POWER PLANT- GENERAL DESCRIPTION

General Description

This modular system has been designed specifically to power  48V telecommunications equipment requiring accurate temperature compensated Float and Equalisation voltages, low output noise and EMI levels.

A typical system comprises a number of rectifiers, depending on the power requirement of the system, and a monitoring and control subsystem comprising a monitoring and control module (MiniCSU-2), a User Interface Board (MUIB 2) and optional modules for monitoring AC power and battery cell voltages.

The system can be configured in a number of ways depending on the customer and application requirements.  The simplest option is shown in Figure 1.0

 

Figure 1.0 System with basic monitoring and control

The AC Distribution may simply consist of circuit breakers, one for each rectifier in the magazine depending on customer requirements along with the single phase monitoring card to monitor ac voltage and it is connected via a 16 pin ribbon cable with MUIB.

The rectifiers housed in one or more magazines are paralleled and the DC output connected to the load via the DC Distribution module and to the battery bank, which may be a single battery or two (or three) batteries connected in parallel. A Low Voltage Disconnect Switch (LVDS) has also be included in series with the batteries in order to prevent over-discharging the battery bank in the event of an unusually long AC power outage.

The monitoring and control signals, such as battery currents, temperature, batteries switch status, LVDS control and status, system voltage and ambient temperature are connected to the monitoring and control module (MiniCSU-2) via an interface card (MUIB-2). This module is in turn connected to the MiniCSU-2 magazine via a 34 way ribbon cable and 16 way ribbon cable.

A 3-wire cable, which carries the digital communications signals that allow control and monitoring of the rectifiers, connects the MiniCSU-2 to all the rectifiers in a parallel arrangement so that all the rectifiers receive the same signal.

System status and operating parameters can be accessed from a PC connected to local communication port on the front panel of the controller.

Remote monitoring of the system can be by means of voltage-free relay contacts. System uses 2 relays to convey DC output fails, DC output over voltage/under voltage, Mains fail.

Boost Charge operation

The boost charge mode becomes available when at least SMR 1 and one battery switch are in boost charge operation. At any other case menus for this mode (located in Battery section between Equalisation section and LVDS) will be hidden. Adjustable parameters are voltage and current. If more than one SMR are diverted to Boost BUS MiniCSU 2 will divide selected current by no. of rectifiers.To start Boost Charge the push-button ENT must be pressed. MiniCSU 2 will perform passive sharing adjustment of the split system.

Boost charge mode is indicated on controller by continous yellow LED and a message “BOOST CHARGE” alternating with the home display. On the rectifiers yellow LED is lit continuously. The Boost charge mode will be terminated when:

-          while viewing menu “stop chg mode” ENT key is pressed.

-          Batteries are switched back to system bus

-          All SMRs used for Boost charge are switched back to system bus

After termination of the Boost charge mode and return of all SMRs to system BUS Controller will perform active sharing of all the modules.

Rectifier Specific Configurations

A typical mechanical arrangement of a system comprising 4 rectifiers is shown in Fig 0.2.  It consists of a rectifier magazine (6U) with provision for air intake (4U) and exhaust (3U) for the rectifiers which are cooled by natural convection. A 1U high shelf accommodates the MiniCSU-2, MUIB-2 & ISAM cardsThe arrangement shown is designed to fit into a standard 19” rack or can be fitted with side flanges for wall mounting. A combined AC and DC distribution module completes the system.

       

 Typical 3 rectifier modular power supply

         

Figure 0.2 Typical 4-rectifier modular power supply

POWER PLANT-SMR SPECIFICATIONS

SMR Specifications

1  Input

1.1    Voltage:

Single phase:                          Active, Neutral and Earth;

Rated voltage:                        220VAC;

Rated voltage tolerance          90– 300VAC;

Fully protected up to 400VAC;

1.2    Current:

7A RMS at 230VAC;

1.3    Frequency:

45 - 66Hz;

1.4    Power Factor:

1.1.5    0.98 at 40% - 100% load;

1.6    Efficiency:

Better than 90% at > 50% load;

1.7    Inrush Current:

< 8A peak at nominal mains voltage;

1.8    Soft Start:

Ramp-up time 8 seconds to full load;

1.9    Protection:

HRC input fuse with fuse option for both lines;

Over voltage shutdown at approx. 300VAC;

Under voltage shutdown at approx. 90VAC;

Input soft start – can be connected to live AC bus;

1.10    Voltage Withstand Test:

1500VAC input to chassis for 1 minute;

(2200VDC 100% testing on production units);

1.1.11 Surge Protection

ANSI C62.41-1991 category B3 - AC lines (Combination Wave 6kV/3kA; Ring Wave 6kV/500A) IEC 61000-4-5; EN61000-4-5*: (Impulse) (Level X: 6kV/3kA Common Mode [CM] on AC lines) Criterion B

(Level X: 6kV/3kA Differential Mode [DM] on AC lines)        Criterion B

IEC 61000-4-12; EN61000-4-12*: (Ring Wave)         (Level X: 6kV/500A, 100kHz CM & DM on AC lines) Criterion A

1.12 EMI

Meets TEC GR No. G/EMI-01/03. MAR 2004 specs.

2    Output

2.1  Voltage:

Float:                                    48 – 58V

Equalise:                           50 – 59.9V

Boost:                                    56-66.3V          

2.2 Current Limit:

Range: 5A – 27A in Float/charge mode

             19A in  Manual Boost Mode

2.3  Static Regulation:

Line:    better than ± 0.02%;

Load:  terminal voltage drops by 0.56V ± 0.03V from zero to 27A (for passive current sharing) for stand alone units, or regulates to better than ±0.05% for MiniCSU-2 controlled units;

2.4  Dynamic Regulation:

± 5% for 10% to 90% to 10% step load change;

± 1% of final value within 1ms of step change;

± 0.1% for a 25% step change in AC input voltage;

2.5  Noise:

< 2mV RMS Psophometrically weighted;

< 10mV RMS (10kHz - 100MHz);

< 100mV peak to peak (10kHz - 100MHz);

2.6  Load Sharing:

Better than ± 5% of full scale with active current sharing from MiniCSU-2;

2.7  Protection:

Fuse at output of SMR protects against reverse polarity connection and protects DC bus when internal components fail;

Relay in output circuit prevents surges when connection is made to a live DC bus;

Over voltage - only faulty unit shuts down;

Over current - can sustain short circuit at output terminals indefinitely. Output current folds back when output voltage drops below 10V;

Over-temperature - gradual reduction of power limit if heat sink temperature exceeds pre-set limit;

2.8  Voltage Withstand Test:

1000VAC output to chassis for 1 minute;

(1500VDC 100% testing on production units);

3    Remote Controls

3.1 Programmable parameters - Battery menu:

·         Float Voltage

·         Equalise Voltage

3.2  Programmable parameters - SMR menu:

·         Current Limit

·         High Voltage Alarm level

·         Low Voltage Alarm level

·         High Voltage Shut-Down level (HVSD)

·         HVSD Reset

3.3  Equalise mode:

The SMR will automatically enter and exit equalise mode at user specified conditions, or can be manually initiated. Under any fault condition the SMR will default to the float value.

3.4  Rectifier Inhibit:

Rectifiers can be inhibited by a signal from a remote Win CSU terminal, transmitted via the MiniCSU;

4  Alarms and Monitoring

4.1 Front Panel LED condition table:

Green	Yellow	Red	Condition
0	0	0	Primary power bad
1	0	0	Normal & Mains Ok
1	F*	0	Alarm
1	1	0	Equalise/Boost
0	F*	1	Shutdown
0	0	1	µP fault

3.1    Note: F* indicates flashing LED.

Primary power bad: Indicates that the input AC is off, too low or too high, or that the primary circuit is faulty;

Normal: Status is normal;

Alarm: See Alarm table;

Equalise: SMR is in equalise mode;

Shutdown: SMR is shut down by remote control, or there is an internal fault in the SMR, such as control loop out of limit or temperature sensor faulty;

µP fault: Internal micro-controller is faulty.

4.2 SMR status monitoring:

MiniCSU-2 and  WinCSU software monitor status of the SMR:

·      Output current;

·      Heat sink temperature;

Current:

Monitored on MiniCSU-2 and WinCSU software with 0.1A resolution; Analog measurement accuracy ± 1% at full load ;bar-graph display on rectifier;

Voltage:

System voltage normally displayed on MiniCSU-2 alpha-numeric LCD display.  Accuracy ± 0.5%

SMR address:

A resistor on the magazine automatically sets the SMR address.

SMR alarm monitoring:

The Alarm table shows alarm conditions that are monitored by the SMR and are displayed on both MiniCSU-2 and WinCSU software.  The mnemonics listed here appear on WinCSU software, but full alarm description appears on MiniCSU.

Alarm table:

Vh *	Output voltage too high
Vl *	Output voltage too low
Il *	Unit is in current limit
Po *	Unit is in power limit
Th *	Heat sink temperature high and thermal limit is active
Nd *	No demand (output terminal voltage higher than internal regulation value)
Lo *	Load current low (less than 0.9A)
Ma *	Operating parameters out of allowable range (or eeprom fault)
Sd	Unit is shut down by remote command - user shutdown
Mr	Internal voltage reference faulty
Mc	SMR communication fault. (Generated within MiniCSU)
Vs	High voltage shut down (output), latched alarm. User setting or fault
Unit Off	Unit is shut down due to AC out of range or SMR primary circuit fault. (normal operation or fault)
Ts	Temperature sensor fault
Dc	DC-DC feedback fault, latched alarm
Ff	Fan failure (only if fan is connected)

Note: * indicates flashing of alarm led on SMR.

5 Environmental

5.1 Temperature:

Operating range:                     -25°C to +70°C

Full power range:                    -25°C to +50°C

Derated operation:                  55% power at +70°C

                                                (approx. -36W/°C over 50°C)

5.2 Humidity:

0 to 95% RH Non-condensing

5.3 Cooling:

Forced cooling using fan

6  Mechanical

6.1 Size:

Width:                          87mm

Height:                         266 mm (6U)

Depth:                         320 mm

Mass:                          < 6kg

6.2 Acoustic Noise:

< 50dB ( A Weighted)

6.3 SUB RACK SIZE:

The SUB RACK magazine allows 3 or 4 rectifiers to fit side by side according to configuration of Power Plant in a standard 19 inch rack and one row of rectifiers in every 10U of rack height.

The magazine fits a rack 400 mm or greater in depth;

7 Connections

Input, Output and Communications:

A multi-purpose connector is mounted on the back of the rectifier module; a matching connector is located at the back of the magazine; mating of connectors occurs when unit is plugged into the magazine; the rectifier is mechanically latched to ensure reliable mating.