SOLAR PUMPING
March 7th2013
1
SD700 SP Introduction
2
Operation modes
3
Hydraulics
4
Submersible pumps
5
SD700SP LCoW
6
SD700SP Ordering Info
7
SD700SP Sample
01 Introduction/ ¿What is Solar Pumping?
¿ WHAT IS SOLAR PUMPING?
SOLAR PANELS
PUMPING
SYSTEM
PUBLIC GRID OR
DIESEL GENERATOR
Solar Pumping consists in supplying water pumps with the energy generated by a PV
Solar Plant.
01 Introduction/ SD700SP Topology
SD700 SP TOPOLOGY
01 Introduction/ SD700SP Topology
SD700 SP TOPOLOGY
SD700SP
AC on-load disconnector
DC On-load disconnector
AC Fuses
DC Fuses
DC terminals (+) and (-)
02 Operation Modes
OPERATION MODES
 SOLAR ASSISTED SYSTEM: SD700SP is connected to the PV farm and to the grid
simultaneously. The PV power is prioritized.
 RENEWABLE ENERGY SELF-SUFFIENCENT: SD700SP is only connected to the PV
field, generating the necessary power to start and speed-up the pump. The motor start will
depend on the systems minimum power required.
GRID CONNECTED: SD700SP is operated as a regular VSD, hence it allow to run the
pump during night hours and during PV farm maintenance seasons.
In no event will the PV farm (DC) and the electric grid (AC) interact, due to the
unidirectional thyristor-diode rectifier bridge in between them.
02 Operation Modes / Solar assisted & Grid Connected
OPERATION MODE: SOLAR ASSISTED & GRID CONNECTED
02 Operation Modes / Renewable Energy Self-sufficient
Minimum System Required
Power
(30Hz-50Hz)
OPERATION MODE: RENEWABLE
ENERGY SELF- SUFFICIENT
Maximum System Power
(50Hz)
03 Hydraulics
VSD CONTROL
The variable speed pump’s control provides unique regulation and performance features.
The variable speed drive modifies the performance curve of the pump in order to meet
the system requirements. The centrifugal pump performance is modeled by the affinity
laws. In theory, the power reduction is proportional to the cubic of speed, for example a
20% speed reduction cause a power saving greater than 47%.
03 Hydraulics
THROTHLING CONTROL VS VARIABLE SPEED DRIVE - OVERVIEW
P50  100kW
80
P40  P50
 40 


 50 
3
3
 51 .2kW
Head in m H2O
P35
80
Head in m H2O
1Xn
1Xn
FLOW
70
50
40
30
0.9 X n
Static height 20 meters
60
0.8 X n
0.7 X n
0.6 X n
90%
80%
70%
60%
50%
100%
70
60
50
40
30
0.5 X n
0.9 X n
0.8 X n
0.7 X n
0.6 X n
0.5 X n
20
20
0.4 X n
0.4 X n
H-Q
curves
10
0
 35 
 P50  
  34.3kW
 50 
20
10
50%
H-Q Curves
30
100%
System curves
10
Q Flow m3/min 0
10
50%
20
100%
30
03 Hydraulics
Height (bar)
Height (bar)
BOTH SYSTEM AND PUMP CURVES DEFINE THE MINIUM START REQ.
CURVE -A
50 Hz
40 Hz
Min Height.
30 Hz
CURVE -B
50 Hz
40 Hz
30 Hz
20 Hz
Min Height.
Q (m3)
Q (m3)
 Curves with high angled slopes offer optimal regulation
 Curves with low angled slopes offer poor regulation
 Better regulations deliver higher savings
 Energy savings are restricted by the regulation range
20
𝑃2 = 𝑃1 ·
50
3
= 𝑃1 · 0.064
40
𝑃2 = 𝑃1 ·
50
INDIVIDUALIZED SYSTEM
ANALYSIS
3
= 𝑃1 · 0.512
03 Hydraulics
PUMP’S PERFORMANCE DEPENDING ON SPEED VARIATION
80
1Xn
30%
50%
70
60%
N = 1480
RPM
70%
80%
0.9 X n
85%
87%
60
50
88%
87%
85%
0.8 X n
80%
0.7 X n
40
30
20
0.6 X n
0.5 X n
Efficiency curves
0.4 X n
Curve H – Q
System curve
10
0
10
20
30
40
Q flow
m3/min
03 Hydraulics
Height (bar)
Height (bar)
MINIMUM FEED IN POWER AND VINIMUM MFT VOLTAGE
CURVE -A
50 Hz
40 Hz
Min Height.
30 Hz
CURVE -B
50 Hz
40 Hz
30 Hz
20 Hz
Min Height.
Q (m3)
 Curves with high angled slopes offer optimal regulation and
lower starting frequencies
 Curves with low angled slopes offer poor regulation and higher
starting frequencies
 Energy savings are restricted by the regulation range
 Better regulations deliver higher savings
20
𝑃2 = 𝑃1 ·
50
Q (m3)
3
= 𝑃1 · 0.064
40
𝑃2 = 𝑃1 ·
50
INDIVIDUALIZED SYSTEM
ANALYSIS
3
= 𝑃1 · 0.512
04 Submersible pumps
SUBMERSIBLE PUMP TOPOLOGY
Water impulsion
Pump Shaft
Pump Impellers
Cooling jacket
Water intake
Motor Shell
Motor
Thrust bearing
04 Submersible pumps
SUBMERSIBLE PUMPS & VSD CONSIDERATIONS




MOTOR CABLES TYPE AND LENGHT
PUMP COOLING
THRUST BEARING COOLING
VSD OPERATION & SETTINGS
04 Submersible pumps
SD700 – RECOMMENDED CABLE TYPE
Desired - Up to 300m
Compatible - Up to 150m
04 Submersible pumps
VOLTAGE FLANGE WAVE FORM
ALL DRIVES ARE NOT THE SAME
Competitors dV/dt values
SD700 STANDARD
04 Submersible pumps
ADMISSIBLE PEAK VOLTAGE LIMIT CURVES IN AC MOTORS TERMINALS:
Peak voltage (kV)
2.4
IEC 60034-25 Curve B
(without filters for motors
up to 690V AC)
2.0
NEMA MG1 Pt31 in
grids of 600V
1.6
1.2
20m
0.8
100m
50m
30m
2.15kV
1.86kV
IEC 60034-25 Curve A
(without filters for motors up to 500V AC)
1.56kV
IEC 60034-17
1.35kV
200m
1.24kV
NEMA MG1 Pt31 in
grids of 400V
10m
Examples of the test results,
SD700 using reinforced copper
wires at 415V rated voltage.
0.4
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Rise time of the voltage pulse (µs)
1.0
1.1
1.2
04 Submersible pumps
PUMP COOLING

Well intake
Keep a minimum speed of the surrounding water.
Vc = 0.08…0.5 m/s ( Consult Manufacturer)
T (ºC)
Q (m3/s)
Cooling Speed - V (m/s)

Cooling flow depends on:
•
Water temperature and properties
•
Pumps geometry and Motor Shell
•
Motor and pump load
•
Well geometry
INCREASE COOLING CAPACITY
REDUCE HEAT LOSSES
Lower water temperature (ºC)
Lower motor load (AP)
Higher pump flow (Q)
Pump speed reduction (Hz)
Wider motor Diameter (mm)
Dp
Higher convection factor (W/mm2)
Dw
Water stream distribution
Low factor between motor
diameter and well diameter
04 Submersible pumps
THRUST BEARING COOLING


Thrust bearings needs a minimum water flow (15-30% of
Qn) to create a thin lubrication layer.
The layer ensures bearing cooling and reduce friction
between fixed parts.
Lubrication layer
04 Submersible pumps
VSD OPERATION AND SETTINGS
YES
YES
How long it takes to empty the pipe?
- Soft start after the empty time
- Soft stop to reduce water hammer
Is there water
release holes in
the pump?
Start and Stop with water-filled
pipe settings
(Maximum head)- CASE 1
1
YES
Start with empty pipe but it
needs a fast speed
transient - CASE 3
3
NO
Soft start and stop – CASE 2
2
NO
Is a Check Valve
integrated in the
pump?
NO
Is there a check
valve on the top of
the hole ?
04 Submersible pumps
START AND STOP WITH WATER-FILLED PIPE
Head (bar)
1
Min Head
50Hz
Min Head - AP
40Hz
30Hz
20Hz
10Hz
Q min (thrust bearing cooling)
Pump
Pump Speed (Hz)
50
Q (m3)
Installation
Slow ramp
- Flow control range
- Reduce sand impulsion
Slow ramp
Water Hammer
Control
40
30
20
10
Fast ramp
Pump stop
Fast ramp
– Min Flow
Time (s)
0
2s
4s- 7200s
30s
1s
04 Submersible pumps
SOFT START AND STOP
Head (bar)
2
Min Head
50Hz
Min Head - AP
40Hz
30Hz
20Hz
10Hz
Q min (thrust bearing cooling)
Pump
Pump Speed (Hz)
50
Fast ramp
– Min Flow
Slow ramp
- Flow control range
- Reduce sand impulsion
Q (m3)
Installation
Slow ramp
Water Hammer
Control
40
30
20
10
4s- 7200s
Time (s)
4s- 7200s
0
1s
1s
04 Submersible pumps
SOFT START AND STOP WITH FAST TRANSIENT
Head (bar)
3
Inst. Head
Min Head
50Hz
Min Head - AP
40Hz
30Hz
20Hz
10Hz
Q min (thrust bearing cooling)
Pump
Pump Speed (Hz)
50
Fast ramp
– Min. Flow
Q (m3)
Installation
Slow ramp
- Flow control range
- Reduce sand impulsion
Slow ramp
Water Hammer Control
40
Fast transient ramp
– Checkvalve opening
30
20
10
Time (s)
4s- 7200s
0
1s
4s- 7200s
1s
4s- 7200s
1s
05 SD700SP LCoW / Grid connected
SD700SP Grid Connected system
 Hydraulic System:
o Pump power:
No restriction
o Pump/line voltage:
From 230Vac to 440Vac.
o Min frequency (Hz):
No restriction
o Min Power (kW):
No restriction
 Solar PV system Sizing:
o Max DC Voltage:
1000Vdc
o MPP tracking:
No, fixed DC voltage
o MPPt range:
Vmppt = sqrt(2) · Vac + 5V
Vmppt_230Vac= 1.41 · 230 +5V = 329V
Vmppt_400Vac= 1.41 · 400 +5V= 569V
o Start feed-in power:
No restriction
 Results:
 Energy Savings:
kWh/ per year
 Fuel/ Electricity cost:
€
05 SD700SP LCoW / Self Sufficient
SD700SP Self Sufficient
 Hydraulic System:
o Pump power:
From 2.2kW up to …. (feasibility limit)
o Pump/line voltage:
From 230Vac to 440Vac.
o Min frequency (Hz):
Required. Hydraulic system modeling
o Min Power (kW):
Required. Hydraulic system modeling
 Solar PV system Sizing:
o Max DC Voltage:
1000Vdc
o MPP tracking:
Yes
o MPPt range:
Vmin (Min.Hz) ….1000V
o Start feed-in power:
Min Power (kW)
 Results:
 Power (kW):
kW Hourly data ( PV sys tool)
 Pumping ratio :
Multiple values - Pump curve dependant
05 SD700SP LCoW / PV sizing
SD700SP Self Sufficient / Hydraulic Sizing- Deep Well to storage
Power PCA - Work flow












Determine the static head (m) of the system.
Determine the desired flow of the system (m3/min)
Select the pump considering Head and flow
Select SD700SP according to pump rated power.
Create new project in Power PCA
Select High Accuracy mode
Introduce pump curves points (P vs Q)
Introduce efficiency pump curves ( Eff vs Q)
Select Variable flow and constant height
Determine the Q min
Introduce different Q values (including Q min)
Save Data as XLS
Min. Frequency. (42.5Hz)
Min. Power (25kW)
80
1Xn
30%
50%
70
60%
Rated flow, head and power
Pump and SD700SP Selection
N = 1480
RPM
70%
80%
0.9 X n
85%
87%
60
50
88%
87%
85%
0.8 X n
80%
0.7 X n
40
30
20
0.6 X n
0.5 X n
Efficiency curves
0.4 X n
Assumptions
 Pipes, valve losses are dismissed.
 Pump performance according to affinity laws.
 Constant height, no well level variation are considered
 Further accuracy requires specific hydraulic SW.
Curve H – Q
System curve
10
0
10
20
30
Min flow: (5 m3/min)
Depend on pump cooling.
40
Q flow
m3/min
05 SD700SP LCoW / PV sizing
SD700SP Self Sufficient / PV sizing
PV Sys – Work flow
 Select Project Design – Grid connected system
 Open an existing inverter
 Introduce Vmin in Minimum MPP Voltage,
depending on the hydraulics limitations ( see next
slide)
 Introduce Pmin in Power Threshold. (error may
appear)
 There are no limitations on nº of DC inputs or
DC/AC ratio.
 Select efficiency = f(P out) and check that
efficiency curves are ready
 Select the appropriate string distribution to
maximize the PV production.
P out
Eff (%)
0%
0
10%
96.5%
30%
98.0%
50%
98.2%
70%
98.6%
90%
98.5%
100%
98.5%
05 SD700SP LCoW / PV sizing
SD700SP Self Sufficient / PV performance
Radiation
Sensor
Minimum Voltage
Minimum Power
06 SD700SP Ordering Info
SD700SP Ordering Info
Project
Pump
Location
Application and control
Solar Pumping Project
Submersible pump
Egypt
[Deep well to storage, lake/river to storage, pressurization]
Other information
[Attach PV sys reports, pump manufacturer curves, Power PCA report, other studies]
: -10ºC
: +45ºC
: IP54 Indoor installation
:4
SD7SP _ _ _ _ 55 S
_ _ _A
_ _ _kW
YES
: [Diesel Genset, Grid-connected ]
Power
: 75 _ kW
Voltage
: 380 _ Vac
Current
: 165_ A
Min. Ambient Temperature
Max. Ambient Temperature
Degree of Protection
Units
Reference number
Nominal Current
Power Motor up to
AC Power Supply
Motor Data
PV plant Data
First Level
Second Level
AC Power Supply Protections (if needed)
Irradiation Sensor
I/O signals
Communication
Door Pushbuttons
Door Pilots
Heating Resistors
Hygrostat
Panel type
: BYD 255 6C
Nº PV panels in series
: 24
Nº of String per combiner box
: 22
ON-load disconnection
: YES
Combiner box fuse rating
: 12A
Number of combiner boxes
:3
Fuse protection
50A
ON-load disconnector
: YES
AC On load disconnector
: YES
AC Semiconductor Protection Fuses
: YES
:
:Included
6 DI, 3 DO, 2 AI, 2AO, 1 PTC, 1 PT100. (Other available under request)
: RS485 – Modbus RTU
: Optional
: Optional
: Optional
: Optional
07 SD700SP Sample
SD700SP Case Study
• Pump:
2x Sulzer 75kW
• SD700SP:
1x SD7SP Frame 4
• Accessories:
• AC Disconnector
• DC ON-load manual disconnector
• DC fuses according to PV sizing
POWER ELECTRONICS
Appreciates your time
For more information please visit:
www.power-electronics.com