CN201740855U - On-line multifunctional monitoring device of generator excited system - Google Patents

Abstract

The utility model discloses an online multifunctional monitoring device for a generator excitation system, which relates to a monitoring technology for the generator excitation system. The structure of the utility model is: generator rotor current and voltage measurement circuit (1), generator stator current and voltage measurement circuit (2), rectifier bridge AC side current and voltage measurement circuit (3) and switch quantity measurement circuit (4) respectively and The pre-sampler computer system (5) is connected; the pre-sampler computer system (5), the background computer (6) and the display device (7) are connected successively. The utility model monitors the state of the excitation system in real time, reflects the state of the generator and the excitation system in time, guides the operation of the equipment, and improves the safe operation level of the generator and the power grid; automatically records waves for sudden events, which is beneficial to fault analysis and monitoring. Accident handling; it can be installed and used on the excitation system of each grid-connected generator.

Description

An online multifunctional monitoring device for generator excitation system

technical field

The utility model relates to a monitoring technology for a generator excitation system, in particular to an online multifunctional monitoring device for a generator excitation system.

Background technique

The excitation system is an important part of the synchronous generator and one of the key control equipment of the generator; it has a direct impact on the operation reliability, economy and other characteristics of the generator; a good excitation system can effectively improve the power system And generator stability limit level and operating technical and economic indicators. Because the excitation system plays an important role in the stable operation of the generator and power system, once the excitation system fails, the impact will be great. In order to ensure the normal operation of the excitation system and reduce the losses caused by failures, on the one hand, it is necessary to use high-reliability excitation equipment; The state of the system is monitored and incident waves are recorded.

In order to facilitate equipment maintenance and fault analysis, generator fault recording devices are installed in many power plants. The generator-transformer fault recorder is one of the important secondary equipment in the power system. It has two functions: one is to monitor and record the changes of various electrical quantities of the system under different operating conditions and fault states, and to understand the electrical parameters of the unit. The change rule of the operating state of the quantity can provide a basis for system analysis; the second is to check the action behavior of the relay protection and safety automatic device of the unit, which plays an important role in ensuring the safe operation of the power system and improving the power quality. However, the fault recorder of the generator-transformer group has limited monitoring of the excitation system, and basically no monitoring of the power unit of the excitation system. When a fault occurs, especially when the excitation system fails, only the cause of the protection trip can be pointed out, and the occurrence and development of the fault cannot be deeply analyzed. The excitation system is a continuous dynamic adjustment process. Its system composition is complex, the causes and phenomena of failures are diverse, and are inextricably linked with many external variables such as generators and power systems. This gives the operation and maintenance personnel the fault judgment posed great difficulties with maintenance decisions.

At present, there is no online multi-function monitoring device configured separately for the generator excitation system in China.

Invention content:

The purpose of the utility model is to provide an on-line multifunctional monitoring device for the generator excitation system in order to overcome the shortcomings and deficiencies of the prior art.

The purpose of this utility model is achieved in that:

The utility model includes a generator rotor current and voltage measurement circuit, a generator stator current and voltage measurement circuit, a rectifier bridge AC side current and voltage measurement circuit, a switching value measurement circuit, a pre-sampler computer system, a background computer and a display device;

The generator rotor current and voltage measurement circuit, the generator stator current and voltage measurement circuit, the rectifier bridge AC side current and voltage measurement circuit and the switching value measurement circuit are respectively connected to the pre-sampler computer system; the pre-sampler computer system, background computer and display The devices are connected sequentially.

working principle

The input end of the generator rotor current and voltage measurement circuit is connected to the generator rotor circuit, directly detects the generator rotor voltage, and detects the generator rotor current through a shunt; the output end of the generator rotor current and voltage measurement circuit is connected to the pre-sampler computer system After being isolated and adjusted, the detected generator rotor voltage and current are sent to the A/D conversion circuit expanded inside and outside the computer system board of the pre-sampler for sampling.

The input end of the generator stator current and voltage measurement circuit is connected to the voltage transformer and current transformer at the generator end, and its output end is connected to the pre-sampler computer system system, and the three-phase AC voltage signal and the three-phase AC current signal are connected to each other. After isolation and conditioning, it is sent to the CPU built-in A/D conversion circuit of the pre-sampler computer system for sampling, and the active power, reactive power and power factor of the generator are obtained through calculation.

The input terminal of the current and voltage measurement circuit on the AC side of the rectifier bridge is connected to the voltage transformer and current transformer on the AC side of the rectifier bridge, and its output terminal is connected to the pre-sampler computer system, and the three-phase AC voltage signal and the three-phase AC current signal are connected to each other. After isolation and conditioning, it is sent to the CPU built-in A/D conversion circuit of the pre-sampler computer system for sampling, and the phase between the over-measurement voltage and current is used to detect the control angle of the rectifier bridge.

The input end of the switching value measurement circuit is connected with signals such as generator outlet circuit breaker, generator field circuit breaker, rectifier bridge AC side switch and DC side switch, and its output end is connected with the pre-sampler computer system. After photoelectric isolation, the The switch value signal is sent to the switch value input circuit in the computer board of the pre-sampler.

The output terminal of the pre-sampler computer system is connected with the input terminal of the background computer, and the detection result is sent to the background computer for on-line status monitoring and wave recording.

The output end of the background computer is connected with the input end of the display device for displaying relevant information.

The background computer is equipped with relevant software to realize online monitoring of the status and parameters of the generator excitation system, record events of the generator excitation system, record waves of generator excitation system faults, and test and evaluate the performance of the generator excitation system.

The utility model has the following advantages and positive effects:

1. Real-time monitoring of the state of the excitation system, timely reflection of the state of the generator and the excitation system, guidance for the operation of the equipment, and improvement of the safe operation level of the generator and the power grid.

2. Automatic recording of sudden events is beneficial to fault analysis and accident handling.

3. It can be installed and used on the excitation system of each grid-connected generator.

Description of drawings

Fig. 1 is a structural block diagram of the utility model.

in:

1- Generator rotor current and voltage measurement circuit;

2- Generator stator current and voltage measurement circuit;

3- Current and voltage measurement circuit on the AC side of the rectifier bridge;

4-Switch measurement circuit;

5- Pre-sampler computer system;

6- background computer;

7 - Display device.

Detailed ways

Below in conjunction with accompanying drawing and embodiment describe in detail:

1. Overall

As shown in Figure 1, the utility model includes a generator rotor current and voltage measurement circuit 1, a generator stator current and voltage measurement circuit 2, a rectifier bridge AC side current and voltage measurement circuit 3, a switching value measurement circuit 4, and a pre-sampler computer system 5 , background computer 6 and display device 7;

Generator rotor current and voltage measurement circuit 1, generator stator current and voltage measurement circuit 2, rectifier bridge AC side current and voltage measurement circuit 3 and switching value measurement circuit 4 are respectively connected to the pre-sampler computer system 5; the pre-sampler computer system 5. The background computer 6 and the display device 7 are connected in sequence.

2. Function block

1. Generator rotor current and voltage measurement circuit 1

The DC voltage drawn from the rotor side of the generator is divided by resistors in the rotor current and voltage measurement circuit 1 of the generator, and then sent to the filter and gain adjustment circuit composed of an operational amplifier through an isolation amplifier (such as ISO122 or ISO124), and the input DC The voltage signal is adjusted so that the voltage signal of 0-10V is sent to the externally expanded A/D conversion circuit of the pre-sampler computer system 5 for measuring the generator rotor voltage.

In addition, the signal from the DC shunt on the rotor side of the generator is sent to the filter and gain adjustment circuit composed of an operational amplifier through an isolation amplifier (such as ISO122 or ISO124), and the input DC voltage signal is adjusted to a voltage signal of 0-10V and sent to To the A/D conversion circuit expanded externally by the pre-sampler computer system 5. Used to measure generator rotor current.

2. Generator stator current and voltage measurement circuit 2

The three-phase voltage drawn from the generator stator side is isolated by the measurement transformer in the generator stator current and voltage measurement circuit 2, and then converted into a 0-10V alternating signal by the operational amplifier, and sent to the pre-sampler computer system 5 built-in A /D conversion circuit. It is used to measure the three-phase AC voltage signal on the stator side of the generator. In addition, the AC voltage signal is converted into a square wave signal by the shaping circuit, and sent to the high-speed signal input loop in the pre-sampler computer system 5 for measuring the frequency and voltage phase of the generator.

At the same time, after the three-phase current drawn from the generator stator side is isolated by the measuring transformer in the generator stator current and voltage measurement circuit 2, it is transformed into an alternating signal of 0-10V by the operational amplifier and sent to the pre-sampler The computer system 5 includes an A/D conversion circuit. It is used to measure the three-phase AC current signal on the stator side of the generator.

3. Current and voltage measurement circuit 3 on the AC side of the rectifier bridge

The three-phase voltage drawn from the AC side of the rectifier bridge is isolated by the measurement transformer in the current and voltage measurement circuit 3 of the AC side of the rectifier bridge, and converted into an alternating signal of 0-10V by the operational amplifier, and sent to the pre-sampler computer system 5 built-in A/D conversion circuit. It is used for the three-phase AC voltage signal on the AC side of the rectifier bridge. In addition, the AC voltage signal is converted into a square wave signal by the shaping circuit, and sent to the high-speed signal input loop in the pre-sampler computer system 5 for measuring the phase of the three-phase AC voltage on the AC side of the rectifier bridge.

At the same time, the three-phase current from the AC side of the rectifier bridge or the AC current signal of the bridge arm of the rectifier bridge is isolated by the measuring transformer in the current and voltage measurement circuit 3 of the AC side of the rectifier bridge, and then transformed into a 0-10V AC signal by an operational amplifier. Change the signal and send it to the pre-sampler computer system 5 built-in A/D conversion circuit. It is used to measure the three-phase AC current signal on the AC side of the rectifier bridge. In addition, the AC current signal is transformed into a square wave signal by the shaping circuit, and sent to the high-speed signal input loop in the pre-sampler computer system 5 for measuring the phase of the three-phase AC current on the AC side of the rectifier bridge.

4. Switch measurement circuit 4

The switching value measurement circuit 4 adopts photoelectric isolation technology, and its function is to send the signals of the generator outlet circuit breaker, generator field circuit breaker, rectifier bridge AC side switch and DC side switch to the pre-sampler computer system 5 after photoelectric isolation Internal switch input circuit.

5. Pre-sampler computer system 5

The pre-sampler computer system 5 is composed of DSP.

Its function is to collect the generator rotor voltage and rotor current introduced by the generator rotor current and voltage measurement circuit 1; collect the generator stator side three-phase voltage and three-phase current introduced by the generator stator current and voltage measurement circuit 2, and measure the generator frequency. And calculate the active power, reactive power and power factor of the generator; collect the three-phase voltage, three-phase current and phase of the rectifier bridge AC side introduced by the rectifier bridge AC side current and voltage measurement circuit 3, and calculate the control angle of the rectifier bridge; collect Switching quantity measuring loop 4 introduces the switching quantity of the generator and the excitation system. And send the calculated data to the background computer 6.

6. Background computer 6

Background computer 6 is made of industrial control computer and display screen.

Its function is to analyze, calculate, display and record the data sent by the pre-sampler.

The background computer 6 is equipped with status and parameter monitoring software, event recording software, fault recording software and test analysis software. In order to realize the online monitoring of the status and parameters of the generator excitation system, record the events of the generator excitation system, record the faults of the generator excitation system, and test and evaluate the performance of the generator excitation system.

7. Display device 7

The display device 7 can be a CRT or a touch screen.

Its function is to display parameters and status, graphs and curves.

Claims (1)

1. online multifunctional monitoring device of generator excited system is characterized in that:

Include generator rotor current voltage measurement circuit (1), generator unit stator current-voltage measurement loop (2), rectifier bridge ac-side current voltage measurement circuit (3), switching value measurement loop (4), preposition sampling thief computer system (5), background computer (6) and display device (7);

Generator rotor current voltage measurement circuit (1), generator unit stator current-voltage measurement loop (2), rectifier bridge ac-side current voltage measurement circuit (3) and switching value are measured loop (4) and are connected with preposition sampling thief computer system (5) respectively; Be connected successively before and after preposition sampling thief computer system (5), background computer (6) and the display device (7).

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