In this section, we will cover how to harden a meter against these magnetic tamper attacks by using shunts for current sensors. For poly-phase implementations, I will go over how to use isolated delta sigma modulators to add the necessary isolation to use shunt current sensors and create magnetically immune poly-phase energy measurement systems. The TIDA-00601 and TIDA-01094 reference designs, which show how to implement a poly-phase isolated shunt measurement system, will be discussed as well as the associated AMC1304 high-side power supplies used in these designs.
The TMP116 digital precision temperature sensor for the -55 to +125ºC range achieves higher accuracy than the Class AA PT sensor with a 1-point calibration. A small PCB including TI's TPD1E10B06 or TPD1E04U04 protection devices can be sealed into a RTD metal tube and meet the EN 61000-4-2 and -4-4 levels of ESD protection. The 64-bit internal EEPROM inside TMP116 stores user defined calibration data into the digital temperature sensor, simplifying integration with application MCUs, such as MSP430FR6047, FR6989 or CC13xx/26xx wireless MCU families.
This section covers what is meter tampering and why is this a problem for utility providers. It also covers the advantages of shunt current sensors. In addition, it introduces the isolated modulator and isolated metrology AFE architectures for adding isolation to shunts.
For both isolated modulator and isolated metrology AFE architectures, high-side power supplies are needed for each phase. In this section, the different high-side power supply options that are available are discussed, which include cap-drop power supplies, isolated DC/DC power supplies with external transformers, as well as isolated DC/DC power supplies with transformers integrated.
In this section, the isolated metrology AFE architecture will be discussed. The software and hardware design considerations for this architecture will be discussed. In addition, the TIDA-01550 isolated metrology AFE reference design will also be discussed.
In this section, the isolated modulator architecture will be discussed. The software and hardware design considerations for this architecture will be discussed. In addition, various isolated modulator designs will also be discussed and compared.
Both isolated modulator and isolated metrology AFE architectures have their advantages with respect to each other. Depending on system requirements, one architecture may be more feasible than the other. This section compares the two isolated shunt sensing architectures and discusses which architecture is best for different system requirements.
In this section, a summary of the entire “Polyphase Current Measurement with Isolated Shunt Sensors” training module would be covered. Links will be provided for the reference designs that were discussed during this training series.