IEC 60308-2005 pdf – Hydraulic turbines — Testing of control systems

IEC 60308-2005 pdf – Hydraulic turbines — Testing of control systems.
1 Scope and object This International Standard deals with the definition and the characteristics of control systems and is the basis for tender documents and technical tenders. It is not limited to the actual controller tasks but also include other tasks which may be assigned to a control system, such as for instance sequence control tasks, safety, provision for the actuating energy. The testing of control systems for hydro turbines can generally fulfil the following tasks: – verification of system characteristics as per contract specification; – verification of general proper functioning in the workshop and/or on site; – tests to prove the fulfilment of guarantees; – assessment of the actual state of an existing control system with regard to the question of repair or replacement. This standard covers the following systems: – speed, power, opening, water level and flow control for all turbine types; – electronic, electrical and fluid power devices; – safety devices; – start-up, shutdown devices etc. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60041 :1 991 , Field acceptance tests to determine the hydraulic performance of hydraulic turbines, storage pumps and pump-turbines IEC 601 93: 1 999, Hydraulic turbines, storage pumps and pump-turbines − Model acceptance tests IEC 60545, Guide for commissioning, operation and maintenance of hydraulic turbines IEC 61 362: 1 998, Guide to specification of hydraulic turbine control systems IEC 61 000-4-2, Electromagnetic compatibility (EMC) – Part 4-2: Testing and measurement techniques – Electrostatic discharge immunity test IEC 61 000-4-3, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test
Careful documentation is particularly important if certain tests are to be repeated at given time intervals (for example for authorities, insurance companies, restarts after revision, etc.). Care has to be taken in order to avoid environmental hazards. The measured values can be recorded and processed either: – by using suitable recording instruments with subsequent manual evaluation, or – on line by a directly connected computer with the printouts forming an integral part of the documentation. In the case of initial start-ups, a final report should demonstrate that – the unit is operating according to specification; – the safety requirements are fulfilled; – the specific contractual guarantees are fulfilled. 6 Control system tests 6.1 General In order to keep the commissioning period as short as possible, it is recommended that the largest part possible of the required contractual tests be carried out in the manufacturer’s works (workshop tests). The on site tests should be limited to the demonstration of such characteristics, which: – are indispensable for the safety, and – which cannot be carried out without the generating unit and the pressure supply system. In the following subclauses, some basic aspects are summarised. 6.2 Recommendations on workshop tests The scope of the tests, the best set up and the extent of the documentation should be stipulated in the contract in accordance with requirements. Thereby type tests, including EMC type tests with certificates shall be considered. It should be stipulated, who will witness the tests. For workshop tests, it is not necessary to set up all components in a complete loop, the following subsystems (which may be different makers’ responsibility) can rather be tested separately: – cabinet with plug-in units for control; – servo-positioners, control valves with a test servomotor if necessary; – oil pressure supply systems.
If certain basic safety measures are taken and guidelines adhered to, testing can concentrate on checking the control systems for proper functioning. Electrical checking is expensive and requires qualified personnel as well as special testing equipment (for example for measuring transient overvoltages, storage oscilloscopes with an upper cut-off frequency of 1 00 MHz are required). Electrical checking is usually performed in the form of type tests. For specifications of the electromagnetic compatibility (EMC) tests refer to IEC 61 000-4-2, IEC 61 000-4-3 and IEC 61 000-4-6. 6.4.2 Selection of test center To carry out the functional checks on site, a centrally located, quiet place (control room) should be selected where all important signals of the process are available. If the controller is not located near the generating unit, provision for local emergency operation should be made. 6.4.3 Power supply The check of the power supply with volt- and amperemeter, oscilloscope or transient recorder should normally be carried out in the workshop and is generally limited to – tolerance limits and ripple factor; – current input; – test of switch-over of the supply voltage and set-in of a redundant voltage of stored energy time after power failure and re-closing behaviour (for small and simple systems, these tests can be reduced); – failure monitoring.