Kaadhka filimka elektaroonigga ah ee awoodda leh ee loo isticmaalo beddelka korontada

Kaadhka filimka elektaroonigga ah ee korontada loo isticmaalo beddelka korontada Sawirka La Soo Bandhigay

Sharaxaad Gaaban:

CRE waxay soo saartaa noocyada capacitors-ka elektaroonigga ah ee soo socda:

Filim balaastig ah oo MKP bir ah, oo is haysta, oo khasaare yar leh. Dhammaan capacitors-ku waa is-bogsiin, tusaale ahaan burburka danabku wuu bogsadaa dhowr ilbiriqsi gudahood sidaas darteedna ma soo saaraan wareeg gaaban.

Noo soo dir emayl Soo dejiso sida PDF ahaan

Faahfaahinta Badeecada

Calaamadaha Alaabta

Hadda waxaan haysannaa shaqaale khibrad leh oo waxqabad leh si ay macaamiisheenna u siiyaan adeeg bixiye tayo sare leh. Badanaa waxaan raacnaa mabda'a macaamiisha ku saleysan, oo diiradda saaraya faahfaahinta loogu talagalay Power electronic film capacitor-ka loo isticmaalo beddelka korontada. Waxaan si daacad ah u rajeyneynaa inaan go'aamino is-dhexgal ku qanacsan oo aan kula yeelano mustaqbalka fog. Waxaan kula socodsiin doonnaa horumarkeenna oo aan la socon doonnaa dhisidda xiriir ganacsi oo joogto ah adiga iyo adiga.
Hadda waxaan haysannaa shaqaale khibrad leh oo wax qabad leh si ay macaamiisheenna ugu keenaan bixiye tayo sare leh. Badanaa waxaan raacnaa mabda'a macaamiisha ku salaysan, oo diiradda saaraya faahfaahinta.capacitor-ka filimka korontadaIn ka badan 26 sano, shirkado xirfadlayaal ah oo ka kala yimid daafaha dunida ayaa naga qaata la-hawlgalayaal muddo dheer ah oo xasilloon. Waxaan xiriir ganacsi oo waara la leenahay in ka badan 200 oo jumladleyaal ah oo ku kala sugan Japan, Kuuriya, Mareykanka, UK, Jarmalka, Kanada, Faransiiska, Talyaaniga, Poland, Koonfur Afrika, Ghana, Nigeria iwm.

Xogta farsamada

Heerkulka hawlgalka kala duwan	Heerkulka ugu badan., Sare, ugu badnaan: +85℃ Heerkulka qaybta sare: +70℃ Heerkulka qaybta hoose: -40℃
kala duwanaanta awoodda	50μF~4000μF
Danab lagu qiimeeyay	450V.DC~4000V.DC
Awoodda awoodda	±5%(J);±10%(K)
U adkeysan danab	Vt-t	1.5Un DC/60S
	Vt-c	1000+2 × Un/√2 (V.AC) 60S (min3000 V.AC)
Danab ka badan	1.1Un (30% ee waqtiga la rarayo.)
	1.15Un (30 daqiiqo/maalintii)
	1.2Un (5 daqiiqo/maalintii)
	1.3Un (1 daqiiqo/maalintii)
	1.5Un (100ms mar kasta, 1000 jeer inta lagu jiro nolosha)
Qodobka kala firdhinta	tgδ≤0.003 f=100Hz
	tgδ0≤0.0002
Iska caabinta dahaarka	Rs*C≥10000S (at20℃ 100V.DC 60s)
Dib-u-dhaca ololka	UL94V-0
Heerka ugu sarreeya	3500m
	Marka jooggu ka sarreeyo 3500m ilaa gudaha 5500m, waxaa lagama maarmaan ah in la tixgeliyo isticmaalka qaddar yar. (kordhin kasta oo 1000m ah, danabka iyo hadda waxaa la dhimi doonaa 10%).
Cimriga cimriga	100000h (Un; Θhotspot≤70 °C)
Heerka tixraaca	IEC61071;GB/T17702;

Muuqaalka

1. Filim balaastig ah oo bir ah;

2. Naqshad yar;

3. Tiknoolajiyada nooca qalalan;

4. Is-bogsiin;

5. Khasaare yar, cimri dheer;

Codsiga

1. Beddelaha Awoodda;
2. Shaandhada awoodda firfircoon;
3. Gaariga EV & HEV;
4. Qalabka dallacaadda;
5. Qalabka caafimaadka;
6. Otomaatig warshadeed;

Cimriga cimriga

Sawir gacmeed dulmar ah

ΦD(mm)	B(mm)	H1(mm)	S	F	M
76	32	20	M12×16	M6 × 10	M8×20
86	32	20	M12×16	M6 × 10	M8×20
96	45	20	M12×16	M6 × 10	M8×20
116	50	22	M12×16	M6 × 10	M8×20
136	50	30	M16×25	M6 × 10	M8×20

Danab	450V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaan (Kg)
380	76	75	50	10	3.8	11.4	45	2.2	4.5	32	0.5
500	76	100	40	8	4.0	12.0	65	1.5	3.2	32	0.6
750	76	130	50	5	3.8	11.3	65	1.6	3.0	32	0.75
500	86	75	50	8	4.0	12.0	55	1.8	3.7	32	0.8
1000	86	130	50	5	5.0	15.0	70	1.5	2.7	32	1.1
650	86	100	40	5	3.3	9.8	75	1.2	3.0	32	0.9
650	86	95	40	5	3.3	9.8	75	1.2	3.0	32	0.85
650	96	75	50	5	3.3	9.8	60	1.5	3.7	45	0.75
1250	96	130	50	4	5.0	15.0	80	1	3.1	45	1.2
1800	116	130	50	4	7.2	21.6	85	0.8	3.5	50	1.6
1450	86	190	60	4	5.8	17.4	90	0.9	2.7	32	1.55
2700	116	190	60	3	8.1	24.3	100	0.8	2.5	50	2.45

Danab	600V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaan (Kg)
250	76	75	40	15	3.8	11.3	40	3.1	4.0	32	0.5
320	76	100	40	10	3.2	9.6	40	2.2	5.7	32	0.6
470	76	130	45	12	5.6	16.9	60	1.8	3.1	32	0.75
330	86	75	40	15	5.0	14.9	45	2.4	4.1	32	0.8
600	86	120	45	12	7.2	21.6	60	1.3	4.3	32	1.05
650	86	130	50	12	7.8	23.4	70	1.2	3.4	32	1.1
650	86	95	50	15	9.8	29.3	65	1.2	3.9	32	0.85
1000	86	180	50	12	12.0	36.0	70	1.5	2.7	32	1.5
420	96	75	45	15	6.3	18.9	50	2	4.0	45	0.75
800	96	130	60	12	9.6	28.8	75	1.5	2.4	45	1.2
950	116	100	60	10	9.5	28.5	90	1.2	2.1	50	1.25
1200	116	130	70	8	9.6	28.8	80	1.2	2.6	50	1.6
1800	116	180	50	8	14.4	43.2	80	1.2	2.6	50	2.4
2700	116	260	70	5	13.5	40.5	100	0.9	2.2	50	3.2
2500	136	180	60	5	12.5	37.5	100	0.8	2.5	50	3.7
3750	136	260	70	4	15.0	45.0	115	0.7	2.2	50	4.7

Danab	700V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaanka
200	76	75	40	15	3.0	9.0	40	4	3.1	32	0.5
400	76	130	45	15	6.0	18.0	60	2	2.8	32	0.75
420	76	130	50	15	6.3	18.9	60	2	2.8	32	0.75
600	86	125	60	15	9.0	27.0	45	3.2	3.1	32	1.05
550	86	130	50	12	6.6	19.8	65	1.8	2.6	32	1.1
680	96	130	45	12	8.2	24.5	75	1.5	2.4	45	1.2
720	96	125	60	12	8.6	25.9	55	2.6	2.5	45	1.15
1000	116	130	50	10	10.0	30.0	80	1	3.1	50	1.6
1000	96	180	60	10	10.0	30.0	75	1.2	3.0	45	1.6
1500	116	180	60	7	10.5	31.5	85	0.9	3.1	50	2.4
2000	116	230	70	7	14.0	42.0	85	0.8	3.5	50	3
2000	136	180	60	7	14.0	42.0	90	0.75	3.3	50	3.7
3000	136	230	70	5	15.0	45.0	100	0.7	2.9	50	4.2
3300	136	260	70	5	16.5	49.5	120	0.6	2.3	50	4.7

Danab	800V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaan (Kg)
110	86	80	45	20	2.2	6.6	75	2	1.8	32	0.8
150	86	95	45	20	3.0	9.0	80	1.5	2.1	32	0.85
250	86	75	45	15	3.8	11.3	45	3.1	3.2	32	0.8
360	86	130	55	12	4.3	13.0	65	2.2	2.2	32	1.1
470	86	130	45	12	5.6	16.9	70	2.8	1.5	32	1.1
600	96	130	55	10	6.0	18.0	75	2.2	1.6	45	1.2
730	86	180	55	10	7.3	21.9	70	1.8	2.3	32	1.5
750	86	180	55	12	9.0	27.0	75	1.8	2.0	32	1.5
1000	96	180	60	10	10.0	30.0	75	1.3	2.7	45	1.6
900	116	130	65	7	6.3	18.9	80	1.4	2.2	50	1.6
1400	116	180	65	7	9.8	29.4	80	0.9	3.5	50	2.4
1000	116	125	60	7	7.0	21.0	70	1.4	2.9	50	1.55
2000	116	230	65	5	10.0	30.0	85	0.9	3.1	50	3
2800	136	230	70	5	14.0	42.0	100	0.8	2.5	50	4.2

Danab	900V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaan (Kg)
160	76	75	40	15	3.0	9.0	35	3	5.4	32	0.5
320	76	130	50	15	5.0	14.9	60	3.2	1.7	32	0.75
350	76	125	50	15	5.0	15.0	40	2.8	4.5	32	0.75
210	86	75	40	15	3.2	9.5	40	2.2	5.7	32	0.8
450	86	125	45	12	5.4	16.2	50	2.7	3.0	32	1.1
420	86	130	45	12	5.0	15.1	65	2.5	1.9	32	1.1
490	86	120	45	10	4.9	14.7	70	1.8	2.3	32	1.05
510	86	120	45	10	5.1	15.3	70	1.8	2.3	32	1.05
660	86	180	50	10	6.6	19.8	70	2	2.0	32	1.5
900	86	230	50	10	9.0	27.0	65	2.1	2.3	32	1.8
580	96	125	50	10	5.8	17.4	55	3.3	2.0	45	1.2
540	96	130	50	7	3.8	11.3	75	1.5	2.4	45	1.2
630	116	100	55	7	4.4	13.2	60	2	2.8	50	1.3
860	116	125	55	7	6.0	18.1	60	2.2	2.5	50	1.55
810	116	130	60	7	5.7	17.0	80	1.2	2.6	50	1.6
1250	116	180	60	7	8.8	26.3	80	1.2	2.6	50	2.4
1700	116	230	60	5	8.5	25.5	80	1.1	2.8	50	3
1700	136	180	65	6	10.2	30.6	100	0.9	2.2	50	3.7
2400	136	230	70	5	12.0	36.0	100	0.95	2.1	50	4.2

Danab	1100V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaanka
130	76	75	40	15	1.9	5.6	35	4.5	3.6	32	0.5
260	76	130	45	15	3.8	11.3	60	2.8	2.0	32	0.75
280	76	125	50	12	3.3	9.9	35	4	4.1	32	0.75
170	86	75	50	15	2.6	7.7	45	5	2.0	32	0.8
360	86	125	55	12	4.3	13.0	35	2.5	6.5	32	1.1
330	86	130	45	15	5.0	15.0	65	2.8	1.7	32	1.1
420	86	136	45	12	5.0	15.0	60	2	2.8	32	1.15
420	86	155	45	12	5.0	15.0	65	1.5	3.2	32	1.25
470	86	180	60	10	4.7	14.1	70	1.8	2.3	32	1.5
500	86	180	60	10	5.0	15.0	70	1.8	2.3	32	1.5
600	86	225	60	10	6.0	18.0	80	1.2	2.6	32	1.8
600	86	225	70	10	6.0	18.0	60	2.2	2.5	32	1.8
600	116	130	50	10	6.0	18.0	75	1.8	2.0	50	1.6
680	86	225	70	12	8.2	24.5	65	2.5	1.9	32	1.8
720	86	230	70	12	8.6	25.9	65	2.5	1.9	32	1.8
460	96	125	65	10	4.6	13.8	55	3.2	2.1	45	1.2
520	96	180	65	12	6.2	18.7	75	1.5	2.4	45	1.6
500	116	100	70	10	5.0	15.0	55	2.5	2.6	50	1.3
680	116	125	70	10	6.8	20.4	60	2.8	2.0	50	1.6
650	116	130	75	10	6.5	19.5	75	1.3	2.7	50	1.6
1000	116	180	75	12	12.0	36.0	75	1.5	2.4	50	2.4
1200	116	230	80	8	9.6	28.8	80	1.5	2.1	50	3
1200	116	230	75	12	14.4	43.2	105	0.9	2.0	50	3
1250	116	230	75	12	15.0	45.0	80	1.5	2.1	50	3
1300	116	230	75	12	15.6	46.8	80	1.5	2.1	50	3
1400	136	180	70	7	9.8	29.4	85	1.3	2.1	50	3.7
1700	136	230	70	5	8.5	25.5	100	1.4	1.4	50	4.2
1900	136	230	75	5	9.5	28.5	100	1.2	1.7	50	4.2
2800	136	335	80	5	14.0	42.0	120	0.8	1.7	50	6.1
3060	136	345	80	5	15.3	45.9	120	0.9	1.5	50	6.2
3200	136	335	80	5	16.0	48.0	120	0.85	1.6	50	6.1

Danab	1200V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaan (Kg)
170	86	75	50	15	2.6	7.7	45	4.5	2.2	32	0.8
420	76	145	50	15	6.3	18.9	30	12	1.9	32	0.85
330	86	130	45	15	5.0	15.0	65	2.8	1.7	32	1.1
420	86	136	45	12	5.0	15.0	65	2	2.4	32	1.15
420	86	155	45	12	5.0	15.0	70	1.5	2.7	32	1.25
420	116	95	55	10	4.2	12.6	80	1.4	2.2	50	1.2
450	86	160	55	12	5.4	16.2	70	2.9	1.4	32	1.3
470	86	180	60	12	5.6	16.9	70	2.8	1.5	32	1.5
470	86	225	60	12	5.6	16.9	70	2.8	1.5	32	1.8
550	86	145	55	12	6.6	19.8	40	11	1.1	32	1,2
600	86	225	60	10	6.0	18.0	80	1.2	2.6	32	1.8
600	86	225	70	10	6.0	18.0	60	2.2	2.5	32	1.8
600	116	130	50	10	6.0	18.0	75	1.8	2.0	50	1.6
680	86	225	70	12	8.2	24.5	65	2.5	1.9	32	1.8
500	116	100	65	10	5.0	15.0	55	2.6	2.5	50	1.2
680	116	125	65	10	6.8	20.4	50	2.8	2.9	50	1.55
650	116	130	65	10	6.5	19.5	80	1.8	1.7	50	1.6
1000	116	180	70	7	7.0	21.0	75	1.3	2.7	50	2.4
1200	116	230	70	7	8.4	25.2	75	1.3	2.7	50	3
1250	116	230	70	7	8.8	26.3	75	1.2	3.0	50	3
1400	136	180	75	7	9.8	29.4	85	1.1	2.5	50	3.7
1700	136	230	80	5	8.5	25.5	85	1	2.8	50	4.2
850	136	125	70	8	6.8	20.4	75	1.6	2.2	50	1.9
950	136	125	60	8	7.6	22.8	80	1.1	2.8	50	2.4
1200	116	180	80	8	9.6	28.8	80	1	3.1	50	2.4
1200	116	180	60	5	6.0	18.0	100	0.8	2.5	50	2.4
1500	136	180	70	5	7.5	22.5	100	0.9	2.2	50	3.7
2700	136	335	80	5	13.5	40.5	110	0.85	1.9	50	6.1

Danab	1300V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaanka
230	86	125	50	15	5.7	17.1	35	5	3.3	32	1.1
210	86	130	50	15	3.2	9.5	70	2	2.0	32	1.1
330	86	180	60	15	5.0	14.9	65	3	1.6	32	1.5
470	86	230	65	12	5.6	16.9	65	3.2	1.5	32	1.8
410	116	130	65	12	4.9	14.8	80	1.8	1.7	50	1.6
650	116	180	65	10	6.5	19.5	85	2	1.4	50	2.4
880	116	230	80	10	8.8	26.4	85	2.2	1.3	50	3
900	136	180	70	7	6.3	18.9	100	1.6	1.3	50	3.7
1200	136	230	80	7	8.4	25.2	105	1.5	1.2	50	4.2

Danab	1500V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaanka
160	86	125	50	15	5.7	17.1	35	5	3.3	32	1.1
160	86	130	50	15	2.4	7.2	60	3.5	1.6	32	1.1
240	86	180	55	15	3.6	10.8	65	5	0.9	32	1.5
320	86	230	55	12	3.8	11.5	60	3.5	1.6	32	1.8
300	116	130	55	12	3.6	10.8	75	2	1.8	50	1.6
470	116	180	60	10	4.7	14.1	75	2.8	1.3	50	2.4
650	116	230	60	10	6.5	19.5	80	2.8	1.1	50	3
660	136	180	60	7	4.6	13.9	100	1.8	1.1	50	3.7
900	136	230	60	6	5.4	16.2	105	1.2	1.5	50	4.2
1000	136	260	70	5	5.0	15.0	120	0.9	1.5	50	4.7

Danab	1800V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaanka
130	86	125	55	15	5.7	17.1	35	5	3.3	32	1.1
120	86	130	55	15	1.8	5.4	60	2.5	2.2	32	1.1
180	86	180	60	15	2.7	8.1	65	2	2.4	32	1.5
260	86	230	60	12	3.1	9.4	60	3	1.9	32	1.8
230	116	130	60	12	2.8	8.3	80	2	1.6	50	1.6
360	116	180	65	10	3.6	10.8	80	3.2	1.0	50	2.4
500	116	230	70	10	5.0	15.0	75	3	1.2	50	3
510	136	180	70	7	3.6	10.7	100	2	1.0	50	3.7
680	136	230	70	7	4.8	14.3	95	2	1.1	50	4.2

Danab	2000V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaanka
100	86	125	55	15	1.5	4.5	35	3.8	4.3	32	1.1
90	86	130	55	15	1.4	4.1	65	2.5	1.9	32	1.1
150	86	180	60	15	2.3	6.8	60	3.5	1.6	32	1.5
200	86	230	60	12	2.4	7.2	65	2	2.4	32	1.8
180	116	130	65	10	1.8	5.4	75	2.5	1.4	50	1.6
280	116	180	70	10	2.8	8.4	70	2	2.0	50	2.4
380	116	230	80	10	3.8	11.4	80	2	1.6	50	3
400	136	180	60	7	2.8	8.4	100	1.6	1.3	50	3.7
550	136	230	70	7	3.9	11.6	100	1.5	1.3	50	4.2
850	136	335	80	5	4.3	12.8	120	1.1	1.3	50	6.1

Danab	2800V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaanka
160	116	180	70	30	4.8	14.4	75	2.2	1.6	50	2.4
210	116	230	75	25	5.3	15.8	70	2.8	1.5	50	3
225	136	180	75	20	4.5	13.5	85	2	1.4	50	3.7
300	136	230	80	15	4.5	13.5	80	2.5	1.3	50	4.2

Danab	4000V.DC
Cn(uF)	φD	H	ESL(nH)	dv/dt(V/μS)	IP(KA)	Waa (KA)	Irms (A) 50℃	ESR (mΩ) @1KHz	Rth(K/W)	B(mm)	miisaanka
70	116	180	70	50	3.5	10.5	70	3.5	1.2	50	2.4
95	116	230	75	40	3.8	11.4	70	3.6	1.1	50	3
100	136	180	75	35	3.5	10.5	85	3	0.9	50	3.7
135	136	230	80	30	4.1	12.2	80	3.5	0.9	50	4.2

CRE Polypropylenecapacitor-ka filimka korontadas waxaa badanaa loo isticmaalaa codsiyada korontada korantada sare sababtoo ah xooggooda dielectric sare, cufnaanta mugga yar, iyo joogtada dielectric ee aadka u hooseysa (tanδ). Capacitors-ka CRE sidoo kale waxay la kulmaan khasaarooyin hooseeya, iyadoo ku xiran baahida codsiga. Xalalka capacitor-ka gaarka ah ee CRE aad bay caan ugu yihiin macaamiisha adduunka oo dhan.

CRE waxay leedahay koox RD ah oo aad u bisil si ay u bixiyaan xal tayo sare leh oo loogu talagalay nidaamka beddelka korontada. Badanaa waxaan raacnaa mabda'a macaamiisha ku salaysan, oo diiradda saaraya faahfaahinta ee Warshad Jaban oo ah Capacitor Filim Elektaroonik ah oo Shiinaha ah, waxaan si daacad ah u rajeyneynaa inaan go'aamino is-dhexgal ku qanacsan oo aan kula yeelano mustaqbalka fog. Waxaan kula socodsiin doonnaa horumarkeenna oo aan la socon doonnaa dhisidda xiriir ganacsi oo yar yar oo joogto ah adiga iyo adiga.

Shirkadda Shiinaha ee PP-ga ah ee ka shaqeysa filimada, in ka badan 26 sano, shirkado xirfadlayaal ah oo ka kala yimid daafaha dunida ayaa naga qaata la-hawlgalayaalkooda muddada dheer iyo kuwa xasilloon. Waxaan xiriir ganacsi oo waara la leenahay in ka badan 200 oo jumladleyaal ah oo ku kala sugan Japan, Kuuriya, Mareykanka, UK, Jarmalka, Kanada, Faransiiska, Talyaaniga, Poland, Koonfur Afrika, Ghana, Nigeria iwm.

Kii hore: Kaadhka filimka elektaroonigga ah ee awoodda leh ee loo isticmaalo beddelka korontada

Xiga: Kondenser-ka Nuugista Qoyaanka