GE Pqm 2 Manual

							CHAPTER 7: APPLICATIONS
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL7–9
Select the communications port of your PC that is connected to the 
PQMII.
Click on OK. 
The following window will appear.
Change the settings in the Properties window to match those shown 
above.
Click on OK. 
You should now have a link to the PQMII. 
Enter the text LOAD in uppercase in the text window of Hyperterminal.
The PQMII Boot Menu should appear in the text window. 
						

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CHAPTER 7: APPLICATIONS
Type “E” to Erase the PQMII flash memory.
Hyperterminal will ask you to verify that you wish to erase the flash 
memory; enter “Y” for yes. The Boot Menu appears again when 
complete.
Now select “B” to blank check the flash memory. 
The PQMII Boot Menu will appear again when complete.
Type “U” to upload software to the PQMII. 
The PQMII is now waiting for a firmware file. 
Select Tr a n s f e r then Send File on the Hyperterminal task bar.
Enter the location and the name of the firmware file you wish to send to 
the PQMII, and ensure the Protocol is 1KXmodem.
Click on Send. 
The PQMII will now proceed to receive the firmware file, this usually 
takes 3 to 4 minutes. When complete the Boot Menu will again appear.
Type “C” to check the installed firmware.
Type “R” to run the flash. 
If the CRC check is bad, erase the flash and re-install the firmware. 
If numerous bad CRC checks are encountered, it is likely that the file 
you are attempting to load is corrupted. Obtain a new file and try again. 
If attempts to use Hyperterminal are unsuccessful, consult the factory. 
						

							CHAPTER 7: APPLICATIONS
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL7–11
7.3 Phasor Implementation
7.3.1 Theory of Phasor Implementation
The purpose of the function Calc_Phasors within the PQMII f irmware is to take a digitally 
sampled periodic signal and generate the equivalent phasor representation of the signal. 
In the conventional sense, a phasor depicts a purely sinusoidal signal which is what we’re 
interested in here; we wish to calculate the phasor for a given signal at the fundamental 
power system frequency. The following Discrete Fourier Series equations calculate the 
phasor in rectangular co-ordinates for an arbitrary digitally sampled signal. The 
justif ication for the equations is beyond the scope of this document but can be found in 
some form in any text on signal analysis.
(EQ 0.1)
where: Re(g) = real component of phasor
Im(
g) = imaginary component of phasor
g = set of N digital samples = {g0, g1,..., gN–1}
gn = nth sample from g
N
 = number of samples
f0 = fundamental frequency in Hertz
ω
0 = 2πf0 = angular frequency in radians
T = 1 /(f0N) = time between samples
The PQMII Trace Memory feature is employed to calculate the phasors. The Trace Memory 
feature samples 16 times per cycle for two cycles for all current and voltage inputs. 
Substituting 
N= 16 (samples/cycle) into the equations yields the following for the real and 
imaginary components of the phasor:
(EQ 0.2)
(EQ 0.3)
The number of multiples in the above equation can be reduced by using the symmetry 
inherent in the sine and cosine functions which is illustrated as follows:
(EQ 0.4)
Let k1 = cos(π/8), k2 = cos(π/4), k3 = cos(3π/8); the equations for the real and imaginary 
components are reduced to:
(EQ 0.5)
Reg ()2
n ---
gnω0nT () cos ⋅
n0 = N1 –
= ;   Img ()2
n ---
gnω0nT () sin ⋅
n0 = N1 –
=
Reg ()1
8 ---
g00 cosg1π
8 ---
cosg22π
8 ------
cos…g3131π
8 ----------
cos ++ ++
 
=
Img ()1
8 ---
g00 sing1π
8 ---
sing22π
8 ------
sin…g3131π
8 ----------
sin ++ ++
 
=
φ cosπφ– () cos –πφ+ () cos –2πφ– () cos == =
φ sinπφ– () sinπφ+ () sin –2πφ– () sin – == =
φ cosπ
2 ---φ –
 
sin =
Reg ()1
8 ---
k1g1g7–g9–g15g17g23–g25–g31++ + ()
k
2g2g6–g10–g14g18g22–g26–g30++ + ()
k
3g3g5–g11–g13g19g21–g27–g29++ + ()g0g8–g16g24– + () +
++ (
) = 
						

							7–12PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 7: APPLICATIONS
(EQ 0.6)
The number of subtractions can be reduced between the calculations of real and 
imaginary components by not repeating the same subtraction twice. The following 
subtractions are repeated:
(EQ 0.7)
Substituting in the above ‘delta’ values results in the form of the equations that will be used 
to calculate the phasors:
(EQ 0.8)
Img ()1
8 ---
k1g3g5g11–g13–g19g21g27–g29– +++ ()
k
2g2g6g10–g14–g18g22g26–g30– +++ ()
k
3g1g7g9–g15–g17g23g25–g31– +++ ()g4g12–g20g28– + () +
++ (
) =
Δ0g0g8– =
Δ
4g4g12==
Δ
8g16g24– =
Δ
12g20g28– =
Δ1g1g9– =
Δ
5g5g13– =
Δ
9g17g25– =
Δ
13g21g29– =
Δ2g2g10– =
Δ
6g6g14– =
Δ
10g18g26– =
Δ
14g22g30– =
Δ3g3g11– =
Δ
7g7g15– =
Δ
11g19g27– =
Δ
15g23g31– =
Reg ()1
8 ---
Δ0Δ8k1Δ1Δ7–Δ9Δ15– + ()k3Δ3Δ5–Δ11Δ13– + () ++ + () =
Img ()1
8 ---
Δ
4Δ12k1Δ3Δ5Δ11Δ13++ + ()k2Δ1Δ7Δ9Δ15+++ () ++ + () = 
						

							CHAPTER 7: APPLICATIONS
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL7–13
7.4 Triggered Trace Memory
7.4.1 Description
The Triggered Trace Memory can be used to detect and record system disturbances. The 
PQMII uses a dedicated continuous sampling rate of 16 samples per cycle to record 
fluctuations in voltage or current as per user def ined levels. The PQMII calculates the true 
RMS value of one consecutive cycle, or 16 samples, and compares this value with the user-
def ined trigger levels to determine if it will record all sampled waveforms. The sampled 
waveforms include Ia, Ib, Ic, In, Va, Vb and Vc.
Since the PQMII requires a minimum 20 V for detection and has an upper voltage input 
limit of 600 V, the following limitation exists for the Trace Memory undervoltage and 
overvoltage trigger levels:
FIGURE 7–1: Trace Memory Phase Voltage Trigger Level Limits
0 20
40 60
80 100
120
140 160
0 50 100 150 200 250 300 350400450 500 550 600
NOMINAL VOLTAGE(V)
TRIGGER LEVEL AS % OF NOMINAL
Maximum
Minimum 
						

							7–14PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 7: APPLICATIONS
7.5 Pulse Output
7.5.1 Pulse Output Considerations
Up to 4 SPDT Form C output relays are configurable as Pulse Initiators based on energy 
quantities calculated by the PQMII. Variables to consider when using the PQMII as a Pulse 
Initiator are:
•PQMII Pulse Output Parameter: The PQMII activates the assigned output relay based 
upon the energy quantity used as the base unit for pulse initiation. These energy 
quantities include ±kWhr, ±kVARh, and kVAh.
•PQMII Pulse Output Interval: The PQMII activates the assigned output relay at the 
accumulation of each Pulse Output Interval as def ined by the user. This interval is 
based upon system parameters such that the PQMII pulse output activates at a rate 
not exceeding the Pulse Acceptance Capability of the end receiver.
•PQMII Pulse Output Width: This user def ined parameter def ines the duration of the 
pulse initiated by the PQMII when a quantity of energy equal to the Pulse Output 
Interval has accumulated. It is based upon system parameters such that the PQMII 
pulse output will activate for a duration that is within the operating parameters of the 
end receiver.
•PQMII Output Relay Operation: This user def ined parameter def ines the normal state 
of the PQMII output relay contacts, i.e. Fail-safe or Non-Failsafe.
•Pulse Acceptance Capability of the End Receiver: This parameter is normally 
expressed as any one of the following: (a) Pulses per Demand Interval; (b) Pulses per 
second, minute or hour; (c) Minimum time between successive closures of the 
contacts.
•Type of Pulse Receiver: There are 4 basic types of Pulse receivers: a) Three-wire, every 
pulse counting; b) Three-wire, every other pulse counting; c) Two-wire, Form A 
normally open, counts only each contact closure; d) Two-wire, counts every state 
change, i.e. recognizes both contact closure and contact opening.
•Maximum Energy Consumed over a Def ined Interval: This is based upon system 
parameters and def ines the maximum amount of energy that may be accumulated 
over a specif ic time.
7.5.2 Connecting to an End Receiver Using KYZ Terminals
Typical end receivers require a contact closure between KY or KZ based upon the type of 
receiver. The PQMII Pulse Output feature can be used with either two- or three-wire 
connections. The PQMII activates the designated Output Relay at each accumulation of 
the def ined Pulse Output Interval for the defined Pulse Output Width. Therefore, each 
PQMII contact operation represents one interval. For end receivers that count each closure 
and opening of the output contacts, the PQMII Pulse Output Interval should be adjusted to 
match the registration of the end receiver. For example, if the end receiver counts each 
closure as 100 kWh and each opening as 100 kWh, the PQMII Pulse Output Interval should 
be set to 200 kWh. 
						

							CHAPTER 7: APPLICATIONS
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL7–15
The PQMII Output Relays can be conf igured as Failsafe or Non-Failsafe to match the 
normally open/closed conf iguration of the KY and KZ connections at the end receiver. The 
K connection is always made to the COM connection of the designated PQMII output relay, 
and the Y and Z connections can be made to the N/O or N/C connections based upon the 
type of end receiver. 
						

							7–16PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 7: APPLICATIONS
7.6 Data Logger Implementation
7.6.1 Data Logger Structure
The Data Logger allows various user def ined parameters to be continually recorded at a 
user-def ined rate. The Data Logger uses 64 samples/cycle data. The PQMII has allocated 
196608 bytes of memory for Data Log storage. The memory structure is partitioned into 
1536 blocks containing 64×2 byte registers as shown below:
FIGURE 7–2: Data Logger Memory Structure
Each entry into the Data Log is called a Record. The Record can vary in size depending 
upon the parameters the user wishes to log. The memory structure can also be partitioned 
into 2 separate Data Logs. The size of the 2 logs is user-def inable. The top of each Data Log 
contains what is called the Header. Each Data Log Header contains the following 
information:
•Log Time Interval: The user-def ined interval that the data log stores entries.
•Present Log Time and Date: The time and date of the most recent Record.
•Log Start Block #: Block number containing the f irst byte of the logged data.
•Log Start Register #: The Register number containing the f irst two bytes of the 
logged data.
•Log Record Size: The size of each Record entry into the Data Log based upon the 
user-def ined Data Log structure.
•Log Total Records: The total number of records available based upon the user 
def ined Data Log parameter structure.
•Block number of First Record: A pointer to the block containing the f irst record in 
the Data Log.
•Register number of First Record: A pointer to the register containing the f irst 
record in the Data log.
•Log Pointer to First Item of First Record: A pointer to the f irst record in the Data 
Log.
•Block number of Next Record to Write: A pointer to the block containing the last 
record in the Data Log.
REGISTER0 BLOCK0
BLOCK1
BLOCK 1534
BLOCK2
BLOCK 1535
REGISTER0
REGISTER0
REGISTER0
REGISTER0REGISTER1
REGISTER1
REGISTER1
REGISTER1
REGISTER1REGISTER63
REGISTER63
REGISTER63
RE
GISTER63
REGISTER63 
						

							CHAPTER 7: APPLICATIONS
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL7–17
•Register number of Next Record to Write: A pointer to the register containing the 
last record in the Data Log.
•Log Pointer to First Item of Record After Last: A pointer to the next record to be 
written into the Data Log.
•Log Status: The current status of the Data Log; i.e.: Running or Stopped.
•Log Records Used: The number of records written into the Data Log.
•Log Time Remaining Until Next Reading: A counter showing how much time 
remains until the next record is to be written into the Data Log.
7.6.2 Modes of Operation
The Data Logger has 2 modes of operation, Run to Fill and Circulate. In the Run to Fill 
mode, the Data Log will stop writing records into the memory structure when there is not 
enough memory to add another record. Depending on the size of each record, the Data 
Log may not necessarily use the entire 196,608 bytes of storage available. In the Circulate 
mode, the Data Log will continue to write new Records into the Log beyond the last 
available Record space. The Log will overwrite the f irst Record after the Header and 
continue to overwrite the Records to follow until the user wishes to stop logging data. The 
Log will act as a rolling window of data in time, going back in time as far as the amount of 
records times the Log T ime Interval will allow in the total space of memory available.
7.6.3 Accessing Data Log Information
The Data Log can be accessed using the EnerVista PQMII Setup Software or manually via 
the serial port . Access via the EnerVista PQMII Setup Software is described in 
Data Logger 
on page 4–12. Access manually via the serial port as follows:
1. Set the Block of data you wish to access at 1268h in the PQMII Memory Map.
2. Read the required amount of data from the 64 Registers in the Block.
Accessing the Data Log in this manner assumes that the user knows which Block they wish 
to access, and knows the size of each Record based upon the parameters they have 
selected to log.
The easiest way to access the data in the Data Log is to read the entire log and export this 
data into a spreadsheet for analysis. This requires def ining the Block to be read, starting at 
Block 0, and reading all 128 bytes of data in each of the 64 Registers within the Block. You 
would then def ine Blocks 1, 2, 3, etc., and repeat the reading of the 64 Registers for each 
block, until Block 1535. This requires 1536 reads of 128 bytes each. The data can then be 
interpreted based upon the parameter conf iguration.
7.6.4 Interpreting Data Log Information
Using two (2) Data Logs in the “Run to Fill” mode, the Data Log is conf igured as shown 
below. 
						

							7–18PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 7: APPLICATIONS
Blocks 0 and 1 are reserved for Data Logger Data Interval information. Block 2 contains 
header information for both Data Logs. The f irst 32 registers of Block 2 are reserved for 
Data Log 1 header information, and the remaining 32 registers are reserved for Data Log 2 
header information. The f irst register of Data Log information resides at Register 0 of Block 
3. This leaves 196224 bytes of data storage.
FIGURE 7–3: Data Log Conf iguration
The location of the f irst Record in Log 2 will depend upon the Log conf iguration. Its location 
is determined by reading the Log 2 Header value for Log Start Address at location 0AB2 
and 0AB3 in the memory map. The Log Start Address consists of the block number (0AB2) 
and the register number (0AB3) which represents the location of the f irst record within the 
Data Log memory structure. This location will always be the starting address for Data Log 
2 for the given conf iguration. Adding or deleting parameters to the conf iguration will 
change the Log 2 Starting Address.
The log pointers contain a value from 0 to 196607 representing a byte within the data Log 
memory structure. Add 1 to this number and then divide this number by 64 (number of 
registers in a Block). Then divide this number by 2 (number of bytes in a register), and 
truncate the remainder of the division to determine the Block number. Multiplying the 
remainder of the division by 64 will determine the Register number. For example, if the Log 
pointer: “Log 2 Pointer to First Item of First Record” was 34235, then the Block and Register 
numbers containing the f irst record of Log 2 are:
Block Number = (34235 + 1) / 64 / 2 = 267.46875
Therefore, Block Number 267 contains the starting record.
Record Number = 0.46875 × 64 = 30
Therefore, Register Number 30 contains the f irst byte of Log 2 data. These calculations can 
be avoided by using the pre-calculated values for Block Number and Record number 
located just prior to the pointer (0AB7 and 0AB8).
The Data Logs will use the maximum amount of memory available, minus a 1 record buffer, 
based upon the user conf iguration. For Example, if the Record Size for a given 
conf iguration was 26 bytes, and there were 28 bytes of memory left in the memory 
structure, the Data Logger will not use those last 28 bytes, regardless of the mode of 
operation. The Data Logger uses the following formula to determine the total record space 
available:
BLOCK3
FIRST RECORD OFDATA
LOG 1HEADERRESERVED RESERVED
LOG 2HEADER
BLOCK1534
BLOCK1535
REGISTER0
REGISTER0
REGISTER0 REGISTER0
REGISTER32 REGISTER33REGISTER63 REGISTER63
REGISTER63
REGISTER63
BLOCK2 BLOCK1 BLOCK0
REGISTER0
REGISTER0REGISTER63
REGISTER63