PM2102DPD SAMES | Alldatasheet
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/c43 /c43 /c43 /c43 Meets the IEC 61036 / 60687 accuracy requirements for class 0.5 active energy measurement Uni-directional and Bi-directional power and energy measurement Current sensing via on-board shunt or CT. Selectable rated conditions, LED pulse rates and counter resolutions sames Energy Meter Evaluation Module PM2102DPD 1/16SPEC-0994 (REV. 1) 02-10-02 Figure 1: Block Diagram /c43 /c43 /c43 /c43 /c43 On-board precision calibration On-board impulse counter or drive facility for stepper- driven counters Energy flow indicator On-board capacitive supply Easy accessible test pins PRELIMINARY INTRODUCTION This application note describes the SAMES PM2102DPD application module to demonstrate the use of the SA2102D as a low cost, accurate watt-hour meter. The PM2102DPD module surpasses the accuracy requirements as quoted in IEC 60687 class 0.5 specification for both unity and ±0.5 power factor over a dynamic range of 800. The measured energy consumption is displayed by means of an on-board counter. Provision has been made for a stepper motor counter to be connected. The Pulse LED is used for calibration purposes, its pulse rate can be selected for either normal or fast operation. When in normal operation, the pulse rate is a low frequency and is proportional to the average power consumption. In fast mode the LED pulse output is set at a high frequency and is proportional to the instantaneous power consumption. This mode is useful for faster calibration times. The Direction LED is used to indicate the energy direction. The metering module can easily be configured for a broad range of pulse constants at different meter ratings. Various examples and standard tables are presented in this application note. Load Voltage sensing Current sensing Power Supply Stepper Counter SA2102D Impulse counter Direction Pulse Vdd GND Vss Neutral Live JP3 Vdd
The PM2102DPD module connects directly to Live and Neutral supply lines by means of a Molex connector (SCK1), and the current is measured by using a shunt on the module. The live is connected to the left terminal of the shunt and live out to the right (as seen in Fig 2 below). The module is setup for a 80A, 220V shunt sensing application using a 625µ shunt./c87 samesPM2102DPD 2/16http://www.sames.co.za PRELIMINARY Table 1: External connector descriptions Name Function Description Optional Stepper motor connector. (Remove jumper J6 to disconnect impulse counter) Mains connector for module power and voltage sense Optional current transformer connector. (Underneath shunt resistor) SCK1 JP2 JP3 Figure 2: Current and mains voltage connection diagram Please take note that the module is referenced to live, and care must be taken when connecting non-isolated test equipment to the module. As an option a stepper motor counter can be directly connected to JP3 and JP2 is used to connect a CT as current sensing element. The resistor values are chosen in such a way that shorting jumper J16 halfs the voltage on the voltage divider output. This feature makes the module compatible for both 220V and 110V supply networks. Ignoring jumper J16 the values of RA and RB can be calculated as follows: RA = R1 + R2 + R3 + R15 The center position of P1 is used in the equation to ensure that calibration can be done by adjusting P1 to a higher or lower value. Combining the two equations gives: (RA + RB) / 220V = RB / 14V Values for resistors were selected as R10 = 47 , R11 = 22k , P1 = 10k and R12 = 1M . Substituting the values result in: RB = 26.29k RA = RB x (220V / 14V -1) RA = 386.84k Choosing standard resistor values for R1, R2, R3, R15 and keeping in mind that J16 must half the output voltage lead to the following values: /c87/c87 /c87/c87 /c87 /c87 The selection and positioning of the current and voltage sense resistors as well as the biasing resistor is very important to ensure the correct operation of the SA2102D. These resistors must be of the same type as specified in the parts list to ensure that temperature effects and noise susceptibility is minimized. The voltage input of the SA2102D is driven with a current of 14µA at the nominal rated main voltage. Please note that this input will saturate with currents bigger than approximately 17µA or 25µA , which translates into a 20% overdrive capability. This also ensures that the device will not saturate with a 10% variance in mains voltage. The mains voltage is divided down via a resistor network (see Figure 3) to 14V. This voltage is fed to a 1M resistor (R12) to realize the 14µA . VOLTAGE INPUT IVP RM S RM S peak RM S/c87
4/16http://www.sames.co.za PRELIMINARY Table 2: Jumper options Name Connecting to VSS will allow only negative energy to be measured. Option Description J1 VSS (-) Connecting to VDD will allow only positive energy to be measured.VDD (+) Connecting to jumper J2 will allow bi-directional energy measurement.J2 Connected to J1 allows for bi-directional energy measurement.J2 J1 These are digital test pins placed immediately next to the device for convenient testing.J3 N/A These are digital test pins placed immediately next to the device for convenient testing.J4 N/A This jumper must be closed when measurement is done via a CT. The jumper connects one side of the current sense resistor to ground. J5 Closed Leave this jumper open when a shunt is used.Open Closing this jumper enables the onboard mechanical counter.J6 Closed Leave unconnected if the onboard mechanical counter is not to be used, or if a stepper motor counter is used.Open This jumper connects the VDD rail of the onboard power supply to the rest of the circuit. Leave open if an external source is to be used. (Used in conjunction with J8) Open This jumper must be closed to connect the onboard power supply VDD rail to the circuit.Closed This jumper connects the VSS rail of the onboard power supply to the rest of the circuit. Leave open if an external source is to be used. (Used in conjunction with J7) Open This jumper must be closed to connect the onboard power supply VDD rail to the circuit.Closed Used to select the required rated conditions. See table 3 and figure 6 for further detail on the various settings possible.J11 VDD (+) VSS Used to select the required rated conditions. See table 3 and figure 6 for further detail on the various settings possible.J12 VDD (+) VSS Used to select the required rated conditions. See table 3 and figure 6 for further detail on the various settings possible.J13 VDD (+) VSS Used to select between fast and normal pulse output mode. When connected to VSS the normal pulse output mode is selected. J14 VSS Connection to VDD selects the fast output pulse mode.VDD (+) This selects the IC manufacturers test mode for normal metering. Connect to VSS.J15 VSS This jumper selects between 220V and 110V supply networks. Leaving this jumper open (default) selects a 220V network.J16 Open Closing this jumper selects a 110V network. See power supply design when opting for the 110V setting.Closed This is a test pin connected to the VDD power supply. If opting for an external supply, the VDD rail can be connected here after J7 is removed.J17 N/A Ground connection pin. Use this pin to connect the external supply mid-rail point.J18 N/A This is a test pin connected to the VSS power supply. If opting for an external supply, the VSS rail can be connected here after J8 is removed.J19 N/A When fast mode is selected this input can be used to enable or disable the internal pulse stability circuitry for the LED output pulses. Connecting to VSS disables this circuitry.SO VSS (-) Connecting to VDD enables this circuitry.VDD (+)
5/16http://www.sames.co.za Table 3: DF_LED and DF_MO factors for SA2102D Figure 6: Jumper positions For selection as indicated: Pulse stability enabled, fast mode with power supply enabled DF_LED 322 322 322 322 536 214 214 DF_MO PRELIMINARY Analog Ground (GND) The GND pin of the SA2102D is connected to the live phase, which is halfway between V and V . The PM2102DPD evaluation module comes with several jumper selections, which allows the user to evaluate all of the DD SS Selection of R1, R2 and R0 for different rated conditions The following equations and table state the basic pulse constants and motor constants obtainable with the PM2102DPD meter. The Output pulse equation is: LED p/kWh = 1160p/sec x (1/DF_LED) x [3600/((Vnom x Imax) / 1000)] The equation for the motor constant is: MOTOR p/kWh = LED p/kWh / DF_MO where dividing factors and are described in Table 3 (R2, R1 and R0 are input pins for SA2102D). DF_LED DF_MO In the above table a “1” implies that the selector is connected to VDD. SA2102D's functionality. Tables 1 and 2 describe the various jumper options. These tables should be used in conjunction with figure 6, which will make it easier to locate the appropriate jumper.
http://www.sames.co.za PRELIMINARY SETUP EXAMPLES The following examples can be used for the setup conditions indicated. Example 1 Example 2 Rated voltage: 220V Rated current: 80A Sensing element: SHUNT (80A, 50mV, 625µ ) Pulse constant: 800 imp/kWh Motor constant: 100 imp/kWh Calculate R6 and R7: R6 = R7 = (IL / 16µA) x RSH / 2 = 80A / 16µA x 625µ / 2. = 1.5625 k A standard value of 1K6 is chosen. The pulse constant is derived from the equation below: Thus using table 3, we see that R0 = 1, R1 = 1, and R2 = 0. Rated voltage: 220V Rated current: 20A Sensing element: SHUNT (80A, 50mV, 625µ ) Pulse constant: 3200 imp/kWh Motor constant: 100 imp/kWh Calculate R6 and R7: R6 = R7 = (IL / 16µA) x RSH / 2 = 20A / 16µA x 625µ / 2. = 390.625 A standard value of 390 is chosen. /c87 /c87 /c87 /c87 /c87 /c87 /c87 /c87 LED p/kWh = 1160 p/sec x 1 / DF_LED) x [3600 / ((Vnom x Imax) / 1000)] = 1160 p/sec x 1 / DF_LED) x [3600 / (220 x 80) / 1000] 800 = 1160 p/sec x (1 / DF_LED ) x 204.54 1 / DF_LED = 0.0033717 DF_LED = 296 MOTOR p/kWh = LED p/kWh / DF_MO 100 = 800 / DF_MO DF_MO = 8 The pulse constant is derived from the equation below: MOTOR p/kWh = LED p/kWh / DF_MO 100 = 320 / DF_MO DF_MO = 32 Thus using table 3, we see that R0 = 1, R1 = 0, and R2 = 0. Rated voltage: 220V Rated current: 40A Sensing element: CT (80A max rated, 1:2500 low phase shift internal impedance of 50 ) Pulse constant: 1600 imp/kWh Motor constant: 100 imp/kWh When a CT is to be used as the sensing element, the terminating or burden resistor (R16) must also be calculated and inserted. R16 is dependent on the type of CT used and can normally be found on a CT datasheet specified as "burden resistor, Rb". The terminating or burden resistor for the TZ76V CT is 5.4 yielding 86.4mV at 40A rated. Calculate R6 and R7: R6 = R7 = (IL / 2500 / 16µA) x Rterminating / 2 = 40 / 2500 / 16µA x 5.4 / 2 = 2700 CT ratio = 2500 A standard value of 2K7 is chosen. LED p/kWh = 60p/sec x (1 / DF_LED) x [3600/((Vnom x Imax)/1000)] = 1160 p/sec x (1 / DF_LED) x [3600 / (220 x 20) / 1000] 3200 = 1160 p/sec x (1 / DF_LED ) x 818.18 1 / DF_LED = 0.003371 DF_LED = 296 IL= Line current Example 3 /c87 /c87 /c87 /c87 Please note that there should ideally be a voltage drop of 86.4mV but not less than a minimum of 20mV across the burden resistor at I . max
7/16http://www.sames.co.za PRELIMINARY Table 4: Different meter constants R2 R1 R0 Rated Condition (V / I) LED Output (p / k W h ) MON, MOP (p / k W h ) 0 0 0 220/10A 6400 100 0 0 1 220/20A 3200 100 0 1 0 220/40A 1600 100 0 1 1 220/80A 800 100 1 0 0 220/6A 6400 100 1 0 1 220/30A 3200 100 1 1 0 220/60A 1600 100 The compensating capacitor C7 is calculated next for a phase shift of 0.18 degrees. Use a standard value 1µF non-polar electrolytic capacitor with a working voltage of at least 16V. The pulse constant is derived from the equation below: Therefore from table 3, R0 = 0, R1 = 1, and R2 = 0. The following table list the most common and frequently used pulse and motor constants for different rated conditions. This is an easy reference for meter manufacturers, and the constants not listed can be calculated from the equations provided in the previous examples. C = 1/ (2 x x mains frequency x R12 x tan (Phase shift angle)) C = 1/ (2 x x 50 x 1M x tan (0.18 degrees)) C = 1.013µF LED p/kWh = 1160p/sec x (1 / DF_LED) x [3600/((Vnom x Imax)/1000)] = 1160 p/sec x (1 / DF_LED) x[3600 / (220 x 40) / 1000] 1600 = 1160 p/sec x (1 / DF_LED ) x 409.0 1 / DF_LED = 0.003372 DF_LED = 296 MOTOR p/kWh = LED p/kWh / DF_MO 100 = 1600 / DF_MO DF_MO= 16 /c112 /c112 Standard meter constants for various rated conditions Module Calibration PCB Design considerations Power supply The output frequency can be adjusted and calibrated by means of the variable resistor P1 connected in the voltage divider as shown in figure 3 on page 3. These are a number of aspects to consider when designing a PCB for a power/energy meter application. Only a few of the more critical aspects are discussed here. The sense resistors on the current input, R6 and R7 must be located as close to the SA2102D-input pins as possible. This also holds true for the 1M resistor (R12), and the biasing resistor R13. Also note that the supply bypass capacitors C1, C2 and C6 must be positioned as close as possible to the supply pins of the SA2102D, and connected to a solid ground plane. It is advisable to keep the ground plane surrounding the device clear of noise that may influence the sensing signals. The module is protected from high transients on the mains voltage input by means of a Metal Oxide Varistor. The MOV will clamp high transients with a sufficiently long rise time, hence protecting the PCB. The onboard power supply consists of a simple capacitive divider to deliver the output voltage that is rectified by a diode pair, and held constant by means of two TL431 regulators. The maximum current available from the power supply is approximately 20mA. Please take note that the module is fitted with a 470nF/250VAC X3 type capacitor for 220VAC mains supply. This capacitor must be changed to 1µF/150VAC X3 type when the mains supply voltage is changed to a 110VAC network. /c87
Figure 8: Linearity at PF = -0.5 samesPM2102DPD Linearity SA2102D PF=-0.5 VDD=5V -0.5 -0.4 -0.3 -0.2 -0.1 0.1 0.2 0.3 0.4 0.5 0.1 1 10 100 I( A m p ) % Error PRELIMINARY
Figure 13 : Schematic diagram of Metering Section OPT 1 2 3 4 5 6 7J3 L 1 2 3 4 5 6 7 8J4 R P4P5 P6 P7 VDD P9 P10 P11P12P13VSSP15P16P17P18 JP2 CT R162R7CT + CT - 220nF D1 1N4148 C3100uF C2 220nF 82k 100k R3 82k D2 1N4148 C4100uF 680R 680R 470nF/250V AC R10 47R R1122k R121M 47k 1.6k 1.6k R13 820n LIVE INNEUTRAL LIVE OUTNEUTRAL R14 625u 80A FAST VDD CNF NC VREF IIP IIN GND IVP DIRI DIRO NC MON VSS LED MOP SO SA2102D SA2102D CNT1Impulse Counter R8 680RR9 680R 1 2 SCK1 Mains J11 R2 J12 R1 J13 R0 J14 FAST VSS VSS VSS VSS VDD VDD VDD VDD DIR VDDVSS P4 P5 P6 P7 P11P12P13P15P16P17P18 LED1 Direction LED2 Calibration J15 CNFVDD C71uF R15 100k J16 VOLTAGE SELECT OR P1 10k 1 2JP3 Stepper Motor J6Count On C82200uF J18 SO VDD VSS J7 J8 Z1MOV J2DIRO GND D3 D4 C10 CT -CT + 10uF 10uF
EVALUATION BOARD COMPONENT LIST Designator Value Description Detail C1, C2 220nF Capacitor Monolithic Ceramic C3, C4 100µF/16V Capacitor Electrolytic Radial C5 470nF/250VAC Capacitor Polyester, X2 or X3 Note 1 C6 820nF Capacitor Monolithic Ceramic C7 1µF / 100V Capacitor Electrolytic Radial, Non-Polarised Note 3 C8 2200µF/25V Capacitor Electrolytic Radial C9, C10 10µF/16V Capacitor Tantalum CNT1 Kuebler, K07.80.240 Impulse counter CT TZ76V TAEHWATRANS optional CT not fitted D1, D2 1N4148 Silicon Diode D3, D4 TL431 Precision Shunt Regulator, J1 DIR 3 Pin SIP Note 2 J2 DIRO Single pin J3 L 7 Pin SIP J4 R 8 Pin SIP J5 GND Enable 2 Pin SIP Note 3 J6 Count On 2 Pin SIP J7 VDD Enable 2 Pin SIP J8 VSS Enable 2 Pin SIP J11 R2 3 Pin SIP J12 R1 3 Pin SIP J13 R0 3 Pin SIP J14 Fast 3 Pin SIP J15 CNF 3 Pin SIP J16 Voltage 2 Pin SIP J17 VDD Single pin J18 GND Single pin J19 VSS Single pin
LED1, LED2 R1, R3 R2, R15 R4, R5 R6, R7 R8, R9 R10 R11 R12 R13 R14 R16 SCK1 SO Value CT Stepper 3mm LED Trimpot, 10k 82k 100k 680R 1k6 680R 47R 22k 47k 80A, 50mV (625µ ) To be calculated Mains Pulse Stability S10/275 /c87
Description
2 Pin Molex, Center square pin, Friction Lock
Red, Green Multi turn, Top Adjust 1/4W, 1% Metal Film Resistor 1/4W, 1% Metal Film Resistor 1/4W, 1% Metal Film Resistor 1/4W, 1% Metal Film Resistor 1/4W, 1% Metal Film Resistor 2W, 5% Wire Wound Resistor 1/4W, 1% Metal Film Resistor 1/4W, 1% Metal Film Resistor 1/4W, 1% Metal Film Resistor Shunt Resistor 1/4W, 1% Metal Film Resistor
2 Pin Molex, Center square pin, Friction Lock <200mil pitch>
3 Pin SIP
- Use 1µF/150V for 115V mains supply 2. Single Inline Pins 3. Only required if a CT is used. 4. Standard 3-pin Molex with centre pin removed. AC
NOTES:
samesPM9607AP samesPM2102DPD DISCLAIMER: The information contained in this document is confidential and proprietary to South African Micro-Electronic Systems (Pty) Ltd ("SAMES") and may not be copied or disclosed to a third party, in whole or in part, without the express written consent of SAMES. The information contained herein is current as of the date of publication; however, delivery of this document shall not under any circumstances create any implication that the information contained herein is correct as of any time subsequent to such date. SAMES does not undertake to inform any recipient of this document of any changes in the information contained herein, and SAMES expressly reserves the right to make changes in such information, without notification, even if such changes would render information contained herein inaccurate or incomplete. SAMES makes no representation or warranty that any circuit designed by reference to the information contained herein, will function without errors and as intended by the designer. Any sales or technical questions may be posted to our e-mail address below: For the latest updates on datasheets, please visit our web site: (012) 333-6021 +27 12 333-6021 (012) 333-8071 +27 12 333-8071 energy@sames.co.za http://www.sames.co.za. SOUTH AFRICAN MICRO-ELECTRONIC SYSTEMS (PTY) LTD Tel: Tel: Int Fax: Fax: Int P O BOX 15888 LYNN EAST 0039 REPUBLIC OF SOUTH AFRICA
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KOEDOESPOORT INDUSTRIAL AREA PRETORIA REPUBLIC OF SOUTH AFRICA http://www.sames.co.za PRELIMINARY