Since any of the generators can provide autonomous operation, and the higher efficiency for the declared power is in the smaller generator (80 kW), the control system provides autonomous operation only for the generator 1 (80 kW).

 The main decisive element of the station control system is the controller, which receives information from the transducers, processes it and outputs control signals to the actuators of the system. 

To measure the electrical parameters of the generators, Diris A20 digital multimeters from Socomec (France) are used, which measure all the electrical parameters of the generators, visually display them and transmit the measured information to the controller via the RS-485 interface.

Generator excitation systems consist of controlled thyristor rectifiers, which are characterized by high speed and are controlled by unified signals of constant voltage 0..10 V, which allows direct (without additional conversion) to control rectifiers from analog outputs of the controller.

Generator 1 has an additional independent excitation from the battery, which is connected to ensure autonomous operation until the voltage at the output of the thyristor rectifier 1.

Control of frequency and active power of station, is provided by turn of blades of turbines of generators. Actuators that rotate the blades of the turbine generators are a DC motor for generator 1 (80 kW, 100 kVA) and a hydraulic pump for generator 2 (200 kW, 250 kVA).

To control the connection of generators to parallel operation with the electrical network, the synchronization column "Eltika" SPE "Electroautomatics" (Ukraine) is used. 

The synchronization column measures the voltages and frequencies of the generators and the network, and provides the controller with signals for controlling the voltages and frequencies of the generators and a signal for connecting the generators to the network.

Three generators with a total capacity of 165 kW. Generators of asynchronous type. Siphon type turbines. Implemented SCADA top-level control system.

Control is carried out by means of PLC (programmable logic controller). WebServer provides the ability to manage and control the hydropower plant remotely. A video monitoring system has been installed.

Electronic parameters of the generators are measured with DIRIS A40 (Socomec, France) digital multimeters with communication modules that transfer the obtained data to the PLC. These multimeters also show the information measured on digital displays. 

Since people have better reaction to needle instruments rather than digital ones, needle analogue ammeters and alternating current voltmeters were used for visual presentation of the currents and voltages of the generators. 

Controllers measure excitation currents and voltage of the generators by mean of measuring converters (ПНС-11, “PNS-11” – Microl, Ukraine) of direct currents and voltage into unified analogue signals. Magnetic ammeters and voltmeters are used to visually represent these values. 

Temperatures of various zones of generator stators and slew drives are taken by means of Pt100 resistance thermometers and a converter to МВ-110 Modbus (Oven, Russia).

CircutorSynchroMAX (Circutor, Spain) automatic synchroniser was chosen for automatic synchronisation of generators with the network. It receives instant measurements of the voltage of the generator and the network, calculates effective voltages, frequency values and phase difference between the generator and the network voltages and gives signals to lower or raise generator frequency and to connect the generator to the network while taking into consideration the time of turning the switch on. 

Automatic synchroniser is turned on by the controller, which also connects measured signals of networks and generators values and is operating simultaneously with the automatic synchroniser. The signals to lower or raise the frequency and the signal to connect a generator to the network are transmitted from the generator to the controller which controls the voltage and frequency of an applicable generator and the operation of an applicable switch. 

Two ПНС-12 (“PNS-12”, Mikrol, Ukraine) converters were used to adjust the effective generator voltage accurately to the effective network voltage. They convert alternating current into a unified analogue signal (one is used for the network voltage and establishes the primary value and the other one is used for the generator voltage and establishes the adjusted value). 

Commutation devices connecting generators to the network are using automatic switches (Moeller, Austria) with motor drives that are highly reliable and also protect generators from current overload and short circuits.

Controlled thyristor rectifiers are used as generator exciters (they are using step-down transformers from 0.4 kV busbars) that are known for their rapid reaction and are controlled by unified signals of 4.20 mA direct current, enabling direct (with no additional conversion) control of the rectifiers from the controller analogue outputs.

Parametric (based on elements parameters) generator-transformer line protection is provided by means of a peak current protection relay АЛ-5 (AL-5) and НЛ-6 (NL-6), НЛ-11 (NL-11), ЕЛ-11 (EL11) voltage relays. 

The generating system is additionally protected by the PLC which receives measurement data and establishes emergency conditions. In the event of such conditions the PLC produces signals to switch off generators, close the generator turbine deflectors and block thyristors.

Control of water feed is realized by means of a deflector control based on a Slew Drive (IMO, Germany). The engine is set for direct current voltage and is powered by storage batteries; this solution allowed to operate the deflector machine even when the in-house voltage was out.

SCADA (Supervisory Control And Data Acquisition) OpenSCADA system (Ukraine). is used to visualise manufacturing processes, acquire and register measured data and information about the conditions of the devices, mechanisms and the systems in general. 

SCADA application enables better adjustment, more accurate measured information, logs of statistical data on the normal routine operation parameters and emergency events. Analyzing this data helps predict the future system operation, understand the causes of emergency situations and prevent them from happening in the future.

Station hydro generators can be operated in the following modes: 

1. Based on the water level (water level remains stable)
2. Based on the active energy (a generator produces a set amount of active energy kW)
3. Based on the reactive energy (a set amount of reactive energy kVAr can be generated or power factor can be used) 4. Autonomous mode (operating without synchronization with the grid for the dynamic active load) (station in-house needs)
5. The generator can work alone as well as with other generators.
6. Manual local control (all operation modes can be regulated directly at the generator)
7. Manual remote control (all operation modes can be regulated by a distribution board in the central control room).
8. Automatic control ( with an HMI panel of generator operation board in the operation room and with the SCADA system by means of a computer from the operator’s room)
9. Automatic remote control (by means of the WebServer through the Ethernet by means of WebBrowser)

Measurement of electrical parameters of generators is provided by digital multimeters DIRIS A40 (Socomec, France), with the established communication modules thanks to which the information measured by these devices is transferred to the PLC. 
These multimeters also display the measured information on a digital display. Because humans respond better to handheld instruments than to digital ones, handheld analog ammeters and AC voltmeters are used to visualize generator currents and voltages. Measurement by the controller of currents and excitation voltages of generators is provided by measuring converters (PNS-11 - Mikrol, Ukraine) of direct voltages and currents in the unified analog signals and digital signals of Modbus RTU.
Magnetoelectric ammeters and voltmeters are used to visually represent these quantities.

CircutorSynchroMAX autosynchronizer (Circutor, Spain) is selected as the means of automatic synchronization of generators with the network. as well as the signal to connect the generator to the network, taking into account the time of switching on the switch.

The auto-synchronizer is switched on by the controller, and also the controller connects measuring signals of voltages of a network and generators which is switched on for parallel work to the auto-synchronizer. The signals to increase or decrease the frequency and the signal to connect the generator to the network are transmitted from the auto-synchronizer to the controller and the controller controls the voltage and frequency of the corresponding generator and the inclusion of the corresponding switch.

To accurately adjust the current value of the generator voltage to the current value of the mains voltage during synchronization, two converters PNS-12 (Microl, Ukraine) AC to a unified analog signal are used (one for the mains voltage - forms the setpoint, and for the generator voltage - forms the adjustable value).

For parametric (based on the parameters of the elements) protection of the generator-transformer lines, the relay control of the EL-11 is used. The generation system is also protected by the PLC - on the basis of the received measuring information it generates accident states, in which case it emits signals to turn off the generators, close the guide devices of the turbine generators and to block the thyristor converters.

The water supply is controlled by a hydraulic regulator of the guide apparatus. At the station the regulation by hydrogenerators is realized in the following modes: By active energy (the generator produces a given amount of active energy kW).

By reactive energy (you can generate a given amount of reactive energy kVAr or using cosine fi). The generator can work as one or in pair with another generator.

Manual local adjustment (you can control all modes of operation of the generator directly next to it).

Electronic parameters of the generators are measured with DIRIS A40 (Socomec, France) digital multimeters with communication modules that transfer the obtained data to the PLC. These multimeters also show the information measured on digital displays.
Since people have better reaction to needle instruments rather than digital ones, needle analogue ammeters and alternating current voltmeters were used for visual presentation of the currents and voltages of the generators.
Controllers measure excitation currents and voltage of the generators by mean of measuring converters (ПНС-11, “PNS-11” – Microl, Ukraine) of direct currents and voltage into unified analogue signals. Magnetic ammeters and voltmeters are used to visually represent these values.
Temperatures of various zones of generator stators and slew drives are taken by means of Pt100 resistance thermometers and a converter to МВ-110 Modbus (Oven, Russia).

Control of water feed is realized by means of a deflector control based on a Slew Drive (IMO, Germany). The engine is set for direct current voltage and is powered by storage batteries; this solution allowed to operate the deflector machine even when the in-house voltage was out.

Controlled thyristor rectifiers are used as generator exciters (they are using step-down transformers from 0.4 kV busbars) that are known for their rapid reaction and are controlled by unified signals of 4.20 mA direct current, enabling direct (with no additional conversion) control of the rectifiers from the controller analogue outputs.

Parametric (based on elements parameters) generator-transformer line protection is provided by means of a peak current protection relay АЛ-5 (AL-5) and НЛ-6 (NL-6), НЛ-11 (NL-11), ЕЛ-11 (EL11) voltage relays. The generating system is additionally protected by the PLC which receives measurement data and establishes emergency conditions. In the event of such conditions the PLC produces signals to switch off generators, close the generator turbine deflectors and block thyristors.

CircutorSynchroMAX (Circutor, Spain) automatic synchroniser was chosen for automatic synchronisation of generators with the network. It receives instant measurements of the voltage of the generator and the network, calculates effective voltages, frequency values and phase difference between the generator and the network voltages and gives signals to lower or raise generator frequency and to connect the generator to the network while taking into consideration the time of turning the switch on. Automatic synchroniser is turned on by the controller, which also connects measured signals of networks and generators values and is operating simultaneously with the automatic synchroniser. The signals to lower or raise the frequency and the signal to connect a generator to the network are transmitted from the generator to the controller which controls the voltage and frequency of an applicable generator and the operation of an applicable switch. Two ПНС-12 (“PNS-12”, Mikrol, Ukraine) converters were used to adjust the effective generator voltage accurately to the effective network voltage. They convert alternating current into a unified analogue signal (one is used for the network voltage and establishes the primary value and the other one is used for the generator voltage and establishes the adjusted value). Commutation devices connecting generators to the network are using automatic switches (Moeller, Austria) with motor drives that are highly reliable and also protect generators from current overload and short circuits.

SCADA (Supervisory Control And Data Acquisition) OpenSCADA system (Ukraine). is used to visualise manufacturing processes, acquire and register measured data and information about the conditions of the devices, mechanisms and the systems in general.
SCADA application enables better adjustment, more accurate measured information, logs of statistical data on the normal routine operation parameters and emergency events. Analyzing this data helps predict the future system operation, understand the causes of emergency situations and prevent them from happening in the future.

Station hydro generators can be operated in the following modes:
1. Based on the water level (water level remains stable); 
2. Based on the active energy (a generator produces a set amount of active energy kW); 
3. Based on the reactive energy (a set amount of reactive energy kVAr can be generated or power factor can be used);
4. Autonomous mode (operating without synchronization with the grid for the dynamic active load) (station in-house needs);
5. The generator can work alone as well as with other generators; 
6.Manual local control (all operation modes can be regulated directly at the generator)
7. Manual remote control (all operation modes can be regulated by a distribution board in the central control room);
8. Automatic control ( with an HMI panel of generator operation board in the operation room and with the SCADA system by means of a computer from the operator’s room); 
9. Automatic remote control (by means of the WebServer through the Ethernet by means of WebBrowser).

Terebleritska HPP has three generators of 9 MW each, the installed capacity is
27 MW. Generation voltage 10.5 kV.

Generators are synchronous, with cascade excitation. Excitation regulation is automatic, by means of RVA-62 installations.

Manual adjustment of excitation by means of the motorized rheostat is also provided. 

Actually repair of these units on two generators was made by us.