Xantrex Technology PV5208-PV30208三相208VAC脉宽调节电源转换系

2024年10月27日发(作者：段亦玉)

PV – 5208, 10208, 15208, 20208 & 30208

POWER CONVERSION SYSTEM FOR

GRID – TIED PHOTOVOLTAIC APPLICATIONS

TECHNICAL DESCRIPTION

Xantrex Technology Inc.

Distributed Industrial and Utility Markets

161-G South Vasco Road

Livermore, CA 94550

Phone: 925/245.5400

Fax: 925/245.1022

Revised May 2001

PV 5208 – 30208 Photovoltaic Power Conversion

System for Grid Tied Application

1.0

General System Overview

This document describes Xantrex Technology’ PV5208 through PV30208 power

conversion systems for grid-connected photovoltaic applications. These inverters

incorporate the advanced, insulated gate bipolar transistor (IGBT) based power

electronics technology developed by Xantrex Technology. The power conversion

system consists of a three-phase, 208 VAC pulse-width-modulated inverter,

switchgear (optionally supplied by Xantrex) for isolation and protection of the

connected AC and DC power systems, and an isolation transformer (also,

optionally supplied by Xantrex). The following technical specifications and diagram

detail the components, operation, and interconnection of the system. A more

detailed description of operation may be found in the operation and maintenance

manual for each individual inverter design.

2.0 Inverter

Xantrex Technology manufactures a patented insulated gate bipolar transistor

(IGBT) based power electronic inverter. There is presently over 2200 MW of

installed capacity of Xantrex Technology inverters throughout the world in wind,

solar photovoltaic, battery energy storage, industrial drive and stand-alone hybrid

power system applications. The production and reliability history that has been

established in this application is unique in the power conversion industry.

2.1 Inverter Hardware

The inverter is detailed on the attached block diagram at the end of this

document. Descriptions of operation of the major components are as

follow.

2.1.1 Inverter Circuit and Capacitor Bank

The inverter matrix utilizes IGBT technology as the main power

semiconductor-switching device. This technology exhibits both the

high power levels and low conduction losses associated with bipolar

devices, as well as the low switching losses and high switching

frequencies associated with MOSFET devices. In addition, Xantrex

Technology employs IPM (Intelligent Power Module) switching

Technology. Together the IGBT and IPM offer protection logic for

short circuit, over temperature, DC overvoltage and AC

over/undervoltage conditions.

2.1.2 Integrated Bus Board (PV5208 through PV20208)

The integrated bus board receives logic level timing signals from the

digital signal processor (DSP) board and converts these signals to

IGBT switching states. Additionally, the integrated bus board

monitors the condition of the IGBTs and reports fault conditions to

the DSP controller. The DSP is plugged directly into the integrated

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PV 5208 – 30208 Photovoltaic Power Conversion

System for Grid Tied Application

bus board and is designed to the industry standard specification PC–

104.

2.1.3 Digital Signal Processor (DSP) Board

The DSP controller board utilizes a digital signal processor integrated

chip to implement control and system monitoring functions. The DSP

software implements the peak power tracker function for optimizing

the power delivery from the PV array.

The DSP commands the integrated bus board to issue the

appropriate gating signal to the IGBTs, as determined from the

digitized current and voltage waveforms at the inverter input and

output, and by the control commands received through the operator

interface. The DSP based control board communicates with the

operator interface board via PC–104 bus.

2.1.4 AC Line Filter

The AC line filter removes harmonic currents at the utility power

system interconnection. Due the high switching frequency and the

pulse-width-modulation (PWM) technique used with the inverter, the

filter is modest in size, and need only remove high frequency

harmonic current components.

2.1.5 Operator Interface

There are three means of operator interface with the PV series

inverter family. An optional configuration (standard configuration on

the PV5208) consists of three LED lights and an on/off toggle switch

located on the front door of the inverter. The LED lights indicate

system status and detail any fault conditions. The two optional

operator interfaces consist of a liquid crystal display and a graphical

user interface (GUI) for use with an external computer. The on/off

toggle switch is used to enable or disable inverter operation and

clear fault conditions. It is included in all operator interface

configurations.

The standard PV series configuration (PV10208 through PV30208)

consists of an LCD display and an on/off toggle switch located on the

front door of the inverter. It consists of a four-line text display, which

continuously reports system status, AC power, DC voltage, DC

current, as well as any fault conditions.

The optional GUI interface program may be used in conjunction with

either the LED or LCD display configurations. The GUI interface

allows access via an RS-232 cable to the inverter system status,

inverter controls, expanded details of operation (line currents, line

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PV 5208 – 30208 Photovoltaic Power Conversion

System for Grid Tied Application

voltages, frequency, etc.), and user adjustable system operation

parameters. Contact Xantrex Technology for further information.

2.2 Power Quality

The state-of-the-art technology used in the Xantrex Technology inverter

results in exceptional power quality. The use of IGBT devices allows for

high switching frequencies. The combination of the high switching

frequencies and AC line filter produces high fidelity waveforms which are

well below the IEEE-519 recommended limits for total harmonic current

distortion.

Unlike line-commutated inverters, the Xantrex Technology inverter allows

power factor to be regulated precisely at unity, eliminating the need for

external reactive power compensation.

2.3 Self-Protective Features

The inverter has many built-in protective features to prevent or limit damage

to the photovoltaic system, the inverter, and the utility distribution system in

the event of a component or system-level malfunction. These features

provide for orderly system shut-down without the need for many external

protective devices. Among the features are:

2.3.1 IGBT Device Protection

IGBTs are protected by DC overvoltage, overcurrent and

overtemperature functions. Setpoints for these functions are fixed at

the time of factory test, and can only be changed through the

diagnostic port on the microprocessor controller inside the enclosure.

2.3.2 Utility Voltage and Frequency Monitoring and Protection

The DSP controller constantly monitors the stability of the utility

voltage waveform. If the waveform degrades beyond allowable limits

the inverter will stop processing power and disconnect from the

utility. Once stable utility voltage is restored for five minutes, the DSP

will automatically clear the fault and resume normal operation. Trip

magnitudes and time delays are user settable through the operator

interface.

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PV 5208 – 30208 Photovoltaic Power Conversion

System for Grid Tied Application

2.3.3 Utility Islanding Protection

Detection of islanding from the utility grid is achieved via AC

over/undervoltage and over/underfrequency detection functions as

well as load destabilization algorithms in compliance with UL1741.

Setpoints and time delays for some of these functions are field

settable through the graphical operator interface program. Settings

are password protected, requiring a certified technician to make any

changes to factory defaults.

2.3.4 Additional Protection

• AC current unbalance detection to prevent single-phasing due to

blown fuses

• DC ground fault detection and annunciation resulting in an

orderly inverter shutdown.

2.3.5 Standards

The Trace family of photovoltaic inverters; PV5208 through PV20208

is in compliance with IEEE519 and IEEE929 utility standards,

Underwriters Laboratories (UL1741) and the National Electric Code

(NEC). The PV30208 is pending UL1741 certification, due July 2001.

Our facility is registered by Underwriters Laboratories Inc. under the

International Organization for Standardization ISO9000.

2.4 Environmental Considerations

The PV Series control hardware is housed in an outdoor rated NEMA4/3R

polyester powder coated steel enclosure. The inverter may be

manufactured to tolerate an outdoor, exposed environment. However, we

recommend protected, indoor installation to maximize the lifetime of the

inverter.

The PV Series should also be protected from harsh and corrosive

environments. The allowable temperature range of operation is -20 to 50°C.

The PV Series should be allowed a 15 minute warm up period prior to

operations when powered up below 0°C.

2.5 Summary of PV Series Inverter Specifications:

PV5208 PV10208 PV15208 PV20208 PV30208

AC Line Interface

Continuous AC Output Power

Full Load Efficiency

Nominal Line Frequency

Nominal Line Voltage

Continuous AC Output

Current

10kW 15kW 20kW 30kW

Greater than 95% (see efficiency curve in section 8.0)

50/60 Hz +/- 0.5Hz

208Vac –12%, +10% (per UL1741 & IEEE929)

15.2Aac 30.5Aac 45.8Aac 61.0Aac 91.6Aac

5kW

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PV 5208 – 30208 Photovoltaic Power Conversion

System for Grid Tied Application

Power Factor

AC Current Distortion

PV Array Configuration

Maximum PV Array Voltage

PV Peak Power Point Window

*Minimum PV Peak Power

Voltage

PV Array Maximum Input

Current

PV Ripple Current

Standard Interface

LED Display

LCD Display

LDC Display Parameters

PV5208 PV10208 PV15208 PV20208 PV30208

Unity +/-0.02

Less than 5% Ithd, 3% Ihd

Monopole-Negative Grounded, Bipolar-Neutral Grounded, or Floated

600Vdc

300* - 600Vdc

280 – 330Vdc dependant upon actual AC line voltage at inverter

17.8Adc 35.7Adc 53.6Adc 71.4Adc 107.1Adc

Less than 5%

Operator Interface

LED LCD LCD LCD LCD

Three LED Display: Green, Yellow, and Red

4 Line Liquid Crystal Display

Target State

Operating State

AC Output Power (kW)

DC Voltage

Fault Descriptions

Operating State

AC Power (kW)

AC Line Voltages (Line–to-Line)

AC Output Phase Currents

PV DC Voltage

PV DC Reference Voltage

Ground Fault Current

Fault Codes and Descriptions

Protective Function Targets

Inverter Status

RS-232 DB9 Female Serial Cable to Computer COM1 Port

PV Start Voltage

Peak Power Point Reference Voltage

PV Shutdown Power

Peak Power Tracker Perturbation Step

Ground Current Fault Threshold

Utility Voltage & Frequency Trip Points*

Utility Voltage & Frequency Time Delays*

Graphical User Interface

(optional)

Operating Display Parameters

Serial Interface

User Settable Parameters

Protective Functions

Active Protection Features

AC Line Over/Under Voltage

DC Over Voltage

AC Line AC Over Current

Inverter Over Temperature

Island Detection/Prevention

AC Line Over/Under Frequency

Environmental

Temperature

Relative Humidity

Elevation

Enclosure Rating

Cooling Natural

Dimensions 20Hx16Wx13

Weight (Approximate) 75lbs

UL1741 Certification

-20°C to +50°C

90% Non-Condensing

Derated above 3300 feet

NEMA4 Outdoor NEMA3R/4

Forced Air Convection

26Hx16Wx1229Hx24Wx16D 52Hx26Wx19

D D

90lbs 175lbs 375lbs

Yes Pending

May 2001

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PV 5208 – 30208 Photovoltaic Power Conversion

System for Grid Tied Application

PV5208 PV10208 PV15208 PV20208 PV30208

Regulatory Compliance NEC, IEEE519, IEEE929

*May only be adjusted by qualified personnel, with agreement from the local utility

3.0 Control and Instrumentation

3.1 Operating Mode

The converter utilizes Xantrex Technology unique power tracking algorithm

to operate in a power maximization mode to ensure there is sufficient

irradiance at all times to overcome inverter losses. Inverter start-up occurs

when the PV open circuit DC input voltage rises above the user settable

wake-up voltage. The inverter transitions back to the idle state for nightly

shutdown when losses exceed input power for user settable time period.

The power-tracking algorithm includes the intelligence and rapid response

time necessary to limit the DC input power to its design value. Cloud

enhancement effects are handled within the algorithm by moving off of the

maximum power point and remaining at the design rated power level. This

eliminates the need for the source circuit dumping contactors, crowbar

circuits, and similar unreliable schemes used to protect other types of

inverters.

3.2 Local Control

Local control is implemented through an on/off toggle switch located on the

front door of the inverter. The switch enables or disables inverter operation

and is used to clear fault conditions.

3.3 Local Instrumentation (Optional)

The following real-time system status parameters are available though the

LCD operator interface:

• AC Voltage

• AC Output Current

• PV Voltage

• Converter Status and Alarm Descriptions

3.4 Remote Control and Instrumentation (Optional)

The DSP control board has provisions for installation of an RS-232

communication link for interface to an external computer and graphical user

interface program. All local interface parameters, as well as additional

operating parameters, status indicators, protective function targets, and

user-adjustable parameters are accessible through from the GUI interface.

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PV 5208 – 30208 Photovoltaic Power Conversion

System for Grid Tied Application

3.5

4.0

User Settable Parameters

The PV series operating parameters are factory set to be in compliance

with UL1741 and IEEE929, as well as to provide stable efficient operation

with most PV installations. Parameters may be adjusted via the optional

graphical user interface. Some parameters related to utility protection

functions may only be adjusted by qualified personnel, with agreement from

the local utility.

Isolation Transformer (Required: Available from Xantrex Technology)

An isolation transformer is required if local regulations require grounding of the PV

system, or if the utility voltage is not 208 VAC. Due to the low level of harmonic

distortion produced by the converter, a general purpose dry type transformer is

suitable for this application. The transformer must have a 208 volt delta secondary

winding, a primary winding rated to match the interconnect voltage, and any local

utility interconnection requirements. An optional enclosed, molded-case, thermal-

magnetic circuit breaker may be provided for transformer over-current protection.

This breaker may serve as the utility disconnect, eliminating the requirement for

the AC disconnect switch described above.

Isolation transformers are available from Xantrex Technology. We commonly

provide transformers with 208V delta (inverter side) to WYE rated at the utility

interconnection voltage, 97-98% efficient, housed in a NEMA3R enclosure.

Contact Xantrex Technology for other available transformer configurations.

PV Series

Inverter

Wt. (lbs.)

Isolation Transformer

(Inches, typical)

19Hx16Wx9D

24H x 22.5W x 22D

30H x 20W x 24D

Mounting

Transformer

Wt. (lbs.)

130

220

300

350

PV5208 75

PV10208 90

PV15208 115

PV20208 180

PV30208 375

5.0

Wall

Floor

6.0

AC and DC Disconnect Switches (Optional)

Disconnect switches for isolating the inverter from AC and DC power sources are

available from Xantrex Technology. These switches are rated for use with the

inverter and PV applications. Fusible and non-fusible models are available. All

Xantrex Technology supplied switches are NEMA3R outdoor rated, pad-lockable,

and equipped with external operator handles. Contact Xantrex Technology for

further information.

Photovoltaic Combiner Boxes (Optional)

Interface enclosures for paralleling multiple PV string circuits are available from

Xantrex Technology. These devices have been listed under UL1741 and are

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PV 5208 – 30208 Photovoltaic Power Conversion

System for Grid Tied Application

NEMA3R outdoor rated. They are capable of paralleling up to 10 or 12 individual

PV source circuits. Circuits may be protected with up to a 20 ampere, 600Vdc

fuse. Diode equipped reverse-current protection models are also available. The 12

circuit model is equipped with ‘touch safe’ break apart fuse holders for additional

personnel safety and protection. Contact Xantrex Technology for further

information.

7.0 Maintenance Requirements

Routine maintenance requirements are minimal, consisting only of periodic

inspection of the cooling fans, enclosure seals, and electrical connections.

8.0 Efficiency Graph

Typical PV Series Inverter Efficiency

97%

96%

95%

94%

93%

92%

91%

90%

89%

88%

87%

86%

10%20%30%40%50%60%70%80%90%100%

Percent Load

9.0 Attachment

Inverter Schematic Block Diagram

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Power Conversion System for Grid-Tied Photovoltaic Application

Electrical and Control Block Diagram Grid Interface Inverter

PV Array

= 600 V max.

mpp

= 280*-600 V

** D.C. Disconnect

Switch

- +- +

Line Filter

** Isolation Transformer and

Circuit Breaker

208

∆ VAC : 208/120 WYE

3-Phase

To AC

Power

Distribution

System

Other utility

voltages

available

PV Voltage Feedback

Intergrated Bus

Board

Grid Voltage Feedback

Inverter Current Feedback

Ground Current Feedback

Digital Signal

Processor

DSP

Grid Voltage Feedback

RS-232

4-line

LCD Display

Optional

Graphical User

Interface for

remote

monitoring

Notes:

* Minimum peak power tracking voltage dependent upon actual line voltage seen at inverter input terminals.

** The Isolation transformer DC disconnect switch, DC combiner box,

laptop computer and AC circuit breaker (not shown) may be customer

supplied or are available from Xantrex Technology.