Compensation method and system of equivalent antimagnetic flux frequency domain electromagnetic method emission system

Abstract

The invention discloses a compensation method for an equivalent antimagnetic flux frequency domain electromagnetic method transmitting system. The compensation method comprises the steps that one end of the input end of a transmitting coil in the equivalent antimagnetic flux frequency domain electromagnetic method transmitting system is connected with a switched capacitor compensation module in series; acquiring a current signal of a sampling resistor corresponding to the transmitting coil and processing the current signal to obtain a corresponding first square wave signal; processing according to the driving signal of the switching tube and the first square wave signal to obtain a second square wave signal; sampling the second square wave signal and generating a switch control signal of the switch capacitance compensation module according to the sampling signal; and a switch control signal is adopted to control the switch capacitance compensation module so as to realize compensation of the equivalent antimagnetic flux frequency domain electromagnetic method emission system. The invention also discloses a system for realizing the compensation method of the equivalent antimagnetic flux frequency domain electromagnetic method emission system. According to the invention, the compensation of the equivalent antimagnetic flux frequency domain electromagnetic method emission system is realized, the reliability is high, the accuracy is good, and the application range is wide.

Description

Technical Field

[0001] The invention belongs to the field of geophysical exploration, and in particular relates to a compensation method and system for an equivalent reverse flux frequency domain electromagnetic method transmitting system. Background Art

[0002] Frequency-Domain Electromagnetic Method (FDEM) is one of the geophysical electromagnetic exploration methods. It is widely used in the fields of geological disaster prediction, pipeline detection, environmental assessment and underground unexploded ordnance identification, and has achieved good application results. The equivalent reverse flux frequency domain electromagnetic method transmission system is generally composed of a transmitting coil, a compensation coil and a receiving coil. The primary electromagnetic field is generated by supplying an alternating current to the transmitting coil. The primary field propagates underground and generates an induced secondary field on the geological anomaly. The receiving coil receives the secondary field from underground to obtain underground geological information. In order to ensure the strength of the received signal, the transmitting and receiving coils are often very close. The changing primary field will generate an induced electromotive force in the coil and affect the reception of the underground secondary field signal. Therefore, the compensation coil is used to calculate and offset the induced electromotive force caused by the change of the primary field in the receiving coil, so that the pure secondary field information of the underground can be obtained.

[0003] However, in actual implementation, the scheme of using compensation coils for offsetting requires complex calculations and errors are difficult to avoid. The equivalent anti-flux device uses upper and lower parallel coaxial transmitting coils, and passes reverse currents through them respectively, forming a zero flux plane in the center plane of the two transmitting coils. In theory, pure secondary field information can be obtained by receiving on this plane, which is more convenient and efficient. The electromagnetic field will continue to attenuate during underground propagation, and the propagation distance is related to the frequency. FDEM achieves the purpose of depth measurement based on the different skin depths of electromagnetic fields at different frequencies. However, the transmitting coil is inductive and will hinder high-frequency signals, affecting the transmitting waveform and transmitting power, resulting in a decrease in the signal-to-noise ratio of the received data and a decrease in accuracy, which will affect the normal work.

[0004] In order to solve the problem that the transmitting coil is inductive and blocks high-frequency signals, the existing solution mainly uses the capacitive reactance of the capacitor to offset the inductive reactance of the coil, making the transmitting circuit purely resistive and in a resonant state, thereby increasing the transmitting current and improving the transmitting power. Depending on whether the frequency of the resonance compensation is adjustable, the existing compensation methods can be roughly divided into two categories: uncontrollable resonance compensation and controllable resonance compensation:

[0005] The uncontrollable resonance method mainly uses various topologies of capacitors and inductors to compensate for the inductive reactance of the transmitting coil. The characteristic of this type of solution is that once the parameters of the components are determined, the transmitting frequency that can be compensated is also determined and cannot be changed. To achieve compensation for other frequencies, the only way is to replace the components in the circuit. This type of solution generally includes single capacitor compensation, LC array compensation, and switch-controlled capacitor array compensation solutions. However, the application scenarios of the single capacitor compensation solution are relatively limited, and are mostly used in situations where only fixed frequencies are concerned; the LC array compensation solution is difficult to calculate, and the actual application can generally only be targeted at some scenarios that are more concerned about specific frequencies, and the application effect is poor; the switch-controlled capacitor array compensation solution still has a limited range of options for the resonant frequency that can be compensated by the existing capacitors in the array, and has a smaller scope of application.

[0006] The controllable resonant compensation method is essentially based on capacitance, but due to the improvement of manufacturing process or the introduction of active devices, the capacitance value can be changed within a certain range, so controllable resonant compensation can be achieved. This type of solution mainly includes varactor diode compensation, variable capacitor compensation, active inverter bridge compensation, thyristor series capacitor compensation and switch capacitor compensation. However, the tunable range of the varactor diode solution is relatively narrow and concentrated in the radio frequency segment, and is mostly used in the radio frequency field; the capacity of the variable capacitor compensation solution is also mostly concentrated in the pF level, and is mostly used in FM radios; the active inverter bridge compensation solution requires complex control algorithms to control the inverter bridge in actual application and requires real-time calculation of the circuit reactive power, and has certain requirements for the main control circuit operation performance. The compensation frequency in the current application case is concentrated in a few hundred hertz; the performance of the thyristor series capacitor compensation solution is affected by the characteristics of the thyristor, and is currently mostly used in low-frequency bands; the switch capacitor compensation solution is mostly used in the field of magnetically coupled wireless power transmission, and usually works at a fixed frequency. Summary of the invention

[0007] One of the purposes of the present invention is to provide a compensation method for an equivalent reverse flux frequency domain electromagnetic method transmitting system with high reliability, good accuracy and wide application range.

[0008] A second object of the present invention is to provide a system for implementing the compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system.

[0009] The compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system provided by the present invention comprises the following steps:

[0010] S1. A switched capacitor compensation module is connected in series to one end of the input end of the transmitting coil in the equivalent reverse flux frequency domain electromagnetic method transmitting system;

[0011] S2. Obtain the current signal of the sampling resistor corresponding to the transmitting coil, and process it to obtain the corresponding first square wave signal;

[0012] S3. Processing the second square wave signal according to the driving signal of the switch tube and the first square wave signal obtained in step S2;

[0013] S4. Sampling the obtained second square wave signal, and generating a switch control signal of the switched capacitor compensation module according to the sampled signal;

[0014] S5. Using the switch control signal obtained in step S4, the switch capacitor compensation module is controlled to achieve compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system.

[0015] The step S1 of connecting a switched capacitor compensation module in series to one end of the input end of the transmitting coil in the equivalent reverse flux frequency domain electromagnetic method transmitting system specifically includes the following steps:

[0016] In the equivalent reverse flux frequency domain electromagnetic method transmitting system, the transmitting coil is connected in series with the sampling resistor and then connected to the output end of the full bridge circuit of the equivalent reverse flux frequency domain electromagnetic method transmitting system;

[0017] One end of the transmitting coil is connected to a sampling resistor; the other end of the transmitting coil is connected in series with a switching capacitor compensation module.

[0018] The switch capacitor compensation module comprises a first compensation capacitor, a second compensation capacitor, a first switch and a second switch; one end of the second compensation capacitor is connected to the transmitting coil, the other end of the second compensation capacitor is connected to the other end of the first compensation capacitor, and one end of the first compensation capacitor is connected to the output end of the full-bridge circuit; the first switch tube and the second switch tube are connected in series and then connected in parallel with the first compensation capacitor;

[0019] The first compensation capacitor is used to realize compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system; the second compensation capacitor is used to improve the stability of the compensation process; the first switch tube and the second switch tube are used to control the operation of the switch capacitor compensation module.

[0020] The equivalent capacitance of the switched capacitor compensation module specifically includes the following steps:

[0021] The equivalent capacitance C of the switched capacitor compensation module is calculated using the following formula: eq :

[0022]

[0023] Wherein C1 is the capacitance value of the first compensation capacitor; C2 is the capacitance value of the second compensation capacitor; α is the conduction angle of the first switch tube or the second switch tube.

[0024] The capacitance value of the first compensation capacitor and the capacitance value of the second compensation capacitor specifically include the following steps:

[0025] The capacitance value of the first compensation capacitor and the capacitance value of the second compensation capacitor are calculated using the following steps:

[0026] According to the target transmission frequency and the inductance of the transmitting coil, the equivalent capacitance value C required to complete the compensation is calculated using the following formula: eq1 :

[0027]

[0028] Where f is the transmitting frequency, L is the transmitting coil inductance; since C1<C eq1 <C2, therefore after leaving a setting margin, the capacitance value of the first compensation capacitor and the capacitance value of the second compensation capacitor are calculated according to the upper limit and the lower limit of the target transmission frequency band.

[0029] The step S2 of obtaining the current signal of the sampling resistor corresponding to the transmitting coil and processing to obtain the corresponding first square wave signal specifically includes the following steps:

[0030] Obtaining a current signal of a sampling resistor connected to the transmitting coil;

[0031] The obtained current signal is subjected to zero-crossing comparison to obtain a first square wave signal.

[0032] The step S3 of processing the driving signal of the switch tube and the first square wave signal obtained in step S2 to obtain the second square wave signal specifically includes the following steps:

[0033] The driving signal of the switch tube in phase with the output voltage of the full-bridge circuit is XORed with the first square wave signal obtained in step S2 to obtain a second square wave signal.

[0034] The step S4 of sampling the obtained second square wave signal and generating a switch control signal of the switch capacitor compensation module according to the sampled signal specifically includes the following steps:

[0035] The obtained second square wave signal is low-pass filtered to obtain a DC signal representing the phase difference between the voltage and current of the transmitting coil, and then the DC signal is sampled, and the sampled signal is calculated by a PID control algorithm to obtain a first control signal;

[0036] Comparing the obtained first control signal with the set sawtooth wave signal to obtain a first PWM control signal;

[0037] The first PWM control signal is used as the control signal of the first switch tube in the switch capacitor compensation module, and the first PWM control signal is delayed by 180° and used as the control signal of the second switch tube in the switch capacitor compensation module.

[0038] The PID control algorithm specifically includes the following steps:

[0039] During initialization, the full bridge circuit of the equivalent reverse flux frequency domain electromagnetic method transmitting system is ensured to be an inductive circuit;

[0040] The DC signal representing the phase difference between the voltage and current of the transmitting coil obtained after the second square wave signal is low-pass filtered is set as the error value;

[0041] In the PID control process, if the error value of the control period T is less than the average value of the period error, the error signal is directly used as the input of the PID control algorithm; if the error value of the control period T is greater than the average value of the period error, the error signal is inverted and used as the input of the PID control algorithm;

[0042] The period error average value is the average value of the error values ​​during the control period T-1 to the control period Tn, where n is the set average period value.

[0043] The present invention also provides a system for implementing the compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system, comprising a circuit connection module, a first square wave module, a second square wave module, a control module and a compensation module; the circuit connection module, the first square wave module, the second square wave module, the control module and the compensation module are connected in series in sequence; the circuit connection module is used to connect the switching capacitor compensation module in series at one end of the input end of the transmitting coil in the equivalent reverse flux frequency domain electromagnetic method transmitting system, and upload the data information to the first square wave module; the first square wave module is used to obtain the current signal of the sampling resistor corresponding to the transmitting coil according to the received data information, and process it to obtain the corresponding first square wave signal, and The data information is uploaded to the second square wave module; the second square wave module is used to process the second square wave signal according to the received data information, the driving signal of the switch tube corresponding to the transmitting coil and the obtained first square wave signal, and upload the data information to the control module; the control module is used to sample the obtained second square wave signal according to the received data information, and generate a switch control signal of the switch capacitor compensation module according to the sampled signal, and upload the data information to the compensation module; the compensation module is used to control the switch capacitor compensation module according to the received data information and the obtained switch control signal, so as to realize compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system.

[0044] The compensation method and system of the equivalent inverse flux frequency domain electromagnetic method transmitting system provided by the present invention, by connecting a switching capacitor compensation module in series to the output end of the equivalent inverse flux frequency domain electromagnetic method transmitting system, and controlling the switching capacitor compensation module according to the output of the equivalent inverse flux frequency domain electromagnetic method transmitting system, not only realizes the compensation of the equivalent inverse flux frequency domain electromagnetic method transmitting system, but also has higher reliability, better accuracy and wider application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The figure is a schematic diagram of the method flow of the present invention.

[0046] Figure 2 The diagram is a connection diagram of the switch capacitor compensation module in the method of the present invention and the full bridge circuit of the equivalent reverse flux frequency domain electromagnetic method transmitting system.

[0047] Figure 3 Schematic diagram of the functional modules of the system of the present invention. DETAILED DESCRIPTION

[0048] like Figure 1 The method flow diagram of the method of the present invention is shown as follows: The compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system provided by the present invention comprises the following steps:

[0049] S1. A switching capacitor compensation module is connected in series to one end of the input end of the transmitting coil in the equivalent reverse flux frequency domain electromagnetic method transmitting system; specifically comprising the following steps:

[0050] In the equivalent reverse flux frequency domain electromagnetic method transmitting system, the transmitting coil is connected in series with the sampling resistor and then connected to the output end of the full bridge circuit of the equivalent reverse flux frequency domain electromagnetic method transmitting system;

[0051] One end of the transmitting coil is connected to a sampling resistor; the other end of the transmitting coil is connected in series with a switched capacitor compensation module;

[0052] In specific implementation, the switch capacitor compensation module is as follows: Figure 2 As shown, it includes a first compensation capacitor C1, a second compensation capacitor C2, a first switch Q1 and a second switch Q2; one end of the second compensation capacitor is connected to a transmitting coil (the transmitting coil equivalent model is marked in the figure), the other end of the second compensation capacitor is connected to the other end of the first compensation capacitor, and one end of the first compensation capacitor is connected to the output end B of the full-bridge circuit; the first switch tube and the second switch tube are connected in series and then connected in parallel with the first compensation capacitor;

[0053] The first compensation capacitor is used to realize compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system; the second compensation capacitor is used to improve the stability of the compensation process; the first switch tube and the second switch tube are used to control the operation of the switch capacitor compensation module;

[0054] At the same time, the equivalent capacitance C of the switch capacitor compensation module is calculated using the following formula: eq :

[0055]

[0056] Wherein C1 is the capacitance value of the first compensation capacitor; C2 is the capacitance value of the second compensation capacitor; α is the conduction angle of the first switch tube or the second switch tube;

[0057] In addition, the capacitance value of the first compensation capacitor and the capacitance value of the second compensation capacitor are calculated using the following steps:

[0058] According to the target transmission frequency and the inductance of the transmitting coil, the equivalent capacitance value C required to complete the compensation is calculated using the following formula: eq1 :

[0059]

[0060] Where f is the transmitting frequency, L is the transmitting coil inductance; since C1<C eq1 <C2, so after leaving a set margin, the capacitance value of the first compensation capacitor and the capacitance value of the second compensation capacitor are calculated according to the upper limit and lower limit of the target transmission frequency band;

[0061] S2. Obtain the current signal of the sampling resistor corresponding to the transmitting coil, and process it to obtain the corresponding first square wave signal; specifically comprising the following steps:

[0062] Get the sampling resistance connected to the transmitting coil ( Figure 2 R in the middle T ) of the current signal ( Figure 2 i T );

[0063] Perform zero-crossing comparison on the obtained current signal and obtain a first square wave signal;

[0064] S3. According to the driving signal of the switch tube and the first square wave signal obtained in step S2, a second square wave signal is obtained by processing; specifically comprising the following steps:

[0065] Performing an XOR operation on the driving signal having the same phase as the output voltage of the full-bridge circuit and the first square wave signal obtained in step S2 to obtain a second square wave signal;

[0066] S4. Sampling the obtained second square wave signal, and generating a switch control signal of the switch capacitor compensation module according to the sampled signal; specifically comprising the following steps:

[0067] The obtained second square wave signal is low-pass filtered to obtain a DC signal representing the phase difference between the voltage and current of the transmitting coil, and then the DC signal is sampled, and the sampled signal is calculated by a PID control algorithm to obtain a first control signal;

[0068] Comparing the obtained first control signal with the set sawtooth wave signal to obtain a first PWM control signal;

[0069] The first PWM control signal is used as the control signal of the first switch tube in the switch capacitor compensation module, and the first PWM control signal is delayed by 180° and used as the control signal of the second switch tube in the switch capacitor compensation module;

[0070] When implemented specifically, the PID control algorithm includes the following steps:

[0071] During initialization, the full bridge circuit of the equivalent reverse flux frequency domain electromagnetic method transmitting system is ensured to be an inductive circuit;

[0072] The DC signal representing the phase difference between the voltage and current of the transmitting coil obtained after the second square wave signal is low-pass filtered is set as the error value;

[0073] When the output voltage and current of the full-bridge circuit are in phase, it means that the load is resistive as a whole, which is also the target of resonance compensation. At this time, the duty cycle of the square wave after XOR is zero, and the output is zero after low-pass filtering. When the circuit is inductive / capacitive, the current lags / leads the voltage; however, regardless of whether the circuit is inductive or capacitive, the voltage value after low-pass filtering is positive, so it is necessary to actively determine the direction of error deviation, that is, to determine the sign of the error, so the following scheme is adopted: During the PID control process, if the error value of the control period T is less than the average value of the period error, the error signal is directly used as the input of the PID control algorithm; if the error value of the control period T is greater than the average value of the period error, the error does not decrease but increases, indicating that the circuit is over-regulated, so the error signal is inverted and used as the input of the PID control algorithm to continue to regulate the circuit in the resistive direction; this cycle is repeated until the regulation is stable and the error value of the control period T is equal to the average value of the period error;

[0074] The period error average value is the average value of the error values ​​during the control period T-1 to the control period Tn, where n is the set average period value;

[0075] S5. Using the switch control signal obtained in step S4, the switch capacitor compensation module is controlled to achieve compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system.

[0076] like Figure 3The functional module schematic diagram of the system of the present invention is shown as follows: the system disclosed in the present invention for realizing the compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system comprises a circuit connection module, a first square wave module, a second square wave module, a control module and a compensation module; the circuit connection module, the first square wave module, the second square wave module, the control module and the compensation module are connected in series in sequence; the circuit connection module is used to connect the switching capacitor compensation module in series at one end of the input end of the transmitting coil in the equivalent reverse flux frequency domain electromagnetic method transmitting system, and upload the data information to the first square wave module; the first square wave module is used to obtain the current signal of the sampling resistor corresponding to the transmitting coil according to the received data information, and process it to obtain the corresponding The first square wave signal is transmitted to the transmitting coil according to the received data information, the driving signal of the switch tube corresponding to the transmitting coil and the obtained first square wave signal, and the data information is uploaded to the control module; the control module is used to sample the obtained second square wave signal according to the received data information, and generate a switch control signal of the switch capacitor compensation module according to the sampling signal, and upload the data information to the compensation module; the compensation module is used to control the switch capacitor compensation module according to the received data information and the obtained switch control signal, so as to realize the compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system.

Claims

1. A compensation method for an equivalent reverse flux frequency domain electromagnetic method transmitting system, comprising the following steps: S1. A switched capacitor compensation module is connected in series to one end of the input end of the transmitting coil in the equivalent reverse flux frequency domain electromagnetic method transmitting system; S2. Obtain the current signal of the sampling resistor corresponding to the transmitting coil, and process it to obtain the corresponding first square wave signal; S3. Processing the first square wave signal obtained in step S2 to obtain a second square wave signal according to the driving signal; S4. Sampling the obtained second square wave signal, and generating a switch control signal of the switched capacitor compensation module according to the sampled signal; S5. Using the switch control signal obtained in step S4, the switch capacitor compensation module is controlled to achieve compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system.

2. The compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system according to claim 1 is characterized in that The step S1 of connecting a switched capacitor compensation module in series to one end of the input end of the transmitting coil in the equivalent reverse flux frequency domain electromagnetic method transmitting system specifically includes the following steps: In the equivalent reverse flux frequency domain electromagnetic method transmitting system, the transmitting coil is connected in series with the sampling resistor and then connected to the output end of the full bridge circuit of the equivalent reverse flux frequency domain electromagnetic method transmitting system; One end of the transmitting coil is connected to a sampling resistor; the other end of the transmitting coil is connected in series with a switching capacitor compensation module.

3. The compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system according to claim 2 is characterized in that The switch capacitor compensation module comprises a first compensation capacitor, a second compensation capacitor, a first switch and a second switch; one end of the second compensation capacitor is connected to the transmitting coil, the other end of the second compensation capacitor is connected to the other end of the first compensation capacitor, and one end of the first compensation capacitor is connected to the output end of the full-bridge circuit; The first switch tube and the second switch tube are connected in series and then connected in parallel with the first compensation capacitor; The first compensation capacitor is used to realize the compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system; the second compensation capacitor is used to improve the stability of the compensation process; The first switch tube and the second switch tube are used to control the operation of the switch capacitor compensation module.

4. The compensation method for the equivalent reverse flux frequency domain electromagnetic method transmitting system according to claim 3 is characterized in that The equivalent capacitance of the switched capacitor compensation module specifically includes the following steps: The equivalent capacitance C of the switched capacitor compensation module is calculated using the following formula: eq : Wherein C1 is the capacitance value of the first compensation capacitor; C2 is the capacitance value of the second compensation capacitor; α is the conduction angle of the first switch tube or the second switch tube.

5. The compensation method for the equivalent reverse flux frequency domain electromagnetic method transmitting system according to claim 4 is characterized in that The capacitance value of the first compensation capacitor and the capacitance value of the second compensation capacitor specifically include the following steps: The capacitance value of the first compensation capacitor and the capacitance value of the second compensation capacitor are calculated using the following steps: According to the target transmission frequency and the inductance of the transmitting coil, the equivalent capacitance value C required to complete the compensation is calculated using the following formula: eq1 : Where f is the transmitting frequency, L is the transmitting coil inductance; since C1<C eq1 <C2, therefore after leaving a setting margin, the capacitance value of the first compensation capacitor and the capacitance value of the second compensation capacitor are calculated according to the upper limit and the lower limit of the target transmission frequency band.

6. The compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system according to claim 5 is characterized in that The step S2 of obtaining the current signal of the sampling resistor corresponding to the transmitting coil and processing to obtain the corresponding first square wave signal specifically includes the following steps: Obtaining a current signal of a sampling resistor connected to the transmitting coil; The obtained current signal is subjected to zero-crossing comparison to obtain a first square wave signal.

7. The compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system according to claim 6 is characterized in that The step S3 of processing the driving signal of the switch tube and the first square wave signal obtained in step S2 to obtain the second square wave signal specifically includes the following steps: The driving signal of the switch tube in phase with the output voltage of the full-bridge circuit is XORed with the first square wave signal obtained in step S2 to obtain a second square wave signal.

8. The compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system according to claim 7 is characterized in that The step S4 of sampling the obtained second square wave signal and generating a switch control signal of the switch capacitor compensation module according to the sampled signal specifically includes the following steps: The obtained second square wave signal is low-pass filtered to obtain a DC signal representing the phase difference between the voltage and current of the transmitting coil, and then the DC signal is sampled, and the sampled signal is calculated by a PID control algorithm to obtain a first control signal; Comparing the obtained first control signal with the set sawtooth wave signal to obtain a first PWM control signal; The first PWM control signal is used as the control signal of the first switch tube in the switch capacitor compensation module, and the first PWM control signal is delayed by 180° and used as the control signal of the second switch tube in the switch capacitor compensation module.

9. The compensation method for the equivalent reverse flux frequency domain electromagnetic method transmitting system according to claim 8 is characterized in that The PID control algorithm specifically includes the following steps: During initialization, the full bridge circuit of the equivalent reverse flux frequency domain electromagnetic method transmitting system is ensured to be an inductive circuit; The DC signal representing the phase difference between the voltage and current of the transmitting coil obtained after the second square wave signal is low-pass filtered is set as the error value; In the PID control process, if the error value of the control period T is less than the average value of the period error, the error signal is directly used as the input of the PID control algorithm; if the error value of the control period T is greater than the average value of the period error, the error signal is inverted and used as the input of the PID control algorithm; The period error average value is the average value of the error values ​​during the control period T-1 to the control period Tn, where n is the set average period value.

10. A system for implementing the compensation method of the equivalent reverse flux frequency domain electromagnetic method transmitting system according to any one of claims 1 to 9, characterized in that It includes a circuit connection module, a first square wave module, a second square wave module, a control module and a compensation module; the circuit connection module, the first square wave module, the second square wave module, the control module and the compensation module are connected in series in sequence; the circuit connection module is used to connect the switch capacitor compensation module in series at one end of the input end of the transmitting coil in the equivalent reverse flux frequency domain electromagnetic method transmitting system, and upload the data information to the first square wave module; the first square wave module is used to obtain the current signal of the sampling resistor corresponding to the transmitting coil according to the received data information, and process it to obtain the corresponding first square wave signal, and upload the data information to the second square wave module; the second square wave module is used to process it according to the received data information, the driving signal of the switch tube corresponding to the transmitting coil and the obtained first square wave signal to obtain the second square wave signal, and upload the data information to the control module; The control module is used to sample the obtained second square wave signal according to the received data information, generate a switch control signal of the switch capacitor compensation module according to the sampled signal, and upload the data information to the compensation module; The compensation module is used to control the switch capacitor compensation module according to the received data information and the obtained switch control signal, so as to realize the compensation of the equivalent reverse flux frequency domain electromagnetic method transmitting system.

Images