 2 in the high-frequency transmission line insulator core, and the impedance matching of the electromagnetic resonance frequency of the high-frequency drive power supply 3 and the high-frequency transmission line insulator core is realized through the transformer; The phase-locked loop frequency tracker collects the output voltage and current of the transformer, supplies the phase frequency tracking circuit to judge the LC electromagnetic resonance frequency change in the high-frequency transmission line insulator core, dynamically tracks the LC electromagnetic resonance frequency in the high-frequency transmission line insulator core, and Regulate the output frequency of the signal generator to achieve frequency dynamic tracking and resonance matching.

As shown in Figure 3, the described AC/DC power converter 4 includes a transformer connected to the two electrodes of the high-voltage ends of the two capacitor columns 1 and 2, a high-frequency rectifier, a filter circuit and a DC-DC converter, the The output of the transformer is connected to a high-frequency rectification circuit, and the high-frequency rectification circuit is connected to a filter circuit. The output of the filter circuit is stabilized and transformed by a DC-DC converter to output a stable DC power supply (0-12V), and the current to the photoelectric current transformer The high-voltage current measurement photoelectric data transmission module 6 on the high-voltage side of the photoelectric measurement system supplies power.

Claims (5)

1. the photoelectric current inductor of transmission line insulator power supply, comprise that one by the electric current photoeletric measuring system of high-voltage current measurement photooptical data transport module, telecommunication optical fiber and current measurement data secondary treating module composition, high-voltage current measurement photooptical data transport module utilizes electromagnetic induction principle to measure the electric current of high voltage side current bus, and current information is converted to photosignal, the current measurement data secondary treating module that current information is sent to low-pressure side by telecommunication optical fiber is carried out data processing; It is characterized in that, the photoelectric current inductor of described transmission line insulator power supply also comprises that a high-frequency drive power supply that is placed in low-pressure side, high frequency transmission line insulator core, one are placed on high-tension side AC/DC supply convertor, this high frequency transmission line insulator core is sent to high-pressure side the high-frequency ac electric energy of the characteristic frequency of high-frequency drive power generation from low-pressure side by LC high-frequency electromagnetic resonance wherein, then by AC/DC supply convertor, is converted to direct current energy and powers to the high-voltage current measurement photooptical data transport module in electric current photoeletric measuring system; Described high frequency transmission line insulator core comprises two capacitor column, each capacitor column forms by the plane-parallel capacitor series connection of identical physical dimension and electric capacity size is stacking, between two capacitor column, the pitch place of equal height is connected with several inductance L, the output of described high-frequency drive power supply connects two electrodes of two capacitor column low pressure ends, and two electrodes of two capacitor column high-pressure sides connect the input of AC/DC supply convertor.

2. the photoelectric current inductor of transmission line insulator power supply as claimed in claim 1, is characterized in that, described two capacitor column are installed side by side.

3. the photoelectric current inductor of transmission line insulator power supply as claimed in claim 1, is characterized in that, one of them makes right cylinder described two capacitor column, and another makes cylindrical drum, then carries out concentric axis suit.

4. the photoelectric current inductor that transmission line insulator as claimed in claim 1 is powered, it is characterized in that, described high-frequency drive power supply comprises AC-DC translation circuit, a signal generator, a frequency of phase locking tracker, a power amplifier and first transformer, and the output of AC-DC translation circuit connects signal generator, frequency of phase locking tracker and power amplifier; The high-frequency signal of signal generator output connects power amplifier, and the output of power amplifier connects the input of the first transformer, and the output of the first transformer is connected with two electrodes of two capacitor column low pressure ends in high frequency transmission line insulator core.

5. the photoelectric current inductor that transmission line insulator as claimed in claim 1 is powered, it is characterized in that, described AC/DC supply convertor comprises second transformer being connected with two electrodes of two capacitor column high-pressure sides, the output of this second transformer connects the input of a high-frequency rectification circuit, the output of high-frequency rectification circuit connects the input of a filtering circuit, the DC power supply of voltage stabilizing conversion stable output is carried out in the output of filtering circuit by DC-DC converter, to high-voltage current measurement photooptical data transport module, power.

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