Abstract: Systems and methods implement measuring, in a test and measurement instrument, operational signal timing parameters of electrical signals being communicated over an electrical bus by a device under test. A bus timing characteristics analyzer identifies nominal signal timing parameters for the acquired electrical signals. The nominal signal timing parameters are defined by the bus protocol and defining timing criteria for the electrical signals. The analyzer measures operational signal timing parameters for each of the acquired electrical signals and compares, for each of the electrical signals, the operational signal timing parameters to the nominal signal timing parameters to determine whether the operational signal timing parameters satisfy the timing criteria. The analyzer then displays, on the test and measurement instrument, a visual indication for each of the electrical signals indicating whether the operational signal timing parameters for the electrical signal satisfy the timing criteria.

Abstract: An oscilloscope includes input channels for receiving at least one voltage signal and at least one current signal from at least one component of a photovoltaic power system under test (SUT), a user interface including a display and one or more controls for receiving one or more test configuration settings from a user, and one or more processors configured to acquire waveforms of the at least one voltage signal and the at least one current signal, and implement a photovoltaic power system compliance test module that automatically determines, in real-time, one or more SUT performance measurements based on the acquired voltage and current waveforms and the one or more test configuration settings, displays, in real-time, the one or more SUT performance measurements to the user on the display. Methods of performing automated hardware-in-the-loop testing of a photovoltaic power system under test using an oscilloscope are also disclosed.

Abstract: A test and measurement system includes a device under test (DUT) interface structured to couple to at least one DUT and a measurement instrument coupled to the interface. The instrument includes one or more processors configured to, when testing the DUT, accept a measurement signal at a first input channel and generate a first sample waveform from the measurement signal using a first set of parameters, accept the measurement signal at a second input channel and generate a second sample from the measurement signal using a second set of parameters, and generate a measurement waveform from a combination of the first sample waveform and the second sample waveform. Additionally, the measurement instrument is structured to determine settling errors in the first pulse of a double-pulse test, and then compensate measurements made in subsequent pulses for the settling errors.

Abstract: A test and measurement instrument includes one or more processors to acquire first, second, and third phase drive signals applied to a three-phase motor. A motor drive analyzer performs a direct-quadrature-zero, DQZ, transformation on the acquired first, second, and third phase drive signals to produce direct (D), quadrature (Q), and zero (Z) components, and generates an overlapped DQ phasor plot illustrating the D and Q components along with frequency domain representations of the D and Q components. The motor driver analyzer displays, on a user interface, the generated overlapped DQ phasor plot and an overlapped DQ spectra plot from the frequency domain representations of the D and Q components to enable a user to detect motor defects through visual characteristics of the overlapped DQ phasor and DQ spectra plots. The motor driver analyzer removes an offset and filters the D and Q components prior generating the overlapped DQ phasor plot.

Abstract: A test and measurement instrument includes one or more sensors configured to measure a mechanical position of a synchronous machine driven by analog three-phase signals, a converter to determine an instantaneous electrical angle from the measured mechanical position, a transform configured to generate DQ0 signals based on the instantaneous electrical angle, and a vector generator structured to produce a resultant vector from the DQ0 signals. Methods are also described.

Abstract: A test and measurement instrument for determining magnetic core losses of a device under test during in circuit operation. The test and measurement instrument receives a primary current signal from a primary winding of a device under test and receives a primary voltage signal measured across a magnetic core of the device under test. Based on the primary electric current signal and the primary voltage signal, the test and measurement instrument determines a magnetic loss of the device under test. In some examples, the test and measurement instrument can use primary and secondary voltage and current inputs to determine the magnetic loss of the device under test. The magnetic loss of the device under test can be displayed on a display of the test and measurement instrument. The magnetic loss can include a total magnetic loss, a hysteresis loss, a copper loss, and/or other losses.

Abstract: A test and measurement instrument includes a user interface, one or more probes to connect to a device under test (DUT), and one or more processors to take measurements during application of a double pulse test to the DUT to create measurement data, identify a measurement start point, find a measurement stop point, use the measurement data between the measurement start point and the measurement stop point to determine an output charge, Qoss, of the DUT, and display the output charge to a user. A method of determining output charge of a device under test (DUT) includes taking measurements during application of a double pulse test to create measurement data, identifying a measurement start point, finding a measurement stop point, using the measurement data between the measurement start point and the measurement stop point to determine an output charge, Qoss, of the DUT, and displaying the output charge.

Abstract: A test and measurement instrument has a user interface, one or more probes to allow the instrument to connect to a device under test (DUT), and one or more processors configured to execute code to cause the one or more processors to: receive one or more user inputs through the user interface, at least one of the user inputs to identify at least one analysis to be performed on the DUT, receive waveform data from the DUT when the DUT is activated by application of power from a power supply, and application of one of a first and second pulse or multiple pulses from a source instrument, perform the at least one analysis on the waveform data, and display the waveform data and analysis on the user interface.

Abstract: A test and measurement instrument has a user interface, one or more probes to connect to a device under test (DUT), and one or more processors configured to execute code to cause the one or more processors to: receive waveform data from the DUT after activation of the DUT by application of power from a power supply, and application of at least a first and second pulse from a source instrument, locate one or more reverse recovery regions in the waveform data, determine a reverse recovery time for the DUT from the reverse recovery region, and display a reverse recovery plot of the one or more reverse recovery regions on the user interface, the reverse recovery plot being automatically configured to display one or more of the reverse recovery regions, and including at least one characteristic for the one or more reverser recovery regions annotated on the reverse recovery plot.

Abstract: A test and measurement instrument includes one or more sensors configured to measure a mechanical position of a synchronous machine driven by analog three-phase signals, a converter to determine an instantaneous electrical angle from the measured mechanical position, a transform configured to generate DQ0 signals based on the instantaneous electrical angle, and a vector generator structured to produce a resultant vector from the DQ0 signals. Methods are also described.

Abstract: A test and measurement instrument, including at least one port configured to receive a signal from a device under test (DUT), the signal including a current signal acquired across a magnetic core of the DUT and a voltage signal acquired across the magnetic core of the DUT, and one or more processors. The one or more processors are configured to determine a hysteresis loop based on the current signal and the voltage signal, determine a magnetic flux of the magnetic core based on the voltage signal and the current signal for a number of sample points for each cycle, and determine a maximum magnetic flux for all cycles and a hysteresis loop cycle that corresponds to the maximum magnetic flux. A display configured to display at least one of the hysteresis loop, the signal received from the DUT, and the hysteresis loop cycle that corresponds to the maximum magnetic flux.

Abstract: A test and measurement instrument for determining magnetic core losses of a device under test during in circuit operation. The test and measurement instrument receives a primary current signal from a primary winding of a device under test and receives a primary voltage signal measured across a magnetic core of the device under test. Based on the primary electric current signal and the primary voltage signal, the test and measurement instrument determines a magnetic loss of the device under test. In some examples, the test and measurement instrument can use primary and secondary voltage and current inputs to determine the magnetic loss of the device under test. The magnetic loss of the device under test can be displayed on a display of the test and measurement instrument. The magnetic loss can include a total magnetic loss, a hysteresis loss, a copper loss, and/or other losses.