CN103698571B - There is current transformer arrangement and the bus current detection method of self energizing low-power consumption - Google Patents

Abstract

The invention discloses a current transformer device with self-supply and low power consumption, comprising a sensing light source, a fast optical attenuator, a first optical fiber coupler, a second optical fiber coupler, a self-supply module, a photoelectric feedback control circuit, a primary The current sensor and the optical fiber jitter monitoring module, the sensing light source is connected to the first optical fiber coupler, one output end of the first optical fiber coupler is connected to the self-powered module, and the other output end is connected to the fast optical attenuation; the electric power of the fast optical attenuator The input end is connected with the photoelectric feedback control circuit, the optical output end of the fast optical attenuator is connected with the second optical fiber coupler; the output end of the second optical fiber coupler is connected with the optical fiber jitter monitoring module and the photoelectric feedback control circuit, and the photoelectric feedback control circuit is connected with the photoelectric feedback control circuit. The primary current sensor is connected; the self-energy supply module is connected with the photoelectric feedback control circuit. The current transformer device has the function of self-supply and low power consumption. At the same time, it also provides a bus current detection method, which has high measurement accuracy.

Description

Current transformer device with self-supply and low power consumption and bus current detection method

technical field

The invention belongs to the field of power system monitoring and protection, in particular to a current transformer device with self-supply and low power consumption and a bus current detection method.

Background technique

In the operation of power production, power transmission and power equipment, various physical quantities need to be monitored, among which the most important physical quantities are current and voltage. The sensor equipment that obtains current and voltage information is a transformer. High current or high voltage is converted to low current or low voltage on the low voltage side. Accurate, reliable and high-performance transformers are one of the important guarantees to ensure the safe, reliable and efficient operation of the power grid.

Traditional transformers are mainly electromagnetic transformers, but their inherent shortcomings such as magnetic saturation, ferromagnetic resonance, small dynamic range, narrow frequency band range, flammability, and explosion have been exposed during long-term operation. At the same time, as the operating voltage level of the power grid becomes higher and higher, the insulation design of traditional transformers will become very complicated, and the volume, weight and cost will also increase sharply.

In recent decades, electronic current transformers (ECT) and optical current transformers (OCT) have gradually emerged and gradually replaced traditional electromagnetic transformers. Compared with traditional electromagnetic transformers, electronic transformers and optical current transformers (OCT) have the following advantages: excellent insulation performance, small size, low cost; no iron core, eliminating magnetic saturation, ferromagnetic resonance No open-circuit high-voltage danger on the low-voltage side; wide frequency response range; no flammable and explosive dangers caused by oil filling; good electromagnetic compatibility and strong confidentiality; adapted to the digital and intelligent development of power metering and protection trend.

At present, optical current transformers are divided into two categories: pure optical type (passive) and hybrid type (active) according to whether they need a primary power supply. In the 1960s, a series of pure optical current and voltage transformers were developed by using Pockels Effect and Faraday Effect. The method is direct, the device is simple, and the precision is high, but its disadvantages are: Sensitive to vibration, temperature, installation and light fluctuations, etc., the measurement stability is poor.

Aiming at these problems, a hybrid optical current transformer came into being. Its measurement accuracy and reliability have withstood the test of actual engineering. The technology is mature and its application prospects are broad. However, due to the need for energy supply at the high voltage end, the cost and complexity of the system are increased. The development of laser fiber energy supply solutions has enabled the realization of high-voltage energy supply, but this technology is monopolized by a few international companies, and the price remains high, which restricts the development of the domestic power industry.

Therefore, reducing the power consumption at the high-voltage end has become a development direction of the hybrid optical current transformer. In 2001, Huazhong University of Science and Technology proposed an OCT solution using Rogowski coils, integrators and voltage-frequency converters, using the traditional CT energy supply solution, but due to the large power consumption of the voltage-frequency converter, the overall power consumption of OCT The decrease is not obvious. In 2005, the University of British Columbia and Nxtphase jointly proposed a hybrid OCT solution based on LiNbO ₃ crystals, passive integrators and Rogowski coils, with zero power consumption at the primary end. However, due to the influence of crystal nonlinearity and passive integration circuit, its actual accuracy is not ideal.

Contents of the invention

Technical problem: The technical problem to be solved by the present invention is to provide a current transformer device with self-supply and low power consumption. , this method has high measurement accuracy.

Technical solution: In order to solve the above-mentioned technical problems, the present invention adopts the following technical solution:

A current transformer device with self-powered low power consumption, the current transformer device includes: a sensing light source, a fast tunable optical attenuator, a first optical fiber coupler with a splitting ratio of m:n, and a splitting ratio of p: q's second fiber optic coupler, self-powered module, photoelectric feedback control circuit, primary current sensor and fiber optic jitter monitoring module, the output end of the sensing light source is connected to the input end of the first fiber optic coupler, and one output of the first fiber optic coupler The other end of the first optical fiber coupler is connected to the optical input end of the fast optical attenuation, the electrical input end of the fast tunable optical attenuator is connected to the photoelectric feedback control circuit, and the fast tunable optical attenuator The optical output end of the second optical fiber coupler is connected to the input end of the second optical fiber coupler, one output end of the second optical fiber coupler is connected to the fiber jitter monitoring module, the other output end of the second optical fiber coupler is connected to the photoelectric feedback control circuit, and the photoelectric feedback control circuit The circuit is connected with the primary current sensor; the self-powered module is connected with the photoelectric feedback control circuit to supply energy for the photoelectric feedback control circuit; m+n=100, and m≥1, n≥1; p+q=100, and p≥1 , q≥1.

Further, the self-powered module includes a beam splitter and a photodiode array, the beam splitter has an input terminal and N output terminals, the photodiode array is formed by connecting N photodiodes in series, and the input terminal of the beam splitter serves as a self-supply The input end of the energy module, the output end of the photodiode array is used as the output end of the self-functional module, the input end of the beam splitter is connected with an output end of the first fiber coupler, the output end of the beam splitter is connected with the input end of the photodiode array terminal, and one output terminal of the beam splitter is connected to a photodiode in the photodiode array, and the output terminal of the photodiode array is connected to the photoelectric feedback control circuit for energy supply; N is an integer greater than or equal to 2.

Further, the photoelectric feedback control circuit includes a differential amplifier module and a first photoelectric receiver, the input terminal of the first photoelectric receiver and the positive phase terminal of the differential amplifier module are used as the input terminal of the photoelectric feedback control circuit, and the output terminal of the differential amplifier module As the output end of the photoelectric feedback control circuit, the input end of the first optical receiver is connected to an optical output port of the second optical fiber coupler, the output end of the first optical receiver is connected to the negative phase end of the differential amplifier module, and the differential amplification The positive phase terminal of the module is connected with the primary current sensor; the output terminal of the differential amplifier module is connected with the driving terminal of the fast tunable optical attenuator, and is used for driving the fast tunable optical attenuator.

Further, the optical fiber jitter monitoring module includes a wavelength division multiplexer, a fiber optic mirror, a wavelength division multiplexer, an optical circulator, a monitoring light source, a second photoelectric receiver, a third photoelectric receiver, a divider and a root One input end of the wavelength division multiplexer is used as the input end of the optical fiber jitter monitoring module, the output end of the divider is used as the output end of the optical fiber jitter monitoring module, and the other input end of the wavelength division multiplexer is connected with the fiber optic mirror, For transmitting monitoring light, the output end of the wavelength division multiplexer is connected with the input end of the wavelength division multiplexer, and one output end of the wavelength division multiplexer is connected with the input end of the third photoelectric receiver, and the wavelength division multiplexer The other output end of the optical circulator is connected with an input end of the optical circulator, the other input end of the optical circulator is connected with the monitoring light source, the output end of the optical circulator is connected with the input end of the second photoelectric receiver, and the second photoelectric receiver The output end of the root opener is connected with the input end of the root opener, the output end of the root opener is connected with one input end of the divider, and the other input end of the divider is connected with the output end of the third photoelectric receiver.

Further, the optical fiber jitter monitoring module includes a fourth photoelectric receiver, a DC and AC separation module, a divider, and an amplifier. The input end of the fourth photoelectric receiver is used as the input end of the optical fiber jitter monitoring module, and the output end of the amplifier is used as an optical fiber The output terminal of the jitter monitoring module and the output terminal of the fourth photoelectric receiver are connected to the input terminals of the DC and AC separation module, and the two output terminals of the DC and AC separation module are respectively connected to the two input terminals of the divider, and the divider's The output terminal is connected to the input terminal of the amplifier.

A bus current detection method of the above-mentioned current transformer equipment, the detection method includes the following process: using a sensing light source to generate sensing light, the sensing light is divided into two parts after passing through the first optical fiber coupler with a splitting ratio of m:n, Among them, m% of the sensing light is input to the photodiode array after passing through the beam splitter, and supplies energy to the photoelectric feedback control circuit, and n% of the sensing light passes through the fast tunable optical attenuator to generate an attenuated optical signal, which is coupled by the second optical fiber The optical device collects the output optical signal of the fast tunable optical attenuator, performs nonlinear correction processing on p% of the output optical signal, reduces the interference caused by the jitter of the first optical fiber and the jitter of the sensing light source, and corrects the interference caused by the fast tunable optical attenuator. The electro-optic modulation is nonlinear, and at the same time, jitter elimination processing is performed on q% of the output light to reduce the interference caused by the second optical fiber jitter; the first optical fiber is connected between the sensing light source and the first optical fiber coupler The second optical fiber refers to the optical fiber connected between the second optical fiber coupler and the optical fiber jitter monitoring module, or the optical fiber connected between the wavelength division multiplexer and the wavelength division multiplexer.

Further, the non-linear correction processing process is as follows: use the primary current sensor to obtain the bus current signal, and generate the primary current sensing signal, and at the same time, the p% optical signal output by the second optical fiber coupler is converted by the first photoelectric receiver into an electrical signal; perform a differential amplification operation on the primary current sensing signal and the electrical signal converted by the first photoelectric receiver to generate a new driving signal for driving the fast tunable optical attenuator, and for the fast tunable optical attenuator The non-linearity of the electro-optical modulation brought about by this method is corrected, and at the same time, the interference caused by the jitter of the first optical fiber and the jitter of the sensing light source is reduced.

Further, the described jitter elimination process is as follows: the monitoring light source is used to generate monitoring light, and the monitoring light passes through the optical circulator, the wave division multiplexer and the wavelength division multiplexer in turn, and reaches the fiber optic reflector, and the fiber reflector generates reflected light , the reflected light passes through the wavelength division multiplexer, the wavelength division multiplexer, and the optical circulator in turn, and reaches the second photoelectric receiver, which performs photoelectric conversion, and the converted electrical signal is obtained by the root opener to obtain the square root After the second electrical signal, the q% output light of the second optical fiber coupler passes through the wavelength division multiplexer and the wavelength division multiplexer in turn, and reaches the third photoelectric receiver. The third photoelectric receiver performs photoelectric conversion to generate the first For the electrical signal, the second electrical signal is divided by the first signal to obtain an output voltage signal; the second optical fiber refers to the optical fiber connected between the wavelength division multiplexer and the wavelength division multiplexer.

Further, the described jitter elimination process is as follows: the q% output light output from the second optical fiber coupler is converted by the fourth photoelectric receiver to generate a sensing signal, which respectively passes through a DC and AC separation module, a divider, and an amplifier to generate output voltage signal; the second optical fiber refers to the optical fiber connected between the second optical fiber coupler and the optical fiber jitter monitoring module.

Beneficial effect: compared with the prior art, the present invention has the following advantages:

(1) The device uses an ultra-low power fast tunable optical attenuator, which can effectively reduce the power supply demand of the high-voltage primary end. The device of the present invention adopts a self-energy supply scheme, and no other energy supply methods are required. The output light of the laser is used as both sensing light and energy supply light, which effectively reduces costs. At the same time, the existing mature communication optical fiber and photodiode (PhotoDiode) array are used , high reliability, good stability, simple structure and low cost. The photoelectric feedback control circuit is used to reduce the drift of the optical attenuation constant, the drift of the optical power of the light source and the error caused by the disturbance of the fiber, and solve the problems of nonlinearity of the fast tunable optical attenuator, the jitter of the light source and the disturbance of the fiber. At the same time, the wavelength division multiplexing technology is used to realize real-time monitoring of the loss along the optical fiber, eliminate the interference of the loss along the optical fiber, and improve the accuracy and stability of the equipment. The whole system uses pure analog circuit, which saves the digital circuit, simplifies the circuit design and reduces the cost.

(2) The optical power jitter of the light source and the disturbance of the optical fiber will also make the optical power unstable, resulting in a nonlinear relationship between the output optical power of the fast tunable optical attenuator and the primary current. In order to solve the problem of non-linearity of optical attenuation constant and jitter of light source and improve the measurement accuracy of the system, the invention adopts a photoelectric feedback control module to reduce errors caused by drift of optical attenuation constant, jitter of light source and disturbance of optical fiber. The output signal of the fast tunable optical attenuator is divided into two bundles by the second fiber coupler. Part of the light attenuation signal is converted into an electrical signal by the first photoelectric receiver, and returned to the negative phase terminal of the differential amplifier module, which is compared with the primary current sensing signal generated by the primary current sensor, and then controlled and adjusted through the integral and integral circuits to generate The new driving voltage is input to the driving end of the fast tunable optical attenuator. Such a design can timely feed back the change of the optical attenuation constant, the jitter of the light source and the disturbance of the optical fiber to the driving end of the fast tunable optical attenuator. When the optical attenuation constant, the optical power of the sensing light source or the loss coefficient of the optical fiber change, the driving signal of the adjustable optical attenuator can be dynamically adjusted through the photoelectric feedback control module, so as to ensure that the optical attenuation multiple is linear with the primary current.

(3) Compensate the fiber perturbation error and improve the accuracy of the system. The present invention adopts the wavelength division multiplexing technology (WDM) to realize the monitoring of the loss along the optical path. In the third photoelectric receiver, the voltage signal proportional to the optical power is processed by multiplication and division algorithm to compensate the optical fiber perturbation error and improve the system accuracy. The present invention can also adopt the AC/DC separation compensation method to monitor the loss along the optical path, process the signal of the fourth photoelectric receiver, compensate the optical fiber perturbation error, and improve the accuracy of the system.

Description of drawings

Fig. 1 is a schematic diagram of the first structure of the current transformer device of the present invention.

Fig. 2 is a second structural schematic diagram of the current transformer device of the present invention.

Fig. 3 is a schematic structural diagram of the self-powered module in the present invention.

Fig. 4 is a structural schematic diagram of a differential module in the photoelectric feedback control module in the present invention.

Fig. 5 is a circuit diagram of the differential module in the photoelectric feedback control module in the present invention.

Fig. 6 is a schematic diagram of the first structure of the optical fiber jitter monitoring module in the present invention.

Fig. 7 is a schematic diagram of the second structure of the optical fiber jitter monitoring module in the present invention.

In the figure are: sensing light source 1, fast tunable optical attenuator 2, second optical fiber coupler 3, wavelength division multiplexer 4, wavelength division multiplexer 5, second photoelectric receiver 6, third photoelectric receiver 7. Optical circulator 8, monitoring light source 9, differential amplification module 10, primary current sensor 11, first photoelectric receiver 13, optical fiber mirror 14, first optical fiber coupler 15, beam splitter 16, photodiode array 17, Differential circuit 18 , proportional amplifier circuit 19 , integral circuit 20 , differential circuit 21 , fourth photoelectric receiver 22 , AC/DC separation module 23 , divider 24 , amplifier 25 , output voltage 26 , and root opener 27 .

detailed description

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

As shown in Figure 1, a current transformer device with self-supply and low power consumption of the present invention includes: a sensing light source 1, a fast tunable optical attenuator 2, and a first optical fiber coupler with a splitting ratio of m:n 15. A second optical fiber coupler 3 with a splitting ratio of p:q, a self-powered module, a photoelectric feedback control circuit, a primary current sensor 11 and an optical fiber jitter monitoring module. The output end of the sensing light source 1 is connected to the input end of the first optical fiber coupler 15, one output end of the first optical fiber coupler 15 is connected to the self-powered module, and the other output end of the first optical fiber coupler 15 is connected to the fast light attenuation 2 The optical input end of the fast tunable optical attenuator 2 is connected to the photoelectric feedback control circuit, the optical output end of the fast tunable optical attenuator 2 is connected to the input end of the second optical fiber coupler 3, and the second optical fiber coupling One output end of the second optical fiber coupler 3 is connected to the optical fiber jitter monitoring module, the other output end of the second optical fiber coupler 3 is connected to the photoelectric feedback control circuit, and the photoelectric feedback control circuit is connected to the primary current sensor 11 . The self-energy supply module is connected with the photoelectric feedback control circuit to supply energy for the photoelectric feedback control circuit. m+n=100, and m≥1, n≥1. For example, m=99, n=1. p+q=100, and p≥1, q≥1, for example, p=20, q=80. m, n, p, and q are all positive integers.

As shown in FIG. 3 , the self-powered module includes a beam splitter 16 and a photodiode array 17 , the beam splitter 16 has one input terminal and N output terminals, and is a 1*N beam splitter. The photodiode array 17 is composed of N photodiodes in series, the input end of the beam splitter 16 is used as the input end of the self-powered module, and the output end of the photodiode array (hereinafter referred to as: PD array) 17 is used as the output end of the self-functional module, The input end of the beam splitter 16 is connected with an output end of the first fiber coupler 15, the output end of the 1*N beam splitter 16 is connected with the input end of the photodiode array 17, and an output end of the beam splitter 16 and One photodiode in the photodiode array 17 is connected, and the output terminal of the photodiode array 17 is connected with the photoelectric feedback control circuit for energy supply. N is an integer greater than or equal to 2.

The m% of the sensing light passing through the first optical fiber coupler 15 with a splitting ratio of m:n passes through the 1*N beam splitter 16 and is equally divided into N beams, which are respectively connected to the photodiode array 17, and N photodiodes are connected in series Form a photodiode array 17 to form a self-powered module.

The photoelectric feedback control circuit comprises a differential amplifier module 10 and a first photoelectric receiver 13, the input terminal of the first photoelectric receiver 13, the positive phase terminal of the differential amplifier module 10 as the input terminal of the photoelectric feedback control circuit, and the output terminal of the differential amplifier module 10 As the output end of the photoelectric feedback control circuit, the input end of the first optical receiver 13 is connected with an optical output port of the second optical fiber coupler 3, and the output end of the first optoelectronic receiver 13 is connected with the negative phase end of the differential amplifier module 10 Connection, the positive phase terminal of the differential amplifier module 10 is connected with the primary current sensor 11;

With reference to Fig. 4, the specific operation of the differential amplification module 10 in the photoelectric feedback control module is as follows: the output terminal of the first photoelectric receiver 13 is connected to the negative phase terminal of the differential circuit 18, and the output terminal of the primary current sensor 11 is connected to the positive phase terminal of the differential circuit 18. end connection. The resulting differential signal then generates a driving signal via the proportional amplifier circuit 19, the integrating circuit 20, and the differential circuit 21, and then inputs it to the driving terminal of the fast tunable optical attenuator 2, and dynamically adjusts the driving voltage of the fast tunable optical attenuator 2, The error caused by the change of the light attenuation constant of the fast tunable optical attenuator 2 is reduced.

Referring to FIG. 4 and FIG. 5 , the signal generated by the first photoelectric receiver 13 is a third electrical signal. The differential amplifier module 10 is composed of a differential amplifier circuit and an integral differential circuit, wherein the differential amplifier circuit includes a differential circuit 18 and a proportional amplifier circuit 19 , and the integral differential circuit includes an integral circuit 20 and a differential circuit 21 . The differential amplifier circuit is composed of a first operational amplifier A1, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. One end of the first resistor R1 is used as the first input end of the differential amplifier circuit, one end of the third resistor R3 is used as the second input end of the differential amplifier circuit, and the output end of the first operational amplifier A1 is used as the output end of the differential amplifier circuit. The other end of the first resistor R1 is connected to the positive phase input terminal of the first operational amplifier A1 and one end of the second resistor R2, the other end of the second resistor R2 is grounded, and the other end of the third resistor R3 is connected to the negative phase input of the first operational amplifier A1 terminal is connected to one terminal of the fourth resistor R4, and the other terminal of the fourth resistor R4 is connected to the output terminal of the first operational amplifier A1. The integral-differential circuit is composed of a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first capacitor C1 and a second operational amplifier A2. One end of the fifth resistor R5 serves as the input end of the integral-differential circuit, and the output end of the second operational amplifier A2 serves as the output end of the integral-differential circuit. The other end of the fifth resistor R5 is connected to the non-inverting input terminal of the second operational amplifier A2, one end of the seventh resistor R7 and one end of the first capacitor C1, and the other end of the seventh resistor R7 is connected to the output terminal of the second operational amplifier A2 The other end of the first capacitor C1 is connected to one end of the eighth resistor R8, the other end of the eighth resistor R8 is connected to the output end of the second operational amplifier A2, and one end of the sixth resistor R6 is connected to the negative terminal of the second operational amplifier A2. The phase input end is connected, and the other end of the sixth resistor R6 is grounded. The primary current sensing signal is connected to one end of the first resistor R1, the third electrical signal is connected to one end of the third resistor R3, the output end of the differential amplifier circuit is connected to the input end of the integral and differential circuit, and the output end of the integral and differential circuit is connected to the driving signal . In the differential module, the first operational amplifier A1 is used to form a differential amplifier circuit, and the primary current sensing signal and the third electrical signal are differentially and proportionally amplified. Using the second operational amplifier A2, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8 and the first capacitor C1 to form an integral differential circuit, the output signal of the differential amplifier circuit is integrated and differentiated to obtain the drive signal .

In this application, the optical fiber jitter monitoring module preferably has two structures.

The first structure: as shown in Figure 1 and Figure 6, the optical fiber jitter monitoring module includes a wavelength division multiplexer 4, a fiber optic mirror 14, a wavelength division multiplexer 5, an optical circulator 8, a monitoring light source 9, a second photoelectric Receiver 6, the third photoelectric receiver 7, divider 24 and root opener 27, an input end of wavelength division multiplexer 4 is used as the input end of optical fiber jitter monitoring module, and the output end of divider 24 is used as optical fiber jitter monitoring module The output end of the wavelength division multiplexer 4 is connected with the fiber optic mirror 14 for transmitting monitoring light, the output end of the wavelength division multiplexer 4 is connected with the input end of the wavelength division multiplexer 5, and the wavelength division multiplexer 4 is connected with the input end of the wavelength division multiplexer 5. An output end of the demultiplexer 5 is connected with the input end of the third photoelectric receiver 7, and another output end of the wave demultiplexer 5 is connected with an input end of the optical circulator 8, and another output end of the optical circulator 8 The input end is connected with the monitoring light source 9, and the output end of the optical circulator 8 is connected with the input end of the second photoelectric receiver 6, and the output end of the second photoelectric receiver 6 is connected with the input end of the root opener 27, and the root opener 27 The output terminal of the divider is connected with an input terminal of the divider 24, and the other input terminal of the divider 24 is connected with the output terminal of the third photoelectric receiver 7. The optical circulator 8 is used for switching the monitoring light generated by the monitoring light source 9 and the output light of the wave division multiplexer 5 .

The second structure: as shown in Figure 2 and Figure 7, the optical fiber jitter monitoring module includes a fourth photoelectric receiver 22, a DC and AC separation module (hereinafter referred to as: AC/DC separation module) 23, a divider 24, an amplifier 25, The input end of the fourth photoelectric receiver 22 is used as the input end of the optical fiber jitter monitoring module, the output end of the amplifier 25 is used as the output end of the optical fiber jitter monitoring module, and the output end of the fourth photoelectric receiver 22 is connected with the input of the AC/DC separation module 23 The two output terminals of the AC/DC separation module 23 are respectively connected to the two input terminals of the divider 24, and the output terminal of the divider 24 is connected to the input terminal of the amplifier 25.

The bus current detection method of the above-mentioned current transformer equipment includes the following process: using the sensing light source 1 to generate sensing light, and the sensing light is divided into two parts after passing through the first optical fiber coupler 15 with a splitting ratio of m:n, wherein m % of the sensing light is input to the photodiode array 17 after passing through the 1*N beam splitter 16, and supplies energy to the photoelectric feedback control module, and the n% of the sensing light passes through the fast tunable optical attenuator 2 to generate an attenuated optical signal. The second optical fiber coupler 3 collects the output optical signal of the fast tunable optical attenuator 2, performs nonlinear correction processing on p% of the output optical signal, reduces the interference caused by the jitter of the first optical fiber and the jitter of the sensing light source, and corrects the fast optical attenuation The electro-optic modulation brought by the device 2 is non-linear, and at the same time, the jitter elimination processing is performed on q% of the output light to reduce the interference caused by the second optical fiber jitter; the first optical fiber is connected between the sensing light source 1 and the first optical fiber. The optical fiber between the optical fiber coupler 15, the second optical fiber refers to the optical fiber connected between the second optical fiber coupler 3 and the optical fiber jitter monitoring module, or the optical fiber connected between the wavelength division multiplexer 4 and the wavelength division multiplexer 5 optical fiber.

In the above bus current detection method, the non-linear correction processing process is: use the primary current sensor 11 to obtain the bus current signal, and generate a primary current sensing signal. The signal is converted into an electrical signal by the first photoelectric receiver 13; a differential amplification operation is performed on the primary current sensing signal and the electrical signal converted by the first photoelectric receiver 13 to generate a new driving signal for driving fast tunable optical The attenuator 2 corrects the non-linearity of the electro-optic modulation brought by the fast tunable optical attenuator 2, and at the same time reduces the interference caused by the jitter of the first optical fiber and the jitter of the sensing light source.

When the first structure is selected for the optical fiber jitter monitoring module, the jitter elimination processing process in the above bus current detection method is: use the monitoring light source 9 to generate monitoring light, and the monitoring light passes through the optical circulator 8, the wave division multiplexer 5 and the The wavelength division multiplexer 4 reaches the optical fiber reflector 14, and the optical fiber reflector 14 generates reflected light, which passes through the wavelength division multiplexer 4, the wavelength division multiplexer 5, and the optical circulator 8 in turn, and reaches the second photoelectric receiver 6, the second photoelectric receiver 6 performs photoelectric conversion, the converted electrical signal passes through the root opener 27 to obtain the second electrical signal after the square root, and the q% output light of the second optical fiber coupler 3 is sequentially subjected to wavelength division multiplexing The device 4 and the wave division multiplexer 5 reach the third photoelectric receiver 7, and the third photoelectric receiver 7 performs photoelectric conversion to generate the first electrical signal, and divides the second electrical signal and the first signal to obtain the output voltage Signal 26. The second photoelectric receiver 6 is to receive the light of 1570nm, that is, the light of the monitoring light source 9 . The third photoelectric receiver 7 receives light of 1550nm, that is, the light of the sensing light source 1 . In this structure, the second optical fiber refers to the optical fiber connected between the wavelength division multiplexer 4 and the wavelength division multiplexer 5 .

When the second structure is selected for the optical fiber jitter monitoring module, the jitter elimination processing process in the above bus current detection method is as follows: the q% output light output from the second optical fiber coupler 3 is converted by the fourth photoelectric receiver 22 to generate a sensor The signal passes through the AC/DC separation module 23 , the divider 24 , and the amplifier 25 to generate an output voltage signal 26 . In this structure, the second optical fiber refers to the optical fiber connected between the second optical fiber coupler 3 and the optical fiber jitter monitoring module.

In the current transformer device with self-supply and low power consumption of the present invention, the sensing light source 1 generates sensing light, and the sensing light is divided into two parts after passing through the first optical fiber coupler 15, and the m% sensing light passes through a 1*N beam splitter After 16, it is equally divided into N paths of light, which are input to the photodiode array 17 for energy supply. n% of the sensing light passes through the fast tunable optical attenuator 2 to generate an attenuated optical signal. The light passing through the fast tunable optical attenuator 2 is transmitted to the second optical fiber coupler 3, and the light is divided into two paths, and the p% light of one path is transmitted through the optical fiber to the first photoelectric receiver 13 and converted into an electrical signal. It is transmitted to the negative phase terminal of the differential amplifier module 10 , and is differentiated from the primary current sensing signal of the primary current sensor 11 to obtain the signal as a driving signal, which is input to the driving terminal of the fast tunable optical attenuator 2 . In this way, errors caused by the instability of the sensing light source 1 and the optical path loss of the first optical fiber can be reduced. At the same time, when the attenuation constant of the fast tunable optical attenuator 2 changes nonlinearly, the changed optical attenuation constant can be fed back to the driving end of the fast tunable optical attenuator 2 through this structure, and the system can be recovered by using the change of the driving voltage The linear balance state reduces the error caused by the nonlinearity of the optical attenuation constant; the other q% of the light is transmitted to the low-voltage end through the second optical fiber. For the optical path loss of the second optical fiber connecting the high-voltage end and the low-voltage end, wavelength division multiplexing technology and AC/DC separation compensation technology are mainly used to eliminate the interference of loss along the optical path. The specific scheme is as follows:

Option One

As shown in Figure 4, the monitoring light source 9 (1570nm) is transmitted to the optical circulator 8 through the optical fiber, and the optical circulator 8 transmits the light to the wavelength division multiplexer 5 through the optical fiber, and then to the wavelength division multiplexer 4 through the optical fiber, and the wavelength division multiplexer 4 A window of the multiplexer 4 transmits the light to the fiber reflector 14, and the reflected light through the fiber reflector 14 and the q% output light of the second fiber coupler 3 are coupled into the same optical fiber through the wavelength division multiplexer 4. For a certain distance transmission, the optical signal is divided into the reflected optical signal of the optical fiber mirror 14 and the q% output optical signal of the second optical fiber coupler 3 by using the wave division multiplexer 5 . Wherein, the q% output optical signal of the second optical fiber coupler 3 is transmitted to the third photoelectric receiver 7 through the optical fiber, and is converted into the first electrical signal V ₁ by the third photoelectric receiver 7, and the reflected optical signal of the optical fiber mirror 14 passes through The optical fiber is transmitted to the optical circulator 8, and the optical circulator 8 transmits the light to the second photoelectric receiver 6 through the optical fiber, and the second photoelectric receiver 6 converts it into a second electrical signal V ₂ , and performs algorithmic processing on V ₁ and V ₂ , to reduce the interference caused by the loss constant α ₁ along the optical fiber b connected between the wavelength division multiplexer 4 and the wavelength division multiplexer 5 . The algorithm is as follows: Let the loss constant along the fiber b be α ₁ , the q% optical power output by the second fiber coupler 3 be P ₁ , the optical power of the monitoring light source 9 be P ₂ , the optical attenuation rate of the fiber mirror is α, and the light The proportional constant of power and voltage value is β, then the first electrical signal V ₁ =P ₁ ·α ₁ ·β converted by the third photoelectric receiver 7, and the second electrical signal V ₂ =P ₂ converted by the second photoelectric receiver 6 ·α·α ₁ ² ·β, V ₂ is obtained through root opener 27 The input terminals of the divider 24 are divided into V ₁ , Divide the two to get Multiply the output of the divider by The sensing signal in an ideal non-interference state proportional to the bus current signal can be obtained.

Option II

As shown in Figure 5, the q% output light of the second optical fiber coupler 3 is converted into an electrical signal by the fourth photoelectric receiver 22, and the electrical signal is divided into AC and DC components by the AC/DC separation module 23, and transmitted to the divider respectively 24 inputs. The divider 24 divides the AC component by the DC component, and the result is transmitted to the input terminal of the amplifier 25, and the output terminal of the amplifier 25 is the signal after fiber jitter correction. The algorithm process is as follows: assume that the loss constant along the second optical fiber c connected between the second optical fiber coupler 3 and the optical fiber jitter monitoring module is α ₂ , the amplification factor of the amplifier 25 is A, and the q% light output by the second optical fiber coupler 3 The power is P ₃ , where the constant optical power is P ₄ , and the power superimposed on the constant optical power is P ₅ , so P ₃ =P ₄ +P ₅ , the proportional constant of optical power and voltage value is β, then the fourth photoelectric receiver The electrical signal V ₄ =P ₃ α ₂ β=P ₄ α ₂ β+P ₅ α2 β converted by the machine 22 and the AC signal processed by the AC/DC separation module 23 is V ₅ =P ₅ α ₂ β, the DC signal is V ₆ =P ₄ α ₂ β, V ₅ divided by V ₆ can eliminate the influence of α ₂ loss along the fiber c, the formula is V ₅ /V ₆ =P ₅ α ₂ . β/(P ₄ ·α ₂ ·β)=P ₅ /P ₄ , the output of the amplifier 25 is A*V ₅ /V ₆ =A*P ₅ /P ₄ , since P ₄ is constant, the output of the amplifier 25 is Proportional to P ₅ . In the bus current detection method of the present invention, the sensing light is generated by the sensing light source 1, passes through the first optical fiber coupler 15, m% of the sensing light is used for the self-powered module, and n% of the sensing light passes through the fast tunable optical attenuator 2 (FVOA, fastvariableopticalattenuator) to generate an attenuated optical signal. The attenuated optical signal is processed by two schemes to reduce interference caused by optical fiber jitter, and an output signal is generated after photoelectric conversion. At the same time, the primary current sensor 11 is used to obtain the bus current signal on the high-voltage line, and after differential, amplification, integration, and differentiation with the feedback electrical signal of the output signal of the fast tunable optical attenuator 2, a new driving signal is generated for driving the fast tunable optical attenuator. Tuning optical attenuator 2.

Claims (5)

1. A current transformer device with self-powered low power consumption, characterized in that the current transformer device comprises: a sensing light source (1), a fast tunable optical attenuator (2), and a splitting ratio of m:n The first optical fiber coupler (15), the second optical fiber coupler (3) with a splitting ratio of p:q, a self-powered module, a photoelectric feedback control circuit, a primary current sensor (11) and an optical fiber jitter monitoring module, and a sensing light source (1) The output end is connected to the input end of the first optical fiber coupler (15), one output end of the first optical fiber coupler (15) is connected to the self-powered module, and the other output end of the first optical fiber coupler (15) It is connected with the optical input end of the fast tunable optical attenuator (2), the electrical input end of the fast tunable optical attenuator (2) is connected with the photoelectric feedback control circuit, and the optical output end of the fast tunable optical attenuator (2) is connected with the The input end of the second optical fiber coupler (3) is connected, one output end of the second optical fiber coupler (3) is connected with the fiber jitter monitoring module, and the other output end of the second optical fiber coupler (3) is connected with the photoelectric feedback control circuit , the photoelectric feedback control circuit is connected with the primary current sensor (11); the self-powered module is connected with the photoelectric feedback control circuit to supply energy for the photoelectric feedback control circuit; m+n=100, and m≥1, n≥1; p+q =100, and p≥1, q≥1; The optical fiber jitter monitoring module includes a wavelength division multiplexer (4), a fiber optic mirror (14), a wavelength division multiplexer (5), an optical circulator (8), a monitoring light source (9), a second photoelectric receiving machine (6), the third photoelectric receiver (7), divider (24) and root opener (27), an input end of the wavelength division multiplexer (4) is used as the input end of the optical fiber jitter monitoring module, and the divider The output end of (24) is used as the output end of the optical fiber jitter monitoring module, and another input end of the wavelength division multiplexer (4) is connected with the optical fiber reflector (14) for transmitting monitoring light, and the wavelength division multiplexer (4) ) output end is connected with the input end of the wave division multiplexer (5), and an output end of the wave division multiplexer (5) is connected with the input end of the third photoelectric receiver (7), and the wave division multiplexer ( 5) the other output end is connected with an input end of the optical circulator (8), the other input end of the optical circulator (8) is connected with the monitoring light source (9), and the output end of the optical circulator (8) is connected with the first The input end of two photoelectric receivers (6) is connected, and the output end of the second photoelectric receiver (6) is connected with the input end of root opener (27), and the output end of root opener (27) is connected with divider (24) One input end of the divider (24) is connected with the output end of the third photoelectric receiver (7); or, The optical fiber jitter monitoring module includes a fourth photoelectric receiver (22), a DC and AC separation module (23), a divider (24), an amplifier (25), and the input end of the fourth photoelectric receiver (22) is used as an optical fiber The input end of the jitter monitoring module, the output end of the amplifier (25) is used as the output end of the optical fiber jitter monitoring module, the output end of the fourth photoelectric receiver (22) is connected with the input end of the DC and AC separation module (23), and the DC and AC The two output terminals of the AC separation module (23) are respectively connected to the two input terminals of the divider (24), and the output terminal of the divider (24) is connected to the input terminal of the amplifier (25). 2. according to the described current transformer equipment with self-powered low power consumption of claim 1, it is characterized in that, described self-powered module comprises beam splitter (16) and photodiode array (17), and beam splitter ( 16) There is an input terminal and N output terminals, the photodiode array (17) is formed by series connection of N photodiodes, the input terminal of the beam splitter (16) is used as the input terminal of the self-powered module, the photodiode array (17) The output end of the beam splitter (16) is connected with an output end of the first optical fiber coupler (15) as the output end of the self-functional module, and the output end of the beam splitter (16) is connected with the photodiode array (17) ), and an output end of the beam splitter (16) is connected with a photodiode in the photodiode array (17), and the output end of the photodiode array (17) is connected with the photoelectric feedback control circuit for supplying can; N is an integer greater than or equal to 2. 3. The current transformer device with self-powered low power consumption according to claim 2, characterized in that, said photoelectric feedback control circuit comprises a differential amplifier module (10) and a first photoelectric receiver (13), the second The input terminal of a photoelectric receiver (13) and the positive phase terminal of the differential amplifier module (10) are used as the input terminal of the photoelectric feedback control circuit, and the output terminal of the differential amplifier module (10) is used as the output terminal of the photoelectric feedback control circuit. The input end of the receiver (13) is connected with an optical output port of the second optical fiber coupler (3), and the output end of the first photoelectric receiver (13) is connected with the negative phase end of the differential amplification module (10), and the differential amplification The positive phase end of the module (10) is connected to the primary current sensor (11); the output end of the differential amplifier module (10) is connected to the driving end of the fast tunable optical attenuator (2), for driving the fast tunable optical attenuator (2). 4. A bus current detection method utilizing the current transformer device claimed in claim 1, characterized in that, the detection method comprises the following process: utilizing a sensing light source (1) to generate sensing light, the sensing light passes through a splitting ratio of m : n is divided into two parts after the first optical fiber coupler (15), wherein m% of the sensing light passes through the self-powered module to supply energy to the photoelectric feedback control circuit, and n% of the sensing light passes through the fast tunable optical attenuator (2) Finally, the attenuated optical signal is generated, the output optical signal of the fast tunable optical attenuator (2) is collected by the second optical fiber coupler (3), and the p% output optical signal is subjected to nonlinear correction processing to reduce the jitter of the first optical fiber and the interference caused by the jitter of the sensing light source, correcting the nonlinearity of the electro-optic modulation brought by the fast tunable optical attenuator (2), and at the same time, performing jitter elimination processing on q% of the output light to reduce the interference caused by the jitter of the second optical fiber ; The first optical fiber refers to the optical fiber connected between the sensing light source (1) and the first optical fiber coupler (15), and the second optical fiber refers to the optical fiber connected between the second optical fiber coupler (3) and the optical fiber jitter monitoring The optical fiber between the modules, or the optical fiber connecting the wavelength division multiplexer (4) and the wavelength division multiplexer (5); The described jitter elimination processing process is: utilize monitoring light source (9) to generate monitoring light, and this monitoring light passes through optical circulator (8), wavelength division multiplexer (5) and wavelength division multiplexer (4) successively, reaches Optical fiber reflector (14), optical fiber reflector (14) produces reflected light, and this reflected light passes through wavelength division multiplexer (4), wave division multiplexer (5), optical circulator (8) successively, reaches the second The photoelectric receiver (6), the second photoelectric receiver (6) carries out photoelectric conversion, the electrical signal after the conversion obtains the second electrical signal after the square root through the root opener (27), and the second optical fiber coupler (3) The q% output light passes through the wavelength division multiplexer (4) and the wavelength division multiplexer (5) in turn, and reaches the third photoelectric receiver (7), and the third photoelectric receiver (7) performs photoelectric conversion to generate the first electrical signal, the second electrical signal is divided by the first electrical signal to obtain an output voltage signal (26); the second optical fiber refers to the connection between the wavelength division multiplexer (4) and the wavelength division multiplexer (5) between the fibers; or, The described jitter elimination process is as follows: the q% output light output from the second optical fiber coupler (3) is converted by the fourth photoelectric receiver (22) to generate sensing signals, which are respectively passed through the DC and AC separation modules (23) , a divider (24), an amplifier (25), and an output voltage signal (26); the second optical fiber refers to an optical fiber connected between the second optical fiber coupler (3) and the optical fiber jitter monitoring module. 5. The bus current detecting method of current transformer equipment according to claim 4, characterized in that, the described nonlinear correction process is: using a primary current sensor (11) to acquire a bus current signal, and generating a primary current transmission At the same time, the p% optical signal output by the second optical fiber coupler (3) is converted into an electrical signal through the photoelectric feedback control circuit; the primary current sensing signal and the electrical signal converted by the photoelectric feedback control circuit are differentially amplified operation to generate a new driving signal for driving the fast tunable optical attenuator (2), correcting the electro-optical modulation nonlinearity brought by the fast tunable optical attenuator (2), and reducing the first fiber jitter and sensing Interference caused by light source jitter.