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Solution of Excitation System Failure of Hydrogenerator

Author: source: date: 2020-06-05 10:33:24

In the last article we talked about the cause and analysis of the excitation device failure. As one of the core special devices in the hydroelectric generating set, once the excitation device fails, it will affect the stability and safety of the power generation and power supply system of the entire hydropower station. This time, let's discuss how to deal with the excitation device failure?

Assuming that the hydropower unit of the hydropower station is equipped with an excitation device with an internal power of about 1200kW, the device is classified as a self-standing class and has an excitation voltage, generally around 80V, and the 240A current is set by itself. The excitation device comes with adjustment equipment, according to the test comparison The internal module structure such as the module and the established unique trigger module, etc. The modules used in the operation can be filtered and adjusted according to the voltage data through the entire current attribute to obtain the voltage control signal of the entire current system. After the above steps are completed, the signal is transferred to the trigger module Zhang Zhi again to complete the existing pulse, and the conduction angle in the thyristor can also be adjusted.

 

The entire excitation device contains a mobile trigger device, which passes through the information output source to control the signal to carry the voltage information. The single-attribute voltage carried by the repetitive configuration unit and the zigzag voltage generated in the circuit can effectively obtain pulses of equal amplitude, and the signal can complete the existing phase operation. The main circuit carries a rectifier bridge that accepts signals by itself. It can automatically trigger when it encounters a rectifying element. At this time, if it encounters reactive power fluctuations within the recognition range, and it can be predicted whether the reactive power fluctuations are conventional inertial fluctuations and a predetermined route, then It can be judged that the excitation equipment is faulty, and the hydro-generator should be stopped immediately, and the various routes should be coordinated for inspection and maintenance.

The most effective and feasible treatment method is to perform the overall test according to the open-loop characteristics. Before testing, the DC property button or the associated switch anode switch provided on the side of the rotor should be opened to connect the entire device to the preset voltage power supply. After the preset voltage regulator, the AC side of the entire flow bridge is connected to the excitation device, and the DC power supply on the thyristor side is connected to an appropriate load resistance. During this operation, the voltage regulating device should be connected in series with the terminal block to form a machine-side replacement accessory for displaying data generated by the transformer. After disassembling the internal circuit of the terminal block with the sensor, adjust the complete adjustment equipment to ensure 100V measurement voltage. After the operation is completed, adjust the anode switch voltage to the highest value and increase it to the highest allowable value. Check the oscilloscope equipment to identify the DC voltage waveform.

 

If the voltage exceeds the predetermined range, the existing DC voltage should be adjusted continuously. Marking the symmetrical bit of the generated waveform, this demarcated point can improve the existing stable state, which means that the measurement situation is normal. In this unit, the measured excitation change voltage is close to the input attribute voltage. There is no need to choose two preset auto-coupler voltage regulators. After connecting with the wire, the special switch during measurement is closed to increase the existing voltage value. The operation uses a clamp-on ammeter to measure the precise current once or twice. When it is found that there is voltage in the road during the measurement, but it has not risen to about 40V, it can be clear that the preset current in the process is increased to about 10A. In this state, the voltage regulator has overheated and has not been preset. Test Data. However, once the circuit configuration voltage regulating device exceeds 40V, due to internal intervention of the thyristor, it cannot be turned on; the DC loop cannot be carried out, and the current loop work has not been completed. The voltage regulator assumes that the loop contains only three attributes of the AC loop mode. Once the current time with large deviation is found, the AC loop should be treated as a load immediately. There is a problem in this process.

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In terms of the origin of the source, the reason can be divided into the diode configuration exists on the common side, so that the state of the grounding meter can appear. In addition, the zero rectification limit provided by the entire current bridge shortens the existing load of the voltage regulator, so that the existing fixed current is increased. A multimeter should be selected for loop check. In this case, once the negative end of the rectifier bridge is found, it should be connected to the ground. Dismantle the multi-meter cable contained in the connecting central control room. To increase the voltage value of the existing equipment, the asset should be restored to the normal current value. The electrical equipment in the hydro-generator should go through the conventional inertial ash removal operation. The preset dust removal will specifically clean the embedded distribution lines. In addition, the accessory-type small accessories focus on removing dust, so that there are parts inside the power. There is no grounding situation to ensure safety.


After the above introduction and analysis, we can see that the excitation device is generally of power type and control type. The device that supplies the DC required by the generator is a power type, which completes the DC properties to build a magnetic field. The control-type device belongs to the control equipment. Once the magnetic device fails, it can be effectively controlled to ensure the safety of the hydro-generator set.

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