AC / DC adaptive electric energy metering system and method

Abstract

The present invention discloses an AC / DC adaptive electric energy metering system and method, including a sampling module, an AC / DC detection module, an AD conversion module, a metering unit, and a management unit. The sampling module includes a resistor R1, a resistor R2, and a manganese-copper shunt. The manganese-copper shunt, the AD conversion module, and the metering unit are connected in sequence. The management unit is connected to the AC / DC detection module and the metering unit respectively. The AC / DC detection module includes a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a capacitor C1, a capacitor C2, a diode D1, and a transistor Q. The metering unit measures the input current under the control of the management unit. The present invention can automatically switch and calculate AC / DC electricity, and adopts different calculation methods for DC electricity in different situations, so that the DC electric energy calculation accuracy is high.

Description

Technical Field

[0001] The invention relates to an AC / DC adaptive electric energy metering system and method, belonging to the technical field of electric energy metering. Background Art

[0002] As green new energy vehicles become more and more popular, the installation of charging piles is also growing rapidly. Charging piles mainly include AC charging piles and DC charging piles, which are used to meet the charging and endurance requirements of electric vehicles. AC and DC charging piles charge electric vehicles in the form of AC / DC respectively. In order to realize the trade settlement of charging piles, high-precision electric energy meters are used for AC / DC electric energy measurement. In order to solve the current situation that AC and DC charging pile trade settlement electric energy meters are not universal, the present invention proposes a design of an AC / DC adaptive electric energy meter, which is suitable for the electric energy metering needs of AC and DC charging piles. When purchasing and installing the electric energy metering device for charging pile trade settlement, there is no need to distinguish the electric energy metering method, which greatly reduces the difficulty of material management and construction and installation of AC and DC charging piles.

[0003] The existing Chinese patent CN106569447A discloses an AC / DC adaptive electric energy meter and an electric energy metering method. The electric energy meter includes a voltage sampling module, a current sampling module, an electric energy metering module and a single-chip control module. The electric energy metering module includes a signal detection unit, a signal processing unit, an A / D conversion unit, a high-pass filter, and an electric energy metering unit. The signal detection unit in the electric energy metering module performs zero-crossing detection and frequency measurement on the input signal. Through the dual judgment conditions of zero signal and frequency domain value, it is distinguished whether the input is an AC signal or a DC signal, thereby adaptively performing AC measurement or DC measurement. Summary of the invention

[0004] Purpose of the invention: In order to make AC and DC metering more accurate, the present invention provides an AC and DC adaptive electric energy metering system.

[0005] Technical solution: To achieve the above purpose, the technical solution adopted by the present invention is:

[0006] An AC / DC adaptive electric energy metering system includes a sampling module, an AC / DC detection module, an AD conversion module, a metering unit, and a management unit, wherein:

[0007] The sampling module includes a resistor R1, a resistor R2, and a manganese copper shunt, wherein one end of the resistor R1 is used to connect to the measurement power supply line, and the other end is connected to the resistor R2, the AC / DC detection module, and the manganese copper shunt; the other end of the resistor R2 is grounded; the manganese copper shunt, the AD conversion module, and the metering unit are connected in sequence, and the management unit is connected to the AC / DC detection module and the metering unit respectively;

[0008] The AC / DC detection module includes a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a capacitor C1, a capacitor C2, a diode D1, and a transistor Q, wherein one end of the resistor R3 is connected to a lead wire 1, and the other end is connected to the collector of the transistor Q; one end of the resistor R4 is connected to the VCC terminal, and the other end is connected to the collector of the transistor Q; one end of the capacitor C1 is connected to a lead wire 1, and the other end is connected to the collector of the transistor Q. The emitter of the transistor Q is connected; the emitter of the transistor Q is grounded, one end of the capacitor C2 is connected to the base of the transistor Q, and the other end is grounded; the cathode of the diode D1 is connected to the base of the transistor Q, and the positive electrode is grounded; one end of the resistor R5 is connected to the base of the transistor Q, and the other end is grounded; the base of the transistor Q, the resistor R6, the resistor R7, the resistor R8, the resistor R9, the resistor R10, and the lead wire 2 are connected in sequence; the lead wire 1 and the lead wire 2 are connected to the management unit;

[0009] The management unit determines whether the current is DC or AC according to the detection signal of the AC / DC detection module, and controls the metering unit to measure the current according to the judgment result; the metering unit measures the input current under the control of the management unit.

[0010] Preferably, the metering unit includes a DC metering module, and the DC metering module measures DC electric energy using the following formula:

[0011]

[0012] in, Represents direct current energy, is the number of sampling points, for Sampling point voltage, for Sampling point current.

[0013] Preferably, the metering unit includes a DC metering module, and the DC metering module performs DC power metering according to the following formula:

[0014]

[0015] in, is the average value DC power under the influence of harmonics, To stabilize the voltage, To stabilize the current, for The average time of the sampling points, is the number of sampling points.

[0016] Preferably, the metering unit includes a DC metering module, and the DC metering module performs DC power metering according to the following formula:

[0017]

[0018] in, It represents the instantaneous power integrated DC energy under the influence of harmonics, is the number of sampling points, To stabilize the voltage, To stabilize the current, is the accumulated time, for The voltage at the sampling point, is the harmonic frequency, is the harmonic phase angle, is the harmonic average current, is the harmonic average frequency.

[0019] Preferably, the metering unit includes an AC metering module, and the AC metering module measures AC power using the following formula:

[0020]

[0021] in, is AC power, is the sampling time, is the sampling number, is the voltage, is the current, is the frequency, is the power factor.

[0022] Preferably, a low-pass filter is included, and the low-pass filter is arranged at the signal input front end of the sampling module, and the parameters of the low-pass filter are:

[0023] = , , , , , the system function is:

[0024] ;

[0025] in, represents the sampling frequency, represents the cut-off frequency, represents the angular cutoff frequency, represents the angular frequency, represents the transition band cutoff frequency, represents the attenuation at the cutoff frequency, It represents the attenuation at the cutoff frequency of the transition band. represents the system transfer function, In digital signal processing Transformation.

[0026] Another object of the present invention is to provide an AC / DC adaptive electric energy metering method, which uses the AC / DC adaptive electric energy metering system and comprises the following steps:

[0027] Step 1: After the voltage channel is divided, the signal is input to the base of the transistor Q;

[0028] Step 2: When the voltage signal is a DC signal, the transistor Q is always turned on, and the signal after the transistor Q is always at a low level; if the voltage signal is an AC signal, the transistor Q is turned on in the positive half-wave and cut off in the negative half-wave. At this time, the signal at the rear end of the transistor Q outputs a low level in the positive half-wave and a high level in the negative half-wave, that is, the voltage at the rear end of the transistor Q is a high level under the AC signal;

[0029] Step 3: The management module detects the level of the back end of the transistor Q. If it is continuously detected as a low level, the current metering mode is determined to be DC metering; if it is continuously detected as a high-low level alternating signal, the current metering mode is determined to be AC ​​metering;

[0030] Step 4: According to the detection result, the management module updates the metering algorithm parameters of the corresponding metering mode to the metering module;

[0031] Step 5: The metering unit measures the input current under the control of the management unit.

[0032] Preferably, the metering unit includes a DC metering module, and the DC metering module measures DC electric energy using the following formula:

[0033]

[0034] in, Represents direct current energy, is the number of sampling points, for Sampling point voltage, for Sampling point current.

[0035] Preferably, the metering unit includes a DC metering module, and the DC metering module performs DC power metering according to the following formula:

[0036]

[0037] in, is the average value DC power under the influence of harmonics, To stabilize the voltage, To stabilize the current, for The average time of the sampling points, is the number of sampling points.

[0038] Preferably, the metering unit includes a DC metering module, and the DC metering module performs DC power metering according to the following formula:

[0039]

[0040] in, It represents the instantaneous power integrated DC energy under the influence of harmonics, is the number of sampling points, To stabilize the voltage, To stabilize the current, is the accumulated time, for The voltage at the sampling point, is the harmonic frequency, is the harmonic phase angle, is the harmonic average current, is the harmonic average frequency.

[0041] Preferably, the metering unit includes an AC metering module, and the AC metering module measures AC power using the following formula:

[0042]

[0043] in, is AC power, is the sampling time, is the sampling number, is the voltage, is the current, is the frequency, is the power factor.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The present invention can automatically switch and calculate alternating and direct current, and adopts different calculation methods for direct current in different situations, so that the calculation accuracy of direct current power is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is the block diagram of the AC / DC adaptive electric energy metering device.

[0047] Figure 2 This is the block diagram of the metering unit.

[0048] Figure 3 This is the schematic diagram of the AC / DC detection module.

[0049] Figure 4 This is the block diagram for AC metering implementation.

[0050] Figure 5 This is the schematic diagram for the AC / DC detection module. DETAILED DESCRIPTION

[0051] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0052] An AC / DC adaptive energy metering system, such as Figure 1-3 As shown, it includes a sampling module, an AC / DC detection module, an AD conversion module, a metering unit, and a management unit, wherein:

[0053] The sampling module includes a resistor R1, a resistor R2, and a manganese-copper shunt, wherein one end of the resistor R1 is used to connect to the measurement power supply line, and the other end is connected to the resistor R2, the AC / DC detection module, and the manganese-copper shunt; the other end of the resistor R2 is grounded; the manganese-copper shunt, the AD conversion module, and the metering unit are connected in sequence, and the management unit is respectively connected to the AC / DC detection module and the metering unit.

[0054] The AC / DC detection module includes a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a capacitor C1, a capacitor C2, a diode D1, and a transistor Q, wherein one end of the resistor R3 is connected to a lead wire 1, and the other end is connected to the collector of the transistor Q; one end of the resistor R4 is connected to the VCC terminal, and the other end is connected to the collector of the transistor Q; one end of the capacitor C1 is connected to a lead wire 1, and the other end is connected to the collector of the transistor Q. The emitter of the transistor Q is connected; the emitter of the transistor Q is grounded, one end of the capacitor C2 is connected to the base of the transistor Q, and the other end is grounded; the cathode of the diode D1 is connected to the base of the transistor Q, and the positive electrode is grounded; one end of the resistor R5 is connected to the base of the transistor Q, and the other end is grounded; the base of the transistor Q, the resistor R6, the resistor R7, the resistor R8, the resistor R9, the resistor R10, and the lead wire 2 are connected in sequence; the lead wire 1 and the lead wire 2 are connected to the management unit.

[0055] like Figure 3 As shown, the voltage signal is used as the input source of the AC / DC detection signal, and the AC / DC detection module realizes the AC / DC access signal detection function.

[0056] Lead wire 2 P4 from Figure 1The resistors R1 and R2 in the middle take the voltage sampling signal. According to the conduction characteristics of the transistor Q, when the signal is an AC signal, such as Figure 5 As shown, when the signal is greater than 0 (in the positive half axis), the transistor Q is turned on, and the input to the microcontroller detection port line is a low level; when the signal is less than 0 (in the negative half axis), the transistor Q is cut off, and the input to the microcontroller detection port line is a high level.

[0057] After the adaptive electric energy metering system is powered on, the timing 5ms transistor Q output high and low level detection function is turned on, and the detection period is 10 cycles (grid frequency 50Hz, detection 200ms): if the high level is all during the detection period, it is determined that it is currently applied to DC metering occasions; if the high and low levels alternate during the detection period, it is determined that it is currently applied to AC metering occasions.

[0058] The management unit determines whether the current is DC or AC according to the detection signal of the AC / DC detection module, and controls the metering unit to measure the current according to the judgment result; the metering unit measures the input current under the control of the management unit.

[0059] In this embodiment, the voltage signal is obtained by voltage sampling and resistor voltage division, and the current is obtained by measuring the voltage and current equivalent signal at both ends of the manganese copper. After the voltage is divided, the signal is output to the management module through the triode, and the signal is pulled up to VCC. The management module detects the high and low levels of the signal to determine the AC and DC. The management module connects the detected AC and DC, and the algorithm module selects the corresponding AC and DC parameters and sends them to the algorithm module for calculation, and outputs the instantaneous quantity data such as the accumulated electric energy pulse, voltage, current, and power.

[0060] The management module stores two sets of parameters for AC / DC measurement: including filter parameters, gain, phase, creep, pulse constant and other parameters of voltage and current channels;

[0061] According to the measurement parameters, the digital signal after AD conversion is processed (obtained through 24-channel ADC sampler). The signal after AD is processed in two ways, such as Figure 2, one for DC metering, and one for AC metering. Among them, the circuit for DC metering includes a UI multiplier, a low-pass filter, and an integrator connected in sequence, thereby obtaining DC electric energy metering. The circuit for AC metering includes a first A-phase current gain 1, a first HPF high-pass filter 1, and a first digital integrator connected in sequence, a first A-phase current gain 2, and a first HPF high-pass filter 2 connected in sequence, the first digital integrator and the first HPF high-pass filter 2 are respectively connected to the first multiplier, the first multiplier, the first LPF low-pass filter, the first A-phase power gain, the first power integrator, the first accumulator, and the first integrator 2 are connected in sequence, and the first integrator 2 needs to be connected to the A-phase fixed digital threshold to obtain the A-phase AC electric energy. The second B-phase current gain 2 and the second HPF high-pass filter 2 are connected in sequence, the second digital integrator and the second HPF high-pass filter 2 are respectively connected to the second multiplier, the second multiplier, the second LPF low-pass filter, the second B-phase power gain, the second power integrator, the second accumulator, and the second integrator 2 are connected in sequence, and the second integrator 2 needs to be connected to the B-phase fixed digital threshold to obtain the B-phase AC power.

[0062] 1) DC metering algorithm analysis:

[0063] Electric energy measurement can be regarded as the integration of power over time. DC power is obtained by multiplying voltage by current, so the power calculation formula is:

[0064]

[0065] in is the DC power, is the DC voltage, is direct current;

[0066] DC voltage definition:

[0067]

[0068]

[0069] Similarly, the DC current is defined as:

[0070]

[0071]

[0072] in, is the average voltage from time to time, for The instantaneous voltage at time, is the average current from time to time, is the voltage at sampling point k, is the average current from time to time, for The instantaneous current at the moment, is the current at sampling point k, is the sampling period, and N is the number of sampling points.

[0073] Then the electric energy is the integral of power over time, and the formula is as follows:

[0074]

[0075] Right now:

[0076]

[0077] in, Represents direct current energy, is the number of sampling points, for Sampling point voltage, for Sampling point current.

[0078] AC metering algorithm analysis:

[0079] AC metering is directly implemented using universal metering chips, such as Figure 4 As shown, it includes an ADC sampler, a CIC filter, an HPF high-pass filter, an instantaneous power calculator, and an LPF low-pass filter connected in sequence, wherein the ADC sampler is used to collect current and voltage, the CIC filter is used to remove high-frequency noise, the HPF high-pass filter is used to remove DC bias, the instantaneous power calculator is used to calculate instantaneous power, and the LPF low-pass filter is used to obtain average power, and the implementation is shown as follows:

[0080] The active power is:

[0081]

[0082]

[0083] =

[0084] in, is the average power, is the function of instantaneous power changing with time, is the discrete power, is the instantaneous voltage, is the instantaneous current, is the effective value of voltage, is the effective value of current, is the power angle, It is the 2 times frequency component after low pass filter.

[0085] The electrical energy is:

[0086]

[0087] Right now:

[0088]

[0089] in, is AC power, is the sampling time, is the sampling number, is the voltage, is the current, is the frequency, is the power factor.

[0090] The system outputs electric energy pulses, voltage, current, active power, reactive power, power factor, frequency, etc.

[0091] The management module accumulates electric energy, records and judges power grid events, executes timed freezing tasks, and implements communication, display, button and other interactive interfaces based on the output of the metering module.

[0092] 2) DC energy measurement based on average value method considering the influence of harmonics

[0093] Stable DC current :

[0094]

[0095] in, is the harmonic amplitude is the harmonic frequency, is the harmonic phase angle. At this time, the average current is:

[0096]

[0097] in, is the average current;

[0098] After N times After the average value of time is calculated, the integral part of the above formula is approximately equal to 0, so the average current .

[0099] The DC power is calculated as:

[0100]

[0101] in, is the average value DC power under the influence of harmonics, To stabilize the voltage, To stabilize the current, for The average time of the sampling points, is the number of sampling points.

[0102] It can be seen that the DC power measurement using the average value algorithm is not affected by ripple.

[0103] 3) DC power measurement based on instantaneous power integration method under the influence of harmonics

[0104] The energy calculated by integrating instantaneous power over time is :

[0105]

[0106] in, It represents the instantaneous power integrated DC energy under the influence of harmonics, is the number of sampling points, To stabilize the voltage, To stabilize the current, is the accumulated time, for The voltage at the sampling point, is the harmonic frequency, is the harmonic phase angle.

[0107] It can be seen from the above formula that the electric energy calculated by the instantaneous power integration method contains a part of the additional measured electric energy, which is caused by the reactive current generated by the equipment in the power grid. The amount of internal electrical energy is:

[0108]

[0109] in, For electrical energy, Assign values ​​to the harmonic current components, Assign values ​​to the harmonic voltage components, is the nth harmonic phase angle, is the time interval.

[0110] Since the amplitude of the harmonic component is very small, the DC voltage ripple factor is less than 2% according to the national standard. In the case of very small Can be ignored.

[0111] In another embodiment, we design a low-pass filter, which is arranged at the signal input front end of the sampling module to filter out high-frequency interference signals. According to the IEC 61850-9-2 sampling standard, the sampling frequency is 4kHz and 12.8kHz, according to Nyquist sampling theorem, the frequency characteristics can only be limited to: The frequency range is greater than this range, and aliasing will occur. Therefore, we select the low-pass filter = , the corresponding frequency , and can analyze up to 11 harmonics (for 4kHz sampling frequency), , , ,but , , this filter is used to filter out high-frequency signals at the front end. It does not have high requirements on the selection of signals, but hopes to obtain the smallest possible phase shift. Therefore, the Butterworth filter is selected, and its system function is:

[0112]

[0113] in, represents the sampling frequency, represents the cut-off frequency, represents the angular frequency, represents the angular cutoff frequency, represents the angular frequency, represents the transition band cutoff frequency, represents the attenuation at the cutoff frequency, represents the transition band cutoff angular frequency, represents the system transfer function, In digital signal processing Transformation.

[0114] In another embodiment, an AC / DC adaptive electric energy metering method is provided, which uses the AC / DC adaptive electric energy metering system and includes the following steps:

[0115] Step 1: After the voltage channel is divided, the signal is input to the base of the transistor Q;

[0116] Step 2: When the voltage signal is a DC signal, the transistor Q is always turned on, and the signal after the transistor Q is always at a low level; if the voltage signal is an AC signal, the transistor Q is turned on in the positive half-wave and cut off in the negative half-wave. At this time, the signal at the rear end of the transistor Q outputs a low level in the positive half-wave and a high level in the negative half-wave, that is, the voltage at the rear end of the transistor Q is a high level under the AC signal;

[0117] Step 3: The management module detects the level of the back end of the transistor Q. If it is continuously detected as a low level, the current metering mode is determined to be DC metering; if it is continuously detected as a high-low level alternating signal, the current metering mode is determined to be AC ​​metering;

[0118] Step 4: According to the detection result, the management module updates the metering algorithm parameters of the corresponding metering mode to the metering module;

[0119] Step 5: The metering unit measures the input current under the control of the management unit.

[0120] The metering unit includes a DC metering module, and the DC metering module performs DC power metering by sampling at the sampling point according to the following formula:

[0121]

[0122] in, Represents direct current energy, is the number of sampling points, for Sampling point voltage, for Sampling point current.

[0123] Considering the average value method of DC power measurement under the influence of harmonics, the DC metering module performs the average value method of DC power measurement under the influence of harmonics by the following formula:

[0124]

[0125] in, is the average value DC power under the influence of harmonics, To stabilize the voltage, To stabilize the current, for The average time of the sampling points, is the number of sampling points.

[0126] Considering the instantaneous power integration method of DC power measurement under the influence of harmonics, the DC metering module performs the average value method of DC power measurement under the influence of harmonics through the following formula:

[0127]

[0128] in, It represents the instantaneous power integrated DC energy under the influence of harmonics, is the number of sampling points, To stabilize the voltage, To stabilize the current, is the accumulated time, for The voltage at the sampling point, is the harmonic frequency, is the harmonic phase angle, is the harmonic average current, is the harmonic average frequency.

[0129] The metering unit includes an AC metering module, which measures AC power using the following formula:

[0130]

[0131] in, is AC power, is the sampling time, is the sampling number, is the voltage, is the current, is the frequency, is the power factor.

[0132] The present invention is applicable to the electric energy metering requirements of AC and DC charging piles. It is not necessary to distinguish the electric energy metering methods when purchasing and installing the electric energy metering device for charging pile trade settlement, which greatly reduces the difficulty of material management and construction and installation of AC and DC charging piles.

[0133] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An AC / DC adaptive electric energy metering system, characterized in that: It includes sampling module, AC / DC detection module, AD conversion module, metering unit and management unit, among which: The sampling module includes a resistor R1, a resistor R2, and a manganese copper shunt, wherein one end of the resistor R1 is used to connect to the measurement power supply line, and the other end is connected to the resistor R2, the AC / DC detection module, and the manganese copper shunt; the other end of the resistor R2 is grounded; the manganese copper shunt, the AD conversion module, and the metering unit are connected in sequence, and the management unit is connected to the AC / DC detection module and the metering unit respectively; The AC / DC detection module includes a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a capacitor C1, a capacitor C2, a diode D1, and a transistor Q, wherein one end of the resistor R3 is connected to a lead wire 1, and the other end is connected to the collector of the transistor Q; one end of the resistor R4 is connected to the VCC terminal, and the other end is connected to the collector of the transistor Q; one end of the capacitor C1 is connected to a lead wire 1, and the other end is connected to the collector of the transistor Q. The emitter of the transistor Q is connected; the emitter of the transistor Q is grounded, one end of the capacitor C2 is connected to the base of the transistor Q, and the other end is grounded; the cathode of the diode D1 is connected to the base of the transistor Q, and the positive electrode is grounded; one end of the resistor R5 is connected to the base of the transistor Q, and the other end is grounded; the base of the transistor Q, the resistor R6, the resistor R7, the resistor R8, the resistor R9, the resistor R10, and the lead wire 2 are connected in sequence; the lead wire 1 and the lead wire 2 are connected to the management unit; The management unit determines whether the current is DC or AC according to the detection signal of the AC / DC detection module, and controls the metering unit to measure the current according to the judgment result; the metering unit measures the input current under the control of the management unit.

2. The AC / DC adaptive electric energy metering system according to claim 1 is characterized in that: The metering unit includes a DC metering module, and the DC metering module performs DC power measurement according to the following formula: in, Represents direct current energy, is the number of sampling points, for Sampling point voltage, for Sampling point current.

3. The AC / DC adaptive electric energy metering system according to claim 1 is characterized in that: The metering unit includes a DC metering module, which measures DC electric energy using the following formula: in, is the average value DC power under the influence of harmonics, To stabilize the voltage, To stabilize the current, for The average time of the sampling points, is the number of sampling points.

4. The AC / DC adaptive electric energy metering system according to claim 1 is characterized in that: The metering unit includes a DC metering module, which measures DC electric energy using the following formula: in, It represents the instantaneous power integrated DC energy under the influence of harmonics, is the number of sampling points, To stabilize the voltage, To stabilize the current, is the accumulated time, for The voltage at the sampling point, is the harmonic frequency, is the harmonic phase angle, is the harmonic average current, is the harmonic average frequency.

5. The AC / DC adaptive electric energy metering system according to any one of claims 1 to 4, characterized in that: The metering unit includes an AC metering module, which measures AC power using the following formula: in, is AC power, is the sampling time, is the sampling number, is the voltage, is the current, is the frequency, is the power factor.

6. The AC / DC adaptive electric energy metering system according to claim 1, characterized in that: A low-pass filter is included, and the low-pass filter is arranged at the signal input front end of the sampling module. The parameters of the low-pass filter are: = , , , , , the system function is: ； in, represents the sampling frequency, represents the cut-off frequency, represents the angular cutoff frequency, represents the angular frequency, represents the transition band cutoff frequency, represents the attenuation at the cutoff frequency, It represents the attenuation at the cutoff frequency of the transition band. represents the system transfer function, In digital signal processing Transformation.

7. An AC / DC adaptive electric energy metering method, characterized in that: The AC / DC adaptive electric energy metering system according to any one of claims 1 to 6 comprises the following steps: Step 1: After the voltage channel is divided, the signal is input to the base of the transistor Q; Step 2: When the voltage signal is a DC signal, the transistor Q is always turned on, and the signal after the transistor Q is always at a low level; if the voltage signal is an AC signal, the transistor Q is turned on in the positive half-wave and cut off in the negative half-wave. At this time, the signal at the rear end of the transistor Q outputs a low level in the positive half-wave and a high level in the negative half-wave, that is, the voltage at the rear end of the transistor Q is a high level under the AC signal; Step 3: The management module detects the level of the back end of the transistor Q. If it is continuously detected as a low level, the current metering mode is determined to be DC metering; if it is continuously detected as a high-low level alternating signal, the current metering mode is determined to be AC ​​metering; Step 4: According to the detection result, the management module updates the metering algorithm parameters of the corresponding metering mode to the metering module; Step 5: The metering unit measures the input current under the control of the management unit.

8. The method for AC / DC adaptive electric energy metering according to claim 7, characterized in that: The metering unit includes a DC metering module, and the DC metering module performs DC power measurement according to the following formula: in, Represents direct current energy, is the number of sampling points, for Sampling point voltage, for Sampling point current.

9. The method for AC / DC adaptive electric energy metering according to claim 7, characterized in that: The metering unit includes a DC metering module, which measures DC electric energy using the following formula: in, is the average value DC power under the influence of harmonics, To stabilize the voltage, To stabilize the current, for The average time of the sampling points, is the number of sampling points.

10. The method for AC / DC adaptive electric energy metering according to claim 7, characterized in that: The metering unit includes a DC metering module, which measures DC electric energy using the following formula: in, It represents the instantaneous power integrated DC energy under the influence of harmonics, is the number of sampling points, To stabilize the voltage, To stabilize the current, is the accumulated time, for The voltage at the sampling point, is the harmonic frequency, is the harmonic phase angle, is the harmonic average current, is the harmonic average frequency.

Images