A POWER-MEASURING DEVICE AND A MEASURING SYSTEM FOR MEASURING THE POWER OF SEVERAL PHASES IN A MULTIPHASE SYSTEM

• US 20170328937A1
• Filed: 05/30/2016
• Published: 11/16/2017
• Est. Priority Date: 05/29/2015
• Status: Active Grant

• Current Assignee: Rohde & Schwarz GmbH & Company KG
• Original Assignee: Hameg Instruments GMBH (Rohde & Schwarz GmbH & Company KG)
• Inventors: SCHUETZ, Andreas, GEIER, Eugen, ASMUSSEN, Holger, VOGEL, Josef
• Granted Patent: US 10,895,590 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 19/2513 Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G01R 22/063 related to remote communication

Abstract

A power-measuring device serves to measure the power of a three-phase system. It comprises a measuring unit for measuring a power of a first phase of the three-phase system, a display unit for displaying measured results and an operating unit for the operation of the power-measuring device by a user. Furthermore, it comprises a communications unit by means of which it can communicate with one or more further power-measuring devices. In this context, the power-measuring device is embodied, jointly with the one or more further power-measuring devices, to measure a power of several phases of the three-phase system.

Claims

1-16. -16. (canceled)

17. A power-measuring device for measuring the power of a multiphase system including a measuring unit for measuring a power of a first phase of the multiphase system, a display unit for displaying measured results and an operating unit for the operation of the power-measuring device by a user, the power measuring device comprising:

a communications unit configured to communicate with at least one additional power-measuring device,

wherein the power-measuring device is configured, jointly with the at least one additional power-measuring device, to measure a power at least of the first phase and of a second phase of the multiphase system.

18. The power-measuring device according to claim 17, wherein:

the power-measuring device is operable in a master-mode in which the power-measuring device controls the at least one additional power-measuring device, and

the power-measuring device is operable in a slave-mode in which the power-measuring device is controlled by the at least one additional power-measuring device.

19. The power-measuring device according to claim 18, wherein:

in the master-mode, the power-measuring device is configured to;

receive measured results from the at least one additional power-measuring device by the communications unit, or

display measured results of the power-measuring device and of the at least one additional power-measuring device on the display unit of the power-measuring device, or

receive and process operating inputs for the power-measuring device and the at least one additional power-measuring device by the operating unit of the power-measuring device, and

in the slave-mode, the measuring device is configured to;

transmit measured results to the at least one additional power-measuring device by the communications unit, or

not display measured results on the display unit of the power-measuring device, or

not receive and process operating inputs by the operating unit of the power-measuring device.

20. The power-measuring device according to claim 17, wherein the measuring unit is configured to measure a current and a voltage on the first phase and to calculate the power of the first phase from the current and the voltage on the first phase.

21. The power-measuring device according to claim 17, wherein the communications unit is configured to connect to a serial, parallel or annular communications bus and communicate with the at least one additional power-measuring device by the communications bus.

22. The power-measuring device according to claim 17, wherein:

the communications unit comprises a bidirectional digital coaxial connector, and

the communications unit is configured to connect to the at least one additional power-measuring device by the bidirectional digital coaxial connector, or

the communications unit comprises a unidirectional digital coaxial-input connector and a unidirectional digital coaxial-output connector, and

the communications unit is configured to be connected to the at least one additional power-measuring device by the unidirectional digital coaxial-input connector and the unidirectional digital coaxial-output connector.

23. The power-measuring device according to claim 17, wherein the communications unit comprises a connector interface, which is configured to establish an automatic connection to the at least one additional power-measuring device either:

directly with a connector interface of the at least one additional power-measuring device in the case of a plugging together of the power-measuring device and the at least one further power-measuring device, or

indirectly by a connector device in the case of a plugging together of the power-measuring device and the connector device.

24. The power-measuring device according to claim 17, wherein the communications unit is configured to:

implement a synchronization of the power-measuring device and the at least one additional power-measuring device for the phase-coherent measurement,

transmit measured results, or

transmit control commands.

25. The power-measuring device according to claim 24, wherein the synchronization of the power-measuring device and the at least one additional power-measuring device, the communications unit is embodied to:

transmit a synchronization message to the at least one additional power-measuring device,

determine a time duration until the arrival of a response of the at least one further power-measuring device, and

estimate half of the time duration until the arrival of the response of the at least one additional power-measuring device as the transmission time of the synchronization message,

wherein in the case of a processing of the measured results of the at least one additional power-measuring device, the measuring unit is configured to take the estimated transmission time of the synchronization message into consideration as a delay of a transmission of control commands and measured results.

26. The power-measuring device according to claim 17, wherein:

the communications unit is configured to communicate with at least two or more additional power-measuring devices,

the power-measuring device is configured, jointly with the at least two or more additional power-measuring devices, to measure a power on further phases of the multiphase system, and

the multiphase system comprises a three-phase system.

27. A measuring system comprising:

the power-measuring device and the at least one additional power-measuring device according to claim 17, wherein;

the communications unit of the power-measuring device and the communications unit of the at least one additional power-measuring device are connected to one another,

the communications unit of the first power-measuring device and the communications unit of the at least one additional power-measuring device are configured to communicate with one another, and

the first power-measuring device and the at least one additional power-measuring device are configured jointly to measure a power on at least two phases of the multiphase system.

28. The measuring system according to claim 27, wherein:

the first power-measuring device is configured to operate in the master-mode, and

the at least one additional power-measuring device is configured to operate in the slave-mode.

29. The measuring system according to claim 28, wherein:

the measuring system comprises at least two or more power-measuring devices,

each of the two or more power-measuring devices is configured to measure a power on a different phase of the multiphase system,

the power-measuring device and the two or more power-measuring devices are configured jointly to measure the power on a plurality of phases of the multiphase system, and

the multiphase system comprises a three-phase system.

30. The measuring system according to 25, wherein:

the power-measuring device is configured to transmit the synchronization message to the at least one additional power-measuring device, and

the at least one additional power-measuring device is configured to transmit a response to the synchronization message to the first power-measuring device as soon it has received the synchronization message.

31. The measuring system according to claim 27, wherein the measuring system comprises measurement lines of identical length for connecting the power-measuring device and the at least one additional power-measuring device to the phases of the multiphase system.

32. The measuring system according to claim 23, wherein the measuring system comprises a connector device for the automatic connection of the power-measuring devices in the case of a plugging together of the respective power-measuring device and the connector device.