CN103973147B - Multi-level high-voltage grounded source electromagnetic transmitting circuit - Google Patents

Abstract

The invention relates to a multi-level high-voltage grounded source electromagnetic transmitting circuit. The circuit adopts multi-level output and is connected with a ground load through a direct-current power supply E1 and a direct-current power supply E2, which are identical in voltage, by a transmitting bridge circuit (H bridge inversion circuit). A high-voltage grounded source electromagnetic-method transmitting bridge circuit mainly comprises 8 IGBTs (insulated gate bipolar translators), 8 fly-wheel diodes, four catching diodes which are connected in parallel in reverse directions and two power supplies. Compared with the prior art, each power device only bears half voltage of a bus, the high-voltage large-power output is realized by adopting a low-voltage-resisting device, so that the cost is reduced; a low-voltage IGBT module can work at a high switch frequency, so that the heating problem is easy to solve, the transmitting circuit can meet the waveform requirement of a frequency-domain electromagnetic method for transmitting 10kHz current, and the high-voltage IGBT heating problem can be overcome.

Description

Multi-level high-voltage grounded source Electromagnetic Launching circuit

Technical field

The present invention relates to the electrical survey (-ing) instrument in a kind of geophysical exploration, it is especially adapted for use in various electrical instrument High-power high voltage inversion discharger.

Background technology

Grounded source electromagnetic method instrument, generally adopts h bridge as the power conversion major loop of discharger, there to be limit for length to connect Ground wire is provided with pulse current for field source to underground, sets up pulsatile once magnetic field in underground, in Primary field tempus intercalare, Observe secondary electricity, the magnetic field parameter of sensing at a certain distance from field source center simultaneously.Due to this method early signal reflection superficial part ground Electrical feature, late period signal reflects deeper part geoelectric cross section, and this just can reach the purpose of depth measurement.Load is by the earth and wire group Become, then load can be equivalent to the series circuit of resistance and inductance.Transmitter current is directly proportional to investigation depth, it is desirable to sending out Radio stream is the bigger the better, and actually wishes that emitting voltage is the bigger the better.Prior art commonly used raising supply voltage, such as The gpd32-ii type multi-functional electrical method work station transmitter parameter 1000v, 45a of zonge company of the U.S.；Canadian phoenix company V8 multi-functional electrical survey (-ing) instrument transmitter is 1000v, 40a to the maximum.But this control technology increased power conversion circuit and produces The intensity of raw electromagnetic interference, and increase the switching loss of bridge switching device.Circuit is frequently with bridge switching device at present Igbt, its high-pressure modular has 3300v, 4500v, 6500v, output bridge design in, due to technique, distributed constant and The impact of safety, general work voltage select rated value 1/1 to two/2nds, can meet 1500v about voltage Requirement.If it is desired to improving voltage to 2000v or 2500v, but due to high-power transmitting to the performance requirement of power device very Height, the price of high power device is again very expensive, if power device bears high electricity for a long time and scolds its stability also corresponding simultaneously Reduce, be difficult to realize the purpose of high pressure transmitting hence with existing single tube bridge as discharger.

The methods adopting are exactly being used in series of power device more at present, and average voltage to be launched is assigned to series connection Power device on, this reduces the upper voltage of each power device, realize high pressure transmitting purpose, but this side Method is there is problems that all pressures of power device are very complicated, it is difficult to ensure that the balance of voltage between the power device of series connection, thus It is easier to lead to the damage of device.

Propose power device series connection Phase Shift Control Study in recent years, by being classified to main power source, to each level power supply phase shift Control, realize the access classes of main power source and withdraw, solve the problems, such as the dynamic voltage balancing of power device in main circuit, but this control Technology processed increased the complexity of governor circuit；Increased the series of main power source；Increased phase-shift control circuit and phase shifting control Power device.Simultaneously because power supply classification adds, the waveform of output is also had a certain impact, the voltage obtaining in load end Waveform presents stepped in raising and lowering.Therefore being used in series of power device is difficult to extensively be applied.

Content of the invention

The purpose of the present invention is aiming at above-mentioned the deficiencies in the prior art, provides one kind to be not only suitable for time domain and is applied to frequency again The multi-level high-voltage grounded source Electromagnetic Launching circuit of the launch requirements in domain.

The purpose of the present invention is achieved through the following technical solutions:

Multi-level high-voltage grounded source electromagnetic method radiating circuit, this circuit adopts many level outputs, is identical by two voltages DC source e₁And e₂Earth load is connected by transmitting bridge.

Transmitting bridge is by 8 igbt (s₁、s₂、s₃、s₄、s₅、s₆、s₇、s₈), 8 fly-wheel diode (d₁、d₂、d₃、d₄、 d₅、d₆、d₇、d₈) four reverse parallel connections clamp diode (v_d1、v_d2、v_d3、v_d4), DC source e1, e2 first connect, then with send out Penetrate bridge in parallel, each brachium pontis is made up of two gate-controlled switch igbt and two fly-wheel diode d: s in the first brachium pontis₁With d₁And Connection, s₂With d₂Parallel connection, then both connect again；S in second brachium pontis₃With d₃Parallel connection, s₄With d₄Parallel connection, then both connect again；The S in three brachium pontis₅With d₅Parallel connection, s₆With d₆Parallel connection, then both connect again；S in four bridge legs₇With d₇Parallel connection, s₈With d₈Parallel connection, so Both connect again afterwards；N point is exactly the voltage midpoint of DC source, four clamp diode (v_d) connect power supply midpoint and bridge respectively Arm midpoint: v_d1Connect midpoint and the power supply midpoint of the first brachium pontis；v_d2Connect midpoint and the power supply midpoint of the second brachium pontis；v_d3Connect The midpoint of the 3rd brachium pontis and power supply midpoint；v_d4Connect midpoint and the power supply midpoint of four bridge legs.First and second brachium pontis junction point For a, the 3rd and four bridge legs junction point be b, 2 points of outfans as transmitting bridge of a, b, draw wire, connect the earth negative Carry.

R is the earth equivalent resistance, and l is the equivalent inductance of earth conductor cable.

Load voltage rising edge is divided into two part: s₁、s₂、s₇First turn on, remaining igbt turns off, now, DC source e1 Voltage e/2 be added between outfan ab, electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply e1；Through too short After between temporarily, s₁、s₂、s₇、s₈Conducting, remaining igbt turns off, and now, voltage sum e of DC source e1, e2 is added in outfan Between ab, electric current is through s₁、s₂、r、l、s₇、s₈Form loop with two power supplys.I.e. load voltage is that have 0 level to become first into e/2 electricity Flat, then e level is changed into from e/2 level.

Load voltage trailing edge is divided into two part: s₁、s₂、s₇It is held on, remaining igbt turns off, now, DC source The voltage e/2 of e1 is added between outfan ab, and electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply e1, that is, load Voltage is that have e level to become first into e/2 level；After the of short duration time, all igbt are turned off, and now load voltage is 0, that is, bear Carry voltage and 0 level is changed into from e/2 level.

Beneficial effect: each power device is subjected only to 1/2 busbar voltage it is possible to be realized high with low pressure device Press high-power output, save cost；Low pressure igbt module can be operated in higher switching frequency, and heating problem is easier to solve Certainly, radiating circuit meet frequency domain electromagnetic method launch 10khz about current waveform requirement, overcome high pressure igbt heating problem.

Brief description:

Accompanying drawing 1: for multi-level high-voltage grounded source Electromagnetic Launching circuit frame figure

Accompanying drawing 2: for transmitting bridge topological diagram in accompanying drawing 1

Accompanying drawing 3: drive signal and output waveform figure

Accompanying drawing 4: the relation (0 represents closing, and 1 represents conducting) between table 1 transmitter output voltage and on off state

Specific embodiment:

Connect drawings and Examples below to be described in further detail:

Multi-level high-voltage grounded source electromagnetic method radiating circuit, this circuit adopts many level outputs, is identical by two voltages DC source e₁And e₂Earth load is connected by transmitting bridge.

Transmitting bridge is by 8 igbt (s₁、s₂、s₃、s₄、s₅、s₆、s₇、s₈), 8 fly-wheel diode (d₁、d₂、d₃、d₄、 d₅、d₆、d₇、d₈) four reverse parallel connections clamp diode (v_d1、v_d2、v_d3、v_d4), DC source e1, e2 first connect, then with send out Penetrate bridge in parallel, each brachium pontis is made up of two gate-controlled switch igbt and two fly-wheel diode d: s in the first brachium pontis₁With d₁And Connection, s₂With d₂Parallel connection, then both connect again；S in second brachium pontis₃With d₃Parallel connection, s₄With d₄Parallel connection, then both connect again；The S in three brachium pontis₅With d₅Parallel connection, s₆With d₆Parallel connection, then both connect again；S in four bridge legs₇With d₇Parallel connection, s₈With d₈Parallel connection, so Both connect again afterwards；N point is exactly the voltage midpoint of DC source, four clamp diode (v_d) connect power supply midpoint and bridge respectively Arm midpoint: v_d1Connect midpoint and the power supply midpoint of the first brachium pontis；v_d2Connect midpoint and the power supply midpoint of the second brachium pontis；v_d3Connect The midpoint of the 3rd brachium pontis and power supply midpoint；v_d4Connect midpoint and the power supply midpoint of four bridge legs.First and second brachium pontis junction point For a, the 3rd and four bridge legs junction point be b, 2 points of outfans as transmitting bridge of a, b, draw wire, connect the earth negative Carry.

R is the earth equivalent resistance, and l is the equivalent inductance of earth conductor cable.

Load voltage rising edge is divided into two part: s₁、s₂、s₇First turn on, remaining igbt turns off, now, DC source e1 Voltage e/2 be added between outfan ab, electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply e1；Through too short After between temporarily, s₁、s₂、s₇、s₈Conducting, remaining igbt turns off, and now, voltage sum e of DC source e1, e2 is added in outfan Between ab, electric current is through s₁、s₂、r、l、s₇、s₈Form loop with two power supplys.I.e. load voltage is that have 0 level to become first into e/2 electricity Flat, then e level is changed into from e/2 level.

Load voltage trailing edge is divided into two part: s₁、s₂、s₇It is held on, remaining igbt turns off, now, DC source The voltage e/2 of e1 is added between outfan ab, and electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply e1, that is, load Voltage is that have e level to become first into e/2 level；After the of short duration time, all igbt are turned off, and now load voltage is 0, that is, bear Carry voltage and 0 level is changed into from e/2 level.

High pressure grounded source electromagnetic method transmitter system block diagram proposed by the present invention is as shown in figure 1, mainly include electromotor, straight Stream power supply, transmitting bridge composition.Typically for the complexity of reduces cost and system, sent out from common three-phase alternating current diesel oil Motor, the frequency of out-put supply is 50hz, and voltage is 380v, by commutator, DC to DC converter (dc/dc), produces and needs The stable DC voltage wanted or electric current.Transmitting bridge provides ambipolar burning voltage or electric current mainly to load, with Meet the requirement that the primary field of electromagnetic surveying is formed.

Many level emission circuit topological structure proposed by the present invention as shown in Fig. 2 mainly include 8 igbt (s1, s2, s3, S4, s5, s6, s7, s8), clamper two pole of four reverse parallel connections of 8 fly-wheel diodes (d1, d2, d3, d4, d5, d6, d7, d8) Pipe (vd1, vd2, vd3, vd4), two power supplys e1, e2, load r, l.Its basic connection framework is two voltage identical direct currents Power supply e1, e2 first connect, more in parallel with transmitting bridge.Transmitting bridge is made up of four brachium pontis, and each brachium pontis has two controlled to open Close device (igbt), two fly-wheel diodes (d) composition: in the first brachium pontis, s1 is in parallel with d1, and s2 is in parallel with d2, then both again Series connection；In second brachium pontis, s3 is in parallel with d3, and s4 is in parallel with d4, and then both connect again；In 3rd brachium pontis, s5 is in parallel with d5, s6 with D6 is in parallel, and then both connect again；In four bridge legs, s7 is in parallel with d7, and s8 is in parallel with d8, and then both connect again.Because two DC source e1, e2 voltage is identical, so n point is exactly the voltage midpoint of DC source, four clamp diodes (vd) connect respectively Connect power supply midpoint and brachium pontis midpoint: vd1 connects midpoint and the power supply midpoint of the first brachium pontis；Vd2 connect the second brachium pontis midpoint with Power supply midpoint；Vd3 connects midpoint and the power supply midpoint of the 3rd brachium pontis；Vd4 connects midpoint and the power supply midpoint of four bridge legs.First With the second brachium pontis junction point be a, the 3rd with four bridge legs junction point be b, 2 points of outfans as transmitting bridge of a, b, extraction Wire, connects earth load (r is the earth equivalent resistance, and l is the equivalent inductance of earth conductor cable).

Multi-level high-voltage grounded source electromagnetic method transmitter can be used for TDEM and frequency domain electromagnetic method, and many level are sent out The control mode of transmit-receive radio road is as shown in figure 4, its basic step includes:

For TDEM:

(1) within the 0-t/4 time period, wherein t is the cycle of emission current waveform, s₁-s₈Cut-off, electricity between outfan ab Pressure uab is 0, and output current iab is 0.

(2) in t/4-t₁In time period, s₁、s₂、s₇Conducting, remaining igbt turns off, now, the voltage e/2 of DC source e1 It is added between outfan ab.Electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply e1, be exactly substantially unidirectional current To inductive load charging process, load voltage electric current can be shown in formula 1 in source:

$\left\{\begin{array}{c}{u}_{\mathrm{ab}}\left(t\right)=\frac{e}{2}\\ i_{\mathrm{ab}}\left(t\right)=\frac{e}{2r}{e}^{\frac{r}{l}t}\end{array}\right.---\left(1\right)$

(3) in t₁-t₂In time period, s₁、s₂、s₇、s₈Conducting, remaining igbt turns off, now, the electricity of DC source e1, e2 Pressure sum e is added between outfan ab.Electric current is through s₁、s₂、r、l、s₇、s₈Form loops with two power supplys, substantially or direct current , to inductive load charging process, load voltage electric current can be shown in formula 2 for power supply:

$\left\{\begin{array}{c}{u}_{\mathrm{ab}}\left(t\right)=e\\ i_{\mathrm{ab}}\left(t\right)=\frac{e}{2r}{e}^{-\frac{r}{l}(t+t_1-\frac{t}{4})}+\frac{e}{r}(1-e^{-\frac{r}{l}t})\end{array}\right.----\left(2\right)$

(4) because time domain operating frequency all ratios are relatively low, working cycle t ＞ ＞ τ, therefore in load voltage u_abDecline moment t₂ Load current i_ab=e/r.In t₂In-t/2 the time period, electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply, etc. The effect circuit model or DC source charging process to inductive load, according to threefactor method, load voltage electric current can be by formula 3 institute Show:

$\left\{\begin{array}{c}{u}_{\mathrm{ab}}\left(t\right)=\frac{e}{2}\\ i_{\mathrm{ab}}\left(t\right)=\frac{e}{2r}(1+e^{-\frac{r}{l}t})\end{array}\right.---\left(3\right)$

(5) within the t/2 3t/4 time period, all switches are turned off.Load current is through diode d₃、d₄、d₅、d₆Afterflow, Two reversal of power are charged, until load current is zero.Within the reverse charging time period, load voltage electric current is as shown in Equation 4:

$\left\{\begin{array}{c}{u}_{\mathrm{ab}}\left(t\right)=-e\\ i_{\mathrm{ab}}\left(t\right)=\frac{e}{2r}(1+e^{-\frac{r}{l}(\frac{t}{2}-t_2)+\frac{e}{r}(e^{-\frac{r}{l}t}-1)})\end{array}\right.---\left(4\right)$

(6) within the t/4-3t/4 time period, load current experienced a positive rising, keeps flat-top, drops to zero Process；Within the 3t/4-5t/4 time period, load current is the process of a reverse charged and discharged, with positive charge and discharge Process is the same, will not be described in detail herein.

For frequency domain electromagnetic methods:

(1) in 0-t₁In time period, s₁、s₂、s₇Conducting, remaining igbt turns off, and now, the voltage e/2 of DC source e1 adds Between outfan ab.Electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply, be exactly substantially DC source pair Inductive load charging process, load voltage electric current can be shown in formula 5:

$\left\{\begin{array}{c}{u}_{\mathrm{ab}}\left(t\right)=\frac{e}{2}\\ i_{\mathrm{ab}}\left(t\right)=\frac{e}{2r}{e}^{\frac{r}{l}t}\end{array}\right.---\left(5\right)$

(2) in t₁-t₂In time period, s₁、s₂、s₇、s₈Conducting, remaining igbt turns off, now, the electricity of DC source e1, e2 Pressure sum e is added between outfan ab.Electric current is through s₁、s₂、r、l、s₇、s₈Form loops with two power supplys, substantially or direct current , to inductive load charging process, load voltage electric current can be shown in formula 6 for power supply:

$\left\{\begin{array}{c}{u}_{\mathrm{ab}}\left(t\right)=e\\ i_{\mathrm{ab}}\left(t\right)=\frac{e}{2r}{e}^{-\frac{r}{l}(t+t_2)}+\frac{e}{r}(1-e^{-\frac{r}{l}t})\end{array}\right.---\left(6\right)$

(3) in t₂In-t/2 the time period, electric current is through s₁、s₂、r、l、s₇、v_d4Form loop, equivalent electric with first power supply e1 The road model or DC source charging process to inductive load, according to threefactor method, load voltage electric current can be shown in formula 7:

$\left\{\begin{array}{c}{u}_{\mathrm{ab}}\left(t\right)=\frac{e}{2}\\ i_{\mathrm{ab}}\left(t\right)=\frac{e}{2r}(1+e^{-\frac{r}{l}t})\end{array}\right.---\left(7\right)$

(4) within the 0-t/2 time period, it is the positive charge process to load, and within the t/2-t time period, is to load Reverse charging process.Similar to positive charge model, no longer describe in detail.

Multi-level high-voltage grounded source electromagnetic method transmitter switch state is as shown in table 1: transmitter output has 5 level, It is 0 level, e/2 level, e level ,-e/2 level and-e level respectively.When master switch Close All, transmitter is output as 0 electricity Flat；As only master switch s₁、s₂、s₇During conducting, transmitter is output as e/2 level；As only master switch s₁、s₂、s₇、s₈Conducting When, transmitter is output as e level；As only master switch s₃、s₅、s₆During conducting, transmitter is output as-e/2 level；Lead when only having Switch s₃、s₄、s₅、s₆During conducting, transmitter is output as-e level.

Claims (2)

1. a kind of multi-level high-voltage grounded source electromagnetic method radiating circuit, this circuit adopts many level outputs, is by two voltage phases Same DC source e₁And e₂Earth load composition is connected by transmitting bridge,

Transmitting bridge is by 8 igbt:s₁、s₂、s₃、s₄、s₅、s₆、s₇、s₈, 8 fly-wheel diode d₁、d₂、d₃、d₄、d₅、d₆、d₇、 d₈Clamp diode v with four reverse parallel connections_d1、v_d2、v_d3、v_d4Composition；

DC source e1 is first connected with e2, more in parallel with transmitting bridge, and each brachium pontis has two gate-controlled switch igbt and two continuous Stream diode composition: s in the first brachium pontis₁With d₁Parallel connection, s₂With d₂Parallel connection, then both connect again；S in second brachium pontis₃With d₃And Connection, s₄With d₄Parallel connection, then both connect again；S in 3rd brachium pontis₅With d₅Parallel connection, s₆With d₆Parallel connection, then both connect again；The S in four bridge legs₇With d₇Parallel connection, s₈With d₈Parallel connection, then both connect again；N point is exactly the voltage midpoint of DC source, four pincers Position diode v_d1、v_d2、v_d3、v_d4Connect power supply midpoint and brachium pontis midpoint: v respectively_d1Connect in midpoint and the power supply of the first brachium pontis Point；v_d2Connect midpoint and the power supply midpoint of the second brachium pontis；v_d3Connect midpoint and the power supply midpoint of the 3rd brachium pontis；v_d4Connect the 4th The midpoint of brachium pontis and power supply midpoint, first and second brachium pontis junction point is a, and the 3rd is b, 2 points of a, b with four bridge legs junction point As the outfan of transmitting bridge, draw wire, connect earth load；

It is characterized in that, load voltage rising edge is divided into two part: s₁、s₂、s₇First turn on, remaining igbt turns off, now, directly The voltage e/2 of stream power supply e1 is added between outfan ab, and electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply e1； Then, s₁、s₂、s₇、s₈Conducting, remaining igbt turns off, now, voltage sum e of DC source e1, e2 be added in outfan ab it Between, electric current is through s₁、s₂、r、l、s₇、s₈Form loop with two power supplys, that is, load voltage is to be changed into e/2 level from 0 level, then by E/2 level is changed into e level；

R is the earth equivalent resistance, and l is the equivalent inductance of earth conductor cable.

2. according to the multi-level high-voltage grounded source electromagnetic method radiating circuit described in claim 1 it is characterised in that under load voltage Fall edge is divided into two part: s₁、s₂、s₇It is held on, remaining igbt turns off, now, the voltage e/2 of DC source e1 is added in defeated Go out and hold between ab, electric current is through s₁、s₂、r、l、s₇、v_d4Form loop with first power supply e1, that is, load voltage is to be changed into from e level E/2 level；Then, all igbt are turned off, and now load voltage is 0, and that is, load voltage is changed into 0 level from e/2 level.