A high-voltage fast pulse group generating system and method for a direct-current electric energy meter

Abstract

This invention discloses a high-voltage fast transient burst generation system and method for DC energy meters, comprising a processor, a high-voltage switching power supply, an electric fast transient burst generation unit, and a signal acquisition unit. The processor controls the high-voltage switching power supply to output the required high-voltage voltage and current for the test according to test parameters, and controls the electric fast transient burst generation unit to generate a pulse trigger signal. The electric fast transient burst generation unit adjusts the frequency of the pulse trigger signal and the amplitude of the high-voltage voltage and current to form a burst. The signal acquisition unit acquires the burst waveform and amplitude, along with DC power supply electrical parameters, and feeds them back to the processor for closed-loop control of the output test burst. This invention improves the accuracy of the burst output through pulse phase-shift control comparison and closed-loop fine adjustment, meeting the requirements of fast transient burst tests for DC energy meters.

Description

Technical Field

[0001] This invention belongs to the field of DC power metering technology, specifically relating to a high-voltage fast pulse group generation system and method for DC power meters. Background Technology

[0002] A DC energy meter is a device for measuring electrical energy in a DC power system. With the rapid development of new energy sources, DC energy meters are increasingly used in applications with unstable input voltages, such as electric vehicle charging infrastructure, telecommunications base stations, low-voltage DC power grids in residential or commercial areas, photovoltaic power generation systems, public transportation DC power supply systems, and railway systems. As DC energy meters become more complex in application environments and have more diverse functional requirements, the factors influencing their errors are also becoming increasingly complex. Domestic and international standards have placed higher demands on the anti-interference performance of DC energy meters, and the corresponding technical indicators and testing requirements are constantly being improved.

[0003] The accuracy of DC energy meters is typically specified and verified under steady-state conditions. However, in reality, the maximum nominal voltage of DC energy meters can reach 1500V, and the nominal current can reach 500A. Furthermore, under high voltage and high current conditions, the load current may frequently change with high amplitude, as seen in temperature-controlled heaters, air conditioning equipment, and arc welding equipment. If the DC energy meter incorrectly executes the current range gain switching algorithm under these conditions, it will exhibit significant accuracy errors, affecting the fairness and impartiality of DC energy trading. Existing pulse group testing systems and related technologies are mainly suitable for testing and evaluating the anti-interference performance of AC energy meters and cannot meet the testing needs of DC energy meters under complex high-voltage and high-current conditions. Summary of the Invention

[0004] The purpose of this invention is to propose a high-voltage fast transient pulse group generation system and method, which is suitable for testing and detection of DC energy meters. This system improves the output accuracy of pulse groups, meets the requirements of fast transient pulse group testing for DC energy meters, and provides technical support for the construction of high-voltage fast transient pulse group testing capabilities for DC energy meters and the evaluation and analysis of the anti-interference performance of DC energy meters.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A high-voltage fast pulse group generation system for DC energy meters includes a processor, a high-voltage switching power supply, an electric fast pulse group generation unit, and a signal acquisition unit;

[0007] The processor is used to control the high voltage and current output of the high voltage switching power supply required for the test according to the test parameters, and to control the electric fast pulse group generation unit to generate a pulse trigger signal.

[0008] The electric fast pulse group generation unit is used to adjust the frequency of the pulse trigger signal and the amplitude of the high voltage and current to form a pulse group. The signal acquisition unit collects the pulse group waveform and amplitude and DC power supply electrical parameter information and feeds them back to the processor for closed-loop control to output the test pulse group.

[0009] As a further improvement of the present invention, the high-voltage switching power supply includes an LLC series resonant main circuit, an output stage circuit, and a voltage doubler rectifier circuit;

[0010] The LLC series resonant main circuit includes field-effect transistors Q1 and Q2, a resonant capacitor Cs, a resonant inductor Ls, and a magnetizing inductor Lm. Field-effect transistors Q1 and Q2 are connected in series with a power supply. The resonant capacitor Cs, resonant inductor Ls, and magnetizing inductor Lm form a resonant cavity, with both ends of the cavity connected to the source (S) terminals of field-effect transistors Q1 and Q2, respectively. The two ends of the magnetizing inductor Lm are connected to the two ends of the output stage circuit.

[0011] The output stage circuit is a winding-branched output stage circuit;

[0012] The voltage doubler rectifier circuit includes multiple half-wave voltage doubler rectifier circuits composed of diodes and capacitors, and the multiple half-wave voltage doubler rectifier circuits are connected in series and superimposed.

[0013] As a further improvement of the present invention, the electric fast pulse group generation unit includes a waveform generation circuit, a pulse comparison circuit, a potential adjustment circuit, and a logic control amplification circuit.

[0014] The waveform generation circuit is mainly used to generate a single high-voltage nanosecond pulse, including a constant current source and a discharge transistor D. T Charging resistor R C Energy storage capacitor C S , Electrical pulse trigger inductor L S Trigger switch K s and load resistance R S The positive terminal of the constant current source is connected in sequence to the discharge transistor D. T Charging resistor R C Energy storage capacitor C S The positive electrode; the energy storage capacitor C S The positive terminal is connected in sequence to the trigger inductor L S Trigger switch K s and load resistance R S The negative terminal of the constant current source is connected in sequence to the energy storage capacitor C. S negative terminal and load resistor R S The negative terminal connection;

[0015] The pulse comparison circuit is used to compare pulse signals. The pulse voltage signal adjusted by the potential adjustment circuit is input to the inverting input terminal of the pulse comparison circuit and compared with the phase shift control voltage signal at the non-inverting input terminal. When the pulse voltage signal is higher than the phase shift control voltage signal, the output signal of the pulse comparison circuit flips and is sent to the logic control amplifier circuit for amplification.

[0016] The potential adjustment circuit is used to adjust the slope and width of the pulse;

[0017] The logic control amplifier circuit is used to generate the preliminary waveforms required for the experiment.

[0018] As a further improvement of the present invention, the trigger switch K s The circuit is a thyristor switch trigger circuit, which includes a zero-crossing detection circuit and a synchronization register. The zero-crossing detection circuit is used to detect the synchronization voltage signal. When the synchronization signal is detected to cross zero, the signal is sent to the synchronization register. After being processed by the synchronization register, the signal is used to control the waveform generation circuit to generate a pulse trigger signal.

[0019] As a further improvement of the present invention, a storage unit connected to the processor is also included, the storage unit being used to read and write pulse group signal generation unit operation information and test parameter information.

[0020] As a further improvement of the present invention, it also includes a human-computer interaction unit connected to the processor, the human-computer interaction module including a touch screen input subunit and a display subunit;

[0021] The touchscreen input subunit adopts a coupled-capacitive LCD touchscreen, which uses coupled capacitive sensing to detect the distance between the finger and the display unit and the touch position.

[0022] The display subunit is used to display pulse group parameter information and pulse group waveform.

[0023] As a further improvement of the present invention, it also includes a peripheral interface unit connected to the electrical fast pulse generation unit, the peripheral interface unit being used to connect to peripheral test equipment and perform information exchange.

[0024] A method for generating high-voltage fast pulse group in a DC energy meter includes:

[0025] The high voltage and current required for the test are controlled according to the test parameters, and a pulse trigger signal is generated accordingly.

[0026] The frequency of the pulse trigger signal and the amplitude of the high voltage and current are obtained and adjusted to form a pulse group;

[0027] Based on the feedback pulse group waveform and amplitude and DC power supply electrical parameters, the closed-loop control outputs the test pulse group.

[0028] As a further improvement of the present invention, the step of controlling the output high voltage and current required for the test according to the test parameters includes:

[0029] Adjusting the parasitic capacitance in the field-effect transistor stores electrical energy, causing the resonant cavity current to lag behind the voltage by a predetermined phase angle;

[0030] By using a winding-type output stage circuit, voltage signals for different test requirements can be output.

[0031] The low-voltage AC voltage is boosted and rectified into a high-voltage DC voltage by using a series superposition method of half-wave voltage doubler rectifier circuits.

[0032] As a further improvement of the present invention, the parasitic capacitance in the regulated field-effect transistor stores electrical energy, including:

[0033] Adjust the duty cycle of field-effect transistors Q1 and Q2;

[0034] Based on the DC gain characteristic curve of the LLC series resonant main circuit, determine the dead time t of field-effect transistors Q1 and Q2. dead The method for determining the dead time is as follows:

[0035] t dead =((t) d_off_max -t d_on_min )+(t p_max -t p_min ))ρ Δ (1)

[0036] In the formula, t d_off_max t is the maximum turn-off delay time of the field-effect transistor. d_on_min t is the minimum turn-on delay time of the field-effect transistor. p_max t is the maximum input / output delay time for driving the MOSFET switch. p_min The minimum input / output delay time for driving the field-effect transistor switch; ρ Δ This is the DC gain coefficient;

[0037] Adjusting the operating frequency f of the high-voltage switching power supply r Make it greater than the resonant frequency f of the LLC series resonant main circuit. m The method for calculating the resonant frequency of the LLC series resonant main circuit is as follows:

[0038]

[0039] The parasitic capacitance stores energy based on the dead time and power supply operating frequency. The method for adjusting the parasitic capacitance stores energy is as follows:

[0040]

[0041] In the formula, C eqi It is the parasitic capacitance of the field-effect transistor Qi that stores electrical energy, I D,off For the resonant cavity current, t dead f is the dead time of the alternating switching of field-effect transistors Q1 and Q2. r This refers to the operating frequency of the high-voltage switching power supply.

[0042] The parasitic capacitance energy storage adjustment method causes the resonant cavity current to lag behind the phase angle corresponding to the voltage, so that the LLC series resonant circuit is in the on state when the voltage is zero and in the off state when the current is zero.

[0043] As a further improvement of the present invention, the step of adjusting the frequency of the pulse trigger signal and the amplitude of the high voltage and current to form a pulse group includes:

[0044] The constant current source outputs a constant current;

[0045] After the discharge transistor discharges, the charging resistor charges the energy storage capacitor.

[0046] When the charging voltage reaches the predetermined value, the electric fast pulse group generation unit generates a synchronization voltage signal and sends it to the zero-crossing detection circuit of the electric pulse trigger switch Ks. The zero-crossing detection circuit detects the synchronization voltage signal. When the synchronization signal is detected to cross zero, the signal is sent to the synchronization register. After processing by the synchronization register, the waveform generation circuit is controlled to generate a pulse trigger signal.

[0047] When the electrical pulse trigger switch Ks is triggered, the energy of the energy storage capacitor is rapidly released through the electrical pulse trigger switch Ks and the load resistor, forming a single high-voltage nanosecond pulse across the load resistor.

[0048] When the energy released from the energy storage capacitor is insufficient to keep the switching device on, the switch is turned off, one pulse ends, and it waits for the next pulse.

[0049] The pulse is sent to the potential adjustment circuit to adjust the pulse slope and width;

[0050] The pulse voltage signal is input to the inverting input terminal of the pulse comparator circuit and compared with the phase shift control voltage signal at the non-inverting input terminal. When the pulse voltage signal is higher than the phase shift control voltage signal, the output signal of the pulse comparator circuit flips; otherwise, it outputs normally.

[0051] The signal is then sent to the logic control amplifier circuit to generate a pulse group.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The high-voltage fast transient burst generation system of this invention is suitable for testing DC energy meters. The high-voltage switching power supply system stores energy by adjusting the parasitic capacitance in the field-effect transistor to ensure that the resonant cavity current lags behind the voltage by a certain phase angle. This allows the LLC series resonant circuit to be on at zero voltage and off at zero current, significantly reducing switching losses compared to traditional Buck, Boost, and Forward PWM modes with peak current transistors. This also reduces the size of the fast burst generation system and improves the efficiency of the electrical fast burst generation. Furthermore, this system improves the accuracy of the burst output value through pulse phase-shift control comparison and closed-loop fine adjustment, meeting the requirements for fast transient burst testing of DC energy meters. Attached Figure Description

[0054] Figure 1 This invention relates to a high-voltage fast pulse group generation system for DC energy meters.

[0055] Figure 2 This invention relates to a high-voltage switching power supply combination circuit;

[0056] Figure 3 This is the logic structure of the electrically fast burst generation unit of the present invention;

[0057] Figure 4 This is the waveform generation circuit of the present invention;

[0058] Figure 5 This invention relates to the high-voltage fast pulse group generation process for DC energy meters. Detailed Implementation

[0059] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0060] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0061] To verify the sensitivity of DC energy meters to rapid changes in load current and ensure their metering accuracy, this invention studies a high-voltage fast transient / burst generation system and method suitable for testing the anti-interference performance of DC energy meters, providing technical support for anti-interference performance testing of DC energy meters. The specific embodiments of this invention are further described in detail below with reference to the accompanying drawings.

[0062] Figure 1 This invention relates to a high-voltage fast pulse group generation system for DC energy meters. The system includes a processor, a high-voltage switching power supply, a fast pulse group generation unit, a signal acquisition unit, a storage unit, a human-machine interface unit, and a peripheral interface unit.

[0063] The anti-interference performance test parameters of the DC energy meter are set through the human-machine interface unit. The processor (preferably an ARM central processing unit) controls the high-voltage switching power supply to output the required voltage and current for the test based on the test parameters. It also controls the electrical fast pulse group generation unit to generate a pulse trigger signal. The electrical fast pulse group generation unit adjusts the frequency of the trigger signal and the amplitude of the high-voltage voltage and current to form a pulse group. The signal acquisition unit collects the waveform and amplitude of the pulse group and the DC power supply electrical parameters, feeding them back to the ARM central processing unit to achieve closed-loop control and output the test pulse group. The peripheral interface unit can connect to external testing equipment of the DC energy meter to complete relevant tests. The specific scheme is as follows:

[0064] The ARM central processing unit, with its core chip being an STM32F407 microprocessor chip, is mainly used to interact with the high-voltage switching power supply, the electrical fast pulse group generation unit, the signal acquisition unit, the storage unit, the human-machine interaction unit, and the peripheral interface unit, and to manage and control their normal operation.

[0065] The storage module mainly includes SDRAM memory and Flash memory, which are used to read and write pulse group signal generation unit operation information and test parameter information.

[0066] The human-computer interaction module includes a touch screen input subunit and a display subunit.

[0067] The touchscreen input subunit adopts a coupling-sensitive LCD touchscreen, which uses coupling capacitance sensing to detect the distance between the finger and the display unit and the touch position, so as to achieve accurate information input.

[0068] The display subunit is mainly used to display pulse group parameter information and pulse group waveform.

[0069] The peripheral interface module is mainly used to connect with peripheral testing equipment and exchange information.

[0070] Figure 2 This invention relates to a high-voltage switching power supply circuit. The high-voltage switching power supply primarily rectifies 220V AC voltage into a higher-level DC voltage. It includes an LLC series resonant main circuit, an output stage circuit, and a voltage doubler rectifier circuit.

[0071] The LLC series resonant main circuit includes field-effect transistors Q1 and Q2, a resonant capacitor Cs, a resonant inductor Ls, and a magnetizing inductor Lm. The field-effect transistors Q1 and Q2 are connected in series with a power supply. The resonant capacitor Cs, resonant inductor Ls, and magnetizing inductor Lm form a resonant cavity. The two ends of the resonant cavity are connected to the source (S) terminals of field-effect transistors Q1 and Q2, respectively. The two ends of the magnetizing inductor Lm are connected to the two ends of the output stage circuit. By adjusting the parasitic capacitance in the field-effect transistors to store electrical energy, the resonant cavity current lags behind the voltage by a certain phase angle, enabling the LLC series resonant circuit to be in the on state at zero voltage and in the off state at zero current.

[0072] The specific adjustment process for storing electrical energy using the parasitic capacitance in the effect transistor is as follows:

[0073] 1) First, adjust the duty cycles of field-effect transistors Q1 and Q2 to 50% each;

[0074] 2) Determine the dead time t of field-effect transistors Q1 and Q2 based on the DC gain characteristic curve of the LLC series resonant main circuit. dead The method for determining the dead time is shown in formula (1).

[0075] t dead =((t) d_off_max -t d_on_min )+(t p_max -tp_min ))ρ Δ (1)

[0076] In the formula, t d_off_max t is the maximum turn-off delay time of the field-effect transistor. d_on_min t is the minimum turn-on delay time of the field-effect transistor. p_max t is the maximum input / output delay time for driving the MOSFET switch. p_min This is the minimum input / output delay time for driving the field-effect transistor (FET) switch. ρ Δ This is the DC gain coefficient.

[0077] 3) Adjust the operating frequency f of the high-voltage switching power supply r Make it greater than the resonant frequency f of the LLC series resonant main circuit. m The method for calculating the resonant frequency of the LLC series resonant main circuit is shown in formula (2).

[0078]

[0079] 4) Then adjust the parasitic capacitance to store electrical energy according to the dead time and the power supply operating frequency as shown in formula (3) to ensure that the resonant cavity current lags behind the voltage by a certain phase angle, so that the LLC series resonant circuit is in the on state when the voltage is zero and in the off state when the current is zero.

[0080] The method for adjusting the energy stored in parasitic capacitance is shown in formula (3):

[0081]

[0082] In the formula, C eqi It is the parasitic capacitance of the field-effect transistor Qi that stores electrical energy, I D,off For the resonant cavity current, t dead f is the dead time for the alternating switching of field-effect transistors Q1 and Q2. r This refers to the operating frequency of the high-voltage switching power supply.

[0083] The output stage circuit is a winding-segmented output stage circuit, used to output voltage signals for different test requirements.

[0084] The voltage doubler rectifier circuit converts low-voltage AC voltage into high-voltage DC voltage by superimposing a series of half-wave voltage doubler rectifier circuits composed of diodes and capacitors.

[0085] The half-wave voltage doubler rectifier circuit series superposition method is as follows: AC voltage is charged and discharged in series and parallel through diodes D1 to Dn in each half cycle to realize the conversion of low-voltage AC input voltage into high-voltage DC output voltage.

[0086] Figure 3 This invention relates to the logic structure of the electrically fast pulse group generation unit.

[0087] The electrical fast pulse group generation unit includes a waveform generation circuit, a pulse comparison circuit, a potential adjustment circuit, and a logic control amplification circuit.

[0088] The waveform generation circuit is mainly used to generate a single high-voltage nanosecond pulse, including a constant current source and a discharge transistor D. T Charging resistor R C Energy storage capacitor C S , Electrical pulse trigger inductor L S Trigger switch K s and load resistance R S The constant current source outputs a constant current. After the discharge transistor discharges, the charging resistor charges the energy storage capacitor. When the charging voltage rises to a certain value, the electrical pulse trigger switch Ks is triggered. The energy of the energy storage capacitor is rapidly released through the electrical pulse trigger switch Ks and the load resistor, forming a single high-voltage nanosecond pulse across the load resistor. When the energy released from the energy storage capacitor is insufficient to maintain the switching device's conduction, the switch turns off, one pulse ends, and the device waits for the next pulse.

[0089] The pulse comparator circuit is mainly used for pulse signal comparison. The pulse voltage signal adjusted by the potential adjustment circuit is input to the inverting input terminal of the pulse comparator circuit and compared with the phase shift control voltage signal at the non-inverting input terminal. When the pulse voltage signal is higher than the phase shift control voltage signal, the output of the pulse comparator circuit flips, and the signal is sent to the logic control amplifier circuit.

[0090] The potential adjustment circuit is mainly used to adjust the slope and width of the pulse.

[0091] The logic control amplifier circuit is mainly used to generate the preliminary waveforms required for the experiment.

[0092] Figure 4 This invention relates to a waveform generation circuit. The waveform generation circuit includes a constant current source and a discharge transistor D. T Charging resistor R C Energy storage capacitor C S , Electrical pulse trigger inductor L S Trigger switch K s and load resistance R S The positive terminal of the constant current source is connected in sequence to the discharge transistor D. T Charging resistor R C Energy storage capacitor C S The positive electrode; the energy storage capacitor C S The positive terminal is connected in sequence to the trigger inductor L S Trigger switch K sand load resistance R S The negative terminal of the constant current source is connected in sequence to the energy storage capacitor C. S negative terminal and load resistor R S The negative terminal connection.

[0093] The constant current source outputs a constant current. After the discharge transistor discharges, the charging resistor charges the energy storage capacitor. When the charging voltage rises to a certain value, the electrical pulse trigger switch Ks is triggered. The energy of the energy storage capacitor is rapidly released through the electrical pulse trigger switch Ks and the load resistor, forming a single high-voltage nanosecond pulse across the load resistor. When the energy released from the energy storage capacitor is insufficient to maintain the switching device's conduction, the switch turns off, one pulse ends, and the device waits for the next pulse.

[0094] The electrical pulse trigger switch Ks is a thyristor switch trigger circuit, including a zero-crossing detection circuit and a synchronization register. When a synchronization voltage signal is input to the trigger circuit, the zero-crossing detection circuit detects the synchronization voltage signal. When the synchronization signal is detected to have crossed zero, the signal is sent to the synchronization register. After processing by the synchronization register, it is used to control the waveform generation circuit to generate a pulse trigger signal and trigger the switch to operate.

[0095] Figure 5 This invention relates to a method for generating high-voltage fast bursts in DC energy meters. The method includes:

[0096] The system initializes, sets test parameters, outputs high power, generates initial pulse groups, acquires and provides feedback on pulse group information, and uses the ARM central processing unit to control the closed-loop output of test pulse groups. The display unit shows the pulse group parameter information and waveforms.

[0097] The specific generation method is as follows:

[0098] (1) System initialization:

[0099] First, the high-voltage fast pulse group generation system of the DC energy meter is powered on and preheated. Based on the DC energy meter testing requirements, the system operating mode is set, the system clock is adjusted, and the system storage unit is initialized. The system operating modes include high-frequency high-voltage pulse generation mode, low-frequency high-voltage pulse mode, high-frequency medium-voltage pulse generation mode, low-frequency medium-voltage pulse generation mode, high-frequency low-voltage pulse generation mode, and low-frequency low-voltage pulse generation mode. To ensure the energy injected by low-frequency and high-frequency pulses is equivalent, when a high-frequency repetition frequency is used instead of a low-frequency frequency, the duration of the pulse group is reduced proportionally to the frequency; conversely, when a low-frequency repetition frequency is used instead of a low-frequency frequency, the duration of the pulse group is reduced proportionally to the frequency.

[0100] (2) Test parameter settings:

[0101] The system running code stored in the Flash memory is loaded into the SDRAM memory to drive the human-machine interface unit. The test personnel set the test parameters through the touch screen input subunit.

[0102] (3) Power supply rectified output:

[0103] After the test parameters are set, the ARM central processing unit controls the high-voltage switching power supply to rectify the 220V AC voltage into a higher-level DC voltage. The specific process is as follows:

[0104] 1) Adjusting the parasitic capacitance of a field-effect transistor

[0105] By adjusting the parasitic capacitance in the field-effect transistor to store electrical energy, the resonant cavity current lags behind the voltage by a certain phase angle, thus enabling the LLC series resonant circuit to be in the on state when there is zero voltage and in the off state when there is zero current.

[0106] The specific adjustment process for the parasitic capacitance storing electrical energy in the effect transistor is as follows:

[0107] 1) First, adjust the duty cycles of field-effect transistors Q1 and Q2 to 50% each;

[0108] 2) Determine the dead time t of field-effect transistors Q1 and Q2 based on the DC gain characteristic curve of the LLC series resonant main circuit. dead The method for determining the dead time is shown in formula (1).

[0109] t dead =((t) d_off_max -t d_on_min )+(t p_max -t p_min ))ρ Δ (1)

[0110] In the formula, t d_off_max t is the maximum turn-off delay time of the field-effect transistor. d_on_min t is the minimum turn-on delay time of the field-effect transistor. p_max t is the maximum input / output delay time for driving the MOSFET switch. p_min This is the minimum input / output delay time for driving the field-effect transistor (FET) switch. ρ Δ This is the DC gain coefficient.

[0111] 3) Adjust the operating frequency f of the high-voltage switching power supply r Make it greater than the resonant frequency f of the LLC series resonant main circuit. m The method for calculating the resonant frequency of the LLC series resonant main circuit is shown in formula (2).

[0112]

[0113] 4) Then adjust the parasitic capacitance to store electrical energy according to the dead time and the power supply operating frequency as shown in formula (3) to ensure that the resonant cavity current lags behind the voltage by a certain phase angle, so that the LLC series resonant circuit is in the on state when the voltage is zero and in the off state when the current is zero.

[0114] The method for adjusting the energy stored in parasitic capacitance is shown in formula (3):

[0115]

[0116] In the formula, C eqi It is the parasitic capacitance of the field-effect transistor Qi that stores electrical energy, I D,off For the resonant cavity current, t dead f is the dead time for the alternating switching of field-effect transistors Q1 and Q2. r This refers to the operating frequency of the high-voltage switching power supply.

[0117] 2) Voltage signal winding segmented output

[0118] By using a winding-type output stage circuit, voltage signals for different test requirements can be output.

[0119] 3) Rectifier boost

[0120] A voltage doubler rectifier circuit is used to boost and rectify low-voltage AC voltage into high-voltage DC voltage by using a series superposition method of half-wave voltage doubler rectifier circuits.

[0121] The half-wave voltage doubler rectifier circuit series superposition method is as follows: AC voltage is charged and discharged in series and parallel through diodes D1 to Dn in each half cycle to realize the conversion of low-voltage AC input voltage into high-voltage DC output voltage.

[0122] (4) Pulse Generation: The ARM central processing unit controls the electrically fast pulse group generation unit to generate a preliminary test pulse group. The specific process is as follows:

[0123] 1) The constant current source of the electric fast pulse group generation unit outputs a constant current;

[0124] 2) After the discharge transistor discharges, the charging resistor charges the energy storage capacitor.

[0125] 3) When the charging voltage rises to a certain value, the electric fast pulse group generation unit generates a synchronization voltage signal and sends it to the zero-crossing detection circuit of the electric pulse trigger switch Ks. The zero-crossing detection circuit detects the synchronization voltage signal. When the synchronization signal is detected to cross zero, the signal is sent to the synchronization register. After being processed by the synchronization register, it is used to control the waveform generation circuit to generate a pulse trigger signal and trigger the switch action.

[0126] 4) When the electrical pulse trigger switch Ks is triggered, the energy of the energy storage capacitor is rapidly released through the electrical pulse trigger switch Ks and the load resistor, forming a single high-voltage nanosecond pulse across the load resistor.

[0127] 5) When the energy released from the energy storage capacitor is insufficient to keep the switching device on, the switch is turned off, one pulse ends, and the device waits for the next pulse.

[0128] 6) The pulse is sent to the potential adjustment circuit for pulse slope and width adjustment;

[0129] 7) The pulse voltage signal is input to the inverting input terminal of the pulse comparator circuit and compared with the phase shift control voltage signal at the non-inverting input terminal. When the pulse voltage signal is higher than the phase shift control voltage signal, the output of the pulse comparator circuit flips; otherwise, it outputs normally.

[0130] 8) The signal is then sent to the logic control amplifier circuit to generate a high-voltage pulse group.

[0131] 9) Repeat steps 2-8 to generate a high-voltage fast pulse group suitable for testing DC energy meters.

[0132] (5) Pulse group information acquisition and feedback: The signal acquisition unit acquires the pulse group waveform and amplitude and DC power supply electrical parameters and feeds them back to the ARM central processing unit;

[0133] (6) Closed-loop control output test pulse group: The ARM central processing unit controls the electric fast pulse group generation unit and the high voltage DC power supply to realize the closed-loop adjustment of the pulse group waveform and amplitude, and the generated pulse waveform meets the test requirements.

[0134] (7) Display unit displays pulse group parameter information and waveform: The display subunit displays pulse group parameter information and pulse group waveform for test personnel to view test information.

[0135] (8) Conduct relevant tests: Connect the test equipment under test through the peripheral interface to start the fast transient burst immunity test of the DC energy meter and exchange information.

[0136] In summary, compared to traditional peak current transistor switches using PWM modes such as Buck, Boost, and Forward, this invention significantly reduces switching losses, decreases the size of the fast transient burst generation system, and improves the efficiency of electrical fast transient burst generation. This system improves the accuracy of the burst output through pulse phase-shift control comparison and closed-loop fine adjustment, meeting the fast transient burst test requirements for DC energy meters.

[0137] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0138] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0139] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0140] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for generating high voltage fast pulse group of direct current energy meter, characterized in that, include: The high voltage and current required for the test are controlled according to the test parameters, and a pulse trigger signal is generated accordingly. The frequency of the pulse trigger signal and the amplitude of the high voltage and current are obtained and adjusted to form a pulse group; Based on the feedback pulse group waveform and amplitude and DC power supply electrical parameters, the closed-loop control outputs the test pulse group; The step of controlling the output high voltage and current required for the test according to the test parameters includes: Adjusting the parasitic capacitance in the field-effect transistor stores electrical energy, causing the resonant cavity current to lag behind the voltage by a predetermined phase angle; By using a winding-type output stage circuit, voltage signals for different test requirements can be output. Based on the voltage doubler rectifier circuit, the low-voltage AC voltage is boosted and rectified into a high-voltage DC voltage by using a series superposition method of half-wave voltage doubler rectifier circuits; The parasitic capacitance in the regulated field-effect transistor stores electrical energy, including: Adjust the duty cycle of field-effect transistors Q1 and Q2; Based on the DC gain characteristic curve of the LLC series resonant main circuit, determine the dead time of field-effect transistors Q1 and Q2. The method for determining the dead time is as follows: （1） In the formula, This is the maximum turn-off delay time of the field-effect transistor. This is the minimum turn-on delay time for the field-effect transistor. This is the maximum input / output delay time for the MOSFET-driven switch. The minimum input / output delay time for driving the field-effect transistor switch; This is the DC gain coefficient; Adjusting the operating frequency of a high-voltage switching power supply to be greater than the LLC series resonant main circuit resonant frequency wherein the LLC series resonant main circuit resonant frequency is calculated by （2） The parasitic capacitance stores energy based on the dead time and power supply operating frequency. The method for adjusting the parasitic capacitance stores energy is as follows: （3） In the formula, is the parasitic capacitance of the field effect transistor Q1 storing electric energy, is the resonant cavity current, is the dead time of the field effect transistors Q1 and Q2 switching alternately, is the operating frequency of the high-voltage switching power supply; The parasitic capacitance energy storage adjustment method causes the resonant cavity current to lag behind the phase angle corresponding to the voltage, so that the LLC series resonant circuit is in the on state when the voltage is zero and in the off state when the current is zero.

2. The method for generating high voltage fast pulse group of direct current watt-hour meter according to claim 1, characterized in that, The step of obtaining the frequency of the pulse trigger signal and adjusting the amplitude of the high voltage and current to form a pulse group includes: The constant current source outputs a constant current; After the discharge transistor discharges, the charging resistor charges the energy storage capacitor. When the charging voltage reaches the predetermined value, the electric fast pulse group generation unit generates a synchronization voltage signal and sends it to the zero-crossing detection circuit of the electric pulse trigger switch Ks. The zero-crossing detection circuit detects the synchronization voltage signal. When the synchronization signal is detected to cross zero, the signal is sent to the synchronization register. After processing by the synchronization register, the waveform generation circuit is controlled to generate a pulse trigger signal. When the electrical pulse trigger switch Ks is triggered, the energy of the energy storage capacitor is rapidly released through the electrical pulse trigger switch Ks and the load resistor, forming a single high-voltage nanosecond pulse across the load resistor. When the energy released from the energy storage capacitor is insufficient to keep the switching device on, the switch is turned off, one pulse ends, and it waits for the next pulse. The pulse is sent to the potential adjustment circuit to adjust the pulse slope and width; The pulse voltage signal is input to the inverting input terminal of the pulse comparator circuit and compared with the phase shift control voltage signal at the non-inverting input terminal. When the pulse voltage signal is higher than the phase shift control voltage signal, the output signal of the pulse comparator circuit flips; otherwise, it outputs normally. The signal is then sent to the logic control amplifier circuit to generate a pulse group.

3. A high-voltage fast pulse group generation system for a DC energy meter, implementing the high-voltage fast pulse group generation method for a DC energy meter as described in claim 1 or 2, characterized in that, Includes a processor, a high-voltage switching power supply, an electrical fast burst generation unit, and a signal acquisition unit; The processor is used to control the high voltage and current output of the high voltage switching power supply required for the test according to the test parameters, and to control the electric fast pulse group generation unit to generate a pulse trigger signal. The electric fast pulse group generation unit is used to adjust the frequency of the pulse trigger signal and the amplitude of the high voltage and current to form a pulse group. The signal acquisition unit collects the pulse group waveform and amplitude and DC power supply electrical parameter information and feeds them back to the processor for closed-loop control to output the test pulse group.

4. The high-voltage fast pulse group generation system for DC energy meters according to claim 3, characterized in that, The high-voltage switching power supply includes an LLC series resonant main circuit, an output stage circuit, and a voltage doubler rectifier circuit. The LLC series resonant main circuit includes field-effect transistors Q1 and Q2, a resonant capacitor Cs, a resonant inductor Ls, and a magnetizing inductor Lm. Field-effect transistors Q1 and Q2 are connected in series with a power supply. The resonant capacitor Cs, resonant inductor Ls, and magnetizing inductor Lm form a resonant cavity, with both ends of the cavity connected to the source (S) terminals of field-effect transistors Q1 and Q2, respectively. The two ends of the magnetizing inductor Lm are connected to the two ends of the output stage circuit. The output stage circuit is a winding-branched output stage circuit; The voltage doubler rectifier circuit includes multiple half-wave voltage doubler rectifier circuits composed of diodes and capacitors, and the multiple half-wave voltage doubler rectifier circuits are connected in series and superimposed.

5. The high voltage fast pulse group generation system for a direct current watt-hour meter according to claim 3, wherein The electrical fast pulse group generation unit includes a waveform generation circuit, a pulse comparison circuit, a potential adjustment circuit, and a logic control amplifier circuit. The waveform generation circuit is used to generate a single high-voltage nanosecond pulse, and includes a constant current source and a discharge transistor D. T Charging resistor R C Energy storage capacitor C S , Electrical pulse trigger inductor L S Trigger switch K s and load resistance R S The positive terminal of the constant current source is connected in sequence to the discharge transistor D. T Charging resistor R C Energy storage capacitor C S The positive electrode; the energy storage capacitor C S The positive terminal is connected in sequence to the trigger inductor L S Trigger switch K s and load resistance R S The negative terminal of the constant current source is connected in sequence to the energy storage capacitor C. S negative terminal and load resistor R S The negative terminal connection; The pulse comparison circuit is used to compare pulse signals. The pulse voltage signal adjusted by the potential adjustment circuit is input to the inverting input terminal of the pulse comparison circuit and compared with the phase shift control voltage signal at the non-inverting input terminal. When the pulse voltage signal is higher than the phase shift control voltage signal, the output signal of the pulse comparison circuit flips and is sent to the logic control amplifier circuit for amplification. The potential adjustment circuit is used to adjust the slope and width of the pulse; The logic control amplifier circuit is used to generate the preliminary waveforms required for the experiment.

6. The high voltage fast burst generator system for a direct current energy meter according to claim 3, wherein, The trigger switch K s The circuit is a thyristor switch trigger circuit, which includes a zero-crossing detection circuit and a synchronization register. The zero-crossing detection circuit is used to detect the synchronization voltage signal. When the synchronization signal is detected to cross zero, the signal is sent to the synchronization register. After being processed by the synchronization register, the signal is used to control the waveform generation circuit to generate a pulse trigger signal.

7. The high voltage fast pulse group generation system for a direct current watt-hour meter according to claim 3, characterized by, It also includes a storage unit connected to the processor, which is used to read and write pulse group signal generation unit operation information and test parameter information.

8. The high voltage fast pulse group generation system for a direct current watt-hour meter according to claim 3, characterized by, It also includes a human-computer interaction unit connected to the processor, the human-computer interaction unit including a touch screen input subunit and a display subunit; The touchscreen input subunit adopts a coupled-capacitive LCD touchscreen, which uses coupled capacitive sensing to detect the distance between the finger and the display unit and the touch position. The display subunit is used to display pulse group parameter information and pulse group waveform.

9. The high voltage fast pulse group generation system for a direct current watt-hour meter according to claim 3, characterized by, It also includes a peripheral interface unit connected to the electrical fast pulse generation unit, the peripheral interface unit being used to connect to peripheral test equipment and exchange information.

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