Power Electronics Tender Technical Evaluation February 2016 Francois van Wyk

2 Contents Mandatory CriteriaQualitative CriteriaType testTraining, drawings and manualsManufacturing capabilityRefurbishmentClarification

Mandatory Technical Evaluation Criteria 10/02/20163 Mandatory Technical Criteria Description 1. Is schedule B completed? 2. Are technical deviations submitted? Note: no waivers on EMC and RFI and safety related requirements will be accepted. 3. Are all required type test reports submitted. 4. Is all information submitted in English? 5. OEM and agent contractual agreement must submitted indicating the OEM requirements for training and commitment to support the product during the contract term and warrantee period. The warrantee shall be honoured from the OEM to the end user. The OEM shall indicate how he authorized the agent in South-Africa to test, commission, maintain, modify, and conduct operating and maintenance training to the end user. The agreement must include a direct communication link on all technical issues between Eskom, agent and the OEM 6. Providing access to software to the level of changing settings

Qualitative Technical Evaluation Criteria 10/02/20164 Qualitative Technical Criteria DescriptionReference to Technical Specification / Tender Returnable Criteria Weighting (%) Criteria Sub Weighting (%) 1. Schedule A and Schedule B Testing The OEM available type testing reports for each individual product offered Drawings, training, manuals Equipment manuals (installation, operating and maintenance) of each category of product offered Information on local technical support and level of support offered and training 5 3.3Drawings of each category of product offered 5 4.Deviations Functional Cosmetics 4 5.OEM and agent agreements 5 6.Installed base and failure reports 5 7.Perceived technical risk 5 8.Practical evaluation 10 TOTAL: 100

Type test The compliance to SANS , SANS , SANS , SANS 1652 and IEC needs to be indicated as part of the type test report submission Type tests within the last five years will be evaluated by the technical evaluation team (TET). Note: SANS was updated in 2012 It is preferred that all type test reports of the offered equipment shall be submitted as part of the tender submission. No type tested products as per the latest Eskom specification, a type test report for a similar product must be submitted with all deviations listed 510/02/2016

Type test At least one of the largest product range must have been type tested by the OEM to the latest IEC /60146 latest revision in order to prove capability Note: The product as part of the contract still needs to be type tested to latest requirements. OEM must have the capability and facilities to perform FATs and type tests at his premises. (routine tests and operational tests) EMC and RFI testing must be done by a reputable local accredited laboratory. OEM must indicate the name of the laboratories used for type test purposes. If EMC and RFI type testing reports are available to the latest Eskom requirements all these must be submitted as part of the tender and if accepted will not require additional EMC and RFI testing but FAT will be required. 610/02/2016

Type test No waivers on type tests will be accepted by Eskom. It is understood that at present there is no capability to perform local type testing for equipment with a supply current greater than 16A. The tenderer shall indicate how they intend to address this for equipment over this limit. IEC for >16A will be required. 710/02/2016

Training, drawings and manuals The training shall include the knowledge and skills to enable individuals to adjust the internal parameters of the equipment to meet specific field conditions and to load firmware upgrades as and when required The necessary configuration tools shall be provided to authorize staff to change these internal parameters Trained and authorized personnel will be issued the required passwords to effect the changes. 810/02/2016

Training, drawings and manuals Comprehensive OEM manuals shall be submitted for the equipment on offer If no products meet the applicable specification, it is required that comprehensive OEM manuals must be submitted for similar equipment. The tenderers shall indicate to Eskom, the required levels of their training, for the different categories of operation and maintenance for the products on offer Specialized training shall be made available to Eskom maintenance and engineering personnel 910/02/2016

Manufacturing capability OEM to provide indication of hours to build a product. OEM to indicate the amount of products that can be produced within a 16 week period 1010/02/2016

Refurbishment Refurbishment of Siemens battery chargers Each supplier will be required to price on the list of components which will be provided for the refurbishment system. Every Tenderer will be granted one day with both a Siemens (BA17),and a Siemens (CHR) charger for the sake of measurements and component inspections. This needs to be arranged with Musiiwa Gidi well in advance. Note: Will be extended to generation chargers. The Tenderers will be (on request) supplied with documentation of the existing chargers to assist in ensuring compatibility with their proposed control system. 1110/02/2016

Number of cells calculation The maximum number of cells that can be connected to the DC bus is limited by the maximum input voltage of the load equipment plus the maximum voltage drop expected along the connecting cables between the battery charger output terminals. The use of a load voltage regulator (LVR) circuit (dropping diode) increases the upper voltage limit of the connected load equipment. This means that the DC bus voltage (battery charging voltage) can be higher which means that more cells can be connected in series. 1210/02/2016

Number of cells calculation 1310/02/2016

Number of cells calculation 1410/02/2016

Number of cells calculation The maximum charging cell voltage is dependent on the type of battery technology and cell chemistry as indicated below: 15 Battery Technology / ChemistryMaximum Charging Voltage [V/cell] Vented Lead Acid2.45 1) Valve Regulated Lead Acid2.40 Vented Nickel Cadmium1.60 Semi-sealed Nickel Cadmium1.45 Note: 1.Boost voltage indicated. If the battery bank should be equalised, then the load is isolated from the battery with a transfer switch or dropping diodes are used. Table 3: Maximum battery charging voltages Note: In cases where dropping diodes (load voltage regulating equipment) are used, the battery charge voltage can be much higher than the maximum load input voltage. 10/02/2016

Number of cells calculation 1610/02/2016

Number of cells calculation 1710/02/2016

Battery sizing method UPS system rating Power(watt)= Volts(V)* Current(I)* power factor(cosø) P=VI*cos ø (kVA) Apparent power Example = 53 kVA Load P=53kVA*0.8 = 42.4 kW We then choose a 60kVA UPS 1810/02/2016

Battery sizing method Important factors Minimum input voltage Maximum input voltage V nomina l = 220VDC Minimum end voltage per cell VEOD = 1,7 V/c According to specification V max of a 220VDC = Cells Input voltage range Volts according to specification Float charge = 2,25 V, Boost charge = 2,5 V, Equalize charge =2,6 V 1910/02/2016

Battery sizing method P =53 kVA*0.8 = 42.4 kW P = 42.4 kW / 0.85 ( Type test indicates the inverter 85% efficient) P = kW needed 2010/02/2016

Battery sizing method Average volts to determine current 110 Cells * 2 V/c (Open circuit voltage)= 220 VDC Discharge volts = 1,7 V * 110 Cells = 187 VDC Average = ( )/2 = Volt Current = kW /203.5 = A Average current for 104 Cells = 258 A 2110/02/2016

Clarification questions and answers ST_ pdf: Clause To ensure that we are working on the latest revisions, please upload the battery standards onto the Eskom Tender Bulletin Portal. 2210/02/2016

Clarification questions and answers ST_ pdf: Clause page 14 of requires charger voltage regulation at -25% Mains Voltage. Equalise and Initial is an infrequent operation. The - 25% Mains combined with the high maximum V/cell requirement, clause 3.39 page 25 to 26 of 198, increases transformer size on thyristor converters. It is requested to relax the requirement to -25% for Float and Boost and to -10% for Equalise and -5% for Initial charge modes. This will maintain normal operation, reduce size, cost and input current requirement and improve power factor. During float and auto-boost, equalise or initial charge mode when subjected to an input voltage variation of ±25% of nominal, the charger shall be capable of maintaining the steady state output voltage produced at the rectifier output, to within ±1% tolerance for float and ±2% for the other charging modes. Answer :Initial charge not required and equalise charge at +- 10% is excepted 23

Clarification questions and answers pdf: Clause is not clearly understood. Is two voltage measurements required, one before the battery isolator and another after the battery isolator? Is two voltage measurements required, one before the load breaker/isolator and another after the load breaker/isolator? Is the “output circuit breaker/isolator” phrase referring to the rectifier portion or is it referring to the load? Monitoring of the rectifier for control purposes and evaluation operation, voltage and current before and after battery isolator and also battery loss, voltage and current before output circuit breaker/isolator and voltage after output circuit breaker/isolator. Temperature and operating status of each charger. Answer: This requirement is required when a battery disconnect is specified on the battery DC bus. Yes,for the output circuit breaker. This requirement is necessary when there is dropping diodes in the circuit. Refers to the load 24

Clarification questions and answers ST_ pdf: Clause and schedule B or Thyristor chargers and schedule B for UPS, indicates that Initial charge is not required. Clause and refer to other charging modes. Please confirm that Initial charge is excluded from the definition of other charging modes. Answer :Yes, the initial charge is not required 25

Clarification questions and answers ST_ pdf: Clauses & refers. Schedule A for Thyristor and switch mode chargers states “Yes, overload protection will be finalised as per design and load profile.” Schedule A Clause requires class || with overload capability of 150% for 1 minute. Does this imply that for the purpose of the tender the overload capability of the rectifier and load circuit should be 150% for 1 minute and any load requirements outside this norm will be agreed on as and when required? Answer: Grading should include 2 *In for 1 second and 150 % for 1 Minute. You will make provision for different options, you will need to know the load profile, and if changes needs to be made and will be cost separately 26

Clarification questions and answers ST_ pdf: Clause Please elaborate / explain the requirement in more detail The individual rectifier module parameters shall be monitored and compared with system level parameters for fault diagnostics (voltage, current, temperature etc.). This is mainly applicable to switch mode rectifiers, in short it means the main controller must be able to interpret and log all conditions of individual rectifiers, it also mean that it must be able to identify if a rectifier setting is outside the controllers parameter settings. For example if the rectifier standalone Float voltage setting is set to 55V but the controller float voltage setting is 54V the controller must flag or prevent the discrepancy. 27

Clarification questions and answers ST_ pdf: Clause and Schedule A. Options are listed in Schedule A. Is the requirement to merely state which options can be achieved for each size or model? Answer:Yes, it is 28

Clarification questions ST_ pdf: Clause and Clause refers to the battery protection and load profile. The Ah of the associated battery and the load profile is not specified. For tender purpose, do we rate on 150% for 1 minute overload rating? Answer:As previous clarification 29

Clarification questions ST_ pdf: Clause and refers to load minimum operating voltage. Clause refers to maximum load voltage. Please state/define the minimum and maximum load voltage. Answer:Determine as per number of cell clarification 30

Clarification on number of cells VoltageNumber cells LANumber cells NiCd 24V V V V The following number of cells will provide adequate flexibility for our designs. The tenderers should make provision for the range.

Clarification questions and answers ST_ pdf: Clause refers to Dropping Diode output capability. Load rating is normally defined as the Rectifier Total current minus the battery charging current. Please define the nominal Load current rating to be used as a percentage of the rectifier total current. Answer: As a standard you can make the diode 90% of the 100% of the rectifier Note: The dropping diode is just necessary for boost charge. 32

Thank you