The production of electrical energy in hydro power plants is exposed to constant stress caused by the starts, stops and partial loading of the turbines. This process inevitably results in fatigue and equipment damage. A properly installed condition monitoring system helps avoid or at least reduce damage from the day-to-day operation of the machine.
Hydro turbines are especially vulnerable to number of parameters that constantly reduce their life time. Due to mechanical forces, material destruction, mechanical contusions, large differences in temperature, cavitation, corrosion, chemical forces, etc. various types of damage can develop.
Hydro turbines are especially vulnerable to number of parameters that constantly reduce their life time. Due to mechanical forces, material destruction, mechanical contusions, large differences in temperature, cavitation, corrosion, chemical forces, etc. various types of damage can develop.
|
Damage causes of hydro generators
Source: IEEE
|
Root causes of insulation damages
Source: IEEE
|
Continuous measurement and tracking of harmful parameters can help in setting alarms that prevent malfunction development. Development of higher quality sensors, probes and micro processing units enables maintenance of the machine in operation on the basis of its real condition supported with processing and diagnostic tools.
Refurbishment and monitoring systems
Very often the equipment in hydro plants is obsolete and worn out and should be modernized and replaced. The scope of refurbishment of generators depends on the aimed goals of the plant operator and usually results in the increased generator power and in the increased efficiency of the generator. The plant refurbishment is a perfect opportunity to install a contemporary monitoring system which will bring an added value to the system and save your money.
|
Supervising the harmful parameters can prevent overall mechanical, generator and turbine specific faults. With monitoring systems plant operators have insight to the machine condition and can therefore better plan or postpone the refurbishment.
|
The refurbishment of any hydro power plant should result in
- prolonged operating life time of the plant
- improved safety and security of operation of the equipment
- improved environmental protection and human health protection
- advanced performance of the equipment adjusted to new operating regimes (increased power, increased efficiency, larger generation of the electric energy)
- improved reliability
- increased availability
- better monitoring of the operation of the machine and condition of the equipment
- decrease of operating cost and decrease of maintenance costs
The same results that improve asset management can be achieved with a monitoring system! Unlike the refurbishment, a monitoring system costs only a fracture of it and can be installed in different phases of plant's lifetime.
Key parameters to measure in a hydro plant
Vibrations are one of the most important values supervised by the monitoring systems. They are monitored on all important unit parts, but also in the form of radial relative movements of the shaft in relation to the bearing housing in two axis that are rectangular to each other. Absolute vibrations are usually monitored by piezoelectric sensors although the technological development has also enabled optical measurement of vibrations. Such measurement is most frequently used only at points where conventional accelerometers are not applicable, mostly due to high voltage.
Typical arrangement of vibration sensors within the bearing level
Vibrations alone are indicative but not sufficient for a high quality assessment of the conditions of a unit. Therefore other values important for recognition of machine faulty conditions are also monitored like the following:
- Speed of rotation that is measured by an inductive sensor and a marker used as a synchronisation probe for individual measuring,
- Clearness and magnetic induction on the stator core due to identification of eccentricity and asymmetry as well as inter-turn short circuits on the rotor and the stator;
- Shaft currents and voltages that can cause bearing damage;
- Load angle during the operation due to control and protection of the stability;
- Partial discharges due to identification of the winding insulation and winding insulation problems;
- Temperature in the stator core and in bearing as well as optical measurement of the temperature on the HV equipment (where conventional sensors, thermal couples or Pt100 probes are not applicable);
- Hydraulic values, in the first line pressures, levels and flows, that give the data on turbine operating parameters, and that can be a useful indicator of deviations of reference operating parameters of the generator;
- Cavitation that can cause an increase erosion of the machine parts placed in the circulating channel;
- Operational electric values of the machine such as power, currents, voltages, power factors, etc. can be measured directly from the generator by appropriate equipment or more frequently transferred by agreed communication protocols from the control system (MODBUS, PROFIBUS, IEC104, etc.).
What is SHCM system?
Small hydro condition monitoring (SHCM) is a solution specifically designed for small hydro plants with installed capacity of up to 5 MW. These days it is very common that large hydro plants have installed monitoring systems. These systems however can be very expensive since they are installed on large equipment and on numerous generators that have to integrate many different sensors, control cabinets and server data bases.
|
Small hydro plants are crucial source of power in some areas. For longer lifetime and better asset management they need to be equipped with a proper monitoring system.
|
Small hydro plants are often neglected because the price of the existing monitoring solutions is rather expensive for buying centers. This is a huge loss for plant operators that don't have insight into the crucial information on turbine condition. They still use the classical approach of breakdown or preventive maintenance during which a lot of valuable resources are wasted because the whole plant needs to be shut down for the equipment inspection. This is even more critical for the plants located in distant areas where the local inhabitants strongly rely on the plants' production.
The SHCM system is designed to measure all key parameters and prolong the life span of small hydro plants. The solution is equipped with most important features for optimized hydro plant management and at the same time cost efficient.
SHCM can also be modified and installed in larger hydro plants without any limitations. As described in our condition monitoring basics section, it is exactly the modularity that is a large benefit of modern monitoring solutions.
The SHCM system is designed to measure all key parameters and prolong the life span of small hydro plants. The solution is equipped with most important features for optimized hydro plant management and at the same time cost efficient.
SHCM can also be modified and installed in larger hydro plants without any limitations. As described in our condition monitoring basics section, it is exactly the modularity that is a large benefit of modern monitoring solutions.
SMART ANALYSIS OF PLANT OPERATIONS WITH SHCM
SHCM uses regression analysis to determine the optimal workload of the machines. Using this option in the web interface allows the users to get information on machine processes that put too much pressure on the equipment and to determine the level of load that is the least harmful for the equipment.
SOFTWARE INTERFACE AND MONITORED VALUES
SHCM system is accessed via a control cabinet on-site and remote online from any computer. The solution is easy, yet effective for everyday usage.
Benefits for the users.
|
EASY IMPLEMENTATION
|
|
CONNECTIVITY
|
|
SMALL HYDRO OPTIMIZED
|
|
SMART FUNCTIONS
|
|
USER FRIENDLY
|
See for yourself why SHCM is the right solution for you by choosing one of the options below or simply contact us.